1 //===------- CGObjCGNU.cpp - Emit LLVM Code from ASTs for a Module --------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This provides Objective-C code generation targeting the GNU runtime. The 11 // class in this file generates structures used by the GNU Objective-C runtime 12 // library. These structures are defined in objc/objc.h and objc/objc-api.h in 13 // the GNU runtime distribution. 14 // 15 //===----------------------------------------------------------------------===// 16 17 #include "CGObjCRuntime.h" 18 #include "CGCleanup.h" 19 #include "CodeGenFunction.h" 20 #include "CodeGenModule.h" 21 #include "clang/AST/ASTContext.h" 22 #include "clang/AST/Decl.h" 23 #include "clang/AST/DeclObjC.h" 24 #include "clang/AST/RecordLayout.h" 25 #include "clang/AST/StmtObjC.h" 26 #include "clang/Basic/FileManager.h" 27 #include "clang/Basic/SourceManager.h" 28 #include "llvm/ADT/SmallVector.h" 29 #include "llvm/ADT/StringMap.h" 30 #include "llvm/IR/CallSite.h" 31 #include "llvm/IR/DataLayout.h" 32 #include "llvm/IR/Intrinsics.h" 33 #include "llvm/IR/LLVMContext.h" 34 #include "llvm/IR/Module.h" 35 #include "llvm/Support/Compiler.h" 36 #include <cstdarg> 37 38 using namespace clang; 39 using namespace CodeGen; 40 41 namespace { 42 /// Class that lazily initialises the runtime function. Avoids inserting the 43 /// types and the function declaration into a module if they're not used, and 44 /// avoids constructing the type more than once if it's used more than once. 45 class LazyRuntimeFunction { 46 CodeGenModule *CGM; 47 llvm::FunctionType *FTy; 48 const char *FunctionName; 49 llvm::Constant *Function; 50 51 public: 52 /// Constructor leaves this class uninitialized, because it is intended to 53 /// be used as a field in another class and not all of the types that are 54 /// used as arguments will necessarily be available at construction time. 55 LazyRuntimeFunction() 56 : CGM(nullptr), FunctionName(nullptr), Function(nullptr) {} 57 58 /// Initialises the lazy function with the name, return type, and the types 59 /// of the arguments. 60 LLVM_END_WITH_NULL 61 void init(CodeGenModule *Mod, const char *name, llvm::Type *RetTy, ...) { 62 CGM = Mod; 63 FunctionName = name; 64 Function = nullptr; 65 std::vector<llvm::Type *> ArgTys; 66 va_list Args; 67 va_start(Args, RetTy); 68 while (llvm::Type *ArgTy = va_arg(Args, llvm::Type *)) 69 ArgTys.push_back(ArgTy); 70 va_end(Args); 71 FTy = llvm::FunctionType::get(RetTy, ArgTys, false); 72 } 73 74 llvm::FunctionType *getType() { return FTy; } 75 76 /// Overloaded cast operator, allows the class to be implicitly cast to an 77 /// LLVM constant. 78 operator llvm::Constant *() { 79 if (!Function) { 80 if (!FunctionName) 81 return nullptr; 82 Function = 83 cast<llvm::Constant>(CGM->CreateRuntimeFunction(FTy, FunctionName)); 84 } 85 return Function; 86 } 87 operator llvm::Function *() { 88 return cast<llvm::Function>((llvm::Constant *)*this); 89 } 90 }; 91 92 93 /// GNU Objective-C runtime code generation. This class implements the parts of 94 /// Objective-C support that are specific to the GNU family of runtimes (GCC, 95 /// GNUstep and ObjFW). 96 class CGObjCGNU : public CGObjCRuntime { 97 protected: 98 /// The LLVM module into which output is inserted 99 llvm::Module &TheModule; 100 /// strut objc_super. Used for sending messages to super. This structure 101 /// contains the receiver (object) and the expected class. 102 llvm::StructType *ObjCSuperTy; 103 /// struct objc_super*. The type of the argument to the superclass message 104 /// lookup functions. 105 llvm::PointerType *PtrToObjCSuperTy; 106 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring 107 /// SEL is included in a header somewhere, in which case it will be whatever 108 /// type is declared in that header, most likely {i8*, i8*}. 109 llvm::PointerType *SelectorTy; 110 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the 111 /// places where it's used 112 llvm::IntegerType *Int8Ty; 113 /// Pointer to i8 - LLVM type of char*, for all of the places where the 114 /// runtime needs to deal with C strings. 115 llvm::PointerType *PtrToInt8Ty; 116 /// Instance Method Pointer type. This is a pointer to a function that takes, 117 /// at a minimum, an object and a selector, and is the generic type for 118 /// Objective-C methods. Due to differences between variadic / non-variadic 119 /// calling conventions, it must always be cast to the correct type before 120 /// actually being used. 121 llvm::PointerType *IMPTy; 122 /// Type of an untyped Objective-C object. Clang treats id as a built-in type 123 /// when compiling Objective-C code, so this may be an opaque pointer (i8*), 124 /// but if the runtime header declaring it is included then it may be a 125 /// pointer to a structure. 126 llvm::PointerType *IdTy; 127 /// Pointer to a pointer to an Objective-C object. Used in the new ABI 128 /// message lookup function and some GC-related functions. 129 llvm::PointerType *PtrToIdTy; 130 /// The clang type of id. Used when using the clang CGCall infrastructure to 131 /// call Objective-C methods. 132 CanQualType ASTIdTy; 133 /// LLVM type for C int type. 134 llvm::IntegerType *IntTy; 135 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is 136 /// used in the code to document the difference between i8* meaning a pointer 137 /// to a C string and i8* meaning a pointer to some opaque type. 138 llvm::PointerType *PtrTy; 139 /// LLVM type for C long type. The runtime uses this in a lot of places where 140 /// it should be using intptr_t, but we can't fix this without breaking 141 /// compatibility with GCC... 142 llvm::IntegerType *LongTy; 143 /// LLVM type for C size_t. Used in various runtime data structures. 144 llvm::IntegerType *SizeTy; 145 /// LLVM type for C intptr_t. 146 llvm::IntegerType *IntPtrTy; 147 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions. 148 llvm::IntegerType *PtrDiffTy; 149 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance 150 /// variables. 151 llvm::PointerType *PtrToIntTy; 152 /// LLVM type for Objective-C BOOL type. 153 llvm::Type *BoolTy; 154 /// 32-bit integer type, to save us needing to look it up every time it's used. 155 llvm::IntegerType *Int32Ty; 156 /// 64-bit integer type, to save us needing to look it up every time it's used. 157 llvm::IntegerType *Int64Ty; 158 /// Metadata kind used to tie method lookups to message sends. The GNUstep 159 /// runtime provides some LLVM passes that can use this to do things like 160 /// automatic IMP caching and speculative inlining. 161 unsigned msgSendMDKind; 162 163 /// Helper function that generates a constant string and returns a pointer to 164 /// the start of the string. The result of this function can be used anywhere 165 /// where the C code specifies const char*. 166 llvm::Constant *MakeConstantString(const std::string &Str, 167 const std::string &Name="") { 168 ConstantAddress Array = CGM.GetAddrOfConstantCString(Str, Name.c_str()); 169 return llvm::ConstantExpr::getGetElementPtr(Array.getElementType(), 170 Array.getPointer(), Zeros); 171 } 172 173 /// Emits a linkonce_odr string, whose name is the prefix followed by the 174 /// string value. This allows the linker to combine the strings between 175 /// different modules. Used for EH typeinfo names, selector strings, and a 176 /// few other things. 177 llvm::Constant *ExportUniqueString(const std::string &Str, 178 const std::string prefix) { 179 std::string name = prefix + Str; 180 auto *ConstStr = TheModule.getGlobalVariable(name); 181 if (!ConstStr) { 182 llvm::Constant *value = llvm::ConstantDataArray::getString(VMContext,Str); 183 ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true, 184 llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str); 185 } 186 return llvm::ConstantExpr::getGetElementPtr(ConstStr->getValueType(), 187 ConstStr, Zeros); 188 } 189 190 /// Generates a global structure, initialized by the elements in the vector. 191 /// The element types must match the types of the structure elements in the 192 /// first argument. 193 llvm::GlobalVariable *MakeGlobal(llvm::StructType *Ty, 194 ArrayRef<llvm::Constant *> V, 195 CharUnits Align, 196 StringRef Name="", 197 llvm::GlobalValue::LinkageTypes linkage 198 =llvm::GlobalValue::InternalLinkage) { 199 llvm::Constant *C = llvm::ConstantStruct::get(Ty, V); 200 auto GV = new llvm::GlobalVariable(TheModule, Ty, false, 201 linkage, C, Name); 202 GV->setAlignment(Align.getQuantity()); 203 return GV; 204 } 205 206 /// Generates a global array. The vector must contain the same number of 207 /// elements that the array type declares, of the type specified as the array 208 /// element type. 209 llvm::GlobalVariable *MakeGlobal(llvm::ArrayType *Ty, 210 ArrayRef<llvm::Constant *> V, 211 CharUnits Align, 212 StringRef Name="", 213 llvm::GlobalValue::LinkageTypes linkage 214 =llvm::GlobalValue::InternalLinkage) { 215 llvm::Constant *C = llvm::ConstantArray::get(Ty, V); 216 auto GV = new llvm::GlobalVariable(TheModule, Ty, false, 217 linkage, C, Name); 218 GV->setAlignment(Align.getQuantity()); 219 return GV; 220 } 221 222 /// Generates a global array, inferring the array type from the specified 223 /// element type and the size of the initialiser. 224 llvm::GlobalVariable *MakeGlobalArray(llvm::Type *Ty, 225 ArrayRef<llvm::Constant *> V, 226 CharUnits Align, 227 StringRef Name="", 228 llvm::GlobalValue::LinkageTypes linkage 229 =llvm::GlobalValue::InternalLinkage) { 230 llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size()); 231 return MakeGlobal(ArrayTy, V, Align, Name, linkage); 232 } 233 234 /// Returns a property name and encoding string. 235 llvm::Constant *MakePropertyEncodingString(const ObjCPropertyDecl *PD, 236 const Decl *Container) { 237 const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime; 238 if ((R.getKind() == ObjCRuntime::GNUstep) && 239 (R.getVersion() >= VersionTuple(1, 6))) { 240 std::string NameAndAttributes; 241 std::string TypeStr; 242 CGM.getContext().getObjCEncodingForPropertyDecl(PD, Container, TypeStr); 243 NameAndAttributes += '\0'; 244 NameAndAttributes += TypeStr.length() + 3; 245 NameAndAttributes += TypeStr; 246 NameAndAttributes += '\0'; 247 NameAndAttributes += PD->getNameAsString(); 248 return MakeConstantString(NameAndAttributes); 249 } 250 return MakeConstantString(PD->getNameAsString()); 251 } 252 253 /// Push the property attributes into two structure fields. 254 void PushPropertyAttributes(std::vector<llvm::Constant*> &Fields, 255 ObjCPropertyDecl *property, bool isSynthesized=true, bool 256 isDynamic=true) { 257 int attrs = property->getPropertyAttributes(); 258 // For read-only properties, clear the copy and retain flags 259 if (attrs & ObjCPropertyDecl::OBJC_PR_readonly) { 260 attrs &= ~ObjCPropertyDecl::OBJC_PR_copy; 261 attrs &= ~ObjCPropertyDecl::OBJC_PR_retain; 262 attrs &= ~ObjCPropertyDecl::OBJC_PR_weak; 263 attrs &= ~ObjCPropertyDecl::OBJC_PR_strong; 264 } 265 // The first flags field has the same attribute values as clang uses internally 266 Fields.push_back(llvm::ConstantInt::get(Int8Ty, attrs & 0xff)); 267 attrs >>= 8; 268 attrs <<= 2; 269 // For protocol properties, synthesized and dynamic have no meaning, so we 270 // reuse these flags to indicate that this is a protocol property (both set 271 // has no meaning, as a property can't be both synthesized and dynamic) 272 attrs |= isSynthesized ? (1<<0) : 0; 273 attrs |= isDynamic ? (1<<1) : 0; 274 // The second field is the next four fields left shifted by two, with the 275 // low bit set to indicate whether the field is synthesized or dynamic. 276 Fields.push_back(llvm::ConstantInt::get(Int8Ty, attrs & 0xff)); 277 // Two padding fields 278 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 279 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 280 } 281 282 /// Ensures that the value has the required type, by inserting a bitcast if 283 /// required. This function lets us avoid inserting bitcasts that are 284 /// redundant. 285 llvm::Value* EnforceType(CGBuilderTy &B, llvm::Value *V, llvm::Type *Ty) { 286 if (V->getType() == Ty) return V; 287 return B.CreateBitCast(V, Ty); 288 } 289 Address EnforceType(CGBuilderTy &B, Address V, llvm::Type *Ty) { 290 if (V.getType() == Ty) return V; 291 return B.CreateBitCast(V, Ty); 292 } 293 294 // Some zeros used for GEPs in lots of places. 295 llvm::Constant *Zeros[2]; 296 /// Null pointer value. Mainly used as a terminator in various arrays. 297 llvm::Constant *NULLPtr; 298 /// LLVM context. 299 llvm::LLVMContext &VMContext; 300 301 private: 302 /// Placeholder for the class. Lots of things refer to the class before we've 303 /// actually emitted it. We use this alias as a placeholder, and then replace 304 /// it with a pointer to the class structure before finally emitting the 305 /// module. 306 llvm::GlobalAlias *ClassPtrAlias; 307 /// Placeholder for the metaclass. Lots of things refer to the class before 308 /// we've / actually emitted it. We use this alias as a placeholder, and then 309 /// replace / it with a pointer to the metaclass structure before finally 310 /// emitting the / module. 311 llvm::GlobalAlias *MetaClassPtrAlias; 312 /// All of the classes that have been generated for this compilation units. 313 std::vector<llvm::Constant*> Classes; 314 /// All of the categories that have been generated for this compilation units. 315 std::vector<llvm::Constant*> Categories; 316 /// All of the Objective-C constant strings that have been generated for this 317 /// compilation units. 318 std::vector<llvm::Constant*> ConstantStrings; 319 /// Map from string values to Objective-C constant strings in the output. 320 /// Used to prevent emitting Objective-C strings more than once. This should 321 /// not be required at all - CodeGenModule should manage this list. 322 llvm::StringMap<llvm::Constant*> ObjCStrings; 323 /// All of the protocols that have been declared. 324 llvm::StringMap<llvm::Constant*> ExistingProtocols; 325 /// For each variant of a selector, we store the type encoding and a 326 /// placeholder value. For an untyped selector, the type will be the empty 327 /// string. Selector references are all done via the module's selector table, 328 /// so we create an alias as a placeholder and then replace it with the real 329 /// value later. 330 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector; 331 /// Type of the selector map. This is roughly equivalent to the structure 332 /// used in the GNUstep runtime, which maintains a list of all of the valid 333 /// types for a selector in a table. 334 typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> > 335 SelectorMap; 336 /// A map from selectors to selector types. This allows us to emit all 337 /// selectors of the same name and type together. 338 SelectorMap SelectorTable; 339 340 /// Selectors related to memory management. When compiling in GC mode, we 341 /// omit these. 342 Selector RetainSel, ReleaseSel, AutoreleaseSel; 343 /// Runtime functions used for memory management in GC mode. Note that clang 344 /// supports code generation for calling these functions, but neither GNU 345 /// runtime actually supports this API properly yet. 346 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn, 347 WeakAssignFn, GlobalAssignFn; 348 349 typedef std::pair<std::string, std::string> ClassAliasPair; 350 /// All classes that have aliases set for them. 351 std::vector<ClassAliasPair> ClassAliases; 352 353 protected: 354 /// Function used for throwing Objective-C exceptions. 355 LazyRuntimeFunction ExceptionThrowFn; 356 /// Function used for rethrowing exceptions, used at the end of \@finally or 357 /// \@synchronize blocks. 358 LazyRuntimeFunction ExceptionReThrowFn; 359 /// Function called when entering a catch function. This is required for 360 /// differentiating Objective-C exceptions and foreign exceptions. 361 LazyRuntimeFunction EnterCatchFn; 362 /// Function called when exiting from a catch block. Used to do exception 363 /// cleanup. 364 LazyRuntimeFunction ExitCatchFn; 365 /// Function called when entering an \@synchronize block. Acquires the lock. 366 LazyRuntimeFunction SyncEnterFn; 367 /// Function called when exiting an \@synchronize block. Releases the lock. 368 LazyRuntimeFunction SyncExitFn; 369 370 private: 371 /// Function called if fast enumeration detects that the collection is 372 /// modified during the update. 373 LazyRuntimeFunction EnumerationMutationFn; 374 /// Function for implementing synthesized property getters that return an 375 /// object. 376 LazyRuntimeFunction GetPropertyFn; 377 /// Function for implementing synthesized property setters that return an 378 /// object. 379 LazyRuntimeFunction SetPropertyFn; 380 /// Function used for non-object declared property getters. 381 LazyRuntimeFunction GetStructPropertyFn; 382 /// Function used for non-object declared property setters. 383 LazyRuntimeFunction SetStructPropertyFn; 384 385 /// The version of the runtime that this class targets. Must match the 386 /// version in the runtime. 387 int RuntimeVersion; 388 /// The version of the protocol class. Used to differentiate between ObjC1 389 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional 390 /// components and can not contain declared properties. We always emit 391 /// Objective-C 2 property structures, but we have to pretend that they're 392 /// Objective-C 1 property structures when targeting the GCC runtime or it 393 /// will abort. 394 const int ProtocolVersion; 395 396 /// Generates an instance variable list structure. This is a structure 397 /// containing a size and an array of structures containing instance variable 398 /// metadata. This is used purely for introspection in the fragile ABI. In 399 /// the non-fragile ABI, it's used for instance variable fixup. 400 llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames, 401 ArrayRef<llvm::Constant *> IvarTypes, 402 ArrayRef<llvm::Constant *> IvarOffsets); 403 404 /// Generates a method list structure. This is a structure containing a size 405 /// and an array of structures containing method metadata. 406 /// 407 /// This structure is used by both classes and categories, and contains a next 408 /// pointer allowing them to be chained together in a linked list. 409 llvm::Constant *GenerateMethodList(StringRef ClassName, 410 StringRef CategoryName, 411 ArrayRef<Selector> MethodSels, 412 ArrayRef<llvm::Constant *> MethodTypes, 413 bool isClassMethodList); 414 415 /// Emits an empty protocol. This is used for \@protocol() where no protocol 416 /// is found. The runtime will (hopefully) fix up the pointer to refer to the 417 /// real protocol. 418 llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName); 419 420 /// Generates a list of property metadata structures. This follows the same 421 /// pattern as method and instance variable metadata lists. 422 llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID, 423 SmallVectorImpl<Selector> &InstanceMethodSels, 424 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes); 425 426 /// Generates a list of referenced protocols. Classes, categories, and 427 /// protocols all use this structure. 428 llvm::Constant *GenerateProtocolList(ArrayRef<std::string> Protocols); 429 430 /// To ensure that all protocols are seen by the runtime, we add a category on 431 /// a class defined in the runtime, declaring no methods, but adopting the 432 /// protocols. This is a horribly ugly hack, but it allows us to collect all 433 /// of the protocols without changing the ABI. 434 void GenerateProtocolHolderCategory(); 435 436 /// Generates a class structure. 437 llvm::Constant *GenerateClassStructure( 438 llvm::Constant *MetaClass, 439 llvm::Constant *SuperClass, 440 unsigned info, 441 const char *Name, 442 llvm::Constant *Version, 443 llvm::Constant *InstanceSize, 444 llvm::Constant *IVars, 445 llvm::Constant *Methods, 446 llvm::Constant *Protocols, 447 llvm::Constant *IvarOffsets, 448 llvm::Constant *Properties, 449 llvm::Constant *StrongIvarBitmap, 450 llvm::Constant *WeakIvarBitmap, 451 bool isMeta=false); 452 453 /// Generates a method list. This is used by protocols to define the required 454 /// and optional methods. 455 llvm::Constant *GenerateProtocolMethodList( 456 ArrayRef<llvm::Constant *> MethodNames, 457 ArrayRef<llvm::Constant *> MethodTypes); 458 459 /// Returns a selector with the specified type encoding. An empty string is 460 /// used to return an untyped selector (with the types field set to NULL). 461 llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel, 462 const std::string &TypeEncoding); 463 464 /// Returns the variable used to store the offset of an instance variable. 465 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID, 466 const ObjCIvarDecl *Ivar); 467 /// Emits a reference to a class. This allows the linker to object if there 468 /// is no class of the matching name. 469 470 protected: 471 void EmitClassRef(const std::string &className); 472 473 /// Emits a pointer to the named class 474 virtual llvm::Value *GetClassNamed(CodeGenFunction &CGF, 475 const std::string &Name, bool isWeak); 476 477 /// Looks up the method for sending a message to the specified object. This 478 /// mechanism differs between the GCC and GNU runtimes, so this method must be 479 /// overridden in subclasses. 480 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 481 llvm::Value *&Receiver, 482 llvm::Value *cmd, 483 llvm::MDNode *node, 484 MessageSendInfo &MSI) = 0; 485 486 /// Looks up the method for sending a message to a superclass. This 487 /// mechanism differs between the GCC and GNU runtimes, so this method must 488 /// be overridden in subclasses. 489 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 490 Address ObjCSuper, 491 llvm::Value *cmd, 492 MessageSendInfo &MSI) = 0; 493 494 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are 495 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63 496 /// bits set to their values, LSB first, while larger ones are stored in a 497 /// structure of this / form: 498 /// 499 /// struct { int32_t length; int32_t values[length]; }; 500 /// 501 /// The values in the array are stored in host-endian format, with the least 502 /// significant bit being assumed to come first in the bitfield. Therefore, 503 /// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, 504 /// while a bitfield / with the 63rd bit set will be 1<<64. 505 llvm::Constant *MakeBitField(ArrayRef<bool> bits); 506 507 public: 508 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 509 unsigned protocolClassVersion); 510 511 ConstantAddress GenerateConstantString(const StringLiteral *) override; 512 513 RValue 514 GenerateMessageSend(CodeGenFunction &CGF, ReturnValueSlot Return, 515 QualType ResultType, Selector Sel, 516 llvm::Value *Receiver, const CallArgList &CallArgs, 517 const ObjCInterfaceDecl *Class, 518 const ObjCMethodDecl *Method) override; 519 RValue 520 GenerateMessageSendSuper(CodeGenFunction &CGF, ReturnValueSlot Return, 521 QualType ResultType, Selector Sel, 522 const ObjCInterfaceDecl *Class, 523 bool isCategoryImpl, llvm::Value *Receiver, 524 bool IsClassMessage, const CallArgList &CallArgs, 525 const ObjCMethodDecl *Method) override; 526 llvm::Value *GetClass(CodeGenFunction &CGF, 527 const ObjCInterfaceDecl *OID) override; 528 llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel) override; 529 Address GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) override; 530 llvm::Value *GetSelector(CodeGenFunction &CGF, 531 const ObjCMethodDecl *Method) override; 532 llvm::Constant *GetEHType(QualType T) override; 533 534 llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 535 const ObjCContainerDecl *CD) override; 536 void GenerateCategory(const ObjCCategoryImplDecl *CMD) override; 537 void GenerateClass(const ObjCImplementationDecl *ClassDecl) override; 538 void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) override; 539 llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF, 540 const ObjCProtocolDecl *PD) override; 541 void GenerateProtocol(const ObjCProtocolDecl *PD) override; 542 llvm::Function *ModuleInitFunction() override; 543 llvm::Constant *GetPropertyGetFunction() override; 544 llvm::Constant *GetPropertySetFunction() override; 545 llvm::Constant *GetOptimizedPropertySetFunction(bool atomic, 546 bool copy) override; 547 llvm::Constant *GetSetStructFunction() override; 548 llvm::Constant *GetGetStructFunction() override; 549 llvm::Constant *GetCppAtomicObjectGetFunction() override; 550 llvm::Constant *GetCppAtomicObjectSetFunction() override; 551 llvm::Constant *EnumerationMutationFunction() override; 552 553 void EmitTryStmt(CodeGenFunction &CGF, 554 const ObjCAtTryStmt &S) override; 555 void EmitSynchronizedStmt(CodeGenFunction &CGF, 556 const ObjCAtSynchronizedStmt &S) override; 557 void EmitThrowStmt(CodeGenFunction &CGF, 558 const ObjCAtThrowStmt &S, 559 bool ClearInsertionPoint=true) override; 560 llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF, 561 Address AddrWeakObj) override; 562 void EmitObjCWeakAssign(CodeGenFunction &CGF, 563 llvm::Value *src, Address dst) override; 564 void EmitObjCGlobalAssign(CodeGenFunction &CGF, 565 llvm::Value *src, Address dest, 566 bool threadlocal=false) override; 567 void EmitObjCIvarAssign(CodeGenFunction &CGF, llvm::Value *src, 568 Address dest, llvm::Value *ivarOffset) override; 569 void EmitObjCStrongCastAssign(CodeGenFunction &CGF, 570 llvm::Value *src, Address dest) override; 571 void EmitGCMemmoveCollectable(CodeGenFunction &CGF, Address DestPtr, 572 Address SrcPtr, 573 llvm::Value *Size) override; 574 LValue EmitObjCValueForIvar(CodeGenFunction &CGF, QualType ObjectTy, 575 llvm::Value *BaseValue, const ObjCIvarDecl *Ivar, 576 unsigned CVRQualifiers) override; 577 llvm::Value *EmitIvarOffset(CodeGenFunction &CGF, 578 const ObjCInterfaceDecl *Interface, 579 const ObjCIvarDecl *Ivar) override; 580 llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) override; 581 llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM, 582 const CGBlockInfo &blockInfo) override { 583 return NULLPtr; 584 } 585 llvm::Constant *BuildRCBlockLayout(CodeGenModule &CGM, 586 const CGBlockInfo &blockInfo) override { 587 return NULLPtr; 588 } 589 590 llvm::Constant *BuildByrefLayout(CodeGenModule &CGM, QualType T) override { 591 return NULLPtr; 592 } 593 594 llvm::GlobalVariable *GetClassGlobal(StringRef Name, 595 bool Weak = false) override { 596 return nullptr; 597 } 598 }; 599 600 /// Class representing the legacy GCC Objective-C ABI. This is the default when 601 /// -fobjc-nonfragile-abi is not specified. 602 /// 603 /// The GCC ABI target actually generates code that is approximately compatible 604 /// with the new GNUstep runtime ABI, but refrains from using any features that 605 /// would not work with the GCC runtime. For example, clang always generates 606 /// the extended form of the class structure, and the extra fields are simply 607 /// ignored by GCC libobjc. 608 class CGObjCGCC : public CGObjCGNU { 609 /// The GCC ABI message lookup function. Returns an IMP pointing to the 610 /// method implementation for this message. 611 LazyRuntimeFunction MsgLookupFn; 612 /// The GCC ABI superclass message lookup function. Takes a pointer to a 613 /// structure describing the receiver and the class, and a selector as 614 /// arguments. Returns the IMP for the corresponding method. 615 LazyRuntimeFunction MsgLookupSuperFn; 616 617 protected: 618 llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver, 619 llvm::Value *cmd, llvm::MDNode *node, 620 MessageSendInfo &MSI) override { 621 CGBuilderTy &Builder = CGF.Builder; 622 llvm::Value *args[] = { 623 EnforceType(Builder, Receiver, IdTy), 624 EnforceType(Builder, cmd, SelectorTy) }; 625 llvm::CallSite imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args); 626 imp->setMetadata(msgSendMDKind, node); 627 return imp.getInstruction(); 628 } 629 630 llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper, 631 llvm::Value *cmd, MessageSendInfo &MSI) override { 632 CGBuilderTy &Builder = CGF.Builder; 633 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 634 PtrToObjCSuperTy).getPointer(), cmd}; 635 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs); 636 } 637 638 public: 639 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) { 640 // IMP objc_msg_lookup(id, SEL); 641 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, 642 nullptr); 643 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 644 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 645 PtrToObjCSuperTy, SelectorTy, nullptr); 646 } 647 }; 648 649 /// Class used when targeting the new GNUstep runtime ABI. 650 class CGObjCGNUstep : public CGObjCGNU { 651 /// The slot lookup function. Returns a pointer to a cacheable structure 652 /// that contains (among other things) the IMP. 653 LazyRuntimeFunction SlotLookupFn; 654 /// The GNUstep ABI superclass message lookup function. Takes a pointer to 655 /// a structure describing the receiver and the class, and a selector as 656 /// arguments. Returns the slot for the corresponding method. Superclass 657 /// message lookup rarely changes, so this is a good caching opportunity. 658 LazyRuntimeFunction SlotLookupSuperFn; 659 /// Specialised function for setting atomic retain properties 660 LazyRuntimeFunction SetPropertyAtomic; 661 /// Specialised function for setting atomic copy properties 662 LazyRuntimeFunction SetPropertyAtomicCopy; 663 /// Specialised function for setting nonatomic retain properties 664 LazyRuntimeFunction SetPropertyNonAtomic; 665 /// Specialised function for setting nonatomic copy properties 666 LazyRuntimeFunction SetPropertyNonAtomicCopy; 667 /// Function to perform atomic copies of C++ objects with nontrivial copy 668 /// constructors from Objective-C ivars. 669 LazyRuntimeFunction CxxAtomicObjectGetFn; 670 /// Function to perform atomic copies of C++ objects with nontrivial copy 671 /// constructors to Objective-C ivars. 672 LazyRuntimeFunction CxxAtomicObjectSetFn; 673 /// Type of an slot structure pointer. This is returned by the various 674 /// lookup functions. 675 llvm::Type *SlotTy; 676 677 public: 678 llvm::Constant *GetEHType(QualType T) override; 679 680 protected: 681 llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver, 682 llvm::Value *cmd, llvm::MDNode *node, 683 MessageSendInfo &MSI) override { 684 CGBuilderTy &Builder = CGF.Builder; 685 llvm::Function *LookupFn = SlotLookupFn; 686 687 // Store the receiver on the stack so that we can reload it later 688 Address ReceiverPtr = 689 CGF.CreateTempAlloca(Receiver->getType(), CGF.getPointerAlign()); 690 Builder.CreateStore(Receiver, ReceiverPtr); 691 692 llvm::Value *self; 693 694 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) { 695 self = CGF.LoadObjCSelf(); 696 } else { 697 self = llvm::ConstantPointerNull::get(IdTy); 698 } 699 700 // The lookup function is guaranteed not to capture the receiver pointer. 701 LookupFn->setDoesNotCapture(1); 702 703 llvm::Value *args[] = { 704 EnforceType(Builder, ReceiverPtr.getPointer(), PtrToIdTy), 705 EnforceType(Builder, cmd, SelectorTy), 706 EnforceType(Builder, self, IdTy) }; 707 llvm::CallSite slot = CGF.EmitRuntimeCallOrInvoke(LookupFn, args); 708 slot.setOnlyReadsMemory(); 709 slot->setMetadata(msgSendMDKind, node); 710 711 // Load the imp from the slot 712 llvm::Value *imp = Builder.CreateAlignedLoad( 713 Builder.CreateStructGEP(nullptr, slot.getInstruction(), 4), 714 CGF.getPointerAlign()); 715 716 // The lookup function may have changed the receiver, so make sure we use 717 // the new one. 718 Receiver = Builder.CreateLoad(ReceiverPtr, true); 719 return imp; 720 } 721 722 llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper, 723 llvm::Value *cmd, 724 MessageSendInfo &MSI) override { 725 CGBuilderTy &Builder = CGF.Builder; 726 llvm::Value *lookupArgs[] = {ObjCSuper.getPointer(), cmd}; 727 728 llvm::CallInst *slot = 729 CGF.EmitNounwindRuntimeCall(SlotLookupSuperFn, lookupArgs); 730 slot->setOnlyReadsMemory(); 731 732 return Builder.CreateAlignedLoad(Builder.CreateStructGEP(nullptr, slot, 4), 733 CGF.getPointerAlign()); 734 } 735 736 public: 737 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) { 738 const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime; 739 740 llvm::StructType *SlotStructTy = llvm::StructType::get(PtrTy, 741 PtrTy, PtrTy, IntTy, IMPTy, nullptr); 742 SlotTy = llvm::PointerType::getUnqual(SlotStructTy); 743 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 744 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy, 745 SelectorTy, IdTy, nullptr); 746 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL); 747 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy, 748 PtrToObjCSuperTy, SelectorTy, nullptr); 749 // If we're in ObjC++ mode, then we want to make 750 if (CGM.getLangOpts().CPlusPlus) { 751 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 752 // void *__cxa_begin_catch(void *e) 753 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, nullptr); 754 // void __cxa_end_catch(void) 755 ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, nullptr); 756 // void _Unwind_Resume_or_Rethrow(void*) 757 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, 758 PtrTy, nullptr); 759 } else if (R.getVersion() >= VersionTuple(1, 7)) { 760 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 761 // id objc_begin_catch(void *e) 762 EnterCatchFn.init(&CGM, "objc_begin_catch", IdTy, PtrTy, nullptr); 763 // void objc_end_catch(void) 764 ExitCatchFn.init(&CGM, "objc_end_catch", VoidTy, nullptr); 765 // void _Unwind_Resume_or_Rethrow(void*) 766 ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy, 767 PtrTy, nullptr); 768 } 769 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 770 SetPropertyAtomic.init(&CGM, "objc_setProperty_atomic", VoidTy, IdTy, 771 SelectorTy, IdTy, PtrDiffTy, nullptr); 772 SetPropertyAtomicCopy.init(&CGM, "objc_setProperty_atomic_copy", VoidTy, 773 IdTy, SelectorTy, IdTy, PtrDiffTy, nullptr); 774 SetPropertyNonAtomic.init(&CGM, "objc_setProperty_nonatomic", VoidTy, 775 IdTy, SelectorTy, IdTy, PtrDiffTy, nullptr); 776 SetPropertyNonAtomicCopy.init(&CGM, "objc_setProperty_nonatomic_copy", 777 VoidTy, IdTy, SelectorTy, IdTy, PtrDiffTy, nullptr); 778 // void objc_setCppObjectAtomic(void *dest, const void *src, void 779 // *helper); 780 CxxAtomicObjectSetFn.init(&CGM, "objc_setCppObjectAtomic", VoidTy, PtrTy, 781 PtrTy, PtrTy, nullptr); 782 // void objc_getCppObjectAtomic(void *dest, const void *src, void 783 // *helper); 784 CxxAtomicObjectGetFn.init(&CGM, "objc_getCppObjectAtomic", VoidTy, PtrTy, 785 PtrTy, PtrTy, nullptr); 786 } 787 788 llvm::Constant *GetCppAtomicObjectGetFunction() override { 789 // The optimised functions were added in version 1.7 of the GNUstep 790 // runtime. 791 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >= 792 VersionTuple(1, 7)); 793 return CxxAtomicObjectGetFn; 794 } 795 796 llvm::Constant *GetCppAtomicObjectSetFunction() override { 797 // The optimised functions were added in version 1.7 of the GNUstep 798 // runtime. 799 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >= 800 VersionTuple(1, 7)); 801 return CxxAtomicObjectSetFn; 802 } 803 804 llvm::Constant *GetOptimizedPropertySetFunction(bool atomic, 805 bool copy) override { 806 // The optimised property functions omit the GC check, and so are not 807 // safe to use in GC mode. The standard functions are fast in GC mode, 808 // so there is less advantage in using them. 809 assert ((CGM.getLangOpts().getGC() == LangOptions::NonGC)); 810 // The optimised functions were added in version 1.7 of the GNUstep 811 // runtime. 812 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >= 813 VersionTuple(1, 7)); 814 815 if (atomic) { 816 if (copy) return SetPropertyAtomicCopy; 817 return SetPropertyAtomic; 818 } 819 820 return copy ? SetPropertyNonAtomicCopy : SetPropertyNonAtomic; 821 } 822 }; 823 824 /// Support for the ObjFW runtime. 825 class CGObjCObjFW: public CGObjCGNU { 826 protected: 827 /// The GCC ABI message lookup function. Returns an IMP pointing to the 828 /// method implementation for this message. 829 LazyRuntimeFunction MsgLookupFn; 830 /// stret lookup function. While this does not seem to make sense at the 831 /// first look, this is required to call the correct forwarding function. 832 LazyRuntimeFunction MsgLookupFnSRet; 833 /// The GCC ABI superclass message lookup function. Takes a pointer to a 834 /// structure describing the receiver and the class, and a selector as 835 /// arguments. Returns the IMP for the corresponding method. 836 LazyRuntimeFunction MsgLookupSuperFn, MsgLookupSuperFnSRet; 837 838 llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver, 839 llvm::Value *cmd, llvm::MDNode *node, 840 MessageSendInfo &MSI) override { 841 CGBuilderTy &Builder = CGF.Builder; 842 llvm::Value *args[] = { 843 EnforceType(Builder, Receiver, IdTy), 844 EnforceType(Builder, cmd, SelectorTy) }; 845 846 llvm::CallSite imp; 847 if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) 848 imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFnSRet, args); 849 else 850 imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args); 851 852 imp->setMetadata(msgSendMDKind, node); 853 return imp.getInstruction(); 854 } 855 856 llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper, 857 llvm::Value *cmd, MessageSendInfo &MSI) override { 858 CGBuilderTy &Builder = CGF.Builder; 859 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper.getPointer(), 860 PtrToObjCSuperTy), cmd}; 861 862 if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) 863 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFnSRet, lookupArgs); 864 else 865 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs); 866 } 867 868 llvm::Value *GetClassNamed(CodeGenFunction &CGF, 869 const std::string &Name, bool isWeak) override { 870 if (isWeak) 871 return CGObjCGNU::GetClassNamed(CGF, Name, isWeak); 872 873 EmitClassRef(Name); 874 875 std::string SymbolName = "_OBJC_CLASS_" + Name; 876 877 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(SymbolName); 878 879 if (!ClassSymbol) 880 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 881 llvm::GlobalValue::ExternalLinkage, 882 nullptr, SymbolName); 883 884 return ClassSymbol; 885 } 886 887 public: 888 CGObjCObjFW(CodeGenModule &Mod): CGObjCGNU(Mod, 9, 3) { 889 // IMP objc_msg_lookup(id, SEL); 890 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, nullptr); 891 MsgLookupFnSRet.init(&CGM, "objc_msg_lookup_stret", IMPTy, IdTy, 892 SelectorTy, nullptr); 893 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 894 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 895 PtrToObjCSuperTy, SelectorTy, nullptr); 896 MsgLookupSuperFnSRet.init(&CGM, "objc_msg_lookup_super_stret", IMPTy, 897 PtrToObjCSuperTy, SelectorTy, nullptr); 898 } 899 }; 900 } // end anonymous namespace 901 902 /// Emits a reference to a dummy variable which is emitted with each class. 903 /// This ensures that a linker error will be generated when trying to link 904 /// together modules where a referenced class is not defined. 905 void CGObjCGNU::EmitClassRef(const std::string &className) { 906 std::string symbolRef = "__objc_class_ref_" + className; 907 // Don't emit two copies of the same symbol 908 if (TheModule.getGlobalVariable(symbolRef)) 909 return; 910 std::string symbolName = "__objc_class_name_" + className; 911 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName); 912 if (!ClassSymbol) { 913 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 914 llvm::GlobalValue::ExternalLinkage, 915 nullptr, symbolName); 916 } 917 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true, 918 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef); 919 } 920 921 static std::string SymbolNameForMethod( StringRef ClassName, 922 StringRef CategoryName, const Selector MethodName, 923 bool isClassMethod) { 924 std::string MethodNameColonStripped = MethodName.getAsString(); 925 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(), 926 ':', '_'); 927 return (Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" + 928 CategoryName + "_" + MethodNameColonStripped).str(); 929 } 930 931 CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 932 unsigned protocolClassVersion) 933 : CGObjCRuntime(cgm), TheModule(CGM.getModule()), 934 VMContext(cgm.getLLVMContext()), ClassPtrAlias(nullptr), 935 MetaClassPtrAlias(nullptr), RuntimeVersion(runtimeABIVersion), 936 ProtocolVersion(protocolClassVersion) { 937 938 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend"); 939 940 CodeGenTypes &Types = CGM.getTypes(); 941 IntTy = cast<llvm::IntegerType>( 942 Types.ConvertType(CGM.getContext().IntTy)); 943 LongTy = cast<llvm::IntegerType>( 944 Types.ConvertType(CGM.getContext().LongTy)); 945 SizeTy = cast<llvm::IntegerType>( 946 Types.ConvertType(CGM.getContext().getSizeType())); 947 PtrDiffTy = cast<llvm::IntegerType>( 948 Types.ConvertType(CGM.getContext().getPointerDiffType())); 949 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy); 950 951 Int8Ty = llvm::Type::getInt8Ty(VMContext); 952 // C string type. Used in lots of places. 953 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); 954 955 Zeros[0] = llvm::ConstantInt::get(LongTy, 0); 956 Zeros[1] = Zeros[0]; 957 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty); 958 // Get the selector Type. 959 QualType selTy = CGM.getContext().getObjCSelType(); 960 if (QualType() == selTy) { 961 SelectorTy = PtrToInt8Ty; 962 } else { 963 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy)); 964 } 965 966 PtrToIntTy = llvm::PointerType::getUnqual(IntTy); 967 PtrTy = PtrToInt8Ty; 968 969 Int32Ty = llvm::Type::getInt32Ty(VMContext); 970 Int64Ty = llvm::Type::getInt64Ty(VMContext); 971 972 IntPtrTy = 973 CGM.getDataLayout().getPointerSizeInBits() == 32 ? Int32Ty : Int64Ty; 974 975 // Object type 976 QualType UnqualIdTy = CGM.getContext().getObjCIdType(); 977 ASTIdTy = CanQualType(); 978 if (UnqualIdTy != QualType()) { 979 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy); 980 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 981 } else { 982 IdTy = PtrToInt8Ty; 983 } 984 PtrToIdTy = llvm::PointerType::getUnqual(IdTy); 985 986 ObjCSuperTy = llvm::StructType::get(IdTy, IdTy, nullptr); 987 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy); 988 989 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 990 991 // void objc_exception_throw(id); 992 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, nullptr); 993 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, nullptr); 994 // int objc_sync_enter(id); 995 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, nullptr); 996 // int objc_sync_exit(id); 997 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, nullptr); 998 999 // void objc_enumerationMutation (id) 1000 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, 1001 IdTy, nullptr); 1002 1003 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL) 1004 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy, 1005 PtrDiffTy, BoolTy, nullptr); 1006 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL) 1007 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy, 1008 PtrDiffTy, IdTy, BoolTy, BoolTy, nullptr); 1009 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 1010 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy, 1011 PtrDiffTy, BoolTy, BoolTy, nullptr); 1012 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 1013 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy, 1014 PtrDiffTy, BoolTy, BoolTy, nullptr); 1015 1016 // IMP type 1017 llvm::Type *IMPArgs[] = { IdTy, SelectorTy }; 1018 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs, 1019 true)); 1020 1021 const LangOptions &Opts = CGM.getLangOpts(); 1022 if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount) 1023 RuntimeVersion = 10; 1024 1025 // Don't bother initialising the GC stuff unless we're compiling in GC mode 1026 if (Opts.getGC() != LangOptions::NonGC) { 1027 // This is a bit of an hack. We should sort this out by having a proper 1028 // CGObjCGNUstep subclass for GC, but we may want to really support the old 1029 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now 1030 // Get selectors needed in GC mode 1031 RetainSel = GetNullarySelector("retain", CGM.getContext()); 1032 ReleaseSel = GetNullarySelector("release", CGM.getContext()); 1033 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext()); 1034 1035 // Get functions needed in GC mode 1036 1037 // id objc_assign_ivar(id, id, ptrdiff_t); 1038 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy, 1039 nullptr); 1040 // id objc_assign_strongCast (id, id*) 1041 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy, 1042 PtrToIdTy, nullptr); 1043 // id objc_assign_global(id, id*); 1044 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy, 1045 nullptr); 1046 // id objc_assign_weak(id, id*); 1047 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, nullptr); 1048 // id objc_read_weak(id*); 1049 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, nullptr); 1050 // void *objc_memmove_collectable(void*, void *, size_t); 1051 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy, 1052 SizeTy, nullptr); 1053 } 1054 } 1055 1056 llvm::Value *CGObjCGNU::GetClassNamed(CodeGenFunction &CGF, 1057 const std::string &Name, 1058 bool isWeak) { 1059 llvm::Constant *ClassName = MakeConstantString(Name); 1060 // With the incompatible ABI, this will need to be replaced with a direct 1061 // reference to the class symbol. For the compatible nonfragile ABI we are 1062 // still performing this lookup at run time but emitting the symbol for the 1063 // class externally so that we can make the switch later. 1064 // 1065 // Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class 1066 // with memoized versions or with static references if it's safe to do so. 1067 if (!isWeak) 1068 EmitClassRef(Name); 1069 1070 llvm::Constant *ClassLookupFn = 1071 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true), 1072 "objc_lookup_class"); 1073 return CGF.EmitNounwindRuntimeCall(ClassLookupFn, ClassName); 1074 } 1075 1076 // This has to perform the lookup every time, since posing and related 1077 // techniques can modify the name -> class mapping. 1078 llvm::Value *CGObjCGNU::GetClass(CodeGenFunction &CGF, 1079 const ObjCInterfaceDecl *OID) { 1080 return GetClassNamed(CGF, OID->getNameAsString(), OID->isWeakImported()); 1081 } 1082 1083 llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) { 1084 return GetClassNamed(CGF, "NSAutoreleasePool", false); 1085 } 1086 1087 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel, 1088 const std::string &TypeEncoding) { 1089 SmallVectorImpl<TypedSelector> &Types = SelectorTable[Sel]; 1090 llvm::GlobalAlias *SelValue = nullptr; 1091 1092 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 1093 e = Types.end() ; i!=e ; i++) { 1094 if (i->first == TypeEncoding) { 1095 SelValue = i->second; 1096 break; 1097 } 1098 } 1099 if (!SelValue) { 1100 SelValue = llvm::GlobalAlias::create( 1101 SelectorTy->getElementType(), 0, llvm::GlobalValue::PrivateLinkage, 1102 ".objc_selector_" + Sel.getAsString(), &TheModule); 1103 Types.emplace_back(TypeEncoding, SelValue); 1104 } 1105 1106 return SelValue; 1107 } 1108 1109 Address CGObjCGNU::GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) { 1110 llvm::Value *SelValue = GetSelector(CGF, Sel); 1111 1112 // Store it to a temporary. Does this satisfy the semantics of 1113 // GetAddrOfSelector? Hopefully. 1114 Address tmp = CGF.CreateTempAlloca(SelValue->getType(), 1115 CGF.getPointerAlign()); 1116 CGF.Builder.CreateStore(SelValue, tmp); 1117 return tmp; 1118 } 1119 1120 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel) { 1121 return GetSelector(CGF, Sel, std::string()); 1122 } 1123 1124 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, 1125 const ObjCMethodDecl *Method) { 1126 std::string SelTypes; 1127 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes); 1128 return GetSelector(CGF, Method->getSelector(), SelTypes); 1129 } 1130 1131 llvm::Constant *CGObjCGNU::GetEHType(QualType T) { 1132 if (T->isObjCIdType() || T->isObjCQualifiedIdType()) { 1133 // With the old ABI, there was only one kind of catchall, which broke 1134 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as 1135 // a pointer indicating object catchalls, and NULL to indicate real 1136 // catchalls 1137 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 1138 return MakeConstantString("@id"); 1139 } else { 1140 return nullptr; 1141 } 1142 } 1143 1144 // All other types should be Objective-C interface pointer types. 1145 const ObjCObjectPointerType *OPT = T->getAs<ObjCObjectPointerType>(); 1146 assert(OPT && "Invalid @catch type."); 1147 const ObjCInterfaceDecl *IDecl = OPT->getObjectType()->getInterface(); 1148 assert(IDecl && "Invalid @catch type."); 1149 return MakeConstantString(IDecl->getIdentifier()->getName()); 1150 } 1151 1152 llvm::Constant *CGObjCGNUstep::GetEHType(QualType T) { 1153 if (!CGM.getLangOpts().CPlusPlus) 1154 return CGObjCGNU::GetEHType(T); 1155 1156 // For Objective-C++, we want to provide the ability to catch both C++ and 1157 // Objective-C objects in the same function. 1158 1159 // There's a particular fixed type info for 'id'. 1160 if (T->isObjCIdType() || 1161 T->isObjCQualifiedIdType()) { 1162 llvm::Constant *IDEHType = 1163 CGM.getModule().getGlobalVariable("__objc_id_type_info"); 1164 if (!IDEHType) 1165 IDEHType = 1166 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty, 1167 false, 1168 llvm::GlobalValue::ExternalLinkage, 1169 nullptr, "__objc_id_type_info"); 1170 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty); 1171 } 1172 1173 const ObjCObjectPointerType *PT = 1174 T->getAs<ObjCObjectPointerType>(); 1175 assert(PT && "Invalid @catch type."); 1176 const ObjCInterfaceType *IT = PT->getInterfaceType(); 1177 assert(IT && "Invalid @catch type."); 1178 std::string className = IT->getDecl()->getIdentifier()->getName(); 1179 1180 std::string typeinfoName = "__objc_eh_typeinfo_" + className; 1181 1182 // Return the existing typeinfo if it exists 1183 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName); 1184 if (typeinfo) 1185 return llvm::ConstantExpr::getBitCast(typeinfo, PtrToInt8Ty); 1186 1187 // Otherwise create it. 1188 1189 // vtable for gnustep::libobjc::__objc_class_type_info 1190 // It's quite ugly hard-coding this. Ideally we'd generate it using the host 1191 // platform's name mangling. 1192 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE"; 1193 auto *Vtable = TheModule.getGlobalVariable(vtableName); 1194 if (!Vtable) { 1195 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true, 1196 llvm::GlobalValue::ExternalLinkage, 1197 nullptr, vtableName); 1198 } 1199 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2); 1200 auto *BVtable = llvm::ConstantExpr::getBitCast( 1201 llvm::ConstantExpr::getGetElementPtr(Vtable->getValueType(), Vtable, Two), 1202 PtrToInt8Ty); 1203 1204 llvm::Constant *typeName = 1205 ExportUniqueString(className, "__objc_eh_typename_"); 1206 1207 std::vector<llvm::Constant*> fields; 1208 fields.push_back(BVtable); 1209 fields.push_back(typeName); 1210 llvm::Constant *TI = 1211 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, nullptr), 1212 fields, CGM.getPointerAlign(), 1213 "__objc_eh_typeinfo_" + className, 1214 llvm::GlobalValue::LinkOnceODRLinkage); 1215 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty); 1216 } 1217 1218 /// Generate an NSConstantString object. 1219 ConstantAddress CGObjCGNU::GenerateConstantString(const StringLiteral *SL) { 1220 1221 std::string Str = SL->getString().str(); 1222 CharUnits Align = CGM.getPointerAlign(); 1223 1224 // Look for an existing one 1225 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str); 1226 if (old != ObjCStrings.end()) 1227 return ConstantAddress(old->getValue(), Align); 1228 1229 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass; 1230 1231 if (StringClass.empty()) StringClass = "NXConstantString"; 1232 1233 std::string Sym = "_OBJC_CLASS_"; 1234 Sym += StringClass; 1235 1236 llvm::Constant *isa = TheModule.getNamedGlobal(Sym); 1237 1238 if (!isa) 1239 isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false, 1240 llvm::GlobalValue::ExternalWeakLinkage, nullptr, Sym); 1241 else if (isa->getType() != PtrToIdTy) 1242 isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy); 1243 1244 std::vector<llvm::Constant*> Ivars; 1245 Ivars.push_back(isa); 1246 Ivars.push_back(MakeConstantString(Str)); 1247 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size())); 1248 llvm::Constant *ObjCStr = MakeGlobal( 1249 llvm::StructType::get(PtrToIdTy, PtrToInt8Ty, IntTy, nullptr), 1250 Ivars, Align, ".objc_str"); 1251 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty); 1252 ObjCStrings[Str] = ObjCStr; 1253 ConstantStrings.push_back(ObjCStr); 1254 return ConstantAddress(ObjCStr, Align); 1255 } 1256 1257 ///Generates a message send where the super is the receiver. This is a message 1258 ///send to self with special delivery semantics indicating which class's method 1259 ///should be called. 1260 RValue 1261 CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF, 1262 ReturnValueSlot Return, 1263 QualType ResultType, 1264 Selector Sel, 1265 const ObjCInterfaceDecl *Class, 1266 bool isCategoryImpl, 1267 llvm::Value *Receiver, 1268 bool IsClassMessage, 1269 const CallArgList &CallArgs, 1270 const ObjCMethodDecl *Method) { 1271 CGBuilderTy &Builder = CGF.Builder; 1272 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) { 1273 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1274 return RValue::get(EnforceType(Builder, Receiver, 1275 CGM.getTypes().ConvertType(ResultType))); 1276 } 1277 if (Sel == ReleaseSel) { 1278 return RValue::get(nullptr); 1279 } 1280 } 1281 1282 llvm::Value *cmd = GetSelector(CGF, Sel); 1283 CallArgList ActualArgs; 1284 1285 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy); 1286 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1287 ActualArgs.addFrom(CallArgs); 1288 1289 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs); 1290 1291 llvm::Value *ReceiverClass = nullptr; 1292 if (isCategoryImpl) { 1293 llvm::Constant *classLookupFunction = nullptr; 1294 if (IsClassMessage) { 1295 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1296 IdTy, PtrTy, true), "objc_get_meta_class"); 1297 } else { 1298 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1299 IdTy, PtrTy, true), "objc_get_class"); 1300 } 1301 ReceiverClass = Builder.CreateCall(classLookupFunction, 1302 MakeConstantString(Class->getNameAsString())); 1303 } else { 1304 // Set up global aliases for the metaclass or class pointer if they do not 1305 // already exist. These will are forward-references which will be set to 1306 // pointers to the class and metaclass structure created for the runtime 1307 // load function. To send a message to super, we look up the value of the 1308 // super_class pointer from either the class or metaclass structure. 1309 if (IsClassMessage) { 1310 if (!MetaClassPtrAlias) { 1311 MetaClassPtrAlias = llvm::GlobalAlias::create( 1312 IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage, 1313 ".objc_metaclass_ref" + Class->getNameAsString(), &TheModule); 1314 } 1315 ReceiverClass = MetaClassPtrAlias; 1316 } else { 1317 if (!ClassPtrAlias) { 1318 ClassPtrAlias = llvm::GlobalAlias::create( 1319 IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage, 1320 ".objc_class_ref" + Class->getNameAsString(), &TheModule); 1321 } 1322 ReceiverClass = ClassPtrAlias; 1323 } 1324 } 1325 // Cast the pointer to a simplified version of the class structure 1326 llvm::Type *CastTy = llvm::StructType::get(IdTy, IdTy, nullptr); 1327 ReceiverClass = Builder.CreateBitCast(ReceiverClass, 1328 llvm::PointerType::getUnqual(CastTy)); 1329 // Get the superclass pointer 1330 ReceiverClass = Builder.CreateStructGEP(CastTy, ReceiverClass, 1); 1331 // Load the superclass pointer 1332 ReceiverClass = 1333 Builder.CreateAlignedLoad(ReceiverClass, CGF.getPointerAlign()); 1334 // Construct the structure used to look up the IMP 1335 llvm::StructType *ObjCSuperTy = llvm::StructType::get( 1336 Receiver->getType(), IdTy, nullptr); 1337 1338 // FIXME: Is this really supposed to be a dynamic alloca? 1339 Address ObjCSuper = Address(Builder.CreateAlloca(ObjCSuperTy), 1340 CGF.getPointerAlign()); 1341 1342 Builder.CreateStore(Receiver, 1343 Builder.CreateStructGEP(ObjCSuper, 0, CharUnits::Zero())); 1344 Builder.CreateStore(ReceiverClass, 1345 Builder.CreateStructGEP(ObjCSuper, 1, CGF.getPointerSize())); 1346 1347 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy); 1348 1349 // Get the IMP 1350 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd, MSI); 1351 imp = EnforceType(Builder, imp, MSI.MessengerType); 1352 1353 llvm::Metadata *impMD[] = { 1354 llvm::MDString::get(VMContext, Sel.getAsString()), 1355 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()), 1356 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( 1357 llvm::Type::getInt1Ty(VMContext), IsClassMessage))}; 1358 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1359 1360 llvm::Instruction *call; 1361 RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs, 1362 CGCalleeInfo(), &call); 1363 call->setMetadata(msgSendMDKind, node); 1364 return msgRet; 1365 } 1366 1367 /// Generate code for a message send expression. 1368 RValue 1369 CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF, 1370 ReturnValueSlot Return, 1371 QualType ResultType, 1372 Selector Sel, 1373 llvm::Value *Receiver, 1374 const CallArgList &CallArgs, 1375 const ObjCInterfaceDecl *Class, 1376 const ObjCMethodDecl *Method) { 1377 CGBuilderTy &Builder = CGF.Builder; 1378 1379 // Strip out message sends to retain / release in GC mode 1380 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) { 1381 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1382 return RValue::get(EnforceType(Builder, Receiver, 1383 CGM.getTypes().ConvertType(ResultType))); 1384 } 1385 if (Sel == ReleaseSel) { 1386 return RValue::get(nullptr); 1387 } 1388 } 1389 1390 // If the return type is something that goes in an integer register, the 1391 // runtime will handle 0 returns. For other cases, we fill in the 0 value 1392 // ourselves. 1393 // 1394 // The language spec says the result of this kind of message send is 1395 // undefined, but lots of people seem to have forgotten to read that 1396 // paragraph and insist on sending messages to nil that have structure 1397 // returns. With GCC, this generates a random return value (whatever happens 1398 // to be on the stack / in those registers at the time) on most platforms, 1399 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts 1400 // the stack. 1401 bool isPointerSizedReturn = (ResultType->isAnyPointerType() || 1402 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType()); 1403 1404 llvm::BasicBlock *startBB = nullptr; 1405 llvm::BasicBlock *messageBB = nullptr; 1406 llvm::BasicBlock *continueBB = nullptr; 1407 1408 if (!isPointerSizedReturn) { 1409 startBB = Builder.GetInsertBlock(); 1410 messageBB = CGF.createBasicBlock("msgSend"); 1411 continueBB = CGF.createBasicBlock("continue"); 1412 1413 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver, 1414 llvm::Constant::getNullValue(Receiver->getType())); 1415 Builder.CreateCondBr(isNil, continueBB, messageBB); 1416 CGF.EmitBlock(messageBB); 1417 } 1418 1419 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 1420 llvm::Value *cmd; 1421 if (Method) 1422 cmd = GetSelector(CGF, Method); 1423 else 1424 cmd = GetSelector(CGF, Sel); 1425 cmd = EnforceType(Builder, cmd, SelectorTy); 1426 Receiver = EnforceType(Builder, Receiver, IdTy); 1427 1428 llvm::Metadata *impMD[] = { 1429 llvm::MDString::get(VMContext, Sel.getAsString()), 1430 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() : ""), 1431 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( 1432 llvm::Type::getInt1Ty(VMContext), Class != nullptr))}; 1433 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1434 1435 CallArgList ActualArgs; 1436 ActualArgs.add(RValue::get(Receiver), ASTIdTy); 1437 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1438 ActualArgs.addFrom(CallArgs); 1439 1440 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs); 1441 1442 // Get the IMP to call 1443 llvm::Value *imp; 1444 1445 // If we have non-legacy dispatch specified, we try using the objc_msgSend() 1446 // functions. These are not supported on all platforms (or all runtimes on a 1447 // given platform), so we 1448 switch (CGM.getCodeGenOpts().getObjCDispatchMethod()) { 1449 case CodeGenOptions::Legacy: 1450 imp = LookupIMP(CGF, Receiver, cmd, node, MSI); 1451 break; 1452 case CodeGenOptions::Mixed: 1453 case CodeGenOptions::NonLegacy: 1454 if (CGM.ReturnTypeUsesFPRet(ResultType)) { 1455 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1456 "objc_msgSend_fpret"); 1457 } else if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) { 1458 // The actual types here don't matter - we're going to bitcast the 1459 // function anyway 1460 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1461 "objc_msgSend_stret"); 1462 } else { 1463 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1464 "objc_msgSend"); 1465 } 1466 } 1467 1468 // Reset the receiver in case the lookup modified it 1469 ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy, false); 1470 1471 imp = EnforceType(Builder, imp, MSI.MessengerType); 1472 1473 llvm::Instruction *call; 1474 RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs, 1475 CGCalleeInfo(), &call); 1476 call->setMetadata(msgSendMDKind, node); 1477 1478 1479 if (!isPointerSizedReturn) { 1480 messageBB = CGF.Builder.GetInsertBlock(); 1481 CGF.Builder.CreateBr(continueBB); 1482 CGF.EmitBlock(continueBB); 1483 if (msgRet.isScalar()) { 1484 llvm::Value *v = msgRet.getScalarVal(); 1485 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1486 phi->addIncoming(v, messageBB); 1487 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB); 1488 msgRet = RValue::get(phi); 1489 } else if (msgRet.isAggregate()) { 1490 Address v = msgRet.getAggregateAddress(); 1491 llvm::PHINode *phi = Builder.CreatePHI(v.getType(), 2); 1492 llvm::Type *RetTy = v.getElementType(); 1493 Address NullVal = CGF.CreateTempAlloca(RetTy, v.getAlignment(), "null"); 1494 CGF.InitTempAlloca(NullVal, llvm::Constant::getNullValue(RetTy)); 1495 phi->addIncoming(v.getPointer(), messageBB); 1496 phi->addIncoming(NullVal.getPointer(), startBB); 1497 msgRet = RValue::getAggregate(Address(phi, v.getAlignment())); 1498 } else /* isComplex() */ { 1499 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal(); 1500 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2); 1501 phi->addIncoming(v.first, messageBB); 1502 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()), 1503 startBB); 1504 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2); 1505 phi2->addIncoming(v.second, messageBB); 1506 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()), 1507 startBB); 1508 msgRet = RValue::getComplex(phi, phi2); 1509 } 1510 } 1511 return msgRet; 1512 } 1513 1514 /// Generates a MethodList. Used in construction of a objc_class and 1515 /// objc_category structures. 1516 llvm::Constant *CGObjCGNU:: 1517 GenerateMethodList(StringRef ClassName, 1518 StringRef CategoryName, 1519 ArrayRef<Selector> MethodSels, 1520 ArrayRef<llvm::Constant *> MethodTypes, 1521 bool isClassMethodList) { 1522 if (MethodSels.empty()) 1523 return NULLPtr; 1524 // Get the method structure type. 1525 llvm::StructType *ObjCMethodTy = llvm::StructType::get( 1526 PtrToInt8Ty, // Really a selector, but the runtime creates it us. 1527 PtrToInt8Ty, // Method types 1528 IMPTy, //Method pointer 1529 nullptr); 1530 std::vector<llvm::Constant*> Methods; 1531 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) { 1532 llvm::Constant *Method = 1533 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName, 1534 MethodSels[i], 1535 isClassMethodList)); 1536 assert(Method && "Can't generate metadata for method that doesn't exist"); 1537 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString()); 1538 Method = llvm::ConstantExpr::getBitCast(Method, 1539 IMPTy); 1540 Methods.push_back( 1541 llvm::ConstantStruct::get(ObjCMethodTy, {C, MethodTypes[i], Method})); 1542 } 1543 1544 // Array of method structures 1545 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy, 1546 Methods.size()); 1547 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy, 1548 Methods); 1549 1550 // Structure containing list pointer, array and array count 1551 llvm::StructType *ObjCMethodListTy = llvm::StructType::create(VMContext); 1552 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(ObjCMethodListTy); 1553 ObjCMethodListTy->setBody( 1554 NextPtrTy, 1555 IntTy, 1556 ObjCMethodArrayTy, 1557 nullptr); 1558 1559 Methods.clear(); 1560 Methods.push_back(llvm::ConstantPointerNull::get( 1561 llvm::PointerType::getUnqual(ObjCMethodListTy))); 1562 Methods.push_back(llvm::ConstantInt::get(Int32Ty, MethodTypes.size())); 1563 Methods.push_back(MethodArray); 1564 1565 // Create an instance of the structure 1566 return MakeGlobal(ObjCMethodListTy, Methods, CGM.getPointerAlign(), 1567 ".objc_method_list"); 1568 } 1569 1570 /// Generates an IvarList. Used in construction of a objc_class. 1571 llvm::Constant *CGObjCGNU:: 1572 GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames, 1573 ArrayRef<llvm::Constant *> IvarTypes, 1574 ArrayRef<llvm::Constant *> IvarOffsets) { 1575 if (IvarNames.size() == 0) 1576 return NULLPtr; 1577 // Get the method structure type. 1578 llvm::StructType *ObjCIvarTy = llvm::StructType::get( 1579 PtrToInt8Ty, 1580 PtrToInt8Ty, 1581 IntTy, 1582 nullptr); 1583 std::vector<llvm::Constant*> Ivars; 1584 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) { 1585 Ivars.push_back(llvm::ConstantStruct::get( 1586 ObjCIvarTy, {IvarNames[i], IvarTypes[i], IvarOffsets[i]})); 1587 } 1588 1589 // Array of method structures 1590 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy, 1591 IvarNames.size()); 1592 1593 llvm::Constant *Elements[] = { 1594 llvm::ConstantInt::get(IntTy, (int)IvarNames.size()), 1595 llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)}; 1596 // Structure containing array and array count 1597 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(IntTy, 1598 ObjCIvarArrayTy, 1599 nullptr); 1600 1601 // Create an instance of the structure 1602 return MakeGlobal(ObjCIvarListTy, Elements, CGM.getPointerAlign(), 1603 ".objc_ivar_list"); 1604 } 1605 1606 /// Generate a class structure 1607 llvm::Constant *CGObjCGNU::GenerateClassStructure( 1608 llvm::Constant *MetaClass, 1609 llvm::Constant *SuperClass, 1610 unsigned info, 1611 const char *Name, 1612 llvm::Constant *Version, 1613 llvm::Constant *InstanceSize, 1614 llvm::Constant *IVars, 1615 llvm::Constant *Methods, 1616 llvm::Constant *Protocols, 1617 llvm::Constant *IvarOffsets, 1618 llvm::Constant *Properties, 1619 llvm::Constant *StrongIvarBitmap, 1620 llvm::Constant *WeakIvarBitmap, 1621 bool isMeta) { 1622 // Set up the class structure 1623 // Note: Several of these are char*s when they should be ids. This is 1624 // because the runtime performs this translation on load. 1625 // 1626 // Fields marked New ABI are part of the GNUstep runtime. We emit them 1627 // anyway; the classes will still work with the GNU runtime, they will just 1628 // be ignored. 1629 llvm::StructType *ClassTy = llvm::StructType::get( 1630 PtrToInt8Ty, // isa 1631 PtrToInt8Ty, // super_class 1632 PtrToInt8Ty, // name 1633 LongTy, // version 1634 LongTy, // info 1635 LongTy, // instance_size 1636 IVars->getType(), // ivars 1637 Methods->getType(), // methods 1638 // These are all filled in by the runtime, so we pretend 1639 PtrTy, // dtable 1640 PtrTy, // subclass_list 1641 PtrTy, // sibling_class 1642 PtrTy, // protocols 1643 PtrTy, // gc_object_type 1644 // New ABI: 1645 LongTy, // abi_version 1646 IvarOffsets->getType(), // ivar_offsets 1647 Properties->getType(), // properties 1648 IntPtrTy, // strong_pointers 1649 IntPtrTy, // weak_pointers 1650 nullptr); 1651 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0); 1652 // Fill in the structure 1653 std::vector<llvm::Constant*> Elements; 1654 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty)); 1655 Elements.push_back(SuperClass); 1656 Elements.push_back(MakeConstantString(Name, ".class_name")); 1657 Elements.push_back(Zero); 1658 Elements.push_back(llvm::ConstantInt::get(LongTy, info)); 1659 if (isMeta) { 1660 llvm::DataLayout td(&TheModule); 1661 Elements.push_back( 1662 llvm::ConstantInt::get(LongTy, 1663 td.getTypeSizeInBits(ClassTy) / 1664 CGM.getContext().getCharWidth())); 1665 } else 1666 Elements.push_back(InstanceSize); 1667 Elements.push_back(IVars); 1668 Elements.push_back(Methods); 1669 Elements.push_back(NULLPtr); 1670 Elements.push_back(NULLPtr); 1671 Elements.push_back(NULLPtr); 1672 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy)); 1673 Elements.push_back(NULLPtr); 1674 Elements.push_back(llvm::ConstantInt::get(LongTy, 1)); 1675 Elements.push_back(IvarOffsets); 1676 Elements.push_back(Properties); 1677 Elements.push_back(StrongIvarBitmap); 1678 Elements.push_back(WeakIvarBitmap); 1679 // Create an instance of the structure 1680 // This is now an externally visible symbol, so that we can speed up class 1681 // messages in the next ABI. We may already have some weak references to 1682 // this, so check and fix them properly. 1683 std::string ClassSym((isMeta ? "_OBJC_METACLASS_": "_OBJC_CLASS_") + 1684 std::string(Name)); 1685 llvm::GlobalVariable *ClassRef = TheModule.getNamedGlobal(ClassSym); 1686 llvm::Constant *Class = 1687 MakeGlobal(ClassTy, Elements, CGM.getPointerAlign(), ClassSym, 1688 llvm::GlobalValue::ExternalLinkage); 1689 if (ClassRef) { 1690 ClassRef->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(Class, 1691 ClassRef->getType())); 1692 ClassRef->removeFromParent(); 1693 Class->setName(ClassSym); 1694 } 1695 return Class; 1696 } 1697 1698 llvm::Constant *CGObjCGNU:: 1699 GenerateProtocolMethodList(ArrayRef<llvm::Constant *> MethodNames, 1700 ArrayRef<llvm::Constant *> MethodTypes) { 1701 // Get the method structure type. 1702 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get( 1703 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us. 1704 PtrToInt8Ty, 1705 nullptr); 1706 std::vector<llvm::Constant*> Methods; 1707 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) { 1708 Methods.push_back(llvm::ConstantStruct::get( 1709 ObjCMethodDescTy, {MethodNames[i], MethodTypes[i]})); 1710 } 1711 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy, 1712 MethodNames.size()); 1713 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy, 1714 Methods); 1715 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get( 1716 IntTy, ObjCMethodArrayTy, nullptr); 1717 Methods.clear(); 1718 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size())); 1719 Methods.push_back(Array); 1720 return MakeGlobal(ObjCMethodDescListTy, Methods, CGM.getPointerAlign(), 1721 ".objc_method_list"); 1722 } 1723 1724 // Create the protocol list structure used in classes, categories and so on 1725 llvm::Constant *CGObjCGNU::GenerateProtocolList(ArrayRef<std::string>Protocols){ 1726 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 1727 Protocols.size()); 1728 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1729 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1730 SizeTy, 1731 ProtocolArrayTy, 1732 nullptr); 1733 std::vector<llvm::Constant*> Elements; 1734 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end(); 1735 iter != endIter ; iter++) { 1736 llvm::Constant *protocol = nullptr; 1737 llvm::StringMap<llvm::Constant*>::iterator value = 1738 ExistingProtocols.find(*iter); 1739 if (value == ExistingProtocols.end()) { 1740 protocol = GenerateEmptyProtocol(*iter); 1741 } else { 1742 protocol = value->getValue(); 1743 } 1744 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol, 1745 PtrToInt8Ty); 1746 Elements.push_back(Ptr); 1747 } 1748 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1749 Elements); 1750 Elements.clear(); 1751 Elements.push_back(NULLPtr); 1752 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size())); 1753 Elements.push_back(ProtocolArray); 1754 return MakeGlobal(ProtocolListTy, Elements, CGM.getPointerAlign(), 1755 ".objc_protocol_list"); 1756 } 1757 1758 llvm::Value *CGObjCGNU::GenerateProtocolRef(CodeGenFunction &CGF, 1759 const ObjCProtocolDecl *PD) { 1760 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()]; 1761 llvm::Type *T = 1762 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType()); 1763 return CGF.Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T)); 1764 } 1765 1766 llvm::Constant *CGObjCGNU::GenerateEmptyProtocol( 1767 const std::string &ProtocolName) { 1768 SmallVector<std::string, 0> EmptyStringVector; 1769 SmallVector<llvm::Constant*, 0> EmptyConstantVector; 1770 1771 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector); 1772 llvm::Constant *MethodList = 1773 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector); 1774 // Protocols are objects containing lists of the methods implemented and 1775 // protocols adopted. 1776 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1777 PtrToInt8Ty, 1778 ProtocolList->getType(), 1779 MethodList->getType(), 1780 MethodList->getType(), 1781 MethodList->getType(), 1782 MethodList->getType(), 1783 nullptr); 1784 // The isa pointer must be set to a magic number so the runtime knows it's 1785 // the correct layout. 1786 llvm::Constant *Elements[] = { 1787 llvm::ConstantExpr::getIntToPtr( 1788 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy), 1789 MakeConstantString(ProtocolName, ".objc_protocol_name"), ProtocolList, 1790 MethodList, MethodList, MethodList, MethodList}; 1791 return MakeGlobal(ProtocolTy, Elements, CGM.getPointerAlign(), 1792 ".objc_protocol"); 1793 } 1794 1795 void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) { 1796 ASTContext &Context = CGM.getContext(); 1797 std::string ProtocolName = PD->getNameAsString(); 1798 1799 // Use the protocol definition, if there is one. 1800 if (const ObjCProtocolDecl *Def = PD->getDefinition()) 1801 PD = Def; 1802 1803 SmallVector<std::string, 16> Protocols; 1804 for (const auto *PI : PD->protocols()) 1805 Protocols.push_back(PI->getNameAsString()); 1806 SmallVector<llvm::Constant*, 16> InstanceMethodNames; 1807 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1808 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames; 1809 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes; 1810 for (const auto *I : PD->instance_methods()) { 1811 std::string TypeStr; 1812 Context.getObjCEncodingForMethodDecl(I, TypeStr); 1813 if (I->getImplementationControl() == ObjCMethodDecl::Optional) { 1814 OptionalInstanceMethodNames.push_back( 1815 MakeConstantString(I->getSelector().getAsString())); 1816 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1817 } else { 1818 InstanceMethodNames.push_back( 1819 MakeConstantString(I->getSelector().getAsString())); 1820 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1821 } 1822 } 1823 // Collect information about class methods: 1824 SmallVector<llvm::Constant*, 16> ClassMethodNames; 1825 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1826 SmallVector<llvm::Constant*, 16> OptionalClassMethodNames; 1827 SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes; 1828 for (const auto *I : PD->class_methods()) { 1829 std::string TypeStr; 1830 Context.getObjCEncodingForMethodDecl(I,TypeStr); 1831 if (I->getImplementationControl() == ObjCMethodDecl::Optional) { 1832 OptionalClassMethodNames.push_back( 1833 MakeConstantString(I->getSelector().getAsString())); 1834 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1835 } else { 1836 ClassMethodNames.push_back( 1837 MakeConstantString(I->getSelector().getAsString())); 1838 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1839 } 1840 } 1841 1842 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols); 1843 llvm::Constant *InstanceMethodList = 1844 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes); 1845 llvm::Constant *ClassMethodList = 1846 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes); 1847 llvm::Constant *OptionalInstanceMethodList = 1848 GenerateProtocolMethodList(OptionalInstanceMethodNames, 1849 OptionalInstanceMethodTypes); 1850 llvm::Constant *OptionalClassMethodList = 1851 GenerateProtocolMethodList(OptionalClassMethodNames, 1852 OptionalClassMethodTypes); 1853 1854 // Property metadata: name, attributes, isSynthesized, setter name, setter 1855 // types, getter name, getter types. 1856 // The isSynthesized value is always set to 0 in a protocol. It exists to 1857 // simplify the runtime library by allowing it to use the same data 1858 // structures for protocol metadata everywhere. 1859 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1860 PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, 1861 PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, nullptr); 1862 std::vector<llvm::Constant*> Properties; 1863 std::vector<llvm::Constant*> OptionalProperties; 1864 1865 // Add all of the property methods need adding to the method list and to the 1866 // property metadata list. 1867 for (auto *property : PD->instance_properties()) { 1868 std::vector<llvm::Constant*> Fields; 1869 1870 Fields.push_back(MakePropertyEncodingString(property, nullptr)); 1871 PushPropertyAttributes(Fields, property); 1872 1873 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1874 std::string TypeStr; 1875 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1876 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1877 InstanceMethodTypes.push_back(TypeEncoding); 1878 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1879 Fields.push_back(TypeEncoding); 1880 } else { 1881 Fields.push_back(NULLPtr); 1882 Fields.push_back(NULLPtr); 1883 } 1884 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1885 std::string TypeStr; 1886 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1887 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1888 InstanceMethodTypes.push_back(TypeEncoding); 1889 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1890 Fields.push_back(TypeEncoding); 1891 } else { 1892 Fields.push_back(NULLPtr); 1893 Fields.push_back(NULLPtr); 1894 } 1895 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) { 1896 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1897 } else { 1898 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1899 } 1900 } 1901 llvm::Constant *PropertyArray = llvm::ConstantArray::get( 1902 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties); 1903 llvm::Constant* PropertyListInitFields[] = 1904 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1905 1906 llvm::Constant *PropertyListInit = 1907 llvm::ConstantStruct::getAnon(PropertyListInitFields); 1908 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule, 1909 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage, 1910 PropertyListInit, ".objc_property_list"); 1911 1912 llvm::Constant *OptionalPropertyArray = 1913 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy, 1914 OptionalProperties.size()) , OptionalProperties); 1915 llvm::Constant* OptionalPropertyListInitFields[] = { 1916 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr, 1917 OptionalPropertyArray }; 1918 1919 llvm::Constant *OptionalPropertyListInit = 1920 llvm::ConstantStruct::getAnon(OptionalPropertyListInitFields); 1921 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule, 1922 OptionalPropertyListInit->getType(), false, 1923 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit, 1924 ".objc_property_list"); 1925 1926 // Protocols are objects containing lists of the methods implemented and 1927 // protocols adopted. 1928 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1929 PtrToInt8Ty, 1930 ProtocolList->getType(), 1931 InstanceMethodList->getType(), 1932 ClassMethodList->getType(), 1933 OptionalInstanceMethodList->getType(), 1934 OptionalClassMethodList->getType(), 1935 PropertyList->getType(), 1936 OptionalPropertyList->getType(), 1937 nullptr); 1938 // The isa pointer must be set to a magic number so the runtime knows it's 1939 // the correct layout. 1940 llvm::Constant *Elements[] = { 1941 llvm::ConstantExpr::getIntToPtr( 1942 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy), 1943 MakeConstantString(ProtocolName, ".objc_protocol_name"), ProtocolList, 1944 InstanceMethodList, ClassMethodList, OptionalInstanceMethodList, 1945 OptionalClassMethodList, PropertyList, OptionalPropertyList}; 1946 ExistingProtocols[ProtocolName] = 1947 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements, 1948 CGM.getPointerAlign(), ".objc_protocol"), IdTy); 1949 } 1950 void CGObjCGNU::GenerateProtocolHolderCategory() { 1951 // Collect information about instance methods 1952 SmallVector<Selector, 1> MethodSels; 1953 SmallVector<llvm::Constant*, 1> MethodTypes; 1954 1955 std::vector<llvm::Constant*> Elements; 1956 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack"; 1957 const std::string CategoryName = "AnotherHack"; 1958 Elements.push_back(MakeConstantString(CategoryName)); 1959 Elements.push_back(MakeConstantString(ClassName)); 1960 // Instance method list 1961 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1962 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy)); 1963 // Class method list 1964 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1965 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy)); 1966 // Protocol list 1967 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy, 1968 ExistingProtocols.size()); 1969 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1970 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1971 SizeTy, 1972 ProtocolArrayTy, 1973 nullptr); 1974 std::vector<llvm::Constant*> ProtocolElements; 1975 for (llvm::StringMapIterator<llvm::Constant*> iter = 1976 ExistingProtocols.begin(), endIter = ExistingProtocols.end(); 1977 iter != endIter ; iter++) { 1978 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(), 1979 PtrTy); 1980 ProtocolElements.push_back(Ptr); 1981 } 1982 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1983 ProtocolElements); 1984 ProtocolElements.clear(); 1985 ProtocolElements.push_back(NULLPtr); 1986 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy, 1987 ExistingProtocols.size())); 1988 ProtocolElements.push_back(ProtocolArray); 1989 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy, 1990 ProtocolElements, CGM.getPointerAlign(), 1991 ".objc_protocol_list"), PtrTy)); 1992 Categories.push_back(llvm::ConstantExpr::getBitCast( 1993 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1994 PtrTy, PtrTy, PtrTy, nullptr), Elements, CGM.getPointerAlign()), 1995 PtrTy)); 1996 } 1997 1998 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are 1999 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63 2000 /// bits set to their values, LSB first, while larger ones are stored in a 2001 /// structure of this / form: 2002 /// 2003 /// struct { int32_t length; int32_t values[length]; }; 2004 /// 2005 /// The values in the array are stored in host-endian format, with the least 2006 /// significant bit being assumed to come first in the bitfield. Therefore, a 2007 /// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a 2008 /// bitfield / with the 63rd bit set will be 1<<64. 2009 llvm::Constant *CGObjCGNU::MakeBitField(ArrayRef<bool> bits) { 2010 int bitCount = bits.size(); 2011 int ptrBits = CGM.getDataLayout().getPointerSizeInBits(); 2012 if (bitCount < ptrBits) { 2013 uint64_t val = 1; 2014 for (int i=0 ; i<bitCount ; ++i) { 2015 if (bits[i]) val |= 1ULL<<(i+1); 2016 } 2017 return llvm::ConstantInt::get(IntPtrTy, val); 2018 } 2019 SmallVector<llvm::Constant *, 8> values; 2020 int v=0; 2021 while (v < bitCount) { 2022 int32_t word = 0; 2023 for (int i=0 ; (i<32) && (v<bitCount) ; ++i) { 2024 if (bits[v]) word |= 1<<i; 2025 v++; 2026 } 2027 values.push_back(llvm::ConstantInt::get(Int32Ty, word)); 2028 } 2029 llvm::ArrayType *arrayTy = llvm::ArrayType::get(Int32Ty, values.size()); 2030 llvm::Constant *array = llvm::ConstantArray::get(arrayTy, values); 2031 llvm::Constant *fields[2] = { 2032 llvm::ConstantInt::get(Int32Ty, values.size()), 2033 array }; 2034 llvm::Constant *GS = MakeGlobal(llvm::StructType::get(Int32Ty, arrayTy, 2035 nullptr), fields, CharUnits::fromQuantity(4)); 2036 llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy); 2037 return ptr; 2038 } 2039 2040 void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) { 2041 std::string ClassName = OCD->getClassInterface()->getNameAsString(); 2042 std::string CategoryName = OCD->getNameAsString(); 2043 // Collect information about instance methods 2044 SmallVector<Selector, 16> InstanceMethodSels; 2045 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 2046 for (const auto *I : OCD->instance_methods()) { 2047 InstanceMethodSels.push_back(I->getSelector()); 2048 std::string TypeStr; 2049 CGM.getContext().getObjCEncodingForMethodDecl(I,TypeStr); 2050 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 2051 } 2052 2053 // Collect information about class methods 2054 SmallVector<Selector, 16> ClassMethodSels; 2055 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 2056 for (const auto *I : OCD->class_methods()) { 2057 ClassMethodSels.push_back(I->getSelector()); 2058 std::string TypeStr; 2059 CGM.getContext().getObjCEncodingForMethodDecl(I,TypeStr); 2060 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 2061 } 2062 2063 // Collect the names of referenced protocols 2064 SmallVector<std::string, 16> Protocols; 2065 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl(); 2066 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols(); 2067 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 2068 E = Protos.end(); I != E; ++I) 2069 Protocols.push_back((*I)->getNameAsString()); 2070 2071 llvm::Constant *Elements[] = { 2072 MakeConstantString(CategoryName), MakeConstantString(ClassName), 2073 // Instance method list 2074 llvm::ConstantExpr::getBitCast( 2075 GenerateMethodList(ClassName, CategoryName, InstanceMethodSels, 2076 InstanceMethodTypes, false), 2077 PtrTy), 2078 // Class method list 2079 llvm::ConstantExpr::getBitCast(GenerateMethodList(ClassName, CategoryName, 2080 ClassMethodSels, 2081 ClassMethodTypes, true), 2082 PtrTy), 2083 // Protocol list 2084 llvm::ConstantExpr::getBitCast(GenerateProtocolList(Protocols), PtrTy)}; 2085 Categories.push_back(llvm::ConstantExpr::getBitCast( 2086 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 2087 PtrTy, PtrTy, PtrTy, nullptr), Elements, CGM.getPointerAlign()), 2088 PtrTy)); 2089 } 2090 2091 llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID, 2092 SmallVectorImpl<Selector> &InstanceMethodSels, 2093 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) { 2094 ASTContext &Context = CGM.getContext(); 2095 // Property metadata: name, attributes, attributes2, padding1, padding2, 2096 // setter name, setter types, getter name, getter types. 2097 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 2098 PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, 2099 PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, nullptr); 2100 std::vector<llvm::Constant*> Properties; 2101 2102 // Add all of the property methods need adding to the method list and to the 2103 // property metadata list. 2104 for (auto *propertyImpl : OID->property_impls()) { 2105 std::vector<llvm::Constant*> Fields; 2106 ObjCPropertyDecl *property = propertyImpl->getPropertyDecl(); 2107 bool isSynthesized = (propertyImpl->getPropertyImplementation() == 2108 ObjCPropertyImplDecl::Synthesize); 2109 bool isDynamic = (propertyImpl->getPropertyImplementation() == 2110 ObjCPropertyImplDecl::Dynamic); 2111 2112 Fields.push_back(MakePropertyEncodingString(property, OID)); 2113 PushPropertyAttributes(Fields, property, isSynthesized, isDynamic); 2114 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 2115 std::string TypeStr; 2116 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 2117 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 2118 if (isSynthesized) { 2119 InstanceMethodTypes.push_back(TypeEncoding); 2120 InstanceMethodSels.push_back(getter->getSelector()); 2121 } 2122 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 2123 Fields.push_back(TypeEncoding); 2124 } else { 2125 Fields.push_back(NULLPtr); 2126 Fields.push_back(NULLPtr); 2127 } 2128 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 2129 std::string TypeStr; 2130 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 2131 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 2132 if (isSynthesized) { 2133 InstanceMethodTypes.push_back(TypeEncoding); 2134 InstanceMethodSels.push_back(setter->getSelector()); 2135 } 2136 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 2137 Fields.push_back(TypeEncoding); 2138 } else { 2139 Fields.push_back(NULLPtr); 2140 Fields.push_back(NULLPtr); 2141 } 2142 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 2143 } 2144 llvm::ArrayType *PropertyArrayTy = 2145 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()); 2146 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy, 2147 Properties); 2148 llvm::Constant* PropertyListInitFields[] = 2149 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 2150 2151 llvm::Constant *PropertyListInit = 2152 llvm::ConstantStruct::getAnon(PropertyListInitFields); 2153 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false, 2154 llvm::GlobalValue::InternalLinkage, PropertyListInit, 2155 ".objc_property_list"); 2156 } 2157 2158 void CGObjCGNU::RegisterAlias(const ObjCCompatibleAliasDecl *OAD) { 2159 // Get the class declaration for which the alias is specified. 2160 ObjCInterfaceDecl *ClassDecl = 2161 const_cast<ObjCInterfaceDecl *>(OAD->getClassInterface()); 2162 ClassAliases.emplace_back(ClassDecl->getNameAsString(), 2163 OAD->getNameAsString()); 2164 } 2165 2166 void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) { 2167 ASTContext &Context = CGM.getContext(); 2168 2169 // Get the superclass name. 2170 const ObjCInterfaceDecl * SuperClassDecl = 2171 OID->getClassInterface()->getSuperClass(); 2172 std::string SuperClassName; 2173 if (SuperClassDecl) { 2174 SuperClassName = SuperClassDecl->getNameAsString(); 2175 EmitClassRef(SuperClassName); 2176 } 2177 2178 // Get the class name 2179 ObjCInterfaceDecl *ClassDecl = 2180 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface()); 2181 std::string ClassName = ClassDecl->getNameAsString(); 2182 // Emit the symbol that is used to generate linker errors if this class is 2183 // referenced in other modules but not declared. 2184 std::string classSymbolName = "__objc_class_name_" + ClassName; 2185 if (llvm::GlobalVariable *symbol = 2186 TheModule.getGlobalVariable(classSymbolName)) { 2187 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0)); 2188 } else { 2189 new llvm::GlobalVariable(TheModule, LongTy, false, 2190 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0), 2191 classSymbolName); 2192 } 2193 2194 // Get the size of instances. 2195 int instanceSize = 2196 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity(); 2197 2198 // Collect information about instance variables. 2199 SmallVector<llvm::Constant*, 16> IvarNames; 2200 SmallVector<llvm::Constant*, 16> IvarTypes; 2201 SmallVector<llvm::Constant*, 16> IvarOffsets; 2202 2203 std::vector<llvm::Constant*> IvarOffsetValues; 2204 SmallVector<bool, 16> WeakIvars; 2205 SmallVector<bool, 16> StrongIvars; 2206 2207 int superInstanceSize = !SuperClassDecl ? 0 : 2208 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity(); 2209 // For non-fragile ivars, set the instance size to 0 - {the size of just this 2210 // class}. The runtime will then set this to the correct value on load. 2211 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 2212 instanceSize = 0 - (instanceSize - superInstanceSize); 2213 } 2214 2215 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 2216 IVD = IVD->getNextIvar()) { 2217 // Store the name 2218 IvarNames.push_back(MakeConstantString(IVD->getNameAsString())); 2219 // Get the type encoding for this ivar 2220 std::string TypeStr; 2221 Context.getObjCEncodingForType(IVD->getType(), TypeStr); 2222 IvarTypes.push_back(MakeConstantString(TypeStr)); 2223 // Get the offset 2224 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD); 2225 uint64_t Offset = BaseOffset; 2226 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 2227 Offset = BaseOffset - superInstanceSize; 2228 } 2229 llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset); 2230 // Create the direct offset value 2231 std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." + 2232 IVD->getNameAsString(); 2233 llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName); 2234 if (OffsetVar) { 2235 OffsetVar->setInitializer(OffsetValue); 2236 // If this is the real definition, change its linkage type so that 2237 // different modules will use this one, rather than their private 2238 // copy. 2239 OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage); 2240 } else 2241 OffsetVar = new llvm::GlobalVariable(TheModule, IntTy, 2242 false, llvm::GlobalValue::ExternalLinkage, 2243 OffsetValue, 2244 "__objc_ivar_offset_value_" + ClassName +"." + 2245 IVD->getNameAsString()); 2246 IvarOffsets.push_back(OffsetValue); 2247 IvarOffsetValues.push_back(OffsetVar); 2248 Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime(); 2249 switch (lt) { 2250 case Qualifiers::OCL_Strong: 2251 StrongIvars.push_back(true); 2252 WeakIvars.push_back(false); 2253 break; 2254 case Qualifiers::OCL_Weak: 2255 StrongIvars.push_back(false); 2256 WeakIvars.push_back(true); 2257 break; 2258 default: 2259 StrongIvars.push_back(false); 2260 WeakIvars.push_back(false); 2261 } 2262 } 2263 llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars); 2264 llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars); 2265 llvm::GlobalVariable *IvarOffsetArray = 2266 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, CGM.getPointerAlign(), 2267 ".ivar.offsets"); 2268 2269 // Collect information about instance methods 2270 SmallVector<Selector, 16> InstanceMethodSels; 2271 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 2272 for (const auto *I : OID->instance_methods()) { 2273 InstanceMethodSels.push_back(I->getSelector()); 2274 std::string TypeStr; 2275 Context.getObjCEncodingForMethodDecl(I,TypeStr); 2276 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 2277 } 2278 2279 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels, 2280 InstanceMethodTypes); 2281 2282 // Collect information about class methods 2283 SmallVector<Selector, 16> ClassMethodSels; 2284 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 2285 for (const auto *I : OID->class_methods()) { 2286 ClassMethodSels.push_back(I->getSelector()); 2287 std::string TypeStr; 2288 Context.getObjCEncodingForMethodDecl(I,TypeStr); 2289 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 2290 } 2291 // Collect the names of referenced protocols 2292 SmallVector<std::string, 16> Protocols; 2293 for (const auto *I : ClassDecl->protocols()) 2294 Protocols.push_back(I->getNameAsString()); 2295 2296 // Get the superclass pointer. 2297 llvm::Constant *SuperClass; 2298 if (!SuperClassName.empty()) { 2299 SuperClass = MakeConstantString(SuperClassName, ".super_class_name"); 2300 } else { 2301 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty); 2302 } 2303 // Empty vector used to construct empty method lists 2304 SmallVector<llvm::Constant*, 1> empty; 2305 // Generate the method and instance variable lists 2306 llvm::Constant *MethodList = GenerateMethodList(ClassName, "", 2307 InstanceMethodSels, InstanceMethodTypes, false); 2308 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "", 2309 ClassMethodSels, ClassMethodTypes, true); 2310 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes, 2311 IvarOffsets); 2312 // Irrespective of whether we are compiling for a fragile or non-fragile ABI, 2313 // we emit a symbol containing the offset for each ivar in the class. This 2314 // allows code compiled for the non-Fragile ABI to inherit from code compiled 2315 // for the legacy ABI, without causing problems. The converse is also 2316 // possible, but causes all ivar accesses to be fragile. 2317 2318 // Offset pointer for getting at the correct field in the ivar list when 2319 // setting up the alias. These are: The base address for the global, the 2320 // ivar array (second field), the ivar in this list (set for each ivar), and 2321 // the offset (third field in ivar structure) 2322 llvm::Type *IndexTy = Int32Ty; 2323 llvm::Constant *offsetPointerIndexes[] = {Zeros[0], 2324 llvm::ConstantInt::get(IndexTy, 1), nullptr, 2325 llvm::ConstantInt::get(IndexTy, 2) }; 2326 2327 unsigned ivarIndex = 0; 2328 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 2329 IVD = IVD->getNextIvar()) { 2330 const std::string Name = "__objc_ivar_offset_" + ClassName + '.' 2331 + IVD->getNameAsString(); 2332 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex); 2333 // Get the correct ivar field 2334 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr( 2335 cast<llvm::GlobalVariable>(IvarList)->getValueType(), IvarList, 2336 offsetPointerIndexes); 2337 // Get the existing variable, if one exists. 2338 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name); 2339 if (offset) { 2340 offset->setInitializer(offsetValue); 2341 // If this is the real definition, change its linkage type so that 2342 // different modules will use this one, rather than their private 2343 // copy. 2344 offset->setLinkage(llvm::GlobalValue::ExternalLinkage); 2345 } else { 2346 // Add a new alias if there isn't one already. 2347 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(), 2348 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name); 2349 (void) offset; // Silence dead store warning. 2350 } 2351 ++ivarIndex; 2352 } 2353 llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0); 2354 //Generate metaclass for class methods 2355 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr, 2356 NULLPtr, 0x12L, ClassName.c_str(), nullptr, Zeros[0], GenerateIvarList( 2357 empty, empty, empty), ClassMethodList, NULLPtr, 2358 NULLPtr, NULLPtr, ZeroPtr, ZeroPtr, true); 2359 2360 // Generate the class structure 2361 llvm::Constant *ClassStruct = 2362 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L, 2363 ClassName.c_str(), nullptr, 2364 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, 2365 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray, 2366 Properties, StrongIvarBitmap, WeakIvarBitmap); 2367 2368 // Resolve the class aliases, if they exist. 2369 if (ClassPtrAlias) { 2370 ClassPtrAlias->replaceAllUsesWith( 2371 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy)); 2372 ClassPtrAlias->eraseFromParent(); 2373 ClassPtrAlias = nullptr; 2374 } 2375 if (MetaClassPtrAlias) { 2376 MetaClassPtrAlias->replaceAllUsesWith( 2377 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy)); 2378 MetaClassPtrAlias->eraseFromParent(); 2379 MetaClassPtrAlias = nullptr; 2380 } 2381 2382 // Add class structure to list to be added to the symtab later 2383 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty); 2384 Classes.push_back(ClassStruct); 2385 } 2386 2387 llvm::Function *CGObjCGNU::ModuleInitFunction() { 2388 // Only emit an ObjC load function if no Objective-C stuff has been called 2389 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() && 2390 ExistingProtocols.empty() && SelectorTable.empty()) 2391 return nullptr; 2392 2393 // Add all referenced protocols to a category. 2394 GenerateProtocolHolderCategory(); 2395 2396 llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>( 2397 SelectorTy->getElementType()); 2398 llvm::Type *SelStructPtrTy = SelectorTy; 2399 if (!SelStructTy) { 2400 SelStructTy = llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, nullptr); 2401 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy); 2402 } 2403 2404 std::vector<llvm::Constant*> Elements; 2405 llvm::Constant *Statics = NULLPtr; 2406 // Generate statics list: 2407 if (!ConstantStrings.empty()) { 2408 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 2409 ConstantStrings.size() + 1); 2410 ConstantStrings.push_back(NULLPtr); 2411 2412 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass; 2413 2414 if (StringClass.empty()) StringClass = "NXConstantString"; 2415 2416 Elements.push_back(MakeConstantString(StringClass, 2417 ".objc_static_class_name")); 2418 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy, 2419 ConstantStrings)); 2420 llvm::StructType *StaticsListTy = 2421 llvm::StructType::get(PtrToInt8Ty, StaticsArrayTy, nullptr); 2422 llvm::Type *StaticsListPtrTy = 2423 llvm::PointerType::getUnqual(StaticsListTy); 2424 Statics = MakeGlobal(StaticsListTy, Elements, CGM.getPointerAlign(), 2425 ".objc_statics"); 2426 llvm::ArrayType *StaticsListArrayTy = 2427 llvm::ArrayType::get(StaticsListPtrTy, 2); 2428 Elements.clear(); 2429 Elements.push_back(Statics); 2430 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy)); 2431 Statics = MakeGlobal(StaticsListArrayTy, Elements, 2432 CGM.getPointerAlign(), ".objc_statics_ptr"); 2433 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy); 2434 } 2435 // Array of classes, categories, and constant objects 2436 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty, 2437 Classes.size() + Categories.size() + 2); 2438 llvm::StructType *SymTabTy = llvm::StructType::get(LongTy, SelStructPtrTy, 2439 llvm::Type::getInt16Ty(VMContext), 2440 llvm::Type::getInt16Ty(VMContext), 2441 ClassListTy, nullptr); 2442 2443 Elements.clear(); 2444 // Pointer to an array of selectors used in this module. 2445 std::vector<llvm::Constant*> Selectors; 2446 std::vector<llvm::GlobalAlias*> SelectorAliases; 2447 for (SelectorMap::iterator iter = SelectorTable.begin(), 2448 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) { 2449 2450 std::string SelNameStr = iter->first.getAsString(); 2451 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name"); 2452 2453 SmallVectorImpl<TypedSelector> &Types = iter->second; 2454 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 2455 e = Types.end() ; i!=e ; i++) { 2456 2457 llvm::Constant *SelectorTypeEncoding = NULLPtr; 2458 if (!i->first.empty()) 2459 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types"); 2460 2461 Elements.push_back(SelName); 2462 Elements.push_back(SelectorTypeEncoding); 2463 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2464 Elements.clear(); 2465 2466 // Store the selector alias for later replacement 2467 SelectorAliases.push_back(i->second); 2468 } 2469 } 2470 unsigned SelectorCount = Selectors.size(); 2471 // NULL-terminate the selector list. This should not actually be required, 2472 // because the selector list has a length field. Unfortunately, the GCC 2473 // runtime decides to ignore the length field and expects a NULL terminator, 2474 // and GCC cooperates with this by always setting the length to 0. 2475 Elements.push_back(NULLPtr); 2476 Elements.push_back(NULLPtr); 2477 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2478 Elements.clear(); 2479 2480 // Number of static selectors 2481 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount)); 2482 llvm::GlobalVariable *SelectorList = 2483 MakeGlobalArray(SelStructTy, Selectors, CGM.getPointerAlign(), 2484 ".objc_selector_list"); 2485 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList, 2486 SelStructPtrTy)); 2487 2488 // Now that all of the static selectors exist, create pointers to them. 2489 for (unsigned int i=0 ; i<SelectorCount ; i++) { 2490 2491 llvm::Constant *Idxs[] = {Zeros[0], 2492 llvm::ConstantInt::get(Int32Ty, i), Zeros[0]}; 2493 // FIXME: We're generating redundant loads and stores here! 2494 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr( 2495 SelectorList->getValueType(), SelectorList, makeArrayRef(Idxs, 2)); 2496 // If selectors are defined as an opaque type, cast the pointer to this 2497 // type. 2498 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy); 2499 SelectorAliases[i]->replaceAllUsesWith(SelPtr); 2500 SelectorAliases[i]->eraseFromParent(); 2501 } 2502 2503 // Number of classes defined. 2504 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2505 Classes.size())); 2506 // Number of categories defined 2507 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2508 Categories.size())); 2509 // Create an array of classes, then categories, then static object instances 2510 Classes.insert(Classes.end(), Categories.begin(), Categories.end()); 2511 // NULL-terminated list of static object instances (mainly constant strings) 2512 Classes.push_back(Statics); 2513 Classes.push_back(NULLPtr); 2514 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes); 2515 Elements.push_back(ClassList); 2516 // Construct the symbol table 2517 llvm::Constant *SymTab = 2518 MakeGlobal(SymTabTy, Elements, CGM.getPointerAlign()); 2519 2520 // The symbol table is contained in a module which has some version-checking 2521 // constants 2522 llvm::StructType * ModuleTy = llvm::StructType::get(LongTy, LongTy, 2523 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), 2524 (RuntimeVersion >= 10) ? IntTy : nullptr, nullptr); 2525 Elements.clear(); 2526 // Runtime version, used for ABI compatibility checking. 2527 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion)); 2528 // sizeof(ModuleTy) 2529 llvm::DataLayout td(&TheModule); 2530 Elements.push_back( 2531 llvm::ConstantInt::get(LongTy, 2532 td.getTypeSizeInBits(ModuleTy) / 2533 CGM.getContext().getCharWidth())); 2534 2535 // The path to the source file where this module was declared 2536 SourceManager &SM = CGM.getContext().getSourceManager(); 2537 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID()); 2538 std::string path = 2539 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName(); 2540 Elements.push_back(MakeConstantString(path, ".objc_source_file_name")); 2541 Elements.push_back(SymTab); 2542 2543 if (RuntimeVersion >= 10) 2544 switch (CGM.getLangOpts().getGC()) { 2545 case LangOptions::GCOnly: 2546 Elements.push_back(llvm::ConstantInt::get(IntTy, 2)); 2547 break; 2548 case LangOptions::NonGC: 2549 if (CGM.getLangOpts().ObjCAutoRefCount) 2550 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2551 else 2552 Elements.push_back(llvm::ConstantInt::get(IntTy, 0)); 2553 break; 2554 case LangOptions::HybridGC: 2555 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2556 break; 2557 } 2558 2559 llvm::Value *Module = MakeGlobal(ModuleTy, Elements, CGM.getPointerAlign()); 2560 2561 // Create the load function calling the runtime entry point with the module 2562 // structure 2563 llvm::Function * LoadFunction = llvm::Function::Create( 2564 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false), 2565 llvm::GlobalValue::InternalLinkage, ".objc_load_function", 2566 &TheModule); 2567 llvm::BasicBlock *EntryBB = 2568 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction); 2569 CGBuilderTy Builder(CGM, VMContext); 2570 Builder.SetInsertPoint(EntryBB); 2571 2572 llvm::FunctionType *FT = 2573 llvm::FunctionType::get(Builder.getVoidTy(), 2574 llvm::PointerType::getUnqual(ModuleTy), true); 2575 llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class"); 2576 Builder.CreateCall(Register, Module); 2577 2578 if (!ClassAliases.empty()) { 2579 llvm::Type *ArgTypes[2] = {PtrTy, PtrToInt8Ty}; 2580 llvm::FunctionType *RegisterAliasTy = 2581 llvm::FunctionType::get(Builder.getVoidTy(), 2582 ArgTypes, false); 2583 llvm::Function *RegisterAlias = llvm::Function::Create( 2584 RegisterAliasTy, 2585 llvm::GlobalValue::ExternalWeakLinkage, "class_registerAlias_np", 2586 &TheModule); 2587 llvm::BasicBlock *AliasBB = 2588 llvm::BasicBlock::Create(VMContext, "alias", LoadFunction); 2589 llvm::BasicBlock *NoAliasBB = 2590 llvm::BasicBlock::Create(VMContext, "no_alias", LoadFunction); 2591 2592 // Branch based on whether the runtime provided class_registerAlias_np() 2593 llvm::Value *HasRegisterAlias = Builder.CreateICmpNE(RegisterAlias, 2594 llvm::Constant::getNullValue(RegisterAlias->getType())); 2595 Builder.CreateCondBr(HasRegisterAlias, AliasBB, NoAliasBB); 2596 2597 // The true branch (has alias registration function): 2598 Builder.SetInsertPoint(AliasBB); 2599 // Emit alias registration calls: 2600 for (std::vector<ClassAliasPair>::iterator iter = ClassAliases.begin(); 2601 iter != ClassAliases.end(); ++iter) { 2602 llvm::Constant *TheClass = 2603 TheModule.getGlobalVariable(("_OBJC_CLASS_" + iter->first).c_str(), 2604 true); 2605 if (TheClass) { 2606 TheClass = llvm::ConstantExpr::getBitCast(TheClass, PtrTy); 2607 Builder.CreateCall(RegisterAlias, 2608 {TheClass, MakeConstantString(iter->second)}); 2609 } 2610 } 2611 // Jump to end: 2612 Builder.CreateBr(NoAliasBB); 2613 2614 // Missing alias registration function, just return from the function: 2615 Builder.SetInsertPoint(NoAliasBB); 2616 } 2617 Builder.CreateRetVoid(); 2618 2619 return LoadFunction; 2620 } 2621 2622 llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD, 2623 const ObjCContainerDecl *CD) { 2624 const ObjCCategoryImplDecl *OCD = 2625 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext()); 2626 StringRef CategoryName = OCD ? OCD->getName() : ""; 2627 StringRef ClassName = CD->getName(); 2628 Selector MethodName = OMD->getSelector(); 2629 bool isClassMethod = !OMD->isInstanceMethod(); 2630 2631 CodeGenTypes &Types = CGM.getTypes(); 2632 llvm::FunctionType *MethodTy = 2633 Types.GetFunctionType(Types.arrangeObjCMethodDeclaration(OMD)); 2634 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName, 2635 MethodName, isClassMethod); 2636 2637 llvm::Function *Method 2638 = llvm::Function::Create(MethodTy, 2639 llvm::GlobalValue::InternalLinkage, 2640 FunctionName, 2641 &TheModule); 2642 return Method; 2643 } 2644 2645 llvm::Constant *CGObjCGNU::GetPropertyGetFunction() { 2646 return GetPropertyFn; 2647 } 2648 2649 llvm::Constant *CGObjCGNU::GetPropertySetFunction() { 2650 return SetPropertyFn; 2651 } 2652 2653 llvm::Constant *CGObjCGNU::GetOptimizedPropertySetFunction(bool atomic, 2654 bool copy) { 2655 return nullptr; 2656 } 2657 2658 llvm::Constant *CGObjCGNU::GetGetStructFunction() { 2659 return GetStructPropertyFn; 2660 } 2661 2662 llvm::Constant *CGObjCGNU::GetSetStructFunction() { 2663 return SetStructPropertyFn; 2664 } 2665 2666 llvm::Constant *CGObjCGNU::GetCppAtomicObjectGetFunction() { 2667 return nullptr; 2668 } 2669 2670 llvm::Constant *CGObjCGNU::GetCppAtomicObjectSetFunction() { 2671 return nullptr; 2672 } 2673 2674 llvm::Constant *CGObjCGNU::EnumerationMutationFunction() { 2675 return EnumerationMutationFn; 2676 } 2677 2678 void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF, 2679 const ObjCAtSynchronizedStmt &S) { 2680 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn); 2681 } 2682 2683 2684 void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF, 2685 const ObjCAtTryStmt &S) { 2686 // Unlike the Apple non-fragile runtimes, which also uses 2687 // unwind-based zero cost exceptions, the GNU Objective C runtime's 2688 // EH support isn't a veneer over C++ EH. Instead, exception 2689 // objects are created by objc_exception_throw and destroyed by 2690 // the personality function; this avoids the need for bracketing 2691 // catch handlers with calls to __blah_begin_catch/__blah_end_catch 2692 // (or even _Unwind_DeleteException), but probably doesn't 2693 // interoperate very well with foreign exceptions. 2694 // 2695 // In Objective-C++ mode, we actually emit something equivalent to the C++ 2696 // exception handler. 2697 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn); 2698 } 2699 2700 void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF, 2701 const ObjCAtThrowStmt &S, 2702 bool ClearInsertionPoint) { 2703 llvm::Value *ExceptionAsObject; 2704 2705 if (const Expr *ThrowExpr = S.getThrowExpr()) { 2706 llvm::Value *Exception = CGF.EmitObjCThrowOperand(ThrowExpr); 2707 ExceptionAsObject = Exception; 2708 } else { 2709 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) && 2710 "Unexpected rethrow outside @catch block."); 2711 ExceptionAsObject = CGF.ObjCEHValueStack.back(); 2712 } 2713 ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy); 2714 llvm::CallSite Throw = 2715 CGF.EmitRuntimeCallOrInvoke(ExceptionThrowFn, ExceptionAsObject); 2716 Throw.setDoesNotReturn(); 2717 CGF.Builder.CreateUnreachable(); 2718 if (ClearInsertionPoint) 2719 CGF.Builder.ClearInsertionPoint(); 2720 } 2721 2722 llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF, 2723 Address AddrWeakObj) { 2724 CGBuilderTy &B = CGF.Builder; 2725 AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy); 2726 return B.CreateCall(WeakReadFn.getType(), WeakReadFn, 2727 AddrWeakObj.getPointer()); 2728 } 2729 2730 void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF, 2731 llvm::Value *src, Address dst) { 2732 CGBuilderTy &B = CGF.Builder; 2733 src = EnforceType(B, src, IdTy); 2734 dst = EnforceType(B, dst, PtrToIdTy); 2735 B.CreateCall(WeakAssignFn.getType(), WeakAssignFn, 2736 {src, dst.getPointer()}); 2737 } 2738 2739 void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF, 2740 llvm::Value *src, Address dst, 2741 bool threadlocal) { 2742 CGBuilderTy &B = CGF.Builder; 2743 src = EnforceType(B, src, IdTy); 2744 dst = EnforceType(B, dst, PtrToIdTy); 2745 // FIXME. Add threadloca assign API 2746 assert(!threadlocal && "EmitObjCGlobalAssign - Threal Local API NYI"); 2747 B.CreateCall(GlobalAssignFn.getType(), GlobalAssignFn, 2748 {src, dst.getPointer()}); 2749 } 2750 2751 void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF, 2752 llvm::Value *src, Address dst, 2753 llvm::Value *ivarOffset) { 2754 CGBuilderTy &B = CGF.Builder; 2755 src = EnforceType(B, src, IdTy); 2756 dst = EnforceType(B, dst, IdTy); 2757 B.CreateCall(IvarAssignFn.getType(), IvarAssignFn, 2758 {src, dst.getPointer(), ivarOffset}); 2759 } 2760 2761 void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF, 2762 llvm::Value *src, Address dst) { 2763 CGBuilderTy &B = CGF.Builder; 2764 src = EnforceType(B, src, IdTy); 2765 dst = EnforceType(B, dst, PtrToIdTy); 2766 B.CreateCall(StrongCastAssignFn.getType(), StrongCastAssignFn, 2767 {src, dst.getPointer()}); 2768 } 2769 2770 void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF, 2771 Address DestPtr, 2772 Address SrcPtr, 2773 llvm::Value *Size) { 2774 CGBuilderTy &B = CGF.Builder; 2775 DestPtr = EnforceType(B, DestPtr, PtrTy); 2776 SrcPtr = EnforceType(B, SrcPtr, PtrTy); 2777 2778 B.CreateCall(MemMoveFn.getType(), MemMoveFn, 2779 {DestPtr.getPointer(), SrcPtr.getPointer(), Size}); 2780 } 2781 2782 llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable( 2783 const ObjCInterfaceDecl *ID, 2784 const ObjCIvarDecl *Ivar) { 2785 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString() 2786 + '.' + Ivar->getNameAsString(); 2787 // Emit the variable and initialize it with what we think the correct value 2788 // is. This allows code compiled with non-fragile ivars to work correctly 2789 // when linked against code which isn't (most of the time). 2790 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name); 2791 if (!IvarOffsetPointer) { 2792 // This will cause a run-time crash if we accidentally use it. A value of 2793 // 0 would seem more sensible, but will silently overwrite the isa pointer 2794 // causing a great deal of confusion. 2795 uint64_t Offset = -1; 2796 // We can't call ComputeIvarBaseOffset() here if we have the 2797 // implementation, because it will create an invalid ASTRecordLayout object 2798 // that we are then stuck with forever, so we only initialize the ivar 2799 // offset variable with a guess if we only have the interface. The 2800 // initializer will be reset later anyway, when we are generating the class 2801 // description. 2802 if (!CGM.getContext().getObjCImplementation( 2803 const_cast<ObjCInterfaceDecl *>(ID))) 2804 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar); 2805 2806 llvm::ConstantInt *OffsetGuess = llvm::ConstantInt::get(Int32Ty, Offset, 2807 /*isSigned*/true); 2808 // Don't emit the guess in non-PIC code because the linker will not be able 2809 // to replace it with the real version for a library. In non-PIC code you 2810 // must compile with the fragile ABI if you want to use ivars from a 2811 // GCC-compiled class. 2812 if (CGM.getLangOpts().PICLevel) { 2813 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule, 2814 Int32Ty, false, 2815 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess"); 2816 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2817 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage, 2818 IvarOffsetGV, Name); 2819 } else { 2820 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2821 llvm::Type::getInt32PtrTy(VMContext), false, 2822 llvm::GlobalValue::ExternalLinkage, nullptr, Name); 2823 } 2824 } 2825 return IvarOffsetPointer; 2826 } 2827 2828 LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF, 2829 QualType ObjectTy, 2830 llvm::Value *BaseValue, 2831 const ObjCIvarDecl *Ivar, 2832 unsigned CVRQualifiers) { 2833 const ObjCInterfaceDecl *ID = 2834 ObjectTy->getAs<ObjCObjectType>()->getInterface(); 2835 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers, 2836 EmitIvarOffset(CGF, ID, Ivar)); 2837 } 2838 2839 static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context, 2840 const ObjCInterfaceDecl *OID, 2841 const ObjCIvarDecl *OIVD) { 2842 for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next; 2843 next = next->getNextIvar()) { 2844 if (OIVD == next) 2845 return OID; 2846 } 2847 2848 // Otherwise check in the super class. 2849 if (const ObjCInterfaceDecl *Super = OID->getSuperClass()) 2850 return FindIvarInterface(Context, Super, OIVD); 2851 2852 return nullptr; 2853 } 2854 2855 llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF, 2856 const ObjCInterfaceDecl *Interface, 2857 const ObjCIvarDecl *Ivar) { 2858 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 2859 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar); 2860 if (RuntimeVersion < 10) 2861 return CGF.Builder.CreateZExtOrBitCast( 2862 CGF.Builder.CreateDefaultAlignedLoad(CGF.Builder.CreateAlignedLoad( 2863 ObjCIvarOffsetVariable(Interface, Ivar), 2864 CGF.getPointerAlign(), "ivar")), 2865 PtrDiffTy); 2866 std::string name = "__objc_ivar_offset_value_" + 2867 Interface->getNameAsString() +"." + Ivar->getNameAsString(); 2868 CharUnits Align = CGM.getIntAlign(); 2869 llvm::Value *Offset = TheModule.getGlobalVariable(name); 2870 if (!Offset) { 2871 auto GV = new llvm::GlobalVariable(TheModule, IntTy, 2872 false, llvm::GlobalValue::LinkOnceAnyLinkage, 2873 llvm::Constant::getNullValue(IntTy), name); 2874 GV->setAlignment(Align.getQuantity()); 2875 Offset = GV; 2876 } 2877 Offset = CGF.Builder.CreateAlignedLoad(Offset, Align); 2878 if (Offset->getType() != PtrDiffTy) 2879 Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy); 2880 return Offset; 2881 } 2882 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar); 2883 return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true); 2884 } 2885 2886 CGObjCRuntime * 2887 clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) { 2888 switch (CGM.getLangOpts().ObjCRuntime.getKind()) { 2889 case ObjCRuntime::GNUstep: 2890 return new CGObjCGNUstep(CGM); 2891 2892 case ObjCRuntime::GCC: 2893 return new CGObjCGCC(CGM); 2894 2895 case ObjCRuntime::ObjFW: 2896 return new CGObjCObjFW(CGM); 2897 2898 case ObjCRuntime::FragileMacOSX: 2899 case ObjCRuntime::MacOSX: 2900 case ObjCRuntime::iOS: 2901 case ObjCRuntime::WatchOS: 2902 llvm_unreachable("these runtimes are not GNU runtimes"); 2903 } 2904 llvm_unreachable("bad runtime"); 2905 } 2906