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/DataLayout.h" 31 #include "llvm/IR/Intrinsics.h" 32 #include "llvm/IR/LLVMContext.h" 33 #include "llvm/IR/Module.h" 34 #include "llvm/Support/CallSite.h" 35 #include "llvm/Support/Compiler.h" 36 #include <cstdarg> 37 38 39 using namespace clang; 40 using namespace CodeGen; 41 42 43 namespace { 44 /// Class that lazily initialises the runtime function. Avoids inserting the 45 /// types and the function declaration into a module if they're not used, and 46 /// avoids constructing the type more than once if it's used more than once. 47 class LazyRuntimeFunction { 48 CodeGenModule *CGM; 49 std::vector<llvm::Type*> ArgTys; 50 const char *FunctionName; 51 llvm::Constant *Function; 52 public: 53 /// Constructor leaves this class uninitialized, because it is intended to 54 /// be used as a field in another class and not all of the types that are 55 /// used as arguments will necessarily be available at construction time. 56 LazyRuntimeFunction() : CGM(0), FunctionName(0), Function(0) {} 57 58 /// Initialises the lazy function with the name, return type, and the types 59 /// of the arguments. 60 END_WITH_NULL 61 void init(CodeGenModule *Mod, const char *name, 62 llvm::Type *RetTy, ...) { 63 CGM =Mod; 64 FunctionName = name; 65 Function = 0; 66 ArgTys.clear(); 67 va_list Args; 68 va_start(Args, RetTy); 69 while (llvm::Type *ArgTy = va_arg(Args, llvm::Type*)) 70 ArgTys.push_back(ArgTy); 71 va_end(Args); 72 // Push the return type on at the end so we can pop it off easily 73 ArgTys.push_back(RetTy); 74 } 75 /// Overloaded cast operator, allows the class to be implicitly cast to an 76 /// LLVM constant. 77 operator llvm::Constant*() { 78 if (!Function) { 79 if (0 == FunctionName) return 0; 80 // We put the return type on the end of the vector, so pop it back off 81 llvm::Type *RetTy = ArgTys.back(); 82 ArgTys.pop_back(); 83 llvm::FunctionType *FTy = llvm::FunctionType::get(RetTy, ArgTys, false); 84 Function = 85 cast<llvm::Constant>(CGM->CreateRuntimeFunction(FTy, FunctionName)); 86 // We won't need to use the types again, so we may as well clean up the 87 // vector now 88 ArgTys.resize(0); 89 } 90 return Function; 91 } 92 operator llvm::Function*() { 93 return cast<llvm::Function>((llvm::Constant*)*this); 94 } 95 96 }; 97 98 99 /// GNU Objective-C runtime code generation. This class implements the parts of 100 /// Objective-C support that are specific to the GNU family of runtimes (GCC, 101 /// GNUstep and ObjFW). 102 class CGObjCGNU : public CGObjCRuntime { 103 protected: 104 /// The LLVM module into which output is inserted 105 llvm::Module &TheModule; 106 /// strut objc_super. Used for sending messages to super. This structure 107 /// contains the receiver (object) and the expected class. 108 llvm::StructType *ObjCSuperTy; 109 /// struct objc_super*. The type of the argument to the superclass message 110 /// lookup functions. 111 llvm::PointerType *PtrToObjCSuperTy; 112 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring 113 /// SEL is included in a header somewhere, in which case it will be whatever 114 /// type is declared in that header, most likely {i8*, i8*}. 115 llvm::PointerType *SelectorTy; 116 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the 117 /// places where it's used 118 llvm::IntegerType *Int8Ty; 119 /// Pointer to i8 - LLVM type of char*, for all of the places where the 120 /// runtime needs to deal with C strings. 121 llvm::PointerType *PtrToInt8Ty; 122 /// Instance Method Pointer type. This is a pointer to a function that takes, 123 /// at a minimum, an object and a selector, and is the generic type for 124 /// Objective-C methods. Due to differences between variadic / non-variadic 125 /// calling conventions, it must always be cast to the correct type before 126 /// actually being used. 127 llvm::PointerType *IMPTy; 128 /// Type of an untyped Objective-C object. Clang treats id as a built-in type 129 /// when compiling Objective-C code, so this may be an opaque pointer (i8*), 130 /// but if the runtime header declaring it is included then it may be a 131 /// pointer to a structure. 132 llvm::PointerType *IdTy; 133 /// Pointer to a pointer to an Objective-C object. Used in the new ABI 134 /// message lookup function and some GC-related functions. 135 llvm::PointerType *PtrToIdTy; 136 /// The clang type of id. Used when using the clang CGCall infrastructure to 137 /// call Objective-C methods. 138 CanQualType ASTIdTy; 139 /// LLVM type for C int type. 140 llvm::IntegerType *IntTy; 141 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is 142 /// used in the code to document the difference between i8* meaning a pointer 143 /// to a C string and i8* meaning a pointer to some opaque type. 144 llvm::PointerType *PtrTy; 145 /// LLVM type for C long type. The runtime uses this in a lot of places where 146 /// it should be using intptr_t, but we can't fix this without breaking 147 /// compatibility with GCC... 148 llvm::IntegerType *LongTy; 149 /// LLVM type for C size_t. Used in various runtime data structures. 150 llvm::IntegerType *SizeTy; 151 /// LLVM type for C intptr_t. 152 llvm::IntegerType *IntPtrTy; 153 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions. 154 llvm::IntegerType *PtrDiffTy; 155 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance 156 /// variables. 157 llvm::PointerType *PtrToIntTy; 158 /// LLVM type for Objective-C BOOL type. 159 llvm::Type *BoolTy; 160 /// 32-bit integer type, to save us needing to look it up every time it's used. 161 llvm::IntegerType *Int32Ty; 162 /// 64-bit integer type, to save us needing to look it up every time it's used. 163 llvm::IntegerType *Int64Ty; 164 /// Metadata kind used to tie method lookups to message sends. The GNUstep 165 /// runtime provides some LLVM passes that can use this to do things like 166 /// automatic IMP caching and speculative inlining. 167 unsigned msgSendMDKind; 168 /// Helper function that generates a constant string and returns a pointer to 169 /// the start of the string. The result of this function can be used anywhere 170 /// where the C code specifies const char*. 171 llvm::Constant *MakeConstantString(const std::string &Str, 172 const std::string &Name="") { 173 llvm::Constant *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str()); 174 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 175 } 176 /// Emits a linkonce_odr string, whose name is the prefix followed by the 177 /// string value. This allows the linker to combine the strings between 178 /// different modules. Used for EH typeinfo names, selector strings, and a 179 /// few other things. 180 llvm::Constant *ExportUniqueString(const std::string &Str, 181 const std::string prefix) { 182 std::string name = prefix + Str; 183 llvm::Constant *ConstStr = TheModule.getGlobalVariable(name); 184 if (!ConstStr) { 185 llvm::Constant *value = llvm::ConstantDataArray::getString(VMContext,Str); 186 ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true, 187 llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str); 188 } 189 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 190 } 191 /// Generates a global structure, initialized by the elements in the vector. 192 /// The element types must match the types of the structure elements in the 193 /// first argument. 194 llvm::GlobalVariable *MakeGlobal(llvm::StructType *Ty, 195 ArrayRef<llvm::Constant *> V, 196 StringRef Name="", 197 llvm::GlobalValue::LinkageTypes linkage 198 =llvm::GlobalValue::InternalLinkage) { 199 llvm::Constant *C = llvm::ConstantStruct::get(Ty, V); 200 return new llvm::GlobalVariable(TheModule, Ty, false, 201 linkage, C, Name); 202 } 203 /// Generates a global array. The vector must contain the same number of 204 /// elements that the array type declares, of the type specified as the array 205 /// element type. 206 llvm::GlobalVariable *MakeGlobal(llvm::ArrayType *Ty, 207 ArrayRef<llvm::Constant *> V, 208 StringRef Name="", 209 llvm::GlobalValue::LinkageTypes linkage 210 =llvm::GlobalValue::InternalLinkage) { 211 llvm::Constant *C = llvm::ConstantArray::get(Ty, V); 212 return new llvm::GlobalVariable(TheModule, Ty, false, 213 linkage, C, Name); 214 } 215 /// Generates a global array, inferring the array type from the specified 216 /// element type and the size of the initialiser. 217 llvm::GlobalVariable *MakeGlobalArray(llvm::Type *Ty, 218 ArrayRef<llvm::Constant *> V, 219 StringRef Name="", 220 llvm::GlobalValue::LinkageTypes linkage 221 =llvm::GlobalValue::InternalLinkage) { 222 llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size()); 223 return MakeGlobal(ArrayTy, V, Name, linkage); 224 } 225 /// Returns a property name and encoding string. 226 llvm::Constant *MakePropertyEncodingString(const ObjCPropertyDecl *PD, 227 const Decl *Container) { 228 const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime; 229 if ((R.getKind() == ObjCRuntime::GNUstep) && 230 (R.getVersion() >= VersionTuple(1, 6))) { 231 std::string NameAndAttributes; 232 std::string TypeStr; 233 CGM.getContext().getObjCEncodingForPropertyDecl(PD, Container, TypeStr); 234 NameAndAttributes += '\0'; 235 NameAndAttributes += TypeStr.length() + 3; 236 NameAndAttributes += TypeStr; 237 NameAndAttributes += '\0'; 238 NameAndAttributes += PD->getNameAsString(); 239 NameAndAttributes += '\0'; 240 return llvm::ConstantExpr::getGetElementPtr( 241 CGM.GetAddrOfConstantString(NameAndAttributes), Zeros); 242 } 243 return MakeConstantString(PD->getNameAsString()); 244 } 245 /// Push the property attributes into two structure fields. 246 void PushPropertyAttributes(std::vector<llvm::Constant*> &Fields, 247 ObjCPropertyDecl *property, bool isSynthesized=true, bool 248 isDynamic=true) { 249 int attrs = property->getPropertyAttributes(); 250 // For read-only properties, clear the copy and retain flags 251 if (attrs & ObjCPropertyDecl::OBJC_PR_readonly) { 252 attrs &= ~ObjCPropertyDecl::OBJC_PR_copy; 253 attrs &= ~ObjCPropertyDecl::OBJC_PR_retain; 254 attrs &= ~ObjCPropertyDecl::OBJC_PR_weak; 255 attrs &= ~ObjCPropertyDecl::OBJC_PR_strong; 256 } 257 // The first flags field has the same attribute values as clang uses internally 258 Fields.push_back(llvm::ConstantInt::get(Int8Ty, attrs & 0xff)); 259 attrs >>= 8; 260 attrs <<= 2; 261 // For protocol properties, synthesized and dynamic have no meaning, so we 262 // reuse these flags to indicate that this is a protocol property (both set 263 // has no meaning, as a property can't be both synthesized and dynamic) 264 attrs |= isSynthesized ? (1<<0) : 0; 265 attrs |= isDynamic ? (1<<1) : 0; 266 // The second field is the next four fields left shifted by two, with the 267 // low bit set to indicate whether the field is synthesized or dynamic. 268 Fields.push_back(llvm::ConstantInt::get(Int8Ty, attrs & 0xff)); 269 // Two padding fields 270 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 271 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 272 } 273 /// Ensures that the value has the required type, by inserting a bitcast if 274 /// required. This function lets us avoid inserting bitcasts that are 275 /// redundant. 276 llvm::Value* EnforceType(CGBuilderTy &B, llvm::Value *V, llvm::Type *Ty) { 277 if (V->getType() == Ty) return V; 278 return B.CreateBitCast(V, Ty); 279 } 280 // Some zeros used for GEPs in lots of places. 281 llvm::Constant *Zeros[2]; 282 /// Null pointer value. Mainly used as a terminator in various arrays. 283 llvm::Constant *NULLPtr; 284 /// LLVM context. 285 llvm::LLVMContext &VMContext; 286 private: 287 /// Placeholder for the class. Lots of things refer to the class before we've 288 /// actually emitted it. We use this alias as a placeholder, and then replace 289 /// it with a pointer to the class structure before finally emitting the 290 /// module. 291 llvm::GlobalAlias *ClassPtrAlias; 292 /// Placeholder for the metaclass. Lots of things refer to the class before 293 /// we've / actually emitted it. We use this alias as a placeholder, and then 294 /// replace / it with a pointer to the metaclass structure before finally 295 /// emitting the / module. 296 llvm::GlobalAlias *MetaClassPtrAlias; 297 /// All of the classes that have been generated for this compilation units. 298 std::vector<llvm::Constant*> Classes; 299 /// All of the categories that have been generated for this compilation units. 300 std::vector<llvm::Constant*> Categories; 301 /// All of the Objective-C constant strings that have been generated for this 302 /// compilation units. 303 std::vector<llvm::Constant*> ConstantStrings; 304 /// Map from string values to Objective-C constant strings in the output. 305 /// Used to prevent emitting Objective-C strings more than once. This should 306 /// not be required at all - CodeGenModule should manage this list. 307 llvm::StringMap<llvm::Constant*> ObjCStrings; 308 /// All of the protocols that have been declared. 309 llvm::StringMap<llvm::Constant*> ExistingProtocols; 310 /// For each variant of a selector, we store the type encoding and a 311 /// placeholder value. For an untyped selector, the type will be the empty 312 /// string. Selector references are all done via the module's selector table, 313 /// so we create an alias as a placeholder and then replace it with the real 314 /// value later. 315 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector; 316 /// Type of the selector map. This is roughly equivalent to the structure 317 /// used in the GNUstep runtime, which maintains a list of all of the valid 318 /// types for a selector in a table. 319 typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> > 320 SelectorMap; 321 /// A map from selectors to selector types. This allows us to emit all 322 /// selectors of the same name and type together. 323 SelectorMap SelectorTable; 324 325 /// Selectors related to memory management. When compiling in GC mode, we 326 /// omit these. 327 Selector RetainSel, ReleaseSel, AutoreleaseSel; 328 /// Runtime functions used for memory management in GC mode. Note that clang 329 /// supports code generation for calling these functions, but neither GNU 330 /// runtime actually supports this API properly yet. 331 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn, 332 WeakAssignFn, GlobalAssignFn; 333 334 typedef std::pair<std::string, std::string> ClassAliasPair; 335 /// All classes that have aliases set for them. 336 std::vector<ClassAliasPair> ClassAliases; 337 338 protected: 339 /// Function used for throwing Objective-C exceptions. 340 LazyRuntimeFunction ExceptionThrowFn; 341 /// Function used for rethrowing exceptions, used at the end of \@finally or 342 /// \@synchronize blocks. 343 LazyRuntimeFunction ExceptionReThrowFn; 344 /// Function called when entering a catch function. This is required for 345 /// differentiating Objective-C exceptions and foreign exceptions. 346 LazyRuntimeFunction EnterCatchFn; 347 /// Function called when exiting from a catch block. Used to do exception 348 /// cleanup. 349 LazyRuntimeFunction ExitCatchFn; 350 /// Function called when entering an \@synchronize block. Acquires the lock. 351 LazyRuntimeFunction SyncEnterFn; 352 /// Function called when exiting an \@synchronize block. Releases the lock. 353 LazyRuntimeFunction SyncExitFn; 354 355 private: 356 357 /// Function called if fast enumeration detects that the collection is 358 /// modified during the update. 359 LazyRuntimeFunction EnumerationMutationFn; 360 /// Function for implementing synthesized property getters that return an 361 /// object. 362 LazyRuntimeFunction GetPropertyFn; 363 /// Function for implementing synthesized property setters that return an 364 /// object. 365 LazyRuntimeFunction SetPropertyFn; 366 /// Function used for non-object declared property getters. 367 LazyRuntimeFunction GetStructPropertyFn; 368 /// Function used for non-object declared property setters. 369 LazyRuntimeFunction SetStructPropertyFn; 370 371 /// The version of the runtime that this class targets. Must match the 372 /// version in the runtime. 373 int RuntimeVersion; 374 /// The version of the protocol class. Used to differentiate between ObjC1 375 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional 376 /// components and can not contain declared properties. We always emit 377 /// Objective-C 2 property structures, but we have to pretend that they're 378 /// Objective-C 1 property structures when targeting the GCC runtime or it 379 /// will abort. 380 const int ProtocolVersion; 381 private: 382 /// Generates an instance variable list structure. This is a structure 383 /// containing a size and an array of structures containing instance variable 384 /// metadata. This is used purely for introspection in the fragile ABI. In 385 /// the non-fragile ABI, it's used for instance variable fixup. 386 llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames, 387 ArrayRef<llvm::Constant *> IvarTypes, 388 ArrayRef<llvm::Constant *> IvarOffsets); 389 /// Generates a method list structure. This is a structure containing a size 390 /// and an array of structures containing method metadata. 391 /// 392 /// This structure is used by both classes and categories, and contains a next 393 /// pointer allowing them to be chained together in a linked list. 394 llvm::Constant *GenerateMethodList(const StringRef &ClassName, 395 const StringRef &CategoryName, 396 ArrayRef<Selector> MethodSels, 397 ArrayRef<llvm::Constant *> MethodTypes, 398 bool isClassMethodList); 399 /// Emits an empty protocol. This is used for \@protocol() where no protocol 400 /// is found. The runtime will (hopefully) fix up the pointer to refer to the 401 /// real protocol. 402 llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName); 403 /// Generates a list of property metadata structures. This follows the same 404 /// pattern as method and instance variable metadata lists. 405 llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID, 406 SmallVectorImpl<Selector> &InstanceMethodSels, 407 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes); 408 /// Generates a list of referenced protocols. Classes, categories, and 409 /// protocols all use this structure. 410 llvm::Constant *GenerateProtocolList(ArrayRef<std::string> Protocols); 411 /// To ensure that all protocols are seen by the runtime, we add a category on 412 /// a class defined in the runtime, declaring no methods, but adopting the 413 /// protocols. This is a horribly ugly hack, but it allows us to collect all 414 /// of the protocols without changing the ABI. 415 void GenerateProtocolHolderCategory(); 416 /// Generates a class structure. 417 llvm::Constant *GenerateClassStructure( 418 llvm::Constant *MetaClass, 419 llvm::Constant *SuperClass, 420 unsigned info, 421 const char *Name, 422 llvm::Constant *Version, 423 llvm::Constant *InstanceSize, 424 llvm::Constant *IVars, 425 llvm::Constant *Methods, 426 llvm::Constant *Protocols, 427 llvm::Constant *IvarOffsets, 428 llvm::Constant *Properties, 429 llvm::Constant *StrongIvarBitmap, 430 llvm::Constant *WeakIvarBitmap, 431 bool isMeta=false); 432 /// Generates a method list. This is used by protocols to define the required 433 /// and optional methods. 434 llvm::Constant *GenerateProtocolMethodList( 435 ArrayRef<llvm::Constant *> MethodNames, 436 ArrayRef<llvm::Constant *> MethodTypes); 437 /// Returns a selector with the specified type encoding. An empty string is 438 /// used to return an untyped selector (with the types field set to NULL). 439 llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel, 440 const std::string &TypeEncoding, bool lval); 441 /// Returns the variable used to store the offset of an instance variable. 442 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID, 443 const ObjCIvarDecl *Ivar); 444 /// Emits a reference to a class. This allows the linker to object if there 445 /// is no class of the matching name. 446 protected: 447 void EmitClassRef(const std::string &className); 448 /// Emits a pointer to the named class 449 virtual llvm::Value *GetClassNamed(CodeGenFunction &CGF, 450 const std::string &Name, bool isWeak); 451 /// Looks up the method for sending a message to the specified object. This 452 /// mechanism differs between the GCC and GNU runtimes, so this method must be 453 /// overridden in subclasses. 454 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 455 llvm::Value *&Receiver, 456 llvm::Value *cmd, 457 llvm::MDNode *node) = 0; 458 /// Looks up the method for sending a message to a superclass. This 459 /// mechanism differs between the GCC and GNU runtimes, so this method must 460 /// be overridden in subclasses. 461 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 462 llvm::Value *ObjCSuper, 463 llvm::Value *cmd) = 0; 464 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are 465 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63 466 /// bits set to their values, LSB first, while larger ones are stored in a 467 /// structure of this / form: 468 /// 469 /// struct { int32_t length; int32_t values[length]; }; 470 /// 471 /// The values in the array are stored in host-endian format, with the least 472 /// significant bit being assumed to come first in the bitfield. Therefore, 473 /// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, 474 /// while a bitfield / with the 63rd bit set will be 1<<64. 475 llvm::Constant *MakeBitField(ArrayRef<bool> bits); 476 public: 477 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 478 unsigned protocolClassVersion); 479 480 virtual llvm::Constant *GenerateConstantString(const StringLiteral *); 481 482 virtual RValue 483 GenerateMessageSend(CodeGenFunction &CGF, 484 ReturnValueSlot Return, 485 QualType ResultType, 486 Selector Sel, 487 llvm::Value *Receiver, 488 const CallArgList &CallArgs, 489 const ObjCInterfaceDecl *Class, 490 const ObjCMethodDecl *Method); 491 virtual RValue 492 GenerateMessageSendSuper(CodeGenFunction &CGF, 493 ReturnValueSlot Return, 494 QualType ResultType, 495 Selector Sel, 496 const ObjCInterfaceDecl *Class, 497 bool isCategoryImpl, 498 llvm::Value *Receiver, 499 bool IsClassMessage, 500 const CallArgList &CallArgs, 501 const ObjCMethodDecl *Method); 502 virtual llvm::Value *GetClass(CodeGenFunction &CGF, 503 const ObjCInterfaceDecl *OID); 504 virtual llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel, 505 bool lval = false); 506 virtual llvm::Value *GetSelector(CodeGenFunction &CGF, const ObjCMethodDecl 507 *Method); 508 virtual llvm::Constant *GetEHType(QualType T); 509 510 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 511 const ObjCContainerDecl *CD); 512 virtual void GenerateCategory(const ObjCCategoryImplDecl *CMD); 513 virtual void GenerateClass(const ObjCImplementationDecl *ClassDecl); 514 virtual void RegisterAlias(const ObjCCompatibleAliasDecl *OAD); 515 virtual llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF, 516 const ObjCProtocolDecl *PD); 517 virtual void GenerateProtocol(const ObjCProtocolDecl *PD); 518 virtual llvm::Function *ModuleInitFunction(); 519 virtual llvm::Constant *GetPropertyGetFunction(); 520 virtual llvm::Constant *GetPropertySetFunction(); 521 virtual llvm::Constant *GetOptimizedPropertySetFunction(bool atomic, 522 bool copy); 523 virtual llvm::Constant *GetSetStructFunction(); 524 virtual llvm::Constant *GetGetStructFunction(); 525 virtual llvm::Constant *GetCppAtomicObjectGetFunction(); 526 virtual llvm::Constant *GetCppAtomicObjectSetFunction(); 527 virtual llvm::Constant *EnumerationMutationFunction(); 528 529 virtual void EmitTryStmt(CodeGenFunction &CGF, 530 const ObjCAtTryStmt &S); 531 virtual void EmitSynchronizedStmt(CodeGenFunction &CGF, 532 const ObjCAtSynchronizedStmt &S); 533 virtual void EmitThrowStmt(CodeGenFunction &CGF, 534 const ObjCAtThrowStmt &S, 535 bool ClearInsertionPoint=true); 536 virtual llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF, 537 llvm::Value *AddrWeakObj); 538 virtual void EmitObjCWeakAssign(CodeGenFunction &CGF, 539 llvm::Value *src, llvm::Value *dst); 540 virtual void EmitObjCGlobalAssign(CodeGenFunction &CGF, 541 llvm::Value *src, llvm::Value *dest, 542 bool threadlocal=false); 543 virtual void EmitObjCIvarAssign(CodeGenFunction &CGF, 544 llvm::Value *src, llvm::Value *dest, 545 llvm::Value *ivarOffset); 546 virtual void EmitObjCStrongCastAssign(CodeGenFunction &CGF, 547 llvm::Value *src, llvm::Value *dest); 548 virtual void EmitGCMemmoveCollectable(CodeGenFunction &CGF, 549 llvm::Value *DestPtr, 550 llvm::Value *SrcPtr, 551 llvm::Value *Size); 552 virtual LValue EmitObjCValueForIvar(CodeGenFunction &CGF, 553 QualType ObjectTy, 554 llvm::Value *BaseValue, 555 const ObjCIvarDecl *Ivar, 556 unsigned CVRQualifiers); 557 virtual llvm::Value *EmitIvarOffset(CodeGenFunction &CGF, 558 const ObjCInterfaceDecl *Interface, 559 const ObjCIvarDecl *Ivar); 560 virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF); 561 virtual llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM, 562 const CGBlockInfo &blockInfo) { 563 return NULLPtr; 564 } 565 virtual llvm::Constant *BuildRCBlockLayout(CodeGenModule &CGM, 566 const CGBlockInfo &blockInfo) { 567 return NULLPtr; 568 } 569 570 virtual llvm::Constant *BuildByrefLayout(CodeGenModule &CGM, 571 QualType T) { 572 return NULLPtr; 573 } 574 575 virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) { 576 return 0; 577 } 578 }; 579 /// Class representing the legacy GCC Objective-C ABI. This is the default when 580 /// -fobjc-nonfragile-abi is not specified. 581 /// 582 /// The GCC ABI target actually generates code that is approximately compatible 583 /// with the new GNUstep runtime ABI, but refrains from using any features that 584 /// would not work with the GCC runtime. For example, clang always generates 585 /// the extended form of the class structure, and the extra fields are simply 586 /// ignored by GCC libobjc. 587 class CGObjCGCC : public CGObjCGNU { 588 /// The GCC ABI message lookup function. Returns an IMP pointing to the 589 /// method implementation for this message. 590 LazyRuntimeFunction MsgLookupFn; 591 /// The GCC ABI superclass message lookup function. Takes a pointer to a 592 /// structure describing the receiver and the class, and a selector as 593 /// arguments. Returns the IMP for the corresponding method. 594 LazyRuntimeFunction MsgLookupSuperFn; 595 protected: 596 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 597 llvm::Value *&Receiver, 598 llvm::Value *cmd, 599 llvm::MDNode *node) { 600 CGBuilderTy &Builder = CGF.Builder; 601 llvm::Value *args[] = { 602 EnforceType(Builder, Receiver, IdTy), 603 EnforceType(Builder, cmd, SelectorTy) }; 604 llvm::CallSite imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args); 605 imp->setMetadata(msgSendMDKind, node); 606 return imp.getInstruction(); 607 } 608 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 609 llvm::Value *ObjCSuper, 610 llvm::Value *cmd) { 611 CGBuilderTy &Builder = CGF.Builder; 612 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 613 PtrToObjCSuperTy), cmd}; 614 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs); 615 } 616 public: 617 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) { 618 // IMP objc_msg_lookup(id, SEL); 619 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 620 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 621 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 622 PtrToObjCSuperTy, SelectorTy, NULL); 623 } 624 }; 625 /// Class used when targeting the new GNUstep runtime ABI. 626 class CGObjCGNUstep : public CGObjCGNU { 627 /// The slot lookup function. Returns a pointer to a cacheable structure 628 /// that contains (among other things) the IMP. 629 LazyRuntimeFunction SlotLookupFn; 630 /// The GNUstep ABI superclass message lookup function. Takes a pointer to 631 /// a structure describing the receiver and the class, and a selector as 632 /// arguments. Returns the slot for the corresponding method. Superclass 633 /// message lookup rarely changes, so this is a good caching opportunity. 634 LazyRuntimeFunction SlotLookupSuperFn; 635 /// Specialised function for setting atomic retain properties 636 LazyRuntimeFunction SetPropertyAtomic; 637 /// Specialised function for setting atomic copy properties 638 LazyRuntimeFunction SetPropertyAtomicCopy; 639 /// Specialised function for setting nonatomic retain properties 640 LazyRuntimeFunction SetPropertyNonAtomic; 641 /// Specialised function for setting nonatomic copy properties 642 LazyRuntimeFunction SetPropertyNonAtomicCopy; 643 /// Function to perform atomic copies of C++ objects with nontrivial copy 644 /// constructors from Objective-C ivars. 645 LazyRuntimeFunction CxxAtomicObjectGetFn; 646 /// Function to perform atomic copies of C++ objects with nontrivial copy 647 /// constructors to Objective-C ivars. 648 LazyRuntimeFunction CxxAtomicObjectSetFn; 649 /// Type of an slot structure pointer. This is returned by the various 650 /// lookup functions. 651 llvm::Type *SlotTy; 652 public: 653 virtual llvm::Constant *GetEHType(QualType T); 654 protected: 655 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 656 llvm::Value *&Receiver, 657 llvm::Value *cmd, 658 llvm::MDNode *node) { 659 CGBuilderTy &Builder = CGF.Builder; 660 llvm::Function *LookupFn = SlotLookupFn; 661 662 // Store the receiver on the stack so that we can reload it later 663 llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType()); 664 Builder.CreateStore(Receiver, ReceiverPtr); 665 666 llvm::Value *self; 667 668 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) { 669 self = CGF.LoadObjCSelf(); 670 } else { 671 self = llvm::ConstantPointerNull::get(IdTy); 672 } 673 674 // The lookup function is guaranteed not to capture the receiver pointer. 675 LookupFn->setDoesNotCapture(1); 676 677 llvm::Value *args[] = { 678 EnforceType(Builder, ReceiverPtr, PtrToIdTy), 679 EnforceType(Builder, cmd, SelectorTy), 680 EnforceType(Builder, self, IdTy) }; 681 llvm::CallSite slot = CGF.EmitRuntimeCallOrInvoke(LookupFn, args); 682 slot.setOnlyReadsMemory(); 683 slot->setMetadata(msgSendMDKind, node); 684 685 // Load the imp from the slot 686 llvm::Value *imp = 687 Builder.CreateLoad(Builder.CreateStructGEP(slot.getInstruction(), 4)); 688 689 // The lookup function may have changed the receiver, so make sure we use 690 // the new one. 691 Receiver = Builder.CreateLoad(ReceiverPtr, true); 692 return imp; 693 } 694 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 695 llvm::Value *ObjCSuper, 696 llvm::Value *cmd) { 697 CGBuilderTy &Builder = CGF.Builder; 698 llvm::Value *lookupArgs[] = {ObjCSuper, cmd}; 699 700 llvm::CallInst *slot = 701 CGF.EmitNounwindRuntimeCall(SlotLookupSuperFn, lookupArgs); 702 slot->setOnlyReadsMemory(); 703 704 return Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 705 } 706 public: 707 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) { 708 const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime; 709 710 llvm::StructType *SlotStructTy = llvm::StructType::get(PtrTy, 711 PtrTy, PtrTy, IntTy, IMPTy, NULL); 712 SlotTy = llvm::PointerType::getUnqual(SlotStructTy); 713 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 714 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy, 715 SelectorTy, IdTy, NULL); 716 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL); 717 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy, 718 PtrToObjCSuperTy, SelectorTy, NULL); 719 // If we're in ObjC++ mode, then we want to make 720 if (CGM.getLangOpts().CPlusPlus) { 721 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 722 // void *__cxa_begin_catch(void *e) 723 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, NULL); 724 // void __cxa_end_catch(void) 725 ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, NULL); 726 // void _Unwind_Resume_or_Rethrow(void*) 727 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, 728 PtrTy, NULL); 729 } else if (R.getVersion() >= VersionTuple(1, 7)) { 730 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 731 // id objc_begin_catch(void *e) 732 EnterCatchFn.init(&CGM, "objc_begin_catch", IdTy, PtrTy, NULL); 733 // void objc_end_catch(void) 734 ExitCatchFn.init(&CGM, "objc_end_catch", VoidTy, NULL); 735 // void _Unwind_Resume_or_Rethrow(void*) 736 ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy, 737 PtrTy, NULL); 738 } 739 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 740 SetPropertyAtomic.init(&CGM, "objc_setProperty_atomic", VoidTy, IdTy, 741 SelectorTy, IdTy, PtrDiffTy, NULL); 742 SetPropertyAtomicCopy.init(&CGM, "objc_setProperty_atomic_copy", VoidTy, 743 IdTy, SelectorTy, IdTy, PtrDiffTy, NULL); 744 SetPropertyNonAtomic.init(&CGM, "objc_setProperty_nonatomic", VoidTy, 745 IdTy, SelectorTy, IdTy, PtrDiffTy, NULL); 746 SetPropertyNonAtomicCopy.init(&CGM, "objc_setProperty_nonatomic_copy", 747 VoidTy, IdTy, SelectorTy, IdTy, PtrDiffTy, NULL); 748 // void objc_setCppObjectAtomic(void *dest, const void *src, void 749 // *helper); 750 CxxAtomicObjectSetFn.init(&CGM, "objc_setCppObjectAtomic", VoidTy, PtrTy, 751 PtrTy, PtrTy, NULL); 752 // void objc_getCppObjectAtomic(void *dest, const void *src, void 753 // *helper); 754 CxxAtomicObjectGetFn.init(&CGM, "objc_getCppObjectAtomic", VoidTy, PtrTy, 755 PtrTy, PtrTy, NULL); 756 } 757 virtual llvm::Constant *GetCppAtomicObjectGetFunction() { 758 // The optimised functions were added in version 1.7 of the GNUstep 759 // runtime. 760 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >= 761 VersionTuple(1, 7)); 762 return CxxAtomicObjectGetFn; 763 } 764 virtual llvm::Constant *GetCppAtomicObjectSetFunction() { 765 // The optimised functions were added in version 1.7 of the GNUstep 766 // runtime. 767 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >= 768 VersionTuple(1, 7)); 769 return CxxAtomicObjectSetFn; 770 } 771 virtual llvm::Constant *GetOptimizedPropertySetFunction(bool atomic, 772 bool copy) { 773 // The optimised property functions omit the GC check, and so are not 774 // safe to use in GC mode. The standard functions are fast in GC mode, 775 // so there is less advantage in using them. 776 assert ((CGM.getLangOpts().getGC() == LangOptions::NonGC)); 777 // The optimised functions were added in version 1.7 of the GNUstep 778 // runtime. 779 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >= 780 VersionTuple(1, 7)); 781 782 if (atomic) { 783 if (copy) return SetPropertyAtomicCopy; 784 return SetPropertyAtomic; 785 } 786 if (copy) return SetPropertyNonAtomicCopy; 787 return SetPropertyNonAtomic; 788 789 return 0; 790 } 791 }; 792 793 /// Support for the ObjFW runtime. Support here is due to 794 /// Jonathan Schleifer <js (at) webkeks.org>, the ObjFW maintainer. 795 class CGObjCObjFW: public CGObjCGNU { 796 protected: 797 /// The GCC ABI message lookup function. Returns an IMP pointing to the 798 /// method implementation for this message. 799 LazyRuntimeFunction MsgLookupFn; 800 /// The GCC ABI superclass message lookup function. Takes a pointer to a 801 /// structure describing the receiver and the class, and a selector as 802 /// arguments. Returns the IMP for the corresponding method. 803 LazyRuntimeFunction MsgLookupSuperFn; 804 805 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 806 llvm::Value *&Receiver, 807 llvm::Value *cmd, 808 llvm::MDNode *node) { 809 CGBuilderTy &Builder = CGF.Builder; 810 llvm::Value *args[] = { 811 EnforceType(Builder, Receiver, IdTy), 812 EnforceType(Builder, cmd, SelectorTy) }; 813 llvm::CallSite imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args); 814 imp->setMetadata(msgSendMDKind, node); 815 return imp.getInstruction(); 816 } 817 818 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 819 llvm::Value *ObjCSuper, 820 llvm::Value *cmd) { 821 CGBuilderTy &Builder = CGF.Builder; 822 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 823 PtrToObjCSuperTy), cmd}; 824 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs); 825 } 826 827 virtual llvm::Value *GetClassNamed(CodeGenFunction &CGF, 828 const std::string &Name, bool isWeak) { 829 if (isWeak) 830 return CGObjCGNU::GetClassNamed(CGF, Name, isWeak); 831 832 EmitClassRef(Name); 833 834 std::string SymbolName = "_OBJC_CLASS_" + Name; 835 836 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(SymbolName); 837 838 if (!ClassSymbol) 839 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 840 llvm::GlobalValue::ExternalLinkage, 841 0, SymbolName); 842 843 return ClassSymbol; 844 } 845 846 public: 847 CGObjCObjFW(CodeGenModule &Mod): CGObjCGNU(Mod, 9, 3) { 848 // IMP objc_msg_lookup(id, SEL); 849 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 850 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 851 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 852 PtrToObjCSuperTy, SelectorTy, NULL); 853 } 854 }; 855 } // end anonymous namespace 856 857 858 /// Emits a reference to a dummy variable which is emitted with each class. 859 /// This ensures that a linker error will be generated when trying to link 860 /// together modules where a referenced class is not defined. 861 void CGObjCGNU::EmitClassRef(const std::string &className) { 862 std::string symbolRef = "__objc_class_ref_" + className; 863 // Don't emit two copies of the same symbol 864 if (TheModule.getGlobalVariable(symbolRef)) 865 return; 866 std::string symbolName = "__objc_class_name_" + className; 867 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName); 868 if (!ClassSymbol) { 869 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 870 llvm::GlobalValue::ExternalLinkage, 0, symbolName); 871 } 872 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true, 873 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef); 874 } 875 876 static std::string SymbolNameForMethod(const StringRef &ClassName, 877 const StringRef &CategoryName, const Selector MethodName, 878 bool isClassMethod) { 879 std::string MethodNameColonStripped = MethodName.getAsString(); 880 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(), 881 ':', '_'); 882 return (Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" + 883 CategoryName + "_" + MethodNameColonStripped).str(); 884 } 885 886 CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 887 unsigned protocolClassVersion) 888 : CGObjCRuntime(cgm), TheModule(CGM.getModule()), 889 VMContext(cgm.getLLVMContext()), ClassPtrAlias(0), MetaClassPtrAlias(0), 890 RuntimeVersion(runtimeABIVersion), ProtocolVersion(protocolClassVersion) { 891 892 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend"); 893 894 CodeGenTypes &Types = CGM.getTypes(); 895 IntTy = cast<llvm::IntegerType>( 896 Types.ConvertType(CGM.getContext().IntTy)); 897 LongTy = cast<llvm::IntegerType>( 898 Types.ConvertType(CGM.getContext().LongTy)); 899 SizeTy = cast<llvm::IntegerType>( 900 Types.ConvertType(CGM.getContext().getSizeType())); 901 PtrDiffTy = cast<llvm::IntegerType>( 902 Types.ConvertType(CGM.getContext().getPointerDiffType())); 903 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy); 904 905 Int8Ty = llvm::Type::getInt8Ty(VMContext); 906 // C string type. Used in lots of places. 907 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); 908 909 Zeros[0] = llvm::ConstantInt::get(LongTy, 0); 910 Zeros[1] = Zeros[0]; 911 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty); 912 // Get the selector Type. 913 QualType selTy = CGM.getContext().getObjCSelType(); 914 if (QualType() == selTy) { 915 SelectorTy = PtrToInt8Ty; 916 } else { 917 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy)); 918 } 919 920 PtrToIntTy = llvm::PointerType::getUnqual(IntTy); 921 PtrTy = PtrToInt8Ty; 922 923 Int32Ty = llvm::Type::getInt32Ty(VMContext); 924 Int64Ty = llvm::Type::getInt64Ty(VMContext); 925 926 IntPtrTy = 927 TheModule.getPointerSize() == llvm::Module::Pointer32 ? Int32Ty : Int64Ty; 928 929 // Object type 930 QualType UnqualIdTy = CGM.getContext().getObjCIdType(); 931 ASTIdTy = CanQualType(); 932 if (UnqualIdTy != QualType()) { 933 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy); 934 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 935 } else { 936 IdTy = PtrToInt8Ty; 937 } 938 PtrToIdTy = llvm::PointerType::getUnqual(IdTy); 939 940 ObjCSuperTy = llvm::StructType::get(IdTy, IdTy, NULL); 941 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy); 942 943 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 944 945 // void objc_exception_throw(id); 946 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 947 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 948 // int objc_sync_enter(id); 949 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, NULL); 950 // int objc_sync_exit(id); 951 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, NULL); 952 953 // void objc_enumerationMutation (id) 954 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, 955 IdTy, NULL); 956 957 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL) 958 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy, 959 PtrDiffTy, BoolTy, NULL); 960 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL) 961 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy, 962 PtrDiffTy, IdTy, BoolTy, BoolTy, NULL); 963 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 964 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy, 965 PtrDiffTy, BoolTy, BoolTy, NULL); 966 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 967 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy, 968 PtrDiffTy, BoolTy, BoolTy, NULL); 969 970 // IMP type 971 llvm::Type *IMPArgs[] = { IdTy, SelectorTy }; 972 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs, 973 true)); 974 975 const LangOptions &Opts = CGM.getLangOpts(); 976 if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount) 977 RuntimeVersion = 10; 978 979 // Don't bother initialising the GC stuff unless we're compiling in GC mode 980 if (Opts.getGC() != LangOptions::NonGC) { 981 // This is a bit of an hack. We should sort this out by having a proper 982 // CGObjCGNUstep subclass for GC, but we may want to really support the old 983 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now 984 // Get selectors needed in GC mode 985 RetainSel = GetNullarySelector("retain", CGM.getContext()); 986 ReleaseSel = GetNullarySelector("release", CGM.getContext()); 987 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext()); 988 989 // Get functions needed in GC mode 990 991 // id objc_assign_ivar(id, id, ptrdiff_t); 992 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy, 993 NULL); 994 // id objc_assign_strongCast (id, id*) 995 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy, 996 PtrToIdTy, NULL); 997 // id objc_assign_global(id, id*); 998 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy, 999 NULL); 1000 // id objc_assign_weak(id, id*); 1001 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, NULL); 1002 // id objc_read_weak(id*); 1003 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, NULL); 1004 // void *objc_memmove_collectable(void*, void *, size_t); 1005 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy, 1006 SizeTy, NULL); 1007 } 1008 } 1009 1010 llvm::Value *CGObjCGNU::GetClassNamed(CodeGenFunction &CGF, 1011 const std::string &Name, 1012 bool isWeak) { 1013 llvm::Value *ClassName = CGM.GetAddrOfConstantCString(Name); 1014 // With the incompatible ABI, this will need to be replaced with a direct 1015 // reference to the class symbol. For the compatible nonfragile ABI we are 1016 // still performing this lookup at run time but emitting the symbol for the 1017 // class externally so that we can make the switch later. 1018 // 1019 // Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class 1020 // with memoized versions or with static references if it's safe to do so. 1021 if (!isWeak) 1022 EmitClassRef(Name); 1023 ClassName = CGF.Builder.CreateStructGEP(ClassName, 0); 1024 1025 llvm::Constant *ClassLookupFn = 1026 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true), 1027 "objc_lookup_class"); 1028 return CGF.EmitNounwindRuntimeCall(ClassLookupFn, ClassName); 1029 } 1030 1031 // This has to perform the lookup every time, since posing and related 1032 // techniques can modify the name -> class mapping. 1033 llvm::Value *CGObjCGNU::GetClass(CodeGenFunction &CGF, 1034 const ObjCInterfaceDecl *OID) { 1035 return GetClassNamed(CGF, OID->getNameAsString(), OID->isWeakImported()); 1036 } 1037 llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) { 1038 return GetClassNamed(CGF, "NSAutoreleasePool", false); 1039 } 1040 1041 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel, 1042 const std::string &TypeEncoding, bool lval) { 1043 1044 SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel]; 1045 llvm::GlobalAlias *SelValue = 0; 1046 1047 1048 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 1049 e = Types.end() ; i!=e ; i++) { 1050 if (i->first == TypeEncoding) { 1051 SelValue = i->second; 1052 break; 1053 } 1054 } 1055 if (0 == SelValue) { 1056 SelValue = new llvm::GlobalAlias(SelectorTy, 1057 llvm::GlobalValue::PrivateLinkage, 1058 ".objc_selector_"+Sel.getAsString(), NULL, 1059 &TheModule); 1060 Types.push_back(TypedSelector(TypeEncoding, SelValue)); 1061 } 1062 1063 if (lval) { 1064 llvm::Value *tmp = CGF.CreateTempAlloca(SelValue->getType()); 1065 CGF.Builder.CreateStore(SelValue, tmp); 1066 return tmp; 1067 } 1068 return SelValue; 1069 } 1070 1071 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel, 1072 bool lval) { 1073 return GetSelector(CGF, Sel, std::string(), lval); 1074 } 1075 1076 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, 1077 const ObjCMethodDecl *Method) { 1078 std::string SelTypes; 1079 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes); 1080 return GetSelector(CGF, Method->getSelector(), SelTypes, false); 1081 } 1082 1083 llvm::Constant *CGObjCGNU::GetEHType(QualType T) { 1084 if (T->isObjCIdType() || T->isObjCQualifiedIdType()) { 1085 // With the old ABI, there was only one kind of catchall, which broke 1086 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as 1087 // a pointer indicating object catchalls, and NULL to indicate real 1088 // catchalls 1089 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 1090 return MakeConstantString("@id"); 1091 } else { 1092 return 0; 1093 } 1094 } 1095 1096 // All other types should be Objective-C interface pointer types. 1097 const ObjCObjectPointerType *OPT = T->getAs<ObjCObjectPointerType>(); 1098 assert(OPT && "Invalid @catch type."); 1099 const ObjCInterfaceDecl *IDecl = OPT->getObjectType()->getInterface(); 1100 assert(IDecl && "Invalid @catch type."); 1101 return MakeConstantString(IDecl->getIdentifier()->getName()); 1102 } 1103 1104 llvm::Constant *CGObjCGNUstep::GetEHType(QualType T) { 1105 if (!CGM.getLangOpts().CPlusPlus) 1106 return CGObjCGNU::GetEHType(T); 1107 1108 // For Objective-C++, we want to provide the ability to catch both C++ and 1109 // Objective-C objects in the same function. 1110 1111 // There's a particular fixed type info for 'id'. 1112 if (T->isObjCIdType() || 1113 T->isObjCQualifiedIdType()) { 1114 llvm::Constant *IDEHType = 1115 CGM.getModule().getGlobalVariable("__objc_id_type_info"); 1116 if (!IDEHType) 1117 IDEHType = 1118 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty, 1119 false, 1120 llvm::GlobalValue::ExternalLinkage, 1121 0, "__objc_id_type_info"); 1122 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty); 1123 } 1124 1125 const ObjCObjectPointerType *PT = 1126 T->getAs<ObjCObjectPointerType>(); 1127 assert(PT && "Invalid @catch type."); 1128 const ObjCInterfaceType *IT = PT->getInterfaceType(); 1129 assert(IT && "Invalid @catch type."); 1130 std::string className = IT->getDecl()->getIdentifier()->getName(); 1131 1132 std::string typeinfoName = "__objc_eh_typeinfo_" + className; 1133 1134 // Return the existing typeinfo if it exists 1135 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName); 1136 if (typeinfo) 1137 return llvm::ConstantExpr::getBitCast(typeinfo, PtrToInt8Ty); 1138 1139 // Otherwise create it. 1140 1141 // vtable for gnustep::libobjc::__objc_class_type_info 1142 // It's quite ugly hard-coding this. Ideally we'd generate it using the host 1143 // platform's name mangling. 1144 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE"; 1145 llvm::Constant *Vtable = TheModule.getGlobalVariable(vtableName); 1146 if (!Vtable) { 1147 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true, 1148 llvm::GlobalValue::ExternalLinkage, 0, vtableName); 1149 } 1150 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2); 1151 Vtable = llvm::ConstantExpr::getGetElementPtr(Vtable, Two); 1152 Vtable = llvm::ConstantExpr::getBitCast(Vtable, PtrToInt8Ty); 1153 1154 llvm::Constant *typeName = 1155 ExportUniqueString(className, "__objc_eh_typename_"); 1156 1157 std::vector<llvm::Constant*> fields; 1158 fields.push_back(Vtable); 1159 fields.push_back(typeName); 1160 llvm::Constant *TI = 1161 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1162 NULL), fields, "__objc_eh_typeinfo_" + className, 1163 llvm::GlobalValue::LinkOnceODRLinkage); 1164 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty); 1165 } 1166 1167 /// Generate an NSConstantString object. 1168 llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) { 1169 1170 std::string Str = SL->getString().str(); 1171 1172 // Look for an existing one 1173 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str); 1174 if (old != ObjCStrings.end()) 1175 return old->getValue(); 1176 1177 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass; 1178 1179 if (StringClass.empty()) StringClass = "NXConstantString"; 1180 1181 std::string Sym = "_OBJC_CLASS_"; 1182 Sym += StringClass; 1183 1184 llvm::Constant *isa = TheModule.getNamedGlobal(Sym); 1185 1186 if (!isa) 1187 isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false, 1188 llvm::GlobalValue::ExternalWeakLinkage, 0, Sym); 1189 else if (isa->getType() != PtrToIdTy) 1190 isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy); 1191 1192 std::vector<llvm::Constant*> Ivars; 1193 Ivars.push_back(isa); 1194 Ivars.push_back(MakeConstantString(Str)); 1195 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size())); 1196 llvm::Constant *ObjCStr = MakeGlobal( 1197 llvm::StructType::get(PtrToIdTy, PtrToInt8Ty, IntTy, NULL), 1198 Ivars, ".objc_str"); 1199 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty); 1200 ObjCStrings[Str] = ObjCStr; 1201 ConstantStrings.push_back(ObjCStr); 1202 return ObjCStr; 1203 } 1204 1205 ///Generates a message send where the super is the receiver. This is a message 1206 ///send to self with special delivery semantics indicating which class's method 1207 ///should be called. 1208 RValue 1209 CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF, 1210 ReturnValueSlot Return, 1211 QualType ResultType, 1212 Selector Sel, 1213 const ObjCInterfaceDecl *Class, 1214 bool isCategoryImpl, 1215 llvm::Value *Receiver, 1216 bool IsClassMessage, 1217 const CallArgList &CallArgs, 1218 const ObjCMethodDecl *Method) { 1219 CGBuilderTy &Builder = CGF.Builder; 1220 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) { 1221 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1222 return RValue::get(EnforceType(Builder, Receiver, 1223 CGM.getTypes().ConvertType(ResultType))); 1224 } 1225 if (Sel == ReleaseSel) { 1226 return RValue::get(0); 1227 } 1228 } 1229 1230 llvm::Value *cmd = GetSelector(CGF, Sel); 1231 1232 1233 CallArgList ActualArgs; 1234 1235 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy); 1236 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1237 ActualArgs.addFrom(CallArgs); 1238 1239 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs); 1240 1241 llvm::Value *ReceiverClass = 0; 1242 if (isCategoryImpl) { 1243 llvm::Constant *classLookupFunction = 0; 1244 if (IsClassMessage) { 1245 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1246 IdTy, PtrTy, true), "objc_get_meta_class"); 1247 } else { 1248 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1249 IdTy, PtrTy, true), "objc_get_class"); 1250 } 1251 ReceiverClass = Builder.CreateCall(classLookupFunction, 1252 MakeConstantString(Class->getNameAsString())); 1253 } else { 1254 // Set up global aliases for the metaclass or class pointer if they do not 1255 // already exist. These will are forward-references which will be set to 1256 // pointers to the class and metaclass structure created for the runtime 1257 // load function. To send a message to super, we look up the value of the 1258 // super_class pointer from either the class or metaclass structure. 1259 if (IsClassMessage) { 1260 if (!MetaClassPtrAlias) { 1261 MetaClassPtrAlias = new llvm::GlobalAlias(IdTy, 1262 llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" + 1263 Class->getNameAsString(), NULL, &TheModule); 1264 } 1265 ReceiverClass = MetaClassPtrAlias; 1266 } else { 1267 if (!ClassPtrAlias) { 1268 ClassPtrAlias = new llvm::GlobalAlias(IdTy, 1269 llvm::GlobalValue::InternalLinkage, ".objc_class_ref" + 1270 Class->getNameAsString(), NULL, &TheModule); 1271 } 1272 ReceiverClass = ClassPtrAlias; 1273 } 1274 } 1275 // Cast the pointer to a simplified version of the class structure 1276 ReceiverClass = Builder.CreateBitCast(ReceiverClass, 1277 llvm::PointerType::getUnqual( 1278 llvm::StructType::get(IdTy, IdTy, NULL))); 1279 // Get the superclass pointer 1280 ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1); 1281 // Load the superclass pointer 1282 ReceiverClass = Builder.CreateLoad(ReceiverClass); 1283 // Construct the structure used to look up the IMP 1284 llvm::StructType *ObjCSuperTy = llvm::StructType::get( 1285 Receiver->getType(), IdTy, NULL); 1286 llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy); 1287 1288 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0)); 1289 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1)); 1290 1291 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy); 1292 1293 // Get the IMP 1294 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd); 1295 imp = EnforceType(Builder, imp, MSI.MessengerType); 1296 1297 llvm::Value *impMD[] = { 1298 llvm::MDString::get(VMContext, Sel.getAsString()), 1299 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()), 1300 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage) 1301 }; 1302 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1303 1304 llvm::Instruction *call; 1305 RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs, 0, &call); 1306 call->setMetadata(msgSendMDKind, node); 1307 return msgRet; 1308 } 1309 1310 /// Generate code for a message send expression. 1311 RValue 1312 CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF, 1313 ReturnValueSlot Return, 1314 QualType ResultType, 1315 Selector Sel, 1316 llvm::Value *Receiver, 1317 const CallArgList &CallArgs, 1318 const ObjCInterfaceDecl *Class, 1319 const ObjCMethodDecl *Method) { 1320 CGBuilderTy &Builder = CGF.Builder; 1321 1322 // Strip out message sends to retain / release in GC mode 1323 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) { 1324 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1325 return RValue::get(EnforceType(Builder, Receiver, 1326 CGM.getTypes().ConvertType(ResultType))); 1327 } 1328 if (Sel == ReleaseSel) { 1329 return RValue::get(0); 1330 } 1331 } 1332 1333 // If the return type is something that goes in an integer register, the 1334 // runtime will handle 0 returns. For other cases, we fill in the 0 value 1335 // ourselves. 1336 // 1337 // The language spec says the result of this kind of message send is 1338 // undefined, but lots of people seem to have forgotten to read that 1339 // paragraph and insist on sending messages to nil that have structure 1340 // returns. With GCC, this generates a random return value (whatever happens 1341 // to be on the stack / in those registers at the time) on most platforms, 1342 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts 1343 // the stack. 1344 bool isPointerSizedReturn = (ResultType->isAnyPointerType() || 1345 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType()); 1346 1347 llvm::BasicBlock *startBB = 0; 1348 llvm::BasicBlock *messageBB = 0; 1349 llvm::BasicBlock *continueBB = 0; 1350 1351 if (!isPointerSizedReturn) { 1352 startBB = Builder.GetInsertBlock(); 1353 messageBB = CGF.createBasicBlock("msgSend"); 1354 continueBB = CGF.createBasicBlock("continue"); 1355 1356 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver, 1357 llvm::Constant::getNullValue(Receiver->getType())); 1358 Builder.CreateCondBr(isNil, continueBB, messageBB); 1359 CGF.EmitBlock(messageBB); 1360 } 1361 1362 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 1363 llvm::Value *cmd; 1364 if (Method) 1365 cmd = GetSelector(CGF, Method); 1366 else 1367 cmd = GetSelector(CGF, Sel); 1368 cmd = EnforceType(Builder, cmd, SelectorTy); 1369 Receiver = EnforceType(Builder, Receiver, IdTy); 1370 1371 llvm::Value *impMD[] = { 1372 llvm::MDString::get(VMContext, Sel.getAsString()), 1373 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""), 1374 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0) 1375 }; 1376 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1377 1378 CallArgList ActualArgs; 1379 ActualArgs.add(RValue::get(Receiver), ASTIdTy); 1380 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1381 ActualArgs.addFrom(CallArgs); 1382 1383 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs); 1384 1385 // Get the IMP to call 1386 llvm::Value *imp; 1387 1388 // If we have non-legacy dispatch specified, we try using the objc_msgSend() 1389 // functions. These are not supported on all platforms (or all runtimes on a 1390 // given platform), so we 1391 switch (CGM.getCodeGenOpts().getObjCDispatchMethod()) { 1392 case CodeGenOptions::Legacy: 1393 imp = LookupIMP(CGF, Receiver, cmd, node); 1394 break; 1395 case CodeGenOptions::Mixed: 1396 case CodeGenOptions::NonLegacy: 1397 if (CGM.ReturnTypeUsesFPRet(ResultType)) { 1398 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1399 "objc_msgSend_fpret"); 1400 } else if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) { 1401 // The actual types here don't matter - we're going to bitcast the 1402 // function anyway 1403 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1404 "objc_msgSend_stret"); 1405 } else { 1406 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1407 "objc_msgSend"); 1408 } 1409 } 1410 1411 // Reset the receiver in case the lookup modified it 1412 ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy, false); 1413 1414 imp = EnforceType(Builder, imp, MSI.MessengerType); 1415 1416 llvm::Instruction *call; 1417 RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs, 1418 0, &call); 1419 call->setMetadata(msgSendMDKind, node); 1420 1421 1422 if (!isPointerSizedReturn) { 1423 messageBB = CGF.Builder.GetInsertBlock(); 1424 CGF.Builder.CreateBr(continueBB); 1425 CGF.EmitBlock(continueBB); 1426 if (msgRet.isScalar()) { 1427 llvm::Value *v = msgRet.getScalarVal(); 1428 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1429 phi->addIncoming(v, messageBB); 1430 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB); 1431 msgRet = RValue::get(phi); 1432 } else if (msgRet.isAggregate()) { 1433 llvm::Value *v = msgRet.getAggregateAddr(); 1434 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1435 llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType()); 1436 llvm::AllocaInst *NullVal = 1437 CGF.CreateTempAlloca(RetTy->getElementType(), "null"); 1438 CGF.InitTempAlloca(NullVal, 1439 llvm::Constant::getNullValue(RetTy->getElementType())); 1440 phi->addIncoming(v, messageBB); 1441 phi->addIncoming(NullVal, startBB); 1442 msgRet = RValue::getAggregate(phi); 1443 } else /* isComplex() */ { 1444 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal(); 1445 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2); 1446 phi->addIncoming(v.first, messageBB); 1447 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()), 1448 startBB); 1449 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2); 1450 phi2->addIncoming(v.second, messageBB); 1451 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()), 1452 startBB); 1453 msgRet = RValue::getComplex(phi, phi2); 1454 } 1455 } 1456 return msgRet; 1457 } 1458 1459 /// Generates a MethodList. Used in construction of a objc_class and 1460 /// objc_category structures. 1461 llvm::Constant *CGObjCGNU:: 1462 GenerateMethodList(const StringRef &ClassName, 1463 const StringRef &CategoryName, 1464 ArrayRef<Selector> MethodSels, 1465 ArrayRef<llvm::Constant *> MethodTypes, 1466 bool isClassMethodList) { 1467 if (MethodSels.empty()) 1468 return NULLPtr; 1469 // Get the method structure type. 1470 llvm::StructType *ObjCMethodTy = llvm::StructType::get( 1471 PtrToInt8Ty, // Really a selector, but the runtime creates it us. 1472 PtrToInt8Ty, // Method types 1473 IMPTy, //Method pointer 1474 NULL); 1475 std::vector<llvm::Constant*> Methods; 1476 std::vector<llvm::Constant*> Elements; 1477 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) { 1478 Elements.clear(); 1479 llvm::Constant *Method = 1480 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName, 1481 MethodSels[i], 1482 isClassMethodList)); 1483 assert(Method && "Can't generate metadata for method that doesn't exist"); 1484 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString()); 1485 Elements.push_back(C); 1486 Elements.push_back(MethodTypes[i]); 1487 Method = llvm::ConstantExpr::getBitCast(Method, 1488 IMPTy); 1489 Elements.push_back(Method); 1490 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements)); 1491 } 1492 1493 // Array of method structures 1494 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy, 1495 Methods.size()); 1496 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy, 1497 Methods); 1498 1499 // Structure containing list pointer, array and array count 1500 llvm::StructType *ObjCMethodListTy = llvm::StructType::create(VMContext); 1501 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(ObjCMethodListTy); 1502 ObjCMethodListTy->setBody( 1503 NextPtrTy, 1504 IntTy, 1505 ObjCMethodArrayTy, 1506 NULL); 1507 1508 Methods.clear(); 1509 Methods.push_back(llvm::ConstantPointerNull::get( 1510 llvm::PointerType::getUnqual(ObjCMethodListTy))); 1511 Methods.push_back(llvm::ConstantInt::get(Int32Ty, MethodTypes.size())); 1512 Methods.push_back(MethodArray); 1513 1514 // Create an instance of the structure 1515 return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list"); 1516 } 1517 1518 /// Generates an IvarList. Used in construction of a objc_class. 1519 llvm::Constant *CGObjCGNU:: 1520 GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames, 1521 ArrayRef<llvm::Constant *> IvarTypes, 1522 ArrayRef<llvm::Constant *> IvarOffsets) { 1523 if (IvarNames.size() == 0) 1524 return NULLPtr; 1525 // Get the method structure type. 1526 llvm::StructType *ObjCIvarTy = llvm::StructType::get( 1527 PtrToInt8Ty, 1528 PtrToInt8Ty, 1529 IntTy, 1530 NULL); 1531 std::vector<llvm::Constant*> Ivars; 1532 std::vector<llvm::Constant*> Elements; 1533 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) { 1534 Elements.clear(); 1535 Elements.push_back(IvarNames[i]); 1536 Elements.push_back(IvarTypes[i]); 1537 Elements.push_back(IvarOffsets[i]); 1538 Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements)); 1539 } 1540 1541 // Array of method structures 1542 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy, 1543 IvarNames.size()); 1544 1545 1546 Elements.clear(); 1547 Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size())); 1548 Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)); 1549 // Structure containing array and array count 1550 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(IntTy, 1551 ObjCIvarArrayTy, 1552 NULL); 1553 1554 // Create an instance of the structure 1555 return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list"); 1556 } 1557 1558 /// Generate a class structure 1559 llvm::Constant *CGObjCGNU::GenerateClassStructure( 1560 llvm::Constant *MetaClass, 1561 llvm::Constant *SuperClass, 1562 unsigned info, 1563 const char *Name, 1564 llvm::Constant *Version, 1565 llvm::Constant *InstanceSize, 1566 llvm::Constant *IVars, 1567 llvm::Constant *Methods, 1568 llvm::Constant *Protocols, 1569 llvm::Constant *IvarOffsets, 1570 llvm::Constant *Properties, 1571 llvm::Constant *StrongIvarBitmap, 1572 llvm::Constant *WeakIvarBitmap, 1573 bool isMeta) { 1574 // Set up the class structure 1575 // Note: Several of these are char*s when they should be ids. This is 1576 // because the runtime performs this translation on load. 1577 // 1578 // Fields marked New ABI are part of the GNUstep runtime. We emit them 1579 // anyway; the classes will still work with the GNU runtime, they will just 1580 // be ignored. 1581 llvm::StructType *ClassTy = llvm::StructType::get( 1582 PtrToInt8Ty, // isa 1583 PtrToInt8Ty, // super_class 1584 PtrToInt8Ty, // name 1585 LongTy, // version 1586 LongTy, // info 1587 LongTy, // instance_size 1588 IVars->getType(), // ivars 1589 Methods->getType(), // methods 1590 // These are all filled in by the runtime, so we pretend 1591 PtrTy, // dtable 1592 PtrTy, // subclass_list 1593 PtrTy, // sibling_class 1594 PtrTy, // protocols 1595 PtrTy, // gc_object_type 1596 // New ABI: 1597 LongTy, // abi_version 1598 IvarOffsets->getType(), // ivar_offsets 1599 Properties->getType(), // properties 1600 IntPtrTy, // strong_pointers 1601 IntPtrTy, // weak_pointers 1602 NULL); 1603 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0); 1604 // Fill in the structure 1605 std::vector<llvm::Constant*> Elements; 1606 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty)); 1607 Elements.push_back(SuperClass); 1608 Elements.push_back(MakeConstantString(Name, ".class_name")); 1609 Elements.push_back(Zero); 1610 Elements.push_back(llvm::ConstantInt::get(LongTy, info)); 1611 if (isMeta) { 1612 llvm::DataLayout td(&TheModule); 1613 Elements.push_back( 1614 llvm::ConstantInt::get(LongTy, 1615 td.getTypeSizeInBits(ClassTy) / 1616 CGM.getContext().getCharWidth())); 1617 } else 1618 Elements.push_back(InstanceSize); 1619 Elements.push_back(IVars); 1620 Elements.push_back(Methods); 1621 Elements.push_back(NULLPtr); 1622 Elements.push_back(NULLPtr); 1623 Elements.push_back(NULLPtr); 1624 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy)); 1625 Elements.push_back(NULLPtr); 1626 Elements.push_back(llvm::ConstantInt::get(LongTy, 1)); 1627 Elements.push_back(IvarOffsets); 1628 Elements.push_back(Properties); 1629 Elements.push_back(StrongIvarBitmap); 1630 Elements.push_back(WeakIvarBitmap); 1631 // Create an instance of the structure 1632 // This is now an externally visible symbol, so that we can speed up class 1633 // messages in the next ABI. We may already have some weak references to 1634 // this, so check and fix them properly. 1635 std::string ClassSym((isMeta ? "_OBJC_METACLASS_": "_OBJC_CLASS_") + 1636 std::string(Name)); 1637 llvm::GlobalVariable *ClassRef = TheModule.getNamedGlobal(ClassSym); 1638 llvm::Constant *Class = MakeGlobal(ClassTy, Elements, ClassSym, 1639 llvm::GlobalValue::ExternalLinkage); 1640 if (ClassRef) { 1641 ClassRef->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(Class, 1642 ClassRef->getType())); 1643 ClassRef->removeFromParent(); 1644 Class->setName(ClassSym); 1645 } 1646 return Class; 1647 } 1648 1649 llvm::Constant *CGObjCGNU:: 1650 GenerateProtocolMethodList(ArrayRef<llvm::Constant *> MethodNames, 1651 ArrayRef<llvm::Constant *> MethodTypes) { 1652 // Get the method structure type. 1653 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get( 1654 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us. 1655 PtrToInt8Ty, 1656 NULL); 1657 std::vector<llvm::Constant*> Methods; 1658 std::vector<llvm::Constant*> Elements; 1659 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) { 1660 Elements.clear(); 1661 Elements.push_back(MethodNames[i]); 1662 Elements.push_back(MethodTypes[i]); 1663 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements)); 1664 } 1665 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy, 1666 MethodNames.size()); 1667 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy, 1668 Methods); 1669 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get( 1670 IntTy, ObjCMethodArrayTy, NULL); 1671 Methods.clear(); 1672 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size())); 1673 Methods.push_back(Array); 1674 return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list"); 1675 } 1676 1677 // Create the protocol list structure used in classes, categories and so on 1678 llvm::Constant *CGObjCGNU::GenerateProtocolList(ArrayRef<std::string>Protocols){ 1679 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 1680 Protocols.size()); 1681 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1682 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1683 SizeTy, 1684 ProtocolArrayTy, 1685 NULL); 1686 std::vector<llvm::Constant*> Elements; 1687 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end(); 1688 iter != endIter ; iter++) { 1689 llvm::Constant *protocol = 0; 1690 llvm::StringMap<llvm::Constant*>::iterator value = 1691 ExistingProtocols.find(*iter); 1692 if (value == ExistingProtocols.end()) { 1693 protocol = GenerateEmptyProtocol(*iter); 1694 } else { 1695 protocol = value->getValue(); 1696 } 1697 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol, 1698 PtrToInt8Ty); 1699 Elements.push_back(Ptr); 1700 } 1701 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1702 Elements); 1703 Elements.clear(); 1704 Elements.push_back(NULLPtr); 1705 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size())); 1706 Elements.push_back(ProtocolArray); 1707 return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list"); 1708 } 1709 1710 llvm::Value *CGObjCGNU::GenerateProtocolRef(CodeGenFunction &CGF, 1711 const ObjCProtocolDecl *PD) { 1712 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()]; 1713 llvm::Type *T = 1714 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType()); 1715 return CGF.Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T)); 1716 } 1717 1718 llvm::Constant *CGObjCGNU::GenerateEmptyProtocol( 1719 const std::string &ProtocolName) { 1720 SmallVector<std::string, 0> EmptyStringVector; 1721 SmallVector<llvm::Constant*, 0> EmptyConstantVector; 1722 1723 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector); 1724 llvm::Constant *MethodList = 1725 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector); 1726 // Protocols are objects containing lists of the methods implemented and 1727 // protocols adopted. 1728 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1729 PtrToInt8Ty, 1730 ProtocolList->getType(), 1731 MethodList->getType(), 1732 MethodList->getType(), 1733 MethodList->getType(), 1734 MethodList->getType(), 1735 NULL); 1736 std::vector<llvm::Constant*> Elements; 1737 // The isa pointer must be set to a magic number so the runtime knows it's 1738 // the correct layout. 1739 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1740 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy)); 1741 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1742 Elements.push_back(ProtocolList); 1743 Elements.push_back(MethodList); 1744 Elements.push_back(MethodList); 1745 Elements.push_back(MethodList); 1746 Elements.push_back(MethodList); 1747 return MakeGlobal(ProtocolTy, Elements, ".objc_protocol"); 1748 } 1749 1750 void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) { 1751 ASTContext &Context = CGM.getContext(); 1752 std::string ProtocolName = PD->getNameAsString(); 1753 1754 // Use the protocol definition, if there is one. 1755 if (const ObjCProtocolDecl *Def = PD->getDefinition()) 1756 PD = Def; 1757 1758 SmallVector<std::string, 16> Protocols; 1759 for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(), 1760 E = PD->protocol_end(); PI != E; ++PI) 1761 Protocols.push_back((*PI)->getNameAsString()); 1762 SmallVector<llvm::Constant*, 16> InstanceMethodNames; 1763 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1764 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames; 1765 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes; 1766 for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(), 1767 E = PD->instmeth_end(); iter != E; iter++) { 1768 std::string TypeStr; 1769 Context.getObjCEncodingForMethodDecl(*iter, TypeStr); 1770 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1771 OptionalInstanceMethodNames.push_back( 1772 MakeConstantString((*iter)->getSelector().getAsString())); 1773 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1774 } else { 1775 InstanceMethodNames.push_back( 1776 MakeConstantString((*iter)->getSelector().getAsString())); 1777 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1778 } 1779 } 1780 // Collect information about class methods: 1781 SmallVector<llvm::Constant*, 16> ClassMethodNames; 1782 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1783 SmallVector<llvm::Constant*, 16> OptionalClassMethodNames; 1784 SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes; 1785 for (ObjCProtocolDecl::classmeth_iterator 1786 iter = PD->classmeth_begin(), endIter = PD->classmeth_end(); 1787 iter != endIter ; iter++) { 1788 std::string TypeStr; 1789 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1790 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1791 OptionalClassMethodNames.push_back( 1792 MakeConstantString((*iter)->getSelector().getAsString())); 1793 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1794 } else { 1795 ClassMethodNames.push_back( 1796 MakeConstantString((*iter)->getSelector().getAsString())); 1797 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1798 } 1799 } 1800 1801 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols); 1802 llvm::Constant *InstanceMethodList = 1803 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes); 1804 llvm::Constant *ClassMethodList = 1805 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes); 1806 llvm::Constant *OptionalInstanceMethodList = 1807 GenerateProtocolMethodList(OptionalInstanceMethodNames, 1808 OptionalInstanceMethodTypes); 1809 llvm::Constant *OptionalClassMethodList = 1810 GenerateProtocolMethodList(OptionalClassMethodNames, 1811 OptionalClassMethodTypes); 1812 1813 // Property metadata: name, attributes, isSynthesized, setter name, setter 1814 // types, getter name, getter types. 1815 // The isSynthesized value is always set to 0 in a protocol. It exists to 1816 // simplify the runtime library by allowing it to use the same data 1817 // structures for protocol metadata everywhere. 1818 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1819 PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, 1820 PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, NULL); 1821 std::vector<llvm::Constant*> Properties; 1822 std::vector<llvm::Constant*> OptionalProperties; 1823 1824 // Add all of the property methods need adding to the method list and to the 1825 // property metadata list. 1826 for (ObjCContainerDecl::prop_iterator 1827 iter = PD->prop_begin(), endIter = PD->prop_end(); 1828 iter != endIter ; iter++) { 1829 std::vector<llvm::Constant*> Fields; 1830 ObjCPropertyDecl *property = *iter; 1831 1832 Fields.push_back(MakePropertyEncodingString(property, 0)); 1833 PushPropertyAttributes(Fields, property); 1834 1835 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1836 std::string TypeStr; 1837 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1838 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1839 InstanceMethodTypes.push_back(TypeEncoding); 1840 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1841 Fields.push_back(TypeEncoding); 1842 } else { 1843 Fields.push_back(NULLPtr); 1844 Fields.push_back(NULLPtr); 1845 } 1846 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1847 std::string TypeStr; 1848 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1849 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1850 InstanceMethodTypes.push_back(TypeEncoding); 1851 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1852 Fields.push_back(TypeEncoding); 1853 } else { 1854 Fields.push_back(NULLPtr); 1855 Fields.push_back(NULLPtr); 1856 } 1857 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) { 1858 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1859 } else { 1860 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1861 } 1862 } 1863 llvm::Constant *PropertyArray = llvm::ConstantArray::get( 1864 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties); 1865 llvm::Constant* PropertyListInitFields[] = 1866 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1867 1868 llvm::Constant *PropertyListInit = 1869 llvm::ConstantStruct::getAnon(PropertyListInitFields); 1870 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule, 1871 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage, 1872 PropertyListInit, ".objc_property_list"); 1873 1874 llvm::Constant *OptionalPropertyArray = 1875 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy, 1876 OptionalProperties.size()) , OptionalProperties); 1877 llvm::Constant* OptionalPropertyListInitFields[] = { 1878 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr, 1879 OptionalPropertyArray }; 1880 1881 llvm::Constant *OptionalPropertyListInit = 1882 llvm::ConstantStruct::getAnon(OptionalPropertyListInitFields); 1883 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule, 1884 OptionalPropertyListInit->getType(), false, 1885 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit, 1886 ".objc_property_list"); 1887 1888 // Protocols are objects containing lists of the methods implemented and 1889 // protocols adopted. 1890 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1891 PtrToInt8Ty, 1892 ProtocolList->getType(), 1893 InstanceMethodList->getType(), 1894 ClassMethodList->getType(), 1895 OptionalInstanceMethodList->getType(), 1896 OptionalClassMethodList->getType(), 1897 PropertyList->getType(), 1898 OptionalPropertyList->getType(), 1899 NULL); 1900 std::vector<llvm::Constant*> Elements; 1901 // The isa pointer must be set to a magic number so the runtime knows it's 1902 // the correct layout. 1903 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1904 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy)); 1905 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1906 Elements.push_back(ProtocolList); 1907 Elements.push_back(InstanceMethodList); 1908 Elements.push_back(ClassMethodList); 1909 Elements.push_back(OptionalInstanceMethodList); 1910 Elements.push_back(OptionalClassMethodList); 1911 Elements.push_back(PropertyList); 1912 Elements.push_back(OptionalPropertyList); 1913 ExistingProtocols[ProtocolName] = 1914 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements, 1915 ".objc_protocol"), IdTy); 1916 } 1917 void CGObjCGNU::GenerateProtocolHolderCategory() { 1918 // Collect information about instance methods 1919 SmallVector<Selector, 1> MethodSels; 1920 SmallVector<llvm::Constant*, 1> MethodTypes; 1921 1922 std::vector<llvm::Constant*> Elements; 1923 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack"; 1924 const std::string CategoryName = "AnotherHack"; 1925 Elements.push_back(MakeConstantString(CategoryName)); 1926 Elements.push_back(MakeConstantString(ClassName)); 1927 // Instance method list 1928 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1929 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy)); 1930 // Class method list 1931 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1932 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy)); 1933 // Protocol list 1934 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy, 1935 ExistingProtocols.size()); 1936 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1937 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1938 SizeTy, 1939 ProtocolArrayTy, 1940 NULL); 1941 std::vector<llvm::Constant*> ProtocolElements; 1942 for (llvm::StringMapIterator<llvm::Constant*> iter = 1943 ExistingProtocols.begin(), endIter = ExistingProtocols.end(); 1944 iter != endIter ; iter++) { 1945 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(), 1946 PtrTy); 1947 ProtocolElements.push_back(Ptr); 1948 } 1949 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1950 ProtocolElements); 1951 ProtocolElements.clear(); 1952 ProtocolElements.push_back(NULLPtr); 1953 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy, 1954 ExistingProtocols.size())); 1955 ProtocolElements.push_back(ProtocolArray); 1956 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy, 1957 ProtocolElements, ".objc_protocol_list"), PtrTy)); 1958 Categories.push_back(llvm::ConstantExpr::getBitCast( 1959 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1960 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1961 } 1962 1963 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are 1964 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63 1965 /// bits set to their values, LSB first, while larger ones are stored in a 1966 /// structure of this / form: 1967 /// 1968 /// struct { int32_t length; int32_t values[length]; }; 1969 /// 1970 /// The values in the array are stored in host-endian format, with the least 1971 /// significant bit being assumed to come first in the bitfield. Therefore, a 1972 /// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a 1973 /// bitfield / with the 63rd bit set will be 1<<64. 1974 llvm::Constant *CGObjCGNU::MakeBitField(ArrayRef<bool> bits) { 1975 int bitCount = bits.size(); 1976 int ptrBits = 1977 (TheModule.getPointerSize() == llvm::Module::Pointer32) ? 32 : 64; 1978 if (bitCount < ptrBits) { 1979 uint64_t val = 1; 1980 for (int i=0 ; i<bitCount ; ++i) { 1981 if (bits[i]) val |= 1ULL<<(i+1); 1982 } 1983 return llvm::ConstantInt::get(IntPtrTy, val); 1984 } 1985 SmallVector<llvm::Constant *, 8> values; 1986 int v=0; 1987 while (v < bitCount) { 1988 int32_t word = 0; 1989 for (int i=0 ; (i<32) && (v<bitCount) ; ++i) { 1990 if (bits[v]) word |= 1<<i; 1991 v++; 1992 } 1993 values.push_back(llvm::ConstantInt::get(Int32Ty, word)); 1994 } 1995 llvm::ArrayType *arrayTy = llvm::ArrayType::get(Int32Ty, values.size()); 1996 llvm::Constant *array = llvm::ConstantArray::get(arrayTy, values); 1997 llvm::Constant *fields[2] = { 1998 llvm::ConstantInt::get(Int32Ty, values.size()), 1999 array }; 2000 llvm::Constant *GS = MakeGlobal(llvm::StructType::get(Int32Ty, arrayTy, 2001 NULL), fields); 2002 llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy); 2003 return ptr; 2004 } 2005 2006 void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) { 2007 std::string ClassName = OCD->getClassInterface()->getNameAsString(); 2008 std::string CategoryName = OCD->getNameAsString(); 2009 // Collect information about instance methods 2010 SmallVector<Selector, 16> InstanceMethodSels; 2011 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 2012 for (ObjCCategoryImplDecl::instmeth_iterator 2013 iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end(); 2014 iter != endIter ; iter++) { 2015 InstanceMethodSels.push_back((*iter)->getSelector()); 2016 std::string TypeStr; 2017 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 2018 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 2019 } 2020 2021 // Collect information about class methods 2022 SmallVector<Selector, 16> ClassMethodSels; 2023 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 2024 for (ObjCCategoryImplDecl::classmeth_iterator 2025 iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end(); 2026 iter != endIter ; iter++) { 2027 ClassMethodSels.push_back((*iter)->getSelector()); 2028 std::string TypeStr; 2029 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 2030 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 2031 } 2032 2033 // Collect the names of referenced protocols 2034 SmallVector<std::string, 16> Protocols; 2035 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl(); 2036 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols(); 2037 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 2038 E = Protos.end(); I != E; ++I) 2039 Protocols.push_back((*I)->getNameAsString()); 2040 2041 std::vector<llvm::Constant*> Elements; 2042 Elements.push_back(MakeConstantString(CategoryName)); 2043 Elements.push_back(MakeConstantString(ClassName)); 2044 // Instance method list 2045 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 2046 ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes, 2047 false), PtrTy)); 2048 // Class method list 2049 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 2050 ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true), 2051 PtrTy)); 2052 // Protocol list 2053 Elements.push_back(llvm::ConstantExpr::getBitCast( 2054 GenerateProtocolList(Protocols), PtrTy)); 2055 Categories.push_back(llvm::ConstantExpr::getBitCast( 2056 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 2057 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 2058 } 2059 2060 llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID, 2061 SmallVectorImpl<Selector> &InstanceMethodSels, 2062 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) { 2063 ASTContext &Context = CGM.getContext(); 2064 // Property metadata: name, attributes, attributes2, padding1, padding2, 2065 // setter name, setter types, getter name, getter types. 2066 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 2067 PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, 2068 PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, NULL); 2069 std::vector<llvm::Constant*> Properties; 2070 2071 // Add all of the property methods need adding to the method list and to the 2072 // property metadata list. 2073 for (ObjCImplDecl::propimpl_iterator 2074 iter = OID->propimpl_begin(), endIter = OID->propimpl_end(); 2075 iter != endIter ; iter++) { 2076 std::vector<llvm::Constant*> Fields; 2077 ObjCPropertyDecl *property = iter->getPropertyDecl(); 2078 ObjCPropertyImplDecl *propertyImpl = *iter; 2079 bool isSynthesized = (propertyImpl->getPropertyImplementation() == 2080 ObjCPropertyImplDecl::Synthesize); 2081 bool isDynamic = (propertyImpl->getPropertyImplementation() == 2082 ObjCPropertyImplDecl::Dynamic); 2083 2084 Fields.push_back(MakePropertyEncodingString(property, OID)); 2085 PushPropertyAttributes(Fields, property, isSynthesized, isDynamic); 2086 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 2087 std::string TypeStr; 2088 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 2089 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 2090 if (isSynthesized) { 2091 InstanceMethodTypes.push_back(TypeEncoding); 2092 InstanceMethodSels.push_back(getter->getSelector()); 2093 } 2094 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 2095 Fields.push_back(TypeEncoding); 2096 } else { 2097 Fields.push_back(NULLPtr); 2098 Fields.push_back(NULLPtr); 2099 } 2100 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 2101 std::string TypeStr; 2102 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 2103 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 2104 if (isSynthesized) { 2105 InstanceMethodTypes.push_back(TypeEncoding); 2106 InstanceMethodSels.push_back(setter->getSelector()); 2107 } 2108 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 2109 Fields.push_back(TypeEncoding); 2110 } else { 2111 Fields.push_back(NULLPtr); 2112 Fields.push_back(NULLPtr); 2113 } 2114 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 2115 } 2116 llvm::ArrayType *PropertyArrayTy = 2117 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()); 2118 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy, 2119 Properties); 2120 llvm::Constant* PropertyListInitFields[] = 2121 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 2122 2123 llvm::Constant *PropertyListInit = 2124 llvm::ConstantStruct::getAnon(PropertyListInitFields); 2125 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false, 2126 llvm::GlobalValue::InternalLinkage, PropertyListInit, 2127 ".objc_property_list"); 2128 } 2129 2130 void CGObjCGNU::RegisterAlias(const ObjCCompatibleAliasDecl *OAD) { 2131 // Get the class declaration for which the alias is specified. 2132 ObjCInterfaceDecl *ClassDecl = 2133 const_cast<ObjCInterfaceDecl *>(OAD->getClassInterface()); 2134 std::string ClassName = ClassDecl->getNameAsString(); 2135 std::string AliasName = OAD->getNameAsString(); 2136 ClassAliases.push_back(ClassAliasPair(ClassName,AliasName)); 2137 } 2138 2139 void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) { 2140 ASTContext &Context = CGM.getContext(); 2141 2142 // Get the superclass name. 2143 const ObjCInterfaceDecl * SuperClassDecl = 2144 OID->getClassInterface()->getSuperClass(); 2145 std::string SuperClassName; 2146 if (SuperClassDecl) { 2147 SuperClassName = SuperClassDecl->getNameAsString(); 2148 EmitClassRef(SuperClassName); 2149 } 2150 2151 // Get the class name 2152 ObjCInterfaceDecl *ClassDecl = 2153 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface()); 2154 std::string ClassName = ClassDecl->getNameAsString(); 2155 // Emit the symbol that is used to generate linker errors if this class is 2156 // referenced in other modules but not declared. 2157 std::string classSymbolName = "__objc_class_name_" + ClassName; 2158 if (llvm::GlobalVariable *symbol = 2159 TheModule.getGlobalVariable(classSymbolName)) { 2160 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0)); 2161 } else { 2162 new llvm::GlobalVariable(TheModule, LongTy, false, 2163 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0), 2164 classSymbolName); 2165 } 2166 2167 // Get the size of instances. 2168 int instanceSize = 2169 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity(); 2170 2171 // Collect information about instance variables. 2172 SmallVector<llvm::Constant*, 16> IvarNames; 2173 SmallVector<llvm::Constant*, 16> IvarTypes; 2174 SmallVector<llvm::Constant*, 16> IvarOffsets; 2175 2176 std::vector<llvm::Constant*> IvarOffsetValues; 2177 SmallVector<bool, 16> WeakIvars; 2178 SmallVector<bool, 16> StrongIvars; 2179 2180 int superInstanceSize = !SuperClassDecl ? 0 : 2181 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity(); 2182 // For non-fragile ivars, set the instance size to 0 - {the size of just this 2183 // class}. The runtime will then set this to the correct value on load. 2184 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 2185 instanceSize = 0 - (instanceSize - superInstanceSize); 2186 } 2187 2188 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 2189 IVD = IVD->getNextIvar()) { 2190 // Store the name 2191 IvarNames.push_back(MakeConstantString(IVD->getNameAsString())); 2192 // Get the type encoding for this ivar 2193 std::string TypeStr; 2194 Context.getObjCEncodingForType(IVD->getType(), TypeStr); 2195 IvarTypes.push_back(MakeConstantString(TypeStr)); 2196 // Get the offset 2197 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD); 2198 uint64_t Offset = BaseOffset; 2199 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 2200 Offset = BaseOffset - superInstanceSize; 2201 } 2202 llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset); 2203 // Create the direct offset value 2204 std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." + 2205 IVD->getNameAsString(); 2206 llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName); 2207 if (OffsetVar) { 2208 OffsetVar->setInitializer(OffsetValue); 2209 // If this is the real definition, change its linkage type so that 2210 // different modules will use this one, rather than their private 2211 // copy. 2212 OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage); 2213 } else 2214 OffsetVar = new llvm::GlobalVariable(TheModule, IntTy, 2215 false, llvm::GlobalValue::ExternalLinkage, 2216 OffsetValue, 2217 "__objc_ivar_offset_value_" + ClassName +"." + 2218 IVD->getNameAsString()); 2219 IvarOffsets.push_back(OffsetValue); 2220 IvarOffsetValues.push_back(OffsetVar); 2221 Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime(); 2222 switch (lt) { 2223 case Qualifiers::OCL_Strong: 2224 StrongIvars.push_back(true); 2225 WeakIvars.push_back(false); 2226 break; 2227 case Qualifiers::OCL_Weak: 2228 StrongIvars.push_back(false); 2229 WeakIvars.push_back(true); 2230 break; 2231 default: 2232 StrongIvars.push_back(false); 2233 WeakIvars.push_back(false); 2234 } 2235 } 2236 llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars); 2237 llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars); 2238 llvm::GlobalVariable *IvarOffsetArray = 2239 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets"); 2240 2241 2242 // Collect information about instance methods 2243 SmallVector<Selector, 16> InstanceMethodSels; 2244 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 2245 for (ObjCImplementationDecl::instmeth_iterator 2246 iter = OID->instmeth_begin(), endIter = OID->instmeth_end(); 2247 iter != endIter ; iter++) { 2248 InstanceMethodSels.push_back((*iter)->getSelector()); 2249 std::string TypeStr; 2250 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 2251 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 2252 } 2253 2254 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels, 2255 InstanceMethodTypes); 2256 2257 2258 // Collect information about class methods 2259 SmallVector<Selector, 16> ClassMethodSels; 2260 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 2261 for (ObjCImplementationDecl::classmeth_iterator 2262 iter = OID->classmeth_begin(), endIter = OID->classmeth_end(); 2263 iter != endIter ; iter++) { 2264 ClassMethodSels.push_back((*iter)->getSelector()); 2265 std::string TypeStr; 2266 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 2267 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 2268 } 2269 // Collect the names of referenced protocols 2270 SmallVector<std::string, 16> Protocols; 2271 for (ObjCInterfaceDecl::protocol_iterator 2272 I = ClassDecl->protocol_begin(), 2273 E = ClassDecl->protocol_end(); I != E; ++I) 2274 Protocols.push_back((*I)->getNameAsString()); 2275 2276 2277 2278 // Get the superclass pointer. 2279 llvm::Constant *SuperClass; 2280 if (!SuperClassName.empty()) { 2281 SuperClass = MakeConstantString(SuperClassName, ".super_class_name"); 2282 } else { 2283 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty); 2284 } 2285 // Empty vector used to construct empty method lists 2286 SmallVector<llvm::Constant*, 1> empty; 2287 // Generate the method and instance variable lists 2288 llvm::Constant *MethodList = GenerateMethodList(ClassName, "", 2289 InstanceMethodSels, InstanceMethodTypes, false); 2290 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "", 2291 ClassMethodSels, ClassMethodTypes, true); 2292 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes, 2293 IvarOffsets); 2294 // Irrespective of whether we are compiling for a fragile or non-fragile ABI, 2295 // we emit a symbol containing the offset for each ivar in the class. This 2296 // allows code compiled for the non-Fragile ABI to inherit from code compiled 2297 // for the legacy ABI, without causing problems. The converse is also 2298 // possible, but causes all ivar accesses to be fragile. 2299 2300 // Offset pointer for getting at the correct field in the ivar list when 2301 // setting up the alias. These are: The base address for the global, the 2302 // ivar array (second field), the ivar in this list (set for each ivar), and 2303 // the offset (third field in ivar structure) 2304 llvm::Type *IndexTy = Int32Ty; 2305 llvm::Constant *offsetPointerIndexes[] = {Zeros[0], 2306 llvm::ConstantInt::get(IndexTy, 1), 0, 2307 llvm::ConstantInt::get(IndexTy, 2) }; 2308 2309 unsigned ivarIndex = 0; 2310 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 2311 IVD = IVD->getNextIvar()) { 2312 const std::string Name = "__objc_ivar_offset_" + ClassName + '.' 2313 + IVD->getNameAsString(); 2314 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex); 2315 // Get the correct ivar field 2316 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr( 2317 IvarList, offsetPointerIndexes); 2318 // Get the existing variable, if one exists. 2319 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name); 2320 if (offset) { 2321 offset->setInitializer(offsetValue); 2322 // If this is the real definition, change its linkage type so that 2323 // different modules will use this one, rather than their private 2324 // copy. 2325 offset->setLinkage(llvm::GlobalValue::ExternalLinkage); 2326 } else { 2327 // Add a new alias if there isn't one already. 2328 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(), 2329 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name); 2330 (void) offset; // Silence dead store warning. 2331 } 2332 ++ivarIndex; 2333 } 2334 llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0); 2335 //Generate metaclass for class methods 2336 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr, 2337 NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList( 2338 empty, empty, empty), ClassMethodList, NULLPtr, 2339 NULLPtr, NULLPtr, ZeroPtr, ZeroPtr, true); 2340 2341 // Generate the class structure 2342 llvm::Constant *ClassStruct = 2343 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L, 2344 ClassName.c_str(), 0, 2345 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, 2346 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray, 2347 Properties, StrongIvarBitmap, WeakIvarBitmap); 2348 2349 // Resolve the class aliases, if they exist. 2350 if (ClassPtrAlias) { 2351 ClassPtrAlias->replaceAllUsesWith( 2352 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy)); 2353 ClassPtrAlias->eraseFromParent(); 2354 ClassPtrAlias = 0; 2355 } 2356 if (MetaClassPtrAlias) { 2357 MetaClassPtrAlias->replaceAllUsesWith( 2358 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy)); 2359 MetaClassPtrAlias->eraseFromParent(); 2360 MetaClassPtrAlias = 0; 2361 } 2362 2363 // Add class structure to list to be added to the symtab later 2364 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty); 2365 Classes.push_back(ClassStruct); 2366 } 2367 2368 2369 llvm::Function *CGObjCGNU::ModuleInitFunction() { 2370 // Only emit an ObjC load function if no Objective-C stuff has been called 2371 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() && 2372 ExistingProtocols.empty() && SelectorTable.empty()) 2373 return NULL; 2374 2375 // Add all referenced protocols to a category. 2376 GenerateProtocolHolderCategory(); 2377 2378 llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>( 2379 SelectorTy->getElementType()); 2380 llvm::Type *SelStructPtrTy = SelectorTy; 2381 if (SelStructTy == 0) { 2382 SelStructTy = llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, NULL); 2383 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy); 2384 } 2385 2386 std::vector<llvm::Constant*> Elements; 2387 llvm::Constant *Statics = NULLPtr; 2388 // Generate statics list: 2389 if (ConstantStrings.size()) { 2390 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 2391 ConstantStrings.size() + 1); 2392 ConstantStrings.push_back(NULLPtr); 2393 2394 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass; 2395 2396 if (StringClass.empty()) StringClass = "NXConstantString"; 2397 2398 Elements.push_back(MakeConstantString(StringClass, 2399 ".objc_static_class_name")); 2400 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy, 2401 ConstantStrings)); 2402 llvm::StructType *StaticsListTy = 2403 llvm::StructType::get(PtrToInt8Ty, StaticsArrayTy, NULL); 2404 llvm::Type *StaticsListPtrTy = 2405 llvm::PointerType::getUnqual(StaticsListTy); 2406 Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics"); 2407 llvm::ArrayType *StaticsListArrayTy = 2408 llvm::ArrayType::get(StaticsListPtrTy, 2); 2409 Elements.clear(); 2410 Elements.push_back(Statics); 2411 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy)); 2412 Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr"); 2413 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy); 2414 } 2415 // Array of classes, categories, and constant objects 2416 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty, 2417 Classes.size() + Categories.size() + 2); 2418 llvm::StructType *SymTabTy = llvm::StructType::get(LongTy, SelStructPtrTy, 2419 llvm::Type::getInt16Ty(VMContext), 2420 llvm::Type::getInt16Ty(VMContext), 2421 ClassListTy, NULL); 2422 2423 Elements.clear(); 2424 // Pointer to an array of selectors used in this module. 2425 std::vector<llvm::Constant*> Selectors; 2426 std::vector<llvm::GlobalAlias*> SelectorAliases; 2427 for (SelectorMap::iterator iter = SelectorTable.begin(), 2428 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) { 2429 2430 std::string SelNameStr = iter->first.getAsString(); 2431 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name"); 2432 2433 SmallVectorImpl<TypedSelector> &Types = iter->second; 2434 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 2435 e = Types.end() ; i!=e ; i++) { 2436 2437 llvm::Constant *SelectorTypeEncoding = NULLPtr; 2438 if (!i->first.empty()) 2439 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types"); 2440 2441 Elements.push_back(SelName); 2442 Elements.push_back(SelectorTypeEncoding); 2443 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2444 Elements.clear(); 2445 2446 // Store the selector alias for later replacement 2447 SelectorAliases.push_back(i->second); 2448 } 2449 } 2450 unsigned SelectorCount = Selectors.size(); 2451 // NULL-terminate the selector list. This should not actually be required, 2452 // because the selector list has a length field. Unfortunately, the GCC 2453 // runtime decides to ignore the length field and expects a NULL terminator, 2454 // and GCC cooperates with this by always setting the length to 0. 2455 Elements.push_back(NULLPtr); 2456 Elements.push_back(NULLPtr); 2457 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2458 Elements.clear(); 2459 2460 // Number of static selectors 2461 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount)); 2462 llvm::Constant *SelectorList = MakeGlobalArray(SelStructTy, Selectors, 2463 ".objc_selector_list"); 2464 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList, 2465 SelStructPtrTy)); 2466 2467 // Now that all of the static selectors exist, create pointers to them. 2468 for (unsigned int i=0 ; i<SelectorCount ; i++) { 2469 2470 llvm::Constant *Idxs[] = {Zeros[0], 2471 llvm::ConstantInt::get(Int32Ty, i), Zeros[0]}; 2472 // FIXME: We're generating redundant loads and stores here! 2473 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(SelectorList, 2474 makeArrayRef(Idxs, 2)); 2475 // If selectors are defined as an opaque type, cast the pointer to this 2476 // type. 2477 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy); 2478 SelectorAliases[i]->replaceAllUsesWith(SelPtr); 2479 SelectorAliases[i]->eraseFromParent(); 2480 } 2481 2482 // Number of classes defined. 2483 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2484 Classes.size())); 2485 // Number of categories defined 2486 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2487 Categories.size())); 2488 // Create an array of classes, then categories, then static object instances 2489 Classes.insert(Classes.end(), Categories.begin(), Categories.end()); 2490 // NULL-terminated list of static object instances (mainly constant strings) 2491 Classes.push_back(Statics); 2492 Classes.push_back(NULLPtr); 2493 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes); 2494 Elements.push_back(ClassList); 2495 // Construct the symbol table 2496 llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements); 2497 2498 // The symbol table is contained in a module which has some version-checking 2499 // constants 2500 llvm::StructType * ModuleTy = llvm::StructType::get(LongTy, LongTy, 2501 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), 2502 (RuntimeVersion >= 10) ? IntTy : NULL, NULL); 2503 Elements.clear(); 2504 // Runtime version, used for ABI compatibility checking. 2505 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion)); 2506 // sizeof(ModuleTy) 2507 llvm::DataLayout td(&TheModule); 2508 Elements.push_back( 2509 llvm::ConstantInt::get(LongTy, 2510 td.getTypeSizeInBits(ModuleTy) / 2511 CGM.getContext().getCharWidth())); 2512 2513 // The path to the source file where this module was declared 2514 SourceManager &SM = CGM.getContext().getSourceManager(); 2515 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID()); 2516 std::string path = 2517 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName(); 2518 Elements.push_back(MakeConstantString(path, ".objc_source_file_name")); 2519 Elements.push_back(SymTab); 2520 2521 if (RuntimeVersion >= 10) 2522 switch (CGM.getLangOpts().getGC()) { 2523 case LangOptions::GCOnly: 2524 Elements.push_back(llvm::ConstantInt::get(IntTy, 2)); 2525 break; 2526 case LangOptions::NonGC: 2527 if (CGM.getLangOpts().ObjCAutoRefCount) 2528 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2529 else 2530 Elements.push_back(llvm::ConstantInt::get(IntTy, 0)); 2531 break; 2532 case LangOptions::HybridGC: 2533 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2534 break; 2535 } 2536 2537 llvm::Value *Module = MakeGlobal(ModuleTy, Elements); 2538 2539 // Create the load function calling the runtime entry point with the module 2540 // structure 2541 llvm::Function * LoadFunction = llvm::Function::Create( 2542 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false), 2543 llvm::GlobalValue::InternalLinkage, ".objc_load_function", 2544 &TheModule); 2545 llvm::BasicBlock *EntryBB = 2546 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction); 2547 CGBuilderTy Builder(VMContext); 2548 Builder.SetInsertPoint(EntryBB); 2549 2550 llvm::FunctionType *FT = 2551 llvm::FunctionType::get(Builder.getVoidTy(), 2552 llvm::PointerType::getUnqual(ModuleTy), true); 2553 llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class"); 2554 Builder.CreateCall(Register, Module); 2555 2556 if (!ClassAliases.empty()) { 2557 llvm::Type *ArgTypes[2] = {PtrTy, PtrToInt8Ty}; 2558 llvm::FunctionType *RegisterAliasTy = 2559 llvm::FunctionType::get(Builder.getVoidTy(), 2560 ArgTypes, false); 2561 llvm::Function *RegisterAlias = llvm::Function::Create( 2562 RegisterAliasTy, 2563 llvm::GlobalValue::ExternalWeakLinkage, "class_registerAlias_np", 2564 &TheModule); 2565 llvm::BasicBlock *AliasBB = 2566 llvm::BasicBlock::Create(VMContext, "alias", LoadFunction); 2567 llvm::BasicBlock *NoAliasBB = 2568 llvm::BasicBlock::Create(VMContext, "no_alias", LoadFunction); 2569 2570 // Branch based on whether the runtime provided class_registerAlias_np() 2571 llvm::Value *HasRegisterAlias = Builder.CreateICmpNE(RegisterAlias, 2572 llvm::Constant::getNullValue(RegisterAlias->getType())); 2573 Builder.CreateCondBr(HasRegisterAlias, AliasBB, NoAliasBB); 2574 2575 // The true branch (has alias registration fucntion): 2576 Builder.SetInsertPoint(AliasBB); 2577 // Emit alias registration calls: 2578 for (std::vector<ClassAliasPair>::iterator iter = ClassAliases.begin(); 2579 iter != ClassAliases.end(); ++iter) { 2580 llvm::Constant *TheClass = 2581 TheModule.getGlobalVariable(("_OBJC_CLASS_" + iter->first).c_str(), 2582 true); 2583 if (0 != TheClass) { 2584 TheClass = llvm::ConstantExpr::getBitCast(TheClass, PtrTy); 2585 Builder.CreateCall2(RegisterAlias, TheClass, 2586 MakeConstantString(iter->second)); 2587 } 2588 } 2589 // Jump to end: 2590 Builder.CreateBr(NoAliasBB); 2591 2592 // Missing alias registration function, just return from the function: 2593 Builder.SetInsertPoint(NoAliasBB); 2594 } 2595 Builder.CreateRetVoid(); 2596 2597 return LoadFunction; 2598 } 2599 2600 llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD, 2601 const ObjCContainerDecl *CD) { 2602 const ObjCCategoryImplDecl *OCD = 2603 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext()); 2604 StringRef CategoryName = OCD ? OCD->getName() : ""; 2605 StringRef ClassName = CD->getName(); 2606 Selector MethodName = OMD->getSelector(); 2607 bool isClassMethod = !OMD->isInstanceMethod(); 2608 2609 CodeGenTypes &Types = CGM.getTypes(); 2610 llvm::FunctionType *MethodTy = 2611 Types.GetFunctionType(Types.arrangeObjCMethodDeclaration(OMD)); 2612 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName, 2613 MethodName, isClassMethod); 2614 2615 llvm::Function *Method 2616 = llvm::Function::Create(MethodTy, 2617 llvm::GlobalValue::InternalLinkage, 2618 FunctionName, 2619 &TheModule); 2620 return Method; 2621 } 2622 2623 llvm::Constant *CGObjCGNU::GetPropertyGetFunction() { 2624 return GetPropertyFn; 2625 } 2626 2627 llvm::Constant *CGObjCGNU::GetPropertySetFunction() { 2628 return SetPropertyFn; 2629 } 2630 2631 llvm::Constant *CGObjCGNU::GetOptimizedPropertySetFunction(bool atomic, 2632 bool copy) { 2633 return 0; 2634 } 2635 2636 llvm::Constant *CGObjCGNU::GetGetStructFunction() { 2637 return GetStructPropertyFn; 2638 } 2639 llvm::Constant *CGObjCGNU::GetSetStructFunction() { 2640 return SetStructPropertyFn; 2641 } 2642 llvm::Constant *CGObjCGNU::GetCppAtomicObjectGetFunction() { 2643 return 0; 2644 } 2645 llvm::Constant *CGObjCGNU::GetCppAtomicObjectSetFunction() { 2646 return 0; 2647 } 2648 2649 llvm::Constant *CGObjCGNU::EnumerationMutationFunction() { 2650 return EnumerationMutationFn; 2651 } 2652 2653 void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF, 2654 const ObjCAtSynchronizedStmt &S) { 2655 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn); 2656 } 2657 2658 2659 void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF, 2660 const ObjCAtTryStmt &S) { 2661 // Unlike the Apple non-fragile runtimes, which also uses 2662 // unwind-based zero cost exceptions, the GNU Objective C runtime's 2663 // EH support isn't a veneer over C++ EH. Instead, exception 2664 // objects are created by objc_exception_throw and destroyed by 2665 // the personality function; this avoids the need for bracketing 2666 // catch handlers with calls to __blah_begin_catch/__blah_end_catch 2667 // (or even _Unwind_DeleteException), but probably doesn't 2668 // interoperate very well with foreign exceptions. 2669 // 2670 // In Objective-C++ mode, we actually emit something equivalent to the C++ 2671 // exception handler. 2672 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn); 2673 return ; 2674 } 2675 2676 void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF, 2677 const ObjCAtThrowStmt &S, 2678 bool ClearInsertionPoint) { 2679 llvm::Value *ExceptionAsObject; 2680 2681 if (const Expr *ThrowExpr = S.getThrowExpr()) { 2682 llvm::Value *Exception = CGF.EmitObjCThrowOperand(ThrowExpr); 2683 ExceptionAsObject = Exception; 2684 } else { 2685 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) && 2686 "Unexpected rethrow outside @catch block."); 2687 ExceptionAsObject = CGF.ObjCEHValueStack.back(); 2688 } 2689 ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy); 2690 llvm::CallSite Throw = 2691 CGF.EmitRuntimeCallOrInvoke(ExceptionThrowFn, ExceptionAsObject); 2692 Throw.setDoesNotReturn(); 2693 CGF.Builder.CreateUnreachable(); 2694 if (ClearInsertionPoint) 2695 CGF.Builder.ClearInsertionPoint(); 2696 } 2697 2698 llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF, 2699 llvm::Value *AddrWeakObj) { 2700 CGBuilderTy &B = CGF.Builder; 2701 AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy); 2702 return B.CreateCall(WeakReadFn, AddrWeakObj); 2703 } 2704 2705 void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF, 2706 llvm::Value *src, llvm::Value *dst) { 2707 CGBuilderTy &B = CGF.Builder; 2708 src = EnforceType(B, src, IdTy); 2709 dst = EnforceType(B, dst, PtrToIdTy); 2710 B.CreateCall2(WeakAssignFn, src, dst); 2711 } 2712 2713 void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF, 2714 llvm::Value *src, llvm::Value *dst, 2715 bool threadlocal) { 2716 CGBuilderTy &B = CGF.Builder; 2717 src = EnforceType(B, src, IdTy); 2718 dst = EnforceType(B, dst, PtrToIdTy); 2719 if (!threadlocal) 2720 B.CreateCall2(GlobalAssignFn, src, dst); 2721 else 2722 // FIXME. Add threadloca assign API 2723 llvm_unreachable("EmitObjCGlobalAssign - Threal Local API NYI"); 2724 } 2725 2726 void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF, 2727 llvm::Value *src, llvm::Value *dst, 2728 llvm::Value *ivarOffset) { 2729 CGBuilderTy &B = CGF.Builder; 2730 src = EnforceType(B, src, IdTy); 2731 dst = EnforceType(B, dst, IdTy); 2732 B.CreateCall3(IvarAssignFn, src, dst, ivarOffset); 2733 } 2734 2735 void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF, 2736 llvm::Value *src, llvm::Value *dst) { 2737 CGBuilderTy &B = CGF.Builder; 2738 src = EnforceType(B, src, IdTy); 2739 dst = EnforceType(B, dst, PtrToIdTy); 2740 B.CreateCall2(StrongCastAssignFn, src, dst); 2741 } 2742 2743 void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF, 2744 llvm::Value *DestPtr, 2745 llvm::Value *SrcPtr, 2746 llvm::Value *Size) { 2747 CGBuilderTy &B = CGF.Builder; 2748 DestPtr = EnforceType(B, DestPtr, PtrTy); 2749 SrcPtr = EnforceType(B, SrcPtr, PtrTy); 2750 2751 B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size); 2752 } 2753 2754 llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable( 2755 const ObjCInterfaceDecl *ID, 2756 const ObjCIvarDecl *Ivar) { 2757 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString() 2758 + '.' + Ivar->getNameAsString(); 2759 // Emit the variable and initialize it with what we think the correct value 2760 // is. This allows code compiled with non-fragile ivars to work correctly 2761 // when linked against code which isn't (most of the time). 2762 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name); 2763 if (!IvarOffsetPointer) { 2764 // This will cause a run-time crash if we accidentally use it. A value of 2765 // 0 would seem more sensible, but will silently overwrite the isa pointer 2766 // causing a great deal of confusion. 2767 uint64_t Offset = -1; 2768 // We can't call ComputeIvarBaseOffset() here if we have the 2769 // implementation, because it will create an invalid ASTRecordLayout object 2770 // that we are then stuck with forever, so we only initialize the ivar 2771 // offset variable with a guess if we only have the interface. The 2772 // initializer will be reset later anyway, when we are generating the class 2773 // description. 2774 if (!CGM.getContext().getObjCImplementation( 2775 const_cast<ObjCInterfaceDecl *>(ID))) 2776 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar); 2777 2778 llvm::ConstantInt *OffsetGuess = llvm::ConstantInt::get(Int32Ty, Offset, 2779 /*isSigned*/true); 2780 // Don't emit the guess in non-PIC code because the linker will not be able 2781 // to replace it with the real version for a library. In non-PIC code you 2782 // must compile with the fragile ABI if you want to use ivars from a 2783 // GCC-compiled class. 2784 if (CGM.getLangOpts().PICLevel || CGM.getLangOpts().PIELevel) { 2785 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule, 2786 Int32Ty, false, 2787 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess"); 2788 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2789 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage, 2790 IvarOffsetGV, Name); 2791 } else { 2792 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2793 llvm::Type::getInt32PtrTy(VMContext), false, 2794 llvm::GlobalValue::ExternalLinkage, 0, Name); 2795 } 2796 } 2797 return IvarOffsetPointer; 2798 } 2799 2800 LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF, 2801 QualType ObjectTy, 2802 llvm::Value *BaseValue, 2803 const ObjCIvarDecl *Ivar, 2804 unsigned CVRQualifiers) { 2805 const ObjCInterfaceDecl *ID = 2806 ObjectTy->getAs<ObjCObjectType>()->getInterface(); 2807 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers, 2808 EmitIvarOffset(CGF, ID, Ivar)); 2809 } 2810 2811 static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context, 2812 const ObjCInterfaceDecl *OID, 2813 const ObjCIvarDecl *OIVD) { 2814 for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next; 2815 next = next->getNextIvar()) { 2816 if (OIVD == next) 2817 return OID; 2818 } 2819 2820 // Otherwise check in the super class. 2821 if (const ObjCInterfaceDecl *Super = OID->getSuperClass()) 2822 return FindIvarInterface(Context, Super, OIVD); 2823 2824 return 0; 2825 } 2826 2827 llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF, 2828 const ObjCInterfaceDecl *Interface, 2829 const ObjCIvarDecl *Ivar) { 2830 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 2831 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar); 2832 if (RuntimeVersion < 10) 2833 return CGF.Builder.CreateZExtOrBitCast( 2834 CGF.Builder.CreateLoad(CGF.Builder.CreateLoad( 2835 ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")), 2836 PtrDiffTy); 2837 std::string name = "__objc_ivar_offset_value_" + 2838 Interface->getNameAsString() +"." + Ivar->getNameAsString(); 2839 llvm::Value *Offset = TheModule.getGlobalVariable(name); 2840 if (!Offset) 2841 Offset = new llvm::GlobalVariable(TheModule, IntTy, 2842 false, llvm::GlobalValue::LinkOnceAnyLinkage, 2843 llvm::Constant::getNullValue(IntTy), name); 2844 Offset = CGF.Builder.CreateLoad(Offset); 2845 if (Offset->getType() != PtrDiffTy) 2846 Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy); 2847 return Offset; 2848 } 2849 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar); 2850 return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true); 2851 } 2852 2853 CGObjCRuntime * 2854 clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) { 2855 switch (CGM.getLangOpts().ObjCRuntime.getKind()) { 2856 case ObjCRuntime::GNUstep: 2857 return new CGObjCGNUstep(CGM); 2858 2859 case ObjCRuntime::GCC: 2860 return new CGObjCGCC(CGM); 2861 2862 case ObjCRuntime::ObjFW: 2863 return new CGObjCObjFW(CGM); 2864 2865 case ObjCRuntime::FragileMacOSX: 2866 case ObjCRuntime::MacOSX: 2867 case ObjCRuntime::iOS: 2868 llvm_unreachable("these runtimes are not GNU runtimes"); 2869 } 2870 llvm_unreachable("bad runtime"); 2871 } 2872