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 "CodeGenModule.h" 19 #include "CodeGenFunction.h" 20 #include "CGCleanup.h" 21 22 #include "clang/AST/ASTContext.h" 23 #include "clang/AST/Decl.h" 24 #include "clang/AST/DeclObjC.h" 25 #include "clang/AST/RecordLayout.h" 26 #include "clang/AST/StmtObjC.h" 27 #include "clang/Basic/SourceManager.h" 28 #include "clang/Basic/FileManager.h" 29 30 #include "llvm/Intrinsics.h" 31 #include "llvm/Module.h" 32 #include "llvm/LLVMContext.h" 33 #include "llvm/ADT/SmallVector.h" 34 #include "llvm/ADT/StringMap.h" 35 #include "llvm/Support/CallSite.h" 36 #include "llvm/Support/Compiler.h" 37 #include "llvm/Target/TargetData.h" 38 39 #include <cstdarg> 40 41 42 using namespace clang; 43 using namespace CodeGen; 44 45 46 namespace { 47 /// Class that lazily initialises the runtime function. Avoids inserting the 48 /// types and the function declaration into a module if they're not used, and 49 /// avoids constructing the type more than once if it's used more than once. 50 class LazyRuntimeFunction { 51 CodeGenModule *CGM; 52 std::vector<llvm::Type*> ArgTys; 53 const char *FunctionName; 54 llvm::Constant *Function; 55 public: 56 /// Constructor leaves this class uninitialized, because it is intended to 57 /// be used as a field in another class and not all of the types that are 58 /// used as arguments will necessarily be available at construction time. 59 LazyRuntimeFunction() : CGM(0), FunctionName(0), Function(0) {} 60 61 /// Initialises the lazy function with the name, return type, and the types 62 /// of the arguments. 63 END_WITH_NULL 64 void init(CodeGenModule *Mod, const char *name, 65 llvm::Type *RetTy, ...) { 66 CGM =Mod; 67 FunctionName = name; 68 Function = 0; 69 ArgTys.clear(); 70 va_list Args; 71 va_start(Args, RetTy); 72 while (llvm::Type *ArgTy = va_arg(Args, llvm::Type*)) 73 ArgTys.push_back(ArgTy); 74 va_end(Args); 75 // Push the return type on at the end so we can pop it off easily 76 ArgTys.push_back(RetTy); 77 } 78 /// Overloaded cast operator, allows the class to be implicitly cast to an 79 /// LLVM constant. 80 operator llvm::Constant*() { 81 if (!Function) { 82 if (0 == FunctionName) return 0; 83 // We put the return type on the end of the vector, so pop it back off 84 llvm::Type *RetTy = ArgTys.back(); 85 ArgTys.pop_back(); 86 llvm::FunctionType *FTy = llvm::FunctionType::get(RetTy, ArgTys, false); 87 Function = 88 cast<llvm::Constant>(CGM->CreateRuntimeFunction(FTy, FunctionName)); 89 // We won't need to use the types again, so we may as well clean up the 90 // vector now 91 ArgTys.resize(0); 92 } 93 return Function; 94 } 95 operator llvm::Function*() { 96 return cast<llvm::Function>((llvm::Constant*)*this); 97 } 98 99 }; 100 101 102 /// GNU Objective-C runtime code generation. This class implements the parts of 103 /// Objective-C support that are specific to the GNU family of runtimes (GCC and 104 /// GNUstep). 105 class CGObjCGNU : public CGObjCRuntime { 106 protected: 107 /// The module that is using this class 108 CodeGenModule &CGM; 109 /// The LLVM module into which output is inserted 110 llvm::Module &TheModule; 111 /// strut objc_super. Used for sending messages to super. This structure 112 /// contains the receiver (object) and the expected class. 113 llvm::StructType *ObjCSuperTy; 114 /// struct objc_super*. The type of the argument to the superclass message 115 /// lookup functions. 116 llvm::PointerType *PtrToObjCSuperTy; 117 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring 118 /// SEL is included in a header somewhere, in which case it will be whatever 119 /// type is declared in that header, most likely {i8*, i8*}. 120 llvm::PointerType *SelectorTy; 121 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the 122 /// places where it's used 123 llvm::IntegerType *Int8Ty; 124 /// Pointer to i8 - LLVM type of char*, for all of the places where the 125 /// runtime needs to deal with C strings. 126 llvm::PointerType *PtrToInt8Ty; 127 /// Instance Method Pointer type. This is a pointer to a function that takes, 128 /// at a minimum, an object and a selector, and is the generic type for 129 /// Objective-C methods. Due to differences between variadic / non-variadic 130 /// calling conventions, it must always be cast to the correct type before 131 /// actually being used. 132 llvm::PointerType *IMPTy; 133 /// Type of an untyped Objective-C object. Clang treats id as a built-in type 134 /// when compiling Objective-C code, so this may be an opaque pointer (i8*), 135 /// but if the runtime header declaring it is included then it may be a 136 /// pointer to a structure. 137 llvm::PointerType *IdTy; 138 /// Pointer to a pointer to an Objective-C object. Used in the new ABI 139 /// message lookup function and some GC-related functions. 140 llvm::PointerType *PtrToIdTy; 141 /// The clang type of id. Used when using the clang CGCall infrastructure to 142 /// call Objective-C methods. 143 CanQualType ASTIdTy; 144 /// LLVM type for C int type. 145 llvm::IntegerType *IntTy; 146 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is 147 /// used in the code to document the difference between i8* meaning a pointer 148 /// to a C string and i8* meaning a pointer to some opaque type. 149 llvm::PointerType *PtrTy; 150 /// LLVM type for C long type. The runtime uses this in a lot of places where 151 /// it should be using intptr_t, but we can't fix this without breaking 152 /// compatibility with GCC... 153 llvm::IntegerType *LongTy; 154 /// LLVM type for C size_t. Used in various runtime data structures. 155 llvm::IntegerType *SizeTy; 156 /// LLVM type for C intptr_t. 157 llvm::IntegerType *IntPtrTy; 158 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions. 159 llvm::IntegerType *PtrDiffTy; 160 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance 161 /// variables. 162 llvm::PointerType *PtrToIntTy; 163 /// LLVM type for Objective-C BOOL type. 164 llvm::Type *BoolTy; 165 /// 32-bit integer type, to save us needing to look it up every time it's used. 166 llvm::IntegerType *Int32Ty; 167 /// 64-bit integer type, to save us needing to look it up every time it's used. 168 llvm::IntegerType *Int64Ty; 169 /// Metadata kind used to tie method lookups to message sends. The GNUstep 170 /// runtime provides some LLVM passes that can use this to do things like 171 /// automatic IMP caching and speculative inlining. 172 unsigned msgSendMDKind; 173 /// Helper function that generates a constant string and returns a pointer to 174 /// the start of the string. The result of this function can be used anywhere 175 /// where the C code specifies const char*. 176 llvm::Constant *MakeConstantString(const std::string &Str, 177 const std::string &Name="") { 178 llvm::Constant *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str()); 179 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 180 } 181 /// Emits a linkonce_odr string, whose name is the prefix followed by the 182 /// string value. This allows the linker to combine the strings between 183 /// different modules. Used for EH typeinfo names, selector strings, and a 184 /// few other things. 185 llvm::Constant *ExportUniqueString(const std::string &Str, 186 const std::string prefix) { 187 std::string name = prefix + Str; 188 llvm::Constant *ConstStr = TheModule.getGlobalVariable(name); 189 if (!ConstStr) { 190 llvm::Constant *value = llvm::ConstantArray::get(VMContext, Str, true); 191 ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true, 192 llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str); 193 } 194 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 195 } 196 /// Generates a global structure, initialized by the elements in the vector. 197 /// The element types must match the types of the structure elements in the 198 /// first argument. 199 llvm::GlobalVariable *MakeGlobal(llvm::StructType *Ty, 200 llvm::ArrayRef<llvm::Constant*> V, 201 StringRef Name="", 202 llvm::GlobalValue::LinkageTypes linkage 203 =llvm::GlobalValue::InternalLinkage) { 204 llvm::Constant *C = llvm::ConstantStruct::get(Ty, V); 205 return new llvm::GlobalVariable(TheModule, Ty, false, 206 linkage, C, Name); 207 } 208 /// Generates a global array. The vector must contain the same number of 209 /// elements that the array type declares, of the type specified as the array 210 /// element type. 211 llvm::GlobalVariable *MakeGlobal(llvm::ArrayType *Ty, 212 llvm::ArrayRef<llvm::Constant*> V, 213 StringRef Name="", 214 llvm::GlobalValue::LinkageTypes linkage 215 =llvm::GlobalValue::InternalLinkage) { 216 llvm::Constant *C = llvm::ConstantArray::get(Ty, V); 217 return new llvm::GlobalVariable(TheModule, Ty, false, 218 linkage, C, Name); 219 } 220 /// Generates a global array, inferring the array type from the specified 221 /// element type and the size of the initialiser. 222 llvm::GlobalVariable *MakeGlobalArray(llvm::Type *Ty, 223 llvm::ArrayRef<llvm::Constant*> V, 224 StringRef Name="", 225 llvm::GlobalValue::LinkageTypes linkage 226 =llvm::GlobalValue::InternalLinkage) { 227 llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size()); 228 return MakeGlobal(ArrayTy, V, Name, linkage); 229 } 230 /// Ensures that the value has the required type, by inserting a bitcast if 231 /// required. This function lets us avoid inserting bitcasts that are 232 /// redundant. 233 llvm::Value* EnforceType(CGBuilderTy B, llvm::Value *V, llvm::Type *Ty){ 234 if (V->getType() == Ty) return V; 235 return B.CreateBitCast(V, Ty); 236 } 237 // Some zeros used for GEPs in lots of places. 238 llvm::Constant *Zeros[2]; 239 /// Null pointer value. Mainly used as a terminator in various arrays. 240 llvm::Constant *NULLPtr; 241 /// LLVM context. 242 llvm::LLVMContext &VMContext; 243 private: 244 /// Placeholder for the class. Lots of things refer to the class before we've 245 /// actually emitted it. We use this alias as a placeholder, and then replace 246 /// it with a pointer to the class structure before finally emitting the 247 /// module. 248 llvm::GlobalAlias *ClassPtrAlias; 249 /// Placeholder for the metaclass. Lots of things refer to the class before 250 /// we've / actually emitted it. We use this alias as a placeholder, and then 251 /// replace / it with a pointer to the metaclass structure before finally 252 /// emitting the / module. 253 llvm::GlobalAlias *MetaClassPtrAlias; 254 /// All of the classes that have been generated for this compilation units. 255 std::vector<llvm::Constant*> Classes; 256 /// All of the categories that have been generated for this compilation units. 257 std::vector<llvm::Constant*> Categories; 258 /// All of the Objective-C constant strings that have been generated for this 259 /// compilation units. 260 std::vector<llvm::Constant*> ConstantStrings; 261 /// Map from string values to Objective-C constant strings in the output. 262 /// Used to prevent emitting Objective-C strings more than once. This should 263 /// not be required at all - CodeGenModule should manage this list. 264 llvm::StringMap<llvm::Constant*> ObjCStrings; 265 /// All of the protocols that have been declared. 266 llvm::StringMap<llvm::Constant*> ExistingProtocols; 267 /// For each variant of a selector, we store the type encoding and a 268 /// placeholder value. For an untyped selector, the type will be the empty 269 /// string. Selector references are all done via the module's selector table, 270 /// so we create an alias as a placeholder and then replace it with the real 271 /// value later. 272 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector; 273 /// Type of the selector map. This is roughly equivalent to the structure 274 /// used in the GNUstep runtime, which maintains a list of all of the valid 275 /// types for a selector in a table. 276 typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> > 277 SelectorMap; 278 /// A map from selectors to selector types. This allows us to emit all 279 /// selectors of the same name and type together. 280 SelectorMap SelectorTable; 281 282 /// Selectors related to memory management. When compiling in GC mode, we 283 /// omit these. 284 Selector RetainSel, ReleaseSel, AutoreleaseSel; 285 /// Runtime functions used for memory management in GC mode. Note that clang 286 /// supports code generation for calling these functions, but neither GNU 287 /// runtime actually supports this API properly yet. 288 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn, 289 WeakAssignFn, GlobalAssignFn; 290 291 protected: 292 /// Function used for throwing Objective-C exceptions. 293 LazyRuntimeFunction ExceptionThrowFn; 294 /// Function used for rethrowing exceptions, used at the end of @finally or 295 /// @synchronize blocks. 296 LazyRuntimeFunction ExceptionReThrowFn; 297 /// Function called when entering a catch function. This is required for 298 /// differentiating Objective-C exceptions and foreign exceptions. 299 LazyRuntimeFunction EnterCatchFn; 300 /// Function called when exiting from a catch block. Used to do exception 301 /// cleanup. 302 LazyRuntimeFunction ExitCatchFn; 303 /// Function called when entering an @synchronize block. Acquires the lock. 304 LazyRuntimeFunction SyncEnterFn; 305 /// Function called when exiting an @synchronize block. Releases the lock. 306 LazyRuntimeFunction SyncExitFn; 307 308 private: 309 310 /// Function called if fast enumeration detects that the collection is 311 /// modified during the update. 312 LazyRuntimeFunction EnumerationMutationFn; 313 /// Function for implementing synthesized property getters that return an 314 /// object. 315 LazyRuntimeFunction GetPropertyFn; 316 /// Function for implementing synthesized property setters that return an 317 /// object. 318 LazyRuntimeFunction SetPropertyFn; 319 /// Function used for non-object declared property getters. 320 LazyRuntimeFunction GetStructPropertyFn; 321 /// Function used for non-object declared property setters. 322 LazyRuntimeFunction SetStructPropertyFn; 323 324 /// The version of the runtime that this class targets. Must match the 325 /// version in the runtime. 326 int RuntimeVersion; 327 /// The version of the protocol class. Used to differentiate between ObjC1 328 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional 329 /// components and can not contain declared properties. We always emit 330 /// Objective-C 2 property structures, but we have to pretend that they're 331 /// Objective-C 1 property structures when targeting the GCC runtime or it 332 /// will abort. 333 const int ProtocolVersion; 334 private: 335 /// Generates an instance variable list structure. This is a structure 336 /// containing a size and an array of structures containing instance variable 337 /// metadata. This is used purely for introspection in the fragile ABI. In 338 /// the non-fragile ABI, it's used for instance variable fixup. 339 llvm::Constant *GenerateIvarList( 340 const SmallVectorImpl<llvm::Constant *> &IvarNames, 341 const SmallVectorImpl<llvm::Constant *> &IvarTypes, 342 const SmallVectorImpl<llvm::Constant *> &IvarOffsets); 343 /// Generates a method list structure. This is a structure containing a size 344 /// and an array of structures containing method metadata. 345 /// 346 /// This structure is used by both classes and categories, and contains a next 347 /// pointer allowing them to be chained together in a linked list. 348 llvm::Constant *GenerateMethodList(const StringRef &ClassName, 349 const StringRef &CategoryName, 350 const SmallVectorImpl<Selector> &MethodSels, 351 const SmallVectorImpl<llvm::Constant *> &MethodTypes, 352 bool isClassMethodList); 353 /// Emits an empty protocol. This is used for @protocol() where no protocol 354 /// is found. The runtime will (hopefully) fix up the pointer to refer to the 355 /// real protocol. 356 llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName); 357 /// Generates a list of property metadata structures. This follows the same 358 /// pattern as method and instance variable metadata lists. 359 llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID, 360 SmallVectorImpl<Selector> &InstanceMethodSels, 361 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes); 362 /// Generates a list of referenced protocols. Classes, categories, and 363 /// protocols all use this structure. 364 llvm::Constant *GenerateProtocolList( 365 const SmallVectorImpl<std::string> &Protocols); 366 /// To ensure that all protocols are seen by the runtime, we add a category on 367 /// a class defined in the runtime, declaring no methods, but adopting the 368 /// protocols. This is a horribly ugly hack, but it allows us to collect all 369 /// of the protocols without changing the ABI. 370 void GenerateProtocolHolderCategory(void); 371 /// Generates a class structure. 372 llvm::Constant *GenerateClassStructure( 373 llvm::Constant *MetaClass, 374 llvm::Constant *SuperClass, 375 unsigned info, 376 const char *Name, 377 llvm::Constant *Version, 378 llvm::Constant *InstanceSize, 379 llvm::Constant *IVars, 380 llvm::Constant *Methods, 381 llvm::Constant *Protocols, 382 llvm::Constant *IvarOffsets, 383 llvm::Constant *Properties, 384 llvm::Constant *StrongIvarBitmap, 385 llvm::Constant *WeakIvarBitmap, 386 bool isMeta=false); 387 /// Generates a method list. This is used by protocols to define the required 388 /// and optional methods. 389 llvm::Constant *GenerateProtocolMethodList( 390 const SmallVectorImpl<llvm::Constant *> &MethodNames, 391 const SmallVectorImpl<llvm::Constant *> &MethodTypes); 392 /// Returns a selector with the specified type encoding. An empty string is 393 /// used to return an untyped selector (with the types field set to NULL). 394 llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 395 const std::string &TypeEncoding, bool lval); 396 /// Returns the variable used to store the offset of an instance variable. 397 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID, 398 const ObjCIvarDecl *Ivar); 399 /// Emits a reference to a class. This allows the linker to object if there 400 /// is no class of the matching name. 401 void EmitClassRef(const std::string &className); 402 /// Emits a pointer to the named class 403 llvm::Value *GetClassNamed(CGBuilderTy &Builder, const std::string &Name, 404 bool isWeak); 405 protected: 406 /// Looks up the method for sending a message to the specified object. This 407 /// mechanism differs between the GCC and GNU runtimes, so this method must be 408 /// overridden in subclasses. 409 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 410 llvm::Value *&Receiver, 411 llvm::Value *cmd, 412 llvm::MDNode *node) = 0; 413 /// Looks up the method for sending a message to a superclass. This 414 /// mechanism differs between the GCC and GNU runtimes, so this method must 415 /// be overridden in subclasses. 416 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 417 llvm::Value *ObjCSuper, 418 llvm::Value *cmd) = 0; 419 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are 420 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63 421 /// bits set to their values, LSB first, while larger ones are stored in a 422 /// structure of this / form: 423 /// 424 /// struct { int32_t length; int32_t values[length]; }; 425 /// 426 /// The values in the array are stored in host-endian format, with the least 427 /// significant bit being assumed to come first in the bitfield. Therefore, 428 /// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, 429 /// while a bitfield / with the 63rd bit set will be 1<<64. 430 llvm::Constant *MakeBitField(llvm::SmallVectorImpl<bool> &bits); 431 public: 432 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 433 unsigned protocolClassVersion); 434 435 virtual llvm::Constant *GenerateConstantString(const StringLiteral *); 436 437 virtual RValue 438 GenerateMessageSend(CodeGenFunction &CGF, 439 ReturnValueSlot Return, 440 QualType ResultType, 441 Selector Sel, 442 llvm::Value *Receiver, 443 const CallArgList &CallArgs, 444 const ObjCInterfaceDecl *Class, 445 const ObjCMethodDecl *Method); 446 virtual RValue 447 GenerateMessageSendSuper(CodeGenFunction &CGF, 448 ReturnValueSlot Return, 449 QualType ResultType, 450 Selector Sel, 451 const ObjCInterfaceDecl *Class, 452 bool isCategoryImpl, 453 llvm::Value *Receiver, 454 bool IsClassMessage, 455 const CallArgList &CallArgs, 456 const ObjCMethodDecl *Method); 457 virtual llvm::Value *GetClass(CGBuilderTy &Builder, 458 const ObjCInterfaceDecl *OID); 459 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 460 bool lval = false); 461 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 462 *Method); 463 virtual llvm::Constant *GetEHType(QualType T); 464 465 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 466 const ObjCContainerDecl *CD); 467 virtual void GenerateCategory(const ObjCCategoryImplDecl *CMD); 468 virtual void GenerateClass(const ObjCImplementationDecl *ClassDecl); 469 virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder, 470 const ObjCProtocolDecl *PD); 471 virtual void GenerateProtocol(const ObjCProtocolDecl *PD); 472 virtual llvm::Function *ModuleInitFunction(); 473 virtual llvm::Constant *GetPropertyGetFunction(); 474 virtual llvm::Constant *GetPropertySetFunction(); 475 virtual llvm::Constant *GetSetStructFunction(); 476 virtual llvm::Constant *GetGetStructFunction(); 477 virtual llvm::Constant *EnumerationMutationFunction(); 478 479 virtual void EmitTryStmt(CodeGenFunction &CGF, 480 const ObjCAtTryStmt &S); 481 virtual void EmitSynchronizedStmt(CodeGenFunction &CGF, 482 const ObjCAtSynchronizedStmt &S); 483 virtual void EmitThrowStmt(CodeGenFunction &CGF, 484 const ObjCAtThrowStmt &S); 485 virtual llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF, 486 llvm::Value *AddrWeakObj); 487 virtual void EmitObjCWeakAssign(CodeGenFunction &CGF, 488 llvm::Value *src, llvm::Value *dst); 489 virtual void EmitObjCGlobalAssign(CodeGenFunction &CGF, 490 llvm::Value *src, llvm::Value *dest, 491 bool threadlocal=false); 492 virtual void EmitObjCIvarAssign(CodeGenFunction &CGF, 493 llvm::Value *src, llvm::Value *dest, 494 llvm::Value *ivarOffset); 495 virtual void EmitObjCStrongCastAssign(CodeGenFunction &CGF, 496 llvm::Value *src, llvm::Value *dest); 497 virtual void EmitGCMemmoveCollectable(CodeGenFunction &CGF, 498 llvm::Value *DestPtr, 499 llvm::Value *SrcPtr, 500 llvm::Value *Size); 501 virtual LValue EmitObjCValueForIvar(CodeGenFunction &CGF, 502 QualType ObjectTy, 503 llvm::Value *BaseValue, 504 const ObjCIvarDecl *Ivar, 505 unsigned CVRQualifiers); 506 virtual llvm::Value *EmitIvarOffset(CodeGenFunction &CGF, 507 const ObjCInterfaceDecl *Interface, 508 const ObjCIvarDecl *Ivar); 509 virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CGBuilderTy &Builder); 510 virtual llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM, 511 const CGBlockInfo &blockInfo) { 512 return NULLPtr; 513 } 514 515 virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) { 516 return 0; 517 } 518 }; 519 /// Class representing the legacy GCC Objective-C ABI. This is the default when 520 /// -fobjc-nonfragile-abi is not specified. 521 /// 522 /// The GCC ABI target actually generates code that is approximately compatible 523 /// with the new GNUstep runtime ABI, but refrains from using any features that 524 /// would not work with the GCC runtime. For example, clang always generates 525 /// the extended form of the class structure, and the extra fields are simply 526 /// ignored by GCC libobjc. 527 class CGObjCGCC : public CGObjCGNU { 528 /// The GCC ABI message lookup function. Returns an IMP pointing to the 529 /// method implementation for this message. 530 LazyRuntimeFunction MsgLookupFn; 531 /// The GCC ABI superclass message lookup function. Takes a pointer to a 532 /// structure describing the receiver and the class, and a selector as 533 /// arguments. Returns the IMP for the corresponding method. 534 LazyRuntimeFunction MsgLookupSuperFn; 535 protected: 536 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 537 llvm::Value *&Receiver, 538 llvm::Value *cmd, 539 llvm::MDNode *node) { 540 CGBuilderTy &Builder = CGF.Builder; 541 llvm::Value *imp = Builder.CreateCall2(MsgLookupFn, 542 EnforceType(Builder, Receiver, IdTy), 543 EnforceType(Builder, cmd, SelectorTy)); 544 cast<llvm::CallInst>(imp)->setMetadata(msgSendMDKind, node); 545 return imp; 546 } 547 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 548 llvm::Value *ObjCSuper, 549 llvm::Value *cmd) { 550 CGBuilderTy &Builder = CGF.Builder; 551 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 552 PtrToObjCSuperTy), cmd}; 553 return Builder.CreateCall(MsgLookupSuperFn, lookupArgs); 554 } 555 public: 556 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) { 557 // IMP objc_msg_lookup(id, SEL); 558 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 559 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 560 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 561 PtrToObjCSuperTy, SelectorTy, NULL); 562 } 563 }; 564 /// Class used when targeting the new GNUstep runtime ABI. 565 class CGObjCGNUstep : public CGObjCGNU { 566 /// The slot lookup function. Returns a pointer to a cacheable structure 567 /// that contains (among other things) the IMP. 568 LazyRuntimeFunction SlotLookupFn; 569 /// The GNUstep ABI superclass message lookup function. Takes a pointer to 570 /// a structure describing the receiver and the class, and a selector as 571 /// arguments. Returns the slot for the corresponding method. Superclass 572 /// message lookup rarely changes, so this is a good caching opportunity. 573 LazyRuntimeFunction SlotLookupSuperFn; 574 /// Type of an slot structure pointer. This is returned by the various 575 /// lookup functions. 576 llvm::Type *SlotTy; 577 protected: 578 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 579 llvm::Value *&Receiver, 580 llvm::Value *cmd, 581 llvm::MDNode *node) { 582 CGBuilderTy &Builder = CGF.Builder; 583 llvm::Function *LookupFn = SlotLookupFn; 584 585 // Store the receiver on the stack so that we can reload it later 586 llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType()); 587 Builder.CreateStore(Receiver, ReceiverPtr); 588 589 llvm::Value *self; 590 591 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) { 592 self = CGF.LoadObjCSelf(); 593 } else { 594 self = llvm::ConstantPointerNull::get(IdTy); 595 } 596 597 // The lookup function is guaranteed not to capture the receiver pointer. 598 LookupFn->setDoesNotCapture(1); 599 600 llvm::CallInst *slot = 601 Builder.CreateCall3(LookupFn, 602 EnforceType(Builder, ReceiverPtr, PtrToIdTy), 603 EnforceType(Builder, cmd, SelectorTy), 604 EnforceType(Builder, self, IdTy)); 605 slot->setOnlyReadsMemory(); 606 slot->setMetadata(msgSendMDKind, node); 607 608 // Load the imp from the slot 609 llvm::Value *imp = Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 610 611 // The lookup function may have changed the receiver, so make sure we use 612 // the new one. 613 Receiver = Builder.CreateLoad(ReceiverPtr, true); 614 return imp; 615 } 616 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 617 llvm::Value *ObjCSuper, 618 llvm::Value *cmd) { 619 CGBuilderTy &Builder = CGF.Builder; 620 llvm::Value *lookupArgs[] = {ObjCSuper, cmd}; 621 622 llvm::CallInst *slot = Builder.CreateCall(SlotLookupSuperFn, lookupArgs); 623 slot->setOnlyReadsMemory(); 624 625 return Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 626 } 627 public: 628 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) { 629 llvm::StructType *SlotStructTy = llvm::StructType::get(PtrTy, 630 PtrTy, PtrTy, IntTy, IMPTy, NULL); 631 SlotTy = llvm::PointerType::getUnqual(SlotStructTy); 632 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 633 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy, 634 SelectorTy, IdTy, NULL); 635 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL); 636 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy, 637 PtrToObjCSuperTy, SelectorTy, NULL); 638 // If we're in ObjC++ mode, then we want to make 639 if (CGM.getLangOptions().CPlusPlus) { 640 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 641 // void *__cxa_begin_catch(void *e) 642 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, NULL); 643 // void __cxa_end_catch(void) 644 ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, NULL); 645 // void _Unwind_Resume_or_Rethrow(void*) 646 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, PtrTy, NULL); 647 } 648 } 649 }; 650 651 } // end anonymous namespace 652 653 654 /// Emits a reference to a dummy variable which is emitted with each class. 655 /// This ensures that a linker error will be generated when trying to link 656 /// together modules where a referenced class is not defined. 657 void CGObjCGNU::EmitClassRef(const std::string &className) { 658 std::string symbolRef = "__objc_class_ref_" + className; 659 // Don't emit two copies of the same symbol 660 if (TheModule.getGlobalVariable(symbolRef)) 661 return; 662 std::string symbolName = "__objc_class_name_" + className; 663 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName); 664 if (!ClassSymbol) { 665 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 666 llvm::GlobalValue::ExternalLinkage, 0, symbolName); 667 } 668 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true, 669 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef); 670 } 671 672 static std::string SymbolNameForMethod(const StringRef &ClassName, 673 const StringRef &CategoryName, const Selector MethodName, 674 bool isClassMethod) { 675 std::string MethodNameColonStripped = MethodName.getAsString(); 676 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(), 677 ':', '_'); 678 return (Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" + 679 CategoryName + "_" + MethodNameColonStripped).str(); 680 } 681 682 CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 683 unsigned protocolClassVersion) 684 : CGM(cgm), TheModule(CGM.getModule()), VMContext(cgm.getLLVMContext()), 685 ClassPtrAlias(0), MetaClassPtrAlias(0), RuntimeVersion(runtimeABIVersion), 686 ProtocolVersion(protocolClassVersion) { 687 688 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend"); 689 690 CodeGenTypes &Types = CGM.getTypes(); 691 IntTy = cast<llvm::IntegerType>( 692 Types.ConvertType(CGM.getContext().IntTy)); 693 LongTy = cast<llvm::IntegerType>( 694 Types.ConvertType(CGM.getContext().LongTy)); 695 SizeTy = cast<llvm::IntegerType>( 696 Types.ConvertType(CGM.getContext().getSizeType())); 697 PtrDiffTy = cast<llvm::IntegerType>( 698 Types.ConvertType(CGM.getContext().getPointerDiffType())); 699 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy); 700 701 Int8Ty = llvm::Type::getInt8Ty(VMContext); 702 // C string type. Used in lots of places. 703 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); 704 705 Zeros[0] = llvm::ConstantInt::get(LongTy, 0); 706 Zeros[1] = Zeros[0]; 707 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty); 708 // Get the selector Type. 709 QualType selTy = CGM.getContext().getObjCSelType(); 710 if (QualType() == selTy) { 711 SelectorTy = PtrToInt8Ty; 712 } else { 713 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy)); 714 } 715 716 PtrToIntTy = llvm::PointerType::getUnqual(IntTy); 717 PtrTy = PtrToInt8Ty; 718 719 Int32Ty = llvm::Type::getInt32Ty(VMContext); 720 Int64Ty = llvm::Type::getInt64Ty(VMContext); 721 722 IntPtrTy = 723 TheModule.getPointerSize() == llvm::Module::Pointer32 ? Int32Ty : Int64Ty; 724 725 // Object type 726 QualType UnqualIdTy = CGM.getContext().getObjCIdType(); 727 ASTIdTy = CanQualType(); 728 if (UnqualIdTy != QualType()) { 729 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy); 730 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 731 } else { 732 IdTy = PtrToInt8Ty; 733 } 734 PtrToIdTy = llvm::PointerType::getUnqual(IdTy); 735 736 ObjCSuperTy = llvm::StructType::get(IdTy, IdTy, NULL); 737 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy); 738 739 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 740 741 // void objc_exception_throw(id); 742 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 743 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 744 // int objc_sync_enter(id); 745 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, NULL); 746 // int objc_sync_exit(id); 747 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, NULL); 748 749 // void objc_enumerationMutation (id) 750 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, 751 IdTy, NULL); 752 753 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL) 754 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy, 755 PtrDiffTy, BoolTy, NULL); 756 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL) 757 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy, 758 PtrDiffTy, IdTy, BoolTy, BoolTy, NULL); 759 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 760 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy, 761 PtrDiffTy, BoolTy, BoolTy, NULL); 762 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 763 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy, 764 PtrDiffTy, BoolTy, BoolTy, NULL); 765 766 // IMP type 767 llvm::Type *IMPArgs[] = { IdTy, SelectorTy }; 768 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs, 769 true)); 770 771 const LangOptions &Opts = CGM.getLangOptions(); 772 if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount) 773 RuntimeVersion = 10; 774 775 // Don't bother initialising the GC stuff unless we're compiling in GC mode 776 if (Opts.getGC() != LangOptions::NonGC) { 777 // This is a bit of an hack. We should sort this out by having a proper 778 // CGObjCGNUstep subclass for GC, but we may want to really support the old 779 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now 780 // Get selectors needed in GC mode 781 RetainSel = GetNullarySelector("retain", CGM.getContext()); 782 ReleaseSel = GetNullarySelector("release", CGM.getContext()); 783 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext()); 784 785 // Get functions needed in GC mode 786 787 // id objc_assign_ivar(id, id, ptrdiff_t); 788 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy, 789 NULL); 790 // id objc_assign_strongCast (id, id*) 791 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy, 792 PtrToIdTy, NULL); 793 // id objc_assign_global(id, id*); 794 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy, 795 NULL); 796 // id objc_assign_weak(id, id*); 797 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, NULL); 798 // id objc_read_weak(id*); 799 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, NULL); 800 // void *objc_memmove_collectable(void*, void *, size_t); 801 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy, 802 SizeTy, NULL); 803 } 804 } 805 806 llvm::Value *CGObjCGNU::GetClassNamed(CGBuilderTy &Builder, 807 const std::string &Name, 808 bool isWeak) { 809 llvm::Value *ClassName = CGM.GetAddrOfConstantCString(Name); 810 // With the incompatible ABI, this will need to be replaced with a direct 811 // reference to the class symbol. For the compatible nonfragile ABI we are 812 // still performing this lookup at run time but emitting the symbol for the 813 // class externally so that we can make the switch later. 814 // 815 // Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class 816 // with memoized versions or with static references if it's safe to do so. 817 if (!isWeak) 818 EmitClassRef(Name); 819 ClassName = Builder.CreateStructGEP(ClassName, 0); 820 821 llvm::Constant *ClassLookupFn = 822 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true), 823 "objc_lookup_class"); 824 return Builder.CreateCall(ClassLookupFn, ClassName); 825 } 826 827 // This has to perform the lookup every time, since posing and related 828 // techniques can modify the name -> class mapping. 829 llvm::Value *CGObjCGNU::GetClass(CGBuilderTy &Builder, 830 const ObjCInterfaceDecl *OID) { 831 return GetClassNamed(Builder, OID->getNameAsString(), OID->isWeakImported()); 832 } 833 llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CGBuilderTy &Builder) { 834 return GetClassNamed(Builder, "NSAutoreleasePool", false); 835 } 836 837 llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 838 const std::string &TypeEncoding, bool lval) { 839 840 SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel]; 841 llvm::GlobalAlias *SelValue = 0; 842 843 844 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 845 e = Types.end() ; i!=e ; i++) { 846 if (i->first == TypeEncoding) { 847 SelValue = i->second; 848 break; 849 } 850 } 851 if (0 == SelValue) { 852 SelValue = new llvm::GlobalAlias(SelectorTy, 853 llvm::GlobalValue::PrivateLinkage, 854 ".objc_selector_"+Sel.getAsString(), NULL, 855 &TheModule); 856 Types.push_back(TypedSelector(TypeEncoding, SelValue)); 857 } 858 859 if (lval) { 860 llvm::Value *tmp = Builder.CreateAlloca(SelValue->getType()); 861 Builder.CreateStore(SelValue, tmp); 862 return tmp; 863 } 864 return SelValue; 865 } 866 867 llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 868 bool lval) { 869 return GetSelector(Builder, Sel, std::string(), lval); 870 } 871 872 llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 873 *Method) { 874 std::string SelTypes; 875 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes); 876 return GetSelector(Builder, Method->getSelector(), SelTypes, false); 877 } 878 879 llvm::Constant *CGObjCGNU::GetEHType(QualType T) { 880 if (!CGM.getLangOptions().CPlusPlus) { 881 if (T->isObjCIdType() 882 || T->isObjCQualifiedIdType()) { 883 // With the old ABI, there was only one kind of catchall, which broke 884 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as 885 // a pointer indicating object catchalls, and NULL to indicate real 886 // catchalls 887 if (CGM.getLangOptions().ObjCNonFragileABI) { 888 return MakeConstantString("@id"); 889 } else { 890 return 0; 891 } 892 } 893 894 // All other types should be Objective-C interface pointer types. 895 const ObjCObjectPointerType *OPT = 896 T->getAs<ObjCObjectPointerType>(); 897 assert(OPT && "Invalid @catch type."); 898 const ObjCInterfaceDecl *IDecl = 899 OPT->getObjectType()->getInterface(); 900 assert(IDecl && "Invalid @catch type."); 901 return MakeConstantString(IDecl->getIdentifier()->getName()); 902 } 903 // For Objective-C++, we want to provide the ability to catch both C++ and 904 // Objective-C objects in the same function. 905 906 // There's a particular fixed type info for 'id'. 907 if (T->isObjCIdType() || 908 T->isObjCQualifiedIdType()) { 909 llvm::Constant *IDEHType = 910 CGM.getModule().getGlobalVariable("__objc_id_type_info"); 911 if (!IDEHType) 912 IDEHType = 913 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty, 914 false, 915 llvm::GlobalValue::ExternalLinkage, 916 0, "__objc_id_type_info"); 917 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty); 918 } 919 920 const ObjCObjectPointerType *PT = 921 T->getAs<ObjCObjectPointerType>(); 922 assert(PT && "Invalid @catch type."); 923 const ObjCInterfaceType *IT = PT->getInterfaceType(); 924 assert(IT && "Invalid @catch type."); 925 std::string className = IT->getDecl()->getIdentifier()->getName(); 926 927 std::string typeinfoName = "__objc_eh_typeinfo_" + className; 928 929 // Return the existing typeinfo if it exists 930 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName); 931 if (typeinfo) return typeinfo; 932 933 // Otherwise create it. 934 935 // vtable for gnustep::libobjc::__objc_class_type_info 936 // It's quite ugly hard-coding this. Ideally we'd generate it using the host 937 // platform's name mangling. 938 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE"; 939 llvm::Constant *Vtable = TheModule.getGlobalVariable(vtableName); 940 if (!Vtable) { 941 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true, 942 llvm::GlobalValue::ExternalLinkage, 0, vtableName); 943 } 944 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2); 945 Vtable = llvm::ConstantExpr::getGetElementPtr(Vtable, Two); 946 Vtable = llvm::ConstantExpr::getBitCast(Vtable, PtrToInt8Ty); 947 948 llvm::Constant *typeName = 949 ExportUniqueString(className, "__objc_eh_typename_"); 950 951 std::vector<llvm::Constant*> fields; 952 fields.push_back(Vtable); 953 fields.push_back(typeName); 954 llvm::Constant *TI = 955 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 956 NULL), fields, "__objc_eh_typeinfo_" + className, 957 llvm::GlobalValue::LinkOnceODRLinkage); 958 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty); 959 } 960 961 /// Generate an NSConstantString object. 962 llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) { 963 964 std::string Str = SL->getString().str(); 965 966 // Look for an existing one 967 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str); 968 if (old != ObjCStrings.end()) 969 return old->getValue(); 970 971 std::vector<llvm::Constant*> Ivars; 972 Ivars.push_back(NULLPtr); 973 Ivars.push_back(MakeConstantString(Str)); 974 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size())); 975 llvm::Constant *ObjCStr = MakeGlobal( 976 llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, IntTy, NULL), 977 Ivars, ".objc_str"); 978 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty); 979 ObjCStrings[Str] = ObjCStr; 980 ConstantStrings.push_back(ObjCStr); 981 return ObjCStr; 982 } 983 984 ///Generates a message send where the super is the receiver. This is a message 985 ///send to self with special delivery semantics indicating which class's method 986 ///should be called. 987 RValue 988 CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF, 989 ReturnValueSlot Return, 990 QualType ResultType, 991 Selector Sel, 992 const ObjCInterfaceDecl *Class, 993 bool isCategoryImpl, 994 llvm::Value *Receiver, 995 bool IsClassMessage, 996 const CallArgList &CallArgs, 997 const ObjCMethodDecl *Method) { 998 CGBuilderTy &Builder = CGF.Builder; 999 if (CGM.getLangOptions().getGC() == LangOptions::GCOnly) { 1000 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1001 return RValue::get(EnforceType(Builder, Receiver, 1002 CGM.getTypes().ConvertType(ResultType))); 1003 } 1004 if (Sel == ReleaseSel) { 1005 return RValue::get(0); 1006 } 1007 } 1008 1009 llvm::Value *cmd = GetSelector(Builder, Sel); 1010 1011 1012 CallArgList ActualArgs; 1013 1014 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy); 1015 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1016 ActualArgs.addFrom(CallArgs); 1017 1018 CodeGenTypes &Types = CGM.getTypes(); 1019 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 1020 FunctionType::ExtInfo()); 1021 1022 llvm::Value *ReceiverClass = 0; 1023 if (isCategoryImpl) { 1024 llvm::Constant *classLookupFunction = 0; 1025 if (IsClassMessage) { 1026 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1027 IdTy, PtrTy, true), "objc_get_meta_class"); 1028 } else { 1029 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1030 IdTy, PtrTy, true), "objc_get_class"); 1031 } 1032 ReceiverClass = Builder.CreateCall(classLookupFunction, 1033 MakeConstantString(Class->getNameAsString())); 1034 } else { 1035 // Set up global aliases for the metaclass or class pointer if they do not 1036 // already exist. These will are forward-references which will be set to 1037 // pointers to the class and metaclass structure created for the runtime 1038 // load function. To send a message to super, we look up the value of the 1039 // super_class pointer from either the class or metaclass structure. 1040 if (IsClassMessage) { 1041 if (!MetaClassPtrAlias) { 1042 MetaClassPtrAlias = new llvm::GlobalAlias(IdTy, 1043 llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" + 1044 Class->getNameAsString(), NULL, &TheModule); 1045 } 1046 ReceiverClass = MetaClassPtrAlias; 1047 } else { 1048 if (!ClassPtrAlias) { 1049 ClassPtrAlias = new llvm::GlobalAlias(IdTy, 1050 llvm::GlobalValue::InternalLinkage, ".objc_class_ref" + 1051 Class->getNameAsString(), NULL, &TheModule); 1052 } 1053 ReceiverClass = ClassPtrAlias; 1054 } 1055 } 1056 // Cast the pointer to a simplified version of the class structure 1057 ReceiverClass = Builder.CreateBitCast(ReceiverClass, 1058 llvm::PointerType::getUnqual( 1059 llvm::StructType::get(IdTy, IdTy, NULL))); 1060 // Get the superclass pointer 1061 ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1); 1062 // Load the superclass pointer 1063 ReceiverClass = Builder.CreateLoad(ReceiverClass); 1064 // Construct the structure used to look up the IMP 1065 llvm::StructType *ObjCSuperTy = llvm::StructType::get( 1066 Receiver->getType(), IdTy, NULL); 1067 llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy); 1068 1069 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0)); 1070 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1)); 1071 1072 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy); 1073 llvm::FunctionType *impType = 1074 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1075 1076 // Get the IMP 1077 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd); 1078 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1079 1080 llvm::Value *impMD[] = { 1081 llvm::MDString::get(VMContext, Sel.getAsString()), 1082 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()), 1083 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage) 1084 }; 1085 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1086 1087 llvm::Instruction *call; 1088 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1089 0, &call); 1090 call->setMetadata(msgSendMDKind, node); 1091 return msgRet; 1092 } 1093 1094 /// Generate code for a message send expression. 1095 RValue 1096 CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF, 1097 ReturnValueSlot Return, 1098 QualType ResultType, 1099 Selector Sel, 1100 llvm::Value *Receiver, 1101 const CallArgList &CallArgs, 1102 const ObjCInterfaceDecl *Class, 1103 const ObjCMethodDecl *Method) { 1104 CGBuilderTy &Builder = CGF.Builder; 1105 1106 // Strip out message sends to retain / release in GC mode 1107 if (CGM.getLangOptions().getGC() == LangOptions::GCOnly) { 1108 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1109 return RValue::get(EnforceType(Builder, Receiver, 1110 CGM.getTypes().ConvertType(ResultType))); 1111 } 1112 if (Sel == ReleaseSel) { 1113 return RValue::get(0); 1114 } 1115 } 1116 1117 // If the return type is something that goes in an integer register, the 1118 // runtime will handle 0 returns. For other cases, we fill in the 0 value 1119 // ourselves. 1120 // 1121 // The language spec says the result of this kind of message send is 1122 // undefined, but lots of people seem to have forgotten to read that 1123 // paragraph and insist on sending messages to nil that have structure 1124 // returns. With GCC, this generates a random return value (whatever happens 1125 // to be on the stack / in those registers at the time) on most platforms, 1126 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts 1127 // the stack. 1128 bool isPointerSizedReturn = (ResultType->isAnyPointerType() || 1129 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType()); 1130 1131 llvm::BasicBlock *startBB = 0; 1132 llvm::BasicBlock *messageBB = 0; 1133 llvm::BasicBlock *continueBB = 0; 1134 1135 if (!isPointerSizedReturn) { 1136 startBB = Builder.GetInsertBlock(); 1137 messageBB = CGF.createBasicBlock("msgSend"); 1138 continueBB = CGF.createBasicBlock("continue"); 1139 1140 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver, 1141 llvm::Constant::getNullValue(Receiver->getType())); 1142 Builder.CreateCondBr(isNil, continueBB, messageBB); 1143 CGF.EmitBlock(messageBB); 1144 } 1145 1146 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 1147 llvm::Value *cmd; 1148 if (Method) 1149 cmd = GetSelector(Builder, Method); 1150 else 1151 cmd = GetSelector(Builder, Sel); 1152 cmd = EnforceType(Builder, cmd, SelectorTy); 1153 Receiver = EnforceType(Builder, Receiver, IdTy); 1154 1155 llvm::Value *impMD[] = { 1156 llvm::MDString::get(VMContext, Sel.getAsString()), 1157 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""), 1158 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0) 1159 }; 1160 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1161 1162 // Get the IMP to call 1163 llvm::Value *imp = LookupIMP(CGF, Receiver, cmd, node); 1164 1165 CallArgList ActualArgs; 1166 ActualArgs.add(RValue::get(Receiver), ASTIdTy); 1167 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1168 ActualArgs.addFrom(CallArgs); 1169 1170 CodeGenTypes &Types = CGM.getTypes(); 1171 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 1172 FunctionType::ExtInfo()); 1173 llvm::FunctionType *impType = 1174 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1175 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1176 1177 1178 // For sender-aware dispatch, we pass the sender as the third argument to a 1179 // lookup function. When sending messages from C code, the sender is nil. 1180 // objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 1181 llvm::Instruction *call; 1182 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1183 0, &call); 1184 call->setMetadata(msgSendMDKind, node); 1185 1186 1187 if (!isPointerSizedReturn) { 1188 messageBB = CGF.Builder.GetInsertBlock(); 1189 CGF.Builder.CreateBr(continueBB); 1190 CGF.EmitBlock(continueBB); 1191 if (msgRet.isScalar()) { 1192 llvm::Value *v = msgRet.getScalarVal(); 1193 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1194 phi->addIncoming(v, messageBB); 1195 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB); 1196 msgRet = RValue::get(phi); 1197 } else if (msgRet.isAggregate()) { 1198 llvm::Value *v = msgRet.getAggregateAddr(); 1199 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1200 llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType()); 1201 llvm::AllocaInst *NullVal = 1202 CGF.CreateTempAlloca(RetTy->getElementType(), "null"); 1203 CGF.InitTempAlloca(NullVal, 1204 llvm::Constant::getNullValue(RetTy->getElementType())); 1205 phi->addIncoming(v, messageBB); 1206 phi->addIncoming(NullVal, startBB); 1207 msgRet = RValue::getAggregate(phi); 1208 } else /* isComplex() */ { 1209 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal(); 1210 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2); 1211 phi->addIncoming(v.first, messageBB); 1212 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()), 1213 startBB); 1214 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2); 1215 phi2->addIncoming(v.second, messageBB); 1216 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()), 1217 startBB); 1218 msgRet = RValue::getComplex(phi, phi2); 1219 } 1220 } 1221 return msgRet; 1222 } 1223 1224 /// Generates a MethodList. Used in construction of a objc_class and 1225 /// objc_category structures. 1226 llvm::Constant *CGObjCGNU::GenerateMethodList(const StringRef &ClassName, 1227 const StringRef &CategoryName, 1228 const SmallVectorImpl<Selector> &MethodSels, 1229 const SmallVectorImpl<llvm::Constant *> &MethodTypes, 1230 bool isClassMethodList) { 1231 if (MethodSels.empty()) 1232 return NULLPtr; 1233 // Get the method structure type. 1234 llvm::StructType *ObjCMethodTy = llvm::StructType::get( 1235 PtrToInt8Ty, // Really a selector, but the runtime creates it us. 1236 PtrToInt8Ty, // Method types 1237 IMPTy, //Method pointer 1238 NULL); 1239 std::vector<llvm::Constant*> Methods; 1240 std::vector<llvm::Constant*> Elements; 1241 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) { 1242 Elements.clear(); 1243 llvm::Constant *Method = 1244 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName, 1245 MethodSels[i], 1246 isClassMethodList)); 1247 assert(Method && "Can't generate metadata for method that doesn't exist"); 1248 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString()); 1249 Elements.push_back(C); 1250 Elements.push_back(MethodTypes[i]); 1251 Method = llvm::ConstantExpr::getBitCast(Method, 1252 IMPTy); 1253 Elements.push_back(Method); 1254 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements)); 1255 } 1256 1257 // Array of method structures 1258 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy, 1259 Methods.size()); 1260 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy, 1261 Methods); 1262 1263 // Structure containing list pointer, array and array count 1264 llvm::StructType *ObjCMethodListTy = llvm::StructType::create(VMContext); 1265 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(ObjCMethodListTy); 1266 ObjCMethodListTy->setBody( 1267 NextPtrTy, 1268 IntTy, 1269 ObjCMethodArrayTy, 1270 NULL); 1271 1272 Methods.clear(); 1273 Methods.push_back(llvm::ConstantPointerNull::get( 1274 llvm::PointerType::getUnqual(ObjCMethodListTy))); 1275 Methods.push_back(llvm::ConstantInt::get(Int32Ty, MethodTypes.size())); 1276 Methods.push_back(MethodArray); 1277 1278 // Create an instance of the structure 1279 return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list"); 1280 } 1281 1282 /// Generates an IvarList. Used in construction of a objc_class. 1283 llvm::Constant *CGObjCGNU::GenerateIvarList( 1284 const SmallVectorImpl<llvm::Constant *> &IvarNames, 1285 const SmallVectorImpl<llvm::Constant *> &IvarTypes, 1286 const SmallVectorImpl<llvm::Constant *> &IvarOffsets) { 1287 if (IvarNames.size() == 0) 1288 return NULLPtr; 1289 // Get the method structure type. 1290 llvm::StructType *ObjCIvarTy = llvm::StructType::get( 1291 PtrToInt8Ty, 1292 PtrToInt8Ty, 1293 IntTy, 1294 NULL); 1295 std::vector<llvm::Constant*> Ivars; 1296 std::vector<llvm::Constant*> Elements; 1297 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) { 1298 Elements.clear(); 1299 Elements.push_back(IvarNames[i]); 1300 Elements.push_back(IvarTypes[i]); 1301 Elements.push_back(IvarOffsets[i]); 1302 Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements)); 1303 } 1304 1305 // Array of method structures 1306 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy, 1307 IvarNames.size()); 1308 1309 1310 Elements.clear(); 1311 Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size())); 1312 Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)); 1313 // Structure containing array and array count 1314 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(IntTy, 1315 ObjCIvarArrayTy, 1316 NULL); 1317 1318 // Create an instance of the structure 1319 return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list"); 1320 } 1321 1322 /// Generate a class structure 1323 llvm::Constant *CGObjCGNU::GenerateClassStructure( 1324 llvm::Constant *MetaClass, 1325 llvm::Constant *SuperClass, 1326 unsigned info, 1327 const char *Name, 1328 llvm::Constant *Version, 1329 llvm::Constant *InstanceSize, 1330 llvm::Constant *IVars, 1331 llvm::Constant *Methods, 1332 llvm::Constant *Protocols, 1333 llvm::Constant *IvarOffsets, 1334 llvm::Constant *Properties, 1335 llvm::Constant *StrongIvarBitmap, 1336 llvm::Constant *WeakIvarBitmap, 1337 bool isMeta) { 1338 // Set up the class structure 1339 // Note: Several of these are char*s when they should be ids. This is 1340 // because the runtime performs this translation on load. 1341 // 1342 // Fields marked New ABI are part of the GNUstep runtime. We emit them 1343 // anyway; the classes will still work with the GNU runtime, they will just 1344 // be ignored. 1345 llvm::StructType *ClassTy = llvm::StructType::get( 1346 PtrToInt8Ty, // class_pointer 1347 PtrToInt8Ty, // super_class 1348 PtrToInt8Ty, // name 1349 LongTy, // version 1350 LongTy, // info 1351 LongTy, // instance_size 1352 IVars->getType(), // ivars 1353 Methods->getType(), // methods 1354 // These are all filled in by the runtime, so we pretend 1355 PtrTy, // dtable 1356 PtrTy, // subclass_list 1357 PtrTy, // sibling_class 1358 PtrTy, // protocols 1359 PtrTy, // gc_object_type 1360 // New ABI: 1361 LongTy, // abi_version 1362 IvarOffsets->getType(), // ivar_offsets 1363 Properties->getType(), // properties 1364 Int64Ty, // strong_pointers 1365 Int64Ty, // weak_pointers 1366 NULL); 1367 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0); 1368 // Fill in the structure 1369 std::vector<llvm::Constant*> Elements; 1370 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty)); 1371 Elements.push_back(SuperClass); 1372 Elements.push_back(MakeConstantString(Name, ".class_name")); 1373 Elements.push_back(Zero); 1374 Elements.push_back(llvm::ConstantInt::get(LongTy, info)); 1375 if (isMeta) { 1376 llvm::TargetData td(&TheModule); 1377 Elements.push_back( 1378 llvm::ConstantInt::get(LongTy, 1379 td.getTypeSizeInBits(ClassTy) / 1380 CGM.getContext().getCharWidth())); 1381 } else 1382 Elements.push_back(InstanceSize); 1383 Elements.push_back(IVars); 1384 Elements.push_back(Methods); 1385 Elements.push_back(NULLPtr); 1386 Elements.push_back(NULLPtr); 1387 Elements.push_back(NULLPtr); 1388 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy)); 1389 Elements.push_back(NULLPtr); 1390 Elements.push_back(llvm::ConstantInt::get(LongTy, 1)); 1391 Elements.push_back(IvarOffsets); 1392 Elements.push_back(Properties); 1393 Elements.push_back(StrongIvarBitmap); 1394 Elements.push_back(WeakIvarBitmap); 1395 // Create an instance of the structure 1396 // This is now an externally visible symbol, so that we can speed up class 1397 // messages in the next ABI. 1398 return MakeGlobal(ClassTy, Elements, (isMeta ? "_OBJC_METACLASS_": 1399 "_OBJC_CLASS_") + std::string(Name), llvm::GlobalValue::ExternalLinkage); 1400 } 1401 1402 llvm::Constant *CGObjCGNU::GenerateProtocolMethodList( 1403 const SmallVectorImpl<llvm::Constant *> &MethodNames, 1404 const SmallVectorImpl<llvm::Constant *> &MethodTypes) { 1405 // Get the method structure type. 1406 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get( 1407 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us. 1408 PtrToInt8Ty, 1409 NULL); 1410 std::vector<llvm::Constant*> Methods; 1411 std::vector<llvm::Constant*> Elements; 1412 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) { 1413 Elements.clear(); 1414 Elements.push_back(MethodNames[i]); 1415 Elements.push_back(MethodTypes[i]); 1416 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements)); 1417 } 1418 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy, 1419 MethodNames.size()); 1420 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy, 1421 Methods); 1422 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get( 1423 IntTy, ObjCMethodArrayTy, NULL); 1424 Methods.clear(); 1425 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size())); 1426 Methods.push_back(Array); 1427 return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list"); 1428 } 1429 1430 // Create the protocol list structure used in classes, categories and so on 1431 llvm::Constant *CGObjCGNU::GenerateProtocolList( 1432 const SmallVectorImpl<std::string> &Protocols) { 1433 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 1434 Protocols.size()); 1435 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1436 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1437 SizeTy, 1438 ProtocolArrayTy, 1439 NULL); 1440 std::vector<llvm::Constant*> Elements; 1441 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end(); 1442 iter != endIter ; iter++) { 1443 llvm::Constant *protocol = 0; 1444 llvm::StringMap<llvm::Constant*>::iterator value = 1445 ExistingProtocols.find(*iter); 1446 if (value == ExistingProtocols.end()) { 1447 protocol = GenerateEmptyProtocol(*iter); 1448 } else { 1449 protocol = value->getValue(); 1450 } 1451 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol, 1452 PtrToInt8Ty); 1453 Elements.push_back(Ptr); 1454 } 1455 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1456 Elements); 1457 Elements.clear(); 1458 Elements.push_back(NULLPtr); 1459 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size())); 1460 Elements.push_back(ProtocolArray); 1461 return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list"); 1462 } 1463 1464 llvm::Value *CGObjCGNU::GenerateProtocolRef(CGBuilderTy &Builder, 1465 const ObjCProtocolDecl *PD) { 1466 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()]; 1467 llvm::Type *T = 1468 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType()); 1469 return Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T)); 1470 } 1471 1472 llvm::Constant *CGObjCGNU::GenerateEmptyProtocol( 1473 const std::string &ProtocolName) { 1474 SmallVector<std::string, 0> EmptyStringVector; 1475 SmallVector<llvm::Constant*, 0> EmptyConstantVector; 1476 1477 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector); 1478 llvm::Constant *MethodList = 1479 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector); 1480 // Protocols are objects containing lists of the methods implemented and 1481 // protocols adopted. 1482 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1483 PtrToInt8Ty, 1484 ProtocolList->getType(), 1485 MethodList->getType(), 1486 MethodList->getType(), 1487 MethodList->getType(), 1488 MethodList->getType(), 1489 NULL); 1490 std::vector<llvm::Constant*> Elements; 1491 // The isa pointer must be set to a magic number so the runtime knows it's 1492 // the correct layout. 1493 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1494 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy)); 1495 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1496 Elements.push_back(ProtocolList); 1497 Elements.push_back(MethodList); 1498 Elements.push_back(MethodList); 1499 Elements.push_back(MethodList); 1500 Elements.push_back(MethodList); 1501 return MakeGlobal(ProtocolTy, Elements, ".objc_protocol"); 1502 } 1503 1504 void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) { 1505 ASTContext &Context = CGM.getContext(); 1506 std::string ProtocolName = PD->getNameAsString(); 1507 SmallVector<std::string, 16> Protocols; 1508 for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(), 1509 E = PD->protocol_end(); PI != E; ++PI) 1510 Protocols.push_back((*PI)->getNameAsString()); 1511 SmallVector<llvm::Constant*, 16> InstanceMethodNames; 1512 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1513 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames; 1514 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes; 1515 for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(), 1516 E = PD->instmeth_end(); iter != E; iter++) { 1517 std::string TypeStr; 1518 Context.getObjCEncodingForMethodDecl(*iter, TypeStr); 1519 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1520 InstanceMethodNames.push_back( 1521 MakeConstantString((*iter)->getSelector().getAsString())); 1522 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1523 } else { 1524 OptionalInstanceMethodNames.push_back( 1525 MakeConstantString((*iter)->getSelector().getAsString())); 1526 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1527 } 1528 } 1529 // Collect information about class methods: 1530 SmallVector<llvm::Constant*, 16> ClassMethodNames; 1531 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1532 SmallVector<llvm::Constant*, 16> OptionalClassMethodNames; 1533 SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes; 1534 for (ObjCProtocolDecl::classmeth_iterator 1535 iter = PD->classmeth_begin(), endIter = PD->classmeth_end(); 1536 iter != endIter ; iter++) { 1537 std::string TypeStr; 1538 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1539 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1540 ClassMethodNames.push_back( 1541 MakeConstantString((*iter)->getSelector().getAsString())); 1542 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1543 } else { 1544 OptionalClassMethodNames.push_back( 1545 MakeConstantString((*iter)->getSelector().getAsString())); 1546 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1547 } 1548 } 1549 1550 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols); 1551 llvm::Constant *InstanceMethodList = 1552 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes); 1553 llvm::Constant *ClassMethodList = 1554 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes); 1555 llvm::Constant *OptionalInstanceMethodList = 1556 GenerateProtocolMethodList(OptionalInstanceMethodNames, 1557 OptionalInstanceMethodTypes); 1558 llvm::Constant *OptionalClassMethodList = 1559 GenerateProtocolMethodList(OptionalClassMethodNames, 1560 OptionalClassMethodTypes); 1561 1562 // Property metadata: name, attributes, isSynthesized, setter name, setter 1563 // types, getter name, getter types. 1564 // The isSynthesized value is always set to 0 in a protocol. It exists to 1565 // simplify the runtime library by allowing it to use the same data 1566 // structures for protocol metadata everywhere. 1567 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1568 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1569 PtrToInt8Ty, NULL); 1570 std::vector<llvm::Constant*> Properties; 1571 std::vector<llvm::Constant*> OptionalProperties; 1572 1573 // Add all of the property methods need adding to the method list and to the 1574 // property metadata list. 1575 for (ObjCContainerDecl::prop_iterator 1576 iter = PD->prop_begin(), endIter = PD->prop_end(); 1577 iter != endIter ; iter++) { 1578 std::vector<llvm::Constant*> Fields; 1579 ObjCPropertyDecl *property = (*iter); 1580 1581 Fields.push_back(MakeConstantString(property->getNameAsString())); 1582 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1583 property->getPropertyAttributes())); 1584 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 1585 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1586 std::string TypeStr; 1587 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1588 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1589 InstanceMethodTypes.push_back(TypeEncoding); 1590 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1591 Fields.push_back(TypeEncoding); 1592 } else { 1593 Fields.push_back(NULLPtr); 1594 Fields.push_back(NULLPtr); 1595 } 1596 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1597 std::string TypeStr; 1598 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1599 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1600 InstanceMethodTypes.push_back(TypeEncoding); 1601 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1602 Fields.push_back(TypeEncoding); 1603 } else { 1604 Fields.push_back(NULLPtr); 1605 Fields.push_back(NULLPtr); 1606 } 1607 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) { 1608 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1609 } else { 1610 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1611 } 1612 } 1613 llvm::Constant *PropertyArray = llvm::ConstantArray::get( 1614 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties); 1615 llvm::Constant* PropertyListInitFields[] = 1616 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1617 1618 llvm::Constant *PropertyListInit = 1619 llvm::ConstantStruct::getAnon(PropertyListInitFields); 1620 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule, 1621 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage, 1622 PropertyListInit, ".objc_property_list"); 1623 1624 llvm::Constant *OptionalPropertyArray = 1625 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy, 1626 OptionalProperties.size()) , OptionalProperties); 1627 llvm::Constant* OptionalPropertyListInitFields[] = { 1628 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr, 1629 OptionalPropertyArray }; 1630 1631 llvm::Constant *OptionalPropertyListInit = 1632 llvm::ConstantStruct::getAnon(OptionalPropertyListInitFields); 1633 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule, 1634 OptionalPropertyListInit->getType(), false, 1635 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit, 1636 ".objc_property_list"); 1637 1638 // Protocols are objects containing lists of the methods implemented and 1639 // protocols adopted. 1640 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1641 PtrToInt8Ty, 1642 ProtocolList->getType(), 1643 InstanceMethodList->getType(), 1644 ClassMethodList->getType(), 1645 OptionalInstanceMethodList->getType(), 1646 OptionalClassMethodList->getType(), 1647 PropertyList->getType(), 1648 OptionalPropertyList->getType(), 1649 NULL); 1650 std::vector<llvm::Constant*> Elements; 1651 // The isa pointer must be set to a magic number so the runtime knows it's 1652 // the correct layout. 1653 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1654 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy)); 1655 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1656 Elements.push_back(ProtocolList); 1657 Elements.push_back(InstanceMethodList); 1658 Elements.push_back(ClassMethodList); 1659 Elements.push_back(OptionalInstanceMethodList); 1660 Elements.push_back(OptionalClassMethodList); 1661 Elements.push_back(PropertyList); 1662 Elements.push_back(OptionalPropertyList); 1663 ExistingProtocols[ProtocolName] = 1664 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements, 1665 ".objc_protocol"), IdTy); 1666 } 1667 void CGObjCGNU::GenerateProtocolHolderCategory(void) { 1668 // Collect information about instance methods 1669 SmallVector<Selector, 1> MethodSels; 1670 SmallVector<llvm::Constant*, 1> MethodTypes; 1671 1672 std::vector<llvm::Constant*> Elements; 1673 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack"; 1674 const std::string CategoryName = "AnotherHack"; 1675 Elements.push_back(MakeConstantString(CategoryName)); 1676 Elements.push_back(MakeConstantString(ClassName)); 1677 // Instance method list 1678 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1679 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy)); 1680 // Class method list 1681 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1682 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy)); 1683 // Protocol list 1684 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy, 1685 ExistingProtocols.size()); 1686 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1687 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1688 SizeTy, 1689 ProtocolArrayTy, 1690 NULL); 1691 std::vector<llvm::Constant*> ProtocolElements; 1692 for (llvm::StringMapIterator<llvm::Constant*> iter = 1693 ExistingProtocols.begin(), endIter = ExistingProtocols.end(); 1694 iter != endIter ; iter++) { 1695 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(), 1696 PtrTy); 1697 ProtocolElements.push_back(Ptr); 1698 } 1699 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1700 ProtocolElements); 1701 ProtocolElements.clear(); 1702 ProtocolElements.push_back(NULLPtr); 1703 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy, 1704 ExistingProtocols.size())); 1705 ProtocolElements.push_back(ProtocolArray); 1706 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy, 1707 ProtocolElements, ".objc_protocol_list"), PtrTy)); 1708 Categories.push_back(llvm::ConstantExpr::getBitCast( 1709 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1710 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1711 } 1712 1713 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are 1714 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63 1715 /// bits set to their values, LSB first, while larger ones are stored in a 1716 /// structure of this / form: 1717 /// 1718 /// struct { int32_t length; int32_t values[length]; }; 1719 /// 1720 /// The values in the array are stored in host-endian format, with the least 1721 /// significant bit being assumed to come first in the bitfield. Therefore, a 1722 /// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a 1723 /// bitfield / with the 63rd bit set will be 1<<64. 1724 llvm::Constant *CGObjCGNU::MakeBitField(llvm::SmallVectorImpl<bool> &bits) { 1725 int bitCount = bits.size(); 1726 if (bitCount < 64) { 1727 uint64_t val = 1; 1728 for (int i=0 ; i<bitCount ; ++i) { 1729 if (bits[i]) val |= 1ULL<<(i+1); 1730 } 1731 return llvm::ConstantInt::get(Int64Ty, val); 1732 } 1733 llvm::SmallVector<llvm::Constant*, 8> values; 1734 int v=0; 1735 while (v < bitCount) { 1736 int32_t word = 0; 1737 for (int i=0 ; (i<32) && (v<bitCount) ; ++i) { 1738 if (bits[v]) word |= 1<<i; 1739 v++; 1740 } 1741 values.push_back(llvm::ConstantInt::get(Int32Ty, word)); 1742 } 1743 llvm::ArrayType *arrayTy = llvm::ArrayType::get(Int32Ty, values.size()); 1744 llvm::Constant *array = llvm::ConstantArray::get(arrayTy, values); 1745 llvm::Constant *fields[2] = { 1746 llvm::ConstantInt::get(Int32Ty, values.size()), 1747 array }; 1748 llvm::Constant *GS = MakeGlobal(llvm::StructType::get(Int32Ty, arrayTy, 1749 NULL), fields); 1750 llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy); 1751 if (IntPtrTy != Int64Ty) 1752 ptr = llvm::ConstantExpr::getZExt(ptr, Int64Ty); 1753 return ptr; 1754 } 1755 1756 void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) { 1757 std::string ClassName = OCD->getClassInterface()->getNameAsString(); 1758 std::string CategoryName = OCD->getNameAsString(); 1759 // Collect information about instance methods 1760 SmallVector<Selector, 16> InstanceMethodSels; 1761 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1762 for (ObjCCategoryImplDecl::instmeth_iterator 1763 iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end(); 1764 iter != endIter ; iter++) { 1765 InstanceMethodSels.push_back((*iter)->getSelector()); 1766 std::string TypeStr; 1767 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1768 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1769 } 1770 1771 // Collect information about class methods 1772 SmallVector<Selector, 16> ClassMethodSels; 1773 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1774 for (ObjCCategoryImplDecl::classmeth_iterator 1775 iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end(); 1776 iter != endIter ; iter++) { 1777 ClassMethodSels.push_back((*iter)->getSelector()); 1778 std::string TypeStr; 1779 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1780 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1781 } 1782 1783 // Collect the names of referenced protocols 1784 SmallVector<std::string, 16> Protocols; 1785 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl(); 1786 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols(); 1787 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1788 E = Protos.end(); I != E; ++I) 1789 Protocols.push_back((*I)->getNameAsString()); 1790 1791 std::vector<llvm::Constant*> Elements; 1792 Elements.push_back(MakeConstantString(CategoryName)); 1793 Elements.push_back(MakeConstantString(ClassName)); 1794 // Instance method list 1795 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1796 ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes, 1797 false), PtrTy)); 1798 // Class method list 1799 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1800 ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true), 1801 PtrTy)); 1802 // Protocol list 1803 Elements.push_back(llvm::ConstantExpr::getBitCast( 1804 GenerateProtocolList(Protocols), PtrTy)); 1805 Categories.push_back(llvm::ConstantExpr::getBitCast( 1806 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1807 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1808 } 1809 1810 llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID, 1811 SmallVectorImpl<Selector> &InstanceMethodSels, 1812 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) { 1813 ASTContext &Context = CGM.getContext(); 1814 // 1815 // Property metadata: name, attributes, isSynthesized, setter name, setter 1816 // types, getter name, getter types. 1817 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1818 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1819 PtrToInt8Ty, NULL); 1820 std::vector<llvm::Constant*> Properties; 1821 1822 1823 // Add all of the property methods need adding to the method list and to the 1824 // property metadata list. 1825 for (ObjCImplDecl::propimpl_iterator 1826 iter = OID->propimpl_begin(), endIter = OID->propimpl_end(); 1827 iter != endIter ; iter++) { 1828 std::vector<llvm::Constant*> Fields; 1829 ObjCPropertyDecl *property = (*iter)->getPropertyDecl(); 1830 ObjCPropertyImplDecl *propertyImpl = *iter; 1831 bool isSynthesized = (propertyImpl->getPropertyImplementation() == 1832 ObjCPropertyImplDecl::Synthesize); 1833 1834 Fields.push_back(MakeConstantString(property->getNameAsString())); 1835 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1836 property->getPropertyAttributes())); 1837 Fields.push_back(llvm::ConstantInt::get(Int8Ty, isSynthesized)); 1838 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1839 std::string TypeStr; 1840 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1841 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1842 if (isSynthesized) { 1843 InstanceMethodTypes.push_back(TypeEncoding); 1844 InstanceMethodSels.push_back(getter->getSelector()); 1845 } 1846 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1847 Fields.push_back(TypeEncoding); 1848 } else { 1849 Fields.push_back(NULLPtr); 1850 Fields.push_back(NULLPtr); 1851 } 1852 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1853 std::string TypeStr; 1854 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1855 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1856 if (isSynthesized) { 1857 InstanceMethodTypes.push_back(TypeEncoding); 1858 InstanceMethodSels.push_back(setter->getSelector()); 1859 } 1860 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1861 Fields.push_back(TypeEncoding); 1862 } else { 1863 Fields.push_back(NULLPtr); 1864 Fields.push_back(NULLPtr); 1865 } 1866 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1867 } 1868 llvm::ArrayType *PropertyArrayTy = 1869 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()); 1870 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy, 1871 Properties); 1872 llvm::Constant* PropertyListInitFields[] = 1873 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1874 1875 llvm::Constant *PropertyListInit = 1876 llvm::ConstantStruct::getAnon(PropertyListInitFields); 1877 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false, 1878 llvm::GlobalValue::InternalLinkage, PropertyListInit, 1879 ".objc_property_list"); 1880 } 1881 1882 void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) { 1883 ASTContext &Context = CGM.getContext(); 1884 1885 // Get the superclass name. 1886 const ObjCInterfaceDecl * SuperClassDecl = 1887 OID->getClassInterface()->getSuperClass(); 1888 std::string SuperClassName; 1889 if (SuperClassDecl) { 1890 SuperClassName = SuperClassDecl->getNameAsString(); 1891 EmitClassRef(SuperClassName); 1892 } 1893 1894 // Get the class name 1895 ObjCInterfaceDecl *ClassDecl = 1896 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface()); 1897 std::string ClassName = ClassDecl->getNameAsString(); 1898 // Emit the symbol that is used to generate linker errors if this class is 1899 // referenced in other modules but not declared. 1900 std::string classSymbolName = "__objc_class_name_" + ClassName; 1901 if (llvm::GlobalVariable *symbol = 1902 TheModule.getGlobalVariable(classSymbolName)) { 1903 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0)); 1904 } else { 1905 new llvm::GlobalVariable(TheModule, LongTy, false, 1906 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0), 1907 classSymbolName); 1908 } 1909 1910 // Get the size of instances. 1911 int instanceSize = 1912 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity(); 1913 1914 // Collect information about instance variables. 1915 SmallVector<llvm::Constant*, 16> IvarNames; 1916 SmallVector<llvm::Constant*, 16> IvarTypes; 1917 SmallVector<llvm::Constant*, 16> IvarOffsets; 1918 1919 std::vector<llvm::Constant*> IvarOffsetValues; 1920 SmallVector<bool, 16> WeakIvars; 1921 SmallVector<bool, 16> StrongIvars; 1922 1923 int superInstanceSize = !SuperClassDecl ? 0 : 1924 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity(); 1925 // For non-fragile ivars, set the instance size to 0 - {the size of just this 1926 // class}. The runtime will then set this to the correct value on load. 1927 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1928 instanceSize = 0 - (instanceSize - superInstanceSize); 1929 } 1930 1931 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 1932 IVD = IVD->getNextIvar()) { 1933 // Store the name 1934 IvarNames.push_back(MakeConstantString(IVD->getNameAsString())); 1935 // Get the type encoding for this ivar 1936 std::string TypeStr; 1937 Context.getObjCEncodingForType(IVD->getType(), TypeStr); 1938 IvarTypes.push_back(MakeConstantString(TypeStr)); 1939 // Get the offset 1940 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD); 1941 uint64_t Offset = BaseOffset; 1942 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1943 Offset = BaseOffset - superInstanceSize; 1944 } 1945 llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset); 1946 // Create the direct offset value 1947 std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." + 1948 IVD->getNameAsString(); 1949 llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName); 1950 if (OffsetVar) { 1951 OffsetVar->setInitializer(OffsetValue); 1952 // If this is the real definition, change its linkage type so that 1953 // different modules will use this one, rather than their private 1954 // copy. 1955 OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage); 1956 } else 1957 OffsetVar = new llvm::GlobalVariable(TheModule, IntTy, 1958 false, llvm::GlobalValue::ExternalLinkage, 1959 OffsetValue, 1960 "__objc_ivar_offset_value_" + ClassName +"." + 1961 IVD->getNameAsString()); 1962 IvarOffsets.push_back(OffsetValue); 1963 IvarOffsetValues.push_back(OffsetVar); 1964 Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime(); 1965 switch (lt) { 1966 case Qualifiers::OCL_Strong: 1967 StrongIvars.push_back(true); 1968 WeakIvars.push_back(false); 1969 break; 1970 case Qualifiers::OCL_Weak: 1971 StrongIvars.push_back(false); 1972 WeakIvars.push_back(true); 1973 break; 1974 default: 1975 StrongIvars.push_back(false); 1976 WeakIvars.push_back(false); 1977 } 1978 } 1979 llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars); 1980 llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars); 1981 llvm::GlobalVariable *IvarOffsetArray = 1982 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets"); 1983 1984 1985 // Collect information about instance methods 1986 SmallVector<Selector, 16> InstanceMethodSels; 1987 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1988 for (ObjCImplementationDecl::instmeth_iterator 1989 iter = OID->instmeth_begin(), endIter = OID->instmeth_end(); 1990 iter != endIter ; iter++) { 1991 InstanceMethodSels.push_back((*iter)->getSelector()); 1992 std::string TypeStr; 1993 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1994 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1995 } 1996 1997 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels, 1998 InstanceMethodTypes); 1999 2000 2001 // Collect information about class methods 2002 SmallVector<Selector, 16> ClassMethodSels; 2003 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 2004 for (ObjCImplementationDecl::classmeth_iterator 2005 iter = OID->classmeth_begin(), endIter = OID->classmeth_end(); 2006 iter != endIter ; iter++) { 2007 ClassMethodSels.push_back((*iter)->getSelector()); 2008 std::string TypeStr; 2009 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 2010 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 2011 } 2012 // Collect the names of referenced protocols 2013 SmallVector<std::string, 16> Protocols; 2014 const ObjCList<ObjCProtocolDecl> &Protos =ClassDecl->getReferencedProtocols(); 2015 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 2016 E = Protos.end(); I != E; ++I) 2017 Protocols.push_back((*I)->getNameAsString()); 2018 2019 2020 2021 // Get the superclass pointer. 2022 llvm::Constant *SuperClass; 2023 if (!SuperClassName.empty()) { 2024 SuperClass = MakeConstantString(SuperClassName, ".super_class_name"); 2025 } else { 2026 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty); 2027 } 2028 // Empty vector used to construct empty method lists 2029 SmallVector<llvm::Constant*, 1> empty; 2030 // Generate the method and instance variable lists 2031 llvm::Constant *MethodList = GenerateMethodList(ClassName, "", 2032 InstanceMethodSels, InstanceMethodTypes, false); 2033 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "", 2034 ClassMethodSels, ClassMethodTypes, true); 2035 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes, 2036 IvarOffsets); 2037 // Irrespective of whether we are compiling for a fragile or non-fragile ABI, 2038 // we emit a symbol containing the offset for each ivar in the class. This 2039 // allows code compiled for the non-Fragile ABI to inherit from code compiled 2040 // for the legacy ABI, without causing problems. The converse is also 2041 // possible, but causes all ivar accesses to be fragile. 2042 2043 // Offset pointer for getting at the correct field in the ivar list when 2044 // setting up the alias. These are: The base address for the global, the 2045 // ivar array (second field), the ivar in this list (set for each ivar), and 2046 // the offset (third field in ivar structure) 2047 llvm::Type *IndexTy = Int32Ty; 2048 llvm::Constant *offsetPointerIndexes[] = {Zeros[0], 2049 llvm::ConstantInt::get(IndexTy, 1), 0, 2050 llvm::ConstantInt::get(IndexTy, 2) }; 2051 2052 unsigned ivarIndex = 0; 2053 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 2054 IVD = IVD->getNextIvar()) { 2055 const std::string Name = "__objc_ivar_offset_" + ClassName + '.' 2056 + IVD->getNameAsString(); 2057 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex); 2058 // Get the correct ivar field 2059 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr( 2060 IvarList, offsetPointerIndexes); 2061 // Get the existing variable, if one exists. 2062 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name); 2063 if (offset) { 2064 offset->setInitializer(offsetValue); 2065 // If this is the real definition, change its linkage type so that 2066 // different modules will use this one, rather than their private 2067 // copy. 2068 offset->setLinkage(llvm::GlobalValue::ExternalLinkage); 2069 } else { 2070 // Add a new alias if there isn't one already. 2071 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(), 2072 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name); 2073 } 2074 ++ivarIndex; 2075 } 2076 llvm::Constant *Zero64 = llvm::ConstantInt::get(Int64Ty, 0); 2077 //Generate metaclass for class methods 2078 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr, 2079 NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList( 2080 empty, empty, empty), ClassMethodList, NULLPtr, 2081 NULLPtr, NULLPtr, Zero64, Zero64, true); 2082 2083 // Generate the class structure 2084 llvm::Constant *ClassStruct = 2085 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L, 2086 ClassName.c_str(), 0, 2087 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, 2088 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray, 2089 Properties, StrongIvarBitmap, WeakIvarBitmap); 2090 2091 // Resolve the class aliases, if they exist. 2092 if (ClassPtrAlias) { 2093 ClassPtrAlias->replaceAllUsesWith( 2094 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy)); 2095 ClassPtrAlias->eraseFromParent(); 2096 ClassPtrAlias = 0; 2097 } 2098 if (MetaClassPtrAlias) { 2099 MetaClassPtrAlias->replaceAllUsesWith( 2100 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy)); 2101 MetaClassPtrAlias->eraseFromParent(); 2102 MetaClassPtrAlias = 0; 2103 } 2104 2105 // Add class structure to list to be added to the symtab later 2106 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty); 2107 Classes.push_back(ClassStruct); 2108 } 2109 2110 2111 llvm::Function *CGObjCGNU::ModuleInitFunction() { 2112 // Only emit an ObjC load function if no Objective-C stuff has been called 2113 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() && 2114 ExistingProtocols.empty() && SelectorTable.empty()) 2115 return NULL; 2116 2117 // Add all referenced protocols to a category. 2118 GenerateProtocolHolderCategory(); 2119 2120 llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>( 2121 SelectorTy->getElementType()); 2122 llvm::Type *SelStructPtrTy = SelectorTy; 2123 if (SelStructTy == 0) { 2124 SelStructTy = llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, NULL); 2125 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy); 2126 } 2127 2128 std::vector<llvm::Constant*> Elements; 2129 llvm::Constant *Statics = NULLPtr; 2130 // Generate statics list: 2131 if (ConstantStrings.size()) { 2132 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 2133 ConstantStrings.size() + 1); 2134 ConstantStrings.push_back(NULLPtr); 2135 2136 StringRef StringClass = CGM.getLangOptions().ObjCConstantStringClass; 2137 2138 if (StringClass.empty()) StringClass = "NXConstantString"; 2139 2140 Elements.push_back(MakeConstantString(StringClass, 2141 ".objc_static_class_name")); 2142 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy, 2143 ConstantStrings)); 2144 llvm::StructType *StaticsListTy = 2145 llvm::StructType::get(PtrToInt8Ty, StaticsArrayTy, NULL); 2146 llvm::Type *StaticsListPtrTy = 2147 llvm::PointerType::getUnqual(StaticsListTy); 2148 Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics"); 2149 llvm::ArrayType *StaticsListArrayTy = 2150 llvm::ArrayType::get(StaticsListPtrTy, 2); 2151 Elements.clear(); 2152 Elements.push_back(Statics); 2153 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy)); 2154 Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr"); 2155 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy); 2156 } 2157 // Array of classes, categories, and constant objects 2158 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty, 2159 Classes.size() + Categories.size() + 2); 2160 llvm::StructType *SymTabTy = llvm::StructType::get(LongTy, SelStructPtrTy, 2161 llvm::Type::getInt16Ty(VMContext), 2162 llvm::Type::getInt16Ty(VMContext), 2163 ClassListTy, NULL); 2164 2165 Elements.clear(); 2166 // Pointer to an array of selectors used in this module. 2167 std::vector<llvm::Constant*> Selectors; 2168 std::vector<llvm::GlobalAlias*> SelectorAliases; 2169 for (SelectorMap::iterator iter = SelectorTable.begin(), 2170 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) { 2171 2172 std::string SelNameStr = iter->first.getAsString(); 2173 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name"); 2174 2175 SmallVectorImpl<TypedSelector> &Types = iter->second; 2176 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 2177 e = Types.end() ; i!=e ; i++) { 2178 2179 llvm::Constant *SelectorTypeEncoding = NULLPtr; 2180 if (!i->first.empty()) 2181 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types"); 2182 2183 Elements.push_back(SelName); 2184 Elements.push_back(SelectorTypeEncoding); 2185 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2186 Elements.clear(); 2187 2188 // Store the selector alias for later replacement 2189 SelectorAliases.push_back(i->second); 2190 } 2191 } 2192 unsigned SelectorCount = Selectors.size(); 2193 // NULL-terminate the selector list. This should not actually be required, 2194 // because the selector list has a length field. Unfortunately, the GCC 2195 // runtime decides to ignore the length field and expects a NULL terminator, 2196 // and GCC cooperates with this by always setting the length to 0. 2197 Elements.push_back(NULLPtr); 2198 Elements.push_back(NULLPtr); 2199 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2200 Elements.clear(); 2201 2202 // Number of static selectors 2203 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount)); 2204 llvm::Constant *SelectorList = MakeGlobalArray(SelStructTy, Selectors, 2205 ".objc_selector_list"); 2206 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList, 2207 SelStructPtrTy)); 2208 2209 // Now that all of the static selectors exist, create pointers to them. 2210 for (unsigned int i=0 ; i<SelectorCount ; i++) { 2211 2212 llvm::Constant *Idxs[] = {Zeros[0], 2213 llvm::ConstantInt::get(Int32Ty, i), Zeros[0]}; 2214 // FIXME: We're generating redundant loads and stores here! 2215 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(SelectorList, 2216 makeArrayRef(Idxs, 2)); 2217 // If selectors are defined as an opaque type, cast the pointer to this 2218 // type. 2219 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy); 2220 SelectorAliases[i]->replaceAllUsesWith(SelPtr); 2221 SelectorAliases[i]->eraseFromParent(); 2222 } 2223 2224 // Number of classes defined. 2225 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2226 Classes.size())); 2227 // Number of categories defined 2228 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2229 Categories.size())); 2230 // Create an array of classes, then categories, then static object instances 2231 Classes.insert(Classes.end(), Categories.begin(), Categories.end()); 2232 // NULL-terminated list of static object instances (mainly constant strings) 2233 Classes.push_back(Statics); 2234 Classes.push_back(NULLPtr); 2235 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes); 2236 Elements.push_back(ClassList); 2237 // Construct the symbol table 2238 llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements); 2239 2240 // The symbol table is contained in a module which has some version-checking 2241 // constants 2242 llvm::StructType * ModuleTy = llvm::StructType::get(LongTy, LongTy, 2243 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), 2244 (RuntimeVersion >= 10) ? IntTy : NULL, NULL); 2245 Elements.clear(); 2246 // Runtime version, used for ABI compatibility checking. 2247 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion)); 2248 // sizeof(ModuleTy) 2249 llvm::TargetData td(&TheModule); 2250 Elements.push_back( 2251 llvm::ConstantInt::get(LongTy, 2252 td.getTypeSizeInBits(ModuleTy) / 2253 CGM.getContext().getCharWidth())); 2254 2255 // The path to the source file where this module was declared 2256 SourceManager &SM = CGM.getContext().getSourceManager(); 2257 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID()); 2258 std::string path = 2259 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName(); 2260 Elements.push_back(MakeConstantString(path, ".objc_source_file_name")); 2261 Elements.push_back(SymTab); 2262 2263 if (RuntimeVersion >= 10) 2264 switch (CGM.getLangOptions().getGC()) { 2265 case LangOptions::GCOnly: 2266 Elements.push_back(llvm::ConstantInt::get(IntTy, 2)); 2267 break; 2268 case LangOptions::NonGC: 2269 if (CGM.getLangOptions().ObjCAutoRefCount) 2270 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2271 else 2272 Elements.push_back(llvm::ConstantInt::get(IntTy, 0)); 2273 break; 2274 case LangOptions::HybridGC: 2275 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2276 break; 2277 } 2278 2279 llvm::Value *Module = MakeGlobal(ModuleTy, Elements); 2280 2281 // Create the load function calling the runtime entry point with the module 2282 // structure 2283 llvm::Function * LoadFunction = llvm::Function::Create( 2284 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false), 2285 llvm::GlobalValue::InternalLinkage, ".objc_load_function", 2286 &TheModule); 2287 llvm::BasicBlock *EntryBB = 2288 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction); 2289 CGBuilderTy Builder(VMContext); 2290 Builder.SetInsertPoint(EntryBB); 2291 2292 llvm::FunctionType *FT = 2293 llvm::FunctionType::get(Builder.getVoidTy(), 2294 llvm::PointerType::getUnqual(ModuleTy), true); 2295 llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class"); 2296 Builder.CreateCall(Register, Module); 2297 Builder.CreateRetVoid(); 2298 2299 return LoadFunction; 2300 } 2301 2302 llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD, 2303 const ObjCContainerDecl *CD) { 2304 const ObjCCategoryImplDecl *OCD = 2305 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext()); 2306 StringRef CategoryName = OCD ? OCD->getName() : ""; 2307 StringRef ClassName = CD->getName(); 2308 Selector MethodName = OMD->getSelector(); 2309 bool isClassMethod = !OMD->isInstanceMethod(); 2310 2311 CodeGenTypes &Types = CGM.getTypes(); 2312 llvm::FunctionType *MethodTy = 2313 Types.GetFunctionType(Types.getFunctionInfo(OMD), OMD->isVariadic()); 2314 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName, 2315 MethodName, isClassMethod); 2316 2317 llvm::Function *Method 2318 = llvm::Function::Create(MethodTy, 2319 llvm::GlobalValue::InternalLinkage, 2320 FunctionName, 2321 &TheModule); 2322 return Method; 2323 } 2324 2325 llvm::Constant *CGObjCGNU::GetPropertyGetFunction() { 2326 return GetPropertyFn; 2327 } 2328 2329 llvm::Constant *CGObjCGNU::GetPropertySetFunction() { 2330 return SetPropertyFn; 2331 } 2332 2333 llvm::Constant *CGObjCGNU::GetGetStructFunction() { 2334 return GetStructPropertyFn; 2335 } 2336 llvm::Constant *CGObjCGNU::GetSetStructFunction() { 2337 return SetStructPropertyFn; 2338 } 2339 2340 llvm::Constant *CGObjCGNU::EnumerationMutationFunction() { 2341 return EnumerationMutationFn; 2342 } 2343 2344 void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF, 2345 const ObjCAtSynchronizedStmt &S) { 2346 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn); 2347 } 2348 2349 2350 void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF, 2351 const ObjCAtTryStmt &S) { 2352 // Unlike the Apple non-fragile runtimes, which also uses 2353 // unwind-based zero cost exceptions, the GNU Objective C runtime's 2354 // EH support isn't a veneer over C++ EH. Instead, exception 2355 // objects are created by __objc_exception_throw and destroyed by 2356 // the personality function; this avoids the need for bracketing 2357 // catch handlers with calls to __blah_begin_catch/__blah_end_catch 2358 // (or even _Unwind_DeleteException), but probably doesn't 2359 // interoperate very well with foreign exceptions. 2360 // 2361 // In Objective-C++ mode, we actually emit something equivalent to the C++ 2362 // exception handler. 2363 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn); 2364 return ; 2365 } 2366 2367 void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF, 2368 const ObjCAtThrowStmt &S) { 2369 llvm::Value *ExceptionAsObject; 2370 2371 if (const Expr *ThrowExpr = S.getThrowExpr()) { 2372 llvm::Value *Exception = CGF.EmitObjCThrowOperand(ThrowExpr); 2373 ExceptionAsObject = Exception; 2374 } else { 2375 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) && 2376 "Unexpected rethrow outside @catch block."); 2377 ExceptionAsObject = CGF.ObjCEHValueStack.back(); 2378 } 2379 ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy); 2380 2381 // Note: This may have to be an invoke, if we want to support constructs like: 2382 // @try { 2383 // @throw(obj); 2384 // } 2385 // @catch(id) ... 2386 // 2387 // This is effectively turning @throw into an incredibly-expensive goto, but 2388 // it may happen as a result of inlining followed by missed optimizations, or 2389 // as a result of stupidity. 2390 llvm::BasicBlock *UnwindBB = CGF.getInvokeDest(); 2391 if (!UnwindBB) { 2392 CGF.Builder.CreateCall(ExceptionThrowFn, ExceptionAsObject); 2393 CGF.Builder.CreateUnreachable(); 2394 } else { 2395 CGF.Builder.CreateInvoke(ExceptionThrowFn, UnwindBB, UnwindBB, 2396 ExceptionAsObject); 2397 } 2398 // Clear the insertion point to indicate we are in unreachable code. 2399 CGF.Builder.ClearInsertionPoint(); 2400 } 2401 2402 llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF, 2403 llvm::Value *AddrWeakObj) { 2404 CGBuilderTy B = CGF.Builder; 2405 AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy); 2406 return B.CreateCall(WeakReadFn, AddrWeakObj); 2407 } 2408 2409 void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF, 2410 llvm::Value *src, llvm::Value *dst) { 2411 CGBuilderTy B = CGF.Builder; 2412 src = EnforceType(B, src, IdTy); 2413 dst = EnforceType(B, dst, PtrToIdTy); 2414 B.CreateCall2(WeakAssignFn, src, dst); 2415 } 2416 2417 void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF, 2418 llvm::Value *src, llvm::Value *dst, 2419 bool threadlocal) { 2420 CGBuilderTy B = CGF.Builder; 2421 src = EnforceType(B, src, IdTy); 2422 dst = EnforceType(B, dst, PtrToIdTy); 2423 if (!threadlocal) 2424 B.CreateCall2(GlobalAssignFn, src, dst); 2425 else 2426 // FIXME. Add threadloca assign API 2427 llvm_unreachable("EmitObjCGlobalAssign - Threal Local API NYI"); 2428 } 2429 2430 void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF, 2431 llvm::Value *src, llvm::Value *dst, 2432 llvm::Value *ivarOffset) { 2433 CGBuilderTy B = CGF.Builder; 2434 src = EnforceType(B, src, IdTy); 2435 dst = EnforceType(B, dst, IdTy); 2436 B.CreateCall3(IvarAssignFn, src, dst, ivarOffset); 2437 } 2438 2439 void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF, 2440 llvm::Value *src, llvm::Value *dst) { 2441 CGBuilderTy B = CGF.Builder; 2442 src = EnforceType(B, src, IdTy); 2443 dst = EnforceType(B, dst, PtrToIdTy); 2444 B.CreateCall2(StrongCastAssignFn, src, dst); 2445 } 2446 2447 void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF, 2448 llvm::Value *DestPtr, 2449 llvm::Value *SrcPtr, 2450 llvm::Value *Size) { 2451 CGBuilderTy B = CGF.Builder; 2452 DestPtr = EnforceType(B, DestPtr, PtrTy); 2453 SrcPtr = EnforceType(B, SrcPtr, PtrTy); 2454 2455 B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size); 2456 } 2457 2458 llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable( 2459 const ObjCInterfaceDecl *ID, 2460 const ObjCIvarDecl *Ivar) { 2461 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString() 2462 + '.' + Ivar->getNameAsString(); 2463 // Emit the variable and initialize it with what we think the correct value 2464 // is. This allows code compiled with non-fragile ivars to work correctly 2465 // when linked against code which isn't (most of the time). 2466 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name); 2467 if (!IvarOffsetPointer) { 2468 // This will cause a run-time crash if we accidentally use it. A value of 2469 // 0 would seem more sensible, but will silently overwrite the isa pointer 2470 // causing a great deal of confusion. 2471 uint64_t Offset = -1; 2472 // We can't call ComputeIvarBaseOffset() here if we have the 2473 // implementation, because it will create an invalid ASTRecordLayout object 2474 // that we are then stuck with forever, so we only initialize the ivar 2475 // offset variable with a guess if we only have the interface. The 2476 // initializer will be reset later anyway, when we are generating the class 2477 // description. 2478 if (!CGM.getContext().getObjCImplementation( 2479 const_cast<ObjCInterfaceDecl *>(ID))) 2480 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar); 2481 2482 llvm::ConstantInt *OffsetGuess = llvm::ConstantInt::get(Int32Ty, Offset, 2483 /*isSigned*/true); 2484 // Don't emit the guess in non-PIC code because the linker will not be able 2485 // to replace it with the real version for a library. In non-PIC code you 2486 // must compile with the fragile ABI if you want to use ivars from a 2487 // GCC-compiled class. 2488 if (CGM.getLangOptions().PICLevel) { 2489 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule, 2490 Int32Ty, false, 2491 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess"); 2492 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2493 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage, 2494 IvarOffsetGV, Name); 2495 } else { 2496 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2497 llvm::Type::getInt32PtrTy(VMContext), false, 2498 llvm::GlobalValue::ExternalLinkage, 0, Name); 2499 } 2500 } 2501 return IvarOffsetPointer; 2502 } 2503 2504 LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF, 2505 QualType ObjectTy, 2506 llvm::Value *BaseValue, 2507 const ObjCIvarDecl *Ivar, 2508 unsigned CVRQualifiers) { 2509 const ObjCInterfaceDecl *ID = 2510 ObjectTy->getAs<ObjCObjectType>()->getInterface(); 2511 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers, 2512 EmitIvarOffset(CGF, ID, Ivar)); 2513 } 2514 2515 static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context, 2516 const ObjCInterfaceDecl *OID, 2517 const ObjCIvarDecl *OIVD) { 2518 for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next; 2519 next = next->getNextIvar()) { 2520 if (OIVD == next) 2521 return OID; 2522 } 2523 2524 // Otherwise check in the super class. 2525 if (const ObjCInterfaceDecl *Super = OID->getSuperClass()) 2526 return FindIvarInterface(Context, Super, OIVD); 2527 2528 return 0; 2529 } 2530 2531 llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF, 2532 const ObjCInterfaceDecl *Interface, 2533 const ObjCIvarDecl *Ivar) { 2534 if (CGM.getLangOptions().ObjCNonFragileABI) { 2535 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar); 2536 if (RuntimeVersion < 10) 2537 return CGF.Builder.CreateZExtOrBitCast( 2538 CGF.Builder.CreateLoad(CGF.Builder.CreateLoad( 2539 ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")), 2540 PtrDiffTy); 2541 std::string name = "__objc_ivar_offset_value_" + 2542 Interface->getNameAsString() +"." + Ivar->getNameAsString(); 2543 llvm::Value *Offset = TheModule.getGlobalVariable(name); 2544 if (!Offset) 2545 Offset = new llvm::GlobalVariable(TheModule, IntTy, 2546 false, llvm::GlobalValue::LinkOnceAnyLinkage, 2547 llvm::Constant::getNullValue(IntTy), name); 2548 return CGF.Builder.CreateLoad(Offset); 2549 } 2550 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar); 2551 return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true); 2552 } 2553 2554 CGObjCRuntime * 2555 clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) { 2556 if (CGM.getLangOptions().ObjCNonFragileABI) 2557 return new CGObjCGNUstep(CGM); 2558 return new CGObjCGCC(CGM); 2559 } 2560