CGObjCGNU.cpp revision 04c9a49ee251424b11d7c4e8b1c23637684cecb6
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 <stdarg.h> 40 41 42using namespace clang; 43using namespace CodeGen; 44using llvm::dyn_cast; 45 46 47namespace { 48/// Class that lazily initialises the runtime function. Avoids inserting the 49/// types and the function declaration into a module if they're not used, and 50/// avoids constructing the type more than once if it's used more than once. 51class LazyRuntimeFunction { 52 CodeGenModule *CGM; 53 std::vector<const llvm::Type*> ArgTys; 54 const char *FunctionName; 55 llvm::Function *Function; 56 public: 57 /// Constructor leaves this class uninitialized, because it is intended to 58 /// be used as a field in another class and not all of the types that are 59 /// used as arguments will necessarily be available at construction time. 60 LazyRuntimeFunction() : CGM(0), FunctionName(0), Function(0) {} 61 62 /// Initialises the lazy function with the name, return type, and the types 63 /// of the arguments. 64 END_WITH_NULL 65 void init(CodeGenModule *Mod, const char *name, 66 const llvm::Type *RetTy, ...) { 67 CGM =Mod; 68 FunctionName = name; 69 Function = 0; 70 ArgTys.clear(); 71 va_list Args; 72 va_start(Args, RetTy); 73 while (const llvm::Type *ArgTy = va_arg(Args, const llvm::Type*)) 74 ArgTys.push_back(ArgTy); 75 va_end(Args); 76 // Push the return type on at the end so we can pop it off easily 77 ArgTys.push_back(RetTy); 78 } 79 /// Overloaded cast operator, allows the class to be implicitly cast to an 80 /// LLVM constant. 81 operator llvm::Function*() { 82 if (!Function) { 83 if (0 == FunctionName) return 0; 84 // We put the return type on the end of the vector, so pop it back off 85 const llvm::Type *RetTy = ArgTys.back(); 86 ArgTys.pop_back(); 87 llvm::FunctionType *FTy = llvm::FunctionType::get(RetTy, ArgTys, false); 88 Function = 89 cast<llvm::Function>(CGM->CreateRuntimeFunction(FTy, FunctionName)); 90 // We won't need to use the types again, so we may as well clean up the 91 // vector now 92 ArgTys.resize(0); 93 } 94 return Function; 95 } 96}; 97 98 99/// GNU Objective-C runtime code generation. This class implements the parts of 100/// Objective-C support that are specific to the GNU family of runtimes (GCC and 101/// GNUstep). 102class CGObjCGNU : public CGObjCRuntime { 103protected: 104 /// The module that is using this class 105 CodeGenModule &CGM; 106 /// The LLVM module into which output is inserted 107 llvm::Module &TheModule; 108 /// strut objc_super. Used for sending messages to super. This structure 109 /// contains the receiver (object) and the expected class. 110 const llvm::StructType *ObjCSuperTy; 111 /// struct objc_super*. The type of the argument to the superclass message 112 /// lookup functions. 113 const llvm::PointerType *PtrToObjCSuperTy; 114 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring 115 /// SEL is included in a header somewhere, in which case it will be whatever 116 /// type is declared in that header, most likely {i8*, i8*}. 117 const llvm::PointerType *SelectorTy; 118 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the 119 /// places where it's used 120 const llvm::IntegerType *Int8Ty; 121 /// Pointer to i8 - LLVM type of char*, for all of the places where the 122 /// runtime needs to deal with C strings. 123 const llvm::PointerType *PtrToInt8Ty; 124 /// Instance Method Pointer type. This is a pointer to a function that takes, 125 /// at a minimum, an object and a selector, and is the generic type for 126 /// Objective-C methods. Due to differences between variadic / non-variadic 127 /// calling conventions, it must always be cast to the correct type before 128 /// actually being used. 129 const llvm::PointerType *IMPTy; 130 /// Type of an untyped Objective-C object. Clang treats id as a built-in type 131 /// when compiling Objective-C code, so this may be an opaque pointer (i8*), 132 /// but if the runtime header declaring it is included then it may be a 133 /// pointer to a structure. 134 const llvm::PointerType *IdTy; 135 /// Pointer to a pointer to an Objective-C object. Used in the new ABI 136 /// message lookup function and some GC-related functions. 137 const llvm::PointerType *PtrToIdTy; 138 /// The clang type of id. Used when using the clang CGCall infrastructure to 139 /// call Objective-C methods. 140 CanQualType ASTIdTy; 141 /// LLVM type for C int type. 142 const llvm::IntegerType *IntTy; 143 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is 144 /// used in the code to document the difference between i8* meaning a pointer 145 /// to a C string and i8* meaning a pointer to some opaque type. 146 const llvm::PointerType *PtrTy; 147 /// LLVM type for C long type. The runtime uses this in a lot of places where 148 /// it should be using intptr_t, but we can't fix this without breaking 149 /// compatibility with GCC... 150 const llvm::IntegerType *LongTy; 151 /// LLVM type for C size_t. Used in various runtime data structures. 152 const llvm::IntegerType *SizeTy; 153 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions. 154 const llvm::IntegerType *PtrDiffTy; 155 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance 156 /// variables. 157 const llvm::PointerType *PtrToIntTy; 158 /// LLVM type for Objective-C BOOL type. 159 const llvm::Type *BoolTy; 160 /// Metadata kind used to tie method lookups to message sends. The GNUstep 161 /// runtime provides some LLVM passes that can use this to do things like 162 /// automatic IMP caching and speculative inlining. 163 unsigned msgSendMDKind; 164 /// Helper function that generates a constant string and returns a pointer to 165 /// the start of the string. The result of this function can be used anywhere 166 /// where the C code specifies const char*. 167 llvm::Constant *MakeConstantString(const std::string &Str, 168 const std::string &Name="") { 169 llvm::Constant *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str()); 170 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros, 2); 171 } 172 /// Emits a linkonce_odr string, whose name is the prefix followed by the 173 /// string value. This allows the linker to combine the strings between 174 /// different modules. Used for EH typeinfo names, selector strings, and a 175 /// few other things. 176 llvm::Constant *ExportUniqueString(const std::string &Str, 177 const std::string prefix) { 178 std::string name = prefix + Str; 179 llvm::Constant *ConstStr = TheModule.getGlobalVariable(name); 180 if (!ConstStr) { 181 llvm::Constant *value = llvm::ConstantArray::get(VMContext, Str, true); 182 ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true, 183 llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str); 184 } 185 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros, 2); 186 } 187 /// Generates a global structure, initialized by the elements in the vector. 188 /// The element types must match the types of the structure elements in the 189 /// first argument. 190 llvm::GlobalVariable *MakeGlobal(const llvm::StructType *Ty, 191 std::vector<llvm::Constant*> &V, 192 llvm::StringRef Name="", 193 llvm::GlobalValue::LinkageTypes linkage 194 =llvm::GlobalValue::InternalLinkage) { 195 llvm::Constant *C = llvm::ConstantStruct::get(Ty, V); 196 return new llvm::GlobalVariable(TheModule, Ty, false, 197 linkage, C, Name); 198 } 199 /// Generates a global array. The vector must contain the same number of 200 /// elements that the array type declares, of the type specified as the array 201 /// element type. 202 llvm::GlobalVariable *MakeGlobal(const llvm::ArrayType *Ty, 203 std::vector<llvm::Constant*> &V, 204 llvm::StringRef Name="", 205 llvm::GlobalValue::LinkageTypes linkage 206 =llvm::GlobalValue::InternalLinkage) { 207 llvm::Constant *C = llvm::ConstantArray::get(Ty, V); 208 return new llvm::GlobalVariable(TheModule, Ty, false, 209 linkage, C, Name); 210 } 211 /// Generates a global array, inferring the array type from the specified 212 /// element type and the size of the initialiser. 213 llvm::GlobalVariable *MakeGlobalArray(const llvm::Type *Ty, 214 std::vector<llvm::Constant*> &V, 215 llvm::StringRef Name="", 216 llvm::GlobalValue::LinkageTypes linkage 217 =llvm::GlobalValue::InternalLinkage) { 218 llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size()); 219 return MakeGlobal(ArrayTy, V, Name, linkage); 220 } 221 /// Ensures that the value has the required type, by inserting a bitcast if 222 /// required. This function lets us avoid inserting bitcasts that are 223 /// redundant. 224 llvm::Value* EnforceType(CGBuilderTy B, llvm::Value *V, const llvm::Type *Ty){ 225 if (V->getType() == Ty) return V; 226 return B.CreateBitCast(V, Ty); 227 } 228 // Some zeros used for GEPs in lots of places. 229 llvm::Constant *Zeros[2]; 230 /// Null pointer value. Mainly used as a terminator in various arrays. 231 llvm::Constant *NULLPtr; 232 /// LLVM context. 233 llvm::LLVMContext &VMContext; 234private: 235 /// Placeholder for the class. Lots of things refer to the class before we've 236 /// actually emitted it. We use this alias as a placeholder, and then replace 237 /// it with a pointer to the class structure before finally emitting the 238 /// module. 239 llvm::GlobalAlias *ClassPtrAlias; 240 /// Placeholder for the metaclass. Lots of things refer to the class before 241 /// we've / actually emitted it. We use this alias as a placeholder, and then 242 /// replace / it with a pointer to the metaclass structure before finally 243 /// emitting the / module. 244 llvm::GlobalAlias *MetaClassPtrAlias; 245 /// All of the classes that have been generated for this compilation units. 246 std::vector<llvm::Constant*> Classes; 247 /// All of the categories that have been generated for this compilation units. 248 std::vector<llvm::Constant*> Categories; 249 /// All of the Objective-C constant strings that have been generated for this 250 /// compilation units. 251 std::vector<llvm::Constant*> ConstantStrings; 252 /// Map from string values to Objective-C constant strings in the output. 253 /// Used to prevent emitting Objective-C strings more than once. This should 254 /// not be required at all - CodeGenModule should manage this list. 255 llvm::StringMap<llvm::Constant*> ObjCStrings; 256 /// All of the protocols that have been declared. 257 llvm::StringMap<llvm::Constant*> ExistingProtocols; 258 /// For each variant of a selector, we store the type encoding and a 259 /// placeholder value. For an untyped selector, the type will be the empty 260 /// string. Selector references are all done via the module's selector table, 261 /// so we create an alias as a placeholder and then replace it with the real 262 /// value later. 263 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector; 264 /// Type of the selector map. This is roughly equivalent to the structure 265 /// used in the GNUstep runtime, which maintains a list of all of the valid 266 /// types for a selector in a table. 267 typedef llvm::DenseMap<Selector, llvm::SmallVector<TypedSelector, 2> > 268 SelectorMap; 269 /// A map from selectors to selector types. This allows us to emit all 270 /// selectors of the same name and type together. 271 SelectorMap SelectorTable; 272 273 /// Selectors related to memory management. When compiling in GC mode, we 274 /// omit these. 275 Selector RetainSel, ReleaseSel, AutoreleaseSel; 276 /// Runtime functions used for memory management in GC mode. Note that clang 277 /// supports code generation for calling these functions, but neither GNU 278 /// runtime actually supports this API properly yet. 279 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn, 280 WeakAssignFn, GlobalAssignFn; 281 282protected: 283 /// Function used for throwing Objective-C exceptions. 284 LazyRuntimeFunction ExceptionThrowFn; 285 /// Function used for rethrowing exceptions, used at the end of @finally or 286 /// @synchronize blocks. 287 LazyRuntimeFunction ExceptionReThrowFn; 288 /// Function called when entering a catch function. This is required for 289 /// differentiating Objective-C exceptions and foreign exceptions. 290 LazyRuntimeFunction EnterCatchFn; 291 /// Function called when exiting from a catch block. Used to do exception 292 /// cleanup. 293 LazyRuntimeFunction ExitCatchFn; 294 /// Function called when entering an @synchronize block. Acquires the lock. 295 LazyRuntimeFunction SyncEnterFn; 296 /// Function called when exiting an @synchronize block. Releases the lock. 297 LazyRuntimeFunction SyncExitFn; 298 299private: 300 301 /// Function called if fast enumeration detects that the collection is 302 /// modified during the update. 303 LazyRuntimeFunction EnumerationMutationFn; 304 /// Function for implementing synthesized property getters that return an 305 /// object. 306 LazyRuntimeFunction GetPropertyFn; 307 /// Function for implementing synthesized property setters that return an 308 /// object. 309 LazyRuntimeFunction SetPropertyFn; 310 /// Function used for non-object declared property getters. 311 LazyRuntimeFunction GetStructPropertyFn; 312 /// Function used for non-object declared property setters. 313 LazyRuntimeFunction SetStructPropertyFn; 314 315 /// The version of the runtime that this class targets. Must match the 316 /// version in the runtime. 317 const int RuntimeVersion; 318 /// The version of the protocol class. Used to differentiate between ObjC1 319 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional 320 /// components and can not contain declared properties. We always emit 321 /// Objective-C 2 property structures, but we have to pretend that they're 322 /// Objective-C 1 property structures when targeting the GCC runtime or it 323 /// will abort. 324 const int ProtocolVersion; 325private: 326 /// Generates an instance variable list structure. This is a structure 327 /// containing a size and an array of structures containing instance variable 328 /// metadata. This is used purely for introspection in the fragile ABI. In 329 /// the non-fragile ABI, it's used for instance variable fixup. 330 llvm::Constant *GenerateIvarList( 331 const llvm::SmallVectorImpl<llvm::Constant *> &IvarNames, 332 const llvm::SmallVectorImpl<llvm::Constant *> &IvarTypes, 333 const llvm::SmallVectorImpl<llvm::Constant *> &IvarOffsets); 334 /// Generates a method list structure. This is a structure containing a size 335 /// and an array of structures containing method metadata. 336 /// 337 /// This structure is used by both classes and categories, and contains a next 338 /// pointer allowing them to be chained together in a linked list. 339 llvm::Constant *GenerateMethodList(const llvm::StringRef &ClassName, 340 const llvm::StringRef &CategoryName, 341 const llvm::SmallVectorImpl<Selector> &MethodSels, 342 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes, 343 bool isClassMethodList); 344 /// Emits an empty protocol. This is used for @protocol() where no protocol 345 /// is found. The runtime will (hopefully) fix up the pointer to refer to the 346 /// real protocol. 347 llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName); 348 /// Generates a list of property metadata structures. This follows the same 349 /// pattern as method and instance variable metadata lists. 350 llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID, 351 llvm::SmallVectorImpl<Selector> &InstanceMethodSels, 352 llvm::SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes); 353 /// Generates a list of referenced protocols. Classes, categories, and 354 /// protocols all use this structure. 355 llvm::Constant *GenerateProtocolList( 356 const llvm::SmallVectorImpl<std::string> &Protocols); 357 /// To ensure that all protocols are seen by the runtime, we add a category on 358 /// a class defined in the runtime, declaring no methods, but adopting the 359 /// protocols. This is a horribly ugly hack, but it allows us to collect all 360 /// of the protocols without changing the ABI. 361 void GenerateProtocolHolderCategory(void); 362 /// Generates a class structure. 363 llvm::Constant *GenerateClassStructure( 364 llvm::Constant *MetaClass, 365 llvm::Constant *SuperClass, 366 unsigned info, 367 const char *Name, 368 llvm::Constant *Version, 369 llvm::Constant *InstanceSize, 370 llvm::Constant *IVars, 371 llvm::Constant *Methods, 372 llvm::Constant *Protocols, 373 llvm::Constant *IvarOffsets, 374 llvm::Constant *Properties, 375 bool isMeta=false); 376 /// Generates a method list. This is used by protocols to define the required 377 /// and optional methods. 378 llvm::Constant *GenerateProtocolMethodList( 379 const llvm::SmallVectorImpl<llvm::Constant *> &MethodNames, 380 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes); 381 /// Returns a selector with the specified type encoding. An empty string is 382 /// used to return an untyped selector (with the types field set to NULL). 383 llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 384 const std::string &TypeEncoding, bool lval); 385 /// Returns the variable used to store the offset of an instance variable. 386 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID, 387 const ObjCIvarDecl *Ivar); 388 /// Emits a reference to a class. This allows the linker to object if there 389 /// is no class of the matching name. 390 void EmitClassRef(const std::string &className); 391protected: 392 /// Looks up the method for sending a message to the specified object. This 393 /// mechanism differs between the GCC and GNU runtimes, so this method must be 394 /// overridden in subclasses. 395 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 396 llvm::Value *&Receiver, 397 llvm::Value *cmd, 398 llvm::MDNode *node) = 0; 399 /// Looks up the method for sending a message to a superclass. This mechanism 400 /// differs between the GCC and GNU runtimes, so this method must be 401 /// overridden in subclasses. 402 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 403 llvm::Value *ObjCSuper, 404 llvm::Value *cmd) = 0; 405public: 406 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 407 unsigned protocolClassVersion); 408 409 virtual llvm::Constant *GenerateConstantString(const StringLiteral *); 410 411 virtual RValue 412 GenerateMessageSend(CodeGenFunction &CGF, 413 ReturnValueSlot Return, 414 QualType ResultType, 415 Selector Sel, 416 llvm::Value *Receiver, 417 const CallArgList &CallArgs, 418 const ObjCInterfaceDecl *Class, 419 const ObjCMethodDecl *Method); 420 virtual RValue 421 GenerateMessageSendSuper(CodeGenFunction &CGF, 422 ReturnValueSlot Return, 423 QualType ResultType, 424 Selector Sel, 425 const ObjCInterfaceDecl *Class, 426 bool isCategoryImpl, 427 llvm::Value *Receiver, 428 bool IsClassMessage, 429 const CallArgList &CallArgs, 430 const ObjCMethodDecl *Method); 431 virtual llvm::Value *GetClass(CGBuilderTy &Builder, 432 const ObjCInterfaceDecl *OID); 433 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 434 bool lval = false); 435 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 436 *Method); 437 virtual llvm::Constant *GetEHType(QualType T); 438 439 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 440 const ObjCContainerDecl *CD); 441 virtual void GenerateCategory(const ObjCCategoryImplDecl *CMD); 442 virtual void GenerateClass(const ObjCImplementationDecl *ClassDecl); 443 virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder, 444 const ObjCProtocolDecl *PD); 445 virtual void GenerateProtocol(const ObjCProtocolDecl *PD); 446 virtual llvm::Function *ModuleInitFunction(); 447 virtual llvm::Function *GetPropertyGetFunction(); 448 virtual llvm::Function *GetPropertySetFunction(); 449 virtual llvm::Function *GetSetStructFunction(); 450 virtual llvm::Function *GetGetStructFunction(); 451 virtual llvm::Constant *EnumerationMutationFunction(); 452 453 virtual void EmitTryStmt(CodeGenFunction &CGF, 454 const ObjCAtTryStmt &S); 455 virtual void EmitSynchronizedStmt(CodeGenFunction &CGF, 456 const ObjCAtSynchronizedStmt &S); 457 virtual void EmitThrowStmt(CodeGenFunction &CGF, 458 const ObjCAtThrowStmt &S); 459 virtual llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF, 460 llvm::Value *AddrWeakObj); 461 virtual void EmitObjCWeakAssign(CodeGenFunction &CGF, 462 llvm::Value *src, llvm::Value *dst); 463 virtual void EmitObjCGlobalAssign(CodeGenFunction &CGF, 464 llvm::Value *src, llvm::Value *dest, 465 bool threadlocal=false); 466 virtual void EmitObjCIvarAssign(CodeGenFunction &CGF, 467 llvm::Value *src, llvm::Value *dest, 468 llvm::Value *ivarOffset); 469 virtual void EmitObjCStrongCastAssign(CodeGenFunction &CGF, 470 llvm::Value *src, llvm::Value *dest); 471 virtual void EmitGCMemmoveCollectable(CodeGenFunction &CGF, 472 llvm::Value *DestPtr, 473 llvm::Value *SrcPtr, 474 llvm::Value *Size); 475 virtual LValue EmitObjCValueForIvar(CodeGenFunction &CGF, 476 QualType ObjectTy, 477 llvm::Value *BaseValue, 478 const ObjCIvarDecl *Ivar, 479 unsigned CVRQualifiers); 480 virtual llvm::Value *EmitIvarOffset(CodeGenFunction &CGF, 481 const ObjCInterfaceDecl *Interface, 482 const ObjCIvarDecl *Ivar); 483 virtual llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM, 484 const CGBlockInfo &blockInfo) { 485 return NULLPtr; 486 } 487}; 488/// Class representing the legacy GCC Objective-C ABI. This is the default when 489/// -fobjc-nonfragile-abi is not specified. 490/// 491/// The GCC ABI target actually generates code that is approximately compatible 492/// with the new GNUstep runtime ABI, but refrains from using any features that 493/// would not work with the GCC runtime. For example, clang always generates 494/// the extended form of the class structure, and the extra fields are simply 495/// ignored by GCC libobjc. 496class CGObjCGCC : public CGObjCGNU { 497 /// The GCC ABI message lookup function. Returns an IMP pointing to the 498 /// method implementation for this message. 499 LazyRuntimeFunction MsgLookupFn; 500 /// The GCC ABI superclass message lookup function. Takes a pointer to a 501 /// structure describing the receiver and the class, and a selector as 502 /// arguments. Returns the IMP for the corresponding method. 503 LazyRuntimeFunction MsgLookupSuperFn; 504protected: 505 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 506 llvm::Value *&Receiver, 507 llvm::Value *cmd, 508 llvm::MDNode *node) { 509 CGBuilderTy &Builder = CGF.Builder; 510 llvm::Value *imp = Builder.CreateCall2(MsgLookupFn, 511 EnforceType(Builder, Receiver, IdTy), 512 EnforceType(Builder, cmd, SelectorTy)); 513 cast<llvm::CallInst>(imp)->setMetadata(msgSendMDKind, node); 514 return imp; 515 } 516 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 517 llvm::Value *ObjCSuper, 518 llvm::Value *cmd) { 519 CGBuilderTy &Builder = CGF.Builder; 520 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 521 PtrToObjCSuperTy), cmd}; 522 return Builder.CreateCall(MsgLookupSuperFn, lookupArgs, lookupArgs+2); 523 } 524 public: 525 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) { 526 // IMP objc_msg_lookup(id, SEL); 527 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 528 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 529 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 530 PtrToObjCSuperTy, SelectorTy, NULL); 531 } 532}; 533/// Class used when targeting the new GNUstep runtime ABI. 534class CGObjCGNUstep : public CGObjCGNU { 535 /// The slot lookup function. Returns a pointer to a cacheable structure 536 /// that contains (among other things) the IMP. 537 LazyRuntimeFunction SlotLookupFn; 538 /// The GNUstep ABI superclass message lookup function. Takes a pointer to 539 /// a structure describing the receiver and the class, and a selector as 540 /// arguments. Returns the slot for the corresponding method. Superclass 541 /// message lookup rarely changes, so this is a good caching opportunity. 542 LazyRuntimeFunction SlotLookupSuperFn; 543 /// Type of an slot structure pointer. This is returned by the various 544 /// lookup functions. 545 llvm::Type *SlotTy; 546 protected: 547 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 548 llvm::Value *&Receiver, 549 llvm::Value *cmd, 550 llvm::MDNode *node) { 551 CGBuilderTy &Builder = CGF.Builder; 552 llvm::Function *LookupFn = SlotLookupFn; 553 554 // Store the receiver on the stack so that we can reload it later 555 llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType()); 556 Builder.CreateStore(Receiver, ReceiverPtr); 557 558 llvm::Value *self; 559 560 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) { 561 self = CGF.LoadObjCSelf(); 562 } else { 563 self = llvm::ConstantPointerNull::get(IdTy); 564 } 565 566 // The lookup function is guaranteed not to capture the receiver pointer. 567 LookupFn->setDoesNotCapture(1); 568 569 llvm::CallInst *slot = 570 Builder.CreateCall3(LookupFn, 571 EnforceType(Builder, ReceiverPtr, PtrToIdTy), 572 EnforceType(Builder, cmd, SelectorTy), 573 EnforceType(Builder, self, IdTy)); 574 slot->setOnlyReadsMemory(); 575 slot->setMetadata(msgSendMDKind, node); 576 577 // Load the imp from the slot 578 llvm::Value *imp = Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 579 580 // The lookup function may have changed the receiver, so make sure we use 581 // the new one. 582 Receiver = Builder.CreateLoad(ReceiverPtr, true); 583 return imp; 584 } 585 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 586 llvm::Value *ObjCSuper, 587 llvm::Value *cmd) { 588 CGBuilderTy &Builder = CGF.Builder; 589 llvm::Value *lookupArgs[] = {ObjCSuper, cmd}; 590 591 llvm::CallInst *slot = Builder.CreateCall(SlotLookupSuperFn, lookupArgs, 592 lookupArgs+2); 593 slot->setOnlyReadsMemory(); 594 595 return Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 596 } 597 public: 598 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) { 599 llvm::StructType *SlotStructTy = llvm::StructType::get(VMContext, PtrTy, 600 PtrTy, PtrTy, IntTy, IMPTy, NULL); 601 SlotTy = llvm::PointerType::getUnqual(SlotStructTy); 602 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 603 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy, 604 SelectorTy, IdTy, NULL); 605 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL); 606 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy, 607 PtrToObjCSuperTy, SelectorTy, NULL); 608 // If we're in ObjC++ mode, then we want to make 609 if (CGM.getLangOptions().CPlusPlus) { 610 const llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 611 // void *__cxa_begin_catch(void *e) 612 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, NULL); 613 // void __cxa_end_catch(void) 614 EnterCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, NULL); 615 // void _Unwind_Resume_or_Rethrow(void*) 616 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, PtrTy, NULL); 617 } 618 } 619}; 620 621} // end anonymous namespace 622 623 624/// Emits a reference to a dummy variable which is emitted with each class. 625/// This ensures that a linker error will be generated when trying to link 626/// together modules where a referenced class is not defined. 627void CGObjCGNU::EmitClassRef(const std::string &className) { 628 std::string symbolRef = "__objc_class_ref_" + className; 629 // Don't emit two copies of the same symbol 630 if (TheModule.getGlobalVariable(symbolRef)) 631 return; 632 std::string symbolName = "__objc_class_name_" + className; 633 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName); 634 if (!ClassSymbol) { 635 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 636 llvm::GlobalValue::ExternalLinkage, 0, symbolName); 637 } 638 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true, 639 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef); 640} 641 642static std::string SymbolNameForMethod(const llvm::StringRef &ClassName, 643 const llvm::StringRef &CategoryName, const Selector MethodName, 644 bool isClassMethod) { 645 std::string MethodNameColonStripped = MethodName.getAsString(); 646 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(), 647 ':', '_'); 648 return (llvm::Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" + 649 CategoryName + "_" + MethodNameColonStripped).str(); 650} 651 652CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 653 unsigned protocolClassVersion) 654 : CGM(cgm), TheModule(CGM.getModule()), VMContext(cgm.getLLVMContext()), 655 ClassPtrAlias(0), MetaClassPtrAlias(0), RuntimeVersion(runtimeABIVersion), 656 ProtocolVersion(protocolClassVersion) { 657 658 659 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend"); 660 661 CodeGenTypes &Types = CGM.getTypes(); 662 IntTy = cast<llvm::IntegerType>( 663 Types.ConvertType(CGM.getContext().IntTy)); 664 LongTy = cast<llvm::IntegerType>( 665 Types.ConvertType(CGM.getContext().LongTy)); 666 SizeTy = cast<llvm::IntegerType>( 667 Types.ConvertType(CGM.getContext().getSizeType())); 668 PtrDiffTy = cast<llvm::IntegerType>( 669 Types.ConvertType(CGM.getContext().getPointerDiffType())); 670 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy); 671 672 Int8Ty = llvm::Type::getInt8Ty(VMContext); 673 // C string type. Used in lots of places. 674 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); 675 676 Zeros[0] = llvm::ConstantInt::get(LongTy, 0); 677 Zeros[1] = Zeros[0]; 678 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty); 679 // Get the selector Type. 680 QualType selTy = CGM.getContext().getObjCSelType(); 681 if (QualType() == selTy) { 682 SelectorTy = PtrToInt8Ty; 683 } else { 684 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy)); 685 } 686 687 PtrToIntTy = llvm::PointerType::getUnqual(IntTy); 688 PtrTy = PtrToInt8Ty; 689 690 // Object type 691 QualType UnqualIdTy = CGM.getContext().getObjCIdType(); 692 ASTIdTy = CanQualType(); 693 if (UnqualIdTy != QualType()) { 694 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy); 695 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 696 } else { 697 IdTy = PtrToInt8Ty; 698 } 699 PtrToIdTy = llvm::PointerType::getUnqual(IdTy); 700 701 ObjCSuperTy = llvm::StructType::get(VMContext, IdTy, IdTy, NULL); 702 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy); 703 704 const llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 705 706 // void objc_exception_throw(id); 707 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 708 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 709 // int objc_sync_enter(id); 710 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, NULL); 711 // int objc_sync_exit(id); 712 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, NULL); 713 714 // void objc_enumerationMutation (id) 715 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, 716 IdTy, NULL); 717 718 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL) 719 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy, 720 PtrDiffTy, BoolTy, NULL); 721 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL) 722 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy, 723 PtrDiffTy, IdTy, BoolTy, BoolTy, NULL); 724 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 725 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy, 726 PtrDiffTy, BoolTy, BoolTy, NULL); 727 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 728 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy, 729 PtrDiffTy, BoolTy, BoolTy, NULL); 730 731 // IMP type 732 std::vector<const llvm::Type*> IMPArgs; 733 IMPArgs.push_back(IdTy); 734 IMPArgs.push_back(SelectorTy); 735 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs, 736 true)); 737 738 // Don't bother initialising the GC stuff unless we're compiling in GC mode 739 if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) { 740 // Get selectors needed in GC mode 741 RetainSel = GetNullarySelector("retain", CGM.getContext()); 742 ReleaseSel = GetNullarySelector("release", CGM.getContext()); 743 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext()); 744 745 // Get functions needed in GC mode 746 747 // id objc_assign_ivar(id, id, ptrdiff_t); 748 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy, 749 NULL); 750 // id objc_assign_strongCast (id, id*) 751 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy, 752 PtrToIdTy, NULL); 753 // id objc_assign_global(id, id*); 754 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy, 755 NULL); 756 // id objc_assign_weak(id, id*); 757 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, NULL); 758 // id objc_read_weak(id*); 759 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, NULL); 760 // void *objc_memmove_collectable(void*, void *, size_t); 761 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy, 762 SizeTy, NULL); 763 } 764} 765 766// This has to perform the lookup every time, since posing and related 767// techniques can modify the name -> class mapping. 768llvm::Value *CGObjCGNU::GetClass(CGBuilderTy &Builder, 769 const ObjCInterfaceDecl *OID) { 770 llvm::Value *ClassName = CGM.GetAddrOfConstantCString(OID->getNameAsString()); 771 // With the incompatible ABI, this will need to be replaced with a direct 772 // reference to the class symbol. For the compatible nonfragile ABI we are 773 // still performing this lookup at run time but emitting the symbol for the 774 // class externally so that we can make the switch later. 775 EmitClassRef(OID->getNameAsString()); 776 ClassName = Builder.CreateStructGEP(ClassName, 0); 777 778 std::vector<const llvm::Type*> Params(1, PtrToInt8Ty); 779 llvm::Constant *ClassLookupFn = 780 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, 781 Params, 782 true), 783 "objc_lookup_class"); 784 return Builder.CreateCall(ClassLookupFn, ClassName); 785} 786 787llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 788 const std::string &TypeEncoding, bool lval) { 789 790 llvm::SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel]; 791 llvm::GlobalAlias *SelValue = 0; 792 793 794 for (llvm::SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 795 e = Types.end() ; i!=e ; i++) { 796 if (i->first == TypeEncoding) { 797 SelValue = i->second; 798 break; 799 } 800 } 801 if (0 == SelValue) { 802 SelValue = new llvm::GlobalAlias(SelectorTy, 803 llvm::GlobalValue::PrivateLinkage, 804 ".objc_selector_"+Sel.getAsString(), NULL, 805 &TheModule); 806 Types.push_back(TypedSelector(TypeEncoding, SelValue)); 807 } 808 809 if (lval) { 810 llvm::Value *tmp = Builder.CreateAlloca(SelValue->getType()); 811 Builder.CreateStore(SelValue, tmp); 812 return tmp; 813 } 814 return SelValue; 815} 816 817llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 818 bool lval) { 819 return GetSelector(Builder, Sel, std::string(), lval); 820} 821 822llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 823 *Method) { 824 std::string SelTypes; 825 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes); 826 return GetSelector(Builder, Method->getSelector(), SelTypes, false); 827} 828 829llvm::Constant *CGObjCGNU::GetEHType(QualType T) { 830 if (!CGM.getLangOptions().CPlusPlus) { 831 if (T->isObjCIdType() 832 || T->isObjCQualifiedIdType()) { 833 // With the old ABI, there was only one kind of catchall, which broke 834 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as 835 // a pointer indicating object catchalls, and NULL to indicate real 836 // catchalls 837 if (CGM.getLangOptions().ObjCNonFragileABI) { 838 return MakeConstantString("@id"); 839 } else { 840 return 0; 841 } 842 } 843 844 // All other types should be Objective-C interface pointer types. 845 const ObjCObjectPointerType *OPT = 846 T->getAs<ObjCObjectPointerType>(); 847 assert(OPT && "Invalid @catch type."); 848 const ObjCInterfaceDecl *IDecl = 849 OPT->getObjectType()->getInterface(); 850 assert(IDecl && "Invalid @catch type."); 851 return MakeConstantString(IDecl->getIdentifier()->getName()); 852 } 853 // For Objective-C++, we want to provide the ability to catch both C++ and 854 // Objective-C objects in the same function. 855 856 // There's a particular fixed type info for 'id'. 857 if (T->isObjCIdType() || 858 T->isObjCQualifiedIdType()) { 859 llvm::Constant *IDEHType = 860 CGM.getModule().getGlobalVariable("__objc_id_type_info"); 861 if (!IDEHType) 862 IDEHType = 863 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty, 864 false, 865 llvm::GlobalValue::ExternalLinkage, 866 0, "__objc_id_type_info"); 867 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty); 868 } 869 870 const ObjCObjectPointerType *PT = 871 T->getAs<ObjCObjectPointerType>(); 872 assert(PT && "Invalid @catch type."); 873 const ObjCInterfaceType *IT = PT->getInterfaceType(); 874 assert(IT && "Invalid @catch type."); 875 std::string className = IT->getDecl()->getIdentifier()->getName(); 876 877 std::string typeinfoName = "__objc_eh_typeinfo_" + className; 878 879 // Return the existing typeinfo if it exists 880 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName); 881 if (typeinfo) return typeinfo; 882 883 // Otherwise create it. 884 885 // vtable for gnustep::libobjc::__objc_class_type_info 886 // It's quite ugly hard-coding this. Ideally we'd generate it using the host 887 // platform's name mangling. 888 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE"; 889 llvm::Constant *Vtable = TheModule.getGlobalVariable(vtableName); 890 if (!Vtable) { 891 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true, 892 llvm::GlobalValue::ExternalLinkage, 0, vtableName); 893 } 894 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2); 895 Vtable = llvm::ConstantExpr::getGetElementPtr(Vtable, &Two, 1); 896 Vtable = llvm::ConstantExpr::getBitCast(Vtable, PtrToInt8Ty); 897 898 llvm::Constant *typeName = 899 ExportUniqueString(className, "__objc_eh_typename_"); 900 901 std::vector<llvm::Constant*> fields; 902 fields.push_back(Vtable); 903 fields.push_back(typeName); 904 llvm::Constant *TI = 905 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 906 NULL), fields, "__objc_eh_typeinfo_" + className, 907 llvm::GlobalValue::LinkOnceODRLinkage); 908 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty); 909} 910 911/// Generate an NSConstantString object. 912llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) { 913 914 std::string Str = SL->getString().str(); 915 916 // Look for an existing one 917 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str); 918 if (old != ObjCStrings.end()) 919 return old->getValue(); 920 921 std::vector<llvm::Constant*> Ivars; 922 Ivars.push_back(NULLPtr); 923 Ivars.push_back(MakeConstantString(Str)); 924 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size())); 925 llvm::Constant *ObjCStr = MakeGlobal( 926 llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, IntTy, NULL), 927 Ivars, ".objc_str"); 928 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty); 929 ObjCStrings[Str] = ObjCStr; 930 ConstantStrings.push_back(ObjCStr); 931 return ObjCStr; 932} 933 934///Generates a message send where the super is the receiver. This is a message 935///send to self with special delivery semantics indicating which class's method 936///should be called. 937RValue 938CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF, 939 ReturnValueSlot Return, 940 QualType ResultType, 941 Selector Sel, 942 const ObjCInterfaceDecl *Class, 943 bool isCategoryImpl, 944 llvm::Value *Receiver, 945 bool IsClassMessage, 946 const CallArgList &CallArgs, 947 const ObjCMethodDecl *Method) { 948 if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) { 949 if (Sel == RetainSel || Sel == AutoreleaseSel) { 950 return RValue::get(Receiver); 951 } 952 if (Sel == ReleaseSel) { 953 return RValue::get(0); 954 } 955 } 956 957 CGBuilderTy &Builder = CGF.Builder; 958 llvm::Value *cmd = GetSelector(Builder, Sel); 959 960 961 CallArgList ActualArgs; 962 963 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy); 964 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 965 ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end()); 966 967 CodeGenTypes &Types = CGM.getTypes(); 968 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 969 FunctionType::ExtInfo()); 970 971 llvm::Value *ReceiverClass = 0; 972 if (isCategoryImpl) { 973 llvm::Constant *classLookupFunction = 0; 974 std::vector<const llvm::Type*> Params; 975 Params.push_back(PtrTy); 976 if (IsClassMessage) { 977 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 978 IdTy, Params, true), "objc_get_meta_class"); 979 } else { 980 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 981 IdTy, Params, true), "objc_get_class"); 982 } 983 ReceiverClass = Builder.CreateCall(classLookupFunction, 984 MakeConstantString(Class->getNameAsString())); 985 } else { 986 // Set up global aliases for the metaclass or class pointer if they do not 987 // already exist. These will are forward-references which will be set to 988 // pointers to the class and metaclass structure created for the runtime 989 // load function. To send a message to super, we look up the value of the 990 // super_class pointer from either the class or metaclass structure. 991 if (IsClassMessage) { 992 if (!MetaClassPtrAlias) { 993 MetaClassPtrAlias = new llvm::GlobalAlias(IdTy, 994 llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" + 995 Class->getNameAsString(), NULL, &TheModule); 996 } 997 ReceiverClass = MetaClassPtrAlias; 998 } else { 999 if (!ClassPtrAlias) { 1000 ClassPtrAlias = new llvm::GlobalAlias(IdTy, 1001 llvm::GlobalValue::InternalLinkage, ".objc_class_ref" + 1002 Class->getNameAsString(), NULL, &TheModule); 1003 } 1004 ReceiverClass = ClassPtrAlias; 1005 } 1006 } 1007 // Cast the pointer to a simplified version of the class structure 1008 ReceiverClass = Builder.CreateBitCast(ReceiverClass, 1009 llvm::PointerType::getUnqual( 1010 llvm::StructType::get(VMContext, IdTy, IdTy, NULL))); 1011 // Get the superclass pointer 1012 ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1); 1013 // Load the superclass pointer 1014 ReceiverClass = Builder.CreateLoad(ReceiverClass); 1015 // Construct the structure used to look up the IMP 1016 llvm::StructType *ObjCSuperTy = llvm::StructType::get(VMContext, 1017 Receiver->getType(), IdTy, NULL); 1018 llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy); 1019 1020 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0)); 1021 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1)); 1022 1023 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy); 1024 const llvm::FunctionType *impType = 1025 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1026 1027 // Get the IMP 1028 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd); 1029 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1030 1031 llvm::Value *impMD[] = { 1032 llvm::MDString::get(VMContext, Sel.getAsString()), 1033 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()), 1034 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage) 1035 }; 1036 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1037 1038 llvm::Instruction *call; 1039 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1040 0, &call); 1041 call->setMetadata(msgSendMDKind, node); 1042 return msgRet; 1043} 1044 1045/// Generate code for a message send expression. 1046RValue 1047CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF, 1048 ReturnValueSlot Return, 1049 QualType ResultType, 1050 Selector Sel, 1051 llvm::Value *Receiver, 1052 const CallArgList &CallArgs, 1053 const ObjCInterfaceDecl *Class, 1054 const ObjCMethodDecl *Method) { 1055 // Strip out message sends to retain / release in GC mode 1056 if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) { 1057 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1058 return RValue::get(Receiver); 1059 } 1060 if (Sel == ReleaseSel) { 1061 return RValue::get(0); 1062 } 1063 } 1064 1065 CGBuilderTy &Builder = CGF.Builder; 1066 1067 // If the return type is something that goes in an integer register, the 1068 // runtime will handle 0 returns. For other cases, we fill in the 0 value 1069 // ourselves. 1070 // 1071 // The language spec says the result of this kind of message send is 1072 // undefined, but lots of people seem to have forgotten to read that 1073 // paragraph and insist on sending messages to nil that have structure 1074 // returns. With GCC, this generates a random return value (whatever happens 1075 // to be on the stack / in those registers at the time) on most platforms, 1076 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts 1077 // the stack. 1078 bool isPointerSizedReturn = (ResultType->isAnyPointerType() || 1079 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType()); 1080 1081 llvm::BasicBlock *startBB = 0; 1082 llvm::BasicBlock *messageBB = 0; 1083 llvm::BasicBlock *continueBB = 0; 1084 1085 if (!isPointerSizedReturn) { 1086 startBB = Builder.GetInsertBlock(); 1087 messageBB = CGF.createBasicBlock("msgSend"); 1088 continueBB = CGF.createBasicBlock("continue"); 1089 1090 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver, 1091 llvm::Constant::getNullValue(Receiver->getType())); 1092 Builder.CreateCondBr(isNil, continueBB, messageBB); 1093 CGF.EmitBlock(messageBB); 1094 } 1095 1096 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 1097 llvm::Value *cmd; 1098 if (Method) 1099 cmd = GetSelector(Builder, Method); 1100 else 1101 cmd = GetSelector(Builder, Sel); 1102 cmd = EnforceType(Builder, cmd, SelectorTy); 1103 Receiver = EnforceType(Builder, Receiver, IdTy); 1104 1105 llvm::Value *impMD[] = { 1106 llvm::MDString::get(VMContext, Sel.getAsString()), 1107 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""), 1108 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0) 1109 }; 1110 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1111 1112 // Get the IMP to call 1113 llvm::Value *imp = LookupIMP(CGF, Receiver, cmd, node); 1114 1115 CallArgList ActualArgs; 1116 ActualArgs.add(RValue::get(Receiver), ASTIdTy); 1117 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1118 ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end()); 1119 1120 CodeGenTypes &Types = CGM.getTypes(); 1121 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 1122 FunctionType::ExtInfo()); 1123 const llvm::FunctionType *impType = 1124 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1125 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1126 1127 1128 // For sender-aware dispatch, we pass the sender as the third argument to a 1129 // lookup function. When sending messages from C code, the sender is nil. 1130 // objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 1131 llvm::Instruction *call; 1132 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1133 0, &call); 1134 call->setMetadata(msgSendMDKind, node); 1135 1136 1137 if (!isPointerSizedReturn) { 1138 messageBB = CGF.Builder.GetInsertBlock(); 1139 CGF.Builder.CreateBr(continueBB); 1140 CGF.EmitBlock(continueBB); 1141 if (msgRet.isScalar()) { 1142 llvm::Value *v = msgRet.getScalarVal(); 1143 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1144 phi->addIncoming(v, messageBB); 1145 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB); 1146 msgRet = RValue::get(phi); 1147 } else if (msgRet.isAggregate()) { 1148 llvm::Value *v = msgRet.getAggregateAddr(); 1149 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1150 const llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType()); 1151 llvm::AllocaInst *NullVal = 1152 CGF.CreateTempAlloca(RetTy->getElementType(), "null"); 1153 CGF.InitTempAlloca(NullVal, 1154 llvm::Constant::getNullValue(RetTy->getElementType())); 1155 phi->addIncoming(v, messageBB); 1156 phi->addIncoming(NullVal, startBB); 1157 msgRet = RValue::getAggregate(phi); 1158 } else /* isComplex() */ { 1159 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal(); 1160 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2); 1161 phi->addIncoming(v.first, messageBB); 1162 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()), 1163 startBB); 1164 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2); 1165 phi2->addIncoming(v.second, messageBB); 1166 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()), 1167 startBB); 1168 msgRet = RValue::getComplex(phi, phi2); 1169 } 1170 } 1171 return msgRet; 1172} 1173 1174/// Generates a MethodList. Used in construction of a objc_class and 1175/// objc_category structures. 1176llvm::Constant *CGObjCGNU::GenerateMethodList(const llvm::StringRef &ClassName, 1177 const llvm::StringRef &CategoryName, 1178 const llvm::SmallVectorImpl<Selector> &MethodSels, 1179 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes, 1180 bool isClassMethodList) { 1181 if (MethodSels.empty()) 1182 return NULLPtr; 1183 // Get the method structure type. 1184 llvm::StructType *ObjCMethodTy = llvm::StructType::get(VMContext, 1185 PtrToInt8Ty, // Really a selector, but the runtime creates it us. 1186 PtrToInt8Ty, // Method types 1187 IMPTy, //Method pointer 1188 NULL); 1189 std::vector<llvm::Constant*> Methods; 1190 std::vector<llvm::Constant*> Elements; 1191 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) { 1192 Elements.clear(); 1193 llvm::Constant *Method = 1194 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName, 1195 MethodSels[i], 1196 isClassMethodList)); 1197 assert(Method && "Can't generate metadata for method that doesn't exist"); 1198 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString()); 1199 Elements.push_back(C); 1200 Elements.push_back(MethodTypes[i]); 1201 Method = llvm::ConstantExpr::getBitCast(Method, 1202 IMPTy); 1203 Elements.push_back(Method); 1204 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements)); 1205 } 1206 1207 // Array of method structures 1208 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy, 1209 Methods.size()); 1210 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy, 1211 Methods); 1212 1213 // Structure containing list pointer, array and array count 1214 llvm::SmallVector<const llvm::Type*, 16> ObjCMethodListFields; 1215 llvm::PATypeHolder OpaqueNextTy = llvm::OpaqueType::get(VMContext); 1216 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(OpaqueNextTy); 1217 llvm::StructType *ObjCMethodListTy = llvm::StructType::get(VMContext, 1218 NextPtrTy, 1219 IntTy, 1220 ObjCMethodArrayTy, 1221 NULL); 1222 // Refine next pointer type to concrete type 1223 llvm::cast<llvm::OpaqueType>( 1224 OpaqueNextTy.get())->refineAbstractTypeTo(ObjCMethodListTy); 1225 ObjCMethodListTy = llvm::cast<llvm::StructType>(OpaqueNextTy.get()); 1226 1227 Methods.clear(); 1228 Methods.push_back(llvm::ConstantPointerNull::get( 1229 llvm::PointerType::getUnqual(ObjCMethodListTy))); 1230 Methods.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1231 MethodTypes.size())); 1232 Methods.push_back(MethodArray); 1233 1234 // Create an instance of the structure 1235 return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list"); 1236} 1237 1238/// Generates an IvarList. Used in construction of a objc_class. 1239llvm::Constant *CGObjCGNU::GenerateIvarList( 1240 const llvm::SmallVectorImpl<llvm::Constant *> &IvarNames, 1241 const llvm::SmallVectorImpl<llvm::Constant *> &IvarTypes, 1242 const llvm::SmallVectorImpl<llvm::Constant *> &IvarOffsets) { 1243 if (IvarNames.size() == 0) 1244 return NULLPtr; 1245 // Get the method structure type. 1246 llvm::StructType *ObjCIvarTy = llvm::StructType::get(VMContext, 1247 PtrToInt8Ty, 1248 PtrToInt8Ty, 1249 IntTy, 1250 NULL); 1251 std::vector<llvm::Constant*> Ivars; 1252 std::vector<llvm::Constant*> Elements; 1253 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) { 1254 Elements.clear(); 1255 Elements.push_back(IvarNames[i]); 1256 Elements.push_back(IvarTypes[i]); 1257 Elements.push_back(IvarOffsets[i]); 1258 Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements)); 1259 } 1260 1261 // Array of method structures 1262 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy, 1263 IvarNames.size()); 1264 1265 1266 Elements.clear(); 1267 Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size())); 1268 Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)); 1269 // Structure containing array and array count 1270 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(VMContext, IntTy, 1271 ObjCIvarArrayTy, 1272 NULL); 1273 1274 // Create an instance of the structure 1275 return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list"); 1276} 1277 1278/// Generate a class structure 1279llvm::Constant *CGObjCGNU::GenerateClassStructure( 1280 llvm::Constant *MetaClass, 1281 llvm::Constant *SuperClass, 1282 unsigned info, 1283 const char *Name, 1284 llvm::Constant *Version, 1285 llvm::Constant *InstanceSize, 1286 llvm::Constant *IVars, 1287 llvm::Constant *Methods, 1288 llvm::Constant *Protocols, 1289 llvm::Constant *IvarOffsets, 1290 llvm::Constant *Properties, 1291 bool isMeta) { 1292 // Set up the class structure 1293 // Note: Several of these are char*s when they should be ids. This is 1294 // because the runtime performs this translation on load. 1295 // 1296 // Fields marked New ABI are part of the GNUstep runtime. We emit them 1297 // anyway; the classes will still work with the GNU runtime, they will just 1298 // be ignored. 1299 llvm::StructType *ClassTy = llvm::StructType::get(VMContext, 1300 PtrToInt8Ty, // class_pointer 1301 PtrToInt8Ty, // super_class 1302 PtrToInt8Ty, // name 1303 LongTy, // version 1304 LongTy, // info 1305 LongTy, // instance_size 1306 IVars->getType(), // ivars 1307 Methods->getType(), // methods 1308 // These are all filled in by the runtime, so we pretend 1309 PtrTy, // dtable 1310 PtrTy, // subclass_list 1311 PtrTy, // sibling_class 1312 PtrTy, // protocols 1313 PtrTy, // gc_object_type 1314 // New ABI: 1315 LongTy, // abi_version 1316 IvarOffsets->getType(), // ivar_offsets 1317 Properties->getType(), // properties 1318 NULL); 1319 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0); 1320 // Fill in the structure 1321 std::vector<llvm::Constant*> Elements; 1322 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty)); 1323 Elements.push_back(SuperClass); 1324 Elements.push_back(MakeConstantString(Name, ".class_name")); 1325 Elements.push_back(Zero); 1326 Elements.push_back(llvm::ConstantInt::get(LongTy, info)); 1327 if (isMeta) { 1328 llvm::TargetData td(&TheModule); 1329 Elements.push_back( 1330 llvm::ConstantInt::get(LongTy, 1331 td.getTypeSizeInBits(ClassTy) / 1332 CGM.getContext().getCharWidth())); 1333 } else 1334 Elements.push_back(InstanceSize); 1335 Elements.push_back(IVars); 1336 Elements.push_back(Methods); 1337 Elements.push_back(NULLPtr); 1338 Elements.push_back(NULLPtr); 1339 Elements.push_back(NULLPtr); 1340 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy)); 1341 Elements.push_back(NULLPtr); 1342 Elements.push_back(Zero); 1343 Elements.push_back(IvarOffsets); 1344 Elements.push_back(Properties); 1345 // Create an instance of the structure 1346 // This is now an externally visible symbol, so that we can speed up class 1347 // messages in the next ABI. 1348 return MakeGlobal(ClassTy, Elements, (isMeta ? "_OBJC_METACLASS_": 1349 "_OBJC_CLASS_") + std::string(Name), llvm::GlobalValue::ExternalLinkage); 1350} 1351 1352llvm::Constant *CGObjCGNU::GenerateProtocolMethodList( 1353 const llvm::SmallVectorImpl<llvm::Constant *> &MethodNames, 1354 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes) { 1355 // Get the method structure type. 1356 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get(VMContext, 1357 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us. 1358 PtrToInt8Ty, 1359 NULL); 1360 std::vector<llvm::Constant*> Methods; 1361 std::vector<llvm::Constant*> Elements; 1362 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) { 1363 Elements.clear(); 1364 Elements.push_back(MethodNames[i]); 1365 Elements.push_back(MethodTypes[i]); 1366 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements)); 1367 } 1368 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy, 1369 MethodNames.size()); 1370 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy, 1371 Methods); 1372 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get(VMContext, 1373 IntTy, ObjCMethodArrayTy, NULL); 1374 Methods.clear(); 1375 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size())); 1376 Methods.push_back(Array); 1377 return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list"); 1378} 1379 1380// Create the protocol list structure used in classes, categories and so on 1381llvm::Constant *CGObjCGNU::GenerateProtocolList( 1382 const llvm::SmallVectorImpl<std::string> &Protocols) { 1383 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 1384 Protocols.size()); 1385 llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext, 1386 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1387 SizeTy, 1388 ProtocolArrayTy, 1389 NULL); 1390 std::vector<llvm::Constant*> Elements; 1391 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end(); 1392 iter != endIter ; iter++) { 1393 llvm::Constant *protocol = 0; 1394 llvm::StringMap<llvm::Constant*>::iterator value = 1395 ExistingProtocols.find(*iter); 1396 if (value == ExistingProtocols.end()) { 1397 protocol = GenerateEmptyProtocol(*iter); 1398 } else { 1399 protocol = value->getValue(); 1400 } 1401 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol, 1402 PtrToInt8Ty); 1403 Elements.push_back(Ptr); 1404 } 1405 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1406 Elements); 1407 Elements.clear(); 1408 Elements.push_back(NULLPtr); 1409 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size())); 1410 Elements.push_back(ProtocolArray); 1411 return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list"); 1412} 1413 1414llvm::Value *CGObjCGNU::GenerateProtocolRef(CGBuilderTy &Builder, 1415 const ObjCProtocolDecl *PD) { 1416 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()]; 1417 const llvm::Type *T = 1418 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType()); 1419 return Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T)); 1420} 1421 1422llvm::Constant *CGObjCGNU::GenerateEmptyProtocol( 1423 const std::string &ProtocolName) { 1424 llvm::SmallVector<std::string, 0> EmptyStringVector; 1425 llvm::SmallVector<llvm::Constant*, 0> EmptyConstantVector; 1426 1427 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector); 1428 llvm::Constant *MethodList = 1429 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector); 1430 // Protocols are objects containing lists of the methods implemented and 1431 // protocols adopted. 1432 llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy, 1433 PtrToInt8Ty, 1434 ProtocolList->getType(), 1435 MethodList->getType(), 1436 MethodList->getType(), 1437 MethodList->getType(), 1438 MethodList->getType(), 1439 NULL); 1440 std::vector<llvm::Constant*> Elements; 1441 // The isa pointer must be set to a magic number so the runtime knows it's 1442 // the correct layout. 1443 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1444 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1445 ProtocolVersion), IdTy)); 1446 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1447 Elements.push_back(ProtocolList); 1448 Elements.push_back(MethodList); 1449 Elements.push_back(MethodList); 1450 Elements.push_back(MethodList); 1451 Elements.push_back(MethodList); 1452 return MakeGlobal(ProtocolTy, Elements, ".objc_protocol"); 1453} 1454 1455void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) { 1456 ASTContext &Context = CGM.getContext(); 1457 std::string ProtocolName = PD->getNameAsString(); 1458 llvm::SmallVector<std::string, 16> Protocols; 1459 for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(), 1460 E = PD->protocol_end(); PI != E; ++PI) 1461 Protocols.push_back((*PI)->getNameAsString()); 1462 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodNames; 1463 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1464 llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames; 1465 llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes; 1466 for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(), 1467 E = PD->instmeth_end(); iter != E; iter++) { 1468 std::string TypeStr; 1469 Context.getObjCEncodingForMethodDecl(*iter, TypeStr); 1470 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1471 InstanceMethodNames.push_back( 1472 MakeConstantString((*iter)->getSelector().getAsString())); 1473 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1474 } else { 1475 OptionalInstanceMethodNames.push_back( 1476 MakeConstantString((*iter)->getSelector().getAsString())); 1477 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1478 } 1479 } 1480 // Collect information about class methods: 1481 llvm::SmallVector<llvm::Constant*, 16> ClassMethodNames; 1482 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1483 llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodNames; 1484 llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes; 1485 for (ObjCProtocolDecl::classmeth_iterator 1486 iter = PD->classmeth_begin(), endIter = PD->classmeth_end(); 1487 iter != endIter ; iter++) { 1488 std::string TypeStr; 1489 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1490 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1491 ClassMethodNames.push_back( 1492 MakeConstantString((*iter)->getSelector().getAsString())); 1493 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1494 } else { 1495 OptionalClassMethodNames.push_back( 1496 MakeConstantString((*iter)->getSelector().getAsString())); 1497 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1498 } 1499 } 1500 1501 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols); 1502 llvm::Constant *InstanceMethodList = 1503 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes); 1504 llvm::Constant *ClassMethodList = 1505 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes); 1506 llvm::Constant *OptionalInstanceMethodList = 1507 GenerateProtocolMethodList(OptionalInstanceMethodNames, 1508 OptionalInstanceMethodTypes); 1509 llvm::Constant *OptionalClassMethodList = 1510 GenerateProtocolMethodList(OptionalClassMethodNames, 1511 OptionalClassMethodTypes); 1512 1513 // Property metadata: name, attributes, isSynthesized, setter name, setter 1514 // types, getter name, getter types. 1515 // The isSynthesized value is always set to 0 in a protocol. It exists to 1516 // simplify the runtime library by allowing it to use the same data 1517 // structures for protocol metadata everywhere. 1518 llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext, 1519 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1520 PtrToInt8Ty, NULL); 1521 std::vector<llvm::Constant*> Properties; 1522 std::vector<llvm::Constant*> OptionalProperties; 1523 1524 // Add all of the property methods need adding to the method list and to the 1525 // property metadata list. 1526 for (ObjCContainerDecl::prop_iterator 1527 iter = PD->prop_begin(), endIter = PD->prop_end(); 1528 iter != endIter ; iter++) { 1529 std::vector<llvm::Constant*> Fields; 1530 ObjCPropertyDecl *property = (*iter); 1531 1532 Fields.push_back(MakeConstantString(property->getNameAsString())); 1533 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1534 property->getPropertyAttributes())); 1535 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 1536 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1537 std::string TypeStr; 1538 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1539 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1540 InstanceMethodTypes.push_back(TypeEncoding); 1541 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1542 Fields.push_back(TypeEncoding); 1543 } else { 1544 Fields.push_back(NULLPtr); 1545 Fields.push_back(NULLPtr); 1546 } 1547 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1548 std::string TypeStr; 1549 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1550 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1551 InstanceMethodTypes.push_back(TypeEncoding); 1552 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1553 Fields.push_back(TypeEncoding); 1554 } else { 1555 Fields.push_back(NULLPtr); 1556 Fields.push_back(NULLPtr); 1557 } 1558 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) { 1559 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1560 } else { 1561 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1562 } 1563 } 1564 llvm::Constant *PropertyArray = llvm::ConstantArray::get( 1565 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties); 1566 llvm::Constant* PropertyListInitFields[] = 1567 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1568 1569 llvm::Constant *PropertyListInit = 1570 llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false); 1571 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule, 1572 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage, 1573 PropertyListInit, ".objc_property_list"); 1574 1575 llvm::Constant *OptionalPropertyArray = 1576 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy, 1577 OptionalProperties.size()) , OptionalProperties); 1578 llvm::Constant* OptionalPropertyListInitFields[] = { 1579 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr, 1580 OptionalPropertyArray }; 1581 1582 llvm::Constant *OptionalPropertyListInit = 1583 llvm::ConstantStruct::get(VMContext, OptionalPropertyListInitFields, 3, false); 1584 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule, 1585 OptionalPropertyListInit->getType(), false, 1586 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit, 1587 ".objc_property_list"); 1588 1589 // Protocols are objects containing lists of the methods implemented and 1590 // protocols adopted. 1591 llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy, 1592 PtrToInt8Ty, 1593 ProtocolList->getType(), 1594 InstanceMethodList->getType(), 1595 ClassMethodList->getType(), 1596 OptionalInstanceMethodList->getType(), 1597 OptionalClassMethodList->getType(), 1598 PropertyList->getType(), 1599 OptionalPropertyList->getType(), 1600 NULL); 1601 std::vector<llvm::Constant*> Elements; 1602 // The isa pointer must be set to a magic number so the runtime knows it's 1603 // the correct layout. 1604 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1605 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1606 ProtocolVersion), IdTy)); 1607 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1608 Elements.push_back(ProtocolList); 1609 Elements.push_back(InstanceMethodList); 1610 Elements.push_back(ClassMethodList); 1611 Elements.push_back(OptionalInstanceMethodList); 1612 Elements.push_back(OptionalClassMethodList); 1613 Elements.push_back(PropertyList); 1614 Elements.push_back(OptionalPropertyList); 1615 ExistingProtocols[ProtocolName] = 1616 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements, 1617 ".objc_protocol"), IdTy); 1618} 1619void CGObjCGNU::GenerateProtocolHolderCategory(void) { 1620 // Collect information about instance methods 1621 llvm::SmallVector<Selector, 1> MethodSels; 1622 llvm::SmallVector<llvm::Constant*, 1> MethodTypes; 1623 1624 std::vector<llvm::Constant*> Elements; 1625 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack"; 1626 const std::string CategoryName = "AnotherHack"; 1627 Elements.push_back(MakeConstantString(CategoryName)); 1628 Elements.push_back(MakeConstantString(ClassName)); 1629 // Instance method list 1630 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1631 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy)); 1632 // Class method list 1633 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1634 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy)); 1635 // Protocol list 1636 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy, 1637 ExistingProtocols.size()); 1638 llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext, 1639 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1640 SizeTy, 1641 ProtocolArrayTy, 1642 NULL); 1643 std::vector<llvm::Constant*> ProtocolElements; 1644 for (llvm::StringMapIterator<llvm::Constant*> iter = 1645 ExistingProtocols.begin(), endIter = ExistingProtocols.end(); 1646 iter != endIter ; iter++) { 1647 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(), 1648 PtrTy); 1649 ProtocolElements.push_back(Ptr); 1650 } 1651 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1652 ProtocolElements); 1653 ProtocolElements.clear(); 1654 ProtocolElements.push_back(NULLPtr); 1655 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy, 1656 ExistingProtocols.size())); 1657 ProtocolElements.push_back(ProtocolArray); 1658 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy, 1659 ProtocolElements, ".objc_protocol_list"), PtrTy)); 1660 Categories.push_back(llvm::ConstantExpr::getBitCast( 1661 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 1662 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1663} 1664 1665void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) { 1666 std::string ClassName = OCD->getClassInterface()->getNameAsString(); 1667 std::string CategoryName = OCD->getNameAsString(); 1668 // Collect information about instance methods 1669 llvm::SmallVector<Selector, 16> InstanceMethodSels; 1670 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1671 for (ObjCCategoryImplDecl::instmeth_iterator 1672 iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end(); 1673 iter != endIter ; iter++) { 1674 InstanceMethodSels.push_back((*iter)->getSelector()); 1675 std::string TypeStr; 1676 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1677 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1678 } 1679 1680 // Collect information about class methods 1681 llvm::SmallVector<Selector, 16> ClassMethodSels; 1682 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1683 for (ObjCCategoryImplDecl::classmeth_iterator 1684 iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end(); 1685 iter != endIter ; iter++) { 1686 ClassMethodSels.push_back((*iter)->getSelector()); 1687 std::string TypeStr; 1688 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1689 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1690 } 1691 1692 // Collect the names of referenced protocols 1693 llvm::SmallVector<std::string, 16> Protocols; 1694 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl(); 1695 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols(); 1696 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1697 E = Protos.end(); I != E; ++I) 1698 Protocols.push_back((*I)->getNameAsString()); 1699 1700 std::vector<llvm::Constant*> Elements; 1701 Elements.push_back(MakeConstantString(CategoryName)); 1702 Elements.push_back(MakeConstantString(ClassName)); 1703 // Instance method list 1704 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1705 ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes, 1706 false), PtrTy)); 1707 // Class method list 1708 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1709 ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true), 1710 PtrTy)); 1711 // Protocol list 1712 Elements.push_back(llvm::ConstantExpr::getBitCast( 1713 GenerateProtocolList(Protocols), PtrTy)); 1714 Categories.push_back(llvm::ConstantExpr::getBitCast( 1715 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 1716 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1717} 1718 1719llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID, 1720 llvm::SmallVectorImpl<Selector> &InstanceMethodSels, 1721 llvm::SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) { 1722 ASTContext &Context = CGM.getContext(); 1723 // 1724 // Property metadata: name, attributes, isSynthesized, setter name, setter 1725 // types, getter name, getter types. 1726 llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext, 1727 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1728 PtrToInt8Ty, NULL); 1729 std::vector<llvm::Constant*> Properties; 1730 1731 1732 // Add all of the property methods need adding to the method list and to the 1733 // property metadata list. 1734 for (ObjCImplDecl::propimpl_iterator 1735 iter = OID->propimpl_begin(), endIter = OID->propimpl_end(); 1736 iter != endIter ; iter++) { 1737 std::vector<llvm::Constant*> Fields; 1738 ObjCPropertyDecl *property = (*iter)->getPropertyDecl(); 1739 ObjCPropertyImplDecl *propertyImpl = *iter; 1740 bool isSynthesized = (propertyImpl->getPropertyImplementation() == 1741 ObjCPropertyImplDecl::Synthesize); 1742 1743 Fields.push_back(MakeConstantString(property->getNameAsString())); 1744 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1745 property->getPropertyAttributes())); 1746 Fields.push_back(llvm::ConstantInt::get(Int8Ty, isSynthesized)); 1747 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1748 std::string TypeStr; 1749 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1750 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1751 if (isSynthesized) { 1752 InstanceMethodTypes.push_back(TypeEncoding); 1753 InstanceMethodSels.push_back(getter->getSelector()); 1754 } 1755 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1756 Fields.push_back(TypeEncoding); 1757 } else { 1758 Fields.push_back(NULLPtr); 1759 Fields.push_back(NULLPtr); 1760 } 1761 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1762 std::string TypeStr; 1763 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1764 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1765 if (isSynthesized) { 1766 InstanceMethodTypes.push_back(TypeEncoding); 1767 InstanceMethodSels.push_back(setter->getSelector()); 1768 } 1769 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1770 Fields.push_back(TypeEncoding); 1771 } else { 1772 Fields.push_back(NULLPtr); 1773 Fields.push_back(NULLPtr); 1774 } 1775 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1776 } 1777 llvm::ArrayType *PropertyArrayTy = 1778 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()); 1779 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy, 1780 Properties); 1781 llvm::Constant* PropertyListInitFields[] = 1782 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1783 1784 llvm::Constant *PropertyListInit = 1785 llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false); 1786 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false, 1787 llvm::GlobalValue::InternalLinkage, PropertyListInit, 1788 ".objc_property_list"); 1789} 1790 1791void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) { 1792 ASTContext &Context = CGM.getContext(); 1793 1794 // Get the superclass name. 1795 const ObjCInterfaceDecl * SuperClassDecl = 1796 OID->getClassInterface()->getSuperClass(); 1797 std::string SuperClassName; 1798 if (SuperClassDecl) { 1799 SuperClassName = SuperClassDecl->getNameAsString(); 1800 EmitClassRef(SuperClassName); 1801 } 1802 1803 // Get the class name 1804 ObjCInterfaceDecl *ClassDecl = 1805 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface()); 1806 std::string ClassName = ClassDecl->getNameAsString(); 1807 // Emit the symbol that is used to generate linker errors if this class is 1808 // referenced in other modules but not declared. 1809 std::string classSymbolName = "__objc_class_name_" + ClassName; 1810 if (llvm::GlobalVariable *symbol = 1811 TheModule.getGlobalVariable(classSymbolName)) { 1812 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0)); 1813 } else { 1814 new llvm::GlobalVariable(TheModule, LongTy, false, 1815 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0), 1816 classSymbolName); 1817 } 1818 1819 // Get the size of instances. 1820 int instanceSize = 1821 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity(); 1822 1823 // Collect information about instance variables. 1824 llvm::SmallVector<llvm::Constant*, 16> IvarNames; 1825 llvm::SmallVector<llvm::Constant*, 16> IvarTypes; 1826 llvm::SmallVector<llvm::Constant*, 16> IvarOffsets; 1827 1828 std::vector<llvm::Constant*> IvarOffsetValues; 1829 1830 int superInstanceSize = !SuperClassDecl ? 0 : 1831 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity(); 1832 // For non-fragile ivars, set the instance size to 0 - {the size of just this 1833 // class}. The runtime will then set this to the correct value on load. 1834 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1835 instanceSize = 0 - (instanceSize - superInstanceSize); 1836 } 1837 1838 // Collect declared and synthesized ivars. 1839 llvm::SmallVector<ObjCIvarDecl*, 16> OIvars; 1840 CGM.getContext().ShallowCollectObjCIvars(ClassDecl, OIvars); 1841 1842 for (unsigned i = 0, e = OIvars.size(); i != e; ++i) { 1843 ObjCIvarDecl *IVD = OIvars[i]; 1844 // Store the name 1845 IvarNames.push_back(MakeConstantString(IVD->getNameAsString())); 1846 // Get the type encoding for this ivar 1847 std::string TypeStr; 1848 Context.getObjCEncodingForType(IVD->getType(), TypeStr); 1849 IvarTypes.push_back(MakeConstantString(TypeStr)); 1850 // Get the offset 1851 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD); 1852 uint64_t Offset = BaseOffset; 1853 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1854 Offset = BaseOffset - superInstanceSize; 1855 } 1856 IvarOffsets.push_back( 1857 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset)); 1858 IvarOffsetValues.push_back(new llvm::GlobalVariable(TheModule, IntTy, 1859 false, llvm::GlobalValue::ExternalLinkage, 1860 llvm::ConstantInt::get(IntTy, Offset), 1861 "__objc_ivar_offset_value_" + ClassName +"." + 1862 IVD->getNameAsString())); 1863 } 1864 llvm::GlobalVariable *IvarOffsetArray = 1865 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets"); 1866 1867 1868 // Collect information about instance methods 1869 llvm::SmallVector<Selector, 16> InstanceMethodSels; 1870 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1871 for (ObjCImplementationDecl::instmeth_iterator 1872 iter = OID->instmeth_begin(), endIter = OID->instmeth_end(); 1873 iter != endIter ; iter++) { 1874 InstanceMethodSels.push_back((*iter)->getSelector()); 1875 std::string TypeStr; 1876 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1877 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1878 } 1879 1880 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels, 1881 InstanceMethodTypes); 1882 1883 1884 // Collect information about class methods 1885 llvm::SmallVector<Selector, 16> ClassMethodSels; 1886 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1887 for (ObjCImplementationDecl::classmeth_iterator 1888 iter = OID->classmeth_begin(), endIter = OID->classmeth_end(); 1889 iter != endIter ; iter++) { 1890 ClassMethodSels.push_back((*iter)->getSelector()); 1891 std::string TypeStr; 1892 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1893 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1894 } 1895 // Collect the names of referenced protocols 1896 llvm::SmallVector<std::string, 16> Protocols; 1897 const ObjCList<ObjCProtocolDecl> &Protos =ClassDecl->getReferencedProtocols(); 1898 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1899 E = Protos.end(); I != E; ++I) 1900 Protocols.push_back((*I)->getNameAsString()); 1901 1902 1903 1904 // Get the superclass pointer. 1905 llvm::Constant *SuperClass; 1906 if (!SuperClassName.empty()) { 1907 SuperClass = MakeConstantString(SuperClassName, ".super_class_name"); 1908 } else { 1909 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty); 1910 } 1911 // Empty vector used to construct empty method lists 1912 llvm::SmallVector<llvm::Constant*, 1> empty; 1913 // Generate the method and instance variable lists 1914 llvm::Constant *MethodList = GenerateMethodList(ClassName, "", 1915 InstanceMethodSels, InstanceMethodTypes, false); 1916 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "", 1917 ClassMethodSels, ClassMethodTypes, true); 1918 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes, 1919 IvarOffsets); 1920 // Irrespective of whether we are compiling for a fragile or non-fragile ABI, 1921 // we emit a symbol containing the offset for each ivar in the class. This 1922 // allows code compiled for the non-Fragile ABI to inherit from code compiled 1923 // for the legacy ABI, without causing problems. The converse is also 1924 // possible, but causes all ivar accesses to be fragile. 1925 1926 // Offset pointer for getting at the correct field in the ivar list when 1927 // setting up the alias. These are: The base address for the global, the 1928 // ivar array (second field), the ivar in this list (set for each ivar), and 1929 // the offset (third field in ivar structure) 1930 const llvm::Type *IndexTy = llvm::Type::getInt32Ty(VMContext); 1931 llvm::Constant *offsetPointerIndexes[] = {Zeros[0], 1932 llvm::ConstantInt::get(IndexTy, 1), 0, 1933 llvm::ConstantInt::get(IndexTy, 2) }; 1934 1935 1936 for (unsigned i = 0, e = OIvars.size(); i != e; ++i) { 1937 ObjCIvarDecl *IVD = OIvars[i]; 1938 const std::string Name = "__objc_ivar_offset_" + ClassName + '.' 1939 + IVD->getNameAsString(); 1940 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, i); 1941 // Get the correct ivar field 1942 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr( 1943 IvarList, offsetPointerIndexes, 4); 1944 // Get the existing variable, if one exists. 1945 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name); 1946 if (offset) { 1947 offset->setInitializer(offsetValue); 1948 // If this is the real definition, change its linkage type so that 1949 // different modules will use this one, rather than their private 1950 // copy. 1951 offset->setLinkage(llvm::GlobalValue::ExternalLinkage); 1952 } else { 1953 // Add a new alias if there isn't one already. 1954 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(), 1955 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name); 1956 } 1957 } 1958 //Generate metaclass for class methods 1959 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr, 1960 NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList( 1961 empty, empty, empty), ClassMethodList, NULLPtr, NULLPtr, NULLPtr, true); 1962 1963 // Generate the class structure 1964 llvm::Constant *ClassStruct = 1965 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L, 1966 ClassName.c_str(), 0, 1967 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, 1968 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray, 1969 Properties); 1970 1971 // Resolve the class aliases, if they exist. 1972 if (ClassPtrAlias) { 1973 ClassPtrAlias->replaceAllUsesWith( 1974 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy)); 1975 ClassPtrAlias->eraseFromParent(); 1976 ClassPtrAlias = 0; 1977 } 1978 if (MetaClassPtrAlias) { 1979 MetaClassPtrAlias->replaceAllUsesWith( 1980 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy)); 1981 MetaClassPtrAlias->eraseFromParent(); 1982 MetaClassPtrAlias = 0; 1983 } 1984 1985 // Add class structure to list to be added to the symtab later 1986 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty); 1987 Classes.push_back(ClassStruct); 1988} 1989 1990 1991llvm::Function *CGObjCGNU::ModuleInitFunction() { 1992 // Only emit an ObjC load function if no Objective-C stuff has been called 1993 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() && 1994 ExistingProtocols.empty() && SelectorTable.empty()) 1995 return NULL; 1996 1997 // Add all referenced protocols to a category. 1998 GenerateProtocolHolderCategory(); 1999 2000 const llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>( 2001 SelectorTy->getElementType()); 2002 const llvm::Type *SelStructPtrTy = SelectorTy; 2003 if (SelStructTy == 0) { 2004 SelStructTy = llvm::StructType::get(VMContext, PtrToInt8Ty, 2005 PtrToInt8Ty, NULL); 2006 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy); 2007 } 2008 2009 // Name the ObjC types to make the IR a bit easier to read 2010 TheModule.addTypeName(".objc_selector", SelStructPtrTy); 2011 TheModule.addTypeName(".objc_id", IdTy); 2012 TheModule.addTypeName(".objc_imp", IMPTy); 2013 2014 std::vector<llvm::Constant*> Elements; 2015 llvm::Constant *Statics = NULLPtr; 2016 // Generate statics list: 2017 if (ConstantStrings.size()) { 2018 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 2019 ConstantStrings.size() + 1); 2020 ConstantStrings.push_back(NULLPtr); 2021 2022 llvm::StringRef StringClass = CGM.getLangOptions().ObjCConstantStringClass; 2023 2024 if (StringClass.empty()) StringClass = "NXConstantString"; 2025 2026 Elements.push_back(MakeConstantString(StringClass, 2027 ".objc_static_class_name")); 2028 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy, 2029 ConstantStrings)); 2030 llvm::StructType *StaticsListTy = 2031 llvm::StructType::get(VMContext, PtrToInt8Ty, StaticsArrayTy, NULL); 2032 llvm::Type *StaticsListPtrTy = 2033 llvm::PointerType::getUnqual(StaticsListTy); 2034 Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics"); 2035 llvm::ArrayType *StaticsListArrayTy = 2036 llvm::ArrayType::get(StaticsListPtrTy, 2); 2037 Elements.clear(); 2038 Elements.push_back(Statics); 2039 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy)); 2040 Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr"); 2041 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy); 2042 } 2043 // Array of classes, categories, and constant objects 2044 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty, 2045 Classes.size() + Categories.size() + 2); 2046 llvm::StructType *SymTabTy = llvm::StructType::get(VMContext, 2047 LongTy, SelStructPtrTy, 2048 llvm::Type::getInt16Ty(VMContext), 2049 llvm::Type::getInt16Ty(VMContext), 2050 ClassListTy, NULL); 2051 2052 Elements.clear(); 2053 // Pointer to an array of selectors used in this module. 2054 std::vector<llvm::Constant*> Selectors; 2055 std::vector<llvm::GlobalAlias*> SelectorAliases; 2056 for (SelectorMap::iterator iter = SelectorTable.begin(), 2057 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) { 2058 2059 std::string SelNameStr = iter->first.getAsString(); 2060 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name"); 2061 2062 llvm::SmallVectorImpl<TypedSelector> &Types = iter->second; 2063 for (llvm::SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 2064 e = Types.end() ; i!=e ; i++) { 2065 2066 llvm::Constant *SelectorTypeEncoding = NULLPtr; 2067 if (!i->first.empty()) 2068 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types"); 2069 2070 Elements.push_back(SelName); 2071 Elements.push_back(SelectorTypeEncoding); 2072 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2073 Elements.clear(); 2074 2075 // Store the selector alias for later replacement 2076 SelectorAliases.push_back(i->second); 2077 } 2078 } 2079 unsigned SelectorCount = Selectors.size(); 2080 // NULL-terminate the selector list. This should not actually be required, 2081 // because the selector list has a length field. Unfortunately, the GCC 2082 // runtime decides to ignore the length field and expects a NULL terminator, 2083 // and GCC cooperates with this by always setting the length to 0. 2084 Elements.push_back(NULLPtr); 2085 Elements.push_back(NULLPtr); 2086 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2087 Elements.clear(); 2088 2089 // Number of static selectors 2090 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount)); 2091 llvm::Constant *SelectorList = MakeGlobalArray(SelStructTy, Selectors, 2092 ".objc_selector_list"); 2093 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList, 2094 SelStructPtrTy)); 2095 2096 // Now that all of the static selectors exist, create pointers to them. 2097 for (unsigned int i=0 ; i<SelectorCount ; i++) { 2098 2099 llvm::Constant *Idxs[] = {Zeros[0], 2100 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), i), Zeros[0]}; 2101 // FIXME: We're generating redundant loads and stores here! 2102 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(SelectorList, 2103 Idxs, 2); 2104 // If selectors are defined as an opaque type, cast the pointer to this 2105 // type. 2106 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy); 2107 SelectorAliases[i]->replaceAllUsesWith(SelPtr); 2108 SelectorAliases[i]->eraseFromParent(); 2109 } 2110 2111 // Number of classes defined. 2112 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2113 Classes.size())); 2114 // Number of categories defined 2115 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2116 Categories.size())); 2117 // Create an array of classes, then categories, then static object instances 2118 Classes.insert(Classes.end(), Categories.begin(), Categories.end()); 2119 // NULL-terminated list of static object instances (mainly constant strings) 2120 Classes.push_back(Statics); 2121 Classes.push_back(NULLPtr); 2122 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes); 2123 Elements.push_back(ClassList); 2124 // Construct the symbol table 2125 llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements); 2126 2127 // The symbol table is contained in a module which has some version-checking 2128 // constants 2129 llvm::StructType * ModuleTy = llvm::StructType::get(VMContext, LongTy, LongTy, 2130 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), NULL); 2131 Elements.clear(); 2132 // Runtime version, used for ABI compatibility checking. 2133 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion)); 2134 // sizeof(ModuleTy) 2135 llvm::TargetData td(&TheModule); 2136 Elements.push_back( 2137 llvm::ConstantInt::get(LongTy, 2138 td.getTypeSizeInBits(ModuleTy) / 2139 CGM.getContext().getCharWidth())); 2140 2141 // The path to the source file where this module was declared 2142 SourceManager &SM = CGM.getContext().getSourceManager(); 2143 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID()); 2144 std::string path = 2145 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName(); 2146 Elements.push_back(MakeConstantString(path, ".objc_source_file_name")); 2147 2148 Elements.push_back(SymTab); 2149 llvm::Value *Module = MakeGlobal(ModuleTy, Elements); 2150 2151 // Create the load function calling the runtime entry point with the module 2152 // structure 2153 llvm::Function * LoadFunction = llvm::Function::Create( 2154 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false), 2155 llvm::GlobalValue::InternalLinkage, ".objc_load_function", 2156 &TheModule); 2157 llvm::BasicBlock *EntryBB = 2158 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction); 2159 CGBuilderTy Builder(VMContext); 2160 Builder.SetInsertPoint(EntryBB); 2161 2162 std::vector<const llvm::Type*> Params(1, 2163 llvm::PointerType::getUnqual(ModuleTy)); 2164 llvm::Value *Register = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 2165 llvm::Type::getVoidTy(VMContext), Params, true), "__objc_exec_class"); 2166 Builder.CreateCall(Register, Module); 2167 Builder.CreateRetVoid(); 2168 2169 return LoadFunction; 2170} 2171 2172llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD, 2173 const ObjCContainerDecl *CD) { 2174 const ObjCCategoryImplDecl *OCD = 2175 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext()); 2176 llvm::StringRef CategoryName = OCD ? OCD->getName() : ""; 2177 llvm::StringRef ClassName = CD->getName(); 2178 Selector MethodName = OMD->getSelector(); 2179 bool isClassMethod = !OMD->isInstanceMethod(); 2180 2181 CodeGenTypes &Types = CGM.getTypes(); 2182 const llvm::FunctionType *MethodTy = 2183 Types.GetFunctionType(Types.getFunctionInfo(OMD), OMD->isVariadic()); 2184 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName, 2185 MethodName, isClassMethod); 2186 2187 llvm::Function *Method 2188 = llvm::Function::Create(MethodTy, 2189 llvm::GlobalValue::InternalLinkage, 2190 FunctionName, 2191 &TheModule); 2192 return Method; 2193} 2194 2195llvm::Function *CGObjCGNU::GetPropertyGetFunction() { 2196 return GetPropertyFn; 2197} 2198 2199llvm::Function *CGObjCGNU::GetPropertySetFunction() { 2200 return SetPropertyFn; 2201} 2202 2203llvm::Function *CGObjCGNU::GetGetStructFunction() { 2204 return GetStructPropertyFn; 2205} 2206llvm::Function *CGObjCGNU::GetSetStructFunction() { 2207 return SetStructPropertyFn; 2208} 2209 2210llvm::Constant *CGObjCGNU::EnumerationMutationFunction() { 2211 return EnumerationMutationFn; 2212} 2213 2214void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF, 2215 const ObjCAtSynchronizedStmt &S) { 2216 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn); 2217} 2218 2219 2220void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF, 2221 const ObjCAtTryStmt &S) { 2222 // Unlike the Apple non-fragile runtimes, which also uses 2223 // unwind-based zero cost exceptions, the GNU Objective C runtime's 2224 // EH support isn't a veneer over C++ EH. Instead, exception 2225 // objects are created by __objc_exception_throw and destroyed by 2226 // the personality function; this avoids the need for bracketing 2227 // catch handlers with calls to __blah_begin_catch/__blah_end_catch 2228 // (or even _Unwind_DeleteException), but probably doesn't 2229 // interoperate very well with foreign exceptions. 2230 // 2231 // In Objective-C++ mode, we actually emit something equivalent to the C++ 2232 // exception handler. 2233 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn); 2234 return ; 2235} 2236 2237void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF, 2238 const ObjCAtThrowStmt &S) { 2239 llvm::Value *ExceptionAsObject; 2240 2241 if (const Expr *ThrowExpr = S.getThrowExpr()) { 2242 llvm::Value *Exception = CGF.EmitScalarExpr(ThrowExpr); 2243 ExceptionAsObject = Exception; 2244 } else { 2245 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) && 2246 "Unexpected rethrow outside @catch block."); 2247 ExceptionAsObject = CGF.ObjCEHValueStack.back(); 2248 } 2249 ExceptionAsObject = 2250 CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy, "tmp"); 2251 2252 // Note: This may have to be an invoke, if we want to support constructs like: 2253 // @try { 2254 // @throw(obj); 2255 // } 2256 // @catch(id) ... 2257 // 2258 // This is effectively turning @throw into an incredibly-expensive goto, but 2259 // it may happen as a result of inlining followed by missed optimizations, or 2260 // as a result of stupidity. 2261 llvm::BasicBlock *UnwindBB = CGF.getInvokeDest(); 2262 if (!UnwindBB) { 2263 CGF.Builder.CreateCall(ExceptionThrowFn, ExceptionAsObject); 2264 CGF.Builder.CreateUnreachable(); 2265 } else { 2266 CGF.Builder.CreateInvoke(ExceptionThrowFn, UnwindBB, UnwindBB, &ExceptionAsObject, 2267 &ExceptionAsObject+1); 2268 } 2269 // Clear the insertion point to indicate we are in unreachable code. 2270 CGF.Builder.ClearInsertionPoint(); 2271} 2272 2273llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF, 2274 llvm::Value *AddrWeakObj) { 2275 CGBuilderTy B = CGF.Builder; 2276 AddrWeakObj = EnforceType(B, AddrWeakObj, IdTy); 2277 return B.CreateCall(WeakReadFn, AddrWeakObj); 2278} 2279 2280void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF, 2281 llvm::Value *src, llvm::Value *dst) { 2282 CGBuilderTy B = CGF.Builder; 2283 src = EnforceType(B, src, IdTy); 2284 dst = EnforceType(B, dst, PtrToIdTy); 2285 B.CreateCall2(WeakAssignFn, src, dst); 2286} 2287 2288void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF, 2289 llvm::Value *src, llvm::Value *dst, 2290 bool threadlocal) { 2291 CGBuilderTy B = CGF.Builder; 2292 src = EnforceType(B, src, IdTy); 2293 dst = EnforceType(B, dst, PtrToIdTy); 2294 if (!threadlocal) 2295 B.CreateCall2(GlobalAssignFn, src, dst); 2296 else 2297 // FIXME. Add threadloca assign API 2298 assert(false && "EmitObjCGlobalAssign - Threal Local API NYI"); 2299} 2300 2301void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF, 2302 llvm::Value *src, llvm::Value *dst, 2303 llvm::Value *ivarOffset) { 2304 CGBuilderTy B = CGF.Builder; 2305 src = EnforceType(B, src, IdTy); 2306 dst = EnforceType(B, dst, PtrToIdTy); 2307 B.CreateCall3(IvarAssignFn, src, dst, ivarOffset); 2308} 2309 2310void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF, 2311 llvm::Value *src, llvm::Value *dst) { 2312 CGBuilderTy B = CGF.Builder; 2313 src = EnforceType(B, src, IdTy); 2314 dst = EnforceType(B, dst, PtrToIdTy); 2315 B.CreateCall2(StrongCastAssignFn, src, dst); 2316} 2317 2318void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF, 2319 llvm::Value *DestPtr, 2320 llvm::Value *SrcPtr, 2321 llvm::Value *Size) { 2322 CGBuilderTy B = CGF.Builder; 2323 DestPtr = EnforceType(B, DestPtr, IdTy); 2324 SrcPtr = EnforceType(B, SrcPtr, PtrToIdTy); 2325 2326 B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size); 2327} 2328 2329llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable( 2330 const ObjCInterfaceDecl *ID, 2331 const ObjCIvarDecl *Ivar) { 2332 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString() 2333 + '.' + Ivar->getNameAsString(); 2334 // Emit the variable and initialize it with what we think the correct value 2335 // is. This allows code compiled with non-fragile ivars to work correctly 2336 // when linked against code which isn't (most of the time). 2337 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name); 2338 if (!IvarOffsetPointer) { 2339 // This will cause a run-time crash if we accidentally use it. A value of 2340 // 0 would seem more sensible, but will silently overwrite the isa pointer 2341 // causing a great deal of confusion. 2342 uint64_t Offset = -1; 2343 // We can't call ComputeIvarBaseOffset() here if we have the 2344 // implementation, because it will create an invalid ASTRecordLayout object 2345 // that we are then stuck with forever, so we only initialize the ivar 2346 // offset variable with a guess if we only have the interface. The 2347 // initializer will be reset later anyway, when we are generating the class 2348 // description. 2349 if (!CGM.getContext().getObjCImplementation( 2350 const_cast<ObjCInterfaceDecl *>(ID))) 2351 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar); 2352 2353 llvm::ConstantInt *OffsetGuess = 2354 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset, "ivar"); 2355 // Don't emit the guess in non-PIC code because the linker will not be able 2356 // to replace it with the real version for a library. In non-PIC code you 2357 // must compile with the fragile ABI if you want to use ivars from a 2358 // GCC-compiled class. 2359 if (CGM.getLangOptions().PICLevel) { 2360 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule, 2361 llvm::Type::getInt32Ty(VMContext), false, 2362 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess"); 2363 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2364 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage, 2365 IvarOffsetGV, Name); 2366 } else { 2367 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2368 llvm::Type::getInt32PtrTy(VMContext), false, 2369 llvm::GlobalValue::ExternalLinkage, 0, Name); 2370 } 2371 } 2372 return IvarOffsetPointer; 2373} 2374 2375LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF, 2376 QualType ObjectTy, 2377 llvm::Value *BaseValue, 2378 const ObjCIvarDecl *Ivar, 2379 unsigned CVRQualifiers) { 2380 const ObjCInterfaceDecl *ID = 2381 ObjectTy->getAs<ObjCObjectType>()->getInterface(); 2382 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers, 2383 EmitIvarOffset(CGF, ID, Ivar)); 2384} 2385 2386static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context, 2387 const ObjCInterfaceDecl *OID, 2388 const ObjCIvarDecl *OIVD) { 2389 llvm::SmallVector<ObjCIvarDecl*, 16> Ivars; 2390 Context.ShallowCollectObjCIvars(OID, Ivars); 2391 for (unsigned k = 0, e = Ivars.size(); k != e; ++k) { 2392 if (OIVD == Ivars[k]) 2393 return OID; 2394 } 2395 2396 // Otherwise check in the super class. 2397 if (const ObjCInterfaceDecl *Super = OID->getSuperClass()) 2398 return FindIvarInterface(Context, Super, OIVD); 2399 2400 return 0; 2401} 2402 2403llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF, 2404 const ObjCInterfaceDecl *Interface, 2405 const ObjCIvarDecl *Ivar) { 2406 if (CGM.getLangOptions().ObjCNonFragileABI) { 2407 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar); 2408 return CGF.Builder.CreateZExtOrBitCast( 2409 CGF.Builder.CreateLoad(CGF.Builder.CreateLoad( 2410 ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")), 2411 PtrDiffTy); 2412 } 2413 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar); 2414 return llvm::ConstantInt::get(PtrDiffTy, Offset, "ivar"); 2415} 2416 2417CGObjCRuntime * 2418clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) { 2419 if (CGM.getLangOptions().ObjCNonFragileABI) 2420 return new CGObjCGNUstep(CGM); 2421 return new CGObjCGCC(CGM); 2422} 2423