CGObjCGNU.cpp revision a2120039ed08a5d5d6096e2560fd32c6128e951a
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 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 virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) { 489 return 0; 490 } 491}; 492/// Class representing the legacy GCC Objective-C ABI. This is the default when 493/// -fobjc-nonfragile-abi is not specified. 494/// 495/// The GCC ABI target actually generates code that is approximately compatible 496/// with the new GNUstep runtime ABI, but refrains from using any features that 497/// would not work with the GCC runtime. For example, clang always generates 498/// the extended form of the class structure, and the extra fields are simply 499/// ignored by GCC libobjc. 500class CGObjCGCC : public CGObjCGNU { 501 /// The GCC ABI message lookup function. Returns an IMP pointing to the 502 /// method implementation for this message. 503 LazyRuntimeFunction MsgLookupFn; 504 /// The GCC ABI superclass message lookup function. Takes a pointer to a 505 /// structure describing the receiver and the class, and a selector as 506 /// arguments. Returns the IMP for the corresponding method. 507 LazyRuntimeFunction MsgLookupSuperFn; 508protected: 509 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 510 llvm::Value *&Receiver, 511 llvm::Value *cmd, 512 llvm::MDNode *node) { 513 CGBuilderTy &Builder = CGF.Builder; 514 llvm::Value *imp = Builder.CreateCall2(MsgLookupFn, 515 EnforceType(Builder, Receiver, IdTy), 516 EnforceType(Builder, cmd, SelectorTy)); 517 cast<llvm::CallInst>(imp)->setMetadata(msgSendMDKind, node); 518 return imp; 519 } 520 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 521 llvm::Value *ObjCSuper, 522 llvm::Value *cmd) { 523 CGBuilderTy &Builder = CGF.Builder; 524 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 525 PtrToObjCSuperTy), cmd}; 526 return Builder.CreateCall(MsgLookupSuperFn, lookupArgs, lookupArgs+2); 527 } 528 public: 529 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) { 530 // IMP objc_msg_lookup(id, SEL); 531 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 532 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 533 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 534 PtrToObjCSuperTy, SelectorTy, NULL); 535 } 536}; 537/// Class used when targeting the new GNUstep runtime ABI. 538class CGObjCGNUstep : public CGObjCGNU { 539 /// The slot lookup function. Returns a pointer to a cacheable structure 540 /// that contains (among other things) the IMP. 541 LazyRuntimeFunction SlotLookupFn; 542 /// The GNUstep ABI superclass message lookup function. Takes a pointer to 543 /// a structure describing the receiver and the class, and a selector as 544 /// arguments. Returns the slot for the corresponding method. Superclass 545 /// message lookup rarely changes, so this is a good caching opportunity. 546 LazyRuntimeFunction SlotLookupSuperFn; 547 /// Type of an slot structure pointer. This is returned by the various 548 /// lookup functions. 549 llvm::Type *SlotTy; 550 protected: 551 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 552 llvm::Value *&Receiver, 553 llvm::Value *cmd, 554 llvm::MDNode *node) { 555 CGBuilderTy &Builder = CGF.Builder; 556 llvm::Function *LookupFn = SlotLookupFn; 557 558 // Store the receiver on the stack so that we can reload it later 559 llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType()); 560 Builder.CreateStore(Receiver, ReceiverPtr); 561 562 llvm::Value *self; 563 564 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) { 565 self = CGF.LoadObjCSelf(); 566 } else { 567 self = llvm::ConstantPointerNull::get(IdTy); 568 } 569 570 // The lookup function is guaranteed not to capture the receiver pointer. 571 LookupFn->setDoesNotCapture(1); 572 573 llvm::CallInst *slot = 574 Builder.CreateCall3(LookupFn, 575 EnforceType(Builder, ReceiverPtr, PtrToIdTy), 576 EnforceType(Builder, cmd, SelectorTy), 577 EnforceType(Builder, self, IdTy)); 578 slot->setOnlyReadsMemory(); 579 slot->setMetadata(msgSendMDKind, node); 580 581 // Load the imp from the slot 582 llvm::Value *imp = Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 583 584 // The lookup function may have changed the receiver, so make sure we use 585 // the new one. 586 Receiver = Builder.CreateLoad(ReceiverPtr, true); 587 return imp; 588 } 589 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 590 llvm::Value *ObjCSuper, 591 llvm::Value *cmd) { 592 CGBuilderTy &Builder = CGF.Builder; 593 llvm::Value *lookupArgs[] = {ObjCSuper, cmd}; 594 595 llvm::CallInst *slot = Builder.CreateCall(SlotLookupSuperFn, lookupArgs, 596 lookupArgs+2); 597 slot->setOnlyReadsMemory(); 598 599 return Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 600 } 601 public: 602 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) { 603 llvm::StructType *SlotStructTy = llvm::StructType::get(VMContext, PtrTy, 604 PtrTy, PtrTy, IntTy, IMPTy, NULL); 605 SlotTy = llvm::PointerType::getUnqual(SlotStructTy); 606 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 607 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy, 608 SelectorTy, IdTy, NULL); 609 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL); 610 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy, 611 PtrToObjCSuperTy, SelectorTy, NULL); 612 // If we're in ObjC++ mode, then we want to make 613 if (CGM.getLangOptions().CPlusPlus) { 614 const llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 615 // void *__cxa_begin_catch(void *e) 616 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, NULL); 617 // void __cxa_end_catch(void) 618 EnterCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, NULL); 619 // void _Unwind_Resume_or_Rethrow(void*) 620 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, PtrTy, NULL); 621 } 622 } 623}; 624 625} // end anonymous namespace 626 627 628/// Emits a reference to a dummy variable which is emitted with each class. 629/// This ensures that a linker error will be generated when trying to link 630/// together modules where a referenced class is not defined. 631void CGObjCGNU::EmitClassRef(const std::string &className) { 632 std::string symbolRef = "__objc_class_ref_" + className; 633 // Don't emit two copies of the same symbol 634 if (TheModule.getGlobalVariable(symbolRef)) 635 return; 636 std::string symbolName = "__objc_class_name_" + className; 637 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName); 638 if (!ClassSymbol) { 639 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 640 llvm::GlobalValue::ExternalLinkage, 0, symbolName); 641 } 642 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true, 643 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef); 644} 645 646static std::string SymbolNameForMethod(const llvm::StringRef &ClassName, 647 const llvm::StringRef &CategoryName, const Selector MethodName, 648 bool isClassMethod) { 649 std::string MethodNameColonStripped = MethodName.getAsString(); 650 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(), 651 ':', '_'); 652 return (llvm::Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" + 653 CategoryName + "_" + MethodNameColonStripped).str(); 654} 655 656CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 657 unsigned protocolClassVersion) 658 : CGM(cgm), TheModule(CGM.getModule()), VMContext(cgm.getLLVMContext()), 659 ClassPtrAlias(0), MetaClassPtrAlias(0), RuntimeVersion(runtimeABIVersion), 660 ProtocolVersion(protocolClassVersion) { 661 662 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend"); 663 664 CodeGenTypes &Types = CGM.getTypes(); 665 IntTy = cast<llvm::IntegerType>( 666 Types.ConvertType(CGM.getContext().IntTy)); 667 LongTy = cast<llvm::IntegerType>( 668 Types.ConvertType(CGM.getContext().LongTy)); 669 SizeTy = cast<llvm::IntegerType>( 670 Types.ConvertType(CGM.getContext().getSizeType())); 671 PtrDiffTy = cast<llvm::IntegerType>( 672 Types.ConvertType(CGM.getContext().getPointerDiffType())); 673 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy); 674 675 Int8Ty = llvm::Type::getInt8Ty(VMContext); 676 // C string type. Used in lots of places. 677 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); 678 679 Zeros[0] = llvm::ConstantInt::get(LongTy, 0); 680 Zeros[1] = Zeros[0]; 681 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty); 682 // Get the selector Type. 683 QualType selTy = CGM.getContext().getObjCSelType(); 684 if (QualType() == selTy) { 685 SelectorTy = PtrToInt8Ty; 686 } else { 687 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy)); 688 } 689 690 PtrToIntTy = llvm::PointerType::getUnqual(IntTy); 691 PtrTy = PtrToInt8Ty; 692 693 // Object type 694 QualType UnqualIdTy = CGM.getContext().getObjCIdType(); 695 ASTIdTy = CanQualType(); 696 if (UnqualIdTy != QualType()) { 697 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy); 698 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 699 } else { 700 IdTy = PtrToInt8Ty; 701 } 702 PtrToIdTy = llvm::PointerType::getUnqual(IdTy); 703 704 ObjCSuperTy = llvm::StructType::get(VMContext, IdTy, IdTy, NULL); 705 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy); 706 707 const llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 708 709 // void objc_exception_throw(id); 710 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 711 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 712 // int objc_sync_enter(id); 713 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, NULL); 714 // int objc_sync_exit(id); 715 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, NULL); 716 717 // void objc_enumerationMutation (id) 718 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, 719 IdTy, NULL); 720 721 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL) 722 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy, 723 PtrDiffTy, BoolTy, NULL); 724 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL) 725 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy, 726 PtrDiffTy, IdTy, BoolTy, BoolTy, NULL); 727 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 728 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy, 729 PtrDiffTy, BoolTy, BoolTy, NULL); 730 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 731 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy, 732 PtrDiffTy, BoolTy, BoolTy, NULL); 733 734 // IMP type 735 std::vector<const llvm::Type*> IMPArgs; 736 IMPArgs.push_back(IdTy); 737 IMPArgs.push_back(SelectorTy); 738 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs, 739 true)); 740 741 // Don't bother initialising the GC stuff unless we're compiling in GC mode 742 if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) { 743 // This is a bit of an hack. We should sort this out by having a proper 744 // CGObjCGNUstep subclass for GC, but we may want to really support the old 745 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now 746 RuntimeVersion = 10; 747 // Get selectors needed in GC mode 748 RetainSel = GetNullarySelector("retain", CGM.getContext()); 749 ReleaseSel = GetNullarySelector("release", CGM.getContext()); 750 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext()); 751 752 // Get functions needed in GC mode 753 754 // id objc_assign_ivar(id, id, ptrdiff_t); 755 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy, 756 NULL); 757 // id objc_assign_strongCast (id, id*) 758 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy, 759 PtrToIdTy, NULL); 760 // id objc_assign_global(id, id*); 761 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy, 762 NULL); 763 // id objc_assign_weak(id, id*); 764 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, NULL); 765 // id objc_read_weak(id*); 766 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, NULL); 767 // void *objc_memmove_collectable(void*, void *, size_t); 768 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy, 769 SizeTy, NULL); 770 } 771} 772 773// This has to perform the lookup every time, since posing and related 774// techniques can modify the name -> class mapping. 775llvm::Value *CGObjCGNU::GetClass(CGBuilderTy &Builder, 776 const ObjCInterfaceDecl *OID) { 777 llvm::Value *ClassName = CGM.GetAddrOfConstantCString(OID->getNameAsString()); 778 // With the incompatible ABI, this will need to be replaced with a direct 779 // reference to the class symbol. For the compatible nonfragile ABI we are 780 // still performing this lookup at run time but emitting the symbol for the 781 // class externally so that we can make the switch later. 782 EmitClassRef(OID->getNameAsString()); 783 ClassName = Builder.CreateStructGEP(ClassName, 0); 784 785 std::vector<const llvm::Type*> Params(1, PtrToInt8Ty); 786 llvm::Constant *ClassLookupFn = 787 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, 788 Params, 789 true), 790 "objc_lookup_class"); 791 return Builder.CreateCall(ClassLookupFn, ClassName); 792} 793 794llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 795 const std::string &TypeEncoding, bool lval) { 796 797 llvm::SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel]; 798 llvm::GlobalAlias *SelValue = 0; 799 800 801 for (llvm::SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 802 e = Types.end() ; i!=e ; i++) { 803 if (i->first == TypeEncoding) { 804 SelValue = i->second; 805 break; 806 } 807 } 808 if (0 == SelValue) { 809 SelValue = new llvm::GlobalAlias(SelectorTy, 810 llvm::GlobalValue::PrivateLinkage, 811 ".objc_selector_"+Sel.getAsString(), NULL, 812 &TheModule); 813 Types.push_back(TypedSelector(TypeEncoding, SelValue)); 814 } 815 816 if (lval) { 817 llvm::Value *tmp = Builder.CreateAlloca(SelValue->getType()); 818 Builder.CreateStore(SelValue, tmp); 819 return tmp; 820 } 821 return SelValue; 822} 823 824llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 825 bool lval) { 826 return GetSelector(Builder, Sel, std::string(), lval); 827} 828 829llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 830 *Method) { 831 std::string SelTypes; 832 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes); 833 return GetSelector(Builder, Method->getSelector(), SelTypes, false); 834} 835 836llvm::Constant *CGObjCGNU::GetEHType(QualType T) { 837 if (!CGM.getLangOptions().CPlusPlus) { 838 if (T->isObjCIdType() 839 || T->isObjCQualifiedIdType()) { 840 // With the old ABI, there was only one kind of catchall, which broke 841 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as 842 // a pointer indicating object catchalls, and NULL to indicate real 843 // catchalls 844 if (CGM.getLangOptions().ObjCNonFragileABI) { 845 return MakeConstantString("@id"); 846 } else { 847 return 0; 848 } 849 } 850 851 // All other types should be Objective-C interface pointer types. 852 const ObjCObjectPointerType *OPT = 853 T->getAs<ObjCObjectPointerType>(); 854 assert(OPT && "Invalid @catch type."); 855 const ObjCInterfaceDecl *IDecl = 856 OPT->getObjectType()->getInterface(); 857 assert(IDecl && "Invalid @catch type."); 858 return MakeConstantString(IDecl->getIdentifier()->getName()); 859 } 860 // For Objective-C++, we want to provide the ability to catch both C++ and 861 // Objective-C objects in the same function. 862 863 // There's a particular fixed type info for 'id'. 864 if (T->isObjCIdType() || 865 T->isObjCQualifiedIdType()) { 866 llvm::Constant *IDEHType = 867 CGM.getModule().getGlobalVariable("__objc_id_type_info"); 868 if (!IDEHType) 869 IDEHType = 870 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty, 871 false, 872 llvm::GlobalValue::ExternalLinkage, 873 0, "__objc_id_type_info"); 874 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty); 875 } 876 877 const ObjCObjectPointerType *PT = 878 T->getAs<ObjCObjectPointerType>(); 879 assert(PT && "Invalid @catch type."); 880 const ObjCInterfaceType *IT = PT->getInterfaceType(); 881 assert(IT && "Invalid @catch type."); 882 std::string className = IT->getDecl()->getIdentifier()->getName(); 883 884 std::string typeinfoName = "__objc_eh_typeinfo_" + className; 885 886 // Return the existing typeinfo if it exists 887 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName); 888 if (typeinfo) return typeinfo; 889 890 // Otherwise create it. 891 892 // vtable for gnustep::libobjc::__objc_class_type_info 893 // It's quite ugly hard-coding this. Ideally we'd generate it using the host 894 // platform's name mangling. 895 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE"; 896 llvm::Constant *Vtable = TheModule.getGlobalVariable(vtableName); 897 if (!Vtable) { 898 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true, 899 llvm::GlobalValue::ExternalLinkage, 0, vtableName); 900 } 901 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2); 902 Vtable = llvm::ConstantExpr::getGetElementPtr(Vtable, &Two, 1); 903 Vtable = llvm::ConstantExpr::getBitCast(Vtable, PtrToInt8Ty); 904 905 llvm::Constant *typeName = 906 ExportUniqueString(className, "__objc_eh_typename_"); 907 908 std::vector<llvm::Constant*> fields; 909 fields.push_back(Vtable); 910 fields.push_back(typeName); 911 llvm::Constant *TI = 912 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 913 NULL), fields, "__objc_eh_typeinfo_" + className, 914 llvm::GlobalValue::LinkOnceODRLinkage); 915 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty); 916} 917 918/// Generate an NSConstantString object. 919llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) { 920 921 std::string Str = SL->getString().str(); 922 923 // Look for an existing one 924 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str); 925 if (old != ObjCStrings.end()) 926 return old->getValue(); 927 928 std::vector<llvm::Constant*> Ivars; 929 Ivars.push_back(NULLPtr); 930 Ivars.push_back(MakeConstantString(Str)); 931 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size())); 932 llvm::Constant *ObjCStr = MakeGlobal( 933 llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, IntTy, NULL), 934 Ivars, ".objc_str"); 935 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty); 936 ObjCStrings[Str] = ObjCStr; 937 ConstantStrings.push_back(ObjCStr); 938 return ObjCStr; 939} 940 941///Generates a message send where the super is the receiver. This is a message 942///send to self with special delivery semantics indicating which class's method 943///should be called. 944RValue 945CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF, 946 ReturnValueSlot Return, 947 QualType ResultType, 948 Selector Sel, 949 const ObjCInterfaceDecl *Class, 950 bool isCategoryImpl, 951 llvm::Value *Receiver, 952 bool IsClassMessage, 953 const CallArgList &CallArgs, 954 const ObjCMethodDecl *Method) { 955 if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) { 956 if (Sel == RetainSel || Sel == AutoreleaseSel) { 957 return RValue::get(Receiver); 958 } 959 if (Sel == ReleaseSel) { 960 return RValue::get(0); 961 } 962 } 963 964 CGBuilderTy &Builder = CGF.Builder; 965 llvm::Value *cmd = GetSelector(Builder, Sel); 966 967 968 CallArgList ActualArgs; 969 970 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy); 971 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 972 ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end()); 973 974 CodeGenTypes &Types = CGM.getTypes(); 975 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 976 FunctionType::ExtInfo()); 977 978 llvm::Value *ReceiverClass = 0; 979 if (isCategoryImpl) { 980 llvm::Constant *classLookupFunction = 0; 981 std::vector<const llvm::Type*> Params; 982 Params.push_back(PtrTy); 983 if (IsClassMessage) { 984 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 985 IdTy, Params, true), "objc_get_meta_class"); 986 } else { 987 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 988 IdTy, Params, true), "objc_get_class"); 989 } 990 ReceiverClass = Builder.CreateCall(classLookupFunction, 991 MakeConstantString(Class->getNameAsString())); 992 } else { 993 // Set up global aliases for the metaclass or class pointer if they do not 994 // already exist. These will are forward-references which will be set to 995 // pointers to the class and metaclass structure created for the runtime 996 // load function. To send a message to super, we look up the value of the 997 // super_class pointer from either the class or metaclass structure. 998 if (IsClassMessage) { 999 if (!MetaClassPtrAlias) { 1000 MetaClassPtrAlias = new llvm::GlobalAlias(IdTy, 1001 llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" + 1002 Class->getNameAsString(), NULL, &TheModule); 1003 } 1004 ReceiverClass = MetaClassPtrAlias; 1005 } else { 1006 if (!ClassPtrAlias) { 1007 ClassPtrAlias = new llvm::GlobalAlias(IdTy, 1008 llvm::GlobalValue::InternalLinkage, ".objc_class_ref" + 1009 Class->getNameAsString(), NULL, &TheModule); 1010 } 1011 ReceiverClass = ClassPtrAlias; 1012 } 1013 } 1014 // Cast the pointer to a simplified version of the class structure 1015 ReceiverClass = Builder.CreateBitCast(ReceiverClass, 1016 llvm::PointerType::getUnqual( 1017 llvm::StructType::get(VMContext, IdTy, IdTy, NULL))); 1018 // Get the superclass pointer 1019 ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1); 1020 // Load the superclass pointer 1021 ReceiverClass = Builder.CreateLoad(ReceiverClass); 1022 // Construct the structure used to look up the IMP 1023 llvm::StructType *ObjCSuperTy = llvm::StructType::get(VMContext, 1024 Receiver->getType(), IdTy, NULL); 1025 llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy); 1026 1027 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0)); 1028 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1)); 1029 1030 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy); 1031 const llvm::FunctionType *impType = 1032 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1033 1034 // Get the IMP 1035 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd); 1036 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1037 1038 llvm::Value *impMD[] = { 1039 llvm::MDString::get(VMContext, Sel.getAsString()), 1040 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()), 1041 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage) 1042 }; 1043 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1044 1045 llvm::Instruction *call; 1046 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1047 0, &call); 1048 call->setMetadata(msgSendMDKind, node); 1049 return msgRet; 1050} 1051 1052/// Generate code for a message send expression. 1053RValue 1054CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF, 1055 ReturnValueSlot Return, 1056 QualType ResultType, 1057 Selector Sel, 1058 llvm::Value *Receiver, 1059 const CallArgList &CallArgs, 1060 const ObjCInterfaceDecl *Class, 1061 const ObjCMethodDecl *Method) { 1062 // Strip out message sends to retain / release in GC mode 1063 if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) { 1064 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1065 return RValue::get(Receiver); 1066 } 1067 if (Sel == ReleaseSel) { 1068 return RValue::get(0); 1069 } 1070 } 1071 1072 CGBuilderTy &Builder = CGF.Builder; 1073 1074 // If the return type is something that goes in an integer register, the 1075 // runtime will handle 0 returns. For other cases, we fill in the 0 value 1076 // ourselves. 1077 // 1078 // The language spec says the result of this kind of message send is 1079 // undefined, but lots of people seem to have forgotten to read that 1080 // paragraph and insist on sending messages to nil that have structure 1081 // returns. With GCC, this generates a random return value (whatever happens 1082 // to be on the stack / in those registers at the time) on most platforms, 1083 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts 1084 // the stack. 1085 bool isPointerSizedReturn = (ResultType->isAnyPointerType() || 1086 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType()); 1087 1088 llvm::BasicBlock *startBB = 0; 1089 llvm::BasicBlock *messageBB = 0; 1090 llvm::BasicBlock *continueBB = 0; 1091 1092 if (!isPointerSizedReturn) { 1093 startBB = Builder.GetInsertBlock(); 1094 messageBB = CGF.createBasicBlock("msgSend"); 1095 continueBB = CGF.createBasicBlock("continue"); 1096 1097 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver, 1098 llvm::Constant::getNullValue(Receiver->getType())); 1099 Builder.CreateCondBr(isNil, continueBB, messageBB); 1100 CGF.EmitBlock(messageBB); 1101 } 1102 1103 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 1104 llvm::Value *cmd; 1105 if (Method) 1106 cmd = GetSelector(Builder, Method); 1107 else 1108 cmd = GetSelector(Builder, Sel); 1109 cmd = EnforceType(Builder, cmd, SelectorTy); 1110 Receiver = EnforceType(Builder, Receiver, IdTy); 1111 1112 llvm::Value *impMD[] = { 1113 llvm::MDString::get(VMContext, Sel.getAsString()), 1114 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""), 1115 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0) 1116 }; 1117 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1118 1119 // Get the IMP to call 1120 llvm::Value *imp = LookupIMP(CGF, Receiver, cmd, node); 1121 1122 CallArgList ActualArgs; 1123 ActualArgs.add(RValue::get(Receiver), ASTIdTy); 1124 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1125 ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end()); 1126 1127 CodeGenTypes &Types = CGM.getTypes(); 1128 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 1129 FunctionType::ExtInfo()); 1130 const llvm::FunctionType *impType = 1131 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1132 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1133 1134 1135 // For sender-aware dispatch, we pass the sender as the third argument to a 1136 // lookup function. When sending messages from C code, the sender is nil. 1137 // objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 1138 llvm::Instruction *call; 1139 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1140 0, &call); 1141 call->setMetadata(msgSendMDKind, node); 1142 1143 1144 if (!isPointerSizedReturn) { 1145 messageBB = CGF.Builder.GetInsertBlock(); 1146 CGF.Builder.CreateBr(continueBB); 1147 CGF.EmitBlock(continueBB); 1148 if (msgRet.isScalar()) { 1149 llvm::Value *v = msgRet.getScalarVal(); 1150 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1151 phi->addIncoming(v, messageBB); 1152 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB); 1153 msgRet = RValue::get(phi); 1154 } else if (msgRet.isAggregate()) { 1155 llvm::Value *v = msgRet.getAggregateAddr(); 1156 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1157 const llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType()); 1158 llvm::AllocaInst *NullVal = 1159 CGF.CreateTempAlloca(RetTy->getElementType(), "null"); 1160 CGF.InitTempAlloca(NullVal, 1161 llvm::Constant::getNullValue(RetTy->getElementType())); 1162 phi->addIncoming(v, messageBB); 1163 phi->addIncoming(NullVal, startBB); 1164 msgRet = RValue::getAggregate(phi); 1165 } else /* isComplex() */ { 1166 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal(); 1167 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2); 1168 phi->addIncoming(v.first, messageBB); 1169 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()), 1170 startBB); 1171 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2); 1172 phi2->addIncoming(v.second, messageBB); 1173 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()), 1174 startBB); 1175 msgRet = RValue::getComplex(phi, phi2); 1176 } 1177 } 1178 return msgRet; 1179} 1180 1181/// Generates a MethodList. Used in construction of a objc_class and 1182/// objc_category structures. 1183llvm::Constant *CGObjCGNU::GenerateMethodList(const llvm::StringRef &ClassName, 1184 const llvm::StringRef &CategoryName, 1185 const llvm::SmallVectorImpl<Selector> &MethodSels, 1186 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes, 1187 bool isClassMethodList) { 1188 if (MethodSels.empty()) 1189 return NULLPtr; 1190 // Get the method structure type. 1191 llvm::StructType *ObjCMethodTy = llvm::StructType::get(VMContext, 1192 PtrToInt8Ty, // Really a selector, but the runtime creates it us. 1193 PtrToInt8Ty, // Method types 1194 IMPTy, //Method pointer 1195 NULL); 1196 std::vector<llvm::Constant*> Methods; 1197 std::vector<llvm::Constant*> Elements; 1198 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) { 1199 Elements.clear(); 1200 llvm::Constant *Method = 1201 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName, 1202 MethodSels[i], 1203 isClassMethodList)); 1204 assert(Method && "Can't generate metadata for method that doesn't exist"); 1205 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString()); 1206 Elements.push_back(C); 1207 Elements.push_back(MethodTypes[i]); 1208 Method = llvm::ConstantExpr::getBitCast(Method, 1209 IMPTy); 1210 Elements.push_back(Method); 1211 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements)); 1212 } 1213 1214 // Array of method structures 1215 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy, 1216 Methods.size()); 1217 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy, 1218 Methods); 1219 1220 // Structure containing list pointer, array and array count 1221 llvm::SmallVector<const llvm::Type*, 16> ObjCMethodListFields; 1222 llvm::PATypeHolder OpaqueNextTy = llvm::OpaqueType::get(VMContext); 1223 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(OpaqueNextTy); 1224 llvm::StructType *ObjCMethodListTy = llvm::StructType::get(VMContext, 1225 NextPtrTy, 1226 IntTy, 1227 ObjCMethodArrayTy, 1228 NULL); 1229 // Refine next pointer type to concrete type 1230 llvm::cast<llvm::OpaqueType>( 1231 OpaqueNextTy.get())->refineAbstractTypeTo(ObjCMethodListTy); 1232 ObjCMethodListTy = llvm::cast<llvm::StructType>(OpaqueNextTy.get()); 1233 1234 Methods.clear(); 1235 Methods.push_back(llvm::ConstantPointerNull::get( 1236 llvm::PointerType::getUnqual(ObjCMethodListTy))); 1237 Methods.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1238 MethodTypes.size())); 1239 Methods.push_back(MethodArray); 1240 1241 // Create an instance of the structure 1242 return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list"); 1243} 1244 1245/// Generates an IvarList. Used in construction of a objc_class. 1246llvm::Constant *CGObjCGNU::GenerateIvarList( 1247 const llvm::SmallVectorImpl<llvm::Constant *> &IvarNames, 1248 const llvm::SmallVectorImpl<llvm::Constant *> &IvarTypes, 1249 const llvm::SmallVectorImpl<llvm::Constant *> &IvarOffsets) { 1250 if (IvarNames.size() == 0) 1251 return NULLPtr; 1252 // Get the method structure type. 1253 llvm::StructType *ObjCIvarTy = llvm::StructType::get(VMContext, 1254 PtrToInt8Ty, 1255 PtrToInt8Ty, 1256 IntTy, 1257 NULL); 1258 std::vector<llvm::Constant*> Ivars; 1259 std::vector<llvm::Constant*> Elements; 1260 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) { 1261 Elements.clear(); 1262 Elements.push_back(IvarNames[i]); 1263 Elements.push_back(IvarTypes[i]); 1264 Elements.push_back(IvarOffsets[i]); 1265 Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements)); 1266 } 1267 1268 // Array of method structures 1269 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy, 1270 IvarNames.size()); 1271 1272 1273 Elements.clear(); 1274 Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size())); 1275 Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)); 1276 // Structure containing array and array count 1277 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(VMContext, IntTy, 1278 ObjCIvarArrayTy, 1279 NULL); 1280 1281 // Create an instance of the structure 1282 return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list"); 1283} 1284 1285/// Generate a class structure 1286llvm::Constant *CGObjCGNU::GenerateClassStructure( 1287 llvm::Constant *MetaClass, 1288 llvm::Constant *SuperClass, 1289 unsigned info, 1290 const char *Name, 1291 llvm::Constant *Version, 1292 llvm::Constant *InstanceSize, 1293 llvm::Constant *IVars, 1294 llvm::Constant *Methods, 1295 llvm::Constant *Protocols, 1296 llvm::Constant *IvarOffsets, 1297 llvm::Constant *Properties, 1298 bool isMeta) { 1299 // Set up the class structure 1300 // Note: Several of these are char*s when they should be ids. This is 1301 // because the runtime performs this translation on load. 1302 // 1303 // Fields marked New ABI are part of the GNUstep runtime. We emit them 1304 // anyway; the classes will still work with the GNU runtime, they will just 1305 // be ignored. 1306 llvm::StructType *ClassTy = llvm::StructType::get(VMContext, 1307 PtrToInt8Ty, // class_pointer 1308 PtrToInt8Ty, // super_class 1309 PtrToInt8Ty, // name 1310 LongTy, // version 1311 LongTy, // info 1312 LongTy, // instance_size 1313 IVars->getType(), // ivars 1314 Methods->getType(), // methods 1315 // These are all filled in by the runtime, so we pretend 1316 PtrTy, // dtable 1317 PtrTy, // subclass_list 1318 PtrTy, // sibling_class 1319 PtrTy, // protocols 1320 PtrTy, // gc_object_type 1321 // New ABI: 1322 LongTy, // abi_version 1323 IvarOffsets->getType(), // ivar_offsets 1324 Properties->getType(), // properties 1325 NULL); 1326 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0); 1327 // Fill in the structure 1328 std::vector<llvm::Constant*> Elements; 1329 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty)); 1330 Elements.push_back(SuperClass); 1331 Elements.push_back(MakeConstantString(Name, ".class_name")); 1332 Elements.push_back(Zero); 1333 Elements.push_back(llvm::ConstantInt::get(LongTy, info)); 1334 if (isMeta) { 1335 llvm::TargetData td(&TheModule); 1336 Elements.push_back( 1337 llvm::ConstantInt::get(LongTy, 1338 td.getTypeSizeInBits(ClassTy) / 1339 CGM.getContext().getCharWidth())); 1340 } else 1341 Elements.push_back(InstanceSize); 1342 Elements.push_back(IVars); 1343 Elements.push_back(Methods); 1344 Elements.push_back(NULLPtr); 1345 Elements.push_back(NULLPtr); 1346 Elements.push_back(NULLPtr); 1347 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy)); 1348 Elements.push_back(NULLPtr); 1349 Elements.push_back(Zero); 1350 Elements.push_back(IvarOffsets); 1351 Elements.push_back(Properties); 1352 // Create an instance of the structure 1353 // This is now an externally visible symbol, so that we can speed up class 1354 // messages in the next ABI. 1355 return MakeGlobal(ClassTy, Elements, (isMeta ? "_OBJC_METACLASS_": 1356 "_OBJC_CLASS_") + std::string(Name), llvm::GlobalValue::ExternalLinkage); 1357} 1358 1359llvm::Constant *CGObjCGNU::GenerateProtocolMethodList( 1360 const llvm::SmallVectorImpl<llvm::Constant *> &MethodNames, 1361 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes) { 1362 // Get the method structure type. 1363 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get(VMContext, 1364 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us. 1365 PtrToInt8Ty, 1366 NULL); 1367 std::vector<llvm::Constant*> Methods; 1368 std::vector<llvm::Constant*> Elements; 1369 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) { 1370 Elements.clear(); 1371 Elements.push_back(MethodNames[i]); 1372 Elements.push_back(MethodTypes[i]); 1373 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements)); 1374 } 1375 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy, 1376 MethodNames.size()); 1377 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy, 1378 Methods); 1379 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get(VMContext, 1380 IntTy, ObjCMethodArrayTy, NULL); 1381 Methods.clear(); 1382 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size())); 1383 Methods.push_back(Array); 1384 return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list"); 1385} 1386 1387// Create the protocol list structure used in classes, categories and so on 1388llvm::Constant *CGObjCGNU::GenerateProtocolList( 1389 const llvm::SmallVectorImpl<std::string> &Protocols) { 1390 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 1391 Protocols.size()); 1392 llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext, 1393 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1394 SizeTy, 1395 ProtocolArrayTy, 1396 NULL); 1397 std::vector<llvm::Constant*> Elements; 1398 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end(); 1399 iter != endIter ; iter++) { 1400 llvm::Constant *protocol = 0; 1401 llvm::StringMap<llvm::Constant*>::iterator value = 1402 ExistingProtocols.find(*iter); 1403 if (value == ExistingProtocols.end()) { 1404 protocol = GenerateEmptyProtocol(*iter); 1405 } else { 1406 protocol = value->getValue(); 1407 } 1408 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol, 1409 PtrToInt8Ty); 1410 Elements.push_back(Ptr); 1411 } 1412 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1413 Elements); 1414 Elements.clear(); 1415 Elements.push_back(NULLPtr); 1416 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size())); 1417 Elements.push_back(ProtocolArray); 1418 return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list"); 1419} 1420 1421llvm::Value *CGObjCGNU::GenerateProtocolRef(CGBuilderTy &Builder, 1422 const ObjCProtocolDecl *PD) { 1423 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()]; 1424 const llvm::Type *T = 1425 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType()); 1426 return Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T)); 1427} 1428 1429llvm::Constant *CGObjCGNU::GenerateEmptyProtocol( 1430 const std::string &ProtocolName) { 1431 llvm::SmallVector<std::string, 0> EmptyStringVector; 1432 llvm::SmallVector<llvm::Constant*, 0> EmptyConstantVector; 1433 1434 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector); 1435 llvm::Constant *MethodList = 1436 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector); 1437 // Protocols are objects containing lists of the methods implemented and 1438 // protocols adopted. 1439 llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy, 1440 PtrToInt8Ty, 1441 ProtocolList->getType(), 1442 MethodList->getType(), 1443 MethodList->getType(), 1444 MethodList->getType(), 1445 MethodList->getType(), 1446 NULL); 1447 std::vector<llvm::Constant*> Elements; 1448 // The isa pointer must be set to a magic number so the runtime knows it's 1449 // the correct layout. 1450 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1451 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1452 ProtocolVersion), IdTy)); 1453 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1454 Elements.push_back(ProtocolList); 1455 Elements.push_back(MethodList); 1456 Elements.push_back(MethodList); 1457 Elements.push_back(MethodList); 1458 Elements.push_back(MethodList); 1459 return MakeGlobal(ProtocolTy, Elements, ".objc_protocol"); 1460} 1461 1462void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) { 1463 ASTContext &Context = CGM.getContext(); 1464 std::string ProtocolName = PD->getNameAsString(); 1465 llvm::SmallVector<std::string, 16> Protocols; 1466 for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(), 1467 E = PD->protocol_end(); PI != E; ++PI) 1468 Protocols.push_back((*PI)->getNameAsString()); 1469 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodNames; 1470 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1471 llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames; 1472 llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes; 1473 for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(), 1474 E = PD->instmeth_end(); iter != E; iter++) { 1475 std::string TypeStr; 1476 Context.getObjCEncodingForMethodDecl(*iter, TypeStr); 1477 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1478 InstanceMethodNames.push_back( 1479 MakeConstantString((*iter)->getSelector().getAsString())); 1480 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1481 } else { 1482 OptionalInstanceMethodNames.push_back( 1483 MakeConstantString((*iter)->getSelector().getAsString())); 1484 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1485 } 1486 } 1487 // Collect information about class methods: 1488 llvm::SmallVector<llvm::Constant*, 16> ClassMethodNames; 1489 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1490 llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodNames; 1491 llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes; 1492 for (ObjCProtocolDecl::classmeth_iterator 1493 iter = PD->classmeth_begin(), endIter = PD->classmeth_end(); 1494 iter != endIter ; iter++) { 1495 std::string TypeStr; 1496 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1497 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1498 ClassMethodNames.push_back( 1499 MakeConstantString((*iter)->getSelector().getAsString())); 1500 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1501 } else { 1502 OptionalClassMethodNames.push_back( 1503 MakeConstantString((*iter)->getSelector().getAsString())); 1504 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1505 } 1506 } 1507 1508 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols); 1509 llvm::Constant *InstanceMethodList = 1510 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes); 1511 llvm::Constant *ClassMethodList = 1512 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes); 1513 llvm::Constant *OptionalInstanceMethodList = 1514 GenerateProtocolMethodList(OptionalInstanceMethodNames, 1515 OptionalInstanceMethodTypes); 1516 llvm::Constant *OptionalClassMethodList = 1517 GenerateProtocolMethodList(OptionalClassMethodNames, 1518 OptionalClassMethodTypes); 1519 1520 // Property metadata: name, attributes, isSynthesized, setter name, setter 1521 // types, getter name, getter types. 1522 // The isSynthesized value is always set to 0 in a protocol. It exists to 1523 // simplify the runtime library by allowing it to use the same data 1524 // structures for protocol metadata everywhere. 1525 llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext, 1526 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1527 PtrToInt8Ty, NULL); 1528 std::vector<llvm::Constant*> Properties; 1529 std::vector<llvm::Constant*> OptionalProperties; 1530 1531 // Add all of the property methods need adding to the method list and to the 1532 // property metadata list. 1533 for (ObjCContainerDecl::prop_iterator 1534 iter = PD->prop_begin(), endIter = PD->prop_end(); 1535 iter != endIter ; iter++) { 1536 std::vector<llvm::Constant*> Fields; 1537 ObjCPropertyDecl *property = (*iter); 1538 1539 Fields.push_back(MakeConstantString(property->getNameAsString())); 1540 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1541 property->getPropertyAttributes())); 1542 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 1543 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1544 std::string TypeStr; 1545 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1546 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1547 InstanceMethodTypes.push_back(TypeEncoding); 1548 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1549 Fields.push_back(TypeEncoding); 1550 } else { 1551 Fields.push_back(NULLPtr); 1552 Fields.push_back(NULLPtr); 1553 } 1554 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1555 std::string TypeStr; 1556 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1557 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1558 InstanceMethodTypes.push_back(TypeEncoding); 1559 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1560 Fields.push_back(TypeEncoding); 1561 } else { 1562 Fields.push_back(NULLPtr); 1563 Fields.push_back(NULLPtr); 1564 } 1565 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) { 1566 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1567 } else { 1568 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1569 } 1570 } 1571 llvm::Constant *PropertyArray = llvm::ConstantArray::get( 1572 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties); 1573 llvm::Constant* PropertyListInitFields[] = 1574 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1575 1576 llvm::Constant *PropertyListInit = 1577 llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false); 1578 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule, 1579 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage, 1580 PropertyListInit, ".objc_property_list"); 1581 1582 llvm::Constant *OptionalPropertyArray = 1583 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy, 1584 OptionalProperties.size()) , OptionalProperties); 1585 llvm::Constant* OptionalPropertyListInitFields[] = { 1586 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr, 1587 OptionalPropertyArray }; 1588 1589 llvm::Constant *OptionalPropertyListInit = 1590 llvm::ConstantStruct::get(VMContext, OptionalPropertyListInitFields, 3, false); 1591 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule, 1592 OptionalPropertyListInit->getType(), false, 1593 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit, 1594 ".objc_property_list"); 1595 1596 // Protocols are objects containing lists of the methods implemented and 1597 // protocols adopted. 1598 llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy, 1599 PtrToInt8Ty, 1600 ProtocolList->getType(), 1601 InstanceMethodList->getType(), 1602 ClassMethodList->getType(), 1603 OptionalInstanceMethodList->getType(), 1604 OptionalClassMethodList->getType(), 1605 PropertyList->getType(), 1606 OptionalPropertyList->getType(), 1607 NULL); 1608 std::vector<llvm::Constant*> Elements; 1609 // The isa pointer must be set to a magic number so the runtime knows it's 1610 // the correct layout. 1611 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1612 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1613 ProtocolVersion), IdTy)); 1614 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1615 Elements.push_back(ProtocolList); 1616 Elements.push_back(InstanceMethodList); 1617 Elements.push_back(ClassMethodList); 1618 Elements.push_back(OptionalInstanceMethodList); 1619 Elements.push_back(OptionalClassMethodList); 1620 Elements.push_back(PropertyList); 1621 Elements.push_back(OptionalPropertyList); 1622 ExistingProtocols[ProtocolName] = 1623 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements, 1624 ".objc_protocol"), IdTy); 1625} 1626void CGObjCGNU::GenerateProtocolHolderCategory(void) { 1627 // Collect information about instance methods 1628 llvm::SmallVector<Selector, 1> MethodSels; 1629 llvm::SmallVector<llvm::Constant*, 1> MethodTypes; 1630 1631 std::vector<llvm::Constant*> Elements; 1632 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack"; 1633 const std::string CategoryName = "AnotherHack"; 1634 Elements.push_back(MakeConstantString(CategoryName)); 1635 Elements.push_back(MakeConstantString(ClassName)); 1636 // Instance method list 1637 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1638 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy)); 1639 // Class method list 1640 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1641 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy)); 1642 // Protocol list 1643 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy, 1644 ExistingProtocols.size()); 1645 llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext, 1646 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1647 SizeTy, 1648 ProtocolArrayTy, 1649 NULL); 1650 std::vector<llvm::Constant*> ProtocolElements; 1651 for (llvm::StringMapIterator<llvm::Constant*> iter = 1652 ExistingProtocols.begin(), endIter = ExistingProtocols.end(); 1653 iter != endIter ; iter++) { 1654 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(), 1655 PtrTy); 1656 ProtocolElements.push_back(Ptr); 1657 } 1658 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1659 ProtocolElements); 1660 ProtocolElements.clear(); 1661 ProtocolElements.push_back(NULLPtr); 1662 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy, 1663 ExistingProtocols.size())); 1664 ProtocolElements.push_back(ProtocolArray); 1665 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy, 1666 ProtocolElements, ".objc_protocol_list"), PtrTy)); 1667 Categories.push_back(llvm::ConstantExpr::getBitCast( 1668 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 1669 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1670} 1671 1672void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) { 1673 std::string ClassName = OCD->getClassInterface()->getNameAsString(); 1674 std::string CategoryName = OCD->getNameAsString(); 1675 // Collect information about instance methods 1676 llvm::SmallVector<Selector, 16> InstanceMethodSels; 1677 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1678 for (ObjCCategoryImplDecl::instmeth_iterator 1679 iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end(); 1680 iter != endIter ; iter++) { 1681 InstanceMethodSels.push_back((*iter)->getSelector()); 1682 std::string TypeStr; 1683 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1684 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1685 } 1686 1687 // Collect information about class methods 1688 llvm::SmallVector<Selector, 16> ClassMethodSels; 1689 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1690 for (ObjCCategoryImplDecl::classmeth_iterator 1691 iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end(); 1692 iter != endIter ; iter++) { 1693 ClassMethodSels.push_back((*iter)->getSelector()); 1694 std::string TypeStr; 1695 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1696 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1697 } 1698 1699 // Collect the names of referenced protocols 1700 llvm::SmallVector<std::string, 16> Protocols; 1701 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl(); 1702 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols(); 1703 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1704 E = Protos.end(); I != E; ++I) 1705 Protocols.push_back((*I)->getNameAsString()); 1706 1707 std::vector<llvm::Constant*> Elements; 1708 Elements.push_back(MakeConstantString(CategoryName)); 1709 Elements.push_back(MakeConstantString(ClassName)); 1710 // Instance method list 1711 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1712 ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes, 1713 false), PtrTy)); 1714 // Class method list 1715 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1716 ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true), 1717 PtrTy)); 1718 // Protocol list 1719 Elements.push_back(llvm::ConstantExpr::getBitCast( 1720 GenerateProtocolList(Protocols), PtrTy)); 1721 Categories.push_back(llvm::ConstantExpr::getBitCast( 1722 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 1723 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1724} 1725 1726llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID, 1727 llvm::SmallVectorImpl<Selector> &InstanceMethodSels, 1728 llvm::SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) { 1729 ASTContext &Context = CGM.getContext(); 1730 // 1731 // Property metadata: name, attributes, isSynthesized, setter name, setter 1732 // types, getter name, getter types. 1733 llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext, 1734 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1735 PtrToInt8Ty, NULL); 1736 std::vector<llvm::Constant*> Properties; 1737 1738 1739 // Add all of the property methods need adding to the method list and to the 1740 // property metadata list. 1741 for (ObjCImplDecl::propimpl_iterator 1742 iter = OID->propimpl_begin(), endIter = OID->propimpl_end(); 1743 iter != endIter ; iter++) { 1744 std::vector<llvm::Constant*> Fields; 1745 ObjCPropertyDecl *property = (*iter)->getPropertyDecl(); 1746 ObjCPropertyImplDecl *propertyImpl = *iter; 1747 bool isSynthesized = (propertyImpl->getPropertyImplementation() == 1748 ObjCPropertyImplDecl::Synthesize); 1749 1750 Fields.push_back(MakeConstantString(property->getNameAsString())); 1751 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1752 property->getPropertyAttributes())); 1753 Fields.push_back(llvm::ConstantInt::get(Int8Ty, isSynthesized)); 1754 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1755 std::string TypeStr; 1756 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1757 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1758 if (isSynthesized) { 1759 InstanceMethodTypes.push_back(TypeEncoding); 1760 InstanceMethodSels.push_back(getter->getSelector()); 1761 } 1762 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1763 Fields.push_back(TypeEncoding); 1764 } else { 1765 Fields.push_back(NULLPtr); 1766 Fields.push_back(NULLPtr); 1767 } 1768 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1769 std::string TypeStr; 1770 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1771 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1772 if (isSynthesized) { 1773 InstanceMethodTypes.push_back(TypeEncoding); 1774 InstanceMethodSels.push_back(setter->getSelector()); 1775 } 1776 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1777 Fields.push_back(TypeEncoding); 1778 } else { 1779 Fields.push_back(NULLPtr); 1780 Fields.push_back(NULLPtr); 1781 } 1782 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1783 } 1784 llvm::ArrayType *PropertyArrayTy = 1785 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()); 1786 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy, 1787 Properties); 1788 llvm::Constant* PropertyListInitFields[] = 1789 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1790 1791 llvm::Constant *PropertyListInit = 1792 llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false); 1793 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false, 1794 llvm::GlobalValue::InternalLinkage, PropertyListInit, 1795 ".objc_property_list"); 1796} 1797 1798void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) { 1799 ASTContext &Context = CGM.getContext(); 1800 1801 // Get the superclass name. 1802 const ObjCInterfaceDecl * SuperClassDecl = 1803 OID->getClassInterface()->getSuperClass(); 1804 std::string SuperClassName; 1805 if (SuperClassDecl) { 1806 SuperClassName = SuperClassDecl->getNameAsString(); 1807 EmitClassRef(SuperClassName); 1808 } 1809 1810 // Get the class name 1811 ObjCInterfaceDecl *ClassDecl = 1812 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface()); 1813 std::string ClassName = ClassDecl->getNameAsString(); 1814 // Emit the symbol that is used to generate linker errors if this class is 1815 // referenced in other modules but not declared. 1816 std::string classSymbolName = "__objc_class_name_" + ClassName; 1817 if (llvm::GlobalVariable *symbol = 1818 TheModule.getGlobalVariable(classSymbolName)) { 1819 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0)); 1820 } else { 1821 new llvm::GlobalVariable(TheModule, LongTy, false, 1822 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0), 1823 classSymbolName); 1824 } 1825 1826 // Get the size of instances. 1827 int instanceSize = 1828 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity(); 1829 1830 // Collect information about instance variables. 1831 llvm::SmallVector<llvm::Constant*, 16> IvarNames; 1832 llvm::SmallVector<llvm::Constant*, 16> IvarTypes; 1833 llvm::SmallVector<llvm::Constant*, 16> IvarOffsets; 1834 1835 std::vector<llvm::Constant*> IvarOffsetValues; 1836 1837 int superInstanceSize = !SuperClassDecl ? 0 : 1838 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity(); 1839 // For non-fragile ivars, set the instance size to 0 - {the size of just this 1840 // class}. The runtime will then set this to the correct value on load. 1841 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1842 instanceSize = 0 - (instanceSize - superInstanceSize); 1843 } 1844 1845 // Collect declared and synthesized ivars. 1846 llvm::SmallVector<ObjCIvarDecl*, 16> OIvars; 1847 CGM.getContext().ShallowCollectObjCIvars(ClassDecl, OIvars); 1848 1849 for (unsigned i = 0, e = OIvars.size(); i != e; ++i) { 1850 ObjCIvarDecl *IVD = OIvars[i]; 1851 // Store the name 1852 IvarNames.push_back(MakeConstantString(IVD->getNameAsString())); 1853 // Get the type encoding for this ivar 1854 std::string TypeStr; 1855 Context.getObjCEncodingForType(IVD->getType(), TypeStr); 1856 IvarTypes.push_back(MakeConstantString(TypeStr)); 1857 // Get the offset 1858 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD); 1859 uint64_t Offset = BaseOffset; 1860 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1861 Offset = BaseOffset - superInstanceSize; 1862 } 1863 IvarOffsets.push_back( 1864 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset)); 1865 IvarOffsetValues.push_back(new llvm::GlobalVariable(TheModule, IntTy, 1866 false, llvm::GlobalValue::ExternalLinkage, 1867 llvm::ConstantInt::get(IntTy, Offset), 1868 "__objc_ivar_offset_value_" + ClassName +"." + 1869 IVD->getNameAsString())); 1870 } 1871 llvm::GlobalVariable *IvarOffsetArray = 1872 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets"); 1873 1874 1875 // Collect information about instance methods 1876 llvm::SmallVector<Selector, 16> InstanceMethodSels; 1877 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1878 for (ObjCImplementationDecl::instmeth_iterator 1879 iter = OID->instmeth_begin(), endIter = OID->instmeth_end(); 1880 iter != endIter ; iter++) { 1881 InstanceMethodSels.push_back((*iter)->getSelector()); 1882 std::string TypeStr; 1883 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1884 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1885 } 1886 1887 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels, 1888 InstanceMethodTypes); 1889 1890 1891 // Collect information about class methods 1892 llvm::SmallVector<Selector, 16> ClassMethodSels; 1893 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1894 for (ObjCImplementationDecl::classmeth_iterator 1895 iter = OID->classmeth_begin(), endIter = OID->classmeth_end(); 1896 iter != endIter ; iter++) { 1897 ClassMethodSels.push_back((*iter)->getSelector()); 1898 std::string TypeStr; 1899 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1900 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1901 } 1902 // Collect the names of referenced protocols 1903 llvm::SmallVector<std::string, 16> Protocols; 1904 const ObjCList<ObjCProtocolDecl> &Protos =ClassDecl->getReferencedProtocols(); 1905 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1906 E = Protos.end(); I != E; ++I) 1907 Protocols.push_back((*I)->getNameAsString()); 1908 1909 1910 1911 // Get the superclass pointer. 1912 llvm::Constant *SuperClass; 1913 if (!SuperClassName.empty()) { 1914 SuperClass = MakeConstantString(SuperClassName, ".super_class_name"); 1915 } else { 1916 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty); 1917 } 1918 // Empty vector used to construct empty method lists 1919 llvm::SmallVector<llvm::Constant*, 1> empty; 1920 // Generate the method and instance variable lists 1921 llvm::Constant *MethodList = GenerateMethodList(ClassName, "", 1922 InstanceMethodSels, InstanceMethodTypes, false); 1923 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "", 1924 ClassMethodSels, ClassMethodTypes, true); 1925 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes, 1926 IvarOffsets); 1927 // Irrespective of whether we are compiling for a fragile or non-fragile ABI, 1928 // we emit a symbol containing the offset for each ivar in the class. This 1929 // allows code compiled for the non-Fragile ABI to inherit from code compiled 1930 // for the legacy ABI, without causing problems. The converse is also 1931 // possible, but causes all ivar accesses to be fragile. 1932 1933 // Offset pointer for getting at the correct field in the ivar list when 1934 // setting up the alias. These are: The base address for the global, the 1935 // ivar array (second field), the ivar in this list (set for each ivar), and 1936 // the offset (third field in ivar structure) 1937 const llvm::Type *IndexTy = llvm::Type::getInt32Ty(VMContext); 1938 llvm::Constant *offsetPointerIndexes[] = {Zeros[0], 1939 llvm::ConstantInt::get(IndexTy, 1), 0, 1940 llvm::ConstantInt::get(IndexTy, 2) }; 1941 1942 1943 for (unsigned i = 0, e = OIvars.size(); i != e; ++i) { 1944 ObjCIvarDecl *IVD = OIvars[i]; 1945 const std::string Name = "__objc_ivar_offset_" + ClassName + '.' 1946 + IVD->getNameAsString(); 1947 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, i); 1948 // Get the correct ivar field 1949 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr( 1950 IvarList, offsetPointerIndexes, 4); 1951 // Get the existing variable, if one exists. 1952 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name); 1953 if (offset) { 1954 offset->setInitializer(offsetValue); 1955 // If this is the real definition, change its linkage type so that 1956 // different modules will use this one, rather than their private 1957 // copy. 1958 offset->setLinkage(llvm::GlobalValue::ExternalLinkage); 1959 } else { 1960 // Add a new alias if there isn't one already. 1961 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(), 1962 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name); 1963 } 1964 } 1965 //Generate metaclass for class methods 1966 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr, 1967 NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList( 1968 empty, empty, empty), ClassMethodList, NULLPtr, NULLPtr, NULLPtr, true); 1969 1970 // Generate the class structure 1971 llvm::Constant *ClassStruct = 1972 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L, 1973 ClassName.c_str(), 0, 1974 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, 1975 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray, 1976 Properties); 1977 1978 // Resolve the class aliases, if they exist. 1979 if (ClassPtrAlias) { 1980 ClassPtrAlias->replaceAllUsesWith( 1981 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy)); 1982 ClassPtrAlias->eraseFromParent(); 1983 ClassPtrAlias = 0; 1984 } 1985 if (MetaClassPtrAlias) { 1986 MetaClassPtrAlias->replaceAllUsesWith( 1987 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy)); 1988 MetaClassPtrAlias->eraseFromParent(); 1989 MetaClassPtrAlias = 0; 1990 } 1991 1992 // Add class structure to list to be added to the symtab later 1993 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty); 1994 Classes.push_back(ClassStruct); 1995} 1996 1997 1998llvm::Function *CGObjCGNU::ModuleInitFunction() { 1999 // Only emit an ObjC load function if no Objective-C stuff has been called 2000 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() && 2001 ExistingProtocols.empty() && SelectorTable.empty()) 2002 return NULL; 2003 2004 // Add all referenced protocols to a category. 2005 GenerateProtocolHolderCategory(); 2006 2007 const llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>( 2008 SelectorTy->getElementType()); 2009 const llvm::Type *SelStructPtrTy = SelectorTy; 2010 if (SelStructTy == 0) { 2011 SelStructTy = llvm::StructType::get(VMContext, PtrToInt8Ty, 2012 PtrToInt8Ty, NULL); 2013 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy); 2014 } 2015 2016 // Name the ObjC types to make the IR a bit easier to read 2017 TheModule.addTypeName(".objc_selector", SelStructPtrTy); 2018 TheModule.addTypeName(".objc_id", IdTy); 2019 TheModule.addTypeName(".objc_imp", IMPTy); 2020 2021 std::vector<llvm::Constant*> Elements; 2022 llvm::Constant *Statics = NULLPtr; 2023 // Generate statics list: 2024 if (ConstantStrings.size()) { 2025 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 2026 ConstantStrings.size() + 1); 2027 ConstantStrings.push_back(NULLPtr); 2028 2029 llvm::StringRef StringClass = CGM.getLangOptions().ObjCConstantStringClass; 2030 2031 if (StringClass.empty()) StringClass = "NXConstantString"; 2032 2033 Elements.push_back(MakeConstantString(StringClass, 2034 ".objc_static_class_name")); 2035 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy, 2036 ConstantStrings)); 2037 llvm::StructType *StaticsListTy = 2038 llvm::StructType::get(VMContext, PtrToInt8Ty, StaticsArrayTy, NULL); 2039 llvm::Type *StaticsListPtrTy = 2040 llvm::PointerType::getUnqual(StaticsListTy); 2041 Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics"); 2042 llvm::ArrayType *StaticsListArrayTy = 2043 llvm::ArrayType::get(StaticsListPtrTy, 2); 2044 Elements.clear(); 2045 Elements.push_back(Statics); 2046 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy)); 2047 Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr"); 2048 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy); 2049 } 2050 // Array of classes, categories, and constant objects 2051 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty, 2052 Classes.size() + Categories.size() + 2); 2053 llvm::StructType *SymTabTy = llvm::StructType::get(VMContext, 2054 LongTy, SelStructPtrTy, 2055 llvm::Type::getInt16Ty(VMContext), 2056 llvm::Type::getInt16Ty(VMContext), 2057 ClassListTy, NULL); 2058 2059 Elements.clear(); 2060 // Pointer to an array of selectors used in this module. 2061 std::vector<llvm::Constant*> Selectors; 2062 std::vector<llvm::GlobalAlias*> SelectorAliases; 2063 for (SelectorMap::iterator iter = SelectorTable.begin(), 2064 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) { 2065 2066 std::string SelNameStr = iter->first.getAsString(); 2067 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name"); 2068 2069 llvm::SmallVectorImpl<TypedSelector> &Types = iter->second; 2070 for (llvm::SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 2071 e = Types.end() ; i!=e ; i++) { 2072 2073 llvm::Constant *SelectorTypeEncoding = NULLPtr; 2074 if (!i->first.empty()) 2075 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types"); 2076 2077 Elements.push_back(SelName); 2078 Elements.push_back(SelectorTypeEncoding); 2079 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2080 Elements.clear(); 2081 2082 // Store the selector alias for later replacement 2083 SelectorAliases.push_back(i->second); 2084 } 2085 } 2086 unsigned SelectorCount = Selectors.size(); 2087 // NULL-terminate the selector list. This should not actually be required, 2088 // because the selector list has a length field. Unfortunately, the GCC 2089 // runtime decides to ignore the length field and expects a NULL terminator, 2090 // and GCC cooperates with this by always setting the length to 0. 2091 Elements.push_back(NULLPtr); 2092 Elements.push_back(NULLPtr); 2093 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2094 Elements.clear(); 2095 2096 // Number of static selectors 2097 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount)); 2098 llvm::Constant *SelectorList = MakeGlobalArray(SelStructTy, Selectors, 2099 ".objc_selector_list"); 2100 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList, 2101 SelStructPtrTy)); 2102 2103 // Now that all of the static selectors exist, create pointers to them. 2104 for (unsigned int i=0 ; i<SelectorCount ; i++) { 2105 2106 llvm::Constant *Idxs[] = {Zeros[0], 2107 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), i), Zeros[0]}; 2108 // FIXME: We're generating redundant loads and stores here! 2109 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(SelectorList, 2110 Idxs, 2); 2111 // If selectors are defined as an opaque type, cast the pointer to this 2112 // type. 2113 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy); 2114 SelectorAliases[i]->replaceAllUsesWith(SelPtr); 2115 SelectorAliases[i]->eraseFromParent(); 2116 } 2117 2118 // Number of classes defined. 2119 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2120 Classes.size())); 2121 // Number of categories defined 2122 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2123 Categories.size())); 2124 // Create an array of classes, then categories, then static object instances 2125 Classes.insert(Classes.end(), Categories.begin(), Categories.end()); 2126 // NULL-terminated list of static object instances (mainly constant strings) 2127 Classes.push_back(Statics); 2128 Classes.push_back(NULLPtr); 2129 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes); 2130 Elements.push_back(ClassList); 2131 // Construct the symbol table 2132 llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements); 2133 2134 // The symbol table is contained in a module which has some version-checking 2135 // constants 2136 llvm::StructType * ModuleTy = llvm::StructType::get(VMContext, LongTy, LongTy, 2137 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), 2138 (CGM.getLangOptions().getGCMode() == LangOptions::NonGC) ? NULL : IntTy, 2139 NULL); 2140 Elements.clear(); 2141 // Runtime version, used for ABI compatibility checking. 2142 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion)); 2143 // sizeof(ModuleTy) 2144 llvm::TargetData td(&TheModule); 2145 Elements.push_back( 2146 llvm::ConstantInt::get(LongTy, 2147 td.getTypeSizeInBits(ModuleTy) / 2148 CGM.getContext().getCharWidth())); 2149 2150 // The path to the source file where this module was declared 2151 SourceManager &SM = CGM.getContext().getSourceManager(); 2152 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID()); 2153 std::string path = 2154 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName(); 2155 Elements.push_back(MakeConstantString(path, ".objc_source_file_name")); 2156 Elements.push_back(SymTab); 2157 2158 switch (CGM.getLangOptions().getGCMode()) { 2159 case LangOptions::GCOnly: 2160 Elements.push_back(llvm::ConstantInt::get(IntTy, 2)); 2161 case LangOptions::NonGC: 2162 break; 2163 case LangOptions::HybridGC: 2164 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2165 } 2166 2167 llvm::Value *Module = MakeGlobal(ModuleTy, Elements); 2168 2169 // Create the load function calling the runtime entry point with the module 2170 // structure 2171 llvm::Function * LoadFunction = llvm::Function::Create( 2172 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false), 2173 llvm::GlobalValue::InternalLinkage, ".objc_load_function", 2174 &TheModule); 2175 llvm::BasicBlock *EntryBB = 2176 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction); 2177 CGBuilderTy Builder(VMContext); 2178 Builder.SetInsertPoint(EntryBB); 2179 2180 std::vector<const llvm::Type*> Params(1, 2181 llvm::PointerType::getUnqual(ModuleTy)); 2182 llvm::Value *Register = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 2183 llvm::Type::getVoidTy(VMContext), Params, true), "__objc_exec_class"); 2184 Builder.CreateCall(Register, Module); 2185 Builder.CreateRetVoid(); 2186 2187 return LoadFunction; 2188} 2189 2190llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD, 2191 const ObjCContainerDecl *CD) { 2192 const ObjCCategoryImplDecl *OCD = 2193 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext()); 2194 llvm::StringRef CategoryName = OCD ? OCD->getName() : ""; 2195 llvm::StringRef ClassName = CD->getName(); 2196 Selector MethodName = OMD->getSelector(); 2197 bool isClassMethod = !OMD->isInstanceMethod(); 2198 2199 CodeGenTypes &Types = CGM.getTypes(); 2200 const llvm::FunctionType *MethodTy = 2201 Types.GetFunctionType(Types.getFunctionInfo(OMD), OMD->isVariadic()); 2202 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName, 2203 MethodName, isClassMethod); 2204 2205 llvm::Function *Method 2206 = llvm::Function::Create(MethodTy, 2207 llvm::GlobalValue::InternalLinkage, 2208 FunctionName, 2209 &TheModule); 2210 return Method; 2211} 2212 2213llvm::Function *CGObjCGNU::GetPropertyGetFunction() { 2214 return GetPropertyFn; 2215} 2216 2217llvm::Function *CGObjCGNU::GetPropertySetFunction() { 2218 return SetPropertyFn; 2219} 2220 2221llvm::Function *CGObjCGNU::GetGetStructFunction() { 2222 return GetStructPropertyFn; 2223} 2224llvm::Function *CGObjCGNU::GetSetStructFunction() { 2225 return SetStructPropertyFn; 2226} 2227 2228llvm::Constant *CGObjCGNU::EnumerationMutationFunction() { 2229 return EnumerationMutationFn; 2230} 2231 2232void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF, 2233 const ObjCAtSynchronizedStmt &S) { 2234 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn); 2235} 2236 2237 2238void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF, 2239 const ObjCAtTryStmt &S) { 2240 // Unlike the Apple non-fragile runtimes, which also uses 2241 // unwind-based zero cost exceptions, the GNU Objective C runtime's 2242 // EH support isn't a veneer over C++ EH. Instead, exception 2243 // objects are created by __objc_exception_throw and destroyed by 2244 // the personality function; this avoids the need for bracketing 2245 // catch handlers with calls to __blah_begin_catch/__blah_end_catch 2246 // (or even _Unwind_DeleteException), but probably doesn't 2247 // interoperate very well with foreign exceptions. 2248 // 2249 // In Objective-C++ mode, we actually emit something equivalent to the C++ 2250 // exception handler. 2251 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn); 2252 return ; 2253} 2254 2255void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF, 2256 const ObjCAtThrowStmt &S) { 2257 llvm::Value *ExceptionAsObject; 2258 2259 if (const Expr *ThrowExpr = S.getThrowExpr()) { 2260 llvm::Value *Exception = CGF.EmitScalarExpr(ThrowExpr); 2261 ExceptionAsObject = Exception; 2262 } else { 2263 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) && 2264 "Unexpected rethrow outside @catch block."); 2265 ExceptionAsObject = CGF.ObjCEHValueStack.back(); 2266 } 2267 ExceptionAsObject = 2268 CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy, "tmp"); 2269 2270 // Note: This may have to be an invoke, if we want to support constructs like: 2271 // @try { 2272 // @throw(obj); 2273 // } 2274 // @catch(id) ... 2275 // 2276 // This is effectively turning @throw into an incredibly-expensive goto, but 2277 // it may happen as a result of inlining followed by missed optimizations, or 2278 // as a result of stupidity. 2279 llvm::BasicBlock *UnwindBB = CGF.getInvokeDest(); 2280 if (!UnwindBB) { 2281 CGF.Builder.CreateCall(ExceptionThrowFn, ExceptionAsObject); 2282 CGF.Builder.CreateUnreachable(); 2283 } else { 2284 CGF.Builder.CreateInvoke(ExceptionThrowFn, UnwindBB, UnwindBB, &ExceptionAsObject, 2285 &ExceptionAsObject+1); 2286 } 2287 // Clear the insertion point to indicate we are in unreachable code. 2288 CGF.Builder.ClearInsertionPoint(); 2289} 2290 2291llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF, 2292 llvm::Value *AddrWeakObj) { 2293 CGBuilderTy B = CGF.Builder; 2294 AddrWeakObj = EnforceType(B, AddrWeakObj, IdTy); 2295 return B.CreateCall(WeakReadFn, AddrWeakObj); 2296} 2297 2298void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF, 2299 llvm::Value *src, llvm::Value *dst) { 2300 CGBuilderTy B = CGF.Builder; 2301 src = EnforceType(B, src, IdTy); 2302 dst = EnforceType(B, dst, PtrToIdTy); 2303 B.CreateCall2(WeakAssignFn, src, dst); 2304} 2305 2306void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF, 2307 llvm::Value *src, llvm::Value *dst, 2308 bool threadlocal) { 2309 CGBuilderTy B = CGF.Builder; 2310 src = EnforceType(B, src, IdTy); 2311 dst = EnforceType(B, dst, PtrToIdTy); 2312 if (!threadlocal) 2313 B.CreateCall2(GlobalAssignFn, src, dst); 2314 else 2315 // FIXME. Add threadloca assign API 2316 assert(false && "EmitObjCGlobalAssign - Threal Local API NYI"); 2317} 2318 2319void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF, 2320 llvm::Value *src, llvm::Value *dst, 2321 llvm::Value *ivarOffset) { 2322 CGBuilderTy B = CGF.Builder; 2323 src = EnforceType(B, src, IdTy); 2324 dst = EnforceType(B, dst, PtrToIdTy); 2325 B.CreateCall3(IvarAssignFn, src, dst, ivarOffset); 2326} 2327 2328void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF, 2329 llvm::Value *src, llvm::Value *dst) { 2330 CGBuilderTy B = CGF.Builder; 2331 src = EnforceType(B, src, IdTy); 2332 dst = EnforceType(B, dst, PtrToIdTy); 2333 B.CreateCall2(StrongCastAssignFn, src, dst); 2334} 2335 2336void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF, 2337 llvm::Value *DestPtr, 2338 llvm::Value *SrcPtr, 2339 llvm::Value *Size) { 2340 CGBuilderTy B = CGF.Builder; 2341 DestPtr = EnforceType(B, DestPtr, IdTy); 2342 SrcPtr = EnforceType(B, SrcPtr, PtrToIdTy); 2343 2344 B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size); 2345} 2346 2347llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable( 2348 const ObjCInterfaceDecl *ID, 2349 const ObjCIvarDecl *Ivar) { 2350 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString() 2351 + '.' + Ivar->getNameAsString(); 2352 // Emit the variable and initialize it with what we think the correct value 2353 // is. This allows code compiled with non-fragile ivars to work correctly 2354 // when linked against code which isn't (most of the time). 2355 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name); 2356 if (!IvarOffsetPointer) { 2357 // This will cause a run-time crash if we accidentally use it. A value of 2358 // 0 would seem more sensible, but will silently overwrite the isa pointer 2359 // causing a great deal of confusion. 2360 uint64_t Offset = -1; 2361 // We can't call ComputeIvarBaseOffset() here if we have the 2362 // implementation, because it will create an invalid ASTRecordLayout object 2363 // that we are then stuck with forever, so we only initialize the ivar 2364 // offset variable with a guess if we only have the interface. The 2365 // initializer will be reset later anyway, when we are generating the class 2366 // description. 2367 if (!CGM.getContext().getObjCImplementation( 2368 const_cast<ObjCInterfaceDecl *>(ID))) 2369 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar); 2370 2371 llvm::ConstantInt *OffsetGuess = 2372 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset, "ivar"); 2373 // Don't emit the guess in non-PIC code because the linker will not be able 2374 // to replace it with the real version for a library. In non-PIC code you 2375 // must compile with the fragile ABI if you want to use ivars from a 2376 // GCC-compiled class. 2377 if (CGM.getLangOptions().PICLevel) { 2378 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule, 2379 llvm::Type::getInt32Ty(VMContext), false, 2380 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess"); 2381 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2382 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage, 2383 IvarOffsetGV, Name); 2384 } else { 2385 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2386 llvm::Type::getInt32PtrTy(VMContext), false, 2387 llvm::GlobalValue::ExternalLinkage, 0, Name); 2388 } 2389 } 2390 return IvarOffsetPointer; 2391} 2392 2393LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF, 2394 QualType ObjectTy, 2395 llvm::Value *BaseValue, 2396 const ObjCIvarDecl *Ivar, 2397 unsigned CVRQualifiers) { 2398 const ObjCInterfaceDecl *ID = 2399 ObjectTy->getAs<ObjCObjectType>()->getInterface(); 2400 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers, 2401 EmitIvarOffset(CGF, ID, Ivar)); 2402} 2403 2404static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context, 2405 const ObjCInterfaceDecl *OID, 2406 const ObjCIvarDecl *OIVD) { 2407 llvm::SmallVector<ObjCIvarDecl*, 16> Ivars; 2408 Context.ShallowCollectObjCIvars(OID, Ivars); 2409 for (unsigned k = 0, e = Ivars.size(); k != e; ++k) { 2410 if (OIVD == Ivars[k]) 2411 return OID; 2412 } 2413 2414 // Otherwise check in the super class. 2415 if (const ObjCInterfaceDecl *Super = OID->getSuperClass()) 2416 return FindIvarInterface(Context, Super, OIVD); 2417 2418 return 0; 2419} 2420 2421llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF, 2422 const ObjCInterfaceDecl *Interface, 2423 const ObjCIvarDecl *Ivar) { 2424 if (CGM.getLangOptions().ObjCNonFragileABI) { 2425 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar); 2426 return CGF.Builder.CreateZExtOrBitCast( 2427 CGF.Builder.CreateLoad(CGF.Builder.CreateLoad( 2428 ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")), 2429 PtrDiffTy); 2430 } 2431 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar); 2432 return llvm::ConstantInt::get(PtrDiffTy, Offset, "ivar"); 2433} 2434 2435CGObjCRuntime * 2436clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) { 2437 if (CGM.getLangOptions().ObjCNonFragileABI) 2438 return new CGObjCGNUstep(CGM); 2439 return new CGObjCGCC(CGM); 2440} 2441