CGObjCGNU.cpp revision bbf3bacb3e0c1ebb3e8a4a8b1330404a7e379315
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 targetting 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 <map> 40#include <stdarg.h> 41 42 43using namespace clang; 44using namespace CodeGen; 45using llvm::dyn_cast; 46 47 48namespace { 49/// Class that lazily initialises the runtime function. Avoids inserting the 50/// types and the function declaration into a module if they're not used, and 51/// avoids constructing the type more than once if it's used more than once. 52class LazyRuntimeFunction { 53 CodeGenModule *CGM; 54 std::vector<const llvm::Type*> ArgTys; 55 const char *FunctionName; 56 llvm::Function *Function; 57 public: 58 /// Constructor leaves this class uninitialized, because it is intended to 59 /// be used as a field in another class and not all of the types that are 60 /// used as arguments will necessarily be available at construction time. 61 LazyRuntimeFunction() : CGM(0), FunctionName(0), Function(0) {} 62 63 /// Initialises the lazy function with the name, return type, and the types 64 /// of the arguments. 65 END_WITH_NULL 66 void init(CodeGenModule *Mod, const char *name, 67 const llvm::Type *RetTy, ...) { 68 CGM =Mod; 69 FunctionName = name; 70 Function = 0; 71 ArgTys.clear(); 72 va_list Args; 73 va_start(Args, RetTy); 74 while (const llvm::Type *ArgTy = va_arg(Args, const llvm::Type*)) 75 ArgTys.push_back(ArgTy); 76 va_end(Args); 77 // Push the return type on at the end so we can pop it off easily 78 ArgTys.push_back(RetTy); 79 } 80 /// Overloaded cast operator, allows the class to be implicitly cast to an 81 /// LLVM constant. 82 operator llvm::Function*() { 83 if (!Function) { 84 if (0 == FunctionName) return 0; 85 // We put the return type on the end of the vector, so pop it back off 86 const llvm::Type *RetTy = ArgTys.back(); 87 ArgTys.pop_back(); 88 llvm::FunctionType *FTy = llvm::FunctionType::get(RetTy, ArgTys, false); 89 Function = 90 cast<llvm::Function>(CGM->CreateRuntimeFunction(FTy, FunctionName)); 91 // We won't need to use the types again, so we may as well clean up the 92 // vector now 93 ArgTys.resize(0); 94 } 95 return Function; 96 } 97}; 98 99 100/// GNU Objective-C runtime code generation. This class implements the parts of 101/// Objective-C support that are specific to the GNU family of runtimes (GCC and 102/// GNUstep). 103class CGObjCGNU : public CGObjCRuntime { 104protected: 105 /// The module that is using this class 106 CodeGenModule &CGM; 107 /// The LLVM module into which output is inserted 108 llvm::Module &TheModule; 109 /// strut objc_super. Used for sending messages to super. This structure 110 /// contains the receiver (object) and the expected class. 111 const llvm::StructType *ObjCSuperTy; 112 /// struct objc_super*. The type of the argument to the superclass message 113 /// lookup functions. 114 const llvm::PointerType *PtrToObjCSuperTy; 115 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring 116 /// SEL is included in a header somewhere, in which case it will be whatever 117 /// type is declared in that header, most likely {i8*, i8*}. 118 const llvm::PointerType *SelectorTy; 119 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the 120 /// places where it's used 121 const llvm::IntegerType *Int8Ty; 122 /// Pointer to i8 - LLVM type of char*, for all of the places where the 123 /// runtime needs to deal with C strings. 124 const llvm::PointerType *PtrToInt8Ty; 125 /// Instance Method Pointer type. This is a pointer to a function that takes, 126 /// at a minimum, an object and a selector, and is the generic type for 127 /// Objective-C methods. Due to differences between variadic / non-variadic 128 /// calling conventions, it must always be cast to the correct type before 129 /// actually being used. 130 const llvm::PointerType *IMPTy; 131 /// Type of an untyped Objective-C object. Clang treats id as a built-in type 132 /// when compiling Objective-C code, so this may be an opaque pointer (i8*), 133 /// but if the runtime header declaring it is included then it may be a 134 /// pointer to a structure. 135 const llvm::PointerType *IdTy; 136 /// Pointer to a pointer to an Objective-C object. Used in the new ABI 137 /// message lookup function and some GC-related functions. 138 const llvm::PointerType *PtrToIdTy; 139 /// The clang type of id. Used when using the clang CGCall infrastructure to 140 /// call Objective-C methods. 141 CanQualType ASTIdTy; 142 /// LLVM type for C int type. 143 const llvm::IntegerType *IntTy; 144 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is 145 /// used in the code to document the difference between i8* meaning a pointer 146 /// to a C string and i8* meaning a pointer to some opaque type. 147 const llvm::PointerType *PtrTy; 148 /// LLVM type for C long type. The runtime uses this in a lot of places where 149 /// it should be using intptr_t, but we can't fix this without breaking 150 /// compatibility with GCC... 151 const llvm::IntegerType *LongTy; 152 /// LLVM type for C size_t. Used in various runtime data structures. 153 const llvm::IntegerType *SizeTy; 154 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions. 155 const llvm::IntegerType *PtrDiffTy; 156 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance 157 /// variables. 158 const llvm::PointerType *PtrToIntTy; 159 /// LLVM type for Objective-C BOOL type. 160 const llvm::Type *BoolTy; 161 /// Metadata kind used to tie method lookups to message sends. The GNUstep 162 /// runtime provides some LLVM passes that can use this to do things like 163 /// automatic IMP caching and speculative inlining. 164 unsigned msgSendMDKind; 165 /// Helper function that generates a constant string and returns a pointer to 166 /// the start of the string. The result of this function can be used anywhere 167 /// where the C code specifies const char*. 168 llvm::Constant *MakeConstantString(const std::string &Str, 169 const std::string &Name="") { 170 llvm::Constant *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str()); 171 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros, 2); 172 } 173 /// Emits a linkonce_odr string, whose name is the prefix followed by the 174 /// string value. This allows the linker to combine the strings between 175 /// different modules. Used for EH typeinfo names, selector strings, and a 176 /// few other things. 177 llvm::Constant *ExportUniqueString(const std::string &Str, 178 const std::string prefix) { 179 std::string name = prefix + Str; 180 llvm::Constant *ConstStr = TheModule.getGlobalVariable(name); 181 if (!ConstStr) { 182 llvm::Constant *value = llvm::ConstantArray::get(VMContext, Str, true); 183 ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true, 184 llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str); 185 } 186 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros, 2); 187 } 188 /// Generates a global structure, initialized by the elements in the vector. 189 /// The element types must match the types of the structure elements in the 190 /// first argument. 191 llvm::GlobalVariable *MakeGlobal(const llvm::StructType *Ty, 192 std::vector<llvm::Constant*> &V, 193 llvm::StringRef Name="", 194 llvm::GlobalValue::LinkageTypes linkage 195 =llvm::GlobalValue::InternalLinkage) { 196 llvm::Constant *C = llvm::ConstantStruct::get(Ty, V); 197 return new llvm::GlobalVariable(TheModule, Ty, false, 198 linkage, C, Name); 199 } 200 /// Generates a global array. The vector must contain the same number of 201 /// elements that the array type declares, of the type specified as the array 202 /// element type. 203 llvm::GlobalVariable *MakeGlobal(const llvm::ArrayType *Ty, 204 std::vector<llvm::Constant*> &V, 205 llvm::StringRef Name="", 206 llvm::GlobalValue::LinkageTypes linkage 207 =llvm::GlobalValue::InternalLinkage) { 208 llvm::Constant *C = llvm::ConstantArray::get(Ty, V); 209 return new llvm::GlobalVariable(TheModule, Ty, false, 210 linkage, C, Name); 211 } 212 /// Generates a global array, inferring the array type from the specified 213 /// element type and the size of the initialiser. 214 llvm::GlobalVariable *MakeGlobalArray(const llvm::Type *Ty, 215 std::vector<llvm::Constant*> &V, 216 llvm::StringRef Name="", 217 llvm::GlobalValue::LinkageTypes linkage 218 =llvm::GlobalValue::InternalLinkage) { 219 llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size()); 220 return MakeGlobal(ArrayTy, V, Name, linkage); 221 } 222 /// Ensures that the value has the required type, by inserting a bitcast if 223 /// required. This function lets us avoid inserting bitcasts that are 224 /// redundant. 225 llvm::Value* EnforceType(CGBuilderTy B, llvm::Value *V, const llvm::Type *Ty){ 226 if (V->getType() == Ty) return V; 227 return B.CreateBitCast(V, Ty); 228 } 229 // Some zeros used for GEPs in lots of places. 230 llvm::Constant *Zeros[2]; 231 /// Null pointer value. Mainly used as a terminator in various arrays. 232 llvm::Constant *NULLPtr; 233 /// LLVM context. 234 llvm::LLVMContext &VMContext; 235private: 236 /// Placeholder for the class. Lots of things refer to the class before we've 237 /// actually emitted it. We use this alias as a placeholder, and then replace 238 /// it with a pointer to the class structure before finally emitting the 239 /// module. 240 llvm::GlobalAlias *ClassPtrAlias; 241 /// Placeholder for the metaclass. Lots of things refer to the class before 242 /// we've / actually emitted it. We use this alias as a placeholder, and then 243 /// replace / it with a pointer to the metaclass structure before finally 244 /// emitting the / module. 245 llvm::GlobalAlias *MetaClassPtrAlias; 246 /// All of the classes that have been generated for this compilation units. 247 std::vector<llvm::Constant*> Classes; 248 /// All of the categories that have been generated for this compilation units. 249 std::vector<llvm::Constant*> Categories; 250 /// All of the Objective-C constant strings that have been generated for this 251 /// compilation units. 252 std::vector<llvm::Constant*> ConstantStrings; 253 /// Map from string values to Objective-C constant strings in the output. 254 /// Used to prevent emitting Objective-C strings more than once. This should 255 /// not be required at all - CodeGenModule should manage this list. 256 llvm::StringMap<llvm::Constant*> ObjCStrings; 257 /// All of the protocols that have been declared. 258 llvm::StringMap<llvm::Constant*> ExistingProtocols; 259 /// For each variant of a selector, we store the type encoding and a 260 /// placeholder value. For an untyped selector, the type will be the empty 261 /// string. Selector references are all done via the module's selector table, 262 /// so we create an alias as a placeholder and then replace it with the real 263 /// value later. 264 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector; 265 /// Type of the selector map. This is roughly equivalent to the structure 266 /// used in the GNUstep runtime, which maintains a list of all of the valid 267 /// types for a selector in a table. 268 typedef llvm::DenseMap<Selector, llvm::SmallVector<TypedSelector, 2> > 269 SelectorMap; 270 /// A map from selectors to selector types. This allows us to emit all 271 /// selectors of the same name and type together. 272 SelectorMap SelectorTable; 273 274 /// Selectors related to memory management. When compiling in GC mode, we 275 /// omit these. 276 Selector RetainSel, ReleaseSel, AutoreleaseSel; 277 /// Runtime functions used for memory management in GC mode. Note that clang 278 /// supports code generation for calling these functions, but neither GNU 279 /// runtime actually supports this API properly yet. 280 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn, 281 WeakAssignFn, GlobalAssignFn; 282 283protected: 284 /// Function used for throwing Objective-C exceptions. 285 LazyRuntimeFunction ExceptionThrowFn; 286 /// Function used for rethrowing exceptions, used at the end of @finally or 287 /// @synchronize blocks. 288 LazyRuntimeFunction ExceptionReThrowFn; 289 /// Function called when entering a catch function. This is required for 290 /// differentiating Objective-C exceptions and foreign exceptions. 291 LazyRuntimeFunction EnterCatchFn; 292 /// Function called when exiting from a catch block. Used to do exception 293 /// cleanup. 294 LazyRuntimeFunction ExitCatchFn; 295 /// Function called when entering an @synchronize block. Acquires the lock. 296 LazyRuntimeFunction SyncEnterFn; 297 /// Function called when exiting an @synchronize block. Releases the lock. 298 LazyRuntimeFunction SyncExitFn; 299 300private: 301 302 /// Function called if fast enumeration detects that the collection is 303 /// modified during the update. 304 LazyRuntimeFunction EnumerationMutationFn; 305 /// Function for implementing synthesized property getters that return an 306 /// object. 307 LazyRuntimeFunction GetPropertyFn; 308 /// Function for implementing synthesized property setters that return an 309 /// object. 310 LazyRuntimeFunction SetPropertyFn; 311 /// Function used for non-object declared property getters. 312 LazyRuntimeFunction GetStructPropertyFn; 313 /// Function used for non-object declared property setters. 314 LazyRuntimeFunction SetStructPropertyFn; 315 316 /// The version of the runtime that this class targets. Must match the 317 /// version in the runtime. 318 const int RuntimeVersion; 319 /// The version of the protocol class. Used to differentiate between ObjC1 320 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional 321 /// components and can not contain declared properties. We always emit 322 /// Objective-C 2 property structures, but we have to pretend that they're 323 /// Objective-C 1 property structures when targeting the GCC runtime or it 324 /// will abort. 325 const int ProtocolVersion; 326private: 327 /// Generates an instance variable list structure. This is a structure 328 /// containing a size and an array of structures containing instance variable 329 /// metadata. This is used purely for introspection in the fragile ABI. In 330 /// the non-fragile ABI, it's used for instance variable fixup. 331 llvm::Constant *GenerateIvarList( 332 const llvm::SmallVectorImpl<llvm::Constant *> &IvarNames, 333 const llvm::SmallVectorImpl<llvm::Constant *> &IvarTypes, 334 const llvm::SmallVectorImpl<llvm::Constant *> &IvarOffsets); 335 /// Generates a method list structure. This is a structure containing a size 336 /// and an array of structures containing method metadata. 337 /// 338 /// This structure is used by both classes and categories, and contains a next 339 /// pointer allowing them to be chained together in a linked list. 340 llvm::Constant *GenerateMethodList(const llvm::StringRef &ClassName, 341 const llvm::StringRef &CategoryName, 342 const llvm::SmallVectorImpl<Selector> &MethodSels, 343 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes, 344 bool isClassMethodList); 345 /// Emits an empty protocol. This is used for @protocol() where no protocol 346 /// is found. The runtime will (hopefully) fix up the pointer to refer to the 347 /// real protocol. 348 llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName); 349 /// Generates a list of property metadata structures. This follows the same 350 /// pattern as method and instance variable metadata lists. 351 llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID, 352 llvm::SmallVectorImpl<Selector> &InstanceMethodSels, 353 llvm::SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes); 354 /// Generates a list of referenced protocols. Classes, categories, and 355 /// protocols all use this structure. 356 llvm::Constant *GenerateProtocolList( 357 const llvm::SmallVectorImpl<std::string> &Protocols); 358 /// To ensure that all protocols are seen by the runtime, we add a category on 359 /// a class defined in the runtime, declaring no methods, but adopting the 360 /// protocols. This is a horribly ugly hack, but it allows us to collect all 361 /// of the protocols without changing the ABI. 362 void GenerateProtocolHolderCategory(void); 363 /// Generates a class structure. 364 llvm::Constant *GenerateClassStructure( 365 llvm::Constant *MetaClass, 366 llvm::Constant *SuperClass, 367 unsigned info, 368 const char *Name, 369 llvm::Constant *Version, 370 llvm::Constant *InstanceSize, 371 llvm::Constant *IVars, 372 llvm::Constant *Methods, 373 llvm::Constant *Protocols, 374 llvm::Constant *IvarOffsets, 375 llvm::Constant *Properties, 376 bool isMeta=false); 377 /// Generates a method list. This is used by protocols to define the required 378 /// and optional methods. 379 llvm::Constant *GenerateProtocolMethodList( 380 const llvm::SmallVectorImpl<llvm::Constant *> &MethodNames, 381 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes); 382 /// Returns a selector with the specified type encoding. An empty string is 383 /// used to return an untyped selector (with the types field set to NULL). 384 llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 385 const std::string &TypeEncoding, bool lval); 386 /// Returns the variable used to store the offset of an instance variable. 387 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID, 388 const ObjCIvarDecl *Ivar); 389 /// Emits a reference to a class. This allows the linker to object if there 390 /// is no class of the matching name. 391 void EmitClassRef(const std::string &className); 392protected: 393 /// Looks up the method for sending a message to the specified object. This 394 /// mechanism differs between the GCC and GNU runtimes, so this method must be 395 /// overridden in subclasses. 396 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 397 llvm::Value *&Receiver, 398 llvm::Value *cmd, 399 llvm::MDNode *node) = 0; 400 /// Looks up the method for sending a message to a superclass. This mechanism 401 /// differs between the GCC and GNU runtimes, so this method must be 402 /// overridden in subclasses. 403 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 404 llvm::Value *ObjCSuper, 405 llvm::Value *cmd) = 0; 406public: 407 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 408 unsigned protocolClassVersion); 409 410 virtual llvm::Constant *GenerateConstantString(const StringLiteral *); 411 412 virtual RValue 413 GenerateMessageSend(CodeGenFunction &CGF, 414 ReturnValueSlot Return, 415 QualType ResultType, 416 Selector Sel, 417 llvm::Value *Receiver, 418 const CallArgList &CallArgs, 419 const ObjCInterfaceDecl *Class, 420 const ObjCMethodDecl *Method); 421 virtual RValue 422 GenerateMessageSendSuper(CodeGenFunction &CGF, 423 ReturnValueSlot Return, 424 QualType ResultType, 425 Selector Sel, 426 const ObjCInterfaceDecl *Class, 427 bool isCategoryImpl, 428 llvm::Value *Receiver, 429 bool IsClassMessage, 430 const CallArgList &CallArgs, 431 const ObjCMethodDecl *Method); 432 virtual llvm::Value *GetClass(CGBuilderTy &Builder, 433 const ObjCInterfaceDecl *OID); 434 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 435 bool lval = false); 436 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 437 *Method); 438 virtual llvm::Constant *GetEHType(QualType T); 439 440 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 441 const ObjCContainerDecl *CD); 442 virtual void GenerateCategory(const ObjCCategoryImplDecl *CMD); 443 virtual void GenerateClass(const ObjCImplementationDecl *ClassDecl); 444 virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder, 445 const ObjCProtocolDecl *PD); 446 virtual void GenerateProtocol(const ObjCProtocolDecl *PD); 447 virtual llvm::Function *ModuleInitFunction(); 448 virtual llvm::Function *GetPropertyGetFunction(); 449 virtual llvm::Function *GetPropertySetFunction(); 450 virtual llvm::Function *GetSetStructFunction(); 451 virtual llvm::Function *GetGetStructFunction(); 452 virtual llvm::Constant *EnumerationMutationFunction(); 453 454 virtual void EmitTryStmt(CodeGenFunction &CGF, 455 const ObjCAtTryStmt &S); 456 virtual void EmitSynchronizedStmt(CodeGenFunction &CGF, 457 const ObjCAtSynchronizedStmt &S); 458 virtual void EmitThrowStmt(CodeGenFunction &CGF, 459 const ObjCAtThrowStmt &S); 460 virtual llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF, 461 llvm::Value *AddrWeakObj); 462 virtual void EmitObjCWeakAssign(CodeGenFunction &CGF, 463 llvm::Value *src, llvm::Value *dst); 464 virtual void EmitObjCGlobalAssign(CodeGenFunction &CGF, 465 llvm::Value *src, llvm::Value *dest, 466 bool threadlocal=false); 467 virtual void EmitObjCIvarAssign(CodeGenFunction &CGF, 468 llvm::Value *src, llvm::Value *dest, 469 llvm::Value *ivarOffset); 470 virtual void EmitObjCStrongCastAssign(CodeGenFunction &CGF, 471 llvm::Value *src, llvm::Value *dest); 472 virtual void EmitGCMemmoveCollectable(CodeGenFunction &CGF, 473 llvm::Value *DestPtr, 474 llvm::Value *SrcPtr, 475 llvm::Value *Size); 476 virtual LValue EmitObjCValueForIvar(CodeGenFunction &CGF, 477 QualType ObjectTy, 478 llvm::Value *BaseValue, 479 const ObjCIvarDecl *Ivar, 480 unsigned CVRQualifiers); 481 virtual llvm::Value *EmitIvarOffset(CodeGenFunction &CGF, 482 const ObjCInterfaceDecl *Interface, 483 const ObjCIvarDecl *Ivar); 484 virtual llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM, 485 const CGBlockInfo &blockInfo) { 486 return NULLPtr; 487 } 488}; 489/// Class representing the legacy GCC Objective-C ABI. This is the default when 490/// -fobjc-nonfragile-abi is not specified. 491/// 492/// The GCC ABI target actually generates code that is approximately compatible 493/// with the new GNUstep runtime ABI, but refrains from using any features that 494/// would not work with the GCC runtime. For example, clang always generates 495/// the extended form of the class structure, and the extra fields are simply 496/// ignored by GCC libobjc. 497class CGObjCGCC : public CGObjCGNU { 498 /// The GCC ABI message lookup function. Returns an IMP pointing to the 499 /// method implementation for this message. 500 LazyRuntimeFunction MsgLookupFn; 501 /// The GCC ABI superclass message lookup function. Takes a pointer to a 502 /// structure describing the receiver and the class, and a selector as 503 /// arguments. Returns the IMP for the corresponding method. 504 LazyRuntimeFunction MsgLookupSuperFn; 505protected: 506 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 507 llvm::Value *&Receiver, 508 llvm::Value *cmd, 509 llvm::MDNode *node) { 510 CGBuilderTy &Builder = CGF.Builder; 511 llvm::Value *imp = Builder.CreateCall2(MsgLookupFn, 512 EnforceType(Builder, Receiver, IdTy), 513 EnforceType(Builder, cmd, SelectorTy)); 514 cast<llvm::CallInst>(imp)->setMetadata(msgSendMDKind, node); 515 return imp; 516 } 517 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 518 llvm::Value *ObjCSuper, 519 llvm::Value *cmd) { 520 CGBuilderTy &Builder = CGF.Builder; 521 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 522 PtrToObjCSuperTy), cmd}; 523 return Builder.CreateCall(MsgLookupSuperFn, lookupArgs, lookupArgs+2); 524 } 525 public: 526 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) { 527 // IMP objc_msg_lookup(id, SEL); 528 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 529 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 530 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 531 PtrToObjCSuperTy, SelectorTy, NULL); 532 } 533}; 534/// Class used when targeting the new GNUstep runtime ABI. 535class CGObjCGNUstep : public CGObjCGNU { 536 /// The slot lookup function. Returns a pointer to a cacheable structure 537 /// that contains (among other things) the IMP. 538 LazyRuntimeFunction SlotLookupFn; 539 /// The GNUstep ABI superclass message lookup function. Takes a pointer to 540 /// a structure describing the receiver and the class, and a selector as 541 /// arguments. Returns the slot for the corresponding method. Superclass 542 /// message lookup rarely changes, so this is a good caching opportunity. 543 LazyRuntimeFunction SlotLookupSuperFn; 544 /// Type of an slot structure pointer. This is returned by the various 545 /// lookup functions. 546 llvm::Type *SlotTy; 547 protected: 548 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 549 llvm::Value *&Receiver, 550 llvm::Value *cmd, 551 llvm::MDNode *node) { 552 CGBuilderTy &Builder = CGF.Builder; 553 llvm::Function *LookupFn = SlotLookupFn; 554 555 // Store the receiver on the stack so that we can reload it later 556 llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType()); 557 Builder.CreateStore(Receiver, ReceiverPtr); 558 559 llvm::Value *self; 560 561 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) { 562 self = CGF.LoadObjCSelf(); 563 } else { 564 self = llvm::ConstantPointerNull::get(IdTy); 565 } 566 567 // The lookup function is guaranteed not to capture the receiver pointer. 568 LookupFn->setDoesNotCapture(1); 569 570 llvm::CallInst *slot = 571 Builder.CreateCall3(LookupFn, 572 EnforceType(Builder, ReceiverPtr, PtrToIdTy), 573 EnforceType(Builder, cmd, SelectorTy), 574 EnforceType(Builder, self, IdTy)); 575 slot->setOnlyReadsMemory(); 576 slot->setMetadata(msgSendMDKind, node); 577 578 // Load the imp from the slot 579 llvm::Value *imp = Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 580 581 // The lookup function may have changed the receiver, so make sure we use 582 // the new one. 583 Receiver = Builder.CreateLoad(ReceiverPtr, true); 584 return imp; 585 } 586 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 587 llvm::Value *ObjCSuper, 588 llvm::Value *cmd) { 589 CGBuilderTy &Builder = CGF.Builder; 590 llvm::Value *lookupArgs[] = {ObjCSuper, cmd}; 591 592 llvm::CallInst *slot = Builder.CreateCall(SlotLookupSuperFn, lookupArgs, 593 lookupArgs+2); 594 slot->setOnlyReadsMemory(); 595 596 return Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 597 } 598 public: 599 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) { 600 llvm::StructType *SlotStructTy = llvm::StructType::get(VMContext, PtrTy, 601 PtrTy, PtrTy, IntTy, IMPTy, NULL); 602 SlotTy = llvm::PointerType::getUnqual(SlotStructTy); 603 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 604 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy, 605 SelectorTy, IdTy, NULL); 606 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL); 607 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy, 608 PtrToObjCSuperTy, SelectorTy, NULL); 609 // If we're in ObjC++ mode, then we want to make 610 if (CGM.getLangOptions().CPlusPlus) { 611 const llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 612 // void *__cxa_begin_catch(void *e) 613 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, NULL); 614 // void __cxa_end_catch(void) 615 EnterCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, NULL); 616 // void _Unwind_Resume_or_Rethrow(void*) 617 EnterCatchFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, PtrTy, NULL); 618 } 619 } 620}; 621 622} // end anonymous namespace 623 624 625/// Emits a reference to a dummy variable which is emitted with each class. 626/// This ensures that a linker error will be generated when trying to link 627/// together modules where a referenced class is not defined. 628void CGObjCGNU::EmitClassRef(const std::string &className) { 629 std::string symbolRef = "__objc_class_ref_" + className; 630 // Don't emit two copies of the same symbol 631 if (TheModule.getGlobalVariable(symbolRef)) 632 return; 633 std::string symbolName = "__objc_class_name_" + className; 634 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName); 635 if (!ClassSymbol) { 636 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 637 llvm::GlobalValue::ExternalLinkage, 0, symbolName); 638 } 639 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true, 640 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef); 641} 642 643static std::string SymbolNameForMethod(const llvm::StringRef &ClassName, 644 const llvm::StringRef &CategoryName, const Selector MethodName, 645 bool isClassMethod) { 646 std::string MethodNameColonStripped = MethodName.getAsString(); 647 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(), 648 ':', '_'); 649 return (llvm::Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" + 650 CategoryName + "_" + MethodNameColonStripped).str(); 651} 652 653CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 654 unsigned protocolClassVersion) 655 : CGM(cgm), TheModule(CGM.getModule()), VMContext(cgm.getLLVMContext()), 656 ClassPtrAlias(0), MetaClassPtrAlias(0), RuntimeVersion(runtimeABIVersion), 657 ProtocolVersion(protocolClassVersion) { 658 659 660 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend"); 661 662 CodeGenTypes &Types = CGM.getTypes(); 663 IntTy = cast<llvm::IntegerType>( 664 Types.ConvertType(CGM.getContext().IntTy)); 665 LongTy = cast<llvm::IntegerType>( 666 Types.ConvertType(CGM.getContext().LongTy)); 667 SizeTy = cast<llvm::IntegerType>( 668 Types.ConvertType(CGM.getContext().getSizeType())); 669 PtrDiffTy = cast<llvm::IntegerType>( 670 Types.ConvertType(CGM.getContext().getPointerDiffType())); 671 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy); 672 673 Int8Ty = llvm::Type::getInt8Ty(VMContext); 674 // C string type. Used in lots of places. 675 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); 676 677 Zeros[0] = llvm::ConstantInt::get(LongTy, 0); 678 Zeros[1] = Zeros[0]; 679 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty); 680 // Get the selector Type. 681 QualType selTy = CGM.getContext().getObjCSelType(); 682 if (QualType() == selTy) { 683 SelectorTy = PtrToInt8Ty; 684 } else { 685 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy)); 686 } 687 688 PtrToIntTy = llvm::PointerType::getUnqual(IntTy); 689 PtrTy = PtrToInt8Ty; 690 691 // Object type 692 ASTIdTy = CGM.getContext().getCanonicalType(CGM.getContext().getObjCIdType()); 693 if (QualType() == ASTIdTy) { 694 IdTy = PtrToInt8Ty; 695 } else { 696 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 697 } 698 PtrToIdTy = llvm::PointerType::getUnqual(IdTy); 699 700 ObjCSuperTy = llvm::StructType::get(VMContext, IdTy, IdTy, NULL); 701 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy); 702 703 const llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 704 705 // void objc_exception_throw(id); 706 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 707 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 708 // int objc_sync_enter(id); 709 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, NULL); 710 // int objc_sync_exit(id); 711 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, NULL); 712 713 // void objc_enumerationMutation (id) 714 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, 715 IdTy, NULL); 716 717 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL) 718 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy, 719 PtrDiffTy, BoolTy, NULL); 720 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL) 721 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy, 722 PtrDiffTy, IdTy, BoolTy, BoolTy, NULL); 723 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 724 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy, 725 PtrDiffTy, BoolTy, BoolTy, NULL); 726 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 727 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy, 728 PtrDiffTy, BoolTy, BoolTy, NULL); 729 730 // IMP type 731 std::vector<const llvm::Type*> IMPArgs; 732 IMPArgs.push_back(IdTy); 733 IMPArgs.push_back(SelectorTy); 734 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs, 735 true)); 736 737 // Don't bother initialising the GC stuff unless we're compiling in GC mode 738 if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) { 739 // Get selectors needed in GC mode 740 RetainSel = GetNullarySelector("retain", CGM.getContext()); 741 ReleaseSel = GetNullarySelector("release", CGM.getContext()); 742 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext()); 743 744 // Get functions needed in GC mode 745 746 // id objc_assign_ivar(id, id, ptrdiff_t); 747 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy, 748 NULL); 749 // id objc_assign_strongCast (id, id*) 750 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy, 751 PtrToIdTy, NULL); 752 // id objc_assign_global(id, id*); 753 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy, 754 NULL); 755 // id objc_assign_weak(id, id*); 756 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, NULL); 757 // id objc_read_weak(id*); 758 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, NULL); 759 // void *objc_memmove_collectable(void*, void *, size_t); 760 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy, 761 SizeTy, NULL); 762 } 763} 764 765// This has to perform the lookup every time, since posing and related 766// techniques can modify the name -> class mapping. 767llvm::Value *CGObjCGNU::GetClass(CGBuilderTy &Builder, 768 const ObjCInterfaceDecl *OID) { 769 llvm::Value *ClassName = CGM.GetAddrOfConstantCString(OID->getNameAsString()); 770 // With the incompatible ABI, this will need to be replaced with a direct 771 // reference to the class symbol. For the compatible nonfragile ABI we are 772 // still performing this lookup at run time but emitting the symbol for the 773 // class externally so that we can make the switch later. 774 EmitClassRef(OID->getNameAsString()); 775 ClassName = Builder.CreateStructGEP(ClassName, 0); 776 777 std::vector<const llvm::Type*> Params(1, PtrToInt8Ty); 778 llvm::Constant *ClassLookupFn = 779 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, 780 Params, 781 true), 782 "objc_lookup_class"); 783 return Builder.CreateCall(ClassLookupFn, ClassName); 784} 785 786llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 787 const std::string &TypeEncoding, bool lval) { 788 789 llvm::SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel]; 790 llvm::GlobalAlias *SelValue = 0; 791 792 793 for (llvm::SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 794 e = Types.end() ; i!=e ; i++) { 795 if (i->first == TypeEncoding) { 796 SelValue = i->second; 797 break; 798 } 799 } 800 if (0 == SelValue) { 801 SelValue = new llvm::GlobalAlias(SelectorTy, 802 llvm::GlobalValue::PrivateLinkage, 803 ".objc_selector_"+Sel.getAsString(), NULL, 804 &TheModule); 805 Types.push_back(TypedSelector(TypeEncoding, SelValue)); 806 } 807 808 if (lval) { 809 llvm::Value *tmp = Builder.CreateAlloca(SelValue->getType()); 810 Builder.CreateStore(SelValue, tmp); 811 return tmp; 812 } 813 return SelValue; 814} 815 816llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 817 bool lval) { 818 return GetSelector(Builder, Sel, std::string(), lval); 819} 820 821llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 822 *Method) { 823 std::string SelTypes; 824 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes); 825 return GetSelector(Builder, Method->getSelector(), SelTypes, false); 826} 827 828llvm::Constant *CGObjCGNU::GetEHType(QualType T) { 829 if (!CGM.getLangOptions().CPlusPlus) { 830 if (T->isObjCIdType() 831 || T->isObjCQualifiedIdType()) { 832 // With the old ABI, there was only one kind of catchall, which broke 833 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as 834 // a pointer indicating object catchalls, and NULL to indicate real 835 // catchalls 836 if (CGM.getLangOptions().ObjCNonFragileABI) { 837 return MakeConstantString("@id"); 838 } else { 839 return 0; 840 } 841 } 842 843 // All other types should be Objective-C interface pointer types. 844 const ObjCObjectPointerType *OPT = 845 T->getAs<ObjCObjectPointerType>(); 846 assert(OPT && "Invalid @catch type."); 847 const ObjCInterfaceDecl *IDecl = 848 OPT->getObjectType()->getInterface(); 849 assert(IDecl && "Invalid @catch type."); 850 return MakeConstantString(IDecl->getIdentifier()->getName()); 851 } 852 // For Objective-C++, we want to provide the ability to catch both C++ and 853 // Objective-C objects in the same function. 854 855 // There's a particular fixed type info for 'id'. 856 if (T->isObjCIdType() || 857 T->isObjCQualifiedIdType()) { 858 llvm::Constant *IDEHType = 859 CGM.getModule().getGlobalVariable("__objc_id_type_info"); 860 if (!IDEHType) 861 IDEHType = 862 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty, 863 false, 864 llvm::GlobalValue::ExternalLinkage, 865 0, "__objc_id_type_info"); 866 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty); 867 } 868 869 const ObjCObjectPointerType *PT = 870 T->getAs<ObjCObjectPointerType>(); 871 assert(PT && "Invalid @catch type."); 872 const ObjCInterfaceType *IT = PT->getInterfaceType(); 873 assert(IT && "Invalid @catch type."); 874 std::string className = IT->getDecl()->getIdentifier()->getName(); 875 876 std::string typeinfoName = "__objc_eh_typeinfo_" + className; 877 878 // Return the existing typeinfo if it exists 879 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName); 880 if (typeinfo) return typeinfo; 881 882 // Otherwise create it. 883 884 // vtable for gnustep::libobjc::__objc_class_type_info 885 // It's quite ugly hard-coding this. Ideally we'd generate it using the host 886 // platform's name mangling. 887 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE"; 888 llvm::Constant *Vtable = TheModule.getGlobalVariable(vtableName); 889 if (!Vtable) { 890 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true, 891 llvm::GlobalValue::ExternalLinkage, 0, vtableName); 892 } 893 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2); 894 Vtable = llvm::ConstantExpr::getGetElementPtr(Vtable, &Two, 1); 895 Vtable = llvm::ConstantExpr::getBitCast(Vtable, PtrToInt8Ty); 896 897 llvm::Constant *typeName = 898 ExportUniqueString(className, "__objc_eh_typename_"); 899 900 std::vector<llvm::Constant*> fields; 901 fields.push_back(Vtable); 902 fields.push_back(typeName); 903 llvm::Constant *TI = 904 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 905 NULL), fields, "__objc_eh_typeinfo_" + className, 906 llvm::GlobalValue::LinkOnceODRLinkage); 907 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty); 908} 909 910/// Generate an NSConstantString object. 911llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) { 912 913 std::string Str = SL->getString().str(); 914 915 // Look for an existing one 916 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str); 917 if (old != ObjCStrings.end()) 918 return old->getValue(); 919 920 std::vector<llvm::Constant*> Ivars; 921 Ivars.push_back(NULLPtr); 922 Ivars.push_back(MakeConstantString(Str)); 923 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size())); 924 llvm::Constant *ObjCStr = MakeGlobal( 925 llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, IntTy, NULL), 926 Ivars, ".objc_str"); 927 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty); 928 ObjCStrings[Str] = ObjCStr; 929 ConstantStrings.push_back(ObjCStr); 930 return ObjCStr; 931} 932 933///Generates a message send where the super is the receiver. This is a message 934///send to self with special delivery semantics indicating which class's method 935///should be called. 936RValue 937CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF, 938 ReturnValueSlot Return, 939 QualType ResultType, 940 Selector Sel, 941 const ObjCInterfaceDecl *Class, 942 bool isCategoryImpl, 943 llvm::Value *Receiver, 944 bool IsClassMessage, 945 const CallArgList &CallArgs, 946 const ObjCMethodDecl *Method) { 947 if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) { 948 if (Sel == RetainSel || Sel == AutoreleaseSel) { 949 return RValue::get(Receiver); 950 } 951 if (Sel == ReleaseSel) { 952 return RValue::get(0); 953 } 954 } 955 956 CGBuilderTy &Builder = CGF.Builder; 957 llvm::Value *cmd = GetSelector(Builder, Sel); 958 959 960 CallArgList ActualArgs; 961 962 ActualArgs.push_back( 963 std::make_pair(RValue::get(EnforceType(Builder, Receiver, IdTy)), 964 ASTIdTy)); 965 ActualArgs.push_back(std::make_pair(RValue::get(cmd), 966 CGF.getContext().getObjCSelType())); 967 ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end()); 968 969 CodeGenTypes &Types = CGM.getTypes(); 970 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 971 FunctionType::ExtInfo()); 972 973 llvm::Value *ReceiverClass = 0; 974 if (isCategoryImpl) { 975 llvm::Constant *classLookupFunction = 0; 976 std::vector<const llvm::Type*> Params; 977 Params.push_back(PtrTy); 978 if (IsClassMessage) { 979 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 980 IdTy, Params, true), "objc_get_meta_class"); 981 } else { 982 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 983 IdTy, Params, true), "objc_get_class"); 984 } 985 ReceiverClass = Builder.CreateCall(classLookupFunction, 986 MakeConstantString(Class->getNameAsString())); 987 } else { 988 // Set up global aliases for the metaclass or class pointer if they do not 989 // already exist. These will are forward-references which will be set to 990 // pointers to the class and metaclass structure created for the runtime 991 // load function. To send a message to super, we look up the value of the 992 // super_class pointer from either the class or metaclass structure. 993 if (IsClassMessage) { 994 if (!MetaClassPtrAlias) { 995 MetaClassPtrAlias = new llvm::GlobalAlias(IdTy, 996 llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" + 997 Class->getNameAsString(), NULL, &TheModule); 998 } 999 ReceiverClass = MetaClassPtrAlias; 1000 } else { 1001 if (!ClassPtrAlias) { 1002 ClassPtrAlias = new llvm::GlobalAlias(IdTy, 1003 llvm::GlobalValue::InternalLinkage, ".objc_class_ref" + 1004 Class->getNameAsString(), NULL, &TheModule); 1005 } 1006 ReceiverClass = ClassPtrAlias; 1007 } 1008 } 1009 // Cast the pointer to a simplified version of the class structure 1010 ReceiverClass = Builder.CreateBitCast(ReceiverClass, 1011 llvm::PointerType::getUnqual( 1012 llvm::StructType::get(VMContext, IdTy, IdTy, NULL))); 1013 // Get the superclass pointer 1014 ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1); 1015 // Load the superclass pointer 1016 ReceiverClass = Builder.CreateLoad(ReceiverClass); 1017 // Construct the structure used to look up the IMP 1018 llvm::StructType *ObjCSuperTy = llvm::StructType::get(VMContext, 1019 Receiver->getType(), IdTy, NULL); 1020 llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy); 1021 1022 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0)); 1023 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1)); 1024 1025 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy); 1026 const llvm::FunctionType *impType = 1027 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1028 1029 // Get the IMP 1030 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd); 1031 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1032 1033 llvm::Value *impMD[] = { 1034 llvm::MDString::get(VMContext, Sel.getAsString()), 1035 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()), 1036 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage) 1037 }; 1038 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD, 3); 1039 1040 llvm::Instruction *call; 1041 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1042 0, &call); 1043 call->setMetadata(msgSendMDKind, node); 1044 return msgRet; 1045} 1046 1047/// Generate code for a message send expression. 1048RValue 1049CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF, 1050 ReturnValueSlot Return, 1051 QualType ResultType, 1052 Selector Sel, 1053 llvm::Value *Receiver, 1054 const CallArgList &CallArgs, 1055 const ObjCInterfaceDecl *Class, 1056 const ObjCMethodDecl *Method) { 1057 // Strip out message sends to retain / release in GC mode 1058 if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) { 1059 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1060 return RValue::get(Receiver); 1061 } 1062 if (Sel == ReleaseSel) { 1063 return RValue::get(0); 1064 } 1065 } 1066 1067 CGBuilderTy &Builder = CGF.Builder; 1068 1069 // If the return type is something that goes in an integer register, the 1070 // runtime will handle 0 returns. For other cases, we fill in the 0 value 1071 // ourselves. 1072 // 1073 // The language spec says the result of this kind of message send is 1074 // undefined, but lots of people seem to have forgotten to read that 1075 // paragraph and insist on sending messages to nil that have structure 1076 // returns. With GCC, this generates a random return value (whatever happens 1077 // to be on the stack / in those registers at the time) on most platforms, 1078 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts 1079 // the stack. 1080 bool isPointerSizedReturn = (ResultType->isAnyPointerType() || 1081 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType()); 1082 1083 llvm::BasicBlock *startBB = 0; 1084 llvm::BasicBlock *messageBB = 0; 1085 llvm::BasicBlock *continueBB = 0; 1086 1087 if (!isPointerSizedReturn) { 1088 startBB = Builder.GetInsertBlock(); 1089 messageBB = CGF.createBasicBlock("msgSend"); 1090 continueBB = CGF.createBasicBlock("continue"); 1091 1092 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver, 1093 llvm::Constant::getNullValue(Receiver->getType())); 1094 Builder.CreateCondBr(isNil, continueBB, messageBB); 1095 CGF.EmitBlock(messageBB); 1096 } 1097 1098 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 1099 llvm::Value *cmd; 1100 if (Method) 1101 cmd = GetSelector(Builder, Method); 1102 else 1103 cmd = GetSelector(Builder, Sel); 1104 cmd = EnforceType(Builder, cmd, SelectorTy); 1105 Receiver = EnforceType(Builder, Receiver, IdTy); 1106 1107 llvm::Value *impMD[] = { 1108 llvm::MDString::get(VMContext, Sel.getAsString()), 1109 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""), 1110 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0) 1111 }; 1112 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD, 3); 1113 1114 // Get the IMP to call 1115 llvm::Value *imp = LookupIMP(CGF, Receiver, cmd, node); 1116 1117 CallArgList ActualArgs; 1118 ActualArgs.push_back( 1119 std::make_pair(RValue::get(Receiver), ASTIdTy)); 1120 ActualArgs.push_back(std::make_pair(RValue::get(cmd), 1121 CGF.getContext().getObjCSelType())); 1122 ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end()); 1123 1124 CodeGenTypes &Types = CGM.getTypes(); 1125 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 1126 FunctionType::ExtInfo()); 1127 const llvm::FunctionType *impType = 1128 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1129 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1130 1131 1132 // For sender-aware dispatch, we pass the sender as the third argument to a 1133 // lookup function. When sending messages from C code, the sender is nil. 1134 // objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 1135 llvm::Instruction *call; 1136 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1137 0, &call); 1138 call->setMetadata(msgSendMDKind, node); 1139 1140 1141 if (!isPointerSizedReturn) { 1142 messageBB = CGF.Builder.GetInsertBlock(); 1143 CGF.Builder.CreateBr(continueBB); 1144 CGF.EmitBlock(continueBB); 1145 if (msgRet.isScalar()) { 1146 llvm::Value *v = msgRet.getScalarVal(); 1147 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1148 phi->addIncoming(v, messageBB); 1149 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB); 1150 msgRet = RValue::get(phi); 1151 } else if (msgRet.isAggregate()) { 1152 llvm::Value *v = msgRet.getAggregateAddr(); 1153 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1154 const llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType()); 1155 llvm::AllocaInst *NullVal = 1156 CGF.CreateTempAlloca(RetTy->getElementType(), "null"); 1157 CGF.InitTempAlloca(NullVal, 1158 llvm::Constant::getNullValue(RetTy->getElementType())); 1159 phi->addIncoming(v, messageBB); 1160 phi->addIncoming(NullVal, startBB); 1161 msgRet = RValue::getAggregate(phi); 1162 } else /* isComplex() */ { 1163 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal(); 1164 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2); 1165 phi->addIncoming(v.first, messageBB); 1166 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()), 1167 startBB); 1168 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2); 1169 phi2->addIncoming(v.second, messageBB); 1170 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()), 1171 startBB); 1172 msgRet = RValue::getComplex(phi, phi2); 1173 } 1174 } 1175 return msgRet; 1176} 1177 1178/// Generates a MethodList. Used in construction of a objc_class and 1179/// objc_category structures. 1180llvm::Constant *CGObjCGNU::GenerateMethodList(const llvm::StringRef &ClassName, 1181 const llvm::StringRef &CategoryName, 1182 const llvm::SmallVectorImpl<Selector> &MethodSels, 1183 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes, 1184 bool isClassMethodList) { 1185 if (MethodSels.empty()) 1186 return NULLPtr; 1187 // Get the method structure type. 1188 llvm::StructType *ObjCMethodTy = llvm::StructType::get(VMContext, 1189 PtrToInt8Ty, // Really a selector, but the runtime creates it us. 1190 PtrToInt8Ty, // Method types 1191 IMPTy, //Method pointer 1192 NULL); 1193 std::vector<llvm::Constant*> Methods; 1194 std::vector<llvm::Constant*> Elements; 1195 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) { 1196 Elements.clear(); 1197 llvm::Constant *Method = 1198 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName, 1199 MethodSels[i], 1200 isClassMethodList)); 1201 assert(Method && "Can't generate metadata for method that doesn't exist"); 1202 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString()); 1203 Elements.push_back(C); 1204 Elements.push_back(MethodTypes[i]); 1205 Method = llvm::ConstantExpr::getBitCast(Method, 1206 IMPTy); 1207 Elements.push_back(Method); 1208 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements)); 1209 } 1210 1211 // Array of method structures 1212 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy, 1213 Methods.size()); 1214 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy, 1215 Methods); 1216 1217 // Structure containing list pointer, array and array count 1218 llvm::SmallVector<const llvm::Type*, 16> ObjCMethodListFields; 1219 llvm::PATypeHolder OpaqueNextTy = llvm::OpaqueType::get(VMContext); 1220 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(OpaqueNextTy); 1221 llvm::StructType *ObjCMethodListTy = llvm::StructType::get(VMContext, 1222 NextPtrTy, 1223 IntTy, 1224 ObjCMethodArrayTy, 1225 NULL); 1226 // Refine next pointer type to concrete type 1227 llvm::cast<llvm::OpaqueType>( 1228 OpaqueNextTy.get())->refineAbstractTypeTo(ObjCMethodListTy); 1229 ObjCMethodListTy = llvm::cast<llvm::StructType>(OpaqueNextTy.get()); 1230 1231 Methods.clear(); 1232 Methods.push_back(llvm::ConstantPointerNull::get( 1233 llvm::PointerType::getUnqual(ObjCMethodListTy))); 1234 Methods.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1235 MethodTypes.size())); 1236 Methods.push_back(MethodArray); 1237 1238 // Create an instance of the structure 1239 return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list"); 1240} 1241 1242/// Generates an IvarList. Used in construction of a objc_class. 1243llvm::Constant *CGObjCGNU::GenerateIvarList( 1244 const llvm::SmallVectorImpl<llvm::Constant *> &IvarNames, 1245 const llvm::SmallVectorImpl<llvm::Constant *> &IvarTypes, 1246 const llvm::SmallVectorImpl<llvm::Constant *> &IvarOffsets) { 1247 if (IvarNames.size() == 0) 1248 return NULLPtr; 1249 // Get the method structure type. 1250 llvm::StructType *ObjCIvarTy = llvm::StructType::get(VMContext, 1251 PtrToInt8Ty, 1252 PtrToInt8Ty, 1253 IntTy, 1254 NULL); 1255 std::vector<llvm::Constant*> Ivars; 1256 std::vector<llvm::Constant*> Elements; 1257 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) { 1258 Elements.clear(); 1259 Elements.push_back(IvarNames[i]); 1260 Elements.push_back(IvarTypes[i]); 1261 Elements.push_back(IvarOffsets[i]); 1262 Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements)); 1263 } 1264 1265 // Array of method structures 1266 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy, 1267 IvarNames.size()); 1268 1269 1270 Elements.clear(); 1271 Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size())); 1272 Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)); 1273 // Structure containing array and array count 1274 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(VMContext, IntTy, 1275 ObjCIvarArrayTy, 1276 NULL); 1277 1278 // Create an instance of the structure 1279 return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list"); 1280} 1281 1282/// Generate a class structure 1283llvm::Constant *CGObjCGNU::GenerateClassStructure( 1284 llvm::Constant *MetaClass, 1285 llvm::Constant *SuperClass, 1286 unsigned info, 1287 const char *Name, 1288 llvm::Constant *Version, 1289 llvm::Constant *InstanceSize, 1290 llvm::Constant *IVars, 1291 llvm::Constant *Methods, 1292 llvm::Constant *Protocols, 1293 llvm::Constant *IvarOffsets, 1294 llvm::Constant *Properties, 1295 bool isMeta) { 1296 // Set up the class structure 1297 // Note: Several of these are char*s when they should be ids. This is 1298 // because the runtime performs this translation on load. 1299 // 1300 // Fields marked New ABI are part of the GNUstep runtime. We emit them 1301 // anyway; the classes will still work with the GNU runtime, they will just 1302 // be ignored. 1303 llvm::StructType *ClassTy = llvm::StructType::get(VMContext, 1304 PtrToInt8Ty, // class_pointer 1305 PtrToInt8Ty, // super_class 1306 PtrToInt8Ty, // name 1307 LongTy, // version 1308 LongTy, // info 1309 LongTy, // instance_size 1310 IVars->getType(), // ivars 1311 Methods->getType(), // methods 1312 // These are all filled in by the runtime, so we pretend 1313 PtrTy, // dtable 1314 PtrTy, // subclass_list 1315 PtrTy, // sibling_class 1316 PtrTy, // protocols 1317 PtrTy, // gc_object_type 1318 // New ABI: 1319 LongTy, // abi_version 1320 IvarOffsets->getType(), // ivar_offsets 1321 Properties->getType(), // properties 1322 NULL); 1323 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0); 1324 // Fill in the structure 1325 std::vector<llvm::Constant*> Elements; 1326 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty)); 1327 Elements.push_back(SuperClass); 1328 Elements.push_back(MakeConstantString(Name, ".class_name")); 1329 Elements.push_back(Zero); 1330 Elements.push_back(llvm::ConstantInt::get(LongTy, info)); 1331 if (isMeta) { 1332 llvm::TargetData td(&TheModule); 1333 Elements.push_back(llvm::ConstantInt::get(LongTy, 1334 td.getTypeSizeInBits(ClassTy)/8)); 1335 } else 1336 Elements.push_back(InstanceSize); 1337 Elements.push_back(IVars); 1338 Elements.push_back(Methods); 1339 Elements.push_back(NULLPtr); 1340 Elements.push_back(NULLPtr); 1341 Elements.push_back(NULLPtr); 1342 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy)); 1343 Elements.push_back(NULLPtr); 1344 Elements.push_back(Zero); 1345 Elements.push_back(IvarOffsets); 1346 Elements.push_back(Properties); 1347 // Create an instance of the structure 1348 // This is now an externally visible symbol, so that we can speed up class 1349 // messages in the next ABI. 1350 return MakeGlobal(ClassTy, Elements, (isMeta ? "_OBJC_METACLASS_": 1351 "_OBJC_CLASS_") + std::string(Name), llvm::GlobalValue::ExternalLinkage); 1352} 1353 1354llvm::Constant *CGObjCGNU::GenerateProtocolMethodList( 1355 const llvm::SmallVectorImpl<llvm::Constant *> &MethodNames, 1356 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes) { 1357 // Get the method structure type. 1358 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get(VMContext, 1359 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us. 1360 PtrToInt8Ty, 1361 NULL); 1362 std::vector<llvm::Constant*> Methods; 1363 std::vector<llvm::Constant*> Elements; 1364 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) { 1365 Elements.clear(); 1366 Elements.push_back(MethodNames[i]); 1367 Elements.push_back(MethodTypes[i]); 1368 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements)); 1369 } 1370 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy, 1371 MethodNames.size()); 1372 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy, 1373 Methods); 1374 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get(VMContext, 1375 IntTy, ObjCMethodArrayTy, NULL); 1376 Methods.clear(); 1377 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size())); 1378 Methods.push_back(Array); 1379 return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list"); 1380} 1381 1382// Create the protocol list structure used in classes, categories and so on 1383llvm::Constant *CGObjCGNU::GenerateProtocolList( 1384 const llvm::SmallVectorImpl<std::string> &Protocols) { 1385 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 1386 Protocols.size()); 1387 llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext, 1388 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1389 SizeTy, 1390 ProtocolArrayTy, 1391 NULL); 1392 std::vector<llvm::Constant*> Elements; 1393 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end(); 1394 iter != endIter ; iter++) { 1395 llvm::Constant *protocol = 0; 1396 llvm::StringMap<llvm::Constant*>::iterator value = 1397 ExistingProtocols.find(*iter); 1398 if (value == ExistingProtocols.end()) { 1399 protocol = GenerateEmptyProtocol(*iter); 1400 } else { 1401 protocol = value->getValue(); 1402 } 1403 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol, 1404 PtrToInt8Ty); 1405 Elements.push_back(Ptr); 1406 } 1407 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1408 Elements); 1409 Elements.clear(); 1410 Elements.push_back(NULLPtr); 1411 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size())); 1412 Elements.push_back(ProtocolArray); 1413 return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list"); 1414} 1415 1416llvm::Value *CGObjCGNU::GenerateProtocolRef(CGBuilderTy &Builder, 1417 const ObjCProtocolDecl *PD) { 1418 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()]; 1419 const llvm::Type *T = 1420 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType()); 1421 return Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T)); 1422} 1423 1424llvm::Constant *CGObjCGNU::GenerateEmptyProtocol( 1425 const std::string &ProtocolName) { 1426 llvm::SmallVector<std::string, 0> EmptyStringVector; 1427 llvm::SmallVector<llvm::Constant*, 0> EmptyConstantVector; 1428 1429 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector); 1430 llvm::Constant *MethodList = 1431 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector); 1432 // Protocols are objects containing lists of the methods implemented and 1433 // protocols adopted. 1434 llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy, 1435 PtrToInt8Ty, 1436 ProtocolList->getType(), 1437 MethodList->getType(), 1438 MethodList->getType(), 1439 MethodList->getType(), 1440 MethodList->getType(), 1441 NULL); 1442 std::vector<llvm::Constant*> Elements; 1443 // The isa pointer must be set to a magic number so the runtime knows it's 1444 // the correct layout. 1445 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1446 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1447 ProtocolVersion), IdTy)); 1448 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1449 Elements.push_back(ProtocolList); 1450 Elements.push_back(MethodList); 1451 Elements.push_back(MethodList); 1452 Elements.push_back(MethodList); 1453 Elements.push_back(MethodList); 1454 return MakeGlobal(ProtocolTy, Elements, ".objc_protocol"); 1455} 1456 1457void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) { 1458 ASTContext &Context = CGM.getContext(); 1459 std::string ProtocolName = PD->getNameAsString(); 1460 llvm::SmallVector<std::string, 16> Protocols; 1461 for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(), 1462 E = PD->protocol_end(); PI != E; ++PI) 1463 Protocols.push_back((*PI)->getNameAsString()); 1464 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodNames; 1465 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1466 llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames; 1467 llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes; 1468 for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(), 1469 E = PD->instmeth_end(); iter != E; iter++) { 1470 std::string TypeStr; 1471 Context.getObjCEncodingForMethodDecl(*iter, TypeStr); 1472 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1473 InstanceMethodNames.push_back( 1474 MakeConstantString((*iter)->getSelector().getAsString())); 1475 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1476 } else { 1477 OptionalInstanceMethodNames.push_back( 1478 MakeConstantString((*iter)->getSelector().getAsString())); 1479 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1480 } 1481 } 1482 // Collect information about class methods: 1483 llvm::SmallVector<llvm::Constant*, 16> ClassMethodNames; 1484 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1485 llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodNames; 1486 llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes; 1487 for (ObjCProtocolDecl::classmeth_iterator 1488 iter = PD->classmeth_begin(), endIter = PD->classmeth_end(); 1489 iter != endIter ; iter++) { 1490 std::string TypeStr; 1491 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1492 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1493 ClassMethodNames.push_back( 1494 MakeConstantString((*iter)->getSelector().getAsString())); 1495 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1496 } else { 1497 OptionalClassMethodNames.push_back( 1498 MakeConstantString((*iter)->getSelector().getAsString())); 1499 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1500 } 1501 } 1502 1503 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols); 1504 llvm::Constant *InstanceMethodList = 1505 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes); 1506 llvm::Constant *ClassMethodList = 1507 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes); 1508 llvm::Constant *OptionalInstanceMethodList = 1509 GenerateProtocolMethodList(OptionalInstanceMethodNames, 1510 OptionalInstanceMethodTypes); 1511 llvm::Constant *OptionalClassMethodList = 1512 GenerateProtocolMethodList(OptionalClassMethodNames, 1513 OptionalClassMethodTypes); 1514 1515 // Property metadata: name, attributes, isSynthesized, setter name, setter 1516 // types, getter name, getter types. 1517 // The isSynthesized value is always set to 0 in a protocol. It exists to 1518 // simplify the runtime library by allowing it to use the same data 1519 // structures for protocol metadata everywhere. 1520 llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext, 1521 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1522 PtrToInt8Ty, NULL); 1523 std::vector<llvm::Constant*> Properties; 1524 std::vector<llvm::Constant*> OptionalProperties; 1525 1526 // Add all of the property methods need adding to the method list and to the 1527 // property metadata list. 1528 for (ObjCContainerDecl::prop_iterator 1529 iter = PD->prop_begin(), endIter = PD->prop_end(); 1530 iter != endIter ; iter++) { 1531 std::vector<llvm::Constant*> Fields; 1532 ObjCPropertyDecl *property = (*iter); 1533 1534 Fields.push_back(MakeConstantString(property->getNameAsString())); 1535 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1536 property->getPropertyAttributes())); 1537 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 1538 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1539 std::string TypeStr; 1540 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1541 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1542 InstanceMethodTypes.push_back(TypeEncoding); 1543 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1544 Fields.push_back(TypeEncoding); 1545 } else { 1546 Fields.push_back(NULLPtr); 1547 Fields.push_back(NULLPtr); 1548 } 1549 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1550 std::string TypeStr; 1551 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1552 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1553 InstanceMethodTypes.push_back(TypeEncoding); 1554 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1555 Fields.push_back(TypeEncoding); 1556 } else { 1557 Fields.push_back(NULLPtr); 1558 Fields.push_back(NULLPtr); 1559 } 1560 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) { 1561 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1562 } else { 1563 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1564 } 1565 } 1566 llvm::Constant *PropertyArray = llvm::ConstantArray::get( 1567 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties); 1568 llvm::Constant* PropertyListInitFields[] = 1569 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1570 1571 llvm::Constant *PropertyListInit = 1572 llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false); 1573 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule, 1574 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage, 1575 PropertyListInit, ".objc_property_list"); 1576 1577 llvm::Constant *OptionalPropertyArray = 1578 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy, 1579 OptionalProperties.size()) , OptionalProperties); 1580 llvm::Constant* OptionalPropertyListInitFields[] = { 1581 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr, 1582 OptionalPropertyArray }; 1583 1584 llvm::Constant *OptionalPropertyListInit = 1585 llvm::ConstantStruct::get(VMContext, OptionalPropertyListInitFields, 3, false); 1586 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule, 1587 OptionalPropertyListInit->getType(), false, 1588 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit, 1589 ".objc_property_list"); 1590 1591 // Protocols are objects containing lists of the methods implemented and 1592 // protocols adopted. 1593 llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy, 1594 PtrToInt8Ty, 1595 ProtocolList->getType(), 1596 InstanceMethodList->getType(), 1597 ClassMethodList->getType(), 1598 OptionalInstanceMethodList->getType(), 1599 OptionalClassMethodList->getType(), 1600 PropertyList->getType(), 1601 OptionalPropertyList->getType(), 1602 NULL); 1603 std::vector<llvm::Constant*> Elements; 1604 // The isa pointer must be set to a magic number so the runtime knows it's 1605 // the correct layout. 1606 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1607 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1608 ProtocolVersion), IdTy)); 1609 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1610 Elements.push_back(ProtocolList); 1611 Elements.push_back(InstanceMethodList); 1612 Elements.push_back(ClassMethodList); 1613 Elements.push_back(OptionalInstanceMethodList); 1614 Elements.push_back(OptionalClassMethodList); 1615 Elements.push_back(PropertyList); 1616 Elements.push_back(OptionalPropertyList); 1617 ExistingProtocols[ProtocolName] = 1618 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements, 1619 ".objc_protocol"), IdTy); 1620} 1621void CGObjCGNU::GenerateProtocolHolderCategory(void) { 1622 // Collect information about instance methods 1623 llvm::SmallVector<Selector, 1> MethodSels; 1624 llvm::SmallVector<llvm::Constant*, 1> MethodTypes; 1625 1626 std::vector<llvm::Constant*> Elements; 1627 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack"; 1628 const std::string CategoryName = "AnotherHack"; 1629 Elements.push_back(MakeConstantString(CategoryName)); 1630 Elements.push_back(MakeConstantString(ClassName)); 1631 // Instance method list 1632 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1633 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy)); 1634 // Class method list 1635 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1636 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy)); 1637 // Protocol list 1638 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy, 1639 ExistingProtocols.size()); 1640 llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext, 1641 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1642 SizeTy, 1643 ProtocolArrayTy, 1644 NULL); 1645 std::vector<llvm::Constant*> ProtocolElements; 1646 for (llvm::StringMapIterator<llvm::Constant*> iter = 1647 ExistingProtocols.begin(), endIter = ExistingProtocols.end(); 1648 iter != endIter ; iter++) { 1649 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(), 1650 PtrTy); 1651 ProtocolElements.push_back(Ptr); 1652 } 1653 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1654 ProtocolElements); 1655 ProtocolElements.clear(); 1656 ProtocolElements.push_back(NULLPtr); 1657 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy, 1658 ExistingProtocols.size())); 1659 ProtocolElements.push_back(ProtocolArray); 1660 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy, 1661 ProtocolElements, ".objc_protocol_list"), PtrTy)); 1662 Categories.push_back(llvm::ConstantExpr::getBitCast( 1663 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 1664 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1665} 1666 1667void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) { 1668 std::string ClassName = OCD->getClassInterface()->getNameAsString(); 1669 std::string CategoryName = OCD->getNameAsString(); 1670 // Collect information about instance methods 1671 llvm::SmallVector<Selector, 16> InstanceMethodSels; 1672 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1673 for (ObjCCategoryImplDecl::instmeth_iterator 1674 iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end(); 1675 iter != endIter ; iter++) { 1676 InstanceMethodSels.push_back((*iter)->getSelector()); 1677 std::string TypeStr; 1678 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1679 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1680 } 1681 1682 // Collect information about class methods 1683 llvm::SmallVector<Selector, 16> ClassMethodSels; 1684 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1685 for (ObjCCategoryImplDecl::classmeth_iterator 1686 iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end(); 1687 iter != endIter ; iter++) { 1688 ClassMethodSels.push_back((*iter)->getSelector()); 1689 std::string TypeStr; 1690 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1691 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1692 } 1693 1694 // Collect the names of referenced protocols 1695 llvm::SmallVector<std::string, 16> Protocols; 1696 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl(); 1697 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols(); 1698 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1699 E = Protos.end(); I != E; ++I) 1700 Protocols.push_back((*I)->getNameAsString()); 1701 1702 std::vector<llvm::Constant*> Elements; 1703 Elements.push_back(MakeConstantString(CategoryName)); 1704 Elements.push_back(MakeConstantString(ClassName)); 1705 // Instance method list 1706 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1707 ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes, 1708 false), PtrTy)); 1709 // Class method list 1710 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1711 ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true), 1712 PtrTy)); 1713 // Protocol list 1714 Elements.push_back(llvm::ConstantExpr::getBitCast( 1715 GenerateProtocolList(Protocols), PtrTy)); 1716 Categories.push_back(llvm::ConstantExpr::getBitCast( 1717 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 1718 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1719} 1720 1721llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID, 1722 llvm::SmallVectorImpl<Selector> &InstanceMethodSels, 1723 llvm::SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) { 1724 ASTContext &Context = CGM.getContext(); 1725 // 1726 // Property metadata: name, attributes, isSynthesized, setter name, setter 1727 // types, getter name, getter types. 1728 llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext, 1729 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1730 PtrToInt8Ty, NULL); 1731 std::vector<llvm::Constant*> Properties; 1732 1733 1734 // Add all of the property methods need adding to the method list and to the 1735 // property metadata list. 1736 for (ObjCImplDecl::propimpl_iterator 1737 iter = OID->propimpl_begin(), endIter = OID->propimpl_end(); 1738 iter != endIter ; iter++) { 1739 std::vector<llvm::Constant*> Fields; 1740 ObjCPropertyDecl *property = (*iter)->getPropertyDecl(); 1741 ObjCPropertyImplDecl *propertyImpl = *iter; 1742 bool isSynthesized = (propertyImpl->getPropertyImplementation() == 1743 ObjCPropertyImplDecl::Synthesize); 1744 1745 Fields.push_back(MakeConstantString(property->getNameAsString())); 1746 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1747 property->getPropertyAttributes())); 1748 Fields.push_back(llvm::ConstantInt::get(Int8Ty, isSynthesized)); 1749 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1750 std::string TypeStr; 1751 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1752 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1753 if (isSynthesized) { 1754 InstanceMethodTypes.push_back(TypeEncoding); 1755 InstanceMethodSels.push_back(getter->getSelector()); 1756 } 1757 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1758 Fields.push_back(TypeEncoding); 1759 } else { 1760 Fields.push_back(NULLPtr); 1761 Fields.push_back(NULLPtr); 1762 } 1763 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1764 std::string TypeStr; 1765 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1766 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1767 if (isSynthesized) { 1768 InstanceMethodTypes.push_back(TypeEncoding); 1769 InstanceMethodSels.push_back(setter->getSelector()); 1770 } 1771 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1772 Fields.push_back(TypeEncoding); 1773 } else { 1774 Fields.push_back(NULLPtr); 1775 Fields.push_back(NULLPtr); 1776 } 1777 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1778 } 1779 llvm::ArrayType *PropertyArrayTy = 1780 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()); 1781 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy, 1782 Properties); 1783 llvm::Constant* PropertyListInitFields[] = 1784 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1785 1786 llvm::Constant *PropertyListInit = 1787 llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false); 1788 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false, 1789 llvm::GlobalValue::InternalLinkage, PropertyListInit, 1790 ".objc_property_list"); 1791} 1792 1793void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) { 1794 ASTContext &Context = CGM.getContext(); 1795 1796 // Get the superclass name. 1797 const ObjCInterfaceDecl * SuperClassDecl = 1798 OID->getClassInterface()->getSuperClass(); 1799 std::string SuperClassName; 1800 if (SuperClassDecl) { 1801 SuperClassName = SuperClassDecl->getNameAsString(); 1802 EmitClassRef(SuperClassName); 1803 } 1804 1805 // Get the class name 1806 ObjCInterfaceDecl *ClassDecl = 1807 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface()); 1808 std::string ClassName = ClassDecl->getNameAsString(); 1809 // Emit the symbol that is used to generate linker errors if this class is 1810 // referenced in other modules but not declared. 1811 std::string classSymbolName = "__objc_class_name_" + ClassName; 1812 if (llvm::GlobalVariable *symbol = 1813 TheModule.getGlobalVariable(classSymbolName)) { 1814 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0)); 1815 } else { 1816 new llvm::GlobalVariable(TheModule, LongTy, false, 1817 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0), 1818 classSymbolName); 1819 } 1820 1821 // Get the size of instances. 1822 int instanceSize = 1823 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity(); 1824 1825 // Collect information about instance variables. 1826 llvm::SmallVector<llvm::Constant*, 16> IvarNames; 1827 llvm::SmallVector<llvm::Constant*, 16> IvarTypes; 1828 llvm::SmallVector<llvm::Constant*, 16> IvarOffsets; 1829 1830 std::vector<llvm::Constant*> IvarOffsetValues; 1831 1832 int superInstanceSize = !SuperClassDecl ? 0 : 1833 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity(); 1834 // For non-fragile ivars, set the instance size to 0 - {the size of just this 1835 // class}. The runtime will then set this to the correct value on load. 1836 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1837 instanceSize = 0 - (instanceSize - superInstanceSize); 1838 } 1839 1840 // Collect declared and synthesized ivars. 1841 llvm::SmallVector<ObjCIvarDecl*, 16> OIvars; 1842 CGM.getContext().ShallowCollectObjCIvars(ClassDecl, OIvars); 1843 1844 for (unsigned i = 0, e = OIvars.size(); i != e; ++i) { 1845 ObjCIvarDecl *IVD = OIvars[i]; 1846 // Store the name 1847 IvarNames.push_back(MakeConstantString(IVD->getNameAsString())); 1848 // Get the type encoding for this ivar 1849 std::string TypeStr; 1850 Context.getObjCEncodingForType(IVD->getType(), TypeStr); 1851 IvarTypes.push_back(MakeConstantString(TypeStr)); 1852 // Get the offset 1853 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD); 1854 uint64_t Offset = BaseOffset; 1855 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1856 Offset = BaseOffset - superInstanceSize; 1857 } 1858 IvarOffsets.push_back( 1859 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset)); 1860 IvarOffsetValues.push_back(new llvm::GlobalVariable(TheModule, IntTy, 1861 false, llvm::GlobalValue::ExternalLinkage, 1862 llvm::ConstantInt::get(IntTy, Offset), 1863 "__objc_ivar_offset_value_" + ClassName +"." + 1864 IVD->getNameAsString())); 1865 } 1866 llvm::GlobalVariable *IvarOffsetArray = 1867 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets"); 1868 1869 1870 // Collect information about instance methods 1871 llvm::SmallVector<Selector, 16> InstanceMethodSels; 1872 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1873 for (ObjCImplementationDecl::instmeth_iterator 1874 iter = OID->instmeth_begin(), endIter = OID->instmeth_end(); 1875 iter != endIter ; iter++) { 1876 InstanceMethodSels.push_back((*iter)->getSelector()); 1877 std::string TypeStr; 1878 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1879 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1880 } 1881 1882 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels, 1883 InstanceMethodTypes); 1884 1885 1886 // Collect information about class methods 1887 llvm::SmallVector<Selector, 16> ClassMethodSels; 1888 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1889 for (ObjCImplementationDecl::classmeth_iterator 1890 iter = OID->classmeth_begin(), endIter = OID->classmeth_end(); 1891 iter != endIter ; iter++) { 1892 ClassMethodSels.push_back((*iter)->getSelector()); 1893 std::string TypeStr; 1894 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1895 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1896 } 1897 // Collect the names of referenced protocols 1898 llvm::SmallVector<std::string, 16> Protocols; 1899 const ObjCList<ObjCProtocolDecl> &Protos =ClassDecl->getReferencedProtocols(); 1900 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1901 E = Protos.end(); I != E; ++I) 1902 Protocols.push_back((*I)->getNameAsString()); 1903 1904 1905 1906 // Get the superclass pointer. 1907 llvm::Constant *SuperClass; 1908 if (!SuperClassName.empty()) { 1909 SuperClass = MakeConstantString(SuperClassName, ".super_class_name"); 1910 } else { 1911 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty); 1912 } 1913 // Empty vector used to construct empty method lists 1914 llvm::SmallVector<llvm::Constant*, 1> empty; 1915 // Generate the method and instance variable lists 1916 llvm::Constant *MethodList = GenerateMethodList(ClassName, "", 1917 InstanceMethodSels, InstanceMethodTypes, false); 1918 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "", 1919 ClassMethodSels, ClassMethodTypes, true); 1920 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes, 1921 IvarOffsets); 1922 // Irrespective of whether we are compiling for a fragile or non-fragile ABI, 1923 // we emit a symbol containing the offset for each ivar in the class. This 1924 // allows code compiled for the non-Fragile ABI to inherit from code compiled 1925 // for the legacy ABI, without causing problems. The converse is also 1926 // possible, but causes all ivar accesses to be fragile. 1927 1928 // Offset pointer for getting at the correct field in the ivar list when 1929 // setting up the alias. These are: The base address for the global, the 1930 // ivar array (second field), the ivar in this list (set for each ivar), and 1931 // the offset (third field in ivar structure) 1932 const llvm::Type *IndexTy = llvm::Type::getInt32Ty(VMContext); 1933 llvm::Constant *offsetPointerIndexes[] = {Zeros[0], 1934 llvm::ConstantInt::get(IndexTy, 1), 0, 1935 llvm::ConstantInt::get(IndexTy, 2) }; 1936 1937 1938 for (unsigned i = 0, e = OIvars.size(); i != e; ++i) { 1939 ObjCIvarDecl *IVD = OIvars[i]; 1940 const std::string Name = "__objc_ivar_offset_" + ClassName + '.' 1941 + IVD->getNameAsString(); 1942 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, i); 1943 // Get the correct ivar field 1944 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr( 1945 IvarList, offsetPointerIndexes, 4); 1946 // Get the existing variable, if one exists. 1947 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name); 1948 if (offset) { 1949 offset->setInitializer(offsetValue); 1950 // If this is the real definition, change its linkage type so that 1951 // different modules will use this one, rather than their private 1952 // copy. 1953 offset->setLinkage(llvm::GlobalValue::ExternalLinkage); 1954 } else { 1955 // Add a new alias if there isn't one already. 1956 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(), 1957 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name); 1958 } 1959 } 1960 //Generate metaclass for class methods 1961 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr, 1962 NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList( 1963 empty, empty, empty), ClassMethodList, NULLPtr, NULLPtr, NULLPtr, true); 1964 1965 // Generate the class structure 1966 llvm::Constant *ClassStruct = 1967 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L, 1968 ClassName.c_str(), 0, 1969 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, 1970 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray, 1971 Properties); 1972 1973 // Resolve the class aliases, if they exist. 1974 if (ClassPtrAlias) { 1975 ClassPtrAlias->replaceAllUsesWith( 1976 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy)); 1977 ClassPtrAlias->eraseFromParent(); 1978 ClassPtrAlias = 0; 1979 } 1980 if (MetaClassPtrAlias) { 1981 MetaClassPtrAlias->replaceAllUsesWith( 1982 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy)); 1983 MetaClassPtrAlias->eraseFromParent(); 1984 MetaClassPtrAlias = 0; 1985 } 1986 1987 // Add class structure to list to be added to the symtab later 1988 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty); 1989 Classes.push_back(ClassStruct); 1990} 1991 1992 1993llvm::Function *CGObjCGNU::ModuleInitFunction() { 1994 // Only emit an ObjC load function if no Objective-C stuff has been called 1995 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() && 1996 ExistingProtocols.empty() && SelectorTable.empty()) 1997 return NULL; 1998 1999 // Add all referenced protocols to a category. 2000 GenerateProtocolHolderCategory(); 2001 2002 const llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>( 2003 SelectorTy->getElementType()); 2004 const llvm::Type *SelStructPtrTy = SelectorTy; 2005 bool isSelOpaque = false; 2006 if (SelStructTy == 0) { 2007 SelStructTy = llvm::StructType::get(VMContext, PtrToInt8Ty, 2008 PtrToInt8Ty, NULL); 2009 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy); 2010 isSelOpaque = true; 2011 } 2012 2013 // Name the ObjC types to make the IR a bit easier to read 2014 TheModule.addTypeName(".objc_selector", SelStructPtrTy); 2015 TheModule.addTypeName(".objc_id", IdTy); 2016 TheModule.addTypeName(".objc_imp", IMPTy); 2017 2018 std::vector<llvm::Constant*> Elements; 2019 llvm::Constant *Statics = NULLPtr; 2020 // Generate statics list: 2021 if (ConstantStrings.size()) { 2022 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 2023 ConstantStrings.size() + 1); 2024 ConstantStrings.push_back(NULLPtr); 2025 2026 llvm::StringRef StringClass = CGM.getLangOptions().ObjCConstantStringClass; 2027 2028 if (StringClass.empty()) StringClass = "NXConstantString"; 2029 2030 Elements.push_back(MakeConstantString(StringClass, 2031 ".objc_static_class_name")); 2032 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy, 2033 ConstantStrings)); 2034 llvm::StructType *StaticsListTy = 2035 llvm::StructType::get(VMContext, PtrToInt8Ty, StaticsArrayTy, NULL); 2036 llvm::Type *StaticsListPtrTy = 2037 llvm::PointerType::getUnqual(StaticsListTy); 2038 Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics"); 2039 llvm::ArrayType *StaticsListArrayTy = 2040 llvm::ArrayType::get(StaticsListPtrTy, 2); 2041 Elements.clear(); 2042 Elements.push_back(Statics); 2043 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy)); 2044 Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr"); 2045 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy); 2046 } 2047 // Array of classes, categories, and constant objects 2048 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty, 2049 Classes.size() + Categories.size() + 2); 2050 llvm::StructType *SymTabTy = llvm::StructType::get(VMContext, 2051 LongTy, SelStructPtrTy, 2052 llvm::Type::getInt16Ty(VMContext), 2053 llvm::Type::getInt16Ty(VMContext), 2054 ClassListTy, NULL); 2055 2056 Elements.clear(); 2057 // Pointer to an array of selectors used in this module. 2058 std::vector<llvm::Constant*> Selectors; 2059 std::vector<llvm::GlobalAlias*> SelectorAliases; 2060 for (SelectorMap::iterator iter = SelectorTable.begin(), 2061 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) { 2062 2063 std::string SelNameStr = iter->first.getAsString(); 2064 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name"); 2065 2066 llvm::SmallVectorImpl<TypedSelector> &Types = iter->second; 2067 for (llvm::SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 2068 e = Types.end() ; i!=e ; i++) { 2069 2070 llvm::Constant *SelectorTypeEncoding = NULLPtr; 2071 if (!i->first.empty()) 2072 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types"); 2073 2074 Elements.push_back(SelName); 2075 Elements.push_back(SelectorTypeEncoding); 2076 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2077 Elements.clear(); 2078 2079 // Store the selector alias for later replacement 2080 SelectorAliases.push_back(i->second); 2081 } 2082 } 2083 unsigned SelectorCount = Selectors.size(); 2084 // NULL-terminate the selector list. This should not actually be required, 2085 // because the selector list has a length field. Unfortunately, the GCC 2086 // runtime decides to ignore the length field and expects a NULL terminator, 2087 // and GCC cooperates with this by always setting the length to 0. 2088 Elements.push_back(NULLPtr); 2089 Elements.push_back(NULLPtr); 2090 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2091 Elements.clear(); 2092 2093 // Number of static selectors 2094 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount)); 2095 llvm::Constant *SelectorList = MakeGlobalArray(SelStructTy, Selectors, 2096 ".objc_selector_list"); 2097 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList, 2098 SelStructPtrTy)); 2099 2100 // Now that all of the static selectors exist, create pointers to them. 2101 for (unsigned int i=0 ; i<SelectorCount ; i++) { 2102 2103 llvm::Constant *Idxs[] = {Zeros[0], 2104 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), i), Zeros[0]}; 2105 // FIXME: We're generating redundant loads and stores here! 2106 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(SelectorList, 2107 Idxs, 2); 2108 // If selectors are defined as an opaque type, cast the pointer to this 2109 // type. 2110 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy); 2111 SelectorAliases[i]->replaceAllUsesWith(SelPtr); 2112 SelectorAliases[i]->eraseFromParent(); 2113 } 2114 2115 // Number of classes defined. 2116 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2117 Classes.size())); 2118 // Number of categories defined 2119 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2120 Categories.size())); 2121 // Create an array of classes, then categories, then static object instances 2122 Classes.insert(Classes.end(), Categories.begin(), Categories.end()); 2123 // NULL-terminated list of static object instances (mainly constant strings) 2124 Classes.push_back(Statics); 2125 Classes.push_back(NULLPtr); 2126 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes); 2127 Elements.push_back(ClassList); 2128 // Construct the symbol table 2129 llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements); 2130 2131 // The symbol table is contained in a module which has some version-checking 2132 // constants 2133 llvm::StructType * ModuleTy = llvm::StructType::get(VMContext, LongTy, LongTy, 2134 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), NULL); 2135 Elements.clear(); 2136 // Runtime version, used for ABI compatibility checking. 2137 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion)); 2138 // sizeof(ModuleTy) 2139 llvm::TargetData td(&TheModule); 2140 Elements.push_back(llvm::ConstantInt::get(LongTy, 2141 td.getTypeSizeInBits(ModuleTy)/8)); 2142 2143 // The path to the source file where this module was declared 2144 SourceManager &SM = CGM.getContext().getSourceManager(); 2145 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID()); 2146 std::string path = 2147 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName(); 2148 Elements.push_back(MakeConstantString(path, ".objc_source_file_name")); 2149 2150 Elements.push_back(SymTab); 2151 llvm::Value *Module = MakeGlobal(ModuleTy, Elements); 2152 2153 // Create the load function calling the runtime entry point with the module 2154 // structure 2155 llvm::Function * LoadFunction = llvm::Function::Create( 2156 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false), 2157 llvm::GlobalValue::InternalLinkage, ".objc_load_function", 2158 &TheModule); 2159 llvm::BasicBlock *EntryBB = 2160 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction); 2161 CGBuilderTy Builder(VMContext); 2162 Builder.SetInsertPoint(EntryBB); 2163 2164 std::vector<const llvm::Type*> Params(1, 2165 llvm::PointerType::getUnqual(ModuleTy)); 2166 llvm::Value *Register = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 2167 llvm::Type::getVoidTy(VMContext), Params, true), "__objc_exec_class"); 2168 Builder.CreateCall(Register, Module); 2169 Builder.CreateRetVoid(); 2170 2171 return LoadFunction; 2172} 2173 2174llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD, 2175 const ObjCContainerDecl *CD) { 2176 const ObjCCategoryImplDecl *OCD = 2177 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext()); 2178 llvm::StringRef CategoryName = OCD ? OCD->getName() : ""; 2179 llvm::StringRef ClassName = CD->getName(); 2180 Selector MethodName = OMD->getSelector(); 2181 bool isClassMethod = !OMD->isInstanceMethod(); 2182 2183 CodeGenTypes &Types = CGM.getTypes(); 2184 const llvm::FunctionType *MethodTy = 2185 Types.GetFunctionType(Types.getFunctionInfo(OMD), OMD->isVariadic()); 2186 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName, 2187 MethodName, isClassMethod); 2188 2189 llvm::Function *Method 2190 = llvm::Function::Create(MethodTy, 2191 llvm::GlobalValue::InternalLinkage, 2192 FunctionName, 2193 &TheModule); 2194 return Method; 2195} 2196 2197llvm::Function *CGObjCGNU::GetPropertyGetFunction() { 2198 return GetPropertyFn; 2199} 2200 2201llvm::Function *CGObjCGNU::GetPropertySetFunction() { 2202 return SetPropertyFn; 2203} 2204 2205llvm::Function *CGObjCGNU::GetGetStructFunction() { 2206 return GetStructPropertyFn; 2207} 2208llvm::Function *CGObjCGNU::GetSetStructFunction() { 2209 return SetStructPropertyFn; 2210} 2211 2212llvm::Constant *CGObjCGNU::EnumerationMutationFunction() { 2213 return EnumerationMutationFn; 2214} 2215 2216void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF, 2217 const ObjCAtSynchronizedStmt &S) { 2218 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn); 2219} 2220 2221 2222void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF, 2223 const ObjCAtTryStmt &S) { 2224 // Unlike the Apple non-fragile runtimes, which also uses 2225 // unwind-based zero cost exceptions, the GNU Objective C runtime's 2226 // EH support isn't a veneer over C++ EH. Instead, exception 2227 // objects are created by __objc_exception_throw and destroyed by 2228 // the personality function; this avoids the need for bracketing 2229 // catch handlers with calls to __blah_begin_catch/__blah_end_catch 2230 // (or even _Unwind_DeleteException), but probably doesn't 2231 // interoperate very well with foreign exceptions. 2232 // 2233 // In Objective-C++ mode, we actually emit something equivalent to the C++ 2234 // exception handler. 2235 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn); 2236 return ; 2237} 2238 2239void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF, 2240 const ObjCAtThrowStmt &S) { 2241 llvm::Value *ExceptionAsObject; 2242 2243 if (const Expr *ThrowExpr = S.getThrowExpr()) { 2244 llvm::Value *Exception = CGF.EmitScalarExpr(ThrowExpr); 2245 ExceptionAsObject = Exception; 2246 } else { 2247 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) && 2248 "Unexpected rethrow outside @catch block."); 2249 ExceptionAsObject = CGF.ObjCEHValueStack.back(); 2250 } 2251 ExceptionAsObject = 2252 CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy, "tmp"); 2253 2254 // Note: This may have to be an invoke, if we want to support constructs like: 2255 // @try { 2256 // @throw(obj); 2257 // } 2258 // @catch(id) ... 2259 // 2260 // This is effectively turning @throw into an incredibly-expensive goto, but 2261 // it may happen as a result of inlining followed by missed optimizations, or 2262 // as a result of stupidity. 2263 llvm::BasicBlock *UnwindBB = CGF.getInvokeDest(); 2264 if (!UnwindBB) { 2265 CGF.Builder.CreateCall(ExceptionThrowFn, ExceptionAsObject); 2266 CGF.Builder.CreateUnreachable(); 2267 } else { 2268 CGF.Builder.CreateInvoke(ExceptionThrowFn, UnwindBB, UnwindBB, &ExceptionAsObject, 2269 &ExceptionAsObject+1); 2270 } 2271 // Clear the insertion point to indicate we are in unreachable code. 2272 CGF.Builder.ClearInsertionPoint(); 2273} 2274 2275llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF, 2276 llvm::Value *AddrWeakObj) { 2277 CGBuilderTy B = CGF.Builder; 2278 AddrWeakObj = EnforceType(B, AddrWeakObj, IdTy); 2279 return B.CreateCall(WeakReadFn, AddrWeakObj); 2280} 2281 2282void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF, 2283 llvm::Value *src, llvm::Value *dst) { 2284 CGBuilderTy B = CGF.Builder; 2285 src = EnforceType(B, src, IdTy); 2286 dst = EnforceType(B, dst, PtrToIdTy); 2287 B.CreateCall2(WeakAssignFn, src, dst); 2288} 2289 2290void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF, 2291 llvm::Value *src, llvm::Value *dst, 2292 bool threadlocal) { 2293 CGBuilderTy B = CGF.Builder; 2294 src = EnforceType(B, src, IdTy); 2295 dst = EnforceType(B, dst, PtrToIdTy); 2296 if (!threadlocal) 2297 B.CreateCall2(GlobalAssignFn, src, dst); 2298 else 2299 // FIXME. Add threadloca assign API 2300 assert(false && "EmitObjCGlobalAssign - Threal Local API NYI"); 2301} 2302 2303void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF, 2304 llvm::Value *src, llvm::Value *dst, 2305 llvm::Value *ivarOffset) { 2306 CGBuilderTy B = CGF.Builder; 2307 src = EnforceType(B, src, IdTy); 2308 dst = EnforceType(B, dst, PtrToIdTy); 2309 B.CreateCall3(IvarAssignFn, src, dst, ivarOffset); 2310} 2311 2312void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF, 2313 llvm::Value *src, llvm::Value *dst) { 2314 CGBuilderTy B = CGF.Builder; 2315 src = EnforceType(B, src, IdTy); 2316 dst = EnforceType(B, dst, PtrToIdTy); 2317 B.CreateCall2(StrongCastAssignFn, src, dst); 2318} 2319 2320void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF, 2321 llvm::Value *DestPtr, 2322 llvm::Value *SrcPtr, 2323 llvm::Value *Size) { 2324 CGBuilderTy B = CGF.Builder; 2325 DestPtr = EnforceType(B, DestPtr, IdTy); 2326 SrcPtr = EnforceType(B, SrcPtr, PtrToIdTy); 2327 2328 B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size); 2329} 2330 2331llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable( 2332 const ObjCInterfaceDecl *ID, 2333 const ObjCIvarDecl *Ivar) { 2334 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString() 2335 + '.' + Ivar->getNameAsString(); 2336 // Emit the variable and initialize it with what we think the correct value 2337 // is. This allows code compiled with non-fragile ivars to work correctly 2338 // when linked against code which isn't (most of the time). 2339 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name); 2340 if (!IvarOffsetPointer) { 2341 // This will cause a run-time crash if we accidentally use it. A value of 2342 // 0 would seem more sensible, but will silently overwrite the isa pointer 2343 // causing a great deal of confusion. 2344 uint64_t Offset = -1; 2345 // We can't call ComputeIvarBaseOffset() here if we have the 2346 // implementation, because it will create an invalid ASTRecordLayout object 2347 // that we are then stuck with forever, so we only initialize the ivar 2348 // offset variable with a guess if we only have the interface. The 2349 // initializer will be reset later anyway, when we are generating the class 2350 // description. 2351 if (!CGM.getContext().getObjCImplementation( 2352 const_cast<ObjCInterfaceDecl *>(ID))) 2353 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar); 2354 2355 llvm::ConstantInt *OffsetGuess = 2356 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset, "ivar"); 2357 // Don't emit the guess in non-PIC code because the linker will not be able 2358 // to replace it with the real version for a library. In non-PIC code you 2359 // must compile with the fragile ABI if you want to use ivars from a 2360 // GCC-compiled class. 2361 if (CGM.getLangOptions().PICLevel) { 2362 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule, 2363 llvm::Type::getInt32Ty(VMContext), false, 2364 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess"); 2365 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2366 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage, 2367 IvarOffsetGV, Name); 2368 } else { 2369 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2370 llvm::Type::getInt32PtrTy(VMContext), false, 2371 llvm::GlobalValue::ExternalLinkage, 0, Name); 2372 } 2373 } 2374 return IvarOffsetPointer; 2375} 2376 2377LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF, 2378 QualType ObjectTy, 2379 llvm::Value *BaseValue, 2380 const ObjCIvarDecl *Ivar, 2381 unsigned CVRQualifiers) { 2382 const ObjCInterfaceDecl *ID = 2383 ObjectTy->getAs<ObjCObjectType>()->getInterface(); 2384 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers, 2385 EmitIvarOffset(CGF, ID, Ivar)); 2386} 2387 2388static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context, 2389 const ObjCInterfaceDecl *OID, 2390 const ObjCIvarDecl *OIVD) { 2391 llvm::SmallVector<ObjCIvarDecl*, 16> Ivars; 2392 Context.ShallowCollectObjCIvars(OID, Ivars); 2393 for (unsigned k = 0, e = Ivars.size(); k != e; ++k) { 2394 if (OIVD == Ivars[k]) 2395 return OID; 2396 } 2397 2398 // Otherwise check in the super class. 2399 if (const ObjCInterfaceDecl *Super = OID->getSuperClass()) 2400 return FindIvarInterface(Context, Super, OIVD); 2401 2402 return 0; 2403} 2404 2405llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF, 2406 const ObjCInterfaceDecl *Interface, 2407 const ObjCIvarDecl *Ivar) { 2408 if (CGM.getLangOptions().ObjCNonFragileABI) { 2409 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar); 2410 return CGF.Builder.CreateZExtOrBitCast( 2411 CGF.Builder.CreateLoad(CGF.Builder.CreateLoad( 2412 ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")), 2413 PtrDiffTy); 2414 } 2415 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar); 2416 return llvm::ConstantInt::get(PtrDiffTy, Offset, "ivar"); 2417} 2418 2419CGObjCRuntime * 2420clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) { 2421 if (CGM.getLangOptions().ObjCNonFragileABI) 2422 return new CGObjCGNUstep(CGM); 2423 return new CGObjCGCC(CGM); 2424} 2425