CGObjCGNU.cpp revision 68e5e1331d99140ae5dd7b27c3dd28618827dfc8
1//===------- CGObjCGNU.cpp - Emit LLVM Code from ASTs for a Module --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This provides Objective-C code generation targeting the GNU runtime. The 11// class in this file generates structures used by the GNU Objective-C runtime 12// library. These structures are defined in objc/objc.h and objc/objc-api.h in 13// the GNU runtime distribution. 14// 15//===----------------------------------------------------------------------===// 16 17#include "CGObjCRuntime.h" 18#include "CodeGenModule.h" 19#include "CodeGenFunction.h" 20#include "CGCleanup.h" 21 22#include "clang/AST/ASTContext.h" 23#include "clang/AST/Decl.h" 24#include "clang/AST/DeclObjC.h" 25#include "clang/AST/RecordLayout.h" 26#include "clang/AST/StmtObjC.h" 27#include "clang/Basic/SourceManager.h" 28#include "clang/Basic/FileManager.h" 29 30#include "llvm/Intrinsics.h" 31#include "llvm/Module.h" 32#include "llvm/LLVMContext.h" 33#include "llvm/ADT/SmallVector.h" 34#include "llvm/ADT/StringMap.h" 35#include "llvm/Support/CallSite.h" 36#include "llvm/Support/Compiler.h" 37#include "llvm/Target/TargetData.h" 38 39#include <stdarg.h> 40 41 42using namespace clang; 43using namespace CodeGen; 44using llvm::dyn_cast; 45 46 47namespace { 48/// Class that lazily initialises the runtime function. Avoids inserting the 49/// types and the function declaration into a module if they're not used, and 50/// avoids constructing the type more than once if it's used more than once. 51class LazyRuntimeFunction { 52 CodeGenModule *CGM; 53 std::vector<const llvm::Type*> ArgTys; 54 const char *FunctionName; 55 llvm::Constant *Function; 56 public: 57 /// Constructor leaves this class uninitialized, because it is intended to 58 /// be used as a field in another class and not all of the types that are 59 /// used as arguments will necessarily be available at construction time. 60 LazyRuntimeFunction() : CGM(0), FunctionName(0), Function(0) {} 61 62 /// Initialises the lazy function with the name, return type, and the types 63 /// of the arguments. 64 END_WITH_NULL 65 void init(CodeGenModule *Mod, const char *name, 66 const llvm::Type *RetTy, ...) { 67 CGM =Mod; 68 FunctionName = name; 69 Function = 0; 70 ArgTys.clear(); 71 va_list Args; 72 va_start(Args, RetTy); 73 while (const llvm::Type *ArgTy = va_arg(Args, const llvm::Type*)) 74 ArgTys.push_back(ArgTy); 75 va_end(Args); 76 // Push the return type on at the end so we can pop it off easily 77 ArgTys.push_back(RetTy); 78 } 79 /// Overloaded cast operator, allows the class to be implicitly cast to an 80 /// LLVM constant. 81 operator llvm::Constant*() { 82 if (!Function) { 83 if (0 == FunctionName) return 0; 84 // We put the return type on the end of the vector, so pop it back off 85 const llvm::Type *RetTy = ArgTys.back(); 86 ArgTys.pop_back(); 87 llvm::FunctionType *FTy = llvm::FunctionType::get(RetTy, ArgTys, false); 88 Function = 89 cast<llvm::Constant>(CGM->CreateRuntimeFunction(FTy, FunctionName)); 90 // We won't need to use the types again, so we may as well clean up the 91 // vector now 92 ArgTys.resize(0); 93 } 94 return Function; 95 } 96 operator llvm::Function*() { 97 return cast<llvm::Function>((llvm::Constant*)*this); 98 } 99 100}; 101 102 103/// GNU Objective-C runtime code generation. This class implements the parts of 104/// Objective-C support that are specific to the GNU family of runtimes (GCC and 105/// GNUstep). 106class CGObjCGNU : public CGObjCRuntime { 107protected: 108 /// The module that is using this class 109 CodeGenModule &CGM; 110 /// The LLVM module into which output is inserted 111 llvm::Module &TheModule; 112 /// strut objc_super. Used for sending messages to super. This structure 113 /// contains the receiver (object) and the expected class. 114 const llvm::StructType *ObjCSuperTy; 115 /// struct objc_super*. The type of the argument to the superclass message 116 /// lookup functions. 117 const llvm::PointerType *PtrToObjCSuperTy; 118 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring 119 /// SEL is included in a header somewhere, in which case it will be whatever 120 /// type is declared in that header, most likely {i8*, i8*}. 121 const llvm::PointerType *SelectorTy; 122 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the 123 /// places where it's used 124 const llvm::IntegerType *Int8Ty; 125 /// Pointer to i8 - LLVM type of char*, for all of the places where the 126 /// runtime needs to deal with C strings. 127 const llvm::PointerType *PtrToInt8Ty; 128 /// Instance Method Pointer type. This is a pointer to a function that takes, 129 /// at a minimum, an object and a selector, and is the generic type for 130 /// Objective-C methods. Due to differences between variadic / non-variadic 131 /// calling conventions, it must always be cast to the correct type before 132 /// actually being used. 133 const llvm::PointerType *IMPTy; 134 /// Type of an untyped Objective-C object. Clang treats id as a built-in type 135 /// when compiling Objective-C code, so this may be an opaque pointer (i8*), 136 /// but if the runtime header declaring it is included then it may be a 137 /// pointer to a structure. 138 const llvm::PointerType *IdTy; 139 /// Pointer to a pointer to an Objective-C object. Used in the new ABI 140 /// message lookup function and some GC-related functions. 141 const llvm::PointerType *PtrToIdTy; 142 /// The clang type of id. Used when using the clang CGCall infrastructure to 143 /// call Objective-C methods. 144 CanQualType ASTIdTy; 145 /// LLVM type for C int type. 146 const llvm::IntegerType *IntTy; 147 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is 148 /// used in the code to document the difference between i8* meaning a pointer 149 /// to a C string and i8* meaning a pointer to some opaque type. 150 const llvm::PointerType *PtrTy; 151 /// LLVM type for C long type. The runtime uses this in a lot of places where 152 /// it should be using intptr_t, but we can't fix this without breaking 153 /// compatibility with GCC... 154 const llvm::IntegerType *LongTy; 155 /// LLVM type for C size_t. Used in various runtime data structures. 156 const llvm::IntegerType *SizeTy; 157 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions. 158 const llvm::IntegerType *PtrDiffTy; 159 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance 160 /// variables. 161 const llvm::PointerType *PtrToIntTy; 162 /// LLVM type for Objective-C BOOL type. 163 const llvm::Type *BoolTy; 164 /// Metadata kind used to tie method lookups to message sends. The GNUstep 165 /// runtime provides some LLVM passes that can use this to do things like 166 /// automatic IMP caching and speculative inlining. 167 unsigned msgSendMDKind; 168 /// Helper function that generates a constant string and returns a pointer to 169 /// the start of the string. The result of this function can be used anywhere 170 /// where the C code specifies const char*. 171 llvm::Constant *MakeConstantString(const std::string &Str, 172 const std::string &Name="") { 173 llvm::Constant *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str()); 174 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros, 2); 175 } 176 /// Emits a linkonce_odr string, whose name is the prefix followed by the 177 /// string value. This allows the linker to combine the strings between 178 /// different modules. Used for EH typeinfo names, selector strings, and a 179 /// few other things. 180 llvm::Constant *ExportUniqueString(const std::string &Str, 181 const std::string prefix) { 182 std::string name = prefix + Str; 183 llvm::Constant *ConstStr = TheModule.getGlobalVariable(name); 184 if (!ConstStr) { 185 llvm::Constant *value = llvm::ConstantArray::get(VMContext, Str, true); 186 ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true, 187 llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str); 188 } 189 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros, 2); 190 } 191 /// Generates a global structure, initialized by the elements in the vector. 192 /// The element types must match the types of the structure elements in the 193 /// first argument. 194 llvm::GlobalVariable *MakeGlobal(const llvm::StructType *Ty, 195 std::vector<llvm::Constant*> &V, 196 llvm::StringRef Name="", 197 llvm::GlobalValue::LinkageTypes linkage 198 =llvm::GlobalValue::InternalLinkage) { 199 llvm::Constant *C = llvm::ConstantStruct::get(Ty, V); 200 return new llvm::GlobalVariable(TheModule, Ty, false, 201 linkage, C, Name); 202 } 203 /// Generates a global array. The vector must contain the same number of 204 /// elements that the array type declares, of the type specified as the array 205 /// element type. 206 llvm::GlobalVariable *MakeGlobal(const llvm::ArrayType *Ty, 207 std::vector<llvm::Constant*> &V, 208 llvm::StringRef Name="", 209 llvm::GlobalValue::LinkageTypes linkage 210 =llvm::GlobalValue::InternalLinkage) { 211 llvm::Constant *C = llvm::ConstantArray::get(Ty, V); 212 return new llvm::GlobalVariable(TheModule, Ty, false, 213 linkage, C, Name); 214 } 215 /// Generates a global array, inferring the array type from the specified 216 /// element type and the size of the initialiser. 217 llvm::GlobalVariable *MakeGlobalArray(const llvm::Type *Ty, 218 std::vector<llvm::Constant*> &V, 219 llvm::StringRef Name="", 220 llvm::GlobalValue::LinkageTypes linkage 221 =llvm::GlobalValue::InternalLinkage) { 222 llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size()); 223 return MakeGlobal(ArrayTy, V, Name, linkage); 224 } 225 /// Ensures that the value has the required type, by inserting a bitcast if 226 /// required. This function lets us avoid inserting bitcasts that are 227 /// redundant. 228 llvm::Value* EnforceType(CGBuilderTy B, llvm::Value *V, const llvm::Type *Ty){ 229 if (V->getType() == Ty) return V; 230 return B.CreateBitCast(V, Ty); 231 } 232 // Some zeros used for GEPs in lots of places. 233 llvm::Constant *Zeros[2]; 234 /// Null pointer value. Mainly used as a terminator in various arrays. 235 llvm::Constant *NULLPtr; 236 /// LLVM context. 237 llvm::LLVMContext &VMContext; 238private: 239 /// Placeholder for the class. Lots of things refer to the class before we've 240 /// actually emitted it. We use this alias as a placeholder, and then replace 241 /// it with a pointer to the class structure before finally emitting the 242 /// module. 243 llvm::GlobalAlias *ClassPtrAlias; 244 /// Placeholder for the metaclass. Lots of things refer to the class before 245 /// we've / actually emitted it. We use this alias as a placeholder, and then 246 /// replace / it with a pointer to the metaclass structure before finally 247 /// emitting the / module. 248 llvm::GlobalAlias *MetaClassPtrAlias; 249 /// All of the classes that have been generated for this compilation units. 250 std::vector<llvm::Constant*> Classes; 251 /// All of the categories that have been generated for this compilation units. 252 std::vector<llvm::Constant*> Categories; 253 /// All of the Objective-C constant strings that have been generated for this 254 /// compilation units. 255 std::vector<llvm::Constant*> ConstantStrings; 256 /// Map from string values to Objective-C constant strings in the output. 257 /// Used to prevent emitting Objective-C strings more than once. This should 258 /// not be required at all - CodeGenModule should manage this list. 259 llvm::StringMap<llvm::Constant*> ObjCStrings; 260 /// All of the protocols that have been declared. 261 llvm::StringMap<llvm::Constant*> ExistingProtocols; 262 /// For each variant of a selector, we store the type encoding and a 263 /// placeholder value. For an untyped selector, the type will be the empty 264 /// string. Selector references are all done via the module's selector table, 265 /// so we create an alias as a placeholder and then replace it with the real 266 /// value later. 267 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector; 268 /// Type of the selector map. This is roughly equivalent to the structure 269 /// used in the GNUstep runtime, which maintains a list of all of the valid 270 /// types for a selector in a table. 271 typedef llvm::DenseMap<Selector, llvm::SmallVector<TypedSelector, 2> > 272 SelectorMap; 273 /// A map from selectors to selector types. This allows us to emit all 274 /// selectors of the same name and type together. 275 SelectorMap SelectorTable; 276 277 /// Selectors related to memory management. When compiling in GC mode, we 278 /// omit these. 279 Selector RetainSel, ReleaseSel, AutoreleaseSel; 280 /// Runtime functions used for memory management in GC mode. Note that clang 281 /// supports code generation for calling these functions, but neither GNU 282 /// runtime actually supports this API properly yet. 283 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn, 284 WeakAssignFn, GlobalAssignFn; 285 286protected: 287 /// Function used for throwing Objective-C exceptions. 288 LazyRuntimeFunction ExceptionThrowFn; 289 /// Function used for rethrowing exceptions, used at the end of @finally or 290 /// @synchronize blocks. 291 LazyRuntimeFunction ExceptionReThrowFn; 292 /// Function called when entering a catch function. This is required for 293 /// differentiating Objective-C exceptions and foreign exceptions. 294 LazyRuntimeFunction EnterCatchFn; 295 /// Function called when exiting from a catch block. Used to do exception 296 /// cleanup. 297 LazyRuntimeFunction ExitCatchFn; 298 /// Function called when entering an @synchronize block. Acquires the lock. 299 LazyRuntimeFunction SyncEnterFn; 300 /// Function called when exiting an @synchronize block. Releases the lock. 301 LazyRuntimeFunction SyncExitFn; 302 303private: 304 305 /// Function called if fast enumeration detects that the collection is 306 /// modified during the update. 307 LazyRuntimeFunction EnumerationMutationFn; 308 /// Function for implementing synthesized property getters that return an 309 /// object. 310 LazyRuntimeFunction GetPropertyFn; 311 /// Function for implementing synthesized property setters that return an 312 /// object. 313 LazyRuntimeFunction SetPropertyFn; 314 /// Function used for non-object declared property getters. 315 LazyRuntimeFunction GetStructPropertyFn; 316 /// Function used for non-object declared property setters. 317 LazyRuntimeFunction SetStructPropertyFn; 318 319 /// The version of the runtime that this class targets. Must match the 320 /// version in the runtime. 321 int RuntimeVersion; 322 /// The version of the protocol class. Used to differentiate between ObjC1 323 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional 324 /// components and can not contain declared properties. We always emit 325 /// Objective-C 2 property structures, but we have to pretend that they're 326 /// Objective-C 1 property structures when targeting the GCC runtime or it 327 /// will abort. 328 const int ProtocolVersion; 329private: 330 /// Generates an instance variable list structure. This is a structure 331 /// containing a size and an array of structures containing instance variable 332 /// metadata. This is used purely for introspection in the fragile ABI. In 333 /// the non-fragile ABI, it's used for instance variable fixup. 334 llvm::Constant *GenerateIvarList( 335 const llvm::SmallVectorImpl<llvm::Constant *> &IvarNames, 336 const llvm::SmallVectorImpl<llvm::Constant *> &IvarTypes, 337 const llvm::SmallVectorImpl<llvm::Constant *> &IvarOffsets); 338 /// Generates a method list structure. This is a structure containing a size 339 /// and an array of structures containing method metadata. 340 /// 341 /// This structure is used by both classes and categories, and contains a next 342 /// pointer allowing them to be chained together in a linked list. 343 llvm::Constant *GenerateMethodList(const llvm::StringRef &ClassName, 344 const llvm::StringRef &CategoryName, 345 const llvm::SmallVectorImpl<Selector> &MethodSels, 346 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes, 347 bool isClassMethodList); 348 /// Emits an empty protocol. This is used for @protocol() where no protocol 349 /// is found. The runtime will (hopefully) fix up the pointer to refer to the 350 /// real protocol. 351 llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName); 352 /// Generates a list of property metadata structures. This follows the same 353 /// pattern as method and instance variable metadata lists. 354 llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID, 355 llvm::SmallVectorImpl<Selector> &InstanceMethodSels, 356 llvm::SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes); 357 /// Generates a list of referenced protocols. Classes, categories, and 358 /// protocols all use this structure. 359 llvm::Constant *GenerateProtocolList( 360 const llvm::SmallVectorImpl<std::string> &Protocols); 361 /// To ensure that all protocols are seen by the runtime, we add a category on 362 /// a class defined in the runtime, declaring no methods, but adopting the 363 /// protocols. This is a horribly ugly hack, but it allows us to collect all 364 /// of the protocols without changing the ABI. 365 void GenerateProtocolHolderCategory(void); 366 /// Generates a class structure. 367 llvm::Constant *GenerateClassStructure( 368 llvm::Constant *MetaClass, 369 llvm::Constant *SuperClass, 370 unsigned info, 371 const char *Name, 372 llvm::Constant *Version, 373 llvm::Constant *InstanceSize, 374 llvm::Constant *IVars, 375 llvm::Constant *Methods, 376 llvm::Constant *Protocols, 377 llvm::Constant *IvarOffsets, 378 llvm::Constant *Properties, 379 bool isMeta=false); 380 /// Generates a method list. This is used by protocols to define the required 381 /// and optional methods. 382 llvm::Constant *GenerateProtocolMethodList( 383 const llvm::SmallVectorImpl<llvm::Constant *> &MethodNames, 384 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes); 385 /// Returns a selector with the specified type encoding. An empty string is 386 /// used to return an untyped selector (with the types field set to NULL). 387 llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 388 const std::string &TypeEncoding, bool lval); 389 /// Returns the variable used to store the offset of an instance variable. 390 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID, 391 const ObjCIvarDecl *Ivar); 392 /// Emits a reference to a class. This allows the linker to object if there 393 /// is no class of the matching name. 394 void EmitClassRef(const std::string &className); 395protected: 396 /// Looks up the method for sending a message to the specified object. This 397 /// mechanism differs between the GCC and GNU runtimes, so this method must be 398 /// overridden in subclasses. 399 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 400 llvm::Value *&Receiver, 401 llvm::Value *cmd, 402 llvm::MDNode *node) = 0; 403 /// Looks up the method for sending a message to a superclass. This mechanism 404 /// differs between the GCC and GNU runtimes, so this method must be 405 /// overridden in subclasses. 406 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 407 llvm::Value *ObjCSuper, 408 llvm::Value *cmd) = 0; 409public: 410 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 411 unsigned protocolClassVersion); 412 413 virtual llvm::Constant *GenerateConstantString(const StringLiteral *); 414 415 virtual RValue 416 GenerateMessageSend(CodeGenFunction &CGF, 417 ReturnValueSlot Return, 418 QualType ResultType, 419 Selector Sel, 420 llvm::Value *Receiver, 421 const CallArgList &CallArgs, 422 const ObjCInterfaceDecl *Class, 423 const ObjCMethodDecl *Method); 424 virtual RValue 425 GenerateMessageSendSuper(CodeGenFunction &CGF, 426 ReturnValueSlot Return, 427 QualType ResultType, 428 Selector Sel, 429 const ObjCInterfaceDecl *Class, 430 bool isCategoryImpl, 431 llvm::Value *Receiver, 432 bool IsClassMessage, 433 const CallArgList &CallArgs, 434 const ObjCMethodDecl *Method); 435 virtual llvm::Value *GetClass(CGBuilderTy &Builder, 436 const ObjCInterfaceDecl *OID); 437 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 438 bool lval = false); 439 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 440 *Method); 441 virtual llvm::Constant *GetEHType(QualType T); 442 443 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 444 const ObjCContainerDecl *CD); 445 virtual void GenerateCategory(const ObjCCategoryImplDecl *CMD); 446 virtual void GenerateClass(const ObjCImplementationDecl *ClassDecl); 447 virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder, 448 const ObjCProtocolDecl *PD); 449 virtual void GenerateProtocol(const ObjCProtocolDecl *PD); 450 virtual llvm::Function *ModuleInitFunction(); 451 virtual llvm::Constant *GetPropertyGetFunction(); 452 virtual llvm::Constant *GetPropertySetFunction(); 453 virtual llvm::Constant *GetSetStructFunction(); 454 virtual llvm::Constant *GetGetStructFunction(); 455 virtual llvm::Constant *EnumerationMutationFunction(); 456 457 virtual void EmitTryStmt(CodeGenFunction &CGF, 458 const ObjCAtTryStmt &S); 459 virtual void EmitSynchronizedStmt(CodeGenFunction &CGF, 460 const ObjCAtSynchronizedStmt &S); 461 virtual void EmitThrowStmt(CodeGenFunction &CGF, 462 const ObjCAtThrowStmt &S); 463 virtual llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF, 464 llvm::Value *AddrWeakObj); 465 virtual void EmitObjCWeakAssign(CodeGenFunction &CGF, 466 llvm::Value *src, llvm::Value *dst); 467 virtual void EmitObjCGlobalAssign(CodeGenFunction &CGF, 468 llvm::Value *src, llvm::Value *dest, 469 bool threadlocal=false); 470 virtual void EmitObjCIvarAssign(CodeGenFunction &CGF, 471 llvm::Value *src, llvm::Value *dest, 472 llvm::Value *ivarOffset); 473 virtual void EmitObjCStrongCastAssign(CodeGenFunction &CGF, 474 llvm::Value *src, llvm::Value *dest); 475 virtual void EmitGCMemmoveCollectable(CodeGenFunction &CGF, 476 llvm::Value *DestPtr, 477 llvm::Value *SrcPtr, 478 llvm::Value *Size); 479 virtual LValue EmitObjCValueForIvar(CodeGenFunction &CGF, 480 QualType ObjectTy, 481 llvm::Value *BaseValue, 482 const ObjCIvarDecl *Ivar, 483 unsigned CVRQualifiers); 484 virtual llvm::Value *EmitIvarOffset(CodeGenFunction &CGF, 485 const ObjCInterfaceDecl *Interface, 486 const ObjCIvarDecl *Ivar); 487 virtual llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM, 488 const CGBlockInfo &blockInfo) { 489 return NULLPtr; 490 } 491 492 virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) { 493 return 0; 494 } 495}; 496/// Class representing the legacy GCC Objective-C ABI. This is the default when 497/// -fobjc-nonfragile-abi is not specified. 498/// 499/// The GCC ABI target actually generates code that is approximately compatible 500/// with the new GNUstep runtime ABI, but refrains from using any features that 501/// would not work with the GCC runtime. For example, clang always generates 502/// the extended form of the class structure, and the extra fields are simply 503/// ignored by GCC libobjc. 504class CGObjCGCC : public CGObjCGNU { 505 /// The GCC ABI message lookup function. Returns an IMP pointing to the 506 /// method implementation for this message. 507 LazyRuntimeFunction MsgLookupFn; 508 /// The GCC ABI superclass message lookup function. Takes a pointer to a 509 /// structure describing the receiver and the class, and a selector as 510 /// arguments. Returns the IMP for the corresponding method. 511 LazyRuntimeFunction MsgLookupSuperFn; 512protected: 513 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 514 llvm::Value *&Receiver, 515 llvm::Value *cmd, 516 llvm::MDNode *node) { 517 CGBuilderTy &Builder = CGF.Builder; 518 llvm::Value *imp = Builder.CreateCall2(MsgLookupFn, 519 EnforceType(Builder, Receiver, IdTy), 520 EnforceType(Builder, cmd, SelectorTy)); 521 cast<llvm::CallInst>(imp)->setMetadata(msgSendMDKind, node); 522 return imp; 523 } 524 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 525 llvm::Value *ObjCSuper, 526 llvm::Value *cmd) { 527 CGBuilderTy &Builder = CGF.Builder; 528 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 529 PtrToObjCSuperTy), cmd}; 530 return Builder.CreateCall(MsgLookupSuperFn, lookupArgs, lookupArgs+2); 531 } 532 public: 533 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) { 534 // IMP objc_msg_lookup(id, SEL); 535 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 536 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 537 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 538 PtrToObjCSuperTy, SelectorTy, NULL); 539 } 540}; 541/// Class used when targeting the new GNUstep runtime ABI. 542class CGObjCGNUstep : public CGObjCGNU { 543 /// The slot lookup function. Returns a pointer to a cacheable structure 544 /// that contains (among other things) the IMP. 545 LazyRuntimeFunction SlotLookupFn; 546 /// The GNUstep ABI superclass message lookup function. Takes a pointer to 547 /// a structure describing the receiver and the class, and a selector as 548 /// arguments. Returns the slot for the corresponding method. Superclass 549 /// message lookup rarely changes, so this is a good caching opportunity. 550 LazyRuntimeFunction SlotLookupSuperFn; 551 /// Type of an slot structure pointer. This is returned by the various 552 /// lookup functions. 553 llvm::Type *SlotTy; 554 protected: 555 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 556 llvm::Value *&Receiver, 557 llvm::Value *cmd, 558 llvm::MDNode *node) { 559 CGBuilderTy &Builder = CGF.Builder; 560 llvm::Function *LookupFn = SlotLookupFn; 561 562 // Store the receiver on the stack so that we can reload it later 563 llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType()); 564 Builder.CreateStore(Receiver, ReceiverPtr); 565 566 llvm::Value *self; 567 568 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) { 569 self = CGF.LoadObjCSelf(); 570 } else { 571 self = llvm::ConstantPointerNull::get(IdTy); 572 } 573 574 // The lookup function is guaranteed not to capture the receiver pointer. 575 LookupFn->setDoesNotCapture(1); 576 577 llvm::CallInst *slot = 578 Builder.CreateCall3(LookupFn, 579 EnforceType(Builder, ReceiverPtr, PtrToIdTy), 580 EnforceType(Builder, cmd, SelectorTy), 581 EnforceType(Builder, self, IdTy)); 582 slot->setOnlyReadsMemory(); 583 slot->setMetadata(msgSendMDKind, node); 584 585 // Load the imp from the slot 586 llvm::Value *imp = Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 587 588 // The lookup function may have changed the receiver, so make sure we use 589 // the new one. 590 Receiver = Builder.CreateLoad(ReceiverPtr, true); 591 return imp; 592 } 593 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 594 llvm::Value *ObjCSuper, 595 llvm::Value *cmd) { 596 CGBuilderTy &Builder = CGF.Builder; 597 llvm::Value *lookupArgs[] = {ObjCSuper, cmd}; 598 599 llvm::CallInst *slot = Builder.CreateCall(SlotLookupSuperFn, lookupArgs, 600 lookupArgs+2); 601 slot->setOnlyReadsMemory(); 602 603 return Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 604 } 605 public: 606 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) { 607 llvm::StructType *SlotStructTy = llvm::StructType::get(VMContext, PtrTy, 608 PtrTy, PtrTy, IntTy, IMPTy, NULL); 609 SlotTy = llvm::PointerType::getUnqual(SlotStructTy); 610 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 611 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy, 612 SelectorTy, IdTy, NULL); 613 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL); 614 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy, 615 PtrToObjCSuperTy, SelectorTy, NULL); 616 // If we're in ObjC++ mode, then we want to make 617 if (CGM.getLangOptions().CPlusPlus) { 618 const llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 619 // void *__cxa_begin_catch(void *e) 620 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, NULL); 621 // void __cxa_end_catch(void) 622 EnterCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, NULL); 623 // void _Unwind_Resume_or_Rethrow(void*) 624 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, PtrTy, NULL); 625 } 626 } 627}; 628 629} // end anonymous namespace 630 631 632/// Emits a reference to a dummy variable which is emitted with each class. 633/// This ensures that a linker error will be generated when trying to link 634/// together modules where a referenced class is not defined. 635void CGObjCGNU::EmitClassRef(const std::string &className) { 636 std::string symbolRef = "__objc_class_ref_" + className; 637 // Don't emit two copies of the same symbol 638 if (TheModule.getGlobalVariable(symbolRef)) 639 return; 640 std::string symbolName = "__objc_class_name_" + className; 641 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName); 642 if (!ClassSymbol) { 643 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 644 llvm::GlobalValue::ExternalLinkage, 0, symbolName); 645 } 646 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true, 647 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef); 648} 649 650static std::string SymbolNameForMethod(const llvm::StringRef &ClassName, 651 const llvm::StringRef &CategoryName, const Selector MethodName, 652 bool isClassMethod) { 653 std::string MethodNameColonStripped = MethodName.getAsString(); 654 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(), 655 ':', '_'); 656 return (llvm::Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" + 657 CategoryName + "_" + MethodNameColonStripped).str(); 658} 659 660CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 661 unsigned protocolClassVersion) 662 : CGM(cgm), TheModule(CGM.getModule()), VMContext(cgm.getLLVMContext()), 663 ClassPtrAlias(0), MetaClassPtrAlias(0), RuntimeVersion(runtimeABIVersion), 664 ProtocolVersion(protocolClassVersion) { 665 666 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend"); 667 668 CodeGenTypes &Types = CGM.getTypes(); 669 IntTy = cast<llvm::IntegerType>( 670 Types.ConvertType(CGM.getContext().IntTy)); 671 LongTy = cast<llvm::IntegerType>( 672 Types.ConvertType(CGM.getContext().LongTy)); 673 SizeTy = cast<llvm::IntegerType>( 674 Types.ConvertType(CGM.getContext().getSizeType())); 675 PtrDiffTy = cast<llvm::IntegerType>( 676 Types.ConvertType(CGM.getContext().getPointerDiffType())); 677 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy); 678 679 Int8Ty = llvm::Type::getInt8Ty(VMContext); 680 // C string type. Used in lots of places. 681 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); 682 683 Zeros[0] = llvm::ConstantInt::get(LongTy, 0); 684 Zeros[1] = Zeros[0]; 685 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty); 686 // Get the selector Type. 687 QualType selTy = CGM.getContext().getObjCSelType(); 688 if (QualType() == selTy) { 689 SelectorTy = PtrToInt8Ty; 690 } else { 691 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy)); 692 } 693 694 PtrToIntTy = llvm::PointerType::getUnqual(IntTy); 695 PtrTy = PtrToInt8Ty; 696 697 // Object type 698 QualType UnqualIdTy = CGM.getContext().getObjCIdType(); 699 ASTIdTy = CanQualType(); 700 if (UnqualIdTy != QualType()) { 701 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy); 702 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 703 } else { 704 IdTy = PtrToInt8Ty; 705 } 706 PtrToIdTy = llvm::PointerType::getUnqual(IdTy); 707 708 ObjCSuperTy = llvm::StructType::get(VMContext, IdTy, IdTy, NULL); 709 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy); 710 711 const llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 712 713 // void objc_exception_throw(id); 714 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 715 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 716 // int objc_sync_enter(id); 717 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, NULL); 718 // int objc_sync_exit(id); 719 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, NULL); 720 721 // void objc_enumerationMutation (id) 722 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, 723 IdTy, NULL); 724 725 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL) 726 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy, 727 PtrDiffTy, BoolTy, NULL); 728 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL) 729 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy, 730 PtrDiffTy, IdTy, BoolTy, BoolTy, NULL); 731 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 732 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy, 733 PtrDiffTy, BoolTy, BoolTy, NULL); 734 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 735 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy, 736 PtrDiffTy, BoolTy, BoolTy, NULL); 737 738 // IMP type 739 std::vector<const llvm::Type*> IMPArgs; 740 IMPArgs.push_back(IdTy); 741 IMPArgs.push_back(SelectorTy); 742 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs, 743 true)); 744 745 // Don't bother initialising the GC stuff unless we're compiling in GC mode 746 if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) { 747 // This is a bit of an hack. We should sort this out by having a proper 748 // CGObjCGNUstep subclass for GC, but we may want to really support the old 749 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now 750 RuntimeVersion = 10; 751 // Get selectors needed in GC mode 752 RetainSel = GetNullarySelector("retain", CGM.getContext()); 753 ReleaseSel = GetNullarySelector("release", CGM.getContext()); 754 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext()); 755 756 // Get functions needed in GC mode 757 758 // id objc_assign_ivar(id, id, ptrdiff_t); 759 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy, 760 NULL); 761 // id objc_assign_strongCast (id, id*) 762 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy, 763 PtrToIdTy, NULL); 764 // id objc_assign_global(id, id*); 765 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy, 766 NULL); 767 // id objc_assign_weak(id, id*); 768 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, NULL); 769 // id objc_read_weak(id*); 770 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, NULL); 771 // void *objc_memmove_collectable(void*, void *, size_t); 772 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy, 773 SizeTy, NULL); 774 } 775} 776 777// This has to perform the lookup every time, since posing and related 778// techniques can modify the name -> class mapping. 779llvm::Value *CGObjCGNU::GetClass(CGBuilderTy &Builder, 780 const ObjCInterfaceDecl *OID) { 781 llvm::Value *ClassName = CGM.GetAddrOfConstantCString(OID->getNameAsString()); 782 // With the incompatible ABI, this will need to be replaced with a direct 783 // reference to the class symbol. For the compatible nonfragile ABI we are 784 // still performing this lookup at run time but emitting the symbol for the 785 // class externally so that we can make the switch later. 786 EmitClassRef(OID->getNameAsString()); 787 ClassName = Builder.CreateStructGEP(ClassName, 0); 788 789 std::vector<const llvm::Type*> Params(1, PtrToInt8Ty); 790 llvm::Constant *ClassLookupFn = 791 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, 792 Params, 793 true), 794 "objc_lookup_class"); 795 return Builder.CreateCall(ClassLookupFn, ClassName); 796} 797 798llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 799 const std::string &TypeEncoding, bool lval) { 800 801 llvm::SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel]; 802 llvm::GlobalAlias *SelValue = 0; 803 804 805 for (llvm::SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 806 e = Types.end() ; i!=e ; i++) { 807 if (i->first == TypeEncoding) { 808 SelValue = i->second; 809 break; 810 } 811 } 812 if (0 == SelValue) { 813 SelValue = new llvm::GlobalAlias(SelectorTy, 814 llvm::GlobalValue::PrivateLinkage, 815 ".objc_selector_"+Sel.getAsString(), NULL, 816 &TheModule); 817 Types.push_back(TypedSelector(TypeEncoding, SelValue)); 818 } 819 820 if (lval) { 821 llvm::Value *tmp = Builder.CreateAlloca(SelValue->getType()); 822 Builder.CreateStore(SelValue, tmp); 823 return tmp; 824 } 825 return SelValue; 826} 827 828llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 829 bool lval) { 830 return GetSelector(Builder, Sel, std::string(), lval); 831} 832 833llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 834 *Method) { 835 std::string SelTypes; 836 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes); 837 return GetSelector(Builder, Method->getSelector(), SelTypes, false); 838} 839 840llvm::Constant *CGObjCGNU::GetEHType(QualType T) { 841 if (!CGM.getLangOptions().CPlusPlus) { 842 if (T->isObjCIdType() 843 || T->isObjCQualifiedIdType()) { 844 // With the old ABI, there was only one kind of catchall, which broke 845 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as 846 // a pointer indicating object catchalls, and NULL to indicate real 847 // catchalls 848 if (CGM.getLangOptions().ObjCNonFragileABI) { 849 return MakeConstantString("@id"); 850 } else { 851 return 0; 852 } 853 } 854 855 // All other types should be Objective-C interface pointer types. 856 const ObjCObjectPointerType *OPT = 857 T->getAs<ObjCObjectPointerType>(); 858 assert(OPT && "Invalid @catch type."); 859 const ObjCInterfaceDecl *IDecl = 860 OPT->getObjectType()->getInterface(); 861 assert(IDecl && "Invalid @catch type."); 862 return MakeConstantString(IDecl->getIdentifier()->getName()); 863 } 864 // For Objective-C++, we want to provide the ability to catch both C++ and 865 // Objective-C objects in the same function. 866 867 // There's a particular fixed type info for 'id'. 868 if (T->isObjCIdType() || 869 T->isObjCQualifiedIdType()) { 870 llvm::Constant *IDEHType = 871 CGM.getModule().getGlobalVariable("__objc_id_type_info"); 872 if (!IDEHType) 873 IDEHType = 874 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty, 875 false, 876 llvm::GlobalValue::ExternalLinkage, 877 0, "__objc_id_type_info"); 878 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty); 879 } 880 881 const ObjCObjectPointerType *PT = 882 T->getAs<ObjCObjectPointerType>(); 883 assert(PT && "Invalid @catch type."); 884 const ObjCInterfaceType *IT = PT->getInterfaceType(); 885 assert(IT && "Invalid @catch type."); 886 std::string className = IT->getDecl()->getIdentifier()->getName(); 887 888 std::string typeinfoName = "__objc_eh_typeinfo_" + className; 889 890 // Return the existing typeinfo if it exists 891 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName); 892 if (typeinfo) return typeinfo; 893 894 // Otherwise create it. 895 896 // vtable for gnustep::libobjc::__objc_class_type_info 897 // It's quite ugly hard-coding this. Ideally we'd generate it using the host 898 // platform's name mangling. 899 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE"; 900 llvm::Constant *Vtable = TheModule.getGlobalVariable(vtableName); 901 if (!Vtable) { 902 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true, 903 llvm::GlobalValue::ExternalLinkage, 0, vtableName); 904 } 905 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2); 906 Vtable = llvm::ConstantExpr::getGetElementPtr(Vtable, &Two, 1); 907 Vtable = llvm::ConstantExpr::getBitCast(Vtable, PtrToInt8Ty); 908 909 llvm::Constant *typeName = 910 ExportUniqueString(className, "__objc_eh_typename_"); 911 912 std::vector<llvm::Constant*> fields; 913 fields.push_back(Vtable); 914 fields.push_back(typeName); 915 llvm::Constant *TI = 916 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 917 NULL), fields, "__objc_eh_typeinfo_" + className, 918 llvm::GlobalValue::LinkOnceODRLinkage); 919 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty); 920} 921 922/// Generate an NSConstantString object. 923llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) { 924 925 std::string Str = SL->getString().str(); 926 927 // Look for an existing one 928 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str); 929 if (old != ObjCStrings.end()) 930 return old->getValue(); 931 932 std::vector<llvm::Constant*> Ivars; 933 Ivars.push_back(NULLPtr); 934 Ivars.push_back(MakeConstantString(Str)); 935 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size())); 936 llvm::Constant *ObjCStr = MakeGlobal( 937 llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, IntTy, NULL), 938 Ivars, ".objc_str"); 939 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty); 940 ObjCStrings[Str] = ObjCStr; 941 ConstantStrings.push_back(ObjCStr); 942 return ObjCStr; 943} 944 945///Generates a message send where the super is the receiver. This is a message 946///send to self with special delivery semantics indicating which class's method 947///should be called. 948RValue 949CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF, 950 ReturnValueSlot Return, 951 QualType ResultType, 952 Selector Sel, 953 const ObjCInterfaceDecl *Class, 954 bool isCategoryImpl, 955 llvm::Value *Receiver, 956 bool IsClassMessage, 957 const CallArgList &CallArgs, 958 const ObjCMethodDecl *Method) { 959 CGBuilderTy &Builder = CGF.Builder; 960 if (CGM.getLangOptions().getGCMode() == LangOptions::GCOnly) { 961 if (Sel == RetainSel || Sel == AutoreleaseSel) { 962 return RValue::get(EnforceType(Builder, Receiver, 963 CGM.getTypes().ConvertType(ResultType))); 964 } 965 if (Sel == ReleaseSel) { 966 return RValue::get(0); 967 } 968 } 969 970 llvm::Value *cmd = GetSelector(Builder, Sel); 971 972 973 CallArgList ActualArgs; 974 975 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy); 976 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 977 ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end()); 978 979 CodeGenTypes &Types = CGM.getTypes(); 980 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 981 FunctionType::ExtInfo()); 982 983 llvm::Value *ReceiverClass = 0; 984 if (isCategoryImpl) { 985 llvm::Constant *classLookupFunction = 0; 986 std::vector<const llvm::Type*> Params; 987 Params.push_back(PtrTy); 988 if (IsClassMessage) { 989 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 990 IdTy, Params, true), "objc_get_meta_class"); 991 } else { 992 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 993 IdTy, Params, true), "objc_get_class"); 994 } 995 ReceiverClass = Builder.CreateCall(classLookupFunction, 996 MakeConstantString(Class->getNameAsString())); 997 } else { 998 // Set up global aliases for the metaclass or class pointer if they do not 999 // already exist. These will are forward-references which will be set to 1000 // pointers to the class and metaclass structure created for the runtime 1001 // load function. To send a message to super, we look up the value of the 1002 // super_class pointer from either the class or metaclass structure. 1003 if (IsClassMessage) { 1004 if (!MetaClassPtrAlias) { 1005 MetaClassPtrAlias = new llvm::GlobalAlias(IdTy, 1006 llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" + 1007 Class->getNameAsString(), NULL, &TheModule); 1008 } 1009 ReceiverClass = MetaClassPtrAlias; 1010 } else { 1011 if (!ClassPtrAlias) { 1012 ClassPtrAlias = new llvm::GlobalAlias(IdTy, 1013 llvm::GlobalValue::InternalLinkage, ".objc_class_ref" + 1014 Class->getNameAsString(), NULL, &TheModule); 1015 } 1016 ReceiverClass = ClassPtrAlias; 1017 } 1018 } 1019 // Cast the pointer to a simplified version of the class structure 1020 ReceiverClass = Builder.CreateBitCast(ReceiverClass, 1021 llvm::PointerType::getUnqual( 1022 llvm::StructType::get(VMContext, IdTy, IdTy, NULL))); 1023 // Get the superclass pointer 1024 ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1); 1025 // Load the superclass pointer 1026 ReceiverClass = Builder.CreateLoad(ReceiverClass); 1027 // Construct the structure used to look up the IMP 1028 llvm::StructType *ObjCSuperTy = llvm::StructType::get(VMContext, 1029 Receiver->getType(), IdTy, NULL); 1030 llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy); 1031 1032 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0)); 1033 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1)); 1034 1035 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy); 1036 const llvm::FunctionType *impType = 1037 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1038 1039 // Get the IMP 1040 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd); 1041 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1042 1043 llvm::Value *impMD[] = { 1044 llvm::MDString::get(VMContext, Sel.getAsString()), 1045 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()), 1046 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage) 1047 }; 1048 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1049 1050 llvm::Instruction *call; 1051 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1052 0, &call); 1053 call->setMetadata(msgSendMDKind, node); 1054 return msgRet; 1055} 1056 1057/// Generate code for a message send expression. 1058RValue 1059CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF, 1060 ReturnValueSlot Return, 1061 QualType ResultType, 1062 Selector Sel, 1063 llvm::Value *Receiver, 1064 const CallArgList &CallArgs, 1065 const ObjCInterfaceDecl *Class, 1066 const ObjCMethodDecl *Method) { 1067 CGBuilderTy &Builder = CGF.Builder; 1068 1069 // Strip out message sends to retain / release in GC mode 1070 if (CGM.getLangOptions().getGCMode() == LangOptions::GCOnly) { 1071 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1072 return RValue::get(EnforceType(Builder, Receiver, 1073 CGM.getTypes().ConvertType(ResultType))); 1074 } 1075 if (Sel == ReleaseSel) { 1076 return RValue::get(0); 1077 } 1078 } 1079 1080 // If the return type is something that goes in an integer register, the 1081 // runtime will handle 0 returns. For other cases, we fill in the 0 value 1082 // ourselves. 1083 // 1084 // The language spec says the result of this kind of message send is 1085 // undefined, but lots of people seem to have forgotten to read that 1086 // paragraph and insist on sending messages to nil that have structure 1087 // returns. With GCC, this generates a random return value (whatever happens 1088 // to be on the stack / in those registers at the time) on most platforms, 1089 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts 1090 // the stack. 1091 bool isPointerSizedReturn = (ResultType->isAnyPointerType() || 1092 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType()); 1093 1094 llvm::BasicBlock *startBB = 0; 1095 llvm::BasicBlock *messageBB = 0; 1096 llvm::BasicBlock *continueBB = 0; 1097 1098 if (!isPointerSizedReturn) { 1099 startBB = Builder.GetInsertBlock(); 1100 messageBB = CGF.createBasicBlock("msgSend"); 1101 continueBB = CGF.createBasicBlock("continue"); 1102 1103 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver, 1104 llvm::Constant::getNullValue(Receiver->getType())); 1105 Builder.CreateCondBr(isNil, continueBB, messageBB); 1106 CGF.EmitBlock(messageBB); 1107 } 1108 1109 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 1110 llvm::Value *cmd; 1111 if (Method) 1112 cmd = GetSelector(Builder, Method); 1113 else 1114 cmd = GetSelector(Builder, Sel); 1115 cmd = EnforceType(Builder, cmd, SelectorTy); 1116 Receiver = EnforceType(Builder, Receiver, IdTy); 1117 1118 llvm::Value *impMD[] = { 1119 llvm::MDString::get(VMContext, Sel.getAsString()), 1120 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""), 1121 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0) 1122 }; 1123 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1124 1125 // Get the IMP to call 1126 llvm::Value *imp = LookupIMP(CGF, Receiver, cmd, node); 1127 1128 CallArgList ActualArgs; 1129 ActualArgs.add(RValue::get(Receiver), ASTIdTy); 1130 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1131 ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end()); 1132 1133 CodeGenTypes &Types = CGM.getTypes(); 1134 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 1135 FunctionType::ExtInfo()); 1136 const llvm::FunctionType *impType = 1137 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1138 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1139 1140 1141 // For sender-aware dispatch, we pass the sender as the third argument to a 1142 // lookup function. When sending messages from C code, the sender is nil. 1143 // objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 1144 llvm::Instruction *call; 1145 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1146 0, &call); 1147 call->setMetadata(msgSendMDKind, node); 1148 1149 1150 if (!isPointerSizedReturn) { 1151 messageBB = CGF.Builder.GetInsertBlock(); 1152 CGF.Builder.CreateBr(continueBB); 1153 CGF.EmitBlock(continueBB); 1154 if (msgRet.isScalar()) { 1155 llvm::Value *v = msgRet.getScalarVal(); 1156 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1157 phi->addIncoming(v, messageBB); 1158 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB); 1159 msgRet = RValue::get(phi); 1160 } else if (msgRet.isAggregate()) { 1161 llvm::Value *v = msgRet.getAggregateAddr(); 1162 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1163 const llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType()); 1164 llvm::AllocaInst *NullVal = 1165 CGF.CreateTempAlloca(RetTy->getElementType(), "null"); 1166 CGF.InitTempAlloca(NullVal, 1167 llvm::Constant::getNullValue(RetTy->getElementType())); 1168 phi->addIncoming(v, messageBB); 1169 phi->addIncoming(NullVal, startBB); 1170 msgRet = RValue::getAggregate(phi); 1171 } else /* isComplex() */ { 1172 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal(); 1173 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2); 1174 phi->addIncoming(v.first, messageBB); 1175 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()), 1176 startBB); 1177 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2); 1178 phi2->addIncoming(v.second, messageBB); 1179 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()), 1180 startBB); 1181 msgRet = RValue::getComplex(phi, phi2); 1182 } 1183 } 1184 return msgRet; 1185} 1186 1187/// Generates a MethodList. Used in construction of a objc_class and 1188/// objc_category structures. 1189llvm::Constant *CGObjCGNU::GenerateMethodList(const llvm::StringRef &ClassName, 1190 const llvm::StringRef &CategoryName, 1191 const llvm::SmallVectorImpl<Selector> &MethodSels, 1192 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes, 1193 bool isClassMethodList) { 1194 if (MethodSels.empty()) 1195 return NULLPtr; 1196 // Get the method structure type. 1197 llvm::StructType *ObjCMethodTy = llvm::StructType::get(VMContext, 1198 PtrToInt8Ty, // Really a selector, but the runtime creates it us. 1199 PtrToInt8Ty, // Method types 1200 IMPTy, //Method pointer 1201 NULL); 1202 std::vector<llvm::Constant*> Methods; 1203 std::vector<llvm::Constant*> Elements; 1204 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) { 1205 Elements.clear(); 1206 llvm::Constant *Method = 1207 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName, 1208 MethodSels[i], 1209 isClassMethodList)); 1210 assert(Method && "Can't generate metadata for method that doesn't exist"); 1211 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString()); 1212 Elements.push_back(C); 1213 Elements.push_back(MethodTypes[i]); 1214 Method = llvm::ConstantExpr::getBitCast(Method, 1215 IMPTy); 1216 Elements.push_back(Method); 1217 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements)); 1218 } 1219 1220 // Array of method structures 1221 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy, 1222 Methods.size()); 1223 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy, 1224 Methods); 1225 1226 // Structure containing list pointer, array and array count 1227 llvm::SmallVector<const llvm::Type*, 16> ObjCMethodListFields; 1228 llvm::PATypeHolder OpaqueNextTy = llvm::OpaqueType::get(VMContext); 1229 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(OpaqueNextTy); 1230 llvm::StructType *ObjCMethodListTy = llvm::StructType::get(VMContext, 1231 NextPtrTy, 1232 IntTy, 1233 ObjCMethodArrayTy, 1234 NULL); 1235 // Refine next pointer type to concrete type 1236 llvm::cast<llvm::OpaqueType>( 1237 OpaqueNextTy.get())->refineAbstractTypeTo(ObjCMethodListTy); 1238 ObjCMethodListTy = llvm::cast<llvm::StructType>(OpaqueNextTy.get()); 1239 1240 Methods.clear(); 1241 Methods.push_back(llvm::ConstantPointerNull::get( 1242 llvm::PointerType::getUnqual(ObjCMethodListTy))); 1243 Methods.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1244 MethodTypes.size())); 1245 Methods.push_back(MethodArray); 1246 1247 // Create an instance of the structure 1248 return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list"); 1249} 1250 1251/// Generates an IvarList. Used in construction of a objc_class. 1252llvm::Constant *CGObjCGNU::GenerateIvarList( 1253 const llvm::SmallVectorImpl<llvm::Constant *> &IvarNames, 1254 const llvm::SmallVectorImpl<llvm::Constant *> &IvarTypes, 1255 const llvm::SmallVectorImpl<llvm::Constant *> &IvarOffsets) { 1256 if (IvarNames.size() == 0) 1257 return NULLPtr; 1258 // Get the method structure type. 1259 llvm::StructType *ObjCIvarTy = llvm::StructType::get(VMContext, 1260 PtrToInt8Ty, 1261 PtrToInt8Ty, 1262 IntTy, 1263 NULL); 1264 std::vector<llvm::Constant*> Ivars; 1265 std::vector<llvm::Constant*> Elements; 1266 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) { 1267 Elements.clear(); 1268 Elements.push_back(IvarNames[i]); 1269 Elements.push_back(IvarTypes[i]); 1270 Elements.push_back(IvarOffsets[i]); 1271 Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements)); 1272 } 1273 1274 // Array of method structures 1275 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy, 1276 IvarNames.size()); 1277 1278 1279 Elements.clear(); 1280 Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size())); 1281 Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)); 1282 // Structure containing array and array count 1283 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(VMContext, IntTy, 1284 ObjCIvarArrayTy, 1285 NULL); 1286 1287 // Create an instance of the structure 1288 return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list"); 1289} 1290 1291/// Generate a class structure 1292llvm::Constant *CGObjCGNU::GenerateClassStructure( 1293 llvm::Constant *MetaClass, 1294 llvm::Constant *SuperClass, 1295 unsigned info, 1296 const char *Name, 1297 llvm::Constant *Version, 1298 llvm::Constant *InstanceSize, 1299 llvm::Constant *IVars, 1300 llvm::Constant *Methods, 1301 llvm::Constant *Protocols, 1302 llvm::Constant *IvarOffsets, 1303 llvm::Constant *Properties, 1304 bool isMeta) { 1305 // Set up the class structure 1306 // Note: Several of these are char*s when they should be ids. This is 1307 // because the runtime performs this translation on load. 1308 // 1309 // Fields marked New ABI are part of the GNUstep runtime. We emit them 1310 // anyway; the classes will still work with the GNU runtime, they will just 1311 // be ignored. 1312 llvm::StructType *ClassTy = llvm::StructType::get(VMContext, 1313 PtrToInt8Ty, // class_pointer 1314 PtrToInt8Ty, // super_class 1315 PtrToInt8Ty, // name 1316 LongTy, // version 1317 LongTy, // info 1318 LongTy, // instance_size 1319 IVars->getType(), // ivars 1320 Methods->getType(), // methods 1321 // These are all filled in by the runtime, so we pretend 1322 PtrTy, // dtable 1323 PtrTy, // subclass_list 1324 PtrTy, // sibling_class 1325 PtrTy, // protocols 1326 PtrTy, // gc_object_type 1327 // New ABI: 1328 LongTy, // abi_version 1329 IvarOffsets->getType(), // ivar_offsets 1330 Properties->getType(), // properties 1331 NULL); 1332 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0); 1333 // Fill in the structure 1334 std::vector<llvm::Constant*> Elements; 1335 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty)); 1336 Elements.push_back(SuperClass); 1337 Elements.push_back(MakeConstantString(Name, ".class_name")); 1338 Elements.push_back(Zero); 1339 Elements.push_back(llvm::ConstantInt::get(LongTy, info)); 1340 if (isMeta) { 1341 llvm::TargetData td(&TheModule); 1342 Elements.push_back( 1343 llvm::ConstantInt::get(LongTy, 1344 td.getTypeSizeInBits(ClassTy) / 1345 CGM.getContext().getCharWidth())); 1346 } else 1347 Elements.push_back(InstanceSize); 1348 Elements.push_back(IVars); 1349 Elements.push_back(Methods); 1350 Elements.push_back(NULLPtr); 1351 Elements.push_back(NULLPtr); 1352 Elements.push_back(NULLPtr); 1353 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy)); 1354 Elements.push_back(NULLPtr); 1355 Elements.push_back(Zero); 1356 Elements.push_back(IvarOffsets); 1357 Elements.push_back(Properties); 1358 // Create an instance of the structure 1359 // This is now an externally visible symbol, so that we can speed up class 1360 // messages in the next ABI. 1361 return MakeGlobal(ClassTy, Elements, (isMeta ? "_OBJC_METACLASS_": 1362 "_OBJC_CLASS_") + std::string(Name), llvm::GlobalValue::ExternalLinkage); 1363} 1364 1365llvm::Constant *CGObjCGNU::GenerateProtocolMethodList( 1366 const llvm::SmallVectorImpl<llvm::Constant *> &MethodNames, 1367 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes) { 1368 // Get the method structure type. 1369 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get(VMContext, 1370 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us. 1371 PtrToInt8Ty, 1372 NULL); 1373 std::vector<llvm::Constant*> Methods; 1374 std::vector<llvm::Constant*> Elements; 1375 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) { 1376 Elements.clear(); 1377 Elements.push_back(MethodNames[i]); 1378 Elements.push_back(MethodTypes[i]); 1379 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements)); 1380 } 1381 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy, 1382 MethodNames.size()); 1383 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy, 1384 Methods); 1385 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get(VMContext, 1386 IntTy, ObjCMethodArrayTy, NULL); 1387 Methods.clear(); 1388 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size())); 1389 Methods.push_back(Array); 1390 return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list"); 1391} 1392 1393// Create the protocol list structure used in classes, categories and so on 1394llvm::Constant *CGObjCGNU::GenerateProtocolList( 1395 const llvm::SmallVectorImpl<std::string> &Protocols) { 1396 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 1397 Protocols.size()); 1398 llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext, 1399 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1400 SizeTy, 1401 ProtocolArrayTy, 1402 NULL); 1403 std::vector<llvm::Constant*> Elements; 1404 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end(); 1405 iter != endIter ; iter++) { 1406 llvm::Constant *protocol = 0; 1407 llvm::StringMap<llvm::Constant*>::iterator value = 1408 ExistingProtocols.find(*iter); 1409 if (value == ExistingProtocols.end()) { 1410 protocol = GenerateEmptyProtocol(*iter); 1411 } else { 1412 protocol = value->getValue(); 1413 } 1414 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol, 1415 PtrToInt8Ty); 1416 Elements.push_back(Ptr); 1417 } 1418 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1419 Elements); 1420 Elements.clear(); 1421 Elements.push_back(NULLPtr); 1422 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size())); 1423 Elements.push_back(ProtocolArray); 1424 return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list"); 1425} 1426 1427llvm::Value *CGObjCGNU::GenerateProtocolRef(CGBuilderTy &Builder, 1428 const ObjCProtocolDecl *PD) { 1429 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()]; 1430 const llvm::Type *T = 1431 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType()); 1432 return Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T)); 1433} 1434 1435llvm::Constant *CGObjCGNU::GenerateEmptyProtocol( 1436 const std::string &ProtocolName) { 1437 llvm::SmallVector<std::string, 0> EmptyStringVector; 1438 llvm::SmallVector<llvm::Constant*, 0> EmptyConstantVector; 1439 1440 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector); 1441 llvm::Constant *MethodList = 1442 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector); 1443 // Protocols are objects containing lists of the methods implemented and 1444 // protocols adopted. 1445 llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy, 1446 PtrToInt8Ty, 1447 ProtocolList->getType(), 1448 MethodList->getType(), 1449 MethodList->getType(), 1450 MethodList->getType(), 1451 MethodList->getType(), 1452 NULL); 1453 std::vector<llvm::Constant*> Elements; 1454 // The isa pointer must be set to a magic number so the runtime knows it's 1455 // the correct layout. 1456 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1457 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1458 ProtocolVersion), IdTy)); 1459 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1460 Elements.push_back(ProtocolList); 1461 Elements.push_back(MethodList); 1462 Elements.push_back(MethodList); 1463 Elements.push_back(MethodList); 1464 Elements.push_back(MethodList); 1465 return MakeGlobal(ProtocolTy, Elements, ".objc_protocol"); 1466} 1467 1468void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) { 1469 ASTContext &Context = CGM.getContext(); 1470 std::string ProtocolName = PD->getNameAsString(); 1471 llvm::SmallVector<std::string, 16> Protocols; 1472 for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(), 1473 E = PD->protocol_end(); PI != E; ++PI) 1474 Protocols.push_back((*PI)->getNameAsString()); 1475 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodNames; 1476 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1477 llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames; 1478 llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes; 1479 for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(), 1480 E = PD->instmeth_end(); iter != E; iter++) { 1481 std::string TypeStr; 1482 Context.getObjCEncodingForMethodDecl(*iter, TypeStr); 1483 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1484 InstanceMethodNames.push_back( 1485 MakeConstantString((*iter)->getSelector().getAsString())); 1486 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1487 } else { 1488 OptionalInstanceMethodNames.push_back( 1489 MakeConstantString((*iter)->getSelector().getAsString())); 1490 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1491 } 1492 } 1493 // Collect information about class methods: 1494 llvm::SmallVector<llvm::Constant*, 16> ClassMethodNames; 1495 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1496 llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodNames; 1497 llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes; 1498 for (ObjCProtocolDecl::classmeth_iterator 1499 iter = PD->classmeth_begin(), endIter = PD->classmeth_end(); 1500 iter != endIter ; iter++) { 1501 std::string TypeStr; 1502 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1503 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1504 ClassMethodNames.push_back( 1505 MakeConstantString((*iter)->getSelector().getAsString())); 1506 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1507 } else { 1508 OptionalClassMethodNames.push_back( 1509 MakeConstantString((*iter)->getSelector().getAsString())); 1510 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1511 } 1512 } 1513 1514 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols); 1515 llvm::Constant *InstanceMethodList = 1516 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes); 1517 llvm::Constant *ClassMethodList = 1518 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes); 1519 llvm::Constant *OptionalInstanceMethodList = 1520 GenerateProtocolMethodList(OptionalInstanceMethodNames, 1521 OptionalInstanceMethodTypes); 1522 llvm::Constant *OptionalClassMethodList = 1523 GenerateProtocolMethodList(OptionalClassMethodNames, 1524 OptionalClassMethodTypes); 1525 1526 // Property metadata: name, attributes, isSynthesized, setter name, setter 1527 // types, getter name, getter types. 1528 // The isSynthesized value is always set to 0 in a protocol. It exists to 1529 // simplify the runtime library by allowing it to use the same data 1530 // structures for protocol metadata everywhere. 1531 llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext, 1532 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1533 PtrToInt8Ty, NULL); 1534 std::vector<llvm::Constant*> Properties; 1535 std::vector<llvm::Constant*> OptionalProperties; 1536 1537 // Add all of the property methods need adding to the method list and to the 1538 // property metadata list. 1539 for (ObjCContainerDecl::prop_iterator 1540 iter = PD->prop_begin(), endIter = PD->prop_end(); 1541 iter != endIter ; iter++) { 1542 std::vector<llvm::Constant*> Fields; 1543 ObjCPropertyDecl *property = (*iter); 1544 1545 Fields.push_back(MakeConstantString(property->getNameAsString())); 1546 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1547 property->getPropertyAttributes())); 1548 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 1549 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1550 std::string TypeStr; 1551 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1552 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1553 InstanceMethodTypes.push_back(TypeEncoding); 1554 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1555 Fields.push_back(TypeEncoding); 1556 } else { 1557 Fields.push_back(NULLPtr); 1558 Fields.push_back(NULLPtr); 1559 } 1560 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1561 std::string TypeStr; 1562 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1563 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1564 InstanceMethodTypes.push_back(TypeEncoding); 1565 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1566 Fields.push_back(TypeEncoding); 1567 } else { 1568 Fields.push_back(NULLPtr); 1569 Fields.push_back(NULLPtr); 1570 } 1571 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) { 1572 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1573 } else { 1574 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1575 } 1576 } 1577 llvm::Constant *PropertyArray = llvm::ConstantArray::get( 1578 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties); 1579 llvm::Constant* PropertyListInitFields[] = 1580 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1581 1582 llvm::Constant *PropertyListInit = 1583 llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false); 1584 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule, 1585 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage, 1586 PropertyListInit, ".objc_property_list"); 1587 1588 llvm::Constant *OptionalPropertyArray = 1589 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy, 1590 OptionalProperties.size()) , OptionalProperties); 1591 llvm::Constant* OptionalPropertyListInitFields[] = { 1592 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr, 1593 OptionalPropertyArray }; 1594 1595 llvm::Constant *OptionalPropertyListInit = 1596 llvm::ConstantStruct::get(VMContext, OptionalPropertyListInitFields, 3, false); 1597 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule, 1598 OptionalPropertyListInit->getType(), false, 1599 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit, 1600 ".objc_property_list"); 1601 1602 // Protocols are objects containing lists of the methods implemented and 1603 // protocols adopted. 1604 llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy, 1605 PtrToInt8Ty, 1606 ProtocolList->getType(), 1607 InstanceMethodList->getType(), 1608 ClassMethodList->getType(), 1609 OptionalInstanceMethodList->getType(), 1610 OptionalClassMethodList->getType(), 1611 PropertyList->getType(), 1612 OptionalPropertyList->getType(), 1613 NULL); 1614 std::vector<llvm::Constant*> Elements; 1615 // The isa pointer must be set to a magic number so the runtime knows it's 1616 // the correct layout. 1617 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1618 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1619 ProtocolVersion), IdTy)); 1620 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1621 Elements.push_back(ProtocolList); 1622 Elements.push_back(InstanceMethodList); 1623 Elements.push_back(ClassMethodList); 1624 Elements.push_back(OptionalInstanceMethodList); 1625 Elements.push_back(OptionalClassMethodList); 1626 Elements.push_back(PropertyList); 1627 Elements.push_back(OptionalPropertyList); 1628 ExistingProtocols[ProtocolName] = 1629 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements, 1630 ".objc_protocol"), IdTy); 1631} 1632void CGObjCGNU::GenerateProtocolHolderCategory(void) { 1633 // Collect information about instance methods 1634 llvm::SmallVector<Selector, 1> MethodSels; 1635 llvm::SmallVector<llvm::Constant*, 1> MethodTypes; 1636 1637 std::vector<llvm::Constant*> Elements; 1638 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack"; 1639 const std::string CategoryName = "AnotherHack"; 1640 Elements.push_back(MakeConstantString(CategoryName)); 1641 Elements.push_back(MakeConstantString(ClassName)); 1642 // Instance method list 1643 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1644 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy)); 1645 // Class method list 1646 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1647 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy)); 1648 // Protocol list 1649 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy, 1650 ExistingProtocols.size()); 1651 llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext, 1652 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1653 SizeTy, 1654 ProtocolArrayTy, 1655 NULL); 1656 std::vector<llvm::Constant*> ProtocolElements; 1657 for (llvm::StringMapIterator<llvm::Constant*> iter = 1658 ExistingProtocols.begin(), endIter = ExistingProtocols.end(); 1659 iter != endIter ; iter++) { 1660 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(), 1661 PtrTy); 1662 ProtocolElements.push_back(Ptr); 1663 } 1664 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1665 ProtocolElements); 1666 ProtocolElements.clear(); 1667 ProtocolElements.push_back(NULLPtr); 1668 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy, 1669 ExistingProtocols.size())); 1670 ProtocolElements.push_back(ProtocolArray); 1671 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy, 1672 ProtocolElements, ".objc_protocol_list"), PtrTy)); 1673 Categories.push_back(llvm::ConstantExpr::getBitCast( 1674 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 1675 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1676} 1677 1678void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) { 1679 std::string ClassName = OCD->getClassInterface()->getNameAsString(); 1680 std::string CategoryName = OCD->getNameAsString(); 1681 // Collect information about instance methods 1682 llvm::SmallVector<Selector, 16> InstanceMethodSels; 1683 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1684 for (ObjCCategoryImplDecl::instmeth_iterator 1685 iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end(); 1686 iter != endIter ; iter++) { 1687 InstanceMethodSels.push_back((*iter)->getSelector()); 1688 std::string TypeStr; 1689 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1690 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1691 } 1692 1693 // Collect information about class methods 1694 llvm::SmallVector<Selector, 16> ClassMethodSels; 1695 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1696 for (ObjCCategoryImplDecl::classmeth_iterator 1697 iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end(); 1698 iter != endIter ; iter++) { 1699 ClassMethodSels.push_back((*iter)->getSelector()); 1700 std::string TypeStr; 1701 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1702 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1703 } 1704 1705 // Collect the names of referenced protocols 1706 llvm::SmallVector<std::string, 16> Protocols; 1707 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl(); 1708 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols(); 1709 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1710 E = Protos.end(); I != E; ++I) 1711 Protocols.push_back((*I)->getNameAsString()); 1712 1713 std::vector<llvm::Constant*> Elements; 1714 Elements.push_back(MakeConstantString(CategoryName)); 1715 Elements.push_back(MakeConstantString(ClassName)); 1716 // Instance method list 1717 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1718 ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes, 1719 false), PtrTy)); 1720 // Class method list 1721 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1722 ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true), 1723 PtrTy)); 1724 // Protocol list 1725 Elements.push_back(llvm::ConstantExpr::getBitCast( 1726 GenerateProtocolList(Protocols), PtrTy)); 1727 Categories.push_back(llvm::ConstantExpr::getBitCast( 1728 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, 1729 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1730} 1731 1732llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID, 1733 llvm::SmallVectorImpl<Selector> &InstanceMethodSels, 1734 llvm::SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) { 1735 ASTContext &Context = CGM.getContext(); 1736 // 1737 // Property metadata: name, attributes, isSynthesized, setter name, setter 1738 // types, getter name, getter types. 1739 llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext, 1740 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1741 PtrToInt8Ty, NULL); 1742 std::vector<llvm::Constant*> Properties; 1743 1744 1745 // Add all of the property methods need adding to the method list and to the 1746 // property metadata list. 1747 for (ObjCImplDecl::propimpl_iterator 1748 iter = OID->propimpl_begin(), endIter = OID->propimpl_end(); 1749 iter != endIter ; iter++) { 1750 std::vector<llvm::Constant*> Fields; 1751 ObjCPropertyDecl *property = (*iter)->getPropertyDecl(); 1752 ObjCPropertyImplDecl *propertyImpl = *iter; 1753 bool isSynthesized = (propertyImpl->getPropertyImplementation() == 1754 ObjCPropertyImplDecl::Synthesize); 1755 1756 Fields.push_back(MakeConstantString(property->getNameAsString())); 1757 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1758 property->getPropertyAttributes())); 1759 Fields.push_back(llvm::ConstantInt::get(Int8Ty, isSynthesized)); 1760 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1761 std::string TypeStr; 1762 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1763 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1764 if (isSynthesized) { 1765 InstanceMethodTypes.push_back(TypeEncoding); 1766 InstanceMethodSels.push_back(getter->getSelector()); 1767 } 1768 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1769 Fields.push_back(TypeEncoding); 1770 } else { 1771 Fields.push_back(NULLPtr); 1772 Fields.push_back(NULLPtr); 1773 } 1774 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1775 std::string TypeStr; 1776 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1777 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1778 if (isSynthesized) { 1779 InstanceMethodTypes.push_back(TypeEncoding); 1780 InstanceMethodSels.push_back(setter->getSelector()); 1781 } 1782 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1783 Fields.push_back(TypeEncoding); 1784 } else { 1785 Fields.push_back(NULLPtr); 1786 Fields.push_back(NULLPtr); 1787 } 1788 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1789 } 1790 llvm::ArrayType *PropertyArrayTy = 1791 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()); 1792 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy, 1793 Properties); 1794 llvm::Constant* PropertyListInitFields[] = 1795 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1796 1797 llvm::Constant *PropertyListInit = 1798 llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false); 1799 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false, 1800 llvm::GlobalValue::InternalLinkage, PropertyListInit, 1801 ".objc_property_list"); 1802} 1803 1804void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) { 1805 ASTContext &Context = CGM.getContext(); 1806 1807 // Get the superclass name. 1808 const ObjCInterfaceDecl * SuperClassDecl = 1809 OID->getClassInterface()->getSuperClass(); 1810 std::string SuperClassName; 1811 if (SuperClassDecl) { 1812 SuperClassName = SuperClassDecl->getNameAsString(); 1813 EmitClassRef(SuperClassName); 1814 } 1815 1816 // Get the class name 1817 ObjCInterfaceDecl *ClassDecl = 1818 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface()); 1819 std::string ClassName = ClassDecl->getNameAsString(); 1820 // Emit the symbol that is used to generate linker errors if this class is 1821 // referenced in other modules but not declared. 1822 std::string classSymbolName = "__objc_class_name_" + ClassName; 1823 if (llvm::GlobalVariable *symbol = 1824 TheModule.getGlobalVariable(classSymbolName)) { 1825 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0)); 1826 } else { 1827 new llvm::GlobalVariable(TheModule, LongTy, false, 1828 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0), 1829 classSymbolName); 1830 } 1831 1832 // Get the size of instances. 1833 int instanceSize = 1834 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity(); 1835 1836 // Collect information about instance variables. 1837 llvm::SmallVector<llvm::Constant*, 16> IvarNames; 1838 llvm::SmallVector<llvm::Constant*, 16> IvarTypes; 1839 llvm::SmallVector<llvm::Constant*, 16> IvarOffsets; 1840 1841 std::vector<llvm::Constant*> IvarOffsetValues; 1842 1843 int superInstanceSize = !SuperClassDecl ? 0 : 1844 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity(); 1845 // For non-fragile ivars, set the instance size to 0 - {the size of just this 1846 // class}. The runtime will then set this to the correct value on load. 1847 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1848 instanceSize = 0 - (instanceSize - superInstanceSize); 1849 } 1850 1851 // Collect declared and synthesized ivars. 1852 llvm::SmallVector<ObjCIvarDecl*, 16> OIvars; 1853 CGM.getContext().ShallowCollectObjCIvars(ClassDecl, OIvars); 1854 1855 for (unsigned i = 0, e = OIvars.size(); i != e; ++i) { 1856 ObjCIvarDecl *IVD = OIvars[i]; 1857 // Store the name 1858 IvarNames.push_back(MakeConstantString(IVD->getNameAsString())); 1859 // Get the type encoding for this ivar 1860 std::string TypeStr; 1861 Context.getObjCEncodingForType(IVD->getType(), TypeStr); 1862 IvarTypes.push_back(MakeConstantString(TypeStr)); 1863 // Get the offset 1864 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD); 1865 uint64_t Offset = BaseOffset; 1866 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1867 Offset = BaseOffset - superInstanceSize; 1868 } 1869 IvarOffsets.push_back( 1870 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset)); 1871 IvarOffsetValues.push_back(new llvm::GlobalVariable(TheModule, IntTy, 1872 false, llvm::GlobalValue::ExternalLinkage, 1873 llvm::ConstantInt::get(IntTy, Offset), 1874 "__objc_ivar_offset_value_" + ClassName +"." + 1875 IVD->getNameAsString())); 1876 } 1877 llvm::GlobalVariable *IvarOffsetArray = 1878 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets"); 1879 1880 1881 // Collect information about instance methods 1882 llvm::SmallVector<Selector, 16> InstanceMethodSels; 1883 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1884 for (ObjCImplementationDecl::instmeth_iterator 1885 iter = OID->instmeth_begin(), endIter = OID->instmeth_end(); 1886 iter != endIter ; iter++) { 1887 InstanceMethodSels.push_back((*iter)->getSelector()); 1888 std::string TypeStr; 1889 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1890 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1891 } 1892 1893 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels, 1894 InstanceMethodTypes); 1895 1896 1897 // Collect information about class methods 1898 llvm::SmallVector<Selector, 16> ClassMethodSels; 1899 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1900 for (ObjCImplementationDecl::classmeth_iterator 1901 iter = OID->classmeth_begin(), endIter = OID->classmeth_end(); 1902 iter != endIter ; iter++) { 1903 ClassMethodSels.push_back((*iter)->getSelector()); 1904 std::string TypeStr; 1905 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1906 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1907 } 1908 // Collect the names of referenced protocols 1909 llvm::SmallVector<std::string, 16> Protocols; 1910 const ObjCList<ObjCProtocolDecl> &Protos =ClassDecl->getReferencedProtocols(); 1911 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1912 E = Protos.end(); I != E; ++I) 1913 Protocols.push_back((*I)->getNameAsString()); 1914 1915 1916 1917 // Get the superclass pointer. 1918 llvm::Constant *SuperClass; 1919 if (!SuperClassName.empty()) { 1920 SuperClass = MakeConstantString(SuperClassName, ".super_class_name"); 1921 } else { 1922 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty); 1923 } 1924 // Empty vector used to construct empty method lists 1925 llvm::SmallVector<llvm::Constant*, 1> empty; 1926 // Generate the method and instance variable lists 1927 llvm::Constant *MethodList = GenerateMethodList(ClassName, "", 1928 InstanceMethodSels, InstanceMethodTypes, false); 1929 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "", 1930 ClassMethodSels, ClassMethodTypes, true); 1931 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes, 1932 IvarOffsets); 1933 // Irrespective of whether we are compiling for a fragile or non-fragile ABI, 1934 // we emit a symbol containing the offset for each ivar in the class. This 1935 // allows code compiled for the non-Fragile ABI to inherit from code compiled 1936 // for the legacy ABI, without causing problems. The converse is also 1937 // possible, but causes all ivar accesses to be fragile. 1938 1939 // Offset pointer for getting at the correct field in the ivar list when 1940 // setting up the alias. These are: The base address for the global, the 1941 // ivar array (second field), the ivar in this list (set for each ivar), and 1942 // the offset (third field in ivar structure) 1943 const llvm::Type *IndexTy = llvm::Type::getInt32Ty(VMContext); 1944 llvm::Constant *offsetPointerIndexes[] = {Zeros[0], 1945 llvm::ConstantInt::get(IndexTy, 1), 0, 1946 llvm::ConstantInt::get(IndexTy, 2) }; 1947 1948 1949 for (unsigned i = 0, e = OIvars.size(); i != e; ++i) { 1950 ObjCIvarDecl *IVD = OIvars[i]; 1951 const std::string Name = "__objc_ivar_offset_" + ClassName + '.' 1952 + IVD->getNameAsString(); 1953 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, i); 1954 // Get the correct ivar field 1955 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr( 1956 IvarList, offsetPointerIndexes, 4); 1957 // Get the existing variable, if one exists. 1958 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name); 1959 if (offset) { 1960 offset->setInitializer(offsetValue); 1961 // If this is the real definition, change its linkage type so that 1962 // different modules will use this one, rather than their private 1963 // copy. 1964 offset->setLinkage(llvm::GlobalValue::ExternalLinkage); 1965 } else { 1966 // Add a new alias if there isn't one already. 1967 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(), 1968 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name); 1969 } 1970 } 1971 //Generate metaclass for class methods 1972 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr, 1973 NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList( 1974 empty, empty, empty), ClassMethodList, NULLPtr, NULLPtr, NULLPtr, true); 1975 1976 // Generate the class structure 1977 llvm::Constant *ClassStruct = 1978 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L, 1979 ClassName.c_str(), 0, 1980 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, 1981 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray, 1982 Properties); 1983 1984 // Resolve the class aliases, if they exist. 1985 if (ClassPtrAlias) { 1986 ClassPtrAlias->replaceAllUsesWith( 1987 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy)); 1988 ClassPtrAlias->eraseFromParent(); 1989 ClassPtrAlias = 0; 1990 } 1991 if (MetaClassPtrAlias) { 1992 MetaClassPtrAlias->replaceAllUsesWith( 1993 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy)); 1994 MetaClassPtrAlias->eraseFromParent(); 1995 MetaClassPtrAlias = 0; 1996 } 1997 1998 // Add class structure to list to be added to the symtab later 1999 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty); 2000 Classes.push_back(ClassStruct); 2001} 2002 2003 2004llvm::Function *CGObjCGNU::ModuleInitFunction() { 2005 // Only emit an ObjC load function if no Objective-C stuff has been called 2006 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() && 2007 ExistingProtocols.empty() && SelectorTable.empty()) 2008 return NULL; 2009 2010 // Add all referenced protocols to a category. 2011 GenerateProtocolHolderCategory(); 2012 2013 const llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>( 2014 SelectorTy->getElementType()); 2015 const llvm::Type *SelStructPtrTy = SelectorTy; 2016 if (SelStructTy == 0) { 2017 SelStructTy = llvm::StructType::get(VMContext, PtrToInt8Ty, 2018 PtrToInt8Ty, NULL); 2019 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy); 2020 } 2021 2022 // Name the ObjC types to make the IR a bit easier to read 2023 TheModule.addTypeName(".objc_selector", SelStructPtrTy); 2024 TheModule.addTypeName(".objc_id", IdTy); 2025 TheModule.addTypeName(".objc_imp", IMPTy); 2026 2027 std::vector<llvm::Constant*> Elements; 2028 llvm::Constant *Statics = NULLPtr; 2029 // Generate statics list: 2030 if (ConstantStrings.size()) { 2031 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 2032 ConstantStrings.size() + 1); 2033 ConstantStrings.push_back(NULLPtr); 2034 2035 llvm::StringRef StringClass = CGM.getLangOptions().ObjCConstantStringClass; 2036 2037 if (StringClass.empty()) StringClass = "NXConstantString"; 2038 2039 Elements.push_back(MakeConstantString(StringClass, 2040 ".objc_static_class_name")); 2041 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy, 2042 ConstantStrings)); 2043 llvm::StructType *StaticsListTy = 2044 llvm::StructType::get(VMContext, PtrToInt8Ty, StaticsArrayTy, NULL); 2045 llvm::Type *StaticsListPtrTy = 2046 llvm::PointerType::getUnqual(StaticsListTy); 2047 Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics"); 2048 llvm::ArrayType *StaticsListArrayTy = 2049 llvm::ArrayType::get(StaticsListPtrTy, 2); 2050 Elements.clear(); 2051 Elements.push_back(Statics); 2052 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy)); 2053 Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr"); 2054 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy); 2055 } 2056 // Array of classes, categories, and constant objects 2057 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty, 2058 Classes.size() + Categories.size() + 2); 2059 llvm::StructType *SymTabTy = llvm::StructType::get(VMContext, 2060 LongTy, SelStructPtrTy, 2061 llvm::Type::getInt16Ty(VMContext), 2062 llvm::Type::getInt16Ty(VMContext), 2063 ClassListTy, NULL); 2064 2065 Elements.clear(); 2066 // Pointer to an array of selectors used in this module. 2067 std::vector<llvm::Constant*> Selectors; 2068 std::vector<llvm::GlobalAlias*> SelectorAliases; 2069 for (SelectorMap::iterator iter = SelectorTable.begin(), 2070 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) { 2071 2072 std::string SelNameStr = iter->first.getAsString(); 2073 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name"); 2074 2075 llvm::SmallVectorImpl<TypedSelector> &Types = iter->second; 2076 for (llvm::SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 2077 e = Types.end() ; i!=e ; i++) { 2078 2079 llvm::Constant *SelectorTypeEncoding = NULLPtr; 2080 if (!i->first.empty()) 2081 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types"); 2082 2083 Elements.push_back(SelName); 2084 Elements.push_back(SelectorTypeEncoding); 2085 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2086 Elements.clear(); 2087 2088 // Store the selector alias for later replacement 2089 SelectorAliases.push_back(i->second); 2090 } 2091 } 2092 unsigned SelectorCount = Selectors.size(); 2093 // NULL-terminate the selector list. This should not actually be required, 2094 // because the selector list has a length field. Unfortunately, the GCC 2095 // runtime decides to ignore the length field and expects a NULL terminator, 2096 // and GCC cooperates with this by always setting the length to 0. 2097 Elements.push_back(NULLPtr); 2098 Elements.push_back(NULLPtr); 2099 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2100 Elements.clear(); 2101 2102 // Number of static selectors 2103 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount)); 2104 llvm::Constant *SelectorList = MakeGlobalArray(SelStructTy, Selectors, 2105 ".objc_selector_list"); 2106 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList, 2107 SelStructPtrTy)); 2108 2109 // Now that all of the static selectors exist, create pointers to them. 2110 for (unsigned int i=0 ; i<SelectorCount ; i++) { 2111 2112 llvm::Constant *Idxs[] = {Zeros[0], 2113 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), i), Zeros[0]}; 2114 // FIXME: We're generating redundant loads and stores here! 2115 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(SelectorList, 2116 Idxs, 2); 2117 // If selectors are defined as an opaque type, cast the pointer to this 2118 // type. 2119 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy); 2120 SelectorAliases[i]->replaceAllUsesWith(SelPtr); 2121 SelectorAliases[i]->eraseFromParent(); 2122 } 2123 2124 // Number of classes defined. 2125 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2126 Classes.size())); 2127 // Number of categories defined 2128 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2129 Categories.size())); 2130 // Create an array of classes, then categories, then static object instances 2131 Classes.insert(Classes.end(), Categories.begin(), Categories.end()); 2132 // NULL-terminated list of static object instances (mainly constant strings) 2133 Classes.push_back(Statics); 2134 Classes.push_back(NULLPtr); 2135 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes); 2136 Elements.push_back(ClassList); 2137 // Construct the symbol table 2138 llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements); 2139 2140 // The symbol table is contained in a module which has some version-checking 2141 // constants 2142 llvm::StructType * ModuleTy = llvm::StructType::get(VMContext, LongTy, LongTy, 2143 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), 2144 (CGM.getLangOptions().getGCMode() == LangOptions::NonGC) ? NULL : IntTy, 2145 NULL); 2146 Elements.clear(); 2147 // Runtime version, used for ABI compatibility checking. 2148 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion)); 2149 // sizeof(ModuleTy) 2150 llvm::TargetData td(&TheModule); 2151 Elements.push_back( 2152 llvm::ConstantInt::get(LongTy, 2153 td.getTypeSizeInBits(ModuleTy) / 2154 CGM.getContext().getCharWidth())); 2155 2156 // The path to the source file where this module was declared 2157 SourceManager &SM = CGM.getContext().getSourceManager(); 2158 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID()); 2159 std::string path = 2160 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName(); 2161 Elements.push_back(MakeConstantString(path, ".objc_source_file_name")); 2162 Elements.push_back(SymTab); 2163 2164 switch (CGM.getLangOptions().getGCMode()) { 2165 case LangOptions::GCOnly: 2166 Elements.push_back(llvm::ConstantInt::get(IntTy, 2)); 2167 case LangOptions::NonGC: 2168 break; 2169 case LangOptions::HybridGC: 2170 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2171 } 2172 2173 llvm::Value *Module = MakeGlobal(ModuleTy, Elements); 2174 2175 // Create the load function calling the runtime entry point with the module 2176 // structure 2177 llvm::Function * LoadFunction = llvm::Function::Create( 2178 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false), 2179 llvm::GlobalValue::InternalLinkage, ".objc_load_function", 2180 &TheModule); 2181 llvm::BasicBlock *EntryBB = 2182 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction); 2183 CGBuilderTy Builder(VMContext); 2184 Builder.SetInsertPoint(EntryBB); 2185 2186 std::vector<const llvm::Type*> Params(1, 2187 llvm::PointerType::getUnqual(ModuleTy)); 2188 llvm::Value *Register = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 2189 llvm::Type::getVoidTy(VMContext), Params, true), "__objc_exec_class"); 2190 Builder.CreateCall(Register, Module); 2191 Builder.CreateRetVoid(); 2192 2193 return LoadFunction; 2194} 2195 2196llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD, 2197 const ObjCContainerDecl *CD) { 2198 const ObjCCategoryImplDecl *OCD = 2199 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext()); 2200 llvm::StringRef CategoryName = OCD ? OCD->getName() : ""; 2201 llvm::StringRef ClassName = CD->getName(); 2202 Selector MethodName = OMD->getSelector(); 2203 bool isClassMethod = !OMD->isInstanceMethod(); 2204 2205 CodeGenTypes &Types = CGM.getTypes(); 2206 const llvm::FunctionType *MethodTy = 2207 Types.GetFunctionType(Types.getFunctionInfo(OMD), OMD->isVariadic()); 2208 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName, 2209 MethodName, isClassMethod); 2210 2211 llvm::Function *Method 2212 = llvm::Function::Create(MethodTy, 2213 llvm::GlobalValue::InternalLinkage, 2214 FunctionName, 2215 &TheModule); 2216 return Method; 2217} 2218 2219llvm::Constant *CGObjCGNU::GetPropertyGetFunction() { 2220 return GetPropertyFn; 2221} 2222 2223llvm::Constant *CGObjCGNU::GetPropertySetFunction() { 2224 return SetPropertyFn; 2225} 2226 2227llvm::Constant *CGObjCGNU::GetGetStructFunction() { 2228 return GetStructPropertyFn; 2229} 2230llvm::Constant *CGObjCGNU::GetSetStructFunction() { 2231 return SetStructPropertyFn; 2232} 2233 2234llvm::Constant *CGObjCGNU::EnumerationMutationFunction() { 2235 return EnumerationMutationFn; 2236} 2237 2238void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF, 2239 const ObjCAtSynchronizedStmt &S) { 2240 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn); 2241} 2242 2243 2244void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF, 2245 const ObjCAtTryStmt &S) { 2246 // Unlike the Apple non-fragile runtimes, which also uses 2247 // unwind-based zero cost exceptions, the GNU Objective C runtime's 2248 // EH support isn't a veneer over C++ EH. Instead, exception 2249 // objects are created by __objc_exception_throw and destroyed by 2250 // the personality function; this avoids the need for bracketing 2251 // catch handlers with calls to __blah_begin_catch/__blah_end_catch 2252 // (or even _Unwind_DeleteException), but probably doesn't 2253 // interoperate very well with foreign exceptions. 2254 // 2255 // In Objective-C++ mode, we actually emit something equivalent to the C++ 2256 // exception handler. 2257 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn); 2258 return ; 2259} 2260 2261void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF, 2262 const ObjCAtThrowStmt &S) { 2263 llvm::Value *ExceptionAsObject; 2264 2265 if (const Expr *ThrowExpr = S.getThrowExpr()) { 2266 llvm::Value *Exception = CGF.EmitScalarExpr(ThrowExpr); 2267 ExceptionAsObject = Exception; 2268 } else { 2269 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) && 2270 "Unexpected rethrow outside @catch block."); 2271 ExceptionAsObject = CGF.ObjCEHValueStack.back(); 2272 } 2273 ExceptionAsObject = 2274 CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy, "tmp"); 2275 2276 // Note: This may have to be an invoke, if we want to support constructs like: 2277 // @try { 2278 // @throw(obj); 2279 // } 2280 // @catch(id) ... 2281 // 2282 // This is effectively turning @throw into an incredibly-expensive goto, but 2283 // it may happen as a result of inlining followed by missed optimizations, or 2284 // as a result of stupidity. 2285 llvm::BasicBlock *UnwindBB = CGF.getInvokeDest(); 2286 if (!UnwindBB) { 2287 CGF.Builder.CreateCall(ExceptionThrowFn, ExceptionAsObject); 2288 CGF.Builder.CreateUnreachable(); 2289 } else { 2290 CGF.Builder.CreateInvoke(ExceptionThrowFn, UnwindBB, UnwindBB, &ExceptionAsObject, 2291 &ExceptionAsObject+1); 2292 } 2293 // Clear the insertion point to indicate we are in unreachable code. 2294 CGF.Builder.ClearInsertionPoint(); 2295} 2296 2297llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF, 2298 llvm::Value *AddrWeakObj) { 2299 CGBuilderTy B = CGF.Builder; 2300 AddrWeakObj = EnforceType(B, AddrWeakObj, IdTy); 2301 return B.CreateCall(WeakReadFn, AddrWeakObj); 2302} 2303 2304void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF, 2305 llvm::Value *src, llvm::Value *dst) { 2306 CGBuilderTy B = CGF.Builder; 2307 src = EnforceType(B, src, IdTy); 2308 dst = EnforceType(B, dst, PtrToIdTy); 2309 B.CreateCall2(WeakAssignFn, src, dst); 2310} 2311 2312void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF, 2313 llvm::Value *src, llvm::Value *dst, 2314 bool threadlocal) { 2315 CGBuilderTy B = CGF.Builder; 2316 src = EnforceType(B, src, IdTy); 2317 dst = EnforceType(B, dst, PtrToIdTy); 2318 if (!threadlocal) 2319 B.CreateCall2(GlobalAssignFn, src, dst); 2320 else 2321 // FIXME. Add threadloca assign API 2322 assert(false && "EmitObjCGlobalAssign - Threal Local API NYI"); 2323} 2324 2325void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF, 2326 llvm::Value *src, llvm::Value *dst, 2327 llvm::Value *ivarOffset) { 2328 CGBuilderTy B = CGF.Builder; 2329 src = EnforceType(B, src, IdTy); 2330 dst = EnforceType(B, dst, IdTy); 2331 B.CreateCall3(IvarAssignFn, src, dst, ivarOffset); 2332} 2333 2334void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF, 2335 llvm::Value *src, llvm::Value *dst) { 2336 CGBuilderTy B = CGF.Builder; 2337 src = EnforceType(B, src, IdTy); 2338 dst = EnforceType(B, dst, PtrToIdTy); 2339 B.CreateCall2(StrongCastAssignFn, src, dst); 2340} 2341 2342void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF, 2343 llvm::Value *DestPtr, 2344 llvm::Value *SrcPtr, 2345 llvm::Value *Size) { 2346 CGBuilderTy B = CGF.Builder; 2347 DestPtr = EnforceType(B, DestPtr, PtrTy); 2348 SrcPtr = EnforceType(B, SrcPtr, PtrTy); 2349 2350 B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size); 2351} 2352 2353llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable( 2354 const ObjCInterfaceDecl *ID, 2355 const ObjCIvarDecl *Ivar) { 2356 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString() 2357 + '.' + Ivar->getNameAsString(); 2358 // Emit the variable and initialize it with what we think the correct value 2359 // is. This allows code compiled with non-fragile ivars to work correctly 2360 // when linked against code which isn't (most of the time). 2361 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name); 2362 if (!IvarOffsetPointer) { 2363 // This will cause a run-time crash if we accidentally use it. A value of 2364 // 0 would seem more sensible, but will silently overwrite the isa pointer 2365 // causing a great deal of confusion. 2366 uint64_t Offset = -1; 2367 // We can't call ComputeIvarBaseOffset() here if we have the 2368 // implementation, because it will create an invalid ASTRecordLayout object 2369 // that we are then stuck with forever, so we only initialize the ivar 2370 // offset variable with a guess if we only have the interface. The 2371 // initializer will be reset later anyway, when we are generating the class 2372 // description. 2373 if (!CGM.getContext().getObjCImplementation( 2374 const_cast<ObjCInterfaceDecl *>(ID))) 2375 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar); 2376 2377 llvm::ConstantInt *OffsetGuess = 2378 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset, "ivar"); 2379 // Don't emit the guess in non-PIC code because the linker will not be able 2380 // to replace it with the real version for a library. In non-PIC code you 2381 // must compile with the fragile ABI if you want to use ivars from a 2382 // GCC-compiled class. 2383 if (CGM.getLangOptions().PICLevel) { 2384 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule, 2385 llvm::Type::getInt32Ty(VMContext), false, 2386 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess"); 2387 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2388 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage, 2389 IvarOffsetGV, Name); 2390 } else { 2391 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2392 llvm::Type::getInt32PtrTy(VMContext), false, 2393 llvm::GlobalValue::ExternalLinkage, 0, Name); 2394 } 2395 } 2396 return IvarOffsetPointer; 2397} 2398 2399LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF, 2400 QualType ObjectTy, 2401 llvm::Value *BaseValue, 2402 const ObjCIvarDecl *Ivar, 2403 unsigned CVRQualifiers) { 2404 const ObjCInterfaceDecl *ID = 2405 ObjectTy->getAs<ObjCObjectType>()->getInterface(); 2406 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers, 2407 EmitIvarOffset(CGF, ID, Ivar)); 2408} 2409 2410static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context, 2411 const ObjCInterfaceDecl *OID, 2412 const ObjCIvarDecl *OIVD) { 2413 llvm::SmallVector<ObjCIvarDecl*, 16> Ivars; 2414 Context.ShallowCollectObjCIvars(OID, Ivars); 2415 for (unsigned k = 0, e = Ivars.size(); k != e; ++k) { 2416 if (OIVD == Ivars[k]) 2417 return OID; 2418 } 2419 2420 // Otherwise check in the super class. 2421 if (const ObjCInterfaceDecl *Super = OID->getSuperClass()) 2422 return FindIvarInterface(Context, Super, OIVD); 2423 2424 return 0; 2425} 2426 2427llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF, 2428 const ObjCInterfaceDecl *Interface, 2429 const ObjCIvarDecl *Ivar) { 2430 if (CGM.getLangOptions().ObjCNonFragileABI) { 2431 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar); 2432 return CGF.Builder.CreateZExtOrBitCast( 2433 CGF.Builder.CreateLoad(CGF.Builder.CreateLoad( 2434 ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")), 2435 PtrDiffTy); 2436 } 2437 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar); 2438 return llvm::ConstantInt::get(PtrDiffTy, Offset, "ivar"); 2439} 2440 2441CGObjCRuntime * 2442clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) { 2443 if (CGM.getLangOptions().ObjCNonFragileABI) 2444 return new CGObjCGNUstep(CGM); 2445 return new CGObjCGCC(CGM); 2446} 2447