CGObjCGNU.cpp revision 3fc81d32314eca98b51846f493a8bc77cf14a701
1//===------- CGObjCGNU.cpp - Emit LLVM Code from ASTs for a Module --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This provides Objective-C code generation targeting the GNU runtime. The 11// class in this file generates structures used by the GNU Objective-C runtime 12// library. These structures are defined in objc/objc.h and objc/objc-api.h in 13// the GNU runtime distribution. 14// 15//===----------------------------------------------------------------------===// 16 17#include "CGObjCRuntime.h" 18#include "CodeGenModule.h" 19#include "CodeGenFunction.h" 20#include "CGCleanup.h" 21 22#include "clang/AST/ASTContext.h" 23#include "clang/AST/Decl.h" 24#include "clang/AST/DeclObjC.h" 25#include "clang/AST/RecordLayout.h" 26#include "clang/AST/StmtObjC.h" 27#include "clang/Basic/SourceManager.h" 28#include "clang/Basic/FileManager.h" 29 30#include "llvm/Intrinsics.h" 31#include "llvm/Module.h" 32#include "llvm/LLVMContext.h" 33#include "llvm/ADT/SmallVector.h" 34#include "llvm/ADT/StringMap.h" 35#include "llvm/Support/CallSite.h" 36#include "llvm/Support/Compiler.h" 37#include "llvm/Target/TargetData.h" 38 39#include <cstdarg> 40 41 42using namespace clang; 43using namespace CodeGen; 44 45 46namespace { 47/// Class that lazily initialises the runtime function. Avoids inserting the 48/// types and the function declaration into a module if they're not used, and 49/// avoids constructing the type more than once if it's used more than once. 50class LazyRuntimeFunction { 51 CodeGenModule *CGM; 52 std::vector<llvm::Type*> ArgTys; 53 const char *FunctionName; 54 llvm::Constant *Function; 55 public: 56 /// Constructor leaves this class uninitialized, because it is intended to 57 /// be used as a field in another class and not all of the types that are 58 /// used as arguments will necessarily be available at construction time. 59 LazyRuntimeFunction() : CGM(0), FunctionName(0), Function(0) {} 60 61 /// Initialises the lazy function with the name, return type, and the types 62 /// of the arguments. 63 END_WITH_NULL 64 void init(CodeGenModule *Mod, const char *name, 65 llvm::Type *RetTy, ...) { 66 CGM =Mod; 67 FunctionName = name; 68 Function = 0; 69 ArgTys.clear(); 70 va_list Args; 71 va_start(Args, RetTy); 72 while (llvm::Type *ArgTy = va_arg(Args, llvm::Type*)) 73 ArgTys.push_back(ArgTy); 74 va_end(Args); 75 // Push the return type on at the end so we can pop it off easily 76 ArgTys.push_back(RetTy); 77 } 78 /// Overloaded cast operator, allows the class to be implicitly cast to an 79 /// LLVM constant. 80 operator llvm::Constant*() { 81 if (!Function) { 82 if (0 == FunctionName) return 0; 83 // We put the return type on the end of the vector, so pop it back off 84 llvm::Type *RetTy = ArgTys.back(); 85 ArgTys.pop_back(); 86 llvm::FunctionType *FTy = llvm::FunctionType::get(RetTy, ArgTys, false); 87 Function = 88 cast<llvm::Constant>(CGM->CreateRuntimeFunction(FTy, FunctionName)); 89 // We won't need to use the types again, so we may as well clean up the 90 // vector now 91 ArgTys.resize(0); 92 } 93 return Function; 94 } 95 operator llvm::Function*() { 96 return cast<llvm::Function>((llvm::Constant*)*this); 97 } 98 99}; 100 101 102/// GNU Objective-C runtime code generation. This class implements the parts of 103/// Objective-C support that are specific to the GNU family of runtimes (GCC and 104/// GNUstep). 105class CGObjCGNU : public CGObjCRuntime { 106protected: 107 /// The module that is using this class 108 CodeGenModule &CGM; 109 /// The LLVM module into which output is inserted 110 llvm::Module &TheModule; 111 /// strut objc_super. Used for sending messages to super. This structure 112 /// contains the receiver (object) and the expected class. 113 llvm::StructType *ObjCSuperTy; 114 /// struct objc_super*. The type of the argument to the superclass message 115 /// lookup functions. 116 llvm::PointerType *PtrToObjCSuperTy; 117 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring 118 /// SEL is included in a header somewhere, in which case it will be whatever 119 /// type is declared in that header, most likely {i8*, i8*}. 120 llvm::PointerType *SelectorTy; 121 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the 122 /// places where it's used 123 llvm::IntegerType *Int8Ty; 124 /// Pointer to i8 - LLVM type of char*, for all of the places where the 125 /// runtime needs to deal with C strings. 126 llvm::PointerType *PtrToInt8Ty; 127 /// Instance Method Pointer type. This is a pointer to a function that takes, 128 /// at a minimum, an object and a selector, and is the generic type for 129 /// Objective-C methods. Due to differences between variadic / non-variadic 130 /// calling conventions, it must always be cast to the correct type before 131 /// actually being used. 132 llvm::PointerType *IMPTy; 133 /// Type of an untyped Objective-C object. Clang treats id as a built-in type 134 /// when compiling Objective-C code, so this may be an opaque pointer (i8*), 135 /// but if the runtime header declaring it is included then it may be a 136 /// pointer to a structure. 137 llvm::PointerType *IdTy; 138 /// Pointer to a pointer to an Objective-C object. Used in the new ABI 139 /// message lookup function and some GC-related functions. 140 llvm::PointerType *PtrToIdTy; 141 /// The clang type of id. Used when using the clang CGCall infrastructure to 142 /// call Objective-C methods. 143 CanQualType ASTIdTy; 144 /// LLVM type for C int type. 145 llvm::IntegerType *IntTy; 146 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is 147 /// used in the code to document the difference between i8* meaning a pointer 148 /// to a C string and i8* meaning a pointer to some opaque type. 149 llvm::PointerType *PtrTy; 150 /// LLVM type for C long type. The runtime uses this in a lot of places where 151 /// it should be using intptr_t, but we can't fix this without breaking 152 /// compatibility with GCC... 153 llvm::IntegerType *LongTy; 154 /// LLVM type for C size_t. Used in various runtime data structures. 155 llvm::IntegerType *SizeTy; 156 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions. 157 llvm::IntegerType *PtrDiffTy; 158 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance 159 /// variables. 160 llvm::PointerType *PtrToIntTy; 161 /// LLVM type for Objective-C BOOL type. 162 llvm::Type *BoolTy; 163 /// Metadata kind used to tie method lookups to message sends. The GNUstep 164 /// runtime provides some LLVM passes that can use this to do things like 165 /// automatic IMP caching and speculative inlining. 166 unsigned msgSendMDKind; 167 /// Helper function that generates a constant string and returns a pointer to 168 /// the start of the string. The result of this function can be used anywhere 169 /// where the C code specifies const char*. 170 llvm::Constant *MakeConstantString(const std::string &Str, 171 const std::string &Name="") { 172 llvm::Constant *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str()); 173 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 174 } 175 /// Emits a linkonce_odr string, whose name is the prefix followed by the 176 /// string value. This allows the linker to combine the strings between 177 /// different modules. Used for EH typeinfo names, selector strings, and a 178 /// few other things. 179 llvm::Constant *ExportUniqueString(const std::string &Str, 180 const std::string prefix) { 181 std::string name = prefix + Str; 182 llvm::Constant *ConstStr = TheModule.getGlobalVariable(name); 183 if (!ConstStr) { 184 llvm::Constant *value = llvm::ConstantArray::get(VMContext, Str, true); 185 ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true, 186 llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str); 187 } 188 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 189 } 190 /// Generates a global structure, initialized by the elements in the vector. 191 /// The element types must match the types of the structure elements in the 192 /// first argument. 193 llvm::GlobalVariable *MakeGlobal(llvm::StructType *Ty, 194 std::vector<llvm::Constant*> &V, 195 StringRef Name="", 196 llvm::GlobalValue::LinkageTypes linkage 197 =llvm::GlobalValue::InternalLinkage) { 198 llvm::Constant *C = llvm::ConstantStruct::get(Ty, V); 199 return new llvm::GlobalVariable(TheModule, Ty, false, 200 linkage, C, Name); 201 } 202 /// Generates a global array. The vector must contain the same number of 203 /// elements that the array type declares, of the type specified as the array 204 /// element type. 205 llvm::GlobalVariable *MakeGlobal(llvm::ArrayType *Ty, 206 std::vector<llvm::Constant*> &V, 207 StringRef Name="", 208 llvm::GlobalValue::LinkageTypes linkage 209 =llvm::GlobalValue::InternalLinkage) { 210 llvm::Constant *C = llvm::ConstantArray::get(Ty, V); 211 return new llvm::GlobalVariable(TheModule, Ty, false, 212 linkage, C, Name); 213 } 214 /// Generates a global array, inferring the array type from the specified 215 /// element type and the size of the initialiser. 216 llvm::GlobalVariable *MakeGlobalArray(llvm::Type *Ty, 217 std::vector<llvm::Constant*> &V, 218 StringRef Name="", 219 llvm::GlobalValue::LinkageTypes linkage 220 =llvm::GlobalValue::InternalLinkage) { 221 llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size()); 222 return MakeGlobal(ArrayTy, V, Name, linkage); 223 } 224 /// Ensures that the value has the required type, by inserting a bitcast if 225 /// required. This function lets us avoid inserting bitcasts that are 226 /// redundant. 227 llvm::Value* EnforceType(CGBuilderTy B, llvm::Value *V, llvm::Type *Ty){ 228 if (V->getType() == Ty) return V; 229 return B.CreateBitCast(V, Ty); 230 } 231 // Some zeros used for GEPs in lots of places. 232 llvm::Constant *Zeros[2]; 233 /// Null pointer value. Mainly used as a terminator in various arrays. 234 llvm::Constant *NULLPtr; 235 /// LLVM context. 236 llvm::LLVMContext &VMContext; 237private: 238 /// Placeholder for the class. Lots of things refer to the class before we've 239 /// actually emitted it. We use this alias as a placeholder, and then replace 240 /// it with a pointer to the class structure before finally emitting the 241 /// module. 242 llvm::GlobalAlias *ClassPtrAlias; 243 /// Placeholder for the metaclass. Lots of things refer to the class before 244 /// we've / actually emitted it. We use this alias as a placeholder, and then 245 /// replace / it with a pointer to the metaclass structure before finally 246 /// emitting the / module. 247 llvm::GlobalAlias *MetaClassPtrAlias; 248 /// All of the classes that have been generated for this compilation units. 249 std::vector<llvm::Constant*> Classes; 250 /// All of the categories that have been generated for this compilation units. 251 std::vector<llvm::Constant*> Categories; 252 /// All of the Objective-C constant strings that have been generated for this 253 /// compilation units. 254 std::vector<llvm::Constant*> ConstantStrings; 255 /// Map from string values to Objective-C constant strings in the output. 256 /// Used to prevent emitting Objective-C strings more than once. This should 257 /// not be required at all - CodeGenModule should manage this list. 258 llvm::StringMap<llvm::Constant*> ObjCStrings; 259 /// All of the protocols that have been declared. 260 llvm::StringMap<llvm::Constant*> ExistingProtocols; 261 /// For each variant of a selector, we store the type encoding and a 262 /// placeholder value. For an untyped selector, the type will be the empty 263 /// string. Selector references are all done via the module's selector table, 264 /// so we create an alias as a placeholder and then replace it with the real 265 /// value later. 266 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector; 267 /// Type of the selector map. This is roughly equivalent to the structure 268 /// used in the GNUstep runtime, which maintains a list of all of the valid 269 /// types for a selector in a table. 270 typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> > 271 SelectorMap; 272 /// A map from selectors to selector types. This allows us to emit all 273 /// selectors of the same name and type together. 274 SelectorMap SelectorTable; 275 276 /// Selectors related to memory management. When compiling in GC mode, we 277 /// omit these. 278 Selector RetainSel, ReleaseSel, AutoreleaseSel; 279 /// Runtime functions used for memory management in GC mode. Note that clang 280 /// supports code generation for calling these functions, but neither GNU 281 /// runtime actually supports this API properly yet. 282 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn, 283 WeakAssignFn, GlobalAssignFn; 284 285protected: 286 /// Function used for throwing Objective-C exceptions. 287 LazyRuntimeFunction ExceptionThrowFn; 288 /// Function used for rethrowing exceptions, used at the end of @finally or 289 /// @synchronize blocks. 290 LazyRuntimeFunction ExceptionReThrowFn; 291 /// Function called when entering a catch function. This is required for 292 /// differentiating Objective-C exceptions and foreign exceptions. 293 LazyRuntimeFunction EnterCatchFn; 294 /// Function called when exiting from a catch block. Used to do exception 295 /// cleanup. 296 LazyRuntimeFunction ExitCatchFn; 297 /// Function called when entering an @synchronize block. Acquires the lock. 298 LazyRuntimeFunction SyncEnterFn; 299 /// Function called when exiting an @synchronize block. Releases the lock. 300 LazyRuntimeFunction SyncExitFn; 301 302private: 303 304 /// Function called if fast enumeration detects that the collection is 305 /// modified during the update. 306 LazyRuntimeFunction EnumerationMutationFn; 307 /// Function for implementing synthesized property getters that return an 308 /// object. 309 LazyRuntimeFunction GetPropertyFn; 310 /// Function for implementing synthesized property setters that return an 311 /// object. 312 LazyRuntimeFunction SetPropertyFn; 313 /// Function used for non-object declared property getters. 314 LazyRuntimeFunction GetStructPropertyFn; 315 /// Function used for non-object declared property setters. 316 LazyRuntimeFunction SetStructPropertyFn; 317 318 /// The version of the runtime that this class targets. Must match the 319 /// version in the runtime. 320 int RuntimeVersion; 321 /// The version of the protocol class. Used to differentiate between ObjC1 322 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional 323 /// components and can not contain declared properties. We always emit 324 /// Objective-C 2 property structures, but we have to pretend that they're 325 /// Objective-C 1 property structures when targeting the GCC runtime or it 326 /// will abort. 327 const int ProtocolVersion; 328private: 329 /// Generates an instance variable list structure. This is a structure 330 /// containing a size and an array of structures containing instance variable 331 /// metadata. This is used purely for introspection in the fragile ABI. In 332 /// the non-fragile ABI, it's used for instance variable fixup. 333 llvm::Constant *GenerateIvarList( 334 const SmallVectorImpl<llvm::Constant *> &IvarNames, 335 const SmallVectorImpl<llvm::Constant *> &IvarTypes, 336 const SmallVectorImpl<llvm::Constant *> &IvarOffsets); 337 /// Generates a method list structure. This is a structure containing a size 338 /// and an array of structures containing method metadata. 339 /// 340 /// This structure is used by both classes and categories, and contains a next 341 /// pointer allowing them to be chained together in a linked list. 342 llvm::Constant *GenerateMethodList(const StringRef &ClassName, 343 const StringRef &CategoryName, 344 const SmallVectorImpl<Selector> &MethodSels, 345 const SmallVectorImpl<llvm::Constant *> &MethodTypes, 346 bool isClassMethodList); 347 /// Emits an empty protocol. This is used for @protocol() where no protocol 348 /// is found. The runtime will (hopefully) fix up the pointer to refer to the 349 /// real protocol. 350 llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName); 351 /// Generates a list of property metadata structures. This follows the same 352 /// pattern as method and instance variable metadata lists. 353 llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID, 354 SmallVectorImpl<Selector> &InstanceMethodSels, 355 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes); 356 /// Generates a list of referenced protocols. Classes, categories, and 357 /// protocols all use this structure. 358 llvm::Constant *GenerateProtocolList( 359 const SmallVectorImpl<std::string> &Protocols); 360 /// To ensure that all protocols are seen by the runtime, we add a category on 361 /// a class defined in the runtime, declaring no methods, but adopting the 362 /// protocols. This is a horribly ugly hack, but it allows us to collect all 363 /// of the protocols without changing the ABI. 364 void GenerateProtocolHolderCategory(void); 365 /// Generates a class structure. 366 llvm::Constant *GenerateClassStructure( 367 llvm::Constant *MetaClass, 368 llvm::Constant *SuperClass, 369 unsigned info, 370 const char *Name, 371 llvm::Constant *Version, 372 llvm::Constant *InstanceSize, 373 llvm::Constant *IVars, 374 llvm::Constant *Methods, 375 llvm::Constant *Protocols, 376 llvm::Constant *IvarOffsets, 377 llvm::Constant *Properties, 378 bool isMeta=false); 379 /// Generates a method list. This is used by protocols to define the required 380 /// and optional methods. 381 llvm::Constant *GenerateProtocolMethodList( 382 const SmallVectorImpl<llvm::Constant *> &MethodNames, 383 const SmallVectorImpl<llvm::Constant *> &MethodTypes); 384 /// Returns a selector with the specified type encoding. An empty string is 385 /// used to return an untyped selector (with the types field set to NULL). 386 llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 387 const std::string &TypeEncoding, bool lval); 388 /// Returns the variable used to store the offset of an instance variable. 389 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID, 390 const ObjCIvarDecl *Ivar); 391 /// Emits a reference to a class. This allows the linker to object if there 392 /// is no class of the matching name. 393 void EmitClassRef(const std::string &className); 394 /// Emits a pointer to the named class 395 llvm::Value *GetClassNamed(CGBuilderTy &Builder, const std::string &Name, 396 bool isWeak); 397protected: 398 /// Looks up the method for sending a message to the specified object. This 399 /// mechanism differs between the GCC and GNU runtimes, so this method must be 400 /// overridden in subclasses. 401 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 402 llvm::Value *&Receiver, 403 llvm::Value *cmd, 404 llvm::MDNode *node) = 0; 405 /// Looks up the method for sending a message to a superclass. This mechanism 406 /// differs between the GCC and GNU runtimes, so this method must be 407 /// overridden in subclasses. 408 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 409 llvm::Value *ObjCSuper, 410 llvm::Value *cmd) = 0; 411public: 412 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 413 unsigned protocolClassVersion); 414 415 virtual llvm::Constant *GenerateConstantString(const StringLiteral *); 416 417 virtual RValue 418 GenerateMessageSend(CodeGenFunction &CGF, 419 ReturnValueSlot Return, 420 QualType ResultType, 421 Selector Sel, 422 llvm::Value *Receiver, 423 const CallArgList &CallArgs, 424 const ObjCInterfaceDecl *Class, 425 const ObjCMethodDecl *Method); 426 virtual RValue 427 GenerateMessageSendSuper(CodeGenFunction &CGF, 428 ReturnValueSlot Return, 429 QualType ResultType, 430 Selector Sel, 431 const ObjCInterfaceDecl *Class, 432 bool isCategoryImpl, 433 llvm::Value *Receiver, 434 bool IsClassMessage, 435 const CallArgList &CallArgs, 436 const ObjCMethodDecl *Method); 437 virtual llvm::Value *GetClass(CGBuilderTy &Builder, 438 const ObjCInterfaceDecl *OID); 439 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 440 bool lval = false); 441 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 442 *Method); 443 virtual llvm::Constant *GetEHType(QualType T); 444 445 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 446 const ObjCContainerDecl *CD); 447 virtual void GenerateCategory(const ObjCCategoryImplDecl *CMD); 448 virtual void GenerateClass(const ObjCImplementationDecl *ClassDecl); 449 virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder, 450 const ObjCProtocolDecl *PD); 451 virtual void GenerateProtocol(const ObjCProtocolDecl *PD); 452 virtual llvm::Function *ModuleInitFunction(); 453 virtual llvm::Constant *GetPropertyGetFunction(); 454 virtual llvm::Constant *GetPropertySetFunction(); 455 virtual llvm::Constant *GetSetStructFunction(); 456 virtual llvm::Constant *GetGetStructFunction(); 457 virtual llvm::Constant *EnumerationMutationFunction(); 458 459 virtual void EmitTryStmt(CodeGenFunction &CGF, 460 const ObjCAtTryStmt &S); 461 virtual void EmitSynchronizedStmt(CodeGenFunction &CGF, 462 const ObjCAtSynchronizedStmt &S); 463 virtual void EmitThrowStmt(CodeGenFunction &CGF, 464 const ObjCAtThrowStmt &S); 465 virtual llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF, 466 llvm::Value *AddrWeakObj); 467 virtual void EmitObjCWeakAssign(CodeGenFunction &CGF, 468 llvm::Value *src, llvm::Value *dst); 469 virtual void EmitObjCGlobalAssign(CodeGenFunction &CGF, 470 llvm::Value *src, llvm::Value *dest, 471 bool threadlocal=false); 472 virtual void EmitObjCIvarAssign(CodeGenFunction &CGF, 473 llvm::Value *src, llvm::Value *dest, 474 llvm::Value *ivarOffset); 475 virtual void EmitObjCStrongCastAssign(CodeGenFunction &CGF, 476 llvm::Value *src, llvm::Value *dest); 477 virtual void EmitGCMemmoveCollectable(CodeGenFunction &CGF, 478 llvm::Value *DestPtr, 479 llvm::Value *SrcPtr, 480 llvm::Value *Size); 481 virtual LValue EmitObjCValueForIvar(CodeGenFunction &CGF, 482 QualType ObjectTy, 483 llvm::Value *BaseValue, 484 const ObjCIvarDecl *Ivar, 485 unsigned CVRQualifiers); 486 virtual llvm::Value *EmitIvarOffset(CodeGenFunction &CGF, 487 const ObjCInterfaceDecl *Interface, 488 const ObjCIvarDecl *Ivar); 489 virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CGBuilderTy &Builder); 490 virtual llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM, 491 const CGBlockInfo &blockInfo) { 492 return NULLPtr; 493 } 494 495 virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) { 496 return 0; 497 } 498}; 499/// Class representing the legacy GCC Objective-C ABI. This is the default when 500/// -fobjc-nonfragile-abi is not specified. 501/// 502/// The GCC ABI target actually generates code that is approximately compatible 503/// with the new GNUstep runtime ABI, but refrains from using any features that 504/// would not work with the GCC runtime. For example, clang always generates 505/// the extended form of the class structure, and the extra fields are simply 506/// ignored by GCC libobjc. 507class CGObjCGCC : public CGObjCGNU { 508 /// The GCC ABI message lookup function. Returns an IMP pointing to the 509 /// method implementation for this message. 510 LazyRuntimeFunction MsgLookupFn; 511 /// The GCC ABI superclass message lookup function. Takes a pointer to a 512 /// structure describing the receiver and the class, and a selector as 513 /// arguments. Returns the IMP for the corresponding method. 514 LazyRuntimeFunction MsgLookupSuperFn; 515protected: 516 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 517 llvm::Value *&Receiver, 518 llvm::Value *cmd, 519 llvm::MDNode *node) { 520 CGBuilderTy &Builder = CGF.Builder; 521 llvm::Value *imp = Builder.CreateCall2(MsgLookupFn, 522 EnforceType(Builder, Receiver, IdTy), 523 EnforceType(Builder, cmd, SelectorTy)); 524 cast<llvm::CallInst>(imp)->setMetadata(msgSendMDKind, node); 525 return imp; 526 } 527 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 528 llvm::Value *ObjCSuper, 529 llvm::Value *cmd) { 530 CGBuilderTy &Builder = CGF.Builder; 531 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 532 PtrToObjCSuperTy), cmd}; 533 return Builder.CreateCall(MsgLookupSuperFn, lookupArgs); 534 } 535 public: 536 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) { 537 // IMP objc_msg_lookup(id, SEL); 538 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 539 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 540 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 541 PtrToObjCSuperTy, SelectorTy, NULL); 542 } 543}; 544/// Class used when targeting the new GNUstep runtime ABI. 545class CGObjCGNUstep : public CGObjCGNU { 546 /// The slot lookup function. Returns a pointer to a cacheable structure 547 /// that contains (among other things) the IMP. 548 LazyRuntimeFunction SlotLookupFn; 549 /// The GNUstep ABI superclass message lookup function. Takes a pointer to 550 /// a structure describing the receiver and the class, and a selector as 551 /// arguments. Returns the slot for the corresponding method. Superclass 552 /// message lookup rarely changes, so this is a good caching opportunity. 553 LazyRuntimeFunction SlotLookupSuperFn; 554 /// Type of an slot structure pointer. This is returned by the various 555 /// lookup functions. 556 llvm::Type *SlotTy; 557 protected: 558 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 559 llvm::Value *&Receiver, 560 llvm::Value *cmd, 561 llvm::MDNode *node) { 562 CGBuilderTy &Builder = CGF.Builder; 563 llvm::Function *LookupFn = SlotLookupFn; 564 565 // Store the receiver on the stack so that we can reload it later 566 llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType()); 567 Builder.CreateStore(Receiver, ReceiverPtr); 568 569 llvm::Value *self; 570 571 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) { 572 self = CGF.LoadObjCSelf(); 573 } else { 574 self = llvm::ConstantPointerNull::get(IdTy); 575 } 576 577 // The lookup function is guaranteed not to capture the receiver pointer. 578 LookupFn->setDoesNotCapture(1); 579 580 llvm::CallInst *slot = 581 Builder.CreateCall3(LookupFn, 582 EnforceType(Builder, ReceiverPtr, PtrToIdTy), 583 EnforceType(Builder, cmd, SelectorTy), 584 EnforceType(Builder, self, IdTy)); 585 slot->setOnlyReadsMemory(); 586 slot->setMetadata(msgSendMDKind, node); 587 588 // Load the imp from the slot 589 llvm::Value *imp = Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 590 591 // The lookup function may have changed the receiver, so make sure we use 592 // the new one. 593 Receiver = Builder.CreateLoad(ReceiverPtr, true); 594 return imp; 595 } 596 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 597 llvm::Value *ObjCSuper, 598 llvm::Value *cmd) { 599 CGBuilderTy &Builder = CGF.Builder; 600 llvm::Value *lookupArgs[] = {ObjCSuper, cmd}; 601 602 llvm::CallInst *slot = Builder.CreateCall(SlotLookupSuperFn, lookupArgs); 603 slot->setOnlyReadsMemory(); 604 605 return Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 606 } 607 public: 608 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) { 609 llvm::StructType *SlotStructTy = llvm::StructType::get(PtrTy, 610 PtrTy, PtrTy, IntTy, IMPTy, NULL); 611 SlotTy = llvm::PointerType::getUnqual(SlotStructTy); 612 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 613 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy, 614 SelectorTy, IdTy, NULL); 615 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL); 616 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy, 617 PtrToObjCSuperTy, SelectorTy, NULL); 618 // If we're in ObjC++ mode, then we want to make 619 if (CGM.getLangOptions().CPlusPlus) { 620 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 621 // void *__cxa_begin_catch(void *e) 622 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, NULL); 623 // void __cxa_end_catch(void) 624 EnterCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, NULL); 625 // void _Unwind_Resume_or_Rethrow(void*) 626 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, PtrTy, NULL); 627 } 628 } 629}; 630 631} // end anonymous namespace 632 633 634/// Emits a reference to a dummy variable which is emitted with each class. 635/// This ensures that a linker error will be generated when trying to link 636/// together modules where a referenced class is not defined. 637void CGObjCGNU::EmitClassRef(const std::string &className) { 638 std::string symbolRef = "__objc_class_ref_" + className; 639 // Don't emit two copies of the same symbol 640 if (TheModule.getGlobalVariable(symbolRef)) 641 return; 642 std::string symbolName = "__objc_class_name_" + className; 643 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName); 644 if (!ClassSymbol) { 645 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 646 llvm::GlobalValue::ExternalLinkage, 0, symbolName); 647 } 648 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true, 649 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef); 650} 651 652static std::string SymbolNameForMethod(const StringRef &ClassName, 653 const StringRef &CategoryName, const Selector MethodName, 654 bool isClassMethod) { 655 std::string MethodNameColonStripped = MethodName.getAsString(); 656 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(), 657 ':', '_'); 658 return (Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" + 659 CategoryName + "_" + MethodNameColonStripped).str(); 660} 661 662CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 663 unsigned protocolClassVersion) 664 : CGM(cgm), TheModule(CGM.getModule()), VMContext(cgm.getLLVMContext()), 665 ClassPtrAlias(0), MetaClassPtrAlias(0), RuntimeVersion(runtimeABIVersion), 666 ProtocolVersion(protocolClassVersion) { 667 668 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend"); 669 670 CodeGenTypes &Types = CGM.getTypes(); 671 IntTy = cast<llvm::IntegerType>( 672 Types.ConvertType(CGM.getContext().IntTy)); 673 LongTy = cast<llvm::IntegerType>( 674 Types.ConvertType(CGM.getContext().LongTy)); 675 SizeTy = cast<llvm::IntegerType>( 676 Types.ConvertType(CGM.getContext().getSizeType())); 677 PtrDiffTy = cast<llvm::IntegerType>( 678 Types.ConvertType(CGM.getContext().getPointerDiffType())); 679 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy); 680 681 Int8Ty = llvm::Type::getInt8Ty(VMContext); 682 // C string type. Used in lots of places. 683 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); 684 685 Zeros[0] = llvm::ConstantInt::get(LongTy, 0); 686 Zeros[1] = Zeros[0]; 687 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty); 688 // Get the selector Type. 689 QualType selTy = CGM.getContext().getObjCSelType(); 690 if (QualType() == selTy) { 691 SelectorTy = PtrToInt8Ty; 692 } else { 693 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy)); 694 } 695 696 PtrToIntTy = llvm::PointerType::getUnqual(IntTy); 697 PtrTy = PtrToInt8Ty; 698 699 // Object type 700 QualType UnqualIdTy = CGM.getContext().getObjCIdType(); 701 ASTIdTy = CanQualType(); 702 if (UnqualIdTy != QualType()) { 703 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy); 704 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 705 } else { 706 IdTy = PtrToInt8Ty; 707 } 708 PtrToIdTy = llvm::PointerType::getUnqual(IdTy); 709 710 ObjCSuperTy = llvm::StructType::get(IdTy, IdTy, NULL); 711 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy); 712 713 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 714 715 // void objc_exception_throw(id); 716 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 717 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 718 // int objc_sync_enter(id); 719 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, NULL); 720 // int objc_sync_exit(id); 721 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, NULL); 722 723 // void objc_enumerationMutation (id) 724 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, 725 IdTy, NULL); 726 727 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL) 728 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy, 729 PtrDiffTy, BoolTy, NULL); 730 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL) 731 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy, 732 PtrDiffTy, IdTy, BoolTy, BoolTy, NULL); 733 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 734 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy, 735 PtrDiffTy, BoolTy, BoolTy, NULL); 736 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 737 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy, 738 PtrDiffTy, BoolTy, BoolTy, NULL); 739 740 // IMP type 741 llvm::Type *IMPArgs[] = { IdTy, SelectorTy }; 742 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs, 743 true)); 744 745 const LangOptions &Opts = CGM.getLangOptions(); 746 if ((Opts.getGCMode() != LangOptions::NonGC) || Opts.ObjCAutoRefCount) 747 RuntimeVersion = 10; 748 749 // Don't bother initialising the GC stuff unless we're compiling in GC mode 750 if (Opts.getGCMode() != LangOptions::NonGC) { 751 // This is a bit of an hack. We should sort this out by having a proper 752 // CGObjCGNUstep subclass for GC, but we may want to really support the old 753 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now 754 // Get selectors needed in GC mode 755 RetainSel = GetNullarySelector("retain", CGM.getContext()); 756 ReleaseSel = GetNullarySelector("release", CGM.getContext()); 757 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext()); 758 759 // Get functions needed in GC mode 760 761 // id objc_assign_ivar(id, id, ptrdiff_t); 762 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy, 763 NULL); 764 // id objc_assign_strongCast (id, id*) 765 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy, 766 PtrToIdTy, NULL); 767 // id objc_assign_global(id, id*); 768 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy, 769 NULL); 770 // id objc_assign_weak(id, id*); 771 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, NULL); 772 // id objc_read_weak(id*); 773 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, NULL); 774 // void *objc_memmove_collectable(void*, void *, size_t); 775 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy, 776 SizeTy, NULL); 777 } 778} 779 780llvm::Value *CGObjCGNU::GetClassNamed(CGBuilderTy &Builder, 781 const std::string &Name, 782 bool isWeak) { 783 llvm::Value *ClassName = CGM.GetAddrOfConstantCString(Name); 784 // With the incompatible ABI, this will need to be replaced with a direct 785 // reference to the class symbol. For the compatible nonfragile ABI we are 786 // still performing this lookup at run time but emitting the symbol for the 787 // class externally so that we can make the switch later. 788 // 789 // Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class 790 // with memoized versions or with static references if it's safe to do so. 791 if (!isWeak) 792 EmitClassRef(Name); 793 ClassName = Builder.CreateStructGEP(ClassName, 0); 794 795 llvm::Constant *ClassLookupFn = 796 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true), 797 "objc_lookup_class"); 798 return Builder.CreateCall(ClassLookupFn, ClassName); 799} 800 801// This has to perform the lookup every time, since posing and related 802// techniques can modify the name -> class mapping. 803llvm::Value *CGObjCGNU::GetClass(CGBuilderTy &Builder, 804 const ObjCInterfaceDecl *OID) { 805 return GetClassNamed(Builder, OID->getNameAsString(), OID->isWeakImported()); 806} 807llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CGBuilderTy &Builder) { 808 return GetClassNamed(Builder, "NSAutoreleasePool", false); 809} 810 811llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 812 const std::string &TypeEncoding, bool lval) { 813 814 SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel]; 815 llvm::GlobalAlias *SelValue = 0; 816 817 818 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 819 e = Types.end() ; i!=e ; i++) { 820 if (i->first == TypeEncoding) { 821 SelValue = i->second; 822 break; 823 } 824 } 825 if (0 == SelValue) { 826 SelValue = new llvm::GlobalAlias(SelectorTy, 827 llvm::GlobalValue::PrivateLinkage, 828 ".objc_selector_"+Sel.getAsString(), NULL, 829 &TheModule); 830 Types.push_back(TypedSelector(TypeEncoding, SelValue)); 831 } 832 833 if (lval) { 834 llvm::Value *tmp = Builder.CreateAlloca(SelValue->getType()); 835 Builder.CreateStore(SelValue, tmp); 836 return tmp; 837 } 838 return SelValue; 839} 840 841llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 842 bool lval) { 843 return GetSelector(Builder, Sel, std::string(), lval); 844} 845 846llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 847 *Method) { 848 std::string SelTypes; 849 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes); 850 return GetSelector(Builder, Method->getSelector(), SelTypes, false); 851} 852 853llvm::Constant *CGObjCGNU::GetEHType(QualType T) { 854 if (!CGM.getLangOptions().CPlusPlus) { 855 if (T->isObjCIdType() 856 || T->isObjCQualifiedIdType()) { 857 // With the old ABI, there was only one kind of catchall, which broke 858 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as 859 // a pointer indicating object catchalls, and NULL to indicate real 860 // catchalls 861 if (CGM.getLangOptions().ObjCNonFragileABI) { 862 return MakeConstantString("@id"); 863 } else { 864 return 0; 865 } 866 } 867 868 // All other types should be Objective-C interface pointer types. 869 const ObjCObjectPointerType *OPT = 870 T->getAs<ObjCObjectPointerType>(); 871 assert(OPT && "Invalid @catch type."); 872 const ObjCInterfaceDecl *IDecl = 873 OPT->getObjectType()->getInterface(); 874 assert(IDecl && "Invalid @catch type."); 875 return MakeConstantString(IDecl->getIdentifier()->getName()); 876 } 877 // For Objective-C++, we want to provide the ability to catch both C++ and 878 // Objective-C objects in the same function. 879 880 // There's a particular fixed type info for 'id'. 881 if (T->isObjCIdType() || 882 T->isObjCQualifiedIdType()) { 883 llvm::Constant *IDEHType = 884 CGM.getModule().getGlobalVariable("__objc_id_type_info"); 885 if (!IDEHType) 886 IDEHType = 887 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty, 888 false, 889 llvm::GlobalValue::ExternalLinkage, 890 0, "__objc_id_type_info"); 891 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty); 892 } 893 894 const ObjCObjectPointerType *PT = 895 T->getAs<ObjCObjectPointerType>(); 896 assert(PT && "Invalid @catch type."); 897 const ObjCInterfaceType *IT = PT->getInterfaceType(); 898 assert(IT && "Invalid @catch type."); 899 std::string className = IT->getDecl()->getIdentifier()->getName(); 900 901 std::string typeinfoName = "__objc_eh_typeinfo_" + className; 902 903 // Return the existing typeinfo if it exists 904 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName); 905 if (typeinfo) return typeinfo; 906 907 // Otherwise create it. 908 909 // vtable for gnustep::libobjc::__objc_class_type_info 910 // It's quite ugly hard-coding this. Ideally we'd generate it using the host 911 // platform's name mangling. 912 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE"; 913 llvm::Constant *Vtable = TheModule.getGlobalVariable(vtableName); 914 if (!Vtable) { 915 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true, 916 llvm::GlobalValue::ExternalLinkage, 0, vtableName); 917 } 918 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2); 919 Vtable = llvm::ConstantExpr::getGetElementPtr(Vtable, Two); 920 Vtable = llvm::ConstantExpr::getBitCast(Vtable, PtrToInt8Ty); 921 922 llvm::Constant *typeName = 923 ExportUniqueString(className, "__objc_eh_typename_"); 924 925 std::vector<llvm::Constant*> fields; 926 fields.push_back(Vtable); 927 fields.push_back(typeName); 928 llvm::Constant *TI = 929 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 930 NULL), fields, "__objc_eh_typeinfo_" + className, 931 llvm::GlobalValue::LinkOnceODRLinkage); 932 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty); 933} 934 935/// Generate an NSConstantString object. 936llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) { 937 938 std::string Str = SL->getString().str(); 939 940 // Look for an existing one 941 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str); 942 if (old != ObjCStrings.end()) 943 return old->getValue(); 944 945 std::vector<llvm::Constant*> Ivars; 946 Ivars.push_back(NULLPtr); 947 Ivars.push_back(MakeConstantString(Str)); 948 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size())); 949 llvm::Constant *ObjCStr = MakeGlobal( 950 llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, IntTy, NULL), 951 Ivars, ".objc_str"); 952 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty); 953 ObjCStrings[Str] = ObjCStr; 954 ConstantStrings.push_back(ObjCStr); 955 return ObjCStr; 956} 957 958///Generates a message send where the super is the receiver. This is a message 959///send to self with special delivery semantics indicating which class's method 960///should be called. 961RValue 962CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF, 963 ReturnValueSlot Return, 964 QualType ResultType, 965 Selector Sel, 966 const ObjCInterfaceDecl *Class, 967 bool isCategoryImpl, 968 llvm::Value *Receiver, 969 bool IsClassMessage, 970 const CallArgList &CallArgs, 971 const ObjCMethodDecl *Method) { 972 CGBuilderTy &Builder = CGF.Builder; 973 if (CGM.getLangOptions().getGCMode() == LangOptions::GCOnly) { 974 if (Sel == RetainSel || Sel == AutoreleaseSel) { 975 return RValue::get(EnforceType(Builder, Receiver, 976 CGM.getTypes().ConvertType(ResultType))); 977 } 978 if (Sel == ReleaseSel) { 979 return RValue::get(0); 980 } 981 } 982 983 llvm::Value *cmd = GetSelector(Builder, Sel); 984 985 986 CallArgList ActualArgs; 987 988 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy); 989 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 990 ActualArgs.addFrom(CallArgs); 991 992 CodeGenTypes &Types = CGM.getTypes(); 993 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 994 FunctionType::ExtInfo()); 995 996 llvm::Value *ReceiverClass = 0; 997 if (isCategoryImpl) { 998 llvm::Constant *classLookupFunction = 0; 999 if (IsClassMessage) { 1000 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1001 IdTy, PtrTy, true), "objc_get_meta_class"); 1002 } else { 1003 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1004 IdTy, PtrTy, true), "objc_get_class"); 1005 } 1006 ReceiverClass = Builder.CreateCall(classLookupFunction, 1007 MakeConstantString(Class->getNameAsString())); 1008 } else { 1009 // Set up global aliases for the metaclass or class pointer if they do not 1010 // already exist. These will are forward-references which will be set to 1011 // pointers to the class and metaclass structure created for the runtime 1012 // load function. To send a message to super, we look up the value of the 1013 // super_class pointer from either the class or metaclass structure. 1014 if (IsClassMessage) { 1015 if (!MetaClassPtrAlias) { 1016 MetaClassPtrAlias = new llvm::GlobalAlias(IdTy, 1017 llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" + 1018 Class->getNameAsString(), NULL, &TheModule); 1019 } 1020 ReceiverClass = MetaClassPtrAlias; 1021 } else { 1022 if (!ClassPtrAlias) { 1023 ClassPtrAlias = new llvm::GlobalAlias(IdTy, 1024 llvm::GlobalValue::InternalLinkage, ".objc_class_ref" + 1025 Class->getNameAsString(), NULL, &TheModule); 1026 } 1027 ReceiverClass = ClassPtrAlias; 1028 } 1029 } 1030 // Cast the pointer to a simplified version of the class structure 1031 ReceiverClass = Builder.CreateBitCast(ReceiverClass, 1032 llvm::PointerType::getUnqual( 1033 llvm::StructType::get(IdTy, IdTy, NULL))); 1034 // Get the superclass pointer 1035 ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1); 1036 // Load the superclass pointer 1037 ReceiverClass = Builder.CreateLoad(ReceiverClass); 1038 // Construct the structure used to look up the IMP 1039 llvm::StructType *ObjCSuperTy = llvm::StructType::get( 1040 Receiver->getType(), IdTy, NULL); 1041 llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy); 1042 1043 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0)); 1044 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1)); 1045 1046 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy); 1047 llvm::FunctionType *impType = 1048 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1049 1050 // Get the IMP 1051 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd); 1052 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1053 1054 llvm::Value *impMD[] = { 1055 llvm::MDString::get(VMContext, Sel.getAsString()), 1056 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()), 1057 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage) 1058 }; 1059 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1060 1061 llvm::Instruction *call; 1062 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1063 0, &call); 1064 call->setMetadata(msgSendMDKind, node); 1065 return msgRet; 1066} 1067 1068/// Generate code for a message send expression. 1069RValue 1070CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF, 1071 ReturnValueSlot Return, 1072 QualType ResultType, 1073 Selector Sel, 1074 llvm::Value *Receiver, 1075 const CallArgList &CallArgs, 1076 const ObjCInterfaceDecl *Class, 1077 const ObjCMethodDecl *Method) { 1078 CGBuilderTy &Builder = CGF.Builder; 1079 1080 // Strip out message sends to retain / release in GC mode 1081 if (CGM.getLangOptions().getGCMode() == LangOptions::GCOnly) { 1082 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1083 return RValue::get(EnforceType(Builder, Receiver, 1084 CGM.getTypes().ConvertType(ResultType))); 1085 } 1086 if (Sel == ReleaseSel) { 1087 return RValue::get(0); 1088 } 1089 } 1090 1091 // If the return type is something that goes in an integer register, the 1092 // runtime will handle 0 returns. For other cases, we fill in the 0 value 1093 // ourselves. 1094 // 1095 // The language spec says the result of this kind of message send is 1096 // undefined, but lots of people seem to have forgotten to read that 1097 // paragraph and insist on sending messages to nil that have structure 1098 // returns. With GCC, this generates a random return value (whatever happens 1099 // to be on the stack / in those registers at the time) on most platforms, 1100 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts 1101 // the stack. 1102 bool isPointerSizedReturn = (ResultType->isAnyPointerType() || 1103 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType()); 1104 1105 llvm::BasicBlock *startBB = 0; 1106 llvm::BasicBlock *messageBB = 0; 1107 llvm::BasicBlock *continueBB = 0; 1108 1109 if (!isPointerSizedReturn) { 1110 startBB = Builder.GetInsertBlock(); 1111 messageBB = CGF.createBasicBlock("msgSend"); 1112 continueBB = CGF.createBasicBlock("continue"); 1113 1114 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver, 1115 llvm::Constant::getNullValue(Receiver->getType())); 1116 Builder.CreateCondBr(isNil, continueBB, messageBB); 1117 CGF.EmitBlock(messageBB); 1118 } 1119 1120 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 1121 llvm::Value *cmd; 1122 if (Method) 1123 cmd = GetSelector(Builder, Method); 1124 else 1125 cmd = GetSelector(Builder, Sel); 1126 cmd = EnforceType(Builder, cmd, SelectorTy); 1127 Receiver = EnforceType(Builder, Receiver, IdTy); 1128 1129 llvm::Value *impMD[] = { 1130 llvm::MDString::get(VMContext, Sel.getAsString()), 1131 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""), 1132 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0) 1133 }; 1134 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1135 1136 // Get the IMP to call 1137 llvm::Value *imp = LookupIMP(CGF, Receiver, cmd, node); 1138 1139 CallArgList ActualArgs; 1140 ActualArgs.add(RValue::get(Receiver), ASTIdTy); 1141 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1142 ActualArgs.addFrom(CallArgs); 1143 1144 CodeGenTypes &Types = CGM.getTypes(); 1145 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 1146 FunctionType::ExtInfo()); 1147 llvm::FunctionType *impType = 1148 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1149 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1150 1151 1152 // For sender-aware dispatch, we pass the sender as the third argument to a 1153 // lookup function. When sending messages from C code, the sender is nil. 1154 // objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 1155 llvm::Instruction *call; 1156 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1157 0, &call); 1158 call->setMetadata(msgSendMDKind, node); 1159 1160 1161 if (!isPointerSizedReturn) { 1162 messageBB = CGF.Builder.GetInsertBlock(); 1163 CGF.Builder.CreateBr(continueBB); 1164 CGF.EmitBlock(continueBB); 1165 if (msgRet.isScalar()) { 1166 llvm::Value *v = msgRet.getScalarVal(); 1167 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1168 phi->addIncoming(v, messageBB); 1169 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB); 1170 msgRet = RValue::get(phi); 1171 } else if (msgRet.isAggregate()) { 1172 llvm::Value *v = msgRet.getAggregateAddr(); 1173 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1174 llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType()); 1175 llvm::AllocaInst *NullVal = 1176 CGF.CreateTempAlloca(RetTy->getElementType(), "null"); 1177 CGF.InitTempAlloca(NullVal, 1178 llvm::Constant::getNullValue(RetTy->getElementType())); 1179 phi->addIncoming(v, messageBB); 1180 phi->addIncoming(NullVal, startBB); 1181 msgRet = RValue::getAggregate(phi); 1182 } else /* isComplex() */ { 1183 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal(); 1184 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2); 1185 phi->addIncoming(v.first, messageBB); 1186 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()), 1187 startBB); 1188 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2); 1189 phi2->addIncoming(v.second, messageBB); 1190 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()), 1191 startBB); 1192 msgRet = RValue::getComplex(phi, phi2); 1193 } 1194 } 1195 return msgRet; 1196} 1197 1198/// Generates a MethodList. Used in construction of a objc_class and 1199/// objc_category structures. 1200llvm::Constant *CGObjCGNU::GenerateMethodList(const StringRef &ClassName, 1201 const StringRef &CategoryName, 1202 const SmallVectorImpl<Selector> &MethodSels, 1203 const SmallVectorImpl<llvm::Constant *> &MethodTypes, 1204 bool isClassMethodList) { 1205 if (MethodSels.empty()) 1206 return NULLPtr; 1207 // Get the method structure type. 1208 llvm::StructType *ObjCMethodTy = llvm::StructType::get( 1209 PtrToInt8Ty, // Really a selector, but the runtime creates it us. 1210 PtrToInt8Ty, // Method types 1211 IMPTy, //Method pointer 1212 NULL); 1213 std::vector<llvm::Constant*> Methods; 1214 std::vector<llvm::Constant*> Elements; 1215 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) { 1216 Elements.clear(); 1217 llvm::Constant *Method = 1218 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName, 1219 MethodSels[i], 1220 isClassMethodList)); 1221 assert(Method && "Can't generate metadata for method that doesn't exist"); 1222 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString()); 1223 Elements.push_back(C); 1224 Elements.push_back(MethodTypes[i]); 1225 Method = llvm::ConstantExpr::getBitCast(Method, 1226 IMPTy); 1227 Elements.push_back(Method); 1228 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements)); 1229 } 1230 1231 // Array of method structures 1232 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy, 1233 Methods.size()); 1234 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy, 1235 Methods); 1236 1237 // Structure containing list pointer, array and array count 1238 llvm::StructType *ObjCMethodListTy = 1239 llvm::StructType::createNamed(VMContext, ""); 1240 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(ObjCMethodListTy); 1241 ObjCMethodListTy->setBody( 1242 NextPtrTy, 1243 IntTy, 1244 ObjCMethodArrayTy, 1245 NULL); 1246 1247 Methods.clear(); 1248 Methods.push_back(llvm::ConstantPointerNull::get( 1249 llvm::PointerType::getUnqual(ObjCMethodListTy))); 1250 Methods.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1251 MethodTypes.size())); 1252 Methods.push_back(MethodArray); 1253 1254 // Create an instance of the structure 1255 return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list"); 1256} 1257 1258/// Generates an IvarList. Used in construction of a objc_class. 1259llvm::Constant *CGObjCGNU::GenerateIvarList( 1260 const SmallVectorImpl<llvm::Constant *> &IvarNames, 1261 const SmallVectorImpl<llvm::Constant *> &IvarTypes, 1262 const SmallVectorImpl<llvm::Constant *> &IvarOffsets) { 1263 if (IvarNames.size() == 0) 1264 return NULLPtr; 1265 // Get the method structure type. 1266 llvm::StructType *ObjCIvarTy = llvm::StructType::get( 1267 PtrToInt8Ty, 1268 PtrToInt8Ty, 1269 IntTy, 1270 NULL); 1271 std::vector<llvm::Constant*> Ivars; 1272 std::vector<llvm::Constant*> Elements; 1273 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) { 1274 Elements.clear(); 1275 Elements.push_back(IvarNames[i]); 1276 Elements.push_back(IvarTypes[i]); 1277 Elements.push_back(IvarOffsets[i]); 1278 Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements)); 1279 } 1280 1281 // Array of method structures 1282 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy, 1283 IvarNames.size()); 1284 1285 1286 Elements.clear(); 1287 Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size())); 1288 Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)); 1289 // Structure containing array and array count 1290 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(IntTy, 1291 ObjCIvarArrayTy, 1292 NULL); 1293 1294 // Create an instance of the structure 1295 return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list"); 1296} 1297 1298/// Generate a class structure 1299llvm::Constant *CGObjCGNU::GenerateClassStructure( 1300 llvm::Constant *MetaClass, 1301 llvm::Constant *SuperClass, 1302 unsigned info, 1303 const char *Name, 1304 llvm::Constant *Version, 1305 llvm::Constant *InstanceSize, 1306 llvm::Constant *IVars, 1307 llvm::Constant *Methods, 1308 llvm::Constant *Protocols, 1309 llvm::Constant *IvarOffsets, 1310 llvm::Constant *Properties, 1311 bool isMeta) { 1312 // Set up the class structure 1313 // Note: Several of these are char*s when they should be ids. This is 1314 // because the runtime performs this translation on load. 1315 // 1316 // Fields marked New ABI are part of the GNUstep runtime. We emit them 1317 // anyway; the classes will still work with the GNU runtime, they will just 1318 // be ignored. 1319 llvm::StructType *ClassTy = llvm::StructType::get( 1320 PtrToInt8Ty, // class_pointer 1321 PtrToInt8Ty, // super_class 1322 PtrToInt8Ty, // name 1323 LongTy, // version 1324 LongTy, // info 1325 LongTy, // instance_size 1326 IVars->getType(), // ivars 1327 Methods->getType(), // methods 1328 // These are all filled in by the runtime, so we pretend 1329 PtrTy, // dtable 1330 PtrTy, // subclass_list 1331 PtrTy, // sibling_class 1332 PtrTy, // protocols 1333 PtrTy, // gc_object_type 1334 // New ABI: 1335 LongTy, // abi_version 1336 IvarOffsets->getType(), // ivar_offsets 1337 Properties->getType(), // properties 1338 NULL); 1339 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0); 1340 // Fill in the structure 1341 std::vector<llvm::Constant*> Elements; 1342 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty)); 1343 Elements.push_back(SuperClass); 1344 Elements.push_back(MakeConstantString(Name, ".class_name")); 1345 Elements.push_back(Zero); 1346 Elements.push_back(llvm::ConstantInt::get(LongTy, info)); 1347 if (isMeta) { 1348 llvm::TargetData td(&TheModule); 1349 Elements.push_back( 1350 llvm::ConstantInt::get(LongTy, 1351 td.getTypeSizeInBits(ClassTy) / 1352 CGM.getContext().getCharWidth())); 1353 } else 1354 Elements.push_back(InstanceSize); 1355 Elements.push_back(IVars); 1356 Elements.push_back(Methods); 1357 Elements.push_back(NULLPtr); 1358 Elements.push_back(NULLPtr); 1359 Elements.push_back(NULLPtr); 1360 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy)); 1361 Elements.push_back(NULLPtr); 1362 Elements.push_back(Zero); 1363 Elements.push_back(IvarOffsets); 1364 Elements.push_back(Properties); 1365 // Create an instance of the structure 1366 // This is now an externally visible symbol, so that we can speed up class 1367 // messages in the next ABI. 1368 return MakeGlobal(ClassTy, Elements, (isMeta ? "_OBJC_METACLASS_": 1369 "_OBJC_CLASS_") + std::string(Name), llvm::GlobalValue::ExternalLinkage); 1370} 1371 1372llvm::Constant *CGObjCGNU::GenerateProtocolMethodList( 1373 const SmallVectorImpl<llvm::Constant *> &MethodNames, 1374 const SmallVectorImpl<llvm::Constant *> &MethodTypes) { 1375 // Get the method structure type. 1376 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get( 1377 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us. 1378 PtrToInt8Ty, 1379 NULL); 1380 std::vector<llvm::Constant*> Methods; 1381 std::vector<llvm::Constant*> Elements; 1382 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) { 1383 Elements.clear(); 1384 Elements.push_back(MethodNames[i]); 1385 Elements.push_back(MethodTypes[i]); 1386 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements)); 1387 } 1388 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy, 1389 MethodNames.size()); 1390 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy, 1391 Methods); 1392 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get( 1393 IntTy, ObjCMethodArrayTy, NULL); 1394 Methods.clear(); 1395 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size())); 1396 Methods.push_back(Array); 1397 return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list"); 1398} 1399 1400// Create the protocol list structure used in classes, categories and so on 1401llvm::Constant *CGObjCGNU::GenerateProtocolList( 1402 const SmallVectorImpl<std::string> &Protocols) { 1403 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 1404 Protocols.size()); 1405 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1406 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1407 SizeTy, 1408 ProtocolArrayTy, 1409 NULL); 1410 std::vector<llvm::Constant*> Elements; 1411 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end(); 1412 iter != endIter ; iter++) { 1413 llvm::Constant *protocol = 0; 1414 llvm::StringMap<llvm::Constant*>::iterator value = 1415 ExistingProtocols.find(*iter); 1416 if (value == ExistingProtocols.end()) { 1417 protocol = GenerateEmptyProtocol(*iter); 1418 } else { 1419 protocol = value->getValue(); 1420 } 1421 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol, 1422 PtrToInt8Ty); 1423 Elements.push_back(Ptr); 1424 } 1425 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1426 Elements); 1427 Elements.clear(); 1428 Elements.push_back(NULLPtr); 1429 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size())); 1430 Elements.push_back(ProtocolArray); 1431 return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list"); 1432} 1433 1434llvm::Value *CGObjCGNU::GenerateProtocolRef(CGBuilderTy &Builder, 1435 const ObjCProtocolDecl *PD) { 1436 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()]; 1437 llvm::Type *T = 1438 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType()); 1439 return Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T)); 1440} 1441 1442llvm::Constant *CGObjCGNU::GenerateEmptyProtocol( 1443 const std::string &ProtocolName) { 1444 SmallVector<std::string, 0> EmptyStringVector; 1445 SmallVector<llvm::Constant*, 0> EmptyConstantVector; 1446 1447 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector); 1448 llvm::Constant *MethodList = 1449 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector); 1450 // Protocols are objects containing lists of the methods implemented and 1451 // protocols adopted. 1452 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1453 PtrToInt8Ty, 1454 ProtocolList->getType(), 1455 MethodList->getType(), 1456 MethodList->getType(), 1457 MethodList->getType(), 1458 MethodList->getType(), 1459 NULL); 1460 std::vector<llvm::Constant*> Elements; 1461 // The isa pointer must be set to a magic number so the runtime knows it's 1462 // the correct layout. 1463 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1464 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1465 ProtocolVersion), IdTy)); 1466 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1467 Elements.push_back(ProtocolList); 1468 Elements.push_back(MethodList); 1469 Elements.push_back(MethodList); 1470 Elements.push_back(MethodList); 1471 Elements.push_back(MethodList); 1472 return MakeGlobal(ProtocolTy, Elements, ".objc_protocol"); 1473} 1474 1475void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) { 1476 ASTContext &Context = CGM.getContext(); 1477 std::string ProtocolName = PD->getNameAsString(); 1478 SmallVector<std::string, 16> Protocols; 1479 for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(), 1480 E = PD->protocol_end(); PI != E; ++PI) 1481 Protocols.push_back((*PI)->getNameAsString()); 1482 SmallVector<llvm::Constant*, 16> InstanceMethodNames; 1483 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1484 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames; 1485 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes; 1486 for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(), 1487 E = PD->instmeth_end(); iter != E; iter++) { 1488 std::string TypeStr; 1489 Context.getObjCEncodingForMethodDecl(*iter, TypeStr); 1490 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1491 InstanceMethodNames.push_back( 1492 MakeConstantString((*iter)->getSelector().getAsString())); 1493 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1494 } else { 1495 OptionalInstanceMethodNames.push_back( 1496 MakeConstantString((*iter)->getSelector().getAsString())); 1497 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1498 } 1499 } 1500 // Collect information about class methods: 1501 SmallVector<llvm::Constant*, 16> ClassMethodNames; 1502 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1503 SmallVector<llvm::Constant*, 16> OptionalClassMethodNames; 1504 SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes; 1505 for (ObjCProtocolDecl::classmeth_iterator 1506 iter = PD->classmeth_begin(), endIter = PD->classmeth_end(); 1507 iter != endIter ; iter++) { 1508 std::string TypeStr; 1509 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1510 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1511 ClassMethodNames.push_back( 1512 MakeConstantString((*iter)->getSelector().getAsString())); 1513 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1514 } else { 1515 OptionalClassMethodNames.push_back( 1516 MakeConstantString((*iter)->getSelector().getAsString())); 1517 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1518 } 1519 } 1520 1521 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols); 1522 llvm::Constant *InstanceMethodList = 1523 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes); 1524 llvm::Constant *ClassMethodList = 1525 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes); 1526 llvm::Constant *OptionalInstanceMethodList = 1527 GenerateProtocolMethodList(OptionalInstanceMethodNames, 1528 OptionalInstanceMethodTypes); 1529 llvm::Constant *OptionalClassMethodList = 1530 GenerateProtocolMethodList(OptionalClassMethodNames, 1531 OptionalClassMethodTypes); 1532 1533 // Property metadata: name, attributes, isSynthesized, setter name, setter 1534 // types, getter name, getter types. 1535 // The isSynthesized value is always set to 0 in a protocol. It exists to 1536 // simplify the runtime library by allowing it to use the same data 1537 // structures for protocol metadata everywhere. 1538 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1539 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1540 PtrToInt8Ty, NULL); 1541 std::vector<llvm::Constant*> Properties; 1542 std::vector<llvm::Constant*> OptionalProperties; 1543 1544 // Add all of the property methods need adding to the method list and to the 1545 // property metadata list. 1546 for (ObjCContainerDecl::prop_iterator 1547 iter = PD->prop_begin(), endIter = PD->prop_end(); 1548 iter != endIter ; iter++) { 1549 std::vector<llvm::Constant*> Fields; 1550 ObjCPropertyDecl *property = (*iter); 1551 1552 Fields.push_back(MakeConstantString(property->getNameAsString())); 1553 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1554 property->getPropertyAttributes())); 1555 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 1556 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1557 std::string TypeStr; 1558 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1559 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1560 InstanceMethodTypes.push_back(TypeEncoding); 1561 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1562 Fields.push_back(TypeEncoding); 1563 } else { 1564 Fields.push_back(NULLPtr); 1565 Fields.push_back(NULLPtr); 1566 } 1567 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1568 std::string TypeStr; 1569 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1570 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1571 InstanceMethodTypes.push_back(TypeEncoding); 1572 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1573 Fields.push_back(TypeEncoding); 1574 } else { 1575 Fields.push_back(NULLPtr); 1576 Fields.push_back(NULLPtr); 1577 } 1578 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) { 1579 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1580 } else { 1581 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1582 } 1583 } 1584 llvm::Constant *PropertyArray = llvm::ConstantArray::get( 1585 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties); 1586 llvm::Constant* PropertyListInitFields[] = 1587 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1588 1589 llvm::Constant *PropertyListInit = 1590 llvm::ConstantStruct::getAnon(PropertyListInitFields); 1591 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule, 1592 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage, 1593 PropertyListInit, ".objc_property_list"); 1594 1595 llvm::Constant *OptionalPropertyArray = 1596 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy, 1597 OptionalProperties.size()) , OptionalProperties); 1598 llvm::Constant* OptionalPropertyListInitFields[] = { 1599 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr, 1600 OptionalPropertyArray }; 1601 1602 llvm::Constant *OptionalPropertyListInit = 1603 llvm::ConstantStruct::getAnon(OptionalPropertyListInitFields); 1604 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule, 1605 OptionalPropertyListInit->getType(), false, 1606 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit, 1607 ".objc_property_list"); 1608 1609 // Protocols are objects containing lists of the methods implemented and 1610 // protocols adopted. 1611 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1612 PtrToInt8Ty, 1613 ProtocolList->getType(), 1614 InstanceMethodList->getType(), 1615 ClassMethodList->getType(), 1616 OptionalInstanceMethodList->getType(), 1617 OptionalClassMethodList->getType(), 1618 PropertyList->getType(), 1619 OptionalPropertyList->getType(), 1620 NULL); 1621 std::vector<llvm::Constant*> Elements; 1622 // The isa pointer must be set to a magic number so the runtime knows it's 1623 // the correct layout. 1624 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1625 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 1626 ProtocolVersion), IdTy)); 1627 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1628 Elements.push_back(ProtocolList); 1629 Elements.push_back(InstanceMethodList); 1630 Elements.push_back(ClassMethodList); 1631 Elements.push_back(OptionalInstanceMethodList); 1632 Elements.push_back(OptionalClassMethodList); 1633 Elements.push_back(PropertyList); 1634 Elements.push_back(OptionalPropertyList); 1635 ExistingProtocols[ProtocolName] = 1636 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements, 1637 ".objc_protocol"), IdTy); 1638} 1639void CGObjCGNU::GenerateProtocolHolderCategory(void) { 1640 // Collect information about instance methods 1641 SmallVector<Selector, 1> MethodSels; 1642 SmallVector<llvm::Constant*, 1> MethodTypes; 1643 1644 std::vector<llvm::Constant*> Elements; 1645 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack"; 1646 const std::string CategoryName = "AnotherHack"; 1647 Elements.push_back(MakeConstantString(CategoryName)); 1648 Elements.push_back(MakeConstantString(ClassName)); 1649 // Instance method list 1650 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1651 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy)); 1652 // Class method list 1653 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1654 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy)); 1655 // Protocol list 1656 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy, 1657 ExistingProtocols.size()); 1658 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1659 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1660 SizeTy, 1661 ProtocolArrayTy, 1662 NULL); 1663 std::vector<llvm::Constant*> ProtocolElements; 1664 for (llvm::StringMapIterator<llvm::Constant*> iter = 1665 ExistingProtocols.begin(), endIter = ExistingProtocols.end(); 1666 iter != endIter ; iter++) { 1667 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(), 1668 PtrTy); 1669 ProtocolElements.push_back(Ptr); 1670 } 1671 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1672 ProtocolElements); 1673 ProtocolElements.clear(); 1674 ProtocolElements.push_back(NULLPtr); 1675 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy, 1676 ExistingProtocols.size())); 1677 ProtocolElements.push_back(ProtocolArray); 1678 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy, 1679 ProtocolElements, ".objc_protocol_list"), PtrTy)); 1680 Categories.push_back(llvm::ConstantExpr::getBitCast( 1681 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1682 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1683} 1684 1685void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) { 1686 std::string ClassName = OCD->getClassInterface()->getNameAsString(); 1687 std::string CategoryName = OCD->getNameAsString(); 1688 // Collect information about instance methods 1689 SmallVector<Selector, 16> InstanceMethodSels; 1690 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1691 for (ObjCCategoryImplDecl::instmeth_iterator 1692 iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end(); 1693 iter != endIter ; iter++) { 1694 InstanceMethodSels.push_back((*iter)->getSelector()); 1695 std::string TypeStr; 1696 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1697 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1698 } 1699 1700 // Collect information about class methods 1701 SmallVector<Selector, 16> ClassMethodSels; 1702 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1703 for (ObjCCategoryImplDecl::classmeth_iterator 1704 iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end(); 1705 iter != endIter ; iter++) { 1706 ClassMethodSels.push_back((*iter)->getSelector()); 1707 std::string TypeStr; 1708 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1709 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1710 } 1711 1712 // Collect the names of referenced protocols 1713 SmallVector<std::string, 16> Protocols; 1714 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl(); 1715 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols(); 1716 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1717 E = Protos.end(); I != E; ++I) 1718 Protocols.push_back((*I)->getNameAsString()); 1719 1720 std::vector<llvm::Constant*> Elements; 1721 Elements.push_back(MakeConstantString(CategoryName)); 1722 Elements.push_back(MakeConstantString(ClassName)); 1723 // Instance method list 1724 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1725 ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes, 1726 false), PtrTy)); 1727 // Class method list 1728 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1729 ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true), 1730 PtrTy)); 1731 // Protocol list 1732 Elements.push_back(llvm::ConstantExpr::getBitCast( 1733 GenerateProtocolList(Protocols), PtrTy)); 1734 Categories.push_back(llvm::ConstantExpr::getBitCast( 1735 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1736 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1737} 1738 1739llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID, 1740 SmallVectorImpl<Selector> &InstanceMethodSels, 1741 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) { 1742 ASTContext &Context = CGM.getContext(); 1743 // 1744 // Property metadata: name, attributes, isSynthesized, setter name, setter 1745 // types, getter name, getter types. 1746 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1747 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1748 PtrToInt8Ty, NULL); 1749 std::vector<llvm::Constant*> Properties; 1750 1751 1752 // Add all of the property methods need adding to the method list and to the 1753 // property metadata list. 1754 for (ObjCImplDecl::propimpl_iterator 1755 iter = OID->propimpl_begin(), endIter = OID->propimpl_end(); 1756 iter != endIter ; iter++) { 1757 std::vector<llvm::Constant*> Fields; 1758 ObjCPropertyDecl *property = (*iter)->getPropertyDecl(); 1759 ObjCPropertyImplDecl *propertyImpl = *iter; 1760 bool isSynthesized = (propertyImpl->getPropertyImplementation() == 1761 ObjCPropertyImplDecl::Synthesize); 1762 1763 Fields.push_back(MakeConstantString(property->getNameAsString())); 1764 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1765 property->getPropertyAttributes())); 1766 Fields.push_back(llvm::ConstantInt::get(Int8Ty, isSynthesized)); 1767 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1768 std::string TypeStr; 1769 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1770 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1771 if (isSynthesized) { 1772 InstanceMethodTypes.push_back(TypeEncoding); 1773 InstanceMethodSels.push_back(getter->getSelector()); 1774 } 1775 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1776 Fields.push_back(TypeEncoding); 1777 } else { 1778 Fields.push_back(NULLPtr); 1779 Fields.push_back(NULLPtr); 1780 } 1781 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1782 std::string TypeStr; 1783 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1784 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1785 if (isSynthesized) { 1786 InstanceMethodTypes.push_back(TypeEncoding); 1787 InstanceMethodSels.push_back(setter->getSelector()); 1788 } 1789 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1790 Fields.push_back(TypeEncoding); 1791 } else { 1792 Fields.push_back(NULLPtr); 1793 Fields.push_back(NULLPtr); 1794 } 1795 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1796 } 1797 llvm::ArrayType *PropertyArrayTy = 1798 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()); 1799 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy, 1800 Properties); 1801 llvm::Constant* PropertyListInitFields[] = 1802 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1803 1804 llvm::Constant *PropertyListInit = 1805 llvm::ConstantStruct::getAnon(PropertyListInitFields); 1806 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false, 1807 llvm::GlobalValue::InternalLinkage, PropertyListInit, 1808 ".objc_property_list"); 1809} 1810 1811void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) { 1812 ASTContext &Context = CGM.getContext(); 1813 1814 // Get the superclass name. 1815 const ObjCInterfaceDecl * SuperClassDecl = 1816 OID->getClassInterface()->getSuperClass(); 1817 std::string SuperClassName; 1818 if (SuperClassDecl) { 1819 SuperClassName = SuperClassDecl->getNameAsString(); 1820 EmitClassRef(SuperClassName); 1821 } 1822 1823 // Get the class name 1824 ObjCInterfaceDecl *ClassDecl = 1825 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface()); 1826 std::string ClassName = ClassDecl->getNameAsString(); 1827 // Emit the symbol that is used to generate linker errors if this class is 1828 // referenced in other modules but not declared. 1829 std::string classSymbolName = "__objc_class_name_" + ClassName; 1830 if (llvm::GlobalVariable *symbol = 1831 TheModule.getGlobalVariable(classSymbolName)) { 1832 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0)); 1833 } else { 1834 new llvm::GlobalVariable(TheModule, LongTy, false, 1835 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0), 1836 classSymbolName); 1837 } 1838 1839 // Get the size of instances. 1840 int instanceSize = 1841 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity(); 1842 1843 // Collect information about instance variables. 1844 SmallVector<llvm::Constant*, 16> IvarNames; 1845 SmallVector<llvm::Constant*, 16> IvarTypes; 1846 SmallVector<llvm::Constant*, 16> IvarOffsets; 1847 1848 std::vector<llvm::Constant*> IvarOffsetValues; 1849 1850 int superInstanceSize = !SuperClassDecl ? 0 : 1851 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity(); 1852 // For non-fragile ivars, set the instance size to 0 - {the size of just this 1853 // class}. The runtime will then set this to the correct value on load. 1854 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1855 instanceSize = 0 - (instanceSize - superInstanceSize); 1856 } 1857 1858 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 1859 IVD = IVD->getNextIvar()) { 1860 // Store the name 1861 IvarNames.push_back(MakeConstantString(IVD->getNameAsString())); 1862 // Get the type encoding for this ivar 1863 std::string TypeStr; 1864 Context.getObjCEncodingForType(IVD->getType(), TypeStr); 1865 IvarTypes.push_back(MakeConstantString(TypeStr)); 1866 // Get the offset 1867 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD); 1868 uint64_t Offset = BaseOffset; 1869 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1870 Offset = BaseOffset - superInstanceSize; 1871 } 1872 llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset); 1873 // Create the direct offset value 1874 std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." + 1875 IVD->getNameAsString(); 1876 llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName); 1877 if (OffsetVar) { 1878 OffsetVar->setInitializer(OffsetValue); 1879 // If this is the real definition, change its linkage type so that 1880 // different modules will use this one, rather than their private 1881 // copy. 1882 OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage); 1883 } else 1884 OffsetVar = new llvm::GlobalVariable(TheModule, IntTy, 1885 false, llvm::GlobalValue::ExternalLinkage, 1886 OffsetValue, 1887 "__objc_ivar_offset_value_" + ClassName +"." + 1888 IVD->getNameAsString()); 1889 IvarOffsets.push_back(OffsetValue); 1890 IvarOffsetValues.push_back(OffsetVar); 1891 } 1892 llvm::GlobalVariable *IvarOffsetArray = 1893 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets"); 1894 1895 1896 // Collect information about instance methods 1897 SmallVector<Selector, 16> InstanceMethodSels; 1898 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1899 for (ObjCImplementationDecl::instmeth_iterator 1900 iter = OID->instmeth_begin(), endIter = OID->instmeth_end(); 1901 iter != endIter ; iter++) { 1902 InstanceMethodSels.push_back((*iter)->getSelector()); 1903 std::string TypeStr; 1904 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1905 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1906 } 1907 1908 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels, 1909 InstanceMethodTypes); 1910 1911 1912 // Collect information about class methods 1913 SmallVector<Selector, 16> ClassMethodSels; 1914 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1915 for (ObjCImplementationDecl::classmeth_iterator 1916 iter = OID->classmeth_begin(), endIter = OID->classmeth_end(); 1917 iter != endIter ; iter++) { 1918 ClassMethodSels.push_back((*iter)->getSelector()); 1919 std::string TypeStr; 1920 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1921 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1922 } 1923 // Collect the names of referenced protocols 1924 SmallVector<std::string, 16> Protocols; 1925 const ObjCList<ObjCProtocolDecl> &Protos =ClassDecl->getReferencedProtocols(); 1926 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1927 E = Protos.end(); I != E; ++I) 1928 Protocols.push_back((*I)->getNameAsString()); 1929 1930 1931 1932 // Get the superclass pointer. 1933 llvm::Constant *SuperClass; 1934 if (!SuperClassName.empty()) { 1935 SuperClass = MakeConstantString(SuperClassName, ".super_class_name"); 1936 } else { 1937 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty); 1938 } 1939 // Empty vector used to construct empty method lists 1940 SmallVector<llvm::Constant*, 1> empty; 1941 // Generate the method and instance variable lists 1942 llvm::Constant *MethodList = GenerateMethodList(ClassName, "", 1943 InstanceMethodSels, InstanceMethodTypes, false); 1944 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "", 1945 ClassMethodSels, ClassMethodTypes, true); 1946 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes, 1947 IvarOffsets); 1948 // Irrespective of whether we are compiling for a fragile or non-fragile ABI, 1949 // we emit a symbol containing the offset for each ivar in the class. This 1950 // allows code compiled for the non-Fragile ABI to inherit from code compiled 1951 // for the legacy ABI, without causing problems. The converse is also 1952 // possible, but causes all ivar accesses to be fragile. 1953 1954 // Offset pointer for getting at the correct field in the ivar list when 1955 // setting up the alias. These are: The base address for the global, the 1956 // ivar array (second field), the ivar in this list (set for each ivar), and 1957 // the offset (third field in ivar structure) 1958 llvm::Type *IndexTy = llvm::Type::getInt32Ty(VMContext); 1959 llvm::Constant *offsetPointerIndexes[] = {Zeros[0], 1960 llvm::ConstantInt::get(IndexTy, 1), 0, 1961 llvm::ConstantInt::get(IndexTy, 2) }; 1962 1963 unsigned ivarIndex = 0; 1964 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 1965 IVD = IVD->getNextIvar()) { 1966 const std::string Name = "__objc_ivar_offset_" + ClassName + '.' 1967 + IVD->getNameAsString(); 1968 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex); 1969 // Get the correct ivar field 1970 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr( 1971 IvarList, offsetPointerIndexes); 1972 // Get the existing variable, if one exists. 1973 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name); 1974 if (offset) { 1975 offset->setInitializer(offsetValue); 1976 // If this is the real definition, change its linkage type so that 1977 // different modules will use this one, rather than their private 1978 // copy. 1979 offset->setLinkage(llvm::GlobalValue::ExternalLinkage); 1980 } else { 1981 // Add a new alias if there isn't one already. 1982 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(), 1983 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name); 1984 } 1985 ++ivarIndex; 1986 } 1987 //Generate metaclass for class methods 1988 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr, 1989 NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList( 1990 empty, empty, empty), ClassMethodList, NULLPtr, NULLPtr, NULLPtr, true); 1991 1992 // Generate the class structure 1993 llvm::Constant *ClassStruct = 1994 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L, 1995 ClassName.c_str(), 0, 1996 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, 1997 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray, 1998 Properties); 1999 2000 // Resolve the class aliases, if they exist. 2001 if (ClassPtrAlias) { 2002 ClassPtrAlias->replaceAllUsesWith( 2003 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy)); 2004 ClassPtrAlias->eraseFromParent(); 2005 ClassPtrAlias = 0; 2006 } 2007 if (MetaClassPtrAlias) { 2008 MetaClassPtrAlias->replaceAllUsesWith( 2009 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy)); 2010 MetaClassPtrAlias->eraseFromParent(); 2011 MetaClassPtrAlias = 0; 2012 } 2013 2014 // Add class structure to list to be added to the symtab later 2015 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty); 2016 Classes.push_back(ClassStruct); 2017} 2018 2019 2020llvm::Function *CGObjCGNU::ModuleInitFunction() { 2021 // Only emit an ObjC load function if no Objective-C stuff has been called 2022 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() && 2023 ExistingProtocols.empty() && SelectorTable.empty()) 2024 return NULL; 2025 2026 // Add all referenced protocols to a category. 2027 GenerateProtocolHolderCategory(); 2028 2029 llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>( 2030 SelectorTy->getElementType()); 2031 llvm::Type *SelStructPtrTy = SelectorTy; 2032 if (SelStructTy == 0) { 2033 SelStructTy = llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, NULL); 2034 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy); 2035 } 2036 2037 std::vector<llvm::Constant*> Elements; 2038 llvm::Constant *Statics = NULLPtr; 2039 // Generate statics list: 2040 if (ConstantStrings.size()) { 2041 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 2042 ConstantStrings.size() + 1); 2043 ConstantStrings.push_back(NULLPtr); 2044 2045 StringRef StringClass = CGM.getLangOptions().ObjCConstantStringClass; 2046 2047 if (StringClass.empty()) StringClass = "NXConstantString"; 2048 2049 Elements.push_back(MakeConstantString(StringClass, 2050 ".objc_static_class_name")); 2051 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy, 2052 ConstantStrings)); 2053 llvm::StructType *StaticsListTy = 2054 llvm::StructType::get(PtrToInt8Ty, StaticsArrayTy, NULL); 2055 llvm::Type *StaticsListPtrTy = 2056 llvm::PointerType::getUnqual(StaticsListTy); 2057 Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics"); 2058 llvm::ArrayType *StaticsListArrayTy = 2059 llvm::ArrayType::get(StaticsListPtrTy, 2); 2060 Elements.clear(); 2061 Elements.push_back(Statics); 2062 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy)); 2063 Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr"); 2064 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy); 2065 } 2066 // Array of classes, categories, and constant objects 2067 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty, 2068 Classes.size() + Categories.size() + 2); 2069 llvm::StructType *SymTabTy = llvm::StructType::get(LongTy, SelStructPtrTy, 2070 llvm::Type::getInt16Ty(VMContext), 2071 llvm::Type::getInt16Ty(VMContext), 2072 ClassListTy, NULL); 2073 2074 Elements.clear(); 2075 // Pointer to an array of selectors used in this module. 2076 std::vector<llvm::Constant*> Selectors; 2077 std::vector<llvm::GlobalAlias*> SelectorAliases; 2078 for (SelectorMap::iterator iter = SelectorTable.begin(), 2079 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) { 2080 2081 std::string SelNameStr = iter->first.getAsString(); 2082 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name"); 2083 2084 SmallVectorImpl<TypedSelector> &Types = iter->second; 2085 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 2086 e = Types.end() ; i!=e ; i++) { 2087 2088 llvm::Constant *SelectorTypeEncoding = NULLPtr; 2089 if (!i->first.empty()) 2090 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types"); 2091 2092 Elements.push_back(SelName); 2093 Elements.push_back(SelectorTypeEncoding); 2094 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2095 Elements.clear(); 2096 2097 // Store the selector alias for later replacement 2098 SelectorAliases.push_back(i->second); 2099 } 2100 } 2101 unsigned SelectorCount = Selectors.size(); 2102 // NULL-terminate the selector list. This should not actually be required, 2103 // because the selector list has a length field. Unfortunately, the GCC 2104 // runtime decides to ignore the length field and expects a NULL terminator, 2105 // and GCC cooperates with this by always setting the length to 0. 2106 Elements.push_back(NULLPtr); 2107 Elements.push_back(NULLPtr); 2108 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2109 Elements.clear(); 2110 2111 // Number of static selectors 2112 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount)); 2113 llvm::Constant *SelectorList = MakeGlobalArray(SelStructTy, Selectors, 2114 ".objc_selector_list"); 2115 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList, 2116 SelStructPtrTy)); 2117 2118 // Now that all of the static selectors exist, create pointers to them. 2119 for (unsigned int i=0 ; i<SelectorCount ; i++) { 2120 2121 llvm::Constant *Idxs[] = {Zeros[0], 2122 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), i), Zeros[0]}; 2123 // FIXME: We're generating redundant loads and stores here! 2124 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(SelectorList, 2125 makeArrayRef(Idxs, 2)); 2126 // If selectors are defined as an opaque type, cast the pointer to this 2127 // type. 2128 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy); 2129 SelectorAliases[i]->replaceAllUsesWith(SelPtr); 2130 SelectorAliases[i]->eraseFromParent(); 2131 } 2132 2133 // Number of classes defined. 2134 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2135 Classes.size())); 2136 // Number of categories defined 2137 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2138 Categories.size())); 2139 // Create an array of classes, then categories, then static object instances 2140 Classes.insert(Classes.end(), Categories.begin(), Categories.end()); 2141 // NULL-terminated list of static object instances (mainly constant strings) 2142 Classes.push_back(Statics); 2143 Classes.push_back(NULLPtr); 2144 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes); 2145 Elements.push_back(ClassList); 2146 // Construct the symbol table 2147 llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements); 2148 2149 // The symbol table is contained in a module which has some version-checking 2150 // constants 2151 llvm::StructType * ModuleTy = llvm::StructType::get(LongTy, LongTy, 2152 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), 2153 (RuntimeVersion >= 10) ? IntTy : NULL, NULL); 2154 Elements.clear(); 2155 // Runtime version, used for ABI compatibility checking. 2156 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion)); 2157 // sizeof(ModuleTy) 2158 llvm::TargetData td(&TheModule); 2159 Elements.push_back( 2160 llvm::ConstantInt::get(LongTy, 2161 td.getTypeSizeInBits(ModuleTy) / 2162 CGM.getContext().getCharWidth())); 2163 2164 // The path to the source file where this module was declared 2165 SourceManager &SM = CGM.getContext().getSourceManager(); 2166 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID()); 2167 std::string path = 2168 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName(); 2169 Elements.push_back(MakeConstantString(path, ".objc_source_file_name")); 2170 Elements.push_back(SymTab); 2171 2172 if (RuntimeVersion >= 10) 2173 switch (CGM.getLangOptions().getGCMode()) { 2174 case LangOptions::GCOnly: 2175 Elements.push_back(llvm::ConstantInt::get(IntTy, 2)); 2176 break; 2177 case LangOptions::NonGC: 2178 if (CGM.getLangOptions().ObjCAutoRefCount) 2179 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2180 else 2181 Elements.push_back(llvm::ConstantInt::get(IntTy, 0)); 2182 break; 2183 case LangOptions::HybridGC: 2184 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2185 break; 2186 } 2187 2188 llvm::Value *Module = MakeGlobal(ModuleTy, Elements); 2189 2190 // Create the load function calling the runtime entry point with the module 2191 // structure 2192 llvm::Function * LoadFunction = llvm::Function::Create( 2193 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false), 2194 llvm::GlobalValue::InternalLinkage, ".objc_load_function", 2195 &TheModule); 2196 llvm::BasicBlock *EntryBB = 2197 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction); 2198 CGBuilderTy Builder(VMContext); 2199 Builder.SetInsertPoint(EntryBB); 2200 2201 llvm::FunctionType *FT = 2202 llvm::FunctionType::get(Builder.getVoidTy(), 2203 llvm::PointerType::getUnqual(ModuleTy), true); 2204 llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class"); 2205 Builder.CreateCall(Register, Module); 2206 Builder.CreateRetVoid(); 2207 2208 return LoadFunction; 2209} 2210 2211llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD, 2212 const ObjCContainerDecl *CD) { 2213 const ObjCCategoryImplDecl *OCD = 2214 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext()); 2215 StringRef CategoryName = OCD ? OCD->getName() : ""; 2216 StringRef ClassName = CD->getName(); 2217 Selector MethodName = OMD->getSelector(); 2218 bool isClassMethod = !OMD->isInstanceMethod(); 2219 2220 CodeGenTypes &Types = CGM.getTypes(); 2221 llvm::FunctionType *MethodTy = 2222 Types.GetFunctionType(Types.getFunctionInfo(OMD), OMD->isVariadic()); 2223 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName, 2224 MethodName, isClassMethod); 2225 2226 llvm::Function *Method 2227 = llvm::Function::Create(MethodTy, 2228 llvm::GlobalValue::InternalLinkage, 2229 FunctionName, 2230 &TheModule); 2231 return Method; 2232} 2233 2234llvm::Constant *CGObjCGNU::GetPropertyGetFunction() { 2235 return GetPropertyFn; 2236} 2237 2238llvm::Constant *CGObjCGNU::GetPropertySetFunction() { 2239 return SetPropertyFn; 2240} 2241 2242llvm::Constant *CGObjCGNU::GetGetStructFunction() { 2243 return GetStructPropertyFn; 2244} 2245llvm::Constant *CGObjCGNU::GetSetStructFunction() { 2246 return SetStructPropertyFn; 2247} 2248 2249llvm::Constant *CGObjCGNU::EnumerationMutationFunction() { 2250 return EnumerationMutationFn; 2251} 2252 2253void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF, 2254 const ObjCAtSynchronizedStmt &S) { 2255 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn); 2256} 2257 2258 2259void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF, 2260 const ObjCAtTryStmt &S) { 2261 // Unlike the Apple non-fragile runtimes, which also uses 2262 // unwind-based zero cost exceptions, the GNU Objective C runtime's 2263 // EH support isn't a veneer over C++ EH. Instead, exception 2264 // objects are created by __objc_exception_throw and destroyed by 2265 // the personality function; this avoids the need for bracketing 2266 // catch handlers with calls to __blah_begin_catch/__blah_end_catch 2267 // (or even _Unwind_DeleteException), but probably doesn't 2268 // interoperate very well with foreign exceptions. 2269 // 2270 // In Objective-C++ mode, we actually emit something equivalent to the C++ 2271 // exception handler. 2272 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn); 2273 return ; 2274} 2275 2276void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF, 2277 const ObjCAtThrowStmt &S) { 2278 llvm::Value *ExceptionAsObject; 2279 2280 if (const Expr *ThrowExpr = S.getThrowExpr()) { 2281 llvm::Value *Exception = CGF.EmitScalarExpr(ThrowExpr); 2282 ExceptionAsObject = Exception; 2283 } else { 2284 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) && 2285 "Unexpected rethrow outside @catch block."); 2286 ExceptionAsObject = CGF.ObjCEHValueStack.back(); 2287 } 2288 ExceptionAsObject = 2289 CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy, "tmp"); 2290 2291 // Note: This may have to be an invoke, if we want to support constructs like: 2292 // @try { 2293 // @throw(obj); 2294 // } 2295 // @catch(id) ... 2296 // 2297 // This is effectively turning @throw into an incredibly-expensive goto, but 2298 // it may happen as a result of inlining followed by missed optimizations, or 2299 // as a result of stupidity. 2300 llvm::BasicBlock *UnwindBB = CGF.getInvokeDest(); 2301 if (!UnwindBB) { 2302 CGF.Builder.CreateCall(ExceptionThrowFn, ExceptionAsObject); 2303 CGF.Builder.CreateUnreachable(); 2304 } else { 2305 CGF.Builder.CreateInvoke(ExceptionThrowFn, UnwindBB, UnwindBB, 2306 ExceptionAsObject); 2307 } 2308 // Clear the insertion point to indicate we are in unreachable code. 2309 CGF.Builder.ClearInsertionPoint(); 2310} 2311 2312llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF, 2313 llvm::Value *AddrWeakObj) { 2314 CGBuilderTy B = CGF.Builder; 2315 AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy); 2316 return B.CreateCall(WeakReadFn, AddrWeakObj); 2317} 2318 2319void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF, 2320 llvm::Value *src, llvm::Value *dst) { 2321 CGBuilderTy B = CGF.Builder; 2322 src = EnforceType(B, src, IdTy); 2323 dst = EnforceType(B, dst, PtrToIdTy); 2324 B.CreateCall2(WeakAssignFn, src, dst); 2325} 2326 2327void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF, 2328 llvm::Value *src, llvm::Value *dst, 2329 bool threadlocal) { 2330 CGBuilderTy B = CGF.Builder; 2331 src = EnforceType(B, src, IdTy); 2332 dst = EnforceType(B, dst, PtrToIdTy); 2333 if (!threadlocal) 2334 B.CreateCall2(GlobalAssignFn, src, dst); 2335 else 2336 // FIXME. Add threadloca assign API 2337 assert(false && "EmitObjCGlobalAssign - Threal Local API NYI"); 2338} 2339 2340void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF, 2341 llvm::Value *src, llvm::Value *dst, 2342 llvm::Value *ivarOffset) { 2343 CGBuilderTy B = CGF.Builder; 2344 src = EnforceType(B, src, IdTy); 2345 dst = EnforceType(B, dst, IdTy); 2346 B.CreateCall3(IvarAssignFn, src, dst, ivarOffset); 2347} 2348 2349void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF, 2350 llvm::Value *src, llvm::Value *dst) { 2351 CGBuilderTy B = CGF.Builder; 2352 src = EnforceType(B, src, IdTy); 2353 dst = EnforceType(B, dst, PtrToIdTy); 2354 B.CreateCall2(StrongCastAssignFn, src, dst); 2355} 2356 2357void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF, 2358 llvm::Value *DestPtr, 2359 llvm::Value *SrcPtr, 2360 llvm::Value *Size) { 2361 CGBuilderTy B = CGF.Builder; 2362 DestPtr = EnforceType(B, DestPtr, PtrTy); 2363 SrcPtr = EnforceType(B, SrcPtr, PtrTy); 2364 2365 B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size); 2366} 2367 2368llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable( 2369 const ObjCInterfaceDecl *ID, 2370 const ObjCIvarDecl *Ivar) { 2371 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString() 2372 + '.' + Ivar->getNameAsString(); 2373 // Emit the variable and initialize it with what we think the correct value 2374 // is. This allows code compiled with non-fragile ivars to work correctly 2375 // when linked against code which isn't (most of the time). 2376 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name); 2377 if (!IvarOffsetPointer) { 2378 // This will cause a run-time crash if we accidentally use it. A value of 2379 // 0 would seem more sensible, but will silently overwrite the isa pointer 2380 // causing a great deal of confusion. 2381 uint64_t Offset = -1; 2382 // We can't call ComputeIvarBaseOffset() here if we have the 2383 // implementation, because it will create an invalid ASTRecordLayout object 2384 // that we are then stuck with forever, so we only initialize the ivar 2385 // offset variable with a guess if we only have the interface. The 2386 // initializer will be reset later anyway, when we are generating the class 2387 // description. 2388 if (!CGM.getContext().getObjCImplementation( 2389 const_cast<ObjCInterfaceDecl *>(ID))) 2390 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar); 2391 2392 llvm::ConstantInt *OffsetGuess = 2393 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset, "ivar"); 2394 // Don't emit the guess in non-PIC code because the linker will not be able 2395 // to replace it with the real version for a library. In non-PIC code you 2396 // must compile with the fragile ABI if you want to use ivars from a 2397 // GCC-compiled class. 2398 if (CGM.getLangOptions().PICLevel) { 2399 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule, 2400 llvm::Type::getInt32Ty(VMContext), false, 2401 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess"); 2402 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2403 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage, 2404 IvarOffsetGV, Name); 2405 } else { 2406 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2407 llvm::Type::getInt32PtrTy(VMContext), false, 2408 llvm::GlobalValue::ExternalLinkage, 0, Name); 2409 } 2410 } 2411 return IvarOffsetPointer; 2412} 2413 2414LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF, 2415 QualType ObjectTy, 2416 llvm::Value *BaseValue, 2417 const ObjCIvarDecl *Ivar, 2418 unsigned CVRQualifiers) { 2419 const ObjCInterfaceDecl *ID = 2420 ObjectTy->getAs<ObjCObjectType>()->getInterface(); 2421 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers, 2422 EmitIvarOffset(CGF, ID, Ivar)); 2423} 2424 2425static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context, 2426 const ObjCInterfaceDecl *OID, 2427 const ObjCIvarDecl *OIVD) { 2428 for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next; 2429 next = next->getNextIvar()) { 2430 if (OIVD == next) 2431 return OID; 2432 } 2433 2434 // Otherwise check in the super class. 2435 if (const ObjCInterfaceDecl *Super = OID->getSuperClass()) 2436 return FindIvarInterface(Context, Super, OIVD); 2437 2438 return 0; 2439} 2440 2441llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF, 2442 const ObjCInterfaceDecl *Interface, 2443 const ObjCIvarDecl *Ivar) { 2444 if (CGM.getLangOptions().ObjCNonFragileABI) { 2445 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar); 2446 if (RuntimeVersion < 10) 2447 return CGF.Builder.CreateZExtOrBitCast( 2448 CGF.Builder.CreateLoad(CGF.Builder.CreateLoad( 2449 ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")), 2450 PtrDiffTy); 2451 std::string name = "__objc_ivar_offset_value_" + 2452 Interface->getNameAsString() +"." + Ivar->getNameAsString(); 2453 llvm::Value *Offset = TheModule.getGlobalVariable(name); 2454 if (!Offset) 2455 Offset = new llvm::GlobalVariable(TheModule, IntTy, 2456 false, llvm::GlobalValue::LinkOnceAnyLinkage, 2457 llvm::Constant::getNullValue(IntTy), name); 2458 return CGF.Builder.CreateLoad(Offset); 2459 } 2460 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar); 2461 return llvm::ConstantInt::get(PtrDiffTy, Offset, "ivar"); 2462} 2463 2464CGObjCRuntime * 2465clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) { 2466 if (CGM.getLangOptions().ObjCNonFragileABI) 2467 return new CGObjCGNUstep(CGM); 2468 return new CGObjCGCC(CGM); 2469} 2470