CGObjCGNU.cpp revision 239462
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#include "clang/AST/ASTContext.h" 22#include "clang/AST/Decl.h" 23#include "clang/AST/DeclObjC.h" 24#include "clang/AST/RecordLayout.h" 25#include "clang/AST/StmtObjC.h" 26#include "clang/Basic/SourceManager.h" 27#include "clang/Basic/FileManager.h" 28 29#include "llvm/Intrinsics.h" 30#include "llvm/Module.h" 31#include "llvm/LLVMContext.h" 32#include "llvm/ADT/SmallVector.h" 33#include "llvm/ADT/StringMap.h" 34#include "llvm/Support/CallSite.h" 35#include "llvm/Support/Compiler.h" 36#include "llvm/Target/TargetData.h" 37 38#include <cstdarg> 39 40 41using namespace clang; 42using namespace CodeGen; 43 44 45namespace { 46/// Class that lazily initialises the runtime function. Avoids inserting the 47/// types and the function declaration into a module if they're not used, and 48/// avoids constructing the type more than once if it's used more than once. 49class LazyRuntimeFunction { 50 CodeGenModule *CGM; 51 std::vector<llvm::Type*> ArgTys; 52 const char *FunctionName; 53 llvm::Constant *Function; 54 public: 55 /// Constructor leaves this class uninitialized, because it is intended to 56 /// be used as a field in another class and not all of the types that are 57 /// used as arguments will necessarily be available at construction time. 58 LazyRuntimeFunction() : CGM(0), FunctionName(0), Function(0) {} 59 60 /// Initialises the lazy function with the name, return type, and the types 61 /// of the arguments. 62 END_WITH_NULL 63 void init(CodeGenModule *Mod, const char *name, 64 llvm::Type *RetTy, ...) { 65 CGM =Mod; 66 FunctionName = name; 67 Function = 0; 68 ArgTys.clear(); 69 va_list Args; 70 va_start(Args, RetTy); 71 while (llvm::Type *ArgTy = va_arg(Args, llvm::Type*)) 72 ArgTys.push_back(ArgTy); 73 va_end(Args); 74 // Push the return type on at the end so we can pop it off easily 75 ArgTys.push_back(RetTy); 76 } 77 /// Overloaded cast operator, allows the class to be implicitly cast to an 78 /// LLVM constant. 79 operator llvm::Constant*() { 80 if (!Function) { 81 if (0 == FunctionName) return 0; 82 // We put the return type on the end of the vector, so pop it back off 83 llvm::Type *RetTy = ArgTys.back(); 84 ArgTys.pop_back(); 85 llvm::FunctionType *FTy = llvm::FunctionType::get(RetTy, ArgTys, false); 86 Function = 87 cast<llvm::Constant>(CGM->CreateRuntimeFunction(FTy, FunctionName)); 88 // We won't need to use the types again, so we may as well clean up the 89 // vector now 90 ArgTys.resize(0); 91 } 92 return Function; 93 } 94 operator llvm::Function*() { 95 return cast<llvm::Function>((llvm::Constant*)*this); 96 } 97 98}; 99 100 101/// GNU Objective-C runtime code generation. This class implements the parts of 102/// Objective-C support that are specific to the GNU family of runtimes (GCC, 103/// GNUstep and ObjFW). 104class CGObjCGNU : public CGObjCRuntime { 105protected: 106 /// The LLVM module into which output is inserted 107 llvm::Module &TheModule; 108 /// strut objc_super. Used for sending messages to super. This structure 109 /// contains the receiver (object) and the expected class. 110 llvm::StructType *ObjCSuperTy; 111 /// struct objc_super*. The type of the argument to the superclass message 112 /// lookup functions. 113 llvm::PointerType *PtrToObjCSuperTy; 114 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring 115 /// SEL is included in a header somewhere, in which case it will be whatever 116 /// type is declared in that header, most likely {i8*, i8*}. 117 llvm::PointerType *SelectorTy; 118 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the 119 /// places where it's used 120 llvm::IntegerType *Int8Ty; 121 /// Pointer to i8 - LLVM type of char*, for all of the places where the 122 /// runtime needs to deal with C strings. 123 llvm::PointerType *PtrToInt8Ty; 124 /// Instance Method Pointer type. This is a pointer to a function that takes, 125 /// at a minimum, an object and a selector, and is the generic type for 126 /// Objective-C methods. Due to differences between variadic / non-variadic 127 /// calling conventions, it must always be cast to the correct type before 128 /// actually being used. 129 llvm::PointerType *IMPTy; 130 /// Type of an untyped Objective-C object. Clang treats id as a built-in type 131 /// when compiling Objective-C code, so this may be an opaque pointer (i8*), 132 /// but if the runtime header declaring it is included then it may be a 133 /// pointer to a structure. 134 llvm::PointerType *IdTy; 135 /// Pointer to a pointer to an Objective-C object. Used in the new ABI 136 /// message lookup function and some GC-related functions. 137 llvm::PointerType *PtrToIdTy; 138 /// The clang type of id. Used when using the clang CGCall infrastructure to 139 /// call Objective-C methods. 140 CanQualType ASTIdTy; 141 /// LLVM type for C int type. 142 llvm::IntegerType *IntTy; 143 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is 144 /// used in the code to document the difference between i8* meaning a pointer 145 /// to a C string and i8* meaning a pointer to some opaque type. 146 llvm::PointerType *PtrTy; 147 /// LLVM type for C long type. The runtime uses this in a lot of places where 148 /// it should be using intptr_t, but we can't fix this without breaking 149 /// compatibility with GCC... 150 llvm::IntegerType *LongTy; 151 /// LLVM type for C size_t. Used in various runtime data structures. 152 llvm::IntegerType *SizeTy; 153 /// LLVM type for C intptr_t. 154 llvm::IntegerType *IntPtrTy; 155 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions. 156 llvm::IntegerType *PtrDiffTy; 157 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance 158 /// variables. 159 llvm::PointerType *PtrToIntTy; 160 /// LLVM type for Objective-C BOOL type. 161 llvm::Type *BoolTy; 162 /// 32-bit integer type, to save us needing to look it up every time it's used. 163 llvm::IntegerType *Int32Ty; 164 /// 64-bit integer type, to save us needing to look it up every time it's used. 165 llvm::IntegerType *Int64Ty; 166 /// Metadata kind used to tie method lookups to message sends. The GNUstep 167 /// runtime provides some LLVM passes that can use this to do things like 168 /// automatic IMP caching and speculative inlining. 169 unsigned msgSendMDKind; 170 /// Helper function that generates a constant string and returns a pointer to 171 /// the start of the string. The result of this function can be used anywhere 172 /// where the C code specifies const char*. 173 llvm::Constant *MakeConstantString(const std::string &Str, 174 const std::string &Name="") { 175 llvm::Constant *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str()); 176 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 177 } 178 /// Emits a linkonce_odr string, whose name is the prefix followed by the 179 /// string value. This allows the linker to combine the strings between 180 /// different modules. Used for EH typeinfo names, selector strings, and a 181 /// few other things. 182 llvm::Constant *ExportUniqueString(const std::string &Str, 183 const std::string prefix) { 184 std::string name = prefix + Str; 185 llvm::Constant *ConstStr = TheModule.getGlobalVariable(name); 186 if (!ConstStr) { 187 llvm::Constant *value = llvm::ConstantDataArray::getString(VMContext,Str); 188 ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true, 189 llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str); 190 } 191 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 192 } 193 /// Generates a global structure, initialized by the elements in the vector. 194 /// The element types must match the types of the structure elements in the 195 /// first argument. 196 llvm::GlobalVariable *MakeGlobal(llvm::StructType *Ty, 197 llvm::ArrayRef<llvm::Constant*> V, 198 StringRef Name="", 199 llvm::GlobalValue::LinkageTypes linkage 200 =llvm::GlobalValue::InternalLinkage) { 201 llvm::Constant *C = llvm::ConstantStruct::get(Ty, V); 202 return new llvm::GlobalVariable(TheModule, Ty, false, 203 linkage, C, Name); 204 } 205 /// Generates a global array. The vector must contain the same number of 206 /// elements that the array type declares, of the type specified as the array 207 /// element type. 208 llvm::GlobalVariable *MakeGlobal(llvm::ArrayType *Ty, 209 llvm::ArrayRef<llvm::Constant*> V, 210 StringRef Name="", 211 llvm::GlobalValue::LinkageTypes linkage 212 =llvm::GlobalValue::InternalLinkage) { 213 llvm::Constant *C = llvm::ConstantArray::get(Ty, V); 214 return new llvm::GlobalVariable(TheModule, Ty, false, 215 linkage, C, Name); 216 } 217 /// Generates a global array, inferring the array type from the specified 218 /// element type and the size of the initialiser. 219 llvm::GlobalVariable *MakeGlobalArray(llvm::Type *Ty, 220 llvm::ArrayRef<llvm::Constant*> V, 221 StringRef Name="", 222 llvm::GlobalValue::LinkageTypes linkage 223 =llvm::GlobalValue::InternalLinkage) { 224 llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size()); 225 return MakeGlobal(ArrayTy, V, Name, linkage); 226 } 227 /// Ensures that the value has the required type, by inserting a bitcast if 228 /// required. This function lets us avoid inserting bitcasts that are 229 /// redundant. 230 llvm::Value* EnforceType(CGBuilderTy B, llvm::Value *V, llvm::Type *Ty){ 231 if (V->getType() == Ty) return V; 232 return B.CreateBitCast(V, Ty); 233 } 234 // Some zeros used for GEPs in lots of places. 235 llvm::Constant *Zeros[2]; 236 /// Null pointer value. Mainly used as a terminator in various arrays. 237 llvm::Constant *NULLPtr; 238 /// LLVM context. 239 llvm::LLVMContext &VMContext; 240private: 241 /// Placeholder for the class. Lots of things refer to the class before we've 242 /// actually emitted it. We use this alias as a placeholder, and then replace 243 /// it with a pointer to the class structure before finally emitting the 244 /// module. 245 llvm::GlobalAlias *ClassPtrAlias; 246 /// Placeholder for the metaclass. Lots of things refer to the class before 247 /// we've / actually emitted it. We use this alias as a placeholder, and then 248 /// replace / it with a pointer to the metaclass structure before finally 249 /// emitting the / module. 250 llvm::GlobalAlias *MetaClassPtrAlias; 251 /// All of the classes that have been generated for this compilation units. 252 std::vector<llvm::Constant*> Classes; 253 /// All of the categories that have been generated for this compilation units. 254 std::vector<llvm::Constant*> Categories; 255 /// All of the Objective-C constant strings that have been generated for this 256 /// compilation units. 257 std::vector<llvm::Constant*> ConstantStrings; 258 /// Map from string values to Objective-C constant strings in the output. 259 /// Used to prevent emitting Objective-C strings more than once. This should 260 /// not be required at all - CodeGenModule should manage this list. 261 llvm::StringMap<llvm::Constant*> ObjCStrings; 262 /// All of the protocols that have been declared. 263 llvm::StringMap<llvm::Constant*> ExistingProtocols; 264 /// For each variant of a selector, we store the type encoding and a 265 /// placeholder value. For an untyped selector, the type will be the empty 266 /// string. Selector references are all done via the module's selector table, 267 /// so we create an alias as a placeholder and then replace it with the real 268 /// value later. 269 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector; 270 /// Type of the selector map. This is roughly equivalent to the structure 271 /// used in the GNUstep runtime, which maintains a list of all of the valid 272 /// types for a selector in a table. 273 typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> > 274 SelectorMap; 275 /// A map from selectors to selector types. This allows us to emit all 276 /// selectors of the same name and type together. 277 SelectorMap SelectorTable; 278 279 /// Selectors related to memory management. When compiling in GC mode, we 280 /// omit these. 281 Selector RetainSel, ReleaseSel, AutoreleaseSel; 282 /// Runtime functions used for memory management in GC mode. Note that clang 283 /// supports code generation for calling these functions, but neither GNU 284 /// runtime actually supports this API properly yet. 285 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn, 286 WeakAssignFn, GlobalAssignFn; 287 288 typedef std::pair<std::string, std::string> ClassAliasPair; 289 /// All classes that have aliases set for them. 290 std::vector<ClassAliasPair> ClassAliases; 291 292protected: 293 /// Function used for throwing Objective-C exceptions. 294 LazyRuntimeFunction ExceptionThrowFn; 295 /// Function used for rethrowing exceptions, used at the end of \@finally or 296 /// \@synchronize blocks. 297 LazyRuntimeFunction ExceptionReThrowFn; 298 /// Function called when entering a catch function. This is required for 299 /// differentiating Objective-C exceptions and foreign exceptions. 300 LazyRuntimeFunction EnterCatchFn; 301 /// Function called when exiting from a catch block. Used to do exception 302 /// cleanup. 303 LazyRuntimeFunction ExitCatchFn; 304 /// Function called when entering an \@synchronize block. Acquires the lock. 305 LazyRuntimeFunction SyncEnterFn; 306 /// Function called when exiting an \@synchronize block. Releases the lock. 307 LazyRuntimeFunction SyncExitFn; 308 309private: 310 311 /// Function called if fast enumeration detects that the collection is 312 /// modified during the update. 313 LazyRuntimeFunction EnumerationMutationFn; 314 /// Function for implementing synthesized property getters that return an 315 /// object. 316 LazyRuntimeFunction GetPropertyFn; 317 /// Function for implementing synthesized property setters that return an 318 /// object. 319 LazyRuntimeFunction SetPropertyFn; 320 /// Function used for non-object declared property getters. 321 LazyRuntimeFunction GetStructPropertyFn; 322 /// Function used for non-object declared property setters. 323 LazyRuntimeFunction SetStructPropertyFn; 324 325 /// The version of the runtime that this class targets. Must match the 326 /// version in the runtime. 327 int RuntimeVersion; 328 /// The version of the protocol class. Used to differentiate between ObjC1 329 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional 330 /// components and can not contain declared properties. We always emit 331 /// Objective-C 2 property structures, but we have to pretend that they're 332 /// Objective-C 1 property structures when targeting the GCC runtime or it 333 /// will abort. 334 const int ProtocolVersion; 335private: 336 /// Generates an instance variable list structure. This is a structure 337 /// containing a size and an array of structures containing instance variable 338 /// metadata. This is used purely for introspection in the fragile ABI. In 339 /// the non-fragile ABI, it's used for instance variable fixup. 340 llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames, 341 ArrayRef<llvm::Constant *> IvarTypes, 342 ArrayRef<llvm::Constant *> IvarOffsets); 343 /// Generates a method list structure. This is a structure containing a size 344 /// and an array of structures containing method metadata. 345 /// 346 /// This structure is used by both classes and categories, and contains a next 347 /// pointer allowing them to be chained together in a linked list. 348 llvm::Constant *GenerateMethodList(const StringRef &ClassName, 349 const StringRef &CategoryName, 350 ArrayRef<Selector> MethodSels, 351 ArrayRef<llvm::Constant *> MethodTypes, 352 bool isClassMethodList); 353 /// Emits an empty protocol. This is used for \@protocol() where no protocol 354 /// is found. The runtime will (hopefully) fix up the pointer to refer to the 355 /// real protocol. 356 llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName); 357 /// Generates a list of property metadata structures. This follows the same 358 /// pattern as method and instance variable metadata lists. 359 llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID, 360 SmallVectorImpl<Selector> &InstanceMethodSels, 361 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes); 362 /// Generates a list of referenced protocols. Classes, categories, and 363 /// protocols all use this structure. 364 llvm::Constant *GenerateProtocolList(ArrayRef<std::string> Protocols); 365 /// To ensure that all protocols are seen by the runtime, we add a category on 366 /// a class defined in the runtime, declaring no methods, but adopting the 367 /// protocols. This is a horribly ugly hack, but it allows us to collect all 368 /// of the protocols without changing the ABI. 369 void GenerateProtocolHolderCategory(void); 370 /// Generates a class structure. 371 llvm::Constant *GenerateClassStructure( 372 llvm::Constant *MetaClass, 373 llvm::Constant *SuperClass, 374 unsigned info, 375 const char *Name, 376 llvm::Constant *Version, 377 llvm::Constant *InstanceSize, 378 llvm::Constant *IVars, 379 llvm::Constant *Methods, 380 llvm::Constant *Protocols, 381 llvm::Constant *IvarOffsets, 382 llvm::Constant *Properties, 383 llvm::Constant *StrongIvarBitmap, 384 llvm::Constant *WeakIvarBitmap, 385 bool isMeta=false); 386 /// Generates a method list. This is used by protocols to define the required 387 /// and optional methods. 388 llvm::Constant *GenerateProtocolMethodList( 389 ArrayRef<llvm::Constant *> MethodNames, 390 ArrayRef<llvm::Constant *> MethodTypes); 391 /// Returns a selector with the specified type encoding. An empty string is 392 /// used to return an untyped selector (with the types field set to NULL). 393 llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 394 const std::string &TypeEncoding, bool lval); 395 /// Returns the variable used to store the offset of an instance variable. 396 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID, 397 const ObjCIvarDecl *Ivar); 398 /// Emits a reference to a class. This allows the linker to object if there 399 /// is no class of the matching name. 400protected: 401 void EmitClassRef(const std::string &className); 402 /// Emits a pointer to the named class 403 virtual llvm::Value *GetClassNamed(CGBuilderTy &Builder, 404 const std::string &Name, bool isWeak); 405 /// Looks up the method for sending a message to the specified object. This 406 /// mechanism differs between the GCC and GNU runtimes, so this method must be 407 /// overridden in subclasses. 408 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 409 llvm::Value *&Receiver, 410 llvm::Value *cmd, 411 llvm::MDNode *node) = 0; 412 /// Looks up the method for sending a message to a superclass. This 413 /// mechanism differs between the GCC and GNU runtimes, so this method must 414 /// be overridden in subclasses. 415 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 416 llvm::Value *ObjCSuper, 417 llvm::Value *cmd) = 0; 418 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are 419 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63 420 /// bits set to their values, LSB first, while larger ones are stored in a 421 /// structure of this / form: 422 /// 423 /// struct { int32_t length; int32_t values[length]; }; 424 /// 425 /// The values in the array are stored in host-endian format, with the least 426 /// significant bit being assumed to come first in the bitfield. Therefore, 427 /// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, 428 /// while a bitfield / with the 63rd bit set will be 1<<64. 429 llvm::Constant *MakeBitField(ArrayRef<bool> bits); 430public: 431 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 432 unsigned protocolClassVersion); 433 434 virtual llvm::Constant *GenerateConstantString(const StringLiteral *); 435 436 virtual RValue 437 GenerateMessageSend(CodeGenFunction &CGF, 438 ReturnValueSlot Return, 439 QualType ResultType, 440 Selector Sel, 441 llvm::Value *Receiver, 442 const CallArgList &CallArgs, 443 const ObjCInterfaceDecl *Class, 444 const ObjCMethodDecl *Method); 445 virtual RValue 446 GenerateMessageSendSuper(CodeGenFunction &CGF, 447 ReturnValueSlot Return, 448 QualType ResultType, 449 Selector Sel, 450 const ObjCInterfaceDecl *Class, 451 bool isCategoryImpl, 452 llvm::Value *Receiver, 453 bool IsClassMessage, 454 const CallArgList &CallArgs, 455 const ObjCMethodDecl *Method); 456 virtual llvm::Value *GetClass(CGBuilderTy &Builder, 457 const ObjCInterfaceDecl *OID); 458 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 459 bool lval = false); 460 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 461 *Method); 462 virtual llvm::Constant *GetEHType(QualType T); 463 464 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 465 const ObjCContainerDecl *CD); 466 virtual void GenerateCategory(const ObjCCategoryImplDecl *CMD); 467 virtual void GenerateClass(const ObjCImplementationDecl *ClassDecl); 468 virtual void RegisterAlias(const ObjCCompatibleAliasDecl *OAD); 469 virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder, 470 const ObjCProtocolDecl *PD); 471 virtual void GenerateProtocol(const ObjCProtocolDecl *PD); 472 virtual llvm::Function *ModuleInitFunction(); 473 virtual llvm::Constant *GetPropertyGetFunction(); 474 virtual llvm::Constant *GetPropertySetFunction(); 475 virtual llvm::Constant *GetOptimizedPropertySetFunction(bool atomic, 476 bool copy); 477 virtual llvm::Constant *GetSetStructFunction(); 478 virtual llvm::Constant *GetCppAtomicObjectFunction(); 479 virtual llvm::Constant *GetGetStructFunction(); 480 virtual llvm::Constant *EnumerationMutationFunction(); 481 482 virtual void EmitTryStmt(CodeGenFunction &CGF, 483 const ObjCAtTryStmt &S); 484 virtual void EmitSynchronizedStmt(CodeGenFunction &CGF, 485 const ObjCAtSynchronizedStmt &S); 486 virtual void EmitThrowStmt(CodeGenFunction &CGF, 487 const ObjCAtThrowStmt &S); 488 virtual llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF, 489 llvm::Value *AddrWeakObj); 490 virtual void EmitObjCWeakAssign(CodeGenFunction &CGF, 491 llvm::Value *src, llvm::Value *dst); 492 virtual void EmitObjCGlobalAssign(CodeGenFunction &CGF, 493 llvm::Value *src, llvm::Value *dest, 494 bool threadlocal=false); 495 virtual void EmitObjCIvarAssign(CodeGenFunction &CGF, 496 llvm::Value *src, llvm::Value *dest, 497 llvm::Value *ivarOffset); 498 virtual void EmitObjCStrongCastAssign(CodeGenFunction &CGF, 499 llvm::Value *src, llvm::Value *dest); 500 virtual void EmitGCMemmoveCollectable(CodeGenFunction &CGF, 501 llvm::Value *DestPtr, 502 llvm::Value *SrcPtr, 503 llvm::Value *Size); 504 virtual LValue EmitObjCValueForIvar(CodeGenFunction &CGF, 505 QualType ObjectTy, 506 llvm::Value *BaseValue, 507 const ObjCIvarDecl *Ivar, 508 unsigned CVRQualifiers); 509 virtual llvm::Value *EmitIvarOffset(CodeGenFunction &CGF, 510 const ObjCInterfaceDecl *Interface, 511 const ObjCIvarDecl *Ivar); 512 virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CGBuilderTy &Builder); 513 virtual llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM, 514 const CGBlockInfo &blockInfo) { 515 return NULLPtr; 516 } 517 518 virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) { 519 return 0; 520 } 521}; 522/// Class representing the legacy GCC Objective-C ABI. This is the default when 523/// -fobjc-nonfragile-abi is not specified. 524/// 525/// The GCC ABI target actually generates code that is approximately compatible 526/// with the new GNUstep runtime ABI, but refrains from using any features that 527/// would not work with the GCC runtime. For example, clang always generates 528/// the extended form of the class structure, and the extra fields are simply 529/// ignored by GCC libobjc. 530class CGObjCGCC : public CGObjCGNU { 531 /// The GCC ABI message lookup function. Returns an IMP pointing to the 532 /// method implementation for this message. 533 LazyRuntimeFunction MsgLookupFn; 534 /// The GCC ABI superclass message lookup function. Takes a pointer to a 535 /// structure describing the receiver and the class, and a selector as 536 /// arguments. Returns the IMP for the corresponding method. 537 LazyRuntimeFunction MsgLookupSuperFn; 538protected: 539 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 540 llvm::Value *&Receiver, 541 llvm::Value *cmd, 542 llvm::MDNode *node) { 543 CGBuilderTy &Builder = CGF.Builder; 544 llvm::Value *args[] = { 545 EnforceType(Builder, Receiver, IdTy), 546 EnforceType(Builder, cmd, SelectorTy) }; 547 llvm::CallSite imp = CGF.EmitCallOrInvoke(MsgLookupFn, args); 548 imp->setMetadata(msgSendMDKind, node); 549 return imp.getInstruction(); 550 } 551 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 552 llvm::Value *ObjCSuper, 553 llvm::Value *cmd) { 554 CGBuilderTy &Builder = CGF.Builder; 555 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 556 PtrToObjCSuperTy), cmd}; 557 return Builder.CreateCall(MsgLookupSuperFn, lookupArgs); 558 } 559 public: 560 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) { 561 // IMP objc_msg_lookup(id, SEL); 562 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 563 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 564 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 565 PtrToObjCSuperTy, SelectorTy, NULL); 566 } 567}; 568/// Class used when targeting the new GNUstep runtime ABI. 569class CGObjCGNUstep : public CGObjCGNU { 570 /// The slot lookup function. Returns a pointer to a cacheable structure 571 /// that contains (among other things) the IMP. 572 LazyRuntimeFunction SlotLookupFn; 573 /// The GNUstep ABI superclass message lookup function. Takes a pointer to 574 /// a structure describing the receiver and the class, and a selector as 575 /// arguments. Returns the slot for the corresponding method. Superclass 576 /// message lookup rarely changes, so this is a good caching opportunity. 577 LazyRuntimeFunction SlotLookupSuperFn; 578 /// Type of an slot structure pointer. This is returned by the various 579 /// lookup functions. 580 llvm::Type *SlotTy; 581 protected: 582 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 583 llvm::Value *&Receiver, 584 llvm::Value *cmd, 585 llvm::MDNode *node) { 586 CGBuilderTy &Builder = CGF.Builder; 587 llvm::Function *LookupFn = SlotLookupFn; 588 589 // Store the receiver on the stack so that we can reload it later 590 llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType()); 591 Builder.CreateStore(Receiver, ReceiverPtr); 592 593 llvm::Value *self; 594 595 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) { 596 self = CGF.LoadObjCSelf(); 597 } else { 598 self = llvm::ConstantPointerNull::get(IdTy); 599 } 600 601 // The lookup function is guaranteed not to capture the receiver pointer. 602 LookupFn->setDoesNotCapture(1); 603 604 llvm::Value *args[] = { 605 EnforceType(Builder, ReceiverPtr, PtrToIdTy), 606 EnforceType(Builder, cmd, SelectorTy), 607 EnforceType(Builder, self, IdTy) }; 608 llvm::CallSite slot = CGF.EmitCallOrInvoke(LookupFn, args); 609 slot.setOnlyReadsMemory(); 610 slot->setMetadata(msgSendMDKind, node); 611 612 // Load the imp from the slot 613 llvm::Value *imp = 614 Builder.CreateLoad(Builder.CreateStructGEP(slot.getInstruction(), 4)); 615 616 // The lookup function may have changed the receiver, so make sure we use 617 // the new one. 618 Receiver = Builder.CreateLoad(ReceiverPtr, true); 619 return imp; 620 } 621 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 622 llvm::Value *ObjCSuper, 623 llvm::Value *cmd) { 624 CGBuilderTy &Builder = CGF.Builder; 625 llvm::Value *lookupArgs[] = {ObjCSuper, cmd}; 626 627 llvm::CallInst *slot = Builder.CreateCall(SlotLookupSuperFn, lookupArgs); 628 slot->setOnlyReadsMemory(); 629 630 return Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 631 } 632 public: 633 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) { 634 llvm::StructType *SlotStructTy = llvm::StructType::get(PtrTy, 635 PtrTy, PtrTy, IntTy, IMPTy, NULL); 636 SlotTy = llvm::PointerType::getUnqual(SlotStructTy); 637 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 638 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy, 639 SelectorTy, IdTy, NULL); 640 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL); 641 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy, 642 PtrToObjCSuperTy, SelectorTy, NULL); 643 // If we're in ObjC++ mode, then we want to make 644 if (CGM.getLangOpts().CPlusPlus) { 645 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 646 // void *__cxa_begin_catch(void *e) 647 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, NULL); 648 // void __cxa_end_catch(void) 649 ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, NULL); 650 // void _Unwind_Resume_or_Rethrow(void*) 651 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, PtrTy, NULL); 652 } 653 } 654}; 655 656/// The ObjFW runtime, which closely follows the GCC runtime's 657/// compiler ABI. Support here is due to Jonathan Schleifer, the 658/// ObjFW maintainer. 659class CGObjCObjFW : public CGObjCGCC { 660 /// Emit class references unconditionally as direct symbol references. 661 virtual llvm::Value *GetClassNamed(CGBuilderTy &Builder, 662 const std::string &Name, bool isWeak) { 663 if (isWeak) 664 return CGObjCGNU::GetClassNamed(Builder, Name, isWeak); 665 666 EmitClassRef(Name); 667 668 std::string SymbolName = "_OBJC_CLASS_" + Name; 669 670 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(SymbolName); 671 672 if (!ClassSymbol) 673 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 674 llvm::GlobalValue::ExternalLinkage, 675 0, SymbolName); 676 677 return ClassSymbol; 678 } 679 680public: 681 CGObjCObjFW(CodeGenModule &Mod): CGObjCGCC(Mod) {} 682}; 683} // end anonymous namespace 684 685 686/// Emits a reference to a dummy variable which is emitted with each class. 687/// This ensures that a linker error will be generated when trying to link 688/// together modules where a referenced class is not defined. 689void CGObjCGNU::EmitClassRef(const std::string &className) { 690 std::string symbolRef = "__objc_class_ref_" + className; 691 // Don't emit two copies of the same symbol 692 if (TheModule.getGlobalVariable(symbolRef)) 693 return; 694 std::string symbolName = "__objc_class_name_" + className; 695 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName); 696 if (!ClassSymbol) { 697 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 698 llvm::GlobalValue::ExternalLinkage, 0, symbolName); 699 } 700 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true, 701 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef); 702} 703 704static std::string SymbolNameForMethod(const StringRef &ClassName, 705 const StringRef &CategoryName, const Selector MethodName, 706 bool isClassMethod) { 707 std::string MethodNameColonStripped = MethodName.getAsString(); 708 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(), 709 ':', '_'); 710 return (Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" + 711 CategoryName + "_" + MethodNameColonStripped).str(); 712} 713 714CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 715 unsigned protocolClassVersion) 716 : CGObjCRuntime(cgm), TheModule(CGM.getModule()), 717 VMContext(cgm.getLLVMContext()), ClassPtrAlias(0), MetaClassPtrAlias(0), 718 RuntimeVersion(runtimeABIVersion), ProtocolVersion(protocolClassVersion) { 719 720 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend"); 721 722 CodeGenTypes &Types = CGM.getTypes(); 723 IntTy = cast<llvm::IntegerType>( 724 Types.ConvertType(CGM.getContext().IntTy)); 725 LongTy = cast<llvm::IntegerType>( 726 Types.ConvertType(CGM.getContext().LongTy)); 727 SizeTy = cast<llvm::IntegerType>( 728 Types.ConvertType(CGM.getContext().getSizeType())); 729 PtrDiffTy = cast<llvm::IntegerType>( 730 Types.ConvertType(CGM.getContext().getPointerDiffType())); 731 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy); 732 733 Int8Ty = llvm::Type::getInt8Ty(VMContext); 734 // C string type. Used in lots of places. 735 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); 736 737 Zeros[0] = llvm::ConstantInt::get(LongTy, 0); 738 Zeros[1] = Zeros[0]; 739 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty); 740 // Get the selector Type. 741 QualType selTy = CGM.getContext().getObjCSelType(); 742 if (QualType() == selTy) { 743 SelectorTy = PtrToInt8Ty; 744 } else { 745 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy)); 746 } 747 748 PtrToIntTy = llvm::PointerType::getUnqual(IntTy); 749 PtrTy = PtrToInt8Ty; 750 751 Int32Ty = llvm::Type::getInt32Ty(VMContext); 752 Int64Ty = llvm::Type::getInt64Ty(VMContext); 753 754 IntPtrTy = 755 TheModule.getPointerSize() == llvm::Module::Pointer32 ? Int32Ty : Int64Ty; 756 757 // Object type 758 QualType UnqualIdTy = CGM.getContext().getObjCIdType(); 759 ASTIdTy = CanQualType(); 760 if (UnqualIdTy != QualType()) { 761 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy); 762 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 763 } else { 764 IdTy = PtrToInt8Ty; 765 } 766 PtrToIdTy = llvm::PointerType::getUnqual(IdTy); 767 768 ObjCSuperTy = llvm::StructType::get(IdTy, IdTy, NULL); 769 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy); 770 771 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 772 773 // void objc_exception_throw(id); 774 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 775 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 776 // int objc_sync_enter(id); 777 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, NULL); 778 // int objc_sync_exit(id); 779 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, NULL); 780 781 // void objc_enumerationMutation (id) 782 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, 783 IdTy, NULL); 784 785 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL) 786 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy, 787 PtrDiffTy, BoolTy, NULL); 788 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL) 789 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy, 790 PtrDiffTy, IdTy, BoolTy, BoolTy, NULL); 791 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 792 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy, 793 PtrDiffTy, BoolTy, BoolTy, NULL); 794 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 795 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy, 796 PtrDiffTy, BoolTy, BoolTy, NULL); 797 798 // IMP type 799 llvm::Type *IMPArgs[] = { IdTy, SelectorTy }; 800 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs, 801 true)); 802 803 const LangOptions &Opts = CGM.getLangOpts(); 804 if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount) 805 RuntimeVersion = 10; 806 807 // Don't bother initialising the GC stuff unless we're compiling in GC mode 808 if (Opts.getGC() != LangOptions::NonGC) { 809 // This is a bit of an hack. We should sort this out by having a proper 810 // CGObjCGNUstep subclass for GC, but we may want to really support the old 811 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now 812 // Get selectors needed in GC mode 813 RetainSel = GetNullarySelector("retain", CGM.getContext()); 814 ReleaseSel = GetNullarySelector("release", CGM.getContext()); 815 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext()); 816 817 // Get functions needed in GC mode 818 819 // id objc_assign_ivar(id, id, ptrdiff_t); 820 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy, 821 NULL); 822 // id objc_assign_strongCast (id, id*) 823 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy, 824 PtrToIdTy, NULL); 825 // id objc_assign_global(id, id*); 826 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy, 827 NULL); 828 // id objc_assign_weak(id, id*); 829 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, NULL); 830 // id objc_read_weak(id*); 831 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, NULL); 832 // void *objc_memmove_collectable(void*, void *, size_t); 833 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy, 834 SizeTy, NULL); 835 } 836} 837 838llvm::Value *CGObjCGNU::GetClassNamed(CGBuilderTy &Builder, 839 const std::string &Name, 840 bool isWeak) { 841 llvm::Value *ClassName = CGM.GetAddrOfConstantCString(Name); 842 // With the incompatible ABI, this will need to be replaced with a direct 843 // reference to the class symbol. For the compatible nonfragile ABI we are 844 // still performing this lookup at run time but emitting the symbol for the 845 // class externally so that we can make the switch later. 846 // 847 // Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class 848 // with memoized versions or with static references if it's safe to do so. 849 if (!isWeak) 850 EmitClassRef(Name); 851 ClassName = Builder.CreateStructGEP(ClassName, 0); 852 853 llvm::Constant *ClassLookupFn = 854 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true), 855 "objc_lookup_class"); 856 return Builder.CreateCall(ClassLookupFn, ClassName); 857} 858 859// This has to perform the lookup every time, since posing and related 860// techniques can modify the name -> class mapping. 861llvm::Value *CGObjCGNU::GetClass(CGBuilderTy &Builder, 862 const ObjCInterfaceDecl *OID) { 863 return GetClassNamed(Builder, OID->getNameAsString(), OID->isWeakImported()); 864} 865llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CGBuilderTy &Builder) { 866 return GetClassNamed(Builder, "NSAutoreleasePool", false); 867} 868 869llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 870 const std::string &TypeEncoding, bool lval) { 871 872 SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel]; 873 llvm::GlobalAlias *SelValue = 0; 874 875 876 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 877 e = Types.end() ; i!=e ; i++) { 878 if (i->first == TypeEncoding) { 879 SelValue = i->second; 880 break; 881 } 882 } 883 if (0 == SelValue) { 884 SelValue = new llvm::GlobalAlias(SelectorTy, 885 llvm::GlobalValue::PrivateLinkage, 886 ".objc_selector_"+Sel.getAsString(), NULL, 887 &TheModule); 888 Types.push_back(TypedSelector(TypeEncoding, SelValue)); 889 } 890 891 if (lval) { 892 llvm::Value *tmp = Builder.CreateAlloca(SelValue->getType()); 893 Builder.CreateStore(SelValue, tmp); 894 return tmp; 895 } 896 return SelValue; 897} 898 899llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 900 bool lval) { 901 return GetSelector(Builder, Sel, std::string(), lval); 902} 903 904llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 905 *Method) { 906 std::string SelTypes; 907 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes); 908 return GetSelector(Builder, Method->getSelector(), SelTypes, false); 909} 910 911llvm::Constant *CGObjCGNU::GetEHType(QualType T) { 912 if (!CGM.getLangOpts().CPlusPlus) { 913 if (T->isObjCIdType() 914 || T->isObjCQualifiedIdType()) { 915 // With the old ABI, there was only one kind of catchall, which broke 916 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as 917 // a pointer indicating object catchalls, and NULL to indicate real 918 // catchalls 919 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 920 return MakeConstantString("@id"); 921 } else { 922 return 0; 923 } 924 } 925 926 // All other types should be Objective-C interface pointer types. 927 const ObjCObjectPointerType *OPT = 928 T->getAs<ObjCObjectPointerType>(); 929 assert(OPT && "Invalid @catch type."); 930 const ObjCInterfaceDecl *IDecl = 931 OPT->getObjectType()->getInterface(); 932 assert(IDecl && "Invalid @catch type."); 933 return MakeConstantString(IDecl->getIdentifier()->getName()); 934 } 935 // For Objective-C++, we want to provide the ability to catch both C++ and 936 // Objective-C objects in the same function. 937 938 // There's a particular fixed type info for 'id'. 939 if (T->isObjCIdType() || 940 T->isObjCQualifiedIdType()) { 941 llvm::Constant *IDEHType = 942 CGM.getModule().getGlobalVariable("__objc_id_type_info"); 943 if (!IDEHType) 944 IDEHType = 945 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty, 946 false, 947 llvm::GlobalValue::ExternalLinkage, 948 0, "__objc_id_type_info"); 949 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty); 950 } 951 952 const ObjCObjectPointerType *PT = 953 T->getAs<ObjCObjectPointerType>(); 954 assert(PT && "Invalid @catch type."); 955 const ObjCInterfaceType *IT = PT->getInterfaceType(); 956 assert(IT && "Invalid @catch type."); 957 std::string className = IT->getDecl()->getIdentifier()->getName(); 958 959 std::string typeinfoName = "__objc_eh_typeinfo_" + className; 960 961 // Return the existing typeinfo if it exists 962 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName); 963 if (typeinfo) 964 return llvm::ConstantExpr::getBitCast(typeinfo, PtrToInt8Ty); 965 966 // Otherwise create it. 967 968 // vtable for gnustep::libobjc::__objc_class_type_info 969 // It's quite ugly hard-coding this. Ideally we'd generate it using the host 970 // platform's name mangling. 971 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE"; 972 llvm::Constant *Vtable = TheModule.getGlobalVariable(vtableName); 973 if (!Vtable) { 974 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true, 975 llvm::GlobalValue::ExternalLinkage, 0, vtableName); 976 } 977 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2); 978 Vtable = llvm::ConstantExpr::getGetElementPtr(Vtable, Two); 979 Vtable = llvm::ConstantExpr::getBitCast(Vtable, PtrToInt8Ty); 980 981 llvm::Constant *typeName = 982 ExportUniqueString(className, "__objc_eh_typename_"); 983 984 std::vector<llvm::Constant*> fields; 985 fields.push_back(Vtable); 986 fields.push_back(typeName); 987 llvm::Constant *TI = 988 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 989 NULL), fields, "__objc_eh_typeinfo_" + className, 990 llvm::GlobalValue::LinkOnceODRLinkage); 991 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty); 992} 993 994/// Generate an NSConstantString object. 995llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) { 996 997 std::string Str = SL->getString().str(); 998 999 // Look for an existing one 1000 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str); 1001 if (old != ObjCStrings.end()) 1002 return old->getValue(); 1003 1004 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass; 1005 1006 if (StringClass.empty()) StringClass = "NXConstantString"; 1007 1008 std::string Sym = "_OBJC_CLASS_"; 1009 Sym += StringClass; 1010 1011 llvm::Constant *isa = TheModule.getNamedGlobal(Sym); 1012 1013 if (!isa) 1014 isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false, 1015 llvm::GlobalValue::ExternalWeakLinkage, 0, Sym); 1016 else if (isa->getType() != PtrToIdTy) 1017 isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy); 1018 1019 std::vector<llvm::Constant*> Ivars; 1020 Ivars.push_back(isa); 1021 Ivars.push_back(MakeConstantString(Str)); 1022 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size())); 1023 llvm::Constant *ObjCStr = MakeGlobal( 1024 llvm::StructType::get(PtrToIdTy, PtrToInt8Ty, IntTy, NULL), 1025 Ivars, ".objc_str"); 1026 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty); 1027 ObjCStrings[Str] = ObjCStr; 1028 ConstantStrings.push_back(ObjCStr); 1029 return ObjCStr; 1030} 1031 1032///Generates a message send where the super is the receiver. This is a message 1033///send to self with special delivery semantics indicating which class's method 1034///should be called. 1035RValue 1036CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF, 1037 ReturnValueSlot Return, 1038 QualType ResultType, 1039 Selector Sel, 1040 const ObjCInterfaceDecl *Class, 1041 bool isCategoryImpl, 1042 llvm::Value *Receiver, 1043 bool IsClassMessage, 1044 const CallArgList &CallArgs, 1045 const ObjCMethodDecl *Method) { 1046 CGBuilderTy &Builder = CGF.Builder; 1047 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) { 1048 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1049 return RValue::get(EnforceType(Builder, Receiver, 1050 CGM.getTypes().ConvertType(ResultType))); 1051 } 1052 if (Sel == ReleaseSel) { 1053 return RValue::get(0); 1054 } 1055 } 1056 1057 llvm::Value *cmd = GetSelector(Builder, Sel); 1058 1059 1060 CallArgList ActualArgs; 1061 1062 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy); 1063 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1064 ActualArgs.addFrom(CallArgs); 1065 1066 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs); 1067 1068 llvm::Value *ReceiverClass = 0; 1069 if (isCategoryImpl) { 1070 llvm::Constant *classLookupFunction = 0; 1071 if (IsClassMessage) { 1072 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1073 IdTy, PtrTy, true), "objc_get_meta_class"); 1074 } else { 1075 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1076 IdTy, PtrTy, true), "objc_get_class"); 1077 } 1078 ReceiverClass = Builder.CreateCall(classLookupFunction, 1079 MakeConstantString(Class->getNameAsString())); 1080 } else { 1081 // Set up global aliases for the metaclass or class pointer if they do not 1082 // already exist. These will are forward-references which will be set to 1083 // pointers to the class and metaclass structure created for the runtime 1084 // load function. To send a message to super, we look up the value of the 1085 // super_class pointer from either the class or metaclass structure. 1086 if (IsClassMessage) { 1087 if (!MetaClassPtrAlias) { 1088 MetaClassPtrAlias = new llvm::GlobalAlias(IdTy, 1089 llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" + 1090 Class->getNameAsString(), NULL, &TheModule); 1091 } 1092 ReceiverClass = MetaClassPtrAlias; 1093 } else { 1094 if (!ClassPtrAlias) { 1095 ClassPtrAlias = new llvm::GlobalAlias(IdTy, 1096 llvm::GlobalValue::InternalLinkage, ".objc_class_ref" + 1097 Class->getNameAsString(), NULL, &TheModule); 1098 } 1099 ReceiverClass = ClassPtrAlias; 1100 } 1101 } 1102 // Cast the pointer to a simplified version of the class structure 1103 ReceiverClass = Builder.CreateBitCast(ReceiverClass, 1104 llvm::PointerType::getUnqual( 1105 llvm::StructType::get(IdTy, IdTy, NULL))); 1106 // Get the superclass pointer 1107 ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1); 1108 // Load the superclass pointer 1109 ReceiverClass = Builder.CreateLoad(ReceiverClass); 1110 // Construct the structure used to look up the IMP 1111 llvm::StructType *ObjCSuperTy = llvm::StructType::get( 1112 Receiver->getType(), IdTy, NULL); 1113 llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy); 1114 1115 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0)); 1116 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1)); 1117 1118 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy); 1119 1120 // Get the IMP 1121 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd); 1122 imp = EnforceType(Builder, imp, MSI.MessengerType); 1123 1124 llvm::Value *impMD[] = { 1125 llvm::MDString::get(VMContext, Sel.getAsString()), 1126 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()), 1127 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage) 1128 }; 1129 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1130 1131 llvm::Instruction *call; 1132 RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs, 0, &call); 1133 call->setMetadata(msgSendMDKind, node); 1134 return msgRet; 1135} 1136 1137/// Generate code for a message send expression. 1138RValue 1139CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF, 1140 ReturnValueSlot Return, 1141 QualType ResultType, 1142 Selector Sel, 1143 llvm::Value *Receiver, 1144 const CallArgList &CallArgs, 1145 const ObjCInterfaceDecl *Class, 1146 const ObjCMethodDecl *Method) { 1147 CGBuilderTy &Builder = CGF.Builder; 1148 1149 // Strip out message sends to retain / release in GC mode 1150 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) { 1151 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1152 return RValue::get(EnforceType(Builder, Receiver, 1153 CGM.getTypes().ConvertType(ResultType))); 1154 } 1155 if (Sel == ReleaseSel) { 1156 return RValue::get(0); 1157 } 1158 } 1159 1160 // If the return type is something that goes in an integer register, the 1161 // runtime will handle 0 returns. For other cases, we fill in the 0 value 1162 // ourselves. 1163 // 1164 // The language spec says the result of this kind of message send is 1165 // undefined, but lots of people seem to have forgotten to read that 1166 // paragraph and insist on sending messages to nil that have structure 1167 // returns. With GCC, this generates a random return value (whatever happens 1168 // to be on the stack / in those registers at the time) on most platforms, 1169 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts 1170 // the stack. 1171 bool isPointerSizedReturn = (ResultType->isAnyPointerType() || 1172 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType()); 1173 1174 llvm::BasicBlock *startBB = 0; 1175 llvm::BasicBlock *messageBB = 0; 1176 llvm::BasicBlock *continueBB = 0; 1177 1178 if (!isPointerSizedReturn) { 1179 startBB = Builder.GetInsertBlock(); 1180 messageBB = CGF.createBasicBlock("msgSend"); 1181 continueBB = CGF.createBasicBlock("continue"); 1182 1183 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver, 1184 llvm::Constant::getNullValue(Receiver->getType())); 1185 Builder.CreateCondBr(isNil, continueBB, messageBB); 1186 CGF.EmitBlock(messageBB); 1187 } 1188 1189 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 1190 llvm::Value *cmd; 1191 if (Method) 1192 cmd = GetSelector(Builder, Method); 1193 else 1194 cmd = GetSelector(Builder, Sel); 1195 cmd = EnforceType(Builder, cmd, SelectorTy); 1196 Receiver = EnforceType(Builder, Receiver, IdTy); 1197 1198 llvm::Value *impMD[] = { 1199 llvm::MDString::get(VMContext, Sel.getAsString()), 1200 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""), 1201 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0) 1202 }; 1203 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1204 1205 CallArgList ActualArgs; 1206 ActualArgs.add(RValue::get(Receiver), ASTIdTy); 1207 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1208 ActualArgs.addFrom(CallArgs); 1209 1210 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs); 1211 1212 // Get the IMP to call 1213 llvm::Value *imp; 1214 1215 // If we have non-legacy dispatch specified, we try using the objc_msgSend() 1216 // functions. These are not supported on all platforms (or all runtimes on a 1217 // given platform), so we 1218 switch (CGM.getCodeGenOpts().getObjCDispatchMethod()) { 1219 case CodeGenOptions::Legacy: 1220 imp = LookupIMP(CGF, Receiver, cmd, node); 1221 break; 1222 case CodeGenOptions::Mixed: 1223 case CodeGenOptions::NonLegacy: 1224 if (CGM.ReturnTypeUsesFPRet(ResultType)) { 1225 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1226 "objc_msgSend_fpret"); 1227 } else if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) { 1228 // The actual types here don't matter - we're going to bitcast the 1229 // function anyway 1230 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1231 "objc_msgSend_stret"); 1232 } else { 1233 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1234 "objc_msgSend"); 1235 } 1236 } 1237 1238 // Reset the receiver in case the lookup modified it 1239 ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy, false); 1240 1241 imp = EnforceType(Builder, imp, MSI.MessengerType); 1242 1243 llvm::Instruction *call; 1244 RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs, 1245 0, &call); 1246 call->setMetadata(msgSendMDKind, node); 1247 1248 1249 if (!isPointerSizedReturn) { 1250 messageBB = CGF.Builder.GetInsertBlock(); 1251 CGF.Builder.CreateBr(continueBB); 1252 CGF.EmitBlock(continueBB); 1253 if (msgRet.isScalar()) { 1254 llvm::Value *v = msgRet.getScalarVal(); 1255 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1256 phi->addIncoming(v, messageBB); 1257 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB); 1258 msgRet = RValue::get(phi); 1259 } else if (msgRet.isAggregate()) { 1260 llvm::Value *v = msgRet.getAggregateAddr(); 1261 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1262 llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType()); 1263 llvm::AllocaInst *NullVal = 1264 CGF.CreateTempAlloca(RetTy->getElementType(), "null"); 1265 CGF.InitTempAlloca(NullVal, 1266 llvm::Constant::getNullValue(RetTy->getElementType())); 1267 phi->addIncoming(v, messageBB); 1268 phi->addIncoming(NullVal, startBB); 1269 msgRet = RValue::getAggregate(phi); 1270 } else /* isComplex() */ { 1271 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal(); 1272 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2); 1273 phi->addIncoming(v.first, messageBB); 1274 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()), 1275 startBB); 1276 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2); 1277 phi2->addIncoming(v.second, messageBB); 1278 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()), 1279 startBB); 1280 msgRet = RValue::getComplex(phi, phi2); 1281 } 1282 } 1283 return msgRet; 1284} 1285 1286/// Generates a MethodList. Used in construction of a objc_class and 1287/// objc_category structures. 1288llvm::Constant *CGObjCGNU:: 1289GenerateMethodList(const StringRef &ClassName, 1290 const StringRef &CategoryName, 1291 ArrayRef<Selector> MethodSels, 1292 ArrayRef<llvm::Constant *> MethodTypes, 1293 bool isClassMethodList) { 1294 if (MethodSels.empty()) 1295 return NULLPtr; 1296 // Get the method structure type. 1297 llvm::StructType *ObjCMethodTy = llvm::StructType::get( 1298 PtrToInt8Ty, // Really a selector, but the runtime creates it us. 1299 PtrToInt8Ty, // Method types 1300 IMPTy, //Method pointer 1301 NULL); 1302 std::vector<llvm::Constant*> Methods; 1303 std::vector<llvm::Constant*> Elements; 1304 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) { 1305 Elements.clear(); 1306 llvm::Constant *Method = 1307 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName, 1308 MethodSels[i], 1309 isClassMethodList)); 1310 assert(Method && "Can't generate metadata for method that doesn't exist"); 1311 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString()); 1312 Elements.push_back(C); 1313 Elements.push_back(MethodTypes[i]); 1314 Method = llvm::ConstantExpr::getBitCast(Method, 1315 IMPTy); 1316 Elements.push_back(Method); 1317 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements)); 1318 } 1319 1320 // Array of method structures 1321 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy, 1322 Methods.size()); 1323 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy, 1324 Methods); 1325 1326 // Structure containing list pointer, array and array count 1327 llvm::StructType *ObjCMethodListTy = llvm::StructType::create(VMContext); 1328 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(ObjCMethodListTy); 1329 ObjCMethodListTy->setBody( 1330 NextPtrTy, 1331 IntTy, 1332 ObjCMethodArrayTy, 1333 NULL); 1334 1335 Methods.clear(); 1336 Methods.push_back(llvm::ConstantPointerNull::get( 1337 llvm::PointerType::getUnqual(ObjCMethodListTy))); 1338 Methods.push_back(llvm::ConstantInt::get(Int32Ty, MethodTypes.size())); 1339 Methods.push_back(MethodArray); 1340 1341 // Create an instance of the structure 1342 return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list"); 1343} 1344 1345/// Generates an IvarList. Used in construction of a objc_class. 1346llvm::Constant *CGObjCGNU:: 1347GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames, 1348 ArrayRef<llvm::Constant *> IvarTypes, 1349 ArrayRef<llvm::Constant *> IvarOffsets) { 1350 if (IvarNames.size() == 0) 1351 return NULLPtr; 1352 // Get the method structure type. 1353 llvm::StructType *ObjCIvarTy = llvm::StructType::get( 1354 PtrToInt8Ty, 1355 PtrToInt8Ty, 1356 IntTy, 1357 NULL); 1358 std::vector<llvm::Constant*> Ivars; 1359 std::vector<llvm::Constant*> Elements; 1360 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) { 1361 Elements.clear(); 1362 Elements.push_back(IvarNames[i]); 1363 Elements.push_back(IvarTypes[i]); 1364 Elements.push_back(IvarOffsets[i]); 1365 Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements)); 1366 } 1367 1368 // Array of method structures 1369 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy, 1370 IvarNames.size()); 1371 1372 1373 Elements.clear(); 1374 Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size())); 1375 Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)); 1376 // Structure containing array and array count 1377 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(IntTy, 1378 ObjCIvarArrayTy, 1379 NULL); 1380 1381 // Create an instance of the structure 1382 return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list"); 1383} 1384 1385/// Generate a class structure 1386llvm::Constant *CGObjCGNU::GenerateClassStructure( 1387 llvm::Constant *MetaClass, 1388 llvm::Constant *SuperClass, 1389 unsigned info, 1390 const char *Name, 1391 llvm::Constant *Version, 1392 llvm::Constant *InstanceSize, 1393 llvm::Constant *IVars, 1394 llvm::Constant *Methods, 1395 llvm::Constant *Protocols, 1396 llvm::Constant *IvarOffsets, 1397 llvm::Constant *Properties, 1398 llvm::Constant *StrongIvarBitmap, 1399 llvm::Constant *WeakIvarBitmap, 1400 bool isMeta) { 1401 // Set up the class structure 1402 // Note: Several of these are char*s when they should be ids. This is 1403 // because the runtime performs this translation on load. 1404 // 1405 // Fields marked New ABI are part of the GNUstep runtime. We emit them 1406 // anyway; the classes will still work with the GNU runtime, they will just 1407 // be ignored. 1408 llvm::StructType *ClassTy = llvm::StructType::get( 1409 PtrToInt8Ty, // isa 1410 PtrToInt8Ty, // super_class 1411 PtrToInt8Ty, // name 1412 LongTy, // version 1413 LongTy, // info 1414 LongTy, // instance_size 1415 IVars->getType(), // ivars 1416 Methods->getType(), // methods 1417 // These are all filled in by the runtime, so we pretend 1418 PtrTy, // dtable 1419 PtrTy, // subclass_list 1420 PtrTy, // sibling_class 1421 PtrTy, // protocols 1422 PtrTy, // gc_object_type 1423 // New ABI: 1424 LongTy, // abi_version 1425 IvarOffsets->getType(), // ivar_offsets 1426 Properties->getType(), // properties 1427 IntPtrTy, // strong_pointers 1428 IntPtrTy, // weak_pointers 1429 NULL); 1430 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0); 1431 // Fill in the structure 1432 std::vector<llvm::Constant*> Elements; 1433 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty)); 1434 Elements.push_back(SuperClass); 1435 Elements.push_back(MakeConstantString(Name, ".class_name")); 1436 Elements.push_back(Zero); 1437 Elements.push_back(llvm::ConstantInt::get(LongTy, info)); 1438 if (isMeta) { 1439 llvm::TargetData td(&TheModule); 1440 Elements.push_back( 1441 llvm::ConstantInt::get(LongTy, 1442 td.getTypeSizeInBits(ClassTy) / 1443 CGM.getContext().getCharWidth())); 1444 } else 1445 Elements.push_back(InstanceSize); 1446 Elements.push_back(IVars); 1447 Elements.push_back(Methods); 1448 Elements.push_back(NULLPtr); 1449 Elements.push_back(NULLPtr); 1450 Elements.push_back(NULLPtr); 1451 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy)); 1452 Elements.push_back(NULLPtr); 1453 Elements.push_back(llvm::ConstantInt::get(LongTy, 1)); 1454 Elements.push_back(IvarOffsets); 1455 Elements.push_back(Properties); 1456 Elements.push_back(StrongIvarBitmap); 1457 Elements.push_back(WeakIvarBitmap); 1458 // Create an instance of the structure 1459 // This is now an externally visible symbol, so that we can speed up class 1460 // messages in the next ABI. We may already have some weak references to 1461 // this, so check and fix them properly. 1462 std::string ClassSym((isMeta ? "_OBJC_METACLASS_": "_OBJC_CLASS_") + 1463 std::string(Name)); 1464 llvm::GlobalVariable *ClassRef = TheModule.getNamedGlobal(ClassSym); 1465 llvm::Constant *Class = MakeGlobal(ClassTy, Elements, ClassSym, 1466 llvm::GlobalValue::ExternalLinkage); 1467 if (ClassRef) { 1468 ClassRef->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(Class, 1469 ClassRef->getType())); 1470 ClassRef->removeFromParent(); 1471 Class->setName(ClassSym); 1472 } 1473 return Class; 1474} 1475 1476llvm::Constant *CGObjCGNU:: 1477GenerateProtocolMethodList(ArrayRef<llvm::Constant *> MethodNames, 1478 ArrayRef<llvm::Constant *> MethodTypes) { 1479 // Get the method structure type. 1480 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get( 1481 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us. 1482 PtrToInt8Ty, 1483 NULL); 1484 std::vector<llvm::Constant*> Methods; 1485 std::vector<llvm::Constant*> Elements; 1486 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) { 1487 Elements.clear(); 1488 Elements.push_back(MethodNames[i]); 1489 Elements.push_back(MethodTypes[i]); 1490 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements)); 1491 } 1492 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy, 1493 MethodNames.size()); 1494 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy, 1495 Methods); 1496 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get( 1497 IntTy, ObjCMethodArrayTy, NULL); 1498 Methods.clear(); 1499 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size())); 1500 Methods.push_back(Array); 1501 return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list"); 1502} 1503 1504// Create the protocol list structure used in classes, categories and so on 1505llvm::Constant *CGObjCGNU::GenerateProtocolList(ArrayRef<std::string>Protocols){ 1506 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 1507 Protocols.size()); 1508 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1509 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1510 SizeTy, 1511 ProtocolArrayTy, 1512 NULL); 1513 std::vector<llvm::Constant*> Elements; 1514 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end(); 1515 iter != endIter ; iter++) { 1516 llvm::Constant *protocol = 0; 1517 llvm::StringMap<llvm::Constant*>::iterator value = 1518 ExistingProtocols.find(*iter); 1519 if (value == ExistingProtocols.end()) { 1520 protocol = GenerateEmptyProtocol(*iter); 1521 } else { 1522 protocol = value->getValue(); 1523 } 1524 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol, 1525 PtrToInt8Ty); 1526 Elements.push_back(Ptr); 1527 } 1528 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1529 Elements); 1530 Elements.clear(); 1531 Elements.push_back(NULLPtr); 1532 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size())); 1533 Elements.push_back(ProtocolArray); 1534 return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list"); 1535} 1536 1537llvm::Value *CGObjCGNU::GenerateProtocolRef(CGBuilderTy &Builder, 1538 const ObjCProtocolDecl *PD) { 1539 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()]; 1540 llvm::Type *T = 1541 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType()); 1542 return Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T)); 1543} 1544 1545llvm::Constant *CGObjCGNU::GenerateEmptyProtocol( 1546 const std::string &ProtocolName) { 1547 SmallVector<std::string, 0> EmptyStringVector; 1548 SmallVector<llvm::Constant*, 0> EmptyConstantVector; 1549 1550 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector); 1551 llvm::Constant *MethodList = 1552 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector); 1553 // Protocols are objects containing lists of the methods implemented and 1554 // protocols adopted. 1555 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1556 PtrToInt8Ty, 1557 ProtocolList->getType(), 1558 MethodList->getType(), 1559 MethodList->getType(), 1560 MethodList->getType(), 1561 MethodList->getType(), 1562 NULL); 1563 std::vector<llvm::Constant*> Elements; 1564 // The isa pointer must be set to a magic number so the runtime knows it's 1565 // the correct layout. 1566 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1567 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy)); 1568 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1569 Elements.push_back(ProtocolList); 1570 Elements.push_back(MethodList); 1571 Elements.push_back(MethodList); 1572 Elements.push_back(MethodList); 1573 Elements.push_back(MethodList); 1574 return MakeGlobal(ProtocolTy, Elements, ".objc_protocol"); 1575} 1576 1577void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) { 1578 ASTContext &Context = CGM.getContext(); 1579 std::string ProtocolName = PD->getNameAsString(); 1580 1581 // Use the protocol definition, if there is one. 1582 if (const ObjCProtocolDecl *Def = PD->getDefinition()) 1583 PD = Def; 1584 1585 SmallVector<std::string, 16> Protocols; 1586 for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(), 1587 E = PD->protocol_end(); PI != E; ++PI) 1588 Protocols.push_back((*PI)->getNameAsString()); 1589 SmallVector<llvm::Constant*, 16> InstanceMethodNames; 1590 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1591 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames; 1592 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes; 1593 for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(), 1594 E = PD->instmeth_end(); iter != E; iter++) { 1595 std::string TypeStr; 1596 Context.getObjCEncodingForMethodDecl(*iter, TypeStr); 1597 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1598 InstanceMethodNames.push_back( 1599 MakeConstantString((*iter)->getSelector().getAsString())); 1600 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1601 } else { 1602 OptionalInstanceMethodNames.push_back( 1603 MakeConstantString((*iter)->getSelector().getAsString())); 1604 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1605 } 1606 } 1607 // Collect information about class methods: 1608 SmallVector<llvm::Constant*, 16> ClassMethodNames; 1609 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1610 SmallVector<llvm::Constant*, 16> OptionalClassMethodNames; 1611 SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes; 1612 for (ObjCProtocolDecl::classmeth_iterator 1613 iter = PD->classmeth_begin(), endIter = PD->classmeth_end(); 1614 iter != endIter ; iter++) { 1615 std::string TypeStr; 1616 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1617 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1618 ClassMethodNames.push_back( 1619 MakeConstantString((*iter)->getSelector().getAsString())); 1620 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1621 } else { 1622 OptionalClassMethodNames.push_back( 1623 MakeConstantString((*iter)->getSelector().getAsString())); 1624 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1625 } 1626 } 1627 1628 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols); 1629 llvm::Constant *InstanceMethodList = 1630 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes); 1631 llvm::Constant *ClassMethodList = 1632 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes); 1633 llvm::Constant *OptionalInstanceMethodList = 1634 GenerateProtocolMethodList(OptionalInstanceMethodNames, 1635 OptionalInstanceMethodTypes); 1636 llvm::Constant *OptionalClassMethodList = 1637 GenerateProtocolMethodList(OptionalClassMethodNames, 1638 OptionalClassMethodTypes); 1639 1640 // Property metadata: name, attributes, isSynthesized, setter name, setter 1641 // types, getter name, getter types. 1642 // The isSynthesized value is always set to 0 in a protocol. It exists to 1643 // simplify the runtime library by allowing it to use the same data 1644 // structures for protocol metadata everywhere. 1645 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1646 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1647 PtrToInt8Ty, NULL); 1648 std::vector<llvm::Constant*> Properties; 1649 std::vector<llvm::Constant*> OptionalProperties; 1650 1651 // Add all of the property methods need adding to the method list and to the 1652 // property metadata list. 1653 for (ObjCContainerDecl::prop_iterator 1654 iter = PD->prop_begin(), endIter = PD->prop_end(); 1655 iter != endIter ; iter++) { 1656 std::vector<llvm::Constant*> Fields; 1657 ObjCPropertyDecl *property = *iter; 1658 1659 Fields.push_back(MakeConstantString(property->getNameAsString())); 1660 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1661 property->getPropertyAttributes())); 1662 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 1663 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1664 std::string TypeStr; 1665 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1666 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1667 InstanceMethodTypes.push_back(TypeEncoding); 1668 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1669 Fields.push_back(TypeEncoding); 1670 } else { 1671 Fields.push_back(NULLPtr); 1672 Fields.push_back(NULLPtr); 1673 } 1674 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1675 std::string TypeStr; 1676 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1677 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1678 InstanceMethodTypes.push_back(TypeEncoding); 1679 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1680 Fields.push_back(TypeEncoding); 1681 } else { 1682 Fields.push_back(NULLPtr); 1683 Fields.push_back(NULLPtr); 1684 } 1685 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) { 1686 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1687 } else { 1688 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1689 } 1690 } 1691 llvm::Constant *PropertyArray = llvm::ConstantArray::get( 1692 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties); 1693 llvm::Constant* PropertyListInitFields[] = 1694 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1695 1696 llvm::Constant *PropertyListInit = 1697 llvm::ConstantStruct::getAnon(PropertyListInitFields); 1698 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule, 1699 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage, 1700 PropertyListInit, ".objc_property_list"); 1701 1702 llvm::Constant *OptionalPropertyArray = 1703 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy, 1704 OptionalProperties.size()) , OptionalProperties); 1705 llvm::Constant* OptionalPropertyListInitFields[] = { 1706 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr, 1707 OptionalPropertyArray }; 1708 1709 llvm::Constant *OptionalPropertyListInit = 1710 llvm::ConstantStruct::getAnon(OptionalPropertyListInitFields); 1711 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule, 1712 OptionalPropertyListInit->getType(), false, 1713 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit, 1714 ".objc_property_list"); 1715 1716 // Protocols are objects containing lists of the methods implemented and 1717 // protocols adopted. 1718 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1719 PtrToInt8Ty, 1720 ProtocolList->getType(), 1721 InstanceMethodList->getType(), 1722 ClassMethodList->getType(), 1723 OptionalInstanceMethodList->getType(), 1724 OptionalClassMethodList->getType(), 1725 PropertyList->getType(), 1726 OptionalPropertyList->getType(), 1727 NULL); 1728 std::vector<llvm::Constant*> Elements; 1729 // The isa pointer must be set to a magic number so the runtime knows it's 1730 // the correct layout. 1731 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1732 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy)); 1733 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1734 Elements.push_back(ProtocolList); 1735 Elements.push_back(InstanceMethodList); 1736 Elements.push_back(ClassMethodList); 1737 Elements.push_back(OptionalInstanceMethodList); 1738 Elements.push_back(OptionalClassMethodList); 1739 Elements.push_back(PropertyList); 1740 Elements.push_back(OptionalPropertyList); 1741 ExistingProtocols[ProtocolName] = 1742 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements, 1743 ".objc_protocol"), IdTy); 1744} 1745void CGObjCGNU::GenerateProtocolHolderCategory(void) { 1746 // Collect information about instance methods 1747 SmallVector<Selector, 1> MethodSels; 1748 SmallVector<llvm::Constant*, 1> MethodTypes; 1749 1750 std::vector<llvm::Constant*> Elements; 1751 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack"; 1752 const std::string CategoryName = "AnotherHack"; 1753 Elements.push_back(MakeConstantString(CategoryName)); 1754 Elements.push_back(MakeConstantString(ClassName)); 1755 // Instance method list 1756 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1757 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy)); 1758 // Class method list 1759 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1760 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy)); 1761 // Protocol list 1762 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy, 1763 ExistingProtocols.size()); 1764 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1765 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1766 SizeTy, 1767 ProtocolArrayTy, 1768 NULL); 1769 std::vector<llvm::Constant*> ProtocolElements; 1770 for (llvm::StringMapIterator<llvm::Constant*> iter = 1771 ExistingProtocols.begin(), endIter = ExistingProtocols.end(); 1772 iter != endIter ; iter++) { 1773 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(), 1774 PtrTy); 1775 ProtocolElements.push_back(Ptr); 1776 } 1777 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1778 ProtocolElements); 1779 ProtocolElements.clear(); 1780 ProtocolElements.push_back(NULLPtr); 1781 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy, 1782 ExistingProtocols.size())); 1783 ProtocolElements.push_back(ProtocolArray); 1784 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy, 1785 ProtocolElements, ".objc_protocol_list"), PtrTy)); 1786 Categories.push_back(llvm::ConstantExpr::getBitCast( 1787 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1788 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1789} 1790 1791/// Libobjc2 uses a bitfield representation where small(ish) bitfields are 1792/// stored in a 64-bit value with the low bit set to 1 and the remaining 63 1793/// bits set to their values, LSB first, while larger ones are stored in a 1794/// structure of this / form: 1795/// 1796/// struct { int32_t length; int32_t values[length]; }; 1797/// 1798/// The values in the array are stored in host-endian format, with the least 1799/// significant bit being assumed to come first in the bitfield. Therefore, a 1800/// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a 1801/// bitfield / with the 63rd bit set will be 1<<64. 1802llvm::Constant *CGObjCGNU::MakeBitField(ArrayRef<bool> bits) { 1803 int bitCount = bits.size(); 1804 int ptrBits = 1805 (TheModule.getPointerSize() == llvm::Module::Pointer32) ? 32 : 64; 1806 if (bitCount < ptrBits) { 1807 uint64_t val = 1; 1808 for (int i=0 ; i<bitCount ; ++i) { 1809 if (bits[i]) val |= 1ULL<<(i+1); 1810 } 1811 return llvm::ConstantInt::get(IntPtrTy, val); 1812 } 1813 llvm::SmallVector<llvm::Constant*, 8> values; 1814 int v=0; 1815 while (v < bitCount) { 1816 int32_t word = 0; 1817 for (int i=0 ; (i<32) && (v<bitCount) ; ++i) { 1818 if (bits[v]) word |= 1<<i; 1819 v++; 1820 } 1821 values.push_back(llvm::ConstantInt::get(Int32Ty, word)); 1822 } 1823 llvm::ArrayType *arrayTy = llvm::ArrayType::get(Int32Ty, values.size()); 1824 llvm::Constant *array = llvm::ConstantArray::get(arrayTy, values); 1825 llvm::Constant *fields[2] = { 1826 llvm::ConstantInt::get(Int32Ty, values.size()), 1827 array }; 1828 llvm::Constant *GS = MakeGlobal(llvm::StructType::get(Int32Ty, arrayTy, 1829 NULL), fields); 1830 llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy); 1831 return ptr; 1832} 1833 1834void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) { 1835 std::string ClassName = OCD->getClassInterface()->getNameAsString(); 1836 std::string CategoryName = OCD->getNameAsString(); 1837 // Collect information about instance methods 1838 SmallVector<Selector, 16> InstanceMethodSels; 1839 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1840 for (ObjCCategoryImplDecl::instmeth_iterator 1841 iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end(); 1842 iter != endIter ; iter++) { 1843 InstanceMethodSels.push_back((*iter)->getSelector()); 1844 std::string TypeStr; 1845 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1846 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1847 } 1848 1849 // Collect information about class methods 1850 SmallVector<Selector, 16> ClassMethodSels; 1851 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1852 for (ObjCCategoryImplDecl::classmeth_iterator 1853 iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end(); 1854 iter != endIter ; iter++) { 1855 ClassMethodSels.push_back((*iter)->getSelector()); 1856 std::string TypeStr; 1857 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1858 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1859 } 1860 1861 // Collect the names of referenced protocols 1862 SmallVector<std::string, 16> Protocols; 1863 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl(); 1864 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols(); 1865 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1866 E = Protos.end(); I != E; ++I) 1867 Protocols.push_back((*I)->getNameAsString()); 1868 1869 std::vector<llvm::Constant*> Elements; 1870 Elements.push_back(MakeConstantString(CategoryName)); 1871 Elements.push_back(MakeConstantString(ClassName)); 1872 // Instance method list 1873 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1874 ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes, 1875 false), PtrTy)); 1876 // Class method list 1877 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1878 ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true), 1879 PtrTy)); 1880 // Protocol list 1881 Elements.push_back(llvm::ConstantExpr::getBitCast( 1882 GenerateProtocolList(Protocols), PtrTy)); 1883 Categories.push_back(llvm::ConstantExpr::getBitCast( 1884 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1885 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1886} 1887 1888llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID, 1889 SmallVectorImpl<Selector> &InstanceMethodSels, 1890 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) { 1891 ASTContext &Context = CGM.getContext(); 1892 // 1893 // Property metadata: name, attributes, isSynthesized, setter name, setter 1894 // types, getter name, getter types. 1895 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1896 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1897 PtrToInt8Ty, NULL); 1898 std::vector<llvm::Constant*> Properties; 1899 1900 1901 // Add all of the property methods need adding to the method list and to the 1902 // property metadata list. 1903 for (ObjCImplDecl::propimpl_iterator 1904 iter = OID->propimpl_begin(), endIter = OID->propimpl_end(); 1905 iter != endIter ; iter++) { 1906 std::vector<llvm::Constant*> Fields; 1907 ObjCPropertyDecl *property = iter->getPropertyDecl(); 1908 ObjCPropertyImplDecl *propertyImpl = *iter; 1909 bool isSynthesized = (propertyImpl->getPropertyImplementation() == 1910 ObjCPropertyImplDecl::Synthesize); 1911 1912 Fields.push_back(MakeConstantString(property->getNameAsString())); 1913 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1914 property->getPropertyAttributes())); 1915 Fields.push_back(llvm::ConstantInt::get(Int8Ty, isSynthesized)); 1916 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1917 std::string TypeStr; 1918 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1919 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1920 if (isSynthesized) { 1921 InstanceMethodTypes.push_back(TypeEncoding); 1922 InstanceMethodSels.push_back(getter->getSelector()); 1923 } 1924 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1925 Fields.push_back(TypeEncoding); 1926 } else { 1927 Fields.push_back(NULLPtr); 1928 Fields.push_back(NULLPtr); 1929 } 1930 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1931 std::string TypeStr; 1932 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1933 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1934 if (isSynthesized) { 1935 InstanceMethodTypes.push_back(TypeEncoding); 1936 InstanceMethodSels.push_back(setter->getSelector()); 1937 } 1938 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1939 Fields.push_back(TypeEncoding); 1940 } else { 1941 Fields.push_back(NULLPtr); 1942 Fields.push_back(NULLPtr); 1943 } 1944 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1945 } 1946 llvm::ArrayType *PropertyArrayTy = 1947 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()); 1948 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy, 1949 Properties); 1950 llvm::Constant* PropertyListInitFields[] = 1951 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1952 1953 llvm::Constant *PropertyListInit = 1954 llvm::ConstantStruct::getAnon(PropertyListInitFields); 1955 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false, 1956 llvm::GlobalValue::InternalLinkage, PropertyListInit, 1957 ".objc_property_list"); 1958} 1959 1960void CGObjCGNU::RegisterAlias(const ObjCCompatibleAliasDecl *OAD) { 1961 // Get the class declaration for which the alias is specified. 1962 ObjCInterfaceDecl *ClassDecl = 1963 const_cast<ObjCInterfaceDecl *>(OAD->getClassInterface()); 1964 std::string ClassName = ClassDecl->getNameAsString(); 1965 std::string AliasName = OAD->getNameAsString(); 1966 ClassAliases.push_back(ClassAliasPair(ClassName,AliasName)); 1967} 1968 1969void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) { 1970 ASTContext &Context = CGM.getContext(); 1971 1972 // Get the superclass name. 1973 const ObjCInterfaceDecl * SuperClassDecl = 1974 OID->getClassInterface()->getSuperClass(); 1975 std::string SuperClassName; 1976 if (SuperClassDecl) { 1977 SuperClassName = SuperClassDecl->getNameAsString(); 1978 EmitClassRef(SuperClassName); 1979 } 1980 1981 // Get the class name 1982 ObjCInterfaceDecl *ClassDecl = 1983 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface()); 1984 std::string ClassName = ClassDecl->getNameAsString(); 1985 // Emit the symbol that is used to generate linker errors if this class is 1986 // referenced in other modules but not declared. 1987 std::string classSymbolName = "__objc_class_name_" + ClassName; 1988 if (llvm::GlobalVariable *symbol = 1989 TheModule.getGlobalVariable(classSymbolName)) { 1990 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0)); 1991 } else { 1992 new llvm::GlobalVariable(TheModule, LongTy, false, 1993 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0), 1994 classSymbolName); 1995 } 1996 1997 // Get the size of instances. 1998 int instanceSize = 1999 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity(); 2000 2001 // Collect information about instance variables. 2002 SmallVector<llvm::Constant*, 16> IvarNames; 2003 SmallVector<llvm::Constant*, 16> IvarTypes; 2004 SmallVector<llvm::Constant*, 16> IvarOffsets; 2005 2006 std::vector<llvm::Constant*> IvarOffsetValues; 2007 SmallVector<bool, 16> WeakIvars; 2008 SmallVector<bool, 16> StrongIvars; 2009 2010 int superInstanceSize = !SuperClassDecl ? 0 : 2011 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity(); 2012 // For non-fragile ivars, set the instance size to 0 - {the size of just this 2013 // class}. The runtime will then set this to the correct value on load. 2014 if (CGM.getContext().getLangOpts().ObjCRuntime.isNonFragile()) { 2015 instanceSize = 0 - (instanceSize - superInstanceSize); 2016 } 2017 2018 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 2019 IVD = IVD->getNextIvar()) { 2020 // Store the name 2021 IvarNames.push_back(MakeConstantString(IVD->getNameAsString())); 2022 // Get the type encoding for this ivar 2023 std::string TypeStr; 2024 Context.getObjCEncodingForType(IVD->getType(), TypeStr); 2025 IvarTypes.push_back(MakeConstantString(TypeStr)); 2026 // Get the offset 2027 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD); 2028 uint64_t Offset = BaseOffset; 2029 if (CGM.getContext().getLangOpts().ObjCRuntime.isNonFragile()) { 2030 Offset = BaseOffset - superInstanceSize; 2031 } 2032 llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset); 2033 // Create the direct offset value 2034 std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." + 2035 IVD->getNameAsString(); 2036 llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName); 2037 if (OffsetVar) { 2038 OffsetVar->setInitializer(OffsetValue); 2039 // If this is the real definition, change its linkage type so that 2040 // different modules will use this one, rather than their private 2041 // copy. 2042 OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage); 2043 } else 2044 OffsetVar = new llvm::GlobalVariable(TheModule, IntTy, 2045 false, llvm::GlobalValue::ExternalLinkage, 2046 OffsetValue, 2047 "__objc_ivar_offset_value_" + ClassName +"." + 2048 IVD->getNameAsString()); 2049 IvarOffsets.push_back(OffsetValue); 2050 IvarOffsetValues.push_back(OffsetVar); 2051 Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime(); 2052 switch (lt) { 2053 case Qualifiers::OCL_Strong: 2054 StrongIvars.push_back(true); 2055 WeakIvars.push_back(false); 2056 break; 2057 case Qualifiers::OCL_Weak: 2058 StrongIvars.push_back(false); 2059 WeakIvars.push_back(true); 2060 break; 2061 default: 2062 StrongIvars.push_back(false); 2063 WeakIvars.push_back(false); 2064 } 2065 } 2066 llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars); 2067 llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars); 2068 llvm::GlobalVariable *IvarOffsetArray = 2069 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets"); 2070 2071 2072 // Collect information about instance methods 2073 SmallVector<Selector, 16> InstanceMethodSels; 2074 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 2075 for (ObjCImplementationDecl::instmeth_iterator 2076 iter = OID->instmeth_begin(), endIter = OID->instmeth_end(); 2077 iter != endIter ; iter++) { 2078 InstanceMethodSels.push_back((*iter)->getSelector()); 2079 std::string TypeStr; 2080 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 2081 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 2082 } 2083 2084 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels, 2085 InstanceMethodTypes); 2086 2087 2088 // Collect information about class methods 2089 SmallVector<Selector, 16> ClassMethodSels; 2090 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 2091 for (ObjCImplementationDecl::classmeth_iterator 2092 iter = OID->classmeth_begin(), endIter = OID->classmeth_end(); 2093 iter != endIter ; iter++) { 2094 ClassMethodSels.push_back((*iter)->getSelector()); 2095 std::string TypeStr; 2096 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 2097 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 2098 } 2099 // Collect the names of referenced protocols 2100 SmallVector<std::string, 16> Protocols; 2101 for (ObjCInterfaceDecl::protocol_iterator 2102 I = ClassDecl->protocol_begin(), 2103 E = ClassDecl->protocol_end(); I != E; ++I) 2104 Protocols.push_back((*I)->getNameAsString()); 2105 2106 2107 2108 // Get the superclass pointer. 2109 llvm::Constant *SuperClass; 2110 if (!SuperClassName.empty()) { 2111 SuperClass = MakeConstantString(SuperClassName, ".super_class_name"); 2112 } else { 2113 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty); 2114 } 2115 // Empty vector used to construct empty method lists 2116 SmallVector<llvm::Constant*, 1> empty; 2117 // Generate the method and instance variable lists 2118 llvm::Constant *MethodList = GenerateMethodList(ClassName, "", 2119 InstanceMethodSels, InstanceMethodTypes, false); 2120 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "", 2121 ClassMethodSels, ClassMethodTypes, true); 2122 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes, 2123 IvarOffsets); 2124 // Irrespective of whether we are compiling for a fragile or non-fragile ABI, 2125 // we emit a symbol containing the offset for each ivar in the class. This 2126 // allows code compiled for the non-Fragile ABI to inherit from code compiled 2127 // for the legacy ABI, without causing problems. The converse is also 2128 // possible, but causes all ivar accesses to be fragile. 2129 2130 // Offset pointer for getting at the correct field in the ivar list when 2131 // setting up the alias. These are: The base address for the global, the 2132 // ivar array (second field), the ivar in this list (set for each ivar), and 2133 // the offset (third field in ivar structure) 2134 llvm::Type *IndexTy = Int32Ty; 2135 llvm::Constant *offsetPointerIndexes[] = {Zeros[0], 2136 llvm::ConstantInt::get(IndexTy, 1), 0, 2137 llvm::ConstantInt::get(IndexTy, 2) }; 2138 2139 unsigned ivarIndex = 0; 2140 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 2141 IVD = IVD->getNextIvar()) { 2142 const std::string Name = "__objc_ivar_offset_" + ClassName + '.' 2143 + IVD->getNameAsString(); 2144 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex); 2145 // Get the correct ivar field 2146 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr( 2147 IvarList, offsetPointerIndexes); 2148 // Get the existing variable, if one exists. 2149 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name); 2150 if (offset) { 2151 offset->setInitializer(offsetValue); 2152 // If this is the real definition, change its linkage type so that 2153 // different modules will use this one, rather than their private 2154 // copy. 2155 offset->setLinkage(llvm::GlobalValue::ExternalLinkage); 2156 } else { 2157 // Add a new alias if there isn't one already. 2158 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(), 2159 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name); 2160 (void) offset; // Silence dead store warning. 2161 } 2162 ++ivarIndex; 2163 } 2164 llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0); 2165 //Generate metaclass for class methods 2166 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr, 2167 NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList( 2168 empty, empty, empty), ClassMethodList, NULLPtr, 2169 NULLPtr, NULLPtr, ZeroPtr, ZeroPtr, true); 2170 2171 // Generate the class structure 2172 llvm::Constant *ClassStruct = 2173 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L, 2174 ClassName.c_str(), 0, 2175 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, 2176 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray, 2177 Properties, StrongIvarBitmap, WeakIvarBitmap); 2178 2179 // Resolve the class aliases, if they exist. 2180 if (ClassPtrAlias) { 2181 ClassPtrAlias->replaceAllUsesWith( 2182 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy)); 2183 ClassPtrAlias->eraseFromParent(); 2184 ClassPtrAlias = 0; 2185 } 2186 if (MetaClassPtrAlias) { 2187 MetaClassPtrAlias->replaceAllUsesWith( 2188 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy)); 2189 MetaClassPtrAlias->eraseFromParent(); 2190 MetaClassPtrAlias = 0; 2191 } 2192 2193 // Add class structure to list to be added to the symtab later 2194 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty); 2195 Classes.push_back(ClassStruct); 2196} 2197 2198 2199llvm::Function *CGObjCGNU::ModuleInitFunction() { 2200 // Only emit an ObjC load function if no Objective-C stuff has been called 2201 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() && 2202 ExistingProtocols.empty() && SelectorTable.empty()) 2203 return NULL; 2204 2205 // Add all referenced protocols to a category. 2206 GenerateProtocolHolderCategory(); 2207 2208 llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>( 2209 SelectorTy->getElementType()); 2210 llvm::Type *SelStructPtrTy = SelectorTy; 2211 if (SelStructTy == 0) { 2212 SelStructTy = llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, NULL); 2213 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy); 2214 } 2215 2216 std::vector<llvm::Constant*> Elements; 2217 llvm::Constant *Statics = NULLPtr; 2218 // Generate statics list: 2219 if (ConstantStrings.size()) { 2220 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 2221 ConstantStrings.size() + 1); 2222 ConstantStrings.push_back(NULLPtr); 2223 2224 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass; 2225 2226 if (StringClass.empty()) StringClass = "NXConstantString"; 2227 2228 Elements.push_back(MakeConstantString(StringClass, 2229 ".objc_static_class_name")); 2230 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy, 2231 ConstantStrings)); 2232 llvm::StructType *StaticsListTy = 2233 llvm::StructType::get(PtrToInt8Ty, StaticsArrayTy, NULL); 2234 llvm::Type *StaticsListPtrTy = 2235 llvm::PointerType::getUnqual(StaticsListTy); 2236 Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics"); 2237 llvm::ArrayType *StaticsListArrayTy = 2238 llvm::ArrayType::get(StaticsListPtrTy, 2); 2239 Elements.clear(); 2240 Elements.push_back(Statics); 2241 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy)); 2242 Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr"); 2243 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy); 2244 } 2245 // Array of classes, categories, and constant objects 2246 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty, 2247 Classes.size() + Categories.size() + 2); 2248 llvm::StructType *SymTabTy = llvm::StructType::get(LongTy, SelStructPtrTy, 2249 llvm::Type::getInt16Ty(VMContext), 2250 llvm::Type::getInt16Ty(VMContext), 2251 ClassListTy, NULL); 2252 2253 Elements.clear(); 2254 // Pointer to an array of selectors used in this module. 2255 std::vector<llvm::Constant*> Selectors; 2256 std::vector<llvm::GlobalAlias*> SelectorAliases; 2257 for (SelectorMap::iterator iter = SelectorTable.begin(), 2258 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) { 2259 2260 std::string SelNameStr = iter->first.getAsString(); 2261 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name"); 2262 2263 SmallVectorImpl<TypedSelector> &Types = iter->second; 2264 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 2265 e = Types.end() ; i!=e ; i++) { 2266 2267 llvm::Constant *SelectorTypeEncoding = NULLPtr; 2268 if (!i->first.empty()) 2269 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types"); 2270 2271 Elements.push_back(SelName); 2272 Elements.push_back(SelectorTypeEncoding); 2273 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2274 Elements.clear(); 2275 2276 // Store the selector alias for later replacement 2277 SelectorAliases.push_back(i->second); 2278 } 2279 } 2280 unsigned SelectorCount = Selectors.size(); 2281 // NULL-terminate the selector list. This should not actually be required, 2282 // because the selector list has a length field. Unfortunately, the GCC 2283 // runtime decides to ignore the length field and expects a NULL terminator, 2284 // and GCC cooperates with this by always setting the length to 0. 2285 Elements.push_back(NULLPtr); 2286 Elements.push_back(NULLPtr); 2287 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2288 Elements.clear(); 2289 2290 // Number of static selectors 2291 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount)); 2292 llvm::Constant *SelectorList = MakeGlobalArray(SelStructTy, Selectors, 2293 ".objc_selector_list"); 2294 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList, 2295 SelStructPtrTy)); 2296 2297 // Now that all of the static selectors exist, create pointers to them. 2298 for (unsigned int i=0 ; i<SelectorCount ; i++) { 2299 2300 llvm::Constant *Idxs[] = {Zeros[0], 2301 llvm::ConstantInt::get(Int32Ty, i), Zeros[0]}; 2302 // FIXME: We're generating redundant loads and stores here! 2303 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(SelectorList, 2304 makeArrayRef(Idxs, 2)); 2305 // If selectors are defined as an opaque type, cast the pointer to this 2306 // type. 2307 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy); 2308 SelectorAliases[i]->replaceAllUsesWith(SelPtr); 2309 SelectorAliases[i]->eraseFromParent(); 2310 } 2311 2312 // Number of classes defined. 2313 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2314 Classes.size())); 2315 // Number of categories defined 2316 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2317 Categories.size())); 2318 // Create an array of classes, then categories, then static object instances 2319 Classes.insert(Classes.end(), Categories.begin(), Categories.end()); 2320 // NULL-terminated list of static object instances (mainly constant strings) 2321 Classes.push_back(Statics); 2322 Classes.push_back(NULLPtr); 2323 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes); 2324 Elements.push_back(ClassList); 2325 // Construct the symbol table 2326 llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements); 2327 2328 // The symbol table is contained in a module which has some version-checking 2329 // constants 2330 llvm::StructType * ModuleTy = llvm::StructType::get(LongTy, LongTy, 2331 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), 2332 (RuntimeVersion >= 10) ? IntTy : NULL, NULL); 2333 Elements.clear(); 2334 // Runtime version, used for ABI compatibility checking. 2335 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion)); 2336 // sizeof(ModuleTy) 2337 llvm::TargetData td(&TheModule); 2338 Elements.push_back( 2339 llvm::ConstantInt::get(LongTy, 2340 td.getTypeSizeInBits(ModuleTy) / 2341 CGM.getContext().getCharWidth())); 2342 2343 // The path to the source file where this module was declared 2344 SourceManager &SM = CGM.getContext().getSourceManager(); 2345 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID()); 2346 std::string path = 2347 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName(); 2348 Elements.push_back(MakeConstantString(path, ".objc_source_file_name")); 2349 Elements.push_back(SymTab); 2350 2351 if (RuntimeVersion >= 10) 2352 switch (CGM.getLangOpts().getGC()) { 2353 case LangOptions::GCOnly: 2354 Elements.push_back(llvm::ConstantInt::get(IntTy, 2)); 2355 break; 2356 case LangOptions::NonGC: 2357 if (CGM.getLangOpts().ObjCAutoRefCount) 2358 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2359 else 2360 Elements.push_back(llvm::ConstantInt::get(IntTy, 0)); 2361 break; 2362 case LangOptions::HybridGC: 2363 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2364 break; 2365 } 2366 2367 llvm::Value *Module = MakeGlobal(ModuleTy, Elements); 2368 2369 // Create the load function calling the runtime entry point with the module 2370 // structure 2371 llvm::Function * LoadFunction = llvm::Function::Create( 2372 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false), 2373 llvm::GlobalValue::InternalLinkage, ".objc_load_function", 2374 &TheModule); 2375 llvm::BasicBlock *EntryBB = 2376 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction); 2377 CGBuilderTy Builder(VMContext); 2378 Builder.SetInsertPoint(EntryBB); 2379 2380 llvm::FunctionType *FT = 2381 llvm::FunctionType::get(Builder.getVoidTy(), 2382 llvm::PointerType::getUnqual(ModuleTy), true); 2383 llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class"); 2384 Builder.CreateCall(Register, Module); 2385 2386 if (!ClassAliases.empty()) { 2387 llvm::Type *ArgTypes[2] = {PtrTy, PtrToInt8Ty}; 2388 llvm::FunctionType *RegisterAliasTy = 2389 llvm::FunctionType::get(Builder.getVoidTy(), 2390 ArgTypes, false); 2391 llvm::Function *RegisterAlias = llvm::Function::Create( 2392 RegisterAliasTy, 2393 llvm::GlobalValue::ExternalWeakLinkage, "class_registerAlias_np", 2394 &TheModule); 2395 llvm::BasicBlock *AliasBB = 2396 llvm::BasicBlock::Create(VMContext, "alias", LoadFunction); 2397 llvm::BasicBlock *NoAliasBB = 2398 llvm::BasicBlock::Create(VMContext, "no_alias", LoadFunction); 2399 2400 // Branch based on whether the runtime provided class_registerAlias_np() 2401 llvm::Value *HasRegisterAlias = Builder.CreateICmpNE(RegisterAlias, 2402 llvm::Constant::getNullValue(RegisterAlias->getType())); 2403 Builder.CreateCondBr(HasRegisterAlias, AliasBB, NoAliasBB); 2404 2405 // The true branch (has alias registration fucntion): 2406 Builder.SetInsertPoint(AliasBB); 2407 // Emit alias registration calls: 2408 for (std::vector<ClassAliasPair>::iterator iter = ClassAliases.begin(); 2409 iter != ClassAliases.end(); ++iter) { 2410 llvm::Constant *TheClass = 2411 TheModule.getGlobalVariable(("_OBJC_CLASS_" + iter->first).c_str(), 2412 true); 2413 if (0 != TheClass) { 2414 TheClass = llvm::ConstantExpr::getBitCast(TheClass, PtrTy); 2415 Builder.CreateCall2(RegisterAlias, TheClass, 2416 MakeConstantString(iter->second)); 2417 } 2418 } 2419 // Jump to end: 2420 Builder.CreateBr(NoAliasBB); 2421 2422 // Missing alias registration function, just return from the function: 2423 Builder.SetInsertPoint(NoAliasBB); 2424 } 2425 Builder.CreateRetVoid(); 2426 2427 return LoadFunction; 2428} 2429 2430llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD, 2431 const ObjCContainerDecl *CD) { 2432 const ObjCCategoryImplDecl *OCD = 2433 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext()); 2434 StringRef CategoryName = OCD ? OCD->getName() : ""; 2435 StringRef ClassName = CD->getName(); 2436 Selector MethodName = OMD->getSelector(); 2437 bool isClassMethod = !OMD->isInstanceMethod(); 2438 2439 CodeGenTypes &Types = CGM.getTypes(); 2440 llvm::FunctionType *MethodTy = 2441 Types.GetFunctionType(Types.arrangeObjCMethodDeclaration(OMD)); 2442 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName, 2443 MethodName, isClassMethod); 2444 2445 llvm::Function *Method 2446 = llvm::Function::Create(MethodTy, 2447 llvm::GlobalValue::InternalLinkage, 2448 FunctionName, 2449 &TheModule); 2450 return Method; 2451} 2452 2453llvm::Constant *CGObjCGNU::GetPropertyGetFunction() { 2454 return GetPropertyFn; 2455} 2456 2457llvm::Constant *CGObjCGNU::GetPropertySetFunction() { 2458 return SetPropertyFn; 2459} 2460 2461llvm::Constant *CGObjCGNU::GetOptimizedPropertySetFunction(bool atomic, 2462 bool copy) { 2463 return 0; 2464} 2465 2466llvm::Constant *CGObjCGNU::GetGetStructFunction() { 2467 return GetStructPropertyFn; 2468} 2469llvm::Constant *CGObjCGNU::GetSetStructFunction() { 2470 return SetStructPropertyFn; 2471} 2472llvm::Constant *CGObjCGNU::GetCppAtomicObjectFunction() { 2473 return 0; 2474} 2475 2476llvm::Constant *CGObjCGNU::EnumerationMutationFunction() { 2477 return EnumerationMutationFn; 2478} 2479 2480void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF, 2481 const ObjCAtSynchronizedStmt &S) { 2482 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn); 2483} 2484 2485 2486void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF, 2487 const ObjCAtTryStmt &S) { 2488 // Unlike the Apple non-fragile runtimes, which also uses 2489 // unwind-based zero cost exceptions, the GNU Objective C runtime's 2490 // EH support isn't a veneer over C++ EH. Instead, exception 2491 // objects are created by __objc_exception_throw and destroyed by 2492 // the personality function; this avoids the need for bracketing 2493 // catch handlers with calls to __blah_begin_catch/__blah_end_catch 2494 // (or even _Unwind_DeleteException), but probably doesn't 2495 // interoperate very well with foreign exceptions. 2496 // 2497 // In Objective-C++ mode, we actually emit something equivalent to the C++ 2498 // exception handler. 2499 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn); 2500 return ; 2501} 2502 2503void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF, 2504 const ObjCAtThrowStmt &S) { 2505 llvm::Value *ExceptionAsObject; 2506 2507 if (const Expr *ThrowExpr = S.getThrowExpr()) { 2508 llvm::Value *Exception = CGF.EmitObjCThrowOperand(ThrowExpr); 2509 ExceptionAsObject = Exception; 2510 } else { 2511 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) && 2512 "Unexpected rethrow outside @catch block."); 2513 ExceptionAsObject = CGF.ObjCEHValueStack.back(); 2514 } 2515 ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy); 2516 CGF.EmitCallOrInvoke(ExceptionThrowFn, ExceptionAsObject); 2517 CGF.Builder.CreateUnreachable(); 2518 CGF.Builder.ClearInsertionPoint(); 2519} 2520 2521llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF, 2522 llvm::Value *AddrWeakObj) { 2523 CGBuilderTy B = CGF.Builder; 2524 AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy); 2525 return B.CreateCall(WeakReadFn, AddrWeakObj); 2526} 2527 2528void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF, 2529 llvm::Value *src, llvm::Value *dst) { 2530 CGBuilderTy B = CGF.Builder; 2531 src = EnforceType(B, src, IdTy); 2532 dst = EnforceType(B, dst, PtrToIdTy); 2533 B.CreateCall2(WeakAssignFn, src, dst); 2534} 2535 2536void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF, 2537 llvm::Value *src, llvm::Value *dst, 2538 bool threadlocal) { 2539 CGBuilderTy B = CGF.Builder; 2540 src = EnforceType(B, src, IdTy); 2541 dst = EnforceType(B, dst, PtrToIdTy); 2542 if (!threadlocal) 2543 B.CreateCall2(GlobalAssignFn, src, dst); 2544 else 2545 // FIXME. Add threadloca assign API 2546 llvm_unreachable("EmitObjCGlobalAssign - Threal Local API NYI"); 2547} 2548 2549void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF, 2550 llvm::Value *src, llvm::Value *dst, 2551 llvm::Value *ivarOffset) { 2552 CGBuilderTy B = CGF.Builder; 2553 src = EnforceType(B, src, IdTy); 2554 dst = EnforceType(B, dst, IdTy); 2555 B.CreateCall3(IvarAssignFn, src, dst, ivarOffset); 2556} 2557 2558void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF, 2559 llvm::Value *src, llvm::Value *dst) { 2560 CGBuilderTy B = CGF.Builder; 2561 src = EnforceType(B, src, IdTy); 2562 dst = EnforceType(B, dst, PtrToIdTy); 2563 B.CreateCall2(StrongCastAssignFn, src, dst); 2564} 2565 2566void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF, 2567 llvm::Value *DestPtr, 2568 llvm::Value *SrcPtr, 2569 llvm::Value *Size) { 2570 CGBuilderTy B = CGF.Builder; 2571 DestPtr = EnforceType(B, DestPtr, PtrTy); 2572 SrcPtr = EnforceType(B, SrcPtr, PtrTy); 2573 2574 B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size); 2575} 2576 2577llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable( 2578 const ObjCInterfaceDecl *ID, 2579 const ObjCIvarDecl *Ivar) { 2580 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString() 2581 + '.' + Ivar->getNameAsString(); 2582 // Emit the variable and initialize it with what we think the correct value 2583 // is. This allows code compiled with non-fragile ivars to work correctly 2584 // when linked against code which isn't (most of the time). 2585 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name); 2586 if (!IvarOffsetPointer) { 2587 // This will cause a run-time crash if we accidentally use it. A value of 2588 // 0 would seem more sensible, but will silently overwrite the isa pointer 2589 // causing a great deal of confusion. 2590 uint64_t Offset = -1; 2591 // We can't call ComputeIvarBaseOffset() here if we have the 2592 // implementation, because it will create an invalid ASTRecordLayout object 2593 // that we are then stuck with forever, so we only initialize the ivar 2594 // offset variable with a guess if we only have the interface. The 2595 // initializer will be reset later anyway, when we are generating the class 2596 // description. 2597 if (!CGM.getContext().getObjCImplementation( 2598 const_cast<ObjCInterfaceDecl *>(ID))) 2599 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar); 2600 2601 llvm::ConstantInt *OffsetGuess = llvm::ConstantInt::get(Int32Ty, Offset, 2602 /*isSigned*/true); 2603 // Don't emit the guess in non-PIC code because the linker will not be able 2604 // to replace it with the real version for a library. In non-PIC code you 2605 // must compile with the fragile ABI if you want to use ivars from a 2606 // GCC-compiled class. 2607 if (CGM.getLangOpts().PICLevel || CGM.getLangOpts().PIELevel) { 2608 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule, 2609 Int32Ty, false, 2610 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess"); 2611 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2612 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage, 2613 IvarOffsetGV, Name); 2614 } else { 2615 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2616 llvm::Type::getInt32PtrTy(VMContext), false, 2617 llvm::GlobalValue::ExternalLinkage, 0, Name); 2618 } 2619 } 2620 return IvarOffsetPointer; 2621} 2622 2623LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF, 2624 QualType ObjectTy, 2625 llvm::Value *BaseValue, 2626 const ObjCIvarDecl *Ivar, 2627 unsigned CVRQualifiers) { 2628 const ObjCInterfaceDecl *ID = 2629 ObjectTy->getAs<ObjCObjectType>()->getInterface(); 2630 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers, 2631 EmitIvarOffset(CGF, ID, Ivar)); 2632} 2633 2634static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context, 2635 const ObjCInterfaceDecl *OID, 2636 const ObjCIvarDecl *OIVD) { 2637 for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next; 2638 next = next->getNextIvar()) { 2639 if (OIVD == next) 2640 return OID; 2641 } 2642 2643 // Otherwise check in the super class. 2644 if (const ObjCInterfaceDecl *Super = OID->getSuperClass()) 2645 return FindIvarInterface(Context, Super, OIVD); 2646 2647 return 0; 2648} 2649 2650llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF, 2651 const ObjCInterfaceDecl *Interface, 2652 const ObjCIvarDecl *Ivar) { 2653 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 2654 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar); 2655 if (RuntimeVersion < 10) 2656 return CGF.Builder.CreateZExtOrBitCast( 2657 CGF.Builder.CreateLoad(CGF.Builder.CreateLoad( 2658 ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")), 2659 PtrDiffTy); 2660 std::string name = "__objc_ivar_offset_value_" + 2661 Interface->getNameAsString() +"." + Ivar->getNameAsString(); 2662 llvm::Value *Offset = TheModule.getGlobalVariable(name); 2663 if (!Offset) 2664 Offset = new llvm::GlobalVariable(TheModule, IntTy, 2665 false, llvm::GlobalValue::LinkOnceAnyLinkage, 2666 llvm::Constant::getNullValue(IntTy), name); 2667 Offset = CGF.Builder.CreateLoad(Offset); 2668 if (Offset->getType() != PtrDiffTy) 2669 Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy); 2670 return Offset; 2671 } 2672 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar); 2673 return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true); 2674} 2675 2676CGObjCRuntime * 2677clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) { 2678 switch (CGM.getLangOpts().ObjCRuntime.getKind()) { 2679 case ObjCRuntime::GNUstep: 2680 return new CGObjCGNUstep(CGM); 2681 2682 case ObjCRuntime::GCC: 2683 return new CGObjCGCC(CGM); 2684 2685 case ObjCRuntime::ObjFW: 2686 return new CGObjCObjFW(CGM); 2687 2688 case ObjCRuntime::FragileMacOSX: 2689 case ObjCRuntime::MacOSX: 2690 case ObjCRuntime::iOS: 2691 llvm_unreachable("these runtimes are not GNU runtimes"); 2692 } 2693 llvm_unreachable("bad runtime"); 2694} 2695