CGObjCGNU.cpp revision 1d784b277cdfd4eba03680715d2a082b3f28d295
1//===------- CGObjCGNU.cpp - Emit LLVM Code from ASTs for a Module --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This provides Objective-C code generation targeting the GNU runtime. The 11// class in this file generates structures used by the GNU Objective-C runtime 12// library. These structures are defined in objc/objc.h and objc/objc-api.h in 13// the GNU runtime distribution. 14// 15//===----------------------------------------------------------------------===// 16 17#include "CGObjCRuntime.h" 18#include "CodeGenModule.h" 19#include "CodeGenFunction.h" 20#include "CGCleanup.h" 21 22#include "clang/AST/ASTContext.h" 23#include "clang/AST/Decl.h" 24#include "clang/AST/DeclObjC.h" 25#include "clang/AST/RecordLayout.h" 26#include "clang/AST/StmtObjC.h" 27#include "clang/Basic/SourceManager.h" 28#include "clang/Basic/FileManager.h" 29 30#include "llvm/Intrinsics.h" 31#include "llvm/Module.h" 32#include "llvm/LLVMContext.h" 33#include "llvm/ADT/SmallVector.h" 34#include "llvm/ADT/StringMap.h" 35#include "llvm/Support/CallSite.h" 36#include "llvm/Support/Compiler.h" 37#include "llvm/Target/TargetData.h" 38 39#include <cstdarg> 40 41 42using namespace clang; 43using namespace CodeGen; 44 45 46namespace { 47/// Class that lazily initialises the runtime function. Avoids inserting the 48/// types and the function declaration into a module if they're not used, and 49/// avoids constructing the type more than once if it's used more than once. 50class LazyRuntimeFunction { 51 CodeGenModule *CGM; 52 std::vector<llvm::Type*> ArgTys; 53 const char *FunctionName; 54 llvm::Constant *Function; 55 public: 56 /// Constructor leaves this class uninitialized, because it is intended to 57 /// be used as a field in another class and not all of the types that are 58 /// used as arguments will necessarily be available at construction time. 59 LazyRuntimeFunction() : CGM(0), FunctionName(0), Function(0) {} 60 61 /// Initialises the lazy function with the name, return type, and the types 62 /// of the arguments. 63 END_WITH_NULL 64 void init(CodeGenModule *Mod, const char *name, 65 llvm::Type *RetTy, ...) { 66 CGM =Mod; 67 FunctionName = name; 68 Function = 0; 69 ArgTys.clear(); 70 va_list Args; 71 va_start(Args, RetTy); 72 while (llvm::Type *ArgTy = va_arg(Args, llvm::Type*)) 73 ArgTys.push_back(ArgTy); 74 va_end(Args); 75 // Push the return type on at the end so we can pop it off easily 76 ArgTys.push_back(RetTy); 77 } 78 /// Overloaded cast operator, allows the class to be implicitly cast to an 79 /// LLVM constant. 80 operator llvm::Constant*() { 81 if (!Function) { 82 if (0 == FunctionName) return 0; 83 // We put the return type on the end of the vector, so pop it back off 84 llvm::Type *RetTy = ArgTys.back(); 85 ArgTys.pop_back(); 86 llvm::FunctionType *FTy = llvm::FunctionType::get(RetTy, ArgTys, false); 87 Function = 88 cast<llvm::Constant>(CGM->CreateRuntimeFunction(FTy, FunctionName)); 89 // We won't need to use the types again, so we may as well clean up the 90 // vector now 91 ArgTys.resize(0); 92 } 93 return Function; 94 } 95 operator llvm::Function*() { 96 return cast<llvm::Function>((llvm::Constant*)*this); 97 } 98 99}; 100 101 102/// GNU Objective-C runtime code generation. This class implements the parts of 103/// Objective-C support that are specific to the GNU family of runtimes (GCC and 104/// GNUstep). 105class CGObjCGNU : public CGObjCRuntime { 106protected: 107 /// The module that is using this class 108 CodeGenModule &CGM; 109 /// The LLVM module into which output is inserted 110 llvm::Module &TheModule; 111 /// strut objc_super. Used for sending messages to super. This structure 112 /// contains the receiver (object) and the expected class. 113 llvm::StructType *ObjCSuperTy; 114 /// struct objc_super*. The type of the argument to the superclass message 115 /// lookup functions. 116 llvm::PointerType *PtrToObjCSuperTy; 117 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring 118 /// SEL is included in a header somewhere, in which case it will be whatever 119 /// type is declared in that header, most likely {i8*, i8*}. 120 llvm::PointerType *SelectorTy; 121 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the 122 /// places where it's used 123 llvm::IntegerType *Int8Ty; 124 /// Pointer to i8 - LLVM type of char*, for all of the places where the 125 /// runtime needs to deal with C strings. 126 llvm::PointerType *PtrToInt8Ty; 127 /// Instance Method Pointer type. This is a pointer to a function that takes, 128 /// at a minimum, an object and a selector, and is the generic type for 129 /// Objective-C methods. Due to differences between variadic / non-variadic 130 /// calling conventions, it must always be cast to the correct type before 131 /// actually being used. 132 llvm::PointerType *IMPTy; 133 /// Type of an untyped Objective-C object. Clang treats id as a built-in type 134 /// when compiling Objective-C code, so this may be an opaque pointer (i8*), 135 /// but if the runtime header declaring it is included then it may be a 136 /// pointer to a structure. 137 llvm::PointerType *IdTy; 138 /// Pointer to a pointer to an Objective-C object. Used in the new ABI 139 /// message lookup function and some GC-related functions. 140 llvm::PointerType *PtrToIdTy; 141 /// The clang type of id. Used when using the clang CGCall infrastructure to 142 /// call Objective-C methods. 143 CanQualType ASTIdTy; 144 /// LLVM type for C int type. 145 llvm::IntegerType *IntTy; 146 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is 147 /// used in the code to document the difference between i8* meaning a pointer 148 /// to a C string and i8* meaning a pointer to some opaque type. 149 llvm::PointerType *PtrTy; 150 /// LLVM type for C long type. The runtime uses this in a lot of places where 151 /// it should be using intptr_t, but we can't fix this without breaking 152 /// compatibility with GCC... 153 llvm::IntegerType *LongTy; 154 /// LLVM type for C size_t. Used in various runtime data structures. 155 llvm::IntegerType *SizeTy; 156 /// LLVM type for C intptr_t. 157 llvm::IntegerType *IntPtrTy; 158 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions. 159 llvm::IntegerType *PtrDiffTy; 160 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance 161 /// variables. 162 llvm::PointerType *PtrToIntTy; 163 /// LLVM type for Objective-C BOOL type. 164 llvm::Type *BoolTy; 165 /// 32-bit integer type, to save us needing to look it up every time it's used. 166 llvm::IntegerType *Int32Ty; 167 /// 64-bit integer type, to save us needing to look it up every time it's used. 168 llvm::IntegerType *Int64Ty; 169 /// Metadata kind used to tie method lookups to message sends. The GNUstep 170 /// runtime provides some LLVM passes that can use this to do things like 171 /// automatic IMP caching and speculative inlining. 172 unsigned msgSendMDKind; 173 /// Helper function that generates a constant string and returns a pointer to 174 /// the start of the string. The result of this function can be used anywhere 175 /// where the C code specifies const char*. 176 llvm::Constant *MakeConstantString(const std::string &Str, 177 const std::string &Name="") { 178 llvm::Constant *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str()); 179 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 180 } 181 /// Emits a linkonce_odr string, whose name is the prefix followed by the 182 /// string value. This allows the linker to combine the strings between 183 /// different modules. Used for EH typeinfo names, selector strings, and a 184 /// few other things. 185 llvm::Constant *ExportUniqueString(const std::string &Str, 186 const std::string prefix) { 187 std::string name = prefix + Str; 188 llvm::Constant *ConstStr = TheModule.getGlobalVariable(name); 189 if (!ConstStr) { 190 llvm::Constant *value = llvm::ConstantArray::get(VMContext, Str, true); 191 ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true, 192 llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str); 193 } 194 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 195 } 196 /// Generates a global structure, initialized by the elements in the vector. 197 /// The element types must match the types of the structure elements in the 198 /// first argument. 199 llvm::GlobalVariable *MakeGlobal(llvm::StructType *Ty, 200 llvm::ArrayRef<llvm::Constant*> V, 201 StringRef Name="", 202 llvm::GlobalValue::LinkageTypes linkage 203 =llvm::GlobalValue::InternalLinkage) { 204 llvm::Constant *C = llvm::ConstantStruct::get(Ty, V); 205 return new llvm::GlobalVariable(TheModule, Ty, false, 206 linkage, C, Name); 207 } 208 /// Generates a global array. The vector must contain the same number of 209 /// elements that the array type declares, of the type specified as the array 210 /// element type. 211 llvm::GlobalVariable *MakeGlobal(llvm::ArrayType *Ty, 212 llvm::ArrayRef<llvm::Constant*> V, 213 StringRef Name="", 214 llvm::GlobalValue::LinkageTypes linkage 215 =llvm::GlobalValue::InternalLinkage) { 216 llvm::Constant *C = llvm::ConstantArray::get(Ty, V); 217 return new llvm::GlobalVariable(TheModule, Ty, false, 218 linkage, C, Name); 219 } 220 /// Generates a global array, inferring the array type from the specified 221 /// element type and the size of the initialiser. 222 llvm::GlobalVariable *MakeGlobalArray(llvm::Type *Ty, 223 llvm::ArrayRef<llvm::Constant*> V, 224 StringRef Name="", 225 llvm::GlobalValue::LinkageTypes linkage 226 =llvm::GlobalValue::InternalLinkage) { 227 llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size()); 228 return MakeGlobal(ArrayTy, V, Name, linkage); 229 } 230 /// Ensures that the value has the required type, by inserting a bitcast if 231 /// required. This function lets us avoid inserting bitcasts that are 232 /// redundant. 233 llvm::Value* EnforceType(CGBuilderTy B, llvm::Value *V, llvm::Type *Ty){ 234 if (V->getType() == Ty) return V; 235 return B.CreateBitCast(V, Ty); 236 } 237 // Some zeros used for GEPs in lots of places. 238 llvm::Constant *Zeros[2]; 239 /// Null pointer value. Mainly used as a terminator in various arrays. 240 llvm::Constant *NULLPtr; 241 /// LLVM context. 242 llvm::LLVMContext &VMContext; 243private: 244 /// Placeholder for the class. Lots of things refer to the class before we've 245 /// actually emitted it. We use this alias as a placeholder, and then replace 246 /// it with a pointer to the class structure before finally emitting the 247 /// module. 248 llvm::GlobalAlias *ClassPtrAlias; 249 /// Placeholder for the metaclass. Lots of things refer to the class before 250 /// we've / actually emitted it. We use this alias as a placeholder, and then 251 /// replace / it with a pointer to the metaclass structure before finally 252 /// emitting the / module. 253 llvm::GlobalAlias *MetaClassPtrAlias; 254 /// All of the classes that have been generated for this compilation units. 255 std::vector<llvm::Constant*> Classes; 256 /// All of the categories that have been generated for this compilation units. 257 std::vector<llvm::Constant*> Categories; 258 /// All of the Objective-C constant strings that have been generated for this 259 /// compilation units. 260 std::vector<llvm::Constant*> ConstantStrings; 261 /// Map from string values to Objective-C constant strings in the output. 262 /// Used to prevent emitting Objective-C strings more than once. This should 263 /// not be required at all - CodeGenModule should manage this list. 264 llvm::StringMap<llvm::Constant*> ObjCStrings; 265 /// All of the protocols that have been declared. 266 llvm::StringMap<llvm::Constant*> ExistingProtocols; 267 /// For each variant of a selector, we store the type encoding and a 268 /// placeholder value. For an untyped selector, the type will be the empty 269 /// string. Selector references are all done via the module's selector table, 270 /// so we create an alias as a placeholder and then replace it with the real 271 /// value later. 272 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector; 273 /// Type of the selector map. This is roughly equivalent to the structure 274 /// used in the GNUstep runtime, which maintains a list of all of the valid 275 /// types for a selector in a table. 276 typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> > 277 SelectorMap; 278 /// A map from selectors to selector types. This allows us to emit all 279 /// selectors of the same name and type together. 280 SelectorMap SelectorTable; 281 282 /// Selectors related to memory management. When compiling in GC mode, we 283 /// omit these. 284 Selector RetainSel, ReleaseSel, AutoreleaseSel; 285 /// Runtime functions used for memory management in GC mode. Note that clang 286 /// supports code generation for calling these functions, but neither GNU 287 /// runtime actually supports this API properly yet. 288 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn, 289 WeakAssignFn, GlobalAssignFn; 290 291protected: 292 /// Function used for throwing Objective-C exceptions. 293 LazyRuntimeFunction ExceptionThrowFn; 294 /// Function used for rethrowing exceptions, used at the end of @finally or 295 /// @synchronize blocks. 296 LazyRuntimeFunction ExceptionReThrowFn; 297 /// Function called when entering a catch function. This is required for 298 /// differentiating Objective-C exceptions and foreign exceptions. 299 LazyRuntimeFunction EnterCatchFn; 300 /// Function called when exiting from a catch block. Used to do exception 301 /// cleanup. 302 LazyRuntimeFunction ExitCatchFn; 303 /// Function called when entering an @synchronize block. Acquires the lock. 304 LazyRuntimeFunction SyncEnterFn; 305 /// Function called when exiting an @synchronize block. Releases the lock. 306 LazyRuntimeFunction SyncExitFn; 307 308private: 309 310 /// Function called if fast enumeration detects that the collection is 311 /// modified during the update. 312 LazyRuntimeFunction EnumerationMutationFn; 313 /// Function for implementing synthesized property getters that return an 314 /// object. 315 LazyRuntimeFunction GetPropertyFn; 316 /// Function for implementing synthesized property setters that return an 317 /// object. 318 LazyRuntimeFunction SetPropertyFn; 319 /// Function used for non-object declared property getters. 320 LazyRuntimeFunction GetStructPropertyFn; 321 /// Function used for non-object declared property setters. 322 LazyRuntimeFunction SetStructPropertyFn; 323 324 /// The version of the runtime that this class targets. Must match the 325 /// version in the runtime. 326 int RuntimeVersion; 327 /// The version of the protocol class. Used to differentiate between ObjC1 328 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional 329 /// components and can not contain declared properties. We always emit 330 /// Objective-C 2 property structures, but we have to pretend that they're 331 /// Objective-C 1 property structures when targeting the GCC runtime or it 332 /// will abort. 333 const int ProtocolVersion; 334private: 335 /// Generates an instance variable list structure. This is a structure 336 /// containing a size and an array of structures containing instance variable 337 /// metadata. This is used purely for introspection in the fragile ABI. In 338 /// the non-fragile ABI, it's used for instance variable fixup. 339 llvm::Constant *GenerateIvarList( 340 const SmallVectorImpl<llvm::Constant *> &IvarNames, 341 const SmallVectorImpl<llvm::Constant *> &IvarTypes, 342 const SmallVectorImpl<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 const SmallVectorImpl<Selector> &MethodSels, 351 const SmallVectorImpl<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( 365 const SmallVectorImpl<std::string> &Protocols); 366 /// To ensure that all protocols are seen by the runtime, we add a category on 367 /// a class defined in the runtime, declaring no methods, but adopting the 368 /// protocols. This is a horribly ugly hack, but it allows us to collect all 369 /// of the protocols without changing the ABI. 370 void GenerateProtocolHolderCategory(void); 371 /// Generates a class structure. 372 llvm::Constant *GenerateClassStructure( 373 llvm::Constant *MetaClass, 374 llvm::Constant *SuperClass, 375 unsigned info, 376 const char *Name, 377 llvm::Constant *Version, 378 llvm::Constant *InstanceSize, 379 llvm::Constant *IVars, 380 llvm::Constant *Methods, 381 llvm::Constant *Protocols, 382 llvm::Constant *IvarOffsets, 383 llvm::Constant *Properties, 384 llvm::Constant *StrongIvarBitmap, 385 llvm::Constant *WeakIvarBitmap, 386 bool isMeta=false); 387 /// Generates a method list. This is used by protocols to define the required 388 /// and optional methods. 389 llvm::Constant *GenerateProtocolMethodList( 390 const SmallVectorImpl<llvm::Constant *> &MethodNames, 391 const SmallVectorImpl<llvm::Constant *> &MethodTypes); 392 /// Returns a selector with the specified type encoding. An empty string is 393 /// used to return an untyped selector (with the types field set to NULL). 394 llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 395 const std::string &TypeEncoding, bool lval); 396 /// Returns the variable used to store the offset of an instance variable. 397 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID, 398 const ObjCIvarDecl *Ivar); 399 /// Emits a reference to a class. This allows the linker to object if there 400 /// is no class of the matching name. 401 void EmitClassRef(const std::string &className); 402 /// Emits a pointer to the named class 403 llvm::Value *GetClassNamed(CGBuilderTy &Builder, const std::string &Name, 404 bool isWeak); 405protected: 406 /// Looks up the method for sending a message to the specified object. This 407 /// mechanism differs between the GCC and GNU runtimes, so this method must be 408 /// overridden in subclasses. 409 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 410 llvm::Value *&Receiver, 411 llvm::Value *cmd, 412 llvm::MDNode *node) = 0; 413 /// Looks up the method for sending a message to a superclass. This 414 /// mechanism differs between the GCC and GNU runtimes, so this method must 415 /// be overridden in subclasses. 416 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 417 llvm::Value *ObjCSuper, 418 llvm::Value *cmd) = 0; 419 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are 420 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63 421 /// bits set to their values, LSB first, while larger ones are stored in a 422 /// structure of this / form: 423 /// 424 /// struct { int32_t length; int32_t values[length]; }; 425 /// 426 /// The values in the array are stored in host-endian format, with the least 427 /// significant bit being assumed to come first in the bitfield. Therefore, 428 /// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, 429 /// while a bitfield / with the 63rd bit set will be 1<<64. 430 llvm::Constant *MakeBitField(llvm::SmallVectorImpl<bool> &bits); 431public: 432 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 433 unsigned protocolClassVersion); 434 435 virtual llvm::Constant *GenerateConstantString(const StringLiteral *); 436 437 virtual RValue 438 GenerateMessageSend(CodeGenFunction &CGF, 439 ReturnValueSlot Return, 440 QualType ResultType, 441 Selector Sel, 442 llvm::Value *Receiver, 443 const CallArgList &CallArgs, 444 const ObjCInterfaceDecl *Class, 445 const ObjCMethodDecl *Method); 446 virtual RValue 447 GenerateMessageSendSuper(CodeGenFunction &CGF, 448 ReturnValueSlot Return, 449 QualType ResultType, 450 Selector Sel, 451 const ObjCInterfaceDecl *Class, 452 bool isCategoryImpl, 453 llvm::Value *Receiver, 454 bool IsClassMessage, 455 const CallArgList &CallArgs, 456 const ObjCMethodDecl *Method); 457 virtual llvm::Value *GetClass(CGBuilderTy &Builder, 458 const ObjCInterfaceDecl *OID); 459 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 460 bool lval = false); 461 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 462 *Method); 463 virtual llvm::Constant *GetEHType(QualType T); 464 465 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 466 const ObjCContainerDecl *CD); 467 virtual void GenerateCategory(const ObjCCategoryImplDecl *CMD); 468 virtual void GenerateClass(const ObjCImplementationDecl *ClassDecl); 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 *GetSetStructFunction(); 476 virtual llvm::Constant *GetGetStructFunction(); 477 virtual llvm::Constant *EnumerationMutationFunction(); 478 479 virtual void EmitTryStmt(CodeGenFunction &CGF, 480 const ObjCAtTryStmt &S); 481 virtual void EmitSynchronizedStmt(CodeGenFunction &CGF, 482 const ObjCAtSynchronizedStmt &S); 483 virtual void EmitThrowStmt(CodeGenFunction &CGF, 484 const ObjCAtThrowStmt &S); 485 virtual llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF, 486 llvm::Value *AddrWeakObj); 487 virtual void EmitObjCWeakAssign(CodeGenFunction &CGF, 488 llvm::Value *src, llvm::Value *dst); 489 virtual void EmitObjCGlobalAssign(CodeGenFunction &CGF, 490 llvm::Value *src, llvm::Value *dest, 491 bool threadlocal=false); 492 virtual void EmitObjCIvarAssign(CodeGenFunction &CGF, 493 llvm::Value *src, llvm::Value *dest, 494 llvm::Value *ivarOffset); 495 virtual void EmitObjCStrongCastAssign(CodeGenFunction &CGF, 496 llvm::Value *src, llvm::Value *dest); 497 virtual void EmitGCMemmoveCollectable(CodeGenFunction &CGF, 498 llvm::Value *DestPtr, 499 llvm::Value *SrcPtr, 500 llvm::Value *Size); 501 virtual LValue EmitObjCValueForIvar(CodeGenFunction &CGF, 502 QualType ObjectTy, 503 llvm::Value *BaseValue, 504 const ObjCIvarDecl *Ivar, 505 unsigned CVRQualifiers); 506 virtual llvm::Value *EmitIvarOffset(CodeGenFunction &CGF, 507 const ObjCInterfaceDecl *Interface, 508 const ObjCIvarDecl *Ivar); 509 virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CGBuilderTy &Builder); 510 virtual llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM, 511 const CGBlockInfo &blockInfo) { 512 return NULLPtr; 513 } 514 515 virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) { 516 return 0; 517 } 518}; 519/// Class representing the legacy GCC Objective-C ABI. This is the default when 520/// -fobjc-nonfragile-abi is not specified. 521/// 522/// The GCC ABI target actually generates code that is approximately compatible 523/// with the new GNUstep runtime ABI, but refrains from using any features that 524/// would not work with the GCC runtime. For example, clang always generates 525/// the extended form of the class structure, and the extra fields are simply 526/// ignored by GCC libobjc. 527class CGObjCGCC : public CGObjCGNU { 528 /// The GCC ABI message lookup function. Returns an IMP pointing to the 529 /// method implementation for this message. 530 LazyRuntimeFunction MsgLookupFn; 531 /// The GCC ABI superclass message lookup function. Takes a pointer to a 532 /// structure describing the receiver and the class, and a selector as 533 /// arguments. Returns the IMP for the corresponding method. 534 LazyRuntimeFunction MsgLookupSuperFn; 535protected: 536 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 537 llvm::Value *&Receiver, 538 llvm::Value *cmd, 539 llvm::MDNode *node) { 540 CGBuilderTy &Builder = CGF.Builder; 541 llvm::Value *args[] = { 542 EnforceType(Builder, Receiver, IdTy), 543 EnforceType(Builder, cmd, SelectorTy) }; 544 llvm::CallSite imp = CGF.EmitCallOrInvoke(MsgLookupFn, args); 545 imp->setMetadata(msgSendMDKind, node); 546 return imp.getInstruction(); 547 } 548 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 549 llvm::Value *ObjCSuper, 550 llvm::Value *cmd) { 551 CGBuilderTy &Builder = CGF.Builder; 552 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 553 PtrToObjCSuperTy), cmd}; 554 return Builder.CreateCall(MsgLookupSuperFn, lookupArgs); 555 } 556 public: 557 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) { 558 // IMP objc_msg_lookup(id, SEL); 559 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 560 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 561 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 562 PtrToObjCSuperTy, SelectorTy, NULL); 563 } 564}; 565/// Class used when targeting the new GNUstep runtime ABI. 566class CGObjCGNUstep : public CGObjCGNU { 567 /// The slot lookup function. Returns a pointer to a cacheable structure 568 /// that contains (among other things) the IMP. 569 LazyRuntimeFunction SlotLookupFn; 570 /// The GNUstep ABI superclass message lookup function. Takes a pointer to 571 /// a structure describing the receiver and the class, and a selector as 572 /// arguments. Returns the slot for the corresponding method. Superclass 573 /// message lookup rarely changes, so this is a good caching opportunity. 574 LazyRuntimeFunction SlotLookupSuperFn; 575 /// Type of an slot structure pointer. This is returned by the various 576 /// lookup functions. 577 llvm::Type *SlotTy; 578 protected: 579 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 580 llvm::Value *&Receiver, 581 llvm::Value *cmd, 582 llvm::MDNode *node) { 583 CGBuilderTy &Builder = CGF.Builder; 584 llvm::Function *LookupFn = SlotLookupFn; 585 586 // Store the receiver on the stack so that we can reload it later 587 llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType()); 588 Builder.CreateStore(Receiver, ReceiverPtr); 589 590 llvm::Value *self; 591 592 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) { 593 self = CGF.LoadObjCSelf(); 594 } else { 595 self = llvm::ConstantPointerNull::get(IdTy); 596 } 597 598 // The lookup function is guaranteed not to capture the receiver pointer. 599 LookupFn->setDoesNotCapture(1); 600 601 llvm::Value *args[] = { 602 EnforceType(Builder, ReceiverPtr, PtrToIdTy), 603 EnforceType(Builder, cmd, SelectorTy), 604 EnforceType(Builder, self, IdTy) }; 605 llvm::CallSite slot = CGF.EmitCallOrInvoke(LookupFn, args); 606 slot.setOnlyReadsMemory(); 607 slot->setMetadata(msgSendMDKind, node); 608 609 // Load the imp from the slot 610 llvm::Value *imp = 611 Builder.CreateLoad(Builder.CreateStructGEP(slot.getInstruction(), 4)); 612 613 // The lookup function may have changed the receiver, so make sure we use 614 // the new one. 615 Receiver = Builder.CreateLoad(ReceiverPtr, true); 616 return imp; 617 } 618 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 619 llvm::Value *ObjCSuper, 620 llvm::Value *cmd) { 621 CGBuilderTy &Builder = CGF.Builder; 622 llvm::Value *lookupArgs[] = {ObjCSuper, cmd}; 623 624 llvm::CallInst *slot = Builder.CreateCall(SlotLookupSuperFn, lookupArgs); 625 slot->setOnlyReadsMemory(); 626 627 return Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 628 } 629 public: 630 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) { 631 llvm::StructType *SlotStructTy = llvm::StructType::get(PtrTy, 632 PtrTy, PtrTy, IntTy, IMPTy, NULL); 633 SlotTy = llvm::PointerType::getUnqual(SlotStructTy); 634 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 635 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy, 636 SelectorTy, IdTy, NULL); 637 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL); 638 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy, 639 PtrToObjCSuperTy, SelectorTy, NULL); 640 // If we're in ObjC++ mode, then we want to make 641 if (CGM.getLangOptions().CPlusPlus) { 642 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 643 // void *__cxa_begin_catch(void *e) 644 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, NULL); 645 // void __cxa_end_catch(void) 646 ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, NULL); 647 // void _Unwind_Resume_or_Rethrow(void*) 648 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, PtrTy, NULL); 649 } 650 } 651}; 652 653} // end anonymous namespace 654 655 656/// Emits a reference to a dummy variable which is emitted with each class. 657/// This ensures that a linker error will be generated when trying to link 658/// together modules where a referenced class is not defined. 659void CGObjCGNU::EmitClassRef(const std::string &className) { 660 std::string symbolRef = "__objc_class_ref_" + className; 661 // Don't emit two copies of the same symbol 662 if (TheModule.getGlobalVariable(symbolRef)) 663 return; 664 std::string symbolName = "__objc_class_name_" + className; 665 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName); 666 if (!ClassSymbol) { 667 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 668 llvm::GlobalValue::ExternalLinkage, 0, symbolName); 669 } 670 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true, 671 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef); 672} 673 674static std::string SymbolNameForMethod(const StringRef &ClassName, 675 const StringRef &CategoryName, const Selector MethodName, 676 bool isClassMethod) { 677 std::string MethodNameColonStripped = MethodName.getAsString(); 678 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(), 679 ':', '_'); 680 return (Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" + 681 CategoryName + "_" + MethodNameColonStripped).str(); 682} 683 684CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 685 unsigned protocolClassVersion) 686 : CGM(cgm), TheModule(CGM.getModule()), VMContext(cgm.getLLVMContext()), 687 ClassPtrAlias(0), MetaClassPtrAlias(0), RuntimeVersion(runtimeABIVersion), 688 ProtocolVersion(protocolClassVersion) { 689 690 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend"); 691 692 CodeGenTypes &Types = CGM.getTypes(); 693 IntTy = cast<llvm::IntegerType>( 694 Types.ConvertType(CGM.getContext().IntTy)); 695 LongTy = cast<llvm::IntegerType>( 696 Types.ConvertType(CGM.getContext().LongTy)); 697 SizeTy = cast<llvm::IntegerType>( 698 Types.ConvertType(CGM.getContext().getSizeType())); 699 PtrDiffTy = cast<llvm::IntegerType>( 700 Types.ConvertType(CGM.getContext().getPointerDiffType())); 701 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy); 702 703 Int8Ty = llvm::Type::getInt8Ty(VMContext); 704 // C string type. Used in lots of places. 705 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); 706 707 Zeros[0] = llvm::ConstantInt::get(LongTy, 0); 708 Zeros[1] = Zeros[0]; 709 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty); 710 // Get the selector Type. 711 QualType selTy = CGM.getContext().getObjCSelType(); 712 if (QualType() == selTy) { 713 SelectorTy = PtrToInt8Ty; 714 } else { 715 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy)); 716 } 717 718 PtrToIntTy = llvm::PointerType::getUnqual(IntTy); 719 PtrTy = PtrToInt8Ty; 720 721 Int32Ty = llvm::Type::getInt32Ty(VMContext); 722 Int64Ty = llvm::Type::getInt64Ty(VMContext); 723 724 IntPtrTy = 725 TheModule.getPointerSize() == llvm::Module::Pointer32 ? Int32Ty : Int64Ty; 726 727 // Object type 728 QualType UnqualIdTy = CGM.getContext().getObjCIdType(); 729 ASTIdTy = CanQualType(); 730 if (UnqualIdTy != QualType()) { 731 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy); 732 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 733 } else { 734 IdTy = PtrToInt8Ty; 735 } 736 PtrToIdTy = llvm::PointerType::getUnqual(IdTy); 737 738 ObjCSuperTy = llvm::StructType::get(IdTy, IdTy, NULL); 739 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy); 740 741 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 742 743 // void objc_exception_throw(id); 744 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 745 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 746 // int objc_sync_enter(id); 747 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, NULL); 748 // int objc_sync_exit(id); 749 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, NULL); 750 751 // void objc_enumerationMutation (id) 752 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, 753 IdTy, NULL); 754 755 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL) 756 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy, 757 PtrDiffTy, BoolTy, NULL); 758 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL) 759 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy, 760 PtrDiffTy, IdTy, BoolTy, BoolTy, NULL); 761 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 762 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy, 763 PtrDiffTy, BoolTy, BoolTy, NULL); 764 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 765 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy, 766 PtrDiffTy, BoolTy, BoolTy, NULL); 767 768 // IMP type 769 llvm::Type *IMPArgs[] = { IdTy, SelectorTy }; 770 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs, 771 true)); 772 773 const LangOptions &Opts = CGM.getLangOptions(); 774 if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount) 775 RuntimeVersion = 10; 776 777 // Don't bother initialising the GC stuff unless we're compiling in GC mode 778 if (Opts.getGC() != LangOptions::NonGC) { 779 // This is a bit of an hack. We should sort this out by having a proper 780 // CGObjCGNUstep subclass for GC, but we may want to really support the old 781 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now 782 // Get selectors needed in GC mode 783 RetainSel = GetNullarySelector("retain", CGM.getContext()); 784 ReleaseSel = GetNullarySelector("release", CGM.getContext()); 785 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext()); 786 787 // Get functions needed in GC mode 788 789 // id objc_assign_ivar(id, id, ptrdiff_t); 790 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy, 791 NULL); 792 // id objc_assign_strongCast (id, id*) 793 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy, 794 PtrToIdTy, NULL); 795 // id objc_assign_global(id, id*); 796 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy, 797 NULL); 798 // id objc_assign_weak(id, id*); 799 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, NULL); 800 // id objc_read_weak(id*); 801 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, NULL); 802 // void *objc_memmove_collectable(void*, void *, size_t); 803 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy, 804 SizeTy, NULL); 805 } 806} 807 808llvm::Value *CGObjCGNU::GetClassNamed(CGBuilderTy &Builder, 809 const std::string &Name, 810 bool isWeak) { 811 llvm::Value *ClassName = CGM.GetAddrOfConstantCString(Name); 812 // With the incompatible ABI, this will need to be replaced with a direct 813 // reference to the class symbol. For the compatible nonfragile ABI we are 814 // still performing this lookup at run time but emitting the symbol for the 815 // class externally so that we can make the switch later. 816 // 817 // Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class 818 // with memoized versions or with static references if it's safe to do so. 819 if (!isWeak) 820 EmitClassRef(Name); 821 ClassName = Builder.CreateStructGEP(ClassName, 0); 822 823 llvm::Constant *ClassLookupFn = 824 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true), 825 "objc_lookup_class"); 826 return Builder.CreateCall(ClassLookupFn, ClassName); 827} 828 829// This has to perform the lookup every time, since posing and related 830// techniques can modify the name -> class mapping. 831llvm::Value *CGObjCGNU::GetClass(CGBuilderTy &Builder, 832 const ObjCInterfaceDecl *OID) { 833 return GetClassNamed(Builder, OID->getNameAsString(), OID->isWeakImported()); 834} 835llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CGBuilderTy &Builder) { 836 return GetClassNamed(Builder, "NSAutoreleasePool", false); 837} 838 839llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 840 const std::string &TypeEncoding, bool lval) { 841 842 SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel]; 843 llvm::GlobalAlias *SelValue = 0; 844 845 846 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 847 e = Types.end() ; i!=e ; i++) { 848 if (i->first == TypeEncoding) { 849 SelValue = i->second; 850 break; 851 } 852 } 853 if (0 == SelValue) { 854 SelValue = new llvm::GlobalAlias(SelectorTy, 855 llvm::GlobalValue::PrivateLinkage, 856 ".objc_selector_"+Sel.getAsString(), NULL, 857 &TheModule); 858 Types.push_back(TypedSelector(TypeEncoding, SelValue)); 859 } 860 861 if (lval) { 862 llvm::Value *tmp = Builder.CreateAlloca(SelValue->getType()); 863 Builder.CreateStore(SelValue, tmp); 864 return tmp; 865 } 866 return SelValue; 867} 868 869llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 870 bool lval) { 871 return GetSelector(Builder, Sel, std::string(), lval); 872} 873 874llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 875 *Method) { 876 std::string SelTypes; 877 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes); 878 return GetSelector(Builder, Method->getSelector(), SelTypes, false); 879} 880 881llvm::Constant *CGObjCGNU::GetEHType(QualType T) { 882 if (!CGM.getLangOptions().CPlusPlus) { 883 if (T->isObjCIdType() 884 || T->isObjCQualifiedIdType()) { 885 // With the old ABI, there was only one kind of catchall, which broke 886 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as 887 // a pointer indicating object catchalls, and NULL to indicate real 888 // catchalls 889 if (CGM.getLangOptions().ObjCNonFragileABI) { 890 return MakeConstantString("@id"); 891 } else { 892 return 0; 893 } 894 } 895 896 // All other types should be Objective-C interface pointer types. 897 const ObjCObjectPointerType *OPT = 898 T->getAs<ObjCObjectPointerType>(); 899 assert(OPT && "Invalid @catch type."); 900 const ObjCInterfaceDecl *IDecl = 901 OPT->getObjectType()->getInterface(); 902 assert(IDecl && "Invalid @catch type."); 903 return MakeConstantString(IDecl->getIdentifier()->getName()); 904 } 905 // For Objective-C++, we want to provide the ability to catch both C++ and 906 // Objective-C objects in the same function. 907 908 // There's a particular fixed type info for 'id'. 909 if (T->isObjCIdType() || 910 T->isObjCQualifiedIdType()) { 911 llvm::Constant *IDEHType = 912 CGM.getModule().getGlobalVariable("__objc_id_type_info"); 913 if (!IDEHType) 914 IDEHType = 915 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty, 916 false, 917 llvm::GlobalValue::ExternalLinkage, 918 0, "__objc_id_type_info"); 919 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty); 920 } 921 922 const ObjCObjectPointerType *PT = 923 T->getAs<ObjCObjectPointerType>(); 924 assert(PT && "Invalid @catch type."); 925 const ObjCInterfaceType *IT = PT->getInterfaceType(); 926 assert(IT && "Invalid @catch type."); 927 std::string className = IT->getDecl()->getIdentifier()->getName(); 928 929 std::string typeinfoName = "__objc_eh_typeinfo_" + className; 930 931 // Return the existing typeinfo if it exists 932 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName); 933 if (typeinfo) return typeinfo; 934 935 // Otherwise create it. 936 937 // vtable for gnustep::libobjc::__objc_class_type_info 938 // It's quite ugly hard-coding this. Ideally we'd generate it using the host 939 // platform's name mangling. 940 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE"; 941 llvm::Constant *Vtable = TheModule.getGlobalVariable(vtableName); 942 if (!Vtable) { 943 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true, 944 llvm::GlobalValue::ExternalLinkage, 0, vtableName); 945 } 946 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2); 947 Vtable = llvm::ConstantExpr::getGetElementPtr(Vtable, Two); 948 Vtable = llvm::ConstantExpr::getBitCast(Vtable, PtrToInt8Ty); 949 950 llvm::Constant *typeName = 951 ExportUniqueString(className, "__objc_eh_typename_"); 952 953 std::vector<llvm::Constant*> fields; 954 fields.push_back(Vtable); 955 fields.push_back(typeName); 956 llvm::Constant *TI = 957 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 958 NULL), fields, "__objc_eh_typeinfo_" + className, 959 llvm::GlobalValue::LinkOnceODRLinkage); 960 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty); 961} 962 963/// Generate an NSConstantString object. 964llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) { 965 966 std::string Str = SL->getString().str(); 967 968 // Look for an existing one 969 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str); 970 if (old != ObjCStrings.end()) 971 return old->getValue(); 972 973 std::vector<llvm::Constant*> Ivars; 974 Ivars.push_back(NULLPtr); 975 Ivars.push_back(MakeConstantString(Str)); 976 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size())); 977 llvm::Constant *ObjCStr = MakeGlobal( 978 llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, IntTy, NULL), 979 Ivars, ".objc_str"); 980 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty); 981 ObjCStrings[Str] = ObjCStr; 982 ConstantStrings.push_back(ObjCStr); 983 return ObjCStr; 984} 985 986///Generates a message send where the super is the receiver. This is a message 987///send to self with special delivery semantics indicating which class's method 988///should be called. 989RValue 990CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF, 991 ReturnValueSlot Return, 992 QualType ResultType, 993 Selector Sel, 994 const ObjCInterfaceDecl *Class, 995 bool isCategoryImpl, 996 llvm::Value *Receiver, 997 bool IsClassMessage, 998 const CallArgList &CallArgs, 999 const ObjCMethodDecl *Method) { 1000 CGBuilderTy &Builder = CGF.Builder; 1001 if (CGM.getLangOptions().getGC() == LangOptions::GCOnly) { 1002 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1003 return RValue::get(EnforceType(Builder, Receiver, 1004 CGM.getTypes().ConvertType(ResultType))); 1005 } 1006 if (Sel == ReleaseSel) { 1007 return RValue::get(0); 1008 } 1009 } 1010 1011 llvm::Value *cmd = GetSelector(Builder, Sel); 1012 1013 1014 CallArgList ActualArgs; 1015 1016 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy); 1017 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1018 ActualArgs.addFrom(CallArgs); 1019 1020 CodeGenTypes &Types = CGM.getTypes(); 1021 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 1022 FunctionType::ExtInfo()); 1023 1024 llvm::Value *ReceiverClass = 0; 1025 if (isCategoryImpl) { 1026 llvm::Constant *classLookupFunction = 0; 1027 if (IsClassMessage) { 1028 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1029 IdTy, PtrTy, true), "objc_get_meta_class"); 1030 } else { 1031 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1032 IdTy, PtrTy, true), "objc_get_class"); 1033 } 1034 ReceiverClass = Builder.CreateCall(classLookupFunction, 1035 MakeConstantString(Class->getNameAsString())); 1036 } else { 1037 // Set up global aliases for the metaclass or class pointer if they do not 1038 // already exist. These will are forward-references which will be set to 1039 // pointers to the class and metaclass structure created for the runtime 1040 // load function. To send a message to super, we look up the value of the 1041 // super_class pointer from either the class or metaclass structure. 1042 if (IsClassMessage) { 1043 if (!MetaClassPtrAlias) { 1044 MetaClassPtrAlias = new llvm::GlobalAlias(IdTy, 1045 llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" + 1046 Class->getNameAsString(), NULL, &TheModule); 1047 } 1048 ReceiverClass = MetaClassPtrAlias; 1049 } else { 1050 if (!ClassPtrAlias) { 1051 ClassPtrAlias = new llvm::GlobalAlias(IdTy, 1052 llvm::GlobalValue::InternalLinkage, ".objc_class_ref" + 1053 Class->getNameAsString(), NULL, &TheModule); 1054 } 1055 ReceiverClass = ClassPtrAlias; 1056 } 1057 } 1058 // Cast the pointer to a simplified version of the class structure 1059 ReceiverClass = Builder.CreateBitCast(ReceiverClass, 1060 llvm::PointerType::getUnqual( 1061 llvm::StructType::get(IdTy, IdTy, NULL))); 1062 // Get the superclass pointer 1063 ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1); 1064 // Load the superclass pointer 1065 ReceiverClass = Builder.CreateLoad(ReceiverClass); 1066 // Construct the structure used to look up the IMP 1067 llvm::StructType *ObjCSuperTy = llvm::StructType::get( 1068 Receiver->getType(), IdTy, NULL); 1069 llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy); 1070 1071 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0)); 1072 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1)); 1073 1074 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy); 1075 llvm::FunctionType *impType = 1076 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1077 1078 // Get the IMP 1079 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd); 1080 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1081 1082 llvm::Value *impMD[] = { 1083 llvm::MDString::get(VMContext, Sel.getAsString()), 1084 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()), 1085 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage) 1086 }; 1087 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1088 1089 llvm::Instruction *call; 1090 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1091 0, &call); 1092 call->setMetadata(msgSendMDKind, node); 1093 return msgRet; 1094} 1095 1096/// Generate code for a message send expression. 1097RValue 1098CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF, 1099 ReturnValueSlot Return, 1100 QualType ResultType, 1101 Selector Sel, 1102 llvm::Value *Receiver, 1103 const CallArgList &CallArgs, 1104 const ObjCInterfaceDecl *Class, 1105 const ObjCMethodDecl *Method) { 1106 CGBuilderTy &Builder = CGF.Builder; 1107 1108 // Strip out message sends to retain / release in GC mode 1109 if (CGM.getLangOptions().getGC() == LangOptions::GCOnly) { 1110 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1111 return RValue::get(EnforceType(Builder, Receiver, 1112 CGM.getTypes().ConvertType(ResultType))); 1113 } 1114 if (Sel == ReleaseSel) { 1115 return RValue::get(0); 1116 } 1117 } 1118 1119 // If the return type is something that goes in an integer register, the 1120 // runtime will handle 0 returns. For other cases, we fill in the 0 value 1121 // ourselves. 1122 // 1123 // The language spec says the result of this kind of message send is 1124 // undefined, but lots of people seem to have forgotten to read that 1125 // paragraph and insist on sending messages to nil that have structure 1126 // returns. With GCC, this generates a random return value (whatever happens 1127 // to be on the stack / in those registers at the time) on most platforms, 1128 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts 1129 // the stack. 1130 bool isPointerSizedReturn = (ResultType->isAnyPointerType() || 1131 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType()); 1132 1133 llvm::BasicBlock *startBB = 0; 1134 llvm::BasicBlock *messageBB = 0; 1135 llvm::BasicBlock *continueBB = 0; 1136 1137 if (!isPointerSizedReturn) { 1138 startBB = Builder.GetInsertBlock(); 1139 messageBB = CGF.createBasicBlock("msgSend"); 1140 continueBB = CGF.createBasicBlock("continue"); 1141 1142 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver, 1143 llvm::Constant::getNullValue(Receiver->getType())); 1144 Builder.CreateCondBr(isNil, continueBB, messageBB); 1145 CGF.EmitBlock(messageBB); 1146 } 1147 1148 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 1149 llvm::Value *cmd; 1150 if (Method) 1151 cmd = GetSelector(Builder, Method); 1152 else 1153 cmd = GetSelector(Builder, Sel); 1154 cmd = EnforceType(Builder, cmd, SelectorTy); 1155 Receiver = EnforceType(Builder, Receiver, IdTy); 1156 1157 llvm::Value *impMD[] = { 1158 llvm::MDString::get(VMContext, Sel.getAsString()), 1159 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""), 1160 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0) 1161 }; 1162 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1163 1164 CodeGenTypes &Types = CGM.getTypes(); 1165 CallArgList ActualArgs; 1166 ActualArgs.add(RValue::get(Receiver), ASTIdTy); 1167 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1168 ActualArgs.addFrom(CallArgs); 1169 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs, 1170 FunctionType::ExtInfo()); 1171 // Get the IMP to call 1172 llvm::Value *imp; 1173 1174 // If we have non-legacy dispatch specified, we try using the objc_msgSend() 1175 // functions. These are not supported on all platforms (or all runtimes on a 1176 // given platform), so we 1177 switch (CGM.getCodeGenOpts().getObjCDispatchMethod()) { 1178 default: 1179 llvm_unreachable("Invalid dispatch method!"); 1180 case CodeGenOptions::Legacy: 1181 imp = LookupIMP(CGF, Receiver, cmd, node); 1182 break; 1183 case CodeGenOptions::Mixed: 1184 case CodeGenOptions::NonLegacy: 1185 if (CGM.ReturnTypeUsesFPRet(ResultType)) { 1186 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1187 "objc_msgSend_fpret"); 1188 } else if (CGM.ReturnTypeUsesSRet(FnInfo)) { 1189 // The actual types here don't matter - we're going to bitcast the 1190 // function anyway 1191 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1192 "objc_msgSend_stret"); 1193 } else { 1194 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1195 "objc_msgSend"); 1196 } 1197 } 1198 1199 // Reset the receiver in case the lookup modified it 1200 ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy, false); 1201 1202 llvm::FunctionType *impType = 1203 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false); 1204 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType)); 1205 1206 llvm::Instruction *call; 1207 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs, 1208 0, &call); 1209 call->setMetadata(msgSendMDKind, node); 1210 1211 1212 if (!isPointerSizedReturn) { 1213 messageBB = CGF.Builder.GetInsertBlock(); 1214 CGF.Builder.CreateBr(continueBB); 1215 CGF.EmitBlock(continueBB); 1216 if (msgRet.isScalar()) { 1217 llvm::Value *v = msgRet.getScalarVal(); 1218 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1219 phi->addIncoming(v, messageBB); 1220 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB); 1221 msgRet = RValue::get(phi); 1222 } else if (msgRet.isAggregate()) { 1223 llvm::Value *v = msgRet.getAggregateAddr(); 1224 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1225 llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType()); 1226 llvm::AllocaInst *NullVal = 1227 CGF.CreateTempAlloca(RetTy->getElementType(), "null"); 1228 CGF.InitTempAlloca(NullVal, 1229 llvm::Constant::getNullValue(RetTy->getElementType())); 1230 phi->addIncoming(v, messageBB); 1231 phi->addIncoming(NullVal, startBB); 1232 msgRet = RValue::getAggregate(phi); 1233 } else /* isComplex() */ { 1234 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal(); 1235 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2); 1236 phi->addIncoming(v.first, messageBB); 1237 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()), 1238 startBB); 1239 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2); 1240 phi2->addIncoming(v.second, messageBB); 1241 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()), 1242 startBB); 1243 msgRet = RValue::getComplex(phi, phi2); 1244 } 1245 } 1246 return msgRet; 1247} 1248 1249/// Generates a MethodList. Used in construction of a objc_class and 1250/// objc_category structures. 1251llvm::Constant *CGObjCGNU::GenerateMethodList(const StringRef &ClassName, 1252 const StringRef &CategoryName, 1253 const SmallVectorImpl<Selector> &MethodSels, 1254 const SmallVectorImpl<llvm::Constant *> &MethodTypes, 1255 bool isClassMethodList) { 1256 if (MethodSels.empty()) 1257 return NULLPtr; 1258 // Get the method structure type. 1259 llvm::StructType *ObjCMethodTy = llvm::StructType::get( 1260 PtrToInt8Ty, // Really a selector, but the runtime creates it us. 1261 PtrToInt8Ty, // Method types 1262 IMPTy, //Method pointer 1263 NULL); 1264 std::vector<llvm::Constant*> Methods; 1265 std::vector<llvm::Constant*> Elements; 1266 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) { 1267 Elements.clear(); 1268 llvm::Constant *Method = 1269 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName, 1270 MethodSels[i], 1271 isClassMethodList)); 1272 assert(Method && "Can't generate metadata for method that doesn't exist"); 1273 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString()); 1274 Elements.push_back(C); 1275 Elements.push_back(MethodTypes[i]); 1276 Method = llvm::ConstantExpr::getBitCast(Method, 1277 IMPTy); 1278 Elements.push_back(Method); 1279 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements)); 1280 } 1281 1282 // Array of method structures 1283 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy, 1284 Methods.size()); 1285 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy, 1286 Methods); 1287 1288 // Structure containing list pointer, array and array count 1289 llvm::StructType *ObjCMethodListTy = llvm::StructType::create(VMContext); 1290 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(ObjCMethodListTy); 1291 ObjCMethodListTy->setBody( 1292 NextPtrTy, 1293 IntTy, 1294 ObjCMethodArrayTy, 1295 NULL); 1296 1297 Methods.clear(); 1298 Methods.push_back(llvm::ConstantPointerNull::get( 1299 llvm::PointerType::getUnqual(ObjCMethodListTy))); 1300 Methods.push_back(llvm::ConstantInt::get(Int32Ty, MethodTypes.size())); 1301 Methods.push_back(MethodArray); 1302 1303 // Create an instance of the structure 1304 return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list"); 1305} 1306 1307/// Generates an IvarList. Used in construction of a objc_class. 1308llvm::Constant *CGObjCGNU::GenerateIvarList( 1309 const SmallVectorImpl<llvm::Constant *> &IvarNames, 1310 const SmallVectorImpl<llvm::Constant *> &IvarTypes, 1311 const SmallVectorImpl<llvm::Constant *> &IvarOffsets) { 1312 if (IvarNames.size() == 0) 1313 return NULLPtr; 1314 // Get the method structure type. 1315 llvm::StructType *ObjCIvarTy = llvm::StructType::get( 1316 PtrToInt8Ty, 1317 PtrToInt8Ty, 1318 IntTy, 1319 NULL); 1320 std::vector<llvm::Constant*> Ivars; 1321 std::vector<llvm::Constant*> Elements; 1322 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) { 1323 Elements.clear(); 1324 Elements.push_back(IvarNames[i]); 1325 Elements.push_back(IvarTypes[i]); 1326 Elements.push_back(IvarOffsets[i]); 1327 Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements)); 1328 } 1329 1330 // Array of method structures 1331 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy, 1332 IvarNames.size()); 1333 1334 1335 Elements.clear(); 1336 Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size())); 1337 Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)); 1338 // Structure containing array and array count 1339 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(IntTy, 1340 ObjCIvarArrayTy, 1341 NULL); 1342 1343 // Create an instance of the structure 1344 return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list"); 1345} 1346 1347/// Generate a class structure 1348llvm::Constant *CGObjCGNU::GenerateClassStructure( 1349 llvm::Constant *MetaClass, 1350 llvm::Constant *SuperClass, 1351 unsigned info, 1352 const char *Name, 1353 llvm::Constant *Version, 1354 llvm::Constant *InstanceSize, 1355 llvm::Constant *IVars, 1356 llvm::Constant *Methods, 1357 llvm::Constant *Protocols, 1358 llvm::Constant *IvarOffsets, 1359 llvm::Constant *Properties, 1360 llvm::Constant *StrongIvarBitmap, 1361 llvm::Constant *WeakIvarBitmap, 1362 bool isMeta) { 1363 // Set up the class structure 1364 // Note: Several of these are char*s when they should be ids. This is 1365 // because the runtime performs this translation on load. 1366 // 1367 // Fields marked New ABI are part of the GNUstep runtime. We emit them 1368 // anyway; the classes will still work with the GNU runtime, they will just 1369 // be ignored. 1370 llvm::StructType *ClassTy = llvm::StructType::get( 1371 PtrToInt8Ty, // class_pointer 1372 PtrToInt8Ty, // super_class 1373 PtrToInt8Ty, // name 1374 LongTy, // version 1375 LongTy, // info 1376 LongTy, // instance_size 1377 IVars->getType(), // ivars 1378 Methods->getType(), // methods 1379 // These are all filled in by the runtime, so we pretend 1380 PtrTy, // dtable 1381 PtrTy, // subclass_list 1382 PtrTy, // sibling_class 1383 PtrTy, // protocols 1384 PtrTy, // gc_object_type 1385 // New ABI: 1386 LongTy, // abi_version 1387 IvarOffsets->getType(), // ivar_offsets 1388 Properties->getType(), // properties 1389 IntPtrTy, // strong_pointers 1390 IntPtrTy, // weak_pointers 1391 NULL); 1392 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0); 1393 // Fill in the structure 1394 std::vector<llvm::Constant*> Elements; 1395 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty)); 1396 Elements.push_back(SuperClass); 1397 Elements.push_back(MakeConstantString(Name, ".class_name")); 1398 Elements.push_back(Zero); 1399 Elements.push_back(llvm::ConstantInt::get(LongTy, info)); 1400 if (isMeta) { 1401 llvm::TargetData td(&TheModule); 1402 Elements.push_back( 1403 llvm::ConstantInt::get(LongTy, 1404 td.getTypeSizeInBits(ClassTy) / 1405 CGM.getContext().getCharWidth())); 1406 } else 1407 Elements.push_back(InstanceSize); 1408 Elements.push_back(IVars); 1409 Elements.push_back(Methods); 1410 Elements.push_back(NULLPtr); 1411 Elements.push_back(NULLPtr); 1412 Elements.push_back(NULLPtr); 1413 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy)); 1414 Elements.push_back(NULLPtr); 1415 Elements.push_back(llvm::ConstantInt::get(LongTy, 1)); 1416 Elements.push_back(IvarOffsets); 1417 Elements.push_back(Properties); 1418 Elements.push_back(StrongIvarBitmap); 1419 Elements.push_back(WeakIvarBitmap); 1420 // Create an instance of the structure 1421 // This is now an externally visible symbol, so that we can speed up class 1422 // messages in the next ABI. 1423 return MakeGlobal(ClassTy, Elements, (isMeta ? "_OBJC_METACLASS_": 1424 "_OBJC_CLASS_") + std::string(Name), llvm::GlobalValue::ExternalLinkage); 1425} 1426 1427llvm::Constant *CGObjCGNU::GenerateProtocolMethodList( 1428 const SmallVectorImpl<llvm::Constant *> &MethodNames, 1429 const SmallVectorImpl<llvm::Constant *> &MethodTypes) { 1430 // Get the method structure type. 1431 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get( 1432 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us. 1433 PtrToInt8Ty, 1434 NULL); 1435 std::vector<llvm::Constant*> Methods; 1436 std::vector<llvm::Constant*> Elements; 1437 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) { 1438 Elements.clear(); 1439 Elements.push_back(MethodNames[i]); 1440 Elements.push_back(MethodTypes[i]); 1441 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements)); 1442 } 1443 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy, 1444 MethodNames.size()); 1445 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy, 1446 Methods); 1447 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get( 1448 IntTy, ObjCMethodArrayTy, NULL); 1449 Methods.clear(); 1450 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size())); 1451 Methods.push_back(Array); 1452 return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list"); 1453} 1454 1455// Create the protocol list structure used in classes, categories and so on 1456llvm::Constant *CGObjCGNU::GenerateProtocolList( 1457 const SmallVectorImpl<std::string> &Protocols) { 1458 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 1459 Protocols.size()); 1460 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1461 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1462 SizeTy, 1463 ProtocolArrayTy, 1464 NULL); 1465 std::vector<llvm::Constant*> Elements; 1466 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end(); 1467 iter != endIter ; iter++) { 1468 llvm::Constant *protocol = 0; 1469 llvm::StringMap<llvm::Constant*>::iterator value = 1470 ExistingProtocols.find(*iter); 1471 if (value == ExistingProtocols.end()) { 1472 protocol = GenerateEmptyProtocol(*iter); 1473 } else { 1474 protocol = value->getValue(); 1475 } 1476 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol, 1477 PtrToInt8Ty); 1478 Elements.push_back(Ptr); 1479 } 1480 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1481 Elements); 1482 Elements.clear(); 1483 Elements.push_back(NULLPtr); 1484 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size())); 1485 Elements.push_back(ProtocolArray); 1486 return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list"); 1487} 1488 1489llvm::Value *CGObjCGNU::GenerateProtocolRef(CGBuilderTy &Builder, 1490 const ObjCProtocolDecl *PD) { 1491 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()]; 1492 llvm::Type *T = 1493 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType()); 1494 return Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T)); 1495} 1496 1497llvm::Constant *CGObjCGNU::GenerateEmptyProtocol( 1498 const std::string &ProtocolName) { 1499 SmallVector<std::string, 0> EmptyStringVector; 1500 SmallVector<llvm::Constant*, 0> EmptyConstantVector; 1501 1502 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector); 1503 llvm::Constant *MethodList = 1504 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector); 1505 // Protocols are objects containing lists of the methods implemented and 1506 // protocols adopted. 1507 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1508 PtrToInt8Ty, 1509 ProtocolList->getType(), 1510 MethodList->getType(), 1511 MethodList->getType(), 1512 MethodList->getType(), 1513 MethodList->getType(), 1514 NULL); 1515 std::vector<llvm::Constant*> Elements; 1516 // The isa pointer must be set to a magic number so the runtime knows it's 1517 // the correct layout. 1518 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1519 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy)); 1520 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1521 Elements.push_back(ProtocolList); 1522 Elements.push_back(MethodList); 1523 Elements.push_back(MethodList); 1524 Elements.push_back(MethodList); 1525 Elements.push_back(MethodList); 1526 return MakeGlobal(ProtocolTy, Elements, ".objc_protocol"); 1527} 1528 1529void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) { 1530 ASTContext &Context = CGM.getContext(); 1531 std::string ProtocolName = PD->getNameAsString(); 1532 1533 // Use the protocol definition, if there is one. 1534 if (const ObjCProtocolDecl *Def = PD->getDefinition()) 1535 PD = Def; 1536 1537 SmallVector<std::string, 16> Protocols; 1538 for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(), 1539 E = PD->protocol_end(); PI != E; ++PI) 1540 Protocols.push_back((*PI)->getNameAsString()); 1541 SmallVector<llvm::Constant*, 16> InstanceMethodNames; 1542 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1543 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames; 1544 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes; 1545 for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(), 1546 E = PD->instmeth_end(); iter != E; iter++) { 1547 std::string TypeStr; 1548 Context.getObjCEncodingForMethodDecl(*iter, TypeStr); 1549 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1550 InstanceMethodNames.push_back( 1551 MakeConstantString((*iter)->getSelector().getAsString())); 1552 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1553 } else { 1554 OptionalInstanceMethodNames.push_back( 1555 MakeConstantString((*iter)->getSelector().getAsString())); 1556 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1557 } 1558 } 1559 // Collect information about class methods: 1560 SmallVector<llvm::Constant*, 16> ClassMethodNames; 1561 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1562 SmallVector<llvm::Constant*, 16> OptionalClassMethodNames; 1563 SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes; 1564 for (ObjCProtocolDecl::classmeth_iterator 1565 iter = PD->classmeth_begin(), endIter = PD->classmeth_end(); 1566 iter != endIter ; iter++) { 1567 std::string TypeStr; 1568 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1569 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1570 ClassMethodNames.push_back( 1571 MakeConstantString((*iter)->getSelector().getAsString())); 1572 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1573 } else { 1574 OptionalClassMethodNames.push_back( 1575 MakeConstantString((*iter)->getSelector().getAsString())); 1576 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1577 } 1578 } 1579 1580 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols); 1581 llvm::Constant *InstanceMethodList = 1582 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes); 1583 llvm::Constant *ClassMethodList = 1584 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes); 1585 llvm::Constant *OptionalInstanceMethodList = 1586 GenerateProtocolMethodList(OptionalInstanceMethodNames, 1587 OptionalInstanceMethodTypes); 1588 llvm::Constant *OptionalClassMethodList = 1589 GenerateProtocolMethodList(OptionalClassMethodNames, 1590 OptionalClassMethodTypes); 1591 1592 // Property metadata: name, attributes, isSynthesized, setter name, setter 1593 // types, getter name, getter types. 1594 // The isSynthesized value is always set to 0 in a protocol. It exists to 1595 // simplify the runtime library by allowing it to use the same data 1596 // structures for protocol metadata everywhere. 1597 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1598 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1599 PtrToInt8Ty, NULL); 1600 std::vector<llvm::Constant*> Properties; 1601 std::vector<llvm::Constant*> OptionalProperties; 1602 1603 // Add all of the property methods need adding to the method list and to the 1604 // property metadata list. 1605 for (ObjCContainerDecl::prop_iterator 1606 iter = PD->prop_begin(), endIter = PD->prop_end(); 1607 iter != endIter ; iter++) { 1608 std::vector<llvm::Constant*> Fields; 1609 ObjCPropertyDecl *property = (*iter); 1610 1611 Fields.push_back(MakeConstantString(property->getNameAsString())); 1612 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1613 property->getPropertyAttributes())); 1614 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 1615 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1616 std::string TypeStr; 1617 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1618 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1619 InstanceMethodTypes.push_back(TypeEncoding); 1620 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1621 Fields.push_back(TypeEncoding); 1622 } else { 1623 Fields.push_back(NULLPtr); 1624 Fields.push_back(NULLPtr); 1625 } 1626 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1627 std::string TypeStr; 1628 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1629 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1630 InstanceMethodTypes.push_back(TypeEncoding); 1631 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1632 Fields.push_back(TypeEncoding); 1633 } else { 1634 Fields.push_back(NULLPtr); 1635 Fields.push_back(NULLPtr); 1636 } 1637 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) { 1638 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1639 } else { 1640 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1641 } 1642 } 1643 llvm::Constant *PropertyArray = llvm::ConstantArray::get( 1644 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties); 1645 llvm::Constant* PropertyListInitFields[] = 1646 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1647 1648 llvm::Constant *PropertyListInit = 1649 llvm::ConstantStruct::getAnon(PropertyListInitFields); 1650 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule, 1651 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage, 1652 PropertyListInit, ".objc_property_list"); 1653 1654 llvm::Constant *OptionalPropertyArray = 1655 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy, 1656 OptionalProperties.size()) , OptionalProperties); 1657 llvm::Constant* OptionalPropertyListInitFields[] = { 1658 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr, 1659 OptionalPropertyArray }; 1660 1661 llvm::Constant *OptionalPropertyListInit = 1662 llvm::ConstantStruct::getAnon(OptionalPropertyListInitFields); 1663 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule, 1664 OptionalPropertyListInit->getType(), false, 1665 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit, 1666 ".objc_property_list"); 1667 1668 // Protocols are objects containing lists of the methods implemented and 1669 // protocols adopted. 1670 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1671 PtrToInt8Ty, 1672 ProtocolList->getType(), 1673 InstanceMethodList->getType(), 1674 ClassMethodList->getType(), 1675 OptionalInstanceMethodList->getType(), 1676 OptionalClassMethodList->getType(), 1677 PropertyList->getType(), 1678 OptionalPropertyList->getType(), 1679 NULL); 1680 std::vector<llvm::Constant*> Elements; 1681 // The isa pointer must be set to a magic number so the runtime knows it's 1682 // the correct layout. 1683 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1684 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy)); 1685 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1686 Elements.push_back(ProtocolList); 1687 Elements.push_back(InstanceMethodList); 1688 Elements.push_back(ClassMethodList); 1689 Elements.push_back(OptionalInstanceMethodList); 1690 Elements.push_back(OptionalClassMethodList); 1691 Elements.push_back(PropertyList); 1692 Elements.push_back(OptionalPropertyList); 1693 ExistingProtocols[ProtocolName] = 1694 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements, 1695 ".objc_protocol"), IdTy); 1696} 1697void CGObjCGNU::GenerateProtocolHolderCategory(void) { 1698 // Collect information about instance methods 1699 SmallVector<Selector, 1> MethodSels; 1700 SmallVector<llvm::Constant*, 1> MethodTypes; 1701 1702 std::vector<llvm::Constant*> Elements; 1703 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack"; 1704 const std::string CategoryName = "AnotherHack"; 1705 Elements.push_back(MakeConstantString(CategoryName)); 1706 Elements.push_back(MakeConstantString(ClassName)); 1707 // Instance method list 1708 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1709 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy)); 1710 // Class method list 1711 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1712 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy)); 1713 // Protocol list 1714 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy, 1715 ExistingProtocols.size()); 1716 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1717 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1718 SizeTy, 1719 ProtocolArrayTy, 1720 NULL); 1721 std::vector<llvm::Constant*> ProtocolElements; 1722 for (llvm::StringMapIterator<llvm::Constant*> iter = 1723 ExistingProtocols.begin(), endIter = ExistingProtocols.end(); 1724 iter != endIter ; iter++) { 1725 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(), 1726 PtrTy); 1727 ProtocolElements.push_back(Ptr); 1728 } 1729 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1730 ProtocolElements); 1731 ProtocolElements.clear(); 1732 ProtocolElements.push_back(NULLPtr); 1733 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy, 1734 ExistingProtocols.size())); 1735 ProtocolElements.push_back(ProtocolArray); 1736 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy, 1737 ProtocolElements, ".objc_protocol_list"), PtrTy)); 1738 Categories.push_back(llvm::ConstantExpr::getBitCast( 1739 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1740 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1741} 1742 1743/// Libobjc2 uses a bitfield representation where small(ish) bitfields are 1744/// stored in a 64-bit value with the low bit set to 1 and the remaining 63 1745/// bits set to their values, LSB first, while larger ones are stored in a 1746/// structure of this / form: 1747/// 1748/// struct { int32_t length; int32_t values[length]; }; 1749/// 1750/// The values in the array are stored in host-endian format, with the least 1751/// significant bit being assumed to come first in the bitfield. Therefore, a 1752/// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a 1753/// bitfield / with the 63rd bit set will be 1<<64. 1754llvm::Constant *CGObjCGNU::MakeBitField(llvm::SmallVectorImpl<bool> &bits) { 1755 int bitCount = bits.size(); 1756 int ptrBits = 1757 (TheModule.getPointerSize() == llvm::Module::Pointer32) ? 32 : 64; 1758 if (bitCount < ptrBits) { 1759 uint64_t val = 1; 1760 for (int i=0 ; i<bitCount ; ++i) { 1761 if (bits[i]) val |= 1ULL<<(i+1); 1762 } 1763 return llvm::ConstantInt::get(IntPtrTy, val); 1764 } 1765 llvm::SmallVector<llvm::Constant*, 8> values; 1766 int v=0; 1767 while (v < bitCount) { 1768 int32_t word = 0; 1769 for (int i=0 ; (i<32) && (v<bitCount) ; ++i) { 1770 if (bits[v]) word |= 1<<i; 1771 v++; 1772 } 1773 values.push_back(llvm::ConstantInt::get(Int32Ty, word)); 1774 } 1775 llvm::ArrayType *arrayTy = llvm::ArrayType::get(Int32Ty, values.size()); 1776 llvm::Constant *array = llvm::ConstantArray::get(arrayTy, values); 1777 llvm::Constant *fields[2] = { 1778 llvm::ConstantInt::get(Int32Ty, values.size()), 1779 array }; 1780 llvm::Constant *GS = MakeGlobal(llvm::StructType::get(Int32Ty, arrayTy, 1781 NULL), fields); 1782 llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy); 1783 return ptr; 1784} 1785 1786void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) { 1787 std::string ClassName = OCD->getClassInterface()->getNameAsString(); 1788 std::string CategoryName = OCD->getNameAsString(); 1789 // Collect information about instance methods 1790 SmallVector<Selector, 16> InstanceMethodSels; 1791 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1792 for (ObjCCategoryImplDecl::instmeth_iterator 1793 iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end(); 1794 iter != endIter ; iter++) { 1795 InstanceMethodSels.push_back((*iter)->getSelector()); 1796 std::string TypeStr; 1797 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1798 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1799 } 1800 1801 // Collect information about class methods 1802 SmallVector<Selector, 16> ClassMethodSels; 1803 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1804 for (ObjCCategoryImplDecl::classmeth_iterator 1805 iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end(); 1806 iter != endIter ; iter++) { 1807 ClassMethodSels.push_back((*iter)->getSelector()); 1808 std::string TypeStr; 1809 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1810 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1811 } 1812 1813 // Collect the names of referenced protocols 1814 SmallVector<std::string, 16> Protocols; 1815 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl(); 1816 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols(); 1817 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1818 E = Protos.end(); I != E; ++I) 1819 Protocols.push_back((*I)->getNameAsString()); 1820 1821 std::vector<llvm::Constant*> Elements; 1822 Elements.push_back(MakeConstantString(CategoryName)); 1823 Elements.push_back(MakeConstantString(ClassName)); 1824 // Instance method list 1825 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1826 ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes, 1827 false), PtrTy)); 1828 // Class method list 1829 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1830 ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true), 1831 PtrTy)); 1832 // Protocol list 1833 Elements.push_back(llvm::ConstantExpr::getBitCast( 1834 GenerateProtocolList(Protocols), PtrTy)); 1835 Categories.push_back(llvm::ConstantExpr::getBitCast( 1836 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1837 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1838} 1839 1840llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID, 1841 SmallVectorImpl<Selector> &InstanceMethodSels, 1842 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) { 1843 ASTContext &Context = CGM.getContext(); 1844 // 1845 // Property metadata: name, attributes, isSynthesized, setter name, setter 1846 // types, getter name, getter types. 1847 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1848 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1849 PtrToInt8Ty, NULL); 1850 std::vector<llvm::Constant*> Properties; 1851 1852 1853 // Add all of the property methods need adding to the method list and to the 1854 // property metadata list. 1855 for (ObjCImplDecl::propimpl_iterator 1856 iter = OID->propimpl_begin(), endIter = OID->propimpl_end(); 1857 iter != endIter ; iter++) { 1858 std::vector<llvm::Constant*> Fields; 1859 ObjCPropertyDecl *property = (*iter)->getPropertyDecl(); 1860 ObjCPropertyImplDecl *propertyImpl = *iter; 1861 bool isSynthesized = (propertyImpl->getPropertyImplementation() == 1862 ObjCPropertyImplDecl::Synthesize); 1863 1864 Fields.push_back(MakeConstantString(property->getNameAsString())); 1865 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1866 property->getPropertyAttributes())); 1867 Fields.push_back(llvm::ConstantInt::get(Int8Ty, isSynthesized)); 1868 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1869 std::string TypeStr; 1870 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1871 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1872 if (isSynthesized) { 1873 InstanceMethodTypes.push_back(TypeEncoding); 1874 InstanceMethodSels.push_back(getter->getSelector()); 1875 } 1876 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1877 Fields.push_back(TypeEncoding); 1878 } else { 1879 Fields.push_back(NULLPtr); 1880 Fields.push_back(NULLPtr); 1881 } 1882 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1883 std::string TypeStr; 1884 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1885 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1886 if (isSynthesized) { 1887 InstanceMethodTypes.push_back(TypeEncoding); 1888 InstanceMethodSels.push_back(setter->getSelector()); 1889 } 1890 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1891 Fields.push_back(TypeEncoding); 1892 } else { 1893 Fields.push_back(NULLPtr); 1894 Fields.push_back(NULLPtr); 1895 } 1896 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1897 } 1898 llvm::ArrayType *PropertyArrayTy = 1899 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()); 1900 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy, 1901 Properties); 1902 llvm::Constant* PropertyListInitFields[] = 1903 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1904 1905 llvm::Constant *PropertyListInit = 1906 llvm::ConstantStruct::getAnon(PropertyListInitFields); 1907 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false, 1908 llvm::GlobalValue::InternalLinkage, PropertyListInit, 1909 ".objc_property_list"); 1910} 1911 1912void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) { 1913 ASTContext &Context = CGM.getContext(); 1914 1915 // Get the superclass name. 1916 const ObjCInterfaceDecl * SuperClassDecl = 1917 OID->getClassInterface()->getSuperClass(); 1918 std::string SuperClassName; 1919 if (SuperClassDecl) { 1920 SuperClassName = SuperClassDecl->getNameAsString(); 1921 EmitClassRef(SuperClassName); 1922 } 1923 1924 // Get the class name 1925 ObjCInterfaceDecl *ClassDecl = 1926 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface()); 1927 std::string ClassName = ClassDecl->getNameAsString(); 1928 // Emit the symbol that is used to generate linker errors if this class is 1929 // referenced in other modules but not declared. 1930 std::string classSymbolName = "__objc_class_name_" + ClassName; 1931 if (llvm::GlobalVariable *symbol = 1932 TheModule.getGlobalVariable(classSymbolName)) { 1933 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0)); 1934 } else { 1935 new llvm::GlobalVariable(TheModule, LongTy, false, 1936 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0), 1937 classSymbolName); 1938 } 1939 1940 // Get the size of instances. 1941 int instanceSize = 1942 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity(); 1943 1944 // Collect information about instance variables. 1945 SmallVector<llvm::Constant*, 16> IvarNames; 1946 SmallVector<llvm::Constant*, 16> IvarTypes; 1947 SmallVector<llvm::Constant*, 16> IvarOffsets; 1948 1949 std::vector<llvm::Constant*> IvarOffsetValues; 1950 SmallVector<bool, 16> WeakIvars; 1951 SmallVector<bool, 16> StrongIvars; 1952 1953 int superInstanceSize = !SuperClassDecl ? 0 : 1954 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity(); 1955 // For non-fragile ivars, set the instance size to 0 - {the size of just this 1956 // class}. The runtime will then set this to the correct value on load. 1957 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1958 instanceSize = 0 - (instanceSize - superInstanceSize); 1959 } 1960 1961 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 1962 IVD = IVD->getNextIvar()) { 1963 // Store the name 1964 IvarNames.push_back(MakeConstantString(IVD->getNameAsString())); 1965 // Get the type encoding for this ivar 1966 std::string TypeStr; 1967 Context.getObjCEncodingForType(IVD->getType(), TypeStr); 1968 IvarTypes.push_back(MakeConstantString(TypeStr)); 1969 // Get the offset 1970 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD); 1971 uint64_t Offset = BaseOffset; 1972 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) { 1973 Offset = BaseOffset - superInstanceSize; 1974 } 1975 llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset); 1976 // Create the direct offset value 1977 std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." + 1978 IVD->getNameAsString(); 1979 llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName); 1980 if (OffsetVar) { 1981 OffsetVar->setInitializer(OffsetValue); 1982 // If this is the real definition, change its linkage type so that 1983 // different modules will use this one, rather than their private 1984 // copy. 1985 OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage); 1986 } else 1987 OffsetVar = new llvm::GlobalVariable(TheModule, IntTy, 1988 false, llvm::GlobalValue::ExternalLinkage, 1989 OffsetValue, 1990 "__objc_ivar_offset_value_" + ClassName +"." + 1991 IVD->getNameAsString()); 1992 IvarOffsets.push_back(OffsetValue); 1993 IvarOffsetValues.push_back(OffsetVar); 1994 Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime(); 1995 switch (lt) { 1996 case Qualifiers::OCL_Strong: 1997 StrongIvars.push_back(true); 1998 WeakIvars.push_back(false); 1999 break; 2000 case Qualifiers::OCL_Weak: 2001 StrongIvars.push_back(false); 2002 WeakIvars.push_back(true); 2003 break; 2004 default: 2005 StrongIvars.push_back(false); 2006 WeakIvars.push_back(false); 2007 } 2008 } 2009 llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars); 2010 llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars); 2011 llvm::GlobalVariable *IvarOffsetArray = 2012 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets"); 2013 2014 2015 // Collect information about instance methods 2016 SmallVector<Selector, 16> InstanceMethodSels; 2017 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 2018 for (ObjCImplementationDecl::instmeth_iterator 2019 iter = OID->instmeth_begin(), endIter = OID->instmeth_end(); 2020 iter != endIter ; iter++) { 2021 InstanceMethodSels.push_back((*iter)->getSelector()); 2022 std::string TypeStr; 2023 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 2024 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 2025 } 2026 2027 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels, 2028 InstanceMethodTypes); 2029 2030 2031 // Collect information about class methods 2032 SmallVector<Selector, 16> ClassMethodSels; 2033 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 2034 for (ObjCImplementationDecl::classmeth_iterator 2035 iter = OID->classmeth_begin(), endIter = OID->classmeth_end(); 2036 iter != endIter ; iter++) { 2037 ClassMethodSels.push_back((*iter)->getSelector()); 2038 std::string TypeStr; 2039 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 2040 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 2041 } 2042 // Collect the names of referenced protocols 2043 SmallVector<std::string, 16> Protocols; 2044 const ObjCList<ObjCProtocolDecl> &Protos =ClassDecl->getReferencedProtocols(); 2045 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 2046 E = Protos.end(); I != E; ++I) 2047 Protocols.push_back((*I)->getNameAsString()); 2048 2049 2050 2051 // Get the superclass pointer. 2052 llvm::Constant *SuperClass; 2053 if (!SuperClassName.empty()) { 2054 SuperClass = MakeConstantString(SuperClassName, ".super_class_name"); 2055 } else { 2056 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty); 2057 } 2058 // Empty vector used to construct empty method lists 2059 SmallVector<llvm::Constant*, 1> empty; 2060 // Generate the method and instance variable lists 2061 llvm::Constant *MethodList = GenerateMethodList(ClassName, "", 2062 InstanceMethodSels, InstanceMethodTypes, false); 2063 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "", 2064 ClassMethodSels, ClassMethodTypes, true); 2065 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes, 2066 IvarOffsets); 2067 // Irrespective of whether we are compiling for a fragile or non-fragile ABI, 2068 // we emit a symbol containing the offset for each ivar in the class. This 2069 // allows code compiled for the non-Fragile ABI to inherit from code compiled 2070 // for the legacy ABI, without causing problems. The converse is also 2071 // possible, but causes all ivar accesses to be fragile. 2072 2073 // Offset pointer for getting at the correct field in the ivar list when 2074 // setting up the alias. These are: The base address for the global, the 2075 // ivar array (second field), the ivar in this list (set for each ivar), and 2076 // the offset (third field in ivar structure) 2077 llvm::Type *IndexTy = Int32Ty; 2078 llvm::Constant *offsetPointerIndexes[] = {Zeros[0], 2079 llvm::ConstantInt::get(IndexTy, 1), 0, 2080 llvm::ConstantInt::get(IndexTy, 2) }; 2081 2082 unsigned ivarIndex = 0; 2083 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 2084 IVD = IVD->getNextIvar()) { 2085 const std::string Name = "__objc_ivar_offset_" + ClassName + '.' 2086 + IVD->getNameAsString(); 2087 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex); 2088 // Get the correct ivar field 2089 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr( 2090 IvarList, offsetPointerIndexes); 2091 // Get the existing variable, if one exists. 2092 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name); 2093 if (offset) { 2094 offset->setInitializer(offsetValue); 2095 // If this is the real definition, change its linkage type so that 2096 // different modules will use this one, rather than their private 2097 // copy. 2098 offset->setLinkage(llvm::GlobalValue::ExternalLinkage); 2099 } else { 2100 // Add a new alias if there isn't one already. 2101 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(), 2102 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name); 2103 } 2104 ++ivarIndex; 2105 } 2106 llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0); 2107 //Generate metaclass for class methods 2108 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr, 2109 NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList( 2110 empty, empty, empty), ClassMethodList, NULLPtr, 2111 NULLPtr, NULLPtr, ZeroPtr, ZeroPtr, true); 2112 2113 // Generate the class structure 2114 llvm::Constant *ClassStruct = 2115 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L, 2116 ClassName.c_str(), 0, 2117 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, 2118 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray, 2119 Properties, StrongIvarBitmap, WeakIvarBitmap); 2120 2121 // Resolve the class aliases, if they exist. 2122 if (ClassPtrAlias) { 2123 ClassPtrAlias->replaceAllUsesWith( 2124 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy)); 2125 ClassPtrAlias->eraseFromParent(); 2126 ClassPtrAlias = 0; 2127 } 2128 if (MetaClassPtrAlias) { 2129 MetaClassPtrAlias->replaceAllUsesWith( 2130 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy)); 2131 MetaClassPtrAlias->eraseFromParent(); 2132 MetaClassPtrAlias = 0; 2133 } 2134 2135 // Add class structure to list to be added to the symtab later 2136 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty); 2137 Classes.push_back(ClassStruct); 2138} 2139 2140 2141llvm::Function *CGObjCGNU::ModuleInitFunction() { 2142 // Only emit an ObjC load function if no Objective-C stuff has been called 2143 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() && 2144 ExistingProtocols.empty() && SelectorTable.empty()) 2145 return NULL; 2146 2147 // Add all referenced protocols to a category. 2148 GenerateProtocolHolderCategory(); 2149 2150 llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>( 2151 SelectorTy->getElementType()); 2152 llvm::Type *SelStructPtrTy = SelectorTy; 2153 if (SelStructTy == 0) { 2154 SelStructTy = llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, NULL); 2155 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy); 2156 } 2157 2158 std::vector<llvm::Constant*> Elements; 2159 llvm::Constant *Statics = NULLPtr; 2160 // Generate statics list: 2161 if (ConstantStrings.size()) { 2162 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 2163 ConstantStrings.size() + 1); 2164 ConstantStrings.push_back(NULLPtr); 2165 2166 StringRef StringClass = CGM.getLangOptions().ObjCConstantStringClass; 2167 2168 if (StringClass.empty()) StringClass = "NXConstantString"; 2169 2170 Elements.push_back(MakeConstantString(StringClass, 2171 ".objc_static_class_name")); 2172 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy, 2173 ConstantStrings)); 2174 llvm::StructType *StaticsListTy = 2175 llvm::StructType::get(PtrToInt8Ty, StaticsArrayTy, NULL); 2176 llvm::Type *StaticsListPtrTy = 2177 llvm::PointerType::getUnqual(StaticsListTy); 2178 Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics"); 2179 llvm::ArrayType *StaticsListArrayTy = 2180 llvm::ArrayType::get(StaticsListPtrTy, 2); 2181 Elements.clear(); 2182 Elements.push_back(Statics); 2183 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy)); 2184 Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr"); 2185 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy); 2186 } 2187 // Array of classes, categories, and constant objects 2188 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty, 2189 Classes.size() + Categories.size() + 2); 2190 llvm::StructType *SymTabTy = llvm::StructType::get(LongTy, SelStructPtrTy, 2191 llvm::Type::getInt16Ty(VMContext), 2192 llvm::Type::getInt16Ty(VMContext), 2193 ClassListTy, NULL); 2194 2195 Elements.clear(); 2196 // Pointer to an array of selectors used in this module. 2197 std::vector<llvm::Constant*> Selectors; 2198 std::vector<llvm::GlobalAlias*> SelectorAliases; 2199 for (SelectorMap::iterator iter = SelectorTable.begin(), 2200 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) { 2201 2202 std::string SelNameStr = iter->first.getAsString(); 2203 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name"); 2204 2205 SmallVectorImpl<TypedSelector> &Types = iter->second; 2206 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 2207 e = Types.end() ; i!=e ; i++) { 2208 2209 llvm::Constant *SelectorTypeEncoding = NULLPtr; 2210 if (!i->first.empty()) 2211 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types"); 2212 2213 Elements.push_back(SelName); 2214 Elements.push_back(SelectorTypeEncoding); 2215 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2216 Elements.clear(); 2217 2218 // Store the selector alias for later replacement 2219 SelectorAliases.push_back(i->second); 2220 } 2221 } 2222 unsigned SelectorCount = Selectors.size(); 2223 // NULL-terminate the selector list. This should not actually be required, 2224 // because the selector list has a length field. Unfortunately, the GCC 2225 // runtime decides to ignore the length field and expects a NULL terminator, 2226 // and GCC cooperates with this by always setting the length to 0. 2227 Elements.push_back(NULLPtr); 2228 Elements.push_back(NULLPtr); 2229 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2230 Elements.clear(); 2231 2232 // Number of static selectors 2233 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount)); 2234 llvm::Constant *SelectorList = MakeGlobalArray(SelStructTy, Selectors, 2235 ".objc_selector_list"); 2236 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList, 2237 SelStructPtrTy)); 2238 2239 // Now that all of the static selectors exist, create pointers to them. 2240 for (unsigned int i=0 ; i<SelectorCount ; i++) { 2241 2242 llvm::Constant *Idxs[] = {Zeros[0], 2243 llvm::ConstantInt::get(Int32Ty, i), Zeros[0]}; 2244 // FIXME: We're generating redundant loads and stores here! 2245 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(SelectorList, 2246 makeArrayRef(Idxs, 2)); 2247 // If selectors are defined as an opaque type, cast the pointer to this 2248 // type. 2249 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy); 2250 SelectorAliases[i]->replaceAllUsesWith(SelPtr); 2251 SelectorAliases[i]->eraseFromParent(); 2252 } 2253 2254 // Number of classes defined. 2255 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2256 Classes.size())); 2257 // Number of categories defined 2258 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2259 Categories.size())); 2260 // Create an array of classes, then categories, then static object instances 2261 Classes.insert(Classes.end(), Categories.begin(), Categories.end()); 2262 // NULL-terminated list of static object instances (mainly constant strings) 2263 Classes.push_back(Statics); 2264 Classes.push_back(NULLPtr); 2265 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes); 2266 Elements.push_back(ClassList); 2267 // Construct the symbol table 2268 llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements); 2269 2270 // The symbol table is contained in a module which has some version-checking 2271 // constants 2272 llvm::StructType * ModuleTy = llvm::StructType::get(LongTy, LongTy, 2273 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), 2274 (RuntimeVersion >= 10) ? IntTy : NULL, NULL); 2275 Elements.clear(); 2276 // Runtime version, used for ABI compatibility checking. 2277 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion)); 2278 // sizeof(ModuleTy) 2279 llvm::TargetData td(&TheModule); 2280 Elements.push_back( 2281 llvm::ConstantInt::get(LongTy, 2282 td.getTypeSizeInBits(ModuleTy) / 2283 CGM.getContext().getCharWidth())); 2284 2285 // The path to the source file where this module was declared 2286 SourceManager &SM = CGM.getContext().getSourceManager(); 2287 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID()); 2288 std::string path = 2289 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName(); 2290 Elements.push_back(MakeConstantString(path, ".objc_source_file_name")); 2291 Elements.push_back(SymTab); 2292 2293 if (RuntimeVersion >= 10) 2294 switch (CGM.getLangOptions().getGC()) { 2295 case LangOptions::GCOnly: 2296 Elements.push_back(llvm::ConstantInt::get(IntTy, 2)); 2297 break; 2298 case LangOptions::NonGC: 2299 if (CGM.getLangOptions().ObjCAutoRefCount) 2300 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2301 else 2302 Elements.push_back(llvm::ConstantInt::get(IntTy, 0)); 2303 break; 2304 case LangOptions::HybridGC: 2305 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2306 break; 2307 } 2308 2309 llvm::Value *Module = MakeGlobal(ModuleTy, Elements); 2310 2311 // Create the load function calling the runtime entry point with the module 2312 // structure 2313 llvm::Function * LoadFunction = llvm::Function::Create( 2314 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false), 2315 llvm::GlobalValue::InternalLinkage, ".objc_load_function", 2316 &TheModule); 2317 llvm::BasicBlock *EntryBB = 2318 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction); 2319 CGBuilderTy Builder(VMContext); 2320 Builder.SetInsertPoint(EntryBB); 2321 2322 llvm::FunctionType *FT = 2323 llvm::FunctionType::get(Builder.getVoidTy(), 2324 llvm::PointerType::getUnqual(ModuleTy), true); 2325 llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class"); 2326 Builder.CreateCall(Register, Module); 2327 Builder.CreateRetVoid(); 2328 2329 return LoadFunction; 2330} 2331 2332llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD, 2333 const ObjCContainerDecl *CD) { 2334 const ObjCCategoryImplDecl *OCD = 2335 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext()); 2336 StringRef CategoryName = OCD ? OCD->getName() : ""; 2337 StringRef ClassName = CD->getName(); 2338 Selector MethodName = OMD->getSelector(); 2339 bool isClassMethod = !OMD->isInstanceMethod(); 2340 2341 CodeGenTypes &Types = CGM.getTypes(); 2342 llvm::FunctionType *MethodTy = 2343 Types.GetFunctionType(Types.getFunctionInfo(OMD), OMD->isVariadic()); 2344 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName, 2345 MethodName, isClassMethod); 2346 2347 llvm::Function *Method 2348 = llvm::Function::Create(MethodTy, 2349 llvm::GlobalValue::InternalLinkage, 2350 FunctionName, 2351 &TheModule); 2352 return Method; 2353} 2354 2355llvm::Constant *CGObjCGNU::GetPropertyGetFunction() { 2356 return GetPropertyFn; 2357} 2358 2359llvm::Constant *CGObjCGNU::GetPropertySetFunction() { 2360 return SetPropertyFn; 2361} 2362 2363llvm::Constant *CGObjCGNU::GetGetStructFunction() { 2364 return GetStructPropertyFn; 2365} 2366llvm::Constant *CGObjCGNU::GetSetStructFunction() { 2367 return SetStructPropertyFn; 2368} 2369 2370llvm::Constant *CGObjCGNU::EnumerationMutationFunction() { 2371 return EnumerationMutationFn; 2372} 2373 2374void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF, 2375 const ObjCAtSynchronizedStmt &S) { 2376 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn); 2377} 2378 2379 2380void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF, 2381 const ObjCAtTryStmt &S) { 2382 // Unlike the Apple non-fragile runtimes, which also uses 2383 // unwind-based zero cost exceptions, the GNU Objective C runtime's 2384 // EH support isn't a veneer over C++ EH. Instead, exception 2385 // objects are created by __objc_exception_throw and destroyed by 2386 // the personality function; this avoids the need for bracketing 2387 // catch handlers with calls to __blah_begin_catch/__blah_end_catch 2388 // (or even _Unwind_DeleteException), but probably doesn't 2389 // interoperate very well with foreign exceptions. 2390 // 2391 // In Objective-C++ mode, we actually emit something equivalent to the C++ 2392 // exception handler. 2393 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn); 2394 return ; 2395} 2396 2397void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF, 2398 const ObjCAtThrowStmt &S) { 2399 llvm::Value *ExceptionAsObject; 2400 2401 if (const Expr *ThrowExpr = S.getThrowExpr()) { 2402 llvm::Value *Exception = CGF.EmitObjCThrowOperand(ThrowExpr); 2403 ExceptionAsObject = Exception; 2404 } else { 2405 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) && 2406 "Unexpected rethrow outside @catch block."); 2407 ExceptionAsObject = CGF.ObjCEHValueStack.back(); 2408 } 2409 ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy); 2410 2411 // Note: This may have to be an invoke, if we want to support constructs like: 2412 // @try { 2413 // @throw(obj); 2414 // } 2415 // @catch(id) ... 2416 // 2417 // This is effectively turning @throw into an incredibly-expensive goto, but 2418 // it may happen as a result of inlining followed by missed optimizations, or 2419 // as a result of stupidity. 2420 llvm::BasicBlock *UnwindBB = CGF.getInvokeDest(); 2421 if (!UnwindBB) { 2422 CGF.Builder.CreateCall(ExceptionThrowFn, ExceptionAsObject); 2423 CGF.Builder.CreateUnreachable(); 2424 } else { 2425 CGF.Builder.CreateInvoke(ExceptionThrowFn, UnwindBB, UnwindBB, 2426 ExceptionAsObject); 2427 } 2428 // Clear the insertion point to indicate we are in unreachable code. 2429 CGF.Builder.ClearInsertionPoint(); 2430} 2431 2432llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF, 2433 llvm::Value *AddrWeakObj) { 2434 CGBuilderTy B = CGF.Builder; 2435 AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy); 2436 return B.CreateCall(WeakReadFn, AddrWeakObj); 2437} 2438 2439void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF, 2440 llvm::Value *src, llvm::Value *dst) { 2441 CGBuilderTy B = CGF.Builder; 2442 src = EnforceType(B, src, IdTy); 2443 dst = EnforceType(B, dst, PtrToIdTy); 2444 B.CreateCall2(WeakAssignFn, src, dst); 2445} 2446 2447void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF, 2448 llvm::Value *src, llvm::Value *dst, 2449 bool threadlocal) { 2450 CGBuilderTy B = CGF.Builder; 2451 src = EnforceType(B, src, IdTy); 2452 dst = EnforceType(B, dst, PtrToIdTy); 2453 if (!threadlocal) 2454 B.CreateCall2(GlobalAssignFn, src, dst); 2455 else 2456 // FIXME. Add threadloca assign API 2457 llvm_unreachable("EmitObjCGlobalAssign - Threal Local API NYI"); 2458} 2459 2460void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF, 2461 llvm::Value *src, llvm::Value *dst, 2462 llvm::Value *ivarOffset) { 2463 CGBuilderTy B = CGF.Builder; 2464 src = EnforceType(B, src, IdTy); 2465 dst = EnforceType(B, dst, IdTy); 2466 B.CreateCall3(IvarAssignFn, src, dst, ivarOffset); 2467} 2468 2469void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF, 2470 llvm::Value *src, llvm::Value *dst) { 2471 CGBuilderTy B = CGF.Builder; 2472 src = EnforceType(B, src, IdTy); 2473 dst = EnforceType(B, dst, PtrToIdTy); 2474 B.CreateCall2(StrongCastAssignFn, src, dst); 2475} 2476 2477void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF, 2478 llvm::Value *DestPtr, 2479 llvm::Value *SrcPtr, 2480 llvm::Value *Size) { 2481 CGBuilderTy B = CGF.Builder; 2482 DestPtr = EnforceType(B, DestPtr, PtrTy); 2483 SrcPtr = EnforceType(B, SrcPtr, PtrTy); 2484 2485 B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size); 2486} 2487 2488llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable( 2489 const ObjCInterfaceDecl *ID, 2490 const ObjCIvarDecl *Ivar) { 2491 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString() 2492 + '.' + Ivar->getNameAsString(); 2493 // Emit the variable and initialize it with what we think the correct value 2494 // is. This allows code compiled with non-fragile ivars to work correctly 2495 // when linked against code which isn't (most of the time). 2496 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name); 2497 if (!IvarOffsetPointer) { 2498 // This will cause a run-time crash if we accidentally use it. A value of 2499 // 0 would seem more sensible, but will silently overwrite the isa pointer 2500 // causing a great deal of confusion. 2501 uint64_t Offset = -1; 2502 // We can't call ComputeIvarBaseOffset() here if we have the 2503 // implementation, because it will create an invalid ASTRecordLayout object 2504 // that we are then stuck with forever, so we only initialize the ivar 2505 // offset variable with a guess if we only have the interface. The 2506 // initializer will be reset later anyway, when we are generating the class 2507 // description. 2508 if (!CGM.getContext().getObjCImplementation( 2509 const_cast<ObjCInterfaceDecl *>(ID))) 2510 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar); 2511 2512 llvm::ConstantInt *OffsetGuess = llvm::ConstantInt::get(Int32Ty, Offset, 2513 /*isSigned*/true); 2514 // Don't emit the guess in non-PIC code because the linker will not be able 2515 // to replace it with the real version for a library. In non-PIC code you 2516 // must compile with the fragile ABI if you want to use ivars from a 2517 // GCC-compiled class. 2518 if (CGM.getLangOptions().PICLevel) { 2519 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule, 2520 Int32Ty, false, 2521 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess"); 2522 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2523 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage, 2524 IvarOffsetGV, Name); 2525 } else { 2526 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2527 llvm::Type::getInt32PtrTy(VMContext), false, 2528 llvm::GlobalValue::ExternalLinkage, 0, Name); 2529 } 2530 } 2531 return IvarOffsetPointer; 2532} 2533 2534LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF, 2535 QualType ObjectTy, 2536 llvm::Value *BaseValue, 2537 const ObjCIvarDecl *Ivar, 2538 unsigned CVRQualifiers) { 2539 const ObjCInterfaceDecl *ID = 2540 ObjectTy->getAs<ObjCObjectType>()->getInterface(); 2541 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers, 2542 EmitIvarOffset(CGF, ID, Ivar)); 2543} 2544 2545static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context, 2546 const ObjCInterfaceDecl *OID, 2547 const ObjCIvarDecl *OIVD) { 2548 for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next; 2549 next = next->getNextIvar()) { 2550 if (OIVD == next) 2551 return OID; 2552 } 2553 2554 // Otherwise check in the super class. 2555 if (const ObjCInterfaceDecl *Super = OID->getSuperClass()) 2556 return FindIvarInterface(Context, Super, OIVD); 2557 2558 return 0; 2559} 2560 2561llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF, 2562 const ObjCInterfaceDecl *Interface, 2563 const ObjCIvarDecl *Ivar) { 2564 if (CGM.getLangOptions().ObjCNonFragileABI) { 2565 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar); 2566 if (RuntimeVersion < 10) 2567 return CGF.Builder.CreateZExtOrBitCast( 2568 CGF.Builder.CreateLoad(CGF.Builder.CreateLoad( 2569 ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")), 2570 PtrDiffTy); 2571 std::string name = "__objc_ivar_offset_value_" + 2572 Interface->getNameAsString() +"." + Ivar->getNameAsString(); 2573 llvm::Value *Offset = TheModule.getGlobalVariable(name); 2574 if (!Offset) 2575 Offset = new llvm::GlobalVariable(TheModule, IntTy, 2576 false, llvm::GlobalValue::LinkOnceAnyLinkage, 2577 llvm::Constant::getNullValue(IntTy), name); 2578 return CGF.Builder.CreateLoad(Offset); 2579 } 2580 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar); 2581 return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true); 2582} 2583 2584CGObjCRuntime * 2585clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) { 2586 if (CGM.getLangOptions().ObjCNonFragileABI) 2587 return new CGObjCGNUstep(CGM); 2588 return new CGObjCGCC(CGM); 2589} 2590