CGObjCGNU.cpp revision 2b07dd350a0d0b132ed529cb449fe2a5a56103b8
1//===------- CGObjCGNU.cpp - Emit LLVM Code from ASTs for a Module --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This provides Objective-C code generation targeting the GNU runtime. The 11// class in this file generates structures used by the GNU Objective-C runtime 12// library. These structures are defined in objc/objc.h and objc/objc-api.h in 13// the GNU runtime distribution. 14// 15//===----------------------------------------------------------------------===// 16 17#include "CGObjCRuntime.h" 18#include "CodeGenModule.h" 19#include "CodeGenFunction.h" 20#include "CGCleanup.h" 21#include "clang/AST/ASTContext.h" 22#include "clang/AST/Decl.h" 23#include "clang/AST/DeclObjC.h" 24#include "clang/AST/RecordLayout.h" 25#include "clang/AST/StmtObjC.h" 26#include "clang/Basic/SourceManager.h" 27#include "clang/Basic/FileManager.h" 28 29#include "llvm/Intrinsics.h" 30#include "llvm/Module.h" 31#include "llvm/LLVMContext.h" 32#include "llvm/ADT/SmallVector.h" 33#include "llvm/ADT/StringMap.h" 34#include "llvm/Support/CallSite.h" 35#include "llvm/Support/Compiler.h" 36#include "llvm/DataLayout.h" 37 38#include <cstdarg> 39 40 41using namespace clang; 42using namespace CodeGen; 43 44 45namespace { 46/// Class that lazily initialises the runtime function. Avoids inserting the 47/// types and the function declaration into a module if they're not used, and 48/// avoids constructing the type more than once if it's used more than once. 49class LazyRuntimeFunction { 50 CodeGenModule *CGM; 51 std::vector<llvm::Type*> ArgTys; 52 const char *FunctionName; 53 llvm::Constant *Function; 54 public: 55 /// Constructor leaves this class uninitialized, because it is intended to 56 /// be used as a field in another class and not all of the types that are 57 /// used as arguments will necessarily be available at construction time. 58 LazyRuntimeFunction() : CGM(0), FunctionName(0), Function(0) {} 59 60 /// Initialises the lazy function with the name, return type, and the types 61 /// of the arguments. 62 END_WITH_NULL 63 void init(CodeGenModule *Mod, const char *name, 64 llvm::Type *RetTy, ...) { 65 CGM =Mod; 66 FunctionName = name; 67 Function = 0; 68 ArgTys.clear(); 69 va_list Args; 70 va_start(Args, RetTy); 71 while (llvm::Type *ArgTy = va_arg(Args, llvm::Type*)) 72 ArgTys.push_back(ArgTy); 73 va_end(Args); 74 // Push the return type on at the end so we can pop it off easily 75 ArgTys.push_back(RetTy); 76 } 77 /// Overloaded cast operator, allows the class to be implicitly cast to an 78 /// LLVM constant. 79 operator llvm::Constant*() { 80 if (!Function) { 81 if (0 == FunctionName) return 0; 82 // We put the return type on the end of the vector, so pop it back off 83 llvm::Type *RetTy = ArgTys.back(); 84 ArgTys.pop_back(); 85 llvm::FunctionType *FTy = llvm::FunctionType::get(RetTy, ArgTys, false); 86 Function = 87 cast<llvm::Constant>(CGM->CreateRuntimeFunction(FTy, FunctionName)); 88 // We won't need to use the types again, so we may as well clean up the 89 // vector now 90 ArgTys.resize(0); 91 } 92 return Function; 93 } 94 operator llvm::Function*() { 95 return cast<llvm::Function>((llvm::Constant*)*this); 96 } 97 98}; 99 100 101/// GNU Objective-C runtime code generation. This class implements the parts of 102/// Objective-C support that are specific to the GNU family of runtimes (GCC, 103/// GNUstep and ObjFW). 104class CGObjCGNU : public CGObjCRuntime { 105protected: 106 /// The LLVM module into which output is inserted 107 llvm::Module &TheModule; 108 /// strut objc_super. Used for sending messages to super. This structure 109 /// contains the receiver (object) and the expected class. 110 llvm::StructType *ObjCSuperTy; 111 /// struct objc_super*. The type of the argument to the superclass message 112 /// lookup functions. 113 llvm::PointerType *PtrToObjCSuperTy; 114 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring 115 /// SEL is included in a header somewhere, in which case it will be whatever 116 /// type is declared in that header, most likely {i8*, i8*}. 117 llvm::PointerType *SelectorTy; 118 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the 119 /// places where it's used 120 llvm::IntegerType *Int8Ty; 121 /// Pointer to i8 - LLVM type of char*, for all of the places where the 122 /// runtime needs to deal with C strings. 123 llvm::PointerType *PtrToInt8Ty; 124 /// Instance Method Pointer type. This is a pointer to a function that takes, 125 /// at a minimum, an object and a selector, and is the generic type for 126 /// Objective-C methods. Due to differences between variadic / non-variadic 127 /// calling conventions, it must always be cast to the correct type before 128 /// actually being used. 129 llvm::PointerType *IMPTy; 130 /// Type of an untyped Objective-C object. Clang treats id as a built-in type 131 /// when compiling Objective-C code, so this may be an opaque pointer (i8*), 132 /// but if the runtime header declaring it is included then it may be a 133 /// pointer to a structure. 134 llvm::PointerType *IdTy; 135 /// Pointer to a pointer to an Objective-C object. Used in the new ABI 136 /// message lookup function and some GC-related functions. 137 llvm::PointerType *PtrToIdTy; 138 /// The clang type of id. Used when using the clang CGCall infrastructure to 139 /// call Objective-C methods. 140 CanQualType ASTIdTy; 141 /// LLVM type for C int type. 142 llvm::IntegerType *IntTy; 143 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is 144 /// used in the code to document the difference between i8* meaning a pointer 145 /// to a C string and i8* meaning a pointer to some opaque type. 146 llvm::PointerType *PtrTy; 147 /// LLVM type for C long type. The runtime uses this in a lot of places where 148 /// it should be using intptr_t, but we can't fix this without breaking 149 /// compatibility with GCC... 150 llvm::IntegerType *LongTy; 151 /// LLVM type for C size_t. Used in various runtime data structures. 152 llvm::IntegerType *SizeTy; 153 /// LLVM type for C intptr_t. 154 llvm::IntegerType *IntPtrTy; 155 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions. 156 llvm::IntegerType *PtrDiffTy; 157 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance 158 /// variables. 159 llvm::PointerType *PtrToIntTy; 160 /// LLVM type for Objective-C BOOL type. 161 llvm::Type *BoolTy; 162 /// 32-bit integer type, to save us needing to look it up every time it's used. 163 llvm::IntegerType *Int32Ty; 164 /// 64-bit integer type, to save us needing to look it up every time it's used. 165 llvm::IntegerType *Int64Ty; 166 /// Metadata kind used to tie method lookups to message sends. The GNUstep 167 /// runtime provides some LLVM passes that can use this to do things like 168 /// automatic IMP caching and speculative inlining. 169 unsigned msgSendMDKind; 170 /// Helper function that generates a constant string and returns a pointer to 171 /// the start of the string. The result of this function can be used anywhere 172 /// where the C code specifies const char*. 173 llvm::Constant *MakeConstantString(const std::string &Str, 174 const std::string &Name="") { 175 llvm::Constant *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str()); 176 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 177 } 178 /// Emits a linkonce_odr string, whose name is the prefix followed by the 179 /// string value. This allows the linker to combine the strings between 180 /// different modules. Used for EH typeinfo names, selector strings, and a 181 /// few other things. 182 llvm::Constant *ExportUniqueString(const std::string &Str, 183 const std::string prefix) { 184 std::string name = prefix + Str; 185 llvm::Constant *ConstStr = TheModule.getGlobalVariable(name); 186 if (!ConstStr) { 187 llvm::Constant *value = llvm::ConstantDataArray::getString(VMContext,Str); 188 ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true, 189 llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str); 190 } 191 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros); 192 } 193 /// Generates a global structure, initialized by the elements in the vector. 194 /// The element types must match the types of the structure elements in the 195 /// first argument. 196 llvm::GlobalVariable *MakeGlobal(llvm::StructType *Ty, 197 llvm::ArrayRef<llvm::Constant*> V, 198 StringRef Name="", 199 llvm::GlobalValue::LinkageTypes linkage 200 =llvm::GlobalValue::InternalLinkage) { 201 llvm::Constant *C = llvm::ConstantStruct::get(Ty, V); 202 return new llvm::GlobalVariable(TheModule, Ty, false, 203 linkage, C, Name); 204 } 205 /// Generates a global array. The vector must contain the same number of 206 /// elements that the array type declares, of the type specified as the array 207 /// element type. 208 llvm::GlobalVariable *MakeGlobal(llvm::ArrayType *Ty, 209 llvm::ArrayRef<llvm::Constant*> V, 210 StringRef Name="", 211 llvm::GlobalValue::LinkageTypes linkage 212 =llvm::GlobalValue::InternalLinkage) { 213 llvm::Constant *C = llvm::ConstantArray::get(Ty, V); 214 return new llvm::GlobalVariable(TheModule, Ty, false, 215 linkage, C, Name); 216 } 217 /// Generates a global array, inferring the array type from the specified 218 /// element type and the size of the initialiser. 219 llvm::GlobalVariable *MakeGlobalArray(llvm::Type *Ty, 220 llvm::ArrayRef<llvm::Constant*> V, 221 StringRef Name="", 222 llvm::GlobalValue::LinkageTypes linkage 223 =llvm::GlobalValue::InternalLinkage) { 224 llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size()); 225 return MakeGlobal(ArrayTy, V, Name, linkage); 226 } 227 /// Returns a property name and encoding string. 228 llvm::Constant *MakePropertyEncodingString(const ObjCPropertyDecl *PD, 229 const Decl *Container) { 230 ObjCRuntime R = CGM.getLangOpts().ObjCRuntime; 231 if ((R.getKind() == ObjCRuntime::GNUstep) && 232 (R.getVersion() >= VersionTuple(1, 6))) { 233 std::string NameAndAttributes; 234 std::string TypeStr; 235 CGM.getContext().getObjCEncodingForPropertyDecl(PD, Container, TypeStr); 236 NameAndAttributes += '\0'; 237 NameAndAttributes += TypeStr.length() + 3; 238 NameAndAttributes += TypeStr; 239 NameAndAttributes += '\0'; 240 NameAndAttributes += PD->getNameAsString(); 241 return llvm::ConstantExpr::getGetElementPtr( 242 CGM.GetAddrOfConstantString(NameAndAttributes), Zeros); 243 } 244 return MakeConstantString(PD->getNameAsString()); 245 } 246 /// Ensures that the value has the required type, by inserting a bitcast if 247 /// required. This function lets us avoid inserting bitcasts that are 248 /// redundant. 249 llvm::Value* EnforceType(CGBuilderTy B, llvm::Value *V, llvm::Type *Ty){ 250 if (V->getType() == Ty) return V; 251 return B.CreateBitCast(V, Ty); 252 } 253 // Some zeros used for GEPs in lots of places. 254 llvm::Constant *Zeros[2]; 255 /// Null pointer value. Mainly used as a terminator in various arrays. 256 llvm::Constant *NULLPtr; 257 /// LLVM context. 258 llvm::LLVMContext &VMContext; 259private: 260 /// Placeholder for the class. Lots of things refer to the class before we've 261 /// actually emitted it. We use this alias as a placeholder, and then replace 262 /// it with a pointer to the class structure before finally emitting the 263 /// module. 264 llvm::GlobalAlias *ClassPtrAlias; 265 /// Placeholder for the metaclass. Lots of things refer to the class before 266 /// we've / actually emitted it. We use this alias as a placeholder, and then 267 /// replace / it with a pointer to the metaclass structure before finally 268 /// emitting the / module. 269 llvm::GlobalAlias *MetaClassPtrAlias; 270 /// All of the classes that have been generated for this compilation units. 271 std::vector<llvm::Constant*> Classes; 272 /// All of the categories that have been generated for this compilation units. 273 std::vector<llvm::Constant*> Categories; 274 /// All of the Objective-C constant strings that have been generated for this 275 /// compilation units. 276 std::vector<llvm::Constant*> ConstantStrings; 277 /// Map from string values to Objective-C constant strings in the output. 278 /// Used to prevent emitting Objective-C strings more than once. This should 279 /// not be required at all - CodeGenModule should manage this list. 280 llvm::StringMap<llvm::Constant*> ObjCStrings; 281 /// All of the protocols that have been declared. 282 llvm::StringMap<llvm::Constant*> ExistingProtocols; 283 /// For each variant of a selector, we store the type encoding and a 284 /// placeholder value. For an untyped selector, the type will be the empty 285 /// string. Selector references are all done via the module's selector table, 286 /// so we create an alias as a placeholder and then replace it with the real 287 /// value later. 288 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector; 289 /// Type of the selector map. This is roughly equivalent to the structure 290 /// used in the GNUstep runtime, which maintains a list of all of the valid 291 /// types for a selector in a table. 292 typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> > 293 SelectorMap; 294 /// A map from selectors to selector types. This allows us to emit all 295 /// selectors of the same name and type together. 296 SelectorMap SelectorTable; 297 298 /// Selectors related to memory management. When compiling in GC mode, we 299 /// omit these. 300 Selector RetainSel, ReleaseSel, AutoreleaseSel; 301 /// Runtime functions used for memory management in GC mode. Note that clang 302 /// supports code generation for calling these functions, but neither GNU 303 /// runtime actually supports this API properly yet. 304 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn, 305 WeakAssignFn, GlobalAssignFn; 306 307 typedef std::pair<std::string, std::string> ClassAliasPair; 308 /// All classes that have aliases set for them. 309 std::vector<ClassAliasPair> ClassAliases; 310 311protected: 312 /// Function used for throwing Objective-C exceptions. 313 LazyRuntimeFunction ExceptionThrowFn; 314 /// Function used for rethrowing exceptions, used at the end of \@finally or 315 /// \@synchronize blocks. 316 LazyRuntimeFunction ExceptionReThrowFn; 317 /// Function called when entering a catch function. This is required for 318 /// differentiating Objective-C exceptions and foreign exceptions. 319 LazyRuntimeFunction EnterCatchFn; 320 /// Function called when exiting from a catch block. Used to do exception 321 /// cleanup. 322 LazyRuntimeFunction ExitCatchFn; 323 /// Function called when entering an \@synchronize block. Acquires the lock. 324 LazyRuntimeFunction SyncEnterFn; 325 /// Function called when exiting an \@synchronize block. Releases the lock. 326 LazyRuntimeFunction SyncExitFn; 327 328private: 329 330 /// Function called if fast enumeration detects that the collection is 331 /// modified during the update. 332 LazyRuntimeFunction EnumerationMutationFn; 333 /// Function for implementing synthesized property getters that return an 334 /// object. 335 LazyRuntimeFunction GetPropertyFn; 336 /// Function for implementing synthesized property setters that return an 337 /// object. 338 LazyRuntimeFunction SetPropertyFn; 339 /// Function used for non-object declared property getters. 340 LazyRuntimeFunction GetStructPropertyFn; 341 /// Function used for non-object declared property setters. 342 LazyRuntimeFunction SetStructPropertyFn; 343 344 /// The version of the runtime that this class targets. Must match the 345 /// version in the runtime. 346 int RuntimeVersion; 347 /// The version of the protocol class. Used to differentiate between ObjC1 348 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional 349 /// components and can not contain declared properties. We always emit 350 /// Objective-C 2 property structures, but we have to pretend that they're 351 /// Objective-C 1 property structures when targeting the GCC runtime or it 352 /// will abort. 353 const int ProtocolVersion; 354private: 355 /// Generates an instance variable list structure. This is a structure 356 /// containing a size and an array of structures containing instance variable 357 /// metadata. This is used purely for introspection in the fragile ABI. In 358 /// the non-fragile ABI, it's used for instance variable fixup. 359 llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames, 360 ArrayRef<llvm::Constant *> IvarTypes, 361 ArrayRef<llvm::Constant *> IvarOffsets); 362 /// Generates a method list structure. This is a structure containing a size 363 /// and an array of structures containing method metadata. 364 /// 365 /// This structure is used by both classes and categories, and contains a next 366 /// pointer allowing them to be chained together in a linked list. 367 llvm::Constant *GenerateMethodList(const StringRef &ClassName, 368 const StringRef &CategoryName, 369 ArrayRef<Selector> MethodSels, 370 ArrayRef<llvm::Constant *> MethodTypes, 371 bool isClassMethodList); 372 /// Emits an empty protocol. This is used for \@protocol() where no protocol 373 /// is found. The runtime will (hopefully) fix up the pointer to refer to the 374 /// real protocol. 375 llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName); 376 /// Generates a list of property metadata structures. This follows the same 377 /// pattern as method and instance variable metadata lists. 378 llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID, 379 SmallVectorImpl<Selector> &InstanceMethodSels, 380 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes); 381 /// Generates a list of referenced protocols. Classes, categories, and 382 /// protocols all use this structure. 383 llvm::Constant *GenerateProtocolList(ArrayRef<std::string> Protocols); 384 /// To ensure that all protocols are seen by the runtime, we add a category on 385 /// a class defined in the runtime, declaring no methods, but adopting the 386 /// protocols. This is a horribly ugly hack, but it allows us to collect all 387 /// of the protocols without changing the ABI. 388 void GenerateProtocolHolderCategory(void); 389 /// Generates a class structure. 390 llvm::Constant *GenerateClassStructure( 391 llvm::Constant *MetaClass, 392 llvm::Constant *SuperClass, 393 unsigned info, 394 const char *Name, 395 llvm::Constant *Version, 396 llvm::Constant *InstanceSize, 397 llvm::Constant *IVars, 398 llvm::Constant *Methods, 399 llvm::Constant *Protocols, 400 llvm::Constant *IvarOffsets, 401 llvm::Constant *Properties, 402 llvm::Constant *StrongIvarBitmap, 403 llvm::Constant *WeakIvarBitmap, 404 bool isMeta=false); 405 /// Generates a method list. This is used by protocols to define the required 406 /// and optional methods. 407 llvm::Constant *GenerateProtocolMethodList( 408 ArrayRef<llvm::Constant *> MethodNames, 409 ArrayRef<llvm::Constant *> MethodTypes); 410 /// Returns a selector with the specified type encoding. An empty string is 411 /// used to return an untyped selector (with the types field set to NULL). 412 llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 413 const std::string &TypeEncoding, bool lval); 414 /// Returns the variable used to store the offset of an instance variable. 415 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID, 416 const ObjCIvarDecl *Ivar); 417 /// Emits a reference to a class. This allows the linker to object if there 418 /// is no class of the matching name. 419protected: 420 void EmitClassRef(const std::string &className); 421 /// Emits a pointer to the named class 422 virtual llvm::Value *GetClassNamed(CGBuilderTy &Builder, 423 const std::string &Name, bool isWeak); 424 /// Looks up the method for sending a message to the specified object. This 425 /// mechanism differs between the GCC and GNU runtimes, so this method must be 426 /// overridden in subclasses. 427 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 428 llvm::Value *&Receiver, 429 llvm::Value *cmd, 430 llvm::MDNode *node) = 0; 431 /// Looks up the method for sending a message to a superclass. This 432 /// mechanism differs between the GCC and GNU runtimes, so this method must 433 /// be overridden in subclasses. 434 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 435 llvm::Value *ObjCSuper, 436 llvm::Value *cmd) = 0; 437 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are 438 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63 439 /// bits set to their values, LSB first, while larger ones are stored in a 440 /// structure of this / form: 441 /// 442 /// struct { int32_t length; int32_t values[length]; }; 443 /// 444 /// The values in the array are stored in host-endian format, with the least 445 /// significant bit being assumed to come first in the bitfield. Therefore, 446 /// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, 447 /// while a bitfield / with the 63rd bit set will be 1<<64. 448 llvm::Constant *MakeBitField(ArrayRef<bool> bits); 449public: 450 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 451 unsigned protocolClassVersion); 452 453 virtual llvm::Constant *GenerateConstantString(const StringLiteral *); 454 455 virtual RValue 456 GenerateMessageSend(CodeGenFunction &CGF, 457 ReturnValueSlot Return, 458 QualType ResultType, 459 Selector Sel, 460 llvm::Value *Receiver, 461 const CallArgList &CallArgs, 462 const ObjCInterfaceDecl *Class, 463 const ObjCMethodDecl *Method); 464 virtual RValue 465 GenerateMessageSendSuper(CodeGenFunction &CGF, 466 ReturnValueSlot Return, 467 QualType ResultType, 468 Selector Sel, 469 const ObjCInterfaceDecl *Class, 470 bool isCategoryImpl, 471 llvm::Value *Receiver, 472 bool IsClassMessage, 473 const CallArgList &CallArgs, 474 const ObjCMethodDecl *Method); 475 virtual llvm::Value *GetClass(CGBuilderTy &Builder, 476 const ObjCInterfaceDecl *OID); 477 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel, 478 bool lval = false); 479 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 480 *Method); 481 virtual llvm::Constant *GetEHType(QualType T); 482 483 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 484 const ObjCContainerDecl *CD); 485 virtual void GenerateCategory(const ObjCCategoryImplDecl *CMD); 486 virtual void GenerateClass(const ObjCImplementationDecl *ClassDecl); 487 virtual void RegisterAlias(const ObjCCompatibleAliasDecl *OAD); 488 virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder, 489 const ObjCProtocolDecl *PD); 490 virtual void GenerateProtocol(const ObjCProtocolDecl *PD); 491 virtual llvm::Function *ModuleInitFunction(); 492 virtual llvm::Constant *GetPropertyGetFunction(); 493 virtual llvm::Constant *GetPropertySetFunction(); 494 virtual llvm::Constant *GetOptimizedPropertySetFunction(bool atomic, 495 bool copy); 496 virtual llvm::Constant *GetSetStructFunction(); 497 virtual llvm::Constant *GetCppAtomicObjectFunction(); 498 virtual llvm::Constant *GetGetStructFunction(); 499 virtual llvm::Constant *EnumerationMutationFunction(); 500 501 virtual void EmitTryStmt(CodeGenFunction &CGF, 502 const ObjCAtTryStmt &S); 503 virtual void EmitSynchronizedStmt(CodeGenFunction &CGF, 504 const ObjCAtSynchronizedStmt &S); 505 virtual void EmitThrowStmt(CodeGenFunction &CGF, 506 const ObjCAtThrowStmt &S); 507 virtual llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF, 508 llvm::Value *AddrWeakObj); 509 virtual void EmitObjCWeakAssign(CodeGenFunction &CGF, 510 llvm::Value *src, llvm::Value *dst); 511 virtual void EmitObjCGlobalAssign(CodeGenFunction &CGF, 512 llvm::Value *src, llvm::Value *dest, 513 bool threadlocal=false); 514 virtual void EmitObjCIvarAssign(CodeGenFunction &CGF, 515 llvm::Value *src, llvm::Value *dest, 516 llvm::Value *ivarOffset); 517 virtual void EmitObjCStrongCastAssign(CodeGenFunction &CGF, 518 llvm::Value *src, llvm::Value *dest); 519 virtual void EmitGCMemmoveCollectable(CodeGenFunction &CGF, 520 llvm::Value *DestPtr, 521 llvm::Value *SrcPtr, 522 llvm::Value *Size); 523 virtual LValue EmitObjCValueForIvar(CodeGenFunction &CGF, 524 QualType ObjectTy, 525 llvm::Value *BaseValue, 526 const ObjCIvarDecl *Ivar, 527 unsigned CVRQualifiers); 528 virtual llvm::Value *EmitIvarOffset(CodeGenFunction &CGF, 529 const ObjCInterfaceDecl *Interface, 530 const ObjCIvarDecl *Ivar); 531 virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CGBuilderTy &Builder); 532 virtual llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM, 533 const CGBlockInfo &blockInfo) { 534 return NULLPtr; 535 } 536 virtual llvm::Constant *BuildRCBlockLayout(CodeGenModule &CGM, 537 const CGBlockInfo &blockInfo) { 538 return NULLPtr; 539 } 540 virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) { 541 return 0; 542 } 543}; 544/// Class representing the legacy GCC Objective-C ABI. This is the default when 545/// -fobjc-nonfragile-abi is not specified. 546/// 547/// The GCC ABI target actually generates code that is approximately compatible 548/// with the new GNUstep runtime ABI, but refrains from using any features that 549/// would not work with the GCC runtime. For example, clang always generates 550/// the extended form of the class structure, and the extra fields are simply 551/// ignored by GCC libobjc. 552class CGObjCGCC : public CGObjCGNU { 553 /// The GCC ABI message lookup function. Returns an IMP pointing to the 554 /// method implementation for this message. 555 LazyRuntimeFunction MsgLookupFn; 556 /// The GCC ABI superclass message lookup function. Takes a pointer to a 557 /// structure describing the receiver and the class, and a selector as 558 /// arguments. Returns the IMP for the corresponding method. 559 LazyRuntimeFunction MsgLookupSuperFn; 560protected: 561 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 562 llvm::Value *&Receiver, 563 llvm::Value *cmd, 564 llvm::MDNode *node) { 565 CGBuilderTy &Builder = CGF.Builder; 566 llvm::Value *args[] = { 567 EnforceType(Builder, Receiver, IdTy), 568 EnforceType(Builder, cmd, SelectorTy) }; 569 llvm::CallSite imp = CGF.EmitCallOrInvoke(MsgLookupFn, args); 570 imp->setMetadata(msgSendMDKind, node); 571 return imp.getInstruction(); 572 } 573 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 574 llvm::Value *ObjCSuper, 575 llvm::Value *cmd) { 576 CGBuilderTy &Builder = CGF.Builder; 577 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 578 PtrToObjCSuperTy), cmd}; 579 return Builder.CreateCall(MsgLookupSuperFn, lookupArgs); 580 } 581 public: 582 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) { 583 // IMP objc_msg_lookup(id, SEL); 584 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 585 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 586 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 587 PtrToObjCSuperTy, SelectorTy, NULL); 588 } 589}; 590/// Class used when targeting the new GNUstep runtime ABI. 591class CGObjCGNUstep : public CGObjCGNU { 592 /// The slot lookup function. Returns a pointer to a cacheable structure 593 /// that contains (among other things) the IMP. 594 LazyRuntimeFunction SlotLookupFn; 595 /// The GNUstep ABI superclass message lookup function. Takes a pointer to 596 /// a structure describing the receiver and the class, and a selector as 597 /// arguments. Returns the slot for the corresponding method. Superclass 598 /// message lookup rarely changes, so this is a good caching opportunity. 599 LazyRuntimeFunction SlotLookupSuperFn; 600 /// Type of an slot structure pointer. This is returned by the various 601 /// lookup functions. 602 llvm::Type *SlotTy; 603 public: 604 virtual llvm::Constant *GetEHType(QualType T); 605 protected: 606 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 607 llvm::Value *&Receiver, 608 llvm::Value *cmd, 609 llvm::MDNode *node) { 610 CGBuilderTy &Builder = CGF.Builder; 611 llvm::Function *LookupFn = SlotLookupFn; 612 613 // Store the receiver on the stack so that we can reload it later 614 llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType()); 615 Builder.CreateStore(Receiver, ReceiverPtr); 616 617 llvm::Value *self; 618 619 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) { 620 self = CGF.LoadObjCSelf(); 621 } else { 622 self = llvm::ConstantPointerNull::get(IdTy); 623 } 624 625 // The lookup function is guaranteed not to capture the receiver pointer. 626 LookupFn->setDoesNotCapture(1); 627 628 llvm::Value *args[] = { 629 EnforceType(Builder, ReceiverPtr, PtrToIdTy), 630 EnforceType(Builder, cmd, SelectorTy), 631 EnforceType(Builder, self, IdTy) }; 632 llvm::CallSite slot = CGF.EmitCallOrInvoke(LookupFn, args); 633 slot.setOnlyReadsMemory(); 634 slot->setMetadata(msgSendMDKind, node); 635 636 // Load the imp from the slot 637 llvm::Value *imp = 638 Builder.CreateLoad(Builder.CreateStructGEP(slot.getInstruction(), 4)); 639 640 // The lookup function may have changed the receiver, so make sure we use 641 // the new one. 642 Receiver = Builder.CreateLoad(ReceiverPtr, true); 643 return imp; 644 } 645 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 646 llvm::Value *ObjCSuper, 647 llvm::Value *cmd) { 648 CGBuilderTy &Builder = CGF.Builder; 649 llvm::Value *lookupArgs[] = {ObjCSuper, cmd}; 650 651 llvm::CallInst *slot = Builder.CreateCall(SlotLookupSuperFn, lookupArgs); 652 slot->setOnlyReadsMemory(); 653 654 return Builder.CreateLoad(Builder.CreateStructGEP(slot, 4)); 655 } 656 public: 657 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) { 658 llvm::StructType *SlotStructTy = llvm::StructType::get(PtrTy, 659 PtrTy, PtrTy, IntTy, IMPTy, NULL); 660 SlotTy = llvm::PointerType::getUnqual(SlotStructTy); 661 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender); 662 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy, 663 SelectorTy, IdTy, NULL); 664 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL); 665 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy, 666 PtrToObjCSuperTy, SelectorTy, NULL); 667 // If we're in ObjC++ mode, then we want to make 668 if (CGM.getLangOpts().CPlusPlus) { 669 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 670 // void *__cxa_begin_catch(void *e) 671 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, NULL); 672 // void __cxa_end_catch(void) 673 ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, NULL); 674 // void _Unwind_Resume_or_Rethrow(void*) 675 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, PtrTy, NULL); 676 } 677 } 678}; 679 680/// Support for the ObjFW runtime. Support here is due to 681/// Jonathan Schleifer <js@webkeks.org>, the ObjFW maintainer. 682class CGObjCObjFW: public CGObjCGNU { 683protected: 684 /// The GCC ABI message lookup function. Returns an IMP pointing to the 685 /// method implementation for this message. 686 LazyRuntimeFunction MsgLookupFn; 687 /// The GCC ABI superclass message lookup function. Takes a pointer to a 688 /// structure describing the receiver and the class, and a selector as 689 /// arguments. Returns the IMP for the corresponding method. 690 LazyRuntimeFunction MsgLookupSuperFn; 691 692 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF, 693 llvm::Value *&Receiver, 694 llvm::Value *cmd, 695 llvm::MDNode *node) { 696 CGBuilderTy &Builder = CGF.Builder; 697 llvm::Value *args[] = { 698 EnforceType(Builder, Receiver, IdTy), 699 EnforceType(Builder, cmd, SelectorTy) }; 700 llvm::CallSite imp = CGF.EmitCallOrInvoke(MsgLookupFn, args); 701 imp->setMetadata(msgSendMDKind, node); 702 return imp.getInstruction(); 703 } 704 705 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, 706 llvm::Value *ObjCSuper, 707 llvm::Value *cmd) { 708 CGBuilderTy &Builder = CGF.Builder; 709 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper, 710 PtrToObjCSuperTy), cmd}; 711 return Builder.CreateCall(MsgLookupSuperFn, lookupArgs); 712 } 713 714 virtual llvm::Value *GetClassNamed(CGBuilderTy &Builder, 715 const std::string &Name, bool isWeak) { 716 if (isWeak) 717 return CGObjCGNU::GetClassNamed(Builder, Name, isWeak); 718 719 EmitClassRef(Name); 720 721 std::string SymbolName = "_OBJC_CLASS_" + Name; 722 723 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(SymbolName); 724 725 if (!ClassSymbol) 726 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 727 llvm::GlobalValue::ExternalLinkage, 728 0, SymbolName); 729 730 return ClassSymbol; 731 } 732 733public: 734 CGObjCObjFW(CodeGenModule &Mod): CGObjCGNU(Mod, 9, 3) { 735 // IMP objc_msg_lookup(id, SEL); 736 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL); 737 // IMP objc_msg_lookup_super(struct objc_super*, SEL); 738 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy, 739 PtrToObjCSuperTy, SelectorTy, NULL); 740 } 741}; 742} // end anonymous namespace 743 744 745/// Emits a reference to a dummy variable which is emitted with each class. 746/// This ensures that a linker error will be generated when trying to link 747/// together modules where a referenced class is not defined. 748void CGObjCGNU::EmitClassRef(const std::string &className) { 749 std::string symbolRef = "__objc_class_ref_" + className; 750 // Don't emit two copies of the same symbol 751 if (TheModule.getGlobalVariable(symbolRef)) 752 return; 753 std::string symbolName = "__objc_class_name_" + className; 754 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName); 755 if (!ClassSymbol) { 756 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false, 757 llvm::GlobalValue::ExternalLinkage, 0, symbolName); 758 } 759 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true, 760 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef); 761} 762 763static std::string SymbolNameForMethod(const StringRef &ClassName, 764 const StringRef &CategoryName, const Selector MethodName, 765 bool isClassMethod) { 766 std::string MethodNameColonStripped = MethodName.getAsString(); 767 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(), 768 ':', '_'); 769 return (Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" + 770 CategoryName + "_" + MethodNameColonStripped).str(); 771} 772 773CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion, 774 unsigned protocolClassVersion) 775 : CGObjCRuntime(cgm), TheModule(CGM.getModule()), 776 VMContext(cgm.getLLVMContext()), ClassPtrAlias(0), MetaClassPtrAlias(0), 777 RuntimeVersion(runtimeABIVersion), ProtocolVersion(protocolClassVersion) { 778 779 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend"); 780 781 CodeGenTypes &Types = CGM.getTypes(); 782 IntTy = cast<llvm::IntegerType>( 783 Types.ConvertType(CGM.getContext().IntTy)); 784 LongTy = cast<llvm::IntegerType>( 785 Types.ConvertType(CGM.getContext().LongTy)); 786 SizeTy = cast<llvm::IntegerType>( 787 Types.ConvertType(CGM.getContext().getSizeType())); 788 PtrDiffTy = cast<llvm::IntegerType>( 789 Types.ConvertType(CGM.getContext().getPointerDiffType())); 790 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy); 791 792 Int8Ty = llvm::Type::getInt8Ty(VMContext); 793 // C string type. Used in lots of places. 794 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty); 795 796 Zeros[0] = llvm::ConstantInt::get(LongTy, 0); 797 Zeros[1] = Zeros[0]; 798 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty); 799 // Get the selector Type. 800 QualType selTy = CGM.getContext().getObjCSelType(); 801 if (QualType() == selTy) { 802 SelectorTy = PtrToInt8Ty; 803 } else { 804 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy)); 805 } 806 807 PtrToIntTy = llvm::PointerType::getUnqual(IntTy); 808 PtrTy = PtrToInt8Ty; 809 810 Int32Ty = llvm::Type::getInt32Ty(VMContext); 811 Int64Ty = llvm::Type::getInt64Ty(VMContext); 812 813 IntPtrTy = 814 TheModule.getPointerSize() == llvm::Module::Pointer32 ? Int32Ty : Int64Ty; 815 816 // Object type 817 QualType UnqualIdTy = CGM.getContext().getObjCIdType(); 818 ASTIdTy = CanQualType(); 819 if (UnqualIdTy != QualType()) { 820 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy); 821 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 822 } else { 823 IdTy = PtrToInt8Ty; 824 } 825 PtrToIdTy = llvm::PointerType::getUnqual(IdTy); 826 827 ObjCSuperTy = llvm::StructType::get(IdTy, IdTy, NULL); 828 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy); 829 830 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext); 831 832 // void objc_exception_throw(id); 833 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 834 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL); 835 // int objc_sync_enter(id); 836 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, NULL); 837 // int objc_sync_exit(id); 838 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, NULL); 839 840 // void objc_enumerationMutation (id) 841 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, 842 IdTy, NULL); 843 844 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL) 845 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy, 846 PtrDiffTy, BoolTy, NULL); 847 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL) 848 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy, 849 PtrDiffTy, IdTy, BoolTy, BoolTy, NULL); 850 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 851 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy, 852 PtrDiffTy, BoolTy, BoolTy, NULL); 853 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL) 854 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy, 855 PtrDiffTy, BoolTy, BoolTy, NULL); 856 857 // IMP type 858 llvm::Type *IMPArgs[] = { IdTy, SelectorTy }; 859 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs, 860 true)); 861 862 const LangOptions &Opts = CGM.getLangOpts(); 863 if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount) 864 RuntimeVersion = 10; 865 866 // Don't bother initialising the GC stuff unless we're compiling in GC mode 867 if (Opts.getGC() != LangOptions::NonGC) { 868 // This is a bit of an hack. We should sort this out by having a proper 869 // CGObjCGNUstep subclass for GC, but we may want to really support the old 870 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now 871 // Get selectors needed in GC mode 872 RetainSel = GetNullarySelector("retain", CGM.getContext()); 873 ReleaseSel = GetNullarySelector("release", CGM.getContext()); 874 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext()); 875 876 // Get functions needed in GC mode 877 878 // id objc_assign_ivar(id, id, ptrdiff_t); 879 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy, 880 NULL); 881 // id objc_assign_strongCast (id, id*) 882 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy, 883 PtrToIdTy, NULL); 884 // id objc_assign_global(id, id*); 885 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy, 886 NULL); 887 // id objc_assign_weak(id, id*); 888 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, NULL); 889 // id objc_read_weak(id*); 890 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, NULL); 891 // void *objc_memmove_collectable(void*, void *, size_t); 892 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy, 893 SizeTy, NULL); 894 } 895} 896 897llvm::Value *CGObjCGNU::GetClassNamed(CGBuilderTy &Builder, 898 const std::string &Name, 899 bool isWeak) { 900 llvm::Value *ClassName = CGM.GetAddrOfConstantCString(Name); 901 // With the incompatible ABI, this will need to be replaced with a direct 902 // reference to the class symbol. For the compatible nonfragile ABI we are 903 // still performing this lookup at run time but emitting the symbol for the 904 // class externally so that we can make the switch later. 905 // 906 // Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class 907 // with memoized versions or with static references if it's safe to do so. 908 if (!isWeak) 909 EmitClassRef(Name); 910 ClassName = Builder.CreateStructGEP(ClassName, 0); 911 912 llvm::Constant *ClassLookupFn = 913 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true), 914 "objc_lookup_class"); 915 return Builder.CreateCall(ClassLookupFn, ClassName); 916} 917 918// This has to perform the lookup every time, since posing and related 919// techniques can modify the name -> class mapping. 920llvm::Value *CGObjCGNU::GetClass(CGBuilderTy &Builder, 921 const ObjCInterfaceDecl *OID) { 922 return GetClassNamed(Builder, OID->getNameAsString(), OID->isWeakImported()); 923} 924llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CGBuilderTy &Builder) { 925 return GetClassNamed(Builder, "NSAutoreleasePool", false); 926} 927 928llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 929 const std::string &TypeEncoding, bool lval) { 930 931 SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel]; 932 llvm::GlobalAlias *SelValue = 0; 933 934 935 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 936 e = Types.end() ; i!=e ; i++) { 937 if (i->first == TypeEncoding) { 938 SelValue = i->second; 939 break; 940 } 941 } 942 if (0 == SelValue) { 943 SelValue = new llvm::GlobalAlias(SelectorTy, 944 llvm::GlobalValue::PrivateLinkage, 945 ".objc_selector_"+Sel.getAsString(), NULL, 946 &TheModule); 947 Types.push_back(TypedSelector(TypeEncoding, SelValue)); 948 } 949 950 if (lval) { 951 llvm::Value *tmp = Builder.CreateAlloca(SelValue->getType()); 952 Builder.CreateStore(SelValue, tmp); 953 return tmp; 954 } 955 return SelValue; 956} 957 958llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel, 959 bool lval) { 960 return GetSelector(Builder, Sel, std::string(), lval); 961} 962 963llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl 964 *Method) { 965 std::string SelTypes; 966 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes); 967 return GetSelector(Builder, Method->getSelector(), SelTypes, false); 968} 969 970llvm::Constant *CGObjCGNU::GetEHType(QualType T) { 971 if (T->isObjCIdType() || T->isObjCQualifiedIdType()) { 972 // With the old ABI, there was only one kind of catchall, which broke 973 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as 974 // a pointer indicating object catchalls, and NULL to indicate real 975 // catchalls 976 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 977 return MakeConstantString("@id"); 978 } else { 979 return 0; 980 } 981 } 982 983 // All other types should be Objective-C interface pointer types. 984 const ObjCObjectPointerType *OPT = T->getAs<ObjCObjectPointerType>(); 985 assert(OPT && "Invalid @catch type."); 986 const ObjCInterfaceDecl *IDecl = OPT->getObjectType()->getInterface(); 987 assert(IDecl && "Invalid @catch type."); 988 return MakeConstantString(IDecl->getIdentifier()->getName()); 989} 990 991llvm::Constant *CGObjCGNUstep::GetEHType(QualType T) { 992 if (!CGM.getLangOpts().CPlusPlus) 993 return CGObjCGNU::GetEHType(T); 994 995 // For Objective-C++, we want to provide the ability to catch both C++ and 996 // Objective-C objects in the same function. 997 998 // There's a particular fixed type info for 'id'. 999 if (T->isObjCIdType() || 1000 T->isObjCQualifiedIdType()) { 1001 llvm::Constant *IDEHType = 1002 CGM.getModule().getGlobalVariable("__objc_id_type_info"); 1003 if (!IDEHType) 1004 IDEHType = 1005 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty, 1006 false, 1007 llvm::GlobalValue::ExternalLinkage, 1008 0, "__objc_id_type_info"); 1009 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty); 1010 } 1011 1012 const ObjCObjectPointerType *PT = 1013 T->getAs<ObjCObjectPointerType>(); 1014 assert(PT && "Invalid @catch type."); 1015 const ObjCInterfaceType *IT = PT->getInterfaceType(); 1016 assert(IT && "Invalid @catch type."); 1017 std::string className = IT->getDecl()->getIdentifier()->getName(); 1018 1019 std::string typeinfoName = "__objc_eh_typeinfo_" + className; 1020 1021 // Return the existing typeinfo if it exists 1022 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName); 1023 if (typeinfo) 1024 return llvm::ConstantExpr::getBitCast(typeinfo, PtrToInt8Ty); 1025 1026 // Otherwise create it. 1027 1028 // vtable for gnustep::libobjc::__objc_class_type_info 1029 // It's quite ugly hard-coding this. Ideally we'd generate it using the host 1030 // platform's name mangling. 1031 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE"; 1032 llvm::Constant *Vtable = TheModule.getGlobalVariable(vtableName); 1033 if (!Vtable) { 1034 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true, 1035 llvm::GlobalValue::ExternalLinkage, 0, vtableName); 1036 } 1037 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2); 1038 Vtable = llvm::ConstantExpr::getGetElementPtr(Vtable, Two); 1039 Vtable = llvm::ConstantExpr::getBitCast(Vtable, PtrToInt8Ty); 1040 1041 llvm::Constant *typeName = 1042 ExportUniqueString(className, "__objc_eh_typename_"); 1043 1044 std::vector<llvm::Constant*> fields; 1045 fields.push_back(Vtable); 1046 fields.push_back(typeName); 1047 llvm::Constant *TI = 1048 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1049 NULL), fields, "__objc_eh_typeinfo_" + className, 1050 llvm::GlobalValue::LinkOnceODRLinkage); 1051 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty); 1052} 1053 1054/// Generate an NSConstantString object. 1055llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) { 1056 1057 std::string Str = SL->getString().str(); 1058 1059 // Look for an existing one 1060 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str); 1061 if (old != ObjCStrings.end()) 1062 return old->getValue(); 1063 1064 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass; 1065 1066 if (StringClass.empty()) StringClass = "NXConstantString"; 1067 1068 std::string Sym = "_OBJC_CLASS_"; 1069 Sym += StringClass; 1070 1071 llvm::Constant *isa = TheModule.getNamedGlobal(Sym); 1072 1073 if (!isa) 1074 isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false, 1075 llvm::GlobalValue::ExternalWeakLinkage, 0, Sym); 1076 else if (isa->getType() != PtrToIdTy) 1077 isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy); 1078 1079 std::vector<llvm::Constant*> Ivars; 1080 Ivars.push_back(isa); 1081 Ivars.push_back(MakeConstantString(Str)); 1082 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size())); 1083 llvm::Constant *ObjCStr = MakeGlobal( 1084 llvm::StructType::get(PtrToIdTy, PtrToInt8Ty, IntTy, NULL), 1085 Ivars, ".objc_str"); 1086 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty); 1087 ObjCStrings[Str] = ObjCStr; 1088 ConstantStrings.push_back(ObjCStr); 1089 return ObjCStr; 1090} 1091 1092///Generates a message send where the super is the receiver. This is a message 1093///send to self with special delivery semantics indicating which class's method 1094///should be called. 1095RValue 1096CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF, 1097 ReturnValueSlot Return, 1098 QualType ResultType, 1099 Selector Sel, 1100 const ObjCInterfaceDecl *Class, 1101 bool isCategoryImpl, 1102 llvm::Value *Receiver, 1103 bool IsClassMessage, 1104 const CallArgList &CallArgs, 1105 const ObjCMethodDecl *Method) { 1106 CGBuilderTy &Builder = CGF.Builder; 1107 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) { 1108 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1109 return RValue::get(EnforceType(Builder, Receiver, 1110 CGM.getTypes().ConvertType(ResultType))); 1111 } 1112 if (Sel == ReleaseSel) { 1113 return RValue::get(0); 1114 } 1115 } 1116 1117 llvm::Value *cmd = GetSelector(Builder, Sel); 1118 1119 1120 CallArgList ActualArgs; 1121 1122 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy); 1123 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1124 ActualArgs.addFrom(CallArgs); 1125 1126 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs); 1127 1128 llvm::Value *ReceiverClass = 0; 1129 if (isCategoryImpl) { 1130 llvm::Constant *classLookupFunction = 0; 1131 if (IsClassMessage) { 1132 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1133 IdTy, PtrTy, true), "objc_get_meta_class"); 1134 } else { 1135 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get( 1136 IdTy, PtrTy, true), "objc_get_class"); 1137 } 1138 ReceiverClass = Builder.CreateCall(classLookupFunction, 1139 MakeConstantString(Class->getNameAsString())); 1140 } else { 1141 // Set up global aliases for the metaclass or class pointer if they do not 1142 // already exist. These will are forward-references which will be set to 1143 // pointers to the class and metaclass structure created for the runtime 1144 // load function. To send a message to super, we look up the value of the 1145 // super_class pointer from either the class or metaclass structure. 1146 if (IsClassMessage) { 1147 if (!MetaClassPtrAlias) { 1148 MetaClassPtrAlias = new llvm::GlobalAlias(IdTy, 1149 llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" + 1150 Class->getNameAsString(), NULL, &TheModule); 1151 } 1152 ReceiverClass = MetaClassPtrAlias; 1153 } else { 1154 if (!ClassPtrAlias) { 1155 ClassPtrAlias = new llvm::GlobalAlias(IdTy, 1156 llvm::GlobalValue::InternalLinkage, ".objc_class_ref" + 1157 Class->getNameAsString(), NULL, &TheModule); 1158 } 1159 ReceiverClass = ClassPtrAlias; 1160 } 1161 } 1162 // Cast the pointer to a simplified version of the class structure 1163 ReceiverClass = Builder.CreateBitCast(ReceiverClass, 1164 llvm::PointerType::getUnqual( 1165 llvm::StructType::get(IdTy, IdTy, NULL))); 1166 // Get the superclass pointer 1167 ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1); 1168 // Load the superclass pointer 1169 ReceiverClass = Builder.CreateLoad(ReceiverClass); 1170 // Construct the structure used to look up the IMP 1171 llvm::StructType *ObjCSuperTy = llvm::StructType::get( 1172 Receiver->getType(), IdTy, NULL); 1173 llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy); 1174 1175 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0)); 1176 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1)); 1177 1178 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy); 1179 1180 // Get the IMP 1181 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd); 1182 imp = EnforceType(Builder, imp, MSI.MessengerType); 1183 1184 llvm::Value *impMD[] = { 1185 llvm::MDString::get(VMContext, Sel.getAsString()), 1186 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()), 1187 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage) 1188 }; 1189 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1190 1191 llvm::Instruction *call; 1192 RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs, 0, &call); 1193 call->setMetadata(msgSendMDKind, node); 1194 return msgRet; 1195} 1196 1197/// Generate code for a message send expression. 1198RValue 1199CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF, 1200 ReturnValueSlot Return, 1201 QualType ResultType, 1202 Selector Sel, 1203 llvm::Value *Receiver, 1204 const CallArgList &CallArgs, 1205 const ObjCInterfaceDecl *Class, 1206 const ObjCMethodDecl *Method) { 1207 CGBuilderTy &Builder = CGF.Builder; 1208 1209 // Strip out message sends to retain / release in GC mode 1210 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) { 1211 if (Sel == RetainSel || Sel == AutoreleaseSel) { 1212 return RValue::get(EnforceType(Builder, Receiver, 1213 CGM.getTypes().ConvertType(ResultType))); 1214 } 1215 if (Sel == ReleaseSel) { 1216 return RValue::get(0); 1217 } 1218 } 1219 1220 // If the return type is something that goes in an integer register, the 1221 // runtime will handle 0 returns. For other cases, we fill in the 0 value 1222 // ourselves. 1223 // 1224 // The language spec says the result of this kind of message send is 1225 // undefined, but lots of people seem to have forgotten to read that 1226 // paragraph and insist on sending messages to nil that have structure 1227 // returns. With GCC, this generates a random return value (whatever happens 1228 // to be on the stack / in those registers at the time) on most platforms, 1229 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts 1230 // the stack. 1231 bool isPointerSizedReturn = (ResultType->isAnyPointerType() || 1232 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType()); 1233 1234 llvm::BasicBlock *startBB = 0; 1235 llvm::BasicBlock *messageBB = 0; 1236 llvm::BasicBlock *continueBB = 0; 1237 1238 if (!isPointerSizedReturn) { 1239 startBB = Builder.GetInsertBlock(); 1240 messageBB = CGF.createBasicBlock("msgSend"); 1241 continueBB = CGF.createBasicBlock("continue"); 1242 1243 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver, 1244 llvm::Constant::getNullValue(Receiver->getType())); 1245 Builder.CreateCondBr(isNil, continueBB, messageBB); 1246 CGF.EmitBlock(messageBB); 1247 } 1248 1249 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy)); 1250 llvm::Value *cmd; 1251 if (Method) 1252 cmd = GetSelector(Builder, Method); 1253 else 1254 cmd = GetSelector(Builder, Sel); 1255 cmd = EnforceType(Builder, cmd, SelectorTy); 1256 Receiver = EnforceType(Builder, Receiver, IdTy); 1257 1258 llvm::Value *impMD[] = { 1259 llvm::MDString::get(VMContext, Sel.getAsString()), 1260 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""), 1261 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0) 1262 }; 1263 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD); 1264 1265 CallArgList ActualArgs; 1266 ActualArgs.add(RValue::get(Receiver), ASTIdTy); 1267 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType()); 1268 ActualArgs.addFrom(CallArgs); 1269 1270 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs); 1271 1272 // Get the IMP to call 1273 llvm::Value *imp; 1274 1275 // If we have non-legacy dispatch specified, we try using the objc_msgSend() 1276 // functions. These are not supported on all platforms (or all runtimes on a 1277 // given platform), so we 1278 switch (CGM.getCodeGenOpts().getObjCDispatchMethod()) { 1279 case CodeGenOptions::Legacy: 1280 imp = LookupIMP(CGF, Receiver, cmd, node); 1281 break; 1282 case CodeGenOptions::Mixed: 1283 case CodeGenOptions::NonLegacy: 1284 if (CGM.ReturnTypeUsesFPRet(ResultType)) { 1285 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1286 "objc_msgSend_fpret"); 1287 } else if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) { 1288 // The actual types here don't matter - we're going to bitcast the 1289 // function anyway 1290 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1291 "objc_msgSend_stret"); 1292 } else { 1293 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true), 1294 "objc_msgSend"); 1295 } 1296 } 1297 1298 // Reset the receiver in case the lookup modified it 1299 ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy, false); 1300 1301 imp = EnforceType(Builder, imp, MSI.MessengerType); 1302 1303 llvm::Instruction *call; 1304 RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs, 1305 0, &call); 1306 call->setMetadata(msgSendMDKind, node); 1307 1308 1309 if (!isPointerSizedReturn) { 1310 messageBB = CGF.Builder.GetInsertBlock(); 1311 CGF.Builder.CreateBr(continueBB); 1312 CGF.EmitBlock(continueBB); 1313 if (msgRet.isScalar()) { 1314 llvm::Value *v = msgRet.getScalarVal(); 1315 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1316 phi->addIncoming(v, messageBB); 1317 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB); 1318 msgRet = RValue::get(phi); 1319 } else if (msgRet.isAggregate()) { 1320 llvm::Value *v = msgRet.getAggregateAddr(); 1321 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2); 1322 llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType()); 1323 llvm::AllocaInst *NullVal = 1324 CGF.CreateTempAlloca(RetTy->getElementType(), "null"); 1325 CGF.InitTempAlloca(NullVal, 1326 llvm::Constant::getNullValue(RetTy->getElementType())); 1327 phi->addIncoming(v, messageBB); 1328 phi->addIncoming(NullVal, startBB); 1329 msgRet = RValue::getAggregate(phi); 1330 } else /* isComplex() */ { 1331 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal(); 1332 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2); 1333 phi->addIncoming(v.first, messageBB); 1334 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()), 1335 startBB); 1336 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2); 1337 phi2->addIncoming(v.second, messageBB); 1338 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()), 1339 startBB); 1340 msgRet = RValue::getComplex(phi, phi2); 1341 } 1342 } 1343 return msgRet; 1344} 1345 1346/// Generates a MethodList. Used in construction of a objc_class and 1347/// objc_category structures. 1348llvm::Constant *CGObjCGNU:: 1349GenerateMethodList(const StringRef &ClassName, 1350 const StringRef &CategoryName, 1351 ArrayRef<Selector> MethodSels, 1352 ArrayRef<llvm::Constant *> MethodTypes, 1353 bool isClassMethodList) { 1354 if (MethodSels.empty()) 1355 return NULLPtr; 1356 // Get the method structure type. 1357 llvm::StructType *ObjCMethodTy = llvm::StructType::get( 1358 PtrToInt8Ty, // Really a selector, but the runtime creates it us. 1359 PtrToInt8Ty, // Method types 1360 IMPTy, //Method pointer 1361 NULL); 1362 std::vector<llvm::Constant*> Methods; 1363 std::vector<llvm::Constant*> Elements; 1364 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) { 1365 Elements.clear(); 1366 llvm::Constant *Method = 1367 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName, 1368 MethodSels[i], 1369 isClassMethodList)); 1370 assert(Method && "Can't generate metadata for method that doesn't exist"); 1371 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString()); 1372 Elements.push_back(C); 1373 Elements.push_back(MethodTypes[i]); 1374 Method = llvm::ConstantExpr::getBitCast(Method, 1375 IMPTy); 1376 Elements.push_back(Method); 1377 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements)); 1378 } 1379 1380 // Array of method structures 1381 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy, 1382 Methods.size()); 1383 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy, 1384 Methods); 1385 1386 // Structure containing list pointer, array and array count 1387 llvm::StructType *ObjCMethodListTy = llvm::StructType::create(VMContext); 1388 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(ObjCMethodListTy); 1389 ObjCMethodListTy->setBody( 1390 NextPtrTy, 1391 IntTy, 1392 ObjCMethodArrayTy, 1393 NULL); 1394 1395 Methods.clear(); 1396 Methods.push_back(llvm::ConstantPointerNull::get( 1397 llvm::PointerType::getUnqual(ObjCMethodListTy))); 1398 Methods.push_back(llvm::ConstantInt::get(Int32Ty, MethodTypes.size())); 1399 Methods.push_back(MethodArray); 1400 1401 // Create an instance of the structure 1402 return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list"); 1403} 1404 1405/// Generates an IvarList. Used in construction of a objc_class. 1406llvm::Constant *CGObjCGNU:: 1407GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames, 1408 ArrayRef<llvm::Constant *> IvarTypes, 1409 ArrayRef<llvm::Constant *> IvarOffsets) { 1410 if (IvarNames.size() == 0) 1411 return NULLPtr; 1412 // Get the method structure type. 1413 llvm::StructType *ObjCIvarTy = llvm::StructType::get( 1414 PtrToInt8Ty, 1415 PtrToInt8Ty, 1416 IntTy, 1417 NULL); 1418 std::vector<llvm::Constant*> Ivars; 1419 std::vector<llvm::Constant*> Elements; 1420 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) { 1421 Elements.clear(); 1422 Elements.push_back(IvarNames[i]); 1423 Elements.push_back(IvarTypes[i]); 1424 Elements.push_back(IvarOffsets[i]); 1425 Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements)); 1426 } 1427 1428 // Array of method structures 1429 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy, 1430 IvarNames.size()); 1431 1432 1433 Elements.clear(); 1434 Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size())); 1435 Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars)); 1436 // Structure containing array and array count 1437 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(IntTy, 1438 ObjCIvarArrayTy, 1439 NULL); 1440 1441 // Create an instance of the structure 1442 return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list"); 1443} 1444 1445/// Generate a class structure 1446llvm::Constant *CGObjCGNU::GenerateClassStructure( 1447 llvm::Constant *MetaClass, 1448 llvm::Constant *SuperClass, 1449 unsigned info, 1450 const char *Name, 1451 llvm::Constant *Version, 1452 llvm::Constant *InstanceSize, 1453 llvm::Constant *IVars, 1454 llvm::Constant *Methods, 1455 llvm::Constant *Protocols, 1456 llvm::Constant *IvarOffsets, 1457 llvm::Constant *Properties, 1458 llvm::Constant *StrongIvarBitmap, 1459 llvm::Constant *WeakIvarBitmap, 1460 bool isMeta) { 1461 // Set up the class structure 1462 // Note: Several of these are char*s when they should be ids. This is 1463 // because the runtime performs this translation on load. 1464 // 1465 // Fields marked New ABI are part of the GNUstep runtime. We emit them 1466 // anyway; the classes will still work with the GNU runtime, they will just 1467 // be ignored. 1468 llvm::StructType *ClassTy = llvm::StructType::get( 1469 PtrToInt8Ty, // isa 1470 PtrToInt8Ty, // super_class 1471 PtrToInt8Ty, // name 1472 LongTy, // version 1473 LongTy, // info 1474 LongTy, // instance_size 1475 IVars->getType(), // ivars 1476 Methods->getType(), // methods 1477 // These are all filled in by the runtime, so we pretend 1478 PtrTy, // dtable 1479 PtrTy, // subclass_list 1480 PtrTy, // sibling_class 1481 PtrTy, // protocols 1482 PtrTy, // gc_object_type 1483 // New ABI: 1484 LongTy, // abi_version 1485 IvarOffsets->getType(), // ivar_offsets 1486 Properties->getType(), // properties 1487 IntPtrTy, // strong_pointers 1488 IntPtrTy, // weak_pointers 1489 NULL); 1490 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0); 1491 // Fill in the structure 1492 std::vector<llvm::Constant*> Elements; 1493 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty)); 1494 Elements.push_back(SuperClass); 1495 Elements.push_back(MakeConstantString(Name, ".class_name")); 1496 Elements.push_back(Zero); 1497 Elements.push_back(llvm::ConstantInt::get(LongTy, info)); 1498 if (isMeta) { 1499 llvm::DataLayout td(&TheModule); 1500 Elements.push_back( 1501 llvm::ConstantInt::get(LongTy, 1502 td.getTypeSizeInBits(ClassTy) / 1503 CGM.getContext().getCharWidth())); 1504 } else 1505 Elements.push_back(InstanceSize); 1506 Elements.push_back(IVars); 1507 Elements.push_back(Methods); 1508 Elements.push_back(NULLPtr); 1509 Elements.push_back(NULLPtr); 1510 Elements.push_back(NULLPtr); 1511 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy)); 1512 Elements.push_back(NULLPtr); 1513 Elements.push_back(llvm::ConstantInt::get(LongTy, 1)); 1514 Elements.push_back(IvarOffsets); 1515 Elements.push_back(Properties); 1516 Elements.push_back(StrongIvarBitmap); 1517 Elements.push_back(WeakIvarBitmap); 1518 // Create an instance of the structure 1519 // This is now an externally visible symbol, so that we can speed up class 1520 // messages in the next ABI. We may already have some weak references to 1521 // this, so check and fix them properly. 1522 std::string ClassSym((isMeta ? "_OBJC_METACLASS_": "_OBJC_CLASS_") + 1523 std::string(Name)); 1524 llvm::GlobalVariable *ClassRef = TheModule.getNamedGlobal(ClassSym); 1525 llvm::Constant *Class = MakeGlobal(ClassTy, Elements, ClassSym, 1526 llvm::GlobalValue::ExternalLinkage); 1527 if (ClassRef) { 1528 ClassRef->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(Class, 1529 ClassRef->getType())); 1530 ClassRef->removeFromParent(); 1531 Class->setName(ClassSym); 1532 } 1533 return Class; 1534} 1535 1536llvm::Constant *CGObjCGNU:: 1537GenerateProtocolMethodList(ArrayRef<llvm::Constant *> MethodNames, 1538 ArrayRef<llvm::Constant *> MethodTypes) { 1539 // Get the method structure type. 1540 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get( 1541 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us. 1542 PtrToInt8Ty, 1543 NULL); 1544 std::vector<llvm::Constant*> Methods; 1545 std::vector<llvm::Constant*> Elements; 1546 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) { 1547 Elements.clear(); 1548 Elements.push_back(MethodNames[i]); 1549 Elements.push_back(MethodTypes[i]); 1550 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements)); 1551 } 1552 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy, 1553 MethodNames.size()); 1554 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy, 1555 Methods); 1556 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get( 1557 IntTy, ObjCMethodArrayTy, NULL); 1558 Methods.clear(); 1559 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size())); 1560 Methods.push_back(Array); 1561 return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list"); 1562} 1563 1564// Create the protocol list structure used in classes, categories and so on 1565llvm::Constant *CGObjCGNU::GenerateProtocolList(ArrayRef<std::string>Protocols){ 1566 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 1567 Protocols.size()); 1568 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1569 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1570 SizeTy, 1571 ProtocolArrayTy, 1572 NULL); 1573 std::vector<llvm::Constant*> Elements; 1574 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end(); 1575 iter != endIter ; iter++) { 1576 llvm::Constant *protocol = 0; 1577 llvm::StringMap<llvm::Constant*>::iterator value = 1578 ExistingProtocols.find(*iter); 1579 if (value == ExistingProtocols.end()) { 1580 protocol = GenerateEmptyProtocol(*iter); 1581 } else { 1582 protocol = value->getValue(); 1583 } 1584 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol, 1585 PtrToInt8Ty); 1586 Elements.push_back(Ptr); 1587 } 1588 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1589 Elements); 1590 Elements.clear(); 1591 Elements.push_back(NULLPtr); 1592 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size())); 1593 Elements.push_back(ProtocolArray); 1594 return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list"); 1595} 1596 1597llvm::Value *CGObjCGNU::GenerateProtocolRef(CGBuilderTy &Builder, 1598 const ObjCProtocolDecl *PD) { 1599 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()]; 1600 llvm::Type *T = 1601 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType()); 1602 return Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T)); 1603} 1604 1605llvm::Constant *CGObjCGNU::GenerateEmptyProtocol( 1606 const std::string &ProtocolName) { 1607 SmallVector<std::string, 0> EmptyStringVector; 1608 SmallVector<llvm::Constant*, 0> EmptyConstantVector; 1609 1610 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector); 1611 llvm::Constant *MethodList = 1612 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector); 1613 // Protocols are objects containing lists of the methods implemented and 1614 // protocols adopted. 1615 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1616 PtrToInt8Ty, 1617 ProtocolList->getType(), 1618 MethodList->getType(), 1619 MethodList->getType(), 1620 MethodList->getType(), 1621 MethodList->getType(), 1622 NULL); 1623 std::vector<llvm::Constant*> Elements; 1624 // The isa pointer must be set to a magic number so the runtime knows it's 1625 // the correct layout. 1626 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1627 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy)); 1628 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1629 Elements.push_back(ProtocolList); 1630 Elements.push_back(MethodList); 1631 Elements.push_back(MethodList); 1632 Elements.push_back(MethodList); 1633 Elements.push_back(MethodList); 1634 return MakeGlobal(ProtocolTy, Elements, ".objc_protocol"); 1635} 1636 1637void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) { 1638 ASTContext &Context = CGM.getContext(); 1639 std::string ProtocolName = PD->getNameAsString(); 1640 1641 // Use the protocol definition, if there is one. 1642 if (const ObjCProtocolDecl *Def = PD->getDefinition()) 1643 PD = Def; 1644 1645 SmallVector<std::string, 16> Protocols; 1646 for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(), 1647 E = PD->protocol_end(); PI != E; ++PI) 1648 Protocols.push_back((*PI)->getNameAsString()); 1649 SmallVector<llvm::Constant*, 16> InstanceMethodNames; 1650 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1651 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames; 1652 SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes; 1653 for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(), 1654 E = PD->instmeth_end(); iter != E; iter++) { 1655 std::string TypeStr; 1656 Context.getObjCEncodingForMethodDecl(*iter, TypeStr); 1657 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1658 OptionalInstanceMethodNames.push_back( 1659 MakeConstantString((*iter)->getSelector().getAsString())); 1660 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1661 } else { 1662 InstanceMethodNames.push_back( 1663 MakeConstantString((*iter)->getSelector().getAsString())); 1664 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1665 } 1666 } 1667 // Collect information about class methods: 1668 SmallVector<llvm::Constant*, 16> ClassMethodNames; 1669 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1670 SmallVector<llvm::Constant*, 16> OptionalClassMethodNames; 1671 SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes; 1672 for (ObjCProtocolDecl::classmeth_iterator 1673 iter = PD->classmeth_begin(), endIter = PD->classmeth_end(); 1674 iter != endIter ; iter++) { 1675 std::string TypeStr; 1676 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 1677 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) { 1678 OptionalClassMethodNames.push_back( 1679 MakeConstantString((*iter)->getSelector().getAsString())); 1680 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1681 } else { 1682 ClassMethodNames.push_back( 1683 MakeConstantString((*iter)->getSelector().getAsString())); 1684 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1685 } 1686 } 1687 1688 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols); 1689 llvm::Constant *InstanceMethodList = 1690 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes); 1691 llvm::Constant *ClassMethodList = 1692 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes); 1693 llvm::Constant *OptionalInstanceMethodList = 1694 GenerateProtocolMethodList(OptionalInstanceMethodNames, 1695 OptionalInstanceMethodTypes); 1696 llvm::Constant *OptionalClassMethodList = 1697 GenerateProtocolMethodList(OptionalClassMethodNames, 1698 OptionalClassMethodTypes); 1699 1700 // Property metadata: name, attributes, isSynthesized, setter name, setter 1701 // types, getter name, getter types. 1702 // The isSynthesized value is always set to 0 in a protocol. It exists to 1703 // simplify the runtime library by allowing it to use the same data 1704 // structures for protocol metadata everywhere. 1705 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1706 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1707 PtrToInt8Ty, NULL); 1708 std::vector<llvm::Constant*> Properties; 1709 std::vector<llvm::Constant*> OptionalProperties; 1710 1711 // Add all of the property methods need adding to the method list and to the 1712 // property metadata list. 1713 for (ObjCContainerDecl::prop_iterator 1714 iter = PD->prop_begin(), endIter = PD->prop_end(); 1715 iter != endIter ; iter++) { 1716 std::vector<llvm::Constant*> Fields; 1717 ObjCPropertyDecl *property = *iter; 1718 1719 1720 Fields.push_back(MakePropertyEncodingString(property, PD)); 1721 1722 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1723 property->getPropertyAttributes())); 1724 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0)); 1725 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1726 std::string TypeStr; 1727 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1728 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1729 InstanceMethodTypes.push_back(TypeEncoding); 1730 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1731 Fields.push_back(TypeEncoding); 1732 } else { 1733 Fields.push_back(NULLPtr); 1734 Fields.push_back(NULLPtr); 1735 } 1736 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1737 std::string TypeStr; 1738 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1739 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1740 InstanceMethodTypes.push_back(TypeEncoding); 1741 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 1742 Fields.push_back(TypeEncoding); 1743 } else { 1744 Fields.push_back(NULLPtr); 1745 Fields.push_back(NULLPtr); 1746 } 1747 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) { 1748 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1749 } else { 1750 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 1751 } 1752 } 1753 llvm::Constant *PropertyArray = llvm::ConstantArray::get( 1754 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties); 1755 llvm::Constant* PropertyListInitFields[] = 1756 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 1757 1758 llvm::Constant *PropertyListInit = 1759 llvm::ConstantStruct::getAnon(PropertyListInitFields); 1760 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule, 1761 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage, 1762 PropertyListInit, ".objc_property_list"); 1763 1764 llvm::Constant *OptionalPropertyArray = 1765 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy, 1766 OptionalProperties.size()) , OptionalProperties); 1767 llvm::Constant* OptionalPropertyListInitFields[] = { 1768 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr, 1769 OptionalPropertyArray }; 1770 1771 llvm::Constant *OptionalPropertyListInit = 1772 llvm::ConstantStruct::getAnon(OptionalPropertyListInitFields); 1773 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule, 1774 OptionalPropertyListInit->getType(), false, 1775 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit, 1776 ".objc_property_list"); 1777 1778 // Protocols are objects containing lists of the methods implemented and 1779 // protocols adopted. 1780 llvm::StructType *ProtocolTy = llvm::StructType::get(IdTy, 1781 PtrToInt8Ty, 1782 ProtocolList->getType(), 1783 InstanceMethodList->getType(), 1784 ClassMethodList->getType(), 1785 OptionalInstanceMethodList->getType(), 1786 OptionalClassMethodList->getType(), 1787 PropertyList->getType(), 1788 OptionalPropertyList->getType(), 1789 NULL); 1790 std::vector<llvm::Constant*> Elements; 1791 // The isa pointer must be set to a magic number so the runtime knows it's 1792 // the correct layout. 1793 Elements.push_back(llvm::ConstantExpr::getIntToPtr( 1794 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy)); 1795 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name")); 1796 Elements.push_back(ProtocolList); 1797 Elements.push_back(InstanceMethodList); 1798 Elements.push_back(ClassMethodList); 1799 Elements.push_back(OptionalInstanceMethodList); 1800 Elements.push_back(OptionalClassMethodList); 1801 Elements.push_back(PropertyList); 1802 Elements.push_back(OptionalPropertyList); 1803 ExistingProtocols[ProtocolName] = 1804 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements, 1805 ".objc_protocol"), IdTy); 1806} 1807void CGObjCGNU::GenerateProtocolHolderCategory(void) { 1808 // Collect information about instance methods 1809 SmallVector<Selector, 1> MethodSels; 1810 SmallVector<llvm::Constant*, 1> MethodTypes; 1811 1812 std::vector<llvm::Constant*> Elements; 1813 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack"; 1814 const std::string CategoryName = "AnotherHack"; 1815 Elements.push_back(MakeConstantString(CategoryName)); 1816 Elements.push_back(MakeConstantString(ClassName)); 1817 // Instance method list 1818 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1819 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy)); 1820 // Class method list 1821 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1822 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy)); 1823 // Protocol list 1824 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy, 1825 ExistingProtocols.size()); 1826 llvm::StructType *ProtocolListTy = llvm::StructType::get( 1827 PtrTy, //Should be a recurisve pointer, but it's always NULL here. 1828 SizeTy, 1829 ProtocolArrayTy, 1830 NULL); 1831 std::vector<llvm::Constant*> ProtocolElements; 1832 for (llvm::StringMapIterator<llvm::Constant*> iter = 1833 ExistingProtocols.begin(), endIter = ExistingProtocols.end(); 1834 iter != endIter ; iter++) { 1835 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(), 1836 PtrTy); 1837 ProtocolElements.push_back(Ptr); 1838 } 1839 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy, 1840 ProtocolElements); 1841 ProtocolElements.clear(); 1842 ProtocolElements.push_back(NULLPtr); 1843 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy, 1844 ExistingProtocols.size())); 1845 ProtocolElements.push_back(ProtocolArray); 1846 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy, 1847 ProtocolElements, ".objc_protocol_list"), PtrTy)); 1848 Categories.push_back(llvm::ConstantExpr::getBitCast( 1849 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1850 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1851} 1852 1853/// Libobjc2 uses a bitfield representation where small(ish) bitfields are 1854/// stored in a 64-bit value with the low bit set to 1 and the remaining 63 1855/// bits set to their values, LSB first, while larger ones are stored in a 1856/// structure of this / form: 1857/// 1858/// struct { int32_t length; int32_t values[length]; }; 1859/// 1860/// The values in the array are stored in host-endian format, with the least 1861/// significant bit being assumed to come first in the bitfield. Therefore, a 1862/// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a 1863/// bitfield / with the 63rd bit set will be 1<<64. 1864llvm::Constant *CGObjCGNU::MakeBitField(ArrayRef<bool> bits) { 1865 int bitCount = bits.size(); 1866 int ptrBits = 1867 (TheModule.getPointerSize() == llvm::Module::Pointer32) ? 32 : 64; 1868 if (bitCount < ptrBits) { 1869 uint64_t val = 1; 1870 for (int i=0 ; i<bitCount ; ++i) { 1871 if (bits[i]) val |= 1ULL<<(i+1); 1872 } 1873 return llvm::ConstantInt::get(IntPtrTy, val); 1874 } 1875 llvm::SmallVector<llvm::Constant*, 8> values; 1876 int v=0; 1877 while (v < bitCount) { 1878 int32_t word = 0; 1879 for (int i=0 ; (i<32) && (v<bitCount) ; ++i) { 1880 if (bits[v]) word |= 1<<i; 1881 v++; 1882 } 1883 values.push_back(llvm::ConstantInt::get(Int32Ty, word)); 1884 } 1885 llvm::ArrayType *arrayTy = llvm::ArrayType::get(Int32Ty, values.size()); 1886 llvm::Constant *array = llvm::ConstantArray::get(arrayTy, values); 1887 llvm::Constant *fields[2] = { 1888 llvm::ConstantInt::get(Int32Ty, values.size()), 1889 array }; 1890 llvm::Constant *GS = MakeGlobal(llvm::StructType::get(Int32Ty, arrayTy, 1891 NULL), fields); 1892 llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy); 1893 return ptr; 1894} 1895 1896void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) { 1897 std::string ClassName = OCD->getClassInterface()->getNameAsString(); 1898 std::string CategoryName = OCD->getNameAsString(); 1899 // Collect information about instance methods 1900 SmallVector<Selector, 16> InstanceMethodSels; 1901 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 1902 for (ObjCCategoryImplDecl::instmeth_iterator 1903 iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end(); 1904 iter != endIter ; iter++) { 1905 InstanceMethodSels.push_back((*iter)->getSelector()); 1906 std::string TypeStr; 1907 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1908 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 1909 } 1910 1911 // Collect information about class methods 1912 SmallVector<Selector, 16> ClassMethodSels; 1913 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 1914 for (ObjCCategoryImplDecl::classmeth_iterator 1915 iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end(); 1916 iter != endIter ; iter++) { 1917 ClassMethodSels.push_back((*iter)->getSelector()); 1918 std::string TypeStr; 1919 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr); 1920 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 1921 } 1922 1923 // Collect the names of referenced protocols 1924 SmallVector<std::string, 16> Protocols; 1925 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl(); 1926 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols(); 1927 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(), 1928 E = Protos.end(); I != E; ++I) 1929 Protocols.push_back((*I)->getNameAsString()); 1930 1931 std::vector<llvm::Constant*> Elements; 1932 Elements.push_back(MakeConstantString(CategoryName)); 1933 Elements.push_back(MakeConstantString(ClassName)); 1934 // Instance method list 1935 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1936 ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes, 1937 false), PtrTy)); 1938 // Class method list 1939 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList( 1940 ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true), 1941 PtrTy)); 1942 // Protocol list 1943 Elements.push_back(llvm::ConstantExpr::getBitCast( 1944 GenerateProtocolList(Protocols), PtrTy)); 1945 Categories.push_back(llvm::ConstantExpr::getBitCast( 1946 MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, 1947 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy)); 1948} 1949 1950llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID, 1951 SmallVectorImpl<Selector> &InstanceMethodSels, 1952 SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) { 1953 ASTContext &Context = CGM.getContext(); 1954 // 1955 // Property metadata: name, attributes, isSynthesized, setter name, setter 1956 // types, getter name, getter types. 1957 llvm::StructType *PropertyMetadataTy = llvm::StructType::get( 1958 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, 1959 PtrToInt8Ty, NULL); 1960 std::vector<llvm::Constant*> Properties; 1961 1962 1963 // Add all of the property methods need adding to the method list and to the 1964 // property metadata list. 1965 for (ObjCImplDecl::propimpl_iterator 1966 iter = OID->propimpl_begin(), endIter = OID->propimpl_end(); 1967 iter != endIter ; iter++) { 1968 std::vector<llvm::Constant*> Fields; 1969 ObjCPropertyDecl *property = iter->getPropertyDecl(); 1970 ObjCPropertyImplDecl *propertyImpl = *iter; 1971 bool isSynthesized = (propertyImpl->getPropertyImplementation() == 1972 ObjCPropertyImplDecl::Synthesize); 1973 1974 Fields.push_back(MakePropertyEncodingString(property, OID)); 1975 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 1976 property->getPropertyAttributes())); 1977 Fields.push_back(llvm::ConstantInt::get(Int8Ty, isSynthesized)); 1978 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) { 1979 std::string TypeStr; 1980 Context.getObjCEncodingForMethodDecl(getter,TypeStr); 1981 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1982 if (isSynthesized) { 1983 InstanceMethodTypes.push_back(TypeEncoding); 1984 InstanceMethodSels.push_back(getter->getSelector()); 1985 } 1986 Fields.push_back(MakeConstantString(getter->getSelector().getAsString())); 1987 Fields.push_back(TypeEncoding); 1988 } else { 1989 Fields.push_back(NULLPtr); 1990 Fields.push_back(NULLPtr); 1991 } 1992 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) { 1993 std::string TypeStr; 1994 Context.getObjCEncodingForMethodDecl(setter,TypeStr); 1995 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr); 1996 if (isSynthesized) { 1997 InstanceMethodTypes.push_back(TypeEncoding); 1998 InstanceMethodSels.push_back(setter->getSelector()); 1999 } 2000 Fields.push_back(MakeConstantString(setter->getSelector().getAsString())); 2001 Fields.push_back(TypeEncoding); 2002 } else { 2003 Fields.push_back(NULLPtr); 2004 Fields.push_back(NULLPtr); 2005 } 2006 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields)); 2007 } 2008 llvm::ArrayType *PropertyArrayTy = 2009 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()); 2010 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy, 2011 Properties); 2012 llvm::Constant* PropertyListInitFields[] = 2013 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray}; 2014 2015 llvm::Constant *PropertyListInit = 2016 llvm::ConstantStruct::getAnon(PropertyListInitFields); 2017 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false, 2018 llvm::GlobalValue::InternalLinkage, PropertyListInit, 2019 ".objc_property_list"); 2020} 2021 2022void CGObjCGNU::RegisterAlias(const ObjCCompatibleAliasDecl *OAD) { 2023 // Get the class declaration for which the alias is specified. 2024 ObjCInterfaceDecl *ClassDecl = 2025 const_cast<ObjCInterfaceDecl *>(OAD->getClassInterface()); 2026 std::string ClassName = ClassDecl->getNameAsString(); 2027 std::string AliasName = OAD->getNameAsString(); 2028 ClassAliases.push_back(ClassAliasPair(ClassName,AliasName)); 2029} 2030 2031void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) { 2032 ASTContext &Context = CGM.getContext(); 2033 2034 // Get the superclass name. 2035 const ObjCInterfaceDecl * SuperClassDecl = 2036 OID->getClassInterface()->getSuperClass(); 2037 std::string SuperClassName; 2038 if (SuperClassDecl) { 2039 SuperClassName = SuperClassDecl->getNameAsString(); 2040 EmitClassRef(SuperClassName); 2041 } 2042 2043 // Get the class name 2044 ObjCInterfaceDecl *ClassDecl = 2045 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface()); 2046 std::string ClassName = ClassDecl->getNameAsString(); 2047 // Emit the symbol that is used to generate linker errors if this class is 2048 // referenced in other modules but not declared. 2049 std::string classSymbolName = "__objc_class_name_" + ClassName; 2050 if (llvm::GlobalVariable *symbol = 2051 TheModule.getGlobalVariable(classSymbolName)) { 2052 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0)); 2053 } else { 2054 new llvm::GlobalVariable(TheModule, LongTy, false, 2055 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0), 2056 classSymbolName); 2057 } 2058 2059 // Get the size of instances. 2060 int instanceSize = 2061 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity(); 2062 2063 // Collect information about instance variables. 2064 SmallVector<llvm::Constant*, 16> IvarNames; 2065 SmallVector<llvm::Constant*, 16> IvarTypes; 2066 SmallVector<llvm::Constant*, 16> IvarOffsets; 2067 2068 std::vector<llvm::Constant*> IvarOffsetValues; 2069 SmallVector<bool, 16> WeakIvars; 2070 SmallVector<bool, 16> StrongIvars; 2071 2072 int superInstanceSize = !SuperClassDecl ? 0 : 2073 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity(); 2074 // For non-fragile ivars, set the instance size to 0 - {the size of just this 2075 // class}. The runtime will then set this to the correct value on load. 2076 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 2077 instanceSize = 0 - (instanceSize - superInstanceSize); 2078 } 2079 2080 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 2081 IVD = IVD->getNextIvar()) { 2082 // Store the name 2083 IvarNames.push_back(MakeConstantString(IVD->getNameAsString())); 2084 // Get the type encoding for this ivar 2085 std::string TypeStr; 2086 Context.getObjCEncodingForType(IVD->getType(), TypeStr); 2087 IvarTypes.push_back(MakeConstantString(TypeStr)); 2088 // Get the offset 2089 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD); 2090 uint64_t Offset = BaseOffset; 2091 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 2092 Offset = BaseOffset - superInstanceSize; 2093 } 2094 llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset); 2095 // Create the direct offset value 2096 std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." + 2097 IVD->getNameAsString(); 2098 llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName); 2099 if (OffsetVar) { 2100 OffsetVar->setInitializer(OffsetValue); 2101 // If this is the real definition, change its linkage type so that 2102 // different modules will use this one, rather than their private 2103 // copy. 2104 OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage); 2105 } else 2106 OffsetVar = new llvm::GlobalVariable(TheModule, IntTy, 2107 false, llvm::GlobalValue::ExternalLinkage, 2108 OffsetValue, 2109 "__objc_ivar_offset_value_" + ClassName +"." + 2110 IVD->getNameAsString()); 2111 IvarOffsets.push_back(OffsetValue); 2112 IvarOffsetValues.push_back(OffsetVar); 2113 Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime(); 2114 switch (lt) { 2115 case Qualifiers::OCL_Strong: 2116 StrongIvars.push_back(true); 2117 WeakIvars.push_back(false); 2118 break; 2119 case Qualifiers::OCL_Weak: 2120 StrongIvars.push_back(false); 2121 WeakIvars.push_back(true); 2122 break; 2123 default: 2124 StrongIvars.push_back(false); 2125 WeakIvars.push_back(false); 2126 } 2127 } 2128 llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars); 2129 llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars); 2130 llvm::GlobalVariable *IvarOffsetArray = 2131 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets"); 2132 2133 2134 // Collect information about instance methods 2135 SmallVector<Selector, 16> InstanceMethodSels; 2136 SmallVector<llvm::Constant*, 16> InstanceMethodTypes; 2137 for (ObjCImplementationDecl::instmeth_iterator 2138 iter = OID->instmeth_begin(), endIter = OID->instmeth_end(); 2139 iter != endIter ; iter++) { 2140 InstanceMethodSels.push_back((*iter)->getSelector()); 2141 std::string TypeStr; 2142 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 2143 InstanceMethodTypes.push_back(MakeConstantString(TypeStr)); 2144 } 2145 2146 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels, 2147 InstanceMethodTypes); 2148 2149 2150 // Collect information about class methods 2151 SmallVector<Selector, 16> ClassMethodSels; 2152 SmallVector<llvm::Constant*, 16> ClassMethodTypes; 2153 for (ObjCImplementationDecl::classmeth_iterator 2154 iter = OID->classmeth_begin(), endIter = OID->classmeth_end(); 2155 iter != endIter ; iter++) { 2156 ClassMethodSels.push_back((*iter)->getSelector()); 2157 std::string TypeStr; 2158 Context.getObjCEncodingForMethodDecl((*iter),TypeStr); 2159 ClassMethodTypes.push_back(MakeConstantString(TypeStr)); 2160 } 2161 // Collect the names of referenced protocols 2162 SmallVector<std::string, 16> Protocols; 2163 for (ObjCInterfaceDecl::protocol_iterator 2164 I = ClassDecl->protocol_begin(), 2165 E = ClassDecl->protocol_end(); I != E; ++I) 2166 Protocols.push_back((*I)->getNameAsString()); 2167 2168 2169 2170 // Get the superclass pointer. 2171 llvm::Constant *SuperClass; 2172 if (!SuperClassName.empty()) { 2173 SuperClass = MakeConstantString(SuperClassName, ".super_class_name"); 2174 } else { 2175 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty); 2176 } 2177 // Empty vector used to construct empty method lists 2178 SmallVector<llvm::Constant*, 1> empty; 2179 // Generate the method and instance variable lists 2180 llvm::Constant *MethodList = GenerateMethodList(ClassName, "", 2181 InstanceMethodSels, InstanceMethodTypes, false); 2182 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "", 2183 ClassMethodSels, ClassMethodTypes, true); 2184 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes, 2185 IvarOffsets); 2186 // Irrespective of whether we are compiling for a fragile or non-fragile ABI, 2187 // we emit a symbol containing the offset for each ivar in the class. This 2188 // allows code compiled for the non-Fragile ABI to inherit from code compiled 2189 // for the legacy ABI, without causing problems. The converse is also 2190 // possible, but causes all ivar accesses to be fragile. 2191 2192 // Offset pointer for getting at the correct field in the ivar list when 2193 // setting up the alias. These are: The base address for the global, the 2194 // ivar array (second field), the ivar in this list (set for each ivar), and 2195 // the offset (third field in ivar structure) 2196 llvm::Type *IndexTy = Int32Ty; 2197 llvm::Constant *offsetPointerIndexes[] = {Zeros[0], 2198 llvm::ConstantInt::get(IndexTy, 1), 0, 2199 llvm::ConstantInt::get(IndexTy, 2) }; 2200 2201 unsigned ivarIndex = 0; 2202 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD; 2203 IVD = IVD->getNextIvar()) { 2204 const std::string Name = "__objc_ivar_offset_" + ClassName + '.' 2205 + IVD->getNameAsString(); 2206 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex); 2207 // Get the correct ivar field 2208 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr( 2209 IvarList, offsetPointerIndexes); 2210 // Get the existing variable, if one exists. 2211 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name); 2212 if (offset) { 2213 offset->setInitializer(offsetValue); 2214 // If this is the real definition, change its linkage type so that 2215 // different modules will use this one, rather than their private 2216 // copy. 2217 offset->setLinkage(llvm::GlobalValue::ExternalLinkage); 2218 } else { 2219 // Add a new alias if there isn't one already. 2220 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(), 2221 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name); 2222 (void) offset; // Silence dead store warning. 2223 } 2224 ++ivarIndex; 2225 } 2226 llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0); 2227 //Generate metaclass for class methods 2228 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr, 2229 NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList( 2230 empty, empty, empty), ClassMethodList, NULLPtr, 2231 NULLPtr, NULLPtr, ZeroPtr, ZeroPtr, true); 2232 2233 // Generate the class structure 2234 llvm::Constant *ClassStruct = 2235 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L, 2236 ClassName.c_str(), 0, 2237 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, 2238 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray, 2239 Properties, StrongIvarBitmap, WeakIvarBitmap); 2240 2241 // Resolve the class aliases, if they exist. 2242 if (ClassPtrAlias) { 2243 ClassPtrAlias->replaceAllUsesWith( 2244 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy)); 2245 ClassPtrAlias->eraseFromParent(); 2246 ClassPtrAlias = 0; 2247 } 2248 if (MetaClassPtrAlias) { 2249 MetaClassPtrAlias->replaceAllUsesWith( 2250 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy)); 2251 MetaClassPtrAlias->eraseFromParent(); 2252 MetaClassPtrAlias = 0; 2253 } 2254 2255 // Add class structure to list to be added to the symtab later 2256 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty); 2257 Classes.push_back(ClassStruct); 2258} 2259 2260 2261llvm::Function *CGObjCGNU::ModuleInitFunction() { 2262 // Only emit an ObjC load function if no Objective-C stuff has been called 2263 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() && 2264 ExistingProtocols.empty() && SelectorTable.empty()) 2265 return NULL; 2266 2267 // Add all referenced protocols to a category. 2268 GenerateProtocolHolderCategory(); 2269 2270 llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>( 2271 SelectorTy->getElementType()); 2272 llvm::Type *SelStructPtrTy = SelectorTy; 2273 if (SelStructTy == 0) { 2274 SelStructTy = llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, NULL); 2275 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy); 2276 } 2277 2278 std::vector<llvm::Constant*> Elements; 2279 llvm::Constant *Statics = NULLPtr; 2280 // Generate statics list: 2281 if (ConstantStrings.size()) { 2282 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty, 2283 ConstantStrings.size() + 1); 2284 ConstantStrings.push_back(NULLPtr); 2285 2286 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass; 2287 2288 if (StringClass.empty()) StringClass = "NXConstantString"; 2289 2290 Elements.push_back(MakeConstantString(StringClass, 2291 ".objc_static_class_name")); 2292 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy, 2293 ConstantStrings)); 2294 llvm::StructType *StaticsListTy = 2295 llvm::StructType::get(PtrToInt8Ty, StaticsArrayTy, NULL); 2296 llvm::Type *StaticsListPtrTy = 2297 llvm::PointerType::getUnqual(StaticsListTy); 2298 Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics"); 2299 llvm::ArrayType *StaticsListArrayTy = 2300 llvm::ArrayType::get(StaticsListPtrTy, 2); 2301 Elements.clear(); 2302 Elements.push_back(Statics); 2303 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy)); 2304 Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr"); 2305 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy); 2306 } 2307 // Array of classes, categories, and constant objects 2308 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty, 2309 Classes.size() + Categories.size() + 2); 2310 llvm::StructType *SymTabTy = llvm::StructType::get(LongTy, SelStructPtrTy, 2311 llvm::Type::getInt16Ty(VMContext), 2312 llvm::Type::getInt16Ty(VMContext), 2313 ClassListTy, NULL); 2314 2315 Elements.clear(); 2316 // Pointer to an array of selectors used in this module. 2317 std::vector<llvm::Constant*> Selectors; 2318 std::vector<llvm::GlobalAlias*> SelectorAliases; 2319 for (SelectorMap::iterator iter = SelectorTable.begin(), 2320 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) { 2321 2322 std::string SelNameStr = iter->first.getAsString(); 2323 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name"); 2324 2325 SmallVectorImpl<TypedSelector> &Types = iter->second; 2326 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(), 2327 e = Types.end() ; i!=e ; i++) { 2328 2329 llvm::Constant *SelectorTypeEncoding = NULLPtr; 2330 if (!i->first.empty()) 2331 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types"); 2332 2333 Elements.push_back(SelName); 2334 Elements.push_back(SelectorTypeEncoding); 2335 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2336 Elements.clear(); 2337 2338 // Store the selector alias for later replacement 2339 SelectorAliases.push_back(i->second); 2340 } 2341 } 2342 unsigned SelectorCount = Selectors.size(); 2343 // NULL-terminate the selector list. This should not actually be required, 2344 // because the selector list has a length field. Unfortunately, the GCC 2345 // runtime decides to ignore the length field and expects a NULL terminator, 2346 // and GCC cooperates with this by always setting the length to 0. 2347 Elements.push_back(NULLPtr); 2348 Elements.push_back(NULLPtr); 2349 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements)); 2350 Elements.clear(); 2351 2352 // Number of static selectors 2353 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount)); 2354 llvm::Constant *SelectorList = MakeGlobalArray(SelStructTy, Selectors, 2355 ".objc_selector_list"); 2356 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList, 2357 SelStructPtrTy)); 2358 2359 // Now that all of the static selectors exist, create pointers to them. 2360 for (unsigned int i=0 ; i<SelectorCount ; i++) { 2361 2362 llvm::Constant *Idxs[] = {Zeros[0], 2363 llvm::ConstantInt::get(Int32Ty, i), Zeros[0]}; 2364 // FIXME: We're generating redundant loads and stores here! 2365 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(SelectorList, 2366 makeArrayRef(Idxs, 2)); 2367 // If selectors are defined as an opaque type, cast the pointer to this 2368 // type. 2369 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy); 2370 SelectorAliases[i]->replaceAllUsesWith(SelPtr); 2371 SelectorAliases[i]->eraseFromParent(); 2372 } 2373 2374 // Number of classes defined. 2375 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2376 Classes.size())); 2377 // Number of categories defined 2378 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext), 2379 Categories.size())); 2380 // Create an array of classes, then categories, then static object instances 2381 Classes.insert(Classes.end(), Categories.begin(), Categories.end()); 2382 // NULL-terminated list of static object instances (mainly constant strings) 2383 Classes.push_back(Statics); 2384 Classes.push_back(NULLPtr); 2385 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes); 2386 Elements.push_back(ClassList); 2387 // Construct the symbol table 2388 llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements); 2389 2390 // The symbol table is contained in a module which has some version-checking 2391 // constants 2392 llvm::StructType * ModuleTy = llvm::StructType::get(LongTy, LongTy, 2393 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), 2394 (RuntimeVersion >= 10) ? IntTy : NULL, NULL); 2395 Elements.clear(); 2396 // Runtime version, used for ABI compatibility checking. 2397 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion)); 2398 // sizeof(ModuleTy) 2399 llvm::DataLayout td(&TheModule); 2400 Elements.push_back( 2401 llvm::ConstantInt::get(LongTy, 2402 td.getTypeSizeInBits(ModuleTy) / 2403 CGM.getContext().getCharWidth())); 2404 2405 // The path to the source file where this module was declared 2406 SourceManager &SM = CGM.getContext().getSourceManager(); 2407 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID()); 2408 std::string path = 2409 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName(); 2410 Elements.push_back(MakeConstantString(path, ".objc_source_file_name")); 2411 Elements.push_back(SymTab); 2412 2413 if (RuntimeVersion >= 10) 2414 switch (CGM.getLangOpts().getGC()) { 2415 case LangOptions::GCOnly: 2416 Elements.push_back(llvm::ConstantInt::get(IntTy, 2)); 2417 break; 2418 case LangOptions::NonGC: 2419 if (CGM.getLangOpts().ObjCAutoRefCount) 2420 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2421 else 2422 Elements.push_back(llvm::ConstantInt::get(IntTy, 0)); 2423 break; 2424 case LangOptions::HybridGC: 2425 Elements.push_back(llvm::ConstantInt::get(IntTy, 1)); 2426 break; 2427 } 2428 2429 llvm::Value *Module = MakeGlobal(ModuleTy, Elements); 2430 2431 // Create the load function calling the runtime entry point with the module 2432 // structure 2433 llvm::Function * LoadFunction = llvm::Function::Create( 2434 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false), 2435 llvm::GlobalValue::InternalLinkage, ".objc_load_function", 2436 &TheModule); 2437 llvm::BasicBlock *EntryBB = 2438 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction); 2439 CGBuilderTy Builder(VMContext); 2440 Builder.SetInsertPoint(EntryBB); 2441 2442 llvm::FunctionType *FT = 2443 llvm::FunctionType::get(Builder.getVoidTy(), 2444 llvm::PointerType::getUnqual(ModuleTy), true); 2445 llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class"); 2446 Builder.CreateCall(Register, Module); 2447 2448 if (!ClassAliases.empty()) { 2449 llvm::Type *ArgTypes[2] = {PtrTy, PtrToInt8Ty}; 2450 llvm::FunctionType *RegisterAliasTy = 2451 llvm::FunctionType::get(Builder.getVoidTy(), 2452 ArgTypes, false); 2453 llvm::Function *RegisterAlias = llvm::Function::Create( 2454 RegisterAliasTy, 2455 llvm::GlobalValue::ExternalWeakLinkage, "class_registerAlias_np", 2456 &TheModule); 2457 llvm::BasicBlock *AliasBB = 2458 llvm::BasicBlock::Create(VMContext, "alias", LoadFunction); 2459 llvm::BasicBlock *NoAliasBB = 2460 llvm::BasicBlock::Create(VMContext, "no_alias", LoadFunction); 2461 2462 // Branch based on whether the runtime provided class_registerAlias_np() 2463 llvm::Value *HasRegisterAlias = Builder.CreateICmpNE(RegisterAlias, 2464 llvm::Constant::getNullValue(RegisterAlias->getType())); 2465 Builder.CreateCondBr(HasRegisterAlias, AliasBB, NoAliasBB); 2466 2467 // The true branch (has alias registration fucntion): 2468 Builder.SetInsertPoint(AliasBB); 2469 // Emit alias registration calls: 2470 for (std::vector<ClassAliasPair>::iterator iter = ClassAliases.begin(); 2471 iter != ClassAliases.end(); ++iter) { 2472 llvm::Constant *TheClass = 2473 TheModule.getGlobalVariable(("_OBJC_CLASS_" + iter->first).c_str(), 2474 true); 2475 if (0 != TheClass) { 2476 TheClass = llvm::ConstantExpr::getBitCast(TheClass, PtrTy); 2477 Builder.CreateCall2(RegisterAlias, TheClass, 2478 MakeConstantString(iter->second)); 2479 } 2480 } 2481 // Jump to end: 2482 Builder.CreateBr(NoAliasBB); 2483 2484 // Missing alias registration function, just return from the function: 2485 Builder.SetInsertPoint(NoAliasBB); 2486 } 2487 Builder.CreateRetVoid(); 2488 2489 return LoadFunction; 2490} 2491 2492llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD, 2493 const ObjCContainerDecl *CD) { 2494 const ObjCCategoryImplDecl *OCD = 2495 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext()); 2496 StringRef CategoryName = OCD ? OCD->getName() : ""; 2497 StringRef ClassName = CD->getName(); 2498 Selector MethodName = OMD->getSelector(); 2499 bool isClassMethod = !OMD->isInstanceMethod(); 2500 2501 CodeGenTypes &Types = CGM.getTypes(); 2502 llvm::FunctionType *MethodTy = 2503 Types.GetFunctionType(Types.arrangeObjCMethodDeclaration(OMD)); 2504 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName, 2505 MethodName, isClassMethod); 2506 2507 llvm::Function *Method 2508 = llvm::Function::Create(MethodTy, 2509 llvm::GlobalValue::InternalLinkage, 2510 FunctionName, 2511 &TheModule); 2512 return Method; 2513} 2514 2515llvm::Constant *CGObjCGNU::GetPropertyGetFunction() { 2516 return GetPropertyFn; 2517} 2518 2519llvm::Constant *CGObjCGNU::GetPropertySetFunction() { 2520 return SetPropertyFn; 2521} 2522 2523llvm::Constant *CGObjCGNU::GetOptimizedPropertySetFunction(bool atomic, 2524 bool copy) { 2525 return 0; 2526} 2527 2528llvm::Constant *CGObjCGNU::GetGetStructFunction() { 2529 return GetStructPropertyFn; 2530} 2531llvm::Constant *CGObjCGNU::GetSetStructFunction() { 2532 return SetStructPropertyFn; 2533} 2534llvm::Constant *CGObjCGNU::GetCppAtomicObjectFunction() { 2535 return 0; 2536} 2537 2538llvm::Constant *CGObjCGNU::EnumerationMutationFunction() { 2539 return EnumerationMutationFn; 2540} 2541 2542void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF, 2543 const ObjCAtSynchronizedStmt &S) { 2544 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn); 2545} 2546 2547 2548void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF, 2549 const ObjCAtTryStmt &S) { 2550 // Unlike the Apple non-fragile runtimes, which also uses 2551 // unwind-based zero cost exceptions, the GNU Objective C runtime's 2552 // EH support isn't a veneer over C++ EH. Instead, exception 2553 // objects are created by objc_exception_throw and destroyed by 2554 // the personality function; this avoids the need for bracketing 2555 // catch handlers with calls to __blah_begin_catch/__blah_end_catch 2556 // (or even _Unwind_DeleteException), but probably doesn't 2557 // interoperate very well with foreign exceptions. 2558 // 2559 // In Objective-C++ mode, we actually emit something equivalent to the C++ 2560 // exception handler. 2561 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn); 2562 return ; 2563} 2564 2565void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF, 2566 const ObjCAtThrowStmt &S) { 2567 llvm::Value *ExceptionAsObject; 2568 2569 if (const Expr *ThrowExpr = S.getThrowExpr()) { 2570 llvm::Value *Exception = CGF.EmitObjCThrowOperand(ThrowExpr); 2571 ExceptionAsObject = Exception; 2572 } else { 2573 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) && 2574 "Unexpected rethrow outside @catch block."); 2575 ExceptionAsObject = CGF.ObjCEHValueStack.back(); 2576 } 2577 ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy); 2578 llvm::CallSite Throw = 2579 CGF.EmitCallOrInvoke(ExceptionThrowFn, ExceptionAsObject); 2580 Throw.setDoesNotReturn(); 2581 CGF.Builder.CreateUnreachable(); 2582 CGF.Builder.ClearInsertionPoint(); 2583} 2584 2585llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF, 2586 llvm::Value *AddrWeakObj) { 2587 CGBuilderTy B = CGF.Builder; 2588 AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy); 2589 return B.CreateCall(WeakReadFn, AddrWeakObj); 2590} 2591 2592void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF, 2593 llvm::Value *src, llvm::Value *dst) { 2594 CGBuilderTy B = CGF.Builder; 2595 src = EnforceType(B, src, IdTy); 2596 dst = EnforceType(B, dst, PtrToIdTy); 2597 B.CreateCall2(WeakAssignFn, src, dst); 2598} 2599 2600void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF, 2601 llvm::Value *src, llvm::Value *dst, 2602 bool threadlocal) { 2603 CGBuilderTy B = CGF.Builder; 2604 src = EnforceType(B, src, IdTy); 2605 dst = EnforceType(B, dst, PtrToIdTy); 2606 if (!threadlocal) 2607 B.CreateCall2(GlobalAssignFn, src, dst); 2608 else 2609 // FIXME. Add threadloca assign API 2610 llvm_unreachable("EmitObjCGlobalAssign - Threal Local API NYI"); 2611} 2612 2613void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF, 2614 llvm::Value *src, llvm::Value *dst, 2615 llvm::Value *ivarOffset) { 2616 CGBuilderTy B = CGF.Builder; 2617 src = EnforceType(B, src, IdTy); 2618 dst = EnforceType(B, dst, IdTy); 2619 B.CreateCall3(IvarAssignFn, src, dst, ivarOffset); 2620} 2621 2622void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF, 2623 llvm::Value *src, llvm::Value *dst) { 2624 CGBuilderTy B = CGF.Builder; 2625 src = EnforceType(B, src, IdTy); 2626 dst = EnforceType(B, dst, PtrToIdTy); 2627 B.CreateCall2(StrongCastAssignFn, src, dst); 2628} 2629 2630void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF, 2631 llvm::Value *DestPtr, 2632 llvm::Value *SrcPtr, 2633 llvm::Value *Size) { 2634 CGBuilderTy B = CGF.Builder; 2635 DestPtr = EnforceType(B, DestPtr, PtrTy); 2636 SrcPtr = EnforceType(B, SrcPtr, PtrTy); 2637 2638 B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size); 2639} 2640 2641llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable( 2642 const ObjCInterfaceDecl *ID, 2643 const ObjCIvarDecl *Ivar) { 2644 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString() 2645 + '.' + Ivar->getNameAsString(); 2646 // Emit the variable and initialize it with what we think the correct value 2647 // is. This allows code compiled with non-fragile ivars to work correctly 2648 // when linked against code which isn't (most of the time). 2649 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name); 2650 if (!IvarOffsetPointer) { 2651 // This will cause a run-time crash if we accidentally use it. A value of 2652 // 0 would seem more sensible, but will silently overwrite the isa pointer 2653 // causing a great deal of confusion. 2654 uint64_t Offset = -1; 2655 // We can't call ComputeIvarBaseOffset() here if we have the 2656 // implementation, because it will create an invalid ASTRecordLayout object 2657 // that we are then stuck with forever, so we only initialize the ivar 2658 // offset variable with a guess if we only have the interface. The 2659 // initializer will be reset later anyway, when we are generating the class 2660 // description. 2661 if (!CGM.getContext().getObjCImplementation( 2662 const_cast<ObjCInterfaceDecl *>(ID))) 2663 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar); 2664 2665 llvm::ConstantInt *OffsetGuess = llvm::ConstantInt::get(Int32Ty, Offset, 2666 /*isSigned*/true); 2667 // Don't emit the guess in non-PIC code because the linker will not be able 2668 // to replace it with the real version for a library. In non-PIC code you 2669 // must compile with the fragile ABI if you want to use ivars from a 2670 // GCC-compiled class. 2671 if (CGM.getLangOpts().PICLevel || CGM.getLangOpts().PIELevel) { 2672 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule, 2673 Int32Ty, false, 2674 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess"); 2675 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2676 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage, 2677 IvarOffsetGV, Name); 2678 } else { 2679 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, 2680 llvm::Type::getInt32PtrTy(VMContext), false, 2681 llvm::GlobalValue::ExternalLinkage, 0, Name); 2682 } 2683 } 2684 return IvarOffsetPointer; 2685} 2686 2687LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF, 2688 QualType ObjectTy, 2689 llvm::Value *BaseValue, 2690 const ObjCIvarDecl *Ivar, 2691 unsigned CVRQualifiers) { 2692 const ObjCInterfaceDecl *ID = 2693 ObjectTy->getAs<ObjCObjectType>()->getInterface(); 2694 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers, 2695 EmitIvarOffset(CGF, ID, Ivar)); 2696} 2697 2698static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context, 2699 const ObjCInterfaceDecl *OID, 2700 const ObjCIvarDecl *OIVD) { 2701 for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next; 2702 next = next->getNextIvar()) { 2703 if (OIVD == next) 2704 return OID; 2705 } 2706 2707 // Otherwise check in the super class. 2708 if (const ObjCInterfaceDecl *Super = OID->getSuperClass()) 2709 return FindIvarInterface(Context, Super, OIVD); 2710 2711 return 0; 2712} 2713 2714llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF, 2715 const ObjCInterfaceDecl *Interface, 2716 const ObjCIvarDecl *Ivar) { 2717 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) { 2718 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar); 2719 if (RuntimeVersion < 10) 2720 return CGF.Builder.CreateZExtOrBitCast( 2721 CGF.Builder.CreateLoad(CGF.Builder.CreateLoad( 2722 ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")), 2723 PtrDiffTy); 2724 std::string name = "__objc_ivar_offset_value_" + 2725 Interface->getNameAsString() +"." + Ivar->getNameAsString(); 2726 llvm::Value *Offset = TheModule.getGlobalVariable(name); 2727 if (!Offset) 2728 Offset = new llvm::GlobalVariable(TheModule, IntTy, 2729 false, llvm::GlobalValue::LinkOnceAnyLinkage, 2730 llvm::Constant::getNullValue(IntTy), name); 2731 Offset = CGF.Builder.CreateLoad(Offset); 2732 if (Offset->getType() != PtrDiffTy) 2733 Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy); 2734 return Offset; 2735 } 2736 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar); 2737 return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true); 2738} 2739 2740CGObjCRuntime * 2741clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) { 2742 switch (CGM.getLangOpts().ObjCRuntime.getKind()) { 2743 case ObjCRuntime::GNUstep: 2744 return new CGObjCGNUstep(CGM); 2745 2746 case ObjCRuntime::GCC: 2747 return new CGObjCGCC(CGM); 2748 2749 case ObjCRuntime::ObjFW: 2750 return new CGObjCObjFW(CGM); 2751 2752 case ObjCRuntime::FragileMacOSX: 2753 case ObjCRuntime::MacOSX: 2754 case ObjCRuntime::iOS: 2755 llvm_unreachable("these runtimes are not GNU runtimes"); 2756 } 2757 llvm_unreachable("bad runtime"); 2758} 2759