1 //===------- CGObjCGNU.cpp - Emit LLVM Code from ASTs for a Module --------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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.
15 //===----------------------------------------------------------------------===//
17 #include "CGObjCRuntime.h"
18 #include "CGCleanup.h"
19 #include "CodeGenFunction.h"
20 #include "CodeGenModule.h"
22 #include "clang/CodeGen/ConstantInitBuilder.h"
23 #include "clang/AST/ASTContext.h"
24 #include "clang/AST/Decl.h"
25 #include "clang/AST/DeclObjC.h"
26 #include "clang/AST/RecordLayout.h"
27 #include "clang/AST/StmtObjC.h"
28 #include "clang/Basic/FileManager.h"
29 #include "clang/Basic/SourceManager.h"
30 #include "llvm/ADT/SmallVector.h"
31 #include "llvm/ADT/StringMap.h"
32 #include "llvm/IR/CallSite.h"
33 #include "llvm/IR/DataLayout.h"
34 #include "llvm/IR/Intrinsics.h"
35 #include "llvm/IR/LLVMContext.h"
36 #include "llvm/IR/Module.h"
37 #include "llvm/Support/Compiler.h"
38 #include "llvm/Support/ConvertUTF.h"
41 using namespace clang;
42 using namespace CodeGen;
46 std::string SymbolNameForMethod( StringRef ClassName,
47 StringRef CategoryName, const Selector MethodName,
49 std::string MethodNameColonStripped = MethodName.getAsString();
50 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(),
52 return (Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" +
53 CategoryName + "_" + MethodNameColonStripped).str();
56 /// Class that lazily initialises the runtime function. Avoids inserting the
57 /// types and the function declaration into a module if they're not used, and
58 /// avoids constructing the type more than once if it's used more than once.
59 class LazyRuntimeFunction {
61 llvm::FunctionType *FTy;
62 const char *FunctionName;
63 llvm::Constant *Function;
66 /// Constructor leaves this class uninitialized, because it is intended to
67 /// be used as a field in another class and not all of the types that are
68 /// used as arguments will necessarily be available at construction time.
70 : CGM(nullptr), FunctionName(nullptr), Function(nullptr) {}
72 /// Initialises the lazy function with the name, return type, and the types
74 template <typename... Tys>
75 void init(CodeGenModule *Mod, const char *name, llvm::Type *RetTy,
81 SmallVector<llvm::Type *, 8> ArgTys({Types...});
82 FTy = llvm::FunctionType::get(RetTy, ArgTys, false);
85 FTy = llvm::FunctionType::get(RetTy, None, false);
89 llvm::FunctionType *getType() { return FTy; }
91 /// Overloaded cast operator, allows the class to be implicitly cast to an
93 operator llvm::Constant *() {
97 Function = CGM->CreateRuntimeFunction(FTy, FunctionName);
101 operator llvm::Function *() {
102 return cast<llvm::Function>((llvm::Constant *)*this);
107 /// GNU Objective-C runtime code generation. This class implements the parts of
108 /// Objective-C support that are specific to the GNU family of runtimes (GCC,
109 /// GNUstep and ObjFW).
110 class CGObjCGNU : public CGObjCRuntime {
112 /// The LLVM module into which output is inserted
113 llvm::Module &TheModule;
114 /// strut objc_super. Used for sending messages to super. This structure
115 /// contains the receiver (object) and the expected class.
116 llvm::StructType *ObjCSuperTy;
117 /// struct objc_super*. The type of the argument to the superclass message
118 /// lookup functions.
119 llvm::PointerType *PtrToObjCSuperTy;
120 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring
121 /// SEL is included in a header somewhere, in which case it will be whatever
122 /// type is declared in that header, most likely {i8*, i8*}.
123 llvm::PointerType *SelectorTy;
124 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the
125 /// places where it's used
126 llvm::IntegerType *Int8Ty;
127 /// Pointer to i8 - LLVM type of char*, for all of the places where the
128 /// runtime needs to deal with C strings.
129 llvm::PointerType *PtrToInt8Ty;
130 /// struct objc_protocol type
131 llvm::StructType *ProtocolTy;
133 llvm::PointerType *ProtocolPtrTy;
134 /// Instance Method Pointer type. This is a pointer to a function that takes,
135 /// at a minimum, an object and a selector, and is the generic type for
136 /// Objective-C methods. Due to differences between variadic / non-variadic
137 /// calling conventions, it must always be cast to the correct type before
138 /// actually being used.
139 llvm::PointerType *IMPTy;
140 /// Type of an untyped Objective-C object. Clang treats id as a built-in type
141 /// when compiling Objective-C code, so this may be an opaque pointer (i8*),
142 /// but if the runtime header declaring it is included then it may be a
143 /// pointer to a structure.
144 llvm::PointerType *IdTy;
145 /// Pointer to a pointer to an Objective-C object. Used in the new ABI
146 /// message lookup function and some GC-related functions.
147 llvm::PointerType *PtrToIdTy;
148 /// The clang type of id. Used when using the clang CGCall infrastructure to
149 /// call Objective-C methods.
151 /// LLVM type for C int type.
152 llvm::IntegerType *IntTy;
153 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is
154 /// used in the code to document the difference between i8* meaning a pointer
155 /// to a C string and i8* meaning a pointer to some opaque type.
156 llvm::PointerType *PtrTy;
157 /// LLVM type for C long type. The runtime uses this in a lot of places where
158 /// it should be using intptr_t, but we can't fix this without breaking
159 /// compatibility with GCC...
160 llvm::IntegerType *LongTy;
161 /// LLVM type for C size_t. Used in various runtime data structures.
162 llvm::IntegerType *SizeTy;
163 /// LLVM type for C intptr_t.
164 llvm::IntegerType *IntPtrTy;
165 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions.
166 llvm::IntegerType *PtrDiffTy;
167 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance
169 llvm::PointerType *PtrToIntTy;
170 /// LLVM type for Objective-C BOOL type.
172 /// 32-bit integer type, to save us needing to look it up every time it's used.
173 llvm::IntegerType *Int32Ty;
174 /// 64-bit integer type, to save us needing to look it up every time it's used.
175 llvm::IntegerType *Int64Ty;
176 /// The type of struct objc_property.
177 llvm::StructType *PropertyMetadataTy;
178 /// Metadata kind used to tie method lookups to message sends. The GNUstep
179 /// runtime provides some LLVM passes that can use this to do things like
180 /// automatic IMP caching and speculative inlining.
181 unsigned msgSendMDKind;
182 /// Does the current target use SEH-based exceptions? False implies
183 /// Itanium-style DWARF unwinding.
184 bool usesSEHExceptions;
186 /// Helper to check if we are targeting a specific runtime version or later.
187 bool isRuntime(ObjCRuntime::Kind kind, unsigned major, unsigned minor=0) {
188 const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
189 return (R.getKind() == kind) &&
190 (R.getVersion() >= VersionTuple(major, minor));
193 std::string SymbolForProtocol(StringRef Name) {
194 return (StringRef("._OBJC_PROTOCOL_") + Name).str();
197 std::string SymbolForProtocolRef(StringRef Name) {
198 return (StringRef("._OBJC_REF_PROTOCOL_") + Name).str();
202 /// Helper function that generates a constant string and returns a pointer to
203 /// the start of the string. The result of this function can be used anywhere
204 /// where the C code specifies const char*.
205 llvm::Constant *MakeConstantString(StringRef Str, const char *Name = "") {
206 ConstantAddress Array = CGM.GetAddrOfConstantCString(Str, Name);
207 return llvm::ConstantExpr::getGetElementPtr(Array.getElementType(),
208 Array.getPointer(), Zeros);
211 /// Emits a linkonce_odr string, whose name is the prefix followed by the
212 /// string value. This allows the linker to combine the strings between
213 /// different modules. Used for EH typeinfo names, selector strings, and a
214 /// few other things.
215 llvm::Constant *ExportUniqueString(const std::string &Str,
216 const std::string &prefix,
217 bool Private=false) {
218 std::string name = prefix + Str;
219 auto *ConstStr = TheModule.getGlobalVariable(name);
221 llvm::Constant *value = llvm::ConstantDataArray::getString(VMContext,Str);
222 auto *GV = new llvm::GlobalVariable(TheModule, value->getType(), true,
223 llvm::GlobalValue::LinkOnceODRLinkage, value, name);
224 GV->setComdat(TheModule.getOrInsertComdat(name));
226 GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
229 return llvm::ConstantExpr::getGetElementPtr(ConstStr->getValueType(),
233 /// Returns a property name and encoding string.
234 llvm::Constant *MakePropertyEncodingString(const ObjCPropertyDecl *PD,
235 const Decl *Container) {
236 assert(!isRuntime(ObjCRuntime::GNUstep, 2));
237 if (isRuntime(ObjCRuntime::GNUstep, 1, 6)) {
238 std::string NameAndAttributes;
239 std::string TypeStr =
240 CGM.getContext().getObjCEncodingForPropertyDecl(PD, Container);
241 NameAndAttributes += '\0';
242 NameAndAttributes += TypeStr.length() + 3;
243 NameAndAttributes += TypeStr;
244 NameAndAttributes += '\0';
245 NameAndAttributes += PD->getNameAsString();
246 return MakeConstantString(NameAndAttributes);
248 return MakeConstantString(PD->getNameAsString());
251 /// Push the property attributes into two structure fields.
252 void PushPropertyAttributes(ConstantStructBuilder &Fields,
253 const ObjCPropertyDecl *property, bool isSynthesized=true, bool
255 int attrs = property->getPropertyAttributes();
256 // For read-only properties, clear the copy and retain flags
257 if (attrs & ObjCPropertyDecl::OBJC_PR_readonly) {
258 attrs &= ~ObjCPropertyDecl::OBJC_PR_copy;
259 attrs &= ~ObjCPropertyDecl::OBJC_PR_retain;
260 attrs &= ~ObjCPropertyDecl::OBJC_PR_weak;
261 attrs &= ~ObjCPropertyDecl::OBJC_PR_strong;
263 // The first flags field has the same attribute values as clang uses internally
264 Fields.addInt(Int8Ty, attrs & 0xff);
267 // For protocol properties, synthesized and dynamic have no meaning, so we
268 // reuse these flags to indicate that this is a protocol property (both set
269 // has no meaning, as a property can't be both synthesized and dynamic)
270 attrs |= isSynthesized ? (1<<0) : 0;
271 attrs |= isDynamic ? (1<<1) : 0;
272 // The second field is the next four fields left shifted by two, with the
273 // low bit set to indicate whether the field is synthesized or dynamic.
274 Fields.addInt(Int8Ty, attrs & 0xff);
275 // Two padding fields
276 Fields.addInt(Int8Ty, 0);
277 Fields.addInt(Int8Ty, 0);
280 virtual ConstantArrayBuilder PushPropertyListHeader(ConstantStructBuilder &Fields,
283 Fields.addInt(IntTy, count);
284 // int size; (only in GNUstep v2 ABI.
285 if (isRuntime(ObjCRuntime::GNUstep, 2)) {
286 llvm::DataLayout td(&TheModule);
287 Fields.addInt(IntTy, td.getTypeSizeInBits(PropertyMetadataTy) /
288 CGM.getContext().getCharWidth());
290 // struct objc_property_list *next;
292 // struct objc_property properties[]
293 return Fields.beginArray(PropertyMetadataTy);
295 virtual void PushProperty(ConstantArrayBuilder &PropertiesArray,
296 const ObjCPropertyDecl *property,
298 bool isSynthesized=true, bool
300 auto Fields = PropertiesArray.beginStruct(PropertyMetadataTy);
301 ASTContext &Context = CGM.getContext();
302 Fields.add(MakePropertyEncodingString(property, OCD));
303 PushPropertyAttributes(Fields, property, isSynthesized, isDynamic);
304 auto addPropertyMethod = [&](const ObjCMethodDecl *accessor) {
306 std::string TypeStr = Context.getObjCEncodingForMethodDecl(accessor);
307 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
308 Fields.add(MakeConstantString(accessor->getSelector().getAsString()));
309 Fields.add(TypeEncoding);
315 addPropertyMethod(property->getGetterMethodDecl());
316 addPropertyMethod(property->getSetterMethodDecl());
317 Fields.finishAndAddTo(PropertiesArray);
320 /// Ensures that the value has the required type, by inserting a bitcast if
321 /// required. This function lets us avoid inserting bitcasts that are
323 llvm::Value* EnforceType(CGBuilderTy &B, llvm::Value *V, llvm::Type *Ty) {
324 if (V->getType() == Ty) return V;
325 return B.CreateBitCast(V, Ty);
327 Address EnforceType(CGBuilderTy &B, Address V, llvm::Type *Ty) {
328 if (V.getType() == Ty) return V;
329 return B.CreateBitCast(V, Ty);
332 // Some zeros used for GEPs in lots of places.
333 llvm::Constant *Zeros[2];
334 /// Null pointer value. Mainly used as a terminator in various arrays.
335 llvm::Constant *NULLPtr;
337 llvm::LLVMContext &VMContext;
341 /// Placeholder for the class. Lots of things refer to the class before we've
342 /// actually emitted it. We use this alias as a placeholder, and then replace
343 /// it with a pointer to the class structure before finally emitting the
345 llvm::GlobalAlias *ClassPtrAlias;
346 /// Placeholder for the metaclass. Lots of things refer to the class before
347 /// we've / actually emitted it. We use this alias as a placeholder, and then
348 /// replace / it with a pointer to the metaclass structure before finally
349 /// emitting the / module.
350 llvm::GlobalAlias *MetaClassPtrAlias;
351 /// All of the classes that have been generated for this compilation units.
352 std::vector<llvm::Constant*> Classes;
353 /// All of the categories that have been generated for this compilation units.
354 std::vector<llvm::Constant*> Categories;
355 /// All of the Objective-C constant strings that have been generated for this
356 /// compilation units.
357 std::vector<llvm::Constant*> ConstantStrings;
358 /// Map from string values to Objective-C constant strings in the output.
359 /// Used to prevent emitting Objective-C strings more than once. This should
360 /// not be required at all - CodeGenModule should manage this list.
361 llvm::StringMap<llvm::Constant*> ObjCStrings;
362 /// All of the protocols that have been declared.
363 llvm::StringMap<llvm::Constant*> ExistingProtocols;
364 /// For each variant of a selector, we store the type encoding and a
365 /// placeholder value. For an untyped selector, the type will be the empty
366 /// string. Selector references are all done via the module's selector table,
367 /// so we create an alias as a placeholder and then replace it with the real
369 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector;
370 /// Type of the selector map. This is roughly equivalent to the structure
371 /// used in the GNUstep runtime, which maintains a list of all of the valid
372 /// types for a selector in a table.
373 typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> >
375 /// A map from selectors to selector types. This allows us to emit all
376 /// selectors of the same name and type together.
377 SelectorMap SelectorTable;
379 /// Selectors related to memory management. When compiling in GC mode, we
381 Selector RetainSel, ReleaseSel, AutoreleaseSel;
382 /// Runtime functions used for memory management in GC mode. Note that clang
383 /// supports code generation for calling these functions, but neither GNU
384 /// runtime actually supports this API properly yet.
385 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn,
386 WeakAssignFn, GlobalAssignFn;
388 typedef std::pair<std::string, std::string> ClassAliasPair;
389 /// All classes that have aliases set for them.
390 std::vector<ClassAliasPair> ClassAliases;
393 /// Function used for throwing Objective-C exceptions.
394 LazyRuntimeFunction ExceptionThrowFn;
395 /// Function used for rethrowing exceptions, used at the end of \@finally or
396 /// \@synchronize blocks.
397 LazyRuntimeFunction ExceptionReThrowFn;
398 /// Function called when entering a catch function. This is required for
399 /// differentiating Objective-C exceptions and foreign exceptions.
400 LazyRuntimeFunction EnterCatchFn;
401 /// Function called when exiting from a catch block. Used to do exception
403 LazyRuntimeFunction ExitCatchFn;
404 /// Function called when entering an \@synchronize block. Acquires the lock.
405 LazyRuntimeFunction SyncEnterFn;
406 /// Function called when exiting an \@synchronize block. Releases the lock.
407 LazyRuntimeFunction SyncExitFn;
410 /// Function called if fast enumeration detects that the collection is
411 /// modified during the update.
412 LazyRuntimeFunction EnumerationMutationFn;
413 /// Function for implementing synthesized property getters that return an
415 LazyRuntimeFunction GetPropertyFn;
416 /// Function for implementing synthesized property setters that return an
418 LazyRuntimeFunction SetPropertyFn;
419 /// Function used for non-object declared property getters.
420 LazyRuntimeFunction GetStructPropertyFn;
421 /// Function used for non-object declared property setters.
422 LazyRuntimeFunction SetStructPropertyFn;
425 /// The version of the runtime that this class targets. Must match the
426 /// version in the runtime.
428 /// The version of the protocol class. Used to differentiate between ObjC1
429 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional
430 /// components and can not contain declared properties. We always emit
431 /// Objective-C 2 property structures, but we have to pretend that they're
432 /// Objective-C 1 property structures when targeting the GCC runtime or it
434 const int ProtocolVersion;
435 /// The version of the class ABI. This value is used in the class structure
436 /// and indicates how various fields should be interpreted.
437 const int ClassABIVersion;
438 /// Generates an instance variable list structure. This is a structure
439 /// containing a size and an array of structures containing instance variable
440 /// metadata. This is used purely for introspection in the fragile ABI. In
441 /// the non-fragile ABI, it's used for instance variable fixup.
442 virtual llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
443 ArrayRef<llvm::Constant *> IvarTypes,
444 ArrayRef<llvm::Constant *> IvarOffsets,
445 ArrayRef<llvm::Constant *> IvarAlign,
446 ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership);
448 /// Generates a method list structure. This is a structure containing a size
449 /// and an array of structures containing method metadata.
451 /// This structure is used by both classes and categories, and contains a next
452 /// pointer allowing them to be chained together in a linked list.
453 llvm::Constant *GenerateMethodList(StringRef ClassName,
454 StringRef CategoryName,
455 ArrayRef<const ObjCMethodDecl*> Methods,
456 bool isClassMethodList);
458 /// Emits an empty protocol. This is used for \@protocol() where no protocol
459 /// is found. The runtime will (hopefully) fix up the pointer to refer to the
461 virtual llvm::Constant *GenerateEmptyProtocol(StringRef ProtocolName);
463 /// Generates a list of property metadata structures. This follows the same
464 /// pattern as method and instance variable metadata lists.
465 llvm::Constant *GeneratePropertyList(const Decl *Container,
466 const ObjCContainerDecl *OCD,
467 bool isClassProperty=false,
468 bool protocolOptionalProperties=false);
470 /// Generates a list of referenced protocols. Classes, categories, and
471 /// protocols all use this structure.
472 llvm::Constant *GenerateProtocolList(ArrayRef<std::string> Protocols);
474 /// To ensure that all protocols are seen by the runtime, we add a category on
475 /// a class defined in the runtime, declaring no methods, but adopting the
476 /// protocols. This is a horribly ugly hack, but it allows us to collect all
477 /// of the protocols without changing the ABI.
478 void GenerateProtocolHolderCategory();
480 /// Generates a class structure.
481 llvm::Constant *GenerateClassStructure(
482 llvm::Constant *MetaClass,
483 llvm::Constant *SuperClass,
486 llvm::Constant *Version,
487 llvm::Constant *InstanceSize,
488 llvm::Constant *IVars,
489 llvm::Constant *Methods,
490 llvm::Constant *Protocols,
491 llvm::Constant *IvarOffsets,
492 llvm::Constant *Properties,
493 llvm::Constant *StrongIvarBitmap,
494 llvm::Constant *WeakIvarBitmap,
497 /// Generates a method list. This is used by protocols to define the required
498 /// and optional methods.
499 virtual llvm::Constant *GenerateProtocolMethodList(
500 ArrayRef<const ObjCMethodDecl*> Methods);
501 /// Emits optional and required method lists.
503 void EmitProtocolMethodList(T &&Methods, llvm::Constant *&Required,
504 llvm::Constant *&Optional) {
505 SmallVector<const ObjCMethodDecl*, 16> RequiredMethods;
506 SmallVector<const ObjCMethodDecl*, 16> OptionalMethods;
507 for (const auto *I : Methods)
509 OptionalMethods.push_back(I);
511 RequiredMethods.push_back(I);
512 Required = GenerateProtocolMethodList(RequiredMethods);
513 Optional = GenerateProtocolMethodList(OptionalMethods);
516 /// Returns a selector with the specified type encoding. An empty string is
517 /// used to return an untyped selector (with the types field set to NULL).
518 virtual llvm::Value *GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
519 const std::string &TypeEncoding);
521 /// Returns the name of ivar offset variables. In the GNUstep v1 ABI, this
522 /// contains the class and ivar names, in the v2 ABI this contains the type
523 /// encoding as well.
524 virtual std::string GetIVarOffsetVariableName(const ObjCInterfaceDecl *ID,
525 const ObjCIvarDecl *Ivar) {
526 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString()
527 + '.' + Ivar->getNameAsString();
530 /// Returns the variable used to store the offset of an instance variable.
531 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID,
532 const ObjCIvarDecl *Ivar);
533 /// Emits a reference to a class. This allows the linker to object if there
534 /// is no class of the matching name.
535 void EmitClassRef(const std::string &className);
537 /// Emits a pointer to the named class
538 virtual llvm::Value *GetClassNamed(CodeGenFunction &CGF,
539 const std::string &Name, bool isWeak);
541 /// Looks up the method for sending a message to the specified object. This
542 /// mechanism differs between the GCC and GNU runtimes, so this method must be
543 /// overridden in subclasses.
544 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF,
545 llvm::Value *&Receiver,
548 MessageSendInfo &MSI) = 0;
550 /// Looks up the method for sending a message to a superclass. This
551 /// mechanism differs between the GCC and GNU runtimes, so this method must
552 /// be overridden in subclasses.
553 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF,
556 MessageSendInfo &MSI) = 0;
558 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are
559 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63
560 /// bits set to their values, LSB first, while larger ones are stored in a
561 /// structure of this / form:
563 /// struct { int32_t length; int32_t values[length]; };
565 /// The values in the array are stored in host-endian format, with the least
566 /// significant bit being assumed to come first in the bitfield. Therefore,
567 /// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] },
568 /// while a bitfield / with the 63rd bit set will be 1<<64.
569 llvm::Constant *MakeBitField(ArrayRef<bool> bits);
572 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
573 unsigned protocolClassVersion, unsigned classABI=1);
575 ConstantAddress GenerateConstantString(const StringLiteral *) override;
578 GenerateMessageSend(CodeGenFunction &CGF, ReturnValueSlot Return,
579 QualType ResultType, Selector Sel,
580 llvm::Value *Receiver, const CallArgList &CallArgs,
581 const ObjCInterfaceDecl *Class,
582 const ObjCMethodDecl *Method) override;
584 GenerateMessageSendSuper(CodeGenFunction &CGF, ReturnValueSlot Return,
585 QualType ResultType, Selector Sel,
586 const ObjCInterfaceDecl *Class,
587 bool isCategoryImpl, llvm::Value *Receiver,
588 bool IsClassMessage, const CallArgList &CallArgs,
589 const ObjCMethodDecl *Method) override;
590 llvm::Value *GetClass(CodeGenFunction &CGF,
591 const ObjCInterfaceDecl *OID) override;
592 llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel) override;
593 Address GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) override;
594 llvm::Value *GetSelector(CodeGenFunction &CGF,
595 const ObjCMethodDecl *Method) override;
596 virtual llvm::Constant *GetConstantSelector(Selector Sel,
597 const std::string &TypeEncoding) {
598 llvm_unreachable("Runtime unable to generate constant selector");
600 llvm::Constant *GetConstantSelector(const ObjCMethodDecl *M) {
601 return GetConstantSelector(M->getSelector(),
602 CGM.getContext().getObjCEncodingForMethodDecl(M));
604 llvm::Constant *GetEHType(QualType T) override;
606 llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
607 const ObjCContainerDecl *CD) override;
608 void GenerateCategory(const ObjCCategoryImplDecl *CMD) override;
609 void GenerateClass(const ObjCImplementationDecl *ClassDecl) override;
610 void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) override;
611 llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
612 const ObjCProtocolDecl *PD) override;
613 void GenerateProtocol(const ObjCProtocolDecl *PD) override;
614 llvm::Function *ModuleInitFunction() override;
615 llvm::Constant *GetPropertyGetFunction() override;
616 llvm::Constant *GetPropertySetFunction() override;
617 llvm::Constant *GetOptimizedPropertySetFunction(bool atomic,
619 llvm::Constant *GetSetStructFunction() override;
620 llvm::Constant *GetGetStructFunction() override;
621 llvm::Constant *GetCppAtomicObjectGetFunction() override;
622 llvm::Constant *GetCppAtomicObjectSetFunction() override;
623 llvm::Constant *EnumerationMutationFunction() override;
625 void EmitTryStmt(CodeGenFunction &CGF,
626 const ObjCAtTryStmt &S) override;
627 void EmitSynchronizedStmt(CodeGenFunction &CGF,
628 const ObjCAtSynchronizedStmt &S) override;
629 void EmitThrowStmt(CodeGenFunction &CGF,
630 const ObjCAtThrowStmt &S,
631 bool ClearInsertionPoint=true) override;
632 llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF,
633 Address AddrWeakObj) override;
634 void EmitObjCWeakAssign(CodeGenFunction &CGF,
635 llvm::Value *src, Address dst) override;
636 void EmitObjCGlobalAssign(CodeGenFunction &CGF,
637 llvm::Value *src, Address dest,
638 bool threadlocal=false) override;
639 void EmitObjCIvarAssign(CodeGenFunction &CGF, llvm::Value *src,
640 Address dest, llvm::Value *ivarOffset) override;
641 void EmitObjCStrongCastAssign(CodeGenFunction &CGF,
642 llvm::Value *src, Address dest) override;
643 void EmitGCMemmoveCollectable(CodeGenFunction &CGF, Address DestPtr,
645 llvm::Value *Size) override;
646 LValue EmitObjCValueForIvar(CodeGenFunction &CGF, QualType ObjectTy,
647 llvm::Value *BaseValue, const ObjCIvarDecl *Ivar,
648 unsigned CVRQualifiers) override;
649 llvm::Value *EmitIvarOffset(CodeGenFunction &CGF,
650 const ObjCInterfaceDecl *Interface,
651 const ObjCIvarDecl *Ivar) override;
652 llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) override;
653 llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM,
654 const CGBlockInfo &blockInfo) override {
657 llvm::Constant *BuildRCBlockLayout(CodeGenModule &CGM,
658 const CGBlockInfo &blockInfo) override {
662 llvm::Constant *BuildByrefLayout(CodeGenModule &CGM, QualType T) override {
667 /// Class representing the legacy GCC Objective-C ABI. This is the default when
668 /// -fobjc-nonfragile-abi is not specified.
670 /// The GCC ABI target actually generates code that is approximately compatible
671 /// with the new GNUstep runtime ABI, but refrains from using any features that
672 /// would not work with the GCC runtime. For example, clang always generates
673 /// the extended form of the class structure, and the extra fields are simply
674 /// ignored by GCC libobjc.
675 class CGObjCGCC : public CGObjCGNU {
676 /// The GCC ABI message lookup function. Returns an IMP pointing to the
677 /// method implementation for this message.
678 LazyRuntimeFunction MsgLookupFn;
679 /// The GCC ABI superclass message lookup function. Takes a pointer to a
680 /// structure describing the receiver and the class, and a selector as
681 /// arguments. Returns the IMP for the corresponding method.
682 LazyRuntimeFunction MsgLookupSuperFn;
685 llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
686 llvm::Value *cmd, llvm::MDNode *node,
687 MessageSendInfo &MSI) override {
688 CGBuilderTy &Builder = CGF.Builder;
689 llvm::Value *args[] = {
690 EnforceType(Builder, Receiver, IdTy),
691 EnforceType(Builder, cmd, SelectorTy) };
692 llvm::CallSite imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);
693 imp->setMetadata(msgSendMDKind, node);
694 return imp.getInstruction();
697 llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
698 llvm::Value *cmd, MessageSendInfo &MSI) override {
699 CGBuilderTy &Builder = CGF.Builder;
700 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper,
701 PtrToObjCSuperTy).getPointer(), cmd};
702 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
706 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) {
707 // IMP objc_msg_lookup(id, SEL);
708 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy);
709 // IMP objc_msg_lookup_super(struct objc_super*, SEL);
710 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
711 PtrToObjCSuperTy, SelectorTy);
715 /// Class used when targeting the new GNUstep runtime ABI.
716 class CGObjCGNUstep : public CGObjCGNU {
717 /// The slot lookup function. Returns a pointer to a cacheable structure
718 /// that contains (among other things) the IMP.
719 LazyRuntimeFunction SlotLookupFn;
720 /// The GNUstep ABI superclass message lookup function. Takes a pointer to
721 /// a structure describing the receiver and the class, and a selector as
722 /// arguments. Returns the slot for the corresponding method. Superclass
723 /// message lookup rarely changes, so this is a good caching opportunity.
724 LazyRuntimeFunction SlotLookupSuperFn;
725 /// Specialised function for setting atomic retain properties
726 LazyRuntimeFunction SetPropertyAtomic;
727 /// Specialised function for setting atomic copy properties
728 LazyRuntimeFunction SetPropertyAtomicCopy;
729 /// Specialised function for setting nonatomic retain properties
730 LazyRuntimeFunction SetPropertyNonAtomic;
731 /// Specialised function for setting nonatomic copy properties
732 LazyRuntimeFunction SetPropertyNonAtomicCopy;
733 /// Function to perform atomic copies of C++ objects with nontrivial copy
734 /// constructors from Objective-C ivars.
735 LazyRuntimeFunction CxxAtomicObjectGetFn;
736 /// Function to perform atomic copies of C++ objects with nontrivial copy
737 /// constructors to Objective-C ivars.
738 LazyRuntimeFunction CxxAtomicObjectSetFn;
739 /// Type of an slot structure pointer. This is returned by the various
740 /// lookup functions.
744 llvm::Constant *GetEHType(QualType T) override;
747 llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
748 llvm::Value *cmd, llvm::MDNode *node,
749 MessageSendInfo &MSI) override {
750 CGBuilderTy &Builder = CGF.Builder;
751 llvm::Function *LookupFn = SlotLookupFn;
753 // Store the receiver on the stack so that we can reload it later
754 Address ReceiverPtr =
755 CGF.CreateTempAlloca(Receiver->getType(), CGF.getPointerAlign());
756 Builder.CreateStore(Receiver, ReceiverPtr);
760 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) {
761 self = CGF.LoadObjCSelf();
763 self = llvm::ConstantPointerNull::get(IdTy);
766 // The lookup function is guaranteed not to capture the receiver pointer.
767 LookupFn->addParamAttr(0, llvm::Attribute::NoCapture);
769 llvm::Value *args[] = {
770 EnforceType(Builder, ReceiverPtr.getPointer(), PtrToIdTy),
771 EnforceType(Builder, cmd, SelectorTy),
772 EnforceType(Builder, self, IdTy) };
773 llvm::CallSite slot = CGF.EmitRuntimeCallOrInvoke(LookupFn, args);
774 slot.setOnlyReadsMemory();
775 slot->setMetadata(msgSendMDKind, node);
777 // Load the imp from the slot
778 llvm::Value *imp = Builder.CreateAlignedLoad(
779 Builder.CreateStructGEP(nullptr, slot.getInstruction(), 4),
780 CGF.getPointerAlign());
782 // The lookup function may have changed the receiver, so make sure we use
784 Receiver = Builder.CreateLoad(ReceiverPtr, true);
788 llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
790 MessageSendInfo &MSI) override {
791 CGBuilderTy &Builder = CGF.Builder;
792 llvm::Value *lookupArgs[] = {ObjCSuper.getPointer(), cmd};
794 llvm::CallInst *slot =
795 CGF.EmitNounwindRuntimeCall(SlotLookupSuperFn, lookupArgs);
796 slot->setOnlyReadsMemory();
798 return Builder.CreateAlignedLoad(Builder.CreateStructGEP(nullptr, slot, 4),
799 CGF.getPointerAlign());
803 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNUstep(Mod, 9, 3, 1) {}
804 CGObjCGNUstep(CodeGenModule &Mod, unsigned ABI, unsigned ProtocolABI,
806 CGObjCGNU(Mod, ABI, ProtocolABI, ClassABI) {
807 const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
809 llvm::StructType *SlotStructTy =
810 llvm::StructType::get(PtrTy, PtrTy, PtrTy, IntTy, IMPTy);
811 SlotTy = llvm::PointerType::getUnqual(SlotStructTy);
812 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender);
813 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy,
815 // Slot_t objc_slot_lookup_super(struct objc_super*, SEL);
816 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy,
817 PtrToObjCSuperTy, SelectorTy);
818 // If we're in ObjC++ mode, then we want to make
819 if (usesSEHExceptions) {
820 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
821 // void objc_exception_rethrow(void)
822 ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy);
823 } else if (CGM.getLangOpts().CPlusPlus) {
824 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
825 // void *__cxa_begin_catch(void *e)
826 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy);
827 // void __cxa_end_catch(void)
828 ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy);
829 // void _Unwind_Resume_or_Rethrow(void*)
830 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy,
832 } else if (R.getVersion() >= VersionTuple(1, 7)) {
833 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
834 // id objc_begin_catch(void *e)
835 EnterCatchFn.init(&CGM, "objc_begin_catch", IdTy, PtrTy);
836 // void objc_end_catch(void)
837 ExitCatchFn.init(&CGM, "objc_end_catch", VoidTy);
838 // void _Unwind_Resume_or_Rethrow(void*)
839 ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy, PtrTy);
841 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
842 SetPropertyAtomic.init(&CGM, "objc_setProperty_atomic", VoidTy, IdTy,
843 SelectorTy, IdTy, PtrDiffTy);
844 SetPropertyAtomicCopy.init(&CGM, "objc_setProperty_atomic_copy", VoidTy,
845 IdTy, SelectorTy, IdTy, PtrDiffTy);
846 SetPropertyNonAtomic.init(&CGM, "objc_setProperty_nonatomic", VoidTy,
847 IdTy, SelectorTy, IdTy, PtrDiffTy);
848 SetPropertyNonAtomicCopy.init(&CGM, "objc_setProperty_nonatomic_copy",
849 VoidTy, IdTy, SelectorTy, IdTy, PtrDiffTy);
850 // void objc_setCppObjectAtomic(void *dest, const void *src, void
852 CxxAtomicObjectSetFn.init(&CGM, "objc_setCppObjectAtomic", VoidTy, PtrTy,
854 // void objc_getCppObjectAtomic(void *dest, const void *src, void
856 CxxAtomicObjectGetFn.init(&CGM, "objc_getCppObjectAtomic", VoidTy, PtrTy,
860 llvm::Constant *GetCppAtomicObjectGetFunction() override {
861 // The optimised functions were added in version 1.7 of the GNUstep
863 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
865 return CxxAtomicObjectGetFn;
868 llvm::Constant *GetCppAtomicObjectSetFunction() override {
869 // The optimised functions were added in version 1.7 of the GNUstep
871 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
873 return CxxAtomicObjectSetFn;
876 llvm::Constant *GetOptimizedPropertySetFunction(bool atomic,
877 bool copy) override {
878 // The optimised property functions omit the GC check, and so are not
879 // safe to use in GC mode. The standard functions are fast in GC mode,
880 // so there is less advantage in using them.
881 assert ((CGM.getLangOpts().getGC() == LangOptions::NonGC));
882 // The optimised functions were added in version 1.7 of the GNUstep
884 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
888 if (copy) return SetPropertyAtomicCopy;
889 return SetPropertyAtomic;
892 return copy ? SetPropertyNonAtomicCopy : SetPropertyNonAtomic;
896 /// GNUstep Objective-C ABI version 2 implementation.
897 /// This is the ABI that provides a clean break with the legacy GCC ABI and
898 /// cleans up a number of things that were added to work around 1980s linkers.
899 class CGObjCGNUstep2 : public CGObjCGNUstep {
904 ClassReferenceSection,
907 ProtocolReferenceSection,
909 ConstantStringSection
911 static const char *const SectionsBaseNames[8];
912 template<SectionKind K>
913 std::string sectionName() {
914 std::string name(SectionsBaseNames[K]);
915 if (CGM.getTriple().isOSBinFormatCOFF())
919 /// The GCC ABI superclass message lookup function. Takes a pointer to a
920 /// structure describing the receiver and the class, and a selector as
921 /// arguments. Returns the IMP for the corresponding method.
922 LazyRuntimeFunction MsgLookupSuperFn;
923 /// A flag indicating if we've emitted at least one protocol.
924 /// If we haven't, then we need to emit an empty protocol, to ensure that the
925 /// __start__objc_protocols and __stop__objc_protocols sections exist.
926 bool EmittedProtocol = false;
927 /// A flag indicating if we've emitted at least one protocol reference.
928 /// If we haven't, then we need to emit an empty protocol, to ensure that the
929 /// __start__objc_protocol_refs and __stop__objc_protocol_refs sections
931 bool EmittedProtocolRef = false;
932 /// A flag indicating if we've emitted at least one class.
933 /// If we haven't, then we need to emit an empty protocol, to ensure that the
934 /// __start__objc_classes and __stop__objc_classes sections / exist.
935 bool EmittedClass = false;
936 /// Generate the name of a symbol for a reference to a class. Accesses to
937 /// classes should be indirected via this.
938 std::string SymbolForClassRef(StringRef Name, bool isWeak) {
940 return (StringRef("._OBJC_WEAK_REF_CLASS_") + Name).str();
942 return (StringRef("._OBJC_REF_CLASS_") + Name).str();
944 /// Generate the name of a class symbol.
945 std::string SymbolForClass(StringRef Name) {
946 return (StringRef("._OBJC_CLASS_") + Name).str();
948 void CallRuntimeFunction(CGBuilderTy &B, StringRef FunctionName,
949 ArrayRef<llvm::Value*> Args) {
950 SmallVector<llvm::Type *,8> Types;
951 for (auto *Arg : Args)
952 Types.push_back(Arg->getType());
953 llvm::FunctionType *FT = llvm::FunctionType::get(B.getVoidTy(), Types,
955 llvm::Value *Fn = CGM.CreateRuntimeFunction(FT, FunctionName);
956 B.CreateCall(Fn, Args);
959 ConstantAddress GenerateConstantString(const StringLiteral *SL) override {
961 auto Str = SL->getString();
962 CharUnits Align = CGM.getPointerAlign();
964 // Look for an existing one
965 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str);
966 if (old != ObjCStrings.end())
967 return ConstantAddress(old->getValue(), Align);
969 bool isNonASCII = SL->containsNonAscii();
971 auto LiteralLength = SL->getLength();
973 if ((CGM.getTarget().getPointerWidth(0) == 64) &&
974 (LiteralLength < 9) && !isNonASCII) {
975 // Tiny strings are only used on 64-bit platforms. They store 8 7-bit
976 // ASCII characters in the high 56 bits, followed by a 4-bit length and a
977 // 3-bit tag (which is always 4).
979 // Fill in the characters
980 for (unsigned i=0 ; i<LiteralLength ; i++)
981 str |= ((uint64_t)SL->getCodeUnit(i)) << ((64 - 4 - 3) - (i*7));
982 // Fill in the length
983 str |= LiteralLength << 3;
986 auto *ObjCStr = llvm::ConstantExpr::getIntToPtr(
987 llvm::ConstantInt::get(Int64Ty, str), IdTy);
988 ObjCStrings[Str] = ObjCStr;
989 return ConstantAddress(ObjCStr, Align);
992 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass;
994 if (StringClass.empty()) StringClass = "NSConstantString";
996 std::string Sym = SymbolForClass(StringClass);
998 llvm::Constant *isa = TheModule.getNamedGlobal(Sym);
1001 isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false,
1002 llvm::GlobalValue::ExternalLinkage, nullptr, Sym);
1003 else if (isa->getType() != PtrToIdTy)
1004 isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy);
1010 // uint32_t length; // Number of codepoints
1011 // uint32_t size; // Number of bytes
1013 // const char *data;
1016 ConstantInitBuilder Builder(CGM);
1017 auto Fields = Builder.beginStruct();
1019 // For now, all non-ASCII strings are represented as UTF-16. As such, the
1020 // number of bytes is simply double the number of UTF-16 codepoints. In
1021 // ASCII strings, the number of bytes is equal to the number of non-ASCII
1024 unsigned NumU8CodeUnits = Str.size();
1025 // A UTF-16 representation of a unicode string contains at most the same
1026 // number of code units as a UTF-8 representation. Allocate that much
1027 // space, plus one for the final null character.
1028 SmallVector<llvm::UTF16, 128> ToBuf(NumU8CodeUnits + 1);
1029 const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)Str.data();
1030 llvm::UTF16 *ToPtr = &ToBuf[0];
1031 (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumU8CodeUnits,
1032 &ToPtr, ToPtr + NumU8CodeUnits, llvm::strictConversion);
1033 uint32_t StringLength = ToPtr - &ToBuf[0];
1034 // Add null terminator
1036 // Flags: 2 indicates UTF-16 encoding
1037 Fields.addInt(Int32Ty, 2);
1038 // Number of UTF-16 codepoints
1039 Fields.addInt(Int32Ty, StringLength);
1041 Fields.addInt(Int32Ty, StringLength * 2);
1042 // Hash. Not currently initialised by the compiler.
1043 Fields.addInt(Int32Ty, 0);
1044 // pointer to the data string.
1045 auto Arr = llvm::makeArrayRef(&ToBuf[0], ToPtr+1);
1046 auto *C = llvm::ConstantDataArray::get(VMContext, Arr);
1047 auto *Buffer = new llvm::GlobalVariable(TheModule, C->getType(),
1048 /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, C, ".str");
1049 Buffer->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1052 // Flags: 0 indicates ASCII encoding
1053 Fields.addInt(Int32Ty, 0);
1054 // Number of UTF-16 codepoints, each ASCII byte is a UTF-16 codepoint
1055 Fields.addInt(Int32Ty, Str.size());
1057 Fields.addInt(Int32Ty, Str.size());
1058 // Hash. Not currently initialised by the compiler.
1059 Fields.addInt(Int32Ty, 0);
1061 Fields.add(MakeConstantString(Str));
1063 std::string StringName;
1064 bool isNamed = !isNonASCII;
1066 StringName = ".objc_str_";
1067 for (int i=0,e=Str.size() ; i<e ; ++i) {
1068 unsigned char c = Str[i];
1080 Fields.finishAndCreateGlobal(
1081 isNamed ? StringRef(StringName) : ".objc_string",
1082 Align, false, isNamed ? llvm::GlobalValue::LinkOnceODRLinkage
1083 : llvm::GlobalValue::PrivateLinkage);
1084 ObjCStrGV->setSection(sectionName<ConstantStringSection>());
1086 ObjCStrGV->setComdat(TheModule.getOrInsertComdat(StringName));
1087 ObjCStrGV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1089 llvm::Constant *ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStrGV, IdTy);
1090 ObjCStrings[Str] = ObjCStr;
1091 ConstantStrings.push_back(ObjCStr);
1092 return ConstantAddress(ObjCStr, Align);
1095 void PushProperty(ConstantArrayBuilder &PropertiesArray,
1096 const ObjCPropertyDecl *property,
1098 bool isSynthesized=true, bool
1099 isDynamic=true) override {
1100 // struct objc_property
1102 // const char *name;
1103 // const char *attributes;
1104 // const char *type;
1108 auto Fields = PropertiesArray.beginStruct(PropertyMetadataTy);
1109 ASTContext &Context = CGM.getContext();
1110 Fields.add(MakeConstantString(property->getNameAsString()));
1111 std::string TypeStr =
1112 CGM.getContext().getObjCEncodingForPropertyDecl(property, OCD);
1113 Fields.add(MakeConstantString(TypeStr));
1114 std::string typeStr;
1115 Context.getObjCEncodingForType(property->getType(), typeStr);
1116 Fields.add(MakeConstantString(typeStr));
1117 auto addPropertyMethod = [&](const ObjCMethodDecl *accessor) {
1119 std::string TypeStr = Context.getObjCEncodingForMethodDecl(accessor);
1120 Fields.add(GetConstantSelector(accessor->getSelector(), TypeStr));
1122 Fields.add(NULLPtr);
1125 addPropertyMethod(property->getGetterMethodDecl());
1126 addPropertyMethod(property->getSetterMethodDecl());
1127 Fields.finishAndAddTo(PropertiesArray);
1131 GenerateProtocolMethodList(ArrayRef<const ObjCMethodDecl*> Methods) override {
1132 // struct objc_protocol_method_description
1135 // const char *types;
1137 llvm::StructType *ObjCMethodDescTy =
1138 llvm::StructType::get(CGM.getLLVMContext(),
1139 { PtrToInt8Ty, PtrToInt8Ty });
1140 ASTContext &Context = CGM.getContext();
1141 ConstantInitBuilder Builder(CGM);
1142 // struct objc_protocol_method_description_list
1146 // struct objc_protocol_method_description methods[];
1148 auto MethodList = Builder.beginStruct();
1150 MethodList.addInt(IntTy, Methods.size());
1151 // int size; // sizeof(struct objc_method_description)
1152 llvm::DataLayout td(&TheModule);
1153 MethodList.addInt(IntTy, td.getTypeSizeInBits(ObjCMethodDescTy) /
1154 CGM.getContext().getCharWidth());
1155 // struct objc_method_description[]
1156 auto MethodArray = MethodList.beginArray(ObjCMethodDescTy);
1157 for (auto *M : Methods) {
1158 auto Method = MethodArray.beginStruct(ObjCMethodDescTy);
1159 Method.add(CGObjCGNU::GetConstantSelector(M));
1160 Method.add(GetTypeString(Context.getObjCEncodingForMethodDecl(M, true)));
1161 Method.finishAndAddTo(MethodArray);
1163 MethodArray.finishAndAddTo(MethodList);
1164 return MethodList.finishAndCreateGlobal(".objc_protocol_method_list",
1165 CGM.getPointerAlign());
1168 llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
1169 llvm::Value *cmd, MessageSendInfo &MSI) override {
1170 // Don't access the slot unless we're trying to cache the result.
1171 CGBuilderTy &Builder = CGF.Builder;
1172 llvm::Value *lookupArgs[] = {CGObjCGNU::EnforceType(Builder, ObjCSuper,
1173 PtrToObjCSuperTy).getPointer(), cmd};
1174 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
1177 llvm::GlobalVariable *GetClassVar(StringRef Name, bool isWeak=false) {
1178 std::string SymbolName = SymbolForClassRef(Name, isWeak);
1179 auto *ClassSymbol = TheModule.getNamedGlobal(SymbolName);
1182 ClassSymbol = new llvm::GlobalVariable(TheModule,
1183 IdTy, false, llvm::GlobalValue::ExternalLinkage,
1184 nullptr, SymbolName);
1185 // If this is a weak symbol, then we are creating a valid definition for
1186 // the symbol, pointing to a weak definition of the real class pointer. If
1187 // this is not a weak reference, then we are expecting another compilation
1188 // unit to provide the real indirection symbol.
1190 ClassSymbol->setInitializer(new llvm::GlobalVariable(TheModule,
1191 Int8Ty, false, llvm::GlobalValue::ExternalWeakLinkage,
1192 nullptr, SymbolForClass(Name)));
1193 assert(ClassSymbol->getName() == SymbolName);
1196 llvm::Value *GetClassNamed(CodeGenFunction &CGF,
1197 const std::string &Name,
1198 bool isWeak) override {
1199 return CGF.Builder.CreateLoad(Address(GetClassVar(Name, isWeak),
1200 CGM.getPointerAlign()));
1202 int32_t FlagsForOwnership(Qualifiers::ObjCLifetime Ownership) {
1204 // ownership_invalid = 0,
1205 // ownership_strong = 1,
1206 // ownership_weak = 2,
1207 // ownership_unsafe = 3
1208 // } ivar_ownership;
1210 switch (Ownership) {
1211 case Qualifiers::OCL_Strong:
1214 case Qualifiers::OCL_Weak:
1217 case Qualifiers::OCL_ExplicitNone:
1220 case Qualifiers::OCL_None:
1221 case Qualifiers::OCL_Autoreleasing:
1222 assert(Ownership != Qualifiers::OCL_Autoreleasing);
1227 llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
1228 ArrayRef<llvm::Constant *> IvarTypes,
1229 ArrayRef<llvm::Constant *> IvarOffsets,
1230 ArrayRef<llvm::Constant *> IvarAlign,
1231 ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership) override {
1232 llvm_unreachable("Method should not be called!");
1235 llvm::Constant *GenerateEmptyProtocol(StringRef ProtocolName) override {
1236 std::string Name = SymbolForProtocol(ProtocolName);
1237 auto *GV = TheModule.getGlobalVariable(Name);
1239 // Emit a placeholder symbol.
1240 GV = new llvm::GlobalVariable(TheModule, ProtocolTy, false,
1241 llvm::GlobalValue::ExternalLinkage, nullptr, Name);
1242 GV->setAlignment(CGM.getPointerAlign().getQuantity());
1244 return llvm::ConstantExpr::getBitCast(GV, ProtocolPtrTy);
1247 /// Existing protocol references.
1248 llvm::StringMap<llvm::Constant*> ExistingProtocolRefs;
1250 llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
1251 const ObjCProtocolDecl *PD) override {
1252 auto Name = PD->getNameAsString();
1253 auto *&Ref = ExistingProtocolRefs[Name];
1255 auto *&Protocol = ExistingProtocols[Name];
1257 Protocol = GenerateProtocolRef(PD);
1258 std::string RefName = SymbolForProtocolRef(Name);
1259 assert(!TheModule.getGlobalVariable(RefName));
1260 // Emit a reference symbol.
1261 auto GV = new llvm::GlobalVariable(TheModule, ProtocolPtrTy,
1262 false, llvm::GlobalValue::LinkOnceODRLinkage,
1263 llvm::ConstantExpr::getBitCast(Protocol, ProtocolPtrTy), RefName);
1264 GV->setComdat(TheModule.getOrInsertComdat(RefName));
1265 GV->setSection(sectionName<ProtocolReferenceSection>());
1266 GV->setAlignment(CGM.getPointerAlign().getQuantity());
1269 EmittedProtocolRef = true;
1270 return CGF.Builder.CreateAlignedLoad(Ref, CGM.getPointerAlign());
1273 llvm::Constant *GenerateProtocolList(ArrayRef<llvm::Constant*> Protocols) {
1274 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(ProtocolPtrTy,
1276 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy,
1278 ConstantInitBuilder builder(CGM);
1279 auto ProtocolBuilder = builder.beginStruct();
1280 ProtocolBuilder.addNullPointer(PtrTy);
1281 ProtocolBuilder.addInt(SizeTy, Protocols.size());
1282 ProtocolBuilder.add(ProtocolArray);
1283 return ProtocolBuilder.finishAndCreateGlobal(".objc_protocol_list",
1284 CGM.getPointerAlign(), false, llvm::GlobalValue::InternalLinkage);
1287 void GenerateProtocol(const ObjCProtocolDecl *PD) override {
1288 // Do nothing - we only emit referenced protocols.
1290 llvm::Constant *GenerateProtocolRef(const ObjCProtocolDecl *PD) {
1291 std::string ProtocolName = PD->getNameAsString();
1292 auto *&Protocol = ExistingProtocols[ProtocolName];
1296 EmittedProtocol = true;
1298 auto SymName = SymbolForProtocol(ProtocolName);
1299 auto *OldGV = TheModule.getGlobalVariable(SymName);
1301 // Use the protocol definition, if there is one.
1302 if (const ObjCProtocolDecl *Def = PD->getDefinition())
1305 // If there is no definition, then create an external linkage symbol and
1306 // hope that someone else fills it in for us (and fail to link if they
1309 Protocol = new llvm::GlobalVariable(TheModule, ProtocolTy,
1310 /*isConstant*/false,
1311 llvm::GlobalValue::ExternalLinkage, nullptr, SymName);
1315 SmallVector<llvm::Constant*, 16> Protocols;
1316 for (const auto *PI : PD->protocols())
1317 Protocols.push_back(
1318 llvm::ConstantExpr::getBitCast(GenerateProtocolRef(PI),
1320 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols);
1322 // Collect information about methods
1323 llvm::Constant *InstanceMethodList, *OptionalInstanceMethodList;
1324 llvm::Constant *ClassMethodList, *OptionalClassMethodList;
1325 EmitProtocolMethodList(PD->instance_methods(), InstanceMethodList,
1326 OptionalInstanceMethodList);
1327 EmitProtocolMethodList(PD->class_methods(), ClassMethodList,
1328 OptionalClassMethodList);
1330 // The isa pointer must be set to a magic number so the runtime knows it's
1331 // the correct layout.
1332 ConstantInitBuilder builder(CGM);
1333 auto ProtocolBuilder = builder.beginStruct();
1334 ProtocolBuilder.add(llvm::ConstantExpr::getIntToPtr(
1335 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
1336 ProtocolBuilder.add(MakeConstantString(ProtocolName));
1337 ProtocolBuilder.add(ProtocolList);
1338 ProtocolBuilder.add(InstanceMethodList);
1339 ProtocolBuilder.add(ClassMethodList);
1340 ProtocolBuilder.add(OptionalInstanceMethodList);
1341 ProtocolBuilder.add(OptionalClassMethodList);
1342 // Required instance properties
1343 ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, false, false));
1344 // Optional instance properties
1345 ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, false, true));
1346 // Required class properties
1347 ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, true, false));
1348 // Optional class properties
1349 ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, true, true));
1351 auto *GV = ProtocolBuilder.finishAndCreateGlobal(SymName,
1352 CGM.getPointerAlign(), false, llvm::GlobalValue::ExternalLinkage);
1353 GV->setSection(sectionName<ProtocolSection>());
1354 GV->setComdat(TheModule.getOrInsertComdat(SymName));
1356 OldGV->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GV,
1358 OldGV->removeFromParent();
1359 GV->setName(SymName);
1364 llvm::Constant *EnforceType(llvm::Constant *Val, llvm::Type *Ty) {
1365 if (Val->getType() == Ty)
1367 return llvm::ConstantExpr::getBitCast(Val, Ty);
1369 llvm::Value *GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
1370 const std::string &TypeEncoding) override {
1371 return GetConstantSelector(Sel, TypeEncoding);
1373 llvm::Constant *GetTypeString(llvm::StringRef TypeEncoding) {
1374 if (TypeEncoding.empty())
1376 std::string MangledTypes = TypeEncoding;
1377 std::replace(MangledTypes.begin(), MangledTypes.end(),
1379 std::string TypesVarName = ".objc_sel_types_" + MangledTypes;
1380 auto *TypesGlobal = TheModule.getGlobalVariable(TypesVarName);
1382 llvm::Constant *Init = llvm::ConstantDataArray::getString(VMContext,
1384 auto *GV = new llvm::GlobalVariable(TheModule, Init->getType(),
1385 true, llvm::GlobalValue::LinkOnceODRLinkage, Init, TypesVarName);
1386 GV->setComdat(TheModule.getOrInsertComdat(TypesVarName));
1387 GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1390 return llvm::ConstantExpr::getGetElementPtr(TypesGlobal->getValueType(),
1391 TypesGlobal, Zeros);
1393 llvm::Constant *GetConstantSelector(Selector Sel,
1394 const std::string &TypeEncoding) override {
1395 // @ is used as a special character in symbol names (used for symbol
1396 // versioning), so mangle the name to not include it. Replace it with a
1397 // character that is not a valid type encoding character (and, being
1398 // non-printable, never will be!)
1399 std::string MangledTypes = TypeEncoding;
1400 std::replace(MangledTypes.begin(), MangledTypes.end(),
1402 auto SelVarName = (StringRef(".objc_selector_") + Sel.getAsString() + "_" +
1403 MangledTypes).str();
1404 if (auto *GV = TheModule.getNamedGlobal(SelVarName))
1405 return EnforceType(GV, SelectorTy);
1406 ConstantInitBuilder builder(CGM);
1407 auto SelBuilder = builder.beginStruct();
1408 SelBuilder.add(ExportUniqueString(Sel.getAsString(), ".objc_sel_name_",
1410 SelBuilder.add(GetTypeString(TypeEncoding));
1411 auto *GV = SelBuilder.finishAndCreateGlobal(SelVarName,
1412 CGM.getPointerAlign(), false, llvm::GlobalValue::LinkOnceODRLinkage);
1413 GV->setComdat(TheModule.getOrInsertComdat(SelVarName));
1414 GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1415 GV->setSection(sectionName<SelectorSection>());
1416 auto *SelVal = EnforceType(GV, SelectorTy);
1419 llvm::StructType *emptyStruct = nullptr;
1421 /// Return pointers to the start and end of a section. On ELF platforms, we
1422 /// use the __start_ and __stop_ symbols that GNU-compatible linkers will set
1423 /// to the start and end of section names, as long as those section names are
1424 /// valid identifiers and the symbols are referenced but not defined. On
1425 /// Windows, we use the fact that MSVC-compatible linkers will lexically sort
1426 /// by subsections and place everything that we want to reference in a middle
1427 /// subsection and then insert zero-sized symbols in subsections a and z.
1428 std::pair<llvm::Constant*,llvm::Constant*>
1429 GetSectionBounds(StringRef Section) {
1430 if (CGM.getTriple().isOSBinFormatCOFF()) {
1431 if (emptyStruct == nullptr) {
1432 emptyStruct = llvm::StructType::create(VMContext, ".objc_section_sentinel");
1433 emptyStruct->setBody({}, /*isPacked*/true);
1435 auto ZeroInit = llvm::Constant::getNullValue(emptyStruct);
1436 auto Sym = [&](StringRef Prefix, StringRef SecSuffix) {
1437 auto *Sym = new llvm::GlobalVariable(TheModule, emptyStruct,
1438 /*isConstant*/false,
1439 llvm::GlobalValue::LinkOnceODRLinkage, ZeroInit, Prefix +
1441 Sym->setVisibility(llvm::GlobalValue::HiddenVisibility);
1442 Sym->setSection((Section + SecSuffix).str());
1443 Sym->setComdat(TheModule.getOrInsertComdat((Prefix +
1445 Sym->setAlignment(1);
1448 return { Sym("__start_", "$a"), Sym("__stop", "$z") };
1450 auto *Start = new llvm::GlobalVariable(TheModule, PtrTy,
1451 /*isConstant*/false,
1452 llvm::GlobalValue::ExternalLinkage, nullptr, StringRef("__start_") +
1454 Start->setVisibility(llvm::GlobalValue::HiddenVisibility);
1455 auto *Stop = new llvm::GlobalVariable(TheModule, PtrTy,
1456 /*isConstant*/false,
1457 llvm::GlobalValue::ExternalLinkage, nullptr, StringRef("__stop_") +
1459 Stop->setVisibility(llvm::GlobalValue::HiddenVisibility);
1460 return { Start, Stop };
1462 CatchTypeInfo getCatchAllTypeInfo() override {
1463 return CGM.getCXXABI().getCatchAllTypeInfo();
1465 llvm::Function *ModuleInitFunction() override {
1466 llvm::Function *LoadFunction = llvm::Function::Create(
1467 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false),
1468 llvm::GlobalValue::LinkOnceODRLinkage, ".objcv2_load_function",
1470 LoadFunction->setVisibility(llvm::GlobalValue::HiddenVisibility);
1471 LoadFunction->setComdat(TheModule.getOrInsertComdat(".objcv2_load_function"));
1473 llvm::BasicBlock *EntryBB =
1474 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction);
1475 CGBuilderTy B(CGM, VMContext);
1476 B.SetInsertPoint(EntryBB);
1477 ConstantInitBuilder builder(CGM);
1478 auto InitStructBuilder = builder.beginStruct();
1479 InitStructBuilder.addInt(Int64Ty, 0);
1480 for (auto *s : SectionsBaseNames) {
1481 auto bounds = GetSectionBounds(s);
1482 InitStructBuilder.add(bounds.first);
1483 InitStructBuilder.add(bounds.second);
1485 auto *InitStruct = InitStructBuilder.finishAndCreateGlobal(".objc_init",
1486 CGM.getPointerAlign(), false, llvm::GlobalValue::LinkOnceODRLinkage);
1487 InitStruct->setVisibility(llvm::GlobalValue::HiddenVisibility);
1488 InitStruct->setComdat(TheModule.getOrInsertComdat(".objc_init"));
1490 CallRuntimeFunction(B, "__objc_load", {InitStruct});;
1492 // Make sure that the optimisers don't delete this function.
1493 CGM.addCompilerUsedGlobal(LoadFunction);
1494 // FIXME: Currently ELF only!
1495 // We have to do this by hand, rather than with @llvm.ctors, so that the
1496 // linker can remove the duplicate invocations.
1497 auto *InitVar = new llvm::GlobalVariable(TheModule, LoadFunction->getType(),
1498 /*isConstant*/true, llvm::GlobalValue::LinkOnceAnyLinkage,
1499 LoadFunction, ".objc_ctor");
1500 // Check that this hasn't been renamed. This shouldn't happen, because
1501 // this function should be called precisely once.
1502 assert(InitVar->getName() == ".objc_ctor");
1503 // In Windows, initialisers are sorted by the suffix. XCL is for library
1504 // initialisers, which run before user initialisers. We are running
1505 // Objective-C loads at the end of library load. This means +load methods
1506 // will run before any other static constructors, but that static
1507 // constructors can see a fully initialised Objective-C state.
1508 if (CGM.getTriple().isOSBinFormatCOFF())
1509 InitVar->setSection(".CRT$XCLz");
1512 if (CGM.getCodeGenOpts().UseInitArray)
1513 InitVar->setSection(".init_array");
1515 InitVar->setSection(".ctors");
1517 InitVar->setVisibility(llvm::GlobalValue::HiddenVisibility);
1518 InitVar->setComdat(TheModule.getOrInsertComdat(".objc_ctor"));
1519 CGM.addUsedGlobal(InitVar);
1520 for (auto *C : Categories) {
1521 auto *Cat = cast<llvm::GlobalVariable>(C->stripPointerCasts());
1522 Cat->setSection(sectionName<CategorySection>());
1523 CGM.addUsedGlobal(Cat);
1525 auto createNullGlobal = [&](StringRef Name, ArrayRef<llvm::Constant*> Init,
1526 StringRef Section) {
1527 auto nullBuilder = builder.beginStruct();
1528 for (auto *F : Init)
1530 auto GV = nullBuilder.finishAndCreateGlobal(Name, CGM.getPointerAlign(),
1531 false, llvm::GlobalValue::LinkOnceODRLinkage);
1532 GV->setSection(Section);
1533 GV->setComdat(TheModule.getOrInsertComdat(Name));
1534 GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1535 CGM.addUsedGlobal(GV);
1538 for (auto clsAlias : ClassAliases)
1539 createNullGlobal(std::string(".objc_class_alias") +
1540 clsAlias.second, { MakeConstantString(clsAlias.second),
1541 GetClassVar(clsAlias.first) }, sectionName<ClassAliasSection>());
1542 // On ELF platforms, add a null value for each special section so that we
1543 // can always guarantee that the _start and _stop symbols will exist and be
1544 // meaningful. This is not required on COFF platforms, where our start and
1545 // stop symbols will create the section.
1546 if (!CGM.getTriple().isOSBinFormatCOFF()) {
1547 createNullGlobal(".objc_null_selector", {NULLPtr, NULLPtr},
1548 sectionName<SelectorSection>());
1549 if (Categories.empty())
1550 createNullGlobal(".objc_null_category", {NULLPtr, NULLPtr,
1551 NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr},
1552 sectionName<CategorySection>());
1553 if (!EmittedClass) {
1554 createNullGlobal(".objc_null_cls_init_ref", NULLPtr,
1555 sectionName<ClassReferenceSection>());
1556 createNullGlobal(".objc_null_class_ref", { NULLPtr, NULLPtr },
1557 sectionName<ClassReferenceSection>());
1559 if (!EmittedProtocol)
1560 createNullGlobal(".objc_null_protocol", {NULLPtr, NULLPtr, NULLPtr,
1561 NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr,
1562 NULLPtr}, sectionName<ProtocolSection>());
1563 if (!EmittedProtocolRef)
1564 createNullGlobal(".objc_null_protocol_ref", {NULLPtr},
1565 sectionName<ProtocolReferenceSection>());
1566 if (ClassAliases.empty())
1567 createNullGlobal(".objc_null_class_alias", { NULLPtr, NULLPtr },
1568 sectionName<ClassAliasSection>());
1569 if (ConstantStrings.empty()) {
1570 auto i32Zero = llvm::ConstantInt::get(Int32Ty, 0);
1571 createNullGlobal(".objc_null_constant_string", { NULLPtr, i32Zero,
1572 i32Zero, i32Zero, i32Zero, NULLPtr },
1573 sectionName<ConstantStringSection>());
1576 ConstantStrings.clear();
1581 /// In the v2 ABI, ivar offset variables use the type encoding in their name
1582 /// to trigger linker failures if the types don't match.
1583 std::string GetIVarOffsetVariableName(const ObjCInterfaceDecl *ID,
1584 const ObjCIvarDecl *Ivar) override {
1585 std::string TypeEncoding;
1586 CGM.getContext().getObjCEncodingForType(Ivar->getType(), TypeEncoding);
1587 // Prevent the @ from being interpreted as a symbol version.
1588 std::replace(TypeEncoding.begin(), TypeEncoding.end(),
1590 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString()
1591 + '.' + Ivar->getNameAsString() + '.' + TypeEncoding;
1594 llvm::Value *EmitIvarOffset(CodeGenFunction &CGF,
1595 const ObjCInterfaceDecl *Interface,
1596 const ObjCIvarDecl *Ivar) override {
1597 const std::string Name = GetIVarOffsetVariableName(Ivar->getContainingInterface(), Ivar);
1598 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name);
1599 if (!IvarOffsetPointer)
1600 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, IntTy, false,
1601 llvm::GlobalValue::ExternalLinkage, nullptr, Name);
1602 CharUnits Align = CGM.getIntAlign();
1603 llvm::Value *Offset = CGF.Builder.CreateAlignedLoad(IvarOffsetPointer, Align);
1604 if (Offset->getType() != PtrDiffTy)
1605 Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy);
1608 void GenerateClass(const ObjCImplementationDecl *OID) override {
1609 ASTContext &Context = CGM.getContext();
1611 // Get the class name
1612 ObjCInterfaceDecl *classDecl =
1613 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
1614 std::string className = classDecl->getNameAsString();
1615 auto *classNameConstant = MakeConstantString(className);
1617 ConstantInitBuilder builder(CGM);
1618 auto metaclassFields = builder.beginStruct();
1619 // struct objc_class *isa;
1620 metaclassFields.addNullPointer(PtrTy);
1621 // struct objc_class *super_class;
1622 metaclassFields.addNullPointer(PtrTy);
1623 // const char *name;
1624 metaclassFields.add(classNameConstant);
1626 metaclassFields.addInt(LongTy, 0);
1627 // unsigned long info;
1628 // objc_class_flag_meta
1629 metaclassFields.addInt(LongTy, 1);
1630 // long instance_size;
1631 // Setting this to zero is consistent with the older ABI, but it might be
1632 // more sensible to set this to sizeof(struct objc_class)
1633 metaclassFields.addInt(LongTy, 0);
1634 // struct objc_ivar_list *ivars;
1635 metaclassFields.addNullPointer(PtrTy);
1636 // struct objc_method_list *methods
1637 // FIXME: Almost identical code is copied and pasted below for the
1638 // class, but refactoring it cleanly requires C++14 generic lambdas.
1639 if (OID->classmeth_begin() == OID->classmeth_end())
1640 metaclassFields.addNullPointer(PtrTy);
1642 SmallVector<ObjCMethodDecl*, 16> ClassMethods;
1643 ClassMethods.insert(ClassMethods.begin(), OID->classmeth_begin(),
1644 OID->classmeth_end());
1645 metaclassFields.addBitCast(
1646 GenerateMethodList(className, "", ClassMethods, true),
1650 metaclassFields.addNullPointer(PtrTy);
1651 // IMP cxx_construct;
1652 metaclassFields.addNullPointer(PtrTy);
1653 // IMP cxx_destruct;
1654 metaclassFields.addNullPointer(PtrTy);
1655 // struct objc_class *subclass_list
1656 metaclassFields.addNullPointer(PtrTy);
1657 // struct objc_class *sibling_class
1658 metaclassFields.addNullPointer(PtrTy);
1659 // struct objc_protocol_list *protocols;
1660 metaclassFields.addNullPointer(PtrTy);
1661 // struct reference_list *extra_data;
1662 metaclassFields.addNullPointer(PtrTy);
1663 // long abi_version;
1664 metaclassFields.addInt(LongTy, 0);
1665 // struct objc_property_list *properties
1666 metaclassFields.add(GeneratePropertyList(OID, classDecl, /*isClassProperty*/true));
1668 auto *metaclass = metaclassFields.finishAndCreateGlobal("._OBJC_METACLASS_"
1669 + className, CGM.getPointerAlign());
1671 auto classFields = builder.beginStruct();
1672 // struct objc_class *isa;
1673 classFields.add(metaclass);
1674 // struct objc_class *super_class;
1675 // Get the superclass name.
1676 const ObjCInterfaceDecl * SuperClassDecl =
1677 OID->getClassInterface()->getSuperClass();
1678 if (SuperClassDecl) {
1679 auto SuperClassName = SymbolForClass(SuperClassDecl->getNameAsString());
1680 llvm::Constant *SuperClass = TheModule.getNamedGlobal(SuperClassName);
1683 SuperClass = new llvm::GlobalVariable(TheModule, PtrTy, false,
1684 llvm::GlobalValue::ExternalLinkage, nullptr, SuperClassName);
1686 classFields.add(llvm::ConstantExpr::getBitCast(SuperClass, PtrTy));
1688 classFields.addNullPointer(PtrTy);
1689 // const char *name;
1690 classFields.add(classNameConstant);
1692 classFields.addInt(LongTy, 0);
1693 // unsigned long info;
1694 // !objc_class_flag_meta
1695 classFields.addInt(LongTy, 0);
1696 // long instance_size;
1697 int superInstanceSize = !SuperClassDecl ? 0 :
1698 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity();
1699 // Instance size is negative for classes that have not yet had their ivar
1700 // layout calculated.
1701 classFields.addInt(LongTy,
1702 0 - (Context.getASTObjCImplementationLayout(OID).getSize().getQuantity() -
1703 superInstanceSize));
1705 if (classDecl->all_declared_ivar_begin() == nullptr)
1706 classFields.addNullPointer(PtrTy);
1709 for (const ObjCIvarDecl *IVD = classDecl->all_declared_ivar_begin(); IVD;
1710 IVD = IVD->getNextIvar()) ivar_count++;
1711 llvm::DataLayout td(&TheModule);
1712 // struct objc_ivar_list *ivars;
1713 ConstantInitBuilder b(CGM);
1714 auto ivarListBuilder = b.beginStruct();
1716 ivarListBuilder.addInt(IntTy, ivar_count);
1718 llvm::StructType *ObjCIvarTy = llvm::StructType::get(
1724 ivarListBuilder.addInt(SizeTy, td.getTypeSizeInBits(ObjCIvarTy) /
1725 CGM.getContext().getCharWidth());
1726 // struct objc_ivar ivars[]
1727 auto ivarArrayBuilder = ivarListBuilder.beginArray();
1728 CodeGenTypes &Types = CGM.getTypes();
1729 for (const ObjCIvarDecl *IVD = classDecl->all_declared_ivar_begin(); IVD;
1730 IVD = IVD->getNextIvar()) {
1731 auto ivarTy = IVD->getType();
1732 auto ivarBuilder = ivarArrayBuilder.beginStruct();
1733 // const char *name;
1734 ivarBuilder.add(MakeConstantString(IVD->getNameAsString()));
1735 // const char *type;
1736 std::string TypeStr;
1737 //Context.getObjCEncodingForType(ivarTy, TypeStr, IVD, true);
1738 Context.getObjCEncodingForMethodParameter(Decl::OBJC_TQ_None, ivarTy, TypeStr, true);
1739 ivarBuilder.add(MakeConstantString(TypeStr));
1741 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD);
1742 uint64_t Offset = BaseOffset - superInstanceSize;
1743 llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset);
1744 std::string OffsetName = GetIVarOffsetVariableName(classDecl, IVD);
1745 llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName);
1747 OffsetVar->setInitializer(OffsetValue);
1749 OffsetVar = new llvm::GlobalVariable(TheModule, IntTy,
1750 false, llvm::GlobalValue::ExternalLinkage,
1751 OffsetValue, OffsetName);
1752 auto ivarVisibility =
1753 (IVD->getAccessControl() == ObjCIvarDecl::Private ||
1754 IVD->getAccessControl() == ObjCIvarDecl::Package ||
1755 classDecl->getVisibility() == HiddenVisibility) ?
1756 llvm::GlobalValue::HiddenVisibility :
1757 llvm::GlobalValue::DefaultVisibility;
1758 OffsetVar->setVisibility(ivarVisibility);
1759 ivarBuilder.add(OffsetVar);
1761 ivarBuilder.addInt(Int32Ty,
1762 td.getTypeSizeInBits(Types.ConvertType(ivarTy)) /
1763 CGM.getContext().getCharWidth());
1764 // Alignment will be stored as a base-2 log of the alignment.
1765 int align = llvm::Log2_32(Context.getTypeAlignInChars(ivarTy).getQuantity());
1766 // Objects that require more than 2^64-byte alignment should be impossible!
1769 // Bits 0-1 are ownership.
1770 // Bit 2 indicates an extended type encoding
1771 // Bits 3-8 contain log2(aligment)
1772 ivarBuilder.addInt(Int32Ty,
1773 (align << 3) | (1<<2) |
1774 FlagsForOwnership(ivarTy.getQualifiers().getObjCLifetime()));
1775 ivarBuilder.finishAndAddTo(ivarArrayBuilder);
1777 ivarArrayBuilder.finishAndAddTo(ivarListBuilder);
1778 auto ivarList = ivarListBuilder.finishAndCreateGlobal(".objc_ivar_list",
1779 CGM.getPointerAlign(), /*constant*/ false,
1780 llvm::GlobalValue::PrivateLinkage);
1781 classFields.add(ivarList);
1783 // struct objc_method_list *methods
1784 SmallVector<const ObjCMethodDecl*, 16> InstanceMethods;
1785 InstanceMethods.insert(InstanceMethods.begin(), OID->instmeth_begin(),
1786 OID->instmeth_end());
1787 for (auto *propImpl : OID->property_impls())
1788 if (propImpl->getPropertyImplementation() ==
1789 ObjCPropertyImplDecl::Synthesize) {
1790 ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
1791 auto addIfExists = [&](const ObjCMethodDecl* OMD) {
1793 InstanceMethods.push_back(OMD);
1795 addIfExists(prop->getGetterMethodDecl());
1796 addIfExists(prop->getSetterMethodDecl());
1799 if (InstanceMethods.size() == 0)
1800 classFields.addNullPointer(PtrTy);
1802 classFields.addBitCast(
1803 GenerateMethodList(className, "", InstanceMethods, false),
1806 classFields.addNullPointer(PtrTy);
1807 // IMP cxx_construct;
1808 classFields.addNullPointer(PtrTy);
1809 // IMP cxx_destruct;
1810 classFields.addNullPointer(PtrTy);
1811 // struct objc_class *subclass_list
1812 classFields.addNullPointer(PtrTy);
1813 // struct objc_class *sibling_class
1814 classFields.addNullPointer(PtrTy);
1815 // struct objc_protocol_list *protocols;
1816 SmallVector<llvm::Constant*, 16> Protocols;
1817 for (const auto *I : classDecl->protocols())
1818 Protocols.push_back(
1819 llvm::ConstantExpr::getBitCast(GenerateProtocolRef(I),
1821 if (Protocols.empty())
1822 classFields.addNullPointer(PtrTy);
1824 classFields.add(GenerateProtocolList(Protocols));
1825 // struct reference_list *extra_data;
1826 classFields.addNullPointer(PtrTy);
1827 // long abi_version;
1828 classFields.addInt(LongTy, 0);
1829 // struct objc_property_list *properties
1830 classFields.add(GeneratePropertyList(OID, classDecl));
1833 classFields.finishAndCreateGlobal(SymbolForClass(className),
1834 CGM.getPointerAlign(), false, llvm::GlobalValue::ExternalLinkage);
1836 if (CGM.getTriple().isOSBinFormatCOFF()) {
1837 auto Storage = llvm::GlobalValue::DefaultStorageClass;
1838 if (OID->getClassInterface()->hasAttr<DLLImportAttr>())
1839 Storage = llvm::GlobalValue::DLLImportStorageClass;
1840 else if (OID->getClassInterface()->hasAttr<DLLExportAttr>())
1841 Storage = llvm::GlobalValue::DLLExportStorageClass;
1842 cast<llvm::GlobalValue>(classStruct)->setDLLStorageClass(Storage);
1845 auto *classRefSymbol = GetClassVar(className);
1846 classRefSymbol->setSection(sectionName<ClassReferenceSection>());
1847 classRefSymbol->setInitializer(llvm::ConstantExpr::getBitCast(classStruct, IdTy));
1850 // Resolve the class aliases, if they exist.
1851 // FIXME: Class pointer aliases shouldn't exist!
1852 if (ClassPtrAlias) {
1853 ClassPtrAlias->replaceAllUsesWith(
1854 llvm::ConstantExpr::getBitCast(classStruct, IdTy));
1855 ClassPtrAlias->eraseFromParent();
1856 ClassPtrAlias = nullptr;
1858 if (auto Placeholder =
1859 TheModule.getNamedGlobal(SymbolForClass(className)))
1860 if (Placeholder != classStruct) {
1861 Placeholder->replaceAllUsesWith(
1862 llvm::ConstantExpr::getBitCast(classStruct, Placeholder->getType()));
1863 Placeholder->eraseFromParent();
1864 classStruct->setName(SymbolForClass(className));
1866 if (MetaClassPtrAlias) {
1867 MetaClassPtrAlias->replaceAllUsesWith(
1868 llvm::ConstantExpr::getBitCast(metaclass, IdTy));
1869 MetaClassPtrAlias->eraseFromParent();
1870 MetaClassPtrAlias = nullptr;
1872 assert(classStruct->getName() == SymbolForClass(className));
1874 auto classInitRef = new llvm::GlobalVariable(TheModule,
1875 classStruct->getType(), false, llvm::GlobalValue::ExternalLinkage,
1876 classStruct, "._OBJC_INIT_CLASS_" + className);
1877 classInitRef->setSection(sectionName<ClassSection>());
1878 CGM.addUsedGlobal(classInitRef);
1880 EmittedClass = true;
1883 CGObjCGNUstep2(CodeGenModule &Mod) : CGObjCGNUstep(Mod, 10, 4, 2) {
1884 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
1885 PtrToObjCSuperTy, SelectorTy);
1886 // struct objc_property
1888 // const char *name;
1889 // const char *attributes;
1890 // const char *type;
1894 PropertyMetadataTy =
1895 llvm::StructType::get(CGM.getLLVMContext(),
1896 { PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty });
1901 const char *const CGObjCGNUstep2::SectionsBaseNames[8] =
1905 "__objc_class_refs",
1908 "__objc_protocol_refs",
1909 "__objc_class_aliases",
1910 "__objc_constant_string"
1913 /// Support for the ObjFW runtime.
1914 class CGObjCObjFW: public CGObjCGNU {
1916 /// The GCC ABI message lookup function. Returns an IMP pointing to the
1917 /// method implementation for this message.
1918 LazyRuntimeFunction MsgLookupFn;
1919 /// stret lookup function. While this does not seem to make sense at the
1920 /// first look, this is required to call the correct forwarding function.
1921 LazyRuntimeFunction MsgLookupFnSRet;
1922 /// The GCC ABI superclass message lookup function. Takes a pointer to a
1923 /// structure describing the receiver and the class, and a selector as
1924 /// arguments. Returns the IMP for the corresponding method.
1925 LazyRuntimeFunction MsgLookupSuperFn, MsgLookupSuperFnSRet;
1927 llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
1928 llvm::Value *cmd, llvm::MDNode *node,
1929 MessageSendInfo &MSI) override {
1930 CGBuilderTy &Builder = CGF.Builder;
1931 llvm::Value *args[] = {
1932 EnforceType(Builder, Receiver, IdTy),
1933 EnforceType(Builder, cmd, SelectorTy) };
1936 if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
1937 imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFnSRet, args);
1939 imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);
1941 imp->setMetadata(msgSendMDKind, node);
1942 return imp.getInstruction();
1945 llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
1946 llvm::Value *cmd, MessageSendInfo &MSI) override {
1947 CGBuilderTy &Builder = CGF.Builder;
1948 llvm::Value *lookupArgs[] = {
1949 EnforceType(Builder, ObjCSuper.getPointer(), PtrToObjCSuperTy), cmd,
1952 if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
1953 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFnSRet, lookupArgs);
1955 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
1958 llvm::Value *GetClassNamed(CodeGenFunction &CGF, const std::string &Name,
1959 bool isWeak) override {
1961 return CGObjCGNU::GetClassNamed(CGF, Name, isWeak);
1964 std::string SymbolName = "_OBJC_CLASS_" + Name;
1965 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(SymbolName);
1967 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
1968 llvm::GlobalValue::ExternalLinkage,
1969 nullptr, SymbolName);
1974 CGObjCObjFW(CodeGenModule &Mod): CGObjCGNU(Mod, 9, 3) {
1975 // IMP objc_msg_lookup(id, SEL);
1976 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy);
1977 MsgLookupFnSRet.init(&CGM, "objc_msg_lookup_stret", IMPTy, IdTy,
1979 // IMP objc_msg_lookup_super(struct objc_super*, SEL);
1980 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
1981 PtrToObjCSuperTy, SelectorTy);
1982 MsgLookupSuperFnSRet.init(&CGM, "objc_msg_lookup_super_stret", IMPTy,
1983 PtrToObjCSuperTy, SelectorTy);
1986 } // end anonymous namespace
1988 /// Emits a reference to a dummy variable which is emitted with each class.
1989 /// This ensures that a linker error will be generated when trying to link
1990 /// together modules where a referenced class is not defined.
1991 void CGObjCGNU::EmitClassRef(const std::string &className) {
1992 std::string symbolRef = "__objc_class_ref_" + className;
1993 // Don't emit two copies of the same symbol
1994 if (TheModule.getGlobalVariable(symbolRef))
1996 std::string symbolName = "__objc_class_name_" + className;
1997 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName);
1999 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
2000 llvm::GlobalValue::ExternalLinkage,
2001 nullptr, symbolName);
2003 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true,
2004 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef);
2007 CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
2008 unsigned protocolClassVersion, unsigned classABI)
2009 : CGObjCRuntime(cgm), TheModule(CGM.getModule()),
2010 VMContext(cgm.getLLVMContext()), ClassPtrAlias(nullptr),
2011 MetaClassPtrAlias(nullptr), RuntimeVersion(runtimeABIVersion),
2012 ProtocolVersion(protocolClassVersion), ClassABIVersion(classABI) {
2014 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend");
2016 cgm.getContext().getTargetInfo().getTriple().isWindowsMSVCEnvironment();
2018 CodeGenTypes &Types = CGM.getTypes();
2019 IntTy = cast<llvm::IntegerType>(
2020 Types.ConvertType(CGM.getContext().IntTy));
2021 LongTy = cast<llvm::IntegerType>(
2022 Types.ConvertType(CGM.getContext().LongTy));
2023 SizeTy = cast<llvm::IntegerType>(
2024 Types.ConvertType(CGM.getContext().getSizeType()));
2025 PtrDiffTy = cast<llvm::IntegerType>(
2026 Types.ConvertType(CGM.getContext().getPointerDiffType()));
2027 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy);
2029 Int8Ty = llvm::Type::getInt8Ty(VMContext);
2030 // C string type. Used in lots of places.
2031 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty);
2032 ProtocolPtrTy = llvm::PointerType::getUnqual(
2033 Types.ConvertType(CGM.getContext().getObjCProtoType()));
2035 Zeros[0] = llvm::ConstantInt::get(LongTy, 0);
2036 Zeros[1] = Zeros[0];
2037 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty);
2038 // Get the selector Type.
2039 QualType selTy = CGM.getContext().getObjCSelType();
2040 if (QualType() == selTy) {
2041 SelectorTy = PtrToInt8Ty;
2043 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy));
2046 PtrToIntTy = llvm::PointerType::getUnqual(IntTy);
2047 PtrTy = PtrToInt8Ty;
2049 Int32Ty = llvm::Type::getInt32Ty(VMContext);
2050 Int64Ty = llvm::Type::getInt64Ty(VMContext);
2053 CGM.getDataLayout().getPointerSizeInBits() == 32 ? Int32Ty : Int64Ty;
2056 QualType UnqualIdTy = CGM.getContext().getObjCIdType();
2057 ASTIdTy = CanQualType();
2058 if (UnqualIdTy != QualType()) {
2059 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy);
2060 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
2064 PtrToIdTy = llvm::PointerType::getUnqual(IdTy);
2065 ProtocolTy = llvm::StructType::get(IdTy,
2066 PtrToInt8Ty, // name
2067 PtrToInt8Ty, // protocols
2068 PtrToInt8Ty, // instance methods
2069 PtrToInt8Ty, // class methods
2070 PtrToInt8Ty, // optional instance methods
2071 PtrToInt8Ty, // optional class methods
2072 PtrToInt8Ty, // properties
2073 PtrToInt8Ty);// optional properties
2075 // struct objc_property_gsv1
2077 // const char *name;
2079 // char attributes2;
2082 // const char *getter_name;
2083 // const char *getter_types;
2084 // const char *setter_name;
2085 // const char *setter_types;
2087 PropertyMetadataTy = llvm::StructType::get(CGM.getLLVMContext(), {
2088 PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty,
2089 PtrToInt8Ty, PtrToInt8Ty });
2091 ObjCSuperTy = llvm::StructType::get(IdTy, IdTy);
2092 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy);
2094 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
2096 // void objc_exception_throw(id);
2097 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
2098 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
2099 // int objc_sync_enter(id);
2100 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy);
2101 // int objc_sync_exit(id);
2102 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy);
2104 // void objc_enumerationMutation (id)
2105 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, IdTy);
2107 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL)
2108 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy,
2110 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL)
2111 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy,
2112 PtrDiffTy, IdTy, BoolTy, BoolTy);
2113 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
2114 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy,
2115 PtrDiffTy, BoolTy, BoolTy);
2116 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
2117 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy,
2118 PtrDiffTy, BoolTy, BoolTy);
2121 llvm::Type *IMPArgs[] = { IdTy, SelectorTy };
2122 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs,
2125 const LangOptions &Opts = CGM.getLangOpts();
2126 if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount)
2127 RuntimeVersion = 10;
2129 // Don't bother initialising the GC stuff unless we're compiling in GC mode
2130 if (Opts.getGC() != LangOptions::NonGC) {
2131 // This is a bit of an hack. We should sort this out by having a proper
2132 // CGObjCGNUstep subclass for GC, but we may want to really support the old
2133 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now
2134 // Get selectors needed in GC mode
2135 RetainSel = GetNullarySelector("retain", CGM.getContext());
2136 ReleaseSel = GetNullarySelector("release", CGM.getContext());
2137 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext());
2139 // Get functions needed in GC mode
2141 // id objc_assign_ivar(id, id, ptrdiff_t);
2142 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy);
2143 // id objc_assign_strongCast (id, id*)
2144 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy,
2146 // id objc_assign_global(id, id*);
2147 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy);
2148 // id objc_assign_weak(id, id*);
2149 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy);
2150 // id objc_read_weak(id*);
2151 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy);
2152 // void *objc_memmove_collectable(void*, void *, size_t);
2153 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy,
2158 llvm::Value *CGObjCGNU::GetClassNamed(CodeGenFunction &CGF,
2159 const std::string &Name, bool isWeak) {
2160 llvm::Constant *ClassName = MakeConstantString(Name);
2161 // With the incompatible ABI, this will need to be replaced with a direct
2162 // reference to the class symbol. For the compatible nonfragile ABI we are
2163 // still performing this lookup at run time but emitting the symbol for the
2164 // class externally so that we can make the switch later.
2166 // Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class
2167 // with memoized versions or with static references if it's safe to do so.
2171 llvm::Constant *ClassLookupFn =
2172 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true),
2173 "objc_lookup_class");
2174 return CGF.EmitNounwindRuntimeCall(ClassLookupFn, ClassName);
2177 // This has to perform the lookup every time, since posing and related
2178 // techniques can modify the name -> class mapping.
2179 llvm::Value *CGObjCGNU::GetClass(CodeGenFunction &CGF,
2180 const ObjCInterfaceDecl *OID) {
2182 GetClassNamed(CGF, OID->getNameAsString(), OID->isWeakImported());
2183 if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value))
2184 CGM.setGVProperties(ClassSymbol, OID);
2188 llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) {
2189 auto *Value = GetClassNamed(CGF, "NSAutoreleasePool", false);
2190 if (CGM.getTriple().isOSBinFormatCOFF()) {
2191 if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value)) {
2192 IdentifierInfo &II = CGF.CGM.getContext().Idents.get("NSAutoreleasePool");
2193 TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
2194 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
2196 const VarDecl *VD = nullptr;
2197 for (const auto &Result : DC->lookup(&II))
2198 if ((VD = dyn_cast<VarDecl>(Result)))
2201 CGM.setGVProperties(ClassSymbol, VD);
2207 llvm::Value *CGObjCGNU::GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
2208 const std::string &TypeEncoding) {
2209 SmallVectorImpl<TypedSelector> &Types = SelectorTable[Sel];
2210 llvm::GlobalAlias *SelValue = nullptr;
2212 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(),
2213 e = Types.end() ; i!=e ; i++) {
2214 if (i->first == TypeEncoding) {
2215 SelValue = i->second;
2220 SelValue = llvm::GlobalAlias::create(
2221 SelectorTy->getElementType(), 0, llvm::GlobalValue::PrivateLinkage,
2222 ".objc_selector_" + Sel.getAsString(), &TheModule);
2223 Types.emplace_back(TypeEncoding, SelValue);
2229 Address CGObjCGNU::GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) {
2230 llvm::Value *SelValue = GetSelector(CGF, Sel);
2232 // Store it to a temporary. Does this satisfy the semantics of
2233 // GetAddrOfSelector? Hopefully.
2234 Address tmp = CGF.CreateTempAlloca(SelValue->getType(),
2235 CGF.getPointerAlign());
2236 CGF.Builder.CreateStore(SelValue, tmp);
2240 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel) {
2241 return GetTypedSelector(CGF, Sel, std::string());
2244 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF,
2245 const ObjCMethodDecl *Method) {
2246 std::string SelTypes = CGM.getContext().getObjCEncodingForMethodDecl(Method);
2247 return GetTypedSelector(CGF, Method->getSelector(), SelTypes);
2250 llvm::Constant *CGObjCGNU::GetEHType(QualType T) {
2251 if (T->isObjCIdType() || T->isObjCQualifiedIdType()) {
2252 // With the old ABI, there was only one kind of catchall, which broke
2253 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as
2254 // a pointer indicating object catchalls, and NULL to indicate real
2256 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
2257 return MakeConstantString("@id");
2263 // All other types should be Objective-C interface pointer types.
2264 const ObjCObjectPointerType *OPT = T->getAs<ObjCObjectPointerType>();
2265 assert(OPT && "Invalid @catch type.");
2266 const ObjCInterfaceDecl *IDecl = OPT->getObjectType()->getInterface();
2267 assert(IDecl && "Invalid @catch type.");
2268 return MakeConstantString(IDecl->getIdentifier()->getName());
2271 llvm::Constant *CGObjCGNUstep::GetEHType(QualType T) {
2272 if (usesSEHExceptions)
2273 return CGM.getCXXABI().getAddrOfRTTIDescriptor(T);
2275 if (!CGM.getLangOpts().CPlusPlus)
2276 return CGObjCGNU::GetEHType(T);
2278 // For Objective-C++, we want to provide the ability to catch both C++ and
2279 // Objective-C objects in the same function.
2281 // There's a particular fixed type info for 'id'.
2282 if (T->isObjCIdType() ||
2283 T->isObjCQualifiedIdType()) {
2284 llvm::Constant *IDEHType =
2285 CGM.getModule().getGlobalVariable("__objc_id_type_info");
2288 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty,
2290 llvm::GlobalValue::ExternalLinkage,
2291 nullptr, "__objc_id_type_info");
2292 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty);
2295 const ObjCObjectPointerType *PT =
2296 T->getAs<ObjCObjectPointerType>();
2297 assert(PT && "Invalid @catch type.");
2298 const ObjCInterfaceType *IT = PT->getInterfaceType();
2299 assert(IT && "Invalid @catch type.");
2300 std::string className = IT->getDecl()->getIdentifier()->getName();
2302 std::string typeinfoName = "__objc_eh_typeinfo_" + className;
2304 // Return the existing typeinfo if it exists
2305 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName);
2307 return llvm::ConstantExpr::getBitCast(typeinfo, PtrToInt8Ty);
2309 // Otherwise create it.
2311 // vtable for gnustep::libobjc::__objc_class_type_info
2312 // It's quite ugly hard-coding this. Ideally we'd generate it using the host
2313 // platform's name mangling.
2314 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE";
2315 auto *Vtable = TheModule.getGlobalVariable(vtableName);
2317 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true,
2318 llvm::GlobalValue::ExternalLinkage,
2319 nullptr, vtableName);
2321 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2);
2322 auto *BVtable = llvm::ConstantExpr::getBitCast(
2323 llvm::ConstantExpr::getGetElementPtr(Vtable->getValueType(), Vtable, Two),
2326 llvm::Constant *typeName =
2327 ExportUniqueString(className, "__objc_eh_typename_");
2329 ConstantInitBuilder builder(CGM);
2330 auto fields = builder.beginStruct();
2331 fields.add(BVtable);
2332 fields.add(typeName);
2333 llvm::Constant *TI =
2334 fields.finishAndCreateGlobal("__objc_eh_typeinfo_" + className,
2335 CGM.getPointerAlign(),
2337 llvm::GlobalValue::LinkOnceODRLinkage);
2338 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty);
2341 /// Generate an NSConstantString object.
2342 ConstantAddress CGObjCGNU::GenerateConstantString(const StringLiteral *SL) {
2344 std::string Str = SL->getString().str();
2345 CharUnits Align = CGM.getPointerAlign();
2347 // Look for an existing one
2348 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str);
2349 if (old != ObjCStrings.end())
2350 return ConstantAddress(old->getValue(), Align);
2352 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass;
2354 if (StringClass.empty()) StringClass = "NSConstantString";
2356 std::string Sym = "_OBJC_CLASS_";
2359 llvm::Constant *isa = TheModule.getNamedGlobal(Sym);
2362 isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false,
2363 llvm::GlobalValue::ExternalWeakLinkage, nullptr, Sym);
2364 else if (isa->getType() != PtrToIdTy)
2365 isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy);
2367 ConstantInitBuilder Builder(CGM);
2368 auto Fields = Builder.beginStruct();
2370 Fields.add(MakeConstantString(Str));
2371 Fields.addInt(IntTy, Str.size());
2372 llvm::Constant *ObjCStr =
2373 Fields.finishAndCreateGlobal(".objc_str", Align);
2374 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty);
2375 ObjCStrings[Str] = ObjCStr;
2376 ConstantStrings.push_back(ObjCStr);
2377 return ConstantAddress(ObjCStr, Align);
2380 ///Generates a message send where the super is the receiver. This is a message
2381 ///send to self with special delivery semantics indicating which class's method
2382 ///should be called.
2384 CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF,
2385 ReturnValueSlot Return,
2386 QualType ResultType,
2388 const ObjCInterfaceDecl *Class,
2389 bool isCategoryImpl,
2390 llvm::Value *Receiver,
2391 bool IsClassMessage,
2392 const CallArgList &CallArgs,
2393 const ObjCMethodDecl *Method) {
2394 CGBuilderTy &Builder = CGF.Builder;
2395 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
2396 if (Sel == RetainSel || Sel == AutoreleaseSel) {
2397 return RValue::get(EnforceType(Builder, Receiver,
2398 CGM.getTypes().ConvertType(ResultType)));
2400 if (Sel == ReleaseSel) {
2401 return RValue::get(nullptr);
2405 llvm::Value *cmd = GetSelector(CGF, Sel);
2406 CallArgList ActualArgs;
2408 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy);
2409 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
2410 ActualArgs.addFrom(CallArgs);
2412 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
2414 llvm::Value *ReceiverClass = nullptr;
2415 bool isV2ABI = isRuntime(ObjCRuntime::GNUstep, 2);
2417 ReceiverClass = GetClassNamed(CGF,
2418 Class->getSuperClass()->getNameAsString(), /*isWeak*/false);
2419 if (IsClassMessage) {
2420 // Load the isa pointer of the superclass is this is a class method.
2421 ReceiverClass = Builder.CreateBitCast(ReceiverClass,
2422 llvm::PointerType::getUnqual(IdTy));
2424 Builder.CreateAlignedLoad(ReceiverClass, CGF.getPointerAlign());
2426 ReceiverClass = EnforceType(Builder, ReceiverClass, IdTy);
2428 if (isCategoryImpl) {
2429 llvm::Constant *classLookupFunction = nullptr;
2430 if (IsClassMessage) {
2431 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
2432 IdTy, PtrTy, true), "objc_get_meta_class");
2434 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
2435 IdTy, PtrTy, true), "objc_get_class");
2437 ReceiverClass = Builder.CreateCall(classLookupFunction,
2438 MakeConstantString(Class->getNameAsString()));
2440 // Set up global aliases for the metaclass or class pointer if they do not
2441 // already exist. These will are forward-references which will be set to
2442 // pointers to the class and metaclass structure created for the runtime
2443 // load function. To send a message to super, we look up the value of the
2444 // super_class pointer from either the class or metaclass structure.
2445 if (IsClassMessage) {
2446 if (!MetaClassPtrAlias) {
2447 MetaClassPtrAlias = llvm::GlobalAlias::create(
2448 IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage,
2449 ".objc_metaclass_ref" + Class->getNameAsString(), &TheModule);
2451 ReceiverClass = MetaClassPtrAlias;
2453 if (!ClassPtrAlias) {
2454 ClassPtrAlias = llvm::GlobalAlias::create(
2455 IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage,
2456 ".objc_class_ref" + Class->getNameAsString(), &TheModule);
2458 ReceiverClass = ClassPtrAlias;
2461 // Cast the pointer to a simplified version of the class structure
2462 llvm::Type *CastTy = llvm::StructType::get(IdTy, IdTy);
2463 ReceiverClass = Builder.CreateBitCast(ReceiverClass,
2464 llvm::PointerType::getUnqual(CastTy));
2465 // Get the superclass pointer
2466 ReceiverClass = Builder.CreateStructGEP(CastTy, ReceiverClass, 1);
2467 // Load the superclass pointer
2469 Builder.CreateAlignedLoad(ReceiverClass, CGF.getPointerAlign());
2471 // Construct the structure used to look up the IMP
2472 llvm::StructType *ObjCSuperTy =
2473 llvm::StructType::get(Receiver->getType(), IdTy);
2475 Address ObjCSuper = CGF.CreateTempAlloca(ObjCSuperTy,
2476 CGF.getPointerAlign());
2478 Builder.CreateStore(Receiver,
2479 Builder.CreateStructGEP(ObjCSuper, 0, CharUnits::Zero()));
2480 Builder.CreateStore(ReceiverClass,
2481 Builder.CreateStructGEP(ObjCSuper, 1, CGF.getPointerSize()));
2483 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy);
2486 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd, MSI);
2487 imp = EnforceType(Builder, imp, MSI.MessengerType);
2489 llvm::Metadata *impMD[] = {
2490 llvm::MDString::get(VMContext, Sel.getAsString()),
2491 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()),
2492 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
2493 llvm::Type::getInt1Ty(VMContext), IsClassMessage))};
2494 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
2496 CGCallee callee(CGCalleeInfo(), imp);
2498 llvm::Instruction *call;
2499 RValue msgRet = CGF.EmitCall(MSI.CallInfo, callee, Return, ActualArgs, &call);
2500 call->setMetadata(msgSendMDKind, node);
2504 /// Generate code for a message send expression.
2506 CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF,
2507 ReturnValueSlot Return,
2508 QualType ResultType,
2510 llvm::Value *Receiver,
2511 const CallArgList &CallArgs,
2512 const ObjCInterfaceDecl *Class,
2513 const ObjCMethodDecl *Method) {
2514 CGBuilderTy &Builder = CGF.Builder;
2516 // Strip out message sends to retain / release in GC mode
2517 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
2518 if (Sel == RetainSel || Sel == AutoreleaseSel) {
2519 return RValue::get(EnforceType(Builder, Receiver,
2520 CGM.getTypes().ConvertType(ResultType)));
2522 if (Sel == ReleaseSel) {
2523 return RValue::get(nullptr);
2527 // If the return type is something that goes in an integer register, the
2528 // runtime will handle 0 returns. For other cases, we fill in the 0 value
2531 // The language spec says the result of this kind of message send is
2532 // undefined, but lots of people seem to have forgotten to read that
2533 // paragraph and insist on sending messages to nil that have structure
2534 // returns. With GCC, this generates a random return value (whatever happens
2535 // to be on the stack / in those registers at the time) on most platforms,
2536 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts
2538 bool isPointerSizedReturn = (ResultType->isAnyPointerType() ||
2539 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType());
2541 llvm::BasicBlock *startBB = nullptr;
2542 llvm::BasicBlock *messageBB = nullptr;
2543 llvm::BasicBlock *continueBB = nullptr;
2545 if (!isPointerSizedReturn) {
2546 startBB = Builder.GetInsertBlock();
2547 messageBB = CGF.createBasicBlock("msgSend");
2548 continueBB = CGF.createBasicBlock("continue");
2550 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver,
2551 llvm::Constant::getNullValue(Receiver->getType()));
2552 Builder.CreateCondBr(isNil, continueBB, messageBB);
2553 CGF.EmitBlock(messageBB);
2556 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
2559 cmd = GetSelector(CGF, Method);
2561 cmd = GetSelector(CGF, Sel);
2562 cmd = EnforceType(Builder, cmd, SelectorTy);
2563 Receiver = EnforceType(Builder, Receiver, IdTy);
2565 llvm::Metadata *impMD[] = {
2566 llvm::MDString::get(VMContext, Sel.getAsString()),
2567 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() : ""),
2568 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
2569 llvm::Type::getInt1Ty(VMContext), Class != nullptr))};
2570 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
2572 CallArgList ActualArgs;
2573 ActualArgs.add(RValue::get(Receiver), ASTIdTy);
2574 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
2575 ActualArgs.addFrom(CallArgs);
2577 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
2579 // Get the IMP to call
2582 // If we have non-legacy dispatch specified, we try using the objc_msgSend()
2583 // functions. These are not supported on all platforms (or all runtimes on a
2584 // given platform), so we
2585 switch (CGM.getCodeGenOpts().getObjCDispatchMethod()) {
2586 case CodeGenOptions::Legacy:
2587 imp = LookupIMP(CGF, Receiver, cmd, node, MSI);
2589 case CodeGenOptions::Mixed:
2590 case CodeGenOptions::NonLegacy:
2591 if (CGM.ReturnTypeUsesFPRet(ResultType)) {
2592 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
2593 "objc_msgSend_fpret");
2594 } else if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) {
2595 // The actual types here don't matter - we're going to bitcast the
2597 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
2598 "objc_msgSend_stret");
2600 imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
2605 // Reset the receiver in case the lookup modified it
2606 ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy);
2608 imp = EnforceType(Builder, imp, MSI.MessengerType);
2610 llvm::Instruction *call;
2611 CGCallee callee(CGCalleeInfo(), imp);
2612 RValue msgRet = CGF.EmitCall(MSI.CallInfo, callee, Return, ActualArgs, &call);
2613 call->setMetadata(msgSendMDKind, node);
2616 if (!isPointerSizedReturn) {
2617 messageBB = CGF.Builder.GetInsertBlock();
2618 CGF.Builder.CreateBr(continueBB);
2619 CGF.EmitBlock(continueBB);
2620 if (msgRet.isScalar()) {
2621 llvm::Value *v = msgRet.getScalarVal();
2622 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2);
2623 phi->addIncoming(v, messageBB);
2624 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB);
2625 msgRet = RValue::get(phi);
2626 } else if (msgRet.isAggregate()) {
2627 Address v = msgRet.getAggregateAddress();
2628 llvm::PHINode *phi = Builder.CreatePHI(v.getType(), 2);
2629 llvm::Type *RetTy = v.getElementType();
2630 Address NullVal = CGF.CreateTempAlloca(RetTy, v.getAlignment(), "null");
2631 CGF.InitTempAlloca(NullVal, llvm::Constant::getNullValue(RetTy));
2632 phi->addIncoming(v.getPointer(), messageBB);
2633 phi->addIncoming(NullVal.getPointer(), startBB);
2634 msgRet = RValue::getAggregate(Address(phi, v.getAlignment()));
2635 } else /* isComplex() */ {
2636 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal();
2637 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2);
2638 phi->addIncoming(v.first, messageBB);
2639 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()),
2641 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2);
2642 phi2->addIncoming(v.second, messageBB);
2643 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()),
2645 msgRet = RValue::getComplex(phi, phi2);
2651 /// Generates a MethodList. Used in construction of a objc_class and
2652 /// objc_category structures.
2653 llvm::Constant *CGObjCGNU::
2654 GenerateMethodList(StringRef ClassName,
2655 StringRef CategoryName,
2656 ArrayRef<const ObjCMethodDecl*> Methods,
2657 bool isClassMethodList) {
2658 if (Methods.empty())
2661 ConstantInitBuilder Builder(CGM);
2663 auto MethodList = Builder.beginStruct();
2664 MethodList.addNullPointer(CGM.Int8PtrTy);
2665 MethodList.addInt(Int32Ty, Methods.size());
2667 // Get the method structure type.
2668 llvm::StructType *ObjCMethodTy =
2669 llvm::StructType::get(CGM.getLLVMContext(), {
2670 PtrToInt8Ty, // Really a selector, but the runtime creates it us.
2671 PtrToInt8Ty, // Method types
2672 IMPTy // Method pointer
2674 bool isV2ABI = isRuntime(ObjCRuntime::GNUstep, 2);
2677 llvm::DataLayout td(&TheModule);
2678 MethodList.addInt(SizeTy, td.getTypeSizeInBits(ObjCMethodTy) /
2679 CGM.getContext().getCharWidth());
2681 llvm::StructType::get(CGM.getLLVMContext(), {
2682 IMPTy, // Method pointer
2683 PtrToInt8Ty, // Selector
2684 PtrToInt8Ty // Extended type encoding
2688 llvm::StructType::get(CGM.getLLVMContext(), {
2689 PtrToInt8Ty, // Really a selector, but the runtime creates it us.
2690 PtrToInt8Ty, // Method types
2691 IMPTy // Method pointer
2694 auto MethodArray = MethodList.beginArray();
2695 ASTContext &Context = CGM.getContext();
2696 for (const auto *OMD : Methods) {
2697 llvm::Constant *FnPtr =
2698 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName,
2700 isClassMethodList));
2701 assert(FnPtr && "Can't generate metadata for method that doesn't exist");
2702 auto Method = MethodArray.beginStruct(ObjCMethodTy);
2704 Method.addBitCast(FnPtr, IMPTy);
2705 Method.add(GetConstantSelector(OMD->getSelector(),
2706 Context.getObjCEncodingForMethodDecl(OMD)));
2707 Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(OMD, true)));
2709 Method.add(MakeConstantString(OMD->getSelector().getAsString()));
2710 Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(OMD)));
2711 Method.addBitCast(FnPtr, IMPTy);
2713 Method.finishAndAddTo(MethodArray);
2715 MethodArray.finishAndAddTo(MethodList);
2717 // Create an instance of the structure
2718 return MethodList.finishAndCreateGlobal(".objc_method_list",
2719 CGM.getPointerAlign());
2722 /// Generates an IvarList. Used in construction of a objc_class.
2723 llvm::Constant *CGObjCGNU::
2724 GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
2725 ArrayRef<llvm::Constant *> IvarTypes,
2726 ArrayRef<llvm::Constant *> IvarOffsets,
2727 ArrayRef<llvm::Constant *> IvarAlign,
2728 ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership) {
2729 if (IvarNames.empty())
2732 ConstantInitBuilder Builder(CGM);
2734 // Structure containing array count followed by array.
2735 auto IvarList = Builder.beginStruct();
2736 IvarList.addInt(IntTy, (int)IvarNames.size());
2738 // Get the ivar structure type.
2739 llvm::StructType *ObjCIvarTy =
2740 llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, IntTy);
2742 // Array of ivar structures.
2743 auto Ivars = IvarList.beginArray(ObjCIvarTy);
2744 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) {
2745 auto Ivar = Ivars.beginStruct(ObjCIvarTy);
2746 Ivar.add(IvarNames[i]);
2747 Ivar.add(IvarTypes[i]);
2748 Ivar.add(IvarOffsets[i]);
2749 Ivar.finishAndAddTo(Ivars);
2751 Ivars.finishAndAddTo(IvarList);
2753 // Create an instance of the structure
2754 return IvarList.finishAndCreateGlobal(".objc_ivar_list",
2755 CGM.getPointerAlign());
2758 /// Generate a class structure
2759 llvm::Constant *CGObjCGNU::GenerateClassStructure(
2760 llvm::Constant *MetaClass,
2761 llvm::Constant *SuperClass,
2764 llvm::Constant *Version,
2765 llvm::Constant *InstanceSize,
2766 llvm::Constant *IVars,
2767 llvm::Constant *Methods,
2768 llvm::Constant *Protocols,
2769 llvm::Constant *IvarOffsets,
2770 llvm::Constant *Properties,
2771 llvm::Constant *StrongIvarBitmap,
2772 llvm::Constant *WeakIvarBitmap,
2774 // Set up the class structure
2775 // Note: Several of these are char*s when they should be ids. This is
2776 // because the runtime performs this translation on load.
2778 // Fields marked New ABI are part of the GNUstep runtime. We emit them
2779 // anyway; the classes will still work with the GNU runtime, they will just
2781 llvm::StructType *ClassTy = llvm::StructType::get(
2783 PtrToInt8Ty, // super_class
2784 PtrToInt8Ty, // name
2787 LongTy, // instance_size
2788 IVars->getType(), // ivars
2789 Methods->getType(), // methods
2790 // These are all filled in by the runtime, so we pretend
2792 PtrTy, // subclass_list
2793 PtrTy, // sibling_class
2795 PtrTy, // gc_object_type
2797 LongTy, // abi_version
2798 IvarOffsets->getType(), // ivar_offsets
2799 Properties->getType(), // properties
2800 IntPtrTy, // strong_pointers
2801 IntPtrTy // weak_pointers
2804 ConstantInitBuilder Builder(CGM);
2805 auto Elements = Builder.beginStruct(ClassTy);
2807 // Fill in the structure
2810 Elements.addBitCast(MetaClass, PtrToInt8Ty);
2812 Elements.add(SuperClass);
2814 Elements.add(MakeConstantString(Name, ".class_name"));
2816 Elements.addInt(LongTy, 0);
2818 Elements.addInt(LongTy, info);
2821 llvm::DataLayout td(&TheModule);
2822 Elements.addInt(LongTy,
2823 td.getTypeSizeInBits(ClassTy) /
2824 CGM.getContext().getCharWidth());
2826 Elements.add(InstanceSize);
2828 Elements.add(IVars);
2830 Elements.add(Methods);
2831 // These are all filled in by the runtime, so we pretend
2833 Elements.add(NULLPtr);
2835 Elements.add(NULLPtr);
2837 Elements.add(NULLPtr);
2839 Elements.addBitCast(Protocols, PtrTy);
2841 Elements.add(NULLPtr);
2843 Elements.addInt(LongTy, ClassABIVersion);
2845 Elements.add(IvarOffsets);
2847 Elements.add(Properties);
2849 Elements.add(StrongIvarBitmap);
2851 Elements.add(WeakIvarBitmap);
2852 // Create an instance of the structure
2853 // This is now an externally visible symbol, so that we can speed up class
2854 // messages in the next ABI. We may already have some weak references to
2855 // this, so check and fix them properly.
2856 std::string ClassSym((isMeta ? "_OBJC_METACLASS_": "_OBJC_CLASS_") +
2858 llvm::GlobalVariable *ClassRef = TheModule.getNamedGlobal(ClassSym);
2859 llvm::Constant *Class =
2860 Elements.finishAndCreateGlobal(ClassSym, CGM.getPointerAlign(), false,
2861 llvm::GlobalValue::ExternalLinkage);
2863 ClassRef->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(Class,
2864 ClassRef->getType()));
2865 ClassRef->removeFromParent();
2866 Class->setName(ClassSym);
2871 llvm::Constant *CGObjCGNU::
2872 GenerateProtocolMethodList(ArrayRef<const ObjCMethodDecl*> Methods) {
2873 // Get the method structure type.
2874 llvm::StructType *ObjCMethodDescTy =
2875 llvm::StructType::get(CGM.getLLVMContext(), { PtrToInt8Ty, PtrToInt8Ty });
2876 ASTContext &Context = CGM.getContext();
2877 ConstantInitBuilder Builder(CGM);
2878 auto MethodList = Builder.beginStruct();
2879 MethodList.addInt(IntTy, Methods.size());
2880 auto MethodArray = MethodList.beginArray(ObjCMethodDescTy);
2881 for (auto *M : Methods) {
2882 auto Method = MethodArray.beginStruct(ObjCMethodDescTy);
2883 Method.add(MakeConstantString(M->getSelector().getAsString()));
2884 Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(M)));
2885 Method.finishAndAddTo(MethodArray);
2887 MethodArray.finishAndAddTo(MethodList);
2888 return MethodList.finishAndCreateGlobal(".objc_method_list",
2889 CGM.getPointerAlign());
2892 // Create the protocol list structure used in classes, categories and so on
2894 CGObjCGNU::GenerateProtocolList(ArrayRef<std::string> Protocols) {
2896 ConstantInitBuilder Builder(CGM);
2897 auto ProtocolList = Builder.beginStruct();
2898 ProtocolList.add(NULLPtr);
2899 ProtocolList.addInt(LongTy, Protocols.size());
2901 auto Elements = ProtocolList.beginArray(PtrToInt8Ty);
2902 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end();
2903 iter != endIter ; iter++) {
2904 llvm::Constant *protocol = nullptr;
2905 llvm::StringMap<llvm::Constant*>::iterator value =
2906 ExistingProtocols.find(*iter);
2907 if (value == ExistingProtocols.end()) {
2908 protocol = GenerateEmptyProtocol(*iter);
2910 protocol = value->getValue();
2912 Elements.addBitCast(protocol, PtrToInt8Ty);
2914 Elements.finishAndAddTo(ProtocolList);
2915 return ProtocolList.finishAndCreateGlobal(".objc_protocol_list",
2916 CGM.getPointerAlign());
2919 llvm::Value *CGObjCGNU::GenerateProtocolRef(CodeGenFunction &CGF,
2920 const ObjCProtocolDecl *PD) {
2921 llvm::Constant *&protocol = ExistingProtocols[PD->getNameAsString()];
2923 GenerateProtocol(PD);
2925 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType());
2926 return CGF.Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T));
2930 CGObjCGNU::GenerateEmptyProtocol(StringRef ProtocolName) {
2931 llvm::Constant *ProtocolList = GenerateProtocolList({});
2932 llvm::Constant *MethodList = GenerateProtocolMethodList({});
2933 MethodList = llvm::ConstantExpr::getBitCast(MethodList, PtrToInt8Ty);
2934 // Protocols are objects containing lists of the methods implemented and
2935 // protocols adopted.
2936 ConstantInitBuilder Builder(CGM);
2937 auto Elements = Builder.beginStruct();
2939 // The isa pointer must be set to a magic number so the runtime knows it's
2940 // the correct layout.
2941 Elements.add(llvm::ConstantExpr::getIntToPtr(
2942 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
2944 Elements.add(MakeConstantString(ProtocolName, ".objc_protocol_name"));
2945 Elements.add(ProtocolList); /* .protocol_list */
2946 Elements.add(MethodList); /* .instance_methods */
2947 Elements.add(MethodList); /* .class_methods */
2948 Elements.add(MethodList); /* .optional_instance_methods */
2949 Elements.add(MethodList); /* .optional_class_methods */
2950 Elements.add(NULLPtr); /* .properties */
2951 Elements.add(NULLPtr); /* .optional_properties */
2952 return Elements.finishAndCreateGlobal(SymbolForProtocol(ProtocolName),
2953 CGM.getPointerAlign());
2956 void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) {
2957 std::string ProtocolName = PD->getNameAsString();
2959 // Use the protocol definition, if there is one.
2960 if (const ObjCProtocolDecl *Def = PD->getDefinition())
2963 SmallVector<std::string, 16> Protocols;
2964 for (const auto *PI : PD->protocols())
2965 Protocols.push_back(PI->getNameAsString());
2966 SmallVector<const ObjCMethodDecl*, 16> InstanceMethods;
2967 SmallVector<const ObjCMethodDecl*, 16> OptionalInstanceMethods;
2968 for (const auto *I : PD->instance_methods())
2969 if (I->isOptional())
2970 OptionalInstanceMethods.push_back(I);
2972 InstanceMethods.push_back(I);
2973 // Collect information about class methods:
2974 SmallVector<const ObjCMethodDecl*, 16> ClassMethods;
2975 SmallVector<const ObjCMethodDecl*, 16> OptionalClassMethods;
2976 for (const auto *I : PD->class_methods())
2977 if (I->isOptional())
2978 OptionalClassMethods.push_back(I);
2980 ClassMethods.push_back(I);
2982 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols);
2983 llvm::Constant *InstanceMethodList =
2984 GenerateProtocolMethodList(InstanceMethods);
2985 llvm::Constant *ClassMethodList =
2986 GenerateProtocolMethodList(ClassMethods);
2987 llvm::Constant *OptionalInstanceMethodList =
2988 GenerateProtocolMethodList(OptionalInstanceMethods);
2989 llvm::Constant *OptionalClassMethodList =
2990 GenerateProtocolMethodList(OptionalClassMethods);
2992 // Property metadata: name, attributes, isSynthesized, setter name, setter
2993 // types, getter name, getter types.
2994 // The isSynthesized value is always set to 0 in a protocol. It exists to
2995 // simplify the runtime library by allowing it to use the same data
2996 // structures for protocol metadata everywhere.
2998 llvm::Constant *PropertyList =
2999 GeneratePropertyList(nullptr, PD, false, false);
3000 llvm::Constant *OptionalPropertyList =
3001 GeneratePropertyList(nullptr, PD, false, true);
3003 // Protocols are objects containing lists of the methods implemented and
3004 // protocols adopted.
3005 // The isa pointer must be set to a magic number so the runtime knows it's
3006 // the correct layout.
3007 ConstantInitBuilder Builder(CGM);
3008 auto Elements = Builder.beginStruct();
3010 llvm::ConstantExpr::getIntToPtr(
3011 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
3012 Elements.add(MakeConstantString(ProtocolName));
3013 Elements.add(ProtocolList);
3014 Elements.add(InstanceMethodList);
3015 Elements.add(ClassMethodList);
3016 Elements.add(OptionalInstanceMethodList);
3017 Elements.add(OptionalClassMethodList);
3018 Elements.add(PropertyList);
3019 Elements.add(OptionalPropertyList);
3020 ExistingProtocols[ProtocolName] =
3021 llvm::ConstantExpr::getBitCast(
3022 Elements.finishAndCreateGlobal(".objc_protocol", CGM.getPointerAlign()),
3025 void CGObjCGNU::GenerateProtocolHolderCategory() {
3026 // Collect information about instance methods
3028 ConstantInitBuilder Builder(CGM);
3029 auto Elements = Builder.beginStruct();
3031 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack";
3032 const std::string CategoryName = "AnotherHack";
3033 Elements.add(MakeConstantString(CategoryName));
3034 Elements.add(MakeConstantString(ClassName));
3035 // Instance method list
3036 Elements.addBitCast(GenerateMethodList(
3037 ClassName, CategoryName, {}, false), PtrTy);
3038 // Class method list
3039 Elements.addBitCast(GenerateMethodList(
3040 ClassName, CategoryName, {}, true), PtrTy);
3043 ConstantInitBuilder ProtocolListBuilder(CGM);
3044 auto ProtocolList = ProtocolListBuilder.beginStruct();
3045 ProtocolList.add(NULLPtr);
3046 ProtocolList.addInt(LongTy, ExistingProtocols.size());
3047 auto ProtocolElements = ProtocolList.beginArray(PtrTy);
3048 for (auto iter = ExistingProtocols.begin(), endIter = ExistingProtocols.end();
3049 iter != endIter ; iter++) {
3050 ProtocolElements.addBitCast(iter->getValue(), PtrTy);
3052 ProtocolElements.finishAndAddTo(ProtocolList);
3053 Elements.addBitCast(
3054 ProtocolList.finishAndCreateGlobal(".objc_protocol_list",
3055 CGM.getPointerAlign()),
3057 Categories.push_back(llvm::ConstantExpr::getBitCast(
3058 Elements.finishAndCreateGlobal("", CGM.getPointerAlign()),
3062 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are
3063 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63
3064 /// bits set to their values, LSB first, while larger ones are stored in a
3065 /// structure of this / form:
3067 /// struct { int32_t length; int32_t values[length]; };
3069 /// The values in the array are stored in host-endian format, with the least
3070 /// significant bit being assumed to come first in the bitfield. Therefore, a
3071 /// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a
3072 /// bitfield / with the 63rd bit set will be 1<<64.
3073 llvm::Constant *CGObjCGNU::MakeBitField(ArrayRef<bool> bits) {
3074 int bitCount = bits.size();
3075 int ptrBits = CGM.getDataLayout().getPointerSizeInBits();
3076 if (bitCount < ptrBits) {
3078 for (int i=0 ; i<bitCount ; ++i) {
3079 if (bits[i]) val |= 1ULL<<(i+1);
3081 return llvm::ConstantInt::get(IntPtrTy, val);
3083 SmallVector<llvm::Constant *, 8> values;
3085 while (v < bitCount) {
3087 for (int i=0 ; (i<32) && (v<bitCount) ; ++i) {
3088 if (bits[v]) word |= 1<<i;
3091 values.push_back(llvm::ConstantInt::get(Int32Ty, word));
3094 ConstantInitBuilder builder(CGM);
3095 auto fields = builder.beginStruct();
3096 fields.addInt(Int32Ty, values.size());
3097 auto array = fields.beginArray();
3098 for (auto v : values) array.add(v);
3099 array.finishAndAddTo(fields);
3101 llvm::Constant *GS =
3102 fields.finishAndCreateGlobal("", CharUnits::fromQuantity(4));
3103 llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy);
3107 void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) {
3108 const ObjCInterfaceDecl *Class = OCD->getClassInterface();
3109 std::string ClassName = Class->getNameAsString();
3110 std::string CategoryName = OCD->getNameAsString();
3112 // Collect the names of referenced protocols
3113 SmallVector<std::string, 16> Protocols;
3114 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl();
3115 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols();
3116 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(),
3117 E = Protos.end(); I != E; ++I)
3118 Protocols.push_back((*I)->getNameAsString());
3120 ConstantInitBuilder Builder(CGM);
3121 auto Elements = Builder.beginStruct();
3122 Elements.add(MakeConstantString(CategoryName));
3123 Elements.add(MakeConstantString(ClassName));
3124 // Instance method list
3125 SmallVector<ObjCMethodDecl*, 16> InstanceMethods;
3126 InstanceMethods.insert(InstanceMethods.begin(), OCD->instmeth_begin(),
3127 OCD->instmeth_end());
3128 Elements.addBitCast(
3129 GenerateMethodList(ClassName, CategoryName, InstanceMethods, false),
3131 // Class method list
3133 SmallVector<ObjCMethodDecl*, 16> ClassMethods;
3134 ClassMethods.insert(ClassMethods.begin(), OCD->classmeth_begin(),
3135 OCD->classmeth_end());
3136 Elements.addBitCast(
3137 GenerateMethodList(ClassName, CategoryName, ClassMethods, true),
3140 Elements.addBitCast(GenerateProtocolList(Protocols), PtrTy);
3141 if (isRuntime(ObjCRuntime::GNUstep, 2)) {
3142 const ObjCCategoryDecl *Category =
3143 Class->FindCategoryDeclaration(OCD->getIdentifier());
3145 // Instance properties
3146 Elements.addBitCast(GeneratePropertyList(OCD, Category, false), PtrTy);
3148 Elements.addBitCast(GeneratePropertyList(OCD, Category, true), PtrTy);
3150 Elements.addNullPointer(PtrTy);
3151 Elements.addNullPointer(PtrTy);
3155 Categories.push_back(llvm::ConstantExpr::getBitCast(
3156 Elements.finishAndCreateGlobal(
3157 std::string(".objc_category_")+ClassName+CategoryName,
3158 CGM.getPointerAlign()),
3162 llvm::Constant *CGObjCGNU::GeneratePropertyList(const Decl *Container,
3163 const ObjCContainerDecl *OCD,
3164 bool isClassProperty,
3165 bool protocolOptionalProperties) {
3167 SmallVector<const ObjCPropertyDecl *, 16> Properties;
3168 llvm::SmallPtrSet<const IdentifierInfo*, 16> PropertySet;
3169 bool isProtocol = isa<ObjCProtocolDecl>(OCD);
3170 ASTContext &Context = CGM.getContext();
3172 std::function<void(const ObjCProtocolDecl *Proto)> collectProtocolProperties
3173 = [&](const ObjCProtocolDecl *Proto) {
3174 for (const auto *P : Proto->protocols())
3175 collectProtocolProperties(P);
3176 for (const auto *PD : Proto->properties()) {
3177 if (isClassProperty != PD->isClassProperty())
3179 // Skip any properties that are declared in protocols that this class
3180 // conforms to but are not actually implemented by this class.
3181 if (!isProtocol && !Context.getObjCPropertyImplDeclForPropertyDecl(PD, Container))
3183 if (!PropertySet.insert(PD->getIdentifier()).second)
3185 Properties.push_back(PD);
3189 if (const ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(OCD))
3190 for (const ObjCCategoryDecl *ClassExt : OID->known_extensions())
3191 for (auto *PD : ClassExt->properties()) {
3192 if (isClassProperty != PD->isClassProperty())
3194 PropertySet.insert(PD->getIdentifier());
3195 Properties.push_back(PD);
3198 for (const auto *PD : OCD->properties()) {
3199 if (isClassProperty != PD->isClassProperty())
3201 // If we're generating a list for a protocol, skip optional / required ones
3202 // when generating the other list.
3203 if (isProtocol && (protocolOptionalProperties != PD->isOptional()))
3205 // Don't emit duplicate metadata for properties that were already in a
3207 if (!PropertySet.insert(PD->getIdentifier()).second)
3210 Properties.push_back(PD);
3213 if (const ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(OCD))
3214 for (const auto *P : OID->all_referenced_protocols())
3215 collectProtocolProperties(P);
3216 else if (const ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(OCD))
3217 for (const auto *P : CD->protocols())
3218 collectProtocolProperties(P);
3220 auto numProperties = Properties.size();
3222 if (numProperties == 0)
3225 ConstantInitBuilder builder(CGM);
3226 auto propertyList = builder.beginStruct();
3227 auto properties = PushPropertyListHeader(propertyList, numProperties);
3229 // Add all of the property methods need adding to the method list and to the
3230 // property metadata list.
3231 for (auto *property : Properties) {
3232 bool isSynthesized = false;
3233 bool isDynamic = false;
3235 auto *propertyImpl = Context.getObjCPropertyImplDeclForPropertyDecl(property, Container);
3237 isSynthesized = (propertyImpl->getPropertyImplementation() ==
3238 ObjCPropertyImplDecl::Synthesize);
3239 isDynamic = (propertyImpl->getPropertyImplementation() ==
3240 ObjCPropertyImplDecl::Dynamic);
3243 PushProperty(properties, property, Container, isSynthesized, isDynamic);
3245 properties.finishAndAddTo(propertyList);
3247 return propertyList.finishAndCreateGlobal(".objc_property_list",
3248 CGM.getPointerAlign());
3251 void CGObjCGNU::RegisterAlias(const ObjCCompatibleAliasDecl *OAD) {
3252 // Get the class declaration for which the alias is specified.
3253 ObjCInterfaceDecl *ClassDecl =
3254 const_cast<ObjCInterfaceDecl *>(OAD->getClassInterface());
3255 ClassAliases.emplace_back(ClassDecl->getNameAsString(),
3256 OAD->getNameAsString());
3259 void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
3260 ASTContext &Context = CGM.getContext();
3262 // Get the superclass name.
3263 const ObjCInterfaceDecl * SuperClassDecl =
3264 OID->getClassInterface()->getSuperClass();
3265 std::string SuperClassName;
3266 if (SuperClassDecl) {
3267 SuperClassName = SuperClassDecl->getNameAsString();
3268 EmitClassRef(SuperClassName);
3271 // Get the class name
3272 ObjCInterfaceDecl *ClassDecl =
3273 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
3274 std::string ClassName = ClassDecl->getNameAsString();
3276 // Emit the symbol that is used to generate linker errors if this class is
3277 // referenced in other modules but not declared.
3278 std::string classSymbolName = "__objc_class_name_" + ClassName;
3279 if (auto *symbol = TheModule.getGlobalVariable(classSymbolName)) {
3280 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0));
3282 new llvm::GlobalVariable(TheModule, LongTy, false,
3283 llvm::GlobalValue::ExternalLinkage,
3284 llvm::ConstantInt::get(LongTy, 0),
3288 // Get the size of instances.
3290 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity();
3292 // Collect information about instance variables.
3293 SmallVector<llvm::Constant*, 16> IvarNames;
3294 SmallVector<llvm::Constant*, 16> IvarTypes;
3295 SmallVector<llvm::Constant*, 16> IvarOffsets;
3296 SmallVector<llvm::Constant*, 16> IvarAligns;
3297 SmallVector<Qualifiers::ObjCLifetime, 16> IvarOwnership;
3299 ConstantInitBuilder IvarOffsetBuilder(CGM);
3300 auto IvarOffsetValues = IvarOffsetBuilder.beginArray(PtrToIntTy);
3301 SmallVector<bool, 16> WeakIvars;
3302 SmallVector<bool, 16> StrongIvars;
3304 int superInstanceSize = !SuperClassDecl ? 0 :
3305 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity();
3306 // For non-fragile ivars, set the instance size to 0 - {the size of just this
3307 // class}. The runtime will then set this to the correct value on load.
3308 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
3309 instanceSize = 0 - (instanceSize - superInstanceSize);
3312 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
3313 IVD = IVD->getNextIvar()) {
3315 IvarNames.push_back(MakeConstantString(IVD->getNameAsString()));
3316 // Get the type encoding for this ivar
3317 std::string TypeStr;
3318 Context.getObjCEncodingForType(IVD->getType(), TypeStr, IVD);
3319 IvarTypes.push_back(MakeConstantString(TypeStr));
3320 IvarAligns.push_back(llvm::ConstantInt::get(IntTy,
3321 Context.getTypeSize(IVD->getType())));
3323 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD);
3324 uint64_t Offset = BaseOffset;
3325 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
3326 Offset = BaseOffset - superInstanceSize;
3328 llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset);
3329 // Create the direct offset value
3330 std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." +
3331 IVD->getNameAsString();
3333 llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName);
3335 OffsetVar->setInitializer(OffsetValue);
3336 // If this is the real definition, change its linkage type so that
3337 // different modules will use this one, rather than their private
3339 OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage);
3341 OffsetVar = new llvm::GlobalVariable(TheModule, Int32Ty,
3342 false, llvm::GlobalValue::ExternalLinkage,
3343 OffsetValue, OffsetName);
3344 IvarOffsets.push_back(OffsetValue);
3345 IvarOffsetValues.add(OffsetVar);
3346 Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime();
3347 IvarOwnership.push_back(lt);
3349 case Qualifiers::OCL_Strong:
3350 StrongIvars.push_back(true);
3351 WeakIvars.push_back(false);
3353 case Qualifiers::OCL_Weak:
3354 StrongIvars.push_back(false);
3355 WeakIvars.push_back(true);
3358 StrongIvars.push_back(false);
3359 WeakIvars.push_back(false);
3362 llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars);
3363 llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars);
3364 llvm::GlobalVariable *IvarOffsetArray =
3365 IvarOffsetValues.finishAndCreateGlobal(".ivar.offsets",
3366 CGM.getPointerAlign());
3368 // Collect information about instance methods
3369 SmallVector<const ObjCMethodDecl*, 16> InstanceMethods;
3370 InstanceMethods.insert(InstanceMethods.begin(), OID->instmeth_begin(),
3371 OID->instmeth_end());
3373 SmallVector<const ObjCMethodDecl*, 16> ClassMethods;
3374 ClassMethods.insert(ClassMethods.begin(), OID->classmeth_begin(),
3375 OID->classmeth_end());
3377 // Collect the same information about synthesized properties, which don't
3378 // show up in the instance method lists.
3379 for (auto *propertyImpl : OID->property_impls())
3380 if (propertyImpl->getPropertyImplementation() ==
3381 ObjCPropertyImplDecl::Synthesize) {
3382 ObjCPropertyDecl *property = propertyImpl->getPropertyDecl();
3383 auto addPropertyMethod = [&](const ObjCMethodDecl *accessor) {
3385 InstanceMethods.push_back(accessor);
3387 addPropertyMethod(property->getGetterMethodDecl());
3388 addPropertyMethod(property->getSetterMethodDecl());
3391 llvm::Constant *Properties = GeneratePropertyList(OID, ClassDecl);
3393 // Collect the names of referenced protocols
3394 SmallVector<std::string, 16> Protocols;
3395 for (const auto *I : ClassDecl->protocols())
3396 Protocols.push_back(I->getNameAsString());
3398 // Get the superclass pointer.
3399 llvm::Constant *SuperClass;
3400 if (!SuperClassName.empty()) {
3401 SuperClass = MakeConstantString(SuperClassName, ".super_class_name");
3403 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty);
3405 // Empty vector used to construct empty method lists
3406 SmallVector<llvm::Constant*, 1> empty;
3407 // Generate the method and instance variable lists
3408 llvm::Constant *MethodList = GenerateMethodList(ClassName, "",
3409 InstanceMethods, false);
3410 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "",
3411 ClassMethods, true);
3412 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes,
3413 IvarOffsets, IvarAligns, IvarOwnership);
3414 // Irrespective of whether we are compiling for a fragile or non-fragile ABI,
3415 // we emit a symbol containing the offset for each ivar in the class. This
3416 // allows code compiled for the non-Fragile ABI to inherit from code compiled
3417 // for the legacy ABI, without causing problems. The converse is also
3418 // possible, but causes all ivar accesses to be fragile.
3420 // Offset pointer for getting at the correct field in the ivar list when
3421 // setting up the alias. These are: The base address for the global, the
3422 // ivar array (second field), the ivar in this list (set for each ivar), and
3423 // the offset (third field in ivar structure)
3424 llvm::Type *IndexTy = Int32Ty;
3425 llvm::Constant *offsetPointerIndexes[] = {Zeros[0],
3426 llvm::ConstantInt::get(IndexTy, ClassABIVersion > 1 ? 2 : 1), nullptr,
3427 llvm::ConstantInt::get(IndexTy, ClassABIVersion > 1 ? 3 : 2) };
3429 unsigned ivarIndex = 0;
3430 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
3431 IVD = IVD->getNextIvar()) {
3432 const std::string Name = GetIVarOffsetVariableName(ClassDecl, IVD);
3433 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex);
3434 // Get the correct ivar field
3435 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr(
3436 cast<llvm::GlobalVariable>(IvarList)->getValueType(), IvarList,
3437 offsetPointerIndexes);
3438 // Get the existing variable, if one exists.
3439 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name);
3441 offset->setInitializer(offsetValue);
3442 // If this is the real definition, change its linkage type so that
3443 // different modules will use this one, rather than their private
3445 offset->setLinkage(llvm::GlobalValue::ExternalLinkage);
3447 // Add a new alias if there isn't one already.
3448 new llvm::GlobalVariable(TheModule, offsetValue->getType(),
3449 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name);
3452 llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0);
3454 //Generate metaclass for class methods
3455 llvm::Constant *MetaClassStruct = GenerateClassStructure(
3456 NULLPtr, NULLPtr, 0x12L, ClassName.c_str(), nullptr, Zeros[0],
3457 NULLPtr, ClassMethodList, NULLPtr, NULLPtr,
3458 GeneratePropertyList(OID, ClassDecl, true), ZeroPtr, ZeroPtr, true);
3459 CGM.setGVProperties(cast<llvm::GlobalValue>(MetaClassStruct),
3460 OID->getClassInterface());
3462 // Generate the class structure
3463 llvm::Constant *ClassStruct = GenerateClassStructure(
3464 MetaClassStruct, SuperClass, 0x11L, ClassName.c_str(), nullptr,
3465 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, MethodList,
3466 GenerateProtocolList(Protocols), IvarOffsetArray, Properties,
3467 StrongIvarBitmap, WeakIvarBitmap);
3468 CGM.setGVProperties(cast<llvm::GlobalValue>(ClassStruct),
3469 OID->getClassInterface());
3471 // Resolve the class aliases, if they exist.
3472 if (ClassPtrAlias) {
3473 ClassPtrAlias->replaceAllUsesWith(
3474 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy));
3475 ClassPtrAlias->eraseFromParent();
3476 ClassPtrAlias = nullptr;
3478 if (MetaClassPtrAlias) {
3479 MetaClassPtrAlias->replaceAllUsesWith(
3480 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy));
3481 MetaClassPtrAlias->eraseFromParent();
3482 MetaClassPtrAlias = nullptr;
3485 // Add class structure to list to be added to the symtab later
3486 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty);
3487 Classes.push_back(ClassStruct);
3490 llvm::Function *CGObjCGNU::ModuleInitFunction() {
3491 // Only emit an ObjC load function if no Objective-C stuff has been called
3492 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() &&
3493 ExistingProtocols.empty() && SelectorTable.empty())
3496 // Add all referenced protocols to a category.
3497 GenerateProtocolHolderCategory();
3499 llvm::StructType *selStructTy =
3500 dyn_cast<llvm::StructType>(SelectorTy->getElementType());
3501 llvm::Type *selStructPtrTy = SelectorTy;
3503 selStructTy = llvm::StructType::get(CGM.getLLVMContext(),
3504 { PtrToInt8Ty, PtrToInt8Ty });
3505 selStructPtrTy = llvm::PointerType::getUnqual(selStructTy);
3508 // Generate statics list:
3509 llvm::Constant *statics = NULLPtr;
3510 if (!ConstantStrings.empty()) {
3511 llvm::GlobalVariable *fileStatics = [&] {
3512 ConstantInitBuilder builder(CGM);
3513 auto staticsStruct = builder.beginStruct();
3515 StringRef stringClass = CGM.getLangOpts().ObjCConstantStringClass;
3516 if (stringClass.empty()) stringClass = "NXConstantString";
3517 staticsStruct.add(MakeConstantString(stringClass,
3518 ".objc_static_class_name"));
3520 auto array = staticsStruct.beginArray();
3521 array.addAll(ConstantStrings);
3523 array.finishAndAddTo(staticsStruct);
3525 return staticsStruct.finishAndCreateGlobal(".objc_statics",
3526 CGM.getPointerAlign());
3529 ConstantInitBuilder builder(CGM);
3530 auto allStaticsArray = builder.beginArray(fileStatics->getType());
3531 allStaticsArray.add(fileStatics);
3532 allStaticsArray.addNullPointer(fileStatics->getType());
3534 statics = allStaticsArray.finishAndCreateGlobal(".objc_statics_ptr",
3535 CGM.getPointerAlign());
3536 statics = llvm::ConstantExpr::getBitCast(statics, PtrTy);
3539 // Array of classes, categories, and constant objects.
3541 SmallVector<llvm::GlobalAlias*, 16> selectorAliases;
3542 unsigned selectorCount;
3544 // Pointer to an array of selectors used in this module.
3545 llvm::GlobalVariable *selectorList = [&] {
3546 ConstantInitBuilder builder(CGM);
3547 auto selectors = builder.beginArray(selStructTy);
3548 auto &table = SelectorTable; // MSVC workaround
3549 for (auto &entry : table) {
3551 std::string selNameStr = entry.first.getAsString();
3552 llvm::Constant *selName = ExportUniqueString(selNameStr, ".objc_sel_name");
3554 for (TypedSelector &sel : entry.second) {
3555 llvm::Constant *selectorTypeEncoding = NULLPtr;
3556 if (!sel.first.empty())
3557 selectorTypeEncoding =
3558 MakeConstantString(sel.first, ".objc_sel_types");
3560 auto selStruct = selectors.beginStruct(selStructTy);
3561 selStruct.add(selName);
3562 selStruct.add(selectorTypeEncoding);
3563 selStruct.finishAndAddTo(selectors);
3565 // Store the selector alias for later replacement
3566 selectorAliases.push_back(sel.second);
3570 // Remember the number of entries in the selector table.
3571 selectorCount = selectors.size();
3573 // NULL-terminate the selector list. This should not actually be required,
3574 // because the selector list has a length field. Unfortunately, the GCC
3575 // runtime decides to ignore the length field and expects a NULL terminator,
3576 // and GCC cooperates with this by always setting the length to 0.
3577 auto selStruct = selectors.beginStruct(selStructTy);
3578 selStruct.add(NULLPtr);
3579 selStruct.add(NULLPtr);
3580 selStruct.finishAndAddTo(selectors);
3582 return selectors.finishAndCreateGlobal(".objc_selector_list",
3583 CGM.getPointerAlign());
3586 // Now that all of the static selectors exist, create pointers to them.
3587 for (unsigned i = 0; i < selectorCount; ++i) {
3588 llvm::Constant *idxs[] = {
3590 llvm::ConstantInt::get(Int32Ty, i)
3592 // FIXME: We're generating redundant loads and stores here!
3593 llvm::Constant *selPtr = llvm::ConstantExpr::getGetElementPtr(
3594 selectorList->getValueType(), selectorList, idxs);
3595 // If selectors are defined as an opaque type, cast the pointer to this
3597 selPtr = llvm::ConstantExpr::getBitCast(selPtr, SelectorTy);
3598 selectorAliases[i]->replaceAllUsesWith(selPtr);
3599 selectorAliases[i]->eraseFromParent();
3602 llvm::GlobalVariable *symtab = [&] {
3603 ConstantInitBuilder builder(CGM);
3604 auto symtab = builder.beginStruct();
3606 // Number of static selectors
3607 symtab.addInt(LongTy, selectorCount);
3609 symtab.addBitCast(selectorList, selStructPtrTy);
3611 // Number of classes defined.
3612 symtab.addInt(CGM.Int16Ty, Classes.size());
3613 // Number of categories defined
3614 symtab.addInt(CGM.Int16Ty, Categories.size());
3616 // Create an array of classes, then categories, then static object instances
3617 auto classList = symtab.beginArray(PtrToInt8Ty);
3618 classList.addAll(Classes);
3619 classList.addAll(Categories);
3620 // NULL-terminated list of static object instances (mainly constant strings)
3621 classList.add(statics);
3622 classList.add(NULLPtr);
3623 classList.finishAndAddTo(symtab);
3625 // Construct the symbol table.
3626 return symtab.finishAndCreateGlobal("", CGM.getPointerAlign());
3629 // The symbol table is contained in a module which has some version-checking
3631 llvm::Constant *module = [&] {
3632 llvm::Type *moduleEltTys[] = {
3633 LongTy, LongTy, PtrToInt8Ty, symtab->getType(), IntTy
3635 llvm::StructType *moduleTy =
3636 llvm::StructType::get(CGM.getLLVMContext(),
3637 makeArrayRef(moduleEltTys).drop_back(unsigned(RuntimeVersion < 10)));
3639 ConstantInitBuilder builder(CGM);
3640 auto module = builder.beginStruct(moduleTy);
3641 // Runtime version, used for ABI compatibility checking.
3642 module.addInt(LongTy, RuntimeVersion);
3644 module.addInt(LongTy, CGM.getDataLayout().getTypeStoreSize(moduleTy));
3646 // The path to the source file where this module was declared
3647 SourceManager &SM = CGM.getContext().getSourceManager();
3648 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID());
3650 (Twine(mainFile->getDir()->getName()) + "/" + mainFile->getName()).str();
3651 module.add(MakeConstantString(path, ".objc_source_file_name"));
3654 if (RuntimeVersion >= 10) {
3655 switch (CGM.getLangOpts().getGC()) {
3656 case LangOptions::GCOnly:
3657 module.addInt(IntTy, 2);
3659 case LangOptions::NonGC:
3660 if (CGM.getLangOpts().ObjCAutoRefCount)
3661 module.addInt(IntTy, 1);
3663 module.addInt(IntTy, 0);
3665 case LangOptions::HybridGC:
3666 module.addInt(IntTy, 1);
3671 return module.finishAndCreateGlobal("", CGM.getPointerAlign());
3674 // Create the load function calling the runtime entry point with the module
3676 llvm::Function * LoadFunction = llvm::Function::Create(
3677 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false),
3678 llvm::GlobalValue::InternalLinkage, ".objc_load_function",
3680 llvm::BasicBlock *EntryBB =
3681 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction);
3682 CGBuilderTy Builder(CGM, VMContext);
3683 Builder.SetInsertPoint(EntryBB);
3685 llvm::FunctionType *FT =
3686 llvm::FunctionType::get(Builder.getVoidTy(), module->getType(), true);
3687 llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class");
3688 Builder.CreateCall(Register, module);
3690 if (!ClassAliases.empty()) {
3691 llvm::Type *ArgTypes[2] = {PtrTy, PtrToInt8Ty};
3692 llvm::FunctionType *RegisterAliasTy =
3693 llvm::FunctionType::get(Builder.getVoidTy(),
3695 llvm::Function *RegisterAlias = llvm::Function::Create(
3697 llvm::GlobalValue::ExternalWeakLinkage, "class_registerAlias_np",
3699 llvm::BasicBlock *AliasBB =
3700 llvm::BasicBlock::Create(VMContext, "alias", LoadFunction);
3701 llvm::BasicBlock *NoAliasBB =
3702 llvm::BasicBlock::Create(VMContext, "no_alias", LoadFunction);
3704 // Branch based on whether the runtime provided class_registerAlias_np()
3705 llvm::Value *HasRegisterAlias = Builder.CreateICmpNE(RegisterAlias,
3706 llvm::Constant::getNullValue(RegisterAlias->getType()));
3707 Builder.CreateCondBr(HasRegisterAlias, AliasBB, NoAliasBB);
3709 // The true branch (has alias registration function):
3710 Builder.SetInsertPoint(AliasBB);
3711 // Emit alias registration calls:
3712 for (std::vector<ClassAliasPair>::iterator iter = ClassAliases.begin();
3713 iter != ClassAliases.end(); ++iter) {
3714 llvm::Constant *TheClass =
3715 TheModule.getGlobalVariable("_OBJC_CLASS_" + iter->first, true);
3717 TheClass = llvm::ConstantExpr::getBitCast(TheClass, PtrTy);
3718 Builder.CreateCall(RegisterAlias,
3719 {TheClass, MakeConstantString(iter->second)});
3723 Builder.CreateBr(NoAliasBB);
3725 // Missing alias registration function, just return from the function:
3726 Builder.SetInsertPoint(NoAliasBB);
3728 Builder.CreateRetVoid();
3730 return LoadFunction;
3733 llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD,
3734 const ObjCContainerDecl *CD) {
3735 const ObjCCategoryImplDecl *OCD =
3736 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext());
3737 StringRef CategoryName = OCD ? OCD->getName() : "";
3738 StringRef ClassName = CD->getName();
3739 Selector MethodName = OMD->getSelector();
3740 bool isClassMethod = !OMD->isInstanceMethod();
3742 CodeGenTypes &Types = CGM.getTypes();
3743 llvm::FunctionType *MethodTy =
3744 Types.GetFunctionType(Types.arrangeObjCMethodDeclaration(OMD));
3745 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName,
3746 MethodName, isClassMethod);
3748 llvm::Function *Method
3749 = llvm::Function::Create(MethodTy,
3750 llvm::GlobalValue::InternalLinkage,
3756 llvm::Constant *CGObjCGNU::GetPropertyGetFunction() {
3757 return GetPropertyFn;
3760 llvm::Constant *CGObjCGNU::GetPropertySetFunction() {
3761 return SetPropertyFn;
3764 llvm::Constant *CGObjCGNU::GetOptimizedPropertySetFunction(bool atomic,
3769 llvm::Constant *CGObjCGNU::GetGetStructFunction() {
3770 return GetStructPropertyFn;
3773 llvm::Constant *CGObjCGNU::GetSetStructFunction() {
3774 return SetStructPropertyFn;
3777 llvm::Constant *CGObjCGNU::GetCppAtomicObjectGetFunction() {
3781 llvm::Constant *CGObjCGNU::GetCppAtomicObjectSetFunction() {
3785 llvm::Constant *CGObjCGNU::EnumerationMutationFunction() {
3786 return EnumerationMutationFn;
3789 void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF,
3790 const ObjCAtSynchronizedStmt &S) {
3791 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn);
3795 void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF,
3796 const ObjCAtTryStmt &S) {
3797 // Unlike the Apple non-fragile runtimes, which also uses
3798 // unwind-based zero cost exceptions, the GNU Objective C runtime's
3799 // EH support isn't a veneer over C++ EH. Instead, exception
3800 // objects are created by objc_exception_throw and destroyed by
3801 // the personality function; this avoids the need for bracketing
3802 // catch handlers with calls to __blah_begin_catch/__blah_end_catch
3803 // (or even _Unwind_DeleteException), but probably doesn't
3804 // interoperate very well with foreign exceptions.
3806 // In Objective-C++ mode, we actually emit something equivalent to the C++
3807 // exception handler.
3808 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn);
3811 void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF,
3812 const ObjCAtThrowStmt &S,
3813 bool ClearInsertionPoint) {
3814 llvm::Value *ExceptionAsObject;
3815 bool isRethrow = false;
3817 if (const Expr *ThrowExpr = S.getThrowExpr()) {
3818 llvm::Value *Exception = CGF.EmitObjCThrowOperand(ThrowExpr);
3819 ExceptionAsObject = Exception;
3821 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) &&
3822 "Unexpected rethrow outside @catch block.");
3823 ExceptionAsObject = CGF.ObjCEHValueStack.back();
3826 if (isRethrow && usesSEHExceptions) {
3827 // For SEH, ExceptionAsObject may be undef, because the catch handler is
3828 // not passed it for catchalls and so it is not visible to the catch
3829 // funclet. The real thrown object will still be live on the stack at this
3830 // point and will be rethrown. If we are explicitly rethrowing the object
3831 // that was passed into the `@catch` block, then this code path is not
3832 // reached and we will instead call `objc_exception_throw` with an explicit
3834 CGF.EmitRuntimeCallOrInvoke(ExceptionReThrowFn).setDoesNotReturn();
3837 ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy);
3838 llvm::CallSite Throw =
3839 CGF.EmitRuntimeCallOrInvoke(ExceptionThrowFn, ExceptionAsObject);
3840 Throw.setDoesNotReturn();
3842 CGF.Builder.CreateUnreachable();
3843 if (ClearInsertionPoint)
3844 CGF.Builder.ClearInsertionPoint();
3847 llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF,
3848 Address AddrWeakObj) {
3849 CGBuilderTy &B = CGF.Builder;
3850 AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy);
3851 return B.CreateCall(WeakReadFn.getType(), WeakReadFn,
3852 AddrWeakObj.getPointer());
3855 void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF,
3856 llvm::Value *src, Address dst) {
3857 CGBuilderTy &B = CGF.Builder;
3858 src = EnforceType(B, src, IdTy);
3859 dst = EnforceType(B, dst, PtrToIdTy);
3860 B.CreateCall(WeakAssignFn.getType(), WeakAssignFn,
3861 {src, dst.getPointer()});
3864 void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF,
3865 llvm::Value *src, Address dst,
3867 CGBuilderTy &B = CGF.Builder;
3868 src = EnforceType(B, src, IdTy);
3869 dst = EnforceType(B, dst, PtrToIdTy);
3870 // FIXME. Add threadloca assign API
3871 assert(!threadlocal && "EmitObjCGlobalAssign - Threal Local API NYI");
3872 B.CreateCall(GlobalAssignFn.getType(), GlobalAssignFn,
3873 {src, dst.getPointer()});
3876 void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF,
3877 llvm::Value *src, Address dst,
3878 llvm::Value *ivarOffset) {
3879 CGBuilderTy &B = CGF.Builder;
3880 src = EnforceType(B, src, IdTy);
3881 dst = EnforceType(B, dst, IdTy);
3882 B.CreateCall(IvarAssignFn.getType(), IvarAssignFn,
3883 {src, dst.getPointer(), ivarOffset});
3886 void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF,
3887 llvm::Value *src, Address dst) {
3888 CGBuilderTy &B = CGF.Builder;
3889 src = EnforceType(B, src, IdTy);
3890 dst = EnforceType(B, dst, PtrToIdTy);
3891 B.CreateCall(StrongCastAssignFn.getType(), StrongCastAssignFn,
3892 {src, dst.getPointer()});
3895 void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF,
3898 llvm::Value *Size) {
3899 CGBuilderTy &B = CGF.Builder;
3900 DestPtr = EnforceType(B, DestPtr, PtrTy);
3901 SrcPtr = EnforceType(B, SrcPtr, PtrTy);
3903 B.CreateCall(MemMoveFn.getType(), MemMoveFn,
3904 {DestPtr.getPointer(), SrcPtr.getPointer(), Size});
3907 llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable(
3908 const ObjCInterfaceDecl *ID,
3909 const ObjCIvarDecl *Ivar) {
3910 const std::string Name = GetIVarOffsetVariableName(ID, Ivar);
3911 // Emit the variable and initialize it with what we think the correct value
3912 // is. This allows code compiled with non-fragile ivars to work correctly
3913 // when linked against code which isn't (most of the time).
3914 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name);
3915 if (!IvarOffsetPointer)
3916 IvarOffsetPointer = new llvm::GlobalVariable(TheModule,
3917 llvm::Type::getInt32PtrTy(VMContext), false,
3918 llvm::GlobalValue::ExternalLinkage, nullptr, Name);
3919 return IvarOffsetPointer;
3922 LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF,
3924 llvm::Value *BaseValue,
3925 const ObjCIvarDecl *Ivar,
3926 unsigned CVRQualifiers) {
3927 const ObjCInterfaceDecl *ID =
3928 ObjectTy->getAs<ObjCObjectType>()->getInterface();
3929 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers,
3930 EmitIvarOffset(CGF, ID, Ivar));
3933 static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context,
3934 const ObjCInterfaceDecl *OID,
3935 const ObjCIvarDecl *OIVD) {
3936 for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next;
3937 next = next->getNextIvar()) {
3942 // Otherwise check in the super class.
3943 if (const ObjCInterfaceDecl *Super = OID->getSuperClass())
3944 return FindIvarInterface(Context, Super, OIVD);
3949 llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF,
3950 const ObjCInterfaceDecl *Interface,
3951 const ObjCIvarDecl *Ivar) {
3952 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
3953 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar);
3955 // The MSVC linker cannot have a single global defined as LinkOnceAnyLinkage
3956 // and ExternalLinkage, so create a reference to the ivar global and rely on
3957 // the definition being created as part of GenerateClass.
3958 if (RuntimeVersion < 10 ||
3959 CGF.CGM.getTarget().getTriple().isKnownWindowsMSVCEnvironment())
3960 return CGF.Builder.CreateZExtOrBitCast(
3961 CGF.Builder.CreateAlignedLoad(
3962 Int32Ty, CGF.Builder.CreateAlignedLoad(
3963 ObjCIvarOffsetVariable(Interface, Ivar),
3964 CGF.getPointerAlign(), "ivar"),
3965 CharUnits::fromQuantity(4)),
3967 std::string name = "__objc_ivar_offset_value_" +
3968 Interface->getNameAsString() +"." + Ivar->getNameAsString();
3969 CharUnits Align = CGM.getIntAlign();
3970 llvm::Value *Offset = TheModule.getGlobalVariable(name);
3972 auto GV = new llvm::GlobalVariable(TheModule, IntTy,
3973 false, llvm::GlobalValue::LinkOnceAnyLinkage,
3974 llvm::Constant::getNullValue(IntTy), name);
3975 GV->setAlignment(Align.getQuantity());
3978 Offset = CGF.Builder.CreateAlignedLoad(Offset, Align);
3979 if (Offset->getType() != PtrDiffTy)
3980 Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy);
3983 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar);
3984 return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true);
3988 clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) {
3989 auto Runtime = CGM.getLangOpts().ObjCRuntime;
3990 switch (Runtime.getKind()) {
3991 case ObjCRuntime::GNUstep:
3992 if (Runtime.getVersion() >= VersionTuple(2, 0))
3993 return new CGObjCGNUstep2(CGM);
3994 return new CGObjCGNUstep(CGM);
3996 case ObjCRuntime::GCC:
3997 return new CGObjCGCC(CGM);
3999 case ObjCRuntime::ObjFW:
4000 return new CGObjCObjFW(CGM);
4002 case ObjCRuntime::FragileMacOSX:
4003 case ObjCRuntime::MacOSX:
4004 case ObjCRuntime::iOS:
4005 case ObjCRuntime::WatchOS:
4006 llvm_unreachable("these runtimes are not GNU runtimes");
4008 llvm_unreachable("bad runtime");