[AMDGPU][AsmParser][NFC] Get rid of custom default operand handlers.
[llvm-project.git] / clang / lib / CodeGen / CGObjCGNU.cpp
blobc7b193e34ea0a349e20652bc77410ae9e8b60293
1 //===------- CGObjCGNU.cpp - Emit LLVM Code from ASTs for a Module --------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This provides Objective-C code generation targeting the GNU runtime. The
10 // class in this file generates structures used by the GNU Objective-C runtime
11 // library. These structures are defined in objc/objc.h and objc/objc-api.h in
12 // the GNU runtime distribution.
14 //===----------------------------------------------------------------------===//
16 #include "CGCXXABI.h"
17 #include "CGCleanup.h"
18 #include "CGObjCRuntime.h"
19 #include "CodeGenFunction.h"
20 #include "CodeGenModule.h"
21 #include "clang/AST/ASTContext.h"
22 #include "clang/AST/Attr.h"
23 #include "clang/AST/Decl.h"
24 #include "clang/AST/DeclObjC.h"
25 #include "clang/AST/RecordLayout.h"
26 #include "clang/AST/StmtObjC.h"
27 #include "clang/Basic/FileManager.h"
28 #include "clang/Basic/SourceManager.h"
29 #include "clang/CodeGen/ConstantInitBuilder.h"
30 #include "llvm/ADT/SmallVector.h"
31 #include "llvm/ADT/StringMap.h"
32 #include "llvm/IR/DataLayout.h"
33 #include "llvm/IR/Intrinsics.h"
34 #include "llvm/IR/LLVMContext.h"
35 #include "llvm/IR/Module.h"
36 #include "llvm/Support/Compiler.h"
37 #include "llvm/Support/ConvertUTF.h"
38 #include <cctype>
40 using namespace clang;
41 using namespace CodeGen;
43 namespace {
45 /// Class that lazily initialises the runtime function. Avoids inserting the
46 /// types and the function declaration into a module if they're not used, and
47 /// avoids constructing the type more than once if it's used more than once.
48 class LazyRuntimeFunction {
49 CodeGenModule *CGM;
50 llvm::FunctionType *FTy;
51 const char *FunctionName;
52 llvm::FunctionCallee Function;
54 public:
55 /// Constructor leaves this class uninitialized, because it is intended to
56 /// be used as a field in another class and not all of the types that are
57 /// used as arguments will necessarily be available at construction time.
58 LazyRuntimeFunction()
59 : CGM(nullptr), FunctionName(nullptr), Function(nullptr) {}
61 /// Initialises the lazy function with the name, return type, and the types
62 /// of the arguments.
63 template <typename... Tys>
64 void init(CodeGenModule *Mod, const char *name, llvm::Type *RetTy,
65 Tys *... Types) {
66 CGM = Mod;
67 FunctionName = name;
68 Function = nullptr;
69 if(sizeof...(Tys)) {
70 SmallVector<llvm::Type *, 8> ArgTys({Types...});
71 FTy = llvm::FunctionType::get(RetTy, ArgTys, false);
73 else {
74 FTy = llvm::FunctionType::get(RetTy, std::nullopt, false);
78 llvm::FunctionType *getType() { return FTy; }
80 /// Overloaded cast operator, allows the class to be implicitly cast to an
81 /// LLVM constant.
82 operator llvm::FunctionCallee() {
83 if (!Function) {
84 if (!FunctionName)
85 return nullptr;
86 Function = CGM->CreateRuntimeFunction(FTy, FunctionName);
88 return Function;
93 /// GNU Objective-C runtime code generation. This class implements the parts of
94 /// Objective-C support that are specific to the GNU family of runtimes (GCC,
95 /// GNUstep and ObjFW).
96 class CGObjCGNU : public CGObjCRuntime {
97 protected:
98 /// The LLVM module into which output is inserted
99 llvm::Module &TheModule;
100 /// strut objc_super. Used for sending messages to super. This structure
101 /// contains the receiver (object) and the expected class.
102 llvm::StructType *ObjCSuperTy;
103 /// struct objc_super*. The type of the argument to the superclass message
104 /// lookup functions.
105 llvm::PointerType *PtrToObjCSuperTy;
106 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring
107 /// SEL is included in a header somewhere, in which case it will be whatever
108 /// type is declared in that header, most likely {i8*, i8*}.
109 llvm::PointerType *SelectorTy;
110 /// Element type of SelectorTy.
111 llvm::Type *SelectorElemTy;
112 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the
113 /// places where it's used
114 llvm::IntegerType *Int8Ty;
115 /// Pointer to i8 - LLVM type of char*, for all of the places where the
116 /// runtime needs to deal with C strings.
117 llvm::PointerType *PtrToInt8Ty;
118 /// struct objc_protocol type
119 llvm::StructType *ProtocolTy;
120 /// Protocol * type.
121 llvm::PointerType *ProtocolPtrTy;
122 /// Instance Method Pointer type. This is a pointer to a function that takes,
123 /// at a minimum, an object and a selector, and is the generic type for
124 /// Objective-C methods. Due to differences between variadic / non-variadic
125 /// calling conventions, it must always be cast to the correct type before
126 /// actually being used.
127 llvm::PointerType *IMPTy;
128 /// Type of an untyped Objective-C object. Clang treats id as a built-in type
129 /// when compiling Objective-C code, so this may be an opaque pointer (i8*),
130 /// but if the runtime header declaring it is included then it may be a
131 /// pointer to a structure.
132 llvm::PointerType *IdTy;
133 /// Element type of IdTy.
134 llvm::Type *IdElemTy;
135 /// Pointer to a pointer to an Objective-C object. Used in the new ABI
136 /// message lookup function and some GC-related functions.
137 llvm::PointerType *PtrToIdTy;
138 /// The clang type of id. Used when using the clang CGCall infrastructure to
139 /// call Objective-C methods.
140 CanQualType ASTIdTy;
141 /// LLVM type for C int type.
142 llvm::IntegerType *IntTy;
143 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is
144 /// used in the code to document the difference between i8* meaning a pointer
145 /// to a C string and i8* meaning a pointer to some opaque type.
146 llvm::PointerType *PtrTy;
147 /// LLVM type for C long type. The runtime uses this in a lot of places where
148 /// it should be using intptr_t, but we can't fix this without breaking
149 /// compatibility with GCC...
150 llvm::IntegerType *LongTy;
151 /// LLVM type for C size_t. Used in various runtime data structures.
152 llvm::IntegerType *SizeTy;
153 /// LLVM type for C intptr_t.
154 llvm::IntegerType *IntPtrTy;
155 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions.
156 llvm::IntegerType *PtrDiffTy;
157 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance
158 /// variables.
159 llvm::PointerType *PtrToIntTy;
160 /// LLVM type for Objective-C BOOL type.
161 llvm::Type *BoolTy;
162 /// 32-bit integer type, to save us needing to look it up every time it's used.
163 llvm::IntegerType *Int32Ty;
164 /// 64-bit integer type, to save us needing to look it up every time it's used.
165 llvm::IntegerType *Int64Ty;
166 /// The type of struct objc_property.
167 llvm::StructType *PropertyMetadataTy;
168 /// Metadata kind used to tie method lookups to message sends. The GNUstep
169 /// runtime provides some LLVM passes that can use this to do things like
170 /// automatic IMP caching and speculative inlining.
171 unsigned msgSendMDKind;
172 /// Does the current target use SEH-based exceptions? False implies
173 /// Itanium-style DWARF unwinding.
174 bool usesSEHExceptions;
176 /// Helper to check if we are targeting a specific runtime version or later.
177 bool isRuntime(ObjCRuntime::Kind kind, unsigned major, unsigned minor=0) {
178 const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
179 return (R.getKind() == kind) &&
180 (R.getVersion() >= VersionTuple(major, minor));
183 std::string ManglePublicSymbol(StringRef Name) {
184 return (StringRef(CGM.getTriple().isOSBinFormatCOFF() ? "$_" : "._") + Name).str();
187 std::string SymbolForProtocol(Twine Name) {
188 return (ManglePublicSymbol("OBJC_PROTOCOL_") + Name).str();
191 std::string SymbolForProtocolRef(StringRef Name) {
192 return (ManglePublicSymbol("OBJC_REF_PROTOCOL_") + Name).str();
196 /// Helper function that generates a constant string and returns a pointer to
197 /// the start of the string. The result of this function can be used anywhere
198 /// where the C code specifies const char*.
199 llvm::Constant *MakeConstantString(StringRef Str, const char *Name = "") {
200 ConstantAddress Array =
201 CGM.GetAddrOfConstantCString(std::string(Str), Name);
202 return llvm::ConstantExpr::getGetElementPtr(Array.getElementType(),
203 Array.getPointer(), Zeros);
206 /// Emits a linkonce_odr string, whose name is the prefix followed by the
207 /// string value. This allows the linker to combine the strings between
208 /// different modules. Used for EH typeinfo names, selector strings, and a
209 /// few other things.
210 llvm::Constant *ExportUniqueString(const std::string &Str,
211 const std::string &prefix,
212 bool Private=false) {
213 std::string name = prefix + Str;
214 auto *ConstStr = TheModule.getGlobalVariable(name);
215 if (!ConstStr) {
216 llvm::Constant *value = llvm::ConstantDataArray::getString(VMContext,Str);
217 auto *GV = new llvm::GlobalVariable(TheModule, value->getType(), true,
218 llvm::GlobalValue::LinkOnceODRLinkage, value, name);
219 GV->setComdat(TheModule.getOrInsertComdat(name));
220 if (Private)
221 GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
222 ConstStr = GV;
224 return llvm::ConstantExpr::getGetElementPtr(ConstStr->getValueType(),
225 ConstStr, Zeros);
228 /// Returns a property name and encoding string.
229 llvm::Constant *MakePropertyEncodingString(const ObjCPropertyDecl *PD,
230 const Decl *Container) {
231 assert(!isRuntime(ObjCRuntime::GNUstep, 2));
232 if (isRuntime(ObjCRuntime::GNUstep, 1, 6)) {
233 std::string NameAndAttributes;
234 std::string TypeStr =
235 CGM.getContext().getObjCEncodingForPropertyDecl(PD, Container);
236 NameAndAttributes += '\0';
237 NameAndAttributes += TypeStr.length() + 3;
238 NameAndAttributes += TypeStr;
239 NameAndAttributes += '\0';
240 NameAndAttributes += PD->getNameAsString();
241 return MakeConstantString(NameAndAttributes);
243 return MakeConstantString(PD->getNameAsString());
246 /// Push the property attributes into two structure fields.
247 void PushPropertyAttributes(ConstantStructBuilder &Fields,
248 const ObjCPropertyDecl *property, bool isSynthesized=true, bool
249 isDynamic=true) {
250 int attrs = property->getPropertyAttributes();
251 // For read-only properties, clear the copy and retain flags
252 if (attrs & ObjCPropertyAttribute::kind_readonly) {
253 attrs &= ~ObjCPropertyAttribute::kind_copy;
254 attrs &= ~ObjCPropertyAttribute::kind_retain;
255 attrs &= ~ObjCPropertyAttribute::kind_weak;
256 attrs &= ~ObjCPropertyAttribute::kind_strong;
258 // The first flags field has the same attribute values as clang uses internally
259 Fields.addInt(Int8Ty, attrs & 0xff);
260 attrs >>= 8;
261 attrs <<= 2;
262 // For protocol properties, synthesized and dynamic have no meaning, so we
263 // reuse these flags to indicate that this is a protocol property (both set
264 // has no meaning, as a property can't be both synthesized and dynamic)
265 attrs |= isSynthesized ? (1<<0) : 0;
266 attrs |= isDynamic ? (1<<1) : 0;
267 // The second field is the next four fields left shifted by two, with the
268 // low bit set to indicate whether the field is synthesized or dynamic.
269 Fields.addInt(Int8Ty, attrs & 0xff);
270 // Two padding fields
271 Fields.addInt(Int8Ty, 0);
272 Fields.addInt(Int8Ty, 0);
275 virtual llvm::Constant *GenerateCategoryProtocolList(const
276 ObjCCategoryDecl *OCD);
277 virtual ConstantArrayBuilder PushPropertyListHeader(ConstantStructBuilder &Fields,
278 int count) {
279 // int count;
280 Fields.addInt(IntTy, count);
281 // int size; (only in GNUstep v2 ABI.
282 if (isRuntime(ObjCRuntime::GNUstep, 2)) {
283 llvm::DataLayout td(&TheModule);
284 Fields.addInt(IntTy, td.getTypeSizeInBits(PropertyMetadataTy) /
285 CGM.getContext().getCharWidth());
287 // struct objc_property_list *next;
288 Fields.add(NULLPtr);
289 // struct objc_property properties[]
290 return Fields.beginArray(PropertyMetadataTy);
292 virtual void PushProperty(ConstantArrayBuilder &PropertiesArray,
293 const ObjCPropertyDecl *property,
294 const Decl *OCD,
295 bool isSynthesized=true, bool
296 isDynamic=true) {
297 auto Fields = PropertiesArray.beginStruct(PropertyMetadataTy);
298 ASTContext &Context = CGM.getContext();
299 Fields.add(MakePropertyEncodingString(property, OCD));
300 PushPropertyAttributes(Fields, property, isSynthesized, isDynamic);
301 auto addPropertyMethod = [&](const ObjCMethodDecl *accessor) {
302 if (accessor) {
303 std::string TypeStr = Context.getObjCEncodingForMethodDecl(accessor);
304 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
305 Fields.add(MakeConstantString(accessor->getSelector().getAsString()));
306 Fields.add(TypeEncoding);
307 } else {
308 Fields.add(NULLPtr);
309 Fields.add(NULLPtr);
312 addPropertyMethod(property->getGetterMethodDecl());
313 addPropertyMethod(property->getSetterMethodDecl());
314 Fields.finishAndAddTo(PropertiesArray);
317 /// Ensures that the value has the required type, by inserting a bitcast if
318 /// required. This function lets us avoid inserting bitcasts that are
319 /// redundant.
320 llvm::Value *EnforceType(CGBuilderTy &B, llvm::Value *V, llvm::Type *Ty) {
321 if (V->getType() == Ty)
322 return V;
323 return B.CreateBitCast(V, Ty);
326 // Some zeros used for GEPs in lots of places.
327 llvm::Constant *Zeros[2];
328 /// Null pointer value. Mainly used as a terminator in various arrays.
329 llvm::Constant *NULLPtr;
330 /// LLVM context.
331 llvm::LLVMContext &VMContext;
333 protected:
335 /// Placeholder for the class. Lots of things refer to the class before we've
336 /// actually emitted it. We use this alias as a placeholder, and then replace
337 /// it with a pointer to the class structure before finally emitting the
338 /// module.
339 llvm::GlobalAlias *ClassPtrAlias;
340 /// Placeholder for the metaclass. Lots of things refer to the class before
341 /// we've / actually emitted it. We use this alias as a placeholder, and then
342 /// replace / it with a pointer to the metaclass structure before finally
343 /// emitting the / module.
344 llvm::GlobalAlias *MetaClassPtrAlias;
345 /// All of the classes that have been generated for this compilation units.
346 std::vector<llvm::Constant*> Classes;
347 /// All of the categories that have been generated for this compilation units.
348 std::vector<llvm::Constant*> Categories;
349 /// All of the Objective-C constant strings that have been generated for this
350 /// compilation units.
351 std::vector<llvm::Constant*> ConstantStrings;
352 /// Map from string values to Objective-C constant strings in the output.
353 /// Used to prevent emitting Objective-C strings more than once. This should
354 /// not be required at all - CodeGenModule should manage this list.
355 llvm::StringMap<llvm::Constant*> ObjCStrings;
356 /// All of the protocols that have been declared.
357 llvm::StringMap<llvm::Constant*> ExistingProtocols;
358 /// For each variant of a selector, we store the type encoding and a
359 /// placeholder value. For an untyped selector, the type will be the empty
360 /// string. Selector references are all done via the module's selector table,
361 /// so we create an alias as a placeholder and then replace it with the real
362 /// value later.
363 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector;
364 /// Type of the selector map. This is roughly equivalent to the structure
365 /// used in the GNUstep runtime, which maintains a list of all of the valid
366 /// types for a selector in a table.
367 typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> >
368 SelectorMap;
369 /// A map from selectors to selector types. This allows us to emit all
370 /// selectors of the same name and type together.
371 SelectorMap SelectorTable;
373 /// Selectors related to memory management. When compiling in GC mode, we
374 /// omit these.
375 Selector RetainSel, ReleaseSel, AutoreleaseSel;
376 /// Runtime functions used for memory management in GC mode. Note that clang
377 /// supports code generation for calling these functions, but neither GNU
378 /// runtime actually supports this API properly yet.
379 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn,
380 WeakAssignFn, GlobalAssignFn;
382 typedef std::pair<std::string, std::string> ClassAliasPair;
383 /// All classes that have aliases set for them.
384 std::vector<ClassAliasPair> ClassAliases;
386 protected:
387 /// Function used for throwing Objective-C exceptions.
388 LazyRuntimeFunction ExceptionThrowFn;
389 /// Function used for rethrowing exceptions, used at the end of \@finally or
390 /// \@synchronize blocks.
391 LazyRuntimeFunction ExceptionReThrowFn;
392 /// Function called when entering a catch function. This is required for
393 /// differentiating Objective-C exceptions and foreign exceptions.
394 LazyRuntimeFunction EnterCatchFn;
395 /// Function called when exiting from a catch block. Used to do exception
396 /// cleanup.
397 LazyRuntimeFunction ExitCatchFn;
398 /// Function called when entering an \@synchronize block. Acquires the lock.
399 LazyRuntimeFunction SyncEnterFn;
400 /// Function called when exiting an \@synchronize block. Releases the lock.
401 LazyRuntimeFunction SyncExitFn;
403 private:
404 /// Function called if fast enumeration detects that the collection is
405 /// modified during the update.
406 LazyRuntimeFunction EnumerationMutationFn;
407 /// Function for implementing synthesized property getters that return an
408 /// object.
409 LazyRuntimeFunction GetPropertyFn;
410 /// Function for implementing synthesized property setters that return an
411 /// object.
412 LazyRuntimeFunction SetPropertyFn;
413 /// Function used for non-object declared property getters.
414 LazyRuntimeFunction GetStructPropertyFn;
415 /// Function used for non-object declared property setters.
416 LazyRuntimeFunction SetStructPropertyFn;
418 protected:
419 /// The version of the runtime that this class targets. Must match the
420 /// version in the runtime.
421 int RuntimeVersion;
422 /// The version of the protocol class. Used to differentiate between ObjC1
423 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional
424 /// components and can not contain declared properties. We always emit
425 /// Objective-C 2 property structures, but we have to pretend that they're
426 /// Objective-C 1 property structures when targeting the GCC runtime or it
427 /// will abort.
428 const int ProtocolVersion;
429 /// The version of the class ABI. This value is used in the class structure
430 /// and indicates how various fields should be interpreted.
431 const int ClassABIVersion;
432 /// Generates an instance variable list structure. This is a structure
433 /// containing a size and an array of structures containing instance variable
434 /// metadata. This is used purely for introspection in the fragile ABI. In
435 /// the non-fragile ABI, it's used for instance variable fixup.
436 virtual llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
437 ArrayRef<llvm::Constant *> IvarTypes,
438 ArrayRef<llvm::Constant *> IvarOffsets,
439 ArrayRef<llvm::Constant *> IvarAlign,
440 ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership);
442 /// Generates a method list structure. This is a structure containing a size
443 /// and an array of structures containing method metadata.
445 /// This structure is used by both classes and categories, and contains a next
446 /// pointer allowing them to be chained together in a linked list.
447 llvm::Constant *GenerateMethodList(StringRef ClassName,
448 StringRef CategoryName,
449 ArrayRef<const ObjCMethodDecl*> Methods,
450 bool isClassMethodList);
452 /// Emits an empty protocol. This is used for \@protocol() where no protocol
453 /// is found. The runtime will (hopefully) fix up the pointer to refer to the
454 /// real protocol.
455 virtual llvm::Constant *GenerateEmptyProtocol(StringRef ProtocolName);
457 /// Generates a list of property metadata structures. This follows the same
458 /// pattern as method and instance variable metadata lists.
459 llvm::Constant *GeneratePropertyList(const Decl *Container,
460 const ObjCContainerDecl *OCD,
461 bool isClassProperty=false,
462 bool protocolOptionalProperties=false);
464 /// Generates a list of referenced protocols. Classes, categories, and
465 /// protocols all use this structure.
466 llvm::Constant *GenerateProtocolList(ArrayRef<std::string> Protocols);
468 /// To ensure that all protocols are seen by the runtime, we add a category on
469 /// a class defined in the runtime, declaring no methods, but adopting the
470 /// protocols. This is a horribly ugly hack, but it allows us to collect all
471 /// of the protocols without changing the ABI.
472 void GenerateProtocolHolderCategory();
474 /// Generates a class structure.
475 llvm::Constant *GenerateClassStructure(
476 llvm::Constant *MetaClass,
477 llvm::Constant *SuperClass,
478 unsigned info,
479 const char *Name,
480 llvm::Constant *Version,
481 llvm::Constant *InstanceSize,
482 llvm::Constant *IVars,
483 llvm::Constant *Methods,
484 llvm::Constant *Protocols,
485 llvm::Constant *IvarOffsets,
486 llvm::Constant *Properties,
487 llvm::Constant *StrongIvarBitmap,
488 llvm::Constant *WeakIvarBitmap,
489 bool isMeta=false);
491 /// Generates a method list. This is used by protocols to define the required
492 /// and optional methods.
493 virtual llvm::Constant *GenerateProtocolMethodList(
494 ArrayRef<const ObjCMethodDecl*> Methods);
495 /// Emits optional and required method lists.
496 template<class T>
497 void EmitProtocolMethodList(T &&Methods, llvm::Constant *&Required,
498 llvm::Constant *&Optional) {
499 SmallVector<const ObjCMethodDecl*, 16> RequiredMethods;
500 SmallVector<const ObjCMethodDecl*, 16> OptionalMethods;
501 for (const auto *I : Methods)
502 if (I->isOptional())
503 OptionalMethods.push_back(I);
504 else
505 RequiredMethods.push_back(I);
506 Required = GenerateProtocolMethodList(RequiredMethods);
507 Optional = GenerateProtocolMethodList(OptionalMethods);
510 /// Returns a selector with the specified type encoding. An empty string is
511 /// used to return an untyped selector (with the types field set to NULL).
512 virtual llvm::Value *GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
513 const std::string &TypeEncoding);
515 /// Returns the name of ivar offset variables. In the GNUstep v1 ABI, this
516 /// contains the class and ivar names, in the v2 ABI this contains the type
517 /// encoding as well.
518 virtual std::string GetIVarOffsetVariableName(const ObjCInterfaceDecl *ID,
519 const ObjCIvarDecl *Ivar) {
520 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString()
521 + '.' + Ivar->getNameAsString();
522 return Name;
524 /// Returns the variable used to store the offset of an instance variable.
525 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID,
526 const ObjCIvarDecl *Ivar);
527 /// Emits a reference to a class. This allows the linker to object if there
528 /// is no class of the matching name.
529 void EmitClassRef(const std::string &className);
531 /// Emits a pointer to the named class
532 virtual llvm::Value *GetClassNamed(CodeGenFunction &CGF,
533 const std::string &Name, bool isWeak);
535 /// Looks up the method for sending a message to the specified object. This
536 /// mechanism differs between the GCC and GNU runtimes, so this method must be
537 /// overridden in subclasses.
538 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF,
539 llvm::Value *&Receiver,
540 llvm::Value *cmd,
541 llvm::MDNode *node,
542 MessageSendInfo &MSI) = 0;
544 /// Looks up the method for sending a message to a superclass. This
545 /// mechanism differs between the GCC and GNU runtimes, so this method must
546 /// be overridden in subclasses.
547 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF,
548 Address ObjCSuper,
549 llvm::Value *cmd,
550 MessageSendInfo &MSI) = 0;
552 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are
553 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63
554 /// bits set to their values, LSB first, while larger ones are stored in a
555 /// structure of this / form:
557 /// struct { int32_t length; int32_t values[length]; };
559 /// The values in the array are stored in host-endian format, with the least
560 /// significant bit being assumed to come first in the bitfield. Therefore,
561 /// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] },
562 /// while a bitfield / with the 63rd bit set will be 1<<64.
563 llvm::Constant *MakeBitField(ArrayRef<bool> bits);
565 public:
566 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
567 unsigned protocolClassVersion, unsigned classABI=1);
569 ConstantAddress GenerateConstantString(const StringLiteral *) override;
571 RValue
572 GenerateMessageSend(CodeGenFunction &CGF, ReturnValueSlot Return,
573 QualType ResultType, Selector Sel,
574 llvm::Value *Receiver, const CallArgList &CallArgs,
575 const ObjCInterfaceDecl *Class,
576 const ObjCMethodDecl *Method) override;
577 RValue
578 GenerateMessageSendSuper(CodeGenFunction &CGF, ReturnValueSlot Return,
579 QualType ResultType, Selector Sel,
580 const ObjCInterfaceDecl *Class,
581 bool isCategoryImpl, llvm::Value *Receiver,
582 bool IsClassMessage, const CallArgList &CallArgs,
583 const ObjCMethodDecl *Method) override;
584 llvm::Value *GetClass(CodeGenFunction &CGF,
585 const ObjCInterfaceDecl *OID) override;
586 llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel) override;
587 Address GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) override;
588 llvm::Value *GetSelector(CodeGenFunction &CGF,
589 const ObjCMethodDecl *Method) override;
590 virtual llvm::Constant *GetConstantSelector(Selector Sel,
591 const std::string &TypeEncoding) {
592 llvm_unreachable("Runtime unable to generate constant selector");
594 llvm::Constant *GetConstantSelector(const ObjCMethodDecl *M) {
595 return GetConstantSelector(M->getSelector(),
596 CGM.getContext().getObjCEncodingForMethodDecl(M));
598 llvm::Constant *GetEHType(QualType T) override;
600 llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
601 const ObjCContainerDecl *CD) override;
602 void GenerateDirectMethodPrologue(CodeGenFunction &CGF, llvm::Function *Fn,
603 const ObjCMethodDecl *OMD,
604 const ObjCContainerDecl *CD) override;
605 void GenerateCategory(const ObjCCategoryImplDecl *CMD) override;
606 void GenerateClass(const ObjCImplementationDecl *ClassDecl) override;
607 void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) override;
608 llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
609 const ObjCProtocolDecl *PD) override;
610 void GenerateProtocol(const ObjCProtocolDecl *PD) override;
612 virtual llvm::Constant *GenerateProtocolRef(const ObjCProtocolDecl *PD);
614 llvm::Constant *GetOrEmitProtocol(const ObjCProtocolDecl *PD) override {
615 return GenerateProtocolRef(PD);
618 llvm::Function *ModuleInitFunction() override;
619 llvm::FunctionCallee GetPropertyGetFunction() override;
620 llvm::FunctionCallee GetPropertySetFunction() override;
621 llvm::FunctionCallee GetOptimizedPropertySetFunction(bool atomic,
622 bool copy) override;
623 llvm::FunctionCallee GetSetStructFunction() override;
624 llvm::FunctionCallee GetGetStructFunction() override;
625 llvm::FunctionCallee GetCppAtomicObjectGetFunction() override;
626 llvm::FunctionCallee GetCppAtomicObjectSetFunction() override;
627 llvm::FunctionCallee EnumerationMutationFunction() override;
629 void EmitTryStmt(CodeGenFunction &CGF,
630 const ObjCAtTryStmt &S) override;
631 void EmitSynchronizedStmt(CodeGenFunction &CGF,
632 const ObjCAtSynchronizedStmt &S) override;
633 void EmitThrowStmt(CodeGenFunction &CGF,
634 const ObjCAtThrowStmt &S,
635 bool ClearInsertionPoint=true) override;
636 llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF,
637 Address AddrWeakObj) override;
638 void EmitObjCWeakAssign(CodeGenFunction &CGF,
639 llvm::Value *src, Address dst) override;
640 void EmitObjCGlobalAssign(CodeGenFunction &CGF,
641 llvm::Value *src, Address dest,
642 bool threadlocal=false) override;
643 void EmitObjCIvarAssign(CodeGenFunction &CGF, llvm::Value *src,
644 Address dest, llvm::Value *ivarOffset) override;
645 void EmitObjCStrongCastAssign(CodeGenFunction &CGF,
646 llvm::Value *src, Address dest) override;
647 void EmitGCMemmoveCollectable(CodeGenFunction &CGF, Address DestPtr,
648 Address SrcPtr,
649 llvm::Value *Size) override;
650 LValue EmitObjCValueForIvar(CodeGenFunction &CGF, QualType ObjectTy,
651 llvm::Value *BaseValue, const ObjCIvarDecl *Ivar,
652 unsigned CVRQualifiers) override;
653 llvm::Value *EmitIvarOffset(CodeGenFunction &CGF,
654 const ObjCInterfaceDecl *Interface,
655 const ObjCIvarDecl *Ivar) override;
656 llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) override;
657 llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM,
658 const CGBlockInfo &blockInfo) override {
659 return NULLPtr;
661 llvm::Constant *BuildRCBlockLayout(CodeGenModule &CGM,
662 const CGBlockInfo &blockInfo) override {
663 return NULLPtr;
666 llvm::Constant *BuildByrefLayout(CodeGenModule &CGM, QualType T) override {
667 return NULLPtr;
671 /// Class representing the legacy GCC Objective-C ABI. This is the default when
672 /// -fobjc-nonfragile-abi is not specified.
674 /// The GCC ABI target actually generates code that is approximately compatible
675 /// with the new GNUstep runtime ABI, but refrains from using any features that
676 /// would not work with the GCC runtime. For example, clang always generates
677 /// the extended form of the class structure, and the extra fields are simply
678 /// ignored by GCC libobjc.
679 class CGObjCGCC : public CGObjCGNU {
680 /// The GCC ABI message lookup function. Returns an IMP pointing to the
681 /// method implementation for this message.
682 LazyRuntimeFunction MsgLookupFn;
683 /// The GCC ABI superclass message lookup function. Takes a pointer to a
684 /// structure describing the receiver and the class, and a selector as
685 /// arguments. Returns the IMP for the corresponding method.
686 LazyRuntimeFunction MsgLookupSuperFn;
688 protected:
689 llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
690 llvm::Value *cmd, llvm::MDNode *node,
691 MessageSendInfo &MSI) override {
692 CGBuilderTy &Builder = CGF.Builder;
693 llvm::Value *args[] = {
694 EnforceType(Builder, Receiver, IdTy),
695 EnforceType(Builder, cmd, SelectorTy) };
696 llvm::CallBase *imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);
697 imp->setMetadata(msgSendMDKind, node);
698 return imp;
701 llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
702 llvm::Value *cmd, MessageSendInfo &MSI) override {
703 CGBuilderTy &Builder = CGF.Builder;
704 llvm::Value *lookupArgs[] = {
705 EnforceType(Builder, ObjCSuper.getPointer(), PtrToObjCSuperTy), cmd};
706 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
709 public:
710 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) {
711 // IMP objc_msg_lookup(id, SEL);
712 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy);
713 // IMP objc_msg_lookup_super(struct objc_super*, SEL);
714 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
715 PtrToObjCSuperTy, SelectorTy);
719 /// Class used when targeting the new GNUstep runtime ABI.
720 class CGObjCGNUstep : public CGObjCGNU {
721 /// The slot lookup function. Returns a pointer to a cacheable structure
722 /// that contains (among other things) the IMP.
723 LazyRuntimeFunction SlotLookupFn;
724 /// The GNUstep ABI superclass message lookup function. Takes a pointer to
725 /// a structure describing the receiver and the class, and a selector as
726 /// arguments. Returns the slot for the corresponding method. Superclass
727 /// message lookup rarely changes, so this is a good caching opportunity.
728 LazyRuntimeFunction SlotLookupSuperFn;
729 /// Specialised function for setting atomic retain properties
730 LazyRuntimeFunction SetPropertyAtomic;
731 /// Specialised function for setting atomic copy properties
732 LazyRuntimeFunction SetPropertyAtomicCopy;
733 /// Specialised function for setting nonatomic retain properties
734 LazyRuntimeFunction SetPropertyNonAtomic;
735 /// Specialised function for setting nonatomic copy properties
736 LazyRuntimeFunction SetPropertyNonAtomicCopy;
737 /// Function to perform atomic copies of C++ objects with nontrivial copy
738 /// constructors from Objective-C ivars.
739 LazyRuntimeFunction CxxAtomicObjectGetFn;
740 /// Function to perform atomic copies of C++ objects with nontrivial copy
741 /// constructors to Objective-C ivars.
742 LazyRuntimeFunction CxxAtomicObjectSetFn;
743 /// Type of a slot structure pointer. This is returned by the various
744 /// lookup functions.
745 llvm::Type *SlotTy;
746 /// Type of a slot structure.
747 llvm::Type *SlotStructTy;
749 public:
750 llvm::Constant *GetEHType(QualType T) override;
752 protected:
753 llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
754 llvm::Value *cmd, llvm::MDNode *node,
755 MessageSendInfo &MSI) override {
756 CGBuilderTy &Builder = CGF.Builder;
757 llvm::FunctionCallee LookupFn = SlotLookupFn;
759 // Store the receiver on the stack so that we can reload it later
760 Address ReceiverPtr =
761 CGF.CreateTempAlloca(Receiver->getType(), CGF.getPointerAlign());
762 Builder.CreateStore(Receiver, ReceiverPtr);
764 llvm::Value *self;
766 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) {
767 self = CGF.LoadObjCSelf();
768 } else {
769 self = llvm::ConstantPointerNull::get(IdTy);
772 // The lookup function is guaranteed not to capture the receiver pointer.
773 if (auto *LookupFn2 = dyn_cast<llvm::Function>(LookupFn.getCallee()))
774 LookupFn2->addParamAttr(0, llvm::Attribute::NoCapture);
776 llvm::Value *args[] = {
777 EnforceType(Builder, ReceiverPtr.getPointer(), PtrToIdTy),
778 EnforceType(Builder, cmd, SelectorTy),
779 EnforceType(Builder, self, IdTy) };
780 llvm::CallBase *slot = CGF.EmitRuntimeCallOrInvoke(LookupFn, args);
781 slot->setOnlyReadsMemory();
782 slot->setMetadata(msgSendMDKind, node);
784 // Load the imp from the slot
785 llvm::Value *imp = Builder.CreateAlignedLoad(
786 IMPTy, Builder.CreateStructGEP(SlotStructTy, slot, 4),
787 CGF.getPointerAlign());
789 // The lookup function may have changed the receiver, so make sure we use
790 // the new one.
791 Receiver = Builder.CreateLoad(ReceiverPtr, true);
792 return imp;
795 llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
796 llvm::Value *cmd,
797 MessageSendInfo &MSI) override {
798 CGBuilderTy &Builder = CGF.Builder;
799 llvm::Value *lookupArgs[] = {ObjCSuper.getPointer(), cmd};
801 llvm::CallInst *slot =
802 CGF.EmitNounwindRuntimeCall(SlotLookupSuperFn, lookupArgs);
803 slot->setOnlyReadsMemory();
805 return Builder.CreateAlignedLoad(
806 IMPTy, Builder.CreateStructGEP(SlotStructTy, slot, 4),
807 CGF.getPointerAlign());
810 public:
811 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNUstep(Mod, 9, 3, 1) {}
812 CGObjCGNUstep(CodeGenModule &Mod, unsigned ABI, unsigned ProtocolABI,
813 unsigned ClassABI) :
814 CGObjCGNU(Mod, ABI, ProtocolABI, ClassABI) {
815 const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
817 SlotStructTy = llvm::StructType::get(PtrTy, PtrTy, PtrTy, IntTy, IMPTy);
818 SlotTy = llvm::PointerType::getUnqual(SlotStructTy);
819 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender);
820 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy,
821 SelectorTy, IdTy);
822 // Slot_t objc_slot_lookup_super(struct objc_super*, SEL);
823 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy,
824 PtrToObjCSuperTy, SelectorTy);
825 // If we're in ObjC++ mode, then we want to make
826 if (usesSEHExceptions) {
827 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
828 // void objc_exception_rethrow(void)
829 ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy);
830 } else if (CGM.getLangOpts().CPlusPlus) {
831 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
832 // void *__cxa_begin_catch(void *e)
833 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy);
834 // void __cxa_end_catch(void)
835 ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy);
836 // void _Unwind_Resume_or_Rethrow(void*)
837 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy,
838 PtrTy);
839 } else if (R.getVersion() >= VersionTuple(1, 7)) {
840 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
841 // id objc_begin_catch(void *e)
842 EnterCatchFn.init(&CGM, "objc_begin_catch", IdTy, PtrTy);
843 // void objc_end_catch(void)
844 ExitCatchFn.init(&CGM, "objc_end_catch", VoidTy);
845 // void _Unwind_Resume_or_Rethrow(void*)
846 ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy, PtrTy);
848 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
849 SetPropertyAtomic.init(&CGM, "objc_setProperty_atomic", VoidTy, IdTy,
850 SelectorTy, IdTy, PtrDiffTy);
851 SetPropertyAtomicCopy.init(&CGM, "objc_setProperty_atomic_copy", VoidTy,
852 IdTy, SelectorTy, IdTy, PtrDiffTy);
853 SetPropertyNonAtomic.init(&CGM, "objc_setProperty_nonatomic", VoidTy,
854 IdTy, SelectorTy, IdTy, PtrDiffTy);
855 SetPropertyNonAtomicCopy.init(&CGM, "objc_setProperty_nonatomic_copy",
856 VoidTy, IdTy, SelectorTy, IdTy, PtrDiffTy);
857 // void objc_setCppObjectAtomic(void *dest, const void *src, void
858 // *helper);
859 CxxAtomicObjectSetFn.init(&CGM, "objc_setCppObjectAtomic", VoidTy, PtrTy,
860 PtrTy, PtrTy);
861 // void objc_getCppObjectAtomic(void *dest, const void *src, void
862 // *helper);
863 CxxAtomicObjectGetFn.init(&CGM, "objc_getCppObjectAtomic", VoidTy, PtrTy,
864 PtrTy, PtrTy);
867 llvm::FunctionCallee GetCppAtomicObjectGetFunction() override {
868 // The optimised functions were added in version 1.7 of the GNUstep
869 // runtime.
870 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
871 VersionTuple(1, 7));
872 return CxxAtomicObjectGetFn;
875 llvm::FunctionCallee GetCppAtomicObjectSetFunction() override {
876 // The optimised functions were added in version 1.7 of the GNUstep
877 // runtime.
878 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
879 VersionTuple(1, 7));
880 return CxxAtomicObjectSetFn;
883 llvm::FunctionCallee GetOptimizedPropertySetFunction(bool atomic,
884 bool copy) override {
885 // The optimised property functions omit the GC check, and so are not
886 // safe to use in GC mode. The standard functions are fast in GC mode,
887 // so there is less advantage in using them.
888 assert ((CGM.getLangOpts().getGC() == LangOptions::NonGC));
889 // The optimised functions were added in version 1.7 of the GNUstep
890 // runtime.
891 assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
892 VersionTuple(1, 7));
894 if (atomic) {
895 if (copy) return SetPropertyAtomicCopy;
896 return SetPropertyAtomic;
899 return copy ? SetPropertyNonAtomicCopy : SetPropertyNonAtomic;
903 /// GNUstep Objective-C ABI version 2 implementation.
904 /// This is the ABI that provides a clean break with the legacy GCC ABI and
905 /// cleans up a number of things that were added to work around 1980s linkers.
906 class CGObjCGNUstep2 : public CGObjCGNUstep {
907 enum SectionKind
909 SelectorSection = 0,
910 ClassSection,
911 ClassReferenceSection,
912 CategorySection,
913 ProtocolSection,
914 ProtocolReferenceSection,
915 ClassAliasSection,
916 ConstantStringSection
918 static const char *const SectionsBaseNames[8];
919 static const char *const PECOFFSectionsBaseNames[8];
920 template<SectionKind K>
921 std::string sectionName() {
922 if (CGM.getTriple().isOSBinFormatCOFF()) {
923 std::string name(PECOFFSectionsBaseNames[K]);
924 name += "$m";
925 return name;
927 return SectionsBaseNames[K];
929 /// The GCC ABI superclass message lookup function. Takes a pointer to a
930 /// structure describing the receiver and the class, and a selector as
931 /// arguments. Returns the IMP for the corresponding method.
932 LazyRuntimeFunction MsgLookupSuperFn;
933 /// A flag indicating if we've emitted at least one protocol.
934 /// If we haven't, then we need to emit an empty protocol, to ensure that the
935 /// __start__objc_protocols and __stop__objc_protocols sections exist.
936 bool EmittedProtocol = false;
937 /// A flag indicating if we've emitted at least one protocol reference.
938 /// If we haven't, then we need to emit an empty protocol, to ensure that the
939 /// __start__objc_protocol_refs and __stop__objc_protocol_refs sections
940 /// exist.
941 bool EmittedProtocolRef = false;
942 /// A flag indicating if we've emitted at least one class.
943 /// If we haven't, then we need to emit an empty protocol, to ensure that the
944 /// __start__objc_classes and __stop__objc_classes sections / exist.
945 bool EmittedClass = false;
946 /// Generate the name of a symbol for a reference to a class. Accesses to
947 /// classes should be indirected via this.
949 typedef std::pair<std::string, std::pair<llvm::GlobalVariable*, int>>
950 EarlyInitPair;
951 std::vector<EarlyInitPair> EarlyInitList;
953 std::string SymbolForClassRef(StringRef Name, bool isWeak) {
954 if (isWeak)
955 return (ManglePublicSymbol("OBJC_WEAK_REF_CLASS_") + Name).str();
956 else
957 return (ManglePublicSymbol("OBJC_REF_CLASS_") + Name).str();
959 /// Generate the name of a class symbol.
960 std::string SymbolForClass(StringRef Name) {
961 return (ManglePublicSymbol("OBJC_CLASS_") + Name).str();
963 void CallRuntimeFunction(CGBuilderTy &B, StringRef FunctionName,
964 ArrayRef<llvm::Value*> Args) {
965 SmallVector<llvm::Type *,8> Types;
966 for (auto *Arg : Args)
967 Types.push_back(Arg->getType());
968 llvm::FunctionType *FT = llvm::FunctionType::get(B.getVoidTy(), Types,
969 false);
970 llvm::FunctionCallee Fn = CGM.CreateRuntimeFunction(FT, FunctionName);
971 B.CreateCall(Fn, Args);
974 ConstantAddress GenerateConstantString(const StringLiteral *SL) override {
976 auto Str = SL->getString();
977 CharUnits Align = CGM.getPointerAlign();
979 // Look for an existing one
980 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str);
981 if (old != ObjCStrings.end())
982 return ConstantAddress(old->getValue(), IdElemTy, Align);
984 bool isNonASCII = SL->containsNonAscii();
986 auto LiteralLength = SL->getLength();
988 if ((CGM.getTarget().getPointerWidth(LangAS::Default) == 64) &&
989 (LiteralLength < 9) && !isNonASCII) {
990 // Tiny strings are only used on 64-bit platforms. They store 8 7-bit
991 // ASCII characters in the high 56 bits, followed by a 4-bit length and a
992 // 3-bit tag (which is always 4).
993 uint64_t str = 0;
994 // Fill in the characters
995 for (unsigned i=0 ; i<LiteralLength ; i++)
996 str |= ((uint64_t)SL->getCodeUnit(i)) << ((64 - 4 - 3) - (i*7));
997 // Fill in the length
998 str |= LiteralLength << 3;
999 // Set the tag
1000 str |= 4;
1001 auto *ObjCStr = llvm::ConstantExpr::getIntToPtr(
1002 llvm::ConstantInt::get(Int64Ty, str), IdTy);
1003 ObjCStrings[Str] = ObjCStr;
1004 return ConstantAddress(ObjCStr, IdElemTy, Align);
1007 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass;
1009 if (StringClass.empty()) StringClass = "NSConstantString";
1011 std::string Sym = SymbolForClass(StringClass);
1013 llvm::Constant *isa = TheModule.getNamedGlobal(Sym);
1015 if (!isa) {
1016 isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false,
1017 llvm::GlobalValue::ExternalLinkage, nullptr, Sym);
1018 if (CGM.getTriple().isOSBinFormatCOFF()) {
1019 cast<llvm::GlobalValue>(isa)->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
1021 } else if (isa->getType() != PtrToIdTy)
1022 isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy);
1024 // struct
1025 // {
1026 // Class isa;
1027 // uint32_t flags;
1028 // uint32_t length; // Number of codepoints
1029 // uint32_t size; // Number of bytes
1030 // uint32_t hash;
1031 // const char *data;
1032 // };
1034 ConstantInitBuilder Builder(CGM);
1035 auto Fields = Builder.beginStruct();
1036 if (!CGM.getTriple().isOSBinFormatCOFF()) {
1037 Fields.add(isa);
1038 } else {
1039 Fields.addNullPointer(PtrTy);
1041 // For now, all non-ASCII strings are represented as UTF-16. As such, the
1042 // number of bytes is simply double the number of UTF-16 codepoints. In
1043 // ASCII strings, the number of bytes is equal to the number of non-ASCII
1044 // codepoints.
1045 if (isNonASCII) {
1046 unsigned NumU8CodeUnits = Str.size();
1047 // A UTF-16 representation of a unicode string contains at most the same
1048 // number of code units as a UTF-8 representation. Allocate that much
1049 // space, plus one for the final null character.
1050 SmallVector<llvm::UTF16, 128> ToBuf(NumU8CodeUnits + 1);
1051 const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)Str.data();
1052 llvm::UTF16 *ToPtr = &ToBuf[0];
1053 (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumU8CodeUnits,
1054 &ToPtr, ToPtr + NumU8CodeUnits, llvm::strictConversion);
1055 uint32_t StringLength = ToPtr - &ToBuf[0];
1056 // Add null terminator
1057 *ToPtr = 0;
1058 // Flags: 2 indicates UTF-16 encoding
1059 Fields.addInt(Int32Ty, 2);
1060 // Number of UTF-16 codepoints
1061 Fields.addInt(Int32Ty, StringLength);
1062 // Number of bytes
1063 Fields.addInt(Int32Ty, StringLength * 2);
1064 // Hash. Not currently initialised by the compiler.
1065 Fields.addInt(Int32Ty, 0);
1066 // pointer to the data string.
1067 auto Arr = llvm::ArrayRef(&ToBuf[0], ToPtr + 1);
1068 auto *C = llvm::ConstantDataArray::get(VMContext, Arr);
1069 auto *Buffer = new llvm::GlobalVariable(TheModule, C->getType(),
1070 /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, C, ".str");
1071 Buffer->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1072 Fields.add(Buffer);
1073 } else {
1074 // Flags: 0 indicates ASCII encoding
1075 Fields.addInt(Int32Ty, 0);
1076 // Number of UTF-16 codepoints, each ASCII byte is a UTF-16 codepoint
1077 Fields.addInt(Int32Ty, Str.size());
1078 // Number of bytes
1079 Fields.addInt(Int32Ty, Str.size());
1080 // Hash. Not currently initialised by the compiler.
1081 Fields.addInt(Int32Ty, 0);
1082 // Data pointer
1083 Fields.add(MakeConstantString(Str));
1085 std::string StringName;
1086 bool isNamed = !isNonASCII;
1087 if (isNamed) {
1088 StringName = ".objc_str_";
1089 for (int i=0,e=Str.size() ; i<e ; ++i) {
1090 unsigned char c = Str[i];
1091 if (isalnum(c))
1092 StringName += c;
1093 else if (c == ' ')
1094 StringName += '_';
1095 else {
1096 isNamed = false;
1097 break;
1101 llvm::GlobalVariable *ObjCStrGV =
1102 Fields.finishAndCreateGlobal(
1103 isNamed ? StringRef(StringName) : ".objc_string",
1104 Align, false, isNamed ? llvm::GlobalValue::LinkOnceODRLinkage
1105 : llvm::GlobalValue::PrivateLinkage);
1106 ObjCStrGV->setSection(sectionName<ConstantStringSection>());
1107 if (isNamed) {
1108 ObjCStrGV->setComdat(TheModule.getOrInsertComdat(StringName));
1109 ObjCStrGV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1111 if (CGM.getTriple().isOSBinFormatCOFF()) {
1112 std::pair<llvm::GlobalVariable*, int> v{ObjCStrGV, 0};
1113 EarlyInitList.emplace_back(Sym, v);
1115 llvm::Constant *ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStrGV, IdTy);
1116 ObjCStrings[Str] = ObjCStr;
1117 ConstantStrings.push_back(ObjCStr);
1118 return ConstantAddress(ObjCStr, IdElemTy, Align);
1121 void PushProperty(ConstantArrayBuilder &PropertiesArray,
1122 const ObjCPropertyDecl *property,
1123 const Decl *OCD,
1124 bool isSynthesized=true, bool
1125 isDynamic=true) override {
1126 // struct objc_property
1127 // {
1128 // const char *name;
1129 // const char *attributes;
1130 // const char *type;
1131 // SEL getter;
1132 // SEL setter;
1133 // };
1134 auto Fields = PropertiesArray.beginStruct(PropertyMetadataTy);
1135 ASTContext &Context = CGM.getContext();
1136 Fields.add(MakeConstantString(property->getNameAsString()));
1137 std::string TypeStr =
1138 CGM.getContext().getObjCEncodingForPropertyDecl(property, OCD);
1139 Fields.add(MakeConstantString(TypeStr));
1140 std::string typeStr;
1141 Context.getObjCEncodingForType(property->getType(), typeStr);
1142 Fields.add(MakeConstantString(typeStr));
1143 auto addPropertyMethod = [&](const ObjCMethodDecl *accessor) {
1144 if (accessor) {
1145 std::string TypeStr = Context.getObjCEncodingForMethodDecl(accessor);
1146 Fields.add(GetConstantSelector(accessor->getSelector(), TypeStr));
1147 } else {
1148 Fields.add(NULLPtr);
1151 addPropertyMethod(property->getGetterMethodDecl());
1152 addPropertyMethod(property->getSetterMethodDecl());
1153 Fields.finishAndAddTo(PropertiesArray);
1156 llvm::Constant *
1157 GenerateProtocolMethodList(ArrayRef<const ObjCMethodDecl*> Methods) override {
1158 // struct objc_protocol_method_description
1159 // {
1160 // SEL selector;
1161 // const char *types;
1162 // };
1163 llvm::StructType *ObjCMethodDescTy =
1164 llvm::StructType::get(CGM.getLLVMContext(),
1165 { PtrToInt8Ty, PtrToInt8Ty });
1166 ASTContext &Context = CGM.getContext();
1167 ConstantInitBuilder Builder(CGM);
1168 // struct objc_protocol_method_description_list
1169 // {
1170 // int count;
1171 // int size;
1172 // struct objc_protocol_method_description methods[];
1173 // };
1174 auto MethodList = Builder.beginStruct();
1175 // int count;
1176 MethodList.addInt(IntTy, Methods.size());
1177 // int size; // sizeof(struct objc_method_description)
1178 llvm::DataLayout td(&TheModule);
1179 MethodList.addInt(IntTy, td.getTypeSizeInBits(ObjCMethodDescTy) /
1180 CGM.getContext().getCharWidth());
1181 // struct objc_method_description[]
1182 auto MethodArray = MethodList.beginArray(ObjCMethodDescTy);
1183 for (auto *M : Methods) {
1184 auto Method = MethodArray.beginStruct(ObjCMethodDescTy);
1185 Method.add(CGObjCGNU::GetConstantSelector(M));
1186 Method.add(GetTypeString(Context.getObjCEncodingForMethodDecl(M, true)));
1187 Method.finishAndAddTo(MethodArray);
1189 MethodArray.finishAndAddTo(MethodList);
1190 return MethodList.finishAndCreateGlobal(".objc_protocol_method_list",
1191 CGM.getPointerAlign());
1193 llvm::Constant *GenerateCategoryProtocolList(const ObjCCategoryDecl *OCD)
1194 override {
1195 const auto &ReferencedProtocols = OCD->getReferencedProtocols();
1196 auto RuntimeProtocols = GetRuntimeProtocolList(ReferencedProtocols.begin(),
1197 ReferencedProtocols.end());
1198 SmallVector<llvm::Constant *, 16> Protocols;
1199 for (const auto *PI : RuntimeProtocols)
1200 Protocols.push_back(
1201 llvm::ConstantExpr::getBitCast(GenerateProtocolRef(PI),
1202 ProtocolPtrTy));
1203 return GenerateProtocolList(Protocols);
1206 llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
1207 llvm::Value *cmd, MessageSendInfo &MSI) override {
1208 // Don't access the slot unless we're trying to cache the result.
1209 CGBuilderTy &Builder = CGF.Builder;
1210 llvm::Value *lookupArgs[] = {CGObjCGNU::EnforceType(Builder,
1211 ObjCSuper.getPointer(),
1212 PtrToObjCSuperTy),
1213 cmd};
1214 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
1217 llvm::GlobalVariable *GetClassVar(StringRef Name, bool isWeak=false) {
1218 std::string SymbolName = SymbolForClassRef(Name, isWeak);
1219 auto *ClassSymbol = TheModule.getNamedGlobal(SymbolName);
1220 if (ClassSymbol)
1221 return ClassSymbol;
1222 ClassSymbol = new llvm::GlobalVariable(TheModule,
1223 IdTy, false, llvm::GlobalValue::ExternalLinkage,
1224 nullptr, SymbolName);
1225 // If this is a weak symbol, then we are creating a valid definition for
1226 // the symbol, pointing to a weak definition of the real class pointer. If
1227 // this is not a weak reference, then we are expecting another compilation
1228 // unit to provide the real indirection symbol.
1229 if (isWeak)
1230 ClassSymbol->setInitializer(new llvm::GlobalVariable(TheModule,
1231 Int8Ty, false, llvm::GlobalValue::ExternalWeakLinkage,
1232 nullptr, SymbolForClass(Name)));
1233 else {
1234 if (CGM.getTriple().isOSBinFormatCOFF()) {
1235 IdentifierInfo &II = CGM.getContext().Idents.get(Name);
1236 TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
1237 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
1239 const ObjCInterfaceDecl *OID = nullptr;
1240 for (const auto *Result : DC->lookup(&II))
1241 if ((OID = dyn_cast<ObjCInterfaceDecl>(Result)))
1242 break;
1244 // The first Interface we find may be a @class,
1245 // which should only be treated as the source of
1246 // truth in the absence of a true declaration.
1247 assert(OID && "Failed to find ObjCInterfaceDecl");
1248 const ObjCInterfaceDecl *OIDDef = OID->getDefinition();
1249 if (OIDDef != nullptr)
1250 OID = OIDDef;
1252 auto Storage = llvm::GlobalValue::DefaultStorageClass;
1253 if (OID->hasAttr<DLLImportAttr>())
1254 Storage = llvm::GlobalValue::DLLImportStorageClass;
1255 else if (OID->hasAttr<DLLExportAttr>())
1256 Storage = llvm::GlobalValue::DLLExportStorageClass;
1258 cast<llvm::GlobalValue>(ClassSymbol)->setDLLStorageClass(Storage);
1261 assert(ClassSymbol->getName() == SymbolName);
1262 return ClassSymbol;
1264 llvm::Value *GetClassNamed(CodeGenFunction &CGF,
1265 const std::string &Name,
1266 bool isWeak) override {
1267 return CGF.Builder.CreateLoad(
1268 Address(GetClassVar(Name, isWeak), IdTy, CGM.getPointerAlign()));
1270 int32_t FlagsForOwnership(Qualifiers::ObjCLifetime Ownership) {
1271 // typedef enum {
1272 // ownership_invalid = 0,
1273 // ownership_strong = 1,
1274 // ownership_weak = 2,
1275 // ownership_unsafe = 3
1276 // } ivar_ownership;
1277 int Flag;
1278 switch (Ownership) {
1279 case Qualifiers::OCL_Strong:
1280 Flag = 1;
1281 break;
1282 case Qualifiers::OCL_Weak:
1283 Flag = 2;
1284 break;
1285 case Qualifiers::OCL_ExplicitNone:
1286 Flag = 3;
1287 break;
1288 case Qualifiers::OCL_None:
1289 case Qualifiers::OCL_Autoreleasing:
1290 assert(Ownership != Qualifiers::OCL_Autoreleasing);
1291 Flag = 0;
1293 return Flag;
1295 llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
1296 ArrayRef<llvm::Constant *> IvarTypes,
1297 ArrayRef<llvm::Constant *> IvarOffsets,
1298 ArrayRef<llvm::Constant *> IvarAlign,
1299 ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership) override {
1300 llvm_unreachable("Method should not be called!");
1303 llvm::Constant *GenerateEmptyProtocol(StringRef ProtocolName) override {
1304 std::string Name = SymbolForProtocol(ProtocolName);
1305 auto *GV = TheModule.getGlobalVariable(Name);
1306 if (!GV) {
1307 // Emit a placeholder symbol.
1308 GV = new llvm::GlobalVariable(TheModule, ProtocolTy, false,
1309 llvm::GlobalValue::ExternalLinkage, nullptr, Name);
1310 GV->setAlignment(CGM.getPointerAlign().getAsAlign());
1312 return llvm::ConstantExpr::getBitCast(GV, ProtocolPtrTy);
1315 /// Existing protocol references.
1316 llvm::StringMap<llvm::Constant*> ExistingProtocolRefs;
1318 llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
1319 const ObjCProtocolDecl *PD) override {
1320 auto Name = PD->getNameAsString();
1321 auto *&Ref = ExistingProtocolRefs[Name];
1322 if (!Ref) {
1323 auto *&Protocol = ExistingProtocols[Name];
1324 if (!Protocol)
1325 Protocol = GenerateProtocolRef(PD);
1326 std::string RefName = SymbolForProtocolRef(Name);
1327 assert(!TheModule.getGlobalVariable(RefName));
1328 // Emit a reference symbol.
1329 auto GV = new llvm::GlobalVariable(TheModule, ProtocolPtrTy,
1330 false, llvm::GlobalValue::LinkOnceODRLinkage,
1331 llvm::ConstantExpr::getBitCast(Protocol, ProtocolPtrTy), RefName);
1332 GV->setComdat(TheModule.getOrInsertComdat(RefName));
1333 GV->setSection(sectionName<ProtocolReferenceSection>());
1334 GV->setAlignment(CGM.getPointerAlign().getAsAlign());
1335 Ref = GV;
1337 EmittedProtocolRef = true;
1338 return CGF.Builder.CreateAlignedLoad(ProtocolPtrTy, Ref,
1339 CGM.getPointerAlign());
1342 llvm::Constant *GenerateProtocolList(ArrayRef<llvm::Constant*> Protocols) {
1343 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(ProtocolPtrTy,
1344 Protocols.size());
1345 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy,
1346 Protocols);
1347 ConstantInitBuilder builder(CGM);
1348 auto ProtocolBuilder = builder.beginStruct();
1349 ProtocolBuilder.addNullPointer(PtrTy);
1350 ProtocolBuilder.addInt(SizeTy, Protocols.size());
1351 ProtocolBuilder.add(ProtocolArray);
1352 return ProtocolBuilder.finishAndCreateGlobal(".objc_protocol_list",
1353 CGM.getPointerAlign(), false, llvm::GlobalValue::InternalLinkage);
1356 void GenerateProtocol(const ObjCProtocolDecl *PD) override {
1357 // Do nothing - we only emit referenced protocols.
1359 llvm::Constant *GenerateProtocolRef(const ObjCProtocolDecl *PD) override {
1360 std::string ProtocolName = PD->getNameAsString();
1361 auto *&Protocol = ExistingProtocols[ProtocolName];
1362 if (Protocol)
1363 return Protocol;
1365 EmittedProtocol = true;
1367 auto SymName = SymbolForProtocol(ProtocolName);
1368 auto *OldGV = TheModule.getGlobalVariable(SymName);
1370 // Use the protocol definition, if there is one.
1371 if (const ObjCProtocolDecl *Def = PD->getDefinition())
1372 PD = Def;
1373 else {
1374 // If there is no definition, then create an external linkage symbol and
1375 // hope that someone else fills it in for us (and fail to link if they
1376 // don't).
1377 assert(!OldGV);
1378 Protocol = new llvm::GlobalVariable(TheModule, ProtocolTy,
1379 /*isConstant*/false,
1380 llvm::GlobalValue::ExternalLinkage, nullptr, SymName);
1381 return Protocol;
1384 SmallVector<llvm::Constant*, 16> Protocols;
1385 auto RuntimeProtocols =
1386 GetRuntimeProtocolList(PD->protocol_begin(), PD->protocol_end());
1387 for (const auto *PI : RuntimeProtocols)
1388 Protocols.push_back(
1389 llvm::ConstantExpr::getBitCast(GenerateProtocolRef(PI),
1390 ProtocolPtrTy));
1391 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols);
1393 // Collect information about methods
1394 llvm::Constant *InstanceMethodList, *OptionalInstanceMethodList;
1395 llvm::Constant *ClassMethodList, *OptionalClassMethodList;
1396 EmitProtocolMethodList(PD->instance_methods(), InstanceMethodList,
1397 OptionalInstanceMethodList);
1398 EmitProtocolMethodList(PD->class_methods(), ClassMethodList,
1399 OptionalClassMethodList);
1401 // The isa pointer must be set to a magic number so the runtime knows it's
1402 // the correct layout.
1403 ConstantInitBuilder builder(CGM);
1404 auto ProtocolBuilder = builder.beginStruct();
1405 ProtocolBuilder.add(llvm::ConstantExpr::getIntToPtr(
1406 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
1407 ProtocolBuilder.add(MakeConstantString(ProtocolName));
1408 ProtocolBuilder.add(ProtocolList);
1409 ProtocolBuilder.add(InstanceMethodList);
1410 ProtocolBuilder.add(ClassMethodList);
1411 ProtocolBuilder.add(OptionalInstanceMethodList);
1412 ProtocolBuilder.add(OptionalClassMethodList);
1413 // Required instance properties
1414 ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, false, false));
1415 // Optional instance properties
1416 ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, false, true));
1417 // Required class properties
1418 ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, true, false));
1419 // Optional class properties
1420 ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, true, true));
1422 auto *GV = ProtocolBuilder.finishAndCreateGlobal(SymName,
1423 CGM.getPointerAlign(), false, llvm::GlobalValue::ExternalLinkage);
1424 GV->setSection(sectionName<ProtocolSection>());
1425 GV->setComdat(TheModule.getOrInsertComdat(SymName));
1426 if (OldGV) {
1427 OldGV->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GV,
1428 OldGV->getType()));
1429 OldGV->removeFromParent();
1430 GV->setName(SymName);
1432 Protocol = GV;
1433 return GV;
1435 llvm::Constant *EnforceType(llvm::Constant *Val, llvm::Type *Ty) {
1436 if (Val->getType() == Ty)
1437 return Val;
1438 return llvm::ConstantExpr::getBitCast(Val, Ty);
1440 llvm::Value *GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
1441 const std::string &TypeEncoding) override {
1442 return GetConstantSelector(Sel, TypeEncoding);
1444 llvm::Constant *GetTypeString(llvm::StringRef TypeEncoding) {
1445 if (TypeEncoding.empty())
1446 return NULLPtr;
1447 std::string MangledTypes = std::string(TypeEncoding);
1448 std::replace(MangledTypes.begin(), MangledTypes.end(),
1449 '@', '\1');
1450 std::string TypesVarName = ".objc_sel_types_" + MangledTypes;
1451 auto *TypesGlobal = TheModule.getGlobalVariable(TypesVarName);
1452 if (!TypesGlobal) {
1453 llvm::Constant *Init = llvm::ConstantDataArray::getString(VMContext,
1454 TypeEncoding);
1455 auto *GV = new llvm::GlobalVariable(TheModule, Init->getType(),
1456 true, llvm::GlobalValue::LinkOnceODRLinkage, Init, TypesVarName);
1457 GV->setComdat(TheModule.getOrInsertComdat(TypesVarName));
1458 GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1459 TypesGlobal = GV;
1461 return llvm::ConstantExpr::getGetElementPtr(TypesGlobal->getValueType(),
1462 TypesGlobal, Zeros);
1464 llvm::Constant *GetConstantSelector(Selector Sel,
1465 const std::string &TypeEncoding) override {
1466 // @ is used as a special character in symbol names (used for symbol
1467 // versioning), so mangle the name to not include it. Replace it with a
1468 // character that is not a valid type encoding character (and, being
1469 // non-printable, never will be!)
1470 std::string MangledTypes = TypeEncoding;
1471 std::replace(MangledTypes.begin(), MangledTypes.end(),
1472 '@', '\1');
1473 auto SelVarName = (StringRef(".objc_selector_") + Sel.getAsString() + "_" +
1474 MangledTypes).str();
1475 if (auto *GV = TheModule.getNamedGlobal(SelVarName))
1476 return EnforceType(GV, SelectorTy);
1477 ConstantInitBuilder builder(CGM);
1478 auto SelBuilder = builder.beginStruct();
1479 SelBuilder.add(ExportUniqueString(Sel.getAsString(), ".objc_sel_name_",
1480 true));
1481 SelBuilder.add(GetTypeString(TypeEncoding));
1482 auto *GV = SelBuilder.finishAndCreateGlobal(SelVarName,
1483 CGM.getPointerAlign(), false, llvm::GlobalValue::LinkOnceODRLinkage);
1484 GV->setComdat(TheModule.getOrInsertComdat(SelVarName));
1485 GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1486 GV->setSection(sectionName<SelectorSection>());
1487 auto *SelVal = EnforceType(GV, SelectorTy);
1488 return SelVal;
1490 llvm::StructType *emptyStruct = nullptr;
1492 /// Return pointers to the start and end of a section. On ELF platforms, we
1493 /// use the __start_ and __stop_ symbols that GNU-compatible linkers will set
1494 /// to the start and end of section names, as long as those section names are
1495 /// valid identifiers and the symbols are referenced but not defined. On
1496 /// Windows, we use the fact that MSVC-compatible linkers will lexically sort
1497 /// by subsections and place everything that we want to reference in a middle
1498 /// subsection and then insert zero-sized symbols in subsections a and z.
1499 std::pair<llvm::Constant*,llvm::Constant*>
1500 GetSectionBounds(StringRef Section) {
1501 if (CGM.getTriple().isOSBinFormatCOFF()) {
1502 if (emptyStruct == nullptr) {
1503 emptyStruct = llvm::StructType::create(VMContext, ".objc_section_sentinel");
1504 emptyStruct->setBody({}, /*isPacked*/true);
1506 auto ZeroInit = llvm::Constant::getNullValue(emptyStruct);
1507 auto Sym = [&](StringRef Prefix, StringRef SecSuffix) {
1508 auto *Sym = new llvm::GlobalVariable(TheModule, emptyStruct,
1509 /*isConstant*/false,
1510 llvm::GlobalValue::LinkOnceODRLinkage, ZeroInit, Prefix +
1511 Section);
1512 Sym->setVisibility(llvm::GlobalValue::HiddenVisibility);
1513 Sym->setSection((Section + SecSuffix).str());
1514 Sym->setComdat(TheModule.getOrInsertComdat((Prefix +
1515 Section).str()));
1516 Sym->setAlignment(CGM.getPointerAlign().getAsAlign());
1517 return Sym;
1519 return { Sym("__start_", "$a"), Sym("__stop", "$z") };
1521 auto *Start = new llvm::GlobalVariable(TheModule, PtrTy,
1522 /*isConstant*/false,
1523 llvm::GlobalValue::ExternalLinkage, nullptr, StringRef("__start_") +
1524 Section);
1525 Start->setVisibility(llvm::GlobalValue::HiddenVisibility);
1526 auto *Stop = new llvm::GlobalVariable(TheModule, PtrTy,
1527 /*isConstant*/false,
1528 llvm::GlobalValue::ExternalLinkage, nullptr, StringRef("__stop_") +
1529 Section);
1530 Stop->setVisibility(llvm::GlobalValue::HiddenVisibility);
1531 return { Start, Stop };
1533 CatchTypeInfo getCatchAllTypeInfo() override {
1534 return CGM.getCXXABI().getCatchAllTypeInfo();
1536 llvm::Function *ModuleInitFunction() override {
1537 llvm::Function *LoadFunction = llvm::Function::Create(
1538 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false),
1539 llvm::GlobalValue::LinkOnceODRLinkage, ".objcv2_load_function",
1540 &TheModule);
1541 LoadFunction->setVisibility(llvm::GlobalValue::HiddenVisibility);
1542 LoadFunction->setComdat(TheModule.getOrInsertComdat(".objcv2_load_function"));
1544 llvm::BasicBlock *EntryBB =
1545 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction);
1546 CGBuilderTy B(CGM, VMContext);
1547 B.SetInsertPoint(EntryBB);
1548 ConstantInitBuilder builder(CGM);
1549 auto InitStructBuilder = builder.beginStruct();
1550 InitStructBuilder.addInt(Int64Ty, 0);
1551 auto &sectionVec = CGM.getTriple().isOSBinFormatCOFF() ? PECOFFSectionsBaseNames : SectionsBaseNames;
1552 for (auto *s : sectionVec) {
1553 auto bounds = GetSectionBounds(s);
1554 InitStructBuilder.add(bounds.first);
1555 InitStructBuilder.add(bounds.second);
1557 auto *InitStruct = InitStructBuilder.finishAndCreateGlobal(".objc_init",
1558 CGM.getPointerAlign(), false, llvm::GlobalValue::LinkOnceODRLinkage);
1559 InitStruct->setVisibility(llvm::GlobalValue::HiddenVisibility);
1560 InitStruct->setComdat(TheModule.getOrInsertComdat(".objc_init"));
1562 CallRuntimeFunction(B, "__objc_load", {InitStruct});;
1563 B.CreateRetVoid();
1564 // Make sure that the optimisers don't delete this function.
1565 CGM.addCompilerUsedGlobal(LoadFunction);
1566 // FIXME: Currently ELF only!
1567 // We have to do this by hand, rather than with @llvm.ctors, so that the
1568 // linker can remove the duplicate invocations.
1569 auto *InitVar = new llvm::GlobalVariable(TheModule, LoadFunction->getType(),
1570 /*isConstant*/false, llvm::GlobalValue::LinkOnceAnyLinkage,
1571 LoadFunction, ".objc_ctor");
1572 // Check that this hasn't been renamed. This shouldn't happen, because
1573 // this function should be called precisely once.
1574 assert(InitVar->getName() == ".objc_ctor");
1575 // In Windows, initialisers are sorted by the suffix. XCL is for library
1576 // initialisers, which run before user initialisers. We are running
1577 // Objective-C loads at the end of library load. This means +load methods
1578 // will run before any other static constructors, but that static
1579 // constructors can see a fully initialised Objective-C state.
1580 if (CGM.getTriple().isOSBinFormatCOFF())
1581 InitVar->setSection(".CRT$XCLz");
1582 else
1584 if (CGM.getCodeGenOpts().UseInitArray)
1585 InitVar->setSection(".init_array");
1586 else
1587 InitVar->setSection(".ctors");
1589 InitVar->setVisibility(llvm::GlobalValue::HiddenVisibility);
1590 InitVar->setComdat(TheModule.getOrInsertComdat(".objc_ctor"));
1591 CGM.addUsedGlobal(InitVar);
1592 for (auto *C : Categories) {
1593 auto *Cat = cast<llvm::GlobalVariable>(C->stripPointerCasts());
1594 Cat->setSection(sectionName<CategorySection>());
1595 CGM.addUsedGlobal(Cat);
1597 auto createNullGlobal = [&](StringRef Name, ArrayRef<llvm::Constant*> Init,
1598 StringRef Section) {
1599 auto nullBuilder = builder.beginStruct();
1600 for (auto *F : Init)
1601 nullBuilder.add(F);
1602 auto GV = nullBuilder.finishAndCreateGlobal(Name, CGM.getPointerAlign(),
1603 false, llvm::GlobalValue::LinkOnceODRLinkage);
1604 GV->setSection(Section);
1605 GV->setComdat(TheModule.getOrInsertComdat(Name));
1606 GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1607 CGM.addUsedGlobal(GV);
1608 return GV;
1610 for (auto clsAlias : ClassAliases)
1611 createNullGlobal(std::string(".objc_class_alias") +
1612 clsAlias.second, { MakeConstantString(clsAlias.second),
1613 GetClassVar(clsAlias.first) }, sectionName<ClassAliasSection>());
1614 // On ELF platforms, add a null value for each special section so that we
1615 // can always guarantee that the _start and _stop symbols will exist and be
1616 // meaningful. This is not required on COFF platforms, where our start and
1617 // stop symbols will create the section.
1618 if (!CGM.getTriple().isOSBinFormatCOFF()) {
1619 createNullGlobal(".objc_null_selector", {NULLPtr, NULLPtr},
1620 sectionName<SelectorSection>());
1621 if (Categories.empty())
1622 createNullGlobal(".objc_null_category", {NULLPtr, NULLPtr,
1623 NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr},
1624 sectionName<CategorySection>());
1625 if (!EmittedClass) {
1626 createNullGlobal(".objc_null_cls_init_ref", NULLPtr,
1627 sectionName<ClassSection>());
1628 createNullGlobal(".objc_null_class_ref", { NULLPtr, NULLPtr },
1629 sectionName<ClassReferenceSection>());
1631 if (!EmittedProtocol)
1632 createNullGlobal(".objc_null_protocol", {NULLPtr, NULLPtr, NULLPtr,
1633 NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr,
1634 NULLPtr}, sectionName<ProtocolSection>());
1635 if (!EmittedProtocolRef)
1636 createNullGlobal(".objc_null_protocol_ref", {NULLPtr},
1637 sectionName<ProtocolReferenceSection>());
1638 if (ClassAliases.empty())
1639 createNullGlobal(".objc_null_class_alias", { NULLPtr, NULLPtr },
1640 sectionName<ClassAliasSection>());
1641 if (ConstantStrings.empty()) {
1642 auto i32Zero = llvm::ConstantInt::get(Int32Ty, 0);
1643 createNullGlobal(".objc_null_constant_string", { NULLPtr, i32Zero,
1644 i32Zero, i32Zero, i32Zero, NULLPtr },
1645 sectionName<ConstantStringSection>());
1648 ConstantStrings.clear();
1649 Categories.clear();
1650 Classes.clear();
1652 if (EarlyInitList.size() > 0) {
1653 auto *Init = llvm::Function::Create(llvm::FunctionType::get(CGM.VoidTy,
1654 {}), llvm::GlobalValue::InternalLinkage, ".objc_early_init",
1655 &CGM.getModule());
1656 llvm::IRBuilder<> b(llvm::BasicBlock::Create(CGM.getLLVMContext(), "entry",
1657 Init));
1658 for (const auto &lateInit : EarlyInitList) {
1659 auto *global = TheModule.getGlobalVariable(lateInit.first);
1660 if (global) {
1661 llvm::GlobalVariable *GV = lateInit.second.first;
1662 b.CreateAlignedStore(
1663 global,
1664 b.CreateStructGEP(GV->getValueType(), GV, lateInit.second.second),
1665 CGM.getPointerAlign().getAsAlign());
1668 b.CreateRetVoid();
1669 // We can't use the normal LLVM global initialisation array, because we
1670 // need to specify that this runs early in library initialisation.
1671 auto *InitVar = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
1672 /*isConstant*/true, llvm::GlobalValue::InternalLinkage,
1673 Init, ".objc_early_init_ptr");
1674 InitVar->setSection(".CRT$XCLb");
1675 CGM.addUsedGlobal(InitVar);
1677 return nullptr;
1679 /// In the v2 ABI, ivar offset variables use the type encoding in their name
1680 /// to trigger linker failures if the types don't match.
1681 std::string GetIVarOffsetVariableName(const ObjCInterfaceDecl *ID,
1682 const ObjCIvarDecl *Ivar) override {
1683 std::string TypeEncoding;
1684 CGM.getContext().getObjCEncodingForType(Ivar->getType(), TypeEncoding);
1685 // Prevent the @ from being interpreted as a symbol version.
1686 std::replace(TypeEncoding.begin(), TypeEncoding.end(),
1687 '@', '\1');
1688 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString()
1689 + '.' + Ivar->getNameAsString() + '.' + TypeEncoding;
1690 return Name;
1692 llvm::Value *EmitIvarOffset(CodeGenFunction &CGF,
1693 const ObjCInterfaceDecl *Interface,
1694 const ObjCIvarDecl *Ivar) override {
1695 const std::string Name = GetIVarOffsetVariableName(Ivar->getContainingInterface(), Ivar);
1696 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name);
1697 if (!IvarOffsetPointer)
1698 IvarOffsetPointer = new llvm::GlobalVariable(TheModule, IntTy, false,
1699 llvm::GlobalValue::ExternalLinkage, nullptr, Name);
1700 CharUnits Align = CGM.getIntAlign();
1701 llvm::Value *Offset =
1702 CGF.Builder.CreateAlignedLoad(IntTy, IvarOffsetPointer, Align);
1703 if (Offset->getType() != PtrDiffTy)
1704 Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy);
1705 return Offset;
1707 void GenerateClass(const ObjCImplementationDecl *OID) override {
1708 ASTContext &Context = CGM.getContext();
1709 bool IsCOFF = CGM.getTriple().isOSBinFormatCOFF();
1711 // Get the class name
1712 ObjCInterfaceDecl *classDecl =
1713 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
1714 std::string className = classDecl->getNameAsString();
1715 auto *classNameConstant = MakeConstantString(className);
1717 ConstantInitBuilder builder(CGM);
1718 auto metaclassFields = builder.beginStruct();
1719 // struct objc_class *isa;
1720 metaclassFields.addNullPointer(PtrTy);
1721 // struct objc_class *super_class;
1722 metaclassFields.addNullPointer(PtrTy);
1723 // const char *name;
1724 metaclassFields.add(classNameConstant);
1725 // long version;
1726 metaclassFields.addInt(LongTy, 0);
1727 // unsigned long info;
1728 // objc_class_flag_meta
1729 metaclassFields.addInt(LongTy, 1);
1730 // long instance_size;
1731 // Setting this to zero is consistent with the older ABI, but it might be
1732 // more sensible to set this to sizeof(struct objc_class)
1733 metaclassFields.addInt(LongTy, 0);
1734 // struct objc_ivar_list *ivars;
1735 metaclassFields.addNullPointer(PtrTy);
1736 // struct objc_method_list *methods
1737 // FIXME: Almost identical code is copied and pasted below for the
1738 // class, but refactoring it cleanly requires C++14 generic lambdas.
1739 if (OID->classmeth_begin() == OID->classmeth_end())
1740 metaclassFields.addNullPointer(PtrTy);
1741 else {
1742 SmallVector<ObjCMethodDecl*, 16> ClassMethods;
1743 ClassMethods.insert(ClassMethods.begin(), OID->classmeth_begin(),
1744 OID->classmeth_end());
1745 metaclassFields.addBitCast(
1746 GenerateMethodList(className, "", ClassMethods, true),
1747 PtrTy);
1749 // void *dtable;
1750 metaclassFields.addNullPointer(PtrTy);
1751 // IMP cxx_construct;
1752 metaclassFields.addNullPointer(PtrTy);
1753 // IMP cxx_destruct;
1754 metaclassFields.addNullPointer(PtrTy);
1755 // struct objc_class *subclass_list
1756 metaclassFields.addNullPointer(PtrTy);
1757 // struct objc_class *sibling_class
1758 metaclassFields.addNullPointer(PtrTy);
1759 // struct objc_protocol_list *protocols;
1760 metaclassFields.addNullPointer(PtrTy);
1761 // struct reference_list *extra_data;
1762 metaclassFields.addNullPointer(PtrTy);
1763 // long abi_version;
1764 metaclassFields.addInt(LongTy, 0);
1765 // struct objc_property_list *properties
1766 metaclassFields.add(GeneratePropertyList(OID, classDecl, /*isClassProperty*/true));
1768 auto *metaclass = metaclassFields.finishAndCreateGlobal(
1769 ManglePublicSymbol("OBJC_METACLASS_") + className,
1770 CGM.getPointerAlign());
1772 auto classFields = builder.beginStruct();
1773 // struct objc_class *isa;
1774 classFields.add(metaclass);
1775 // struct objc_class *super_class;
1776 // Get the superclass name.
1777 const ObjCInterfaceDecl * SuperClassDecl =
1778 OID->getClassInterface()->getSuperClass();
1779 llvm::Constant *SuperClass = nullptr;
1780 if (SuperClassDecl) {
1781 auto SuperClassName = SymbolForClass(SuperClassDecl->getNameAsString());
1782 SuperClass = TheModule.getNamedGlobal(SuperClassName);
1783 if (!SuperClass)
1785 SuperClass = new llvm::GlobalVariable(TheModule, PtrTy, false,
1786 llvm::GlobalValue::ExternalLinkage, nullptr, SuperClassName);
1787 if (IsCOFF) {
1788 auto Storage = llvm::GlobalValue::DefaultStorageClass;
1789 if (SuperClassDecl->hasAttr<DLLImportAttr>())
1790 Storage = llvm::GlobalValue::DLLImportStorageClass;
1791 else if (SuperClassDecl->hasAttr<DLLExportAttr>())
1792 Storage = llvm::GlobalValue::DLLExportStorageClass;
1794 cast<llvm::GlobalValue>(SuperClass)->setDLLStorageClass(Storage);
1797 if (!IsCOFF)
1798 classFields.add(llvm::ConstantExpr::getBitCast(SuperClass, PtrTy));
1799 else
1800 classFields.addNullPointer(PtrTy);
1801 } else
1802 classFields.addNullPointer(PtrTy);
1803 // const char *name;
1804 classFields.add(classNameConstant);
1805 // long version;
1806 classFields.addInt(LongTy, 0);
1807 // unsigned long info;
1808 // !objc_class_flag_meta
1809 classFields.addInt(LongTy, 0);
1810 // long instance_size;
1811 int superInstanceSize = !SuperClassDecl ? 0 :
1812 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity();
1813 // Instance size is negative for classes that have not yet had their ivar
1814 // layout calculated.
1815 classFields.addInt(LongTy,
1816 0 - (Context.getASTObjCImplementationLayout(OID).getSize().getQuantity() -
1817 superInstanceSize));
1819 if (classDecl->all_declared_ivar_begin() == nullptr)
1820 classFields.addNullPointer(PtrTy);
1821 else {
1822 int ivar_count = 0;
1823 for (const ObjCIvarDecl *IVD = classDecl->all_declared_ivar_begin(); IVD;
1824 IVD = IVD->getNextIvar()) ivar_count++;
1825 llvm::DataLayout td(&TheModule);
1826 // struct objc_ivar_list *ivars;
1827 ConstantInitBuilder b(CGM);
1828 auto ivarListBuilder = b.beginStruct();
1829 // int count;
1830 ivarListBuilder.addInt(IntTy, ivar_count);
1831 // size_t size;
1832 llvm::StructType *ObjCIvarTy = llvm::StructType::get(
1833 PtrToInt8Ty,
1834 PtrToInt8Ty,
1835 PtrToInt8Ty,
1836 Int32Ty,
1837 Int32Ty);
1838 ivarListBuilder.addInt(SizeTy, td.getTypeSizeInBits(ObjCIvarTy) /
1839 CGM.getContext().getCharWidth());
1840 // struct objc_ivar ivars[]
1841 auto ivarArrayBuilder = ivarListBuilder.beginArray();
1842 for (const ObjCIvarDecl *IVD = classDecl->all_declared_ivar_begin(); IVD;
1843 IVD = IVD->getNextIvar()) {
1844 auto ivarTy = IVD->getType();
1845 auto ivarBuilder = ivarArrayBuilder.beginStruct();
1846 // const char *name;
1847 ivarBuilder.add(MakeConstantString(IVD->getNameAsString()));
1848 // const char *type;
1849 std::string TypeStr;
1850 //Context.getObjCEncodingForType(ivarTy, TypeStr, IVD, true);
1851 Context.getObjCEncodingForMethodParameter(Decl::OBJC_TQ_None, ivarTy, TypeStr, true);
1852 ivarBuilder.add(MakeConstantString(TypeStr));
1853 // int *offset;
1854 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD);
1855 uint64_t Offset = BaseOffset - superInstanceSize;
1856 llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset);
1857 std::string OffsetName = GetIVarOffsetVariableName(classDecl, IVD);
1858 llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName);
1859 if (OffsetVar)
1860 OffsetVar->setInitializer(OffsetValue);
1861 else
1862 OffsetVar = new llvm::GlobalVariable(TheModule, IntTy,
1863 false, llvm::GlobalValue::ExternalLinkage,
1864 OffsetValue, OffsetName);
1865 auto ivarVisibility =
1866 (IVD->getAccessControl() == ObjCIvarDecl::Private ||
1867 IVD->getAccessControl() == ObjCIvarDecl::Package ||
1868 classDecl->getVisibility() == HiddenVisibility) ?
1869 llvm::GlobalValue::HiddenVisibility :
1870 llvm::GlobalValue::DefaultVisibility;
1871 OffsetVar->setVisibility(ivarVisibility);
1872 ivarBuilder.add(OffsetVar);
1873 // Ivar size
1874 ivarBuilder.addInt(Int32Ty,
1875 CGM.getContext().getTypeSizeInChars(ivarTy).getQuantity());
1876 // Alignment will be stored as a base-2 log of the alignment.
1877 unsigned align =
1878 llvm::Log2_32(Context.getTypeAlignInChars(ivarTy).getQuantity());
1879 // Objects that require more than 2^64-byte alignment should be impossible!
1880 assert(align < 64);
1881 // uint32_t flags;
1882 // Bits 0-1 are ownership.
1883 // Bit 2 indicates an extended type encoding
1884 // Bits 3-8 contain log2(aligment)
1885 ivarBuilder.addInt(Int32Ty,
1886 (align << 3) | (1<<2) |
1887 FlagsForOwnership(ivarTy.getQualifiers().getObjCLifetime()));
1888 ivarBuilder.finishAndAddTo(ivarArrayBuilder);
1890 ivarArrayBuilder.finishAndAddTo(ivarListBuilder);
1891 auto ivarList = ivarListBuilder.finishAndCreateGlobal(".objc_ivar_list",
1892 CGM.getPointerAlign(), /*constant*/ false,
1893 llvm::GlobalValue::PrivateLinkage);
1894 classFields.add(ivarList);
1896 // struct objc_method_list *methods
1897 SmallVector<const ObjCMethodDecl*, 16> InstanceMethods;
1898 InstanceMethods.insert(InstanceMethods.begin(), OID->instmeth_begin(),
1899 OID->instmeth_end());
1900 for (auto *propImpl : OID->property_impls())
1901 if (propImpl->getPropertyImplementation() ==
1902 ObjCPropertyImplDecl::Synthesize) {
1903 auto addIfExists = [&](const ObjCMethodDecl *OMD) {
1904 if (OMD && OMD->hasBody())
1905 InstanceMethods.push_back(OMD);
1907 addIfExists(propImpl->getGetterMethodDecl());
1908 addIfExists(propImpl->getSetterMethodDecl());
1911 if (InstanceMethods.size() == 0)
1912 classFields.addNullPointer(PtrTy);
1913 else
1914 classFields.addBitCast(
1915 GenerateMethodList(className, "", InstanceMethods, false),
1916 PtrTy);
1917 // void *dtable;
1918 classFields.addNullPointer(PtrTy);
1919 // IMP cxx_construct;
1920 classFields.addNullPointer(PtrTy);
1921 // IMP cxx_destruct;
1922 classFields.addNullPointer(PtrTy);
1923 // struct objc_class *subclass_list
1924 classFields.addNullPointer(PtrTy);
1925 // struct objc_class *sibling_class
1926 classFields.addNullPointer(PtrTy);
1927 // struct objc_protocol_list *protocols;
1928 auto RuntimeProtocols = GetRuntimeProtocolList(classDecl->protocol_begin(),
1929 classDecl->protocol_end());
1930 SmallVector<llvm::Constant *, 16> Protocols;
1931 for (const auto *I : RuntimeProtocols)
1932 Protocols.push_back(
1933 llvm::ConstantExpr::getBitCast(GenerateProtocolRef(I),
1934 ProtocolPtrTy));
1935 if (Protocols.empty())
1936 classFields.addNullPointer(PtrTy);
1937 else
1938 classFields.add(GenerateProtocolList(Protocols));
1939 // struct reference_list *extra_data;
1940 classFields.addNullPointer(PtrTy);
1941 // long abi_version;
1942 classFields.addInt(LongTy, 0);
1943 // struct objc_property_list *properties
1944 classFields.add(GeneratePropertyList(OID, classDecl));
1946 llvm::GlobalVariable *classStruct =
1947 classFields.finishAndCreateGlobal(SymbolForClass(className),
1948 CGM.getPointerAlign(), false, llvm::GlobalValue::ExternalLinkage);
1950 auto *classRefSymbol = GetClassVar(className);
1951 classRefSymbol->setSection(sectionName<ClassReferenceSection>());
1952 classRefSymbol->setInitializer(llvm::ConstantExpr::getBitCast(classStruct, IdTy));
1954 if (IsCOFF) {
1955 // we can't import a class struct.
1956 if (OID->getClassInterface()->hasAttr<DLLExportAttr>()) {
1957 classStruct->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
1958 cast<llvm::GlobalValue>(classRefSymbol)->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
1961 if (SuperClass) {
1962 std::pair<llvm::GlobalVariable*, int> v{classStruct, 1};
1963 EarlyInitList.emplace_back(std::string(SuperClass->getName()),
1964 std::move(v));
1970 // Resolve the class aliases, if they exist.
1971 // FIXME: Class pointer aliases shouldn't exist!
1972 if (ClassPtrAlias) {
1973 ClassPtrAlias->replaceAllUsesWith(
1974 llvm::ConstantExpr::getBitCast(classStruct, IdTy));
1975 ClassPtrAlias->eraseFromParent();
1976 ClassPtrAlias = nullptr;
1978 if (auto Placeholder =
1979 TheModule.getNamedGlobal(SymbolForClass(className)))
1980 if (Placeholder != classStruct) {
1981 Placeholder->replaceAllUsesWith(
1982 llvm::ConstantExpr::getBitCast(classStruct, Placeholder->getType()));
1983 Placeholder->eraseFromParent();
1984 classStruct->setName(SymbolForClass(className));
1986 if (MetaClassPtrAlias) {
1987 MetaClassPtrAlias->replaceAllUsesWith(
1988 llvm::ConstantExpr::getBitCast(metaclass, IdTy));
1989 MetaClassPtrAlias->eraseFromParent();
1990 MetaClassPtrAlias = nullptr;
1992 assert(classStruct->getName() == SymbolForClass(className));
1994 auto classInitRef = new llvm::GlobalVariable(TheModule,
1995 classStruct->getType(), false, llvm::GlobalValue::ExternalLinkage,
1996 classStruct, ManglePublicSymbol("OBJC_INIT_CLASS_") + className);
1997 classInitRef->setSection(sectionName<ClassSection>());
1998 CGM.addUsedGlobal(classInitRef);
2000 EmittedClass = true;
2002 public:
2003 CGObjCGNUstep2(CodeGenModule &Mod) : CGObjCGNUstep(Mod, 10, 4, 2) {
2004 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
2005 PtrToObjCSuperTy, SelectorTy);
2006 // struct objc_property
2007 // {
2008 // const char *name;
2009 // const char *attributes;
2010 // const char *type;
2011 // SEL getter;
2012 // SEL setter;
2013 // }
2014 PropertyMetadataTy =
2015 llvm::StructType::get(CGM.getLLVMContext(),
2016 { PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty });
2021 const char *const CGObjCGNUstep2::SectionsBaseNames[8] =
2023 "__objc_selectors",
2024 "__objc_classes",
2025 "__objc_class_refs",
2026 "__objc_cats",
2027 "__objc_protocols",
2028 "__objc_protocol_refs",
2029 "__objc_class_aliases",
2030 "__objc_constant_string"
2033 const char *const CGObjCGNUstep2::PECOFFSectionsBaseNames[8] =
2035 ".objcrt$SEL",
2036 ".objcrt$CLS",
2037 ".objcrt$CLR",
2038 ".objcrt$CAT",
2039 ".objcrt$PCL",
2040 ".objcrt$PCR",
2041 ".objcrt$CAL",
2042 ".objcrt$STR"
2045 /// Support for the ObjFW runtime.
2046 class CGObjCObjFW: public CGObjCGNU {
2047 protected:
2048 /// The GCC ABI message lookup function. Returns an IMP pointing to the
2049 /// method implementation for this message.
2050 LazyRuntimeFunction MsgLookupFn;
2051 /// stret lookup function. While this does not seem to make sense at the
2052 /// first look, this is required to call the correct forwarding function.
2053 LazyRuntimeFunction MsgLookupFnSRet;
2054 /// The GCC ABI superclass message lookup function. Takes a pointer to a
2055 /// structure describing the receiver and the class, and a selector as
2056 /// arguments. Returns the IMP for the corresponding method.
2057 LazyRuntimeFunction MsgLookupSuperFn, MsgLookupSuperFnSRet;
2059 llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
2060 llvm::Value *cmd, llvm::MDNode *node,
2061 MessageSendInfo &MSI) override {
2062 CGBuilderTy &Builder = CGF.Builder;
2063 llvm::Value *args[] = {
2064 EnforceType(Builder, Receiver, IdTy),
2065 EnforceType(Builder, cmd, SelectorTy) };
2067 llvm::CallBase *imp;
2068 if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
2069 imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFnSRet, args);
2070 else
2071 imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);
2073 imp->setMetadata(msgSendMDKind, node);
2074 return imp;
2077 llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
2078 llvm::Value *cmd, MessageSendInfo &MSI) override {
2079 CGBuilderTy &Builder = CGF.Builder;
2080 llvm::Value *lookupArgs[] = {
2081 EnforceType(Builder, ObjCSuper.getPointer(), PtrToObjCSuperTy), cmd,
2084 if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
2085 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFnSRet, lookupArgs);
2086 else
2087 return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
2090 llvm::Value *GetClassNamed(CodeGenFunction &CGF, const std::string &Name,
2091 bool isWeak) override {
2092 if (isWeak)
2093 return CGObjCGNU::GetClassNamed(CGF, Name, isWeak);
2095 EmitClassRef(Name);
2096 std::string SymbolName = "_OBJC_CLASS_" + Name;
2097 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(SymbolName);
2098 if (!ClassSymbol)
2099 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
2100 llvm::GlobalValue::ExternalLinkage,
2101 nullptr, SymbolName);
2102 return ClassSymbol;
2105 public:
2106 CGObjCObjFW(CodeGenModule &Mod): CGObjCGNU(Mod, 9, 3) {
2107 // IMP objc_msg_lookup(id, SEL);
2108 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy);
2109 MsgLookupFnSRet.init(&CGM, "objc_msg_lookup_stret", IMPTy, IdTy,
2110 SelectorTy);
2111 // IMP objc_msg_lookup_super(struct objc_super*, SEL);
2112 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
2113 PtrToObjCSuperTy, SelectorTy);
2114 MsgLookupSuperFnSRet.init(&CGM, "objc_msg_lookup_super_stret", IMPTy,
2115 PtrToObjCSuperTy, SelectorTy);
2118 } // end anonymous namespace
2120 /// Emits a reference to a dummy variable which is emitted with each class.
2121 /// This ensures that a linker error will be generated when trying to link
2122 /// together modules where a referenced class is not defined.
2123 void CGObjCGNU::EmitClassRef(const std::string &className) {
2124 std::string symbolRef = "__objc_class_ref_" + className;
2125 // Don't emit two copies of the same symbol
2126 if (TheModule.getGlobalVariable(symbolRef))
2127 return;
2128 std::string symbolName = "__objc_class_name_" + className;
2129 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName);
2130 if (!ClassSymbol) {
2131 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
2132 llvm::GlobalValue::ExternalLinkage,
2133 nullptr, symbolName);
2135 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true,
2136 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef);
2139 CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
2140 unsigned protocolClassVersion, unsigned classABI)
2141 : CGObjCRuntime(cgm), TheModule(CGM.getModule()),
2142 VMContext(cgm.getLLVMContext()), ClassPtrAlias(nullptr),
2143 MetaClassPtrAlias(nullptr), RuntimeVersion(runtimeABIVersion),
2144 ProtocolVersion(protocolClassVersion), ClassABIVersion(classABI) {
2146 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend");
2147 usesSEHExceptions =
2148 cgm.getContext().getTargetInfo().getTriple().isWindowsMSVCEnvironment();
2150 CodeGenTypes &Types = CGM.getTypes();
2151 IntTy = cast<llvm::IntegerType>(
2152 Types.ConvertType(CGM.getContext().IntTy));
2153 LongTy = cast<llvm::IntegerType>(
2154 Types.ConvertType(CGM.getContext().LongTy));
2155 SizeTy = cast<llvm::IntegerType>(
2156 Types.ConvertType(CGM.getContext().getSizeType()));
2157 PtrDiffTy = cast<llvm::IntegerType>(
2158 Types.ConvertType(CGM.getContext().getPointerDiffType()));
2159 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy);
2161 Int8Ty = llvm::Type::getInt8Ty(VMContext);
2162 // C string type. Used in lots of places.
2163 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty);
2164 ProtocolPtrTy = llvm::PointerType::getUnqual(
2165 Types.ConvertType(CGM.getContext().getObjCProtoType()));
2167 Zeros[0] = llvm::ConstantInt::get(LongTy, 0);
2168 Zeros[1] = Zeros[0];
2169 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty);
2170 // Get the selector Type.
2171 QualType selTy = CGM.getContext().getObjCSelType();
2172 if (QualType() == selTy) {
2173 SelectorTy = PtrToInt8Ty;
2174 SelectorElemTy = Int8Ty;
2175 } else {
2176 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy));
2177 SelectorElemTy = CGM.getTypes().ConvertTypeForMem(selTy->getPointeeType());
2180 PtrToIntTy = llvm::PointerType::getUnqual(IntTy);
2181 PtrTy = PtrToInt8Ty;
2183 Int32Ty = llvm::Type::getInt32Ty(VMContext);
2184 Int64Ty = llvm::Type::getInt64Ty(VMContext);
2186 IntPtrTy =
2187 CGM.getDataLayout().getPointerSizeInBits() == 32 ? Int32Ty : Int64Ty;
2189 // Object type
2190 QualType UnqualIdTy = CGM.getContext().getObjCIdType();
2191 ASTIdTy = CanQualType();
2192 if (UnqualIdTy != QualType()) {
2193 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy);
2194 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
2195 IdElemTy = CGM.getTypes().ConvertTypeForMem(
2196 ASTIdTy.getTypePtr()->getPointeeType());
2197 } else {
2198 IdTy = PtrToInt8Ty;
2199 IdElemTy = Int8Ty;
2201 PtrToIdTy = llvm::PointerType::getUnqual(IdTy);
2202 ProtocolTy = llvm::StructType::get(IdTy,
2203 PtrToInt8Ty, // name
2204 PtrToInt8Ty, // protocols
2205 PtrToInt8Ty, // instance methods
2206 PtrToInt8Ty, // class methods
2207 PtrToInt8Ty, // optional instance methods
2208 PtrToInt8Ty, // optional class methods
2209 PtrToInt8Ty, // properties
2210 PtrToInt8Ty);// optional properties
2212 // struct objc_property_gsv1
2213 // {
2214 // const char *name;
2215 // char attributes;
2216 // char attributes2;
2217 // char unused1;
2218 // char unused2;
2219 // const char *getter_name;
2220 // const char *getter_types;
2221 // const char *setter_name;
2222 // const char *setter_types;
2223 // }
2224 PropertyMetadataTy = llvm::StructType::get(CGM.getLLVMContext(), {
2225 PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty,
2226 PtrToInt8Ty, PtrToInt8Ty });
2228 ObjCSuperTy = llvm::StructType::get(IdTy, IdTy);
2229 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy);
2231 llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
2233 // void objc_exception_throw(id);
2234 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
2235 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
2236 // int objc_sync_enter(id);
2237 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy);
2238 // int objc_sync_exit(id);
2239 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy);
2241 // void objc_enumerationMutation (id)
2242 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, IdTy);
2244 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL)
2245 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy,
2246 PtrDiffTy, BoolTy);
2247 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL)
2248 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy,
2249 PtrDiffTy, IdTy, BoolTy, BoolTy);
2250 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
2251 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy,
2252 PtrDiffTy, BoolTy, BoolTy);
2253 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
2254 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy,
2255 PtrDiffTy, BoolTy, BoolTy);
2257 // IMP type
2258 llvm::Type *IMPArgs[] = { IdTy, SelectorTy };
2259 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs,
2260 true));
2262 const LangOptions &Opts = CGM.getLangOpts();
2263 if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount)
2264 RuntimeVersion = 10;
2266 // Don't bother initialising the GC stuff unless we're compiling in GC mode
2267 if (Opts.getGC() != LangOptions::NonGC) {
2268 // This is a bit of an hack. We should sort this out by having a proper
2269 // CGObjCGNUstep subclass for GC, but we may want to really support the old
2270 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now
2271 // Get selectors needed in GC mode
2272 RetainSel = GetNullarySelector("retain", CGM.getContext());
2273 ReleaseSel = GetNullarySelector("release", CGM.getContext());
2274 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext());
2276 // Get functions needed in GC mode
2278 // id objc_assign_ivar(id, id, ptrdiff_t);
2279 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy);
2280 // id objc_assign_strongCast (id, id*)
2281 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy,
2282 PtrToIdTy);
2283 // id objc_assign_global(id, id*);
2284 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy);
2285 // id objc_assign_weak(id, id*);
2286 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy);
2287 // id objc_read_weak(id*);
2288 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy);
2289 // void *objc_memmove_collectable(void*, void *, size_t);
2290 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy,
2291 SizeTy);
2295 llvm::Value *CGObjCGNU::GetClassNamed(CodeGenFunction &CGF,
2296 const std::string &Name, bool isWeak) {
2297 llvm::Constant *ClassName = MakeConstantString(Name);
2298 // With the incompatible ABI, this will need to be replaced with a direct
2299 // reference to the class symbol. For the compatible nonfragile ABI we are
2300 // still performing this lookup at run time but emitting the symbol for the
2301 // class externally so that we can make the switch later.
2303 // Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class
2304 // with memoized versions or with static references if it's safe to do so.
2305 if (!isWeak)
2306 EmitClassRef(Name);
2308 llvm::FunctionCallee ClassLookupFn = CGM.CreateRuntimeFunction(
2309 llvm::FunctionType::get(IdTy, PtrToInt8Ty, true), "objc_lookup_class");
2310 return CGF.EmitNounwindRuntimeCall(ClassLookupFn, ClassName);
2313 // This has to perform the lookup every time, since posing and related
2314 // techniques can modify the name -> class mapping.
2315 llvm::Value *CGObjCGNU::GetClass(CodeGenFunction &CGF,
2316 const ObjCInterfaceDecl *OID) {
2317 auto *Value =
2318 GetClassNamed(CGF, OID->getNameAsString(), OID->isWeakImported());
2319 if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value))
2320 CGM.setGVProperties(ClassSymbol, OID);
2321 return Value;
2324 llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) {
2325 auto *Value = GetClassNamed(CGF, "NSAutoreleasePool", false);
2326 if (CGM.getTriple().isOSBinFormatCOFF()) {
2327 if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value)) {
2328 IdentifierInfo &II = CGF.CGM.getContext().Idents.get("NSAutoreleasePool");
2329 TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
2330 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
2332 const VarDecl *VD = nullptr;
2333 for (const auto *Result : DC->lookup(&II))
2334 if ((VD = dyn_cast<VarDecl>(Result)))
2335 break;
2337 CGM.setGVProperties(ClassSymbol, VD);
2340 return Value;
2343 llvm::Value *CGObjCGNU::GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
2344 const std::string &TypeEncoding) {
2345 SmallVectorImpl<TypedSelector> &Types = SelectorTable[Sel];
2346 llvm::GlobalAlias *SelValue = nullptr;
2348 for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(),
2349 e = Types.end() ; i!=e ; i++) {
2350 if (i->first == TypeEncoding) {
2351 SelValue = i->second;
2352 break;
2355 if (!SelValue) {
2356 SelValue = llvm::GlobalAlias::create(SelectorElemTy, 0,
2357 llvm::GlobalValue::PrivateLinkage,
2358 ".objc_selector_" + Sel.getAsString(),
2359 &TheModule);
2360 Types.emplace_back(TypeEncoding, SelValue);
2363 return SelValue;
2366 Address CGObjCGNU::GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) {
2367 llvm::Value *SelValue = GetSelector(CGF, Sel);
2369 // Store it to a temporary. Does this satisfy the semantics of
2370 // GetAddrOfSelector? Hopefully.
2371 Address tmp = CGF.CreateTempAlloca(SelValue->getType(),
2372 CGF.getPointerAlign());
2373 CGF.Builder.CreateStore(SelValue, tmp);
2374 return tmp;
2377 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel) {
2378 return GetTypedSelector(CGF, Sel, std::string());
2381 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF,
2382 const ObjCMethodDecl *Method) {
2383 std::string SelTypes = CGM.getContext().getObjCEncodingForMethodDecl(Method);
2384 return GetTypedSelector(CGF, Method->getSelector(), SelTypes);
2387 llvm::Constant *CGObjCGNU::GetEHType(QualType T) {
2388 if (T->isObjCIdType() || T->isObjCQualifiedIdType()) {
2389 // With the old ABI, there was only one kind of catchall, which broke
2390 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as
2391 // a pointer indicating object catchalls, and NULL to indicate real
2392 // catchalls
2393 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
2394 return MakeConstantString("@id");
2395 } else {
2396 return nullptr;
2400 // All other types should be Objective-C interface pointer types.
2401 const ObjCObjectPointerType *OPT = T->getAs<ObjCObjectPointerType>();
2402 assert(OPT && "Invalid @catch type.");
2403 const ObjCInterfaceDecl *IDecl = OPT->getObjectType()->getInterface();
2404 assert(IDecl && "Invalid @catch type.");
2405 return MakeConstantString(IDecl->getIdentifier()->getName());
2408 llvm::Constant *CGObjCGNUstep::GetEHType(QualType T) {
2409 if (usesSEHExceptions)
2410 return CGM.getCXXABI().getAddrOfRTTIDescriptor(T);
2412 if (!CGM.getLangOpts().CPlusPlus)
2413 return CGObjCGNU::GetEHType(T);
2415 // For Objective-C++, we want to provide the ability to catch both C++ and
2416 // Objective-C objects in the same function.
2418 // There's a particular fixed type info for 'id'.
2419 if (T->isObjCIdType() ||
2420 T->isObjCQualifiedIdType()) {
2421 llvm::Constant *IDEHType =
2422 CGM.getModule().getGlobalVariable("__objc_id_type_info");
2423 if (!IDEHType)
2424 IDEHType =
2425 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty,
2426 false,
2427 llvm::GlobalValue::ExternalLinkage,
2428 nullptr, "__objc_id_type_info");
2429 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty);
2432 const ObjCObjectPointerType *PT =
2433 T->getAs<ObjCObjectPointerType>();
2434 assert(PT && "Invalid @catch type.");
2435 const ObjCInterfaceType *IT = PT->getInterfaceType();
2436 assert(IT && "Invalid @catch type.");
2437 std::string className =
2438 std::string(IT->getDecl()->getIdentifier()->getName());
2440 std::string typeinfoName = "__objc_eh_typeinfo_" + className;
2442 // Return the existing typeinfo if it exists
2443 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName);
2444 if (typeinfo)
2445 return llvm::ConstantExpr::getBitCast(typeinfo, PtrToInt8Ty);
2447 // Otherwise create it.
2449 // vtable for gnustep::libobjc::__objc_class_type_info
2450 // It's quite ugly hard-coding this. Ideally we'd generate it using the host
2451 // platform's name mangling.
2452 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE";
2453 auto *Vtable = TheModule.getGlobalVariable(vtableName);
2454 if (!Vtable) {
2455 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true,
2456 llvm::GlobalValue::ExternalLinkage,
2457 nullptr, vtableName);
2459 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2);
2460 auto *BVtable = llvm::ConstantExpr::getBitCast(
2461 llvm::ConstantExpr::getGetElementPtr(Vtable->getValueType(), Vtable, Two),
2462 PtrToInt8Ty);
2464 llvm::Constant *typeName =
2465 ExportUniqueString(className, "__objc_eh_typename_");
2467 ConstantInitBuilder builder(CGM);
2468 auto fields = builder.beginStruct();
2469 fields.add(BVtable);
2470 fields.add(typeName);
2471 llvm::Constant *TI =
2472 fields.finishAndCreateGlobal("__objc_eh_typeinfo_" + className,
2473 CGM.getPointerAlign(),
2474 /*constant*/ false,
2475 llvm::GlobalValue::LinkOnceODRLinkage);
2476 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty);
2479 /// Generate an NSConstantString object.
2480 ConstantAddress CGObjCGNU::GenerateConstantString(const StringLiteral *SL) {
2482 std::string Str = SL->getString().str();
2483 CharUnits Align = CGM.getPointerAlign();
2485 // Look for an existing one
2486 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str);
2487 if (old != ObjCStrings.end())
2488 return ConstantAddress(old->getValue(), Int8Ty, Align);
2490 StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass;
2492 if (StringClass.empty()) StringClass = "NSConstantString";
2494 std::string Sym = "_OBJC_CLASS_";
2495 Sym += StringClass;
2497 llvm::Constant *isa = TheModule.getNamedGlobal(Sym);
2499 if (!isa)
2500 isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false,
2501 llvm::GlobalValue::ExternalWeakLinkage, nullptr, Sym);
2502 else if (isa->getType() != PtrToIdTy)
2503 isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy);
2505 ConstantInitBuilder Builder(CGM);
2506 auto Fields = Builder.beginStruct();
2507 Fields.add(isa);
2508 Fields.add(MakeConstantString(Str));
2509 Fields.addInt(IntTy, Str.size());
2510 llvm::Constant *ObjCStr =
2511 Fields.finishAndCreateGlobal(".objc_str", Align);
2512 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty);
2513 ObjCStrings[Str] = ObjCStr;
2514 ConstantStrings.push_back(ObjCStr);
2515 return ConstantAddress(ObjCStr, Int8Ty, Align);
2518 ///Generates a message send where the super is the receiver. This is a message
2519 ///send to self with special delivery semantics indicating which class's method
2520 ///should be called.
2521 RValue
2522 CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF,
2523 ReturnValueSlot Return,
2524 QualType ResultType,
2525 Selector Sel,
2526 const ObjCInterfaceDecl *Class,
2527 bool isCategoryImpl,
2528 llvm::Value *Receiver,
2529 bool IsClassMessage,
2530 const CallArgList &CallArgs,
2531 const ObjCMethodDecl *Method) {
2532 CGBuilderTy &Builder = CGF.Builder;
2533 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
2534 if (Sel == RetainSel || Sel == AutoreleaseSel) {
2535 return RValue::get(EnforceType(Builder, Receiver,
2536 CGM.getTypes().ConvertType(ResultType)));
2538 if (Sel == ReleaseSel) {
2539 return RValue::get(nullptr);
2543 llvm::Value *cmd = GetSelector(CGF, Sel);
2544 CallArgList ActualArgs;
2546 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy);
2547 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
2548 ActualArgs.addFrom(CallArgs);
2550 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
2552 llvm::Value *ReceiverClass = nullptr;
2553 bool isV2ABI = isRuntime(ObjCRuntime::GNUstep, 2);
2554 if (isV2ABI) {
2555 ReceiverClass = GetClassNamed(CGF,
2556 Class->getSuperClass()->getNameAsString(), /*isWeak*/false);
2557 if (IsClassMessage) {
2558 // Load the isa pointer of the superclass is this is a class method.
2559 ReceiverClass = Builder.CreateBitCast(ReceiverClass,
2560 llvm::PointerType::getUnqual(IdTy));
2561 ReceiverClass =
2562 Builder.CreateAlignedLoad(IdTy, ReceiverClass, CGF.getPointerAlign());
2564 ReceiverClass = EnforceType(Builder, ReceiverClass, IdTy);
2565 } else {
2566 if (isCategoryImpl) {
2567 llvm::FunctionCallee classLookupFunction = nullptr;
2568 if (IsClassMessage) {
2569 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
2570 IdTy, PtrTy, true), "objc_get_meta_class");
2571 } else {
2572 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
2573 IdTy, PtrTy, true), "objc_get_class");
2575 ReceiverClass = Builder.CreateCall(classLookupFunction,
2576 MakeConstantString(Class->getNameAsString()));
2577 } else {
2578 // Set up global aliases for the metaclass or class pointer if they do not
2579 // already exist. These will are forward-references which will be set to
2580 // pointers to the class and metaclass structure created for the runtime
2581 // load function. To send a message to super, we look up the value of the
2582 // super_class pointer from either the class or metaclass structure.
2583 if (IsClassMessage) {
2584 if (!MetaClassPtrAlias) {
2585 MetaClassPtrAlias = llvm::GlobalAlias::create(
2586 IdElemTy, 0, llvm::GlobalValue::InternalLinkage,
2587 ".objc_metaclass_ref" + Class->getNameAsString(), &TheModule);
2589 ReceiverClass = MetaClassPtrAlias;
2590 } else {
2591 if (!ClassPtrAlias) {
2592 ClassPtrAlias = llvm::GlobalAlias::create(
2593 IdElemTy, 0, llvm::GlobalValue::InternalLinkage,
2594 ".objc_class_ref" + Class->getNameAsString(), &TheModule);
2596 ReceiverClass = ClassPtrAlias;
2599 // Cast the pointer to a simplified version of the class structure
2600 llvm::Type *CastTy = llvm::StructType::get(IdTy, IdTy);
2601 ReceiverClass = Builder.CreateBitCast(ReceiverClass,
2602 llvm::PointerType::getUnqual(CastTy));
2603 // Get the superclass pointer
2604 ReceiverClass = Builder.CreateStructGEP(CastTy, ReceiverClass, 1);
2605 // Load the superclass pointer
2606 ReceiverClass =
2607 Builder.CreateAlignedLoad(IdTy, ReceiverClass, CGF.getPointerAlign());
2609 // Construct the structure used to look up the IMP
2610 llvm::StructType *ObjCSuperTy =
2611 llvm::StructType::get(Receiver->getType(), IdTy);
2613 Address ObjCSuper = CGF.CreateTempAlloca(ObjCSuperTy,
2614 CGF.getPointerAlign());
2616 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0));
2617 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1));
2619 // Get the IMP
2620 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd, MSI);
2621 imp = EnforceType(Builder, imp, MSI.MessengerType);
2623 llvm::Metadata *impMD[] = {
2624 llvm::MDString::get(VMContext, Sel.getAsString()),
2625 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()),
2626 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
2627 llvm::Type::getInt1Ty(VMContext), IsClassMessage))};
2628 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
2630 CGCallee callee(CGCalleeInfo(), imp);
2632 llvm::CallBase *call;
2633 RValue msgRet = CGF.EmitCall(MSI.CallInfo, callee, Return, ActualArgs, &call);
2634 call->setMetadata(msgSendMDKind, node);
2635 return msgRet;
2638 /// Generate code for a message send expression.
2639 RValue
2640 CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF,
2641 ReturnValueSlot Return,
2642 QualType ResultType,
2643 Selector Sel,
2644 llvm::Value *Receiver,
2645 const CallArgList &CallArgs,
2646 const ObjCInterfaceDecl *Class,
2647 const ObjCMethodDecl *Method) {
2648 CGBuilderTy &Builder = CGF.Builder;
2650 // Strip out message sends to retain / release in GC mode
2651 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
2652 if (Sel == RetainSel || Sel == AutoreleaseSel) {
2653 return RValue::get(EnforceType(Builder, Receiver,
2654 CGM.getTypes().ConvertType(ResultType)));
2656 if (Sel == ReleaseSel) {
2657 return RValue::get(nullptr);
2661 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
2662 llvm::Value *cmd;
2663 if (Method)
2664 cmd = GetSelector(CGF, Method);
2665 else
2666 cmd = GetSelector(CGF, Sel);
2667 cmd = EnforceType(Builder, cmd, SelectorTy);
2668 Receiver = EnforceType(Builder, Receiver, IdTy);
2670 llvm::Metadata *impMD[] = {
2671 llvm::MDString::get(VMContext, Sel.getAsString()),
2672 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() : ""),
2673 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
2674 llvm::Type::getInt1Ty(VMContext), Class != nullptr))};
2675 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
2677 CallArgList ActualArgs;
2678 ActualArgs.add(RValue::get(Receiver), ASTIdTy);
2679 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
2680 ActualArgs.addFrom(CallArgs);
2682 MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
2684 // Message sends are expected to return a zero value when the
2685 // receiver is nil. At one point, this was only guaranteed for
2686 // simple integer and pointer types, but expectations have grown
2687 // over time.
2689 // Given a nil receiver, the GNU runtime's message lookup will
2690 // return a stub function that simply sets various return-value
2691 // registers to zero and then returns. That's good enough for us
2692 // if and only if (1) the calling conventions of that stub are
2693 // compatible with the signature we're using and (2) the registers
2694 // it sets are sufficient to produce a zero value of the return type.
2695 // Rather than doing a whole target-specific analysis, we assume it
2696 // only works for void, integer, and pointer types, and in all
2697 // other cases we do an explicit nil check is emitted code. In
2698 // addition to ensuring we produe a zero value for other types, this
2699 // sidesteps the few outright CC incompatibilities we know about that
2700 // could otherwise lead to crashes, like when a method is expected to
2701 // return on the x87 floating point stack or adjust the stack pointer
2702 // because of an indirect return.
2703 bool hasParamDestroyedInCallee = false;
2704 bool requiresExplicitZeroResult = false;
2705 bool requiresNilReceiverCheck = [&] {
2706 // We never need a check if we statically know the receiver isn't nil.
2707 if (!canMessageReceiverBeNull(CGF, Method, /*IsSuper*/ false,
2708 Class, Receiver))
2709 return false;
2711 // If there's a consumed argument, we need a nil check.
2712 if (Method && Method->hasParamDestroyedInCallee()) {
2713 hasParamDestroyedInCallee = true;
2716 // If the return value isn't flagged as unused, and the result
2717 // type isn't in our narrow set where we assume compatibility,
2718 // we need a nil check to ensure a nil value.
2719 if (!Return.isUnused()) {
2720 if (ResultType->isVoidType()) {
2721 // void results are definitely okay.
2722 } else if (ResultType->hasPointerRepresentation() &&
2723 CGM.getTypes().isZeroInitializable(ResultType)) {
2724 // Pointer types should be fine as long as they have
2725 // bitwise-zero null pointers. But do we need to worry
2726 // about unusual address spaces?
2727 } else if (ResultType->isIntegralOrEnumerationType()) {
2728 // Bitwise zero should always be zero for integral types.
2729 // FIXME: we probably need a size limit here, but we've
2730 // never imposed one before
2731 } else {
2732 // Otherwise, use an explicit check just to be sure.
2733 requiresExplicitZeroResult = true;
2737 return hasParamDestroyedInCallee || requiresExplicitZeroResult;
2738 }();
2740 // We will need to explicitly zero-initialize an aggregate result slot
2741 // if we generally require explicit zeroing and we have an aggregate
2742 // result.
2743 bool requiresExplicitAggZeroing =
2744 requiresExplicitZeroResult && CGF.hasAggregateEvaluationKind(ResultType);
2746 // The block we're going to end up in after any message send or nil path.
2747 llvm::BasicBlock *continueBB = nullptr;
2748 // The block that eventually branched to continueBB along the nil path.
2749 llvm::BasicBlock *nilPathBB = nullptr;
2750 // The block to do explicit work in along the nil path, if necessary.
2751 llvm::BasicBlock *nilCleanupBB = nullptr;
2753 // Emit the nil-receiver check.
2754 if (requiresNilReceiverCheck) {
2755 llvm::BasicBlock *messageBB = CGF.createBasicBlock("msgSend");
2756 continueBB = CGF.createBasicBlock("continue");
2758 // If we need to zero-initialize an aggregate result or destroy
2759 // consumed arguments, we'll need a separate cleanup block.
2760 // Otherwise we can just branch directly to the continuation block.
2761 if (requiresExplicitAggZeroing || hasParamDestroyedInCallee) {
2762 nilCleanupBB = CGF.createBasicBlock("nilReceiverCleanup");
2763 } else {
2764 nilPathBB = Builder.GetInsertBlock();
2767 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver,
2768 llvm::Constant::getNullValue(Receiver->getType()));
2769 Builder.CreateCondBr(isNil, nilCleanupBB ? nilCleanupBB : continueBB,
2770 messageBB);
2771 CGF.EmitBlock(messageBB);
2774 // Get the IMP to call
2775 llvm::Value *imp;
2777 // If we have non-legacy dispatch specified, we try using the objc_msgSend()
2778 // functions. These are not supported on all platforms (or all runtimes on a
2779 // given platform), so we
2780 switch (CGM.getCodeGenOpts().getObjCDispatchMethod()) {
2781 case CodeGenOptions::Legacy:
2782 imp = LookupIMP(CGF, Receiver, cmd, node, MSI);
2783 break;
2784 case CodeGenOptions::Mixed:
2785 case CodeGenOptions::NonLegacy:
2786 if (CGM.ReturnTypeUsesFPRet(ResultType)) {
2787 imp =
2788 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
2789 "objc_msgSend_fpret")
2790 .getCallee();
2791 } else if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) {
2792 // The actual types here don't matter - we're going to bitcast the
2793 // function anyway
2794 imp =
2795 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
2796 "objc_msgSend_stret")
2797 .getCallee();
2798 } else {
2799 imp = CGM.CreateRuntimeFunction(
2800 llvm::FunctionType::get(IdTy, IdTy, true), "objc_msgSend")
2801 .getCallee();
2805 // Reset the receiver in case the lookup modified it
2806 ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy);
2808 imp = EnforceType(Builder, imp, MSI.MessengerType);
2810 llvm::CallBase *call;
2811 CGCallee callee(CGCalleeInfo(), imp);
2812 RValue msgRet = CGF.EmitCall(MSI.CallInfo, callee, Return, ActualArgs, &call);
2813 call->setMetadata(msgSendMDKind, node);
2815 if (requiresNilReceiverCheck) {
2816 llvm::BasicBlock *nonNilPathBB = CGF.Builder.GetInsertBlock();
2817 CGF.Builder.CreateBr(continueBB);
2819 // Emit the nil path if we decided it was necessary above.
2820 if (nilCleanupBB) {
2821 CGF.EmitBlock(nilCleanupBB);
2823 if (hasParamDestroyedInCallee) {
2824 destroyCalleeDestroyedArguments(CGF, Method, CallArgs);
2827 if (requiresExplicitAggZeroing) {
2828 assert(msgRet.isAggregate());
2829 Address addr = msgRet.getAggregateAddress();
2830 CGF.EmitNullInitialization(addr, ResultType);
2833 nilPathBB = CGF.Builder.GetInsertBlock();
2834 CGF.Builder.CreateBr(continueBB);
2837 // Enter the continuation block and emit a phi if required.
2838 CGF.EmitBlock(continueBB);
2839 if (msgRet.isScalar()) {
2840 // If the return type is void, do nothing
2841 if (llvm::Value *v = msgRet.getScalarVal()) {
2842 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2);
2843 phi->addIncoming(v, nonNilPathBB);
2844 phi->addIncoming(CGM.EmitNullConstant(ResultType), nilPathBB);
2845 msgRet = RValue::get(phi);
2847 } else if (msgRet.isAggregate()) {
2848 // Aggregate zeroing is handled in nilCleanupBB when it's required.
2849 } else /* isComplex() */ {
2850 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal();
2851 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2);
2852 phi->addIncoming(v.first, nonNilPathBB);
2853 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()),
2854 nilPathBB);
2855 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2);
2856 phi2->addIncoming(v.second, nonNilPathBB);
2857 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()),
2858 nilPathBB);
2859 msgRet = RValue::getComplex(phi, phi2);
2862 return msgRet;
2865 /// Generates a MethodList. Used in construction of a objc_class and
2866 /// objc_category structures.
2867 llvm::Constant *CGObjCGNU::
2868 GenerateMethodList(StringRef ClassName,
2869 StringRef CategoryName,
2870 ArrayRef<const ObjCMethodDecl*> Methods,
2871 bool isClassMethodList) {
2872 if (Methods.empty())
2873 return NULLPtr;
2875 ConstantInitBuilder Builder(CGM);
2877 auto MethodList = Builder.beginStruct();
2878 MethodList.addNullPointer(CGM.Int8PtrTy);
2879 MethodList.addInt(Int32Ty, Methods.size());
2881 // Get the method structure type.
2882 llvm::StructType *ObjCMethodTy =
2883 llvm::StructType::get(CGM.getLLVMContext(), {
2884 PtrToInt8Ty, // Really a selector, but the runtime creates it us.
2885 PtrToInt8Ty, // Method types
2886 IMPTy // Method pointer
2888 bool isV2ABI = isRuntime(ObjCRuntime::GNUstep, 2);
2889 if (isV2ABI) {
2890 // size_t size;
2891 llvm::DataLayout td(&TheModule);
2892 MethodList.addInt(SizeTy, td.getTypeSizeInBits(ObjCMethodTy) /
2893 CGM.getContext().getCharWidth());
2894 ObjCMethodTy =
2895 llvm::StructType::get(CGM.getLLVMContext(), {
2896 IMPTy, // Method pointer
2897 PtrToInt8Ty, // Selector
2898 PtrToInt8Ty // Extended type encoding
2900 } else {
2901 ObjCMethodTy =
2902 llvm::StructType::get(CGM.getLLVMContext(), {
2903 PtrToInt8Ty, // Really a selector, but the runtime creates it us.
2904 PtrToInt8Ty, // Method types
2905 IMPTy // Method pointer
2908 auto MethodArray = MethodList.beginArray();
2909 ASTContext &Context = CGM.getContext();
2910 for (const auto *OMD : Methods) {
2911 llvm::Constant *FnPtr =
2912 TheModule.getFunction(getSymbolNameForMethod(OMD));
2913 assert(FnPtr && "Can't generate metadata for method that doesn't exist");
2914 auto Method = MethodArray.beginStruct(ObjCMethodTy);
2915 if (isV2ABI) {
2916 Method.addBitCast(FnPtr, IMPTy);
2917 Method.add(GetConstantSelector(OMD->getSelector(),
2918 Context.getObjCEncodingForMethodDecl(OMD)));
2919 Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(OMD, true)));
2920 } else {
2921 Method.add(MakeConstantString(OMD->getSelector().getAsString()));
2922 Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(OMD)));
2923 Method.addBitCast(FnPtr, IMPTy);
2925 Method.finishAndAddTo(MethodArray);
2927 MethodArray.finishAndAddTo(MethodList);
2929 // Create an instance of the structure
2930 return MethodList.finishAndCreateGlobal(".objc_method_list",
2931 CGM.getPointerAlign());
2934 /// Generates an IvarList. Used in construction of a objc_class.
2935 llvm::Constant *CGObjCGNU::
2936 GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
2937 ArrayRef<llvm::Constant *> IvarTypes,
2938 ArrayRef<llvm::Constant *> IvarOffsets,
2939 ArrayRef<llvm::Constant *> IvarAlign,
2940 ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership) {
2941 if (IvarNames.empty())
2942 return NULLPtr;
2944 ConstantInitBuilder Builder(CGM);
2946 // Structure containing array count followed by array.
2947 auto IvarList = Builder.beginStruct();
2948 IvarList.addInt(IntTy, (int)IvarNames.size());
2950 // Get the ivar structure type.
2951 llvm::StructType *ObjCIvarTy =
2952 llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, IntTy);
2954 // Array of ivar structures.
2955 auto Ivars = IvarList.beginArray(ObjCIvarTy);
2956 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) {
2957 auto Ivar = Ivars.beginStruct(ObjCIvarTy);
2958 Ivar.add(IvarNames[i]);
2959 Ivar.add(IvarTypes[i]);
2960 Ivar.add(IvarOffsets[i]);
2961 Ivar.finishAndAddTo(Ivars);
2963 Ivars.finishAndAddTo(IvarList);
2965 // Create an instance of the structure
2966 return IvarList.finishAndCreateGlobal(".objc_ivar_list",
2967 CGM.getPointerAlign());
2970 /// Generate a class structure
2971 llvm::Constant *CGObjCGNU::GenerateClassStructure(
2972 llvm::Constant *MetaClass,
2973 llvm::Constant *SuperClass,
2974 unsigned info,
2975 const char *Name,
2976 llvm::Constant *Version,
2977 llvm::Constant *InstanceSize,
2978 llvm::Constant *IVars,
2979 llvm::Constant *Methods,
2980 llvm::Constant *Protocols,
2981 llvm::Constant *IvarOffsets,
2982 llvm::Constant *Properties,
2983 llvm::Constant *StrongIvarBitmap,
2984 llvm::Constant *WeakIvarBitmap,
2985 bool isMeta) {
2986 // Set up the class structure
2987 // Note: Several of these are char*s when they should be ids. This is
2988 // because the runtime performs this translation on load.
2990 // Fields marked New ABI are part of the GNUstep runtime. We emit them
2991 // anyway; the classes will still work with the GNU runtime, they will just
2992 // be ignored.
2993 llvm::StructType *ClassTy = llvm::StructType::get(
2994 PtrToInt8Ty, // isa
2995 PtrToInt8Ty, // super_class
2996 PtrToInt8Ty, // name
2997 LongTy, // version
2998 LongTy, // info
2999 LongTy, // instance_size
3000 IVars->getType(), // ivars
3001 Methods->getType(), // methods
3002 // These are all filled in by the runtime, so we pretend
3003 PtrTy, // dtable
3004 PtrTy, // subclass_list
3005 PtrTy, // sibling_class
3006 PtrTy, // protocols
3007 PtrTy, // gc_object_type
3008 // New ABI:
3009 LongTy, // abi_version
3010 IvarOffsets->getType(), // ivar_offsets
3011 Properties->getType(), // properties
3012 IntPtrTy, // strong_pointers
3013 IntPtrTy // weak_pointers
3016 ConstantInitBuilder Builder(CGM);
3017 auto Elements = Builder.beginStruct(ClassTy);
3019 // Fill in the structure
3021 // isa
3022 Elements.addBitCast(MetaClass, PtrToInt8Ty);
3023 // super_class
3024 Elements.add(SuperClass);
3025 // name
3026 Elements.add(MakeConstantString(Name, ".class_name"));
3027 // version
3028 Elements.addInt(LongTy, 0);
3029 // info
3030 Elements.addInt(LongTy, info);
3031 // instance_size
3032 if (isMeta) {
3033 llvm::DataLayout td(&TheModule);
3034 Elements.addInt(LongTy,
3035 td.getTypeSizeInBits(ClassTy) /
3036 CGM.getContext().getCharWidth());
3037 } else
3038 Elements.add(InstanceSize);
3039 // ivars
3040 Elements.add(IVars);
3041 // methods
3042 Elements.add(Methods);
3043 // These are all filled in by the runtime, so we pretend
3044 // dtable
3045 Elements.add(NULLPtr);
3046 // subclass_list
3047 Elements.add(NULLPtr);
3048 // sibling_class
3049 Elements.add(NULLPtr);
3050 // protocols
3051 Elements.addBitCast(Protocols, PtrTy);
3052 // gc_object_type
3053 Elements.add(NULLPtr);
3054 // abi_version
3055 Elements.addInt(LongTy, ClassABIVersion);
3056 // ivar_offsets
3057 Elements.add(IvarOffsets);
3058 // properties
3059 Elements.add(Properties);
3060 // strong_pointers
3061 Elements.add(StrongIvarBitmap);
3062 // weak_pointers
3063 Elements.add(WeakIvarBitmap);
3064 // Create an instance of the structure
3065 // This is now an externally visible symbol, so that we can speed up class
3066 // messages in the next ABI. We may already have some weak references to
3067 // this, so check and fix them properly.
3068 std::string ClassSym((isMeta ? "_OBJC_METACLASS_": "_OBJC_CLASS_") +
3069 std::string(Name));
3070 llvm::GlobalVariable *ClassRef = TheModule.getNamedGlobal(ClassSym);
3071 llvm::Constant *Class =
3072 Elements.finishAndCreateGlobal(ClassSym, CGM.getPointerAlign(), false,
3073 llvm::GlobalValue::ExternalLinkage);
3074 if (ClassRef) {
3075 ClassRef->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(Class,
3076 ClassRef->getType()));
3077 ClassRef->removeFromParent();
3078 Class->setName(ClassSym);
3080 return Class;
3083 llvm::Constant *CGObjCGNU::
3084 GenerateProtocolMethodList(ArrayRef<const ObjCMethodDecl*> Methods) {
3085 // Get the method structure type.
3086 llvm::StructType *ObjCMethodDescTy =
3087 llvm::StructType::get(CGM.getLLVMContext(), { PtrToInt8Ty, PtrToInt8Ty });
3088 ASTContext &Context = CGM.getContext();
3089 ConstantInitBuilder Builder(CGM);
3090 auto MethodList = Builder.beginStruct();
3091 MethodList.addInt(IntTy, Methods.size());
3092 auto MethodArray = MethodList.beginArray(ObjCMethodDescTy);
3093 for (auto *M : Methods) {
3094 auto Method = MethodArray.beginStruct(ObjCMethodDescTy);
3095 Method.add(MakeConstantString(M->getSelector().getAsString()));
3096 Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(M)));
3097 Method.finishAndAddTo(MethodArray);
3099 MethodArray.finishAndAddTo(MethodList);
3100 return MethodList.finishAndCreateGlobal(".objc_method_list",
3101 CGM.getPointerAlign());
3104 // Create the protocol list structure used in classes, categories and so on
3105 llvm::Constant *
3106 CGObjCGNU::GenerateProtocolList(ArrayRef<std::string> Protocols) {
3108 ConstantInitBuilder Builder(CGM);
3109 auto ProtocolList = Builder.beginStruct();
3110 ProtocolList.add(NULLPtr);
3111 ProtocolList.addInt(LongTy, Protocols.size());
3113 auto Elements = ProtocolList.beginArray(PtrToInt8Ty);
3114 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end();
3115 iter != endIter ; iter++) {
3116 llvm::Constant *protocol = nullptr;
3117 llvm::StringMap<llvm::Constant*>::iterator value =
3118 ExistingProtocols.find(*iter);
3119 if (value == ExistingProtocols.end()) {
3120 protocol = GenerateEmptyProtocol(*iter);
3121 } else {
3122 protocol = value->getValue();
3124 Elements.addBitCast(protocol, PtrToInt8Ty);
3126 Elements.finishAndAddTo(ProtocolList);
3127 return ProtocolList.finishAndCreateGlobal(".objc_protocol_list",
3128 CGM.getPointerAlign());
3131 llvm::Value *CGObjCGNU::GenerateProtocolRef(CodeGenFunction &CGF,
3132 const ObjCProtocolDecl *PD) {
3133 auto protocol = GenerateProtocolRef(PD);
3134 llvm::Type *T =
3135 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType());
3136 return CGF.Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T));
3139 llvm::Constant *CGObjCGNU::GenerateProtocolRef(const ObjCProtocolDecl *PD) {
3140 llvm::Constant *&protocol = ExistingProtocols[PD->getNameAsString()];
3141 if (!protocol)
3142 GenerateProtocol(PD);
3143 assert(protocol && "Unknown protocol");
3144 return protocol;
3147 llvm::Constant *
3148 CGObjCGNU::GenerateEmptyProtocol(StringRef ProtocolName) {
3149 llvm::Constant *ProtocolList = GenerateProtocolList({});
3150 llvm::Constant *MethodList = GenerateProtocolMethodList({});
3151 MethodList = llvm::ConstantExpr::getBitCast(MethodList, PtrToInt8Ty);
3152 // Protocols are objects containing lists of the methods implemented and
3153 // protocols adopted.
3154 ConstantInitBuilder Builder(CGM);
3155 auto Elements = Builder.beginStruct();
3157 // The isa pointer must be set to a magic number so the runtime knows it's
3158 // the correct layout.
3159 Elements.add(llvm::ConstantExpr::getIntToPtr(
3160 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
3162 Elements.add(MakeConstantString(ProtocolName, ".objc_protocol_name"));
3163 Elements.add(ProtocolList); /* .protocol_list */
3164 Elements.add(MethodList); /* .instance_methods */
3165 Elements.add(MethodList); /* .class_methods */
3166 Elements.add(MethodList); /* .optional_instance_methods */
3167 Elements.add(MethodList); /* .optional_class_methods */
3168 Elements.add(NULLPtr); /* .properties */
3169 Elements.add(NULLPtr); /* .optional_properties */
3170 return Elements.finishAndCreateGlobal(SymbolForProtocol(ProtocolName),
3171 CGM.getPointerAlign());
3174 void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) {
3175 if (PD->isNonRuntimeProtocol())
3176 return;
3178 std::string ProtocolName = PD->getNameAsString();
3180 // Use the protocol definition, if there is one.
3181 if (const ObjCProtocolDecl *Def = PD->getDefinition())
3182 PD = Def;
3184 SmallVector<std::string, 16> Protocols;
3185 for (const auto *PI : PD->protocols())
3186 Protocols.push_back(PI->getNameAsString());
3187 SmallVector<const ObjCMethodDecl*, 16> InstanceMethods;
3188 SmallVector<const ObjCMethodDecl*, 16> OptionalInstanceMethods;
3189 for (const auto *I : PD->instance_methods())
3190 if (I->isOptional())
3191 OptionalInstanceMethods.push_back(I);
3192 else
3193 InstanceMethods.push_back(I);
3194 // Collect information about class methods:
3195 SmallVector<const ObjCMethodDecl*, 16> ClassMethods;
3196 SmallVector<const ObjCMethodDecl*, 16> OptionalClassMethods;
3197 for (const auto *I : PD->class_methods())
3198 if (I->isOptional())
3199 OptionalClassMethods.push_back(I);
3200 else
3201 ClassMethods.push_back(I);
3203 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols);
3204 llvm::Constant *InstanceMethodList =
3205 GenerateProtocolMethodList(InstanceMethods);
3206 llvm::Constant *ClassMethodList =
3207 GenerateProtocolMethodList(ClassMethods);
3208 llvm::Constant *OptionalInstanceMethodList =
3209 GenerateProtocolMethodList(OptionalInstanceMethods);
3210 llvm::Constant *OptionalClassMethodList =
3211 GenerateProtocolMethodList(OptionalClassMethods);
3213 // Property metadata: name, attributes, isSynthesized, setter name, setter
3214 // types, getter name, getter types.
3215 // The isSynthesized value is always set to 0 in a protocol. It exists to
3216 // simplify the runtime library by allowing it to use the same data
3217 // structures for protocol metadata everywhere.
3219 llvm::Constant *PropertyList =
3220 GeneratePropertyList(nullptr, PD, false, false);
3221 llvm::Constant *OptionalPropertyList =
3222 GeneratePropertyList(nullptr, PD, false, true);
3224 // Protocols are objects containing lists of the methods implemented and
3225 // protocols adopted.
3226 // The isa pointer must be set to a magic number so the runtime knows it's
3227 // the correct layout.
3228 ConstantInitBuilder Builder(CGM);
3229 auto Elements = Builder.beginStruct();
3230 Elements.add(
3231 llvm::ConstantExpr::getIntToPtr(
3232 llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
3233 Elements.add(MakeConstantString(ProtocolName));
3234 Elements.add(ProtocolList);
3235 Elements.add(InstanceMethodList);
3236 Elements.add(ClassMethodList);
3237 Elements.add(OptionalInstanceMethodList);
3238 Elements.add(OptionalClassMethodList);
3239 Elements.add(PropertyList);
3240 Elements.add(OptionalPropertyList);
3241 ExistingProtocols[ProtocolName] =
3242 llvm::ConstantExpr::getBitCast(
3243 Elements.finishAndCreateGlobal(".objc_protocol", CGM.getPointerAlign()),
3244 IdTy);
3246 void CGObjCGNU::GenerateProtocolHolderCategory() {
3247 // Collect information about instance methods
3249 ConstantInitBuilder Builder(CGM);
3250 auto Elements = Builder.beginStruct();
3252 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack";
3253 const std::string CategoryName = "AnotherHack";
3254 Elements.add(MakeConstantString(CategoryName));
3255 Elements.add(MakeConstantString(ClassName));
3256 // Instance method list
3257 Elements.addBitCast(GenerateMethodList(
3258 ClassName, CategoryName, {}, false), PtrTy);
3259 // Class method list
3260 Elements.addBitCast(GenerateMethodList(
3261 ClassName, CategoryName, {}, true), PtrTy);
3263 // Protocol list
3264 ConstantInitBuilder ProtocolListBuilder(CGM);
3265 auto ProtocolList = ProtocolListBuilder.beginStruct();
3266 ProtocolList.add(NULLPtr);
3267 ProtocolList.addInt(LongTy, ExistingProtocols.size());
3268 auto ProtocolElements = ProtocolList.beginArray(PtrTy);
3269 for (auto iter = ExistingProtocols.begin(), endIter = ExistingProtocols.end();
3270 iter != endIter ; iter++) {
3271 ProtocolElements.addBitCast(iter->getValue(), PtrTy);
3273 ProtocolElements.finishAndAddTo(ProtocolList);
3274 Elements.addBitCast(
3275 ProtocolList.finishAndCreateGlobal(".objc_protocol_list",
3276 CGM.getPointerAlign()),
3277 PtrTy);
3278 Categories.push_back(llvm::ConstantExpr::getBitCast(
3279 Elements.finishAndCreateGlobal("", CGM.getPointerAlign()),
3280 PtrTy));
3283 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are
3284 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63
3285 /// bits set to their values, LSB first, while larger ones are stored in a
3286 /// structure of this / form:
3288 /// struct { int32_t length; int32_t values[length]; };
3290 /// The values in the array are stored in host-endian format, with the least
3291 /// significant bit being assumed to come first in the bitfield. Therefore, a
3292 /// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a
3293 /// bitfield / with the 63rd bit set will be 1<<64.
3294 llvm::Constant *CGObjCGNU::MakeBitField(ArrayRef<bool> bits) {
3295 int bitCount = bits.size();
3296 int ptrBits = CGM.getDataLayout().getPointerSizeInBits();
3297 if (bitCount < ptrBits) {
3298 uint64_t val = 1;
3299 for (int i=0 ; i<bitCount ; ++i) {
3300 if (bits[i]) val |= 1ULL<<(i+1);
3302 return llvm::ConstantInt::get(IntPtrTy, val);
3304 SmallVector<llvm::Constant *, 8> values;
3305 int v=0;
3306 while (v < bitCount) {
3307 int32_t word = 0;
3308 for (int i=0 ; (i<32) && (v<bitCount) ; ++i) {
3309 if (bits[v]) word |= 1<<i;
3310 v++;
3312 values.push_back(llvm::ConstantInt::get(Int32Ty, word));
3315 ConstantInitBuilder builder(CGM);
3316 auto fields = builder.beginStruct();
3317 fields.addInt(Int32Ty, values.size());
3318 auto array = fields.beginArray();
3319 for (auto *v : values) array.add(v);
3320 array.finishAndAddTo(fields);
3322 llvm::Constant *GS =
3323 fields.finishAndCreateGlobal("", CharUnits::fromQuantity(4));
3324 llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy);
3325 return ptr;
3328 llvm::Constant *CGObjCGNU::GenerateCategoryProtocolList(const
3329 ObjCCategoryDecl *OCD) {
3330 const auto &RefPro = OCD->getReferencedProtocols();
3331 const auto RuntimeProtos =
3332 GetRuntimeProtocolList(RefPro.begin(), RefPro.end());
3333 SmallVector<std::string, 16> Protocols;
3334 for (const auto *PD : RuntimeProtos)
3335 Protocols.push_back(PD->getNameAsString());
3336 return GenerateProtocolList(Protocols);
3339 void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) {
3340 const ObjCInterfaceDecl *Class = OCD->getClassInterface();
3341 std::string ClassName = Class->getNameAsString();
3342 std::string CategoryName = OCD->getNameAsString();
3344 // Collect the names of referenced protocols
3345 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl();
3347 ConstantInitBuilder Builder(CGM);
3348 auto Elements = Builder.beginStruct();
3349 Elements.add(MakeConstantString(CategoryName));
3350 Elements.add(MakeConstantString(ClassName));
3351 // Instance method list
3352 SmallVector<ObjCMethodDecl*, 16> InstanceMethods;
3353 InstanceMethods.insert(InstanceMethods.begin(), OCD->instmeth_begin(),
3354 OCD->instmeth_end());
3355 Elements.addBitCast(
3356 GenerateMethodList(ClassName, CategoryName, InstanceMethods, false),
3357 PtrTy);
3358 // Class method list
3360 SmallVector<ObjCMethodDecl*, 16> ClassMethods;
3361 ClassMethods.insert(ClassMethods.begin(), OCD->classmeth_begin(),
3362 OCD->classmeth_end());
3363 Elements.addBitCast(
3364 GenerateMethodList(ClassName, CategoryName, ClassMethods, true),
3365 PtrTy);
3366 // Protocol list
3367 Elements.addBitCast(GenerateCategoryProtocolList(CatDecl), PtrTy);
3368 if (isRuntime(ObjCRuntime::GNUstep, 2)) {
3369 const ObjCCategoryDecl *Category =
3370 Class->FindCategoryDeclaration(OCD->getIdentifier());
3371 if (Category) {
3372 // Instance properties
3373 Elements.addBitCast(GeneratePropertyList(OCD, Category, false), PtrTy);
3374 // Class properties
3375 Elements.addBitCast(GeneratePropertyList(OCD, Category, true), PtrTy);
3376 } else {
3377 Elements.addNullPointer(PtrTy);
3378 Elements.addNullPointer(PtrTy);
3382 Categories.push_back(llvm::ConstantExpr::getBitCast(
3383 Elements.finishAndCreateGlobal(
3384 std::string(".objc_category_")+ClassName+CategoryName,
3385 CGM.getPointerAlign()),
3386 PtrTy));
3389 llvm::Constant *CGObjCGNU::GeneratePropertyList(const Decl *Container,
3390 const ObjCContainerDecl *OCD,
3391 bool isClassProperty,
3392 bool protocolOptionalProperties) {
3394 SmallVector<const ObjCPropertyDecl *, 16> Properties;
3395 llvm::SmallPtrSet<const IdentifierInfo*, 16> PropertySet;
3396 bool isProtocol = isa<ObjCProtocolDecl>(OCD);
3397 ASTContext &Context = CGM.getContext();
3399 std::function<void(const ObjCProtocolDecl *Proto)> collectProtocolProperties
3400 = [&](const ObjCProtocolDecl *Proto) {
3401 for (const auto *P : Proto->protocols())
3402 collectProtocolProperties(P);
3403 for (const auto *PD : Proto->properties()) {
3404 if (isClassProperty != PD->isClassProperty())
3405 continue;
3406 // Skip any properties that are declared in protocols that this class
3407 // conforms to but are not actually implemented by this class.
3408 if (!isProtocol && !Context.getObjCPropertyImplDeclForPropertyDecl(PD, Container))
3409 continue;
3410 if (!PropertySet.insert(PD->getIdentifier()).second)
3411 continue;
3412 Properties.push_back(PD);
3416 if (const ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(OCD))
3417 for (const ObjCCategoryDecl *ClassExt : OID->known_extensions())
3418 for (auto *PD : ClassExt->properties()) {
3419 if (isClassProperty != PD->isClassProperty())
3420 continue;
3421 PropertySet.insert(PD->getIdentifier());
3422 Properties.push_back(PD);
3425 for (const auto *PD : OCD->properties()) {
3426 if (isClassProperty != PD->isClassProperty())
3427 continue;
3428 // If we're generating a list for a protocol, skip optional / required ones
3429 // when generating the other list.
3430 if (isProtocol && (protocolOptionalProperties != PD->isOptional()))
3431 continue;
3432 // Don't emit duplicate metadata for properties that were already in a
3433 // class extension.
3434 if (!PropertySet.insert(PD->getIdentifier()).second)
3435 continue;
3437 Properties.push_back(PD);
3440 if (const ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(OCD))
3441 for (const auto *P : OID->all_referenced_protocols())
3442 collectProtocolProperties(P);
3443 else if (const ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(OCD))
3444 for (const auto *P : CD->protocols())
3445 collectProtocolProperties(P);
3447 auto numProperties = Properties.size();
3449 if (numProperties == 0)
3450 return NULLPtr;
3452 ConstantInitBuilder builder(CGM);
3453 auto propertyList = builder.beginStruct();
3454 auto properties = PushPropertyListHeader(propertyList, numProperties);
3456 // Add all of the property methods need adding to the method list and to the
3457 // property metadata list.
3458 for (auto *property : Properties) {
3459 bool isSynthesized = false;
3460 bool isDynamic = false;
3461 if (!isProtocol) {
3462 auto *propertyImpl = Context.getObjCPropertyImplDeclForPropertyDecl(property, Container);
3463 if (propertyImpl) {
3464 isSynthesized = (propertyImpl->getPropertyImplementation() ==
3465 ObjCPropertyImplDecl::Synthesize);
3466 isDynamic = (propertyImpl->getPropertyImplementation() ==
3467 ObjCPropertyImplDecl::Dynamic);
3470 PushProperty(properties, property, Container, isSynthesized, isDynamic);
3472 properties.finishAndAddTo(propertyList);
3474 return propertyList.finishAndCreateGlobal(".objc_property_list",
3475 CGM.getPointerAlign());
3478 void CGObjCGNU::RegisterAlias(const ObjCCompatibleAliasDecl *OAD) {
3479 // Get the class declaration for which the alias is specified.
3480 ObjCInterfaceDecl *ClassDecl =
3481 const_cast<ObjCInterfaceDecl *>(OAD->getClassInterface());
3482 ClassAliases.emplace_back(ClassDecl->getNameAsString(),
3483 OAD->getNameAsString());
3486 void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
3487 ASTContext &Context = CGM.getContext();
3489 // Get the superclass name.
3490 const ObjCInterfaceDecl * SuperClassDecl =
3491 OID->getClassInterface()->getSuperClass();
3492 std::string SuperClassName;
3493 if (SuperClassDecl) {
3494 SuperClassName = SuperClassDecl->getNameAsString();
3495 EmitClassRef(SuperClassName);
3498 // Get the class name
3499 ObjCInterfaceDecl *ClassDecl =
3500 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
3501 std::string ClassName = ClassDecl->getNameAsString();
3503 // Emit the symbol that is used to generate linker errors if this class is
3504 // referenced in other modules but not declared.
3505 std::string classSymbolName = "__objc_class_name_" + ClassName;
3506 if (auto *symbol = TheModule.getGlobalVariable(classSymbolName)) {
3507 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0));
3508 } else {
3509 new llvm::GlobalVariable(TheModule, LongTy, false,
3510 llvm::GlobalValue::ExternalLinkage,
3511 llvm::ConstantInt::get(LongTy, 0),
3512 classSymbolName);
3515 // Get the size of instances.
3516 int instanceSize =
3517 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity();
3519 // Collect information about instance variables.
3520 SmallVector<llvm::Constant*, 16> IvarNames;
3521 SmallVector<llvm::Constant*, 16> IvarTypes;
3522 SmallVector<llvm::Constant*, 16> IvarOffsets;
3523 SmallVector<llvm::Constant*, 16> IvarAligns;
3524 SmallVector<Qualifiers::ObjCLifetime, 16> IvarOwnership;
3526 ConstantInitBuilder IvarOffsetBuilder(CGM);
3527 auto IvarOffsetValues = IvarOffsetBuilder.beginArray(PtrToIntTy);
3528 SmallVector<bool, 16> WeakIvars;
3529 SmallVector<bool, 16> StrongIvars;
3531 int superInstanceSize = !SuperClassDecl ? 0 :
3532 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity();
3533 // For non-fragile ivars, set the instance size to 0 - {the size of just this
3534 // class}. The runtime will then set this to the correct value on load.
3535 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
3536 instanceSize = 0 - (instanceSize - superInstanceSize);
3539 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
3540 IVD = IVD->getNextIvar()) {
3541 // Store the name
3542 IvarNames.push_back(MakeConstantString(IVD->getNameAsString()));
3543 // Get the type encoding for this ivar
3544 std::string TypeStr;
3545 Context.getObjCEncodingForType(IVD->getType(), TypeStr, IVD);
3546 IvarTypes.push_back(MakeConstantString(TypeStr));
3547 IvarAligns.push_back(llvm::ConstantInt::get(IntTy,
3548 Context.getTypeSize(IVD->getType())));
3549 // Get the offset
3550 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD);
3551 uint64_t Offset = BaseOffset;
3552 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
3553 Offset = BaseOffset - superInstanceSize;
3555 llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset);
3556 // Create the direct offset value
3557 std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." +
3558 IVD->getNameAsString();
3560 llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName);
3561 if (OffsetVar) {
3562 OffsetVar->setInitializer(OffsetValue);
3563 // If this is the real definition, change its linkage type so that
3564 // different modules will use this one, rather than their private
3565 // copy.
3566 OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage);
3567 } else
3568 OffsetVar = new llvm::GlobalVariable(TheModule, Int32Ty,
3569 false, llvm::GlobalValue::ExternalLinkage,
3570 OffsetValue, OffsetName);
3571 IvarOffsets.push_back(OffsetValue);
3572 IvarOffsetValues.add(OffsetVar);
3573 Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime();
3574 IvarOwnership.push_back(lt);
3575 switch (lt) {
3576 case Qualifiers::OCL_Strong:
3577 StrongIvars.push_back(true);
3578 WeakIvars.push_back(false);
3579 break;
3580 case Qualifiers::OCL_Weak:
3581 StrongIvars.push_back(false);
3582 WeakIvars.push_back(true);
3583 break;
3584 default:
3585 StrongIvars.push_back(false);
3586 WeakIvars.push_back(false);
3589 llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars);
3590 llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars);
3591 llvm::GlobalVariable *IvarOffsetArray =
3592 IvarOffsetValues.finishAndCreateGlobal(".ivar.offsets",
3593 CGM.getPointerAlign());
3595 // Collect information about instance methods
3596 SmallVector<const ObjCMethodDecl*, 16> InstanceMethods;
3597 InstanceMethods.insert(InstanceMethods.begin(), OID->instmeth_begin(),
3598 OID->instmeth_end());
3600 SmallVector<const ObjCMethodDecl*, 16> ClassMethods;
3601 ClassMethods.insert(ClassMethods.begin(), OID->classmeth_begin(),
3602 OID->classmeth_end());
3604 llvm::Constant *Properties = GeneratePropertyList(OID, ClassDecl);
3606 // Collect the names of referenced protocols
3607 auto RefProtocols = ClassDecl->protocols();
3608 auto RuntimeProtocols =
3609 GetRuntimeProtocolList(RefProtocols.begin(), RefProtocols.end());
3610 SmallVector<std::string, 16> Protocols;
3611 for (const auto *I : RuntimeProtocols)
3612 Protocols.push_back(I->getNameAsString());
3614 // Get the superclass pointer.
3615 llvm::Constant *SuperClass;
3616 if (!SuperClassName.empty()) {
3617 SuperClass = MakeConstantString(SuperClassName, ".super_class_name");
3618 } else {
3619 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty);
3621 // Empty vector used to construct empty method lists
3622 SmallVector<llvm::Constant*, 1> empty;
3623 // Generate the method and instance variable lists
3624 llvm::Constant *MethodList = GenerateMethodList(ClassName, "",
3625 InstanceMethods, false);
3626 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "",
3627 ClassMethods, true);
3628 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes,
3629 IvarOffsets, IvarAligns, IvarOwnership);
3630 // Irrespective of whether we are compiling for a fragile or non-fragile ABI,
3631 // we emit a symbol containing the offset for each ivar in the class. This
3632 // allows code compiled for the non-Fragile ABI to inherit from code compiled
3633 // for the legacy ABI, without causing problems. The converse is also
3634 // possible, but causes all ivar accesses to be fragile.
3636 // Offset pointer for getting at the correct field in the ivar list when
3637 // setting up the alias. These are: The base address for the global, the
3638 // ivar array (second field), the ivar in this list (set for each ivar), and
3639 // the offset (third field in ivar structure)
3640 llvm::Type *IndexTy = Int32Ty;
3641 llvm::Constant *offsetPointerIndexes[] = {Zeros[0],
3642 llvm::ConstantInt::get(IndexTy, ClassABIVersion > 1 ? 2 : 1), nullptr,
3643 llvm::ConstantInt::get(IndexTy, ClassABIVersion > 1 ? 3 : 2) };
3645 unsigned ivarIndex = 0;
3646 for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
3647 IVD = IVD->getNextIvar()) {
3648 const std::string Name = GetIVarOffsetVariableName(ClassDecl, IVD);
3649 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex);
3650 // Get the correct ivar field
3651 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr(
3652 cast<llvm::GlobalVariable>(IvarList)->getValueType(), IvarList,
3653 offsetPointerIndexes);
3654 // Get the existing variable, if one exists.
3655 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name);
3656 if (offset) {
3657 offset->setInitializer(offsetValue);
3658 // If this is the real definition, change its linkage type so that
3659 // different modules will use this one, rather than their private
3660 // copy.
3661 offset->setLinkage(llvm::GlobalValue::ExternalLinkage);
3662 } else
3663 // Add a new alias if there isn't one already.
3664 new llvm::GlobalVariable(TheModule, offsetValue->getType(),
3665 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name);
3666 ++ivarIndex;
3668 llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0);
3670 //Generate metaclass for class methods
3671 llvm::Constant *MetaClassStruct = GenerateClassStructure(
3672 NULLPtr, NULLPtr, 0x12L, ClassName.c_str(), nullptr, Zeros[0],
3673 NULLPtr, ClassMethodList, NULLPtr, NULLPtr,
3674 GeneratePropertyList(OID, ClassDecl, true), ZeroPtr, ZeroPtr, true);
3675 CGM.setGVProperties(cast<llvm::GlobalValue>(MetaClassStruct),
3676 OID->getClassInterface());
3678 // Generate the class structure
3679 llvm::Constant *ClassStruct = GenerateClassStructure(
3680 MetaClassStruct, SuperClass, 0x11L, ClassName.c_str(), nullptr,
3681 llvm::ConstantInt::get(LongTy, instanceSize), IvarList, MethodList,
3682 GenerateProtocolList(Protocols), IvarOffsetArray, Properties,
3683 StrongIvarBitmap, WeakIvarBitmap);
3684 CGM.setGVProperties(cast<llvm::GlobalValue>(ClassStruct),
3685 OID->getClassInterface());
3687 // Resolve the class aliases, if they exist.
3688 if (ClassPtrAlias) {
3689 ClassPtrAlias->replaceAllUsesWith(
3690 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy));
3691 ClassPtrAlias->eraseFromParent();
3692 ClassPtrAlias = nullptr;
3694 if (MetaClassPtrAlias) {
3695 MetaClassPtrAlias->replaceAllUsesWith(
3696 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy));
3697 MetaClassPtrAlias->eraseFromParent();
3698 MetaClassPtrAlias = nullptr;
3701 // Add class structure to list to be added to the symtab later
3702 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty);
3703 Classes.push_back(ClassStruct);
3706 llvm::Function *CGObjCGNU::ModuleInitFunction() {
3707 // Only emit an ObjC load function if no Objective-C stuff has been called
3708 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() &&
3709 ExistingProtocols.empty() && SelectorTable.empty())
3710 return nullptr;
3712 // Add all referenced protocols to a category.
3713 GenerateProtocolHolderCategory();
3715 llvm::StructType *selStructTy = dyn_cast<llvm::StructType>(SelectorElemTy);
3716 llvm::Type *selStructPtrTy = SelectorTy;
3717 if (!selStructTy) {
3718 selStructTy = llvm::StructType::get(CGM.getLLVMContext(),
3719 { PtrToInt8Ty, PtrToInt8Ty });
3720 selStructPtrTy = llvm::PointerType::getUnqual(selStructTy);
3723 // Generate statics list:
3724 llvm::Constant *statics = NULLPtr;
3725 if (!ConstantStrings.empty()) {
3726 llvm::GlobalVariable *fileStatics = [&] {
3727 ConstantInitBuilder builder(CGM);
3728 auto staticsStruct = builder.beginStruct();
3730 StringRef stringClass = CGM.getLangOpts().ObjCConstantStringClass;
3731 if (stringClass.empty()) stringClass = "NXConstantString";
3732 staticsStruct.add(MakeConstantString(stringClass,
3733 ".objc_static_class_name"));
3735 auto array = staticsStruct.beginArray();
3736 array.addAll(ConstantStrings);
3737 array.add(NULLPtr);
3738 array.finishAndAddTo(staticsStruct);
3740 return staticsStruct.finishAndCreateGlobal(".objc_statics",
3741 CGM.getPointerAlign());
3742 }();
3744 ConstantInitBuilder builder(CGM);
3745 auto allStaticsArray = builder.beginArray(fileStatics->getType());
3746 allStaticsArray.add(fileStatics);
3747 allStaticsArray.addNullPointer(fileStatics->getType());
3749 statics = allStaticsArray.finishAndCreateGlobal(".objc_statics_ptr",
3750 CGM.getPointerAlign());
3751 statics = llvm::ConstantExpr::getBitCast(statics, PtrTy);
3754 // Array of classes, categories, and constant objects.
3756 SmallVector<llvm::GlobalAlias*, 16> selectorAliases;
3757 unsigned selectorCount;
3759 // Pointer to an array of selectors used in this module.
3760 llvm::GlobalVariable *selectorList = [&] {
3761 ConstantInitBuilder builder(CGM);
3762 auto selectors = builder.beginArray(selStructTy);
3763 auto &table = SelectorTable; // MSVC workaround
3764 std::vector<Selector> allSelectors;
3765 for (auto &entry : table)
3766 allSelectors.push_back(entry.first);
3767 llvm::sort(allSelectors);
3769 for (auto &untypedSel : allSelectors) {
3770 std::string selNameStr = untypedSel.getAsString();
3771 llvm::Constant *selName = ExportUniqueString(selNameStr, ".objc_sel_name");
3773 for (TypedSelector &sel : table[untypedSel]) {
3774 llvm::Constant *selectorTypeEncoding = NULLPtr;
3775 if (!sel.first.empty())
3776 selectorTypeEncoding =
3777 MakeConstantString(sel.first, ".objc_sel_types");
3779 auto selStruct = selectors.beginStruct(selStructTy);
3780 selStruct.add(selName);
3781 selStruct.add(selectorTypeEncoding);
3782 selStruct.finishAndAddTo(selectors);
3784 // Store the selector alias for later replacement
3785 selectorAliases.push_back(sel.second);
3789 // Remember the number of entries in the selector table.
3790 selectorCount = selectors.size();
3792 // NULL-terminate the selector list. This should not actually be required,
3793 // because the selector list has a length field. Unfortunately, the GCC
3794 // runtime decides to ignore the length field and expects a NULL terminator,
3795 // and GCC cooperates with this by always setting the length to 0.
3796 auto selStruct = selectors.beginStruct(selStructTy);
3797 selStruct.add(NULLPtr);
3798 selStruct.add(NULLPtr);
3799 selStruct.finishAndAddTo(selectors);
3801 return selectors.finishAndCreateGlobal(".objc_selector_list",
3802 CGM.getPointerAlign());
3803 }();
3805 // Now that all of the static selectors exist, create pointers to them.
3806 for (unsigned i = 0; i < selectorCount; ++i) {
3807 llvm::Constant *idxs[] = {
3808 Zeros[0],
3809 llvm::ConstantInt::get(Int32Ty, i)
3811 // FIXME: We're generating redundant loads and stores here!
3812 llvm::Constant *selPtr = llvm::ConstantExpr::getGetElementPtr(
3813 selectorList->getValueType(), selectorList, idxs);
3814 // If selectors are defined as an opaque type, cast the pointer to this
3815 // type.
3816 selPtr = llvm::ConstantExpr::getBitCast(selPtr, SelectorTy);
3817 selectorAliases[i]->replaceAllUsesWith(selPtr);
3818 selectorAliases[i]->eraseFromParent();
3821 llvm::GlobalVariable *symtab = [&] {
3822 ConstantInitBuilder builder(CGM);
3823 auto symtab = builder.beginStruct();
3825 // Number of static selectors
3826 symtab.addInt(LongTy, selectorCount);
3828 symtab.addBitCast(selectorList, selStructPtrTy);
3830 // Number of classes defined.
3831 symtab.addInt(CGM.Int16Ty, Classes.size());
3832 // Number of categories defined
3833 symtab.addInt(CGM.Int16Ty, Categories.size());
3835 // Create an array of classes, then categories, then static object instances
3836 auto classList = symtab.beginArray(PtrToInt8Ty);
3837 classList.addAll(Classes);
3838 classList.addAll(Categories);
3839 // NULL-terminated list of static object instances (mainly constant strings)
3840 classList.add(statics);
3841 classList.add(NULLPtr);
3842 classList.finishAndAddTo(symtab);
3844 // Construct the symbol table.
3845 return symtab.finishAndCreateGlobal("", CGM.getPointerAlign());
3846 }();
3848 // The symbol table is contained in a module which has some version-checking
3849 // constants
3850 llvm::Constant *module = [&] {
3851 llvm::Type *moduleEltTys[] = {
3852 LongTy, LongTy, PtrToInt8Ty, symtab->getType(), IntTy
3854 llvm::StructType *moduleTy = llvm::StructType::get(
3855 CGM.getLLVMContext(),
3856 ArrayRef(moduleEltTys).drop_back(unsigned(RuntimeVersion < 10)));
3858 ConstantInitBuilder builder(CGM);
3859 auto module = builder.beginStruct(moduleTy);
3860 // Runtime version, used for ABI compatibility checking.
3861 module.addInt(LongTy, RuntimeVersion);
3862 // sizeof(ModuleTy)
3863 module.addInt(LongTy, CGM.getDataLayout().getTypeStoreSize(moduleTy));
3865 // The path to the source file where this module was declared
3866 SourceManager &SM = CGM.getContext().getSourceManager();
3867 OptionalFileEntryRef mainFile = SM.getFileEntryRefForID(SM.getMainFileID());
3868 std::string path =
3869 (mainFile->getDir().getName() + "/" + mainFile->getName()).str();
3870 module.add(MakeConstantString(path, ".objc_source_file_name"));
3871 module.add(symtab);
3873 if (RuntimeVersion >= 10) {
3874 switch (CGM.getLangOpts().getGC()) {
3875 case LangOptions::GCOnly:
3876 module.addInt(IntTy, 2);
3877 break;
3878 case LangOptions::NonGC:
3879 if (CGM.getLangOpts().ObjCAutoRefCount)
3880 module.addInt(IntTy, 1);
3881 else
3882 module.addInt(IntTy, 0);
3883 break;
3884 case LangOptions::HybridGC:
3885 module.addInt(IntTy, 1);
3886 break;
3890 return module.finishAndCreateGlobal("", CGM.getPointerAlign());
3891 }();
3893 // Create the load function calling the runtime entry point with the module
3894 // structure
3895 llvm::Function * LoadFunction = llvm::Function::Create(
3896 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false),
3897 llvm::GlobalValue::InternalLinkage, ".objc_load_function",
3898 &TheModule);
3899 llvm::BasicBlock *EntryBB =
3900 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction);
3901 CGBuilderTy Builder(CGM, VMContext);
3902 Builder.SetInsertPoint(EntryBB);
3904 llvm::FunctionType *FT =
3905 llvm::FunctionType::get(Builder.getVoidTy(), module->getType(), true);
3906 llvm::FunctionCallee Register =
3907 CGM.CreateRuntimeFunction(FT, "__objc_exec_class");
3908 Builder.CreateCall(Register, module);
3910 if (!ClassAliases.empty()) {
3911 llvm::Type *ArgTypes[2] = {PtrTy, PtrToInt8Ty};
3912 llvm::FunctionType *RegisterAliasTy =
3913 llvm::FunctionType::get(Builder.getVoidTy(),
3914 ArgTypes, false);
3915 llvm::Function *RegisterAlias = llvm::Function::Create(
3916 RegisterAliasTy,
3917 llvm::GlobalValue::ExternalWeakLinkage, "class_registerAlias_np",
3918 &TheModule);
3919 llvm::BasicBlock *AliasBB =
3920 llvm::BasicBlock::Create(VMContext, "alias", LoadFunction);
3921 llvm::BasicBlock *NoAliasBB =
3922 llvm::BasicBlock::Create(VMContext, "no_alias", LoadFunction);
3924 // Branch based on whether the runtime provided class_registerAlias_np()
3925 llvm::Value *HasRegisterAlias = Builder.CreateICmpNE(RegisterAlias,
3926 llvm::Constant::getNullValue(RegisterAlias->getType()));
3927 Builder.CreateCondBr(HasRegisterAlias, AliasBB, NoAliasBB);
3929 // The true branch (has alias registration function):
3930 Builder.SetInsertPoint(AliasBB);
3931 // Emit alias registration calls:
3932 for (std::vector<ClassAliasPair>::iterator iter = ClassAliases.begin();
3933 iter != ClassAliases.end(); ++iter) {
3934 llvm::Constant *TheClass =
3935 TheModule.getGlobalVariable("_OBJC_CLASS_" + iter->first, true);
3936 if (TheClass) {
3937 TheClass = llvm::ConstantExpr::getBitCast(TheClass, PtrTy);
3938 Builder.CreateCall(RegisterAlias,
3939 {TheClass, MakeConstantString(iter->second)});
3942 // Jump to end:
3943 Builder.CreateBr(NoAliasBB);
3945 // Missing alias registration function, just return from the function:
3946 Builder.SetInsertPoint(NoAliasBB);
3948 Builder.CreateRetVoid();
3950 return LoadFunction;
3953 llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD,
3954 const ObjCContainerDecl *CD) {
3955 CodeGenTypes &Types = CGM.getTypes();
3956 llvm::FunctionType *MethodTy =
3957 Types.GetFunctionType(Types.arrangeObjCMethodDeclaration(OMD));
3958 std::string FunctionName = getSymbolNameForMethod(OMD);
3960 llvm::Function *Method
3961 = llvm::Function::Create(MethodTy,
3962 llvm::GlobalValue::InternalLinkage,
3963 FunctionName,
3964 &TheModule);
3965 return Method;
3968 void CGObjCGNU::GenerateDirectMethodPrologue(CodeGenFunction &CGF,
3969 llvm::Function *Fn,
3970 const ObjCMethodDecl *OMD,
3971 const ObjCContainerDecl *CD) {
3972 // GNU runtime doesn't support direct calls at this time
3975 llvm::FunctionCallee CGObjCGNU::GetPropertyGetFunction() {
3976 return GetPropertyFn;
3979 llvm::FunctionCallee CGObjCGNU::GetPropertySetFunction() {
3980 return SetPropertyFn;
3983 llvm::FunctionCallee CGObjCGNU::GetOptimizedPropertySetFunction(bool atomic,
3984 bool copy) {
3985 return nullptr;
3988 llvm::FunctionCallee CGObjCGNU::GetGetStructFunction() {
3989 return GetStructPropertyFn;
3992 llvm::FunctionCallee CGObjCGNU::GetSetStructFunction() {
3993 return SetStructPropertyFn;
3996 llvm::FunctionCallee CGObjCGNU::GetCppAtomicObjectGetFunction() {
3997 return nullptr;
4000 llvm::FunctionCallee CGObjCGNU::GetCppAtomicObjectSetFunction() {
4001 return nullptr;
4004 llvm::FunctionCallee CGObjCGNU::EnumerationMutationFunction() {
4005 return EnumerationMutationFn;
4008 void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF,
4009 const ObjCAtSynchronizedStmt &S) {
4010 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn);
4014 void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF,
4015 const ObjCAtTryStmt &S) {
4016 // Unlike the Apple non-fragile runtimes, which also uses
4017 // unwind-based zero cost exceptions, the GNU Objective C runtime's
4018 // EH support isn't a veneer over C++ EH. Instead, exception
4019 // objects are created by objc_exception_throw and destroyed by
4020 // the personality function; this avoids the need for bracketing
4021 // catch handlers with calls to __blah_begin_catch/__blah_end_catch
4022 // (or even _Unwind_DeleteException), but probably doesn't
4023 // interoperate very well with foreign exceptions.
4025 // In Objective-C++ mode, we actually emit something equivalent to the C++
4026 // exception handler.
4027 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn);
4030 void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF,
4031 const ObjCAtThrowStmt &S,
4032 bool ClearInsertionPoint) {
4033 llvm::Value *ExceptionAsObject;
4034 bool isRethrow = false;
4036 if (const Expr *ThrowExpr = S.getThrowExpr()) {
4037 llvm::Value *Exception = CGF.EmitObjCThrowOperand(ThrowExpr);
4038 ExceptionAsObject = Exception;
4039 } else {
4040 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) &&
4041 "Unexpected rethrow outside @catch block.");
4042 ExceptionAsObject = CGF.ObjCEHValueStack.back();
4043 isRethrow = true;
4045 if (isRethrow && usesSEHExceptions) {
4046 // For SEH, ExceptionAsObject may be undef, because the catch handler is
4047 // not passed it for catchalls and so it is not visible to the catch
4048 // funclet. The real thrown object will still be live on the stack at this
4049 // point and will be rethrown. If we are explicitly rethrowing the object
4050 // that was passed into the `@catch` block, then this code path is not
4051 // reached and we will instead call `objc_exception_throw` with an explicit
4052 // argument.
4053 llvm::CallBase *Throw = CGF.EmitRuntimeCallOrInvoke(ExceptionReThrowFn);
4054 Throw->setDoesNotReturn();
4056 else {
4057 ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy);
4058 llvm::CallBase *Throw =
4059 CGF.EmitRuntimeCallOrInvoke(ExceptionThrowFn, ExceptionAsObject);
4060 Throw->setDoesNotReturn();
4062 CGF.Builder.CreateUnreachable();
4063 if (ClearInsertionPoint)
4064 CGF.Builder.ClearInsertionPoint();
4067 llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF,
4068 Address AddrWeakObj) {
4069 CGBuilderTy &B = CGF.Builder;
4070 return B.CreateCall(WeakReadFn,
4071 EnforceType(B, AddrWeakObj.getPointer(), PtrToIdTy));
4074 void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF,
4075 llvm::Value *src, Address dst) {
4076 CGBuilderTy &B = CGF.Builder;
4077 src = EnforceType(B, src, IdTy);
4078 llvm::Value *dstVal = EnforceType(B, dst.getPointer(), PtrToIdTy);
4079 B.CreateCall(WeakAssignFn, {src, dstVal});
4082 void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF,
4083 llvm::Value *src, Address dst,
4084 bool threadlocal) {
4085 CGBuilderTy &B = CGF.Builder;
4086 src = EnforceType(B, src, IdTy);
4087 llvm::Value *dstVal = EnforceType(B, dst.getPointer(), PtrToIdTy);
4088 // FIXME. Add threadloca assign API
4089 assert(!threadlocal && "EmitObjCGlobalAssign - Threal Local API NYI");
4090 B.CreateCall(GlobalAssignFn, {src, dstVal});
4093 void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF,
4094 llvm::Value *src, Address dst,
4095 llvm::Value *ivarOffset) {
4096 CGBuilderTy &B = CGF.Builder;
4097 src = EnforceType(B, src, IdTy);
4098 llvm::Value *dstVal = EnforceType(B, dst.getPointer(), IdTy);
4099 B.CreateCall(IvarAssignFn, {src, dstVal, ivarOffset});
4102 void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF,
4103 llvm::Value *src, Address dst) {
4104 CGBuilderTy &B = CGF.Builder;
4105 src = EnforceType(B, src, IdTy);
4106 llvm::Value *dstVal = EnforceType(B, dst.getPointer(), PtrToIdTy);
4107 B.CreateCall(StrongCastAssignFn, {src, dstVal});
4110 void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF,
4111 Address DestPtr,
4112 Address SrcPtr,
4113 llvm::Value *Size) {
4114 CGBuilderTy &B = CGF.Builder;
4115 llvm::Value *DestPtrVal = EnforceType(B, DestPtr.getPointer(), PtrTy);
4116 llvm::Value *SrcPtrVal = EnforceType(B, SrcPtr.getPointer(), PtrTy);
4118 B.CreateCall(MemMoveFn, {DestPtrVal, SrcPtrVal, Size});
4121 llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable(
4122 const ObjCInterfaceDecl *ID,
4123 const ObjCIvarDecl *Ivar) {
4124 const std::string Name = GetIVarOffsetVariableName(ID, Ivar);
4125 // Emit the variable and initialize it with what we think the correct value
4126 // is. This allows code compiled with non-fragile ivars to work correctly
4127 // when linked against code which isn't (most of the time).
4128 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name);
4129 if (!IvarOffsetPointer)
4130 IvarOffsetPointer = new llvm::GlobalVariable(TheModule,
4131 llvm::Type::getInt32PtrTy(VMContext), false,
4132 llvm::GlobalValue::ExternalLinkage, nullptr, Name);
4133 return IvarOffsetPointer;
4136 LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF,
4137 QualType ObjectTy,
4138 llvm::Value *BaseValue,
4139 const ObjCIvarDecl *Ivar,
4140 unsigned CVRQualifiers) {
4141 const ObjCInterfaceDecl *ID =
4142 ObjectTy->castAs<ObjCObjectType>()->getInterface();
4143 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers,
4144 EmitIvarOffset(CGF, ID, Ivar));
4147 static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context,
4148 const ObjCInterfaceDecl *OID,
4149 const ObjCIvarDecl *OIVD) {
4150 for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next;
4151 next = next->getNextIvar()) {
4152 if (OIVD == next)
4153 return OID;
4156 // Otherwise check in the super class.
4157 if (const ObjCInterfaceDecl *Super = OID->getSuperClass())
4158 return FindIvarInterface(Context, Super, OIVD);
4160 return nullptr;
4163 llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF,
4164 const ObjCInterfaceDecl *Interface,
4165 const ObjCIvarDecl *Ivar) {
4166 if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
4167 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar);
4169 // The MSVC linker cannot have a single global defined as LinkOnceAnyLinkage
4170 // and ExternalLinkage, so create a reference to the ivar global and rely on
4171 // the definition being created as part of GenerateClass.
4172 if (RuntimeVersion < 10 ||
4173 CGF.CGM.getTarget().getTriple().isKnownWindowsMSVCEnvironment())
4174 return CGF.Builder.CreateZExtOrBitCast(
4175 CGF.Builder.CreateAlignedLoad(
4176 Int32Ty, CGF.Builder.CreateAlignedLoad(
4177 llvm::Type::getInt32PtrTy(VMContext),
4178 ObjCIvarOffsetVariable(Interface, Ivar),
4179 CGF.getPointerAlign(), "ivar"),
4180 CharUnits::fromQuantity(4)),
4181 PtrDiffTy);
4182 std::string name = "__objc_ivar_offset_value_" +
4183 Interface->getNameAsString() +"." + Ivar->getNameAsString();
4184 CharUnits Align = CGM.getIntAlign();
4185 llvm::Value *Offset = TheModule.getGlobalVariable(name);
4186 if (!Offset) {
4187 auto GV = new llvm::GlobalVariable(TheModule, IntTy,
4188 false, llvm::GlobalValue::LinkOnceAnyLinkage,
4189 llvm::Constant::getNullValue(IntTy), name);
4190 GV->setAlignment(Align.getAsAlign());
4191 Offset = GV;
4193 Offset = CGF.Builder.CreateAlignedLoad(IntTy, Offset, Align);
4194 if (Offset->getType() != PtrDiffTy)
4195 Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy);
4196 return Offset;
4198 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar);
4199 return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true);
4202 CGObjCRuntime *
4203 clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) {
4204 auto Runtime = CGM.getLangOpts().ObjCRuntime;
4205 switch (Runtime.getKind()) {
4206 case ObjCRuntime::GNUstep:
4207 if (Runtime.getVersion() >= VersionTuple(2, 0))
4208 return new CGObjCGNUstep2(CGM);
4209 return new CGObjCGNUstep(CGM);
4211 case ObjCRuntime::GCC:
4212 return new CGObjCGCC(CGM);
4214 case ObjCRuntime::ObjFW:
4215 return new CGObjCObjFW(CGM);
4217 case ObjCRuntime::FragileMacOSX:
4218 case ObjCRuntime::MacOSX:
4219 case ObjCRuntime::iOS:
4220 case ObjCRuntime::WatchOS:
4221 llvm_unreachable("these runtimes are not GNU runtimes");
4223 llvm_unreachable("bad runtime");