clang  6.0.0svn
CGObjCGNU.cpp
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1 //===------- CGObjCGNU.cpp - Emit LLVM Code from ASTs for a Module --------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This provides Objective-C code generation targeting the GNU runtime. The
11 // class in this file generates structures used by the GNU Objective-C runtime
12 // library. These structures are defined in objc/objc.h and objc/objc-api.h in
13 // the GNU runtime distribution.
14 //
15 //===----------------------------------------------------------------------===//
16 
17 #include "CGObjCRuntime.h"
18 #include "CGCleanup.h"
19 #include "CodeGenFunction.h"
20 #include "CodeGenModule.h"
22 #include "clang/AST/ASTContext.h"
23 #include "clang/AST/Decl.h"
24 #include "clang/AST/DeclObjC.h"
25 #include "clang/AST/RecordLayout.h"
26 #include "clang/AST/StmtObjC.h"
29 #include "llvm/ADT/SmallVector.h"
30 #include "llvm/ADT/StringMap.h"
31 #include "llvm/IR/CallSite.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 
38 using namespace clang;
39 using namespace CodeGen;
40 
41 namespace {
42 /// Class that lazily initialises the runtime function. Avoids inserting the
43 /// types and the function declaration into a module if they're not used, and
44 /// avoids constructing the type more than once if it's used more than once.
45 class LazyRuntimeFunction {
46  CodeGenModule *CGM;
47  llvm::FunctionType *FTy;
48  const char *FunctionName;
49  llvm::Constant *Function;
50 
51 public:
52  /// Constructor leaves this class uninitialized, because it is intended to
53  /// be used as a field in another class and not all of the types that are
54  /// used as arguments will necessarily be available at construction time.
55  LazyRuntimeFunction()
56  : CGM(nullptr), FunctionName(nullptr), Function(nullptr) {}
57 
58  /// Initialises the lazy function with the name, return type, and the types
59  /// of the arguments.
60  template <typename... Tys>
61  void init(CodeGenModule *Mod, const char *name, llvm::Type *RetTy,
62  Tys *... Types) {
63  CGM = Mod;
64  FunctionName = name;
65  Function = nullptr;
66  if(sizeof...(Tys)) {
67  SmallVector<llvm::Type *, 8> ArgTys({Types...});
68  FTy = llvm::FunctionType::get(RetTy, ArgTys, false);
69  }
70  else {
71  FTy = llvm::FunctionType::get(RetTy, None, false);
72  }
73  }
74 
75  llvm::FunctionType *getType() { return FTy; }
76 
77  /// Overloaded cast operator, allows the class to be implicitly cast to an
78  /// LLVM constant.
79  operator llvm::Constant *() {
80  if (!Function) {
81  if (!FunctionName)
82  return nullptr;
83  Function =
84  cast<llvm::Constant>(CGM->CreateRuntimeFunction(FTy, FunctionName));
85  }
86  return Function;
87  }
88  operator llvm::Function *() {
89  return cast<llvm::Function>((llvm::Constant *)*this);
90  }
91 };
92 
93 
94 /// GNU Objective-C runtime code generation. This class implements the parts of
95 /// Objective-C support that are specific to the GNU family of runtimes (GCC,
96 /// GNUstep and ObjFW).
97 class CGObjCGNU : public CGObjCRuntime {
98 protected:
99  /// The LLVM module into which output is inserted
100  llvm::Module &TheModule;
101  /// strut objc_super. Used for sending messages to super. This structure
102  /// contains the receiver (object) and the expected class.
103  llvm::StructType *ObjCSuperTy;
104  /// struct objc_super*. The type of the argument to the superclass message
105  /// lookup functions.
106  llvm::PointerType *PtrToObjCSuperTy;
107  /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring
108  /// SEL is included in a header somewhere, in which case it will be whatever
109  /// type is declared in that header, most likely {i8*, i8*}.
110  llvm::PointerType *SelectorTy;
111  /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the
112  /// places where it's used
113  llvm::IntegerType *Int8Ty;
114  /// Pointer to i8 - LLVM type of char*, for all of the places where the
115  /// runtime needs to deal with C strings.
116  llvm::PointerType *PtrToInt8Ty;
117  /// Instance Method Pointer type. This is a pointer to a function that takes,
118  /// at a minimum, an object and a selector, and is the generic type for
119  /// Objective-C methods. Due to differences between variadic / non-variadic
120  /// calling conventions, it must always be cast to the correct type before
121  /// actually being used.
122  llvm::PointerType *IMPTy;
123  /// Type of an untyped Objective-C object. Clang treats id as a built-in type
124  /// when compiling Objective-C code, so this may be an opaque pointer (i8*),
125  /// but if the runtime header declaring it is included then it may be a
126  /// pointer to a structure.
127  llvm::PointerType *IdTy;
128  /// Pointer to a pointer to an Objective-C object. Used in the new ABI
129  /// message lookup function and some GC-related functions.
130  llvm::PointerType *PtrToIdTy;
131  /// The clang type of id. Used when using the clang CGCall infrastructure to
132  /// call Objective-C methods.
133  CanQualType ASTIdTy;
134  /// LLVM type for C int type.
135  llvm::IntegerType *IntTy;
136  /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is
137  /// used in the code to document the difference between i8* meaning a pointer
138  /// to a C string and i8* meaning a pointer to some opaque type.
139  llvm::PointerType *PtrTy;
140  /// LLVM type for C long type. The runtime uses this in a lot of places where
141  /// it should be using intptr_t, but we can't fix this without breaking
142  /// compatibility with GCC...
143  llvm::IntegerType *LongTy;
144  /// LLVM type for C size_t. Used in various runtime data structures.
145  llvm::IntegerType *SizeTy;
146  /// LLVM type for C intptr_t.
147  llvm::IntegerType *IntPtrTy;
148  /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions.
149  llvm::IntegerType *PtrDiffTy;
150  /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance
151  /// variables.
152  llvm::PointerType *PtrToIntTy;
153  /// LLVM type for Objective-C BOOL type.
154  llvm::Type *BoolTy;
155  /// 32-bit integer type, to save us needing to look it up every time it's used.
156  llvm::IntegerType *Int32Ty;
157  /// 64-bit integer type, to save us needing to look it up every time it's used.
158  llvm::IntegerType *Int64Ty;
159  /// Metadata kind used to tie method lookups to message sends. The GNUstep
160  /// runtime provides some LLVM passes that can use this to do things like
161  /// automatic IMP caching and speculative inlining.
162  unsigned msgSendMDKind;
163 
164  /// Helper function that generates a constant string and returns a pointer to
165  /// the start of the string. The result of this function can be used anywhere
166  /// where the C code specifies const char*.
167  llvm::Constant *MakeConstantString(StringRef Str, const char *Name = "") {
168  ConstantAddress Array = CGM.GetAddrOfConstantCString(Str, Name);
169  return llvm::ConstantExpr::getGetElementPtr(Array.getElementType(),
170  Array.getPointer(), Zeros);
171  }
172 
173  /// Emits a linkonce_odr string, whose name is the prefix followed by the
174  /// string value. This allows the linker to combine the strings between
175  /// different modules. Used for EH typeinfo names, selector strings, and a
176  /// few other things.
177  llvm::Constant *ExportUniqueString(const std::string &Str, StringRef Prefix) {
178  std::string Name = Prefix.str() + Str;
179  auto *ConstStr = TheModule.getGlobalVariable(Name);
180  if (!ConstStr) {
181  llvm::Constant *value = llvm::ConstantDataArray::getString(VMContext,Str);
182  ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true,
183  llvm::GlobalValue::LinkOnceODRLinkage,
184  value, Name);
185  }
186  return llvm::ConstantExpr::getGetElementPtr(ConstStr->getValueType(),
187  ConstStr, Zeros);
188  }
189 
190  /// Generates a global structure, initialized by the elements in the vector.
191  /// The element types must match the types of the structure elements in the
192  /// first argument.
193  llvm::GlobalVariable *MakeGlobal(llvm::Constant *C,
194  CharUnits Align,
195  StringRef Name="",
196  llvm::GlobalValue::LinkageTypes linkage
198  auto GV = new llvm::GlobalVariable(TheModule, C->getType(), false,
199  linkage, C, Name);
200  GV->setAlignment(Align.getQuantity());
201  return GV;
202  }
203 
204  /// Returns a property name and encoding string.
205  llvm::Constant *MakePropertyEncodingString(const ObjCPropertyDecl *PD,
206  const Decl *Container) {
207  const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
208  if ((R.getKind() == ObjCRuntime::GNUstep) &&
209  (R.getVersion() >= VersionTuple(1, 6))) {
210  std::string NameAndAttributes;
211  std::string TypeStr =
212  CGM.getContext().getObjCEncodingForPropertyDecl(PD, Container);
213  NameAndAttributes += '\0';
214  NameAndAttributes += TypeStr.length() + 3;
215  NameAndAttributes += TypeStr;
216  NameAndAttributes += '\0';
217  NameAndAttributes += PD->getNameAsString();
218  return MakeConstantString(NameAndAttributes);
219  }
220  return MakeConstantString(PD->getNameAsString());
221  }
222 
223  /// Push the property attributes into two structure fields.
224  void PushPropertyAttributes(ConstantStructBuilder &Fields,
225  ObjCPropertyDecl *property, bool isSynthesized=true, bool
226  isDynamic=true) {
227  int attrs = property->getPropertyAttributes();
228  // For read-only properties, clear the copy and retain flags
230  attrs &= ~ObjCPropertyDecl::OBJC_PR_copy;
231  attrs &= ~ObjCPropertyDecl::OBJC_PR_retain;
232  attrs &= ~ObjCPropertyDecl::OBJC_PR_weak;
233  attrs &= ~ObjCPropertyDecl::OBJC_PR_strong;
234  }
235  // The first flags field has the same attribute values as clang uses internally
236  Fields.addInt(Int8Ty, attrs & 0xff);
237  attrs >>= 8;
238  attrs <<= 2;
239  // For protocol properties, synthesized and dynamic have no meaning, so we
240  // reuse these flags to indicate that this is a protocol property (both set
241  // has no meaning, as a property can't be both synthesized and dynamic)
242  attrs |= isSynthesized ? (1<<0) : 0;
243  attrs |= isDynamic ? (1<<1) : 0;
244  // The second field is the next four fields left shifted by two, with the
245  // low bit set to indicate whether the field is synthesized or dynamic.
246  Fields.addInt(Int8Ty, attrs & 0xff);
247  // Two padding fields
248  Fields.addInt(Int8Ty, 0);
249  Fields.addInt(Int8Ty, 0);
250  }
251 
252  /// Ensures that the value has the required type, by inserting a bitcast if
253  /// required. This function lets us avoid inserting bitcasts that are
254  /// redundant.
255  llvm::Value* EnforceType(CGBuilderTy &B, llvm::Value *V, llvm::Type *Ty) {
256  if (V->getType() == Ty) return V;
257  return B.CreateBitCast(V, Ty);
258  }
259  Address EnforceType(CGBuilderTy &B, Address V, llvm::Type *Ty) {
260  if (V.getType() == Ty) return V;
261  return B.CreateBitCast(V, Ty);
262  }
263 
264  // Some zeros used for GEPs in lots of places.
265  llvm::Constant *Zeros[2];
266  /// Null pointer value. Mainly used as a terminator in various arrays.
267  llvm::Constant *NULLPtr;
268  /// LLVM context.
269  llvm::LLVMContext &VMContext;
270 
271 private:
272  /// Placeholder for the class. Lots of things refer to the class before we've
273  /// actually emitted it. We use this alias as a placeholder, and then replace
274  /// it with a pointer to the class structure before finally emitting the
275  /// module.
276  llvm::GlobalAlias *ClassPtrAlias;
277  /// Placeholder for the metaclass. Lots of things refer to the class before
278  /// we've / actually emitted it. We use this alias as a placeholder, and then
279  /// replace / it with a pointer to the metaclass structure before finally
280  /// emitting the / module.
281  llvm::GlobalAlias *MetaClassPtrAlias;
282  /// All of the classes that have been generated for this compilation units.
283  std::vector<llvm::Constant*> Classes;
284  /// All of the categories that have been generated for this compilation units.
285  std::vector<llvm::Constant*> Categories;
286  /// All of the Objective-C constant strings that have been generated for this
287  /// compilation units.
288  std::vector<llvm::Constant*> ConstantStrings;
289  /// Map from string values to Objective-C constant strings in the output.
290  /// Used to prevent emitting Objective-C strings more than once. This should
291  /// not be required at all - CodeGenModule should manage this list.
292  llvm::StringMap<llvm::Constant*> ObjCStrings;
293  /// All of the protocols that have been declared.
294  llvm::StringMap<llvm::Constant*> ExistingProtocols;
295  /// For each variant of a selector, we store the type encoding and a
296  /// placeholder value. For an untyped selector, the type will be the empty
297  /// string. Selector references are all done via the module's selector table,
298  /// so we create an alias as a placeholder and then replace it with the real
299  /// value later.
300  typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector;
301  /// Type of the selector map. This is roughly equivalent to the structure
302  /// used in the GNUstep runtime, which maintains a list of all of the valid
303  /// types for a selector in a table.
304  typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> >
305  SelectorMap;
306  /// A map from selectors to selector types. This allows us to emit all
307  /// selectors of the same name and type together.
308  SelectorMap SelectorTable;
309 
310  /// Selectors related to memory management. When compiling in GC mode, we
311  /// omit these.
312  Selector RetainSel, ReleaseSel, AutoreleaseSel;
313  /// Runtime functions used for memory management in GC mode. Note that clang
314  /// supports code generation for calling these functions, but neither GNU
315  /// runtime actually supports this API properly yet.
316  LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn,
317  WeakAssignFn, GlobalAssignFn;
318 
319  typedef std::pair<std::string, std::string> ClassAliasPair;
320  /// All classes that have aliases set for them.
321  std::vector<ClassAliasPair> ClassAliases;
322 
323 protected:
324  /// Function used for throwing Objective-C exceptions.
325  LazyRuntimeFunction ExceptionThrowFn;
326  /// Function used for rethrowing exceptions, used at the end of \@finally or
327  /// \@synchronize blocks.
328  LazyRuntimeFunction ExceptionReThrowFn;
329  /// Function called when entering a catch function. This is required for
330  /// differentiating Objective-C exceptions and foreign exceptions.
331  LazyRuntimeFunction EnterCatchFn;
332  /// Function called when exiting from a catch block. Used to do exception
333  /// cleanup.
334  LazyRuntimeFunction ExitCatchFn;
335  /// Function called when entering an \@synchronize block. Acquires the lock.
336  LazyRuntimeFunction SyncEnterFn;
337  /// Function called when exiting an \@synchronize block. Releases the lock.
338  LazyRuntimeFunction SyncExitFn;
339 
340 private:
341  /// Function called if fast enumeration detects that the collection is
342  /// modified during the update.
343  LazyRuntimeFunction EnumerationMutationFn;
344  /// Function for implementing synthesized property getters that return an
345  /// object.
346  LazyRuntimeFunction GetPropertyFn;
347  /// Function for implementing synthesized property setters that return an
348  /// object.
349  LazyRuntimeFunction SetPropertyFn;
350  /// Function used for non-object declared property getters.
351  LazyRuntimeFunction GetStructPropertyFn;
352  /// Function used for non-object declared property setters.
353  LazyRuntimeFunction SetStructPropertyFn;
354 
355  /// The version of the runtime that this class targets. Must match the
356  /// version in the runtime.
357  int RuntimeVersion;
358  /// The version of the protocol class. Used to differentiate between ObjC1
359  /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional
360  /// components and can not contain declared properties. We always emit
361  /// Objective-C 2 property structures, but we have to pretend that they're
362  /// Objective-C 1 property structures when targeting the GCC runtime or it
363  /// will abort.
364  const int ProtocolVersion;
365 
366  /// Generates an instance variable list structure. This is a structure
367  /// containing a size and an array of structures containing instance variable
368  /// metadata. This is used purely for introspection in the fragile ABI. In
369  /// the non-fragile ABI, it's used for instance variable fixup.
370  llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
371  ArrayRef<llvm::Constant *> IvarTypes,
372  ArrayRef<llvm::Constant *> IvarOffsets);
373 
374  /// Generates a method list structure. This is a structure containing a size
375  /// and an array of structures containing method metadata.
376  ///
377  /// This structure is used by both classes and categories, and contains a next
378  /// pointer allowing them to be chained together in a linked list.
379  llvm::Constant *GenerateMethodList(StringRef ClassName,
380  StringRef CategoryName,
381  ArrayRef<Selector> MethodSels,
382  ArrayRef<llvm::Constant *> MethodTypes,
383  bool isClassMethodList);
384 
385  /// Emits an empty protocol. This is used for \@protocol() where no protocol
386  /// is found. The runtime will (hopefully) fix up the pointer to refer to the
387  /// real protocol.
388  llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName);
389 
390  /// Generates a list of property metadata structures. This follows the same
391  /// pattern as method and instance variable metadata lists.
392  llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID,
393  SmallVectorImpl<Selector> &InstanceMethodSels,
394  SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes);
395 
396  /// Generates a list of referenced protocols. Classes, categories, and
397  /// protocols all use this structure.
398  llvm::Constant *GenerateProtocolList(ArrayRef<std::string> Protocols);
399 
400  /// To ensure that all protocols are seen by the runtime, we add a category on
401  /// a class defined in the runtime, declaring no methods, but adopting the
402  /// protocols. This is a horribly ugly hack, but it allows us to collect all
403  /// of the protocols without changing the ABI.
404  void GenerateProtocolHolderCategory();
405 
406  /// Generates a class structure.
407  llvm::Constant *GenerateClassStructure(
408  llvm::Constant *MetaClass,
409  llvm::Constant *SuperClass,
410  unsigned info,
411  const char *Name,
412  llvm::Constant *Version,
413  llvm::Constant *InstanceSize,
414  llvm::Constant *IVars,
415  llvm::Constant *Methods,
416  llvm::Constant *Protocols,
417  llvm::Constant *IvarOffsets,
418  llvm::Constant *Properties,
419  llvm::Constant *StrongIvarBitmap,
420  llvm::Constant *WeakIvarBitmap,
421  bool isMeta=false);
422 
423  /// Generates a method list. This is used by protocols to define the required
424  /// and optional methods.
425  llvm::Constant *GenerateProtocolMethodList(
426  ArrayRef<llvm::Constant *> MethodNames,
427  ArrayRef<llvm::Constant *> MethodTypes);
428 
429  /// Returns a selector with the specified type encoding. An empty string is
430  /// used to return an untyped selector (with the types field set to NULL).
431  llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel,
432  const std::string &TypeEncoding);
433 
434  /// Returns the variable used to store the offset of an instance variable.
435  llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID,
436  const ObjCIvarDecl *Ivar);
437  /// Emits a reference to a class. This allows the linker to object if there
438  /// is no class of the matching name.
439 
440 protected:
441  void EmitClassRef(const std::string &className);
442 
443  /// Emits a pointer to the named class
444  virtual llvm::Value *GetClassNamed(CodeGenFunction &CGF,
445  const std::string &Name, bool isWeak);
446 
447  /// Looks up the method for sending a message to the specified object. This
448  /// mechanism differs between the GCC and GNU runtimes, so this method must be
449  /// overridden in subclasses.
450  virtual llvm::Value *LookupIMP(CodeGenFunction &CGF,
451  llvm::Value *&Receiver,
452  llvm::Value *cmd,
453  llvm::MDNode *node,
454  MessageSendInfo &MSI) = 0;
455 
456  /// Looks up the method for sending a message to a superclass. This
457  /// mechanism differs between the GCC and GNU runtimes, so this method must
458  /// be overridden in subclasses.
459  virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF,
460  Address ObjCSuper,
461  llvm::Value *cmd,
462  MessageSendInfo &MSI) = 0;
463 
464  /// Libobjc2 uses a bitfield representation where small(ish) bitfields are
465  /// stored in a 64-bit value with the low bit set to 1 and the remaining 63
466  /// bits set to their values, LSB first, while larger ones are stored in a
467  /// structure of this / form:
468  ///
469  /// struct { int32_t length; int32_t values[length]; };
470  ///
471  /// The values in the array are stored in host-endian format, with the least
472  /// significant bit being assumed to come first in the bitfield. Therefore,
473  /// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] },
474  /// while a bitfield / with the 63rd bit set will be 1<<64.
475  llvm::Constant *MakeBitField(ArrayRef<bool> bits);
476 
477 public:
478  CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
479  unsigned protocolClassVersion);
480 
481  ConstantAddress GenerateConstantString(const StringLiteral *) override;
482 
483  RValue
484  GenerateMessageSend(CodeGenFunction &CGF, ReturnValueSlot Return,
485  QualType ResultType, Selector Sel,
486  llvm::Value *Receiver, const CallArgList &CallArgs,
487  const ObjCInterfaceDecl *Class,
488  const ObjCMethodDecl *Method) override;
489  RValue
490  GenerateMessageSendSuper(CodeGenFunction &CGF, ReturnValueSlot Return,
491  QualType ResultType, Selector Sel,
492  const ObjCInterfaceDecl *Class,
493  bool isCategoryImpl, llvm::Value *Receiver,
494  bool IsClassMessage, const CallArgList &CallArgs,
495  const ObjCMethodDecl *Method) override;
496  llvm::Value *GetClass(CodeGenFunction &CGF,
497  const ObjCInterfaceDecl *OID) override;
498  llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel) override;
499  Address GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) override;
500  llvm::Value *GetSelector(CodeGenFunction &CGF,
501  const ObjCMethodDecl *Method) override;
502  llvm::Constant *GetEHType(QualType T) override;
503 
504  llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
505  const ObjCContainerDecl *CD) override;
506  void GenerateCategory(const ObjCCategoryImplDecl *CMD) override;
507  void GenerateClass(const ObjCImplementationDecl *ClassDecl) override;
508  void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) override;
509  llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
510  const ObjCProtocolDecl *PD) override;
511  void GenerateProtocol(const ObjCProtocolDecl *PD) override;
512  llvm::Function *ModuleInitFunction() override;
513  llvm::Constant *GetPropertyGetFunction() override;
514  llvm::Constant *GetPropertySetFunction() override;
515  llvm::Constant *GetOptimizedPropertySetFunction(bool atomic,
516  bool copy) override;
517  llvm::Constant *GetSetStructFunction() override;
518  llvm::Constant *GetGetStructFunction() override;
519  llvm::Constant *GetCppAtomicObjectGetFunction() override;
520  llvm::Constant *GetCppAtomicObjectSetFunction() override;
521  llvm::Constant *EnumerationMutationFunction() override;
522 
523  void EmitTryStmt(CodeGenFunction &CGF,
524  const ObjCAtTryStmt &S) override;
525  void EmitSynchronizedStmt(CodeGenFunction &CGF,
526  const ObjCAtSynchronizedStmt &S) override;
527  void EmitThrowStmt(CodeGenFunction &CGF,
528  const ObjCAtThrowStmt &S,
529  bool ClearInsertionPoint=true) override;
530  llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF,
531  Address AddrWeakObj) override;
532  void EmitObjCWeakAssign(CodeGenFunction &CGF,
533  llvm::Value *src, Address dst) override;
534  void EmitObjCGlobalAssign(CodeGenFunction &CGF,
535  llvm::Value *src, Address dest,
536  bool threadlocal=false) override;
537  void EmitObjCIvarAssign(CodeGenFunction &CGF, llvm::Value *src,
538  Address dest, llvm::Value *ivarOffset) override;
539  void EmitObjCStrongCastAssign(CodeGenFunction &CGF,
540  llvm::Value *src, Address dest) override;
541  void EmitGCMemmoveCollectable(CodeGenFunction &CGF, Address DestPtr,
542  Address SrcPtr,
543  llvm::Value *Size) override;
544  LValue EmitObjCValueForIvar(CodeGenFunction &CGF, QualType ObjectTy,
545  llvm::Value *BaseValue, const ObjCIvarDecl *Ivar,
546  unsigned CVRQualifiers) override;
547  llvm::Value *EmitIvarOffset(CodeGenFunction &CGF,
548  const ObjCInterfaceDecl *Interface,
549  const ObjCIvarDecl *Ivar) override;
550  llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) override;
551  llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM,
552  const CGBlockInfo &blockInfo) override {
553  return NULLPtr;
554  }
555  llvm::Constant *BuildRCBlockLayout(CodeGenModule &CGM,
556  const CGBlockInfo &blockInfo) override {
557  return NULLPtr;
558  }
559 
560  llvm::Constant *BuildByrefLayout(CodeGenModule &CGM, QualType T) override {
561  return NULLPtr;
562  }
563 };
564 
565 /// Class representing the legacy GCC Objective-C ABI. This is the default when
566 /// -fobjc-nonfragile-abi is not specified.
567 ///
568 /// The GCC ABI target actually generates code that is approximately compatible
569 /// with the new GNUstep runtime ABI, but refrains from using any features that
570 /// would not work with the GCC runtime. For example, clang always generates
571 /// the extended form of the class structure, and the extra fields are simply
572 /// ignored by GCC libobjc.
573 class CGObjCGCC : public CGObjCGNU {
574  /// The GCC ABI message lookup function. Returns an IMP pointing to the
575  /// method implementation for this message.
576  LazyRuntimeFunction MsgLookupFn;
577  /// The GCC ABI superclass message lookup function. Takes a pointer to a
578  /// structure describing the receiver and the class, and a selector as
579  /// arguments. Returns the IMP for the corresponding method.
580  LazyRuntimeFunction MsgLookupSuperFn;
581 
582 protected:
583  llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
584  llvm::Value *cmd, llvm::MDNode *node,
585  MessageSendInfo &MSI) override {
586  CGBuilderTy &Builder = CGF.Builder;
587  llvm::Value *args[] = {
588  EnforceType(Builder, Receiver, IdTy),
589  EnforceType(Builder, cmd, SelectorTy) };
590  llvm::CallSite imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);
591  imp->setMetadata(msgSendMDKind, node);
592  return imp.getInstruction();
593  }
594 
595  llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
596  llvm::Value *cmd, MessageSendInfo &MSI) override {
597  CGBuilderTy &Builder = CGF.Builder;
598  llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper,
599  PtrToObjCSuperTy).getPointer(), cmd};
600  return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
601  }
602 
603 public:
604  CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) {
605  // IMP objc_msg_lookup(id, SEL);
606  MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy);
607  // IMP objc_msg_lookup_super(struct objc_super*, SEL);
608  MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
609  PtrToObjCSuperTy, SelectorTy);
610  }
611 };
612 
613 /// Class used when targeting the new GNUstep runtime ABI.
614 class CGObjCGNUstep : public CGObjCGNU {
615  /// The slot lookup function. Returns a pointer to a cacheable structure
616  /// that contains (among other things) the IMP.
617  LazyRuntimeFunction SlotLookupFn;
618  /// The GNUstep ABI superclass message lookup function. Takes a pointer to
619  /// a structure describing the receiver and the class, and a selector as
620  /// arguments. Returns the slot for the corresponding method. Superclass
621  /// message lookup rarely changes, so this is a good caching opportunity.
622  LazyRuntimeFunction SlotLookupSuperFn;
623  /// Specialised function for setting atomic retain properties
624  LazyRuntimeFunction SetPropertyAtomic;
625  /// Specialised function for setting atomic copy properties
626  LazyRuntimeFunction SetPropertyAtomicCopy;
627  /// Specialised function for setting nonatomic retain properties
628  LazyRuntimeFunction SetPropertyNonAtomic;
629  /// Specialised function for setting nonatomic copy properties
630  LazyRuntimeFunction SetPropertyNonAtomicCopy;
631  /// Function to perform atomic copies of C++ objects with nontrivial copy
632  /// constructors from Objective-C ivars.
633  LazyRuntimeFunction CxxAtomicObjectGetFn;
634  /// Function to perform atomic copies of C++ objects with nontrivial copy
635  /// constructors to Objective-C ivars.
636  LazyRuntimeFunction CxxAtomicObjectSetFn;
637  /// Type of an slot structure pointer. This is returned by the various
638  /// lookup functions.
639  llvm::Type *SlotTy;
640 
641  public:
642  llvm::Constant *GetEHType(QualType T) override;
643 
644  protected:
645  llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
646  llvm::Value *cmd, llvm::MDNode *node,
647  MessageSendInfo &MSI) override {
648  CGBuilderTy &Builder = CGF.Builder;
649  llvm::Function *LookupFn = SlotLookupFn;
650 
651  // Store the receiver on the stack so that we can reload it later
652  Address ReceiverPtr =
653  CGF.CreateTempAlloca(Receiver->getType(), CGF.getPointerAlign());
654  Builder.CreateStore(Receiver, ReceiverPtr);
655 
656  llvm::Value *self;
657 
658  if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) {
659  self = CGF.LoadObjCSelf();
660  } else {
661  self = llvm::ConstantPointerNull::get(IdTy);
662  }
663 
664  // The lookup function is guaranteed not to capture the receiver pointer.
665  LookupFn->addParamAttr(0, llvm::Attribute::NoCapture);
666 
667  llvm::Value *args[] = {
668  EnforceType(Builder, ReceiverPtr.getPointer(), PtrToIdTy),
669  EnforceType(Builder, cmd, SelectorTy),
670  EnforceType(Builder, self, IdTy) };
671  llvm::CallSite slot = CGF.EmitRuntimeCallOrInvoke(LookupFn, args);
672  slot.setOnlyReadsMemory();
673  slot->setMetadata(msgSendMDKind, node);
674 
675  // Load the imp from the slot
676  llvm::Value *imp = Builder.CreateAlignedLoad(
677  Builder.CreateStructGEP(nullptr, slot.getInstruction(), 4),
678  CGF.getPointerAlign());
679 
680  // The lookup function may have changed the receiver, so make sure we use
681  // the new one.
682  Receiver = Builder.CreateLoad(ReceiverPtr, true);
683  return imp;
684  }
685 
686  llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
687  llvm::Value *cmd,
688  MessageSendInfo &MSI) override {
689  CGBuilderTy &Builder = CGF.Builder;
690  llvm::Value *lookupArgs[] = {ObjCSuper.getPointer(), cmd};
691 
692  llvm::CallInst *slot =
693  CGF.EmitNounwindRuntimeCall(SlotLookupSuperFn, lookupArgs);
694  slot->setOnlyReadsMemory();
695 
696  return Builder.CreateAlignedLoad(Builder.CreateStructGEP(nullptr, slot, 4),
697  CGF.getPointerAlign());
698  }
699 
700  public:
701  CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) {
702  const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
703 
704  llvm::StructType *SlotStructTy =
705  llvm::StructType::get(PtrTy, PtrTy, PtrTy, IntTy, IMPTy);
706  SlotTy = llvm::PointerType::getUnqual(SlotStructTy);
707  // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender);
708  SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy,
709  SelectorTy, IdTy);
710  // Slot_t objc_msg_lookup_super(struct objc_super*, SEL);
711  SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy,
712  PtrToObjCSuperTy, SelectorTy);
713  // If we're in ObjC++ mode, then we want to make
714  if (CGM.getLangOpts().CPlusPlus) {
715  llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
716  // void *__cxa_begin_catch(void *e)
717  EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy);
718  // void __cxa_end_catch(void)
719  ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy);
720  // void _Unwind_Resume_or_Rethrow(void*)
721  ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy,
722  PtrTy);
723  } else if (R.getVersion() >= VersionTuple(1, 7)) {
724  llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
725  // id objc_begin_catch(void *e)
726  EnterCatchFn.init(&CGM, "objc_begin_catch", IdTy, PtrTy);
727  // void objc_end_catch(void)
728  ExitCatchFn.init(&CGM, "objc_end_catch", VoidTy);
729  // void _Unwind_Resume_or_Rethrow(void*)
730  ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy, PtrTy);
731  }
732  llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
733  SetPropertyAtomic.init(&CGM, "objc_setProperty_atomic", VoidTy, IdTy,
734  SelectorTy, IdTy, PtrDiffTy);
735  SetPropertyAtomicCopy.init(&CGM, "objc_setProperty_atomic_copy", VoidTy,
736  IdTy, SelectorTy, IdTy, PtrDiffTy);
737  SetPropertyNonAtomic.init(&CGM, "objc_setProperty_nonatomic", VoidTy,
738  IdTy, SelectorTy, IdTy, PtrDiffTy);
739  SetPropertyNonAtomicCopy.init(&CGM, "objc_setProperty_nonatomic_copy",
740  VoidTy, IdTy, SelectorTy, IdTy, PtrDiffTy);
741  // void objc_setCppObjectAtomic(void *dest, const void *src, void
742  // *helper);
743  CxxAtomicObjectSetFn.init(&CGM, "objc_setCppObjectAtomic", VoidTy, PtrTy,
744  PtrTy, PtrTy);
745  // void objc_getCppObjectAtomic(void *dest, const void *src, void
746  // *helper);
747  CxxAtomicObjectGetFn.init(&CGM, "objc_getCppObjectAtomic", VoidTy, PtrTy,
748  PtrTy, PtrTy);
749  }
750 
751  llvm::Constant *GetCppAtomicObjectGetFunction() override {
752  // The optimised functions were added in version 1.7 of the GNUstep
753  // runtime.
754  assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
755  VersionTuple(1, 7));
756  return CxxAtomicObjectGetFn;
757  }
758 
759  llvm::Constant *GetCppAtomicObjectSetFunction() override {
760  // The optimised functions were added in version 1.7 of the GNUstep
761  // runtime.
762  assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
763  VersionTuple(1, 7));
764  return CxxAtomicObjectSetFn;
765  }
766 
767  llvm::Constant *GetOptimizedPropertySetFunction(bool atomic,
768  bool copy) override {
769  // The optimised property functions omit the GC check, and so are not
770  // safe to use in GC mode. The standard functions are fast in GC mode,
771  // so there is less advantage in using them.
772  assert ((CGM.getLangOpts().getGC() == LangOptions::NonGC));
773  // The optimised functions were added in version 1.7 of the GNUstep
774  // runtime.
775  assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
776  VersionTuple(1, 7));
777 
778  if (atomic) {
779  if (copy) return SetPropertyAtomicCopy;
780  return SetPropertyAtomic;
781  }
782 
783  return copy ? SetPropertyNonAtomicCopy : SetPropertyNonAtomic;
784  }
785 };
786 
787 /// Support for the ObjFW runtime.
788 class CGObjCObjFW: public CGObjCGNU {
789 protected:
790  /// The GCC ABI message lookup function. Returns an IMP pointing to the
791  /// method implementation for this message.
792  LazyRuntimeFunction MsgLookupFn;
793  /// stret lookup function. While this does not seem to make sense at the
794  /// first look, this is required to call the correct forwarding function.
795  LazyRuntimeFunction MsgLookupFnSRet;
796  /// The GCC ABI superclass message lookup function. Takes a pointer to a
797  /// structure describing the receiver and the class, and a selector as
798  /// arguments. Returns the IMP for the corresponding method.
799  LazyRuntimeFunction MsgLookupSuperFn, MsgLookupSuperFnSRet;
800 
801  llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
802  llvm::Value *cmd, llvm::MDNode *node,
803  MessageSendInfo &MSI) override {
804  CGBuilderTy &Builder = CGF.Builder;
805  llvm::Value *args[] = {
806  EnforceType(Builder, Receiver, IdTy),
807  EnforceType(Builder, cmd, SelectorTy) };
808 
809  llvm::CallSite imp;
810  if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
811  imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFnSRet, args);
812  else
813  imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);
814 
815  imp->setMetadata(msgSendMDKind, node);
816  return imp.getInstruction();
817  }
818 
819  llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
820  llvm::Value *cmd, MessageSendInfo &MSI) override {
821  CGBuilderTy &Builder = CGF.Builder;
822  llvm::Value *lookupArgs[] = {
823  EnforceType(Builder, ObjCSuper.getPointer(), PtrToObjCSuperTy), cmd,
824  };
825 
826  if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
827  return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFnSRet, lookupArgs);
828  else
829  return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
830  }
831 
832  llvm::Value *GetClassNamed(CodeGenFunction &CGF, const std::string &Name,
833  bool isWeak) override {
834  if (isWeak)
835  return CGObjCGNU::GetClassNamed(CGF, Name, isWeak);
836 
837  EmitClassRef(Name);
838  std::string SymbolName = "_OBJC_CLASS_" + Name;
839  llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(SymbolName);
840  if (!ClassSymbol)
841  ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
843  nullptr, SymbolName);
844  return ClassSymbol;
845  }
846 
847 public:
848  CGObjCObjFW(CodeGenModule &Mod): CGObjCGNU(Mod, 9, 3) {
849  // IMP objc_msg_lookup(id, SEL);
850  MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy);
851  MsgLookupFnSRet.init(&CGM, "objc_msg_lookup_stret", IMPTy, IdTy,
852  SelectorTy);
853  // IMP objc_msg_lookup_super(struct objc_super*, SEL);
854  MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
855  PtrToObjCSuperTy, SelectorTy);
856  MsgLookupSuperFnSRet.init(&CGM, "objc_msg_lookup_super_stret", IMPTy,
857  PtrToObjCSuperTy, SelectorTy);
858  }
859 };
860 } // end anonymous namespace
861 
862 /// Emits a reference to a dummy variable which is emitted with each class.
863 /// This ensures that a linker error will be generated when trying to link
864 /// together modules where a referenced class is not defined.
865 void CGObjCGNU::EmitClassRef(const std::string &className) {
866  std::string symbolRef = "__objc_class_ref_" + className;
867  // Don't emit two copies of the same symbol
868  if (TheModule.getGlobalVariable(symbolRef))
869  return;
870  std::string symbolName = "__objc_class_name_" + className;
871  llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName);
872  if (!ClassSymbol) {
873  ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
875  nullptr, symbolName);
876  }
877  new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true,
878  llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef);
879 }
880 
881 static std::string SymbolNameForMethod( StringRef ClassName,
882  StringRef CategoryName, const Selector MethodName,
883  bool isClassMethod) {
884  std::string MethodNameColonStripped = MethodName.getAsString();
885  std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(),
886  ':', '_');
887  return (Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" +
888  CategoryName + "_" + MethodNameColonStripped).str();
889 }
890 
891 CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
892  unsigned protocolClassVersion)
893  : CGObjCRuntime(cgm), TheModule(CGM.getModule()),
894  VMContext(cgm.getLLVMContext()), ClassPtrAlias(nullptr),
895  MetaClassPtrAlias(nullptr), RuntimeVersion(runtimeABIVersion),
896  ProtocolVersion(protocolClassVersion) {
897 
898  msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend");
899 
900  CodeGenTypes &Types = CGM.getTypes();
901  IntTy = cast<llvm::IntegerType>(
902  Types.ConvertType(CGM.getContext().IntTy));
903  LongTy = cast<llvm::IntegerType>(
904  Types.ConvertType(CGM.getContext().LongTy));
905  SizeTy = cast<llvm::IntegerType>(
906  Types.ConvertType(CGM.getContext().getSizeType()));
907  PtrDiffTy = cast<llvm::IntegerType>(
908  Types.ConvertType(CGM.getContext().getPointerDiffType()));
909  BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy);
910 
911  Int8Ty = llvm::Type::getInt8Ty(VMContext);
912  // C string type. Used in lots of places.
913  PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty);
914 
915  Zeros[0] = llvm::ConstantInt::get(LongTy, 0);
916  Zeros[1] = Zeros[0];
917  NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty);
918  // Get the selector Type.
919  QualType selTy = CGM.getContext().getObjCSelType();
920  if (QualType() == selTy) {
921  SelectorTy = PtrToInt8Ty;
922  } else {
923  SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy));
924  }
925 
926  PtrToIntTy = llvm::PointerType::getUnqual(IntTy);
927  PtrTy = PtrToInt8Ty;
928 
929  Int32Ty = llvm::Type::getInt32Ty(VMContext);
930  Int64Ty = llvm::Type::getInt64Ty(VMContext);
931 
932  IntPtrTy =
933  CGM.getDataLayout().getPointerSizeInBits() == 32 ? Int32Ty : Int64Ty;
934 
935  // Object type
936  QualType UnqualIdTy = CGM.getContext().getObjCIdType();
937  ASTIdTy = CanQualType();
938  if (UnqualIdTy != QualType()) {
939  ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy);
940  IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
941  } else {
942  IdTy = PtrToInt8Ty;
943  }
944  PtrToIdTy = llvm::PointerType::getUnqual(IdTy);
945 
946  ObjCSuperTy = llvm::StructType::get(IdTy, IdTy);
947  PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy);
948 
949  llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
950 
951  // void objc_exception_throw(id);
952  ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
953  ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
954  // int objc_sync_enter(id);
955  SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy);
956  // int objc_sync_exit(id);
957  SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy);
958 
959  // void objc_enumerationMutation (id)
960  EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, IdTy);
961 
962  // id objc_getProperty(id, SEL, ptrdiff_t, BOOL)
963  GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy,
964  PtrDiffTy, BoolTy);
965  // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL)
966  SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy,
967  PtrDiffTy, IdTy, BoolTy, BoolTy);
968  // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
969  GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy,
970  PtrDiffTy, BoolTy, BoolTy);
971  // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
972  SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy,
973  PtrDiffTy, BoolTy, BoolTy);
974 
975  // IMP type
976  llvm::Type *IMPArgs[] = { IdTy, SelectorTy };
977  IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs,
978  true));
979 
980  const LangOptions &Opts = CGM.getLangOpts();
981  if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount)
982  RuntimeVersion = 10;
983 
984  // Don't bother initialising the GC stuff unless we're compiling in GC mode
985  if (Opts.getGC() != LangOptions::NonGC) {
986  // This is a bit of an hack. We should sort this out by having a proper
987  // CGObjCGNUstep subclass for GC, but we may want to really support the old
988  // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now
989  // Get selectors needed in GC mode
990  RetainSel = GetNullarySelector("retain", CGM.getContext());
991  ReleaseSel = GetNullarySelector("release", CGM.getContext());
992  AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext());
993 
994  // Get functions needed in GC mode
995 
996  // id objc_assign_ivar(id, id, ptrdiff_t);
997  IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy);
998  // id objc_assign_strongCast (id, id*)
999  StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy,
1000  PtrToIdTy);
1001  // id objc_assign_global(id, id*);
1002  GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy);
1003  // id objc_assign_weak(id, id*);
1004  WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy);
1005  // id objc_read_weak(id*);
1006  WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy);
1007  // void *objc_memmove_collectable(void*, void *, size_t);
1008  MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy,
1009  SizeTy);
1010  }
1011 }
1012 
1013 llvm::Value *CGObjCGNU::GetClassNamed(CodeGenFunction &CGF,
1014  const std::string &Name, bool isWeak) {
1015  llvm::Constant *ClassName = MakeConstantString(Name);
1016  // With the incompatible ABI, this will need to be replaced with a direct
1017  // reference to the class symbol. For the compatible nonfragile ABI we are
1018  // still performing this lookup at run time but emitting the symbol for the
1019  // class externally so that we can make the switch later.
1020  //
1021  // Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class
1022  // with memoized versions or with static references if it's safe to do so.
1023  if (!isWeak)
1024  EmitClassRef(Name);
1025 
1026  llvm::Constant *ClassLookupFn =
1027  CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true),
1028  "objc_lookup_class");
1029  return CGF.EmitNounwindRuntimeCall(ClassLookupFn, ClassName);
1030 }
1031 
1032 // This has to perform the lookup every time, since posing and related
1033 // techniques can modify the name -> class mapping.
1034 llvm::Value *CGObjCGNU::GetClass(CodeGenFunction &CGF,
1035  const ObjCInterfaceDecl *OID) {
1036  auto *Value =
1037  GetClassNamed(CGF, OID->getNameAsString(), OID->isWeakImported());
1038  if (CGM.getTriple().isOSBinFormatCOFF()) {
1039  if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value)) {
1040  auto DLLStorage = llvm::GlobalValue::DefaultStorageClass;
1041  if (OID->hasAttr<DLLExportAttr>())
1042  DLLStorage = llvm::GlobalValue::DLLExportStorageClass;
1043  else if (OID->hasAttr<DLLImportAttr>())
1044  DLLStorage = llvm::GlobalValue::DLLImportStorageClass;
1045  ClassSymbol->setDLLStorageClass(DLLStorage);
1046  }
1047  }
1048  return Value;
1049 }
1050 
1051 llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) {
1052  auto *Value = GetClassNamed(CGF, "NSAutoreleasePool", false);
1053  if (CGM.getTriple().isOSBinFormatCOFF()) {
1054  if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value)) {
1055  IdentifierInfo &II = CGF.CGM.getContext().Idents.get("NSAutoreleasePool");
1058 
1059  const VarDecl *VD = nullptr;
1060  for (const auto &Result : DC->lookup(&II))
1061  if ((VD = dyn_cast<VarDecl>(Result)))
1062  break;
1063 
1064  auto DLLStorage = llvm::GlobalValue::DefaultStorageClass;
1065  if (!VD || VD->hasAttr<DLLImportAttr>())
1066  DLLStorage = llvm::GlobalValue::DLLImportStorageClass;
1067  else if (VD->hasAttr<DLLExportAttr>())
1068  DLLStorage = llvm::GlobalValue::DLLExportStorageClass;
1069 
1070  ClassSymbol->setDLLStorageClass(DLLStorage);
1071  }
1072  }
1073  return Value;
1074 }
1075 
1076 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel,
1077  const std::string &TypeEncoding) {
1079  llvm::GlobalAlias *SelValue = nullptr;
1080 
1081  for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(),
1082  e = Types.end() ; i!=e ; i++) {
1083  if (i->first == TypeEncoding) {
1084  SelValue = i->second;
1085  break;
1086  }
1087  }
1088  if (!SelValue) {
1089  SelValue = llvm::GlobalAlias::create(
1090  SelectorTy->getElementType(), 0, llvm::GlobalValue::PrivateLinkage,
1091  ".objc_selector_" + Sel.getAsString(), &TheModule);
1092  Types.emplace_back(TypeEncoding, SelValue);
1093  }
1094 
1095  return SelValue;
1096 }
1097 
1098 Address CGObjCGNU::GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) {
1099  llvm::Value *SelValue = GetSelector(CGF, Sel);
1100 
1101  // Store it to a temporary. Does this satisfy the semantics of
1102  // GetAddrOfSelector? Hopefully.
1103  Address tmp = CGF.CreateTempAlloca(SelValue->getType(),
1104  CGF.getPointerAlign());
1105  CGF.Builder.CreateStore(SelValue, tmp);
1106  return tmp;
1107 }
1108 
1109 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel) {
1110  return GetSelector(CGF, Sel, std::string());
1111 }
1112 
1113 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF,
1114  const ObjCMethodDecl *Method) {
1115  std::string SelTypes = CGM.getContext().getObjCEncodingForMethodDecl(Method);
1116  return GetSelector(CGF, Method->getSelector(), SelTypes);
1117 }
1118 
1119 llvm::Constant *CGObjCGNU::GetEHType(QualType T) {
1120  if (T->isObjCIdType() || T->isObjCQualifiedIdType()) {
1121  // With the old ABI, there was only one kind of catchall, which broke
1122  // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as
1123  // a pointer indicating object catchalls, and NULL to indicate real
1124  // catchalls
1125  if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
1126  return MakeConstantString("@id");
1127  } else {
1128  return nullptr;
1129  }
1130  }
1131 
1132  // All other types should be Objective-C interface pointer types.
1134  assert(OPT && "Invalid @catch type.");
1135  const ObjCInterfaceDecl *IDecl = OPT->getObjectType()->getInterface();
1136  assert(IDecl && "Invalid @catch type.");
1137  return MakeConstantString(IDecl->getIdentifier()->getName());
1138 }
1139 
1140 llvm::Constant *CGObjCGNUstep::GetEHType(QualType T) {
1141  if (!CGM.getLangOpts().CPlusPlus)
1142  return CGObjCGNU::GetEHType(T);
1143 
1144  // For Objective-C++, we want to provide the ability to catch both C++ and
1145  // Objective-C objects in the same function.
1146 
1147  // There's a particular fixed type info for 'id'.
1148  if (T->isObjCIdType() ||
1149  T->isObjCQualifiedIdType()) {
1150  llvm::Constant *IDEHType =
1151  CGM.getModule().getGlobalVariable("__objc_id_type_info");
1152  if (!IDEHType)
1153  IDEHType =
1154  new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty,
1155  false,
1157  nullptr, "__objc_id_type_info");
1158  return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty);
1159  }
1160 
1161  const ObjCObjectPointerType *PT =
1163  assert(PT && "Invalid @catch type.");
1164  const ObjCInterfaceType *IT = PT->getInterfaceType();
1165  assert(IT && "Invalid @catch type.");
1166  std::string className = IT->getDecl()->getIdentifier()->getName();
1167 
1168  std::string typeinfoName = "__objc_eh_typeinfo_" + className;
1169 
1170  // Return the existing typeinfo if it exists
1171  llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName);
1172  if (typeinfo)
1173  return llvm::ConstantExpr::getBitCast(typeinfo, PtrToInt8Ty);
1174 
1175  // Otherwise create it.
1176 
1177  // vtable for gnustep::libobjc::__objc_class_type_info
1178  // It's quite ugly hard-coding this. Ideally we'd generate it using the host
1179  // platform's name mangling.
1180  const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE";
1181  auto *Vtable = TheModule.getGlobalVariable(vtableName);
1182  if (!Vtable) {
1183  Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true,
1185  nullptr, vtableName);
1186  }
1187  llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2);
1188  auto *BVtable = llvm::ConstantExpr::getBitCast(
1189  llvm::ConstantExpr::getGetElementPtr(Vtable->getValueType(), Vtable, Two),
1190  PtrToInt8Ty);
1191 
1192  llvm::Constant *typeName =
1193  ExportUniqueString(className, "__objc_eh_typename_");
1194 
1195  ConstantInitBuilder builder(CGM);
1196  auto fields = builder.beginStruct();
1197  fields.add(BVtable);
1198  fields.add(typeName);
1199  llvm::Constant *TI =
1200  fields.finishAndCreateGlobal("__objc_eh_typeinfo_" + className,
1201  CGM.getPointerAlign(),
1202  /*constant*/ false,
1203  llvm::GlobalValue::LinkOnceODRLinkage);
1204  return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty);
1205 }
1206 
1207 /// Generate an NSConstantString object.
1208 ConstantAddress CGObjCGNU::GenerateConstantString(const StringLiteral *SL) {
1209 
1210  std::string Str = SL->getString().str();
1211  CharUnits Align = CGM.getPointerAlign();
1212 
1213  // Look for an existing one
1214  llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str);
1215  if (old != ObjCStrings.end())
1216  return ConstantAddress(old->getValue(), Align);
1217 
1218  StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass;
1219 
1220  if (StringClass.empty()) StringClass = "NXConstantString";
1221 
1222  std::string Sym = "_OBJC_CLASS_";
1223  Sym += StringClass;
1224 
1225  llvm::Constant *isa = TheModule.getNamedGlobal(Sym);
1226 
1227  if (!isa)
1228  isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false,
1229  llvm::GlobalValue::ExternalWeakLinkage, nullptr, Sym);
1230  else if (isa->getType() != PtrToIdTy)
1231  isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy);
1232 
1233  ConstantInitBuilder Builder(CGM);
1234  auto Fields = Builder.beginStruct();
1235  Fields.add(isa);
1236  Fields.add(MakeConstantString(Str));
1237  Fields.addInt(IntTy, Str.size());
1238  llvm::Constant *ObjCStr =
1239  Fields.finishAndCreateGlobal(".objc_str", Align);
1240  ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty);
1241  ObjCStrings[Str] = ObjCStr;
1242  ConstantStrings.push_back(ObjCStr);
1243  return ConstantAddress(ObjCStr, Align);
1244 }
1245 
1246 ///Generates a message send where the super is the receiver. This is a message
1247 ///send to self with special delivery semantics indicating which class's method
1248 ///should be called.
1249 RValue
1250 CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF,
1251  ReturnValueSlot Return,
1252  QualType ResultType,
1253  Selector Sel,
1254  const ObjCInterfaceDecl *Class,
1255  bool isCategoryImpl,
1256  llvm::Value *Receiver,
1257  bool IsClassMessage,
1258  const CallArgList &CallArgs,
1259  const ObjCMethodDecl *Method) {
1260  CGBuilderTy &Builder = CGF.Builder;
1261  if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
1262  if (Sel == RetainSel || Sel == AutoreleaseSel) {
1263  return RValue::get(EnforceType(Builder, Receiver,
1264  CGM.getTypes().ConvertType(ResultType)));
1265  }
1266  if (Sel == ReleaseSel) {
1267  return RValue::get(nullptr);
1268  }
1269  }
1270 
1271  llvm::Value *cmd = GetSelector(CGF, Sel);
1272  CallArgList ActualArgs;
1273 
1274  ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy);
1275  ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
1276  ActualArgs.addFrom(CallArgs);
1277 
1278  MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
1279 
1280  llvm::Value *ReceiverClass = nullptr;
1281  if (isCategoryImpl) {
1282  llvm::Constant *classLookupFunction = nullptr;
1283  if (IsClassMessage) {
1284  classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
1285  IdTy, PtrTy, true), "objc_get_meta_class");
1286  } else {
1287  classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
1288  IdTy, PtrTy, true), "objc_get_class");
1289  }
1290  ReceiverClass = Builder.CreateCall(classLookupFunction,
1291  MakeConstantString(Class->getNameAsString()));
1292  } else {
1293  // Set up global aliases for the metaclass or class pointer if they do not
1294  // already exist. These will are forward-references which will be set to
1295  // pointers to the class and metaclass structure created for the runtime
1296  // load function. To send a message to super, we look up the value of the
1297  // super_class pointer from either the class or metaclass structure.
1298  if (IsClassMessage) {
1299  if (!MetaClassPtrAlias) {
1300  MetaClassPtrAlias = llvm::GlobalAlias::create(
1301  IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage,
1302  ".objc_metaclass_ref" + Class->getNameAsString(), &TheModule);
1303  }
1304  ReceiverClass = MetaClassPtrAlias;
1305  } else {
1306  if (!ClassPtrAlias) {
1307  ClassPtrAlias = llvm::GlobalAlias::create(
1308  IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage,
1309  ".objc_class_ref" + Class->getNameAsString(), &TheModule);
1310  }
1311  ReceiverClass = ClassPtrAlias;
1312  }
1313  }
1314  // Cast the pointer to a simplified version of the class structure
1315  llvm::Type *CastTy = llvm::StructType::get(IdTy, IdTy);
1316  ReceiverClass = Builder.CreateBitCast(ReceiverClass,
1317  llvm::PointerType::getUnqual(CastTy));
1318  // Get the superclass pointer
1319  ReceiverClass = Builder.CreateStructGEP(CastTy, ReceiverClass, 1);
1320  // Load the superclass pointer
1321  ReceiverClass =
1322  Builder.CreateAlignedLoad(ReceiverClass, CGF.getPointerAlign());
1323  // Construct the structure used to look up the IMP
1324  llvm::StructType *ObjCSuperTy =
1325  llvm::StructType::get(Receiver->getType(), IdTy);
1326 
1327  // FIXME: Is this really supposed to be a dynamic alloca?
1328  Address ObjCSuper = Address(Builder.CreateAlloca(ObjCSuperTy),
1329  CGF.getPointerAlign());
1330 
1331  Builder.CreateStore(Receiver,
1332  Builder.CreateStructGEP(ObjCSuper, 0, CharUnits::Zero()));
1333  Builder.CreateStore(ReceiverClass,
1334  Builder.CreateStructGEP(ObjCSuper, 1, CGF.getPointerSize()));
1335 
1336  ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy);
1337 
1338  // Get the IMP
1339  llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd, MSI);
1340  imp = EnforceType(Builder, imp, MSI.MessengerType);
1341 
1342  llvm::Metadata *impMD[] = {
1343  llvm::MDString::get(VMContext, Sel.getAsString()),
1344  llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()),
1345  llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1346  llvm::Type::getInt1Ty(VMContext), IsClassMessage))};
1347  llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
1348 
1349  CGCallee callee(CGCalleeInfo(), imp);
1350 
1351  llvm::Instruction *call;
1352  RValue msgRet = CGF.EmitCall(MSI.CallInfo, callee, Return, ActualArgs, &call);
1353  call->setMetadata(msgSendMDKind, node);
1354  return msgRet;
1355 }
1356 
1357 /// Generate code for a message send expression.
1358 RValue
1359 CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF,
1360  ReturnValueSlot Return,
1361  QualType ResultType,
1362  Selector Sel,
1363  llvm::Value *Receiver,
1364  const CallArgList &CallArgs,
1365  const ObjCInterfaceDecl *Class,
1366  const ObjCMethodDecl *Method) {
1367  CGBuilderTy &Builder = CGF.Builder;
1368 
1369  // Strip out message sends to retain / release in GC mode
1370  if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
1371  if (Sel == RetainSel || Sel == AutoreleaseSel) {
1372  return RValue::get(EnforceType(Builder, Receiver,
1373  CGM.getTypes().ConvertType(ResultType)));
1374  }
1375  if (Sel == ReleaseSel) {
1376  return RValue::get(nullptr);
1377  }
1378  }
1379 
1380  // If the return type is something that goes in an integer register, the
1381  // runtime will handle 0 returns. For other cases, we fill in the 0 value
1382  // ourselves.
1383  //
1384  // The language spec says the result of this kind of message send is
1385  // undefined, but lots of people seem to have forgotten to read that
1386  // paragraph and insist on sending messages to nil that have structure
1387  // returns. With GCC, this generates a random return value (whatever happens
1388  // to be on the stack / in those registers at the time) on most platforms,
1389  // and generates an illegal instruction trap on SPARC. With LLVM it corrupts
1390  // the stack.
1391  bool isPointerSizedReturn = (ResultType->isAnyPointerType() ||
1392  ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType());
1393 
1394  llvm::BasicBlock *startBB = nullptr;
1395  llvm::BasicBlock *messageBB = nullptr;
1396  llvm::BasicBlock *continueBB = nullptr;
1397 
1398  if (!isPointerSizedReturn) {
1399  startBB = Builder.GetInsertBlock();
1400  messageBB = CGF.createBasicBlock("msgSend");
1401  continueBB = CGF.createBasicBlock("continue");
1402 
1403  llvm::Value *isNil = Builder.CreateICmpEQ(Receiver,
1404  llvm::Constant::getNullValue(Receiver->getType()));
1405  Builder.CreateCondBr(isNil, continueBB, messageBB);
1406  CGF.EmitBlock(messageBB);
1407  }
1408 
1409  IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
1410  llvm::Value *cmd;
1411  if (Method)
1412  cmd = GetSelector(CGF, Method);
1413  else
1414  cmd = GetSelector(CGF, Sel);
1415  cmd = EnforceType(Builder, cmd, SelectorTy);
1416  Receiver = EnforceType(Builder, Receiver, IdTy);
1417 
1418  llvm::Metadata *impMD[] = {
1419  llvm::MDString::get(VMContext, Sel.getAsString()),
1420  llvm::MDString::get(VMContext, Class ? Class->getNameAsString() : ""),
1421  llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1422  llvm::Type::getInt1Ty(VMContext), Class != nullptr))};
1423  llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
1424 
1425  CallArgList ActualArgs;
1426  ActualArgs.add(RValue::get(Receiver), ASTIdTy);
1427  ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
1428  ActualArgs.addFrom(CallArgs);
1429 
1430  MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
1431 
1432  // Get the IMP to call
1433  llvm::Value *imp;
1434 
1435  // If we have non-legacy dispatch specified, we try using the objc_msgSend()
1436  // functions. These are not supported on all platforms (or all runtimes on a
1437  // given platform), so we
1438  switch (CGM.getCodeGenOpts().getObjCDispatchMethod()) {
1440  imp = LookupIMP(CGF, Receiver, cmd, node, MSI);
1441  break;
1442  case CodeGenOptions::Mixed:
1444  if (CGM.ReturnTypeUsesFPRet(ResultType)) {
1445  imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
1446  "objc_msgSend_fpret");
1447  } else if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) {
1448  // The actual types here don't matter - we're going to bitcast the
1449  // function anyway
1450  imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
1451  "objc_msgSend_stret");
1452  } else {
1453  imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
1454  "objc_msgSend");
1455  }
1456  }
1457 
1458  // Reset the receiver in case the lookup modified it
1459  ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy, false);
1460 
1461  imp = EnforceType(Builder, imp, MSI.MessengerType);
1462 
1463  llvm::Instruction *call;
1464  CGCallee callee(CGCalleeInfo(), imp);
1465  RValue msgRet = CGF.EmitCall(MSI.CallInfo, callee, Return, ActualArgs, &call);
1466  call->setMetadata(msgSendMDKind, node);
1467 
1468 
1469  if (!isPointerSizedReturn) {
1470  messageBB = CGF.Builder.GetInsertBlock();
1471  CGF.Builder.CreateBr(continueBB);
1472  CGF.EmitBlock(continueBB);
1473  if (msgRet.isScalar()) {
1474  llvm::Value *v = msgRet.getScalarVal();
1475  llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2);
1476  phi->addIncoming(v, messageBB);
1477  phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB);
1478  msgRet = RValue::get(phi);
1479  } else if (msgRet.isAggregate()) {
1480  Address v = msgRet.getAggregateAddress();
1481  llvm::PHINode *phi = Builder.CreatePHI(v.getType(), 2);
1482  llvm::Type *RetTy = v.getElementType();
1483  Address NullVal = CGF.CreateTempAlloca(RetTy, v.getAlignment(), "null");
1484  CGF.InitTempAlloca(NullVal, llvm::Constant::getNullValue(RetTy));
1485  phi->addIncoming(v.getPointer(), messageBB);
1486  phi->addIncoming(NullVal.getPointer(), startBB);
1487  msgRet = RValue::getAggregate(Address(phi, v.getAlignment()));
1488  } else /* isComplex() */ {
1489  std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal();
1490  llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2);
1491  phi->addIncoming(v.first, messageBB);
1492  phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()),
1493  startBB);
1494  llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2);
1495  phi2->addIncoming(v.second, messageBB);
1496  phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()),
1497  startBB);
1498  msgRet = RValue::getComplex(phi, phi2);
1499  }
1500  }
1501  return msgRet;
1502 }
1503 
1504 /// Generates a MethodList. Used in construction of a objc_class and
1505 /// objc_category structures.
1506 llvm::Constant *CGObjCGNU::
1507 GenerateMethodList(StringRef ClassName,
1508  StringRef CategoryName,
1509  ArrayRef<Selector> MethodSels,
1510  ArrayRef<llvm::Constant *> MethodTypes,
1511  bool isClassMethodList) {
1512  if (MethodSels.empty())
1513  return NULLPtr;
1514 
1515  ConstantInitBuilder Builder(CGM);
1516 
1517  auto MethodList = Builder.beginStruct();
1518  MethodList.addNullPointer(CGM.Int8PtrTy);
1519  MethodList.addInt(Int32Ty, MethodTypes.size());
1520 
1521  // Get the method structure type.
1522  llvm::StructType *ObjCMethodTy =
1523  llvm::StructType::get(CGM.getLLVMContext(), {
1524  PtrToInt8Ty, // Really a selector, but the runtime creates it us.
1525  PtrToInt8Ty, // Method types
1526  IMPTy // Method pointer
1527  });
1528  auto Methods = MethodList.beginArray();
1529  for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) {
1530  llvm::Constant *FnPtr =
1531  TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName,
1532  MethodSels[i],
1533  isClassMethodList));
1534  assert(FnPtr && "Can't generate metadata for method that doesn't exist");
1535  auto Method = Methods.beginStruct(ObjCMethodTy);
1536  Method.add(MakeConstantString(MethodSels[i].getAsString()));
1537  Method.add(MethodTypes[i]);
1538  Method.addBitCast(FnPtr, IMPTy);
1539  Method.finishAndAddTo(Methods);
1540  }
1541  Methods.finishAndAddTo(MethodList);
1542 
1543  // Create an instance of the structure
1544  return MethodList.finishAndCreateGlobal(".objc_method_list",
1545  CGM.getPointerAlign());
1546 }
1547 
1548 /// Generates an IvarList. Used in construction of a objc_class.
1549 llvm::Constant *CGObjCGNU::
1550 GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
1551  ArrayRef<llvm::Constant *> IvarTypes,
1552  ArrayRef<llvm::Constant *> IvarOffsets) {
1553  if (IvarNames.empty())
1554  return NULLPtr;
1555 
1556  ConstantInitBuilder Builder(CGM);
1557 
1558  // Structure containing array count followed by array.
1559  auto IvarList = Builder.beginStruct();
1560  IvarList.addInt(IntTy, (int)IvarNames.size());
1561 
1562  // Get the ivar structure type.
1563  llvm::StructType *ObjCIvarTy =
1564  llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, IntTy);
1565 
1566  // Array of ivar structures.
1567  auto Ivars = IvarList.beginArray(ObjCIvarTy);
1568  for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) {
1569  auto Ivar = Ivars.beginStruct(ObjCIvarTy);
1570  Ivar.add(IvarNames[i]);
1571  Ivar.add(IvarTypes[i]);
1572  Ivar.add(IvarOffsets[i]);
1573  Ivar.finishAndAddTo(Ivars);
1574  }
1575  Ivars.finishAndAddTo(IvarList);
1576 
1577  // Create an instance of the structure
1578  return IvarList.finishAndCreateGlobal(".objc_ivar_list",
1579  CGM.getPointerAlign());
1580 }
1581 
1582 /// Generate a class structure
1583 llvm::Constant *CGObjCGNU::GenerateClassStructure(
1584  llvm::Constant *MetaClass,
1585  llvm::Constant *SuperClass,
1586  unsigned info,
1587  const char *Name,
1588  llvm::Constant *Version,
1589  llvm::Constant *InstanceSize,
1590  llvm::Constant *IVars,
1591  llvm::Constant *Methods,
1592  llvm::Constant *Protocols,
1593  llvm::Constant *IvarOffsets,
1594  llvm::Constant *Properties,
1595  llvm::Constant *StrongIvarBitmap,
1596  llvm::Constant *WeakIvarBitmap,
1597  bool isMeta) {
1598  // Set up the class structure
1599  // Note: Several of these are char*s when they should be ids. This is
1600  // because the runtime performs this translation on load.
1601  //
1602  // Fields marked New ABI are part of the GNUstep runtime. We emit them
1603  // anyway; the classes will still work with the GNU runtime, they will just
1604  // be ignored.
1605  llvm::StructType *ClassTy = llvm::StructType::get(
1606  PtrToInt8Ty, // isa
1607  PtrToInt8Ty, // super_class
1608  PtrToInt8Ty, // name
1609  LongTy, // version
1610  LongTy, // info
1611  LongTy, // instance_size
1612  IVars->getType(), // ivars
1613  Methods->getType(), // methods
1614  // These are all filled in by the runtime, so we pretend
1615  PtrTy, // dtable
1616  PtrTy, // subclass_list
1617  PtrTy, // sibling_class
1618  PtrTy, // protocols
1619  PtrTy, // gc_object_type
1620  // New ABI:
1621  LongTy, // abi_version
1622  IvarOffsets->getType(), // ivar_offsets
1623  Properties->getType(), // properties
1624  IntPtrTy, // strong_pointers
1625  IntPtrTy // weak_pointers
1626  );
1627 
1628  ConstantInitBuilder Builder(CGM);
1629  auto Elements = Builder.beginStruct(ClassTy);
1630 
1631  // Fill in the structure
1632 
1633  // isa
1634  Elements.addBitCast(MetaClass, PtrToInt8Ty);
1635  // super_class
1636  Elements.add(SuperClass);
1637  // name
1638  Elements.add(MakeConstantString(Name, ".class_name"));
1639  // version
1640  Elements.addInt(LongTy, 0);
1641  // info
1642  Elements.addInt(LongTy, info);
1643  // instance_size
1644  if (isMeta) {
1645  llvm::DataLayout td(&TheModule);
1646  Elements.addInt(LongTy,
1647  td.getTypeSizeInBits(ClassTy) /
1648  CGM.getContext().getCharWidth());
1649  } else
1650  Elements.add(InstanceSize);
1651  // ivars
1652  Elements.add(IVars);
1653  // methods
1654  Elements.add(Methods);
1655  // These are all filled in by the runtime, so we pretend
1656  // dtable
1657  Elements.add(NULLPtr);
1658  // subclass_list
1659  Elements.add(NULLPtr);
1660  // sibling_class
1661  Elements.add(NULLPtr);
1662  // protocols
1663  Elements.addBitCast(Protocols, PtrTy);
1664  // gc_object_type
1665  Elements.add(NULLPtr);
1666  // abi_version
1667  Elements.addInt(LongTy, 1);
1668  // ivar_offsets
1669  Elements.add(IvarOffsets);
1670  // properties
1671  Elements.add(Properties);
1672  // strong_pointers
1673  Elements.add(StrongIvarBitmap);
1674  // weak_pointers
1675  Elements.add(WeakIvarBitmap);
1676  // Create an instance of the structure
1677  // This is now an externally visible symbol, so that we can speed up class
1678  // messages in the next ABI. We may already have some weak references to
1679  // this, so check and fix them properly.
1680  std::string ClassSym((isMeta ? "_OBJC_METACLASS_": "_OBJC_CLASS_") +
1681  std::string(Name));
1682  llvm::GlobalVariable *ClassRef = TheModule.getNamedGlobal(ClassSym);
1683  llvm::Constant *Class =
1684  Elements.finishAndCreateGlobal(ClassSym, CGM.getPointerAlign(), false,
1686  if (ClassRef) {
1687  ClassRef->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(Class,
1688  ClassRef->getType()));
1689  ClassRef->removeFromParent();
1690  Class->setName(ClassSym);
1691  }
1692  return Class;
1693 }
1694 
1695 llvm::Constant *CGObjCGNU::
1696 GenerateProtocolMethodList(ArrayRef<llvm::Constant *> MethodNames,
1697  ArrayRef<llvm::Constant *> MethodTypes) {
1698  // Get the method structure type.
1699  llvm::StructType *ObjCMethodDescTy =
1700  llvm::StructType::get(CGM.getLLVMContext(), { PtrToInt8Ty, PtrToInt8Ty });
1701  ConstantInitBuilder Builder(CGM);
1702  auto MethodList = Builder.beginStruct();
1703  MethodList.addInt(IntTy, MethodNames.size());
1704  auto Methods = MethodList.beginArray(ObjCMethodDescTy);
1705  for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) {
1706  auto Method = Methods.beginStruct(ObjCMethodDescTy);
1707  Method.add(MethodNames[i]);
1708  Method.add(MethodTypes[i]);
1709  Method.finishAndAddTo(Methods);
1710  }
1711  Methods.finishAndAddTo(MethodList);
1712  return MethodList.finishAndCreateGlobal(".objc_method_list",
1713  CGM.getPointerAlign());
1714 }
1715 
1716 // Create the protocol list structure used in classes, categories and so on
1717 llvm::Constant *
1718 CGObjCGNU::GenerateProtocolList(ArrayRef<std::string> Protocols) {
1719 
1720  ConstantInitBuilder Builder(CGM);
1721  auto ProtocolList = Builder.beginStruct();
1722  ProtocolList.add(NULLPtr);
1723  ProtocolList.addInt(LongTy, Protocols.size());
1724 
1725  auto Elements = ProtocolList.beginArray(PtrToInt8Ty);
1726  for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end();
1727  iter != endIter ; iter++) {
1728  llvm::Constant *protocol = nullptr;
1729  llvm::StringMap<llvm::Constant*>::iterator value =
1730  ExistingProtocols.find(*iter);
1731  if (value == ExistingProtocols.end()) {
1732  protocol = GenerateEmptyProtocol(*iter);
1733  } else {
1734  protocol = value->getValue();
1735  }
1736  Elements.addBitCast(protocol, PtrToInt8Ty);
1737  }
1738  Elements.finishAndAddTo(ProtocolList);
1739  return ProtocolList.finishAndCreateGlobal(".objc_protocol_list",
1740  CGM.getPointerAlign());
1741 }
1742 
1743 llvm::Value *CGObjCGNU::GenerateProtocolRef(CodeGenFunction &CGF,
1744  const ObjCProtocolDecl *PD) {
1745  llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()];
1746  llvm::Type *T =
1748  return CGF.Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T));
1749 }
1750 
1751 llvm::Constant *
1752 CGObjCGNU::GenerateEmptyProtocol(const std::string &ProtocolName) {
1753  llvm::Constant *ProtocolList = GenerateProtocolList({});
1754  llvm::Constant *MethodList = GenerateProtocolMethodList({}, {});
1755  // Protocols are objects containing lists of the methods implemented and
1756  // protocols adopted.
1757  ConstantInitBuilder Builder(CGM);
1758  auto Elements = Builder.beginStruct();
1759 
1760  // The isa pointer must be set to a magic number so the runtime knows it's
1761  // the correct layout.
1762  Elements.add(llvm::ConstantExpr::getIntToPtr(
1763  llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
1764 
1765  Elements.add(MakeConstantString(ProtocolName, ".objc_protocol_name"));
1766  Elements.add(ProtocolList);
1767  Elements.add(MethodList);
1768  Elements.add(MethodList);
1769  Elements.add(MethodList);
1770  Elements.add(MethodList);
1771  return Elements.finishAndCreateGlobal(".objc_protocol",
1772  CGM.getPointerAlign());
1773 }
1774 
1775 void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) {
1776  ASTContext &Context = CGM.getContext();
1777  std::string ProtocolName = PD->getNameAsString();
1778 
1779  // Use the protocol definition, if there is one.
1780  if (const ObjCProtocolDecl *Def = PD->getDefinition())
1781  PD = Def;
1782 
1783  SmallVector<std::string, 16> Protocols;
1784  for (const auto *PI : PD->protocols())
1785  Protocols.push_back(PI->getNameAsString());
1786  SmallVector<llvm::Constant*, 16> InstanceMethodNames;
1787  SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
1788  SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames;
1789  SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes;
1790  for (const auto *I : PD->instance_methods()) {
1791  std::string TypeStr = Context.getObjCEncodingForMethodDecl(I);
1792  if (I->getImplementationControl() == ObjCMethodDecl::Optional) {
1793  OptionalInstanceMethodNames.push_back(
1794  MakeConstantString(I->getSelector().getAsString()));
1795  OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr));
1796  } else {
1797  InstanceMethodNames.push_back(
1798  MakeConstantString(I->getSelector().getAsString()));
1799  InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
1800  }
1801  }
1802  // Collect information about class methods:
1803  SmallVector<llvm::Constant*, 16> ClassMethodNames;
1804  SmallVector<llvm::Constant*, 16> ClassMethodTypes;
1805  SmallVector<llvm::Constant*, 16> OptionalClassMethodNames;
1806  SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes;
1807  for (const auto *I : PD->class_methods()) {
1808  std::string TypeStr = Context.getObjCEncodingForMethodDecl(I);
1809  if (I->getImplementationControl() == ObjCMethodDecl::Optional) {
1810  OptionalClassMethodNames.push_back(
1811  MakeConstantString(I->getSelector().getAsString()));
1812  OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr));
1813  } else {
1814  ClassMethodNames.push_back(
1815  MakeConstantString(I->getSelector().getAsString()));
1816  ClassMethodTypes.push_back(MakeConstantString(TypeStr));
1817  }
1818  }
1819 
1820  llvm::Constant *ProtocolList = GenerateProtocolList(Protocols);
1821  llvm::Constant *InstanceMethodList =
1822  GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes);
1823  llvm::Constant *ClassMethodList =
1824  GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes);
1825  llvm::Constant *OptionalInstanceMethodList =
1826  GenerateProtocolMethodList(OptionalInstanceMethodNames,
1827  OptionalInstanceMethodTypes);
1828  llvm::Constant *OptionalClassMethodList =
1829  GenerateProtocolMethodList(OptionalClassMethodNames,
1830  OptionalClassMethodTypes);
1831 
1832  // Property metadata: name, attributes, isSynthesized, setter name, setter
1833  // types, getter name, getter types.
1834  // The isSynthesized value is always set to 0 in a protocol. It exists to
1835  // simplify the runtime library by allowing it to use the same data
1836  // structures for protocol metadata everywhere.
1837 
1838  llvm::Constant *PropertyList;
1839  llvm::Constant *OptionalPropertyList;
1840  {
1841  llvm::StructType *propertyMetadataTy =
1842  llvm::StructType::get(CGM.getLLVMContext(),
1843  { PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty,
1844  PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty });
1845 
1846  unsigned numReqProperties = 0, numOptProperties = 0;
1847  for (auto property : PD->instance_properties()) {
1848  if (property->isOptional())
1849  numOptProperties++;
1850  else
1851  numReqProperties++;
1852  }
1853 
1854  ConstantInitBuilder reqPropertyListBuilder(CGM);
1855  auto reqPropertiesList = reqPropertyListBuilder.beginStruct();
1856  reqPropertiesList.addInt(IntTy, numReqProperties);
1857  reqPropertiesList.add(NULLPtr);
1858  auto reqPropertiesArray = reqPropertiesList.beginArray(propertyMetadataTy);
1859 
1860  ConstantInitBuilder optPropertyListBuilder(CGM);
1861  auto optPropertiesList = optPropertyListBuilder.beginStruct();
1862  optPropertiesList.addInt(IntTy, numOptProperties);
1863  optPropertiesList.add(NULLPtr);
1864  auto optPropertiesArray = optPropertiesList.beginArray(propertyMetadataTy);
1865 
1866  // Add all of the property methods need adding to the method list and to the
1867  // property metadata list.
1868  for (auto *property : PD->instance_properties()) {
1869  auto &propertiesArray =
1870  (property->isOptional() ? optPropertiesArray : reqPropertiesArray);
1871  auto fields = propertiesArray.beginStruct(propertyMetadataTy);
1872 
1873  fields.add(MakePropertyEncodingString(property, nullptr));
1874  PushPropertyAttributes(fields, property);
1875 
1876  if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) {
1877  std::string typeStr = Context.getObjCEncodingForMethodDecl(getter);
1878  llvm::Constant *typeEncoding = MakeConstantString(typeStr);
1879  InstanceMethodTypes.push_back(typeEncoding);
1880  fields.add(MakeConstantString(getter->getSelector().getAsString()));
1881  fields.add(typeEncoding);
1882  } else {
1883  fields.add(NULLPtr);
1884  fields.add(NULLPtr);
1885  }
1886  if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) {
1887  std::string typeStr = Context.getObjCEncodingForMethodDecl(setter);
1888  llvm::Constant *typeEncoding = MakeConstantString(typeStr);
1889  InstanceMethodTypes.push_back(typeEncoding);
1890  fields.add(MakeConstantString(setter->getSelector().getAsString()));
1891  fields.add(typeEncoding);
1892  } else {
1893  fields.add(NULLPtr);
1894  fields.add(NULLPtr);
1895  }
1896 
1897  fields.finishAndAddTo(propertiesArray);
1898  }
1899 
1900  reqPropertiesArray.finishAndAddTo(reqPropertiesList);
1901  PropertyList =
1902  reqPropertiesList.finishAndCreateGlobal(".objc_property_list",
1903  CGM.getPointerAlign());
1904 
1905  optPropertiesArray.finishAndAddTo(optPropertiesList);
1906  OptionalPropertyList =
1907  optPropertiesList.finishAndCreateGlobal(".objc_property_list",
1908  CGM.getPointerAlign());
1909  }
1910 
1911  // Protocols are objects containing lists of the methods implemented and
1912  // protocols adopted.
1913  // The isa pointer must be set to a magic number so the runtime knows it's
1914  // the correct layout.
1915  ConstantInitBuilder Builder(CGM);
1916  auto Elements = Builder.beginStruct();
1917  Elements.add(
1918  llvm::ConstantExpr::getIntToPtr(
1919  llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
1920  Elements.add(
1921  MakeConstantString(ProtocolName, ".objc_protocol_name"));
1922  Elements.add(ProtocolList);
1923  Elements.add(InstanceMethodList);
1924  Elements.add(ClassMethodList);
1925  Elements.add(OptionalInstanceMethodList);
1926  Elements.add(OptionalClassMethodList);
1927  Elements.add(PropertyList);
1928  Elements.add(OptionalPropertyList);
1929  ExistingProtocols[ProtocolName] =
1930  llvm::ConstantExpr::getBitCast(
1931  Elements.finishAndCreateGlobal(".objc_protocol", CGM.getPointerAlign()),
1932  IdTy);
1933 }
1934 void CGObjCGNU::GenerateProtocolHolderCategory() {
1935  // Collect information about instance methods
1936  SmallVector<Selector, 1> MethodSels;
1937  SmallVector<llvm::Constant*, 1> MethodTypes;
1938 
1939  ConstantInitBuilder Builder(CGM);
1940  auto Elements = Builder.beginStruct();
1941 
1942  const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack";
1943  const std::string CategoryName = "AnotherHack";
1944  Elements.add(MakeConstantString(CategoryName));
1945  Elements.add(MakeConstantString(ClassName));
1946  // Instance method list
1947  Elements.addBitCast(GenerateMethodList(
1948  ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy);
1949  // Class method list
1950  Elements.addBitCast(GenerateMethodList(
1951  ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy);
1952 
1953  // Protocol list
1954  ConstantInitBuilder ProtocolListBuilder(CGM);
1955  auto ProtocolList = ProtocolListBuilder.beginStruct();
1956  ProtocolList.add(NULLPtr);
1957  ProtocolList.addInt(LongTy, ExistingProtocols.size());
1958  auto ProtocolElements = ProtocolList.beginArray(PtrTy);
1959  for (auto iter = ExistingProtocols.begin(), endIter = ExistingProtocols.end();
1960  iter != endIter ; iter++) {
1961  ProtocolElements.addBitCast(iter->getValue(), PtrTy);
1962  }
1963  ProtocolElements.finishAndAddTo(ProtocolList);
1964  Elements.addBitCast(
1965  ProtocolList.finishAndCreateGlobal(".objc_protocol_list",
1966  CGM.getPointerAlign()),
1967  PtrTy);
1968  Categories.push_back(llvm::ConstantExpr::getBitCast(
1969  Elements.finishAndCreateGlobal("", CGM.getPointerAlign()),
1970  PtrTy));
1971 }
1972 
1973 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are
1974 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63
1975 /// bits set to their values, LSB first, while larger ones are stored in a
1976 /// structure of this / form:
1977 ///
1978 /// struct { int32_t length; int32_t values[length]; };
1979 ///
1980 /// The values in the array are stored in host-endian format, with the least
1981 /// significant bit being assumed to come first in the bitfield. Therefore, a
1982 /// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a
1983 /// bitfield / with the 63rd bit set will be 1<<64.
1984 llvm::Constant *CGObjCGNU::MakeBitField(ArrayRef<bool> bits) {
1985  int bitCount = bits.size();
1986  int ptrBits = CGM.getDataLayout().getPointerSizeInBits();
1987  if (bitCount < ptrBits) {
1988  uint64_t val = 1;
1989  for (int i=0 ; i<bitCount ; ++i) {
1990  if (bits[i]) val |= 1ULL<<(i+1);
1991  }
1992  return llvm::ConstantInt::get(IntPtrTy, val);
1993  }
1995  int v=0;
1996  while (v < bitCount) {
1997  int32_t word = 0;
1998  for (int i=0 ; (i<32) && (v<bitCount) ; ++i) {
1999  if (bits[v]) word |= 1<<i;
2000  v++;
2001  }
2002  values.push_back(llvm::ConstantInt::get(Int32Ty, word));
2003  }
2004 
2005  ConstantInitBuilder builder(CGM);
2006  auto fields = builder.beginStruct();
2007  fields.addInt(Int32Ty, values.size());
2008  auto array = fields.beginArray();
2009  for (auto v : values) array.add(v);
2010  array.finishAndAddTo(fields);
2011 
2012  llvm::Constant *GS =
2013  fields.finishAndCreateGlobal("", CharUnits::fromQuantity(4));
2014  llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy);
2015  return ptr;
2016 }
2017 
2018 void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) {
2019  std::string ClassName = OCD->getClassInterface()->getNameAsString();
2020  std::string CategoryName = OCD->getNameAsString();
2021  // Collect information about instance methods
2022  SmallVector<Selector, 16> InstanceMethodSels;
2023  SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
2024  for (const auto *I : OCD->instance_methods()) {
2025  InstanceMethodSels.push_back(I->getSelector());
2026  std::string TypeStr = CGM.getContext().getObjCEncodingForMethodDecl(I);
2027  InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
2028  }
2029 
2030  // Collect information about class methods
2031  SmallVector<Selector, 16> ClassMethodSels;
2032  SmallVector<llvm::Constant*, 16> ClassMethodTypes;
2033  for (const auto *I : OCD->class_methods()) {
2034  ClassMethodSels.push_back(I->getSelector());
2035  std::string TypeStr = CGM.getContext().getObjCEncodingForMethodDecl(I);
2036  ClassMethodTypes.push_back(MakeConstantString(TypeStr));
2037  }
2038 
2039  // Collect the names of referenced protocols
2040  SmallVector<std::string, 16> Protocols;
2041  const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl();
2042  const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols();
2043  for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(),
2044  E = Protos.end(); I != E; ++I)
2045  Protocols.push_back((*I)->getNameAsString());
2046 
2047  ConstantInitBuilder Builder(CGM);
2048  auto Elements = Builder.beginStruct();
2049  Elements.add(MakeConstantString(CategoryName));
2050  Elements.add(MakeConstantString(ClassName));
2051  // Instance method list
2052  Elements.addBitCast(
2053  GenerateMethodList(ClassName, CategoryName, InstanceMethodSels,
2054  InstanceMethodTypes, false),
2055  PtrTy);
2056  // Class method list
2057  Elements.addBitCast(
2058  GenerateMethodList(ClassName, CategoryName, ClassMethodSels,
2059  ClassMethodTypes, true),
2060  PtrTy);
2061  // Protocol list
2062  Elements.addBitCast(GenerateProtocolList(Protocols), PtrTy);
2063  Categories.push_back(llvm::ConstantExpr::getBitCast(
2064  Elements.finishAndCreateGlobal("", CGM.getPointerAlign()),
2065  PtrTy));
2066 }
2067 
2068 llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID,
2069  SmallVectorImpl<Selector> &InstanceMethodSels,
2070  SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) {
2071  ASTContext &Context = CGM.getContext();
2072  // Property metadata: name, attributes, attributes2, padding1, padding2,
2073  // setter name, setter types, getter name, getter types.
2074  llvm::StructType *propertyMetadataTy =
2075  llvm::StructType::get(CGM.getLLVMContext(),
2076  { PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty,
2077  PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty });
2078 
2079  unsigned numProperties = 0;
2080  for (auto *propertyImpl : OID->property_impls()) {
2081  (void) propertyImpl;
2082  numProperties++;
2083  }
2084 
2085  ConstantInitBuilder builder(CGM);
2086  auto propertyList = builder.beginStruct();
2087  propertyList.addInt(IntTy, numProperties);
2088  propertyList.add(NULLPtr);
2089  auto properties = propertyList.beginArray(propertyMetadataTy);
2090 
2091  // Add all of the property methods need adding to the method list and to the
2092  // property metadata list.
2093  for (auto *propertyImpl : OID->property_impls()) {
2094  auto fields = properties.beginStruct(propertyMetadataTy);
2095  ObjCPropertyDecl *property = propertyImpl->getPropertyDecl();
2096  bool isSynthesized = (propertyImpl->getPropertyImplementation() ==
2098  bool isDynamic = (propertyImpl->getPropertyImplementation() ==
2100 
2101  fields.add(MakePropertyEncodingString(property, OID));
2102  PushPropertyAttributes(fields, property, isSynthesized, isDynamic);
2103  if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) {
2104  std::string TypeStr = Context.getObjCEncodingForMethodDecl(getter);
2105  llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
2106  if (isSynthesized) {
2107  InstanceMethodTypes.push_back(TypeEncoding);
2108  InstanceMethodSels.push_back(getter->getSelector());
2109  }
2110  fields.add(MakeConstantString(getter->getSelector().getAsString()));
2111  fields.add(TypeEncoding);
2112  } else {
2113  fields.add(NULLPtr);
2114  fields.add(NULLPtr);
2115  }
2116  if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) {
2117  std::string TypeStr = Context.getObjCEncodingForMethodDecl(setter);
2118  llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
2119  if (isSynthesized) {
2120  InstanceMethodTypes.push_back(TypeEncoding);
2121  InstanceMethodSels.push_back(setter->getSelector());
2122  }
2123  fields.add(MakeConstantString(setter->getSelector().getAsString()));
2124  fields.add(TypeEncoding);
2125  } else {
2126  fields.add(NULLPtr);
2127  fields.add(NULLPtr);
2128  }
2129  fields.finishAndAddTo(properties);
2130  }
2131  properties.finishAndAddTo(propertyList);
2132 
2133  return propertyList.finishAndCreateGlobal(".objc_property_list",
2134  CGM.getPointerAlign());
2135 }
2136 
2137 void CGObjCGNU::RegisterAlias(const ObjCCompatibleAliasDecl *OAD) {
2138  // Get the class declaration for which the alias is specified.
2139  ObjCInterfaceDecl *ClassDecl =
2140  const_cast<ObjCInterfaceDecl *>(OAD->getClassInterface());
2141  ClassAliases.emplace_back(ClassDecl->getNameAsString(),
2142  OAD->getNameAsString());
2143 }
2144 
2145 void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
2146  ASTContext &Context = CGM.getContext();
2147 
2148  // Get the superclass name.
2149  const ObjCInterfaceDecl * SuperClassDecl =
2150  OID->getClassInterface()->getSuperClass();
2151  std::string SuperClassName;
2152  if (SuperClassDecl) {
2153  SuperClassName = SuperClassDecl->getNameAsString();
2154  EmitClassRef(SuperClassName);
2155  }
2156 
2157  // Get the class name
2158  ObjCInterfaceDecl *ClassDecl =
2159  const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
2160  std::string ClassName = ClassDecl->getNameAsString();
2161 
2162  // Emit the symbol that is used to generate linker errors if this class is
2163  // referenced in other modules but not declared.
2164  std::string classSymbolName = "__objc_class_name_" + ClassName;
2165  if (auto *symbol = TheModule.getGlobalVariable(classSymbolName)) {
2166  symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0));
2167  } else {
2168  new llvm::GlobalVariable(TheModule, LongTy, false,
2170  llvm::ConstantInt::get(LongTy, 0),
2171  classSymbolName);
2172  }
2173 
2174  // Get the size of instances.
2175  int instanceSize =
2177 
2178  // Collect information about instance variables.
2182 
2183  ConstantInitBuilder IvarOffsetBuilder(CGM);
2184  auto IvarOffsetValues = IvarOffsetBuilder.beginArray(PtrToIntTy);
2185  SmallVector<bool, 16> WeakIvars;
2186  SmallVector<bool, 16> StrongIvars;
2187 
2188  int superInstanceSize = !SuperClassDecl ? 0 :
2189  Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity();
2190  // For non-fragile ivars, set the instance size to 0 - {the size of just this
2191  // class}. The runtime will then set this to the correct value on load.
2192  if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
2193  instanceSize = 0 - (instanceSize - superInstanceSize);
2194  }
2195 
2196  for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
2197  IVD = IVD->getNextIvar()) {
2198  // Store the name
2199  IvarNames.push_back(MakeConstantString(IVD->getNameAsString()));
2200  // Get the type encoding for this ivar
2201  std::string TypeStr;
2202  Context.getObjCEncodingForType(IVD->getType(), TypeStr, IVD);
2203  IvarTypes.push_back(MakeConstantString(TypeStr));
2204  // Get the offset
2205  uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD);
2206  uint64_t Offset = BaseOffset;
2207  if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
2208  Offset = BaseOffset - superInstanceSize;
2209  }
2210  llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset);
2211  // Create the direct offset value
2212  std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." +
2213  IVD->getNameAsString();
2214  llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName);
2215  if (OffsetVar) {
2216  OffsetVar->setInitializer(OffsetValue);
2217  // If this is the real definition, change its linkage type so that
2218  // different modules will use this one, rather than their private
2219  // copy.
2220  OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage);
2221  } else
2222  OffsetVar = new llvm::GlobalVariable(TheModule, IntTy,
2224  OffsetValue,
2225  "__objc_ivar_offset_value_" + ClassName +"." +
2226  IVD->getNameAsString());
2227  IvarOffsets.push_back(OffsetValue);
2228  IvarOffsetValues.add(OffsetVar);
2229  Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime();
2230  switch (lt) {
2232  StrongIvars.push_back(true);
2233  WeakIvars.push_back(false);
2234  break;
2235  case Qualifiers::OCL_Weak:
2236  StrongIvars.push_back(false);
2237  WeakIvars.push_back(true);
2238  break;
2239  default:
2240  StrongIvars.push_back(false);
2241  WeakIvars.push_back(false);
2242  }
2243  }
2244  llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars);
2245  llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars);
2246  llvm::GlobalVariable *IvarOffsetArray =
2247  IvarOffsetValues.finishAndCreateGlobal(".ivar.offsets",
2248  CGM.getPointerAlign());
2249 
2250  // Collect information about instance methods
2251  SmallVector<Selector, 16> InstanceMethodSels;
2252  SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
2253  for (const auto *I : OID->instance_methods()) {
2254  InstanceMethodSels.push_back(I->getSelector());
2255  std::string TypeStr = Context.getObjCEncodingForMethodDecl(I);
2256  InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
2257  }
2258 
2259  llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels,
2260  InstanceMethodTypes);
2261 
2262  // Collect information about class methods
2263  SmallVector<Selector, 16> ClassMethodSels;
2264  SmallVector<llvm::Constant*, 16> ClassMethodTypes;
2265  for (const auto *I : OID->class_methods()) {
2266  ClassMethodSels.push_back(I->getSelector());
2267  std::string TypeStr = Context.getObjCEncodingForMethodDecl(I);
2268  ClassMethodTypes.push_back(MakeConstantString(TypeStr));
2269  }
2270  // Collect the names of referenced protocols
2271  SmallVector<std::string, 16> Protocols;
2272  for (const auto *I : ClassDecl->protocols())
2273  Protocols.push_back(I->getNameAsString());
2274 
2275  // Get the superclass pointer.
2276  llvm::Constant *SuperClass;
2277  if (!SuperClassName.empty()) {
2278  SuperClass = MakeConstantString(SuperClassName, ".super_class_name");
2279  } else {
2280  SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty);
2281  }
2282  // Empty vector used to construct empty method lists
2284  // Generate the method and instance variable lists
2285  llvm::Constant *MethodList = GenerateMethodList(ClassName, "",
2286  InstanceMethodSels, InstanceMethodTypes, false);
2287  llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "",
2288  ClassMethodSels, ClassMethodTypes, true);
2289  llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes,
2290  IvarOffsets);
2291  // Irrespective of whether we are compiling for a fragile or non-fragile ABI,
2292  // we emit a symbol containing the offset for each ivar in the class. This
2293  // allows code compiled for the non-Fragile ABI to inherit from code compiled
2294  // for the legacy ABI, without causing problems. The converse is also
2295  // possible, but causes all ivar accesses to be fragile.
2296 
2297  // Offset pointer for getting at the correct field in the ivar list when
2298  // setting up the alias. These are: The base address for the global, the
2299  // ivar array (second field), the ivar in this list (set for each ivar), and
2300  // the offset (third field in ivar structure)
2301  llvm::Type *IndexTy = Int32Ty;
2302  llvm::Constant *offsetPointerIndexes[] = {Zeros[0],
2303  llvm::ConstantInt::get(IndexTy, 1), nullptr,
2304  llvm::ConstantInt::get(IndexTy, 2) };
2305 
2306  unsigned ivarIndex = 0;
2307  for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
2308  IVD = IVD->getNextIvar()) {
2309  const std::string Name = "__objc_ivar_offset_" + ClassName + '.'
2310  + IVD->getNameAsString();
2311  offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex);
2312  // Get the correct ivar field
2313  llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr(
2314  cast<llvm::GlobalVariable>(IvarList)->getValueType(), IvarList,
2315  offsetPointerIndexes);
2316  // Get the existing variable, if one exists.
2317  llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name);
2318  if (offset) {
2319  offset->setInitializer(offsetValue);
2320  // If this is the real definition, change its linkage type so that
2321  // different modules will use this one, rather than their private
2322  // copy.
2323  offset->setLinkage(llvm::GlobalValue::ExternalLinkage);
2324  } else {
2325  // Add a new alias if there isn't one already.
2326  offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(),
2327  false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name);
2328  (void) offset; // Silence dead store warning.
2329  }
2330  ++ivarIndex;
2331  }
2332  llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0);
2333 
2334  //Generate metaclass for class methods
2335  llvm::Constant *MetaClassStruct = GenerateClassStructure(
2336  NULLPtr, NULLPtr, 0x12L, ClassName.c_str(), nullptr, Zeros[0],
2337  GenerateIvarList(empty, empty, empty), ClassMethodList, NULLPtr, NULLPtr,
2338  NULLPtr, ZeroPtr, ZeroPtr, true);
2339  if (CGM.getTriple().isOSBinFormatCOFF()) {
2340  auto Storage = llvm::GlobalValue::DefaultStorageClass;
2341  if (OID->getClassInterface()->hasAttr<DLLImportAttr>())
2342  Storage = llvm::GlobalValue::DLLImportStorageClass;
2343  else if (OID->getClassInterface()->hasAttr<DLLExportAttr>())
2344  Storage = llvm::GlobalValue::DLLExportStorageClass;
2345  cast<llvm::GlobalValue>(MetaClassStruct)->setDLLStorageClass(Storage);
2346  }
2347 
2348  // Generate the class structure
2349  llvm::Constant *ClassStruct = GenerateClassStructure(
2350  MetaClassStruct, SuperClass, 0x11L, ClassName.c_str(), nullptr,
2351  llvm::ConstantInt::get(LongTy, instanceSize), IvarList, MethodList,
2352  GenerateProtocolList(Protocols), IvarOffsetArray, Properties,
2353  StrongIvarBitmap, WeakIvarBitmap);
2354  if (CGM.getTriple().isOSBinFormatCOFF()) {
2355  auto Storage = llvm::GlobalValue::DefaultStorageClass;
2356  if (OID->getClassInterface()->hasAttr<DLLImportAttr>())
2357  Storage = llvm::GlobalValue::DLLImportStorageClass;
2358  else if (OID->getClassInterface()->hasAttr<DLLExportAttr>())
2359  Storage = llvm::GlobalValue::DLLExportStorageClass;
2360  cast<llvm::GlobalValue>(ClassStruct)->setDLLStorageClass(Storage);
2361  }
2362 
2363  // Resolve the class aliases, if they exist.
2364  if (ClassPtrAlias) {
2365  ClassPtrAlias->replaceAllUsesWith(
2366  llvm::ConstantExpr::getBitCast(ClassStruct, IdTy));
2367  ClassPtrAlias->eraseFromParent();
2368  ClassPtrAlias = nullptr;
2369  }
2370  if (MetaClassPtrAlias) {
2371  MetaClassPtrAlias->replaceAllUsesWith(
2372  llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy));
2373  MetaClassPtrAlias->eraseFromParent();
2374  MetaClassPtrAlias = nullptr;
2375  }
2376 
2377  // Add class structure to list to be added to the symtab later
2378  ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty);
2379  Classes.push_back(ClassStruct);
2380 }
2381 
2382 llvm::Function *CGObjCGNU::ModuleInitFunction() {
2383  // Only emit an ObjC load function if no Objective-C stuff has been called
2384  if (Classes.empty() && Categories.empty() && ConstantStrings.empty() &&
2385  ExistingProtocols.empty() && SelectorTable.empty())
2386  return nullptr;
2387 
2388  // Add all referenced protocols to a category.
2389  GenerateProtocolHolderCategory();
2390 
2391  llvm::StructType *selStructTy =
2392  dyn_cast<llvm::StructType>(SelectorTy->getElementType());
2393  llvm::Type *selStructPtrTy = SelectorTy;
2394  if (!selStructTy) {
2395  selStructTy = llvm::StructType::get(CGM.getLLVMContext(),
2396  { PtrToInt8Ty, PtrToInt8Ty });
2397  selStructPtrTy = llvm::PointerType::getUnqual(selStructTy);
2398  }
2399 
2400  // Generate statics list:
2401  llvm::Constant *statics = NULLPtr;
2402  if (!ConstantStrings.empty()) {
2403  llvm::GlobalVariable *fileStatics = [&] {
2404  ConstantInitBuilder builder(CGM);
2405  auto staticsStruct = builder.beginStruct();
2406 
2407  StringRef stringClass = CGM.getLangOpts().ObjCConstantStringClass;
2408  if (stringClass.empty()) stringClass = "NXConstantString";
2409  staticsStruct.add(MakeConstantString(stringClass,
2410  ".objc_static_class_name"));
2411 
2412  auto array = staticsStruct.beginArray();
2413  array.addAll(ConstantStrings);
2414  array.add(NULLPtr);
2415  array.finishAndAddTo(staticsStruct);
2416 
2417  return staticsStruct.finishAndCreateGlobal(".objc_statics",
2418  CGM.getPointerAlign());
2419  }();
2420 
2421  ConstantInitBuilder builder(CGM);
2422  auto allStaticsArray = builder.beginArray(fileStatics->getType());
2423  allStaticsArray.add(fileStatics);
2424  allStaticsArray.addNullPointer(fileStatics->getType());
2425 
2426  statics = allStaticsArray.finishAndCreateGlobal(".objc_statics_ptr",
2427  CGM.getPointerAlign());
2428  statics = llvm::ConstantExpr::getBitCast(statics, PtrTy);
2429  }
2430 
2431  // Array of classes, categories, and constant objects.
2432 
2433  SmallVector<llvm::GlobalAlias*, 16> selectorAliases;
2434  unsigned selectorCount;
2435 
2436  // Pointer to an array of selectors used in this module.
2437  llvm::GlobalVariable *selectorList = [&] {
2438  ConstantInitBuilder builder(CGM);
2439  auto selectors = builder.beginArray(selStructTy);
2440  auto &table = SelectorTable; // MSVC workaround
2441  for (auto &entry : table) {
2442 
2443  std::string selNameStr = entry.first.getAsString();
2444  llvm::Constant *selName = ExportUniqueString(selNameStr, ".objc_sel_name");
2445 
2446  for (TypedSelector &sel : entry.second) {
2447  llvm::Constant *selectorTypeEncoding = NULLPtr;
2448  if (!sel.first.empty())
2449  selectorTypeEncoding =
2450  MakeConstantString(sel.first, ".objc_sel_types");
2451 
2452  auto selStruct = selectors.beginStruct(selStructTy);
2453  selStruct.add(selName);
2454  selStruct.add(selectorTypeEncoding);
2455  selStruct.finishAndAddTo(selectors);
2456 
2457  // Store the selector alias for later replacement
2458  selectorAliases.push_back(sel.second);
2459  }
2460  }
2461 
2462  // Remember the number of entries in the selector table.
2463  selectorCount = selectors.size();
2464 
2465  // NULL-terminate the selector list. This should not actually be required,
2466  // because the selector list has a length field. Unfortunately, the GCC
2467  // runtime decides to ignore the length field and expects a NULL terminator,
2468  // and GCC cooperates with this by always setting the length to 0.
2469  auto selStruct = selectors.beginStruct(selStructTy);
2470  selStruct.add(NULLPtr);
2471  selStruct.add(NULLPtr);
2472  selStruct.finishAndAddTo(selectors);
2473 
2474  return selectors.finishAndCreateGlobal(".objc_selector_list",
2475  CGM.getPointerAlign());
2476  }();
2477 
2478  // Now that all of the static selectors exist, create pointers to them.
2479  for (unsigned i = 0; i < selectorCount; ++i) {
2480  llvm::Constant *idxs[] = {
2481  Zeros[0],
2482  llvm::ConstantInt::get(Int32Ty, i)
2483  };
2484  // FIXME: We're generating redundant loads and stores here!
2485  llvm::Constant *selPtr = llvm::ConstantExpr::getGetElementPtr(
2486  selectorList->getValueType(), selectorList, idxs);
2487  // If selectors are defined as an opaque type, cast the pointer to this
2488  // type.
2489  selPtr = llvm::ConstantExpr::getBitCast(selPtr, SelectorTy);
2490  selectorAliases[i]->replaceAllUsesWith(selPtr);
2491  selectorAliases[i]->eraseFromParent();
2492  }
2493 
2494  llvm::GlobalVariable *symtab = [&] {
2495  ConstantInitBuilder builder(CGM);
2496  auto symtab = builder.beginStruct();
2497 
2498  // Number of static selectors
2499  symtab.addInt(LongTy, selectorCount);
2500 
2501  symtab.addBitCast(selectorList, selStructPtrTy);
2502 
2503  // Number of classes defined.
2504  symtab.addInt(CGM.Int16Ty, Classes.size());
2505  // Number of categories defined
2506  symtab.addInt(CGM.Int16Ty, Categories.size());
2507 
2508  // Create an array of classes, then categories, then static object instances
2509  auto classList = symtab.beginArray(PtrToInt8Ty);
2510  classList.addAll(Classes);
2511  classList.addAll(Categories);
2512  // NULL-terminated list of static object instances (mainly constant strings)
2513  classList.add(statics);
2514  classList.add(NULLPtr);
2515  classList.finishAndAddTo(symtab);
2516 
2517  // Construct the symbol table.
2518  return symtab.finishAndCreateGlobal("", CGM.getPointerAlign());
2519  }();
2520 
2521  // The symbol table is contained in a module which has some version-checking
2522  // constants
2523  llvm::Constant *module = [&] {
2524  llvm::Type *moduleEltTys[] = {
2525  LongTy, LongTy, PtrToInt8Ty, symtab->getType(), IntTy
2526  };
2527  llvm::StructType *moduleTy =
2528  llvm::StructType::get(CGM.getLLVMContext(),
2529  makeArrayRef(moduleEltTys).drop_back(unsigned(RuntimeVersion < 10)));
2530 
2531  ConstantInitBuilder builder(CGM);
2532  auto module = builder.beginStruct(moduleTy);
2533  // Runtime version, used for ABI compatibility checking.
2534  module.addInt(LongTy, RuntimeVersion);
2535  // sizeof(ModuleTy)
2536  module.addInt(LongTy, CGM.getDataLayout().getTypeStoreSize(moduleTy));
2537 
2538  // The path to the source file where this module was declared
2540  const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID());
2541  std::string path =
2542  (Twine(mainFile->getDir()->getName()) + "/" + mainFile->getName()).str();
2543  module.add(MakeConstantString(path, ".objc_source_file_name"));
2544  module.add(symtab);
2545 
2546  if (RuntimeVersion >= 10) {
2547  switch (CGM.getLangOpts().getGC()) {
2548  case LangOptions::GCOnly:
2549  module.addInt(IntTy, 2);
2550  break;
2551  case LangOptions::NonGC:
2552  if (CGM.getLangOpts().ObjCAutoRefCount)
2553  module.addInt(IntTy, 1);
2554  else
2555  module.addInt(IntTy, 0);
2556  break;
2557  case LangOptions::HybridGC:
2558  module.addInt(IntTy, 1);
2559  break;
2560  }
2561  }
2562 
2563  return module.finishAndCreateGlobal("", CGM.getPointerAlign());
2564  }();
2565 
2566  // Create the load function calling the runtime entry point with the module
2567  // structure
2568  llvm::Function * LoadFunction = llvm::Function::Create(
2569  llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false),
2570  llvm::GlobalValue::InternalLinkage, ".objc_load_function",
2571  &TheModule);
2572  llvm::BasicBlock *EntryBB =
2573  llvm::BasicBlock::Create(VMContext, "entry", LoadFunction);
2574  CGBuilderTy Builder(CGM, VMContext);
2575  Builder.SetInsertPoint(EntryBB);
2576 
2577  llvm::FunctionType *FT =
2578  llvm::FunctionType::get(Builder.getVoidTy(), module->getType(), true);
2579  llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class");
2580  Builder.CreateCall(Register, module);
2581 
2582  if (!ClassAliases.empty()) {
2583  llvm::Type *ArgTypes[2] = {PtrTy, PtrToInt8Ty};
2584  llvm::FunctionType *RegisterAliasTy =
2585  llvm::FunctionType::get(Builder.getVoidTy(),
2586  ArgTypes, false);
2587  llvm::Function *RegisterAlias = llvm::Function::Create(
2588  RegisterAliasTy,
2589  llvm::GlobalValue::ExternalWeakLinkage, "class_registerAlias_np",
2590  &TheModule);
2591  llvm::BasicBlock *AliasBB =
2592  llvm::BasicBlock::Create(VMContext, "alias", LoadFunction);
2593  llvm::BasicBlock *NoAliasBB =
2594  llvm::BasicBlock::Create(VMContext, "no_alias", LoadFunction);
2595 
2596  // Branch based on whether the runtime provided class_registerAlias_np()
2597  llvm::Value *HasRegisterAlias = Builder.CreateICmpNE(RegisterAlias,
2598  llvm::Constant::getNullValue(RegisterAlias->getType()));
2599  Builder.CreateCondBr(HasRegisterAlias, AliasBB, NoAliasBB);
2600 
2601  // The true branch (has alias registration function):
2602  Builder.SetInsertPoint(AliasBB);
2603  // Emit alias registration calls:
2604  for (std::vector<ClassAliasPair>::iterator iter = ClassAliases.begin();
2605  iter != ClassAliases.end(); ++iter) {
2606  llvm::Constant *TheClass =
2607  TheModule.getGlobalVariable("_OBJC_CLASS_" + iter->first, true);
2608  if (TheClass) {
2609  TheClass = llvm::ConstantExpr::getBitCast(TheClass, PtrTy);
2610  Builder.CreateCall(RegisterAlias,
2611  {TheClass, MakeConstantString(iter->second)});
2612  }
2613  }
2614  // Jump to end:
2615  Builder.CreateBr(NoAliasBB);
2616 
2617  // Missing alias registration function, just return from the function:
2618  Builder.SetInsertPoint(NoAliasBB);
2619  }
2620  Builder.CreateRetVoid();
2621 
2622  return LoadFunction;
2623 }
2624 
2625 llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD,
2626  const ObjCContainerDecl *CD) {
2627  const ObjCCategoryImplDecl *OCD =
2628  dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext());
2629  StringRef CategoryName = OCD ? OCD->getName() : "";
2630  StringRef ClassName = CD->getName();
2631  Selector MethodName = OMD->getSelector();
2632  bool isClassMethod = !OMD->isInstanceMethod();
2633 
2634  CodeGenTypes &Types = CGM.getTypes();
2635  llvm::FunctionType *MethodTy =
2637  std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName,
2638  MethodName, isClassMethod);
2639 
2640  llvm::Function *Method
2641  = llvm::Function::Create(MethodTy,
2643  FunctionName,
2644  &TheModule);
2645  return Method;
2646 }
2647 
2648 llvm::Constant *CGObjCGNU::GetPropertyGetFunction() {
2649  return GetPropertyFn;
2650 }
2651 
2652 llvm::Constant *CGObjCGNU::GetPropertySetFunction() {
2653  return SetPropertyFn;
2654 }
2655 
2656 llvm::Constant *CGObjCGNU::GetOptimizedPropertySetFunction(bool atomic,
2657  bool copy) {
2658  return nullptr;
2659 }
2660 
2661 llvm::Constant *CGObjCGNU::GetGetStructFunction() {
2662  return GetStructPropertyFn;
2663 }
2664 
2665 llvm::Constant *CGObjCGNU::GetSetStructFunction() {
2666  return SetStructPropertyFn;
2667 }
2668 
2669 llvm::Constant *CGObjCGNU::GetCppAtomicObjectGetFunction() {
2670  return nullptr;
2671 }
2672 
2673 llvm::Constant *CGObjCGNU::GetCppAtomicObjectSetFunction() {
2674  return nullptr;
2675 }
2676 
2677 llvm::Constant *CGObjCGNU::EnumerationMutationFunction() {
2678  return EnumerationMutationFn;
2679 }
2680 
2681 void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF,
2682  const ObjCAtSynchronizedStmt &S) {
2683  EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn);
2684 }
2685 
2686 
2687 void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF,
2688  const ObjCAtTryStmt &S) {
2689  // Unlike the Apple non-fragile runtimes, which also uses
2690  // unwind-based zero cost exceptions, the GNU Objective C runtime's
2691  // EH support isn't a veneer over C++ EH. Instead, exception
2692  // objects are created by objc_exception_throw and destroyed by
2693  // the personality function; this avoids the need for bracketing
2694  // catch handlers with calls to __blah_begin_catch/__blah_end_catch
2695  // (or even _Unwind_DeleteException), but probably doesn't
2696  // interoperate very well with foreign exceptions.
2697  //
2698  // In Objective-C++ mode, we actually emit something equivalent to the C++
2699  // exception handler.
2700  EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn);
2701 }
2702 
2703 void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF,
2704  const ObjCAtThrowStmt &S,
2705  bool ClearInsertionPoint) {
2706  llvm::Value *ExceptionAsObject;
2707 
2708  if (const Expr *ThrowExpr = S.getThrowExpr()) {
2709  llvm::Value *Exception = CGF.EmitObjCThrowOperand(ThrowExpr);
2710  ExceptionAsObject = Exception;
2711  } else {
2712  assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) &&
2713  "Unexpected rethrow outside @catch block.");
2714  ExceptionAsObject = CGF.ObjCEHValueStack.back();
2715  }
2716  ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy);
2717  llvm::CallSite Throw =
2718  CGF.EmitRuntimeCallOrInvoke(ExceptionThrowFn, ExceptionAsObject);
2719  Throw.setDoesNotReturn();
2720  CGF.Builder.CreateUnreachable();
2721  if (ClearInsertionPoint)
2722  CGF.Builder.ClearInsertionPoint();
2723 }
2724 
2725 llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF,
2726  Address AddrWeakObj) {
2727  CGBuilderTy &B = CGF.Builder;
2728  AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy);
2729  return B.CreateCall(WeakReadFn.getType(), WeakReadFn,
2730  AddrWeakObj.getPointer());
2731 }
2732 
2733 void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF,
2734  llvm::Value *src, Address dst) {
2735  CGBuilderTy &B = CGF.Builder;
2736  src = EnforceType(B, src, IdTy);
2737  dst = EnforceType(B, dst, PtrToIdTy);
2738  B.CreateCall(WeakAssignFn.getType(), WeakAssignFn,
2739  {src, dst.getPointer()});
2740 }
2741 
2742 void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF,
2743  llvm::Value *src, Address dst,
2744  bool threadlocal) {
2745  CGBuilderTy &B = CGF.Builder;
2746  src = EnforceType(B, src, IdTy);
2747  dst = EnforceType(B, dst, PtrToIdTy);
2748  // FIXME. Add threadloca assign API
2749  assert(!threadlocal && "EmitObjCGlobalAssign - Threal Local API NYI");
2750  B.CreateCall(GlobalAssignFn.getType(), GlobalAssignFn,
2751  {src, dst.getPointer()});
2752 }
2753 
2754 void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF,
2755  llvm::Value *src, Address dst,
2756  llvm::Value *ivarOffset) {
2757  CGBuilderTy &B = CGF.Builder;
2758  src = EnforceType(B, src, IdTy);
2759  dst = EnforceType(B, dst, IdTy);
2760  B.CreateCall(IvarAssignFn.getType(), IvarAssignFn,
2761  {src, dst.getPointer(), ivarOffset});
2762 }
2763 
2764 void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF,
2765  llvm::Value *src, Address dst) {
2766  CGBuilderTy &B = CGF.Builder;
2767  src = EnforceType(B, src, IdTy);
2768  dst = EnforceType(B, dst, PtrToIdTy);
2769  B.CreateCall(StrongCastAssignFn.getType(), StrongCastAssignFn,
2770  {src, dst.getPointer()});
2771 }
2772 
2773 void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF,
2774  Address DestPtr,
2775  Address SrcPtr,
2776  llvm::Value *Size) {
2777  CGBuilderTy &B = CGF.Builder;
2778  DestPtr = EnforceType(B, DestPtr, PtrTy);
2779  SrcPtr = EnforceType(B, SrcPtr, PtrTy);
2780 
2781  B.CreateCall(MemMoveFn.getType(), MemMoveFn,
2782  {DestPtr.getPointer(), SrcPtr.getPointer(), Size});
2783 }
2784 
2785 llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable(
2786  const ObjCInterfaceDecl *ID,
2787  const ObjCIvarDecl *Ivar) {
2788  const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString()
2789  + '.' + Ivar->getNameAsString();
2790  // Emit the variable and initialize it with what we think the correct value
2791  // is. This allows code compiled with non-fragile ivars to work correctly
2792  // when linked against code which isn't (most of the time).
2793  llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name);
2794  if (!IvarOffsetPointer) {
2795  // This will cause a run-time crash if we accidentally use it. A value of
2796  // 0 would seem more sensible, but will silently overwrite the isa pointer
2797  // causing a great deal of confusion.
2798  uint64_t Offset = -1;
2799  // We can't call ComputeIvarBaseOffset() here if we have the
2800  // implementation, because it will create an invalid ASTRecordLayout object
2801  // that we are then stuck with forever, so we only initialize the ivar
2802  // offset variable with a guess if we only have the interface. The
2803  // initializer will be reset later anyway, when we are generating the class
2804  // description.
2805  if (!CGM.getContext().getObjCImplementation(
2806  const_cast<ObjCInterfaceDecl *>(ID)))
2807  Offset = ComputeIvarBaseOffset(CGM, ID, Ivar);
2808 
2809  llvm::ConstantInt *OffsetGuess = llvm::ConstantInt::get(Int32Ty, Offset,
2810  /*isSigned*/true);
2811  // Don't emit the guess in non-PIC code because the linker will not be able
2812  // to replace it with the real version for a library. In non-PIC code you
2813  // must compile with the fragile ABI if you want to use ivars from a
2814  // GCC-compiled class.
2815  if (CGM.getLangOpts().PICLevel) {
2816  llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule,
2817  Int32Ty, false,
2818  llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess");
2819  IvarOffsetPointer = new llvm::GlobalVariable(TheModule,
2820  IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage,
2821  IvarOffsetGV, Name);
2822  } else {
2823  IvarOffsetPointer = new llvm::GlobalVariable(TheModule,
2824  llvm::Type::getInt32PtrTy(VMContext), false,
2825  llvm::GlobalValue::ExternalLinkage, nullptr, Name);
2826  }
2827  }
2828  return IvarOffsetPointer;
2829 }
2830 
2831 LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF,
2832  QualType ObjectTy,
2833  llvm::Value *BaseValue,
2834  const ObjCIvarDecl *Ivar,
2835  unsigned CVRQualifiers) {
2836  const ObjCInterfaceDecl *ID =
2837  ObjectTy->getAs<ObjCObjectType>()->getInterface();
2838  return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers,
2839  EmitIvarOffset(CGF, ID, Ivar));
2840 }
2841 
2843  const ObjCInterfaceDecl *OID,
2844  const ObjCIvarDecl *OIVD) {
2845  for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next;
2846  next = next->getNextIvar()) {
2847  if (OIVD == next)
2848  return OID;
2849  }
2850 
2851  // Otherwise check in the super class.
2852  if (const ObjCInterfaceDecl *Super = OID->getSuperClass())
2853  return FindIvarInterface(Context, Super, OIVD);
2854 
2855  return nullptr;
2856 }
2857 
2858 llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF,
2859  const ObjCInterfaceDecl *Interface,
2860  const ObjCIvarDecl *Ivar) {
2861  if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
2862  Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar);
2863 
2864  // The MSVC linker cannot have a single global defined as LinkOnceAnyLinkage
2865  // and ExternalLinkage, so create a reference to the ivar global and rely on
2866  // the definition being created as part of GenerateClass.
2867  if (RuntimeVersion < 10 ||
2868  CGF.CGM.getTarget().getTriple().isKnownWindowsMSVCEnvironment())
2869  return CGF.Builder.CreateZExtOrBitCast(
2871  Int32Ty, CGF.Builder.CreateAlignedLoad(
2872  ObjCIvarOffsetVariable(Interface, Ivar),
2873  CGF.getPointerAlign(), "ivar"),
2875  PtrDiffTy);
2876  std::string name = "__objc_ivar_offset_value_" +
2877  Interface->getNameAsString() +"." + Ivar->getNameAsString();
2878  CharUnits Align = CGM.getIntAlign();
2879  llvm::Value *Offset = TheModule.getGlobalVariable(name);
2880  if (!Offset) {
2881  auto GV = new llvm::GlobalVariable(TheModule, IntTy,
2882  false, llvm::GlobalValue::LinkOnceAnyLinkage,
2883  llvm::Constant::getNullValue(IntTy), name);
2884  GV->setAlignment(Align.getQuantity());
2885  Offset = GV;
2886  }
2887  Offset = CGF.Builder.CreateAlignedLoad(Offset, Align);
2888  if (Offset->getType() != PtrDiffTy)
2889  Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy);
2890  return Offset;
2891  }
2892  uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar);
2893  return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true);
2894 }
2895 
2896 CGObjCRuntime *
2898  switch (CGM.getLangOpts().ObjCRuntime.getKind()) {
2899  case ObjCRuntime::GNUstep:
2900  return new CGObjCGNUstep(CGM);
2901 
2902  case ObjCRuntime::GCC:
2903  return new CGObjCGCC(CGM);
2904 
2905  case ObjCRuntime::ObjFW:
2906  return new CGObjCObjFW(CGM);
2907 
2909  case ObjCRuntime::MacOSX:
2910  case ObjCRuntime::iOS:
2911  case ObjCRuntime::WatchOS:
2912  llvm_unreachable("these runtimes are not GNU runtimes");
2913  }
2914  llvm_unreachable("bad runtime");
2915 }
bool isAggregate() const
Definition: CGValue.h:54
const llvm::DataLayout & getDataLayout() const
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:281
const ObjCInterfaceType * getInterfaceType() const
If this pointer points to an Objective C @interface type, gets the type for that interface.
Definition: Type.cpp:1507
Defines the clang::ASTContext interface.
static std::string SymbolNameForMethod(StringRef ClassName, StringRef CategoryName, const Selector MethodName, bool isClassMethod)
Definition: CGObjCGNU.cpp:881
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:61
protocol_range protocols() const
Definition: DeclObjC.h:1385
Smart pointer class that efficiently represents Objective-C method names.
QualType getObjCIdType() const
Represents the Objective-CC id type.
Definition: ASTContext.h:1800
A (possibly-)qualified type.
Definition: Type.h:653
bool ReturnTypeUsesSRet(const CGFunctionInfo &FI)
Return true iff the given type uses &#39;sret&#39; when used as a return type.
Definition: CGCall.cpp:1481
Represents a version number in the form major[.minor[.subminor[.build]]].
Definition: VersionTuple.h:26
const CodeGenOptions & getCodeGenOpts() const
iterator begin() const
Definition: DeclObjC.h:91
Defines the clang::FileManager interface and associated types.
llvm::LLVMContext & getLLVMContext()
QualType getPointerDiffType() const
Return the unique type for "ptrdiff_t" (C99 7.17) defined in <stddef.h>.
The standard implementation of ConstantInitBuilder used in Clang.
const ObjCProtocolList & getReferencedProtocols() const
Definition: DeclObjC.h:2368
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:790
Implements runtime-specific code generation functions.
Definition: CGObjCRuntime.h:63
Defines the SourceManager interface.
const ASTRecordLayout & getASTObjCImplementationLayout(const ObjCImplementationDecl *D) const
Get or compute information about the layout of the specified Objective-C implementation.
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:86
const Decl * CurCodeDecl
CurCodeDecl - This is the inner-most code context, which includes blocks.
static void add(Kind k)
Definition: DeclBase.cpp:193
Represents Objective-C&#39;s @throw statement.
Definition: StmtObjC.h:313
CanQualType LongTy
Definition: ASTContext.h:1004
bool isOptional() const
Definition: DeclObjC.h:954
&#39;gcc&#39; is the Objective-C runtime shipped with GCC, implementing a fragile Objective-C ABI ...
Definition: ObjCRuntime.h:50
VarDecl - An instance of this class is created to represent a variable declaration or definition...
Definition: Decl.h:807
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6307
llvm::GlobalVariable * finishAndCreateGlobal(As &&...args)
Given that this builder was created by beginning an array or struct directly on a ConstantInitBuilder...
ObjCMethodDecl - Represents an instance or class method declaration.
Definition: DeclObjC.h:139
ObjCImplementationDecl * getObjCImplementation(ObjCInterfaceDecl *D)
Get the implementation of the ObjCInterfaceDecl D, or nullptr if none exists.
llvm::Value * getPointer() const
Definition: Address.h:38
Defines the Objective-C statement AST node classes.
classmeth_range class_methods() const
Definition: DeclObjC.h:1089
protocol_range protocols() const
Definition: DeclObjC.h:2148
iterator end() const
Definition: DeclObjC.h:92
llvm::Value * EmitObjCThrowOperand(const Expr *expr)
Definition: CGObjC.cpp:3018
IdentifierInfo * getIdentifier() const
getIdentifier - Get the identifier that names this declaration, if there is one.
Definition: Decl.h:265
instprop_range instance_properties() const
Definition: DeclObjC.h:1021
One of these records is kept for each identifier that is lexed.
&#39;macosx-fragile&#39; is the Apple-provided NeXT-derived runtime on Mac OS X platforms that use the fragil...
Definition: ObjCRuntime.h:37
This table allows us to fully hide how we implement multi-keyword caching.
Represents a class type in Objective C.
Definition: Type.h:5186
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
llvm::Type * ConvertType(QualType T)
ConvertType - Convert type T into a llvm::Type.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:149
bool isObjCIdType() const
Definition: Type.h:6070
static const ObjCInterfaceDecl * FindIvarInterface(ASTContext &Context, const ObjCInterfaceDecl *OID, const ObjCIvarDecl *OIVD)
Definition: CGObjCGNU.cpp:2842
instmeth_range instance_methods() const
Definition: DeclObjC.h:1072
ObjCMethodDecl * getSetterMethodDecl() const
Definition: DeclObjC.h:942
virtual bool isDynamic(OpenMPScheduleClauseKind ScheduleKind) const
Check if the specified ScheduleKind is dynamic.
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:53
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:48
const ASTRecordLayout & getASTObjCInterfaceLayout(const ObjCInterfaceDecl *D) const
Get or compute information about the layout of the specified Objective-C interface.
void InitTempAlloca(Address Alloca, llvm::Value *Value)
InitTempAlloca - Provide an initial value for the given alloca which will be observable at all locati...
Definition: CGExpr.cpp:114
bool isIntegralOrEnumerationType() const
Determine whether this type is an integral or enumeration type.
Definition: Type.h:6221
IdentifierTable & Idents
Definition: ASTContext.h:537
bool isNonFragile() const
Does this runtime follow the set of implied behaviors for a "non-fragile" ABI?
Definition: ObjCRuntime.h:80
ObjCContainerDecl - Represents a container for method declarations.
Definition: DeclObjC.h:986
const Expr * getThrowExpr() const
Definition: StmtObjC.h:325
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:38
uint32_t Offset
Definition: CacheTokens.cpp:43
CharUnits getAlignment() const
Return the alignment of this pointer.
Definition: Address.h:67
Selector GetNullarySelector(StringRef name, ASTContext &Ctx)
Utility function for constructing a nullary selector.
Definition: ASTContext.h:2845
ObjCProtocolDecl * getDefinition()
Retrieve the definition of this protocol, if any.
Definition: DeclObjC.h:2229
llvm::BasicBlock * createBasicBlock(const Twine &name="", llvm::Function *parent=nullptr, llvm::BasicBlock *before=nullptr)
createBasicBlock - Create an LLVM basic block.
Represents an Objective-C protocol declaration.
Definition: DeclObjC.h:2083
llvm::AllocaInst * CreateTempAlloca(llvm::Type *Ty, const Twine &Name="tmp", llvm::Value *ArraySize=nullptr)
CreateTempAlloca - This creates an alloca and inserts it into the entry block if ArraySize is nullptr...
Definition: CGExpr.cpp:94
Represents an ObjC class declaration.
Definition: DeclObjC.h:1191
ObjCInterfaceDecl * getInterface() const
Gets the interface declaration for this object type, if the base type really is an interface...
Definition: Type.h:5421
QualType getObjCProtoType() const
Retrieve the type of the Objective-C Protocol class.
Definition: ASTContext.h:1846
Address getAggregateAddress() const
getAggregateAddr() - Return the Value* of the address of the aggregate.
Definition: CGValue.h:71
std::string getObjCEncodingForMethodDecl(const ObjCMethodDecl *Decl, bool Extended=false) const
Emit the encoded type for the method declaration Decl into S.
llvm::Constant * CreateRuntimeFunction(llvm::FunctionType *Ty, StringRef Name, llvm::AttributeList ExtraAttrs=llvm::AttributeList(), bool Local=false)
Create a new runtime function with the specified type and name.
lookup_result lookup(DeclarationName Name) const
lookup - Find the declarations (if any) with the given Name in this context.
Definition: DeclBase.cpp:1521
&#39;watchos&#39; is a variant of iOS for Apple&#39;s watchOS.
Definition: ObjCRuntime.h:46
bool hasAttr() const
Definition: DeclBase.h:535
StringRef getString() const
Definition: Expr.h:1557
void addFrom(const CallArgList &other)
Add all the arguments from another CallArgList to this one.
Definition: CGCall.h:214
llvm::CallInst * EmitNounwindRuntimeCall(llvm::Value *callee, const Twine &name="")
CGBlockInfo - Information to generate a block literal.
Definition: CGBlocks.h:149
RValue - This trivial value class is used to represent the result of an expression that is evaluated...
Definition: CGValue.h:39
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
Expr - This represents one expression.
Definition: Expr.h:106
&#39;macosx&#39; is the Apple-provided NeXT-derived runtime on Mac OS X platforms that use the non-fragile AB...
Definition: ObjCRuntime.h:32
llvm::StringRef getAsString(SyncScope S)
Definition: SyncScope.h:51
const FileEntry * getFileEntryForID(FileID FID) const
Returns the FileEntry record for the provided FileID.
const FunctionProtoType * T
std::pair< llvm::Value *, llvm::Value * > getComplexVal() const
getComplexVal - Return the real/imag components of this complex value.
Definition: CGValue.h:66
std::string getObjCEncodingForPropertyDecl(const ObjCPropertyDecl *PD, const Decl *Container) const
getObjCEncodingForPropertyDecl - Return the encoded type for this method declaration.
llvm::PointerType * getType() const
Return the type of the pointer value.
Definition: Address.h:44
DeclContext * getDeclContext()
Definition: DeclBase.h:425
Represents Objective-C&#39;s @synchronized statement.
Definition: StmtObjC.h:262
ObjCInterfaceDecl * getSuperClass() const
Definition: DeclObjC.cpp:330
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:63
void add(RValue rvalue, QualType type, bool needscopy=false)
Definition: CGCall.h:207
clang::ObjCRuntime ObjCRuntime
Definition: LangOptions.h:117
propimpl_range property_impls() const
Definition: DeclObjC.h:2486
bool isa(CodeGen::Address addr)
Definition: Address.h:112
bool isInstanceMethod() const
Definition: DeclObjC.h:452
const TargetInfo & getTarget() const
Selector getSelector() const
Definition: DeclObjC.h:359
&#39;gnustep&#39; is the modern non-fragile GNUstep runtime.
Definition: ObjCRuntime.h:53
const LangOptions & getLangOpts() const
ASTContext & getContext() const
do v
Definition: arm_acle.h:78
const SourceManager & SM
Definition: Format.cpp:1337
The l-value was considered opaque, so the alignment was determined from a type.
const DirectoryEntry * getDir() const
Return the directory the file lives in.
Definition: FileManager.h:94
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:142
std::string getAsString() const
Derive the full selector name (e.g.
Assigning into this object requires the old value to be released and the new value to be retained...
Definition: Type.h:180
bool ReturnTypeUsesFPRet(QualType ResultType)
Return true iff the given type uses &#39;fpret&#39; when used as a return type.
Definition: CGCall.cpp:1490
ObjCInterfaceDecl * getDecl() const
Get the declaration of this interface.
Definition: Type.h:5399
static DeclContext * castToDeclContext(const TranslationUnitDecl *D)
Definition: Decl.h:129
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
StringRef getName() const
Definition: FileManager.h:84
Interfaces are the core concept in Objective-C for object oriented design.
Definition: Type.h:5386
&#39;objfw&#39; is the Objective-C runtime included in ObjFW
Definition: ObjCRuntime.h:56
SmallVector< llvm::Value *, 8 > ObjCEHValueStack
ObjCEHValueStack - Stack of Objective-C exception values, used for rethrows.
std::string getNameAsString() const
getNameAsString - Get a human-readable name for the declaration, even if it is one of the special kin...
Definition: Decl.h:285
llvm::CallSite EmitRuntimeCallOrInvoke(llvm::Value *callee, ArrayRef< llvm::Value *> args, const Twine &name="")
Emits a call or invoke instruction to the given runtime function.
Definition: CGCall.cpp:3666
Kind getKind() const
Definition: ObjCRuntime.h:75
ObjCCategoryDecl * getCategoryDecl() const
Definition: DeclObjC.cpp:2029
QualType getObjCSelType() const
Retrieve the type that corresponds to the predefined Objective-C &#39;SEL&#39; type.
Definition: ASTContext.h:1810
Cached information about one file (either on disk or in the virtual file system). ...
Definition: FileManager.h:59
const CGFunctionInfo & arrangeObjCMethodDeclaration(const ObjCMethodDecl *MD)
Objective-C methods are C functions with some implicit parameters.
Definition: CGCall.cpp:442
ObjCCategoryDecl - Represents a category declaration.
Definition: DeclObjC.h:2299
CanQual< Type > CanQualType
Represents a canonical, potentially-qualified type.
bool isAnyPointerType() const
Definition: Type.h:5948
An aligned address.
Definition: Address.h:25
Represents one property declaration in an Objective-C interface.
Definition: DeclObjC.h:746
All available information about a concrete callee.
Definition: CGCall.h:66
const VersionTuple & getVersion() const
Definition: ObjCRuntime.h:76
bool isWeakImported() const
Determine whether this is a weak-imported symbol.
Definition: DeclBase.cpp:672
ConstantAddress GetAddrOfConstantCString(const std::string &Str, const char *GlobalName=nullptr)
Returns a pointer to a character array containing the literal and a terminating &#39;\0&#39; character...
StringRef getName() const
Return the actual identifier string.
ObjCIvarDecl * getNextIvar()
Definition: DeclObjC.h:1997
llvm::Value * getScalarVal() const
getScalarVal() - Return the Value* of this scalar value.
Definition: CGValue.h:59
This class organizes the cross-function state that is used while generating LLVM code.
const ObjCInterfaceDecl * getClassInterface() const
Definition: DeclObjC.h:2459
Dataflow Directional Tag Classes.
CharUnits getSize() const
getSize - Get the record size in characters.
Definition: RecordLayout.h:174
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1252
static RValue getComplex(llvm::Value *V1, llvm::Value *V2)
Definition: CGValue.h:93
The basic abstraction for the target Objective-C runtime.
Definition: ObjCRuntime.h:25
Address CreateStructGEP(Address Addr, unsigned Index, CharUnits Offset, const llvm::Twine &Name="")
Definition: CGBuilder.h:172
llvm::LoadInst * CreateAlignedLoad(llvm::Value *Addr, CharUnits Align, const llvm::Twine &Name="")
Definition: CGBuilder.h:91
FileID getMainFileID() const
Returns the FileID of the main source file.
llvm::Constant * getPointer() const
Definition: Address.h:84
std::unique_ptr< DiagnosticConsumer > create(StringRef OutputFile, DiagnosticOptions *Diags, bool MergeChildRecords=false)
Returns a DiagnosticConsumer that serializes diagnostics to a bitcode file.
llvm::LoadInst * CreateLoad(Address Addr, const llvm::Twine &Name="")
Definition: CGBuilder.h:70
const ObjCObjectType * getObjectType() const
Gets the type pointed to by this ObjC pointer.
Definition: Type.h:5483
llvm::StoreInst * CreateStore(llvm::Value *Val, Address Addr, bool IsVolatile=false)
Definition: CGBuilder.h:108
llvm::Module & getModule() const
const ObjCInterfaceDecl * getClassInterface() const
Definition: DeclObjC.h:2766
&#39;ios&#39; is the Apple-provided NeXT-derived runtime on iOS or the iOS simulator; it is always non-fragil...
Definition: ObjCRuntime.h:42
Represents a pointer to an Objective C object.
Definition: Type.h:5442
ObjCImplementationDecl - Represents a class definition - this is where method definitions are specifi...
Definition: DeclObjC.h:2571
StructBuilder beginStruct(llvm::StructType *structTy=nullptr)
llvm::Type * getElementType() const
Return the type of the values stored in this address.
Definition: Address.h:52
uint64_t getCharWidth() const
Return the size of the character type, in bits.
Definition: ASTContext.h:2011
This class organizes the cross-module state that is used while lowering AST types to LLVM types...
Definition: CodeGenTypes.h:120
void getObjCEncodingForType(QualType T, std::string &S, const FieldDecl *Field=nullptr, QualType *NotEncodedT=nullptr) const
Emit the Objective-CC type encoding for the given type T into S.
bool isObjCQualifiedIdType() const
Definition: Type.h:6058
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:33
void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false)
EmitBlock - Emit the given block.
Definition: CGStmt.cpp:436
SourceManager & getSourceManager()
Definition: ASTContext.h:643
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2174
ArrayBuilder beginArray(llvm::Type *eltTy=nullptr)
Reading or writing from this object requires a barrier call.
Definition: Type.h:183
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:989
bool isVoidType() const
Definition: Type.h:6171
A specialization of Address that requires the address to be an LLVM Constant.
Definition: Address.h:75
ObjCIvarDecl - Represents an ObjC instance variable.
Definition: DeclObjC.h:1964
A helper class of ConstantInitBuilder, used for building constant struct initializers.
Represents Objective-C&#39;s @try ... @catch ... @finally statement.
Definition: StmtObjC.h:154
StringLiteral - This represents a string literal expression, e.g.
Definition: Expr.h:1509
StringRef getName() const
getName - Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:270
CanQualType IntTy
Definition: ASTContext.h:1004
TranslationUnitDecl - The top declaration context.
Definition: Decl.h:107
static RValue get(llvm::Value *V)
Definition: CGValue.h:86
llvm::Value * LoadObjCSelf()
LoadObjCSelf - Load the value of self.
Definition: CGObjC.cpp:1457
std::string ObjCConstantStringClass
Definition: LangOptions.h:119
static RValue getAggregate(Address addr, bool isVolatile=false)
Definition: CGValue.h:107
LValue - This represents an lvalue references.
Definition: CGValue.h:167
ObjCMethodDecl * getGetterMethodDecl() const
Definition: DeclObjC.h:939
ObjCIvarDecl * all_declared_ivar_begin()
all_declared_ivar_begin - return first ivar declared in this class, its extensions and its implementa...
Definition: DeclObjC.cpp:1556
CanQualType BoolTy
Definition: ASTContext.h:997
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:182
ObjCCategoryImplDecl - An object of this class encapsulates a category @implementation declaration...
Definition: DeclObjC.h:2518
This class handles loading and caching of source files into memory.
Abstract information about a function or function prototype.
Definition: CGCall.h:44
bool isScalar() const
Definition: CGValue.h:52
RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee, ReturnValueSlot ReturnValue, const CallArgList &Args, llvm::Instruction **callOrInvoke=nullptr)
EmitCall - Generate a call of the given function, expecting the given result type, and using the given argument list which specifies both the LLVM arguments and the types they were derived from.
Definition: CGCall.cpp:3717
ObjCCompatibleAliasDecl - Represents alias of a class.
Definition: DeclObjC.h:2748
static OMPLinearClause * Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc, OpenMPLinearClauseKind Modifier, SourceLocation ModifierLoc, SourceLocation ColonLoc, SourceLocation EndLoc, ArrayRef< Expr *> VL, ArrayRef< Expr *> PL, ArrayRef< Expr *> IL, Expr *Step, Expr *CalcStep, Stmt *PreInit, Expr *PostUpdate)
Creates clause with a list of variables VL and a linear step Step.
StringRef getName() const
Definition: FileManager.h:51
CanQualType getSizeType() const
Return the unique type for "size_t" (C99 7.17), defined in <stddef.h>.
CGObjCRuntime * CreateGNUObjCRuntime(CodeGenModule &CGM)
Creates an instance of an Objective-C runtime class.
Definition: CGObjCGNU.cpp:2897
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1524
const llvm::Triple & getTriple() const