clang  8.0.0svn
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"
21 #include "CGCXXABI.h"
23 #include "clang/AST/ASTContext.h"
24 #include "clang/AST/Decl.h"
25 #include "clang/AST/DeclObjC.h"
26 #include "clang/AST/RecordLayout.h"
27 #include "clang/AST/StmtObjC.h"
30 #include "llvm/ADT/SmallVector.h"
31 #include "llvm/ADT/StringMap.h"
32 #include "llvm/IR/CallSite.h"
33 #include "llvm/IR/DataLayout.h"
34 #include "llvm/IR/Intrinsics.h"
35 #include "llvm/IR/LLVMContext.h"
36 #include "llvm/IR/Module.h"
37 #include "llvm/Support/Compiler.h"
38 #include "llvm/Support/ConvertUTF.h"
39 #include <cctype>
40 
41 using namespace clang;
42 using namespace CodeGen;
43 
44 namespace {
45 
46 std::string SymbolNameForMethod( StringRef ClassName,
47  StringRef CategoryName, const Selector MethodName,
48  bool isClassMethod) {
49  std::string MethodNameColonStripped = MethodName.getAsString();
50  std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(),
51  ':', '_');
52  return (Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" +
53  CategoryName + "_" + MethodNameColonStripped).str();
54 }
55 
56 /// Class that lazily initialises the runtime function. Avoids inserting the
57 /// types and the function declaration into a module if they're not used, and
58 /// avoids constructing the type more than once if it's used more than once.
59 class LazyRuntimeFunction {
60  CodeGenModule *CGM;
61  llvm::FunctionType *FTy;
62  const char *FunctionName;
63  llvm::Constant *Function;
64 
65 public:
66  /// Constructor leaves this class uninitialized, because it is intended to
67  /// be used as a field in another class and not all of the types that are
68  /// used as arguments will necessarily be available at construction time.
69  LazyRuntimeFunction()
70  : CGM(nullptr), FunctionName(nullptr), Function(nullptr) {}
71 
72  /// Initialises the lazy function with the name, return type, and the types
73  /// of the arguments.
74  template <typename... Tys>
75  void init(CodeGenModule *Mod, const char *name, llvm::Type *RetTy,
76  Tys *... Types) {
77  CGM = Mod;
78  FunctionName = name;
79  Function = nullptr;
80  if(sizeof...(Tys)) {
81  SmallVector<llvm::Type *, 8> ArgTys({Types...});
82  FTy = llvm::FunctionType::get(RetTy, ArgTys, false);
83  }
84  else {
85  FTy = llvm::FunctionType::get(RetTy, None, false);
86  }
87  }
88 
89  llvm::FunctionType *getType() { return FTy; }
90 
91  /// Overloaded cast operator, allows the class to be implicitly cast to an
92  /// LLVM constant.
93  operator llvm::Constant *() {
94  if (!Function) {
95  if (!FunctionName)
96  return nullptr;
97  Function = CGM->CreateRuntimeFunction(FTy, FunctionName);
98  }
99  return Function;
100  }
101  operator llvm::Function *() {
102  return cast<llvm::Function>((llvm::Constant *)*this);
103  }
104 };
105 
106 
107 /// GNU Objective-C runtime code generation. This class implements the parts of
108 /// Objective-C support that are specific to the GNU family of runtimes (GCC,
109 /// GNUstep and ObjFW).
110 class CGObjCGNU : public CGObjCRuntime {
111 protected:
112  /// The LLVM module into which output is inserted
113  llvm::Module &TheModule;
114  /// strut objc_super. Used for sending messages to super. This structure
115  /// contains the receiver (object) and the expected class.
116  llvm::StructType *ObjCSuperTy;
117  /// struct objc_super*. The type of the argument to the superclass message
118  /// lookup functions.
119  llvm::PointerType *PtrToObjCSuperTy;
120  /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring
121  /// SEL is included in a header somewhere, in which case it will be whatever
122  /// type is declared in that header, most likely {i8*, i8*}.
123  llvm::PointerType *SelectorTy;
124  /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the
125  /// places where it's used
126  llvm::IntegerType *Int8Ty;
127  /// Pointer to i8 - LLVM type of char*, for all of the places where the
128  /// runtime needs to deal with C strings.
129  llvm::PointerType *PtrToInt8Ty;
130  /// struct objc_protocol type
131  llvm::StructType *ProtocolTy;
132  /// Protocol * type.
133  llvm::PointerType *ProtocolPtrTy;
134  /// Instance Method Pointer type. This is a pointer to a function that takes,
135  /// at a minimum, an object and a selector, and is the generic type for
136  /// Objective-C methods. Due to differences between variadic / non-variadic
137  /// calling conventions, it must always be cast to the correct type before
138  /// actually being used.
139  llvm::PointerType *IMPTy;
140  /// Type of an untyped Objective-C object. Clang treats id as a built-in type
141  /// when compiling Objective-C code, so this may be an opaque pointer (i8*),
142  /// but if the runtime header declaring it is included then it may be a
143  /// pointer to a structure.
144  llvm::PointerType *IdTy;
145  /// Pointer to a pointer to an Objective-C object. Used in the new ABI
146  /// message lookup function and some GC-related functions.
147  llvm::PointerType *PtrToIdTy;
148  /// The clang type of id. Used when using the clang CGCall infrastructure to
149  /// call Objective-C methods.
150  CanQualType ASTIdTy;
151  /// LLVM type for C int type.
152  llvm::IntegerType *IntTy;
153  /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is
154  /// used in the code to document the difference between i8* meaning a pointer
155  /// to a C string and i8* meaning a pointer to some opaque type.
156  llvm::PointerType *PtrTy;
157  /// LLVM type for C long type. The runtime uses this in a lot of places where
158  /// it should be using intptr_t, but we can't fix this without breaking
159  /// compatibility with GCC...
160  llvm::IntegerType *LongTy;
161  /// LLVM type for C size_t. Used in various runtime data structures.
162  llvm::IntegerType *SizeTy;
163  /// LLVM type for C intptr_t.
164  llvm::IntegerType *IntPtrTy;
165  /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions.
166  llvm::IntegerType *PtrDiffTy;
167  /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance
168  /// variables.
169  llvm::PointerType *PtrToIntTy;
170  /// LLVM type for Objective-C BOOL type.
171  llvm::Type *BoolTy;
172  /// 32-bit integer type, to save us needing to look it up every time it's used.
173  llvm::IntegerType *Int32Ty;
174  /// 64-bit integer type, to save us needing to look it up every time it's used.
175  llvm::IntegerType *Int64Ty;
176  /// The type of struct objc_property.
177  llvm::StructType *PropertyMetadataTy;
178  /// Metadata kind used to tie method lookups to message sends. The GNUstep
179  /// runtime provides some LLVM passes that can use this to do things like
180  /// automatic IMP caching and speculative inlining.
181  unsigned msgSendMDKind;
182  /// Does the current target use SEH-based exceptions? False implies
183  /// Itanium-style DWARF unwinding.
184  bool usesSEHExceptions;
185 
186  /// Helper to check if we are targeting a specific runtime version or later.
187  bool isRuntime(ObjCRuntime::Kind kind, unsigned major, unsigned minor=0) {
188  const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
189  return (R.getKind() == kind) &&
190  (R.getVersion() >= VersionTuple(major, minor));
191  }
192 
193  std::string SymbolForProtocol(StringRef Name) {
194  return (StringRef("._OBJC_PROTOCOL_") + Name).str();
195  }
196 
197  std::string SymbolForProtocolRef(StringRef Name) {
198  return (StringRef("._OBJC_REF_PROTOCOL_") + Name).str();
199  }
200 
201 
202  /// Helper function that generates a constant string and returns a pointer to
203  /// the start of the string. The result of this function can be used anywhere
204  /// where the C code specifies const char*.
205  llvm::Constant *MakeConstantString(StringRef Str, const char *Name = "") {
206  ConstantAddress Array = CGM.GetAddrOfConstantCString(Str, Name);
207  return llvm::ConstantExpr::getGetElementPtr(Array.getElementType(),
208  Array.getPointer(), Zeros);
209  }
210 
211  /// Emits a linkonce_odr string, whose name is the prefix followed by the
212  /// string value. This allows the linker to combine the strings between
213  /// different modules. Used for EH typeinfo names, selector strings, and a
214  /// few other things.
215  llvm::Constant *ExportUniqueString(const std::string &Str,
216  const std::string &prefix,
217  bool Private=false) {
218  std::string name = prefix + Str;
219  auto *ConstStr = TheModule.getGlobalVariable(name);
220  if (!ConstStr) {
221  llvm::Constant *value = llvm::ConstantDataArray::getString(VMContext,Str);
222  auto *GV = new llvm::GlobalVariable(TheModule, value->getType(), true,
223  llvm::GlobalValue::LinkOnceODRLinkage, value, name);
224  GV->setComdat(TheModule.getOrInsertComdat(name));
225  if (Private)
226  GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
227  ConstStr = GV;
228  }
229  return llvm::ConstantExpr::getGetElementPtr(ConstStr->getValueType(),
230  ConstStr, Zeros);
231  }
232 
233  /// Returns a property name and encoding string.
234  llvm::Constant *MakePropertyEncodingString(const ObjCPropertyDecl *PD,
235  const Decl *Container) {
236  assert(!isRuntime(ObjCRuntime::GNUstep, 2));
237  if (isRuntime(ObjCRuntime::GNUstep, 1, 6)) {
238  std::string NameAndAttributes;
239  std::string TypeStr =
240  CGM.getContext().getObjCEncodingForPropertyDecl(PD, Container);
241  NameAndAttributes += '\0';
242  NameAndAttributes += TypeStr.length() + 3;
243  NameAndAttributes += TypeStr;
244  NameAndAttributes += '\0';
245  NameAndAttributes += PD->getNameAsString();
246  return MakeConstantString(NameAndAttributes);
247  }
248  return MakeConstantString(PD->getNameAsString());
249  }
250 
251  /// Push the property attributes into two structure fields.
252  void PushPropertyAttributes(ConstantStructBuilder &Fields,
253  const ObjCPropertyDecl *property, bool isSynthesized=true, bool
254  isDynamic=true) {
255  int attrs = property->getPropertyAttributes();
256  // For read-only properties, clear the copy and retain flags
258  attrs &= ~ObjCPropertyDecl::OBJC_PR_copy;
259  attrs &= ~ObjCPropertyDecl::OBJC_PR_retain;
260  attrs &= ~ObjCPropertyDecl::OBJC_PR_weak;
261  attrs &= ~ObjCPropertyDecl::OBJC_PR_strong;
262  }
263  // The first flags field has the same attribute values as clang uses internally
264  Fields.addInt(Int8Ty, attrs & 0xff);
265  attrs >>= 8;
266  attrs <<= 2;
267  // For protocol properties, synthesized and dynamic have no meaning, so we
268  // reuse these flags to indicate that this is a protocol property (both set
269  // has no meaning, as a property can't be both synthesized and dynamic)
270  attrs |= isSynthesized ? (1<<0) : 0;
271  attrs |= isDynamic ? (1<<1) : 0;
272  // The second field is the next four fields left shifted by two, with the
273  // low bit set to indicate whether the field is synthesized or dynamic.
274  Fields.addInt(Int8Ty, attrs & 0xff);
275  // Two padding fields
276  Fields.addInt(Int8Ty, 0);
277  Fields.addInt(Int8Ty, 0);
278  }
279 
280  virtual ConstantArrayBuilder PushPropertyListHeader(ConstantStructBuilder &Fields,
281  int count) {
282  // int count;
283  Fields.addInt(IntTy, count);
284  // int size; (only in GNUstep v2 ABI.
285  if (isRuntime(ObjCRuntime::GNUstep, 2)) {
286  llvm::DataLayout td(&TheModule);
287  Fields.addInt(IntTy, td.getTypeSizeInBits(PropertyMetadataTy) /
288  CGM.getContext().getCharWidth());
289  }
290  // struct objc_property_list *next;
291  Fields.add(NULLPtr);
292  // struct objc_property properties[]
293  return Fields.beginArray(PropertyMetadataTy);
294  }
295  virtual void PushProperty(ConstantArrayBuilder &PropertiesArray,
296  const ObjCPropertyDecl *property,
297  const Decl *OCD,
298  bool isSynthesized=true, bool
299  isDynamic=true) {
300  auto Fields = PropertiesArray.beginStruct(PropertyMetadataTy);
301  ASTContext &Context = CGM.getContext();
302  Fields.add(MakePropertyEncodingString(property, OCD));
303  PushPropertyAttributes(Fields, property, isSynthesized, isDynamic);
304  auto addPropertyMethod = [&](const ObjCMethodDecl *accessor) {
305  if (accessor) {
306  std::string TypeStr = Context.getObjCEncodingForMethodDecl(accessor);
307  llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
308  Fields.add(MakeConstantString(accessor->getSelector().getAsString()));
309  Fields.add(TypeEncoding);
310  } else {
311  Fields.add(NULLPtr);
312  Fields.add(NULLPtr);
313  }
314  };
315  addPropertyMethod(property->getGetterMethodDecl());
316  addPropertyMethod(property->getSetterMethodDecl());
317  Fields.finishAndAddTo(PropertiesArray);
318  }
319 
320  /// Ensures that the value has the required type, by inserting a bitcast if
321  /// required. This function lets us avoid inserting bitcasts that are
322  /// redundant.
323  llvm::Value* EnforceType(CGBuilderTy &B, llvm::Value *V, llvm::Type *Ty) {
324  if (V->getType() == Ty) return V;
325  return B.CreateBitCast(V, Ty);
326  }
327  Address EnforceType(CGBuilderTy &B, Address V, llvm::Type *Ty) {
328  if (V.getType() == Ty) return V;
329  return B.CreateBitCast(V, Ty);
330  }
331 
332  // Some zeros used for GEPs in lots of places.
333  llvm::Constant *Zeros[2];
334  /// Null pointer value. Mainly used as a terminator in various arrays.
335  llvm::Constant *NULLPtr;
336  /// LLVM context.
337  llvm::LLVMContext &VMContext;
338 
339 protected:
340 
341  /// Placeholder for the class. Lots of things refer to the class before we've
342  /// actually emitted it. We use this alias as a placeholder, and then replace
343  /// it with a pointer to the class structure before finally emitting the
344  /// module.
345  llvm::GlobalAlias *ClassPtrAlias;
346  /// Placeholder for the metaclass. Lots of things refer to the class before
347  /// we've / actually emitted it. We use this alias as a placeholder, and then
348  /// replace / it with a pointer to the metaclass structure before finally
349  /// emitting the / module.
350  llvm::GlobalAlias *MetaClassPtrAlias;
351  /// All of the classes that have been generated for this compilation units.
352  std::vector<llvm::Constant*> Classes;
353  /// All of the categories that have been generated for this compilation units.
354  std::vector<llvm::Constant*> Categories;
355  /// All of the Objective-C constant strings that have been generated for this
356  /// compilation units.
357  std::vector<llvm::Constant*> ConstantStrings;
358  /// Map from string values to Objective-C constant strings in the output.
359  /// Used to prevent emitting Objective-C strings more than once. This should
360  /// not be required at all - CodeGenModule should manage this list.
361  llvm::StringMap<llvm::Constant*> ObjCStrings;
362  /// All of the protocols that have been declared.
363  llvm::StringMap<llvm::Constant*> ExistingProtocols;
364  /// For each variant of a selector, we store the type encoding and a
365  /// placeholder value. For an untyped selector, the type will be the empty
366  /// string. Selector references are all done via the module's selector table,
367  /// so we create an alias as a placeholder and then replace it with the real
368  /// value later.
369  typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector;
370  /// Type of the selector map. This is roughly equivalent to the structure
371  /// used in the GNUstep runtime, which maintains a list of all of the valid
372  /// types for a selector in a table.
373  typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> >
374  SelectorMap;
375  /// A map from selectors to selector types. This allows us to emit all
376  /// selectors of the same name and type together.
377  SelectorMap SelectorTable;
378 
379  /// Selectors related to memory management. When compiling in GC mode, we
380  /// omit these.
381  Selector RetainSel, ReleaseSel, AutoreleaseSel;
382  /// Runtime functions used for memory management in GC mode. Note that clang
383  /// supports code generation for calling these functions, but neither GNU
384  /// runtime actually supports this API properly yet.
385  LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn,
386  WeakAssignFn, GlobalAssignFn;
387 
388  typedef std::pair<std::string, std::string> ClassAliasPair;
389  /// All classes that have aliases set for them.
390  std::vector<ClassAliasPair> ClassAliases;
391 
392 protected:
393  /// Function used for throwing Objective-C exceptions.
394  LazyRuntimeFunction ExceptionThrowFn;
395  /// Function used for rethrowing exceptions, used at the end of \@finally or
396  /// \@synchronize blocks.
397  LazyRuntimeFunction ExceptionReThrowFn;
398  /// Function called when entering a catch function. This is required for
399  /// differentiating Objective-C exceptions and foreign exceptions.
400  LazyRuntimeFunction EnterCatchFn;
401  /// Function called when exiting from a catch block. Used to do exception
402  /// cleanup.
403  LazyRuntimeFunction ExitCatchFn;
404  /// Function called when entering an \@synchronize block. Acquires the lock.
405  LazyRuntimeFunction SyncEnterFn;
406  /// Function called when exiting an \@synchronize block. Releases the lock.
407  LazyRuntimeFunction SyncExitFn;
408 
409 private:
410  /// Function called if fast enumeration detects that the collection is
411  /// modified during the update.
412  LazyRuntimeFunction EnumerationMutationFn;
413  /// Function for implementing synthesized property getters that return an
414  /// object.
415  LazyRuntimeFunction GetPropertyFn;
416  /// Function for implementing synthesized property setters that return an
417  /// object.
418  LazyRuntimeFunction SetPropertyFn;
419  /// Function used for non-object declared property getters.
420  LazyRuntimeFunction GetStructPropertyFn;
421  /// Function used for non-object declared property setters.
422  LazyRuntimeFunction SetStructPropertyFn;
423 
424 protected:
425  /// The version of the runtime that this class targets. Must match the
426  /// version in the runtime.
427  int RuntimeVersion;
428  /// The version of the protocol class. Used to differentiate between ObjC1
429  /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional
430  /// components and can not contain declared properties. We always emit
431  /// Objective-C 2 property structures, but we have to pretend that they're
432  /// Objective-C 1 property structures when targeting the GCC runtime or it
433  /// will abort.
434  const int ProtocolVersion;
435  /// The version of the class ABI. This value is used in the class structure
436  /// and indicates how various fields should be interpreted.
437  const int ClassABIVersion;
438  /// Generates an instance variable list structure. This is a structure
439  /// containing a size and an array of structures containing instance variable
440  /// metadata. This is used purely for introspection in the fragile ABI. In
441  /// the non-fragile ABI, it's used for instance variable fixup.
442  virtual llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
443  ArrayRef<llvm::Constant *> IvarTypes,
444  ArrayRef<llvm::Constant *> IvarOffsets,
445  ArrayRef<llvm::Constant *> IvarAlign,
446  ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership);
447 
448  /// Generates a method list structure. This is a structure containing a size
449  /// and an array of structures containing method metadata.
450  ///
451  /// This structure is used by both classes and categories, and contains a next
452  /// pointer allowing them to be chained together in a linked list.
453  llvm::Constant *GenerateMethodList(StringRef ClassName,
454  StringRef CategoryName,
456  bool isClassMethodList);
457 
458  /// Emits an empty protocol. This is used for \@protocol() where no protocol
459  /// is found. The runtime will (hopefully) fix up the pointer to refer to the
460  /// real protocol.
461  virtual llvm::Constant *GenerateEmptyProtocol(StringRef ProtocolName);
462 
463  /// Generates a list of property metadata structures. This follows the same
464  /// pattern as method and instance variable metadata lists.
465  llvm::Constant *GeneratePropertyList(const Decl *Container,
466  const ObjCContainerDecl *OCD,
467  bool isClassProperty=false,
468  bool protocolOptionalProperties=false);
469 
470  /// Generates a list of referenced protocols. Classes, categories, and
471  /// protocols all use this structure.
472  llvm::Constant *GenerateProtocolList(ArrayRef<std::string> Protocols);
473 
474  /// To ensure that all protocols are seen by the runtime, we add a category on
475  /// a class defined in the runtime, declaring no methods, but adopting the
476  /// protocols. This is a horribly ugly hack, but it allows us to collect all
477  /// of the protocols without changing the ABI.
478  void GenerateProtocolHolderCategory();
479 
480  /// Generates a class structure.
481  llvm::Constant *GenerateClassStructure(
482  llvm::Constant *MetaClass,
483  llvm::Constant *SuperClass,
484  unsigned info,
485  const char *Name,
486  llvm::Constant *Version,
487  llvm::Constant *InstanceSize,
488  llvm::Constant *IVars,
489  llvm::Constant *Methods,
490  llvm::Constant *Protocols,
491  llvm::Constant *IvarOffsets,
492  llvm::Constant *Properties,
493  llvm::Constant *StrongIvarBitmap,
494  llvm::Constant *WeakIvarBitmap,
495  bool isMeta=false);
496 
497  /// Generates a method list. This is used by protocols to define the required
498  /// and optional methods.
499  virtual llvm::Constant *GenerateProtocolMethodList(
501  /// Emits optional and required method lists.
502  template<class T>
503  void EmitProtocolMethodList(T &&Methods, llvm::Constant *&Required,
504  llvm::Constant *&Optional) {
507  for (const auto *I : Methods)
508  if (I->isOptional())
509  OptionalMethods.push_back(I);
510  else
511  RequiredMethods.push_back(I);
512  Required = GenerateProtocolMethodList(RequiredMethods);
513  Optional = GenerateProtocolMethodList(OptionalMethods);
514  }
515 
516  /// Returns a selector with the specified type encoding. An empty string is
517  /// used to return an untyped selector (with the types field set to NULL).
518  virtual llvm::Value *GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
519  const std::string &TypeEncoding);
520 
521  /// Returns the name of ivar offset variables. In the GNUstep v1 ABI, this
522  /// contains the class and ivar names, in the v2 ABI this contains the type
523  /// encoding as well.
524  virtual std::string GetIVarOffsetVariableName(const ObjCInterfaceDecl *ID,
525  const ObjCIvarDecl *Ivar) {
526  const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString()
527  + '.' + Ivar->getNameAsString();
528  return Name;
529  }
530  /// Returns the variable used to store the offset of an instance variable.
531  llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID,
532  const ObjCIvarDecl *Ivar);
533  /// Emits a reference to a class. This allows the linker to object if there
534  /// is no class of the matching name.
535  void EmitClassRef(const std::string &className);
536 
537  /// Emits a pointer to the named class
538  virtual llvm::Value *GetClassNamed(CodeGenFunction &CGF,
539  const std::string &Name, bool isWeak);
540 
541  /// Looks up the method for sending a message to the specified object. This
542  /// mechanism differs between the GCC and GNU runtimes, so this method must be
543  /// overridden in subclasses.
544  virtual llvm::Value *LookupIMP(CodeGenFunction &CGF,
545  llvm::Value *&Receiver,
546  llvm::Value *cmd,
547  llvm::MDNode *node,
548  MessageSendInfo &MSI) = 0;
549 
550  /// Looks up the method for sending a message to a superclass. This
551  /// mechanism differs between the GCC and GNU runtimes, so this method must
552  /// be overridden in subclasses.
553  virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF,
554  Address ObjCSuper,
555  llvm::Value *cmd,
556  MessageSendInfo &MSI) = 0;
557 
558  /// Libobjc2 uses a bitfield representation where small(ish) bitfields are
559  /// stored in a 64-bit value with the low bit set to 1 and the remaining 63
560  /// bits set to their values, LSB first, while larger ones are stored in a
561  /// structure of this / form:
562  ///
563  /// struct { int32_t length; int32_t values[length]; };
564  ///
565  /// The values in the array are stored in host-endian format, with the least
566  /// significant bit being assumed to come first in the bitfield. Therefore,
567  /// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] },
568  /// while a bitfield / with the 63rd bit set will be 1<<64.
569  llvm::Constant *MakeBitField(ArrayRef<bool> bits);
570 
571 public:
572  CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
573  unsigned protocolClassVersion, unsigned classABI=1);
574 
575  ConstantAddress GenerateConstantString(const StringLiteral *) override;
576 
577  RValue
578  GenerateMessageSend(CodeGenFunction &CGF, ReturnValueSlot Return,
579  QualType ResultType, Selector Sel,
580  llvm::Value *Receiver, const CallArgList &CallArgs,
581  const ObjCInterfaceDecl *Class,
582  const ObjCMethodDecl *Method) override;
583  RValue
584  GenerateMessageSendSuper(CodeGenFunction &CGF, ReturnValueSlot Return,
585  QualType ResultType, Selector Sel,
586  const ObjCInterfaceDecl *Class,
587  bool isCategoryImpl, llvm::Value *Receiver,
588  bool IsClassMessage, const CallArgList &CallArgs,
589  const ObjCMethodDecl *Method) override;
590  llvm::Value *GetClass(CodeGenFunction &CGF,
591  const ObjCInterfaceDecl *OID) override;
592  llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel) override;
593  Address GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) override;
594  llvm::Value *GetSelector(CodeGenFunction &CGF,
595  const ObjCMethodDecl *Method) override;
596  virtual llvm::Constant *GetConstantSelector(Selector Sel,
597  const std::string &TypeEncoding) {
598  llvm_unreachable("Runtime unable to generate constant selector");
599  }
600  llvm::Constant *GetConstantSelector(const ObjCMethodDecl *M) {
601  return GetConstantSelector(M->getSelector(),
603  }
604  llvm::Constant *GetEHType(QualType T) override;
605 
606  llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
607  const ObjCContainerDecl *CD) override;
608  void GenerateCategory(const ObjCCategoryImplDecl *CMD) override;
609  void GenerateClass(const ObjCImplementationDecl *ClassDecl) override;
610  void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) override;
611  llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
612  const ObjCProtocolDecl *PD) override;
613  void GenerateProtocol(const ObjCProtocolDecl *PD) override;
614  llvm::Function *ModuleInitFunction() override;
615  llvm::Constant *GetPropertyGetFunction() override;
616  llvm::Constant *GetPropertySetFunction() override;
617  llvm::Constant *GetOptimizedPropertySetFunction(bool atomic,
618  bool copy) override;
619  llvm::Constant *GetSetStructFunction() override;
620  llvm::Constant *GetGetStructFunction() override;
621  llvm::Constant *GetCppAtomicObjectGetFunction() override;
622  llvm::Constant *GetCppAtomicObjectSetFunction() override;
623  llvm::Constant *EnumerationMutationFunction() override;
624 
625  void EmitTryStmt(CodeGenFunction &CGF,
626  const ObjCAtTryStmt &S) override;
627  void EmitSynchronizedStmt(CodeGenFunction &CGF,
628  const ObjCAtSynchronizedStmt &S) override;
629  void EmitThrowStmt(CodeGenFunction &CGF,
630  const ObjCAtThrowStmt &S,
631  bool ClearInsertionPoint=true) override;
632  llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF,
633  Address AddrWeakObj) override;
634  void EmitObjCWeakAssign(CodeGenFunction &CGF,
635  llvm::Value *src, Address dst) override;
636  void EmitObjCGlobalAssign(CodeGenFunction &CGF,
637  llvm::Value *src, Address dest,
638  bool threadlocal=false) override;
639  void EmitObjCIvarAssign(CodeGenFunction &CGF, llvm::Value *src,
640  Address dest, llvm::Value *ivarOffset) override;
641  void EmitObjCStrongCastAssign(CodeGenFunction &CGF,
642  llvm::Value *src, Address dest) override;
643  void EmitGCMemmoveCollectable(CodeGenFunction &CGF, Address DestPtr,
644  Address SrcPtr,
645  llvm::Value *Size) override;
646  LValue EmitObjCValueForIvar(CodeGenFunction &CGF, QualType ObjectTy,
647  llvm::Value *BaseValue, const ObjCIvarDecl *Ivar,
648  unsigned CVRQualifiers) override;
649  llvm::Value *EmitIvarOffset(CodeGenFunction &CGF,
650  const ObjCInterfaceDecl *Interface,
651  const ObjCIvarDecl *Ivar) override;
652  llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) override;
653  llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM,
654  const CGBlockInfo &blockInfo) override {
655  return NULLPtr;
656  }
657  llvm::Constant *BuildRCBlockLayout(CodeGenModule &CGM,
658  const CGBlockInfo &blockInfo) override {
659  return NULLPtr;
660  }
661 
662  llvm::Constant *BuildByrefLayout(CodeGenModule &CGM, QualType T) override {
663  return NULLPtr;
664  }
665 };
666 
667 /// Class representing the legacy GCC Objective-C ABI. This is the default when
668 /// -fobjc-nonfragile-abi is not specified.
669 ///
670 /// The GCC ABI target actually generates code that is approximately compatible
671 /// with the new GNUstep runtime ABI, but refrains from using any features that
672 /// would not work with the GCC runtime. For example, clang always generates
673 /// the extended form of the class structure, and the extra fields are simply
674 /// ignored by GCC libobjc.
675 class CGObjCGCC : public CGObjCGNU {
676  /// The GCC ABI message lookup function. Returns an IMP pointing to the
677  /// method implementation for this message.
678  LazyRuntimeFunction MsgLookupFn;
679  /// The GCC ABI superclass message lookup function. Takes a pointer to a
680  /// structure describing the receiver and the class, and a selector as
681  /// arguments. Returns the IMP for the corresponding method.
682  LazyRuntimeFunction MsgLookupSuperFn;
683 
684 protected:
685  llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
686  llvm::Value *cmd, llvm::MDNode *node,
687  MessageSendInfo &MSI) override {
688  CGBuilderTy &Builder = CGF.Builder;
689  llvm::Value *args[] = {
690  EnforceType(Builder, Receiver, IdTy),
691  EnforceType(Builder, cmd, SelectorTy) };
692  llvm::CallSite imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);
693  imp->setMetadata(msgSendMDKind, node);
694  return imp.getInstruction();
695  }
696 
697  llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
698  llvm::Value *cmd, MessageSendInfo &MSI) override {
699  CGBuilderTy &Builder = CGF.Builder;
700  llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper,
701  PtrToObjCSuperTy).getPointer(), cmd};
702  return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
703  }
704 
705 public:
706  CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) {
707  // IMP objc_msg_lookup(id, SEL);
708  MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy);
709  // IMP objc_msg_lookup_super(struct objc_super*, SEL);
710  MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
711  PtrToObjCSuperTy, SelectorTy);
712  }
713 };
714 
715 /// Class used when targeting the new GNUstep runtime ABI.
716 class CGObjCGNUstep : public CGObjCGNU {
717  /// The slot lookup function. Returns a pointer to a cacheable structure
718  /// that contains (among other things) the IMP.
719  LazyRuntimeFunction SlotLookupFn;
720  /// The GNUstep ABI superclass message lookup function. Takes a pointer to
721  /// a structure describing the receiver and the class, and a selector as
722  /// arguments. Returns the slot for the corresponding method. Superclass
723  /// message lookup rarely changes, so this is a good caching opportunity.
724  LazyRuntimeFunction SlotLookupSuperFn;
725  /// Specialised function for setting atomic retain properties
726  LazyRuntimeFunction SetPropertyAtomic;
727  /// Specialised function for setting atomic copy properties
728  LazyRuntimeFunction SetPropertyAtomicCopy;
729  /// Specialised function for setting nonatomic retain properties
730  LazyRuntimeFunction SetPropertyNonAtomic;
731  /// Specialised function for setting nonatomic copy properties
732  LazyRuntimeFunction SetPropertyNonAtomicCopy;
733  /// Function to perform atomic copies of C++ objects with nontrivial copy
734  /// constructors from Objective-C ivars.
735  LazyRuntimeFunction CxxAtomicObjectGetFn;
736  /// Function to perform atomic copies of C++ objects with nontrivial copy
737  /// constructors to Objective-C ivars.
738  LazyRuntimeFunction CxxAtomicObjectSetFn;
739  /// Type of an slot structure pointer. This is returned by the various
740  /// lookup functions.
741  llvm::Type *SlotTy;
742 
743  public:
744  llvm::Constant *GetEHType(QualType T) override;
745 
746  protected:
747  llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
748  llvm::Value *cmd, llvm::MDNode *node,
749  MessageSendInfo &MSI) override {
750  CGBuilderTy &Builder = CGF.Builder;
751  llvm::Function *LookupFn = SlotLookupFn;
752 
753  // Store the receiver on the stack so that we can reload it later
754  Address ReceiverPtr =
755  CGF.CreateTempAlloca(Receiver->getType(), CGF.getPointerAlign());
756  Builder.CreateStore(Receiver, ReceiverPtr);
757 
758  llvm::Value *self;
759 
760  if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) {
761  self = CGF.LoadObjCSelf();
762  } else {
763  self = llvm::ConstantPointerNull::get(IdTy);
764  }
765 
766  // The lookup function is guaranteed not to capture the receiver pointer.
767  LookupFn->addParamAttr(0, llvm::Attribute::NoCapture);
768 
769  llvm::Value *args[] = {
770  EnforceType(Builder, ReceiverPtr.getPointer(), PtrToIdTy),
771  EnforceType(Builder, cmd, SelectorTy),
772  EnforceType(Builder, self, IdTy) };
773  llvm::CallSite slot = CGF.EmitRuntimeCallOrInvoke(LookupFn, args);
774  slot.setOnlyReadsMemory();
775  slot->setMetadata(msgSendMDKind, node);
776 
777  // Load the imp from the slot
778  llvm::Value *imp = Builder.CreateAlignedLoad(
779  Builder.CreateStructGEP(nullptr, slot.getInstruction(), 4),
780  CGF.getPointerAlign());
781 
782  // The lookup function may have changed the receiver, so make sure we use
783  // the new one.
784  Receiver = Builder.CreateLoad(ReceiverPtr, true);
785  return imp;
786  }
787 
788  llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
789  llvm::Value *cmd,
790  MessageSendInfo &MSI) override {
791  CGBuilderTy &Builder = CGF.Builder;
792  llvm::Value *lookupArgs[] = {ObjCSuper.getPointer(), cmd};
793 
794  llvm::CallInst *slot =
795  CGF.EmitNounwindRuntimeCall(SlotLookupSuperFn, lookupArgs);
796  slot->setOnlyReadsMemory();
797 
798  return Builder.CreateAlignedLoad(Builder.CreateStructGEP(nullptr, slot, 4),
799  CGF.getPointerAlign());
800  }
801 
802  public:
803  CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNUstep(Mod, 9, 3, 1) {}
804  CGObjCGNUstep(CodeGenModule &Mod, unsigned ABI, unsigned ProtocolABI,
805  unsigned ClassABI) :
806  CGObjCGNU(Mod, ABI, ProtocolABI, ClassABI) {
807  const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
808 
809  llvm::StructType *SlotStructTy =
810  llvm::StructType::get(PtrTy, PtrTy, PtrTy, IntTy, IMPTy);
811  SlotTy = llvm::PointerType::getUnqual(SlotStructTy);
812  // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender);
813  SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy,
814  SelectorTy, IdTy);
815  // Slot_t objc_slot_lookup_super(struct objc_super*, SEL);
816  SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy,
817  PtrToObjCSuperTy, SelectorTy);
818  // If we're in ObjC++ mode, then we want to make
819  if (usesSEHExceptions) {
820  llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
821  // void objc_exception_rethrow(void)
822  ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy);
823  } else if (CGM.getLangOpts().CPlusPlus) {
824  llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
825  // void *__cxa_begin_catch(void *e)
826  EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy);
827  // void __cxa_end_catch(void)
828  ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy);
829  // void _Unwind_Resume_or_Rethrow(void*)
830  ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy,
831  PtrTy);
832  } else if (R.getVersion() >= VersionTuple(1, 7)) {
833  llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
834  // id objc_begin_catch(void *e)
835  EnterCatchFn.init(&CGM, "objc_begin_catch", IdTy, PtrTy);
836  // void objc_end_catch(void)
837  ExitCatchFn.init(&CGM, "objc_end_catch", VoidTy);
838  // void _Unwind_Resume_or_Rethrow(void*)
839  ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy, PtrTy);
840  }
841  llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
842  SetPropertyAtomic.init(&CGM, "objc_setProperty_atomic", VoidTy, IdTy,
843  SelectorTy, IdTy, PtrDiffTy);
844  SetPropertyAtomicCopy.init(&CGM, "objc_setProperty_atomic_copy", VoidTy,
845  IdTy, SelectorTy, IdTy, PtrDiffTy);
846  SetPropertyNonAtomic.init(&CGM, "objc_setProperty_nonatomic", VoidTy,
847  IdTy, SelectorTy, IdTy, PtrDiffTy);
848  SetPropertyNonAtomicCopy.init(&CGM, "objc_setProperty_nonatomic_copy",
849  VoidTy, IdTy, SelectorTy, IdTy, PtrDiffTy);
850  // void objc_setCppObjectAtomic(void *dest, const void *src, void
851  // *helper);
852  CxxAtomicObjectSetFn.init(&CGM, "objc_setCppObjectAtomic", VoidTy, PtrTy,
853  PtrTy, PtrTy);
854  // void objc_getCppObjectAtomic(void *dest, const void *src, void
855  // *helper);
856  CxxAtomicObjectGetFn.init(&CGM, "objc_getCppObjectAtomic", VoidTy, PtrTy,
857  PtrTy, PtrTy);
858  }
859 
860  llvm::Constant *GetCppAtomicObjectGetFunction() override {
861  // The optimised functions were added in version 1.7 of the GNUstep
862  // runtime.
863  assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
864  VersionTuple(1, 7));
865  return CxxAtomicObjectGetFn;
866  }
867 
868  llvm::Constant *GetCppAtomicObjectSetFunction() override {
869  // The optimised functions were added in version 1.7 of the GNUstep
870  // runtime.
871  assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
872  VersionTuple(1, 7));
873  return CxxAtomicObjectSetFn;
874  }
875 
876  llvm::Constant *GetOptimizedPropertySetFunction(bool atomic,
877  bool copy) override {
878  // The optimised property functions omit the GC check, and so are not
879  // safe to use in GC mode. The standard functions are fast in GC mode,
880  // so there is less advantage in using them.
881  assert ((CGM.getLangOpts().getGC() == LangOptions::NonGC));
882  // The optimised functions were added in version 1.7 of the GNUstep
883  // runtime.
884  assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
885  VersionTuple(1, 7));
886 
887  if (atomic) {
888  if (copy) return SetPropertyAtomicCopy;
889  return SetPropertyAtomic;
890  }
891 
892  return copy ? SetPropertyNonAtomicCopy : SetPropertyNonAtomic;
893  }
894 };
895 
896 /// GNUstep Objective-C ABI version 2 implementation.
897 /// This is the ABI that provides a clean break with the legacy GCC ABI and
898 /// cleans up a number of things that were added to work around 1980s linkers.
899 class CGObjCGNUstep2 : public CGObjCGNUstep {
900  enum SectionKind
901  {
902  SelectorSection = 0,
903  ClassSection,
904  ClassReferenceSection,
905  CategorySection,
906  ProtocolSection,
907  ProtocolReferenceSection,
908  ClassAliasSection,
909  ConstantStringSection
910  };
911  static const char *const SectionsBaseNames[8];
912  template<SectionKind K>
913  std::string sectionName() {
914  std::string name(SectionsBaseNames[K]);
915  if (CGM.getTriple().isOSBinFormatCOFF())
916  name += "$m";
917  return name;
918  }
919  /// The GCC ABI superclass message lookup function. Takes a pointer to a
920  /// structure describing the receiver and the class, and a selector as
921  /// arguments. Returns the IMP for the corresponding method.
922  LazyRuntimeFunction MsgLookupSuperFn;
923  /// A flag indicating if we've emitted at least one protocol.
924  /// If we haven't, then we need to emit an empty protocol, to ensure that the
925  /// __start__objc_protocols and __stop__objc_protocols sections exist.
926  bool EmittedProtocol = false;
927  /// A flag indicating if we've emitted at least one protocol reference.
928  /// If we haven't, then we need to emit an empty protocol, to ensure that the
929  /// __start__objc_protocol_refs and __stop__objc_protocol_refs sections
930  /// exist.
931  bool EmittedProtocolRef = false;
932  /// A flag indicating if we've emitted at least one class.
933  /// If we haven't, then we need to emit an empty protocol, to ensure that the
934  /// __start__objc_classes and __stop__objc_classes sections / exist.
935  bool EmittedClass = false;
936  /// Generate the name of a symbol for a reference to a class. Accesses to
937  /// classes should be indirected via this.
938  std::string SymbolForClassRef(StringRef Name, bool isWeak) {
939  if (isWeak)
940  return (StringRef("._OBJC_WEAK_REF_CLASS_") + Name).str();
941  else
942  return (StringRef("._OBJC_REF_CLASS_") + Name).str();
943  }
944  /// Generate the name of a class symbol.
945  std::string SymbolForClass(StringRef Name) {
946  return (StringRef("._OBJC_CLASS_") + Name).str();
947  }
948  void CallRuntimeFunction(CGBuilderTy &B, StringRef FunctionName,
949  ArrayRef<llvm::Value*> Args) {
951  for (auto *Arg : Args)
952  Types.push_back(Arg->getType());
953  llvm::FunctionType *FT = llvm::FunctionType::get(B.getVoidTy(), Types,
954  false);
955  llvm::Value *Fn = CGM.CreateRuntimeFunction(FT, FunctionName);
956  B.CreateCall(Fn, Args);
957  }
958 
959  ConstantAddress GenerateConstantString(const StringLiteral *SL) override {
960 
961  auto Str = SL->getString();
962  CharUnits Align = CGM.getPointerAlign();
963 
964  // Look for an existing one
965  llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str);
966  if (old != ObjCStrings.end())
967  return ConstantAddress(old->getValue(), Align);
968 
969  bool isNonASCII = SL->containsNonAscii();
970 
971  auto LiteralLength = SL->getLength();
972 
973  if ((CGM.getTarget().getPointerWidth(0) == 64) &&
974  (LiteralLength < 9) && !isNonASCII) {
975  // Tiny strings are only used on 64-bit platforms. They store 8 7-bit
976  // ASCII characters in the high 56 bits, followed by a 4-bit length and a
977  // 3-bit tag (which is always 4).
978  uint64_t str = 0;
979  // Fill in the characters
980  for (unsigned i=0 ; i<LiteralLength ; i++)
981  str |= ((uint64_t)SL->getCodeUnit(i)) << ((64 - 4 - 3) - (i*7));
982  // Fill in the length
983  str |= LiteralLength << 3;
984  // Set the tag
985  str |= 4;
986  auto *ObjCStr = llvm::ConstantExpr::getIntToPtr(
987  llvm::ConstantInt::get(Int64Ty, str), IdTy);
988  ObjCStrings[Str] = ObjCStr;
989  return ConstantAddress(ObjCStr, Align);
990  }
991 
992  StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass;
993 
994  if (StringClass.empty()) StringClass = "NSConstantString";
995 
996  std::string Sym = SymbolForClass(StringClass);
997 
998  llvm::Constant *isa = TheModule.getNamedGlobal(Sym);
999 
1000  if (!isa)
1001  isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false,
1002  llvm::GlobalValue::ExternalLinkage, nullptr, Sym);
1003  else if (isa->getType() != PtrToIdTy)
1004  isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy);
1005 
1006  // struct
1007  // {
1008  // Class isa;
1009  // uint32_t flags;
1010  // uint32_t length; // Number of codepoints
1011  // uint32_t size; // Number of bytes
1012  // uint32_t hash;
1013  // const char *data;
1014  // };
1015 
1016  ConstantInitBuilder Builder(CGM);
1017  auto Fields = Builder.beginStruct();
1018  Fields.add(isa);
1019  // For now, all non-ASCII strings are represented as UTF-16. As such, the
1020  // number of bytes is simply double the number of UTF-16 codepoints. In
1021  // ASCII strings, the number of bytes is equal to the number of non-ASCII
1022  // codepoints.
1023  if (isNonASCII) {
1024  unsigned NumU8CodeUnits = Str.size();
1025  // A UTF-16 representation of a unicode string contains at most the same
1026  // number of code units as a UTF-8 representation. Allocate that much
1027  // space, plus one for the final null character.
1028  SmallVector<llvm::UTF16, 128> ToBuf(NumU8CodeUnits + 1);
1029  const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)Str.data();
1030  llvm::UTF16 *ToPtr = &ToBuf[0];
1031  (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumU8CodeUnits,
1032  &ToPtr, ToPtr + NumU8CodeUnits, llvm::strictConversion);
1033  uint32_t StringLength = ToPtr - &ToBuf[0];
1034  // Add null terminator
1035  *ToPtr = 0;
1036  // Flags: 2 indicates UTF-16 encoding
1037  Fields.addInt(Int32Ty, 2);
1038  // Number of UTF-16 codepoints
1039  Fields.addInt(Int32Ty, StringLength);
1040  // Number of bytes
1041  Fields.addInt(Int32Ty, StringLength * 2);
1042  // Hash. Not currently initialised by the compiler.
1043  Fields.addInt(Int32Ty, 0);
1044  // pointer to the data string.
1045  auto Arr = llvm::makeArrayRef(&ToBuf[0], ToPtr+1);
1046  auto *C = llvm::ConstantDataArray::get(VMContext, Arr);
1047  auto *Buffer = new llvm::GlobalVariable(TheModule, C->getType(),
1048  /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, C, ".str");
1049  Buffer->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1050  Fields.add(Buffer);
1051  } else {
1052  // Flags: 0 indicates ASCII encoding
1053  Fields.addInt(Int32Ty, 0);
1054  // Number of UTF-16 codepoints, each ASCII byte is a UTF-16 codepoint
1055  Fields.addInt(Int32Ty, Str.size());
1056  // Number of bytes
1057  Fields.addInt(Int32Ty, Str.size());
1058  // Hash. Not currently initialised by the compiler.
1059  Fields.addInt(Int32Ty, 0);
1060  // Data pointer
1061  Fields.add(MakeConstantString(Str));
1062  }
1063  std::string StringName;
1064  bool isNamed = !isNonASCII;
1065  if (isNamed) {
1066  StringName = ".objc_str_";
1067  for (int i=0,e=Str.size() ; i<e ; ++i) {
1068  unsigned char c = Str[i];
1069  if (isalnum(c))
1070  StringName += c;
1071  else if (c == ' ')
1072  StringName += '_';
1073  else {
1074  isNamed = false;
1075  break;
1076  }
1077  }
1078  }
1079  auto *ObjCStrGV =
1080  Fields.finishAndCreateGlobal(
1081  isNamed ? StringRef(StringName) : ".objc_string",
1082  Align, false, isNamed ? llvm::GlobalValue::LinkOnceODRLinkage
1083  : llvm::GlobalValue::PrivateLinkage);
1084  ObjCStrGV->setSection(sectionName<ConstantStringSection>());
1085  if (isNamed) {
1086  ObjCStrGV->setComdat(TheModule.getOrInsertComdat(StringName));
1087  ObjCStrGV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1088  }
1089  llvm::Constant *ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStrGV, IdTy);
1090  ObjCStrings[Str] = ObjCStr;
1091  ConstantStrings.push_back(ObjCStr);
1092  return ConstantAddress(ObjCStr, Align);
1093  }
1094 
1095  void PushProperty(ConstantArrayBuilder &PropertiesArray,
1096  const ObjCPropertyDecl *property,
1097  const Decl *OCD,
1098  bool isSynthesized=true, bool
1099  isDynamic=true) override {
1100  // struct objc_property
1101  // {
1102  // const char *name;
1103  // const char *attributes;
1104  // const char *type;
1105  // SEL getter;
1106  // SEL setter;
1107  // };
1108  auto Fields = PropertiesArray.beginStruct(PropertyMetadataTy);
1109  ASTContext &Context = CGM.getContext();
1110  Fields.add(MakeConstantString(property->getNameAsString()));
1111  std::string TypeStr =
1112  CGM.getContext().getObjCEncodingForPropertyDecl(property, OCD);
1113  Fields.add(MakeConstantString(TypeStr));
1114  std::string typeStr;
1115  Context.getObjCEncodingForType(property->getType(), typeStr);
1116  Fields.add(MakeConstantString(typeStr));
1117  auto addPropertyMethod = [&](const ObjCMethodDecl *accessor) {
1118  if (accessor) {
1119  std::string TypeStr = Context.getObjCEncodingForMethodDecl(accessor);
1120  Fields.add(GetConstantSelector(accessor->getSelector(), TypeStr));
1121  } else {
1122  Fields.add(NULLPtr);
1123  }
1124  };
1125  addPropertyMethod(property->getGetterMethodDecl());
1126  addPropertyMethod(property->getSetterMethodDecl());
1127  Fields.finishAndAddTo(PropertiesArray);
1128  }
1129 
1130  llvm::Constant *
1131  GenerateProtocolMethodList(ArrayRef<const ObjCMethodDecl*> Methods) override {
1132  // struct objc_protocol_method_description
1133  // {
1134  // SEL selector;
1135  // const char *types;
1136  // };
1137  llvm::StructType *ObjCMethodDescTy =
1138  llvm::StructType::get(CGM.getLLVMContext(),
1139  { PtrToInt8Ty, PtrToInt8Ty });
1140  ASTContext &Context = CGM.getContext();
1141  ConstantInitBuilder Builder(CGM);
1142  // struct objc_protocol_method_description_list
1143  // {
1144  // int count;
1145  // int size;
1146  // struct objc_protocol_method_description methods[];
1147  // };
1148  auto MethodList = Builder.beginStruct();
1149  // int count;
1150  MethodList.addInt(IntTy, Methods.size());
1151  // int size; // sizeof(struct objc_method_description)
1152  llvm::DataLayout td(&TheModule);
1153  MethodList.addInt(IntTy, td.getTypeSizeInBits(ObjCMethodDescTy) /
1154  CGM.getContext().getCharWidth());
1155  // struct objc_method_description[]
1156  auto MethodArray = MethodList.beginArray(ObjCMethodDescTy);
1157  for (auto *M : Methods) {
1158  auto Method = MethodArray.beginStruct(ObjCMethodDescTy);
1159  Method.add(CGObjCGNU::GetConstantSelector(M));
1160  Method.add(GetTypeString(Context.getObjCEncodingForMethodDecl(M, true)));
1161  Method.finishAndAddTo(MethodArray);
1162  }
1163  MethodArray.finishAndAddTo(MethodList);
1164  return MethodList.finishAndCreateGlobal(".objc_protocol_method_list",
1165  CGM.getPointerAlign());
1166  }
1167 
1168  llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
1169  llvm::Value *cmd, MessageSendInfo &MSI) override {
1170  // Don't access the slot unless we're trying to cache the result.
1171  CGBuilderTy &Builder = CGF.Builder;
1172  llvm::Value *lookupArgs[] = {CGObjCGNU::EnforceType(Builder, ObjCSuper,
1173  PtrToObjCSuperTy).getPointer(), cmd};
1174  return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
1175  }
1176 
1177  llvm::GlobalVariable *GetClassVar(StringRef Name, bool isWeak=false) {
1178  std::string SymbolName = SymbolForClassRef(Name, isWeak);
1179  auto *ClassSymbol = TheModule.getNamedGlobal(SymbolName);
1180  if (ClassSymbol)
1181  return ClassSymbol;
1182  ClassSymbol = new llvm::GlobalVariable(TheModule,
1184  nullptr, SymbolName);
1185  // If this is a weak symbol, then we are creating a valid definition for
1186  // the symbol, pointing to a weak definition of the real class pointer. If
1187  // this is not a weak reference, then we are expecting another compilation
1188  // unit to provide the real indirection symbol.
1189  if (isWeak)
1190  ClassSymbol->setInitializer(new llvm::GlobalVariable(TheModule,
1191  Int8Ty, false, llvm::GlobalValue::ExternalWeakLinkage,
1192  nullptr, SymbolForClass(Name)));
1193  assert(ClassSymbol->getName() == SymbolName);
1194  return ClassSymbol;
1195  }
1196  llvm::Value *GetClassNamed(CodeGenFunction &CGF,
1197  const std::string &Name,
1198  bool isWeak) override {
1199  return CGF.Builder.CreateLoad(Address(GetClassVar(Name, isWeak),
1200  CGM.getPointerAlign()));
1201  }
1202  int32_t FlagsForOwnership(Qualifiers::ObjCLifetime Ownership) {
1203  // typedef enum {
1204  // ownership_invalid = 0,
1205  // ownership_strong = 1,
1206  // ownership_weak = 2,
1207  // ownership_unsafe = 3
1208  // } ivar_ownership;
1209  int Flag;
1210  switch (Ownership) {
1212  Flag = 1;
1213  break;
1214  case Qualifiers::OCL_Weak:
1215  Flag = 2;
1216  break;
1218  Flag = 3;
1219  break;
1220  case Qualifiers::OCL_None:
1222  assert(Ownership != Qualifiers::OCL_Autoreleasing);
1223  Flag = 0;
1224  }
1225  return Flag;
1226  }
1227  llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
1228  ArrayRef<llvm::Constant *> IvarTypes,
1229  ArrayRef<llvm::Constant *> IvarOffsets,
1230  ArrayRef<llvm::Constant *> IvarAlign,
1231  ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership) override {
1232  llvm_unreachable("Method should not be called!");
1233  }
1234 
1235  llvm::Constant *GenerateEmptyProtocol(StringRef ProtocolName) override {
1236  std::string Name = SymbolForProtocol(ProtocolName);
1237  auto *GV = TheModule.getGlobalVariable(Name);
1238  if (!GV) {
1239  // Emit a placeholder symbol.
1240  GV = new llvm::GlobalVariable(TheModule, ProtocolTy, false,
1241  llvm::GlobalValue::ExternalLinkage, nullptr, Name);
1242  GV->setAlignment(CGM.getPointerAlign().getQuantity());
1243  }
1244  return llvm::ConstantExpr::getBitCast(GV, ProtocolPtrTy);
1245  }
1246 
1247  /// Existing protocol references.
1248  llvm::StringMap<llvm::Constant*> ExistingProtocolRefs;
1249 
1250  llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
1251  const ObjCProtocolDecl *PD) override {
1252  auto Name = PD->getNameAsString();
1253  auto *&Ref = ExistingProtocolRefs[Name];
1254  if (!Ref) {
1255  auto *&Protocol = ExistingProtocols[Name];
1256  if (!Protocol)
1257  Protocol = GenerateProtocolRef(PD);
1258  std::string RefName = SymbolForProtocolRef(Name);
1259  assert(!TheModule.getGlobalVariable(RefName));
1260  // Emit a reference symbol.
1261  auto GV = new llvm::GlobalVariable(TheModule, ProtocolPtrTy,
1262  false, llvm::GlobalValue::LinkOnceODRLinkage,
1263  llvm::ConstantExpr::getBitCast(Protocol, ProtocolPtrTy), RefName);
1264  GV->setComdat(TheModule.getOrInsertComdat(RefName));
1265  GV->setSection(sectionName<ProtocolReferenceSection>());
1266  GV->setAlignment(CGM.getPointerAlign().getQuantity());
1267  Ref = GV;
1268  }
1269  EmittedProtocolRef = true;
1270  return CGF.Builder.CreateAlignedLoad(Ref, CGM.getPointerAlign());
1271  }
1272 
1273  llvm::Constant *GenerateProtocolList(ArrayRef<llvm::Constant*> Protocols) {
1274  llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(ProtocolPtrTy,
1275  Protocols.size());
1276  llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy,
1277  Protocols);
1278  ConstantInitBuilder builder(CGM);
1279  auto ProtocolBuilder = builder.beginStruct();
1280  ProtocolBuilder.addNullPointer(PtrTy);
1281  ProtocolBuilder.addInt(SizeTy, Protocols.size());
1282  ProtocolBuilder.add(ProtocolArray);
1283  return ProtocolBuilder.finishAndCreateGlobal(".objc_protocol_list",
1285  }
1286 
1287  void GenerateProtocol(const ObjCProtocolDecl *PD) override {
1288  // Do nothing - we only emit referenced protocols.
1289  }
1290  llvm::Constant *GenerateProtocolRef(const ObjCProtocolDecl *PD) {
1291  std::string ProtocolName = PD->getNameAsString();
1292  auto *&Protocol = ExistingProtocols[ProtocolName];
1293  if (Protocol)
1294  return Protocol;
1295 
1296  EmittedProtocol = true;
1297 
1298  auto SymName = SymbolForProtocol(ProtocolName);
1299  auto *OldGV = TheModule.getGlobalVariable(SymName);
1300 
1301  // Use the protocol definition, if there is one.
1302  if (const ObjCProtocolDecl *Def = PD->getDefinition())
1303  PD = Def;
1304  else {
1305  // If there is no definition, then create an external linkage symbol and
1306  // hope that someone else fills it in for us (and fail to link if they
1307  // don't).
1308  assert(!OldGV);
1309  Protocol = new llvm::GlobalVariable(TheModule, ProtocolTy,
1310  /*isConstant*/false,
1311  llvm::GlobalValue::ExternalLinkage, nullptr, SymName);
1312  return Protocol;
1313  }
1314 
1316  for (const auto *PI : PD->protocols())
1317  Protocols.push_back(
1318  llvm::ConstantExpr::getBitCast(GenerateProtocolRef(PI),
1319  ProtocolPtrTy));
1320  llvm::Constant *ProtocolList = GenerateProtocolList(Protocols);
1321 
1322  // Collect information about methods
1323  llvm::Constant *InstanceMethodList, *OptionalInstanceMethodList;
1324  llvm::Constant *ClassMethodList, *OptionalClassMethodList;
1325  EmitProtocolMethodList(PD->instance_methods(), InstanceMethodList,
1326  OptionalInstanceMethodList);
1327  EmitProtocolMethodList(PD->class_methods(), ClassMethodList,
1328  OptionalClassMethodList);
1329 
1330  // The isa pointer must be set to a magic number so the runtime knows it's
1331  // the correct layout.
1332  ConstantInitBuilder builder(CGM);
1333  auto ProtocolBuilder = builder.beginStruct();
1334  ProtocolBuilder.add(llvm::ConstantExpr::getIntToPtr(
1335  llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
1336  ProtocolBuilder.add(MakeConstantString(ProtocolName));
1337  ProtocolBuilder.add(ProtocolList);
1338  ProtocolBuilder.add(InstanceMethodList);
1339  ProtocolBuilder.add(ClassMethodList);
1340  ProtocolBuilder.add(OptionalInstanceMethodList);
1341  ProtocolBuilder.add(OptionalClassMethodList);
1342  // Required instance properties
1343  ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, false, false));
1344  // Optional instance properties
1345  ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, false, true));
1346  // Required class properties
1347  ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, true, false));
1348  // Optional class properties
1349  ProtocolBuilder.add(GeneratePropertyList(nullptr, PD, true, true));
1350 
1351  auto *GV = ProtocolBuilder.finishAndCreateGlobal(SymName,
1353  GV->setSection(sectionName<ProtocolSection>());
1354  GV->setComdat(TheModule.getOrInsertComdat(SymName));
1355  if (OldGV) {
1356  OldGV->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GV,
1357  OldGV->getType()));
1358  OldGV->removeFromParent();
1359  GV->setName(SymName);
1360  }
1361  Protocol = GV;
1362  return GV;
1363  }
1364  llvm::Constant *EnforceType(llvm::Constant *Val, llvm::Type *Ty) {
1365  if (Val->getType() == Ty)
1366  return Val;
1367  return llvm::ConstantExpr::getBitCast(Val, Ty);
1368  }
1369  llvm::Value *GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
1370  const std::string &TypeEncoding) override {
1371  return GetConstantSelector(Sel, TypeEncoding);
1372  }
1373  llvm::Constant *GetTypeString(llvm::StringRef TypeEncoding) {
1374  if (TypeEncoding.empty())
1375  return NULLPtr;
1376  std::string MangledTypes = TypeEncoding;
1377  std::replace(MangledTypes.begin(), MangledTypes.end(),
1378  '@', '\1');
1379  std::string TypesVarName = ".objc_sel_types_" + MangledTypes;
1380  auto *TypesGlobal = TheModule.getGlobalVariable(TypesVarName);
1381  if (!TypesGlobal) {
1382  llvm::Constant *Init = llvm::ConstantDataArray::getString(VMContext,
1383  TypeEncoding);
1384  auto *GV = new llvm::GlobalVariable(TheModule, Init->getType(),
1385  true, llvm::GlobalValue::LinkOnceODRLinkage, Init, TypesVarName);
1386  GV->setComdat(TheModule.getOrInsertComdat(TypesVarName));
1387  GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1388  TypesGlobal = GV;
1389  }
1390  return llvm::ConstantExpr::getGetElementPtr(TypesGlobal->getValueType(),
1391  TypesGlobal, Zeros);
1392  }
1393  llvm::Constant *GetConstantSelector(Selector Sel,
1394  const std::string &TypeEncoding) override {
1395  // @ is used as a special character in symbol names (used for symbol
1396  // versioning), so mangle the name to not include it. Replace it with a
1397  // character that is not a valid type encoding character (and, being
1398  // non-printable, never will be!)
1399  std::string MangledTypes = TypeEncoding;
1400  std::replace(MangledTypes.begin(), MangledTypes.end(),
1401  '@', '\1');
1402  auto SelVarName = (StringRef(".objc_selector_") + Sel.getAsString() + "_" +
1403  MangledTypes).str();
1404  if (auto *GV = TheModule.getNamedGlobal(SelVarName))
1405  return EnforceType(GV, SelectorTy);
1406  ConstantInitBuilder builder(CGM);
1407  auto SelBuilder = builder.beginStruct();
1408  SelBuilder.add(ExportUniqueString(Sel.getAsString(), ".objc_sel_name_",
1409  true));
1410  SelBuilder.add(GetTypeString(TypeEncoding));
1411  auto *GV = SelBuilder.finishAndCreateGlobal(SelVarName,
1412  CGM.getPointerAlign(), false, llvm::GlobalValue::LinkOnceODRLinkage);
1413  GV->setComdat(TheModule.getOrInsertComdat(SelVarName));
1414  GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1415  GV->setSection(sectionName<SelectorSection>());
1416  auto *SelVal = EnforceType(GV, SelectorTy);
1417  return SelVal;
1418  }
1419  llvm::StructType *emptyStruct = nullptr;
1420 
1421  /// Return pointers to the start and end of a section. On ELF platforms, we
1422  /// use the __start_ and __stop_ symbols that GNU-compatible linkers will set
1423  /// to the start and end of section names, as long as those section names are
1424  /// valid identifiers and the symbols are referenced but not defined. On
1425  /// Windows, we use the fact that MSVC-compatible linkers will lexically sort
1426  /// by subsections and place everything that we want to reference in a middle
1427  /// subsection and then insert zero-sized symbols in subsections a and z.
1428  std::pair<llvm::Constant*,llvm::Constant*>
1429  GetSectionBounds(StringRef Section) {
1430  if (CGM.getTriple().isOSBinFormatCOFF()) {
1431  if (emptyStruct == nullptr) {
1432  emptyStruct = llvm::StructType::create(VMContext, ".objc_section_sentinel");
1433  emptyStruct->setBody({}, /*isPacked*/true);
1434  }
1435  auto ZeroInit = llvm::Constant::getNullValue(emptyStruct);
1436  auto Sym = [&](StringRef Prefix, StringRef SecSuffix) {
1437  auto *Sym = new llvm::GlobalVariable(TheModule, emptyStruct,
1438  /*isConstant*/false,
1439  llvm::GlobalValue::LinkOnceODRLinkage, ZeroInit, Prefix +
1440  Section);
1441  Sym->setVisibility(llvm::GlobalValue::HiddenVisibility);
1442  Sym->setSection((Section + SecSuffix).str());
1443  Sym->setComdat(TheModule.getOrInsertComdat((Prefix +
1444  Section).str()));
1445  Sym->setAlignment(1);
1446  return Sym;
1447  };
1448  return { Sym("__start_", "$a"), Sym("__stop", "$z") };
1449  }
1450  auto *Start = new llvm::GlobalVariable(TheModule, PtrTy,
1451  /*isConstant*/false,
1452  llvm::GlobalValue::ExternalLinkage, nullptr, StringRef("__start_") +
1453  Section);
1454  Start->setVisibility(llvm::GlobalValue::HiddenVisibility);
1455  auto *Stop = new llvm::GlobalVariable(TheModule, PtrTy,
1456  /*isConstant*/false,
1457  llvm::GlobalValue::ExternalLinkage, nullptr, StringRef("__stop_") +
1458  Section);
1459  Stop->setVisibility(llvm::GlobalValue::HiddenVisibility);
1460  return { Start, Stop };
1461  }
1462  CatchTypeInfo getCatchAllTypeInfo() override {
1463  return CGM.getCXXABI().getCatchAllTypeInfo();
1464  }
1465  llvm::Function *ModuleInitFunction() override {
1466  llvm::Function *LoadFunction = llvm::Function::Create(
1467  llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false),
1468  llvm::GlobalValue::LinkOnceODRLinkage, ".objcv2_load_function",
1469  &TheModule);
1470  LoadFunction->setVisibility(llvm::GlobalValue::HiddenVisibility);
1471  LoadFunction->setComdat(TheModule.getOrInsertComdat(".objcv2_load_function"));
1472 
1473  llvm::BasicBlock *EntryBB =
1474  llvm::BasicBlock::Create(VMContext, "entry", LoadFunction);
1475  CGBuilderTy B(CGM, VMContext);
1476  B.SetInsertPoint(EntryBB);
1477  ConstantInitBuilder builder(CGM);
1478  auto InitStructBuilder = builder.beginStruct();
1479  InitStructBuilder.addInt(Int64Ty, 0);
1480  for (auto *s : SectionsBaseNames) {
1481  auto bounds = GetSectionBounds(s);
1482  InitStructBuilder.add(bounds.first);
1483  InitStructBuilder.add(bounds.second);
1484  };
1485  auto *InitStruct = InitStructBuilder.finishAndCreateGlobal(".objc_init",
1486  CGM.getPointerAlign(), false, llvm::GlobalValue::LinkOnceODRLinkage);
1487  InitStruct->setVisibility(llvm::GlobalValue::HiddenVisibility);
1488  InitStruct->setComdat(TheModule.getOrInsertComdat(".objc_init"));
1489 
1490  CallRuntimeFunction(B, "__objc_load", {InitStruct});;
1491  B.CreateRetVoid();
1492  // Make sure that the optimisers don't delete this function.
1493  CGM.addCompilerUsedGlobal(LoadFunction);
1494  // FIXME: Currently ELF only!
1495  // We have to do this by hand, rather than with @llvm.ctors, so that the
1496  // linker can remove the duplicate invocations.
1497  auto *InitVar = new llvm::GlobalVariable(TheModule, LoadFunction->getType(),
1498  /*isConstant*/true, llvm::GlobalValue::LinkOnceAnyLinkage,
1499  LoadFunction, ".objc_ctor");
1500  // Check that this hasn't been renamed. This shouldn't happen, because
1501  // this function should be called precisely once.
1502  assert(InitVar->getName() == ".objc_ctor");
1503  // In Windows, initialisers are sorted by the suffix. XCL is for library
1504  // initialisers, which run before user initialisers. We are running
1505  // Objective-C loads at the end of library load. This means +load methods
1506  // will run before any other static constructors, but that static
1507  // constructors can see a fully initialised Objective-C state.
1508  if (CGM.getTriple().isOSBinFormatCOFF())
1509  InitVar->setSection(".CRT$XCLz");
1510  else
1511  InitVar->setSection(".ctors");
1512  InitVar->setVisibility(llvm::GlobalValue::HiddenVisibility);
1513  InitVar->setComdat(TheModule.getOrInsertComdat(".objc_ctor"));
1514  CGM.addUsedGlobal(InitVar);
1515  for (auto *C : Categories) {
1516  auto *Cat = cast<llvm::GlobalVariable>(C->stripPointerCasts());
1517  Cat->setSection(sectionName<CategorySection>());
1518  CGM.addUsedGlobal(Cat);
1519  }
1520  auto createNullGlobal = [&](StringRef Name, ArrayRef<llvm::Constant*> Init,
1521  StringRef Section) {
1522  auto nullBuilder = builder.beginStruct();
1523  for (auto *F : Init)
1524  nullBuilder.add(F);
1525  auto GV = nullBuilder.finishAndCreateGlobal(Name, CGM.getPointerAlign(),
1526  false, llvm::GlobalValue::LinkOnceODRLinkage);
1527  GV->setSection(Section);
1528  GV->setComdat(TheModule.getOrInsertComdat(Name));
1529  GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1530  CGM.addUsedGlobal(GV);
1531  return GV;
1532  };
1533  for (auto clsAlias : ClassAliases)
1534  createNullGlobal(std::string(".objc_class_alias") +
1535  clsAlias.second, { MakeConstantString(clsAlias.second),
1536  GetClassVar(clsAlias.first) }, sectionName<ClassAliasSection>());
1537  // On ELF platforms, add a null value for each special section so that we
1538  // can always guarantee that the _start and _stop symbols will exist and be
1539  // meaningful. This is not required on COFF platforms, where our start and
1540  // stop symbols will create the section.
1541  if (!CGM.getTriple().isOSBinFormatCOFF()) {
1542  createNullGlobal(".objc_null_selector", {NULLPtr, NULLPtr},
1543  sectionName<SelectorSection>());
1544  if (Categories.empty())
1545  createNullGlobal(".objc_null_category", {NULLPtr, NULLPtr,
1546  NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr},
1547  sectionName<CategorySection>());
1548  if (!EmittedClass) {
1549  createNullGlobal(".objc_null_cls_init_ref", NULLPtr,
1550  sectionName<ClassReferenceSection>());
1551  createNullGlobal(".objc_null_class_ref", { NULLPtr, NULLPtr },
1552  sectionName<ClassReferenceSection>());
1553  }
1554  if (!EmittedProtocol)
1555  createNullGlobal(".objc_null_protocol", {NULLPtr, NULLPtr, NULLPtr,
1556  NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr, NULLPtr,
1557  NULLPtr}, sectionName<ProtocolSection>());
1558  if (!EmittedProtocolRef)
1559  createNullGlobal(".objc_null_protocol_ref", {NULLPtr},
1560  sectionName<ProtocolReferenceSection>());
1561  if (ClassAliases.empty())
1562  createNullGlobal(".objc_null_class_alias", { NULLPtr, NULLPtr },
1563  sectionName<ClassAliasSection>());
1564  if (ConstantStrings.empty()) {
1565  auto i32Zero = llvm::ConstantInt::get(Int32Ty, 0);
1566  createNullGlobal(".objc_null_constant_string", { NULLPtr, i32Zero,
1567  i32Zero, i32Zero, i32Zero, NULLPtr },
1568  sectionName<ConstantStringSection>());
1569  }
1570  }
1571  ConstantStrings.clear();
1572  Categories.clear();
1573  Classes.clear();
1574  return nullptr;
1575  }
1576  /// In the v2 ABI, ivar offset variables use the type encoding in their name
1577  /// to trigger linker failures if the types don't match.
1578  std::string GetIVarOffsetVariableName(const ObjCInterfaceDecl *ID,
1579  const ObjCIvarDecl *Ivar) override {
1580  std::string TypeEncoding;
1581  CGM.getContext().getObjCEncodingForType(Ivar->getType(), TypeEncoding);
1582  // Prevent the @ from being interpreted as a symbol version.
1583  std::replace(TypeEncoding.begin(), TypeEncoding.end(),
1584  '@', '\1');
1585  const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString()
1586  + '.' + Ivar->getNameAsString() + '.' + TypeEncoding;
1587  return Name;
1588  }
1589  llvm::Value *EmitIvarOffset(CodeGenFunction &CGF,
1590  const ObjCInterfaceDecl *Interface,
1591  const ObjCIvarDecl *Ivar) override {
1592  const std::string Name = GetIVarOffsetVariableName(Ivar->getContainingInterface(), Ivar);
1593  llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name);
1594  if (!IvarOffsetPointer)
1595  IvarOffsetPointer = new llvm::GlobalVariable(TheModule, IntTy, false,
1596  llvm::GlobalValue::ExternalLinkage, nullptr, Name);
1597  CharUnits Align = CGM.getIntAlign();
1598  llvm::Value *Offset = CGF.Builder.CreateAlignedLoad(IvarOffsetPointer, Align);
1599  if (Offset->getType() != PtrDiffTy)
1600  Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy);
1601  return Offset;
1602  }
1603  void GenerateClass(const ObjCImplementationDecl *OID) override {
1604  ASTContext &Context = CGM.getContext();
1605 
1606  // Get the class name
1607  ObjCInterfaceDecl *classDecl =
1608  const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
1609  std::string className = classDecl->getNameAsString();
1610  auto *classNameConstant = MakeConstantString(className);
1611 
1612  ConstantInitBuilder builder(CGM);
1613  auto metaclassFields = builder.beginStruct();
1614  // struct objc_class *isa;
1615  metaclassFields.addNullPointer(PtrTy);
1616  // struct objc_class *super_class;
1617  metaclassFields.addNullPointer(PtrTy);
1618  // const char *name;
1619  metaclassFields.add(classNameConstant);
1620  // long version;
1621  metaclassFields.addInt(LongTy, 0);
1622  // unsigned long info;
1623  // objc_class_flag_meta
1624  metaclassFields.addInt(LongTy, 1);
1625  // long instance_size;
1626  // Setting this to zero is consistent with the older ABI, but it might be
1627  // more sensible to set this to sizeof(struct objc_class)
1628  metaclassFields.addInt(LongTy, 0);
1629  // struct objc_ivar_list *ivars;
1630  metaclassFields.addNullPointer(PtrTy);
1631  // struct objc_method_list *methods
1632  // FIXME: Almost identical code is copied and pasted below for the
1633  // class, but refactoring it cleanly requires C++14 generic lambdas.
1634  if (OID->classmeth_begin() == OID->classmeth_end())
1635  metaclassFields.addNullPointer(PtrTy);
1636  else {
1637  SmallVector<ObjCMethodDecl*, 16> ClassMethods;
1638  ClassMethods.insert(ClassMethods.begin(), OID->classmeth_begin(),
1639  OID->classmeth_end());
1640  metaclassFields.addBitCast(
1641  GenerateMethodList(className, "", ClassMethods, true),
1642  PtrTy);
1643  }
1644  // void *dtable;
1645  metaclassFields.addNullPointer(PtrTy);
1646  // IMP cxx_construct;
1647  metaclassFields.addNullPointer(PtrTy);
1648  // IMP cxx_destruct;
1649  metaclassFields.addNullPointer(PtrTy);
1650  // struct objc_class *subclass_list
1651  metaclassFields.addNullPointer(PtrTy);
1652  // struct objc_class *sibling_class
1653  metaclassFields.addNullPointer(PtrTy);
1654  // struct objc_protocol_list *protocols;
1655  metaclassFields.addNullPointer(PtrTy);
1656  // struct reference_list *extra_data;
1657  metaclassFields.addNullPointer(PtrTy);
1658  // long abi_version;
1659  metaclassFields.addInt(LongTy, 0);
1660  // struct objc_property_list *properties
1661  metaclassFields.add(GeneratePropertyList(OID, classDecl, /*isClassProperty*/true));
1662 
1663  auto *metaclass = metaclassFields.finishAndCreateGlobal("._OBJC_METACLASS_"
1664  + className, CGM.getPointerAlign());
1665 
1666  auto classFields = builder.beginStruct();
1667  // struct objc_class *isa;
1668  classFields.add(metaclass);
1669  // struct objc_class *super_class;
1670  // Get the superclass name.
1671  const ObjCInterfaceDecl * SuperClassDecl =
1672  OID->getClassInterface()->getSuperClass();
1673  if (SuperClassDecl) {
1674  auto SuperClassName = SymbolForClass(SuperClassDecl->getNameAsString());
1675  llvm::Constant *SuperClass = TheModule.getNamedGlobal(SuperClassName);
1676  if (!SuperClass)
1677  {
1678  SuperClass = new llvm::GlobalVariable(TheModule, PtrTy, false,
1679  llvm::GlobalValue::ExternalLinkage, nullptr, SuperClassName);
1680  }
1681  classFields.add(llvm::ConstantExpr::getBitCast(SuperClass, PtrTy));
1682  } else
1683  classFields.addNullPointer(PtrTy);
1684  // const char *name;
1685  classFields.add(classNameConstant);
1686  // long version;
1687  classFields.addInt(LongTy, 0);
1688  // unsigned long info;
1689  // !objc_class_flag_meta
1690  classFields.addInt(LongTy, 0);
1691  // long instance_size;
1692  int superInstanceSize = !SuperClassDecl ? 0 :
1693  Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity();
1694  // Instance size is negative for classes that have not yet had their ivar
1695  // layout calculated.
1696  classFields.addInt(LongTy,
1697  0 - (Context.getASTObjCImplementationLayout(OID).getSize().getQuantity() -
1698  superInstanceSize));
1699 
1700  if (classDecl->all_declared_ivar_begin() == nullptr)
1701  classFields.addNullPointer(PtrTy);
1702  else {
1703  int ivar_count = 0;
1704  for (const ObjCIvarDecl *IVD = classDecl->all_declared_ivar_begin(); IVD;
1705  IVD = IVD->getNextIvar()) ivar_count++;
1706  llvm::DataLayout td(&TheModule);
1707  // struct objc_ivar_list *ivars;
1708  ConstantInitBuilder b(CGM);
1709  auto ivarListBuilder = b.beginStruct();
1710  // int count;
1711  ivarListBuilder.addInt(IntTy, ivar_count);
1712  // size_t size;
1713  llvm::StructType *ObjCIvarTy = llvm::StructType::get(
1714  PtrToInt8Ty,
1715  PtrToInt8Ty,
1716  PtrToInt8Ty,
1717  Int32Ty,
1718  Int32Ty);
1719  ivarListBuilder.addInt(SizeTy, td.getTypeSizeInBits(ObjCIvarTy) /
1720  CGM.getContext().getCharWidth());
1721  // struct objc_ivar ivars[]
1722  auto ivarArrayBuilder = ivarListBuilder.beginArray();
1723  CodeGenTypes &Types = CGM.getTypes();
1724  for (const ObjCIvarDecl *IVD = classDecl->all_declared_ivar_begin(); IVD;
1725  IVD = IVD->getNextIvar()) {
1726  auto ivarTy = IVD->getType();
1727  auto ivarBuilder = ivarArrayBuilder.beginStruct();
1728  // const char *name;
1729  ivarBuilder.add(MakeConstantString(IVD->getNameAsString()));
1730  // const char *type;
1731  std::string TypeStr;
1732  //Context.getObjCEncodingForType(ivarTy, TypeStr, IVD, true);
1733  Context.getObjCEncodingForMethodParameter(Decl::OBJC_TQ_None, ivarTy, TypeStr, true);
1734  ivarBuilder.add(MakeConstantString(TypeStr));
1735  // int *offset;
1736  uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD);
1737  uint64_t Offset = BaseOffset - superInstanceSize;
1738  llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset);
1739  std::string OffsetName = GetIVarOffsetVariableName(classDecl, IVD);
1740  llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName);
1741  if (OffsetVar)
1742  OffsetVar->setInitializer(OffsetValue);
1743  else
1744  OffsetVar = new llvm::GlobalVariable(TheModule, IntTy,
1746  OffsetValue, OffsetName);
1747  auto ivarVisibility =
1748  (IVD->getAccessControl() == ObjCIvarDecl::Private ||
1749  IVD->getAccessControl() == ObjCIvarDecl::Package ||
1750  classDecl->getVisibility() == HiddenVisibility) ?
1753  OffsetVar->setVisibility(ivarVisibility);
1754  ivarBuilder.add(OffsetVar);
1755  // Ivar size
1756  ivarBuilder.addInt(Int32Ty,
1757  td.getTypeSizeInBits(Types.ConvertType(ivarTy)) /
1758  CGM.getContext().getCharWidth());
1759  // Alignment will be stored as a base-2 log of the alignment.
1760  int align = llvm::Log2_32(Context.getTypeAlignInChars(ivarTy).getQuantity());
1761  // Objects that require more than 2^64-byte alignment should be impossible!
1762  assert(align < 64);
1763  // uint32_t flags;
1764  // Bits 0-1 are ownership.
1765  // Bit 2 indicates an extended type encoding
1766  // Bits 3-8 contain log2(aligment)
1767  ivarBuilder.addInt(Int32Ty,
1768  (align << 3) | (1<<2) |
1769  FlagsForOwnership(ivarTy.getQualifiers().getObjCLifetime()));
1770  ivarBuilder.finishAndAddTo(ivarArrayBuilder);
1771  }
1772  ivarArrayBuilder.finishAndAddTo(ivarListBuilder);
1773  auto ivarList = ivarListBuilder.finishAndCreateGlobal(".objc_ivar_list",
1774  CGM.getPointerAlign(), /*constant*/ false,
1775  llvm::GlobalValue::PrivateLinkage);
1776  classFields.add(ivarList);
1777  }
1778  // struct objc_method_list *methods
1780  InstanceMethods.insert(InstanceMethods.begin(), OID->instmeth_begin(),
1781  OID->instmeth_end());
1782  for (auto *propImpl : OID->property_impls())
1783  if (propImpl->getPropertyImplementation() ==
1785  ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
1786  auto addIfExists = [&](const ObjCMethodDecl* OMD) {
1787  if (OMD)
1788  InstanceMethods.push_back(OMD);
1789  };
1790  addIfExists(prop->getGetterMethodDecl());
1791  addIfExists(prop->getSetterMethodDecl());
1792  }
1793 
1794  if (InstanceMethods.size() == 0)
1795  classFields.addNullPointer(PtrTy);
1796  else
1797  classFields.addBitCast(
1798  GenerateMethodList(className, "", InstanceMethods, false),
1799  PtrTy);
1800  // void *dtable;
1801  classFields.addNullPointer(PtrTy);
1802  // IMP cxx_construct;
1803  classFields.addNullPointer(PtrTy);
1804  // IMP cxx_destruct;
1805  classFields.addNullPointer(PtrTy);
1806  // struct objc_class *subclass_list
1807  classFields.addNullPointer(PtrTy);
1808  // struct objc_class *sibling_class
1809  classFields.addNullPointer(PtrTy);
1810  // struct objc_protocol_list *protocols;
1812  for (const auto *I : classDecl->protocols())
1813  Protocols.push_back(
1814  llvm::ConstantExpr::getBitCast(GenerateProtocolRef(I),
1815  ProtocolPtrTy));
1816  if (Protocols.empty())
1817  classFields.addNullPointer(PtrTy);
1818  else
1819  classFields.add(GenerateProtocolList(Protocols));
1820  // struct reference_list *extra_data;
1821  classFields.addNullPointer(PtrTy);
1822  // long abi_version;
1823  classFields.addInt(LongTy, 0);
1824  // struct objc_property_list *properties
1825  classFields.add(GeneratePropertyList(OID, classDecl));
1826 
1827  auto *classStruct =
1828  classFields.finishAndCreateGlobal(SymbolForClass(className),
1830 
1831  if (CGM.getTriple().isOSBinFormatCOFF()) {
1832  auto Storage = llvm::GlobalValue::DefaultStorageClass;
1833  if (OID->getClassInterface()->hasAttr<DLLImportAttr>())
1834  Storage = llvm::GlobalValue::DLLImportStorageClass;
1835  else if (OID->getClassInterface()->hasAttr<DLLExportAttr>())
1836  Storage = llvm::GlobalValue::DLLExportStorageClass;
1837  cast<llvm::GlobalValue>(classStruct)->setDLLStorageClass(Storage);
1838  }
1839 
1840  auto *classRefSymbol = GetClassVar(className);
1841  classRefSymbol->setSection(sectionName<ClassReferenceSection>());
1842  classRefSymbol->setInitializer(llvm::ConstantExpr::getBitCast(classStruct, IdTy));
1843 
1844 
1845  // Resolve the class aliases, if they exist.
1846  // FIXME: Class pointer aliases shouldn't exist!
1847  if (ClassPtrAlias) {
1848  ClassPtrAlias->replaceAllUsesWith(
1849  llvm::ConstantExpr::getBitCast(classStruct, IdTy));
1850  ClassPtrAlias->eraseFromParent();
1851  ClassPtrAlias = nullptr;
1852  }
1853  if (auto Placeholder =
1854  TheModule.getNamedGlobal(SymbolForClass(className)))
1855  if (Placeholder != classStruct) {
1856  Placeholder->replaceAllUsesWith(
1857  llvm::ConstantExpr::getBitCast(classStruct, Placeholder->getType()));
1858  Placeholder->eraseFromParent();
1859  classStruct->setName(SymbolForClass(className));
1860  }
1861  if (MetaClassPtrAlias) {
1862  MetaClassPtrAlias->replaceAllUsesWith(
1863  llvm::ConstantExpr::getBitCast(metaclass, IdTy));
1864  MetaClassPtrAlias->eraseFromParent();
1865  MetaClassPtrAlias = nullptr;
1866  }
1867  assert(classStruct->getName() == SymbolForClass(className));
1868 
1869  auto classInitRef = new llvm::GlobalVariable(TheModule,
1870  classStruct->getType(), false, llvm::GlobalValue::ExternalLinkage,
1871  classStruct, "._OBJC_INIT_CLASS_" + className);
1872  classInitRef->setSection(sectionName<ClassSection>());
1873  CGM.addUsedGlobal(classInitRef);
1874 
1875  EmittedClass = true;
1876  }
1877  public:
1878  CGObjCGNUstep2(CodeGenModule &Mod) : CGObjCGNUstep(Mod, 10, 4, 2) {
1879  MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
1880  PtrToObjCSuperTy, SelectorTy);
1881  // struct objc_property
1882  // {
1883  // const char *name;
1884  // const char *attributes;
1885  // const char *type;
1886  // SEL getter;
1887  // SEL setter;
1888  // }
1889  PropertyMetadataTy =
1890  llvm::StructType::get(CGM.getLLVMContext(),
1891  { PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty });
1892  }
1893 
1894 };
1895 
1896 const char *const CGObjCGNUstep2::SectionsBaseNames[8] =
1897 {
1898 "__objc_selectors",
1899 "__objc_classes",
1900 "__objc_class_refs",
1901 "__objc_cats",
1902 "__objc_protocols",
1903 "__objc_protocol_refs",
1904 "__objc_class_aliases",
1905 "__objc_constant_string"
1906 };
1907 
1908 /// Support for the ObjFW runtime.
1909 class CGObjCObjFW: public CGObjCGNU {
1910 protected:
1911  /// The GCC ABI message lookup function. Returns an IMP pointing to the
1912  /// method implementation for this message.
1913  LazyRuntimeFunction MsgLookupFn;
1914  /// stret lookup function. While this does not seem to make sense at the
1915  /// first look, this is required to call the correct forwarding function.
1916  LazyRuntimeFunction MsgLookupFnSRet;
1917  /// The GCC ABI superclass message lookup function. Takes a pointer to a
1918  /// structure describing the receiver and the class, and a selector as
1919  /// arguments. Returns the IMP for the corresponding method.
1920  LazyRuntimeFunction MsgLookupSuperFn, MsgLookupSuperFnSRet;
1921 
1922  llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
1923  llvm::Value *cmd, llvm::MDNode *node,
1924  MessageSendInfo &MSI) override {
1925  CGBuilderTy &Builder = CGF.Builder;
1926  llvm::Value *args[] = {
1927  EnforceType(Builder, Receiver, IdTy),
1928  EnforceType(Builder, cmd, SelectorTy) };
1929 
1930  llvm::CallSite imp;
1931  if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
1932  imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFnSRet, args);
1933  else
1934  imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);
1935 
1936  imp->setMetadata(msgSendMDKind, node);
1937  return imp.getInstruction();
1938  }
1939 
1940  llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, Address ObjCSuper,
1941  llvm::Value *cmd, MessageSendInfo &MSI) override {
1942  CGBuilderTy &Builder = CGF.Builder;
1943  llvm::Value *lookupArgs[] = {
1944  EnforceType(Builder, ObjCSuper.getPointer(), PtrToObjCSuperTy), cmd,
1945  };
1946 
1947  if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
1948  return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFnSRet, lookupArgs);
1949  else
1950  return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
1951  }
1952 
1953  llvm::Value *GetClassNamed(CodeGenFunction &CGF, const std::string &Name,
1954  bool isWeak) override {
1955  if (isWeak)
1956  return CGObjCGNU::GetClassNamed(CGF, Name, isWeak);
1957 
1958  EmitClassRef(Name);
1959  std::string SymbolName = "_OBJC_CLASS_" + Name;
1960  llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(SymbolName);
1961  if (!ClassSymbol)
1962  ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
1964  nullptr, SymbolName);
1965  return ClassSymbol;
1966  }
1967 
1968 public:
1969  CGObjCObjFW(CodeGenModule &Mod): CGObjCGNU(Mod, 9, 3) {
1970  // IMP objc_msg_lookup(id, SEL);
1971  MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy);
1972  MsgLookupFnSRet.init(&CGM, "objc_msg_lookup_stret", IMPTy, IdTy,
1973  SelectorTy);
1974  // IMP objc_msg_lookup_super(struct objc_super*, SEL);
1975  MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
1976  PtrToObjCSuperTy, SelectorTy);
1977  MsgLookupSuperFnSRet.init(&CGM, "objc_msg_lookup_super_stret", IMPTy,
1978  PtrToObjCSuperTy, SelectorTy);
1979  }
1980 };
1981 } // end anonymous namespace
1982 
1983 /// Emits a reference to a dummy variable which is emitted with each class.
1984 /// This ensures that a linker error will be generated when trying to link
1985 /// together modules where a referenced class is not defined.
1986 void CGObjCGNU::EmitClassRef(const std::string &className) {
1987  std::string symbolRef = "__objc_class_ref_" + className;
1988  // Don't emit two copies of the same symbol
1989  if (TheModule.getGlobalVariable(symbolRef))
1990  return;
1991  std::string symbolName = "__objc_class_name_" + className;
1992  llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName);
1993  if (!ClassSymbol) {
1994  ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
1996  nullptr, symbolName);
1997  }
1998  new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true,
1999  llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef);
2000 }
2001 
2002 CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
2003  unsigned protocolClassVersion, unsigned classABI)
2004  : CGObjCRuntime(cgm), TheModule(CGM.getModule()),
2005  VMContext(cgm.getLLVMContext()), ClassPtrAlias(nullptr),
2006  MetaClassPtrAlias(nullptr), RuntimeVersion(runtimeABIVersion),
2007  ProtocolVersion(protocolClassVersion), ClassABIVersion(classABI) {
2008 
2009  msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend");
2010  usesSEHExceptions =
2011  cgm.getContext().getTargetInfo().getTriple().isWindowsMSVCEnvironment();
2012 
2013  CodeGenTypes &Types = CGM.getTypes();
2014  IntTy = cast<llvm::IntegerType>(
2015  Types.ConvertType(CGM.getContext().IntTy));
2016  LongTy = cast<llvm::IntegerType>(
2017  Types.ConvertType(CGM.getContext().LongTy));
2018  SizeTy = cast<llvm::IntegerType>(
2019  Types.ConvertType(CGM.getContext().getSizeType()));
2020  PtrDiffTy = cast<llvm::IntegerType>(
2021  Types.ConvertType(CGM.getContext().getPointerDiffType()));
2022  BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy);
2023 
2024  Int8Ty = llvm::Type::getInt8Ty(VMContext);
2025  // C string type. Used in lots of places.
2026  PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty);
2027  ProtocolPtrTy = llvm::PointerType::getUnqual(
2028  Types.ConvertType(CGM.getContext().getObjCProtoType()));
2029 
2030  Zeros[0] = llvm::ConstantInt::get(LongTy, 0);
2031  Zeros[1] = Zeros[0];
2032  NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty);
2033  // Get the selector Type.
2034  QualType selTy = CGM.getContext().getObjCSelType();
2035  if (QualType() == selTy) {
2036  SelectorTy = PtrToInt8Ty;
2037  } else {
2038  SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy));
2039  }
2040 
2041  PtrToIntTy = llvm::PointerType::getUnqual(IntTy);
2042  PtrTy = PtrToInt8Ty;
2043 
2044  Int32Ty = llvm::Type::getInt32Ty(VMContext);
2045  Int64Ty = llvm::Type::getInt64Ty(VMContext);
2046 
2047  IntPtrTy =
2048  CGM.getDataLayout().getPointerSizeInBits() == 32 ? Int32Ty : Int64Ty;
2049 
2050  // Object type
2051  QualType UnqualIdTy = CGM.getContext().getObjCIdType();
2052  ASTIdTy = CanQualType();
2053  if (UnqualIdTy != QualType()) {
2054  ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy);
2055  IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
2056  } else {
2057  IdTy = PtrToInt8Ty;
2058  }
2059  PtrToIdTy = llvm::PointerType::getUnqual(IdTy);
2060  ProtocolTy = llvm::StructType::get(IdTy,
2061  PtrToInt8Ty, // name
2062  PtrToInt8Ty, // protocols
2063  PtrToInt8Ty, // instance methods
2064  PtrToInt8Ty, // class methods
2065  PtrToInt8Ty, // optional instance methods
2066  PtrToInt8Ty, // optional class methods
2067  PtrToInt8Ty, // properties
2068  PtrToInt8Ty);// optional properties
2069 
2070  // struct objc_property_gsv1
2071  // {
2072  // const char *name;
2073  // char attributes;
2074  // char attributes2;
2075  // char unused1;
2076  // char unused2;
2077  // const char *getter_name;
2078  // const char *getter_types;
2079  // const char *setter_name;
2080  // const char *setter_types;
2081  // }
2082  PropertyMetadataTy = llvm::StructType::get(CGM.getLLVMContext(), {
2083  PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty,
2084  PtrToInt8Ty, PtrToInt8Ty });
2085 
2086  ObjCSuperTy = llvm::StructType::get(IdTy, IdTy);
2087  PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy);
2088 
2089  llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
2090 
2091  // void objc_exception_throw(id);
2092  ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
2093  ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy);
2094  // int objc_sync_enter(id);
2095  SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy);
2096  // int objc_sync_exit(id);
2097  SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy);
2098 
2099  // void objc_enumerationMutation (id)
2100  EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy, IdTy);
2101 
2102  // id objc_getProperty(id, SEL, ptrdiff_t, BOOL)
2103  GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy,
2104  PtrDiffTy, BoolTy);
2105  // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL)
2106  SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy,
2107  PtrDiffTy, IdTy, BoolTy, BoolTy);
2108  // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
2109  GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy,
2110  PtrDiffTy, BoolTy, BoolTy);
2111  // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
2112  SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy,
2113  PtrDiffTy, BoolTy, BoolTy);
2114 
2115  // IMP type
2116  llvm::Type *IMPArgs[] = { IdTy, SelectorTy };
2117  IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs,
2118  true));
2119 
2120  const LangOptions &Opts = CGM.getLangOpts();
2121  if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount)
2122  RuntimeVersion = 10;
2123 
2124  // Don't bother initialising the GC stuff unless we're compiling in GC mode
2125  if (Opts.getGC() != LangOptions::NonGC) {
2126  // This is a bit of an hack. We should sort this out by having a proper
2127  // CGObjCGNUstep subclass for GC, but we may want to really support the old
2128  // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now
2129  // Get selectors needed in GC mode
2130  RetainSel = GetNullarySelector("retain", CGM.getContext());
2131  ReleaseSel = GetNullarySelector("release", CGM.getContext());
2132  AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext());
2133 
2134  // Get functions needed in GC mode
2135 
2136  // id objc_assign_ivar(id, id, ptrdiff_t);
2137  IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy);
2138  // id objc_assign_strongCast (id, id*)
2139  StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy,
2140  PtrToIdTy);
2141  // id objc_assign_global(id, id*);
2142  GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy);
2143  // id objc_assign_weak(id, id*);
2144  WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy);
2145  // id objc_read_weak(id*);
2146  WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy);
2147  // void *objc_memmove_collectable(void*, void *, size_t);
2148  MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy,
2149  SizeTy);
2150  }
2151 }
2152 
2153 llvm::Value *CGObjCGNU::GetClassNamed(CodeGenFunction &CGF,
2154  const std::string &Name, bool isWeak) {
2155  llvm::Constant *ClassName = MakeConstantString(Name);
2156  // With the incompatible ABI, this will need to be replaced with a direct
2157  // reference to the class symbol. For the compatible nonfragile ABI we are
2158  // still performing this lookup at run time but emitting the symbol for the
2159  // class externally so that we can make the switch later.
2160  //
2161  // Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class
2162  // with memoized versions or with static references if it's safe to do so.
2163  if (!isWeak)
2164  EmitClassRef(Name);
2165 
2166  llvm::Constant *ClassLookupFn =
2167  CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true),
2168  "objc_lookup_class");
2169  return CGF.EmitNounwindRuntimeCall(ClassLookupFn, ClassName);
2170 }
2171 
2172 // This has to perform the lookup every time, since posing and related
2173 // techniques can modify the name -> class mapping.
2174 llvm::Value *CGObjCGNU::GetClass(CodeGenFunction &CGF,
2175  const ObjCInterfaceDecl *OID) {
2176  auto *Value =
2177  GetClassNamed(CGF, OID->getNameAsString(), OID->isWeakImported());
2178  if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value))
2179  CGM.setGVProperties(ClassSymbol, OID);
2180  return Value;
2181 }
2182 
2183 llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) {
2184  auto *Value = GetClassNamed(CGF, "NSAutoreleasePool", false);
2185  if (CGM.getTriple().isOSBinFormatCOFF()) {
2186  if (auto *ClassSymbol = dyn_cast<llvm::GlobalVariable>(Value)) {
2187  IdentifierInfo &II = CGF.CGM.getContext().Idents.get("NSAutoreleasePool");
2190 
2191  const VarDecl *VD = nullptr;
2192  for (const auto &Result : DC->lookup(&II))
2193  if ((VD = dyn_cast<VarDecl>(Result)))
2194  break;
2195 
2196  CGM.setGVProperties(ClassSymbol, VD);
2197  }
2198  }
2199  return Value;
2200 }
2201 
2202 llvm::Value *CGObjCGNU::GetTypedSelector(CodeGenFunction &CGF, Selector Sel,
2203  const std::string &TypeEncoding) {
2204  SmallVectorImpl<TypedSelector> &Types = SelectorTable[Sel];
2205  llvm::GlobalAlias *SelValue = nullptr;
2206 
2207  for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(),
2208  e = Types.end() ; i!=e ; i++) {
2209  if (i->first == TypeEncoding) {
2210  SelValue = i->second;
2211  break;
2212  }
2213  }
2214  if (!SelValue) {
2215  SelValue = llvm::GlobalAlias::create(
2216  SelectorTy->getElementType(), 0, llvm::GlobalValue::PrivateLinkage,
2217  ".objc_selector_" + Sel.getAsString(), &TheModule);
2218  Types.emplace_back(TypeEncoding, SelValue);
2219  }
2220 
2221  return SelValue;
2222 }
2223 
2224 Address CGObjCGNU::GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) {
2225  llvm::Value *SelValue = GetSelector(CGF, Sel);
2226 
2227  // Store it to a temporary. Does this satisfy the semantics of
2228  // GetAddrOfSelector? Hopefully.
2229  Address tmp = CGF.CreateTempAlloca(SelValue->getType(),
2230  CGF.getPointerAlign());
2231  CGF.Builder.CreateStore(SelValue, tmp);
2232  return tmp;
2233 }
2234 
2235 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel) {
2236  return GetTypedSelector(CGF, Sel, std::string());
2237 }
2238 
2239 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF,
2240  const ObjCMethodDecl *Method) {
2241  std::string SelTypes = CGM.getContext().getObjCEncodingForMethodDecl(Method);
2242  return GetTypedSelector(CGF, Method->getSelector(), SelTypes);
2243 }
2244 
2245 llvm::Constant *CGObjCGNU::GetEHType(QualType T) {
2246  if (T->isObjCIdType() || T->isObjCQualifiedIdType()) {
2247  // With the old ABI, there was only one kind of catchall, which broke
2248  // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as
2249  // a pointer indicating object catchalls, and NULL to indicate real
2250  // catchalls
2251  if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
2252  return MakeConstantString("@id");
2253  } else {
2254  return nullptr;
2255  }
2256  }
2257 
2258  // All other types should be Objective-C interface pointer types.
2260  assert(OPT && "Invalid @catch type.");
2261  const ObjCInterfaceDecl *IDecl = OPT->getObjectType()->getInterface();
2262  assert(IDecl && "Invalid @catch type.");
2263  return MakeConstantString(IDecl->getIdentifier()->getName());
2264 }
2265 
2266 llvm::Constant *CGObjCGNUstep::GetEHType(QualType T) {
2267  if (usesSEHExceptions)
2268  return CGM.getCXXABI().getAddrOfRTTIDescriptor(T);
2269 
2270  if (!CGM.getLangOpts().CPlusPlus)
2271  return CGObjCGNU::GetEHType(T);
2272 
2273  // For Objective-C++, we want to provide the ability to catch both C++ and
2274  // Objective-C objects in the same function.
2275 
2276  // There's a particular fixed type info for 'id'.
2277  if (T->isObjCIdType() ||
2278  T->isObjCQualifiedIdType()) {
2279  llvm::Constant *IDEHType =
2280  CGM.getModule().getGlobalVariable("__objc_id_type_info");
2281  if (!IDEHType)
2282  IDEHType =
2283  new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty,
2284  false,
2286  nullptr, "__objc_id_type_info");
2287  return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty);
2288  }
2289 
2290  const ObjCObjectPointerType *PT =
2292  assert(PT && "Invalid @catch type.");
2293  const ObjCInterfaceType *IT = PT->getInterfaceType();
2294  assert(IT && "Invalid @catch type.");
2295  std::string className = IT->getDecl()->getIdentifier()->getName();
2296 
2297  std::string typeinfoName = "__objc_eh_typeinfo_" + className;
2298 
2299  // Return the existing typeinfo if it exists
2300  llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName);
2301  if (typeinfo)
2302  return llvm::ConstantExpr::getBitCast(typeinfo, PtrToInt8Ty);
2303 
2304  // Otherwise create it.
2305 
2306  // vtable for gnustep::libobjc::__objc_class_type_info
2307  // It's quite ugly hard-coding this. Ideally we'd generate it using the host
2308  // platform's name mangling.
2309  const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE";
2310  auto *Vtable = TheModule.getGlobalVariable(vtableName);
2311  if (!Vtable) {
2312  Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true,
2314  nullptr, vtableName);
2315  }
2316  llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2);
2317  auto *BVtable = llvm::ConstantExpr::getBitCast(
2318  llvm::ConstantExpr::getGetElementPtr(Vtable->getValueType(), Vtable, Two),
2319  PtrToInt8Ty);
2320 
2321  llvm::Constant *typeName =
2322  ExportUniqueString(className, "__objc_eh_typename_");
2323 
2324  ConstantInitBuilder builder(CGM);
2325  auto fields = builder.beginStruct();
2326  fields.add(BVtable);
2327  fields.add(typeName);
2328  llvm::Constant *TI =
2329  fields.finishAndCreateGlobal("__objc_eh_typeinfo_" + className,
2330  CGM.getPointerAlign(),
2331  /*constant*/ false,
2332  llvm::GlobalValue::LinkOnceODRLinkage);
2333  return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty);
2334 }
2335 
2336 /// Generate an NSConstantString object.
2337 ConstantAddress CGObjCGNU::GenerateConstantString(const StringLiteral *SL) {
2338 
2339  std::string Str = SL->getString().str();
2340  CharUnits Align = CGM.getPointerAlign();
2341 
2342  // Look for an existing one
2343  llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str);
2344  if (old != ObjCStrings.end())
2345  return ConstantAddress(old->getValue(), Align);
2346 
2347  StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass;
2348 
2349  if (StringClass.empty()) StringClass = "NSConstantString";
2350 
2351  std::string Sym = "_OBJC_CLASS_";
2352  Sym += StringClass;
2353 
2354  llvm::Constant *isa = TheModule.getNamedGlobal(Sym);
2355 
2356  if (!isa)
2357  isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false,
2358  llvm::GlobalValue::ExternalWeakLinkage, nullptr, Sym);
2359  else if (isa->getType() != PtrToIdTy)
2360  isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy);
2361 
2362  ConstantInitBuilder Builder(CGM);
2363  auto Fields = Builder.beginStruct();
2364  Fields.add(isa);
2365  Fields.add(MakeConstantString(Str));
2366  Fields.addInt(IntTy, Str.size());
2367  llvm::Constant *ObjCStr =
2368  Fields.finishAndCreateGlobal(".objc_str", Align);
2369  ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty);
2370  ObjCStrings[Str] = ObjCStr;
2371  ConstantStrings.push_back(ObjCStr);
2372  return ConstantAddress(ObjCStr, Align);
2373 }
2374 
2375 ///Generates a message send where the super is the receiver. This is a message
2376 ///send to self with special delivery semantics indicating which class's method
2377 ///should be called.
2378 RValue
2379 CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF,
2380  ReturnValueSlot Return,
2381  QualType ResultType,
2382  Selector Sel,
2383  const ObjCInterfaceDecl *Class,
2384  bool isCategoryImpl,
2385  llvm::Value *Receiver,
2386  bool IsClassMessage,
2387  const CallArgList &CallArgs,
2388  const ObjCMethodDecl *Method) {
2389  CGBuilderTy &Builder = CGF.Builder;
2390  if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
2391  if (Sel == RetainSel || Sel == AutoreleaseSel) {
2392  return RValue::get(EnforceType(Builder, Receiver,
2393  CGM.getTypes().ConvertType(ResultType)));
2394  }
2395  if (Sel == ReleaseSel) {
2396  return RValue::get(nullptr);
2397  }
2398  }
2399 
2400  llvm::Value *cmd = GetSelector(CGF, Sel);
2401  CallArgList ActualArgs;
2402 
2403  ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy);
2404  ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
2405  ActualArgs.addFrom(CallArgs);
2406 
2407  MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
2408 
2409  llvm::Value *ReceiverClass = nullptr;
2410  bool isV2ABI = isRuntime(ObjCRuntime::GNUstep, 2);
2411  if (isV2ABI) {
2412  ReceiverClass = GetClassNamed(CGF,
2413  Class->getSuperClass()->getNameAsString(), /*isWeak*/false);
2414  if (IsClassMessage) {
2415  // Load the isa pointer of the superclass is this is a class method.
2416  ReceiverClass = Builder.CreateBitCast(ReceiverClass,
2417  llvm::PointerType::getUnqual(IdTy));
2418  ReceiverClass =
2419  Builder.CreateAlignedLoad(ReceiverClass, CGF.getPointerAlign());
2420  }
2421  ReceiverClass = EnforceType(Builder, ReceiverClass, IdTy);
2422  } else {
2423  if (isCategoryImpl) {
2424  llvm::Constant *classLookupFunction = nullptr;
2425  if (IsClassMessage) {
2426  classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
2427  IdTy, PtrTy, true), "objc_get_meta_class");
2428  } else {
2429  classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
2430  IdTy, PtrTy, true), "objc_get_class");
2431  }
2432  ReceiverClass = Builder.CreateCall(classLookupFunction,
2433  MakeConstantString(Class->getNameAsString()));
2434  } else {
2435  // Set up global aliases for the metaclass or class pointer if they do not
2436  // already exist. These will are forward-references which will be set to
2437  // pointers to the class and metaclass structure created for the runtime
2438  // load function. To send a message to super, we look up the value of the
2439  // super_class pointer from either the class or metaclass structure.
2440  if (IsClassMessage) {
2441  if (!MetaClassPtrAlias) {
2442  MetaClassPtrAlias = llvm::GlobalAlias::create(
2443  IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage,
2444  ".objc_metaclass_ref" + Class->getNameAsString(), &TheModule);
2445  }
2446  ReceiverClass = MetaClassPtrAlias;
2447  } else {
2448  if (!ClassPtrAlias) {
2449  ClassPtrAlias = llvm::GlobalAlias::create(
2450  IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage,
2451  ".objc_class_ref" + Class->getNameAsString(), &TheModule);
2452  }
2453  ReceiverClass = ClassPtrAlias;
2454  }
2455  }
2456  // Cast the pointer to a simplified version of the class structure
2457  llvm::Type *CastTy = llvm::StructType::get(IdTy, IdTy);
2458  ReceiverClass = Builder.CreateBitCast(ReceiverClass,
2459  llvm::PointerType::getUnqual(CastTy));
2460  // Get the superclass pointer
2461  ReceiverClass = Builder.CreateStructGEP(CastTy, ReceiverClass, 1);
2462  // Load the superclass pointer
2463  ReceiverClass =
2464  Builder.CreateAlignedLoad(ReceiverClass, CGF.getPointerAlign());
2465  }
2466  // Construct the structure used to look up the IMP
2467  llvm::StructType *ObjCSuperTy =
2468  llvm::StructType::get(Receiver->getType(), IdTy);
2469 
2470  Address ObjCSuper = CGF.CreateTempAlloca(ObjCSuperTy,
2471  CGF.getPointerAlign());
2472 
2473  Builder.CreateStore(Receiver,
2474  Builder.CreateStructGEP(ObjCSuper, 0, CharUnits::Zero()));
2475  Builder.CreateStore(ReceiverClass,
2476  Builder.CreateStructGEP(ObjCSuper, 1, CGF.getPointerSize()));
2477 
2478  ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy);
2479 
2480  // Get the IMP
2481  llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd, MSI);
2482  imp = EnforceType(Builder, imp, MSI.MessengerType);
2483 
2484  llvm::Metadata *impMD[] = {
2485  llvm::MDString::get(VMContext, Sel.getAsString()),
2486  llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()),
2487  llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
2488  llvm::Type::getInt1Ty(VMContext), IsClassMessage))};
2489  llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
2490 
2491  CGCallee callee(CGCalleeInfo(), imp);
2492 
2493  llvm::Instruction *call;
2494  RValue msgRet = CGF.EmitCall(MSI.CallInfo, callee, Return, ActualArgs, &call);
2495  call->setMetadata(msgSendMDKind, node);
2496  return msgRet;
2497 }
2498 
2499 /// Generate code for a message send expression.
2500 RValue
2501 CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF,
2502  ReturnValueSlot Return,
2503  QualType ResultType,
2504  Selector Sel,
2505  llvm::Value *Receiver,
2506  const CallArgList &CallArgs,
2507  const ObjCInterfaceDecl *Class,
2508  const ObjCMethodDecl *Method) {
2509  CGBuilderTy &Builder = CGF.Builder;
2510 
2511  // Strip out message sends to retain / release in GC mode
2512  if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
2513  if (Sel == RetainSel || Sel == AutoreleaseSel) {
2514  return RValue::get(EnforceType(Builder, Receiver,
2515  CGM.getTypes().ConvertType(ResultType)));
2516  }
2517  if (Sel == ReleaseSel) {
2518  return RValue::get(nullptr);
2519  }
2520  }
2521 
2522  // If the return type is something that goes in an integer register, the
2523  // runtime will handle 0 returns. For other cases, we fill in the 0 value
2524  // ourselves.
2525  //
2526  // The language spec says the result of this kind of message send is
2527  // undefined, but lots of people seem to have forgotten to read that
2528  // paragraph and insist on sending messages to nil that have structure
2529  // returns. With GCC, this generates a random return value (whatever happens
2530  // to be on the stack / in those registers at the time) on most platforms,
2531  // and generates an illegal instruction trap on SPARC. With LLVM it corrupts
2532  // the stack.
2533  bool isPointerSizedReturn = (ResultType->isAnyPointerType() ||
2534  ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType());
2535 
2536  llvm::BasicBlock *startBB = nullptr;
2537  llvm::BasicBlock *messageBB = nullptr;
2538  llvm::BasicBlock *continueBB = nullptr;
2539 
2540  if (!isPointerSizedReturn) {
2541  startBB = Builder.GetInsertBlock();
2542  messageBB = CGF.createBasicBlock("msgSend");
2543  continueBB = CGF.createBasicBlock("continue");
2544 
2545  llvm::Value *isNil = Builder.CreateICmpEQ(Receiver,
2546  llvm::Constant::getNullValue(Receiver->getType()));
2547  Builder.CreateCondBr(isNil, continueBB, messageBB);
2548  CGF.EmitBlock(messageBB);
2549  }
2550 
2551  IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
2552  llvm::Value *cmd;
2553  if (Method)
2554  cmd = GetSelector(CGF, Method);
2555  else
2556  cmd = GetSelector(CGF, Sel);
2557  cmd = EnforceType(Builder, cmd, SelectorTy);
2558  Receiver = EnforceType(Builder, Receiver, IdTy);
2559 
2560  llvm::Metadata *impMD[] = {
2561  llvm::MDString::get(VMContext, Sel.getAsString()),
2562  llvm::MDString::get(VMContext, Class ? Class->getNameAsString() : ""),
2563  llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
2564  llvm::Type::getInt1Ty(VMContext), Class != nullptr))};
2565  llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
2566 
2567  CallArgList ActualArgs;
2568  ActualArgs.add(RValue::get(Receiver), ASTIdTy);
2569  ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
2570  ActualArgs.addFrom(CallArgs);
2571 
2572  MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
2573 
2574  // Get the IMP to call
2575  llvm::Value *imp;
2576 
2577  // If we have non-legacy dispatch specified, we try using the objc_msgSend()
2578  // functions. These are not supported on all platforms (or all runtimes on a
2579  // given platform), so we
2580  switch (CGM.getCodeGenOpts().getObjCDispatchMethod()) {
2582  imp = LookupIMP(CGF, Receiver, cmd, node, MSI);
2583  break;
2584  case CodeGenOptions::Mixed:
2586  if (CGM.ReturnTypeUsesFPRet(ResultType)) {
2587  imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
2588  "objc_msgSend_fpret");
2589  } else if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) {
2590  // The actual types here don't matter - we're going to bitcast the
2591  // function anyway
2592  imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
2593  "objc_msgSend_stret");
2594  } else {
2595  imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
2596  "objc_msgSend");
2597  }
2598  }
2599 
2600  // Reset the receiver in case the lookup modified it
2601  ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy);
2602 
2603  imp = EnforceType(Builder, imp, MSI.MessengerType);
2604 
2605  llvm::Instruction *call;
2606  CGCallee callee(CGCalleeInfo(), imp);
2607  RValue msgRet = CGF.EmitCall(MSI.CallInfo, callee, Return, ActualArgs, &call);
2608  call->setMetadata(msgSendMDKind, node);
2609 
2610 
2611  if (!isPointerSizedReturn) {
2612  messageBB = CGF.Builder.GetInsertBlock();
2613  CGF.Builder.CreateBr(continueBB);
2614  CGF.EmitBlock(continueBB);
2615  if (msgRet.isScalar()) {
2616  llvm::Value *v = msgRet.getScalarVal();
2617  llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2);
2618  phi->addIncoming(v, messageBB);
2619  phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB);
2620  msgRet = RValue::get(phi);
2621  } else if (msgRet.isAggregate()) {
2622  Address v = msgRet.getAggregateAddress();
2623  llvm::PHINode *phi = Builder.CreatePHI(v.getType(), 2);
2624  llvm::Type *RetTy = v.getElementType();
2625  Address NullVal = CGF.CreateTempAlloca(RetTy, v.getAlignment(), "null");
2626  CGF.InitTempAlloca(NullVal, llvm::Constant::getNullValue(RetTy));
2627  phi->addIncoming(v.getPointer(), messageBB);
2628  phi->addIncoming(NullVal.getPointer(), startBB);
2629  msgRet = RValue::getAggregate(Address(phi, v.getAlignment()));
2630  } else /* isComplex() */ {
2631  std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal();
2632  llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2);
2633  phi->addIncoming(v.first, messageBB);
2634  phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()),
2635  startBB);
2636  llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2);
2637  phi2->addIncoming(v.second, messageBB);
2638  phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()),
2639  startBB);
2640  msgRet = RValue::getComplex(phi, phi2);
2641  }
2642  }
2643  return msgRet;
2644 }
2645 
2646 /// Generates a MethodList. Used in construction of a objc_class and
2647 /// objc_category structures.
2648 llvm::Constant *CGObjCGNU::
2649 GenerateMethodList(StringRef ClassName,
2650  StringRef CategoryName,
2652  bool isClassMethodList) {
2653  if (Methods.empty())
2654  return NULLPtr;
2655 
2656  ConstantInitBuilder Builder(CGM);
2657 
2658  auto MethodList = Builder.beginStruct();
2659  MethodList.addNullPointer(CGM.Int8PtrTy);
2660  MethodList.addInt(Int32Ty, Methods.size());
2661 
2662  // Get the method structure type.
2663  llvm::StructType *ObjCMethodTy =
2664  llvm::StructType::get(CGM.getLLVMContext(), {
2665  PtrToInt8Ty, // Really a selector, but the runtime creates it us.
2666  PtrToInt8Ty, // Method types
2667  IMPTy // Method pointer
2668  });
2669  bool isV2ABI = isRuntime(ObjCRuntime::GNUstep, 2);
2670  if (isV2ABI) {
2671  // size_t size;
2672  llvm::DataLayout td(&TheModule);
2673  MethodList.addInt(SizeTy, td.getTypeSizeInBits(ObjCMethodTy) /
2674  CGM.getContext().getCharWidth());
2675  ObjCMethodTy =
2676  llvm::StructType::get(CGM.getLLVMContext(), {
2677  IMPTy, // Method pointer
2678  PtrToInt8Ty, // Selector
2679  PtrToInt8Ty // Extended type encoding
2680  });
2681  } else {
2682  ObjCMethodTy =
2683  llvm::StructType::get(CGM.getLLVMContext(), {
2684  PtrToInt8Ty, // Really a selector, but the runtime creates it us.
2685  PtrToInt8Ty, // Method types
2686  IMPTy // Method pointer
2687  });
2688  }
2689  auto MethodArray = MethodList.beginArray();
2690  ASTContext &Context = CGM.getContext();
2691  for (const auto *OMD : Methods) {
2692  llvm::Constant *FnPtr =
2693  TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName,
2694  OMD->getSelector(),
2695  isClassMethodList));
2696  assert(FnPtr && "Can't generate metadata for method that doesn't exist");
2697  auto Method = MethodArray.beginStruct(ObjCMethodTy);
2698  if (isV2ABI) {
2699  Method.addBitCast(FnPtr, IMPTy);
2700  Method.add(GetConstantSelector(OMD->getSelector(),
2701  Context.getObjCEncodingForMethodDecl(OMD)));
2702  Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(OMD, true)));
2703  } else {
2704  Method.add(MakeConstantString(OMD->getSelector().getAsString()));
2705  Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(OMD)));
2706  Method.addBitCast(FnPtr, IMPTy);
2707  }
2708  Method.finishAndAddTo(MethodArray);
2709  }
2710  MethodArray.finishAndAddTo(MethodList);
2711 
2712  // Create an instance of the structure
2713  return MethodList.finishAndCreateGlobal(".objc_method_list",
2714  CGM.getPointerAlign());
2715 }
2716 
2717 /// Generates an IvarList. Used in construction of a objc_class.
2718 llvm::Constant *CGObjCGNU::
2719 GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
2720  ArrayRef<llvm::Constant *> IvarTypes,
2721  ArrayRef<llvm::Constant *> IvarOffsets,
2722  ArrayRef<llvm::Constant *> IvarAlign,
2723  ArrayRef<Qualifiers::ObjCLifetime> IvarOwnership) {
2724  if (IvarNames.empty())
2725  return NULLPtr;
2726 
2727  ConstantInitBuilder Builder(CGM);
2728 
2729  // Structure containing array count followed by array.
2730  auto IvarList = Builder.beginStruct();
2731  IvarList.addInt(IntTy, (int)IvarNames.size());
2732 
2733  // Get the ivar structure type.
2734  llvm::StructType *ObjCIvarTy =
2735  llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, IntTy);
2736 
2737  // Array of ivar structures.
2738  auto Ivars = IvarList.beginArray(ObjCIvarTy);
2739  for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) {
2740  auto Ivar = Ivars.beginStruct(ObjCIvarTy);
2741  Ivar.add(IvarNames[i]);
2742  Ivar.add(IvarTypes[i]);
2743  Ivar.add(IvarOffsets[i]);
2744  Ivar.finishAndAddTo(Ivars);
2745  }
2746  Ivars.finishAndAddTo(IvarList);
2747 
2748  // Create an instance of the structure
2749  return IvarList.finishAndCreateGlobal(".objc_ivar_list",
2750  CGM.getPointerAlign());
2751 }
2752 
2753 /// Generate a class structure
2754 llvm::Constant *CGObjCGNU::GenerateClassStructure(
2755  llvm::Constant *MetaClass,
2756  llvm::Constant *SuperClass,
2757  unsigned info,
2758  const char *Name,
2759  llvm::Constant *Version,
2760  llvm::Constant *InstanceSize,
2761  llvm::Constant *IVars,
2762  llvm::Constant *Methods,
2763  llvm::Constant *Protocols,
2764  llvm::Constant *IvarOffsets,
2765  llvm::Constant *Properties,
2766  llvm::Constant *StrongIvarBitmap,
2767  llvm::Constant *WeakIvarBitmap,
2768  bool isMeta) {
2769  // Set up the class structure
2770  // Note: Several of these are char*s when they should be ids. This is
2771  // because the runtime performs this translation on load.
2772  //
2773  // Fields marked New ABI are part of the GNUstep runtime. We emit them
2774  // anyway; the classes will still work with the GNU runtime, they will just
2775  // be ignored.
2776  llvm::StructType *ClassTy = llvm::StructType::get(
2777  PtrToInt8Ty, // isa
2778  PtrToInt8Ty, // super_class
2779  PtrToInt8Ty, // name
2780  LongTy, // version
2781  LongTy, // info
2782  LongTy, // instance_size
2783  IVars->getType(), // ivars
2784  Methods->getType(), // methods
2785  // These are all filled in by the runtime, so we pretend
2786  PtrTy, // dtable
2787  PtrTy, // subclass_list
2788  PtrTy, // sibling_class
2789  PtrTy, // protocols
2790  PtrTy, // gc_object_type
2791  // New ABI:
2792  LongTy, // abi_version
2793  IvarOffsets->getType(), // ivar_offsets
2794  Properties->getType(), // properties
2795  IntPtrTy, // strong_pointers
2796  IntPtrTy // weak_pointers
2797  );
2798 
2799  ConstantInitBuilder Builder(CGM);
2800  auto Elements = Builder.beginStruct(ClassTy);
2801 
2802  // Fill in the structure
2803 
2804  // isa
2805  Elements.addBitCast(MetaClass, PtrToInt8Ty);
2806  // super_class
2807  Elements.add(SuperClass);
2808  // name
2809  Elements.add(MakeConstantString(Name, ".class_name"));
2810  // version
2811  Elements.addInt(LongTy, 0);
2812  // info
2813  Elements.addInt(LongTy, info);
2814  // instance_size
2815  if (isMeta) {
2816  llvm::DataLayout td(&TheModule);
2817  Elements.addInt(LongTy,
2818  td.getTypeSizeInBits(ClassTy) /
2819  CGM.getContext().getCharWidth());
2820  } else
2821  Elements.add(InstanceSize);
2822  // ivars
2823  Elements.add(IVars);
2824  // methods
2825  Elements.add(Methods);
2826  // These are all filled in by the runtime, so we pretend
2827  // dtable
2828  Elements.add(NULLPtr);
2829  // subclass_list
2830  Elements.add(NULLPtr);
2831  // sibling_class
2832  Elements.add(NULLPtr);
2833  // protocols
2834  Elements.addBitCast(Protocols, PtrTy);
2835  // gc_object_type
2836  Elements.add(NULLPtr);
2837  // abi_version
2838  Elements.addInt(LongTy, ClassABIVersion);
2839  // ivar_offsets
2840  Elements.add(IvarOffsets);
2841  // properties
2842  Elements.add(Properties);
2843  // strong_pointers
2844  Elements.add(StrongIvarBitmap);
2845  // weak_pointers
2846  Elements.add(WeakIvarBitmap);
2847  // Create an instance of the structure
2848  // This is now an externally visible symbol, so that we can speed up class
2849  // messages in the next ABI. We may already have some weak references to
2850  // this, so check and fix them properly.
2851  std::string ClassSym((isMeta ? "_OBJC_METACLASS_": "_OBJC_CLASS_") +
2852  std::string(Name));
2853  llvm::GlobalVariable *ClassRef = TheModule.getNamedGlobal(ClassSym);
2854  llvm::Constant *Class =
2855  Elements.finishAndCreateGlobal(ClassSym, CGM.getPointerAlign(), false,
2857  if (ClassRef) {
2858  ClassRef->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(Class,
2859  ClassRef->getType()));
2860  ClassRef->removeFromParent();
2861  Class->setName(ClassSym);
2862  }
2863  return Class;
2864 }
2865 
2866 llvm::Constant *CGObjCGNU::
2867 GenerateProtocolMethodList(ArrayRef<const ObjCMethodDecl*> Methods) {
2868  // Get the method structure type.
2869  llvm::StructType *ObjCMethodDescTy =
2870  llvm::StructType::get(CGM.getLLVMContext(), { PtrToInt8Ty, PtrToInt8Ty });
2871  ASTContext &Context = CGM.getContext();
2872  ConstantInitBuilder Builder(CGM);
2873  auto MethodList = Builder.beginStruct();
2874  MethodList.addInt(IntTy, Methods.size());
2875  auto MethodArray = MethodList.beginArray(ObjCMethodDescTy);
2876  for (auto *M : Methods) {
2877  auto Method = MethodArray.beginStruct(ObjCMethodDescTy);
2878  Method.add(MakeConstantString(M->getSelector().getAsString()));
2879  Method.add(MakeConstantString(Context.getObjCEncodingForMethodDecl(M)));
2880  Method.finishAndAddTo(MethodArray);
2881  }
2882  MethodArray.finishAndAddTo(MethodList);
2883  return MethodList.finishAndCreateGlobal(".objc_method_list",
2884  CGM.getPointerAlign());
2885 }
2886 
2887 // Create the protocol list structure used in classes, categories and so on
2888 llvm::Constant *
2889 CGObjCGNU::GenerateProtocolList(ArrayRef<std::string> Protocols) {
2890 
2891  ConstantInitBuilder Builder(CGM);
2892  auto ProtocolList = Builder.beginStruct();
2893  ProtocolList.add(NULLPtr);
2894  ProtocolList.addInt(LongTy, Protocols.size());
2895 
2896  auto Elements = ProtocolList.beginArray(PtrToInt8Ty);
2897  for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end();
2898  iter != endIter ; iter++) {
2899  llvm::Constant *protocol = nullptr;
2900  llvm::StringMap<llvm::Constant*>::iterator value =
2901  ExistingProtocols.find(*iter);
2902  if (value == ExistingProtocols.end()) {
2903  protocol = GenerateEmptyProtocol(*iter);
2904  } else {
2905  protocol = value->getValue();
2906  }
2907  Elements.addBitCast(protocol, PtrToInt8Ty);
2908  }
2909  Elements.finishAndAddTo(ProtocolList);
2910  return ProtocolList.finishAndCreateGlobal(".objc_protocol_list",
2911  CGM.getPointerAlign());
2912 }
2913 
2914 llvm::Value *CGObjCGNU::GenerateProtocolRef(CodeGenFunction &CGF,
2915  const ObjCProtocolDecl *PD) {
2916  llvm::Constant *&protocol = ExistingProtocols[PD->getNameAsString()];
2917  if (!protocol)
2918  GenerateProtocol(PD);
2919  llvm::Type *T =
2921  return CGF.Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T));
2922 }
2923 
2924 llvm::Constant *
2925 CGObjCGNU::GenerateEmptyProtocol(StringRef ProtocolName) {
2926  llvm::Constant *ProtocolList = GenerateProtocolList({});
2927  llvm::Constant *MethodList = GenerateProtocolMethodList({});
2928  MethodList = llvm::ConstantExpr::getBitCast(MethodList, PtrToInt8Ty);
2929  // Protocols are objects containing lists of the methods implemented and
2930  // protocols adopted.
2931  ConstantInitBuilder Builder(CGM);
2932  auto Elements = Builder.beginStruct();
2933 
2934  // The isa pointer must be set to a magic number so the runtime knows it's
2935  // the correct layout.
2936  Elements.add(llvm::ConstantExpr::getIntToPtr(
2937  llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
2938 
2939  Elements.add(MakeConstantString(ProtocolName, ".objc_protocol_name"));
2940  Elements.add(ProtocolList); /* .protocol_list */
2941  Elements.add(MethodList); /* .instance_methods */
2942  Elements.add(MethodList); /* .class_methods */
2943  Elements.add(MethodList); /* .optional_instance_methods */
2944  Elements.add(MethodList); /* .optional_class_methods */
2945  Elements.add(NULLPtr); /* .properties */
2946  Elements.add(NULLPtr); /* .optional_properties */
2947  return Elements.finishAndCreateGlobal(SymbolForProtocol(ProtocolName),
2948  CGM.getPointerAlign());
2949 }
2950 
2951 void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) {
2952  std::string ProtocolName = PD->getNameAsString();
2953 
2954  // Use the protocol definition, if there is one.
2955  if (const ObjCProtocolDecl *Def = PD->getDefinition())
2956  PD = Def;
2957 
2958  SmallVector<std::string, 16> Protocols;
2959  for (const auto *PI : PD->protocols())
2960  Protocols.push_back(PI->getNameAsString());
2962  SmallVector<const ObjCMethodDecl*, 16> OptionalInstanceMethods;
2963  for (const auto *I : PD->instance_methods())
2964  if (I->isOptional())
2965  OptionalInstanceMethods.push_back(I);
2966  else
2967  InstanceMethods.push_back(I);
2968  // Collect information about class methods:
2970  SmallVector<const ObjCMethodDecl*, 16> OptionalClassMethods;
2971  for (const auto *I : PD->class_methods())
2972  if (I->isOptional())
2973  OptionalClassMethods.push_back(I);
2974  else
2975  ClassMethods.push_back(I);
2976 
2977  llvm::Constant *ProtocolList = GenerateProtocolList(Protocols);
2978  llvm::Constant *InstanceMethodList =
2979  GenerateProtocolMethodList(InstanceMethods);
2980  llvm::Constant *ClassMethodList =
2981  GenerateProtocolMethodList(ClassMethods);
2982  llvm::Constant *OptionalInstanceMethodList =
2983  GenerateProtocolMethodList(OptionalInstanceMethods);
2984  llvm::Constant *OptionalClassMethodList =
2985  GenerateProtocolMethodList(OptionalClassMethods);
2986 
2987  // Property metadata: name, attributes, isSynthesized, setter name, setter
2988  // types, getter name, getter types.
2989  // The isSynthesized value is always set to 0 in a protocol. It exists to
2990  // simplify the runtime library by allowing it to use the same data
2991  // structures for protocol metadata everywhere.
2992 
2993  llvm::Constant *PropertyList =
2994  GeneratePropertyList(nullptr, PD, false, false);
2995  llvm::Constant *OptionalPropertyList =
2996  GeneratePropertyList(nullptr, PD, false, true);
2997 
2998  // Protocols are objects containing lists of the methods implemented and
2999  // protocols adopted.
3000  // The isa pointer must be set to a magic number so the runtime knows it's
3001  // the correct layout.
3002  ConstantInitBuilder Builder(CGM);
3003  auto Elements = Builder.beginStruct();
3004  Elements.add(
3005  llvm::ConstantExpr::getIntToPtr(
3006  llvm::ConstantInt::get(Int32Ty, ProtocolVersion), IdTy));
3007  Elements.add(MakeConstantString(ProtocolName));
3008  Elements.add(ProtocolList);
3009  Elements.add(InstanceMethodList);
3010  Elements.add(ClassMethodList);
3011  Elements.add(OptionalInstanceMethodList);
3012  Elements.add(OptionalClassMethodList);
3013  Elements.add(PropertyList);
3014  Elements.add(OptionalPropertyList);
3015  ExistingProtocols[ProtocolName] =
3016  llvm::ConstantExpr::getBitCast(
3017  Elements.finishAndCreateGlobal(".objc_protocol", CGM.getPointerAlign()),
3018  IdTy);
3019 }
3020 void CGObjCGNU::GenerateProtocolHolderCategory() {
3021  // Collect information about instance methods
3022 
3023  ConstantInitBuilder Builder(CGM);
3024  auto Elements = Builder.beginStruct();
3025 
3026  const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack";
3027  const std::string CategoryName = "AnotherHack";
3028  Elements.add(MakeConstantString(CategoryName));
3029  Elements.add(MakeConstantString(ClassName));
3030  // Instance method list
3031  Elements.addBitCast(GenerateMethodList(
3032  ClassName, CategoryName, {}, false), PtrTy);
3033  // Class method list
3034  Elements.addBitCast(GenerateMethodList(
3035  ClassName, CategoryName, {}, true), PtrTy);
3036 
3037  // Protocol list
3038  ConstantInitBuilder ProtocolListBuilder(CGM);
3039  auto ProtocolList = ProtocolListBuilder.beginStruct();
3040  ProtocolList.add(NULLPtr);
3041  ProtocolList.addInt(LongTy, ExistingProtocols.size());
3042  auto ProtocolElements = ProtocolList.beginArray(PtrTy);
3043  for (auto iter = ExistingProtocols.begin(), endIter = ExistingProtocols.end();
3044  iter != endIter ; iter++) {
3045  ProtocolElements.addBitCast(iter->getValue(), PtrTy);
3046  }
3047  ProtocolElements.finishAndAddTo(ProtocolList);
3048  Elements.addBitCast(
3049  ProtocolList.finishAndCreateGlobal(".objc_protocol_list",
3050  CGM.getPointerAlign()),
3051  PtrTy);
3052  Categories.push_back(llvm::ConstantExpr::getBitCast(
3053  Elements.finishAndCreateGlobal("", CGM.getPointerAlign()),
3054  PtrTy));
3055 }
3056 
3057 /// Libobjc2 uses a bitfield representation where small(ish) bitfields are
3058 /// stored in a 64-bit value with the low bit set to 1 and the remaining 63
3059 /// bits set to their values, LSB first, while larger ones are stored in a
3060 /// structure of this / form:
3061 ///
3062 /// struct { int32_t length; int32_t values[length]; };
3063 ///
3064 /// The values in the array are stored in host-endian format, with the least
3065 /// significant bit being assumed to come first in the bitfield. Therefore, a
3066 /// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a
3067 /// bitfield / with the 63rd bit set will be 1<<64.
3068 llvm::Constant *CGObjCGNU::MakeBitField(ArrayRef<bool> bits) {
3069  int bitCount = bits.size();
3070  int ptrBits = CGM.getDataLayout().getPointerSizeInBits();
3071  if (bitCount < ptrBits) {
3072  uint64_t val = 1;
3073  for (int i=0 ; i<bitCount ; ++i) {
3074  if (bits[i]) val |= 1ULL<<(i+1);
3075  }
3076  return llvm::ConstantInt::get(IntPtrTy, val);
3077  }
3079  int v=0;
3080  while (v < bitCount) {
3081  int32_t word = 0;
3082  for (int i=0 ; (i<32) && (v<bitCount) ; ++i) {
3083  if (bits[v]) word |= 1<<i;
3084  v++;
3085  }
3086  values.push_back(llvm::ConstantInt::get(Int32Ty, word));
3087  }
3088 
3089  ConstantInitBuilder builder(CGM);
3090  auto fields = builder.beginStruct();
3091  fields.addInt(Int32Ty, values.size());
3092  auto array = fields.beginArray();
3093  for (auto v : values) array.add(v);
3094  array.finishAndAddTo(fields);
3095 
3096  llvm::Constant *GS =
3097  fields.finishAndCreateGlobal("", CharUnits::fromQuantity(4));
3098  llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy);
3099  return ptr;
3100 }
3101 
3102 void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) {
3103  const ObjCInterfaceDecl *Class = OCD->getClassInterface();
3104  std::string ClassName = Class->getNameAsString();
3105  std::string CategoryName = OCD->getNameAsString();
3106 
3107  // Collect the names of referenced protocols
3108  SmallVector<std::string, 16> Protocols;
3109  const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl();
3110  const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols();
3111  for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(),
3112  E = Protos.end(); I != E; ++I)
3113  Protocols.push_back((*I)->getNameAsString());
3114 
3115  ConstantInitBuilder Builder(CGM);
3116  auto Elements = Builder.beginStruct();
3117  Elements.add(MakeConstantString(CategoryName));
3118  Elements.add(MakeConstantString(ClassName));
3119  // Instance method list
3120  SmallVector<ObjCMethodDecl*, 16> InstanceMethods;
3121  InstanceMethods.insert(InstanceMethods.begin(), OCD->instmeth_begin(),
3122  OCD->instmeth_end());
3123  Elements.addBitCast(
3124  GenerateMethodList(ClassName, CategoryName, InstanceMethods, false),
3125  PtrTy);
3126  // Class method list
3127 
3128  SmallVector<ObjCMethodDecl*, 16> ClassMethods;
3129  ClassMethods.insert(ClassMethods.begin(), OCD->classmeth_begin(),
3130  OCD->classmeth_end());
3131  Elements.addBitCast(
3132  GenerateMethodList(ClassName, CategoryName, ClassMethods, true),
3133  PtrTy);
3134  // Protocol list
3135  Elements.addBitCast(GenerateProtocolList(Protocols), PtrTy);
3136  if (isRuntime(ObjCRuntime::GNUstep, 2)) {
3137  const ObjCCategoryDecl *Category =
3138  Class->FindCategoryDeclaration(OCD->getIdentifier());
3139  if (Category) {
3140  // Instance properties
3141  Elements.addBitCast(GeneratePropertyList(OCD, Category, false), PtrTy);
3142  // Class properties
3143  Elements.addBitCast(GeneratePropertyList(OCD, Category, true), PtrTy);
3144  } else {
3145  Elements.addNullPointer(PtrTy);
3146  Elements.addNullPointer(PtrTy);
3147  }
3148  }
3149 
3150  Categories.push_back(llvm::ConstantExpr::getBitCast(
3151  Elements.finishAndCreateGlobal(
3152  std::string(".objc_category_")+ClassName+CategoryName,
3153  CGM.getPointerAlign()),
3154  PtrTy));
3155 }
3156 
3157 llvm::Constant *CGObjCGNU::GeneratePropertyList(const Decl *Container,
3158  const ObjCContainerDecl *OCD,
3159  bool isClassProperty,
3160  bool protocolOptionalProperties) {
3161 
3163  llvm::SmallPtrSet<const IdentifierInfo*, 16> PropertySet;
3164  bool isProtocol = isa<ObjCProtocolDecl>(OCD);
3165  ASTContext &Context = CGM.getContext();
3166 
3167  std::function<void(const ObjCProtocolDecl *Proto)> collectProtocolProperties
3168  = [&](const ObjCProtocolDecl *Proto) {
3169  for (const auto *P : Proto->protocols())
3170  collectProtocolProperties(P);
3171  for (const auto *PD : Proto->properties()) {
3172  if (isClassProperty != PD->isClassProperty())
3173  continue;
3174  // Skip any properties that are declared in protocols that this class
3175  // conforms to but are not actually implemented by this class.
3176  if (!isProtocol && !Context.getObjCPropertyImplDeclForPropertyDecl(PD, Container))
3177  continue;
3178  if (!PropertySet.insert(PD->getIdentifier()).second)
3179  continue;
3180  Properties.push_back(PD);
3181  }
3182  };
3183 
3184  if (const ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(OCD))
3185  for (const ObjCCategoryDecl *ClassExt : OID->known_extensions())
3186  for (auto *PD : ClassExt->properties()) {
3187  if (isClassProperty != PD->isClassProperty())
3188  continue;
3189  PropertySet.insert(PD->getIdentifier());
3190  Properties.push_back(PD);
3191  }
3192 
3193  for (const auto *PD : OCD->properties()) {
3194  if (isClassProperty != PD->isClassProperty())
3195  continue;
3196  // If we're generating a list for a protocol, skip optional / required ones
3197  // when generating the other list.
3198  if (isProtocol && (protocolOptionalProperties != PD->isOptional()))
3199  continue;
3200  // Don't emit duplicate metadata for properties that were already in a
3201  // class extension.
3202  if (!PropertySet.insert(PD->getIdentifier()).second)
3203  continue;
3204 
3205  Properties.push_back(PD);
3206  }
3207 
3208  if (const ObjCInterfaceDecl *OID = dyn_cast<ObjCInterfaceDecl>(OCD))
3209  for (const auto *P : OID->all_referenced_protocols())
3210  collectProtocolProperties(P);
3211  else if (const ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(OCD))
3212  for (const auto *P : CD->protocols())
3213  collectProtocolProperties(P);
3214 
3215  auto numProperties = Properties.size();
3216 
3217  if (numProperties == 0)
3218  return NULLPtr;
3219 
3220  ConstantInitBuilder builder(CGM);
3221  auto propertyList = builder.beginStruct();
3222  auto properties = PushPropertyListHeader(propertyList, numProperties);
3223 
3224  // Add all of the property methods need adding to the method list and to the
3225  // property metadata list.
3226  for (auto *property : Properties) {
3227  bool isSynthesized = false;
3228  bool isDynamic = false;
3229  if (!isProtocol) {
3230  auto *propertyImpl = Context.getObjCPropertyImplDeclForPropertyDecl(property, Container);
3231  if (propertyImpl) {
3232  isSynthesized = (propertyImpl->getPropertyImplementation() ==
3234  isDynamic = (propertyImpl->getPropertyImplementation() ==
3236  }
3237  }
3238  PushProperty(properties, property, Container, isSynthesized, isDynamic);
3239  }
3240  properties.finishAndAddTo(propertyList);
3241 
3242  return propertyList.finishAndCreateGlobal(".objc_property_list",
3243  CGM.getPointerAlign());
3244 }
3245 
3246 void CGObjCGNU::RegisterAlias(const ObjCCompatibleAliasDecl *OAD) {
3247  // Get the class declaration for which the alias is specified.
3248  ObjCInterfaceDecl *ClassDecl =
3249  const_cast<ObjCInterfaceDecl *>(OAD->getClassInterface());
3250  ClassAliases.emplace_back(ClassDecl->getNameAsString(),
3251  OAD->getNameAsString());
3252 }
3253 
3254 void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
3255  ASTContext &Context = CGM.getContext();
3256 
3257  // Get the superclass name.
3258  const ObjCInterfaceDecl * SuperClassDecl =
3259  OID->getClassInterface()->getSuperClass();
3260  std::string SuperClassName;
3261  if (SuperClassDecl) {
3262  SuperClassName = SuperClassDecl->getNameAsString();
3263  EmitClassRef(SuperClassName);
3264  }
3265 
3266  // Get the class name
3267  ObjCInterfaceDecl *ClassDecl =
3268  const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
3269  std::string ClassName = ClassDecl->getNameAsString();
3270 
3271  // Emit the symbol that is used to generate linker errors if this class is
3272  // referenced in other modules but not declared.
3273  std::string classSymbolName = "__objc_class_name_" + ClassName;
3274  if (auto *symbol = TheModule.getGlobalVariable(classSymbolName)) {
3275  symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0));
3276  } else {
3277  new llvm::GlobalVariable(TheModule, LongTy, false,
3279  llvm::ConstantInt::get(LongTy, 0),
3280  classSymbolName);
3281  }
3282 
3283  // Get the size of instances.
3284  int instanceSize =
3286 
3287  // Collect information about instance variables.
3293 
3294  ConstantInitBuilder IvarOffsetBuilder(CGM);
3295  auto IvarOffsetValues = IvarOffsetBuilder.beginArray(PtrToIntTy);
3296  SmallVector<bool, 16> WeakIvars;
3297  SmallVector<bool, 16> StrongIvars;
3298 
3299  int superInstanceSize = !SuperClassDecl ? 0 :
3300  Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity();
3301  // For non-fragile ivars, set the instance size to 0 - {the size of just this
3302  // class}. The runtime will then set this to the correct value on load.
3303  if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
3304  instanceSize = 0 - (instanceSize - superInstanceSize);
3305  }
3306 
3307  for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
3308  IVD = IVD->getNextIvar()) {
3309  // Store the name
3310  IvarNames.push_back(MakeConstantString(IVD->getNameAsString()));
3311  // Get the type encoding for this ivar
3312  std::string TypeStr;
3313  Context.getObjCEncodingForType(IVD->getType(), TypeStr, IVD);
3314  IvarTypes.push_back(MakeConstantString(TypeStr));
3315  IvarAligns.push_back(llvm::ConstantInt::get(IntTy,
3316  Context.getTypeSize(IVD->getType())));
3317  // Get the offset
3318  uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD);
3319  uint64_t Offset = BaseOffset;
3320  if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
3321  Offset = BaseOffset - superInstanceSize;
3322  }
3323  llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset);
3324  // Create the direct offset value
3325  std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." +
3326  IVD->getNameAsString();
3327 
3328  llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName);
3329  if (OffsetVar) {
3330  OffsetVar->setInitializer(OffsetValue);
3331  // If this is the real definition, change its linkage type so that
3332  // different modules will use this one, rather than their private
3333  // copy.
3334  OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage);
3335  } else
3336  OffsetVar = new llvm::GlobalVariable(TheModule, Int32Ty,
3338  OffsetValue, OffsetName);
3339  IvarOffsets.push_back(OffsetValue);
3340  IvarOffsetValues.add(OffsetVar);
3341  Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime();
3342  IvarOwnership.push_back(lt);
3343  switch (lt) {
3345  StrongIvars.push_back(true);
3346  WeakIvars.push_back(false);
3347  break;
3348  case Qualifiers::OCL_Weak:
3349  StrongIvars.push_back(false);
3350  WeakIvars.push_back(true);
3351  break;
3352  default:
3353  StrongIvars.push_back(false);
3354  WeakIvars.push_back(false);
3355  }
3356  }
3357  llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars);
3358  llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars);
3359  llvm::GlobalVariable *IvarOffsetArray =
3360  IvarOffsetValues.finishAndCreateGlobal(".ivar.offsets",
3361  CGM.getPointerAlign());
3362 
3363  // Collect information about instance methods
3365  InstanceMethods.insert(InstanceMethods.begin(), OID->instmeth_begin(),
3366  OID->instmeth_end());
3367 
3369  ClassMethods.insert(ClassMethods.begin(), OID->classmeth_begin(),
3370  OID->classmeth_end());
3371 
3372  // Collect the same information about synthesized properties, which don't
3373  // show up in the instance method lists.
3374  for (auto *propertyImpl : OID->property_impls())
3375  if (propertyImpl->getPropertyImplementation() ==
3377  ObjCPropertyDecl *property = propertyImpl->getPropertyDecl();
3378  auto addPropertyMethod = [&](const ObjCMethodDecl *accessor) {
3379  if (accessor)
3380  InstanceMethods.push_back(accessor);
3381  };
3382  addPropertyMethod(property->getGetterMethodDecl());
3383  addPropertyMethod(property->getSetterMethodDecl());
3384  }
3385 
3386  llvm::Constant *Properties = GeneratePropertyList(OID, ClassDecl);
3387 
3388  // Collect the names of referenced protocols
3389  SmallVector<std::string, 16> Protocols;
3390  for (const auto *I : ClassDecl->protocols())
3391  Protocols.push_back(I->getNameAsString());
3392 
3393  // Get the superclass pointer.
3394  llvm::Constant *SuperClass;
3395  if (!SuperClassName.empty()) {
3396  SuperClass = MakeConstantString(SuperClassName, ".super_class_name");
3397  } else {
3398  SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty);
3399  }
3400  // Empty vector used to construct empty method lists
3402  // Generate the method and instance variable lists
3403  llvm::Constant *MethodList = GenerateMethodList(ClassName, "",
3404  InstanceMethods, false);
3405  llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "",
3406  ClassMethods, true);
3407  llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes,
3408  IvarOffsets, IvarAligns, IvarOwnership);
3409  // Irrespective of whether we are compiling for a fragile or non-fragile ABI,
3410  // we emit a symbol containing the offset for each ivar in the class. This
3411  // allows code compiled for the non-Fragile ABI to inherit from code compiled
3412  // for the legacy ABI, without causing problems. The converse is also
3413  // possible, but causes all ivar accesses to be fragile.
3414 
3415  // Offset pointer for getting at the correct field in the ivar list when
3416  // setting up the alias. These are: The base address for the global, the
3417  // ivar array (second field), the ivar in this list (set for each ivar), and
3418  // the offset (third field in ivar structure)
3419  llvm::Type *IndexTy = Int32Ty;
3420  llvm::Constant *offsetPointerIndexes[] = {Zeros[0],
3421  llvm::ConstantInt::get(IndexTy, ClassABIVersion > 1 ? 2 : 1), nullptr,
3422  llvm::ConstantInt::get(IndexTy, ClassABIVersion > 1 ? 3 : 2) };
3423 
3424  unsigned ivarIndex = 0;
3425  for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
3426  IVD = IVD->getNextIvar()) {
3427  const std::string Name = GetIVarOffsetVariableName(ClassDecl, IVD);
3428  offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex);
3429  // Get the correct ivar field
3430  llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr(
3431  cast<llvm::GlobalVariable>(IvarList)->getValueType(), IvarList,
3432  offsetPointerIndexes);
3433  // Get the existing variable, if one exists.
3434  llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name);
3435  if (offset) {
3436  offset->setInitializer(offsetValue);
3437  // If this is the real definition, change its linkage type so that
3438  // different modules will use this one, rather than their private
3439  // copy.
3440  offset->setLinkage(llvm::GlobalValue::ExternalLinkage);
3441  } else
3442  // Add a new alias if there isn't one already.
3443  new llvm::GlobalVariable(TheModule, offsetValue->getType(),
3444  false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name);
3445  ++ivarIndex;
3446  }
3447  llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0);
3448 
3449  //Generate metaclass for class methods
3450  llvm::Constant *MetaClassStruct = GenerateClassStructure(
3451  NULLPtr, NULLPtr, 0x12L, ClassName.c_str(), nullptr, Zeros[0],
3452  NULLPtr, ClassMethodList, NULLPtr, NULLPtr,
3453  GeneratePropertyList(OID, ClassDecl, true), ZeroPtr, ZeroPtr, true);
3454  CGM.setGVProperties(cast<llvm::GlobalValue>(MetaClassStruct),
3455  OID->getClassInterface());
3456 
3457  // Generate the class structure
3458  llvm::Constant *ClassStruct = GenerateClassStructure(
3459  MetaClassStruct, SuperClass, 0x11L, ClassName.c_str(), nullptr,
3460  llvm::ConstantInt::get(LongTy, instanceSize), IvarList, MethodList,
3461  GenerateProtocolList(Protocols), IvarOffsetArray, Properties,
3462  StrongIvarBitmap, WeakIvarBitmap);
3463  CGM.setGVProperties(cast<llvm::GlobalValue>(ClassStruct),
3464  OID->getClassInterface());
3465 
3466  // Resolve the class aliases, if they exist.
3467  if (ClassPtrAlias) {
3468  ClassPtrAlias->replaceAllUsesWith(
3469  llvm::ConstantExpr::getBitCast(ClassStruct, IdTy));
3470  ClassPtrAlias->eraseFromParent();
3471  ClassPtrAlias = nullptr;
3472  }
3473  if (MetaClassPtrAlias) {
3474  MetaClassPtrAlias->replaceAllUsesWith(
3475  llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy));
3476  MetaClassPtrAlias->eraseFromParent();
3477  MetaClassPtrAlias = nullptr;
3478  }
3479 
3480  // Add class structure to list to be added to the symtab later
3481  ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty);
3482  Classes.push_back(ClassStruct);
3483 }
3484 
3485 llvm::Function *CGObjCGNU::ModuleInitFunction() {
3486  // Only emit an ObjC load function if no Objective-C stuff has been called
3487  if (Classes.empty() && Categories.empty() && ConstantStrings.empty() &&
3488  ExistingProtocols.empty() && SelectorTable.empty())
3489  return nullptr;
3490 
3491  // Add all referenced protocols to a category.
3492  GenerateProtocolHolderCategory();
3493 
3494  llvm::StructType *selStructTy =
3495  dyn_cast<llvm::StructType>(SelectorTy->getElementType());
3496  llvm::Type *selStructPtrTy = SelectorTy;
3497  if (!selStructTy) {
3498  selStructTy = llvm::StructType::get(CGM.getLLVMContext(),
3499  { PtrToInt8Ty, PtrToInt8Ty });
3500  selStructPtrTy = llvm::PointerType::getUnqual(selStructTy);
3501  }
3502 
3503  // Generate statics list:
3504  llvm::Constant *statics = NULLPtr;
3505  if (!ConstantStrings.empty()) {
3506  llvm::GlobalVariable *fileStatics = [&] {
3507  ConstantInitBuilder builder(CGM);
3508  auto staticsStruct = builder.beginStruct();
3509 
3510  StringRef stringClass = CGM.getLangOpts().ObjCConstantStringClass;
3511  if (stringClass.empty()) stringClass = "NXConstantString";
3512  staticsStruct.add(MakeConstantString(stringClass,
3513  ".objc_static_class_name"));
3514 
3515  auto array = staticsStruct.beginArray();
3516  array.addAll(ConstantStrings);
3517  array.add(NULLPtr);
3518  array.finishAndAddTo(staticsStruct);
3519 
3520  return staticsStruct.finishAndCreateGlobal(".objc_statics",
3521  CGM.getPointerAlign());
3522  }();
3523 
3524  ConstantInitBuilder builder(CGM);
3525  auto allStaticsArray = builder.beginArray(fileStatics->getType());
3526  allStaticsArray.add(fileStatics);
3527  allStaticsArray.addNullPointer(fileStatics->getType());
3528 
3529  statics = allStaticsArray.finishAndCreateGlobal(".objc_statics_ptr",
3530  CGM.getPointerAlign());
3531  statics = llvm::ConstantExpr::getBitCast(statics, PtrTy);
3532  }
3533 
3534  // Array of classes, categories, and constant objects.
3535 
3536  SmallVector<llvm::GlobalAlias*, 16> selectorAliases;
3537  unsigned selectorCount;
3538 
3539  // Pointer to an array of selectors used in this module.
3540  llvm::GlobalVariable *selectorList = [&] {
3541  ConstantInitBuilder builder(CGM);
3542  auto selectors = builder.beginArray(selStructTy);
3543  auto &table = SelectorTable; // MSVC workaround
3544  std::vector<Selector> allSelectors;
3545  for (auto &entry : table)
3546  allSelectors.push_back(entry.first);
3547  llvm::sort(allSelectors.begin(), allSelectors.end());
3548 
3549  for (auto &untypedSel : allSelectors) {
3550  std::string selNameStr = untypedSel.getAsString();
3551  llvm::Constant *selName = ExportUniqueString(selNameStr, ".objc_sel_name");
3552 
3553  for (TypedSelector &sel : table[untypedSel]) {
3554  llvm::Constant *selectorTypeEncoding = NULLPtr;
3555  if (!sel.first.empty())
3556  selectorTypeEncoding =
3557  MakeConstantString(sel.first, ".objc_sel_types");
3558 
3559  auto selStruct = selectors.beginStruct(selStructTy);
3560  selStruct.add(selName);
3561  selStruct.add(selectorTypeEncoding);
3562  selStruct.finishAndAddTo(selectors);
3563 
3564  // Store the selector alias for later replacement
3565  selectorAliases.push_back(sel.second);
3566  }
3567  }
3568 
3569  // Remember the number of entries in the selector table.
3570  selectorCount = selectors.size();
3571 
3572  // NULL-terminate the selector list. This should not actually be required,
3573  // because the selector list has a length field. Unfortunately, the GCC
3574  // runtime decides to ignore the length field and expects a NULL terminator,
3575  // and GCC cooperates with this by always setting the length to 0.
3576  auto selStruct = selectors.beginStruct(selStructTy);
3577  selStruct.add(NULLPtr);
3578  selStruct.add(NULLPtr);
3579  selStruct.finishAndAddTo(selectors);
3580 
3581  return selectors.finishAndCreateGlobal(".objc_selector_list",
3582  CGM.getPointerAlign());
3583  }();
3584 
3585  // Now that all of the static selectors exist, create pointers to them.
3586  for (unsigned i = 0; i < selectorCount; ++i) {
3587  llvm::Constant *idxs[] = {
3588  Zeros[0],
3589  llvm::ConstantInt::get(Int32Ty, i)
3590  };
3591  // FIXME: We're generating redundant loads and stores here!
3592  llvm::Constant *selPtr = llvm::ConstantExpr::getGetElementPtr(
3593  selectorList->getValueType(), selectorList, idxs);
3594  // If selectors are defined as an opaque type, cast the pointer to this
3595  // type.
3596  selPtr = llvm::ConstantExpr::getBitCast(selPtr, SelectorTy);
3597  selectorAliases[i]->replaceAllUsesWith(selPtr);
3598  selectorAliases[i]->eraseFromParent();
3599  }
3600 
3601  llvm::GlobalVariable *symtab = [&] {
3602  ConstantInitBuilder builder(CGM);
3603  auto symtab = builder.beginStruct();
3604 
3605  // Number of static selectors
3606  symtab.addInt(LongTy, selectorCount);
3607 
3608  symtab.addBitCast(selectorList, selStructPtrTy);
3609 
3610  // Number of classes defined.
3611  symtab.addInt(CGM.Int16Ty, Classes.size());
3612  // Number of categories defined
3613  symtab.addInt(CGM.Int16Ty, Categories.size());
3614 
3615  // Create an array of classes, then categories, then static object instances
3616  auto classList = symtab.beginArray(PtrToInt8Ty);
3617  classList.addAll(Classes);
3618  classList.addAll(Categories);
3619  // NULL-terminated list of static object instances (mainly constant strings)
3620  classList.add(statics);
3621  classList.add(NULLPtr);
3622  classList.finishAndAddTo(symtab);
3623 
3624  // Construct the symbol table.
3625  return symtab.finishAndCreateGlobal("", CGM.getPointerAlign());
3626  }();
3627 
3628  // The symbol table is contained in a module which has some version-checking
3629  // constants
3630  llvm::Constant *module = [&] {
3631  llvm::Type *moduleEltTys[] = {
3632  LongTy, LongTy, PtrToInt8Ty, symtab->getType(), IntTy
3633  };
3634  llvm::StructType *moduleTy =
3635  llvm::StructType::get(CGM.getLLVMContext(),
3636  makeArrayRef(moduleEltTys).drop_back(unsigned(RuntimeVersion < 10)));
3637 
3638  ConstantInitBuilder builder(CGM);
3639  auto module = builder.beginStruct(moduleTy);
3640  // Runtime version, used for ABI compatibility checking.
3641  module.addInt(LongTy, RuntimeVersion);
3642  // sizeof(ModuleTy)
3643  module.addInt(LongTy, CGM.getDataLayout().getTypeStoreSize(moduleTy));
3644 
3645  // The path to the source file where this module was declared
3647  const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID());
3648  std::string path =
3649  (Twine(mainFile->getDir()->getName()) + "/" + mainFile->getName()).str();
3650  module.add(MakeConstantString(path, ".objc_source_file_name"));
3651  module.add(symtab);
3652 
3653  if (RuntimeVersion >= 10) {
3654  switch (CGM.getLangOpts().getGC()) {
3655  case LangOptions::GCOnly:
3656  module.addInt(IntTy, 2);
3657  break;
3658  case LangOptions::NonGC:
3659  if (CGM.getLangOpts().ObjCAutoRefCount)
3660  module.addInt(IntTy, 1);
3661  else
3662  module.addInt(IntTy, 0);
3663  break;
3664  case LangOptions::HybridGC:
3665  module.addInt(IntTy, 1);
3666  break;
3667  }
3668  }
3669 
3670  return module.finishAndCreateGlobal("", CGM.getPointerAlign());
3671  }();
3672 
3673  // Create the load function calling the runtime entry point with the module
3674  // structure
3675  llvm::Function * LoadFunction = llvm::Function::Create(
3676  llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false),
3677  llvm::GlobalValue::InternalLinkage, ".objc_load_function",
3678  &TheModule);
3679  llvm::BasicBlock *EntryBB =
3680  llvm::BasicBlock::Create(VMContext, "entry", LoadFunction);
3681  CGBuilderTy Builder(CGM, VMContext);
3682  Builder.SetInsertPoint(EntryBB);
3683 
3684  llvm::FunctionType *FT =
3685  llvm::FunctionType::get(Builder.getVoidTy(), module->getType(), true);
3686  llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class");
3687  Builder.CreateCall(Register, module);
3688 
3689  if (!ClassAliases.empty()) {
3690  llvm::Type *ArgTypes[2] = {PtrTy, PtrToInt8Ty};
3691  llvm::FunctionType *RegisterAliasTy =
3692  llvm::FunctionType::get(Builder.getVoidTy(),
3693  ArgTypes, false);
3694  llvm::Function *RegisterAlias = llvm::Function::Create(
3695  RegisterAliasTy,
3696  llvm::GlobalValue::ExternalWeakLinkage, "class_registerAlias_np",
3697  &TheModule);
3698  llvm::BasicBlock *AliasBB =
3699  llvm::BasicBlock::Create(VMContext, "alias", LoadFunction);
3700  llvm::BasicBlock *NoAliasBB =
3701  llvm::BasicBlock::Create(VMContext, "no_alias", LoadFunction);
3702 
3703  // Branch based on whether the runtime provided class_registerAlias_np()
3704  llvm::Value *HasRegisterAlias = Builder.CreateICmpNE(RegisterAlias,
3705  llvm::Constant::getNullValue(RegisterAlias->getType()));
3706  Builder.CreateCondBr(HasRegisterAlias, AliasBB, NoAliasBB);
3707 
3708  // The true branch (has alias registration function):
3709  Builder.SetInsertPoint(AliasBB);
3710  // Emit alias registration calls:
3711  for (std::vector<ClassAliasPair>::iterator iter = ClassAliases.begin();
3712  iter != ClassAliases.end(); ++iter) {
3713  llvm::Constant *TheClass =
3714  TheModule.getGlobalVariable("_OBJC_CLASS_" + iter->first, true);
3715  if (TheClass) {
3716  TheClass = llvm::ConstantExpr::getBitCast(TheClass, PtrTy);
3717  Builder.CreateCall(RegisterAlias,
3718  {TheClass, MakeConstantString(iter->second)});
3719  }
3720  }
3721  // Jump to end:
3722  Builder.CreateBr(NoAliasBB);
3723 
3724  // Missing alias registration function, just return from the function:
3725  Builder.SetInsertPoint(NoAliasBB);
3726  }
3727  Builder.CreateRetVoid();
3728 
3729  return LoadFunction;
3730 }
3731 
3732 llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD,
3733  const ObjCContainerDecl *CD) {
3734  const ObjCCategoryImplDecl *OCD =
3735  dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext());
3736  StringRef CategoryName = OCD ? OCD->getName() : "";
3737  StringRef ClassName = CD->getName();
3738  Selector MethodName = OMD->getSelector();
3739  bool isClassMethod = !OMD->isInstanceMethod();
3740 
3741  CodeGenTypes &Types = CGM.getTypes();
3742  llvm::FunctionType *MethodTy =
3744  std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName,
3745  MethodName, isClassMethod);
3746 
3747  llvm::Function *Method
3748  = llvm::Function::Create(MethodTy,
3750  FunctionName,
3751  &TheModule);
3752  return Method;
3753 }
3754 
3755 llvm::Constant *CGObjCGNU::GetPropertyGetFunction() {
3756  return GetPropertyFn;
3757 }
3758 
3759 llvm::Constant *CGObjCGNU::GetPropertySetFunction() {
3760  return SetPropertyFn;
3761 }
3762 
3763 llvm::Constant *CGObjCGNU::GetOptimizedPropertySetFunction(bool atomic,
3764  bool copy) {
3765  return nullptr;
3766 }
3767 
3768 llvm::Constant *CGObjCGNU::GetGetStructFunction() {
3769  return GetStructPropertyFn;
3770 }
3771 
3772 llvm::Constant *CGObjCGNU::GetSetStructFunction() {
3773  return SetStructPropertyFn;
3774 }
3775 
3776 llvm::Constant *CGObjCGNU::GetCppAtomicObjectGetFunction() {
3777  return nullptr;
3778 }
3779 
3780 llvm::Constant *CGObjCGNU::GetCppAtomicObjectSetFunction() {
3781  return nullptr;
3782 }
3783 
3784 llvm::Constant *CGObjCGNU::EnumerationMutationFunction() {
3785  return EnumerationMutationFn;
3786 }
3787 
3788 void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF,
3789  const ObjCAtSynchronizedStmt &S) {
3790  EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn);
3791 }
3792 
3793 
3794 void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF,
3795  const ObjCAtTryStmt &S) {
3796  // Unlike the Apple non-fragile runtimes, which also uses
3797  // unwind-based zero cost exceptions, the GNU Objective C runtime's
3798  // EH support isn't a veneer over C++ EH. Instead, exception
3799  // objects are created by objc_exception_throw and destroyed by
3800  // the personality function; this avoids the need for bracketing
3801  // catch handlers with calls to __blah_begin_catch/__blah_end_catch
3802  // (or even _Unwind_DeleteException), but probably doesn't
3803  // interoperate very well with foreign exceptions.
3804  //
3805  // In Objective-C++ mode, we actually emit something equivalent to the C++
3806  // exception handler.
3807  EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn);
3808 }
3809 
3810 void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF,
3811  const ObjCAtThrowStmt &S,
3812  bool ClearInsertionPoint) {
3813  llvm::Value *ExceptionAsObject;
3814  bool isRethrow = false;
3815 
3816  if (const Expr *ThrowExpr = S.getThrowExpr()) {
3817  llvm::Value *Exception = CGF.EmitObjCThrowOperand(ThrowExpr);
3818  ExceptionAsObject = Exception;
3819  } else {
3820  assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) &&
3821  "Unexpected rethrow outside @catch block.");
3822  ExceptionAsObject = CGF.ObjCEHValueStack.back();
3823  isRethrow = true;
3824  }
3825  if (isRethrow && usesSEHExceptions) {
3826  // For SEH, ExceptionAsObject may be undef, because the catch handler is
3827  // not passed it for catchalls and so it is not visible to the catch
3828  // funclet. The real thrown object will still be live on the stack at this
3829  // point and will be rethrown. If we are explicitly rethrowing the object
3830  // that was passed into the `@catch` block, then this code path is not
3831  // reached and we will instead call `objc_exception_throw` with an explicit
3832  // argument.
3833  CGF.EmitRuntimeCallOrInvoke(ExceptionReThrowFn).setDoesNotReturn();
3834  }
3835  else {
3836  ExceptionAsObject = CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy);
3837  llvm::CallSite Throw =
3838  CGF.EmitRuntimeCallOrInvoke(ExceptionThrowFn, ExceptionAsObject);
3839  Throw.setDoesNotReturn();
3840  }
3841  CGF.Builder.CreateUnreachable();
3842  if (ClearInsertionPoint)
3843  CGF.Builder.ClearInsertionPoint();
3844 }
3845 
3846 llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF,
3847  Address AddrWeakObj) {
3848  CGBuilderTy &B = CGF.Builder;
3849  AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy);
3850  return B.CreateCall(WeakReadFn.getType(), WeakReadFn,
3851  AddrWeakObj.getPointer());
3852 }
3853 
3854 void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF,
3855  llvm::Value *src, Address dst) {
3856  CGBuilderTy &B = CGF.Builder;
3857  src = EnforceType(B, src, IdTy);
3858  dst = EnforceType(B, dst, PtrToIdTy);
3859  B.CreateCall(WeakAssignFn.getType(), WeakAssignFn,
3860  {src, dst.getPointer()});
3861 }
3862 
3863 void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF,
3864  llvm::Value *src, Address dst,
3865  bool threadlocal) {
3866  CGBuilderTy &B = CGF.Builder;
3867  src = EnforceType(B, src, IdTy);
3868  dst = EnforceType(B, dst, PtrToIdTy);
3869  // FIXME. Add threadloca assign API
3870  assert(!threadlocal && "EmitObjCGlobalAssign - Threal Local API NYI");
3871  B.CreateCall(GlobalAssignFn.getType(), GlobalAssignFn,
3872  {src, dst.getPointer()});
3873 }
3874 
3875 void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF,
3876  llvm::Value *src, Address dst,
3877  llvm::Value *ivarOffset) {
3878  CGBuilderTy &B = CGF.Builder;
3879  src = EnforceType(B, src, IdTy);
3880  dst = EnforceType(B, dst, IdTy);
3881  B.CreateCall(IvarAssignFn.getType(), IvarAssignFn,
3882  {src, dst.getPointer(), ivarOffset});
3883 }
3884 
3885 void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF,
3886  llvm::Value *src, Address dst) {
3887  CGBuilderTy &B = CGF.Builder;
3888  src = EnforceType(B, src, IdTy);
3889  dst = EnforceType(B, dst, PtrToIdTy);
3890  B.CreateCall(StrongCastAssignFn.getType(), StrongCastAssignFn,
3891  {src, dst.getPointer()});
3892 }
3893 
3894 void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF,
3895  Address DestPtr,
3896  Address SrcPtr,
3897  llvm::Value *Size) {
3898  CGBuilderTy &B = CGF.Builder;
3899  DestPtr = EnforceType(B, DestPtr, PtrTy);
3900  SrcPtr = EnforceType(B, SrcPtr, PtrTy);
3901 
3902  B.CreateCall(MemMoveFn.getType(), MemMoveFn,
3903  {DestPtr.getPointer(), SrcPtr.getPointer(), Size});
3904 }
3905 
3906 llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable(
3907  const ObjCInterfaceDecl *ID,
3908  const ObjCIvarDecl *Ivar) {
3909  const std::string Name = GetIVarOffsetVariableName(ID, Ivar);
3910  // Emit the variable and initialize it with what we think the correct value
3911  // is. This allows code compiled with non-fragile ivars to work correctly
3912  // when linked against code which isn't (most of the time).
3913  llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name);
3914  if (!IvarOffsetPointer)
3915  IvarOffsetPointer = new llvm::GlobalVariable(TheModule,
3916  llvm::Type::getInt32PtrTy(VMContext), false,
3917  llvm::GlobalValue::ExternalLinkage, nullptr, Name);
3918  return IvarOffsetPointer;
3919 }
3920 
3921 LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF,
3922  QualType ObjectTy,
3923  llvm::Value *BaseValue,
3924  const ObjCIvarDecl *Ivar,
3925  unsigned CVRQualifiers) {
3926  const ObjCInterfaceDecl *ID =
3927  ObjectTy->getAs<ObjCObjectType>()->getInterface();
3928  return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers,
3929  EmitIvarOffset(CGF, ID, Ivar));
3930 }
3931 
3933  const ObjCInterfaceDecl *OID,
3934  const ObjCIvarDecl *OIVD) {
3935  for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next;
3936  next = next->getNextIvar()) {
3937  if (OIVD == next)
3938  return OID;
3939  }
3940 
3941  // Otherwise check in the super class.
3942  if (const ObjCInterfaceDecl *Super = OID->getSuperClass())
3943  return FindIvarInterface(Context, Super, OIVD);
3944 
3945  return nullptr;
3946 }
3947 
3948 llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF,
3949  const ObjCInterfaceDecl *Interface,
3950  const ObjCIvarDecl *Ivar) {
3951  if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
3952  Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar);
3953 
3954  // The MSVC linker cannot have a single global defined as LinkOnceAnyLinkage
3955  // and ExternalLinkage, so create a reference to the ivar global and rely on
3956  // the definition being created as part of GenerateClass.
3957  if (RuntimeVersion < 10 ||
3958  CGF.CGM.getTarget().getTriple().isKnownWindowsMSVCEnvironment())
3959  return CGF.Builder.CreateZExtOrBitCast(
3961  Int32Ty, CGF.Builder.CreateAlignedLoad(
3962  ObjCIvarOffsetVariable(Interface, Ivar),
3963  CGF.getPointerAlign(), "ivar"),
3965  PtrDiffTy);
3966  std::string name = "__objc_ivar_offset_value_" +
3967  Interface->getNameAsString() +"." + Ivar->getNameAsString();
3968  CharUnits Align = CGM.getIntAlign();
3969  llvm::Value *Offset = TheModule.getGlobalVariable(name);
3970  if (!Offset) {
3971  auto GV = new llvm::GlobalVariable(TheModule, IntTy,
3972  false, llvm::GlobalValue::LinkOnceAnyLinkage,
3973  llvm::Constant::getNullValue(IntTy), name);
3974  GV->setAlignment(Align.getQuantity());
3975  Offset = GV;
3976  }
3977  Offset = CGF.Builder.CreateAlignedLoad(Offset, Align);
3978  if (Offset->getType() != PtrDiffTy)
3979  Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy);
3980  return Offset;
3981  }
3982  uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar);
3983  return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true);
3984 }
3985 
3986 CGObjCRuntime *
3988  auto Runtime = CGM.getLangOpts().ObjCRuntime;
3989  switch (Runtime.getKind()) {
3990  case ObjCRuntime::GNUstep:
3991  if (Runtime.getVersion() >= VersionTuple(2, 0))
3992  return new CGObjCGNUstep2(CGM);
3993  return new CGObjCGNUstep(CGM);
3994 
3995  case ObjCRuntime::GCC:
3996  return new CGObjCGCC(CGM);
3997 
3998  case ObjCRuntime::ObjFW:
3999  return new CGObjCObjFW(CGM);
4000 
4002  case ObjCRuntime::MacOSX:
4003  case ObjCRuntime::iOS:
4004  case ObjCRuntime::WatchOS:
4005  llvm_unreachable("these runtimes are not GNU runtimes");
4006  }
4007  llvm_unreachable("bad runtime");
4008 }
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:361
const ObjCInterfaceType * getInterfaceType() const
If this pointer points to an Objective C @interface type, gets the type for that interface.
Definition: Type.cpp:1522
Defines the clang::ASTContext interface.
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:60
protocol_range protocols() const
Definition: DeclObjC.h:1358
Smart pointer class that efficiently represents Objective-C method names.
QualType getObjCIdType() const
Represents the Objective-CC id type.
Definition: ASTContext.h:1855
A (possibly-)qualified type.
Definition: Type.h:642
bool ReturnTypeUsesSRet(const CGFunctionInfo &FI)
Return true iff the given type uses &#39;sret&#39; when used as a return type.
Definition: CGCall.cpp:1500
const CodeGenOptions & getCodeGenOpts() const
all_protocol_range all_referenced_protocols() const
Definition: DeclObjC.h:1416
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:2341
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:949
Implements runtime-specific code generation functions.
Definition: CGObjCRuntime.h:64
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:87
const Decl * CurCodeDecl
CurCodeDecl - This is the inner-most code context, which includes blocks.
static void add(Kind k)
Definition: DeclBase.cpp:193
StringRef P
Represents Objective-C&#39;s @throw statement.
Definition: StmtObjC.h:313
CanQualType LongTy
Definition: ASTContext.h:1034
const TargetInfo & getTargetInfo() const
Definition: ASTContext.h:699
instmeth_iterator instmeth_end() const
Definition: DeclObjC.h:1054
constexpr XRayInstrMask Function
Definition: XRayInstr.h:39
&#39;gcc&#39; is the Objective-C runtime shipped with GCC, implementing a fragile Objective-C ABI ...
Definition: ObjCRuntime.h:53
RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee, ReturnValueSlot ReturnValue, const CallArgList &Args, llvm::Instruction **callOrInvoke, SourceLocation Loc)
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:3785
Represents a variable declaration or definition.
Definition: Decl.h:812
uint64_t ComputeIvarBaseOffset(CodeGen::CodeGenModule &CGM, const ObjCInterfaceDecl *OID, const ObjCIvarDecl *Ivar)
Compute an offset to the given ivar, suitable for passing to EmitValueForIvarAtOffset.
Objects with "hidden" visibility are not seen by the dynamic linker.
Definition: Visibility.h:37
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6590
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
llvm::Value * getPointer() const
Definition: Address.h:38
Defines the Objective-C statement AST node classes.
classmeth_range class_methods() const
Definition: DeclObjC.h:1063
protocol_range protocols() const
Definition: DeclObjC.h:2121
void add(RValue rvalue, QualType type)
Definition: CGCall.h:285
iterator end() const
Definition: DeclObjC.h:92
llvm::Value * EmitObjCThrowOperand(const Expr *expr)
Definition: CGObjC.cpp:3017
IdentifierInfo * getIdentifier() const
Get the identifier that names this declaration, if there is one.
Definition: Decl.h:269
uint64_t getPointerWidth(unsigned AddrSpace) const
Return the width of pointers on this target, for the specified address space.
Definition: TargetInfo.h:348
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:40
This table allows us to fully hide how we implement multi-keyword caching.
Represents a class type in Objective C.
Definition: Type.h:5419
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:154
bool isObjCIdType() const
Definition: Type.h:6303
static const ObjCInterfaceDecl * FindIvarInterface(ASTContext &Context, const ObjCInterfaceDecl *OID, const ObjCIvarDecl *OIVD)
Definition: CGObjCGNU.cpp:3932
instmeth_range instance_methods() const
Definition: DeclObjC.h:1046
ObjCMethodDecl * getSetterMethodDecl() const
Definition: DeclObjC.h:917
virtual bool isDynamic(OpenMPScheduleClauseKind ScheduleKind) const
Check if the specified ScheduleKind is dynamic.
prop_range properties() const
Definition: DeclObjC.h:980
int Category
Definition: Format.cpp:1605
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:50
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:126
bool isIntegralOrEnumerationType() const
Determine whether this type is an integral or enumeration type.
Definition: Type.h:6504
IdentifierTable & Idents
Definition: ASTContext.h:565
Objects with "default" visibility are seen by the dynamic linker and act like normal objects...
Definition: Visibility.h:46
virtual llvm::Value * EmitIvarOffset(CodeGen::CodeGenFunction &CGF, const ObjCInterfaceDecl *Interface, const ObjCIvarDecl *Ivar)=0
MessageSendInfo getMessageSendInfo(const ObjCMethodDecl *method, QualType resultType, CallArgList &callArgs)
Compute the pointer-to-function type to which a message send should be casted in order to correctly c...
unsigned getLength() const
Definition: Expr.h:1649
bool isNonFragile() const
Does this runtime follow the set of implied behaviors for a "non-fragile" ABI?
Definition: ObjCRuntime.h:82
ObjCContainerDecl - Represents a container for method declarations.
Definition: DeclObjC.h:961
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:2959
ObjCProtocolDecl * getDefinition()
Retrieve the definition of this protocol, if any.
Definition: DeclObjC.h:2202
llvm::BasicBlock * createBasicBlock(const Twine &name="", llvm::Function *parent=nullptr, llvm::BasicBlock *before=nullptr)
createBasicBlock - Create an LLVM basic block.
void addCompilerUsedGlobal(llvm::GlobalValue *GV)
Add a global to a list to be added to the llvm.compiler.used metadata.
Represents an Objective-C protocol declaration.
Definition: DeclObjC.h:2056
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:106
Represents an ObjC class declaration.
Definition: DeclObjC.h:1164
ObjCInterfaceDecl * getInterface() const
Gets the interface declaration for this object type, if the base type really is an interface...
Definition: Type.h:5654
Address getAggregateAddress() const
getAggregateAddr() - Return the Value* of the address of the aggregate.
Definition: CGValue.h:71
QualType getObjCProtoType() const
Retrieve the type of the Objective-C Protocol class.
Definition: ASTContext.h:1901
std::string getObjCEncodingForMethodDecl(const ObjCMethodDecl *Decl, bool Extended=false) const
Emit the encoded type for the method declaration Decl into S.
This object can be modified without requiring retains or releases.
Definition: Type.h:162
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:1566
&#39;watchos&#39; is a variant of iOS for Apple&#39;s watchOS.
Definition: ObjCRuntime.h:49
bool hasAttr() const
Definition: DeclBase.h:537
StringRef getString() const
Definition: Expr.h:1616
void addFrom(const CallArgList &other)
Add all the arguments from another CallArgList to this one.
Definition: CGCall.h:294
llvm::CallInst * EmitNounwindRuntimeCall(llvm::Value *callee, const Twine &name="")
ArrayBuilder beginArray(llvm::Type *eltTy=nullptr)
CGBlockInfo - Information to generate a block literal.
Definition: CGBlocks.h:153
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
This represents one expression.
Definition: Expr.h:105
known_extensions_range known_extensions() const
Definition: DeclObjC.h:1753
&#39;macosx&#39; is the Apple-provided NeXT-derived runtime on Mac OS X platforms that use the non-fragile AB...
Definition: ObjCRuntime.h:35
const FileEntry * getFileEntryForID(FileID FID) const
Returns the FileEntry record for the provided FileID.
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.
virtual void RegisterAlias(const ObjCCompatibleAliasDecl *OAD)=0
Register an class alias.
llvm::PointerType * getType() const
Return the type of the pointer value.
Definition: Address.h:44
CharUnits getTypeAlignInChars(QualType T) const
Return the ABI-specified alignment of a (complete) type T, in characters.
DeclContext * getDeclContext()
Definition: DeclBase.h:427
uint32_t getCodeUnit(size_t i) const
Definition: Expr.h:1638
Represents Objective-C&#39;s @synchronized statement.
Definition: StmtObjC.h:262
ObjCInterfaceDecl * getSuperClass() const
Definition: DeclObjC.cpp:338
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:63
void EmitAtSynchronizedStmt(CodeGenFunction &CGF, const ObjCAtSynchronizedStmt &S, llvm::Function *syncEnterFn, llvm::Function *syncExitFn)
Emits an @synchronize() statement, using the syncEnterFn and syncExitFn arguments as the functions ca...
virtual llvm::Value * GetSelector(CodeGenFunction &CGF, Selector Sel)=0
Get a selector for the specified name and type values.
clang::ObjCRuntime ObjCRuntime
Definition: LangOptions.h:176
propimpl_range property_impls() const
Definition: DeclObjC.h:2459
bool isa(CodeGen::Address addr)
Definition: Address.h:112
bool isInstanceMethod() const
Definition: DeclObjC.h:414
const TargetInfo & getTarget() const
Selector getSelector() const
Definition: DeclObjC.h:321
&#39;gnustep&#39; is the modern non-fragile GNUstep runtime.
Definition: ObjCRuntime.h:56
const LangOptions & getLangOpts() const
ASTContext & getContext() const
QualType getType() const
Definition: DeclObjC.h:821
do v
Definition: arm_acle.h:78
const SourceManager & SM
Definition: Format.cpp:1472
static bool isNamed(const NamedDecl *ND, const char(&Str)[Len])
Definition: Decl.cpp:2734
void finishAndAddTo(AggregateBuilderBase &parent)
Given that this builder was created by beginning an array or struct component on the given parent bui...
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
There is no lifetime qualification on this type.
Definition: Type.h:158
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:169
bool ReturnTypeUsesFPRet(QualType ResultType)
Return true iff the given type uses &#39;fpret&#39; when used as a return type.
Definition: CGCall.cpp:1510
classmeth_iterator classmeth_end() const
Definition: DeclObjC.h:1071
ObjCInterfaceDecl * getDecl() const
Get the declaration of this interface.
Definition: Type.h:5632
static DeclContext * castToDeclContext(const TranslationUnitDecl *D)
Definition: Decl.h:129
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
virtual void GenerateProtocol(const ObjCProtocolDecl *OPD)=0
Generate the named protocol.
StringRef getName() const
Definition: FileManager.h:84
Interfaces are the core concept in Objective-C for object oriented design.
Definition: Type.h:5619
&#39;objfw&#39; is the Objective-C runtime included in ObjFW
Definition: ObjCRuntime.h:59
SmallVector< llvm::Value *, 8 > ObjCEHValueStack
ObjCEHValueStack - Stack of Objective-C exception values, used for rethrows.
std::string getNameAsString() const
Get a human-readable name for the declaration, even if it is one of the special kinds of names (C++ c...
Definition: Decl.h:291
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:3744
void setGVProperties(llvm::GlobalValue *GV, GlobalDecl GD) const
Set visibility, dllimport/dllexport and dso_local.
Kind getKind() const
Definition: ObjCRuntime.h:77
ObjCCategoryDecl * getCategoryDecl() const
Definition: DeclObjC.cpp:2064
QualType getObjCSelType() const
Retrieve the type that corresponds to the predefined Objective-C &#39;SEL&#39; type.
Definition: ASTContext.h:1865
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:455
virtual CatchTypeInfo getCatchAllTypeInfo()
Definition: CGCXXABI.cpp:315
ObjCCategoryDecl - Represents a category declaration.
Definition: DeclObjC.h:2272
CanQual< Type > CanQualType
Represents a canonical, potentially-qualified type.
bool isAnyPointerType() const
Definition: Type.h:6181
An aligned address.
Definition: Address.h:25
Represents one property declaration in an Objective-C interface.
Definition: DeclObjC.h:721
All available information about a concrete callee.
Definition: CGCall.h:67
Assigning into this object requires a lifetime extension.
Definition: Type.h:175
const VersionTuple & getVersion() const
Definition: ObjCRuntime.h:78
classmeth_iterator classmeth_begin() const
Definition: DeclObjC.h:1067
The MS C++ ABI needs a pointer to RTTI data plus some flags to describe the type of a catch handler...
Definition: CGCleanup.h:38
bool isWeakImported() const
Determine whether this is a weak-imported symbol.
Definition: DeclBase.cpp:685
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.
void addUsedGlobal(llvm::GlobalValue *GV)
Add a global to a list to be added to the llvm.used metadata.
ObjCIvarDecl * getNextIvar()
Definition: DeclObjC.h:1970
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.
StructBuilder beginStruct(llvm::StructType *ty=nullptr)
const ObjCInterfaceDecl * getClassInterface() const
Definition: DeclObjC.h:2432
Dataflow Directional Tag Classes.
CharUnits getSize() const
getSize - Get the record size in characters.
Definition: RecordLayout.h:184
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1268
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:28
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:5716
const ObjCInterfaceDecl * getContainingInterface() const
Return the class interface that this ivar is logically contained in; this is either the interface whe...
Definition: DeclObjC.cpp:1790
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:2739
&#39;ios&#39; is the Apple-provided NeXT-derived runtime on iOS or the iOS simulator; it is always non-fragil...
Definition: ObjCRuntime.h:45
Represents a pointer to an Objective C object.
Definition: Type.h:5675
ObjCImplementationDecl - Represents a class definition - this is where method definitions are specifi...
Definition: DeclObjC.h:2544
virtual llvm::Constant * getAddrOfRTTIDescriptor(QualType Ty)=0
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:2080
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:6291
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:32
void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false)
EmitBlock - Emit the given block.
Definition: CGStmt.cpp:445
uint64_t getTypeSize(QualType T) const
Return the size of the specified (complete) type T, in bits.
Definition: ASTContext.h:2076
SourceManager & getSourceManager()
Definition: ASTContext.h:671
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2259
Reading or writing from this object requires a barrier call.
Definition: Type.h:172
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:1018
bool isVoidType() const
Definition: Type.h:6404
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:1937
A helper class of ConstantInitBuilder, used for building constant struct initializers.
bool containsNonAscii() const
Definition: Expr.h:1666
void getObjCEncodingForMethodParameter(Decl::ObjCDeclQualifier QT, QualType T, std::string &S, bool Extended) const
getObjCEncodingForMethodParameter - Return the encoded type for a single method parameter or return t...
unsigned kind
All of the diagnostics that can be emitted by the frontend.
Definition: DiagnosticIDs.h:61
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:1568
StringRef getName() const
Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:275
CGCXXABI & getCXXABI() const
CanQualType IntTy
Definition: ASTContext.h:1034
The top declaration context.
Definition: Decl.h:107
void EmitTryCatchStmt(CodeGenFunction &CGF, const ObjCAtTryStmt &S, llvm::Constant *beginCatchFn, llvm::Constant *endCatchFn, llvm::Constant *exceptionRethrowFn)
Emits a try / catch statement.
static RValue get(llvm::Value *V)
Definition: CGValue.h:86
Visibility getVisibility() const
Determines the visibility of this entity.
Definition: Decl.h:390
LValue EmitValueForIvarAtOffset(CodeGen::CodeGenFunction &CGF, const ObjCInterfaceDecl *OID, llvm::Value *BaseValue, const ObjCIvarDecl *Ivar, unsigned CVRQualifiers, llvm::Value *Offset)
llvm::Value * LoadObjCSelf()
LoadObjCSelf - Load the value of self.
Definition: CGObjC.cpp:1460
QualType getType() const
Definition: Decl.h:647
std::string ObjCConstantStringClass
Definition: LangOptions.h:178
static RValue getAggregate(Address addr, bool isVolatile=false)
Definition: CGValue.h:107
instmeth_iterator instmeth_begin() const
Definition: DeclObjC.h:1050
LValue - This represents an lvalue references.
Definition: CGValue.h:167
ObjCMethodDecl * getGetterMethodDecl() const
Definition: DeclObjC.h:914
ObjCIvarDecl * all_declared_ivar_begin()
all_declared_ivar_begin - return first ivar declared in this class, its extensions and its implementa...
Definition: DeclObjC.cpp:1592
CanQualType BoolTy
Definition: ASTContext.h:1026
Kind
The basic Objective-C runtimes that we know about.
Definition: ObjCRuntime.h:31
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:260
ObjCCategoryImplDecl - An object of this class encapsulates a category @implementation declaration...
Definition: DeclObjC.h:2491
This class handles loading and caching of source files into memory.
A helper class of ConstantInitBuilder, used for building constant array initializers.
Abstract information about a function or function prototype.
Definition: CGCall.h:45
bool isScalar() const
Definition: CGValue.h:52
ObjCCompatibleAliasDecl - Represents alias of a class.
Definition: DeclObjC.h:2721
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:3987
ObjCCategoryDecl * FindCategoryDeclaration(IdentifierInfo *CategoryId) const
FindCategoryDeclaration - Finds category declaration in the list of categories for this class and ret...
Definition: DeclObjC.cpp:1664
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1544
const llvm::Triple & getTriple() const