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llvm-project/clang/lib/CodeGen/CGObjCGNU.cpp

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//===------- CGObjCGNU.cpp - Emit LLVM Code from ASTs for a Module --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This provides Objective-C code generation targetting the GNU runtime. The
// class in this file generates structures used by the GNU Objective-C runtime
// library. These structures are defined in objc/objc.h and objc/objc-api.h in
// the GNU runtime distribution.
//
//===----------------------------------------------------------------------===//
#include "CGObjCRuntime.h"
#include "CodeGenModule.h"
#include "CodeGenFunction.h"
#include "CGCleanup.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/StmtObjC.h"
#include "llvm/Intrinsics.h"
#include "llvm/Module.h"
#include "llvm/LLVMContext.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Target/TargetData.h"
#include <map>
using namespace clang;
using namespace CodeGen;
using llvm::dyn_cast;
// The version of the runtime that this class targets. Must match the version
// in the runtime.
static const int RuntimeVersion = 8;
static const int NonFragileRuntimeVersion = 9;
static const int ProtocolVersion = 2;
static const int NonFragileProtocolVersion = 3;
namespace {
class CGObjCGNU : public CodeGen::CGObjCRuntime {
private:
CodeGen::CodeGenModule &CGM;
llvm::Module &TheModule;
const llvm::PointerType *SelectorTy;
const llvm::IntegerType *Int8Ty;
const llvm::PointerType *PtrToInt8Ty;
const llvm::FunctionType *IMPTy;
const llvm::PointerType *IdTy;
const llvm::PointerType *PtrToIdTy;
CanQualType ASTIdTy;
const llvm::IntegerType *IntTy;
const llvm::PointerType *PtrTy;
const llvm::IntegerType *LongTy;
const llvm::IntegerType *SizeTy;
const llvm::IntegerType *PtrDiffTy;
const llvm::PointerType *PtrToIntTy;
const llvm::Type *BoolTy;
llvm::GlobalAlias *ClassPtrAlias;
llvm::GlobalAlias *MetaClassPtrAlias;
std::vector<llvm::Constant*> Classes;
std::vector<llvm::Constant*> Categories;
std::vector<llvm::Constant*> ConstantStrings;
llvm::StringMap<llvm::Constant*> ObjCStrings;
llvm::Function *LoadFunction;
llvm::StringMap<llvm::Constant*> ExistingProtocols;
typedef std::pair<std::string, std::string> TypedSelector;
std::map<TypedSelector, llvm::GlobalAlias*> TypedSelectors;
llvm::StringMap<llvm::GlobalAlias*> UntypedSelectors;
// Selectors that we don't emit in GC mode
Selector RetainSel, ReleaseSel, AutoreleaseSel;
// Functions used for GC.
llvm::Constant *IvarAssignFn, *StrongCastAssignFn, *MemMoveFn, *WeakReadFn,
*WeakAssignFn, *GlobalAssignFn;
// Some zeros used for GEPs in lots of places.
llvm::Constant *Zeros[2];
llvm::Constant *NULLPtr;
llvm::LLVMContext &VMContext;
/// Metadata kind used to tie method lookups to message sends.
unsigned msgSendMDKind;
private:
llvm::Constant *GenerateIvarList(
const llvm::SmallVectorImpl<llvm::Constant *> &IvarNames,
const llvm::SmallVectorImpl<llvm::Constant *> &IvarTypes,
const llvm::SmallVectorImpl<llvm::Constant *> &IvarOffsets);
llvm::Constant *GenerateMethodList(const std::string &ClassName,
const std::string &CategoryName,
const llvm::SmallVectorImpl<Selector> &MethodSels,
const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes,
bool isClassMethodList);
llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName);
llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID,
llvm::SmallVectorImpl<Selector> &InstanceMethodSels,
llvm::SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes);
llvm::Constant *GenerateProtocolList(
const llvm::SmallVectorImpl<std::string> &Protocols);
// To ensure that all protocols are seen by the runtime, we add a category on
// a class defined in the runtime, declaring no methods, but adopting the
// protocols.
void GenerateProtocolHolderCategory(void);
llvm::Constant *GenerateClassStructure(
llvm::Constant *MetaClass,
llvm::Constant *SuperClass,
unsigned info,
const char *Name,
llvm::Constant *Version,
llvm::Constant *InstanceSize,
llvm::Constant *IVars,
llvm::Constant *Methods,
llvm::Constant *Protocols,
llvm::Constant *IvarOffsets,
llvm::Constant *Properties,
bool isMeta=false);
llvm::Constant *GenerateProtocolMethodList(
const llvm::SmallVectorImpl<llvm::Constant *> &MethodNames,
const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes);
llvm::Constant *MakeConstantString(const std::string &Str, const std::string
&Name="");
llvm::Constant *ExportUniqueString(const std::string &Str, const std::string
prefix);
llvm::Constant *MakeGlobal(const llvm::StructType *Ty,
std::vector<llvm::Constant*> &V, llvm::StringRef Name="",
llvm::GlobalValue::LinkageTypes linkage=llvm::GlobalValue::InternalLinkage);
llvm::Constant *MakeGlobal(const llvm::ArrayType *Ty,
std::vector<llvm::Constant*> &V, llvm::StringRef Name="",
llvm::GlobalValue::LinkageTypes linkage=llvm::GlobalValue::InternalLinkage);
llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID,
const ObjCIvarDecl *Ivar);
void EmitClassRef(const std::string &className);
llvm::Value* EnforceType(CGBuilderTy B, llvm::Value *V, const llvm::Type *Ty){
if (V->getType() == Ty) return V;
return B.CreateBitCast(V, Ty);
}
public:
CGObjCGNU(CodeGen::CodeGenModule &cgm);
virtual llvm::Constant *GenerateConstantString(const StringLiteral *);
virtual CodeGen::RValue
GenerateMessageSend(CodeGen::CodeGenFunction &CGF,
ReturnValueSlot Return,
QualType ResultType,
Selector Sel,
llvm::Value *Receiver,
const CallArgList &CallArgs,
const ObjCInterfaceDecl *Class,
const ObjCMethodDecl *Method);
virtual CodeGen::RValue
GenerateMessageSendSuper(CodeGen::CodeGenFunction &CGF,
ReturnValueSlot Return,
QualType ResultType,
Selector Sel,
const ObjCInterfaceDecl *Class,
bool isCategoryImpl,
llvm::Value *Receiver,
bool IsClassMessage,
const CallArgList &CallArgs,
const ObjCMethodDecl *Method);
virtual llvm::Value *GetClass(CGBuilderTy &Builder,
const ObjCInterfaceDecl *OID);
virtual llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel,
bool lval = false);
virtual llvm::Value *GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl
*Method);
virtual llvm::Constant *GetEHType(QualType T);
virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
const ObjCContainerDecl *CD);
virtual void GenerateCategory(const ObjCCategoryImplDecl *CMD);
virtual void GenerateClass(const ObjCImplementationDecl *ClassDecl);
virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder,
const ObjCProtocolDecl *PD);
virtual void GenerateProtocol(const ObjCProtocolDecl *PD);
virtual llvm::Function *ModuleInitFunction();
virtual llvm::Function *GetPropertyGetFunction();
virtual llvm::Function *GetPropertySetFunction();
virtual llvm::Function *GetSetStructFunction();
virtual llvm::Function *GetGetStructFunction();
virtual llvm::Constant *EnumerationMutationFunction();
virtual void EmitTryStmt(CodeGen::CodeGenFunction &CGF,
const ObjCAtTryStmt &S);
virtual void EmitSynchronizedStmt(CodeGen::CodeGenFunction &CGF,
const ObjCAtSynchronizedStmt &S);
virtual void EmitThrowStmt(CodeGen::CodeGenFunction &CGF,
const ObjCAtThrowStmt &S);
virtual llvm::Value * EmitObjCWeakRead(CodeGen::CodeGenFunction &CGF,
llvm::Value *AddrWeakObj);
virtual void EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dst);
virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dest,
bool threadlocal=false);
virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dest,
llvm::Value *ivarOffset);
virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dest);
virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF,
llvm::Value *DestPtr,
llvm::Value *SrcPtr,
llvm::Value *Size);
virtual LValue EmitObjCValueForIvar(CodeGen::CodeGenFunction &CGF,
QualType ObjectTy,
llvm::Value *BaseValue,
const ObjCIvarDecl *Ivar,
unsigned CVRQualifiers);
virtual llvm::Value *EmitIvarOffset(CodeGen::CodeGenFunction &CGF,
const ObjCInterfaceDecl *Interface,
const ObjCIvarDecl *Ivar);
virtual llvm::Constant *GCBlockLayout(CodeGen::CodeGenFunction &CGF,
const llvm::SmallVectorImpl<const Expr *> &) {
return NULLPtr;
}
};
} // end anonymous namespace
/// Emits a reference to a dummy variable which is emitted with each class.
/// This ensures that a linker error will be generated when trying to link
/// together modules where a referenced class is not defined.
void CGObjCGNU::EmitClassRef(const std::string &className) {
std::string symbolRef = "__objc_class_ref_" + className;
// Don't emit two copies of the same symbol
if (TheModule.getGlobalVariable(symbolRef))
return;
std::string symbolName = "__objc_class_name_" + className;
llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName);
if (!ClassSymbol) {
ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
llvm::GlobalValue::ExternalLinkage, 0, symbolName);
}
new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true,
llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef);
}
static std::string SymbolNameForMethod(const std::string &ClassName, const
std::string &CategoryName, const std::string &MethodName, bool isClassMethod)
{
std::string MethodNameColonStripped = MethodName;
std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(),
':', '_');
return std::string(isClassMethod ? "_c_" : "_i_") + ClassName + "_" +
CategoryName + "_" + MethodNameColonStripped;
}
static std::string MangleSelectorTypes(const std::string &TypeString) {
std::string Mangled = TypeString;
// Simple mangling to avoid breaking when we mix JIT / static code.
// Not part of the ABI, subject to change without notice.
std::replace(Mangled.begin(), Mangled.end(), '@', '_');
std::replace(Mangled.begin(), Mangled.end(), ':', 'J');
std::replace(Mangled.begin(), Mangled.end(), '*', 'e');
std::replace(Mangled.begin(), Mangled.end(), '#', 'E');
std::replace(Mangled.begin(), Mangled.end(), ':', 'j');
std::replace(Mangled.begin(), Mangled.end(), '(', 'g');
std::replace(Mangled.begin(), Mangled.end(), ')', 'G');
std::replace(Mangled.begin(), Mangled.end(), '[', 'h');
std::replace(Mangled.begin(), Mangled.end(), ']', 'H');
return Mangled;
}
CGObjCGNU::CGObjCGNU(CodeGen::CodeGenModule &cgm)
: CGM(cgm), TheModule(CGM.getModule()), ClassPtrAlias(0),
MetaClassPtrAlias(0), VMContext(cgm.getLLVMContext()) {
msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend");
IntTy = cast<llvm::IntegerType>(
CGM.getTypes().ConvertType(CGM.getContext().IntTy));
LongTy = cast<llvm::IntegerType>(
CGM.getTypes().ConvertType(CGM.getContext().LongTy));
SizeTy = cast<llvm::IntegerType>(
CGM.getTypes().ConvertType(CGM.getContext().getSizeType()));
PtrDiffTy = cast<llvm::IntegerType>(
CGM.getTypes().ConvertType(CGM.getContext().getPointerDiffType()));
BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy);
Int8Ty = llvm::Type::getInt8Ty(VMContext);
// C string type. Used in lots of places.
PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty);
Zeros[0] = llvm::ConstantInt::get(LongTy, 0);
Zeros[1] = Zeros[0];
NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty);
// Get the selector Type.
QualType selTy = CGM.getContext().getObjCSelType();
if (QualType() == selTy) {
SelectorTy = PtrToInt8Ty;
} else {
SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy));
}
PtrToIntTy = llvm::PointerType::getUnqual(IntTy);
PtrTy = PtrToInt8Ty;
// Object type
ASTIdTy = CGM.getContext().getCanonicalType(CGM.getContext().getObjCIdType());
if (QualType() == ASTIdTy) {
IdTy = PtrToInt8Ty;
} else {
IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
}
PtrToIdTy = llvm::PointerType::getUnqual(IdTy);
// IMP type
std::vector<const llvm::Type*> IMPArgs;
IMPArgs.push_back(IdTy);
IMPArgs.push_back(SelectorTy);
IMPTy = llvm::FunctionType::get(IdTy, IMPArgs, true);
if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) {
// Get selectors needed in GC mode
RetainSel = GetNullarySelector("retain", CGM.getContext());
ReleaseSel = GetNullarySelector("release", CGM.getContext());
AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext());
// Get functions needed in GC mode
// id objc_assign_ivar(id, id, ptrdiff_t);
std::vector<const llvm::Type*> Args(1, IdTy);
Args.push_back(PtrToIdTy);
Args.push_back(PtrDiffTy);
llvm::FunctionType *FTy = llvm::FunctionType::get(IdTy, Args, false);
IvarAssignFn = CGM.CreateRuntimeFunction(FTy, "objc_assign_ivar");
// id objc_assign_strongCast (id, id*)
Args.pop_back();
FTy = llvm::FunctionType::get(IdTy, Args, false);
StrongCastAssignFn =
CGM.CreateRuntimeFunction(FTy, "objc_assign_strongCast");
// id objc_assign_global(id, id*);
FTy = llvm::FunctionType::get(IdTy, Args, false);
GlobalAssignFn = CGM.CreateRuntimeFunction(FTy, "objc_assign_global");
// id objc_assign_weak(id, id*);
FTy = llvm::FunctionType::get(IdTy, Args, false);
WeakAssignFn = CGM.CreateRuntimeFunction(FTy, "objc_assign_weak");
// id objc_read_weak(id*);
Args.clear();
Args.push_back(PtrToIdTy);
FTy = llvm::FunctionType::get(IdTy, Args, false);
WeakReadFn = CGM.CreateRuntimeFunction(FTy, "objc_read_weak");
// void *objc_memmove_collectable(void*, void *, size_t);
Args.clear();
Args.push_back(PtrToInt8Ty);
Args.push_back(PtrToInt8Ty);
Args.push_back(SizeTy);
FTy = llvm::FunctionType::get(IdTy, Args, false);
MemMoveFn = CGM.CreateRuntimeFunction(FTy, "objc_memmove_collectable");
}
}
// This has to perform the lookup every time, since posing and related
// techniques can modify the name -> class mapping.
llvm::Value *CGObjCGNU::GetClass(CGBuilderTy &Builder,
const ObjCInterfaceDecl *OID) {
llvm::Value *ClassName = CGM.GetAddrOfConstantCString(OID->getNameAsString());
// With the incompatible ABI, this will need to be replaced with a direct
// reference to the class symbol. For the compatible nonfragile ABI we are
// still performing this lookup at run time but emitting the symbol for the
// class externally so that we can make the switch later.
EmitClassRef(OID->getNameAsString());
ClassName = Builder.CreateStructGEP(ClassName, 0);
std::vector<const llvm::Type*> Params(1, PtrToInt8Ty);
llvm::Constant *ClassLookupFn =
CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy,
Params,
true),
"objc_lookup_class");
return Builder.CreateCall(ClassLookupFn, ClassName);
}
llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel,
bool lval) {
llvm::GlobalAlias *&US = UntypedSelectors[Sel.getAsString()];
if (US == 0)
US = new llvm::GlobalAlias(llvm::PointerType::getUnqual(SelectorTy),
llvm::GlobalValue::PrivateLinkage,
".objc_untyped_selector_alias"+Sel.getAsString(),
NULL, &TheModule);
if (lval)
return US;
return Builder.CreateLoad(US);
}
llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl
*Method) {
std::string SelName = Method->getSelector().getAsString();
std::string SelTypes;
CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes);
// Typed selectors
TypedSelector Selector = TypedSelector(SelName,
SelTypes);
// If it's already cached, return it.
if (TypedSelectors[Selector]) {
return Builder.CreateLoad(TypedSelectors[Selector]);
}
// If it isn't, cache it.
llvm::GlobalAlias *Sel = new llvm::GlobalAlias(
llvm::PointerType::getUnqual(SelectorTy),
llvm::GlobalValue::PrivateLinkage, ".objc_selector_alias" + SelName,
NULL, &TheModule);
TypedSelectors[Selector] = Sel;
return Builder.CreateLoad(Sel);
}
llvm::Constant *CGObjCGNU::GetEHType(QualType T) {
llvm_unreachable("asking for catch type for ObjC type in GNU runtime");
return 0;
}
llvm::Constant *CGObjCGNU::MakeConstantString(const std::string &Str,
const std::string &Name) {
llvm::Constant *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str());
return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros, 2);
}
llvm::Constant *CGObjCGNU::ExportUniqueString(const std::string &Str,
const std::string prefix) {
std::string name = prefix + Str;
llvm::Constant *ConstStr = TheModule.getGlobalVariable(name);
if (!ConstStr) {
llvm::Constant *value = llvm::ConstantArray::get(VMContext, Str, true);
ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true,
llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str);
}
return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros, 2);
}
llvm::Constant *CGObjCGNU::MakeGlobal(const llvm::StructType *Ty,
std::vector<llvm::Constant*> &V, llvm::StringRef Name,
llvm::GlobalValue::LinkageTypes linkage) {
llvm::Constant *C = llvm::ConstantStruct::get(Ty, V);
return new llvm::GlobalVariable(TheModule, Ty, false,
linkage, C, Name);
}
llvm::Constant *CGObjCGNU::MakeGlobal(const llvm::ArrayType *Ty,
std::vector<llvm::Constant*> &V, llvm::StringRef Name,
llvm::GlobalValue::LinkageTypes linkage) {
llvm::Constant *C = llvm::ConstantArray::get(Ty, V);
return new llvm::GlobalVariable(TheModule, Ty, false,
linkage, C, Name);
}
/// Generate an NSConstantString object.
llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) {
std::string Str = SL->getString().str();
// Look for an existing one
llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str);
if (old != ObjCStrings.end())
return old->getValue();
std::vector<llvm::Constant*> Ivars;
Ivars.push_back(NULLPtr);
Ivars.push_back(MakeConstantString(Str));
Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size()));
llvm::Constant *ObjCStr = MakeGlobal(
llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, IntTy, NULL),
Ivars, ".objc_str");
ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty);
ObjCStrings[Str] = ObjCStr;
ConstantStrings.push_back(ObjCStr);
return ObjCStr;
}
///Generates a message send where the super is the receiver. This is a message
///send to self with special delivery semantics indicating which class's method
///should be called.
CodeGen::RValue
CGObjCGNU::GenerateMessageSendSuper(CodeGen::CodeGenFunction &CGF,
ReturnValueSlot Return,
QualType ResultType,
Selector Sel,
const ObjCInterfaceDecl *Class,
bool isCategoryImpl,
llvm::Value *Receiver,
bool IsClassMessage,
const CallArgList &CallArgs,
const ObjCMethodDecl *Method) {
if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) {
if (Sel == RetainSel || Sel == AutoreleaseSel) {
return RValue::get(Receiver);
}
if (Sel == ReleaseSel) {
return RValue::get(0);
}
}
CGBuilderTy &Builder = CGF.Builder;
llvm::Value *cmd = GetSelector(Builder, Sel);
CallArgList ActualArgs;
ActualArgs.push_back(
std::make_pair(RValue::get(Builder.CreateBitCast(Receiver, IdTy)),
ASTIdTy));
ActualArgs.push_back(std::make_pair(RValue::get(cmd),
CGF.getContext().getObjCSelType()));
ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end());
CodeGenTypes &Types = CGM.getTypes();
const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs,
FunctionType::ExtInfo());
const llvm::FunctionType *impType =
Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false);
llvm::Value *ReceiverClass = 0;
if (isCategoryImpl) {
llvm::Constant *classLookupFunction = 0;
std::vector<const llvm::Type*> Params;
Params.push_back(PtrTy);
if (IsClassMessage) {
classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
IdTy, Params, true), "objc_get_meta_class");
} else {
classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
IdTy, Params, true), "objc_get_class");
}
ReceiverClass = Builder.CreateCall(classLookupFunction,
MakeConstantString(Class->getNameAsString()));
} else {
// Set up global aliases for the metaclass or class pointer if they do not
// already exist. These will are forward-references which will be set to
// pointers to the class and metaclass structure created for the runtime
// load function. To send a message to super, we look up the value of the
// super_class pointer from either the class or metaclass structure.
if (IsClassMessage) {
if (!MetaClassPtrAlias) {
MetaClassPtrAlias = new llvm::GlobalAlias(IdTy,
llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" +
Class->getNameAsString(), NULL, &TheModule);
}
ReceiverClass = MetaClassPtrAlias;
} else {
if (!ClassPtrAlias) {
ClassPtrAlias = new llvm::GlobalAlias(IdTy,
llvm::GlobalValue::InternalLinkage, ".objc_class_ref" +
Class->getNameAsString(), NULL, &TheModule);
}
ReceiverClass = ClassPtrAlias;
}
}
// Cast the pointer to a simplified version of the class structure
ReceiverClass = Builder.CreateBitCast(ReceiverClass,
llvm::PointerType::getUnqual(
llvm::StructType::get(VMContext, IdTy, IdTy, NULL)));
// Get the superclass pointer
ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1);
// Load the superclass pointer
ReceiverClass = Builder.CreateLoad(ReceiverClass);
// Construct the structure used to look up the IMP
llvm::StructType *ObjCSuperTy = llvm::StructType::get(VMContext,
Receiver->getType(), IdTy, NULL);
llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy);
Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0));
Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1));
// Get the IMP
std::vector<const llvm::Type*> Params;
Params.push_back(llvm::PointerType::getUnqual(ObjCSuperTy));
Params.push_back(SelectorTy);
llvm::Value *lookupArgs[] = {ObjCSuper, cmd};
llvm::Value *imp;
if (CGM.getContext().getLangOptions().ObjCNonFragileABI) {
// The lookup function returns a slot, which can be safely cached.
llvm::Type *SlotTy = llvm::StructType::get(VMContext, PtrTy, PtrTy, PtrTy,
IntTy, llvm::PointerType::getUnqual(impType), NULL);
llvm::Constant *lookupFunction =
CGM.CreateRuntimeFunction(llvm::FunctionType::get(
llvm::PointerType::getUnqual(SlotTy), Params, true),
"objc_slot_lookup_super");
llvm::CallInst *slot = Builder.CreateCall(lookupFunction, lookupArgs,
lookupArgs+2);
slot->setOnlyReadsMemory();
imp = Builder.CreateLoad(Builder.CreateStructGEP(slot, 4));
} else {
llvm::Constant *lookupFunction =
CGM.CreateRuntimeFunction(llvm::FunctionType::get(
llvm::PointerType::getUnqual(impType), Params, true),
"objc_msg_lookup_super");
imp = Builder.CreateCall(lookupFunction, lookupArgs, lookupArgs+2);
}
llvm::Value *impMD[] = {
llvm::MDString::get(VMContext, Sel.getAsString()),
llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()),
llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage)
};
llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD, 3);
llvm::Instruction *call;
RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs,
0, &call);
call->setMetadata(msgSendMDKind, node);
return msgRet;
}
/// Generate code for a message send expression.
CodeGen::RValue
CGObjCGNU::GenerateMessageSend(CodeGen::CodeGenFunction &CGF,
ReturnValueSlot Return,
QualType ResultType,
Selector Sel,
llvm::Value *Receiver,
const CallArgList &CallArgs,
const ObjCInterfaceDecl *Class,
const ObjCMethodDecl *Method) {
// Strip out message sends to retain / release in GC mode
if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) {
if (Sel == RetainSel || Sel == AutoreleaseSel) {
return RValue::get(Receiver);
}
if (Sel == ReleaseSel) {
return RValue::get(0);
}
}
CGBuilderTy &Builder = CGF.Builder;
// If the return type is something that goes in an integer register, the
// runtime will handle 0 returns. For other cases, we fill in the 0 value
// ourselves.
//
// The language spec says the result of this kind of message send is
// undefined, but lots of people seem to have forgotten to read that
// paragraph and insist on sending messages to nil that have structure
// returns. With GCC, this generates a random return value (whatever happens
// to be on the stack / in those registers at the time) on most platforms,
// and generates a SegV on SPARC. With LLVM it corrupts the stack.
bool isPointerSizedReturn = false;
if (ResultType->isAnyPointerType() ||
ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType())
isPointerSizedReturn = true;
llvm::BasicBlock *startBB = 0;
llvm::BasicBlock *messageBB = 0;
llvm::BasicBlock *continueBB = 0;
if (!isPointerSizedReturn) {
startBB = Builder.GetInsertBlock();
messageBB = CGF.createBasicBlock("msgSend");
continueBB = CGF.createBasicBlock("continue");
llvm::Value *isNil = Builder.CreateICmpEQ(Receiver,
llvm::Constant::getNullValue(Receiver->getType()));
Builder.CreateCondBr(isNil, continueBB, messageBB);
CGF.EmitBlock(messageBB);
}
IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
llvm::Value *cmd;
if (Method)
cmd = GetSelector(Builder, Method);
else
cmd = GetSelector(Builder, Sel);
CallArgList ActualArgs;
Receiver = Builder.CreateBitCast(Receiver, IdTy);
ActualArgs.push_back(
std::make_pair(RValue::get(Receiver), ASTIdTy));
ActualArgs.push_back(std::make_pair(RValue::get(cmd),
CGF.getContext().getObjCSelType()));
ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end());
CodeGenTypes &Types = CGM.getTypes();
const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs,
FunctionType::ExtInfo());
const llvm::FunctionType *impType =
Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false);
llvm::Value *impMD[] = {
llvm::MDString::get(VMContext, Sel.getAsString()),
llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""),
llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0)
};
llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD, 3);
llvm::Value *imp;
// For sender-aware dispatch, we pass the sender as the third argument to a
// lookup function. When sending messages from C code, the sender is nil.
// objc_msg_lookup_sender(id *receiver, SEL selector, id sender);
if (CGM.getContext().getLangOptions().ObjCNonFragileABI) {
std::vector<const llvm::Type*> Params;
llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType());
Builder.CreateStore(Receiver, ReceiverPtr);
Params.push_back(ReceiverPtr->getType());
Params.push_back(SelectorTy);
llvm::Value *self;
if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) {
self = CGF.LoadObjCSelf();
} else {
self = llvm::ConstantPointerNull::get(IdTy);
}
Params.push_back(self->getType());
// The lookup function returns a slot, which can be safely cached.
llvm::Type *SlotTy = llvm::StructType::get(VMContext, PtrTy, PtrTy, PtrTy,
IntTy, llvm::PointerType::getUnqual(impType), NULL);
llvm::Constant *lookupFunction =
CGM.CreateRuntimeFunction(llvm::FunctionType::get(
llvm::PointerType::getUnqual(SlotTy), Params, true),
"objc_msg_lookup_sender");
// The lookup function is guaranteed not to capture the receiver pointer.
if (llvm::Function *LookupFn = dyn_cast<llvm::Function>(lookupFunction)) {
LookupFn->setDoesNotCapture(1);
}
llvm::CallInst *slot =
Builder.CreateCall3(lookupFunction, ReceiverPtr, cmd, self);
slot->setOnlyReadsMemory();
slot->setMetadata(msgSendMDKind, node);
imp = Builder.CreateLoad(Builder.CreateStructGEP(slot, 4));
// The lookup function may have changed the receiver, so make sure we use
// the new one.
ActualArgs[0] = std::make_pair(RValue::get(
Builder.CreateLoad(ReceiverPtr, true)), ASTIdTy);
} else {
std::vector<const llvm::Type*> Params;
Params.push_back(Receiver->getType());
Params.push_back(SelectorTy);
llvm::Constant *lookupFunction =
CGM.CreateRuntimeFunction(llvm::FunctionType::get(
llvm::PointerType::getUnqual(impType), Params, true),
"objc_msg_lookup");
imp = Builder.CreateCall2(lookupFunction, Receiver, cmd);
cast<llvm::CallInst>(imp)->setMetadata(msgSendMDKind, node);
}
llvm::Instruction *call;
RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs,
0, &call);
call->setMetadata(msgSendMDKind, node);
if (!isPointerSizedReturn) {
messageBB = CGF.Builder.GetInsertBlock();
CGF.Builder.CreateBr(continueBB);
CGF.EmitBlock(continueBB);
if (msgRet.isScalar()) {
llvm::Value *v = msgRet.getScalarVal();
llvm::PHINode *phi = Builder.CreatePHI(v->getType());
phi->addIncoming(v, messageBB);
phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB);
msgRet = RValue::get(phi);
} else if (msgRet.isAggregate()) {
llvm::Value *v = msgRet.getAggregateAddr();
llvm::PHINode *phi = Builder.CreatePHI(v->getType());
const llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType());
llvm::AllocaInst *NullVal =
CGF.CreateTempAlloca(RetTy->getElementType(), "null");
CGF.InitTempAlloca(NullVal,
llvm::Constant::getNullValue(RetTy->getElementType()));
phi->addIncoming(v, messageBB);
phi->addIncoming(NullVal, startBB);
msgRet = RValue::getAggregate(phi);
} else /* isComplex() */ {
std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal();
llvm::PHINode *phi = Builder.CreatePHI(v.first->getType());
phi->addIncoming(v.first, messageBB);
phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()),
startBB);
llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType());
phi2->addIncoming(v.second, messageBB);
phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()),
startBB);
msgRet = RValue::getComplex(phi, phi2);
}
}
return msgRet;
}
/// Generates a MethodList. Used in construction of a objc_class and
/// objc_category structures.
llvm::Constant *CGObjCGNU::GenerateMethodList(const std::string &ClassName,
const std::string &CategoryName,
const llvm::SmallVectorImpl<Selector> &MethodSels,
const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes,
bool isClassMethodList) {
if (MethodSels.empty())
return NULLPtr;
// Get the method structure type.
llvm::StructType *ObjCMethodTy = llvm::StructType::get(VMContext,
PtrToInt8Ty, // Really a selector, but the runtime creates it us.
PtrToInt8Ty, // Method types
llvm::PointerType::getUnqual(IMPTy), //Method pointer
NULL);
std::vector<llvm::Constant*> Methods;
std::vector<llvm::Constant*> Elements;
for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) {
Elements.clear();
if (llvm::Constant *Method =
TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName,
MethodSels[i].getAsString(),
isClassMethodList))) {
llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString());
Elements.push_back(C);
Elements.push_back(MethodTypes[i]);
Method = llvm::ConstantExpr::getBitCast(Method,
llvm::PointerType::getUnqual(IMPTy));
Elements.push_back(Method);
Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements));
}
}
// Array of method structures
llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy,
Methods.size());
llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy,
Methods);
// Structure containing list pointer, array and array count
llvm::SmallVector<const llvm::Type*, 16> ObjCMethodListFields;
llvm::PATypeHolder OpaqueNextTy = llvm::OpaqueType::get(VMContext);
llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(OpaqueNextTy);
llvm::StructType *ObjCMethodListTy = llvm::StructType::get(VMContext,
NextPtrTy,
IntTy,
ObjCMethodArrayTy,
NULL);
// Refine next pointer type to concrete type
llvm::cast<llvm::OpaqueType>(
OpaqueNextTy.get())->refineAbstractTypeTo(ObjCMethodListTy);
ObjCMethodListTy = llvm::cast<llvm::StructType>(OpaqueNextTy.get());
Methods.clear();
Methods.push_back(llvm::ConstantPointerNull::get(
llvm::PointerType::getUnqual(ObjCMethodListTy)));
Methods.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
MethodTypes.size()));
Methods.push_back(MethodArray);
// Create an instance of the structure
return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list");
}
/// Generates an IvarList. Used in construction of a objc_class.
llvm::Constant *CGObjCGNU::GenerateIvarList(
const llvm::SmallVectorImpl<llvm::Constant *> &IvarNames,
const llvm::SmallVectorImpl<llvm::Constant *> &IvarTypes,
const llvm::SmallVectorImpl<llvm::Constant *> &IvarOffsets) {
if (IvarNames.size() == 0)
return NULLPtr;
// Get the method structure type.
llvm::StructType *ObjCIvarTy = llvm::StructType::get(VMContext,
PtrToInt8Ty,
PtrToInt8Ty,
IntTy,
NULL);
std::vector<llvm::Constant*> Ivars;
std::vector<llvm::Constant*> Elements;
for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) {
Elements.clear();
Elements.push_back(IvarNames[i]);
Elements.push_back(IvarTypes[i]);
Elements.push_back(IvarOffsets[i]);
Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements));
}
// Array of method structures
llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy,
IvarNames.size());
Elements.clear();
Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size()));
Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars));
// Structure containing array and array count
llvm::StructType *ObjCIvarListTy = llvm::StructType::get(VMContext, IntTy,
ObjCIvarArrayTy,
NULL);
// Create an instance of the structure
return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list");
}
/// Generate a class structure
llvm::Constant *CGObjCGNU::GenerateClassStructure(
llvm::Constant *MetaClass,
llvm::Constant *SuperClass,
unsigned info,
const char *Name,
llvm::Constant *Version,
llvm::Constant *InstanceSize,
llvm::Constant *IVars,
llvm::Constant *Methods,
llvm::Constant *Protocols,
llvm::Constant *IvarOffsets,
llvm::Constant *Properties,
bool isMeta) {
// Set up the class structure
// Note: Several of these are char*s when they should be ids. This is
// because the runtime performs this translation on load.
//
// Fields marked New ABI are part of the GNUstep runtime. We emit them
// anyway; the classes will still work with the GNU runtime, they will just
// be ignored.
llvm::StructType *ClassTy = llvm::StructType::get(VMContext,
PtrToInt8Ty, // class_pointer
PtrToInt8Ty, // super_class
PtrToInt8Ty, // name
LongTy, // version
LongTy, // info
LongTy, // instance_size
IVars->getType(), // ivars
Methods->getType(), // methods
// These are all filled in by the runtime, so we pretend
PtrTy, // dtable
PtrTy, // subclass_list
PtrTy, // sibling_class
PtrTy, // protocols
PtrTy, // gc_object_type
// New ABI:
LongTy, // abi_version
IvarOffsets->getType(), // ivar_offsets
Properties->getType(), // properties
NULL);
llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0);
// Fill in the structure
std::vector<llvm::Constant*> Elements;
Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty));
Elements.push_back(SuperClass);
Elements.push_back(MakeConstantString(Name, ".class_name"));
Elements.push_back(Zero);
Elements.push_back(llvm::ConstantInt::get(LongTy, info));
Elements.push_back(InstanceSize);
Elements.push_back(IVars);
Elements.push_back(Methods);
Elements.push_back(NULLPtr);
Elements.push_back(NULLPtr);
Elements.push_back(NULLPtr);
Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy));
Elements.push_back(NULLPtr);
Elements.push_back(Zero);
Elements.push_back(IvarOffsets);
Elements.push_back(Properties);
// Create an instance of the structure
// This is now an externally visible symbol, so that we can speed up class
// messages in the next ABI.
return MakeGlobal(ClassTy, Elements, (isMeta ? "_OBJC_METACLASS_":
"_OBJC_CLASS_") + std::string(Name), llvm::GlobalValue::ExternalLinkage);
}
llvm::Constant *CGObjCGNU::GenerateProtocolMethodList(
const llvm::SmallVectorImpl<llvm::Constant *> &MethodNames,
const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes) {
// Get the method structure type.
llvm::StructType *ObjCMethodDescTy = llvm::StructType::get(VMContext,
PtrToInt8Ty, // Really a selector, but the runtime does the casting for us.
PtrToInt8Ty,
NULL);
std::vector<llvm::Constant*> Methods;
std::vector<llvm::Constant*> Elements;
for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) {
Elements.clear();
Elements.push_back(MethodNames[i]);
Elements.push_back(MethodTypes[i]);
Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements));
}
llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy,
MethodNames.size());
llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy,
Methods);
llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get(VMContext,
IntTy, ObjCMethodArrayTy, NULL);
Methods.clear();
Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size()));
Methods.push_back(Array);
return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list");
}
// Create the protocol list structure used in classes, categories and so on
llvm::Constant *CGObjCGNU::GenerateProtocolList(
const llvm::SmallVectorImpl<std::string> &Protocols) {
llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty,
Protocols.size());
llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext,
PtrTy, //Should be a recurisve pointer, but it's always NULL here.
SizeTy,
ProtocolArrayTy,
NULL);
std::vector<llvm::Constant*> Elements;
for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end();
iter != endIter ; iter++) {
llvm::Constant *protocol = 0;
llvm::StringMap<llvm::Constant*>::iterator value =
ExistingProtocols.find(*iter);
if (value == ExistingProtocols.end()) {
protocol = GenerateEmptyProtocol(*iter);
} else {
protocol = value->getValue();
}
llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol,
PtrToInt8Ty);
Elements.push_back(Ptr);
}
llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy,
Elements);
Elements.clear();
Elements.push_back(NULLPtr);
Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size()));
Elements.push_back(ProtocolArray);
return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list");
}
llvm::Value *CGObjCGNU::GenerateProtocolRef(CGBuilderTy &Builder,
const ObjCProtocolDecl *PD) {
llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()];
const llvm::Type *T =
CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType());
return Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T));
}
llvm::Constant *CGObjCGNU::GenerateEmptyProtocol(
const std::string &ProtocolName) {
llvm::SmallVector<std::string, 0> EmptyStringVector;
llvm::SmallVector<llvm::Constant*, 0> EmptyConstantVector;
llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector);
llvm::Constant *MethodList =
GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector);
// Protocols are objects containing lists of the methods implemented and
// protocols adopted.
llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy,
PtrToInt8Ty,
ProtocolList->getType(),
MethodList->getType(),
MethodList->getType(),
MethodList->getType(),
MethodList->getType(),
NULL);
std::vector<llvm::Constant*> Elements;
// The isa pointer must be set to a magic number so the runtime knows it's
// the correct layout.
int Version = CGM.getContext().getLangOptions().ObjCNonFragileABI ?
NonFragileProtocolVersion : ProtocolVersion;
Elements.push_back(llvm::ConstantExpr::getIntToPtr(
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Version), IdTy));
Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name"));
Elements.push_back(ProtocolList);
Elements.push_back(MethodList);
Elements.push_back(MethodList);
Elements.push_back(MethodList);
Elements.push_back(MethodList);
return MakeGlobal(ProtocolTy, Elements, ".objc_protocol");
}
void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) {
ASTContext &Context = CGM.getContext();
std::string ProtocolName = PD->getNameAsString();
llvm::SmallVector<std::string, 16> Protocols;
for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(),
E = PD->protocol_end(); PI != E; ++PI)
Protocols.push_back((*PI)->getNameAsString());
llvm::SmallVector<llvm::Constant*, 16> InstanceMethodNames;
llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames;
llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes;
for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(),
E = PD->instmeth_end(); iter != E; iter++) {
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(*iter, TypeStr);
if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) {
InstanceMethodNames.push_back(
MakeConstantString((*iter)->getSelector().getAsString()));
InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
} else {
OptionalInstanceMethodNames.push_back(
MakeConstantString((*iter)->getSelector().getAsString()));
OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr));
}
}
// Collect information about class methods:
llvm::SmallVector<llvm::Constant*, 16> ClassMethodNames;
llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes;
llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodNames;
llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes;
for (ObjCProtocolDecl::classmeth_iterator
iter = PD->classmeth_begin(), endIter = PD->classmeth_end();
iter != endIter ; iter++) {
std::string TypeStr;
Context.getObjCEncodingForMethodDecl((*iter),TypeStr);
if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) {
ClassMethodNames.push_back(
MakeConstantString((*iter)->getSelector().getAsString()));
ClassMethodTypes.push_back(MakeConstantString(TypeStr));
} else {
OptionalClassMethodNames.push_back(
MakeConstantString((*iter)->getSelector().getAsString()));
OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr));
}
}
llvm::Constant *ProtocolList = GenerateProtocolList(Protocols);
llvm::Constant *InstanceMethodList =
GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes);
llvm::Constant *ClassMethodList =
GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes);
llvm::Constant *OptionalInstanceMethodList =
GenerateProtocolMethodList(OptionalInstanceMethodNames,
OptionalInstanceMethodTypes);
llvm::Constant *OptionalClassMethodList =
GenerateProtocolMethodList(OptionalClassMethodNames,
OptionalClassMethodTypes);
// Property metadata: name, attributes, isSynthesized, setter name, setter
// types, getter name, getter types.
// The isSynthesized value is always set to 0 in a protocol. It exists to
// simplify the runtime library by allowing it to use the same data
// structures for protocol metadata everywhere.
llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext,
PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty,
PtrToInt8Ty, NULL);
std::vector<llvm::Constant*> Properties;
std::vector<llvm::Constant*> OptionalProperties;
// Add all of the property methods need adding to the method list and to the
// property metadata list.
for (ObjCContainerDecl::prop_iterator
iter = PD->prop_begin(), endIter = PD->prop_end();
iter != endIter ; iter++) {
std::vector<llvm::Constant*> Fields;
ObjCPropertyDecl *property = (*iter);
Fields.push_back(MakeConstantString(property->getNameAsString()));
Fields.push_back(llvm::ConstantInt::get(Int8Ty,
property->getPropertyAttributes()));
Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0));
if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) {
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(getter,TypeStr);
llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
InstanceMethodTypes.push_back(TypeEncoding);
Fields.push_back(MakeConstantString(getter->getSelector().getAsString()));
Fields.push_back(TypeEncoding);
} else {
Fields.push_back(NULLPtr);
Fields.push_back(NULLPtr);
}
if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) {
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(setter,TypeStr);
llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
InstanceMethodTypes.push_back(TypeEncoding);
Fields.push_back(MakeConstantString(setter->getSelector().getAsString()));
Fields.push_back(TypeEncoding);
} else {
Fields.push_back(NULLPtr);
Fields.push_back(NULLPtr);
}
if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) {
OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields));
} else {
Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields));
}
}
llvm::Constant *PropertyArray = llvm::ConstantArray::get(
llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties);
llvm::Constant* PropertyListInitFields[] =
{llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray};
llvm::Constant *PropertyListInit =
llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false);
llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule,
PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage,
PropertyListInit, ".objc_property_list");
llvm::Constant *OptionalPropertyArray =
llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy,
OptionalProperties.size()) , OptionalProperties);
llvm::Constant* OptionalPropertyListInitFields[] = {
llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr,
OptionalPropertyArray };
llvm::Constant *OptionalPropertyListInit =
llvm::ConstantStruct::get(VMContext, OptionalPropertyListInitFields, 3, false);
llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule,
OptionalPropertyListInit->getType(), false,
llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit,
".objc_property_list");
// Protocols are objects containing lists of the methods implemented and
// protocols adopted.
llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy,
PtrToInt8Ty,
ProtocolList->getType(),
InstanceMethodList->getType(),
ClassMethodList->getType(),
OptionalInstanceMethodList->getType(),
OptionalClassMethodList->getType(),
PropertyList->getType(),
OptionalPropertyList->getType(),
NULL);
std::vector<llvm::Constant*> Elements;
// The isa pointer must be set to a magic number so the runtime knows it's
// the correct layout.
int Version = CGM.getContext().getLangOptions().ObjCNonFragileABI ?
NonFragileProtocolVersion : ProtocolVersion;
Elements.push_back(llvm::ConstantExpr::getIntToPtr(
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Version), IdTy));
Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name"));
Elements.push_back(ProtocolList);
Elements.push_back(InstanceMethodList);
Elements.push_back(ClassMethodList);
Elements.push_back(OptionalInstanceMethodList);
Elements.push_back(OptionalClassMethodList);
Elements.push_back(PropertyList);
Elements.push_back(OptionalPropertyList);
ExistingProtocols[ProtocolName] =
llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements,
".objc_protocol"), IdTy);
}
void CGObjCGNU::GenerateProtocolHolderCategory(void) {
// Collect information about instance methods
llvm::SmallVector<Selector, 1> MethodSels;
llvm::SmallVector<llvm::Constant*, 1> MethodTypes;
std::vector<llvm::Constant*> Elements;
const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack";
const std::string CategoryName = "AnotherHack";
Elements.push_back(MakeConstantString(CategoryName));
Elements.push_back(MakeConstantString(ClassName));
// Instance method list
Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList(
ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy));
// Class method list
Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList(
ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy));
// Protocol list
llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy,
ExistingProtocols.size());
llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext,
PtrTy, //Should be a recurisve pointer, but it's always NULL here.
SizeTy,
ProtocolArrayTy,
NULL);
std::vector<llvm::Constant*> ProtocolElements;
for (llvm::StringMapIterator<llvm::Constant*> iter =
ExistingProtocols.begin(), endIter = ExistingProtocols.end();
iter != endIter ; iter++) {
llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(),
PtrTy);
ProtocolElements.push_back(Ptr);
}
llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy,
ProtocolElements);
ProtocolElements.clear();
ProtocolElements.push_back(NULLPtr);
ProtocolElements.push_back(llvm::ConstantInt::get(LongTy,
ExistingProtocols.size()));
ProtocolElements.push_back(ProtocolArray);
Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy,
ProtocolElements, ".objc_protocol_list"), PtrTy));
Categories.push_back(llvm::ConstantExpr::getBitCast(
MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty,
PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy));
}
void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) {
std::string ClassName = OCD->getClassInterface()->getNameAsString();
std::string CategoryName = OCD->getNameAsString();
// Collect information about instance methods
llvm::SmallVector<Selector, 16> InstanceMethodSels;
llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
for (ObjCCategoryImplDecl::instmeth_iterator
iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end();
iter != endIter ; iter++) {
InstanceMethodSels.push_back((*iter)->getSelector());
std::string TypeStr;
CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr);
InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
}
// Collect information about class methods
llvm::SmallVector<Selector, 16> ClassMethodSels;
llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes;
for (ObjCCategoryImplDecl::classmeth_iterator
iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end();
iter != endIter ; iter++) {
ClassMethodSels.push_back((*iter)->getSelector());
std::string TypeStr;
CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr);
ClassMethodTypes.push_back(MakeConstantString(TypeStr));
}
// Collect the names of referenced protocols
llvm::SmallVector<std::string, 16> Protocols;
const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl();
const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols();
for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(),
E = Protos.end(); I != E; ++I)
Protocols.push_back((*I)->getNameAsString());
std::vector<llvm::Constant*> Elements;
Elements.push_back(MakeConstantString(CategoryName));
Elements.push_back(MakeConstantString(ClassName));
// Instance method list
Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList(
ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes,
false), PtrTy));
// Class method list
Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList(
ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true),
PtrTy));
// Protocol list
Elements.push_back(llvm::ConstantExpr::getBitCast(
GenerateProtocolList(Protocols), PtrTy));
Categories.push_back(llvm::ConstantExpr::getBitCast(
MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty,
PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy));
}
llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID,
llvm::SmallVectorImpl<Selector> &InstanceMethodSels,
llvm::SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) {
ASTContext &Context = CGM.getContext();
//
// Property metadata: name, attributes, isSynthesized, setter name, setter
// types, getter name, getter types.
llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext,
PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty,
PtrToInt8Ty, NULL);
std::vector<llvm::Constant*> Properties;
// Add all of the property methods need adding to the method list and to the
// property metadata list.
for (ObjCImplDecl::propimpl_iterator
iter = OID->propimpl_begin(), endIter = OID->propimpl_end();
iter != endIter ; iter++) {
std::vector<llvm::Constant*> Fields;
ObjCPropertyDecl *property = (*iter)->getPropertyDecl();
ObjCPropertyImplDecl *propertyImpl = *iter;
bool isSynthesized = (propertyImpl->getPropertyImplementation() ==
ObjCPropertyImplDecl::Synthesize);
Fields.push_back(MakeConstantString(property->getNameAsString()));
Fields.push_back(llvm::ConstantInt::get(Int8Ty,
property->getPropertyAttributes()));
Fields.push_back(llvm::ConstantInt::get(Int8Ty, isSynthesized));
if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) {
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(getter,TypeStr);
llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
if (isSynthesized) {
InstanceMethodTypes.push_back(TypeEncoding);
InstanceMethodSels.push_back(getter->getSelector());
}
Fields.push_back(MakeConstantString(getter->getSelector().getAsString()));
Fields.push_back(TypeEncoding);
} else {
Fields.push_back(NULLPtr);
Fields.push_back(NULLPtr);
}
if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) {
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(setter,TypeStr);
llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
if (isSynthesized) {
InstanceMethodTypes.push_back(TypeEncoding);
InstanceMethodSels.push_back(setter->getSelector());
}
Fields.push_back(MakeConstantString(setter->getSelector().getAsString()));
Fields.push_back(TypeEncoding);
} else {
Fields.push_back(NULLPtr);
Fields.push_back(NULLPtr);
}
Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields));
}
llvm::ArrayType *PropertyArrayTy =
llvm::ArrayType::get(PropertyMetadataTy, Properties.size());
llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy,
Properties);
llvm::Constant* PropertyListInitFields[] =
{llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray};
llvm::Constant *PropertyListInit =
llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false);
return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false,
llvm::GlobalValue::InternalLinkage, PropertyListInit,
".objc_property_list");
}
void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
ASTContext &Context = CGM.getContext();
// Get the superclass name.
const ObjCInterfaceDecl * SuperClassDecl =
OID->getClassInterface()->getSuperClass();
std::string SuperClassName;
if (SuperClassDecl) {
SuperClassName = SuperClassDecl->getNameAsString();
EmitClassRef(SuperClassName);
}
// Get the class name
ObjCInterfaceDecl *ClassDecl =
const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
std::string ClassName = ClassDecl->getNameAsString();
// Emit the symbol that is used to generate linker errors if this class is
// referenced in other modules but not declared.
std::string classSymbolName = "__objc_class_name_" + ClassName;
if (llvm::GlobalVariable *symbol =
TheModule.getGlobalVariable(classSymbolName)) {
symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0));
} else {
new llvm::GlobalVariable(TheModule, LongTy, false,
llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0),
classSymbolName);
}
// Get the size of instances.
int instanceSize = Context.getASTObjCImplementationLayout(OID).getSize() / 8;
// Collect information about instance variables.
llvm::SmallVector<llvm::Constant*, 16> IvarNames;
llvm::SmallVector<llvm::Constant*, 16> IvarTypes;
llvm::SmallVector<llvm::Constant*, 16> IvarOffsets;
std::vector<llvm::Constant*> IvarOffsetValues;
int superInstanceSize = !SuperClassDecl ? 0 :
Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize() / 8;
// For non-fragile ivars, set the instance size to 0 - {the size of just this
// class}. The runtime will then set this to the correct value on load.
if (CGM.getContext().getLangOptions().ObjCNonFragileABI) {
instanceSize = 0 - (instanceSize - superInstanceSize);
}
// Collect declared and synthesized ivars.
llvm::SmallVector<ObjCIvarDecl*, 16> OIvars;
CGM.getContext().ShallowCollectObjCIvars(ClassDecl, OIvars);
for (unsigned i = 0, e = OIvars.size(); i != e; ++i) {
ObjCIvarDecl *IVD = OIvars[i];
// Store the name
IvarNames.push_back(MakeConstantString(IVD->getNameAsString()));
// Get the type encoding for this ivar
std::string TypeStr;
Context.getObjCEncodingForType(IVD->getType(), TypeStr);
IvarTypes.push_back(MakeConstantString(TypeStr));
// Get the offset
uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD);
uint64_t Offset = BaseOffset;
if (CGM.getContext().getLangOptions().ObjCNonFragileABI) {
Offset = BaseOffset - superInstanceSize;
}
IvarOffsets.push_back(
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset));
IvarOffsetValues.push_back(new llvm::GlobalVariable(TheModule, IntTy,
false, llvm::GlobalValue::ExternalLinkage,
llvm::ConstantInt::get(IntTy, Offset),
"__objc_ivar_offset_value_" + ClassName +"." +
IVD->getNameAsString()));
}
llvm::Constant *IvarOffsetArrayInit =
llvm::ConstantArray::get(llvm::ArrayType::get(PtrToIntTy,
IvarOffsetValues.size()), IvarOffsetValues);
llvm::GlobalVariable *IvarOffsetArray = new llvm::GlobalVariable(TheModule,
IvarOffsetArrayInit->getType(), false,
llvm::GlobalValue::InternalLinkage, IvarOffsetArrayInit,
".ivar.offsets");
// Collect information about instance methods
llvm::SmallVector<Selector, 16> InstanceMethodSels;
llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
for (ObjCImplementationDecl::instmeth_iterator
iter = OID->instmeth_begin(), endIter = OID->instmeth_end();
iter != endIter ; iter++) {
InstanceMethodSels.push_back((*iter)->getSelector());
std::string TypeStr;
Context.getObjCEncodingForMethodDecl((*iter),TypeStr);
InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
}
llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels,
InstanceMethodTypes);
// Collect information about class methods
llvm::SmallVector<Selector, 16> ClassMethodSels;
llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes;
for (ObjCImplementationDecl::classmeth_iterator
iter = OID->classmeth_begin(), endIter = OID->classmeth_end();
iter != endIter ; iter++) {
ClassMethodSels.push_back((*iter)->getSelector());
std::string TypeStr;
Context.getObjCEncodingForMethodDecl((*iter),TypeStr);
ClassMethodTypes.push_back(MakeConstantString(TypeStr));
}
// Collect the names of referenced protocols
llvm::SmallVector<std::string, 16> Protocols;
const ObjCList<ObjCProtocolDecl> &Protos =ClassDecl->getReferencedProtocols();
for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(),
E = Protos.end(); I != E; ++I)
Protocols.push_back((*I)->getNameAsString());
// Get the superclass pointer.
llvm::Constant *SuperClass;
if (!SuperClassName.empty()) {
SuperClass = MakeConstantString(SuperClassName, ".super_class_name");
} else {
SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty);
}
// Empty vector used to construct empty method lists
llvm::SmallVector<llvm::Constant*, 1> empty;
// Generate the method and instance variable lists
llvm::Constant *MethodList = GenerateMethodList(ClassName, "",
InstanceMethodSels, InstanceMethodTypes, false);
llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "",
ClassMethodSels, ClassMethodTypes, true);
llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes,
IvarOffsets);
// Irrespective of whether we are compiling for a fragile or non-fragile ABI,
// we emit a symbol containing the offset for each ivar in the class. This
// allows code compiled for the non-Fragile ABI to inherit from code compiled
// for the legacy ABI, without causing problems. The converse is also
// possible, but causes all ivar accesses to be fragile.
// Offset pointer for getting at the correct field in the ivar list when
// setting up the alias. These are: The base address for the global, the
// ivar array (second field), the ivar in this list (set for each ivar), and
// the offset (third field in ivar structure)
const llvm::Type *IndexTy = llvm::Type::getInt32Ty(VMContext);
llvm::Constant *offsetPointerIndexes[] = {Zeros[0],
llvm::ConstantInt::get(IndexTy, 1), 0,
llvm::ConstantInt::get(IndexTy, 2) };
for (unsigned i = 0, e = OIvars.size(); i != e; ++i) {
ObjCIvarDecl *IVD = OIvars[i];
const std::string Name = "__objc_ivar_offset_" + ClassName + '.'
+ IVD->getNameAsString();
offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, i);
// Get the correct ivar field
llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr(
IvarList, offsetPointerIndexes, 4);
// Get the existing variable, if one exists.
llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name);
if (offset) {
offset->setInitializer(offsetValue);
// If this is the real definition, change its linkage type so that
// different modules will use this one, rather than their private
// copy.
offset->setLinkage(llvm::GlobalValue::ExternalLinkage);
} else {
// Add a new alias if there isn't one already.
offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(),
false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name);
}
}
//Generate metaclass for class methods
llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr,
NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList(
empty, empty, empty), ClassMethodList, NULLPtr, NULLPtr, NULLPtr, true);
// Generate the class structure
llvm::Constant *ClassStruct =
GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L,
ClassName.c_str(), 0,
llvm::ConstantInt::get(LongTy, instanceSize), IvarList,
MethodList, GenerateProtocolList(Protocols), IvarOffsetArray,
Properties);
// Resolve the class aliases, if they exist.
if (ClassPtrAlias) {
ClassPtrAlias->replaceAllUsesWith(
llvm::ConstantExpr::getBitCast(ClassStruct, IdTy));
ClassPtrAlias->eraseFromParent();
ClassPtrAlias = 0;
}
if (MetaClassPtrAlias) {
MetaClassPtrAlias->replaceAllUsesWith(
llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy));
MetaClassPtrAlias->eraseFromParent();
MetaClassPtrAlias = 0;
}
// Add class structure to list to be added to the symtab later
ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty);
Classes.push_back(ClassStruct);
}
llvm::Function *CGObjCGNU::ModuleInitFunction() {
// Only emit an ObjC load function if no Objective-C stuff has been called
if (Classes.empty() && Categories.empty() && ConstantStrings.empty() &&
ExistingProtocols.empty() && TypedSelectors.empty() &&
UntypedSelectors.empty())
return NULL;
// Add all referenced protocols to a category.
GenerateProtocolHolderCategory();
const llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>(
SelectorTy->getElementType());
const llvm::Type *SelStructPtrTy = SelectorTy;
bool isSelOpaque = false;
if (SelStructTy == 0) {
SelStructTy = llvm::StructType::get(VMContext, PtrToInt8Ty,
PtrToInt8Ty, NULL);
SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy);
isSelOpaque = true;
}
// Name the ObjC types to make the IR a bit easier to read
TheModule.addTypeName(".objc_selector", SelStructPtrTy);
TheModule.addTypeName(".objc_id", IdTy);
TheModule.addTypeName(".objc_imp", IMPTy);
std::vector<llvm::Constant*> Elements;
llvm::Constant *Statics = NULLPtr;
// Generate statics list:
if (ConstantStrings.size()) {
llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty,
ConstantStrings.size() + 1);
ConstantStrings.push_back(NULLPtr);
llvm::StringRef StringClass = CGM.getLangOptions().ObjCConstantStringClass;
if (StringClass.empty()) StringClass = "NXConstantString";
Elements.push_back(MakeConstantString(StringClass,
".objc_static_class_name"));
Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy,
ConstantStrings));
llvm::StructType *StaticsListTy =
llvm::StructType::get(VMContext, PtrToInt8Ty, StaticsArrayTy, NULL);
llvm::Type *StaticsListPtrTy =
llvm::PointerType::getUnqual(StaticsListTy);
Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics");
llvm::ArrayType *StaticsListArrayTy =
llvm::ArrayType::get(StaticsListPtrTy, 2);
Elements.clear();
Elements.push_back(Statics);
Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy));
Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr");
Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy);
}
// Array of classes, categories, and constant objects
llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty,
Classes.size() + Categories.size() + 2);
llvm::StructType *SymTabTy = llvm::StructType::get(VMContext,
LongTy, SelStructPtrTy,
llvm::Type::getInt16Ty(VMContext),
llvm::Type::getInt16Ty(VMContext),
ClassListTy, NULL);
Elements.clear();
// Pointer to an array of selectors used in this module.
std::vector<llvm::Constant*> Selectors;
for (std::map<TypedSelector, llvm::GlobalAlias*>::iterator
iter = TypedSelectors.begin(), iterEnd = TypedSelectors.end();
iter != iterEnd ; ++iter) {
Elements.push_back(ExportUniqueString(iter->first.first, ".objc_sel_name"));
Elements.push_back(MakeConstantString(iter->first.second,
".objc_sel_types"));
Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements));
Elements.clear();
}
for (llvm::StringMap<llvm::GlobalAlias*>::iterator
iter = UntypedSelectors.begin(), iterEnd = UntypedSelectors.end();
iter != iterEnd; ++iter) {
Elements.push_back(
ExportUniqueString(iter->getKeyData(), ".objc_sel_name"));
Elements.push_back(NULLPtr);
Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements));
Elements.clear();
}
Elements.push_back(NULLPtr);
Elements.push_back(NULLPtr);
Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements));
Elements.clear();
// Number of static selectors
Elements.push_back(llvm::ConstantInt::get(LongTy, Selectors.size() ));
llvm::Constant *SelectorList = MakeGlobal(
llvm::ArrayType::get(SelStructTy, Selectors.size()), Selectors,
".objc_selector_list");
Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList,
SelStructPtrTy));
// Now that all of the static selectors exist, create pointers to them.
int index = 0;
for (std::map<TypedSelector, llvm::GlobalAlias*>::iterator
iter=TypedSelectors.begin(), iterEnd =TypedSelectors.end();
iter != iterEnd; ++iter) {
llvm::Constant *Idxs[] = {Zeros[0],
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), index++), Zeros[0]};
llvm::Constant *SelPtr = new llvm::GlobalVariable(TheModule, SelStructPtrTy,
true, llvm::GlobalValue::LinkOnceODRLinkage,
llvm::ConstantExpr::getGetElementPtr(SelectorList, Idxs, 2),
MangleSelectorTypes(".objc_sel_ptr"+iter->first.first+"."+
iter->first.second));
// If selectors are defined as an opaque type, cast the pointer to this
// type.
if (isSelOpaque) {
SelPtr = llvm::ConstantExpr::getBitCast(SelPtr,
llvm::PointerType::getUnqual(SelectorTy));
}
(*iter).second->replaceAllUsesWith(SelPtr);
(*iter).second->eraseFromParent();
}
for (llvm::StringMap<llvm::GlobalAlias*>::iterator
iter=UntypedSelectors.begin(), iterEnd = UntypedSelectors.end();
iter != iterEnd; iter++) {
llvm::Constant *Idxs[] = {Zeros[0],
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), index++), Zeros[0]};
llvm::Constant *SelPtr = new llvm::GlobalVariable(TheModule, SelStructPtrTy,
true, llvm::GlobalValue::LinkOnceODRLinkage,
llvm::ConstantExpr::getGetElementPtr(SelectorList, Idxs, 2),
MangleSelectorTypes(std::string(".objc_sel_ptr")+iter->getKey().str()));
// If selectors are defined as an opaque type, cast the pointer to this
// type.
if (isSelOpaque) {
SelPtr = llvm::ConstantExpr::getBitCast(SelPtr,
llvm::PointerType::getUnqual(SelectorTy));
}
(*iter).second->replaceAllUsesWith(SelPtr);
(*iter).second->eraseFromParent();
}
// Number of classes defined.
Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext),
Classes.size()));
// Number of categories defined
Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext),
Categories.size()));
// Create an array of classes, then categories, then static object instances
Classes.insert(Classes.end(), Categories.begin(), Categories.end());
// NULL-terminated list of static object instances (mainly constant strings)
Classes.push_back(Statics);
Classes.push_back(NULLPtr);
llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes);
Elements.push_back(ClassList);
// Construct the symbol table
llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements);
// The symbol table is contained in a module which has some version-checking
// constants
llvm::StructType * ModuleTy = llvm::StructType::get(VMContext, LongTy, LongTy,
PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy), NULL);
Elements.clear();
// Runtime version used for compatibility checking.
if (CGM.getContext().getLangOptions().ObjCNonFragileABI) {
Elements.push_back(llvm::ConstantInt::get(LongTy,
NonFragileRuntimeVersion));
} else {
Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion));
}
// sizeof(ModuleTy)
llvm::TargetData td(&TheModule);
Elements.push_back(llvm::ConstantInt::get(LongTy,
td.getTypeSizeInBits(ModuleTy)/8));
//FIXME: Should be the path to the file where this module was declared
Elements.push_back(NULLPtr);
Elements.push_back(SymTab);
llvm::Value *Module = MakeGlobal(ModuleTy, Elements);
// Create the load function calling the runtime entry point with the module
// structure
llvm::Function * LoadFunction = llvm::Function::Create(
llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false),
llvm::GlobalValue::InternalLinkage, ".objc_load_function",
&TheModule);
llvm::BasicBlock *EntryBB =
llvm::BasicBlock::Create(VMContext, "entry", LoadFunction);
CGBuilderTy Builder(VMContext);
Builder.SetInsertPoint(EntryBB);
std::vector<const llvm::Type*> Params(1,
llvm::PointerType::getUnqual(ModuleTy));
llvm::Value *Register = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
llvm::Type::getVoidTy(VMContext), Params, true), "__objc_exec_class");
Builder.CreateCall(Register, Module);
Builder.CreateRetVoid();
return LoadFunction;
}
llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD,
const ObjCContainerDecl *CD) {
const ObjCCategoryImplDecl *OCD =
dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext());
std::string CategoryName = OCD ? OCD->getNameAsString() : "";
std::string ClassName = CD->getName();
std::string MethodName = OMD->getSelector().getAsString();
bool isClassMethod = !OMD->isInstanceMethod();
CodeGenTypes &Types = CGM.getTypes();
const llvm::FunctionType *MethodTy =
Types.GetFunctionType(Types.getFunctionInfo(OMD), OMD->isVariadic());
std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName,
MethodName, isClassMethod);
llvm::Function *Method
= llvm::Function::Create(MethodTy,
llvm::GlobalValue::InternalLinkage,
FunctionName,
&TheModule);
return Method;
}
llvm::Function *CGObjCGNU::GetPropertyGetFunction() {
std::vector<const llvm::Type*> Params;
Params.push_back(IdTy);
Params.push_back(SelectorTy);
Params.push_back(IntTy);
Params.push_back(BoolTy);
// void objc_getProperty (id, SEL, int, bool)
const llvm::FunctionType *FTy =
llvm::FunctionType::get(IdTy, Params, false);
return cast<llvm::Function>(CGM.CreateRuntimeFunction(FTy,
"objc_getProperty"));
}
llvm::Function *CGObjCGNU::GetPropertySetFunction() {
std::vector<const llvm::Type*> Params;
Params.push_back(IdTy);
Params.push_back(SelectorTy);
Params.push_back(IntTy);
Params.push_back(IdTy);
Params.push_back(BoolTy);
Params.push_back(BoolTy);
// void objc_setProperty (id, SEL, int, id, bool, bool)
const llvm::FunctionType *FTy =
llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), Params, false);
return cast<llvm::Function>(CGM.CreateRuntimeFunction(FTy,
"objc_setProperty"));
}
llvm::Function *CGObjCGNU::GetGetStructFunction() {
std::vector<const llvm::Type*> Params;
Params.push_back(PtrTy);
Params.push_back(PtrTy);
Params.push_back(PtrDiffTy);
Params.push_back(BoolTy);
Params.push_back(BoolTy);
// objc_setPropertyStruct (void*, void*, ptrdiff_t, BOOL, BOOL)
const llvm::FunctionType *FTy =
llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), Params, false);
return cast<llvm::Function>(CGM.CreateRuntimeFunction(FTy,
"objc_getPropertyStruct"));
}
llvm::Function *CGObjCGNU::GetSetStructFunction() {
std::vector<const llvm::Type*> Params;
Params.push_back(PtrTy);
Params.push_back(PtrTy);
Params.push_back(PtrDiffTy);
Params.push_back(BoolTy);
Params.push_back(BoolTy);
// objc_setPropertyStruct (void*, void*, ptrdiff_t, BOOL, BOOL)
const llvm::FunctionType *FTy =
llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), Params, false);
return cast<llvm::Function>(CGM.CreateRuntimeFunction(FTy,
"objc_setPropertyStruct"));
}
llvm::Constant *CGObjCGNU::EnumerationMutationFunction() {
CodeGen::CodeGenTypes &Types = CGM.getTypes();
ASTContext &Ctx = CGM.getContext();
// void objc_enumerationMutation (id)
llvm::SmallVector<CanQualType,1> Params;
Params.push_back(ASTIdTy);
const llvm::FunctionType *FTy =
Types.GetFunctionType(Types.getFunctionInfo(Ctx.VoidTy, Params,
FunctionType::ExtInfo()), false);
return CGM.CreateRuntimeFunction(FTy, "objc_enumerationMutation");
}
namespace {
struct CallSyncExit : EHScopeStack::Cleanup {
llvm::Value *SyncExitFn;
llvm::Value *SyncArg;
CallSyncExit(llvm::Value *SyncExitFn, llvm::Value *SyncArg)
: SyncExitFn(SyncExitFn), SyncArg(SyncArg) {}
void Emit(CodeGenFunction &CGF, bool IsForEHCleanup) {
CGF.Builder.CreateCall(SyncExitFn, SyncArg)->setDoesNotThrow();
}
};
}
void CGObjCGNU::EmitSynchronizedStmt(CodeGen::CodeGenFunction &CGF,
const ObjCAtSynchronizedStmt &S) {
std::vector<const llvm::Type*> Args(1, IdTy);
llvm::FunctionType *FTy =
llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), Args, false);
// Evaluate the lock operand. This should dominate the cleanup.
llvm::Value *SyncArg =
CGF.EmitScalarExpr(S.getSynchExpr());
// Acquire the lock.
llvm::Value *SyncEnter = CGM.CreateRuntimeFunction(FTy, "objc_sync_enter");
SyncArg = CGF.Builder.CreateBitCast(SyncArg, IdTy);
CGF.Builder.CreateCall(SyncEnter, SyncArg);
// Register an all-paths cleanup to release the lock.
llvm::Value *SyncExit = CGM.CreateRuntimeFunction(FTy, "objc_sync_exit");
CGF.EHStack.pushCleanup<CallSyncExit>(NormalAndEHCleanup, SyncExit, SyncArg);
// Emit the body of the statement.
CGF.EmitStmt(S.getSynchBody());
// Pop the lock-release cleanup.
CGF.PopCleanupBlock();
}
namespace {
struct CatchHandler {
const VarDecl *Variable;
const Stmt *Body;
llvm::BasicBlock *Block;
llvm::Value *TypeInfo;
};
}
void CGObjCGNU::EmitTryStmt(CodeGen::CodeGenFunction &CGF,
const ObjCAtTryStmt &S) {
// Unlike the Apple non-fragile runtimes, which also uses
// unwind-based zero cost exceptions, the GNU Objective C runtime's
// EH support isn't a veneer over C++ EH. Instead, exception
// objects are created by __objc_exception_throw and destroyed by
// the personality function; this avoids the need for bracketing
// catch handlers with calls to __blah_begin_catch/__blah_end_catch
// (or even _Unwind_DeleteException), but probably doesn't
// interoperate very well with foreign exceptions.
// Jump destination for falling out of catch bodies.
CodeGenFunction::JumpDest Cont;
if (S.getNumCatchStmts())
Cont = CGF.getJumpDestInCurrentScope("eh.cont");
// We handle @finally statements by pushing them as a cleanup
// before entering the catch.
CodeGenFunction::FinallyInfo FinallyInfo;
if (const ObjCAtFinallyStmt *Finally = S.getFinallyStmt()) {
std::vector<const llvm::Type*> Args(1, IdTy);
llvm::FunctionType *FTy =
llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), Args, false);
llvm::Constant *Rethrow =
CGM.CreateRuntimeFunction(FTy, "objc_exception_throw");
FinallyInfo = CGF.EnterFinallyBlock(Finally->getFinallyBody(), 0, 0,
Rethrow);
}
llvm::SmallVector<CatchHandler, 8> Handlers;
// Enter the catch, if there is one.
if (S.getNumCatchStmts()) {
for (unsigned I = 0, N = S.getNumCatchStmts(); I != N; ++I) {
const ObjCAtCatchStmt *CatchStmt = S.getCatchStmt(I);
const VarDecl *CatchDecl = CatchStmt->getCatchParamDecl();
Handlers.push_back(CatchHandler());
CatchHandler &Handler = Handlers.back();
Handler.Variable = CatchDecl;
Handler.Body = CatchStmt->getCatchBody();
Handler.Block = CGF.createBasicBlock("catch");
// @catch() and @catch(id) both catch any ObjC exception.
// Treat them as catch-alls.
// FIXME: this is what this code was doing before, but should 'id'
// really be catching foreign exceptions?
if (!CatchDecl
|| CatchDecl->getType()->isObjCIdType()
|| CatchDecl->getType()->isObjCQualifiedIdType()) {
Handler.TypeInfo = 0; // catch-all
// Don't consider any other catches.
break;
}
// All other types should be Objective-C interface pointer types.
const ObjCObjectPointerType *OPT =
CatchDecl->getType()->getAs<ObjCObjectPointerType>();
assert(OPT && "Invalid @catch type.");
const ObjCInterfaceDecl *IDecl =
OPT->getObjectType()->getInterface();
assert(IDecl && "Invalid @catch type.");
Handler.TypeInfo = MakeConstantString(IDecl->getNameAsString());
}
EHCatchScope *Catch = CGF.EHStack.pushCatch(Handlers.size());
for (unsigned I = 0, E = Handlers.size(); I != E; ++I)
Catch->setHandler(I, Handlers[I].TypeInfo, Handlers[I].Block);
}
// Emit the try body.
CGF.EmitStmt(S.getTryBody());
// Leave the try.
if (S.getNumCatchStmts())
CGF.EHStack.popCatch();
// Remember where we were.
CGBuilderTy::InsertPoint SavedIP = CGF.Builder.saveAndClearIP();
// Emit the handlers.
for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
CatchHandler &Handler = Handlers[I];
CGF.EmitBlock(Handler.Block);
llvm::Value *Exn = CGF.Builder.CreateLoad(CGF.getExceptionSlot());
// Bind the catch parameter if it exists.
if (const VarDecl *CatchParam = Handler.Variable) {
const llvm::Type *CatchType = CGF.ConvertType(CatchParam->getType());
Exn = CGF.Builder.CreateBitCast(Exn, CatchType);
CGF.EmitAutoVarDecl(*CatchParam);
CGF.Builder.CreateStore(Exn, CGF.GetAddrOfLocalVar(CatchParam));
}
CGF.ObjCEHValueStack.push_back(Exn);
CGF.EmitStmt(Handler.Body);
CGF.ObjCEHValueStack.pop_back();
CGF.EmitBranchThroughCleanup(Cont);
}
// Go back to the try-statement fallthrough.
CGF.Builder.restoreIP(SavedIP);
// Pop out of the finally.
if (S.getFinallyStmt())
CGF.ExitFinallyBlock(FinallyInfo);
if (Cont.isValid()) {
if (Cont.getBlock()->use_empty())
delete Cont.getBlock();
else
CGF.EmitBlock(Cont.getBlock());
}
}
void CGObjCGNU::EmitThrowStmt(CodeGen::CodeGenFunction &CGF,
const ObjCAtThrowStmt &S) {
llvm::Value *ExceptionAsObject;
std::vector<const llvm::Type*> Args(1, IdTy);
llvm::FunctionType *FTy =
llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), Args, false);
llvm::Value *ThrowFn =
CGM.CreateRuntimeFunction(FTy, "objc_exception_throw");
if (const Expr *ThrowExpr = S.getThrowExpr()) {
llvm::Value *Exception = CGF.EmitScalarExpr(ThrowExpr);
ExceptionAsObject = Exception;
} else {
assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) &&
"Unexpected rethrow outside @catch block.");
ExceptionAsObject = CGF.ObjCEHValueStack.back();
}
ExceptionAsObject =
CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy, "tmp");
// Note: This may have to be an invoke, if we want to support constructs like:
// @try {
// @throw(obj);
// }
// @catch(id) ...
//
// This is effectively turning @throw into an incredibly-expensive goto, but
// it may happen as a result of inlining followed by missed optimizations, or
// as a result of stupidity.
llvm::BasicBlock *UnwindBB = CGF.getInvokeDest();
if (!UnwindBB) {
CGF.Builder.CreateCall(ThrowFn, ExceptionAsObject);
CGF.Builder.CreateUnreachable();
} else {
CGF.Builder.CreateInvoke(ThrowFn, UnwindBB, UnwindBB, &ExceptionAsObject,
&ExceptionAsObject+1);
}
// Clear the insertion point to indicate we are in unreachable code.
CGF.Builder.ClearInsertionPoint();
}
llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGen::CodeGenFunction &CGF,
llvm::Value *AddrWeakObj) {
CGBuilderTy B = CGF.Builder;
AddrWeakObj = EnforceType(B, AddrWeakObj, IdTy);
return B.CreateCall(WeakReadFn, AddrWeakObj);
}
void CGObjCGNU::EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dst) {
CGBuilderTy B = CGF.Builder;
src = EnforceType(B, src, IdTy);
dst = EnforceType(B, dst, PtrToIdTy);
B.CreateCall2(WeakAssignFn, src, dst);
}
void CGObjCGNU::EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dst,
bool threadlocal) {
CGBuilderTy B = CGF.Builder;
src = EnforceType(B, src, IdTy);
dst = EnforceType(B, dst, PtrToIdTy);
if (!threadlocal)
B.CreateCall2(GlobalAssignFn, src, dst);
else
// FIXME. Add threadloca assign API
assert(false && "EmitObjCGlobalAssign - Threal Local API NYI");
}
void CGObjCGNU::EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dst,
llvm::Value *ivarOffset) {
CGBuilderTy B = CGF.Builder;
src = EnforceType(B, src, IdTy);
dst = EnforceType(B, dst, PtrToIdTy);
B.CreateCall3(IvarAssignFn, src, dst, ivarOffset);
}
void CGObjCGNU::EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dst) {
CGBuilderTy B = CGF.Builder;
src = EnforceType(B, src, IdTy);
dst = EnforceType(B, dst, PtrToIdTy);
B.CreateCall2(StrongCastAssignFn, src, dst);
}
void CGObjCGNU::EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF,
llvm::Value *DestPtr,
llvm::Value *SrcPtr,
llvm::Value *Size) {
CGBuilderTy B = CGF.Builder;
DestPtr = EnforceType(B, DestPtr, IdTy);
SrcPtr = EnforceType(B, SrcPtr, PtrToIdTy);
B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size);
}
llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable(
const ObjCInterfaceDecl *ID,
const ObjCIvarDecl *Ivar) {
const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString()
+ '.' + Ivar->getNameAsString();
// Emit the variable and initialize it with what we think the correct value
// is. This allows code compiled with non-fragile ivars to work correctly
// when linked against code which isn't (most of the time).
llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name);
if (!IvarOffsetPointer) {
// This will cause a run-time crash if we accidentally use it. A value of
// 0 would seem more sensible, but will silently overwrite the isa pointer
// causing a great deal of confusion.
uint64_t Offset = -1;
// We can't call ComputeIvarBaseOffset() here if we have the
// implementation, because it will create an invalid ASTRecordLayout object
// that we are then stuck with forever, so we only initialize the ivar
// offset variable with a guess if we only have the interface. The
// initializer will be reset later anyway, when we are generating the class
// description.
if (!CGM.getContext().getObjCImplementation(
const_cast<ObjCInterfaceDecl *>(ID)))
Offset = ComputeIvarBaseOffset(CGM, ID, Ivar);
llvm::ConstantInt *OffsetGuess =
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset, "ivar");
// Don't emit the guess in non-PIC code because the linker will not be able
// to replace it with the real version for a library. In non-PIC code you
// must compile with the fragile ABI if you want to use ivars from a
// GCC-compiled class.
if (CGM.getLangOptions().PICLevel) {
llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule,
llvm::Type::getInt32Ty(VMContext), false,
llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess");
IvarOffsetPointer = new llvm::GlobalVariable(TheModule,
IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage,
IvarOffsetGV, Name);
} else {
IvarOffsetPointer = new llvm::GlobalVariable(TheModule,
llvm::Type::getInt32PtrTy(VMContext), false,
llvm::GlobalValue::ExternalLinkage, 0, Name);
}
}
return IvarOffsetPointer;
}
LValue CGObjCGNU::EmitObjCValueForIvar(CodeGen::CodeGenFunction &CGF,
QualType ObjectTy,
llvm::Value *BaseValue,
const ObjCIvarDecl *Ivar,
unsigned CVRQualifiers) {
const ObjCInterfaceDecl *ID =
ObjectTy->getAs<ObjCObjectType>()->getInterface();
return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers,
EmitIvarOffset(CGF, ID, Ivar));
}
static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context,
const ObjCInterfaceDecl *OID,
const ObjCIvarDecl *OIVD) {
llvm::SmallVector<ObjCIvarDecl*, 16> Ivars;
Context.ShallowCollectObjCIvars(OID, Ivars);
for (unsigned k = 0, e = Ivars.size(); k != e; ++k) {
if (OIVD == Ivars[k])
return OID;
}
// Otherwise check in the super class.
if (const ObjCInterfaceDecl *Super = OID->getSuperClass())
return FindIvarInterface(Context, Super, OIVD);
return 0;
}
llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGen::CodeGenFunction &CGF,
const ObjCInterfaceDecl *Interface,
const ObjCIvarDecl *Ivar) {
if (CGM.getLangOptions().ObjCNonFragileABI) {
Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar);
return CGF.Builder.CreateLoad(CGF.Builder.CreateLoad(
ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar"));
}
uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar);
return llvm::ConstantInt::get(LongTy, Offset, "ivar");
}
CodeGen::CGObjCRuntime *
CodeGen::CreateGNUObjCRuntime(CodeGen::CodeGenModule &CGM) {
return new CGObjCGNU(CGM);
}
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