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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 targeting 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 "CGCleanup.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.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 "clang/Basic/FileManager.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/Compiler.h"
#include <cstdarg>
using namespace clang;
using namespace CodeGen;
namespace {
/// Class that lazily initialises the runtime function. Avoids inserting the
/// types and the function declaration into a module if they're not used, and
/// avoids constructing the type more than once if it's used more than once.
class LazyRuntimeFunction {
CodeGenModule *CGM;
std::vector<llvm::Type*> ArgTys;
const char *FunctionName;
llvm::Constant *Function;
public:
/// Constructor leaves this class uninitialized, because it is intended to
/// be used as a field in another class and not all of the types that are
/// used as arguments will necessarily be available at construction time.
LazyRuntimeFunction()
: CGM(nullptr), FunctionName(nullptr), Function(nullptr) {}
/// Initialises the lazy function with the name, return type, and the types
/// of the arguments.
LLVM_END_WITH_NULL
void init(CodeGenModule *Mod, const char *name,
llvm::Type *RetTy, ...) {
CGM =Mod;
FunctionName = name;
Function = nullptr;
ArgTys.clear();
va_list Args;
va_start(Args, RetTy);
while (llvm::Type *ArgTy = va_arg(Args, llvm::Type*))
ArgTys.push_back(ArgTy);
va_end(Args);
// Push the return type on at the end so we can pop it off easily
ArgTys.push_back(RetTy);
}
/// Overloaded cast operator, allows the class to be implicitly cast to an
/// LLVM constant.
operator llvm::Constant*() {
if (!Function) {
if (!FunctionName) return nullptr;
// We put the return type on the end of the vector, so pop it back off
llvm::Type *RetTy = ArgTys.back();
ArgTys.pop_back();
llvm::FunctionType *FTy = llvm::FunctionType::get(RetTy, ArgTys, false);
Function =
cast<llvm::Constant>(CGM->CreateRuntimeFunction(FTy, FunctionName));
// We won't need to use the types again, so we may as well clean up the
// vector now
ArgTys.resize(0);
}
return Function;
}
operator llvm::Function*() {
return cast<llvm::Function>((llvm::Constant*)*this);
}
};
/// GNU Objective-C runtime code generation. This class implements the parts of
/// Objective-C support that are specific to the GNU family of runtimes (GCC,
/// GNUstep and ObjFW).
class CGObjCGNU : public CGObjCRuntime {
protected:
/// The LLVM module into which output is inserted
llvm::Module &TheModule;
/// strut objc_super. Used for sending messages to super. This structure
/// contains the receiver (object) and the expected class.
llvm::StructType *ObjCSuperTy;
/// struct objc_super*. The type of the argument to the superclass message
/// lookup functions.
llvm::PointerType *PtrToObjCSuperTy;
/// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring
/// SEL is included in a header somewhere, in which case it will be whatever
/// type is declared in that header, most likely {i8*, i8*}.
llvm::PointerType *SelectorTy;
/// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the
/// places where it's used
llvm::IntegerType *Int8Ty;
/// Pointer to i8 - LLVM type of char*, for all of the places where the
/// runtime needs to deal with C strings.
llvm::PointerType *PtrToInt8Ty;
/// Instance Method Pointer type. This is a pointer to a function that takes,
/// at a minimum, an object and a selector, and is the generic type for
/// Objective-C methods. Due to differences between variadic / non-variadic
/// calling conventions, it must always be cast to the correct type before
/// actually being used.
llvm::PointerType *IMPTy;
/// Type of an untyped Objective-C object. Clang treats id as a built-in type
/// when compiling Objective-C code, so this may be an opaque pointer (i8*),
/// but if the runtime header declaring it is included then it may be a
/// pointer to a structure.
llvm::PointerType *IdTy;
/// Pointer to a pointer to an Objective-C object. Used in the new ABI
/// message lookup function and some GC-related functions.
llvm::PointerType *PtrToIdTy;
/// The clang type of id. Used when using the clang CGCall infrastructure to
/// call Objective-C methods.
CanQualType ASTIdTy;
/// LLVM type for C int type.
llvm::IntegerType *IntTy;
/// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is
/// used in the code to document the difference between i8* meaning a pointer
/// to a C string and i8* meaning a pointer to some opaque type.
llvm::PointerType *PtrTy;
/// LLVM type for C long type. The runtime uses this in a lot of places where
/// it should be using intptr_t, but we can't fix this without breaking
/// compatibility with GCC...
llvm::IntegerType *LongTy;
/// LLVM type for C size_t. Used in various runtime data structures.
llvm::IntegerType *SizeTy;
/// LLVM type for C intptr_t.
llvm::IntegerType *IntPtrTy;
/// LLVM type for C ptrdiff_t. Mainly used in property accessor functions.
llvm::IntegerType *PtrDiffTy;
/// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance
/// variables.
llvm::PointerType *PtrToIntTy;
/// LLVM type for Objective-C BOOL type.
llvm::Type *BoolTy;
/// 32-bit integer type, to save us needing to look it up every time it's used.
llvm::IntegerType *Int32Ty;
/// 64-bit integer type, to save us needing to look it up every time it's used.
llvm::IntegerType *Int64Ty;
/// Metadata kind used to tie method lookups to message sends. The GNUstep
/// runtime provides some LLVM passes that can use this to do things like
/// automatic IMP caching and speculative inlining.
unsigned msgSendMDKind;
/// Helper function that generates a constant string and returns a pointer to
/// the start of the string. The result of this function can be used anywhere
/// where the C code specifies const char*.
llvm::Constant *MakeConstantString(const std::string &Str,
const std::string &Name="") {
auto *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str());
return llvm::ConstantExpr::getGetElementPtr(ConstStr->getValueType(),
ConstStr, Zeros);
}
/// Emits a linkonce_odr string, whose name is the prefix followed by the
/// string value. This allows the linker to combine the strings between
/// different modules. Used for EH typeinfo names, selector strings, and a
/// few other things.
llvm::Constant *ExportUniqueString(const std::string &Str,
const std::string prefix) {
std::string name = prefix + Str;
auto *ConstStr = TheModule.getGlobalVariable(name);
if (!ConstStr) {
llvm::Constant *value = llvm::ConstantDataArray::getString(VMContext,Str);
ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true,
llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str);
}
return llvm::ConstantExpr::getGetElementPtr(ConstStr->getValueType(),
ConstStr, Zeros);
}
/// Generates a global structure, initialized by the elements in the vector.
/// The element types must match the types of the structure elements in the
/// first argument.
llvm::GlobalVariable *MakeGlobal(llvm::StructType *Ty,
ArrayRef<llvm::Constant *> V,
StringRef Name="",
llvm::GlobalValue::LinkageTypes linkage
=llvm::GlobalValue::InternalLinkage) {
llvm::Constant *C = llvm::ConstantStruct::get(Ty, V);
return new llvm::GlobalVariable(TheModule, Ty, false,
linkage, C, Name);
}
/// Generates a global array. The vector must contain the same number of
/// elements that the array type declares, of the type specified as the array
/// element type.
llvm::GlobalVariable *MakeGlobal(llvm::ArrayType *Ty,
ArrayRef<llvm::Constant *> V,
StringRef Name="",
llvm::GlobalValue::LinkageTypes linkage
=llvm::GlobalValue::InternalLinkage) {
llvm::Constant *C = llvm::ConstantArray::get(Ty, V);
return new llvm::GlobalVariable(TheModule, Ty, false,
linkage, C, Name);
}
/// Generates a global array, inferring the array type from the specified
/// element type and the size of the initialiser.
llvm::GlobalVariable *MakeGlobalArray(llvm::Type *Ty,
ArrayRef<llvm::Constant *> V,
StringRef Name="",
llvm::GlobalValue::LinkageTypes linkage
=llvm::GlobalValue::InternalLinkage) {
llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size());
return MakeGlobal(ArrayTy, V, Name, linkage);
}
/// Returns a property name and encoding string.
llvm::Constant *MakePropertyEncodingString(const ObjCPropertyDecl *PD,
const Decl *Container) {
const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
if ((R.getKind() == ObjCRuntime::GNUstep) &&
(R.getVersion() >= VersionTuple(1, 6))) {
std::string NameAndAttributes;
std::string TypeStr;
CGM.getContext().getObjCEncodingForPropertyDecl(PD, Container, TypeStr);
NameAndAttributes += '\0';
NameAndAttributes += TypeStr.length() + 3;
NameAndAttributes += TypeStr;
NameAndAttributes += '\0';
NameAndAttributes += PD->getNameAsString();
auto *ConstStr = CGM.GetAddrOfConstantCString(NameAndAttributes);
return llvm::ConstantExpr::getGetElementPtr(ConstStr->getValueType(),
ConstStr, Zeros);
}
return MakeConstantString(PD->getNameAsString());
}
/// Push the property attributes into two structure fields.
void PushPropertyAttributes(std::vector<llvm::Constant*> &Fields,
ObjCPropertyDecl *property, bool isSynthesized=true, bool
isDynamic=true) {
int attrs = property->getPropertyAttributes();
// For read-only properties, clear the copy and retain flags
if (attrs & ObjCPropertyDecl::OBJC_PR_readonly) {
attrs &= ~ObjCPropertyDecl::OBJC_PR_copy;
attrs &= ~ObjCPropertyDecl::OBJC_PR_retain;
attrs &= ~ObjCPropertyDecl::OBJC_PR_weak;
attrs &= ~ObjCPropertyDecl::OBJC_PR_strong;
}
// The first flags field has the same attribute values as clang uses internally
Fields.push_back(llvm::ConstantInt::get(Int8Ty, attrs & 0xff));
attrs >>= 8;
attrs <<= 2;
// For protocol properties, synthesized and dynamic have no meaning, so we
// reuse these flags to indicate that this is a protocol property (both set
// has no meaning, as a property can't be both synthesized and dynamic)
attrs |= isSynthesized ? (1<<0) : 0;
attrs |= isDynamic ? (1<<1) : 0;
// The second field is the next four fields left shifted by two, with the
// low bit set to indicate whether the field is synthesized or dynamic.
Fields.push_back(llvm::ConstantInt::get(Int8Ty, attrs & 0xff));
// Two padding fields
Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0));
Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0));
}
/// Ensures that the value has the required type, by inserting a bitcast if
/// required. This function lets us avoid inserting bitcasts that are
/// redundant.
llvm::Value* EnforceType(CGBuilderTy &B, llvm::Value *V, llvm::Type *Ty) {
if (V->getType() == Ty) return V;
return B.CreateBitCast(V, Ty);
}
// Some zeros used for GEPs in lots of places.
llvm::Constant *Zeros[2];
/// Null pointer value. Mainly used as a terminator in various arrays.
llvm::Constant *NULLPtr;
/// LLVM context.
llvm::LLVMContext &VMContext;
private:
/// Placeholder for the class. Lots of things refer to the class before we've
/// actually emitted it. We use this alias as a placeholder, and then replace
/// it with a pointer to the class structure before finally emitting the
/// module.
llvm::GlobalAlias *ClassPtrAlias;
/// Placeholder for the metaclass. Lots of things refer to the class before
/// we've / actually emitted it. We use this alias as a placeholder, and then
/// replace / it with a pointer to the metaclass structure before finally
/// emitting the / module.
llvm::GlobalAlias *MetaClassPtrAlias;
/// All of the classes that have been generated for this compilation units.
std::vector<llvm::Constant*> Classes;
/// All of the categories that have been generated for this compilation units.
std::vector<llvm::Constant*> Categories;
/// All of the Objective-C constant strings that have been generated for this
/// compilation units.
std::vector<llvm::Constant*> ConstantStrings;
/// Map from string values to Objective-C constant strings in the output.
/// Used to prevent emitting Objective-C strings more than once. This should
/// not be required at all - CodeGenModule should manage this list.
llvm::StringMap<llvm::Constant*> ObjCStrings;
/// All of the protocols that have been declared.
llvm::StringMap<llvm::Constant*> ExistingProtocols;
/// For each variant of a selector, we store the type encoding and a
/// placeholder value. For an untyped selector, the type will be the empty
/// string. Selector references are all done via the module's selector table,
/// so we create an alias as a placeholder and then replace it with the real
/// value later.
typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector;
/// Type of the selector map. This is roughly equivalent to the structure
/// used in the GNUstep runtime, which maintains a list of all of the valid
/// types for a selector in a table.
typedef llvm::DenseMap<Selector, SmallVector<TypedSelector, 2> >
SelectorMap;
/// A map from selectors to selector types. This allows us to emit all
/// selectors of the same name and type together.
SelectorMap SelectorTable;
/// Selectors related to memory management. When compiling in GC mode, we
/// omit these.
Selector RetainSel, ReleaseSel, AutoreleaseSel;
/// Runtime functions used for memory management in GC mode. Note that clang
/// supports code generation for calling these functions, but neither GNU
/// runtime actually supports this API properly yet.
LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn,
WeakAssignFn, GlobalAssignFn;
typedef std::pair<std::string, std::string> ClassAliasPair;
/// All classes that have aliases set for them.
std::vector<ClassAliasPair> ClassAliases;
protected:
/// Function used for throwing Objective-C exceptions.
LazyRuntimeFunction ExceptionThrowFn;
/// Function used for rethrowing exceptions, used at the end of \@finally or
/// \@synchronize blocks.
LazyRuntimeFunction ExceptionReThrowFn;
/// Function called when entering a catch function. This is required for
/// differentiating Objective-C exceptions and foreign exceptions.
LazyRuntimeFunction EnterCatchFn;
/// Function called when exiting from a catch block. Used to do exception
/// cleanup.
LazyRuntimeFunction ExitCatchFn;
/// Function called when entering an \@synchronize block. Acquires the lock.
LazyRuntimeFunction SyncEnterFn;
/// Function called when exiting an \@synchronize block. Releases the lock.
LazyRuntimeFunction SyncExitFn;
private:
/// Function called if fast enumeration detects that the collection is
/// modified during the update.
LazyRuntimeFunction EnumerationMutationFn;
/// Function for implementing synthesized property getters that return an
/// object.
LazyRuntimeFunction GetPropertyFn;
/// Function for implementing synthesized property setters that return an
/// object.
LazyRuntimeFunction SetPropertyFn;
/// Function used for non-object declared property getters.
LazyRuntimeFunction GetStructPropertyFn;
/// Function used for non-object declared property setters.
LazyRuntimeFunction SetStructPropertyFn;
/// The version of the runtime that this class targets. Must match the
/// version in the runtime.
int RuntimeVersion;
/// The version of the protocol class. Used to differentiate between ObjC1
/// and ObjC2 protocols. Objective-C 1 protocols can not contain optional
/// components and can not contain declared properties. We always emit
/// Objective-C 2 property structures, but we have to pretend that they're
/// Objective-C 1 property structures when targeting the GCC runtime or it
/// will abort.
const int ProtocolVersion;
private:
/// Generates an instance variable list structure. This is a structure
/// containing a size and an array of structures containing instance variable
/// metadata. This is used purely for introspection in the fragile ABI. In
/// the non-fragile ABI, it's used for instance variable fixup.
llvm::Constant *GenerateIvarList(ArrayRef<llvm::Constant *> IvarNames,
ArrayRef<llvm::Constant *> IvarTypes,
ArrayRef<llvm::Constant *> IvarOffsets);
/// Generates a method list structure. This is a structure containing a size
/// and an array of structures containing method metadata.
///
/// This structure is used by both classes and categories, and contains a next
/// pointer allowing them to be chained together in a linked list.
llvm::Constant *GenerateMethodList(StringRef ClassName,
StringRef CategoryName,
ArrayRef<Selector> MethodSels,
ArrayRef<llvm::Constant *> MethodTypes,
bool isClassMethodList);
/// Emits an empty protocol. This is used for \@protocol() where no protocol
/// is found. The runtime will (hopefully) fix up the pointer to refer to the
/// real protocol.
llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName);
/// Generates a list of property metadata structures. This follows the same
/// pattern as method and instance variable metadata lists.
llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID,
SmallVectorImpl<Selector> &InstanceMethodSels,
SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes);
/// Generates a list of referenced protocols. Classes, categories, and
/// protocols all use this structure.
llvm::Constant *GenerateProtocolList(ArrayRef<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. This is a horribly ugly hack, but it allows us to collect all
/// of the protocols without changing the ABI.
void GenerateProtocolHolderCategory();
/// Generates a class structure.
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,
llvm::Constant *StrongIvarBitmap,
llvm::Constant *WeakIvarBitmap,
bool isMeta=false);
/// Generates a method list. This is used by protocols to define the required
/// and optional methods.
llvm::Constant *GenerateProtocolMethodList(
ArrayRef<llvm::Constant *> MethodNames,
ArrayRef<llvm::Constant *> MethodTypes);
/// Returns a selector with the specified type encoding. An empty string is
/// used to return an untyped selector (with the types field set to NULL).
llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel,
const std::string &TypeEncoding, bool lval);
/// Returns the variable used to store the offset of an instance variable.
llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID,
const ObjCIvarDecl *Ivar);
/// Emits a reference to a class. This allows the linker to object if there
/// is no class of the matching name.
protected:
void EmitClassRef(const std::string &className);
/// Emits a pointer to the named class
virtual llvm::Value *GetClassNamed(CodeGenFunction &CGF,
const std::string &Name, bool isWeak);
/// Looks up the method for sending a message to the specified object. This
/// mechanism differs between the GCC and GNU runtimes, so this method must be
/// overridden in subclasses.
virtual llvm::Value *LookupIMP(CodeGenFunction &CGF,
llvm::Value *&Receiver,
llvm::Value *cmd,
llvm::MDNode *node,
MessageSendInfo &MSI) = 0;
/// Looks up the method for sending a message to a superclass. This
/// mechanism differs between the GCC and GNU runtimes, so this method must
/// be overridden in subclasses.
virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF,
llvm::Value *ObjCSuper,
llvm::Value *cmd,
MessageSendInfo &MSI) = 0;
/// Libobjc2 uses a bitfield representation where small(ish) bitfields are
/// stored in a 64-bit value with the low bit set to 1 and the remaining 63
/// bits set to their values, LSB first, while larger ones are stored in a
/// structure of this / form:
///
/// struct { int32_t length; int32_t values[length]; };
///
/// The values in the array are stored in host-endian format, with the least
/// significant bit being assumed to come first in the bitfield. Therefore,
/// a bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] },
/// while a bitfield / with the 63rd bit set will be 1<<64.
llvm::Constant *MakeBitField(ArrayRef<bool> bits);
public:
CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
unsigned protocolClassVersion);
llvm::Constant *GenerateConstantString(const StringLiteral *) override;
RValue
GenerateMessageSend(CodeGenFunction &CGF, ReturnValueSlot Return,
QualType ResultType, Selector Sel,
llvm::Value *Receiver, const CallArgList &CallArgs,
const ObjCInterfaceDecl *Class,
const ObjCMethodDecl *Method) override;
RValue
GenerateMessageSendSuper(CodeGenFunction &CGF, ReturnValueSlot Return,
QualType ResultType, Selector Sel,
const ObjCInterfaceDecl *Class,
bool isCategoryImpl, llvm::Value *Receiver,
bool IsClassMessage, const CallArgList &CallArgs,
const ObjCMethodDecl *Method) override;
llvm::Value *GetClass(CodeGenFunction &CGF,
const ObjCInterfaceDecl *OID) override;
llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel,
bool lval = false) override;
llvm::Value *GetSelector(CodeGenFunction &CGF,
const ObjCMethodDecl *Method) override;
llvm::Constant *GetEHType(QualType T) override;
llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
const ObjCContainerDecl *CD) override;
void GenerateCategory(const ObjCCategoryImplDecl *CMD) override;
void GenerateClass(const ObjCImplementationDecl *ClassDecl) override;
void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) override;
llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
const ObjCProtocolDecl *PD) override;
void GenerateProtocol(const ObjCProtocolDecl *PD) override;
llvm::Function *ModuleInitFunction() override;
llvm::Constant *GetPropertyGetFunction() override;
llvm::Constant *GetPropertySetFunction() override;
llvm::Constant *GetOptimizedPropertySetFunction(bool atomic,
bool copy) override;
llvm::Constant *GetSetStructFunction() override;
llvm::Constant *GetGetStructFunction() override;
llvm::Constant *GetCppAtomicObjectGetFunction() override;
llvm::Constant *GetCppAtomicObjectSetFunction() override;
llvm::Constant *EnumerationMutationFunction() override;
void EmitTryStmt(CodeGenFunction &CGF,
const ObjCAtTryStmt &S) override;
void EmitSynchronizedStmt(CodeGenFunction &CGF,
const ObjCAtSynchronizedStmt &S) override;
void EmitThrowStmt(CodeGenFunction &CGF,
const ObjCAtThrowStmt &S,
bool ClearInsertionPoint=true) override;
llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF,
llvm::Value *AddrWeakObj) override;
void EmitObjCWeakAssign(CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dst) override;
void EmitObjCGlobalAssign(CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dest,
bool threadlocal=false) override;
void EmitObjCIvarAssign(CodeGenFunction &CGF, llvm::Value *src,
llvm::Value *dest, llvm::Value *ivarOffset) override;
void EmitObjCStrongCastAssign(CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dest) override;
void EmitGCMemmoveCollectable(CodeGenFunction &CGF, llvm::Value *DestPtr,
llvm::Value *SrcPtr,
llvm::Value *Size) override;
LValue EmitObjCValueForIvar(CodeGenFunction &CGF, QualType ObjectTy,
llvm::Value *BaseValue, const ObjCIvarDecl *Ivar,
unsigned CVRQualifiers) override;
llvm::Value *EmitIvarOffset(CodeGenFunction &CGF,
const ObjCInterfaceDecl *Interface,
const ObjCIvarDecl *Ivar) override;
llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) override;
llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM,
const CGBlockInfo &blockInfo) override {
return NULLPtr;
}
llvm::Constant *BuildRCBlockLayout(CodeGenModule &CGM,
const CGBlockInfo &blockInfo) override {
return NULLPtr;
}
llvm::Constant *BuildByrefLayout(CodeGenModule &CGM, QualType T) override {
return NULLPtr;
}
llvm::GlobalVariable *GetClassGlobal(const std::string &Name,
bool Weak = false) override {
return nullptr;
}
};
/// Class representing the legacy GCC Objective-C ABI. This is the default when
/// -fobjc-nonfragile-abi is not specified.
///
/// The GCC ABI target actually generates code that is approximately compatible
/// with the new GNUstep runtime ABI, but refrains from using any features that
/// would not work with the GCC runtime. For example, clang always generates
/// the extended form of the class structure, and the extra fields are simply
/// ignored by GCC libobjc.
class CGObjCGCC : public CGObjCGNU {
/// The GCC ABI message lookup function. Returns an IMP pointing to the
/// method implementation for this message.
LazyRuntimeFunction MsgLookupFn;
/// The GCC ABI superclass message lookup function. Takes a pointer to a
/// structure describing the receiver and the class, and a selector as
/// arguments. Returns the IMP for the corresponding method.
LazyRuntimeFunction MsgLookupSuperFn;
protected:
llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
llvm::Value *cmd, llvm::MDNode *node,
MessageSendInfo &MSI) override {
CGBuilderTy &Builder = CGF.Builder;
llvm::Value *args[] = {
EnforceType(Builder, Receiver, IdTy),
EnforceType(Builder, cmd, SelectorTy) };
llvm::CallSite imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);
imp->setMetadata(msgSendMDKind, node);
return imp.getInstruction();
}
llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, llvm::Value *ObjCSuper,
llvm::Value *cmd, MessageSendInfo &MSI) override {
CGBuilderTy &Builder = CGF.Builder;
llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper,
PtrToObjCSuperTy), cmd};
return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
}
public:
CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) {
// IMP objc_msg_lookup(id, SEL);
MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy,
nullptr);
// IMP objc_msg_lookup_super(struct objc_super*, SEL);
MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
PtrToObjCSuperTy, SelectorTy, nullptr);
}
};
/// Class used when targeting the new GNUstep runtime ABI.
class CGObjCGNUstep : public CGObjCGNU {
/// The slot lookup function. Returns a pointer to a cacheable structure
/// that contains (among other things) the IMP.
LazyRuntimeFunction SlotLookupFn;
/// The GNUstep ABI superclass message lookup function. Takes a pointer to
/// a structure describing the receiver and the class, and a selector as
/// arguments. Returns the slot for the corresponding method. Superclass
/// message lookup rarely changes, so this is a good caching opportunity.
LazyRuntimeFunction SlotLookupSuperFn;
/// Specialised function for setting atomic retain properties
LazyRuntimeFunction SetPropertyAtomic;
/// Specialised function for setting atomic copy properties
LazyRuntimeFunction SetPropertyAtomicCopy;
/// Specialised function for setting nonatomic retain properties
LazyRuntimeFunction SetPropertyNonAtomic;
/// Specialised function for setting nonatomic copy properties
LazyRuntimeFunction SetPropertyNonAtomicCopy;
/// Function to perform atomic copies of C++ objects with nontrivial copy
/// constructors from Objective-C ivars.
LazyRuntimeFunction CxxAtomicObjectGetFn;
/// Function to perform atomic copies of C++ objects with nontrivial copy
/// constructors to Objective-C ivars.
LazyRuntimeFunction CxxAtomicObjectSetFn;
/// Type of an slot structure pointer. This is returned by the various
/// lookup functions.
llvm::Type *SlotTy;
public:
llvm::Constant *GetEHType(QualType T) override;
protected:
llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
llvm::Value *cmd, llvm::MDNode *node,
MessageSendInfo &MSI) override {
CGBuilderTy &Builder = CGF.Builder;
llvm::Function *LookupFn = SlotLookupFn;
// Store the receiver on the stack so that we can reload it later
llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType());
Builder.CreateStore(Receiver, ReceiverPtr);
llvm::Value *self;
if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) {
self = CGF.LoadObjCSelf();
} else {
self = llvm::ConstantPointerNull::get(IdTy);
}
// The lookup function is guaranteed not to capture the receiver pointer.
LookupFn->setDoesNotCapture(1);
llvm::Value *args[] = {
EnforceType(Builder, ReceiverPtr, PtrToIdTy),
EnforceType(Builder, cmd, SelectorTy),
EnforceType(Builder, self, IdTy) };
llvm::CallSite slot = CGF.EmitRuntimeCallOrInvoke(LookupFn, args);
slot.setOnlyReadsMemory();
slot->setMetadata(msgSendMDKind, node);
// Load the imp from the slot
llvm::Value *imp = Builder.CreateLoad(
Builder.CreateStructGEP(nullptr, slot.getInstruction(), 4));
// The lookup function may have changed the receiver, so make sure we use
// the new one.
Receiver = Builder.CreateLoad(ReceiverPtr, true);
return imp;
}
llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, llvm::Value *ObjCSuper,
llvm::Value *cmd,
MessageSendInfo &MSI) override {
CGBuilderTy &Builder = CGF.Builder;
llvm::Value *lookupArgs[] = {ObjCSuper, cmd};
llvm::CallInst *slot =
CGF.EmitNounwindRuntimeCall(SlotLookupSuperFn, lookupArgs);
slot->setOnlyReadsMemory();
return Builder.CreateLoad(Builder.CreateStructGEP(nullptr, slot, 4));
}
public:
CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) {
const ObjCRuntime &R = CGM.getLangOpts().ObjCRuntime;
llvm::StructType *SlotStructTy = llvm::StructType::get(PtrTy,
PtrTy, PtrTy, IntTy, IMPTy, nullptr);
SlotTy = llvm::PointerType::getUnqual(SlotStructTy);
// Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender);
SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy,
SelectorTy, IdTy, nullptr);
// Slot_t objc_msg_lookup_super(struct objc_super*, SEL);
SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy,
PtrToObjCSuperTy, SelectorTy, nullptr);
// If we're in ObjC++ mode, then we want to make
if (CGM.getLangOpts().CPlusPlus) {
llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
// void *__cxa_begin_catch(void *e)
EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, nullptr);
// void __cxa_end_catch(void)
ExitCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, nullptr);
// void _Unwind_Resume_or_Rethrow(void*)
ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy,
PtrTy, nullptr);
} else if (R.getVersion() >= VersionTuple(1, 7)) {
llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
// id objc_begin_catch(void *e)
EnterCatchFn.init(&CGM, "objc_begin_catch", IdTy, PtrTy, nullptr);
// void objc_end_catch(void)
ExitCatchFn.init(&CGM, "objc_end_catch", VoidTy, nullptr);
// void _Unwind_Resume_or_Rethrow(void*)
ExceptionReThrowFn.init(&CGM, "objc_exception_rethrow", VoidTy,
PtrTy, nullptr);
}
llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
SetPropertyAtomic.init(&CGM, "objc_setProperty_atomic", VoidTy, IdTy,
SelectorTy, IdTy, PtrDiffTy, nullptr);
SetPropertyAtomicCopy.init(&CGM, "objc_setProperty_atomic_copy", VoidTy,
IdTy, SelectorTy, IdTy, PtrDiffTy, nullptr);
SetPropertyNonAtomic.init(&CGM, "objc_setProperty_nonatomic", VoidTy,
IdTy, SelectorTy, IdTy, PtrDiffTy, nullptr);
SetPropertyNonAtomicCopy.init(&CGM, "objc_setProperty_nonatomic_copy",
VoidTy, IdTy, SelectorTy, IdTy, PtrDiffTy, nullptr);
// void objc_setCppObjectAtomic(void *dest, const void *src, void
// *helper);
CxxAtomicObjectSetFn.init(&CGM, "objc_setCppObjectAtomic", VoidTy, PtrTy,
PtrTy, PtrTy, nullptr);
// void objc_getCppObjectAtomic(void *dest, const void *src, void
// *helper);
CxxAtomicObjectGetFn.init(&CGM, "objc_getCppObjectAtomic", VoidTy, PtrTy,
PtrTy, PtrTy, nullptr);
}
llvm::Constant *GetCppAtomicObjectGetFunction() override {
// The optimised functions were added in version 1.7 of the GNUstep
// runtime.
assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
VersionTuple(1, 7));
return CxxAtomicObjectGetFn;
}
llvm::Constant *GetCppAtomicObjectSetFunction() override {
// The optimised functions were added in version 1.7 of the GNUstep
// runtime.
assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
VersionTuple(1, 7));
return CxxAtomicObjectSetFn;
}
llvm::Constant *GetOptimizedPropertySetFunction(bool atomic,
bool copy) override {
// The optimised property functions omit the GC check, and so are not
// safe to use in GC mode. The standard functions are fast in GC mode,
// so there is less advantage in using them.
assert ((CGM.getLangOpts().getGC() == LangOptions::NonGC));
// The optimised functions were added in version 1.7 of the GNUstep
// runtime.
assert (CGM.getLangOpts().ObjCRuntime.getVersion() >=
VersionTuple(1, 7));
if (atomic) {
if (copy) return SetPropertyAtomicCopy;
return SetPropertyAtomic;
}
return copy ? SetPropertyNonAtomicCopy : SetPropertyNonAtomic;
}
};
/// Support for the ObjFW runtime.
class CGObjCObjFW: public CGObjCGNU {
protected:
/// The GCC ABI message lookup function. Returns an IMP pointing to the
/// method implementation for this message.
LazyRuntimeFunction MsgLookupFn;
/// stret lookup function. While this does not seem to make sense at the
/// first look, this is required to call the correct forwarding function.
LazyRuntimeFunction MsgLookupFnSRet;
/// The GCC ABI superclass message lookup function. Takes a pointer to a
/// structure describing the receiver and the class, and a selector as
/// arguments. Returns the IMP for the corresponding method.
LazyRuntimeFunction MsgLookupSuperFn, MsgLookupSuperFnSRet;
llvm::Value *LookupIMP(CodeGenFunction &CGF, llvm::Value *&Receiver,
llvm::Value *cmd, llvm::MDNode *node,
MessageSendInfo &MSI) override {
CGBuilderTy &Builder = CGF.Builder;
llvm::Value *args[] = {
EnforceType(Builder, Receiver, IdTy),
EnforceType(Builder, cmd, SelectorTy) };
llvm::CallSite imp;
if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFnSRet, args);
else
imp = CGF.EmitRuntimeCallOrInvoke(MsgLookupFn, args);
imp->setMetadata(msgSendMDKind, node);
return imp.getInstruction();
}
llvm::Value *LookupIMPSuper(CodeGenFunction &CGF, llvm::Value *ObjCSuper,
llvm::Value *cmd, MessageSendInfo &MSI) override {
CGBuilderTy &Builder = CGF.Builder;
llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper,
PtrToObjCSuperTy), cmd};
if (CGM.ReturnTypeUsesSRet(MSI.CallInfo))
return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFnSRet, lookupArgs);
else
return CGF.EmitNounwindRuntimeCall(MsgLookupSuperFn, lookupArgs);
}
llvm::Value *GetClassNamed(CodeGenFunction &CGF,
const std::string &Name, bool isWeak) override {
if (isWeak)
return CGObjCGNU::GetClassNamed(CGF, Name, isWeak);
EmitClassRef(Name);
std::string SymbolName = "_OBJC_CLASS_" + Name;
llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(SymbolName);
if (!ClassSymbol)
ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
llvm::GlobalValue::ExternalLinkage,
nullptr, SymbolName);
return ClassSymbol;
}
public:
CGObjCObjFW(CodeGenModule &Mod): CGObjCGNU(Mod, 9, 3) {
// IMP objc_msg_lookup(id, SEL);
MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, nullptr);
MsgLookupFnSRet.init(&CGM, "objc_msg_lookup_stret", IMPTy, IdTy,
SelectorTy, nullptr);
// IMP objc_msg_lookup_super(struct objc_super*, SEL);
MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
PtrToObjCSuperTy, SelectorTy, nullptr);
MsgLookupSuperFnSRet.init(&CGM, "objc_msg_lookup_super_stret", IMPTy,
PtrToObjCSuperTy, SelectorTy, 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,
nullptr, symbolName);
}
new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true,
llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef);
}
static std::string SymbolNameForMethod( StringRef ClassName,
StringRef CategoryName, const Selector MethodName,
bool isClassMethod) {
std::string MethodNameColonStripped = MethodName.getAsString();
std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(),
':', '_');
return (Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" +
CategoryName + "_" + MethodNameColonStripped).str();
}
CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
unsigned protocolClassVersion)
: CGObjCRuntime(cgm), TheModule(CGM.getModule()),
VMContext(cgm.getLLVMContext()), ClassPtrAlias(nullptr),
MetaClassPtrAlias(nullptr), RuntimeVersion(runtimeABIVersion),
ProtocolVersion(protocolClassVersion) {
msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend");
CodeGenTypes &Types = CGM.getTypes();
IntTy = cast<llvm::IntegerType>(
Types.ConvertType(CGM.getContext().IntTy));
LongTy = cast<llvm::IntegerType>(
Types.ConvertType(CGM.getContext().LongTy));
SizeTy = cast<llvm::IntegerType>(
Types.ConvertType(CGM.getContext().getSizeType()));
PtrDiffTy = cast<llvm::IntegerType>(
Types.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;
Int32Ty = llvm::Type::getInt32Ty(VMContext);
Int64Ty = llvm::Type::getInt64Ty(VMContext);
IntPtrTy =
CGM.getDataLayout().getPointerSizeInBits() == 32 ? Int32Ty : Int64Ty;
// Object type
QualType UnqualIdTy = CGM.getContext().getObjCIdType();
ASTIdTy = CanQualType();
if (UnqualIdTy != QualType()) {
ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy);
IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
} else {
IdTy = PtrToInt8Ty;
}
PtrToIdTy = llvm::PointerType::getUnqual(IdTy);
ObjCSuperTy = llvm::StructType::get(IdTy, IdTy, nullptr);
PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy);
llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
// void objc_exception_throw(id);
ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, nullptr);
ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, nullptr);
// int objc_sync_enter(id);
SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, nullptr);
// int objc_sync_exit(id);
SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, nullptr);
// void objc_enumerationMutation (id)
EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy,
IdTy, nullptr);
// id objc_getProperty(id, SEL, ptrdiff_t, BOOL)
GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy,
PtrDiffTy, BoolTy, nullptr);
// void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL)
SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy,
PtrDiffTy, IdTy, BoolTy, BoolTy, nullptr);
// void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy,
PtrDiffTy, BoolTy, BoolTy, nullptr);
// void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy,
PtrDiffTy, BoolTy, BoolTy, nullptr);
// IMP type
llvm::Type *IMPArgs[] = { IdTy, SelectorTy };
IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs,
true));
const LangOptions &Opts = CGM.getLangOpts();
if ((Opts.getGC() != LangOptions::NonGC) || Opts.ObjCAutoRefCount)
RuntimeVersion = 10;
// Don't bother initialising the GC stuff unless we're compiling in GC mode
if (Opts.getGC() != LangOptions::NonGC) {
// This is a bit of an hack. We should sort this out by having a proper
// CGObjCGNUstep subclass for GC, but we may want to really support the old
// ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now
// 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);
IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy,
nullptr);
// id objc_assign_strongCast (id, id*)
StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy,
PtrToIdTy, nullptr);
// id objc_assign_global(id, id*);
GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy,
nullptr);
// id objc_assign_weak(id, id*);
WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, nullptr);
// id objc_read_weak(id*);
WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, nullptr);
// void *objc_memmove_collectable(void*, void *, size_t);
MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy,
SizeTy, nullptr);
}
}
llvm::Value *CGObjCGNU::GetClassNamed(CodeGenFunction &CGF,
const std::string &Name,
bool isWeak) {
llvm::GlobalVariable *ClassNameGV = CGM.GetAddrOfConstantCString(Name);
// 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.
//
// Libobjc2 contains an LLVM pass that replaces calls to objc_lookup_class
// with memoized versions or with static references if it's safe to do so.
if (!isWeak)
EmitClassRef(Name);
llvm::Value *ClassName =
CGF.Builder.CreateStructGEP(ClassNameGV->getValueType(), ClassNameGV, 0);
llvm::Constant *ClassLookupFn =
CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true),
"objc_lookup_class");
return CGF.EmitNounwindRuntimeCall(ClassLookupFn, ClassName);
}
// This has to perform the lookup every time, since posing and related
// techniques can modify the name -> class mapping.
llvm::Value *CGObjCGNU::GetClass(CodeGenFunction &CGF,
const ObjCInterfaceDecl *OID) {
return GetClassNamed(CGF, OID->getNameAsString(), OID->isWeakImported());
}
llvm::Value *CGObjCGNU::EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) {
return GetClassNamed(CGF, "NSAutoreleasePool", false);
}
llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel,
const std::string &TypeEncoding, bool lval) {
SmallVectorImpl<TypedSelector> &Types = SelectorTable[Sel];
llvm::GlobalAlias *SelValue = nullptr;
for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(),
e = Types.end() ; i!=e ; i++) {
if (i->first == TypeEncoding) {
SelValue = i->second;
break;
}
}
if (!SelValue) {
SelValue = llvm::GlobalAlias::create(
SelectorTy->getElementType(), 0, llvm::GlobalValue::PrivateLinkage,
".objc_selector_" + Sel.getAsString(), &TheModule);
Types.push_back(TypedSelector(TypeEncoding, SelValue));
}
if (lval) {
llvm::Value *tmp = CGF.CreateTempAlloca(SelValue->getType());
CGF.Builder.CreateStore(SelValue, tmp);
return tmp;
}
return SelValue;
}
llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel,
bool lval) {
return GetSelector(CGF, Sel, std::string(), lval);
}
llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF,
const ObjCMethodDecl *Method) {
std::string SelTypes;
CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes);
return GetSelector(CGF, Method->getSelector(), SelTypes, false);
}
llvm::Constant *CGObjCGNU::GetEHType(QualType T) {
if (T->isObjCIdType() || T->isObjCQualifiedIdType()) {
// With the old ABI, there was only one kind of catchall, which broke
// foreign exceptions. With the new ABI, we use __objc_id_typeinfo as
// a pointer indicating object catchalls, and NULL to indicate real
// catchalls
if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
return MakeConstantString("@id");
} else {
return nullptr;
}
}
// All other types should be Objective-C interface pointer types.
const ObjCObjectPointerType *OPT = T->getAs<ObjCObjectPointerType>();
assert(OPT && "Invalid @catch type.");
const ObjCInterfaceDecl *IDecl = OPT->getObjectType()->getInterface();
assert(IDecl && "Invalid @catch type.");
return MakeConstantString(IDecl->getIdentifier()->getName());
}
llvm::Constant *CGObjCGNUstep::GetEHType(QualType T) {
if (!CGM.getLangOpts().CPlusPlus)
return CGObjCGNU::GetEHType(T);
// For Objective-C++, we want to provide the ability to catch both C++ and
// Objective-C objects in the same function.
// There's a particular fixed type info for 'id'.
if (T->isObjCIdType() ||
T->isObjCQualifiedIdType()) {
llvm::Constant *IDEHType =
CGM.getModule().getGlobalVariable("__objc_id_type_info");
if (!IDEHType)
IDEHType =
new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty,
false,
llvm::GlobalValue::ExternalLinkage,
nullptr, "__objc_id_type_info");
return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty);
}
const ObjCObjectPointerType *PT =
T->getAs<ObjCObjectPointerType>();
assert(PT && "Invalid @catch type.");
const ObjCInterfaceType *IT = PT->getInterfaceType();
assert(IT && "Invalid @catch type.");
std::string className = IT->getDecl()->getIdentifier()->getName();
std::string typeinfoName = "__objc_eh_typeinfo_" + className;
// Return the existing typeinfo if it exists
llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName);
if (typeinfo)
return llvm::ConstantExpr::getBitCast(typeinfo, PtrToInt8Ty);
// Otherwise create it.
// vtable for gnustep::libobjc::__objc_class_type_info
// It's quite ugly hard-coding this. Ideally we'd generate it using the host
// platform's name mangling.
const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE";
auto *Vtable = TheModule.getGlobalVariable(vtableName);
if (!Vtable) {
Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true,
llvm::GlobalValue::ExternalLinkage,
nullptr, vtableName);
}
llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2);
auto *BVtable = llvm::ConstantExpr::getBitCast(
llvm::ConstantExpr::getGetElementPtr(Vtable->getValueType(), Vtable, Two),
PtrToInt8Ty);
llvm::Constant *typeName =
ExportUniqueString(className, "__objc_eh_typename_");
std::vector<llvm::Constant*> fields;
fields.push_back(BVtable);
fields.push_back(typeName);
llvm::Constant *TI =
MakeGlobal(llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty,
nullptr), fields, "__objc_eh_typeinfo_" + className,
llvm::GlobalValue::LinkOnceODRLinkage);
return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty);
}
/// 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();
StringRef StringClass = CGM.getLangOpts().ObjCConstantStringClass;
if (StringClass.empty()) StringClass = "NXConstantString";
std::string Sym = "_OBJC_CLASS_";
Sym += StringClass;
llvm::Constant *isa = TheModule.getNamedGlobal(Sym);
if (!isa)
isa = new llvm::GlobalVariable(TheModule, IdTy, /* isConstant */false,
llvm::GlobalValue::ExternalWeakLinkage, nullptr, Sym);
else if (isa->getType() != PtrToIdTy)
isa = llvm::ConstantExpr::getBitCast(isa, PtrToIdTy);
std::vector<llvm::Constant*> Ivars;
Ivars.push_back(isa);
Ivars.push_back(MakeConstantString(Str));
Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size()));
llvm::Constant *ObjCStr = MakeGlobal(
llvm::StructType::get(PtrToIdTy, PtrToInt8Ty, IntTy, nullptr),
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.
RValue
CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF,
ReturnValueSlot Return,
QualType ResultType,
Selector Sel,
const ObjCInterfaceDecl *Class,
bool isCategoryImpl,
llvm::Value *Receiver,
bool IsClassMessage,
const CallArgList &CallArgs,
const ObjCMethodDecl *Method) {
CGBuilderTy &Builder = CGF.Builder;
if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
if (Sel == RetainSel || Sel == AutoreleaseSel) {
return RValue::get(EnforceType(Builder, Receiver,
CGM.getTypes().ConvertType(ResultType)));
}
if (Sel == ReleaseSel) {
return RValue::get(nullptr);
}
}
llvm::Value *cmd = GetSelector(CGF, Sel);
CallArgList ActualArgs;
ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy);
ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
ActualArgs.addFrom(CallArgs);
MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
llvm::Value *ReceiverClass = nullptr;
if (isCategoryImpl) {
llvm::Constant *classLookupFunction = nullptr;
if (IsClassMessage) {
classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
IdTy, PtrTy, true), "objc_get_meta_class");
} else {
classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
IdTy, PtrTy, 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 = llvm::GlobalAlias::create(
IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage,
".objc_metaclass_ref" + Class->getNameAsString(), &TheModule);
}
ReceiverClass = MetaClassPtrAlias;
} else {
if (!ClassPtrAlias) {
ClassPtrAlias = llvm::GlobalAlias::create(
IdTy->getElementType(), 0, llvm::GlobalValue::InternalLinkage,
".objc_class_ref" + Class->getNameAsString(), &TheModule);
}
ReceiverClass = ClassPtrAlias;
}
}
// Cast the pointer to a simplified version of the class structure
llvm::Type *CastTy = llvm::StructType::get(IdTy, IdTy, nullptr);
ReceiverClass = Builder.CreateBitCast(ReceiverClass,
llvm::PointerType::getUnqual(CastTy));
// Get the superclass pointer
ReceiverClass = Builder.CreateStructGEP(CastTy, 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(
Receiver->getType(), IdTy, nullptr);
llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy);
Builder.CreateStore(Receiver,
Builder.CreateStructGEP(ObjCSuperTy, ObjCSuper, 0));
Builder.CreateStore(ReceiverClass,
Builder.CreateStructGEP(ObjCSuperTy, ObjCSuper, 1));
ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy);
// Get the IMP
llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd, MSI);
imp = EnforceType(Builder, imp, MSI.MessengerType);
llvm::Metadata *impMD[] = {
llvm::MDString::get(VMContext, Sel.getAsString()),
llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()),
llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
llvm::Type::getInt1Ty(VMContext), IsClassMessage))};
llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
llvm::Instruction *call;
RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs, nullptr,
&call);
call->setMetadata(msgSendMDKind, node);
return msgRet;
}
/// Generate code for a message send expression.
RValue
CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF,
ReturnValueSlot Return,
QualType ResultType,
Selector Sel,
llvm::Value *Receiver,
const CallArgList &CallArgs,
const ObjCInterfaceDecl *Class,
const ObjCMethodDecl *Method) {
CGBuilderTy &Builder = CGF.Builder;
// Strip out message sends to retain / release in GC mode
if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
if (Sel == RetainSel || Sel == AutoreleaseSel) {
return RValue::get(EnforceType(Builder, Receiver,
CGM.getTypes().ConvertType(ResultType)));
}
if (Sel == ReleaseSel) {
return RValue::get(nullptr);
}
}
// 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 an illegal instruction trap on SPARC. With LLVM it corrupts
// the stack.
bool isPointerSizedReturn = (ResultType->isAnyPointerType() ||
ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType());
llvm::BasicBlock *startBB = nullptr;
llvm::BasicBlock *messageBB = nullptr;
llvm::BasicBlock *continueBB = nullptr;
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(CGF, Method);
else
cmd = GetSelector(CGF, Sel);
cmd = EnforceType(Builder, cmd, SelectorTy);
Receiver = EnforceType(Builder, Receiver, IdTy);
llvm::Metadata *impMD[] = {
llvm::MDString::get(VMContext, Sel.getAsString()),
llvm::MDString::get(VMContext, Class ? Class->getNameAsString() : ""),
llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
llvm::Type::getInt1Ty(VMContext), Class != nullptr))};
llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
CallArgList ActualArgs;
ActualArgs.add(RValue::get(Receiver), ASTIdTy);
ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
ActualArgs.addFrom(CallArgs);
MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
// Get the IMP to call
llvm::Value *imp;
// If we have non-legacy dispatch specified, we try using the objc_msgSend()
// functions. These are not supported on all platforms (or all runtimes on a
// given platform), so we
switch (CGM.getCodeGenOpts().getObjCDispatchMethod()) {
case CodeGenOptions::Legacy:
imp = LookupIMP(CGF, Receiver, cmd, node, MSI);
break;
case CodeGenOptions::Mixed:
case CodeGenOptions::NonLegacy:
if (CGM.ReturnTypeUsesFPRet(ResultType)) {
imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
"objc_msgSend_fpret");
} else if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) {
// The actual types here don't matter - we're going to bitcast the
// function anyway
imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
"objc_msgSend_stret");
} else {
imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
"objc_msgSend");
}
}
// Reset the receiver in case the lookup modified it
ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy, false);
imp = EnforceType(Builder, imp, MSI.MessengerType);
llvm::Instruction *call;
RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs, nullptr,
&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(), 2);
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(), 2);
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(), 2);
phi->addIncoming(v.first, messageBB);
phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()),
startBB);
llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2);
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(StringRef ClassName,
StringRef CategoryName,
ArrayRef<Selector> MethodSels,
ArrayRef<llvm::Constant *> MethodTypes,
bool isClassMethodList) {
if (MethodSels.empty())
return NULLPtr;
// Get the method structure type.
llvm::StructType *ObjCMethodTy = llvm::StructType::get(
PtrToInt8Ty, // Really a selector, but the runtime creates it us.
PtrToInt8Ty, // Method types
IMPTy, //Method pointer
nullptr);
std::vector<llvm::Constant*> Methods;
std::vector<llvm::Constant*> Elements;
for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) {
Elements.clear();
llvm::Constant *Method =
TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName,
MethodSels[i],
isClassMethodList));
assert(Method && "Can't generate metadata for method that doesn't exist");
llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString());
Elements.push_back(C);
Elements.push_back(MethodTypes[i]);
Method = llvm::ConstantExpr::getBitCast(Method,
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::StructType *ObjCMethodListTy = llvm::StructType::create(VMContext);
llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(ObjCMethodListTy);
ObjCMethodListTy->setBody(
NextPtrTy,
IntTy,
ObjCMethodArrayTy,
nullptr);
Methods.clear();
Methods.push_back(llvm::ConstantPointerNull::get(
llvm::PointerType::getUnqual(ObjCMethodListTy)));
Methods.push_back(llvm::ConstantInt::get(Int32Ty, 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(ArrayRef<llvm::Constant *> IvarNames,
ArrayRef<llvm::Constant *> IvarTypes,
ArrayRef<llvm::Constant *> IvarOffsets) {
if (IvarNames.size() == 0)
return NULLPtr;
// Get the method structure type.
llvm::StructType *ObjCIvarTy = llvm::StructType::get(
PtrToInt8Ty,
PtrToInt8Ty,
IntTy,
nullptr);
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(IntTy,
ObjCIvarArrayTy,
nullptr);
// 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,
llvm::Constant *StrongIvarBitmap,
llvm::Constant *WeakIvarBitmap,
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(
PtrToInt8Ty, // isa
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
IntPtrTy, // strong_pointers
IntPtrTy, // weak_pointers
nullptr);
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));
if (isMeta) {
llvm::DataLayout td(&TheModule);
Elements.push_back(
llvm::ConstantInt::get(LongTy,
td.getTypeSizeInBits(ClassTy) /
CGM.getContext().getCharWidth()));
} else
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(llvm::ConstantInt::get(LongTy, 1));
Elements.push_back(IvarOffsets);
Elements.push_back(Properties);
Elements.push_back(StrongIvarBitmap);
Elements.push_back(WeakIvarBitmap);
// 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. We may already have some weak references to
// this, so check and fix them properly.
std::string ClassSym((isMeta ? "_OBJC_METACLASS_": "_OBJC_CLASS_") +
std::string(Name));
llvm::GlobalVariable *ClassRef = TheModule.getNamedGlobal(ClassSym);
llvm::Constant *Class = MakeGlobal(ClassTy, Elements, ClassSym,
llvm::GlobalValue::ExternalLinkage);
if (ClassRef) {
ClassRef->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(Class,
ClassRef->getType()));
ClassRef->removeFromParent();
Class->setName(ClassSym);
}
return Class;
}
llvm::Constant *CGObjCGNU::
GenerateProtocolMethodList(ArrayRef<llvm::Constant *> MethodNames,
ArrayRef<llvm::Constant *> MethodTypes) {
// Get the method structure type.
llvm::StructType *ObjCMethodDescTy = llvm::StructType::get(
PtrToInt8Ty, // Really a selector, but the runtime does the casting for us.
PtrToInt8Ty,
nullptr);
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(
IntTy, ObjCMethodArrayTy, nullptr);
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(ArrayRef<std::string>Protocols){
llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty,
Protocols.size());
llvm::StructType *ProtocolListTy = llvm::StructType::get(
PtrTy, //Should be a recurisve pointer, but it's always NULL here.
SizeTy,
ProtocolArrayTy,
nullptr);
std::vector<llvm::Constant*> Elements;
for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end();
iter != endIter ; iter++) {
llvm::Constant *protocol = nullptr;
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(CodeGenFunction &CGF,
const ObjCProtocolDecl *PD) {
llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()];
llvm::Type *T =
CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType());
return CGF.Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T));
}
llvm::Constant *CGObjCGNU::GenerateEmptyProtocol(
const std::string &ProtocolName) {
SmallVector<std::string, 0> EmptyStringVector;
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(IdTy,
PtrToInt8Ty,
ProtocolList->getType(),
MethodList->getType(),
MethodList->getType(),
MethodList->getType(),
MethodList->getType(),
nullptr);
std::vector<llvm::Constant*> Elements;
// The isa pointer must be set to a magic number so the runtime knows it's
// the correct layout.
Elements.push_back(llvm::ConstantExpr::getIntToPtr(
llvm::ConstantInt::get(Int32Ty, ProtocolVersion), 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();
// Use the protocol definition, if there is one.
if (const ObjCProtocolDecl *Def = PD->getDefinition())
PD = Def;
SmallVector<std::string, 16> Protocols;
for (const auto *PI : PD->protocols())
Protocols.push_back(PI->getNameAsString());
SmallVector<llvm::Constant*, 16> InstanceMethodNames;
SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames;
SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes;
for (const auto *I : PD->instance_methods()) {
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(I, TypeStr);
if (I->getImplementationControl() == ObjCMethodDecl::Optional) {
OptionalInstanceMethodNames.push_back(
MakeConstantString(I->getSelector().getAsString()));
OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr));
} else {
InstanceMethodNames.push_back(
MakeConstantString(I->getSelector().getAsString()));
InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
}
}
// Collect information about class methods:
SmallVector<llvm::Constant*, 16> ClassMethodNames;
SmallVector<llvm::Constant*, 16> ClassMethodTypes;
SmallVector<llvm::Constant*, 16> OptionalClassMethodNames;
SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes;
for (const auto *I : PD->class_methods()) {
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(I,TypeStr);
if (I->getImplementationControl() == ObjCMethodDecl::Optional) {
OptionalClassMethodNames.push_back(
MakeConstantString(I->getSelector().getAsString()));
OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr));
} else {
ClassMethodNames.push_back(
MakeConstantString(I->getSelector().getAsString()));
ClassMethodTypes.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(
PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty,
PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, nullptr);
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 (auto *property : PD->properties()) {
std::vector<llvm::Constant*> Fields;
Fields.push_back(MakePropertyEncodingString(property, nullptr));
PushPropertyAttributes(Fields, property);
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::getAnon(PropertyListInitFields);
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::getAnon(OptionalPropertyListInitFields);
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(IdTy,
PtrToInt8Ty,
ProtocolList->getType(),
InstanceMethodList->getType(),
ClassMethodList->getType(),
OptionalInstanceMethodList->getType(),
OptionalClassMethodList->getType(),
PropertyList->getType(),
OptionalPropertyList->getType(),
nullptr);
std::vector<llvm::Constant*> Elements;
// The isa pointer must be set to a magic number so the runtime knows it's
// the correct layout.
Elements.push_back(llvm::ConstantExpr::getIntToPtr(
llvm::ConstantInt::get(Int32Ty, ProtocolVersion), 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() {
// Collect information about instance methods
SmallVector<Selector, 1> MethodSels;
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(
PtrTy, //Should be a recurisve pointer, but it's always NULL here.
SizeTy,
ProtocolArrayTy,
nullptr);
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(PtrToInt8Ty, PtrToInt8Ty,
PtrTy, PtrTy, PtrTy, nullptr), Elements), PtrTy));
}
/// Libobjc2 uses a bitfield representation where small(ish) bitfields are
/// stored in a 64-bit value with the low bit set to 1 and the remaining 63
/// bits set to their values, LSB first, while larger ones are stored in a
/// structure of this / form:
///
/// struct { int32_t length; int32_t values[length]; };
///
/// The values in the array are stored in host-endian format, with the least
/// significant bit being assumed to come first in the bitfield. Therefore, a
/// bitfield with the 64th bit set will be (int64_t)&{ 2, [0, 1<<31] }, while a
/// bitfield / with the 63rd bit set will be 1<<64.
llvm::Constant *CGObjCGNU::MakeBitField(ArrayRef<bool> bits) {
int bitCount = bits.size();
int ptrBits = CGM.getDataLayout().getPointerSizeInBits();
if (bitCount < ptrBits) {
uint64_t val = 1;
for (int i=0 ; i<bitCount ; ++i) {
if (bits[i]) val |= 1ULL<<(i+1);
}
return llvm::ConstantInt::get(IntPtrTy, val);
}
SmallVector<llvm::Constant *, 8> values;
int v=0;
while (v < bitCount) {
int32_t word = 0;
for (int i=0 ; (i<32) && (v<bitCount) ; ++i) {
if (bits[v]) word |= 1<<i;
v++;
}
values.push_back(llvm::ConstantInt::get(Int32Ty, word));
}
llvm::ArrayType *arrayTy = llvm::ArrayType::get(Int32Ty, values.size());
llvm::Constant *array = llvm::ConstantArray::get(arrayTy, values);
llvm::Constant *fields[2] = {
llvm::ConstantInt::get(Int32Ty, values.size()),
array };
llvm::Constant *GS = MakeGlobal(llvm::StructType::get(Int32Ty, arrayTy,
nullptr), fields);
llvm::Constant *ptr = llvm::ConstantExpr::getPtrToInt(GS, IntPtrTy);
return ptr;
}
void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) {
std::string ClassName = OCD->getClassInterface()->getNameAsString();
std::string CategoryName = OCD->getNameAsString();
// Collect information about instance methods
SmallVector<Selector, 16> InstanceMethodSels;
SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
for (const auto *I : OCD->instance_methods()) {
InstanceMethodSels.push_back(I->getSelector());
std::string TypeStr;
CGM.getContext().getObjCEncodingForMethodDecl(I,TypeStr);
InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
}
// Collect information about class methods
SmallVector<Selector, 16> ClassMethodSels;
SmallVector<llvm::Constant*, 16> ClassMethodTypes;
for (const auto *I : OCD->class_methods()) {
ClassMethodSels.push_back(I->getSelector());
std::string TypeStr;
CGM.getContext().getObjCEncodingForMethodDecl(I,TypeStr);
ClassMethodTypes.push_back(MakeConstantString(TypeStr));
}
// Collect the names of referenced protocols
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(PtrToInt8Ty, PtrToInt8Ty,
PtrTy, PtrTy, PtrTy, nullptr), Elements), PtrTy));
}
llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID,
SmallVectorImpl<Selector> &InstanceMethodSels,
SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) {
ASTContext &Context = CGM.getContext();
// Property metadata: name, attributes, attributes2, padding1, padding2,
// setter name, setter types, getter name, getter types.
llvm::StructType *PropertyMetadataTy = llvm::StructType::get(
PtrToInt8Ty, Int8Ty, Int8Ty, Int8Ty, Int8Ty, PtrToInt8Ty,
PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty, nullptr);
std::vector<llvm::Constant*> Properties;
// Add all of the property methods need adding to the method list and to the
// property metadata list.
for (auto *propertyImpl : OID->property_impls()) {
std::vector<llvm::Constant*> Fields;
ObjCPropertyDecl *property = propertyImpl->getPropertyDecl();
bool isSynthesized = (propertyImpl->getPropertyImplementation() ==
ObjCPropertyImplDecl::Synthesize);
bool isDynamic = (propertyImpl->getPropertyImplementation() ==
ObjCPropertyImplDecl::Dynamic);
Fields.push_back(MakePropertyEncodingString(property, OID));
PushPropertyAttributes(Fields, property, isSynthesized, isDynamic);
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::getAnon(PropertyListInitFields);
return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false,
llvm::GlobalValue::InternalLinkage, PropertyListInit,
".objc_property_list");
}
void CGObjCGNU::RegisterAlias(const ObjCCompatibleAliasDecl *OAD) {
// Get the class declaration for which the alias is specified.
ObjCInterfaceDecl *ClassDecl =
const_cast<ObjCInterfaceDecl *>(OAD->getClassInterface());
std::string ClassName = ClassDecl->getNameAsString();
std::string AliasName = OAD->getNameAsString();
ClassAliases.push_back(ClassAliasPair(ClassName,AliasName));
}
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().getQuantity();
// Collect information about instance variables.
SmallVector<llvm::Constant*, 16> IvarNames;
SmallVector<llvm::Constant*, 16> IvarTypes;
SmallVector<llvm::Constant*, 16> IvarOffsets;
std::vector<llvm::Constant*> IvarOffsetValues;
SmallVector<bool, 16> WeakIvars;
SmallVector<bool, 16> StrongIvars;
int superInstanceSize = !SuperClassDecl ? 0 :
Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity();
// 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.getLangOpts().ObjCRuntime.isNonFragile()) {
instanceSize = 0 - (instanceSize - superInstanceSize);
}
for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
IVD = IVD->getNextIvar()) {
// 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.getLangOpts().ObjCRuntime.isNonFragile()) {
Offset = BaseOffset - superInstanceSize;
}
llvm::Constant *OffsetValue = llvm::ConstantInt::get(IntTy, Offset);
// Create the direct offset value
std::string OffsetName = "__objc_ivar_offset_value_" + ClassName +"." +
IVD->getNameAsString();
llvm::GlobalVariable *OffsetVar = TheModule.getGlobalVariable(OffsetName);
if (OffsetVar) {
OffsetVar->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.
OffsetVar->setLinkage(llvm::GlobalValue::ExternalLinkage);
} else
OffsetVar = new llvm::GlobalVariable(TheModule, IntTy,
false, llvm::GlobalValue::ExternalLinkage,
OffsetValue,
"__objc_ivar_offset_value_" + ClassName +"." +
IVD->getNameAsString());
IvarOffsets.push_back(OffsetValue);
IvarOffsetValues.push_back(OffsetVar);
Qualifiers::ObjCLifetime lt = IVD->getType().getQualifiers().getObjCLifetime();
switch (lt) {
case Qualifiers::OCL_Strong:
StrongIvars.push_back(true);
WeakIvars.push_back(false);
break;
case Qualifiers::OCL_Weak:
StrongIvars.push_back(false);
WeakIvars.push_back(true);
break;
default:
StrongIvars.push_back(false);
WeakIvars.push_back(false);
}
}
llvm::Constant *StrongIvarBitmap = MakeBitField(StrongIvars);
llvm::Constant *WeakIvarBitmap = MakeBitField(WeakIvars);
llvm::GlobalVariable *IvarOffsetArray =
MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets");
// Collect information about instance methods
SmallVector<Selector, 16> InstanceMethodSels;
SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
for (const auto *I : OID->instance_methods()) {
InstanceMethodSels.push_back(I->getSelector());
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(I,TypeStr);
InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
}
llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels,
InstanceMethodTypes);
// Collect information about class methods
SmallVector<Selector, 16> ClassMethodSels;
SmallVector<llvm::Constant*, 16> ClassMethodTypes;
for (const auto *I : OID->class_methods()) {
ClassMethodSels.push_back(I->getSelector());
std::string TypeStr;
Context.getObjCEncodingForMethodDecl(I,TypeStr);
ClassMethodTypes.push_back(MakeConstantString(TypeStr));
}
// Collect the names of referenced protocols
SmallVector<std::string, 16> Protocols;
for (const auto *I : ClassDecl->protocols())
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
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)
llvm::Type *IndexTy = Int32Ty;
llvm::Constant *offsetPointerIndexes[] = {Zeros[0],
llvm::ConstantInt::get(IndexTy, 1), nullptr,
llvm::ConstantInt::get(IndexTy, 2) };
unsigned ivarIndex = 0;
for (const ObjCIvarDecl *IVD = ClassDecl->all_declared_ivar_begin(); IVD;
IVD = IVD->getNextIvar()) {
const std::string Name = "__objc_ivar_offset_" + ClassName + '.'
+ IVD->getNameAsString();
offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, ivarIndex);
// Get the correct ivar field
llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr(
cast<llvm::GlobalVariable>(IvarList)->getValueType(), IvarList,
offsetPointerIndexes);
// 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);
(void) offset; // Silence dead store warning.
}
++ivarIndex;
}
llvm::Constant *ZeroPtr = llvm::ConstantInt::get(IntPtrTy, 0);
//Generate metaclass for class methods
llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr,
NULLPtr, 0x12L, ClassName.c_str(), nullptr, Zeros[0], GenerateIvarList(
empty, empty, empty), ClassMethodList, NULLPtr,
NULLPtr, NULLPtr, ZeroPtr, ZeroPtr, true);
// Generate the class structure
llvm::Constant *ClassStruct =
GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L,
ClassName.c_str(), nullptr,
llvm::ConstantInt::get(LongTy, instanceSize), IvarList,
MethodList, GenerateProtocolList(Protocols), IvarOffsetArray,
Properties, StrongIvarBitmap, WeakIvarBitmap);
// Resolve the class aliases, if they exist.
if (ClassPtrAlias) {
ClassPtrAlias->replaceAllUsesWith(
llvm::ConstantExpr::getBitCast(ClassStruct, IdTy));
ClassPtrAlias->eraseFromParent();
ClassPtrAlias = nullptr;
}
if (MetaClassPtrAlias) {
MetaClassPtrAlias->replaceAllUsesWith(
llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy));
MetaClassPtrAlias->eraseFromParent();
MetaClassPtrAlias = nullptr;
}
// 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() && SelectorTable.empty())
return nullptr;
// Add all referenced protocols to a category.
GenerateProtocolHolderCategory();
llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>(
SelectorTy->getElementType());
llvm::Type *SelStructPtrTy = SelectorTy;
if (!SelStructTy) {
SelStructTy = llvm::StructType::get(PtrToInt8Ty, PtrToInt8Ty, nullptr);
SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy);
}
std::vector<llvm::Constant*> Elements;
llvm::Constant *Statics = NULLPtr;
// Generate statics list:
if (!ConstantStrings.empty()) {
llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty,
ConstantStrings.size() + 1);
ConstantStrings.push_back(NULLPtr);
StringRef StringClass = CGM.getLangOpts().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(PtrToInt8Ty, StaticsArrayTy, nullptr);
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(LongTy, SelStructPtrTy,
llvm::Type::getInt16Ty(VMContext),
llvm::Type::getInt16Ty(VMContext),
ClassListTy, nullptr);
Elements.clear();
// Pointer to an array of selectors used in this module.
std::vector<llvm::Constant*> Selectors;
std::vector<llvm::GlobalAlias*> SelectorAliases;
for (SelectorMap::iterator iter = SelectorTable.begin(),
iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) {
std::string SelNameStr = iter->first.getAsString();
llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name");
SmallVectorImpl<TypedSelector> &Types = iter->second;
for (SmallVectorImpl<TypedSelector>::iterator i = Types.begin(),
e = Types.end() ; i!=e ; i++) {
llvm::Constant *SelectorTypeEncoding = NULLPtr;
if (!i->first.empty())
SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types");
Elements.push_back(SelName);
Elements.push_back(SelectorTypeEncoding);
Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements));
Elements.clear();
// Store the selector alias for later replacement
SelectorAliases.push_back(i->second);
}
}
unsigned SelectorCount = Selectors.size();
// NULL-terminate the selector list. This should not actually be required,
// because the selector list has a length field. Unfortunately, the GCC
// runtime decides to ignore the length field and expects a NULL terminator,
// and GCC cooperates with this by always setting the length to 0.
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, SelectorCount));
llvm::GlobalVariable *SelectorList =
MakeGlobalArray(SelStructTy, Selectors, ".objc_selector_list");
Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList,
SelStructPtrTy));
// Now that all of the static selectors exist, create pointers to them.
for (unsigned int i=0 ; i<SelectorCount ; i++) {
llvm::Constant *Idxs[] = {Zeros[0],
llvm::ConstantInt::get(Int32Ty, i), Zeros[0]};
// FIXME: We're generating redundant loads and stores here!
llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(
SelectorList->getValueType(), SelectorList, makeArrayRef(Idxs, 2));
// If selectors are defined as an opaque type, cast the pointer to this
// type.
SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy);
SelectorAliases[i]->replaceAllUsesWith(SelPtr);
SelectorAliases[i]->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(LongTy, LongTy,
PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy),
(RuntimeVersion >= 10) ? IntTy : nullptr, nullptr);
Elements.clear();
// Runtime version, used for ABI compatibility checking.
Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion));
// sizeof(ModuleTy)
llvm::DataLayout td(&TheModule);
Elements.push_back(
llvm::ConstantInt::get(LongTy,
td.getTypeSizeInBits(ModuleTy) /
CGM.getContext().getCharWidth()));
// The path to the source file where this module was declared
SourceManager &SM = CGM.getContext().getSourceManager();
const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID());
std::string path =
std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName();
Elements.push_back(MakeConstantString(path, ".objc_source_file_name"));
Elements.push_back(SymTab);
if (RuntimeVersion >= 10)
switch (CGM.getLangOpts().getGC()) {
case LangOptions::GCOnly:
Elements.push_back(llvm::ConstantInt::get(IntTy, 2));
break;
case LangOptions::NonGC:
if (CGM.getLangOpts().ObjCAutoRefCount)
Elements.push_back(llvm::ConstantInt::get(IntTy, 1));
else
Elements.push_back(llvm::ConstantInt::get(IntTy, 0));
break;
case LangOptions::HybridGC:
Elements.push_back(llvm::ConstantInt::get(IntTy, 1));
break;
}
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);
llvm::FunctionType *FT =
llvm::FunctionType::get(Builder.getVoidTy(),
llvm::PointerType::getUnqual(ModuleTy), true);
llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class");
Builder.CreateCall(Register, Module);
if (!ClassAliases.empty()) {
llvm::Type *ArgTypes[2] = {PtrTy, PtrToInt8Ty};
llvm::FunctionType *RegisterAliasTy =
llvm::FunctionType::get(Builder.getVoidTy(),
ArgTypes, false);
llvm::Function *RegisterAlias = llvm::Function::Create(
RegisterAliasTy,
llvm::GlobalValue::ExternalWeakLinkage, "class_registerAlias_np",
&TheModule);
llvm::BasicBlock *AliasBB =
llvm::BasicBlock::Create(VMContext, "alias", LoadFunction);
llvm::BasicBlock *NoAliasBB =
llvm::BasicBlock::Create(VMContext, "no_alias", LoadFunction);
// Branch based on whether the runtime provided class_registerAlias_np()
llvm::Value *HasRegisterAlias = Builder.CreateICmpNE(RegisterAlias,
llvm::Constant::getNullValue(RegisterAlias->getType()));
Builder.CreateCondBr(HasRegisterAlias, AliasBB, NoAliasBB);
// The true branch (has alias registration function):
Builder.SetInsertPoint(AliasBB);
// Emit alias registration calls:
for (std::vector<ClassAliasPair>::iterator iter = ClassAliases.begin();
iter != ClassAliases.end(); ++iter) {
llvm::Constant *TheClass =
TheModule.getGlobalVariable(("_OBJC_CLASS_" + iter->first).c_str(),
true);
if (TheClass) {
TheClass = llvm::ConstantExpr::getBitCast(TheClass, PtrTy);
Builder.CreateCall2(RegisterAlias, TheClass,
MakeConstantString(iter->second));
}
}
// Jump to end:
Builder.CreateBr(NoAliasBB);
// Missing alias registration function, just return from the function:
Builder.SetInsertPoint(NoAliasBB);
}
Builder.CreateRetVoid();
return LoadFunction;
}
llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD,
const ObjCContainerDecl *CD) {
const ObjCCategoryImplDecl *OCD =
dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext());
StringRef CategoryName = OCD ? OCD->getName() : "";
StringRef ClassName = CD->getName();
Selector MethodName = OMD->getSelector();
bool isClassMethod = !OMD->isInstanceMethod();
CodeGenTypes &Types = CGM.getTypes();
llvm::FunctionType *MethodTy =
Types.GetFunctionType(Types.arrangeObjCMethodDeclaration(OMD));
std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName,
MethodName, isClassMethod);
llvm::Function *Method
= llvm::Function::Create(MethodTy,
llvm::GlobalValue::InternalLinkage,
FunctionName,
&TheModule);
return Method;
}
llvm::Constant *CGObjCGNU::GetPropertyGetFunction() {
return GetPropertyFn;
}
llvm::Constant *CGObjCGNU::GetPropertySetFunction() {
return SetPropertyFn;
}
llvm::Constant *CGObjCGNU::GetOptimizedPropertySetFunction(bool atomic,
bool copy) {
return nullptr;
}
llvm::Constant *CGObjCGNU::GetGetStructFunction() {
return GetStructPropertyFn;
}
llvm::Constant *CGObjCGNU::GetSetStructFunction() {
return SetStructPropertyFn;
}
llvm::Constant *CGObjCGNU::GetCppAtomicObjectGetFunction() {
return nullptr;
}
llvm::Constant *CGObjCGNU::GetCppAtomicObjectSetFunction() {
return nullptr;
}
llvm::Constant *CGObjCGNU::EnumerationMutationFunction() {
return EnumerationMutationFn;
}
void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF,
const ObjCAtSynchronizedStmt &S) {
EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn);
}
void CGObjCGNU::EmitTryStmt(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.
//
// In Objective-C++ mode, we actually emit something equivalent to the C++
// exception handler.
EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn);
return ;
}
void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF,
const ObjCAtThrowStmt &S,
bool ClearInsertionPoint) {
llvm::Value *ExceptionAsObject;
if (const Expr *ThrowExpr = S.getThrowExpr()) {
llvm::Value *Exception = CGF.EmitObjCThrowOperand(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);
llvm::CallSite Throw =
CGF.EmitRuntimeCallOrInvoke(ExceptionThrowFn, ExceptionAsObject);
Throw.setDoesNotReturn();
CGF.Builder.CreateUnreachable();
if (ClearInsertionPoint)
CGF.Builder.ClearInsertionPoint();
}
llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF,
llvm::Value *AddrWeakObj) {
CGBuilderTy &B = CGF.Builder;
AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy);
return B.CreateCall(WeakReadFn, AddrWeakObj);
}
void CGObjCGNU::EmitObjCWeakAssign(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(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
llvm_unreachable("EmitObjCGlobalAssign - Threal Local API NYI");
}
void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF,
llvm::Value *src, llvm::Value *dst,
llvm::Value *ivarOffset) {
CGBuilderTy &B = CGF.Builder;
src = EnforceType(B, src, IdTy);
dst = EnforceType(B, dst, IdTy);
B.CreateCall3(IvarAssignFn, src, dst, ivarOffset);
}
void CGObjCGNU::EmitObjCStrongCastAssign(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(CodeGenFunction &CGF,
llvm::Value *DestPtr,
llvm::Value *SrcPtr,
llvm::Value *Size) {
CGBuilderTy &B = CGF.Builder;
DestPtr = EnforceType(B, DestPtr, PtrTy);
SrcPtr = EnforceType(B, SrcPtr, PtrTy);
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(Int32Ty, Offset,
/*isSigned*/true);
// 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.getLangOpts().PICLevel || CGM.getLangOpts().PIELevel) {
llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule,
Int32Ty, 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, nullptr, Name);
}
}
return IvarOffsetPointer;
}
LValue CGObjCGNU::EmitObjCValueForIvar(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) {
for (const ObjCIvarDecl *next = OID->all_declared_ivar_begin(); next;
next = next->getNextIvar()) {
if (OIVD == next)
return OID;
}
// Otherwise check in the super class.
if (const ObjCInterfaceDecl *Super = OID->getSuperClass())
return FindIvarInterface(Context, Super, OIVD);
return nullptr;
}
llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF,
const ObjCInterfaceDecl *Interface,
const ObjCIvarDecl *Ivar) {
if (CGM.getLangOpts().ObjCRuntime.isNonFragile()) {
Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar);
if (RuntimeVersion < 10)
return CGF.Builder.CreateZExtOrBitCast(
CGF.Builder.CreateLoad(CGF.Builder.CreateLoad(
ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")),
PtrDiffTy);
std::string name = "__objc_ivar_offset_value_" +
Interface->getNameAsString() +"." + Ivar->getNameAsString();
llvm::Value *Offset = TheModule.getGlobalVariable(name);
if (!Offset)
Offset = new llvm::GlobalVariable(TheModule, IntTy,
false, llvm::GlobalValue::LinkOnceAnyLinkage,
llvm::Constant::getNullValue(IntTy), name);
Offset = CGF.Builder.CreateLoad(Offset);
if (Offset->getType() != PtrDiffTy)
Offset = CGF.Builder.CreateZExtOrBitCast(Offset, PtrDiffTy);
return Offset;
}
uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar);
return llvm::ConstantInt::get(PtrDiffTy, Offset, /*isSigned*/true);
}
CGObjCRuntime *
clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) {
switch (CGM.getLangOpts().ObjCRuntime.getKind()) {
case ObjCRuntime::GNUstep:
return new CGObjCGNUstep(CGM);
case ObjCRuntime::GCC:
return new CGObjCGCC(CGM);
case ObjCRuntime::ObjFW:
return new CGObjCObjFW(CGM);
case ObjCRuntime::FragileMacOSX:
case ObjCRuntime::MacOSX:
case ObjCRuntime::iOS:
llvm_unreachable("these runtimes are not GNU runtimes");
}
llvm_unreachable("bad runtime");
}
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