1226031Sstas//===----- CGObjCRuntime.h - Interface to ObjC Runtimes ---------*- C++ -*-===// 2226031Sstas// 3226031Sstas// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4226031Sstas// See https://llvm.org/LICENSE.txt for license information. 5226031Sstas// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6226031Sstas// 7226031Sstas//===----------------------------------------------------------------------===// 8226031Sstas// 9226031Sstas// This provides an abstract class for Objective-C code generation. Concrete 10226031Sstas// subclasses of this implement code generation for specific Objective-C 11226031Sstas// runtime libraries. 12226031Sstas// 13226031Sstas//===----------------------------------------------------------------------===// 14226031Sstas 15226031Sstas#ifndef LLVM_CLANG_LIB_CODEGEN_CGOBJCRUNTIME_H 16226031Sstas#define LLVM_CLANG_LIB_CODEGEN_CGOBJCRUNTIME_H 17226031Sstas#include "CGBuilder.h" 18226031Sstas#include "CGCall.h" 19226031Sstas#include "CGCleanup.h" 20226031Sstas#include "CGValue.h" 21226031Sstas#include "clang/AST/DeclObjC.h" 22226031Sstas#include "clang/Basic/IdentifierTable.h" // Selector 23226031Sstas#include "llvm/ADT/UniqueVector.h" 24226031Sstas 25226031Sstasnamespace llvm { 26226031Sstas class Constant; 27226031Sstas class Function; 28226031Sstas class Module; 29226031Sstas class StructLayout; 30226031Sstas class StructType; 31226031Sstas class Type; 32226031Sstas class Value; 33226031Sstas} 34226031Sstas 35226031Sstasnamespace clang { 36226031Sstasnamespace CodeGen { 37226031Sstas class CodeGenFunction; 38226031Sstas} 39226031Sstas 40226031Sstas class FieldDecl; 41226031Sstas class ObjCAtTryStmt; 42226031Sstas class ObjCAtThrowStmt; 43226031Sstas class ObjCAtSynchronizedStmt; 44226031Sstas class ObjCContainerDecl; 45226031Sstas class ObjCCategoryImplDecl; 46226031Sstas class ObjCImplementationDecl; 47226031Sstas class ObjCInterfaceDecl; 48226031Sstas class ObjCMessageExpr; 49226031Sstas class ObjCMethodDecl; 50226031Sstas class ObjCProtocolDecl; 51226031Sstas class Selector; 52226031Sstas class ObjCIvarDecl; 53226031Sstas class ObjCStringLiteral; 54226031Sstas class BlockDeclRefExpr; 55226031Sstas 56226031Sstasnamespace CodeGen { 57226031Sstas class CodeGenModule; 58226031Sstas class CGBlockInfo; 59226031Sstas 60226031Sstas// FIXME: Several methods should be pure virtual but aren't to avoid the 61226031Sstas// partially-implemented subclass breaking. 62226031Sstas 63226031Sstas/// Implements runtime-specific code generation functions. 64226031Sstasclass CGObjCRuntime { 65226031Sstasprotected: 66226031Sstas CodeGen::CodeGenModule &CGM; 67226031Sstas CGObjCRuntime(CodeGen::CodeGenModule &CGM) : CGM(CGM) {} 68226031Sstas 69226031Sstas // Utility functions for unified ivar access. These need to 70226031Sstas // eventually be folded into other places (the structure layout 71226031Sstas // code). 72226031Sstas 73226031Sstas /// Compute an offset to the given ivar, suitable for passing to 74226031Sstas /// EmitValueForIvarAtOffset. Note that the correct handling of 75226031Sstas /// bit-fields is carefully coordinated by these two, use caution! 76226031Sstas /// 77226031Sstas /// The latter overload is suitable for computing the offset of a 78226031Sstas /// sythesized ivar. 79226031Sstas uint64_t ComputeIvarBaseOffset(CodeGen::CodeGenModule &CGM, 80226031Sstas const ObjCInterfaceDecl *OID, 81226031Sstas const ObjCIvarDecl *Ivar); 82226031Sstas uint64_t ComputeIvarBaseOffset(CodeGen::CodeGenModule &CGM, 83226031Sstas const ObjCImplementationDecl *OID, 84226031Sstas const ObjCIvarDecl *Ivar); 85226031Sstas 86226031Sstas LValue EmitValueForIvarAtOffset(CodeGen::CodeGenFunction &CGF, 87226031Sstas const ObjCInterfaceDecl *OID, 88226031Sstas llvm::Value *BaseValue, 89226031Sstas const ObjCIvarDecl *Ivar, 90226031Sstas unsigned CVRQualifiers, 91226031Sstas llvm::Value *Offset); 92 /// Emits a try / catch statement. This function is intended to be called by 93 /// subclasses, and provides a generic mechanism for generating these, which 94 /// should be usable by all runtimes. The caller must provide the functions 95 /// to call when entering and exiting a \@catch() block, and the function 96 /// used to rethrow exceptions. If the begin and end catch functions are 97 /// NULL, then the function assumes that the EH personality function provides 98 /// the thrown object directly. 99 void EmitTryCatchStmt(CodeGenFunction &CGF, const ObjCAtTryStmt &S, 100 llvm::FunctionCallee beginCatchFn, 101 llvm::FunctionCallee endCatchFn, 102 llvm::FunctionCallee exceptionRethrowFn); 103 104 void EmitInitOfCatchParam(CodeGenFunction &CGF, llvm::Value *exn, 105 const VarDecl *paramDecl); 106 107 /// Emits an \@synchronize() statement, using the \p syncEnterFn and 108 /// \p syncExitFn arguments as the functions called to lock and unlock 109 /// the object. This function can be called by subclasses that use 110 /// zero-cost exception handling. 111 void EmitAtSynchronizedStmt(CodeGenFunction &CGF, 112 const ObjCAtSynchronizedStmt &S, 113 llvm::FunctionCallee syncEnterFn, 114 llvm::FunctionCallee syncExitFn); 115 116public: 117 virtual ~CGObjCRuntime(); 118 119 std::string getSymbolNameForMethod(const ObjCMethodDecl *method, 120 bool includeCategoryName = true); 121 122 /// Generate the function required to register all Objective-C components in 123 /// this compilation unit with the runtime library. 124 virtual llvm::Function *ModuleInitFunction() = 0; 125 126 /// Get a selector for the specified name and type values. 127 /// The result should have the LLVM type for ASTContext::getObjCSelType(). 128 virtual llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel) = 0; 129 130 /// Get the address of a selector for the specified name and type values. 131 /// This is a rarely-used language extension, but sadly it exists. 132 /// 133 /// The result should have the LLVM type for a pointer to 134 /// ASTContext::getObjCSelType(). 135 virtual Address GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) = 0; 136 137 /// Get a typed selector. 138 virtual llvm::Value *GetSelector(CodeGenFunction &CGF, 139 const ObjCMethodDecl *Method) = 0; 140 141 /// Get the type constant to catch for the given ObjC pointer type. 142 /// This is used externally to implement catching ObjC types in C++. 143 /// Runtimes which don't support this should add the appropriate 144 /// error to Sema. 145 virtual llvm::Constant *GetEHType(QualType T) = 0; 146 147 virtual CatchTypeInfo getCatchAllTypeInfo() { return { nullptr, 0 }; } 148 149 /// Generate a constant string object. 150 virtual ConstantAddress GenerateConstantString(const StringLiteral *) = 0; 151 152 /// Generate a category. A category contains a list of methods (and 153 /// accompanying metadata) and a list of protocols. 154 virtual void GenerateCategory(const ObjCCategoryImplDecl *OCD) = 0; 155 156 /// Generate a class structure for this class. 157 virtual void GenerateClass(const ObjCImplementationDecl *OID) = 0; 158 159 /// Register an class alias. 160 virtual void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) = 0; 161 162 /// Generate an Objective-C message send operation. 163 /// 164 /// \param Method - The method being called, this may be null if synthesizing 165 /// a property setter or getter. 166 virtual CodeGen::RValue 167 GenerateMessageSend(CodeGen::CodeGenFunction &CGF, 168 ReturnValueSlot ReturnSlot, 169 QualType ResultType, 170 Selector Sel, 171 llvm::Value *Receiver, 172 const CallArgList &CallArgs, 173 const ObjCInterfaceDecl *Class = nullptr, 174 const ObjCMethodDecl *Method = nullptr) = 0; 175 176 /// Generate an Objective-C message send operation. 177 /// 178 /// This variant allows for the call to be substituted with an optimized 179 /// variant. 180 CodeGen::RValue 181 GeneratePossiblySpecializedMessageSend(CodeGenFunction &CGF, 182 ReturnValueSlot Return, 183 QualType ResultType, 184 Selector Sel, 185 llvm::Value *Receiver, 186 const CallArgList& Args, 187 const ObjCInterfaceDecl *OID, 188 const ObjCMethodDecl *Method, 189 bool isClassMessage); 190 191 /// Generate an Objective-C message send operation to the super 192 /// class initiated in a method for Class and with the given Self 193 /// object. 194 /// 195 /// \param Method - The method being called, this may be null if synthesizing 196 /// a property setter or getter. 197 virtual CodeGen::RValue 198 GenerateMessageSendSuper(CodeGen::CodeGenFunction &CGF, 199 ReturnValueSlot ReturnSlot, 200 QualType ResultType, 201 Selector Sel, 202 const ObjCInterfaceDecl *Class, 203 bool isCategoryImpl, 204 llvm::Value *Self, 205 bool IsClassMessage, 206 const CallArgList &CallArgs, 207 const ObjCMethodDecl *Method = nullptr) = 0; 208 209 /// Walk the list of protocol references from a class, category or 210 /// protocol to traverse the DAG formed from it's inheritance hierarchy. Find 211 /// the list of protocols that ends each walk at either a runtime 212 /// protocol or a non-runtime protocol with no parents. For the common case of 213 /// just a list of standard runtime protocols this just returns the same list 214 /// that was passed in. 215 std::vector<const ObjCProtocolDecl *> 216 GetRuntimeProtocolList(ObjCProtocolDecl::protocol_iterator begin, 217 ObjCProtocolDecl::protocol_iterator end); 218 219 /// Emit the code to return the named protocol as an object, as in a 220 /// \@protocol expression. 221 virtual llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF, 222 const ObjCProtocolDecl *OPD) = 0; 223 224 /// Generate the named protocol. Protocols contain method metadata but no 225 /// implementations. 226 virtual void GenerateProtocol(const ObjCProtocolDecl *OPD) = 0; 227 228 /// GetOrEmitProtocol - Get the protocol object for the given 229 /// declaration, emitting it if necessary. The return value has type 230 /// ProtocolPtrTy. 231 virtual llvm::Constant *GetOrEmitProtocol(const ObjCProtocolDecl *PD) = 0; 232 233 /// Generate a function preamble for a method with the specified 234 /// types. 235 236 // FIXME: Current this just generates the Function definition, but really this 237 // should also be generating the loads of the parameters, as the runtime 238 // should have full control over how parameters are passed. 239 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 240 const ObjCContainerDecl *CD) = 0; 241 242 /// Generates prologue for direct Objective-C Methods. 243 virtual void GenerateDirectMethodPrologue(CodeGenFunction &CGF, 244 llvm::Function *Fn, 245 const ObjCMethodDecl *OMD, 246 const ObjCContainerDecl *CD) = 0; 247 248 /// Return the runtime function for getting properties. 249 virtual llvm::FunctionCallee GetPropertyGetFunction() = 0; 250 251 /// Return the runtime function for setting properties. 252 virtual llvm::FunctionCallee GetPropertySetFunction() = 0; 253 254 /// Return the runtime function for optimized setting properties. 255 virtual llvm::FunctionCallee GetOptimizedPropertySetFunction(bool atomic, 256 bool copy) = 0; 257 258 // API for atomic copying of qualified aggregates in getter. 259 virtual llvm::FunctionCallee GetGetStructFunction() = 0; 260 // API for atomic copying of qualified aggregates in setter. 261 virtual llvm::FunctionCallee GetSetStructFunction() = 0; 262 /// API for atomic copying of qualified aggregates with non-trivial copy 263 /// assignment (c++) in setter. 264 virtual llvm::FunctionCallee GetCppAtomicObjectSetFunction() = 0; 265 /// API for atomic copying of qualified aggregates with non-trivial copy 266 /// assignment (c++) in getter. 267 virtual llvm::FunctionCallee GetCppAtomicObjectGetFunction() = 0; 268 269 /// GetClass - Return a reference to the class for the given 270 /// interface decl. 271 virtual llvm::Value *GetClass(CodeGenFunction &CGF, 272 const ObjCInterfaceDecl *OID) = 0; 273 274 275 virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) { 276 llvm_unreachable("autoreleasepool unsupported in this ABI"); 277 } 278 279 /// EnumerationMutationFunction - Return the function that's called by the 280 /// compiler when a mutation is detected during foreach iteration. 281 virtual llvm::FunctionCallee EnumerationMutationFunction() = 0; 282 283 virtual void EmitSynchronizedStmt(CodeGen::CodeGenFunction &CGF, 284 const ObjCAtSynchronizedStmt &S) = 0; 285 virtual void EmitTryStmt(CodeGen::CodeGenFunction &CGF, 286 const ObjCAtTryStmt &S) = 0; 287 virtual void EmitThrowStmt(CodeGen::CodeGenFunction &CGF, 288 const ObjCAtThrowStmt &S, 289 bool ClearInsertionPoint=true) = 0; 290 virtual llvm::Value *EmitObjCWeakRead(CodeGen::CodeGenFunction &CGF, 291 Address AddrWeakObj) = 0; 292 virtual void EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF, 293 llvm::Value *src, Address dest) = 0; 294 virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF, 295 llvm::Value *src, Address dest, 296 bool threadlocal=false) = 0; 297 virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF, 298 llvm::Value *src, Address dest, 299 llvm::Value *ivarOffset) = 0; 300 virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF, 301 llvm::Value *src, Address dest) = 0; 302 303 virtual LValue EmitObjCValueForIvar(CodeGen::CodeGenFunction &CGF, 304 QualType ObjectTy, 305 llvm::Value *BaseValue, 306 const ObjCIvarDecl *Ivar, 307 unsigned CVRQualifiers) = 0; 308 virtual llvm::Value *EmitIvarOffset(CodeGen::CodeGenFunction &CGF, 309 const ObjCInterfaceDecl *Interface, 310 const ObjCIvarDecl *Ivar) = 0; 311 virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF, 312 Address DestPtr, 313 Address SrcPtr, 314 llvm::Value *Size) = 0; 315 virtual llvm::Constant *BuildGCBlockLayout(CodeGen::CodeGenModule &CGM, 316 const CodeGen::CGBlockInfo &blockInfo) = 0; 317 virtual llvm::Constant *BuildRCBlockLayout(CodeGen::CodeGenModule &CGM, 318 const CodeGen::CGBlockInfo &blockInfo) = 0; 319 virtual std::string getRCBlockLayoutStr(CodeGen::CodeGenModule &CGM, 320 const CGBlockInfo &blockInfo) { 321 return {}; 322 } 323 324 /// Returns an i8* which points to the byref layout information. 325 virtual llvm::Constant *BuildByrefLayout(CodeGen::CodeGenModule &CGM, 326 QualType T) = 0; 327 328 struct MessageSendInfo { 329 const CGFunctionInfo &CallInfo; 330 llvm::PointerType *MessengerType; 331 332 MessageSendInfo(const CGFunctionInfo &callInfo, 333 llvm::PointerType *messengerType) 334 : CallInfo(callInfo), MessengerType(messengerType) {} 335 }; 336 337 MessageSendInfo getMessageSendInfo(const ObjCMethodDecl *method, 338 QualType resultType, 339 CallArgList &callArgs); 340 341 // FIXME: This probably shouldn't be here, but the code to compute 342 // it is here. 343 unsigned ComputeBitfieldBitOffset(CodeGen::CodeGenModule &CGM, 344 const ObjCInterfaceDecl *ID, 345 const ObjCIvarDecl *Ivar); 346}; 347 348/// Creates an instance of an Objective-C runtime class. 349//TODO: This should include some way of selecting which runtime to target. 350CGObjCRuntime *CreateGNUObjCRuntime(CodeGenModule &CGM); 351CGObjCRuntime *CreateMacObjCRuntime(CodeGenModule &CGM); 352} 353} 354#endif 355