1 //===----- CGObjCRuntime.h - Interface to ObjC Runtimes ---------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This provides an abstract class for Objective-C code generation. Concrete 11 // subclasses of this implement code generation for specific Objective-C 12 // runtime libraries. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_CLANG_LIB_CODEGEN_CGOBJCRUNTIME_H 17 #define LLVM_CLANG_LIB_CODEGEN_CGOBJCRUNTIME_H 18 #include "CGBuilder.h" 19 #include "CGCall.h" 20 #include "CGValue.h" 21 #include "clang/AST/DeclObjC.h" 22 #include "clang/Basic/IdentifierTable.h" // Selector 23 24 namespace llvm { 25 class Constant; 26 class Function; 27 class Module; 28 class StructLayout; 29 class StructType; 30 class Type; 31 class Value; 32 } 33 34 namespace clang { 35 namespace CodeGen { 36 class CodeGenFunction; 37 } 38 39 class FieldDecl; 40 class ObjCAtTryStmt; 41 class ObjCAtThrowStmt; 42 class ObjCAtSynchronizedStmt; 43 class ObjCContainerDecl; 44 class ObjCCategoryImplDecl; 45 class ObjCImplementationDecl; 46 class ObjCInterfaceDecl; 47 class ObjCMessageExpr; 48 class ObjCMethodDecl; 49 class ObjCProtocolDecl; 50 class Selector; 51 class ObjCIvarDecl; 52 class ObjCStringLiteral; 53 class BlockDeclRefExpr; 54 55 namespace CodeGen { 56 class CodeGenModule; 57 class CGBlockInfo; 58 59 // FIXME: Several methods should be pure virtual but aren't to avoid the 60 // partially-implemented subclass breaking. 61 62 /// Implements runtime-specific code generation functions. 63 class CGObjCRuntime { 64 protected: 65 CodeGen::CodeGenModule &CGM; 66 CGObjCRuntime(CodeGen::CodeGenModule &CGM) : CGM(CGM) {} 67 68 // Utility functions for unified ivar access. These need to 69 // eventually be folded into other places (the structure layout 70 // code). 71 72 /// Compute an offset to the given ivar, suitable for passing to 73 /// EmitValueForIvarAtOffset. Note that the correct handling of 74 /// bit-fields is carefully coordinated by these two, use caution! 75 /// 76 /// The latter overload is suitable for computing the offset of a 77 /// sythesized ivar. 78 uint64_t ComputeIvarBaseOffset(CodeGen::CodeGenModule &CGM, 79 const ObjCInterfaceDecl *OID, 80 const ObjCIvarDecl *Ivar); 81 uint64_t ComputeIvarBaseOffset(CodeGen::CodeGenModule &CGM, 82 const ObjCImplementationDecl *OID, 83 const ObjCIvarDecl *Ivar); 84 85 LValue EmitValueForIvarAtOffset(CodeGen::CodeGenFunction &CGF, 86 const ObjCInterfaceDecl *OID, 87 llvm::Value *BaseValue, 88 const ObjCIvarDecl *Ivar, 89 unsigned CVRQualifiers, 90 llvm::Value *Offset); 91 /// Emits a try / catch statement. This function is intended to be called by 92 /// subclasses, and provides a generic mechanism for generating these, which 93 /// should be usable by all runtimes. The caller must provide the functions 94 /// to call when entering and exiting a \@catch() block, and the function 95 /// used to rethrow exceptions. If the begin and end catch functions are 96 /// NULL, then the function assumes that the EH personality function provides 97 /// the thrown object directly. 98 void EmitTryCatchStmt(CodeGenFunction &CGF, 99 const ObjCAtTryStmt &S, 100 llvm::Constant *beginCatchFn, 101 llvm::Constant *endCatchFn, 102 llvm::Constant *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::Function *syncEnterFn, 114 llvm::Function *syncExitFn); 115 116 public: 117 virtual ~CGObjCRuntime(); 118 119 /// Generate the function required to register all Objective-C components in 120 /// this compilation unit with the runtime library. 121 virtual llvm::Function *ModuleInitFunction() = 0; 122 123 /// Get a selector for the specified name and type values. 124 /// The result should have the LLVM type for ASTContext::getObjCSelType(). 125 virtual llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel) = 0; 126 127 /// Get the address of a selector for the specified name and type values. 128 /// This is a rarely-used language extension, but sadly it exists. 129 /// 130 /// The result should have the LLVM type for a pointer to 131 /// ASTContext::getObjCSelType(). 132 virtual Address GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) = 0; 133 134 /// Get a typed selector. 135 virtual llvm::Value *GetSelector(CodeGenFunction &CGF, 136 const ObjCMethodDecl *Method) = 0; 137 138 /// Get the type constant to catch for the given ObjC pointer type. 139 /// This is used externally to implement catching ObjC types in C++. 140 /// Runtimes which don't support this should add the appropriate 141 /// error to Sema. 142 virtual llvm::Constant *GetEHType(QualType T) = 0; 143 144 /// Generate a constant string object. 145 virtual ConstantAddress GenerateConstantString(const StringLiteral *) = 0; 146 147 /// Generate a category. A category contains a list of methods (and 148 /// accompanying metadata) and a list of protocols. 149 virtual void GenerateCategory(const ObjCCategoryImplDecl *OCD) = 0; 150 151 /// Generate a class structure for this class. 152 virtual void GenerateClass(const ObjCImplementationDecl *OID) = 0; 153 154 /// Register an class alias. 155 virtual void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) = 0; 156 157 /// Generate an Objective-C message send operation. 158 /// 159 /// \param Method - The method being called, this may be null if synthesizing 160 /// a property setter or getter. 161 virtual CodeGen::RValue 162 GenerateMessageSend(CodeGen::CodeGenFunction &CGF, 163 ReturnValueSlot ReturnSlot, 164 QualType ResultType, 165 Selector Sel, 166 llvm::Value *Receiver, 167 const CallArgList &CallArgs, 168 const ObjCInterfaceDecl *Class = nullptr, 169 const ObjCMethodDecl *Method = nullptr) = 0; 170 171 /// Generate an Objective-C message send operation to the super 172 /// class initiated in a method for Class and with the given Self 173 /// object. 174 /// 175 /// \param Method - The method being called, this may be null if synthesizing 176 /// a property setter or getter. 177 virtual CodeGen::RValue 178 GenerateMessageSendSuper(CodeGen::CodeGenFunction &CGF, 179 ReturnValueSlot ReturnSlot, 180 QualType ResultType, 181 Selector Sel, 182 const ObjCInterfaceDecl *Class, 183 bool isCategoryImpl, 184 llvm::Value *Self, 185 bool IsClassMessage, 186 const CallArgList &CallArgs, 187 const ObjCMethodDecl *Method = nullptr) = 0; 188 189 /// Emit the code to return the named protocol as an object, as in a 190 /// \@protocol expression. 191 virtual llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF, 192 const ObjCProtocolDecl *OPD) = 0; 193 194 /// Generate the named protocol. Protocols contain method metadata but no 195 /// implementations. 196 virtual void GenerateProtocol(const ObjCProtocolDecl *OPD) = 0; 197 198 /// Generate a function preamble for a method with the specified 199 /// types. 200 201 // FIXME: Current this just generates the Function definition, but really this 202 // should also be generating the loads of the parameters, as the runtime 203 // should have full control over how parameters are passed. 204 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 205 const ObjCContainerDecl *CD) = 0; 206 207 /// Return the runtime function for getting properties. 208 virtual llvm::Constant *GetPropertyGetFunction() = 0; 209 210 /// Return the runtime function for setting properties. 211 virtual llvm::Constant *GetPropertySetFunction() = 0; 212 213 /// Return the runtime function for optimized setting properties. 214 virtual llvm::Constant *GetOptimizedPropertySetFunction(bool atomic, 215 bool copy) = 0; 216 217 // API for atomic copying of qualified aggregates in getter. 218 virtual llvm::Constant *GetGetStructFunction() = 0; 219 // API for atomic copying of qualified aggregates in setter. 220 virtual llvm::Constant *GetSetStructFunction() = 0; 221 /// API for atomic copying of qualified aggregates with non-trivial copy 222 /// assignment (c++) in setter. 223 virtual llvm::Constant *GetCppAtomicObjectSetFunction() = 0; 224 /// API for atomic copying of qualified aggregates with non-trivial copy 225 /// assignment (c++) in getter. 226 virtual llvm::Constant *GetCppAtomicObjectGetFunction() = 0; 227 228 /// GetClass - Return a reference to the class for the given 229 /// interface decl. 230 virtual llvm::Value *GetClass(CodeGenFunction &CGF, 231 const ObjCInterfaceDecl *OID) = 0; 232 233 234 virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) { 235 llvm_unreachable("autoreleasepool unsupported in this ABI"); 236 } 237 238 /// EnumerationMutationFunction - Return the function that's called by the 239 /// compiler when a mutation is detected during foreach iteration. 240 virtual llvm::Constant *EnumerationMutationFunction() = 0; 241 242 virtual void EmitSynchronizedStmt(CodeGen::CodeGenFunction &CGF, 243 const ObjCAtSynchronizedStmt &S) = 0; 244 virtual void EmitTryStmt(CodeGen::CodeGenFunction &CGF, 245 const ObjCAtTryStmt &S) = 0; 246 virtual void EmitThrowStmt(CodeGen::CodeGenFunction &CGF, 247 const ObjCAtThrowStmt &S, 248 bool ClearInsertionPoint=true) = 0; 249 virtual llvm::Value *EmitObjCWeakRead(CodeGen::CodeGenFunction &CGF, 250 Address AddrWeakObj) = 0; 251 virtual void EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF, 252 llvm::Value *src, Address dest) = 0; 253 virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF, 254 llvm::Value *src, Address dest, 255 bool threadlocal=false) = 0; 256 virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF, 257 llvm::Value *src, Address dest, 258 llvm::Value *ivarOffset) = 0; 259 virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF, 260 llvm::Value *src, Address dest) = 0; 261 262 virtual LValue EmitObjCValueForIvar(CodeGen::CodeGenFunction &CGF, 263 QualType ObjectTy, 264 llvm::Value *BaseValue, 265 const ObjCIvarDecl *Ivar, 266 unsigned CVRQualifiers) = 0; 267 virtual llvm::Value *EmitIvarOffset(CodeGen::CodeGenFunction &CGF, 268 const ObjCInterfaceDecl *Interface, 269 const ObjCIvarDecl *Ivar) = 0; 270 virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF, 271 Address DestPtr, 272 Address SrcPtr, 273 llvm::Value *Size) = 0; 274 virtual llvm::Constant *BuildGCBlockLayout(CodeGen::CodeGenModule &CGM, 275 const CodeGen::CGBlockInfo &blockInfo) = 0; 276 virtual llvm::Constant *BuildRCBlockLayout(CodeGen::CodeGenModule &CGM, 277 const CodeGen::CGBlockInfo &blockInfo) = 0; 278 279 /// Returns an i8* which points to the byref layout information. 280 virtual llvm::Constant *BuildByrefLayout(CodeGen::CodeGenModule &CGM, 281 QualType T) = 0; 282 283 virtual llvm::GlobalVariable *GetClassGlobal(StringRef Name, 284 bool Weak = false) = 0; 285 286 struct MessageSendInfo { 287 const CGFunctionInfo &CallInfo; 288 llvm::PointerType *MessengerType; 289 290 MessageSendInfo(const CGFunctionInfo &callInfo, 291 llvm::PointerType *messengerType) 292 : CallInfo(callInfo), MessengerType(messengerType) {} 293 }; 294 295 MessageSendInfo getMessageSendInfo(const ObjCMethodDecl *method, 296 QualType resultType, 297 CallArgList &callArgs); 298 299 // FIXME: This probably shouldn't be here, but the code to compute 300 // it is here. 301 unsigned ComputeBitfieldBitOffset(CodeGen::CodeGenModule &CGM, 302 const ObjCInterfaceDecl *ID, 303 const ObjCIvarDecl *Ivar); 304 }; 305 306 /// Creates an instance of an Objective-C runtime class. 307 //TODO: This should include some way of selecting which runtime to target. 308 CGObjCRuntime *CreateGNUObjCRuntime(CodeGenModule &CGM); 309 CGObjCRuntime *CreateMacObjCRuntime(CodeGenModule &CGM); 310 } 311 } 312 #endif 313
