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 CLANG_CODEGEN_OBCJRUNTIME_H 17 #define CLANG_CODEGEN_OBCJRUNTIME_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 /// Emits an \@synchronize() statement, using the \p syncEnterFn and 104 /// \p syncExitFn arguments as the functions called to lock and unlock 105 /// the object. This function can be called by subclasses that use 106 /// zero-cost exception handling. 107 void EmitAtSynchronizedStmt(CodeGenFunction &CGF, 108 const ObjCAtSynchronizedStmt &S, 109 llvm::Function *syncEnterFn, 110 llvm::Function *syncExitFn); 111 112 public: 113 virtual ~CGObjCRuntime(); 114 115 /// Generate the function required to register all Objective-C components in 116 /// this compilation unit with the runtime library. 117 virtual llvm::Function *ModuleInitFunction() = 0; 118 119 /// Get a selector for the specified name and type values. The 120 /// return value should have the LLVM type for pointer-to 121 /// ASTContext::getObjCSelType(). 122 virtual llvm::Value *GetSelector(CodeGenFunction &CGF, 123 Selector Sel, bool lval=false) = 0; 124 125 /// Get a typed selector. 126 virtual llvm::Value *GetSelector(CodeGenFunction &CGF, 127 const ObjCMethodDecl *Method) = 0; 128 129 /// Get the type constant to catch for the given ObjC pointer type. 130 /// This is used externally to implement catching ObjC types in C++. 131 /// Runtimes which don't support this should add the appropriate 132 /// error to Sema. 133 virtual llvm::Constant *GetEHType(QualType T) = 0; 134 135 /// Generate a constant string object. 136 virtual llvm::Constant *GenerateConstantString(const StringLiteral *) = 0; 137 138 /// Generate a category. A category contains a list of methods (and 139 /// accompanying metadata) and a list of protocols. 140 virtual void GenerateCategory(const ObjCCategoryImplDecl *OCD) = 0; 141 142 /// Generate a class structure for this class. 143 virtual void GenerateClass(const ObjCImplementationDecl *OID) = 0; 144 145 /// Register an class alias. 146 virtual void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) = 0; 147 148 /// Generate an Objective-C message send operation. 149 /// 150 /// \param Method - The method being called, this may be null if synthesizing 151 /// a property setter or getter. 152 virtual CodeGen::RValue 153 GenerateMessageSend(CodeGen::CodeGenFunction &CGF, 154 ReturnValueSlot ReturnSlot, 155 QualType ResultType, 156 Selector Sel, 157 llvm::Value *Receiver, 158 const CallArgList &CallArgs, 159 const ObjCInterfaceDecl *Class = nullptr, 160 const ObjCMethodDecl *Method = nullptr) = 0; 161 162 /// Generate an Objective-C message send operation to the super 163 /// class initiated in a method for Class and with the given Self 164 /// object. 165 /// 166 /// \param Method - The method being called, this may be null if synthesizing 167 /// a property setter or getter. 168 virtual CodeGen::RValue 169 GenerateMessageSendSuper(CodeGen::CodeGenFunction &CGF, 170 ReturnValueSlot ReturnSlot, 171 QualType ResultType, 172 Selector Sel, 173 const ObjCInterfaceDecl *Class, 174 bool isCategoryImpl, 175 llvm::Value *Self, 176 bool IsClassMessage, 177 const CallArgList &CallArgs, 178 const ObjCMethodDecl *Method = nullptr) = 0; 179 180 /// Emit the code to return the named protocol as an object, as in a 181 /// \@protocol expression. 182 virtual llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF, 183 const ObjCProtocolDecl *OPD) = 0; 184 185 /// Generate the named protocol. Protocols contain method metadata but no 186 /// implementations. 187 virtual void GenerateProtocol(const ObjCProtocolDecl *OPD) = 0; 188 189 /// Generate a function preamble for a method with the specified 190 /// types. 191 192 // FIXME: Current this just generates the Function definition, but really this 193 // should also be generating the loads of the parameters, as the runtime 194 // should have full control over how parameters are passed. 195 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD, 196 const ObjCContainerDecl *CD) = 0; 197 198 /// Return the runtime function for getting properties. 199 virtual llvm::Constant *GetPropertyGetFunction() = 0; 200 201 /// Return the runtime function for setting properties. 202 virtual llvm::Constant *GetPropertySetFunction() = 0; 203 204 /// Return the runtime function for optimized setting properties. 205 virtual llvm::Constant *GetOptimizedPropertySetFunction(bool atomic, 206 bool copy) = 0; 207 208 // API for atomic copying of qualified aggregates in getter. 209 virtual llvm::Constant *GetGetStructFunction() = 0; 210 // API for atomic copying of qualified aggregates in setter. 211 virtual llvm::Constant *GetSetStructFunction() = 0; 212 /// API for atomic copying of qualified aggregates with non-trivial copy 213 /// assignment (c++) in setter. 214 virtual llvm::Constant *GetCppAtomicObjectSetFunction() = 0; 215 /// API for atomic copying of qualified aggregates with non-trivial copy 216 /// assignment (c++) in getter. 217 virtual llvm::Constant *GetCppAtomicObjectGetFunction() = 0; 218 219 /// GetClass - Return a reference to the class for the given 220 /// interface decl. 221 virtual llvm::Value *GetClass(CodeGenFunction &CGF, 222 const ObjCInterfaceDecl *OID) = 0; 223 224 225 virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) { 226 llvm_unreachable("autoreleasepool unsupported in this ABI"); 227 } 228 229 /// EnumerationMutationFunction - Return the function that's called by the 230 /// compiler when a mutation is detected during foreach iteration. 231 virtual llvm::Constant *EnumerationMutationFunction() = 0; 232 233 virtual void EmitSynchronizedStmt(CodeGen::CodeGenFunction &CGF, 234 const ObjCAtSynchronizedStmt &S) = 0; 235 virtual void EmitTryStmt(CodeGen::CodeGenFunction &CGF, 236 const ObjCAtTryStmt &S) = 0; 237 virtual void EmitThrowStmt(CodeGen::CodeGenFunction &CGF, 238 const ObjCAtThrowStmt &S, 239 bool ClearInsertionPoint=true) = 0; 240 virtual llvm::Value *EmitObjCWeakRead(CodeGen::CodeGenFunction &CGF, 241 llvm::Value *AddrWeakObj) = 0; 242 virtual void EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF, 243 llvm::Value *src, llvm::Value *dest) = 0; 244 virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF, 245 llvm::Value *src, llvm::Value *dest, 246 bool threadlocal=false) = 0; 247 virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF, 248 llvm::Value *src, llvm::Value *dest, 249 llvm::Value *ivarOffset) = 0; 250 virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF, 251 llvm::Value *src, llvm::Value *dest) = 0; 252 253 virtual LValue EmitObjCValueForIvar(CodeGen::CodeGenFunction &CGF, 254 QualType ObjectTy, 255 llvm::Value *BaseValue, 256 const ObjCIvarDecl *Ivar, 257 unsigned CVRQualifiers) = 0; 258 virtual llvm::Value *EmitIvarOffset(CodeGen::CodeGenFunction &CGF, 259 const ObjCInterfaceDecl *Interface, 260 const ObjCIvarDecl *Ivar) = 0; 261 virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF, 262 llvm::Value *DestPtr, 263 llvm::Value *SrcPtr, 264 llvm::Value *Size) = 0; 265 virtual llvm::Constant *BuildGCBlockLayout(CodeGen::CodeGenModule &CGM, 266 const CodeGen::CGBlockInfo &blockInfo) = 0; 267 virtual llvm::Constant *BuildRCBlockLayout(CodeGen::CodeGenModule &CGM, 268 const CodeGen::CGBlockInfo &blockInfo) = 0; 269 virtual llvm::Constant *BuildByrefLayout(CodeGen::CodeGenModule &CGM, 270 QualType T) = 0; 271 virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name, 272 bool Weak = false) = 0; 273 274 struct MessageSendInfo { 275 const CGFunctionInfo &CallInfo; 276 llvm::PointerType *MessengerType; 277 278 MessageSendInfo(const CGFunctionInfo &callInfo, 279 llvm::PointerType *messengerType) 280 : CallInfo(callInfo), MessengerType(messengerType) {} 281 }; 282 283 MessageSendInfo getMessageSendInfo(const ObjCMethodDecl *method, 284 QualType resultType, 285 CallArgList &callArgs); 286 287 // FIXME: This probably shouldn't be here, but the code to compute 288 // it is here. 289 unsigned ComputeBitfieldBitOffset(CodeGen::CodeGenModule &CGM, 290 const ObjCInterfaceDecl *ID, 291 const ObjCIvarDecl *Ivar); 292 }; 293 294 /// Creates an instance of an Objective-C runtime class. 295 //TODO: This should include some way of selecting which runtime to target. 296 CGObjCRuntime *CreateGNUObjCRuntime(CodeGenModule &CGM); 297 CGObjCRuntime *CreateMacObjCRuntime(CodeGenModule &CGM); 298 } 299 } 300 #endif 301
