1 //===----- CGObjCRuntime.h - Interface to ObjC Runtimes ---------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This provides an abstract class for Objective-C code generation. Concrete
10 // subclasses of this implement code generation for specific Objective-C
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CLANG_LIB_CODEGEN_CGOBJCRUNTIME_H
16 #define LLVM_CLANG_LIB_CODEGEN_CGOBJCRUNTIME_H
17 #include "CGBuilder.h"
19 #include "CGCleanup.h"
21 #include "clang/AST/DeclObjC.h"
22 #include "clang/Basic/IdentifierTable.h" // Selector
36 class CodeGenFunction;
41 class ObjCAtThrowStmt;
42 class ObjCAtSynchronizedStmt;
43 class ObjCContainerDecl;
44 class ObjCCategoryImplDecl;
45 class ObjCImplementationDecl;
46 class ObjCInterfaceDecl;
47 class ObjCMessageExpr;
49 class ObjCProtocolDecl;
52 class ObjCStringLiteral;
53 class BlockDeclRefExpr;
59 // FIXME: Several methods should be pure virtual but aren't to avoid the
60 // partially-implemented subclass breaking.
62 /// Implements runtime-specific code generation functions.
65 CodeGen::CodeGenModule &CGM;
66 CGObjCRuntime(CodeGen::CodeGenModule &CGM) : CGM(CGM) {}
68 // Utility functions for unified ivar access. These need to
69 // eventually be folded into other places (the structure layout
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!
76 /// The latter overload is suitable for computing the offset of a
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);
85 LValue EmitValueForIvarAtOffset(CodeGen::CodeGenFunction &CGF,
86 const ObjCInterfaceDecl *OID,
87 llvm::Value *BaseValue,
88 const ObjCIvarDecl *Ivar,
89 unsigned CVRQualifiers,
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, const ObjCAtTryStmt &S,
99 llvm::FunctionCallee beginCatchFn,
100 llvm::FunctionCallee endCatchFn,
101 llvm::FunctionCallee exceptionRethrowFn);
103 void EmitInitOfCatchParam(CodeGenFunction &CGF, llvm::Value *exn,
104 const VarDecl *paramDecl);
106 /// Emits an \@synchronize() statement, using the \p syncEnterFn and
107 /// \p syncExitFn arguments as the functions called to lock and unlock
108 /// the object. This function can be called by subclasses that use
109 /// zero-cost exception handling.
110 void EmitAtSynchronizedStmt(CodeGenFunction &CGF,
111 const ObjCAtSynchronizedStmt &S,
112 llvm::FunctionCallee syncEnterFn,
113 llvm::FunctionCallee syncExitFn);
116 virtual ~CGObjCRuntime();
118 /// Generate the function required to register all Objective-C components in
119 /// this compilation unit with the runtime library.
120 virtual llvm::Function *ModuleInitFunction() = 0;
122 /// Get a selector for the specified name and type values.
123 /// The result should have the LLVM type for ASTContext::getObjCSelType().
124 virtual llvm::Value *GetSelector(CodeGenFunction &CGF, Selector Sel) = 0;
126 /// Get the address of a selector for the specified name and type values.
127 /// This is a rarely-used language extension, but sadly it exists.
129 /// The result should have the LLVM type for a pointer to
130 /// ASTContext::getObjCSelType().
131 virtual Address GetAddrOfSelector(CodeGenFunction &CGF, Selector Sel) = 0;
133 /// Get a typed selector.
134 virtual llvm::Value *GetSelector(CodeGenFunction &CGF,
135 const ObjCMethodDecl *Method) = 0;
137 /// Get the type constant to catch for the given ObjC pointer type.
138 /// This is used externally to implement catching ObjC types in C++.
139 /// Runtimes which don't support this should add the appropriate
141 virtual llvm::Constant *GetEHType(QualType T) = 0;
143 virtual CatchTypeInfo getCatchAllTypeInfo() { return { nullptr, 0 }; }
145 /// Generate a constant string object.
146 virtual ConstantAddress GenerateConstantString(const StringLiteral *) = 0;
148 /// Generate a category. A category contains a list of methods (and
149 /// accompanying metadata) and a list of protocols.
150 virtual void GenerateCategory(const ObjCCategoryImplDecl *OCD) = 0;
152 /// Generate a class structure for this class.
153 virtual void GenerateClass(const ObjCImplementationDecl *OID) = 0;
155 /// Register an class alias.
156 virtual void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) = 0;
158 /// Generate an Objective-C message send operation.
160 /// \param Method - The method being called, this may be null if synthesizing
161 /// a property setter or getter.
162 virtual CodeGen::RValue
163 GenerateMessageSend(CodeGen::CodeGenFunction &CGF,
164 ReturnValueSlot ReturnSlot,
167 llvm::Value *Receiver,
168 const CallArgList &CallArgs,
169 const ObjCInterfaceDecl *Class = nullptr,
170 const ObjCMethodDecl *Method = nullptr) = 0;
172 /// Generate an Objective-C message send operation.
174 /// This variant allows for the call to be substituted with an optimized
177 GeneratePossiblySpecializedMessageSend(CodeGenFunction &CGF,
178 ReturnValueSlot Return,
181 llvm::Value *Receiver,
182 const CallArgList& Args,
183 const ObjCInterfaceDecl *OID,
184 const ObjCMethodDecl *Method,
185 bool isClassMessage);
187 /// Generate an Objective-C message send operation to the super
188 /// class initiated in a method for Class and with the given Self
191 /// \param Method - The method being called, this may be null if synthesizing
192 /// a property setter or getter.
193 virtual CodeGen::RValue
194 GenerateMessageSendSuper(CodeGen::CodeGenFunction &CGF,
195 ReturnValueSlot ReturnSlot,
198 const ObjCInterfaceDecl *Class,
202 const CallArgList &CallArgs,
203 const ObjCMethodDecl *Method = nullptr) = 0;
205 /// Emit the code to return the named protocol as an object, as in a
206 /// \@protocol expression.
207 virtual llvm::Value *GenerateProtocolRef(CodeGenFunction &CGF,
208 const ObjCProtocolDecl *OPD) = 0;
210 /// Generate the named protocol. Protocols contain method metadata but no
212 virtual void GenerateProtocol(const ObjCProtocolDecl *OPD) = 0;
214 /// Generate a function preamble for a method with the specified
217 // FIXME: Current this just generates the Function definition, but really this
218 // should also be generating the loads of the parameters, as the runtime
219 // should have full control over how parameters are passed.
220 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
221 const ObjCContainerDecl *CD) = 0;
223 /// Generates prologue for direct Objective-C Methods.
224 virtual void GenerateDirectMethodPrologue(CodeGenFunction &CGF,
226 const ObjCMethodDecl *OMD,
227 const ObjCContainerDecl *CD) = 0;
229 /// Return the runtime function for getting properties.
230 virtual llvm::FunctionCallee GetPropertyGetFunction() = 0;
232 /// Return the runtime function for setting properties.
233 virtual llvm::FunctionCallee GetPropertySetFunction() = 0;
235 /// Return the runtime function for optimized setting properties.
236 virtual llvm::FunctionCallee GetOptimizedPropertySetFunction(bool atomic,
239 // API for atomic copying of qualified aggregates in getter.
240 virtual llvm::FunctionCallee GetGetStructFunction() = 0;
241 // API for atomic copying of qualified aggregates in setter.
242 virtual llvm::FunctionCallee GetSetStructFunction() = 0;
243 /// API for atomic copying of qualified aggregates with non-trivial copy
244 /// assignment (c++) in setter.
245 virtual llvm::FunctionCallee GetCppAtomicObjectSetFunction() = 0;
246 /// API for atomic copying of qualified aggregates with non-trivial copy
247 /// assignment (c++) in getter.
248 virtual llvm::FunctionCallee GetCppAtomicObjectGetFunction() = 0;
250 /// GetClass - Return a reference to the class for the given
252 virtual llvm::Value *GetClass(CodeGenFunction &CGF,
253 const ObjCInterfaceDecl *OID) = 0;
256 virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CodeGenFunction &CGF) {
257 llvm_unreachable("autoreleasepool unsupported in this ABI");
260 /// EnumerationMutationFunction - Return the function that's called by the
261 /// compiler when a mutation is detected during foreach iteration.
262 virtual llvm::FunctionCallee EnumerationMutationFunction() = 0;
264 virtual void EmitSynchronizedStmt(CodeGen::CodeGenFunction &CGF,
265 const ObjCAtSynchronizedStmt &S) = 0;
266 virtual void EmitTryStmt(CodeGen::CodeGenFunction &CGF,
267 const ObjCAtTryStmt &S) = 0;
268 virtual void EmitThrowStmt(CodeGen::CodeGenFunction &CGF,
269 const ObjCAtThrowStmt &S,
270 bool ClearInsertionPoint=true) = 0;
271 virtual llvm::Value *EmitObjCWeakRead(CodeGen::CodeGenFunction &CGF,
272 Address AddrWeakObj) = 0;
273 virtual void EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF,
274 llvm::Value *src, Address dest) = 0;
275 virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
276 llvm::Value *src, Address dest,
277 bool threadlocal=false) = 0;
278 virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
279 llvm::Value *src, Address dest,
280 llvm::Value *ivarOffset) = 0;
281 virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
282 llvm::Value *src, Address dest) = 0;
284 virtual LValue EmitObjCValueForIvar(CodeGen::CodeGenFunction &CGF,
286 llvm::Value *BaseValue,
287 const ObjCIvarDecl *Ivar,
288 unsigned CVRQualifiers) = 0;
289 virtual llvm::Value *EmitIvarOffset(CodeGen::CodeGenFunction &CGF,
290 const ObjCInterfaceDecl *Interface,
291 const ObjCIvarDecl *Ivar) = 0;
292 virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF,
295 llvm::Value *Size) = 0;
296 virtual llvm::Constant *BuildGCBlockLayout(CodeGen::CodeGenModule &CGM,
297 const CodeGen::CGBlockInfo &blockInfo) = 0;
298 virtual llvm::Constant *BuildRCBlockLayout(CodeGen::CodeGenModule &CGM,
299 const CodeGen::CGBlockInfo &blockInfo) = 0;
300 virtual std::string getRCBlockLayoutStr(CodeGen::CodeGenModule &CGM,
301 const CGBlockInfo &blockInfo) {
305 /// Returns an i8* which points to the byref layout information.
306 virtual llvm::Constant *BuildByrefLayout(CodeGen::CodeGenModule &CGM,
309 struct MessageSendInfo {
310 const CGFunctionInfo &CallInfo;
311 llvm::PointerType *MessengerType;
313 MessageSendInfo(const CGFunctionInfo &callInfo,
314 llvm::PointerType *messengerType)
315 : CallInfo(callInfo), MessengerType(messengerType) {}
318 MessageSendInfo getMessageSendInfo(const ObjCMethodDecl *method,
320 CallArgList &callArgs);
322 // FIXME: This probably shouldn't be here, but the code to compute
324 unsigned ComputeBitfieldBitOffset(CodeGen::CodeGenModule &CGM,
325 const ObjCInterfaceDecl *ID,
326 const ObjCIvarDecl *Ivar);
329 /// Creates an instance of an Objective-C runtime class.
330 //TODO: This should include some way of selecting which runtime to target.
331 CGObjCRuntime *CreateGNUObjCRuntime(CodeGenModule &CGM);
332 CGObjCRuntime *CreateMacObjCRuntime(CodeGenModule &CGM);