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
24namespace llvm {
25  class Constant;
26  class Function;
27  class Module;
28  class StructLayout;
29  class StructType;
30  class Type;
31  class Value;
32}
33
34namespace clang {
35namespace 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
55namespace 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.
63class CGObjCRuntime {
64protected:
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
112public:
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.
296CGObjCRuntime *CreateGNUObjCRuntime(CodeGenModule &CGM);
297CGObjCRuntime *CreateMacObjCRuntime(CodeGenModule &CGM);
298}
299}
300#endif
301