CGObjCRuntime.h revision 234353 
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 "clang/Basic/IdentifierTable.h" // Selector
19#include "clang/AST/DeclObjC.h"
20
21#include "CGBuilder.h"
22#include "CGCall.h"
23#include "CGValue.h"
24
25namespace llvm {
26  class Constant;
27  class Function;
28  class Module;
29  class StructLayout;
30  class StructType;
31  class Type;
32  class Value;
33}
34
35namespace clang {
36namespace CodeGen {
37  class CodeGenFunction;
38}
39
40  class FieldDecl;
41  class ObjCAtTryStmt;
42  class ObjCAtThrowStmt;
43  class ObjCAtSynchronizedStmt;
44  class ObjCContainerDecl;
45  class ObjCCategoryImplDecl;
46  class ObjCImplementationDecl;
47  class ObjCInterfaceDecl;
48  class ObjCMessageExpr;
49  class ObjCMethodDecl;
50  class ObjCProtocolDecl;
51  class Selector;
52  class ObjCIvarDecl;
53  class ObjCStringLiteral;
54  class BlockDeclRefExpr;
55
56namespace CodeGen {
57  class CodeGenModule;
58  class CGBlockInfo;
59
60// FIXME: Several methods should be pure virtual but aren't to avoid the
61// partially-implemented subclass breaking.
62
63/// Implements runtime-specific code generation functions.
64class CGObjCRuntime {
65protected:
66  CodeGen::CodeGenModule &CGM;
67  CGObjCRuntime(CodeGen::CodeGenModule &CGM) : CGM(CGM) {}
68
69  // Utility functions for unified ivar access. These need to
70  // eventually be folded into other places (the structure layout
71  // code).
72
73  /// Compute an offset to the given ivar, suitable for passing to
74  /// EmitValueForIvarAtOffset.  Note that the correct handling of
75  /// bit-fields is carefully coordinated by these two, use caution!
76  ///
77  /// The latter overload is suitable for computing the offset of a
78  /// sythesized ivar.
79  uint64_t ComputeIvarBaseOffset(CodeGen::CodeGenModule &CGM,
80                                 const ObjCInterfaceDecl *OID,
81                                 const ObjCIvarDecl *Ivar);
82  uint64_t ComputeIvarBaseOffset(CodeGen::CodeGenModule &CGM,
83                                 const ObjCImplementationDecl *OID,
84                                 const ObjCIvarDecl *Ivar);
85
86  LValue EmitValueForIvarAtOffset(CodeGen::CodeGenFunction &CGF,
87                                  const ObjCInterfaceDecl *OID,
88                                  llvm::Value *BaseValue,
89                                  const ObjCIvarDecl *Ivar,
90                                  unsigned CVRQualifiers,
91                                  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 to
95  /// call when entering and exiting a @catch() block, and the function used to
96  /// rethrow exceptions.  If the begin and end catch functions are NULL, then
97  /// the function assumes that the EH personality function provides the
98  /// thrown object directly.
99  void EmitTryCatchStmt(CodeGenFunction &CGF,
100                        const ObjCAtTryStmt &S,
101                        llvm::Constant *beginCatchFn,
102                        llvm::Constant *endCatchFn,
103                        llvm::Constant *exceptionRethrowFn);
104  /// Emits an @synchronize() statement, using the syncEnterFn and syncExitFn
105  /// arguments as the functions called to lock and unlock the object.  This
106  /// function can be called by subclasses that use zero-cost exception
107  /// handling.
108  void EmitAtSynchronizedStmt(CodeGenFunction &CGF,
109                            const ObjCAtSynchronizedStmt &S,
110                            llvm::Function *syncEnterFn,
111                            llvm::Function *syncExitFn);
112
113public:
114  virtual ~CGObjCRuntime();
115
116  /// Generate the function required to register all Objective-C components in
117  /// this compilation unit with the runtime library.
118  virtual llvm::Function *ModuleInitFunction() = 0;
119
120  /// Get a selector for the specified name and type values. The
121  /// return value should have the LLVM type for pointer-to
122  /// ASTContext::getObjCSelType().
123  virtual llvm::Value *GetSelector(CGBuilderTy &Builder,
124                                   Selector Sel, bool lval=false) = 0;
125
126  /// Get a typed selector.
127  virtual llvm::Value *GetSelector(CGBuilderTy &Builder,
128                                   const ObjCMethodDecl *Method) = 0;
129
130  /// Get the type constant to catch for the given ObjC pointer type.
131  /// This is used externally to implement catching ObjC types in C++.
132  /// Runtimes which don't support this should add the appropriate
133  /// error to Sema.
134  virtual llvm::Constant *GetEHType(QualType T) = 0;
135
136  /// Generate a constant string object.
137  virtual llvm::Constant *GenerateConstantString(const StringLiteral *) = 0;
138
139  /// Generate a category.  A category contains a list of methods (and
140  /// accompanying metadata) and a list of protocols.
141  virtual void GenerateCategory(const ObjCCategoryImplDecl *OCD) = 0;
142
143  /// Generate a class structure for this class.
144  virtual void GenerateClass(const ObjCImplementationDecl *OID) = 0;
145
146  /// Register an class alias.
147  virtual void RegisterAlias(const ObjCCompatibleAliasDecl *OAD) = 0;
148
149  /// Generate an Objective-C message send operation.
150  ///
151  /// \param Method - The method being called, this may be null if synthesizing
152  /// a property setter or getter.
153  virtual CodeGen::RValue
154  GenerateMessageSend(CodeGen::CodeGenFunction &CGF,
155                      ReturnValueSlot ReturnSlot,
156                      QualType ResultType,
157                      Selector Sel,
158                      llvm::Value *Receiver,
159                      const CallArgList &CallArgs,
160                      const ObjCInterfaceDecl *Class = 0,
161                      const ObjCMethodDecl *Method = 0) = 0;
162
163  /// Generate an Objective-C message send operation to the super
164  /// class initiated in a method for Class and with the given Self
165  /// object.
166  ///
167  /// \param Method - The method being called, this may be null if synthesizing
168  /// a property setter or getter.
169  virtual CodeGen::RValue
170  GenerateMessageSendSuper(CodeGen::CodeGenFunction &CGF,
171                           ReturnValueSlot ReturnSlot,
172                           QualType ResultType,
173                           Selector Sel,
174                           const ObjCInterfaceDecl *Class,
175                           bool isCategoryImpl,
176                           llvm::Value *Self,
177                           bool IsClassMessage,
178                           const CallArgList &CallArgs,
179                           const ObjCMethodDecl *Method = 0) = 0;
180
181  /// Emit the code to return the named protocol as an object, as in a
182  /// @protocol expression.
183  virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder,
184                                           const ObjCProtocolDecl *OPD) = 0;
185
186  /// Generate the named protocol.  Protocols contain method metadata but no
187  /// implementations.
188  virtual void GenerateProtocol(const ObjCProtocolDecl *OPD) = 0;
189
190  /// Generate a function preamble for a method with the specified
191  /// types.
192
193  // FIXME: Current this just generates the Function definition, but really this
194  // should also be generating the loads of the parameters, as the runtime
195  // should have full control over how parameters are passed.
196  virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
197                                         const ObjCContainerDecl *CD) = 0;
198
199  /// Return the runtime function for getting properties.
200  virtual llvm::Constant *GetPropertyGetFunction() = 0;
201
202  /// Return the runtime function for setting properties.
203  virtual llvm::Constant *GetPropertySetFunction() = 0;
204
205  /// Return the runtime function for optimized setting properties.
206  virtual llvm::Constant *GetOptimizedPropertySetFunction(bool atomic,
207                                                          bool copy) = 0;
208
209  // API for atomic copying of qualified aggregates in getter.
210  virtual llvm::Constant *GetGetStructFunction() = 0;
211  // API for atomic copying of qualified aggregates in setter.
212  virtual llvm::Constant *GetSetStructFunction() = 0;
213  // API for atomic copying of qualified aggregates with non-trivial copy
214  // assignment (c++) in setter/getter.
215  virtual llvm::Constant *GetCppAtomicObjectFunction() = 0;
216
217  /// GetClass - Return a reference to the class for the given
218  /// interface decl.
219  virtual llvm::Value *GetClass(CGBuilderTy &Builder,
220                                const ObjCInterfaceDecl *OID) = 0;
221
222
223  virtual llvm::Value *EmitNSAutoreleasePoolClassRef(CGBuilderTy &Builder) {
224    llvm_unreachable("autoreleasepool unsupported in this ABI");
225  }
226
227  /// EnumerationMutationFunction - Return the function that's called by the
228  /// compiler when a mutation is detected during foreach iteration.
229  virtual llvm::Constant *EnumerationMutationFunction() = 0;
230
231  virtual void EmitSynchronizedStmt(CodeGen::CodeGenFunction &CGF,
232                                    const ObjCAtSynchronizedStmt &S) = 0;
233  virtual void EmitTryStmt(CodeGen::CodeGenFunction &CGF,
234                           const ObjCAtTryStmt &S) = 0;
235  virtual void EmitThrowStmt(CodeGen::CodeGenFunction &CGF,
236                             const ObjCAtThrowStmt &S) = 0;
237  virtual llvm::Value *EmitObjCWeakRead(CodeGen::CodeGenFunction &CGF,
238                                        llvm::Value *AddrWeakObj) = 0;
239  virtual void EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF,
240                                  llvm::Value *src, llvm::Value *dest) = 0;
241  virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
242                                    llvm::Value *src, llvm::Value *dest,
243                                    bool threadlocal=false) = 0;
244  virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
245                                  llvm::Value *src, llvm::Value *dest,
246                                  llvm::Value *ivarOffset) = 0;
247  virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
248                                        llvm::Value *src, llvm::Value *dest) = 0;
249
250  virtual LValue EmitObjCValueForIvar(CodeGen::CodeGenFunction &CGF,
251                                      QualType ObjectTy,
252                                      llvm::Value *BaseValue,
253                                      const ObjCIvarDecl *Ivar,
254                                      unsigned CVRQualifiers) = 0;
255  virtual llvm::Value *EmitIvarOffset(CodeGen::CodeGenFunction &CGF,
256                                      const ObjCInterfaceDecl *Interface,
257                                      const ObjCIvarDecl *Ivar) = 0;
258  virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF,
259                                        llvm::Value *DestPtr,
260                                        llvm::Value *SrcPtr,
261                                        llvm::Value *Size) = 0;
262  virtual llvm::Constant *BuildGCBlockLayout(CodeGen::CodeGenModule &CGM,
263                                  const CodeGen::CGBlockInfo &blockInfo) = 0;
264  virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) = 0;
265
266  struct MessageSendInfo {
267    const CGFunctionInfo &CallInfo;
268    llvm::PointerType *MessengerType;
269
270    MessageSendInfo(const CGFunctionInfo &callInfo,
271                    llvm::PointerType *messengerType)
272      : CallInfo(callInfo), MessengerType(messengerType) {}
273  };
274
275  MessageSendInfo getMessageSendInfo(const ObjCMethodDecl *method,
276                                     QualType resultType,
277                                     CallArgList &callArgs);
278};
279
280/// Creates an instance of an Objective-C runtime class.
281//TODO: This should include some way of selecting which runtime to target.
282CGObjCRuntime *CreateGNUObjCRuntime(CodeGenModule &CGM);
283CGObjCRuntime *CreateMacObjCRuntime(CodeGenModule &CGM);
284}
285}
286#endif
287