CGObjCRuntime.h revision 9735ca6e01113aec6a825dd5b1cb1b98fb377d31 
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#include <string>
21
22#include "CGBuilder.h"
23#include "CGCall.h"
24#include "CGValue.h"
25
26namespace llvm {
27  class Constant;
28  class Function;
29  class Module;
30  class StructLayout;
31  class StructType;
32  class Type;
33  class Value;
34}
35
36namespace clang {
37namespace CodeGen {
38  class CodeGenFunction;
39}
40
41  class FieldDecl;
42  class ObjCAtTryStmt;
43  class ObjCAtThrowStmt;
44  class ObjCAtSynchronizedStmt;
45  class ObjCContainerDecl;
46  class ObjCCategoryImplDecl;
47  class ObjCImplementationDecl;
48  class ObjCInterfaceDecl;
49  class ObjCMessageExpr;
50  class ObjCMethodDecl;
51  class ObjCProtocolDecl;
52  class Selector;
53  class ObjCIvarDecl;
54  class ObjCStringLiteral;
55  class BlockDeclRefExpr;
56
57namespace CodeGen {
58  class CodeGenModule;
59  class CGBlockInfo;
60
61// FIXME: Several methods should be pure virtual but aren't to avoid the
62// partially-implemented subclass breaking.
63
64/// Implements runtime-specific code generation functions.
65class CGObjCRuntime {
66protected:
67  // Utility functions for unified ivar access. These need to
68  // eventually be folded into other places (the structure layout
69  // code).
70
71  /// Compute an offset to the given ivar, suitable for passing to
72  /// EmitValueForIvarAtOffset.  Note that the correct handling of
73  /// bit-fields is carefully coordinated by these two, use caution!
74  ///
75  /// The latter overload is suitable for computing the offset of a
76  /// sythesized ivar.
77  uint64_t ComputeIvarBaseOffset(CodeGen::CodeGenModule &CGM,
78                                 const ObjCInterfaceDecl *OID,
79                                 const ObjCIvarDecl *Ivar);
80  uint64_t ComputeIvarBaseOffset(CodeGen::CodeGenModule &CGM,
81                                 const ObjCImplementationDecl *OID,
82                                 const ObjCIvarDecl *Ivar);
83
84  LValue EmitValueForIvarAtOffset(CodeGen::CodeGenFunction &CGF,
85                                  const ObjCInterfaceDecl *OID,
86                                  llvm::Value *BaseValue,
87                                  const ObjCIvarDecl *Ivar,
88                                  unsigned CVRQualifiers,
89                                  llvm::Value *Offset);
90  /// Emits a try / catch statement.  This function is intended to be called by
91  /// subclasses, and provides a generic mechanism for generating these, which
92  /// should be usable by all runtimes.  The caller must provide the functions to
93  /// call when entering and exiting a @catch() block, and the function used to
94  /// rethrow exceptions.  If the begin and end catch functions are NULL, then
95  /// the function assumes that the EH personality function provides the
96  /// thrown object directly.
97  void EmitTryCatchStmt(CodeGenFunction &CGF,
98                        const ObjCAtTryStmt &S,
99                        llvm::Function *beginCatchFn,
100                        llvm::Function *endCatchFn,
101                        llvm::Function *exceptionRethrowFn);
102  /// Emits an @synchronize() statement, using the syncEnterFn and syncExitFn
103  /// arguments as the functions called to lock and unlock the object.  This
104  /// function can be called by subclasses that use zero-cost exception
105  /// handling.
106  void EmitAtSynchronizedStmt(CodeGenFunction &CGF,
107                            const ObjCAtSynchronizedStmt &S,
108                            llvm::Function *syncEnterFn,
109                            llvm::Function *syncExitFn);
110
111public:
112  virtual ~CGObjCRuntime();
113
114  /// Generate the function required to register all Objective-C components in
115  /// this compilation unit with the runtime library.
116  virtual llvm::Function *ModuleInitFunction() = 0;
117
118  /// Get a selector for the specified name and type values. The
119  /// return value should have the LLVM type for pointer-to
120  /// ASTContext::getObjCSelType().
121  virtual llvm::Value *GetSelector(CGBuilderTy &Builder,
122                                   Selector Sel, bool lval=false) = 0;
123
124  /// Get a typed selector.
125  virtual llvm::Value *GetSelector(CGBuilderTy &Builder,
126                                   const ObjCMethodDecl *Method) = 0;
127
128  /// Get the type constant to catch for the given ObjC pointer type.
129  /// This is used externally to implement catching ObjC types in C++.
130  /// Runtimes which don't support this should add the appropriate
131  /// error to Sema.
132  virtual llvm::Constant *GetEHType(QualType T) = 0;
133
134  /// Generate a constant string object.
135  virtual llvm::Constant *GenerateConstantString(const StringLiteral *) = 0;
136
137  /// Generate a category.  A category contains a list of methods (and
138  /// accompanying metadata) and a list of protocols.
139  virtual void GenerateCategory(const ObjCCategoryImplDecl *OCD) = 0;
140
141  /// Generate a class stucture for this class.
142  virtual void GenerateClass(const ObjCImplementationDecl *OID) = 0;
143
144  /// Generate an Objective-C message send operation.
145  ///
146  /// \param Method - The method being called, this may be null if synthesizing
147  /// a property setter or getter.
148  virtual CodeGen::RValue
149  GenerateMessageSend(CodeGen::CodeGenFunction &CGF,
150                      ReturnValueSlot ReturnSlot,
151                      QualType ResultType,
152                      Selector Sel,
153                      llvm::Value *Receiver,
154                      const CallArgList &CallArgs,
155                      const ObjCInterfaceDecl *Class = 0,
156                      const ObjCMethodDecl *Method = 0) = 0;
157
158  /// Generate an Objective-C message send operation to the super
159  /// class initiated in a method for Class and with the given Self
160  /// object.
161  ///
162  /// \param Method - The method being called, this may be null if synthesizing
163  /// a property setter or getter.
164  virtual CodeGen::RValue
165  GenerateMessageSendSuper(CodeGen::CodeGenFunction &CGF,
166                           ReturnValueSlot ReturnSlot,
167                           QualType ResultType,
168                           Selector Sel,
169                           const ObjCInterfaceDecl *Class,
170                           bool isCategoryImpl,
171                           llvm::Value *Self,
172                           bool IsClassMessage,
173                           const CallArgList &CallArgs,
174                           const ObjCMethodDecl *Method = 0) = 0;
175
176  /// Emit the code to return the named protocol as an object, as in a
177  /// @protocol expression.
178  virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder,
179                                           const ObjCProtocolDecl *OPD) = 0;
180
181  /// Generate the named protocol.  Protocols contain method metadata but no
182  /// implementations.
183  virtual void GenerateProtocol(const ObjCProtocolDecl *OPD) = 0;
184
185  /// Generate a function preamble for a method with the specified
186  /// types.
187
188  // FIXME: Current this just generates the Function definition, but really this
189  // should also be generating the loads of the parameters, as the runtime
190  // should have full control over how parameters are passed.
191  virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
192                                         const ObjCContainerDecl *CD) = 0;
193
194  /// Return the runtime function for getting properties.
195  virtual llvm::Constant *GetPropertyGetFunction() = 0;
196
197  /// Return the runtime function for setting properties.
198  virtual llvm::Constant *GetPropertySetFunction() = 0;
199
200  // API for atomic copying of qualified aggregates in getter.
201  virtual llvm::Constant *GetGetStructFunction() = 0;
202  // API for atomic copying of qualified aggregates in setter.
203  virtual llvm::Constant *GetSetStructFunction() = 0;
204
205  /// GetClass - Return a reference to the class for the given
206  /// interface decl.
207  virtual llvm::Value *GetClass(CGBuilderTy &Builder,
208                                const ObjCInterfaceDecl *OID) = 0;
209
210  /// EnumerationMutationFunction - Return the function that's called by the
211  /// compiler when a mutation is detected during foreach iteration.
212  virtual llvm::Constant *EnumerationMutationFunction() = 0;
213
214  virtual void EmitSynchronizedStmt(CodeGen::CodeGenFunction &CGF,
215                                    const ObjCAtSynchronizedStmt &S) = 0;
216  virtual void EmitTryStmt(CodeGen::CodeGenFunction &CGF,
217                           const ObjCAtTryStmt &S) = 0;
218  virtual void EmitThrowStmt(CodeGen::CodeGenFunction &CGF,
219                             const ObjCAtThrowStmt &S) = 0;
220  virtual llvm::Value *EmitObjCWeakRead(CodeGen::CodeGenFunction &CGF,
221                                        llvm::Value *AddrWeakObj) = 0;
222  virtual void EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF,
223                                  llvm::Value *src, llvm::Value *dest) = 0;
224  virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
225                                    llvm::Value *src, llvm::Value *dest,
226                                    bool threadlocal=false) = 0;
227  virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
228                                  llvm::Value *src, llvm::Value *dest,
229                                  llvm::Value *ivarOffset) = 0;
230  virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
231                                        llvm::Value *src, llvm::Value *dest) = 0;
232
233  virtual LValue EmitObjCValueForIvar(CodeGen::CodeGenFunction &CGF,
234                                      QualType ObjectTy,
235                                      llvm::Value *BaseValue,
236                                      const ObjCIvarDecl *Ivar,
237                                      unsigned CVRQualifiers) = 0;
238  virtual llvm::Value *EmitIvarOffset(CodeGen::CodeGenFunction &CGF,
239                                      const ObjCInterfaceDecl *Interface,
240                                      const ObjCIvarDecl *Ivar) = 0;
241  virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF,
242                                        llvm::Value *DestPtr,
243                                        llvm::Value *SrcPtr,
244                                        llvm::Value *Size) = 0;
245  virtual llvm::Constant *BuildGCBlockLayout(CodeGen::CodeGenModule &CGM,
246                                  const CodeGen::CGBlockInfo &blockInfo) = 0;
247};
248
249/// Creates an instance of an Objective-C runtime class.
250//TODO: This should include some way of selecting which runtime to target.
251CGObjCRuntime *CreateGNUObjCRuntime(CodeGenModule &CGM);
252CGObjCRuntime *CreateMacObjCRuntime(CodeGenModule &CGM);
253}
254}
255#endif
256