CGObjCRuntime.h revision 193326 
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 "llvm/ADT/SmallVector.h"
20#include "clang/AST/DeclObjC.h"
21#include <string>
22
23#include "CGBuilder.h"
24#include "CGCall.h"
25#include "CGValue.h"
26
27namespace llvm {
28  class Constant;
29  class Function;
30  class Module;
31  class StructLayout;
32  class StructType;
33  class Type;
34  class Value;
35}
36
37namespace clang {
38namespace CodeGen {
39  class CodeGenFunction;
40}
41
42  class FieldDecl;
43  class ObjCAtTryStmt;
44  class ObjCAtThrowStmt;
45  class ObjCAtSynchronizedStmt;
46  class ObjCContainerDecl;
47  class ObjCCategoryImplDecl;
48  class ObjCImplementationDecl;
49  class ObjCInterfaceDecl;
50  class ObjCMessageExpr;
51  class ObjCMethodDecl;
52  class ObjCProtocolDecl;
53  class Selector;
54  class ObjCIvarDecl;
55  class ObjCStringLiteral;
56
57namespace CodeGen {
58  class CodeGenModule;
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 {
65public:
66  // Utility functions for unified ivar access. These need to
67  // eventually be folded into other places (the structure layout
68  // code).
69
70protected:
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
91public:
92  virtual ~CGObjCRuntime();
93
94  /// Generate the function required to register all Objective-C components in
95  /// this compilation unit with the runtime library.
96  virtual llvm::Function *ModuleInitFunction() = 0;
97
98  /// Get a selector for the specified name and type values. The
99  /// return value should have the LLVM type for pointer-to
100  /// ASTContext::getObjCSelType().
101  virtual llvm::Value *GetSelector(CGBuilderTy &Builder,
102                                   Selector Sel) = 0;
103
104  /// Get a typed selector.
105  virtual llvm::Value *GetSelector(CGBuilderTy &Builder,
106                                   const ObjCMethodDecl *Method) = 0;
107
108  /// Generate a constant string object.
109  virtual llvm::Constant *GenerateConstantString(const ObjCStringLiteral *) = 0;
110
111  /// Generate a category.  A category contains a list of methods (and
112  /// accompanying metadata) and a list of protocols.
113  virtual void GenerateCategory(const ObjCCategoryImplDecl *OCD) = 0;
114
115  /// Generate a class stucture for this class.
116  virtual void GenerateClass(const ObjCImplementationDecl *OID) = 0;
117
118  /// Generate an Objective-C message send operation.
119  virtual CodeGen::RValue
120  GenerateMessageSend(CodeGen::CodeGenFunction &CGF,
121                      QualType ResultType,
122                      Selector Sel,
123                      llvm::Value *Receiver,
124                      bool IsClassMessage,
125                      const CallArgList &CallArgs,
126                      const ObjCMethodDecl *Method=0) = 0;
127
128  /// Generate an Objective-C message send operation to the super
129  /// class initiated in a method for Class and with the given Self
130  /// object.
131  virtual CodeGen::RValue
132  GenerateMessageSendSuper(CodeGen::CodeGenFunction &CGF,
133                           QualType ResultType,
134                           Selector Sel,
135                           const ObjCInterfaceDecl *Class,
136                           bool isCategoryImpl,
137                           llvm::Value *Self,
138                           bool IsClassMessage,
139                           const CallArgList &CallArgs) = 0;
140
141  /// Emit the code to return the named protocol as an object, as in a
142  /// @protocol expression.
143  virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder,
144                                           const ObjCProtocolDecl *OPD) = 0;
145
146  /// Generate the named protocol.  Protocols contain method metadata but no
147  /// implementations.
148  virtual void GenerateProtocol(const ObjCProtocolDecl *OPD) = 0;
149
150  /// Generate a function preamble for a method with the specified
151  /// types.
152
153  // FIXME: Current this just generates the Function definition, but really this
154  // should also be generating the loads of the parameters, as the runtime
155  // should have full control over how parameters are passed.
156  virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
157                                         const ObjCContainerDecl *CD) = 0;
158
159  /// Return the runtime function for getting properties.
160  virtual llvm::Constant *GetPropertyGetFunction() = 0;
161
162  /// Return the runtime function for setting properties.
163  virtual llvm::Constant *GetPropertySetFunction() = 0;
164
165  /// GetClass - Return a reference to the class for the given
166  /// interface decl.
167  virtual llvm::Value *GetClass(CGBuilderTy &Builder,
168                                const ObjCInterfaceDecl *OID) = 0;
169
170  /// EnumerationMutationFunction - Return the function that's called by the
171  /// compiler when a mutation is detected during foreach iteration.
172  virtual llvm::Constant *EnumerationMutationFunction() = 0;
173
174  virtual void EmitTryOrSynchronizedStmt(CodeGen::CodeGenFunction &CGF,
175                                         const Stmt &S) = 0;
176  virtual void EmitThrowStmt(CodeGen::CodeGenFunction &CGF,
177                             const ObjCAtThrowStmt &S) = 0;
178  virtual llvm::Value *EmitObjCWeakRead(CodeGen::CodeGenFunction &CGF,
179                                        llvm::Value *AddrWeakObj) = 0;
180  virtual void EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF,
181                                  llvm::Value *src, llvm::Value *dest) = 0;
182  virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
183                                    llvm::Value *src, llvm::Value *dest) = 0;
184  virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
185                                  llvm::Value *src, llvm::Value *dest) = 0;
186  virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
187                                        llvm::Value *src, llvm::Value *dest) = 0;
188
189  virtual LValue EmitObjCValueForIvar(CodeGen::CodeGenFunction &CGF,
190                                      QualType ObjectTy,
191                                      llvm::Value *BaseValue,
192                                      const ObjCIvarDecl *Ivar,
193                                      unsigned CVRQualifiers) = 0;
194  virtual llvm::Value *EmitIvarOffset(CodeGen::CodeGenFunction &CGF,
195                                      const ObjCInterfaceDecl *Interface,
196                                      const ObjCIvarDecl *Ivar) = 0;
197};
198
199/// Creates an instance of an Objective-C runtime class.
200//TODO: This should include some way of selecting which runtime to target.
201CGObjCRuntime *CreateGNUObjCRuntime(CodeGenModule &CGM);
202CGObjCRuntime *CreateMacObjCRuntime(CodeGenModule &CGM);
203CGObjCRuntime *CreateMacNonFragileABIObjCRuntime(CodeGenModule &CGM);
204}
205}
206#endif
207