CGObjCRuntime.h revision 195099 
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  /// Add metadata globals to the 'used' globals for final output.
99  virtual void MergeMetadataGlobals(std::vector<llvm::Constant*> &UsedArray) = 0;
100
101  /// Get a selector for the specified name and type values. The
102  /// return value should have the LLVM type for pointer-to
103  /// ASTContext::getObjCSelType().
104  virtual llvm::Value *GetSelector(CGBuilderTy &Builder,
105                                   Selector Sel) = 0;
106
107  /// Get a typed selector.
108  virtual llvm::Value *GetSelector(CGBuilderTy &Builder,
109                                   const ObjCMethodDecl *Method) = 0;
110
111  /// Generate a constant string object.
112  virtual llvm::Constant *GenerateConstantString(const ObjCStringLiteral *) = 0;
113
114  /// Generate a category.  A category contains a list of methods (and
115  /// accompanying metadata) and a list of protocols.
116  virtual void GenerateCategory(const ObjCCategoryImplDecl *OCD) = 0;
117
118  /// Generate a class stucture for this class.
119  virtual void GenerateClass(const ObjCImplementationDecl *OID) = 0;
120
121  /// Generate an Objective-C message send operation.
122  virtual CodeGen::RValue
123  GenerateMessageSend(CodeGen::CodeGenFunction &CGF,
124                      QualType ResultType,
125                      Selector Sel,
126                      llvm::Value *Receiver,
127                      bool IsClassMessage,
128                      const CallArgList &CallArgs,
129                      const ObjCMethodDecl *Method=0) = 0;
130
131  /// Generate an Objective-C message send operation to the super
132  /// class initiated in a method for Class and with the given Self
133  /// object.
134  virtual CodeGen::RValue
135  GenerateMessageSendSuper(CodeGen::CodeGenFunction &CGF,
136                           QualType ResultType,
137                           Selector Sel,
138                           const ObjCInterfaceDecl *Class,
139                           bool isCategoryImpl,
140                           llvm::Value *Self,
141                           bool IsClassMessage,
142                           const CallArgList &CallArgs) = 0;
143
144  /// Emit the code to return the named protocol as an object, as in a
145  /// @protocol expression.
146  virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder,
147                                           const ObjCProtocolDecl *OPD) = 0;
148
149  /// Generate the named protocol.  Protocols contain method metadata but no
150  /// implementations.
151  virtual void GenerateProtocol(const ObjCProtocolDecl *OPD) = 0;
152
153  /// Generate a function preamble for a method with the specified
154  /// types.
155
156  // FIXME: Current this just generates the Function definition, but really this
157  // should also be generating the loads of the parameters, as the runtime
158  // should have full control over how parameters are passed.
159  virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
160                                         const ObjCContainerDecl *CD) = 0;
161
162  /// Return the runtime function for getting properties.
163  virtual llvm::Constant *GetPropertyGetFunction() = 0;
164
165  /// Return the runtime function for setting properties.
166  virtual llvm::Constant *GetPropertySetFunction() = 0;
167
168  /// GetClass - Return a reference to the class for the given
169  /// interface decl.
170  virtual llvm::Value *GetClass(CGBuilderTy &Builder,
171                                const ObjCInterfaceDecl *OID) = 0;
172
173  /// EnumerationMutationFunction - Return the function that's called by the
174  /// compiler when a mutation is detected during foreach iteration.
175  virtual llvm::Constant *EnumerationMutationFunction() = 0;
176
177  virtual void EmitTryOrSynchronizedStmt(CodeGen::CodeGenFunction &CGF,
178                                         const Stmt &S) = 0;
179  virtual void EmitThrowStmt(CodeGen::CodeGenFunction &CGF,
180                             const ObjCAtThrowStmt &S) = 0;
181  virtual llvm::Value *EmitObjCWeakRead(CodeGen::CodeGenFunction &CGF,
182                                        llvm::Value *AddrWeakObj) = 0;
183  virtual void EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF,
184                                  llvm::Value *src, llvm::Value *dest) = 0;
185  virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
186                                    llvm::Value *src, llvm::Value *dest) = 0;
187  virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
188                                  llvm::Value *src, llvm::Value *dest) = 0;
189  virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
190                                        llvm::Value *src, llvm::Value *dest) = 0;
191
192  virtual LValue EmitObjCValueForIvar(CodeGen::CodeGenFunction &CGF,
193                                      QualType ObjectTy,
194                                      llvm::Value *BaseValue,
195                                      const ObjCIvarDecl *Ivar,
196                                      unsigned CVRQualifiers) = 0;
197  virtual llvm::Value *EmitIvarOffset(CodeGen::CodeGenFunction &CGF,
198                                      const ObjCInterfaceDecl *Interface,
199                                      const ObjCIvarDecl *Ivar) = 0;
200};
201
202/// Creates an instance of an Objective-C runtime class.
203//TODO: This should include some way of selecting which runtime to target.
204CGObjCRuntime *CreateGNUObjCRuntime(CodeGenModule &CGM);
205CGObjCRuntime *CreateMacObjCRuntime(CodeGenModule &CGM);
206CGObjCRuntime *CreateMacNonFragileABIObjCRuntime(CodeGenModule &CGM);
207}
208}
209#endif
210