1//===-- CGBlocks.h - state for LLVM CodeGen for blocks ----------*- 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 is the internal state used for llvm translation for block literals.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef CLANG_CODEGEN_CGBLOCKS_H
15#define CLANG_CODEGEN_CGBLOCKS_H
16
17#include "CodeGenTypes.h"
18#include "clang/AST/Type.h"
19#include "llvm/Module.h"
20#include "clang/Basic/TargetInfo.h"
21#include "clang/AST/CharUnits.h"
22#include "clang/AST/Expr.h"
23#include "clang/AST/ExprCXX.h"
24#include "clang/AST/ExprObjC.h"
25
26#include "CodeGenFunction.h"
27#include "CGBuilder.h"
28#include "CGCall.h"
29#include "CGValue.h"
30
31namespace llvm {
32  class Module;
33  class Constant;
34  class Function;
35  class GlobalValue;
36  class TargetData;
37  class FunctionType;
38  class PointerType;
39  class Value;
40  class LLVMContext;
41}
42
43namespace clang {
44
45namespace CodeGen {
46
47class CodeGenModule;
48class CGBlockInfo;
49
50enum BlockFlag_t {
51  BLOCK_HAS_COPY_DISPOSE =  (1 << 25),
52  BLOCK_HAS_CXX_OBJ =       (1 << 26),
53  BLOCK_IS_GLOBAL =         (1 << 28),
54  BLOCK_USE_STRET =         (1 << 29),
55  BLOCK_HAS_SIGNATURE  =    (1 << 30)
56};
57class BlockFlags {
58  uint32_t flags;
59
60  BlockFlags(uint32_t flags) : flags(flags) {}
61public:
62  BlockFlags() : flags(0) {}
63  BlockFlags(BlockFlag_t flag) : flags(flag) {}
64
65  uint32_t getBitMask() const { return flags; }
66  bool empty() const { return flags == 0; }
67
68  friend BlockFlags operator|(BlockFlags l, BlockFlags r) {
69    return BlockFlags(l.flags | r.flags);
70  }
71  friend BlockFlags &operator|=(BlockFlags &l, BlockFlags r) {
72    l.flags |= r.flags;
73    return l;
74  }
75  friend bool operator&(BlockFlags l, BlockFlags r) {
76    return (l.flags & r.flags);
77  }
78};
79inline BlockFlags operator|(BlockFlag_t l, BlockFlag_t r) {
80  return BlockFlags(l) | BlockFlags(r);
81}
82
83enum BlockFieldFlag_t {
84  BLOCK_FIELD_IS_OBJECT   = 0x03,  /* id, NSObject, __attribute__((NSObject)),
85                                    block, ... */
86  BLOCK_FIELD_IS_BLOCK    = 0x07,  /* a block variable */
87
88  BLOCK_FIELD_IS_BYREF    = 0x08,  /* the on stack structure holding the __block
89                                    variable */
90  BLOCK_FIELD_IS_WEAK     = 0x10,  /* declared __weak, only used in byref copy
91                                    helpers */
92  BLOCK_FIELD_IS_ARC      = 0x40,  /* field has ARC-specific semantics */
93  BLOCK_BYREF_CALLER      = 128,   /* called from __block (byref) copy/dispose
94                                      support routines */
95  BLOCK_BYREF_CURRENT_MAX = 256
96};
97
98class BlockFieldFlags {
99  uint32_t flags;
100
101  BlockFieldFlags(uint32_t flags) : flags(flags) {}
102public:
103  BlockFieldFlags() : flags(0) {}
104  BlockFieldFlags(BlockFieldFlag_t flag) : flags(flag) {}
105
106  uint32_t getBitMask() const { return flags; }
107  bool empty() const { return flags == 0; }
108
109  /// Answers whether the flags indicate that this field is an object
110  /// or block pointer that requires _Block_object_assign/dispose.
111  bool isSpecialPointer() const { return flags & BLOCK_FIELD_IS_OBJECT; }
112
113  friend BlockFieldFlags operator|(BlockFieldFlags l, BlockFieldFlags r) {
114    return BlockFieldFlags(l.flags | r.flags);
115  }
116  friend BlockFieldFlags &operator|=(BlockFieldFlags &l, BlockFieldFlags r) {
117    l.flags |= r.flags;
118    return l;
119  }
120  friend bool operator&(BlockFieldFlags l, BlockFieldFlags r) {
121    return (l.flags & r.flags);
122  }
123};
124inline BlockFieldFlags operator|(BlockFieldFlag_t l, BlockFieldFlag_t r) {
125  return BlockFieldFlags(l) | BlockFieldFlags(r);
126}
127
128/// CGBlockInfo - Information to generate a block literal.
129class CGBlockInfo {
130public:
131  /// Name - The name of the block, kindof.
132  llvm::StringRef Name;
133
134  /// The field index of 'this' within the block, if there is one.
135  unsigned CXXThisIndex;
136
137  class Capture {
138    uintptr_t Data;
139    EHScopeStack::stable_iterator Cleanup;
140
141  public:
142    bool isIndex() const { return (Data & 1) != 0; }
143    bool isConstant() const { return !isIndex(); }
144    unsigned getIndex() const { assert(isIndex()); return Data >> 1; }
145    llvm::Value *getConstant() const {
146      assert(isConstant());
147      return reinterpret_cast<llvm::Value*>(Data);
148    }
149    EHScopeStack::stable_iterator getCleanup() const {
150      assert(isIndex());
151      return Cleanup;
152    }
153    void setCleanup(EHScopeStack::stable_iterator cleanup) {
154      assert(isIndex());
155      Cleanup = cleanup;
156    }
157
158    static Capture makeIndex(unsigned index) {
159      Capture v;
160      v.Data = (index << 1) | 1;
161      return v;
162    }
163
164    static Capture makeConstant(llvm::Value *value) {
165      Capture v;
166      v.Data = reinterpret_cast<uintptr_t>(value);
167      return v;
168    }
169  };
170
171  /// CanBeGlobal - True if the block can be global, i.e. it has
172  /// no non-constant captures.
173  bool CanBeGlobal : 1;
174
175  /// True if the block needs a custom copy or dispose function.
176  bool NeedsCopyDispose : 1;
177
178  /// HasCXXObject - True if the block's custom copy/dispose functions
179  /// need to be run even in GC mode.
180  bool HasCXXObject : 1;
181
182  /// UsesStret : True if the block uses an stret return.  Mutable
183  /// because it gets set later in the block-creation process.
184  mutable bool UsesStret : 1;
185
186  /// The mapping of allocated indexes within the block.
187  llvm::DenseMap<const VarDecl*, Capture> Captures;
188
189  llvm::AllocaInst *Address;
190  llvm::StructType *StructureType;
191  const BlockDecl *Block;
192  const BlockExpr *BlockExpression;
193  CharUnits BlockSize;
194  CharUnits BlockAlign;
195
196  /// An instruction which dominates the full-expression that the
197  /// block is inside.
198  llvm::Instruction *DominatingIP;
199
200  /// The next block in the block-info chain.  Invalid if this block
201  /// info is not part of the CGF's block-info chain, which is true
202  /// if it corresponds to a global block or a block whose expression
203  /// has been encountered.
204  CGBlockInfo *NextBlockInfo;
205
206  const Capture &getCapture(const VarDecl *var) const {
207    return const_cast<CGBlockInfo*>(this)->getCapture(var);
208  }
209  Capture &getCapture(const VarDecl *var) {
210    llvm::DenseMap<const VarDecl*, Capture>::iterator
211      it = Captures.find(var);
212    assert(it != Captures.end() && "no entry for variable!");
213    return it->second;
214  }
215
216  const BlockDecl *getBlockDecl() const { return Block; }
217  const BlockExpr *getBlockExpr() const {
218    assert(BlockExpression);
219    assert(BlockExpression->getBlockDecl() == Block);
220    return BlockExpression;
221  }
222
223  CGBlockInfo(const BlockDecl *blockDecl, llvm::StringRef Name);
224};
225
226}  // end namespace CodeGen
227}  // end namespace clang
228
229#endif
230