clang  3.7.0
CGBlocks.h
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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 LLVM_CLANG_LIB_CODEGEN_CGBLOCKS_H
15 #define LLVM_CLANG_LIB_CODEGEN_CGBLOCKS_H
16 
17 #include "CGBuilder.h"
18 #include "CGCall.h"
19 #include "CGValue.h"
20 #include "CodeGenFunction.h"
21 #include "CodeGenTypes.h"
22 #include "clang/AST/CharUnits.h"
23 #include "clang/AST/Expr.h"
24 #include "clang/AST/ExprCXX.h"
25 #include "clang/AST/ExprObjC.h"
26 #include "clang/AST/Type.h"
27 #include "clang/Basic/TargetInfo.h"
28 #include "llvm/IR/Module.h"
29 
30 namespace llvm {
31 class Module;
32 class Constant;
33 class Function;
34 class GlobalValue;
35 class DataLayout;
36 class FunctionType;
37 class PointerType;
38 class Value;
39 class LLVMContext;
40 }
41 
42 namespace clang {
43 
44 namespace CodeGen {
45 
46 class CodeGenModule;
47 class CGBlockInfo;
48 
49 // Flags stored in __block variables.
51  BLOCK_BYREF_HAS_COPY_DISPOSE = (1 << 25), // compiler
52  BLOCK_BYREF_LAYOUT_MASK = (0xF << 28), // compiler
58 };
59 
62  BLOCK_HAS_CXX_OBJ = (1 << 26),
63  BLOCK_IS_GLOBAL = (1 << 28),
64  BLOCK_USE_STRET = (1 << 29),
65  BLOCK_HAS_SIGNATURE = (1 << 30),
67 };
68 class BlockFlags {
69  uint32_t flags;
70 
71 public:
72  BlockFlags(uint32_t flags) : flags(flags) {}
73  BlockFlags() : flags(0) {}
74  BlockFlags(BlockLiteralFlags flag) : flags(flag) {}
75  BlockFlags(BlockByrefFlags flag) : flags(flag) {}
76 
77  uint32_t getBitMask() const { return flags; }
78  bool empty() const { return flags == 0; }
79 
81  return BlockFlags(l.flags | r.flags);
82  }
84  l.flags |= r.flags;
85  return l;
86  }
87  friend bool operator&(BlockFlags l, BlockFlags r) {
88  return (l.flags & r.flags);
89  }
91  return (flags == r.flags);
92  }
93 };
95  return BlockFlags(l) | BlockFlags(r);
96 }
97 
99  BLOCK_FIELD_IS_OBJECT = 0x03, /* id, NSObject, __attribute__((NSObject)),
100  block, ... */
101  BLOCK_FIELD_IS_BLOCK = 0x07, /* a block variable */
102 
103  BLOCK_FIELD_IS_BYREF = 0x08, /* the on stack structure holding the __block
104  variable */
105  BLOCK_FIELD_IS_WEAK = 0x10, /* declared __weak, only used in byref copy
106  helpers */
107  BLOCK_FIELD_IS_ARC = 0x40, /* field has ARC-specific semantics */
108  BLOCK_BYREF_CALLER = 128, /* called from __block (byref) copy/dispose
109  support routines */
111 };
112 
114  uint32_t flags;
115 
116  BlockFieldFlags(uint32_t flags) : flags(flags) {}
117 public:
118  BlockFieldFlags() : flags(0) {}
119  BlockFieldFlags(BlockFieldFlag_t flag) : flags(flag) {}
120 
121  uint32_t getBitMask() const { return flags; }
122  bool empty() const { return flags == 0; }
123 
124  /// Answers whether the flags indicate that this field is an object
125  /// or block pointer that requires _Block_object_assign/dispose.
126  bool isSpecialPointer() const { return flags & BLOCK_FIELD_IS_OBJECT; }
127 
129  return BlockFieldFlags(l.flags | r.flags);
130  }
132  l.flags |= r.flags;
133  return l;
134  }
136  return (l.flags & r.flags);
137  }
138 };
140  return BlockFieldFlags(l) | BlockFieldFlags(r);
141 }
142 
143 /// CGBlockInfo - Information to generate a block literal.
144 class CGBlockInfo {
145 public:
146  /// Name - The name of the block, kindof.
147  StringRef Name;
148 
149  /// The field index of 'this' within the block, if there is one.
150  unsigned CXXThisIndex;
151 
152  class Capture {
153  uintptr_t Data;
155 
156  public:
157  bool isIndex() const { return (Data & 1) != 0; }
158  bool isConstant() const { return !isIndex(); }
159  unsigned getIndex() const { assert(isIndex()); return Data >> 1; }
161  assert(isConstant());
162  return reinterpret_cast<llvm::Value*>(Data);
163  }
165  assert(isIndex());
166  return Cleanup;
167  }
169  assert(isIndex());
170  Cleanup = cleanup;
171  }
172 
173  static Capture makeIndex(unsigned index) {
174  Capture v;
175  v.Data = (index << 1) | 1;
176  return v;
177  }
178 
180  Capture v;
181  v.Data = reinterpret_cast<uintptr_t>(value);
182  return v;
183  }
184  };
185 
186  /// CanBeGlobal - True if the block can be global, i.e. it has
187  /// no non-constant captures.
188  bool CanBeGlobal : 1;
189 
190  /// True if the block needs a custom copy or dispose function.
192 
193  /// HasCXXObject - True if the block's custom copy/dispose functions
194  /// need to be run even in GC mode.
195  bool HasCXXObject : 1;
196 
197  /// UsesStret : True if the block uses an stret return. Mutable
198  /// because it gets set later in the block-creation process.
199  mutable bool UsesStret : 1;
200 
201  /// HasCapturedVariableLayout : True if block has captured variables
202  /// and their layout meta-data has been generated.
204 
205  /// The mapping of allocated indexes within the block.
206  llvm::DenseMap<const VarDecl*, Capture> Captures;
207 
208  llvm::AllocaInst *Address;
209  llvm::StructType *StructureType;
210  const BlockDecl *Block;
214 
215  // Offset of the gap caused by block header having a smaller
216  // alignment than the alignment of the block descriptor. This
217  // is the gap offset before the first capturued field.
219  // Gap size caused by aligning first field after block header.
220  // This could be zero if no forced alignment is required.
222 
223  /// An instruction which dominates the full-expression that the
224  /// block is inside.
225  llvm::Instruction *DominatingIP;
226 
227  /// The next block in the block-info chain. Invalid if this block
228  /// info is not part of the CGF's block-info chain, which is true
229  /// if it corresponds to a global block or a block whose expression
230  /// has been encountered.
232 
233  const Capture &getCapture(const VarDecl *var) const {
234  return const_cast<CGBlockInfo*>(this)->getCapture(var);
235  }
236  Capture &getCapture(const VarDecl *var) {
237  llvm::DenseMap<const VarDecl*, Capture>::iterator
238  it = Captures.find(var);
239  assert(it != Captures.end() && "no entry for variable!");
240  return it->second;
241  }
242 
243  const BlockDecl *getBlockDecl() const { return Block; }
244  const BlockExpr *getBlockExpr() const {
245  assert(BlockExpression);
246  assert(BlockExpression->getBlockDecl() == Block);
247  return BlockExpression;
248  }
249 
250  CGBlockInfo(const BlockDecl *blockDecl, StringRef Name);
251 };
252 
253 } // end namespace CodeGen
254 } // end namespace clang
255 
256 #endif
CharUnits BlockHeaderForcedGapOffset
Definition: CGBlocks.h:218
Capture & getCapture(const VarDecl *var)
Definition: CGBlocks.h:236
BlockFlags operator|(BlockLiteralFlags l, BlockLiteralFlags r)
Definition: CGBlocks.h:94
static Capture makeIndex(unsigned index)
Definition: CGBlocks.h:173
friend BlockFieldFlags operator|(BlockFieldFlags l, BlockFieldFlags r)
Definition: CGBlocks.h:128
bool operator==(BlockFlags r)
Definition: CGBlocks.h:90
BlockFlags(uint32_t flags)
Definition: CGBlocks.h:72
uint32_t getBitMask() const
Definition: CGBlocks.h:121
CGBlockInfo(const BlockDecl *blockDecl, StringRef Name)
Definition: CGBlocks.cpp:30
Defines the clang::Expr interface and subclasses for C++ expressions.
const BlockDecl * Block
Definition: CGBlocks.h:210
BlockFlags(BlockByrefFlags flag)
Definition: CGBlocks.h:75
friend bool operator&(BlockFieldFlags l, BlockFieldFlags r)
Definition: CGBlocks.h:135
const Capture & getCapture(const VarDecl *var) const
Definition: CGBlocks.h:233
BlockFieldFlags(BlockFieldFlag_t flag)
Definition: CGBlocks.h:119
static Capture makeConstant(llvm::Value *value)
Definition: CGBlocks.h:179
friend BlockFieldFlags & operator|=(BlockFieldFlags &l, BlockFieldFlags r)
Definition: CGBlocks.h:131
StringRef Name
Name - The name of the block, kindof.
Definition: CGBlocks.h:147
bool NeedsCopyDispose
True if the block needs a custom copy or dispose function.
Definition: CGBlocks.h:191
const BlockExpr * BlockExpression
Definition: CGBlocks.h:211
CGBlockInfo - Information to generate a block literal.
Definition: CGBlocks.h:144
BlockFlags(BlockLiteralFlags flag)
Definition: CGBlocks.h:74
CGBlockInfo * NextBlockInfo
Definition: CGBlocks.h:231
bool isSpecialPointer() const
Definition: CGBlocks.h:126
friend BlockFlags operator|(BlockFlags l, BlockFlags r)
Definition: CGBlocks.h:80
do v
Definition: arm_acle.h:77
EHScopeStack::stable_iterator getCleanup() const
Definition: CGBlocks.h:164
llvm::StructType * StructureType
Definition: CGBlocks.h:209
bool empty() const
Definition: CGBlocks.h:78
llvm::DenseMap< const VarDecl *, Capture > Captures
The mapping of allocated indexes within the block.
Definition: CGBlocks.h:206
unsigned CXXThisIndex
The field index of 'this' within the block, if there is one.
Definition: CGBlocks.h:150
const BlockDecl * getBlockDecl() const
Definition: Expr.h:4616
llvm::AllocaInst * Address
Definition: CGBlocks.h:208
llvm::Value * getConstant() const
Definition: CGBlocks.h:160
friend BlockFlags & operator|=(BlockFlags &l, BlockFlags r)
Definition: CGBlocks.h:83
friend bool operator&(BlockFlags l, BlockFlags r)
Definition: CGBlocks.h:87
uint32_t getBitMask() const
Definition: CGBlocks.h:77
const BlockDecl * getBlockDecl() const
Definition: CGBlocks.h:243
CharUnits BlockHeaderForcedGapSize
Definition: CGBlocks.h:221
Defines the clang::TargetInfo interface.
const BlockExpr * getBlockExpr() const
Definition: CGBlocks.h:244
llvm::Instruction * DominatingIP
Definition: CGBlocks.h:225
void setCleanup(EHScopeStack::stable_iterator cleanup)
Definition: CGBlocks.h:168