1 //===-- CGBlocks.h - state for LLVM CodeGen for blocks ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This is the internal state used for llvm translation for block literals.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_LIB_CODEGEN_CGBLOCKS_H
15 #define LLVM_CLANG_LIB_CODEGEN_CGBLOCKS_H
17 #include "CGBuilder.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"
45 // Flags stored in __block variables.
46 enum BlockByrefFlags {
47 BLOCK_BYREF_HAS_COPY_DISPOSE = (1 << 25), // compiler
48 BLOCK_BYREF_LAYOUT_MASK = (0xF << 28), // compiler
49 BLOCK_BYREF_LAYOUT_EXTENDED = (1 << 28),
50 BLOCK_BYREF_LAYOUT_NON_OBJECT = (2 << 28),
51 BLOCK_BYREF_LAYOUT_STRONG = (3 << 28),
52 BLOCK_BYREF_LAYOUT_WEAK = (4 << 28),
53 BLOCK_BYREF_LAYOUT_UNRETAINED = (5 << 28)
56 enum BlockLiteralFlags {
57 BLOCK_HAS_COPY_DISPOSE = (1 << 25),
58 BLOCK_HAS_CXX_OBJ = (1 << 26),
59 BLOCK_IS_GLOBAL = (1 << 28),
60 BLOCK_USE_STRET = (1 << 29),
61 BLOCK_HAS_SIGNATURE = (1 << 30),
62 BLOCK_HAS_EXTENDED_LAYOUT = (1 << 31)
68 BlockFlags(uint32_t flags) : flags(flags) {}
69 BlockFlags() : flags(0) {}
70 BlockFlags(BlockLiteralFlags flag) : flags(flag) {}
71 BlockFlags(BlockByrefFlags flag) : flags(flag) {}
73 uint32_t getBitMask() const { return flags; }
74 bool empty() const { return flags == 0; }
76 friend BlockFlags operator|(BlockFlags l, BlockFlags r) {
77 return BlockFlags(l.flags | r.flags);
79 friend BlockFlags &operator|=(BlockFlags &l, BlockFlags r) {
83 friend bool operator&(BlockFlags l, BlockFlags r) {
84 return (l.flags & r.flags);
86 bool operator==(BlockFlags r) {
87 return (flags == r.flags);
90 inline BlockFlags operator|(BlockLiteralFlags l, BlockLiteralFlags r) {
91 return BlockFlags(l) | BlockFlags(r);
94 enum BlockFieldFlag_t {
95 BLOCK_FIELD_IS_OBJECT = 0x03, /* id, NSObject, __attribute__((NSObject)),
97 BLOCK_FIELD_IS_BLOCK = 0x07, /* a block variable */
99 BLOCK_FIELD_IS_BYREF = 0x08, /* the on stack structure holding the __block
101 BLOCK_FIELD_IS_WEAK = 0x10, /* declared __weak, only used in byref copy
103 BLOCK_FIELD_IS_ARC = 0x40, /* field has ARC-specific semantics */
104 BLOCK_BYREF_CALLER = 128, /* called from __block (byref) copy/dispose
106 BLOCK_BYREF_CURRENT_MAX = 256
109 class BlockFieldFlags {
112 BlockFieldFlags(uint32_t flags) : flags(flags) {}
114 BlockFieldFlags() : flags(0) {}
115 BlockFieldFlags(BlockFieldFlag_t flag) : flags(flag) {}
117 uint32_t getBitMask() const { return flags; }
118 bool empty() const { return flags == 0; }
120 /// Answers whether the flags indicate that this field is an object
121 /// or block pointer that requires _Block_object_assign/dispose.
122 bool isSpecialPointer() const { return flags & BLOCK_FIELD_IS_OBJECT; }
124 friend BlockFieldFlags operator|(BlockFieldFlags l, BlockFieldFlags r) {
125 return BlockFieldFlags(l.flags | r.flags);
127 friend BlockFieldFlags &operator|=(BlockFieldFlags &l, BlockFieldFlags r) {
131 friend bool operator&(BlockFieldFlags l, BlockFieldFlags r) {
132 return (l.flags & r.flags);
135 inline BlockFieldFlags operator|(BlockFieldFlag_t l, BlockFieldFlag_t r) {
136 return BlockFieldFlags(l) | BlockFieldFlags(r);
139 /// Information about the layout of a __block variable.
140 class BlockByrefInfo {
142 llvm::StructType *Type;
144 CharUnits ByrefAlignment;
145 CharUnits FieldOffset;
148 /// CGBlockInfo - Information to generate a block literal.
151 /// Name - The name of the block, kindof.
154 /// The field index of 'this' within the block, if there is one.
155 unsigned CXXThisIndex;
159 EHScopeStack::stable_iterator Cleanup;
160 CharUnits::QuantityType Offset;
162 /// Type of the capture field. Normally, this is identical to the type of
163 /// the capture's VarDecl, but can be different if there is an enclosing
168 bool isIndex() const { return (Data & 1) != 0; }
169 bool isConstant() const { return !isIndex(); }
171 unsigned getIndex() const {
175 CharUnits getOffset() const {
177 return CharUnits::fromQuantity(Offset);
179 EHScopeStack::stable_iterator getCleanup() const {
183 void setCleanup(EHScopeStack::stable_iterator cleanup) {
188 llvm::Value *getConstant() const {
189 assert(isConstant());
190 return reinterpret_cast<llvm::Value*>(Data);
193 QualType fieldType() const {
197 static Capture makeIndex(unsigned index, CharUnits offset,
198 QualType FieldType) {
200 v.Data = (index << 1) | 1;
201 v.Offset = offset.getQuantity();
202 v.FieldType = FieldType;
206 static Capture makeConstant(llvm::Value *value) {
208 v.Data = reinterpret_cast<uintptr_t>(value);
213 /// CanBeGlobal - True if the block can be global, i.e. it has
214 /// no non-constant captures.
215 bool CanBeGlobal : 1;
217 /// True if the block needs a custom copy or dispose function.
218 bool NeedsCopyDispose : 1;
220 /// HasCXXObject - True if the block's custom copy/dispose functions
221 /// need to be run even in GC mode.
222 bool HasCXXObject : 1;
224 /// UsesStret : True if the block uses an stret return. Mutable
225 /// because it gets set later in the block-creation process.
226 mutable bool UsesStret : 1;
228 /// HasCapturedVariableLayout : True if block has captured variables
229 /// and their layout meta-data has been generated.
230 bool HasCapturedVariableLayout : 1;
232 /// The mapping of allocated indexes within the block.
233 llvm::DenseMap<const VarDecl*, Capture> Captures;
235 Address LocalAddress;
236 llvm::StructType *StructureType;
237 const BlockDecl *Block;
238 const BlockExpr *BlockExpression;
240 CharUnits BlockAlign;
241 CharUnits CXXThisOffset;
243 // Offset of the gap caused by block header having a smaller
244 // alignment than the alignment of the block descriptor. This
245 // is the gap offset before the first capturued field.
246 CharUnits BlockHeaderForcedGapOffset;
247 // Gap size caused by aligning first field after block header.
248 // This could be zero if no forced alignment is required.
249 CharUnits BlockHeaderForcedGapSize;
251 /// An instruction which dominates the full-expression that the
253 llvm::Instruction *DominatingIP;
255 /// The next block in the block-info chain. Invalid if this block
256 /// info is not part of the CGF's block-info chain, which is true
257 /// if it corresponds to a global block or a block whose expression
258 /// has been encountered.
259 CGBlockInfo *NextBlockInfo;
261 const Capture &getCapture(const VarDecl *var) const {
262 return const_cast<CGBlockInfo*>(this)->getCapture(var);
264 Capture &getCapture(const VarDecl *var) {
265 llvm::DenseMap<const VarDecl*, Capture>::iterator
266 it = Captures.find(var);
267 assert(it != Captures.end() && "no entry for variable!");
271 const BlockDecl *getBlockDecl() const { return Block; }
272 const BlockExpr *getBlockExpr() const {
273 assert(BlockExpression);
274 assert(BlockExpression->getBlockDecl() == Block);
275 return BlockExpression;
278 CGBlockInfo(const BlockDecl *blockDecl, StringRef Name);
281 } // end namespace CodeGen
282 } // end namespace clang