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Diffstat (limited to 'clang/lib/CodeGen/CGBlocks.h')
| -rw-r--r-- | clang/lib/CodeGen/CGBlocks.h | 298 | 
1 files changed, 298 insertions, 0 deletions
| diff --git a/clang/lib/CodeGen/CGBlocks.h b/clang/lib/CodeGen/CGBlocks.h new file mode 100644 index 000000000000..c4bfde666154 --- /dev/null +++ b/clang/lib/CodeGen/CGBlocks.h @@ -0,0 +1,298 @@ +//===-- CGBlocks.h - state for LLVM CodeGen for blocks ----------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This is the internal state used for llvm translation for block literals. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CLANG_LIB_CODEGEN_CGBLOCKS_H +#define LLVM_CLANG_LIB_CODEGEN_CGBLOCKS_H + +#include "CGBuilder.h" +#include "CGCall.h" +#include "CGValue.h" +#include "CodeGenFunction.h" +#include "CodeGenTypes.h" +#include "clang/AST/CharUnits.h" +#include "clang/AST/Expr.h" +#include "clang/AST/ExprCXX.h" +#include "clang/AST/ExprObjC.h" +#include "clang/AST/Type.h" +#include "clang/Basic/TargetInfo.h" + +namespace llvm { +class Constant; +class Function; +class GlobalValue; +class DataLayout; +class FunctionType; +class PointerType; +class Value; +class LLVMContext; +} + +namespace clang { +namespace CodeGen { + +class CGBlockInfo; + +// Flags stored in __block variables. +enum BlockByrefFlags { +  BLOCK_BYREF_HAS_COPY_DISPOSE         = (1   << 25), // compiler +  BLOCK_BYREF_LAYOUT_MASK              = (0xF << 28), // compiler +  BLOCK_BYREF_LAYOUT_EXTENDED          = (1   << 28), +  BLOCK_BYREF_LAYOUT_NON_OBJECT        = (2   << 28), +  BLOCK_BYREF_LAYOUT_STRONG            = (3   << 28), +  BLOCK_BYREF_LAYOUT_WEAK              = (4   << 28), +  BLOCK_BYREF_LAYOUT_UNRETAINED        = (5   << 28) +}; + +enum BlockLiteralFlags { +  BLOCK_IS_NOESCAPE      =  (1 << 23), +  BLOCK_HAS_COPY_DISPOSE =  (1 << 25), +  BLOCK_HAS_CXX_OBJ =       (1 << 26), +  BLOCK_IS_GLOBAL =         (1 << 28), +  BLOCK_USE_STRET =         (1 << 29), +  BLOCK_HAS_SIGNATURE  =    (1 << 30), +  BLOCK_HAS_EXTENDED_LAYOUT = (1u << 31) +}; +class BlockFlags { +  uint32_t flags; + +public: +  BlockFlags(uint32_t flags) : flags(flags) {} +  BlockFlags() : flags(0) {} +  BlockFlags(BlockLiteralFlags flag) : flags(flag) {} +  BlockFlags(BlockByrefFlags flag) : flags(flag) {} + +  uint32_t getBitMask() const { return flags; } +  bool empty() const { return flags == 0; } + +  friend BlockFlags operator|(BlockFlags l, BlockFlags r) { +    return BlockFlags(l.flags | r.flags); +  } +  friend BlockFlags &operator|=(BlockFlags &l, BlockFlags r) { +    l.flags |= r.flags; +    return l; +  } +  friend bool operator&(BlockFlags l, BlockFlags r) { +    return (l.flags & r.flags); +  } +  bool operator==(BlockFlags r) { +    return (flags == r.flags); +  } +}; +inline BlockFlags operator|(BlockLiteralFlags l, BlockLiteralFlags r) { +  return BlockFlags(l) | BlockFlags(r); +} + +enum BlockFieldFlag_t { +  BLOCK_FIELD_IS_OBJECT   = 0x03,  /* id, NSObject, __attribute__((NSObject)), +                                    block, ... */ +  BLOCK_FIELD_IS_BLOCK    = 0x07,  /* a block variable */ + +  BLOCK_FIELD_IS_BYREF    = 0x08,  /* the on stack structure holding the __block +                                    variable */ +  BLOCK_FIELD_IS_WEAK     = 0x10,  /* declared __weak, only used in byref copy +                                    helpers */ +  BLOCK_FIELD_IS_ARC      = 0x40,  /* field has ARC-specific semantics */ +  BLOCK_BYREF_CALLER      = 128,   /* called from __block (byref) copy/dispose +                                      support routines */ +  BLOCK_BYREF_CURRENT_MAX = 256 +}; + +class BlockFieldFlags { +  uint32_t flags; + +  BlockFieldFlags(uint32_t flags) : flags(flags) {} +public: +  BlockFieldFlags() : flags(0) {} +  BlockFieldFlags(BlockFieldFlag_t flag) : flags(flag) {} + +  uint32_t getBitMask() const { return flags; } +  bool empty() const { return flags == 0; } + +  /// Answers whether the flags indicate that this field is an object +  /// or block pointer that requires _Block_object_assign/dispose. +  bool isSpecialPointer() const { return flags & BLOCK_FIELD_IS_OBJECT; } + +  friend BlockFieldFlags operator|(BlockFieldFlags l, BlockFieldFlags r) { +    return BlockFieldFlags(l.flags | r.flags); +  } +  friend BlockFieldFlags &operator|=(BlockFieldFlags &l, BlockFieldFlags r) { +    l.flags |= r.flags; +    return l; +  } +  friend bool operator&(BlockFieldFlags l, BlockFieldFlags r) { +    return (l.flags & r.flags); +  } +  bool operator==(BlockFieldFlags Other) const { +    return flags == Other.flags; +  } +}; +inline BlockFieldFlags operator|(BlockFieldFlag_t l, BlockFieldFlag_t r) { +  return BlockFieldFlags(l) | BlockFieldFlags(r); +} + +/// Information about the layout of a __block variable. +class BlockByrefInfo { +public: +  llvm::StructType *Type; +  unsigned FieldIndex; +  CharUnits ByrefAlignment; +  CharUnits FieldOffset; +}; + +/// CGBlockInfo - Information to generate a block literal. +class CGBlockInfo { +public: +  /// Name - The name of the block, kindof. +  StringRef Name; + +  /// The field index of 'this' within the block, if there is one. +  unsigned CXXThisIndex; + +  class Capture { +    uintptr_t Data; +    EHScopeStack::stable_iterator Cleanup; +    CharUnits::QuantityType Offset; + +    /// Type of the capture field. Normally, this is identical to the type of +    /// the capture's VarDecl, but can be different if there is an enclosing +    /// lambda. +    QualType FieldType; + +  public: +    bool isIndex() const { return (Data & 1) != 0; } +    bool isConstant() const { return !isIndex(); } + +    unsigned getIndex() const { +      assert(isIndex()); +      return Data >> 1; +    } +    CharUnits getOffset() const { +      assert(isIndex()); +      return CharUnits::fromQuantity(Offset); +    } +    EHScopeStack::stable_iterator getCleanup() const { +      assert(isIndex()); +      return Cleanup; +    } +    void setCleanup(EHScopeStack::stable_iterator cleanup) { +      assert(isIndex()); +      Cleanup = cleanup; +    } + +    llvm::Value *getConstant() const { +      assert(isConstant()); +      return reinterpret_cast<llvm::Value*>(Data); +    } + +    QualType fieldType() const { +      return FieldType; +    } + +    static Capture makeIndex(unsigned index, CharUnits offset, +                             QualType FieldType) { +      Capture v; +      v.Data = (index << 1) | 1; +      v.Offset = offset.getQuantity(); +      v.FieldType = FieldType; +      return v; +    } + +    static Capture makeConstant(llvm::Value *value) { +      Capture v; +      v.Data = reinterpret_cast<uintptr_t>(value); +      return v; +    } +  }; + +  /// CanBeGlobal - True if the block can be global, i.e. it has +  /// no non-constant captures. +  bool CanBeGlobal : 1; + +  /// True if the block has captures that would necessitate custom copy or +  /// dispose helper functions if the block were escaping. +  bool NeedsCopyDispose : 1; + +  /// HasCXXObject - True if the block's custom copy/dispose functions +  /// need to be run even in GC mode. +  bool HasCXXObject : 1; + +  /// UsesStret : True if the block uses an stret return.  Mutable +  /// because it gets set later in the block-creation process. +  mutable bool UsesStret : 1; + +  /// HasCapturedVariableLayout : True if block has captured variables +  /// and their layout meta-data has been generated. +  bool HasCapturedVariableLayout : 1; + +  /// Indicates whether an object of a non-external C++ class is captured. This +  /// bit is used to determine the linkage of the block copy/destroy helper +  /// functions. +  bool CapturesNonExternalType : 1; + +  /// The mapping of allocated indexes within the block. +  llvm::DenseMap<const VarDecl*, Capture> Captures; + +  Address LocalAddress; +  llvm::StructType *StructureType; +  const BlockDecl *Block; +  const BlockExpr *BlockExpression; +  CharUnits BlockSize; +  CharUnits BlockAlign; +  CharUnits CXXThisOffset; + +  // Offset of the gap caused by block header having a smaller +  // alignment than the alignment of the block descriptor. This +  // is the gap offset before the first capturued field. +  CharUnits BlockHeaderForcedGapOffset; +  // Gap size caused by aligning first field after block header. +  // This could be zero if no forced alignment is required. +  CharUnits BlockHeaderForcedGapSize; + +  /// An instruction which dominates the full-expression that the +  /// block is inside. +  llvm::Instruction *DominatingIP; + +  /// The next block in the block-info chain.  Invalid if this block +  /// info is not part of the CGF's block-info chain, which is true +  /// if it corresponds to a global block or a block whose expression +  /// has been encountered. +  CGBlockInfo *NextBlockInfo; + +  const Capture &getCapture(const VarDecl *var) const { +    return const_cast<CGBlockInfo*>(this)->getCapture(var); +  } +  Capture &getCapture(const VarDecl *var) { +    llvm::DenseMap<const VarDecl*, Capture>::iterator +      it = Captures.find(var); +    assert(it != Captures.end() && "no entry for variable!"); +    return it->second; +  } + +  const BlockDecl *getBlockDecl() const { return Block; } +  const BlockExpr *getBlockExpr() const { +    assert(BlockExpression); +    assert(BlockExpression->getBlockDecl() == Block); +    return BlockExpression; +  } + +  CGBlockInfo(const BlockDecl *blockDecl, StringRef Name); + +  // Indicates whether the block needs a custom copy or dispose function. +  bool needsCopyDisposeHelpers() const { +    return NeedsCopyDispose && !Block->doesNotEscape(); +  } +}; + +}  // end namespace CodeGen +}  // end namespace clang + +#endif | 
