| //===-- 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; |
| |
| /// 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 |