| //===--- CGBlocks.cpp - Emit LLVM Code for declarations -------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This contains code to emit blocks. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CGDebugInfo.h" |
| #include "CodeGenFunction.h" |
| #include "CGObjCRuntime.h" |
| #include "CodeGenModule.h" |
| #include "CGBlocks.h" |
| #include "clang/AST/DeclObjC.h" |
| #include "llvm/Module.h" |
| #include "llvm/ADT/SmallSet.h" |
| #include "llvm/Target/TargetData.h" |
| #include <algorithm> |
| |
| using namespace clang; |
| using namespace CodeGen; |
| |
| CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name) |
| : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false), |
| HasCXXObject(false), UsesStret(false), StructureType(0), Block(block), |
| DominatingIP(0) { |
| |
| // Skip asm prefix, if any. 'name' is usually taken directly from |
| // the mangled name of the enclosing function. |
| if (!name.empty() && name[0] == '\01') |
| name = name.substr(1); |
| } |
| |
| // Anchor the vtable to this translation unit. |
| CodeGenModule::ByrefHelpers::~ByrefHelpers() {} |
| |
| /// Build the given block as a global block. |
| static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM, |
| const CGBlockInfo &blockInfo, |
| llvm::Constant *blockFn); |
| |
| /// Build the helper function to copy a block. |
| static llvm::Constant *buildCopyHelper(CodeGenModule &CGM, |
| const CGBlockInfo &blockInfo) { |
| return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo); |
| } |
| |
| /// Build the helper function to dipose of a block. |
| static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM, |
| const CGBlockInfo &blockInfo) { |
| return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo); |
| } |
| |
| /// Build the block descriptor constant for a block. |
| static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM, |
| const CGBlockInfo &blockInfo) { |
| ASTContext &C = CGM.getContext(); |
| |
| llvm::Type *ulong = CGM.getTypes().ConvertType(C.UnsignedLongTy); |
| llvm::Type *i8p = CGM.getTypes().ConvertType(C.VoidPtrTy); |
| |
| SmallVector<llvm::Constant*, 6> elements; |
| |
| // reserved |
| elements.push_back(llvm::ConstantInt::get(ulong, 0)); |
| |
| // Size |
| // FIXME: What is the right way to say this doesn't fit? We should give |
| // a user diagnostic in that case. Better fix would be to change the |
| // API to size_t. |
| elements.push_back(llvm::ConstantInt::get(ulong, |
| blockInfo.BlockSize.getQuantity())); |
| |
| // Optional copy/dispose helpers. |
| if (blockInfo.NeedsCopyDispose) { |
| // copy_func_helper_decl |
| elements.push_back(buildCopyHelper(CGM, blockInfo)); |
| |
| // destroy_func_decl |
| elements.push_back(buildDisposeHelper(CGM, blockInfo)); |
| } |
| |
| // Signature. Mandatory ObjC-style method descriptor @encode sequence. |
| std::string typeAtEncoding = |
| CGM.getContext().getObjCEncodingForBlock(blockInfo.getBlockExpr()); |
| elements.push_back(llvm::ConstantExpr::getBitCast( |
| CGM.GetAddrOfConstantCString(typeAtEncoding), i8p)); |
| |
| // GC layout. |
| if (C.getLangOpts().ObjC1) |
| elements.push_back(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo)); |
| else |
| elements.push_back(llvm::Constant::getNullValue(i8p)); |
| |
| llvm::Constant *init = llvm::ConstantStruct::getAnon(elements); |
| |
| llvm::GlobalVariable *global = |
| new llvm::GlobalVariable(CGM.getModule(), init->getType(), true, |
| llvm::GlobalValue::InternalLinkage, |
| init, "__block_descriptor_tmp"); |
| |
| return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType()); |
| } |
| |
| /* |
| Purely notional variadic template describing the layout of a block. |
| |
| template <class _ResultType, class... _ParamTypes, class... _CaptureTypes> |
| struct Block_literal { |
| /// Initialized to one of: |
| /// extern void *_NSConcreteStackBlock[]; |
| /// extern void *_NSConcreteGlobalBlock[]; |
| /// |
| /// In theory, we could start one off malloc'ed by setting |
| /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using |
| /// this isa: |
| /// extern void *_NSConcreteMallocBlock[]; |
| struct objc_class *isa; |
| |
| /// These are the flags (with corresponding bit number) that the |
| /// compiler is actually supposed to know about. |
| /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block |
| /// descriptor provides copy and dispose helper functions |
| /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured |
| /// object with a nontrivial destructor or copy constructor |
| /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated |
| /// as global memory |
| /// 29. BLOCK_USE_STRET - indicates that the block function |
| /// uses stret, which objc_msgSend needs to know about |
| /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an |
| /// @encoded signature string |
| /// And we're not supposed to manipulate these: |
| /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved |
| /// to malloc'ed memory |
| /// 27. BLOCK_IS_GC - indicates that the block has been moved to |
| /// to GC-allocated memory |
| /// Additionally, the bottom 16 bits are a reference count which |
| /// should be zero on the stack. |
| int flags; |
| |
| /// Reserved; should be zero-initialized. |
| int reserved; |
| |
| /// Function pointer generated from block literal. |
| _ResultType (*invoke)(Block_literal *, _ParamTypes...); |
| |
| /// Block description metadata generated from block literal. |
| struct Block_descriptor *block_descriptor; |
| |
| /// Captured values follow. |
| _CapturesTypes captures...; |
| }; |
| */ |
| |
| /// The number of fields in a block header. |
| const unsigned BlockHeaderSize = 5; |
| |
| namespace { |
| /// A chunk of data that we actually have to capture in the block. |
| struct BlockLayoutChunk { |
| CharUnits Alignment; |
| CharUnits Size; |
| const BlockDecl::Capture *Capture; // null for 'this' |
| llvm::Type *Type; |
| |
| BlockLayoutChunk(CharUnits align, CharUnits size, |
| const BlockDecl::Capture *capture, |
| llvm::Type *type) |
| : Alignment(align), Size(size), Capture(capture), Type(type) {} |
| |
| /// Tell the block info that this chunk has the given field index. |
| void setIndex(CGBlockInfo &info, unsigned index) { |
| if (!Capture) |
| info.CXXThisIndex = index; |
| else |
| info.Captures[Capture->getVariable()] |
| = CGBlockInfo::Capture::makeIndex(index); |
| } |
| }; |
| |
| /// Order by descending alignment. |
| bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) { |
| return left.Alignment > right.Alignment; |
| } |
| } |
| |
| /// Determines if the given type is safe for constant capture in C++. |
| static bool isSafeForCXXConstantCapture(QualType type) { |
| const RecordType *recordType = |
| type->getBaseElementTypeUnsafe()->getAs<RecordType>(); |
| |
| // Only records can be unsafe. |
| if (!recordType) return true; |
| |
| const CXXRecordDecl *record = cast<CXXRecordDecl>(recordType->getDecl()); |
| |
| // Maintain semantics for classes with non-trivial dtors or copy ctors. |
| if (!record->hasTrivialDestructor()) return false; |
| if (!record->hasTrivialCopyConstructor()) return false; |
| |
| // Otherwise, we just have to make sure there aren't any mutable |
| // fields that might have changed since initialization. |
| return !record->hasMutableFields(); |
| } |
| |
| /// It is illegal to modify a const object after initialization. |
| /// Therefore, if a const object has a constant initializer, we don't |
| /// actually need to keep storage for it in the block; we'll just |
| /// rematerialize it at the start of the block function. This is |
| /// acceptable because we make no promises about address stability of |
| /// captured variables. |
| static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM, |
| CodeGenFunction *CGF, |
| const VarDecl *var) { |
| QualType type = var->getType(); |
| |
| // We can only do this if the variable is const. |
| if (!type.isConstQualified()) return 0; |
| |
| // Furthermore, in C++ we have to worry about mutable fields: |
| // C++ [dcl.type.cv]p4: |
| // Except that any class member declared mutable can be |
| // modified, any attempt to modify a const object during its |
| // lifetime results in undefined behavior. |
| if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type)) |
| return 0; |
| |
| // If the variable doesn't have any initializer (shouldn't this be |
| // invalid?), it's not clear what we should do. Maybe capture as |
| // zero? |
| const Expr *init = var->getInit(); |
| if (!init) return 0; |
| |
| return CGM.EmitConstantInit(*var, CGF); |
| } |
| |
| /// Get the low bit of a nonzero character count. This is the |
| /// alignment of the nth byte if the 0th byte is universally aligned. |
| static CharUnits getLowBit(CharUnits v) { |
| return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1)); |
| } |
| |
| static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info, |
| SmallVectorImpl<llvm::Type*> &elementTypes) { |
| ASTContext &C = CGM.getContext(); |
| |
| // The header is basically a 'struct { void *; int; int; void *; void *; }'. |
| CharUnits ptrSize, ptrAlign, intSize, intAlign; |
| llvm::tie(ptrSize, ptrAlign) = C.getTypeInfoInChars(C.VoidPtrTy); |
| llvm::tie(intSize, intAlign) = C.getTypeInfoInChars(C.IntTy); |
| |
| // Are there crazy embedded platforms where this isn't true? |
| assert(intSize <= ptrSize && "layout assumptions horribly violated"); |
| |
| CharUnits headerSize = ptrSize; |
| if (2 * intSize < ptrAlign) headerSize += ptrSize; |
| else headerSize += 2 * intSize; |
| headerSize += 2 * ptrSize; |
| |
| info.BlockAlign = ptrAlign; |
| info.BlockSize = headerSize; |
| |
| assert(elementTypes.empty()); |
| llvm::Type *i8p = CGM.getTypes().ConvertType(C.VoidPtrTy); |
| llvm::Type *intTy = CGM.getTypes().ConvertType(C.IntTy); |
| elementTypes.push_back(i8p); |
| elementTypes.push_back(intTy); |
| elementTypes.push_back(intTy); |
| elementTypes.push_back(i8p); |
| elementTypes.push_back(CGM.getBlockDescriptorType()); |
| |
| assert(elementTypes.size() == BlockHeaderSize); |
| } |
| |
| /// Compute the layout of the given block. Attempts to lay the block |
| /// out with minimal space requirements. |
| static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF, |
| CGBlockInfo &info) { |
| ASTContext &C = CGM.getContext(); |
| const BlockDecl *block = info.getBlockDecl(); |
| |
| SmallVector<llvm::Type*, 8> elementTypes; |
| initializeForBlockHeader(CGM, info, elementTypes); |
| |
| if (!block->hasCaptures()) { |
| info.StructureType = |
| llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); |
| info.CanBeGlobal = true; |
| return; |
| } |
| |
| // Collect the layout chunks. |
| SmallVector<BlockLayoutChunk, 16> layout; |
| layout.reserve(block->capturesCXXThis() + |
| (block->capture_end() - block->capture_begin())); |
| |
| CharUnits maxFieldAlign; |
| |
| // First, 'this'. |
| if (block->capturesCXXThis()) { |
| const DeclContext *DC = block->getDeclContext(); |
| for (; isa<BlockDecl>(DC); DC = cast<BlockDecl>(DC)->getDeclContext()) |
| ; |
| QualType thisType; |
| if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) |
| thisType = C.getPointerType(C.getRecordType(RD)); |
| else |
| thisType = cast<CXXMethodDecl>(DC)->getThisType(C); |
| |
| llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType); |
| std::pair<CharUnits,CharUnits> tinfo |
| = CGM.getContext().getTypeInfoInChars(thisType); |
| maxFieldAlign = std::max(maxFieldAlign, tinfo.second); |
| |
| layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first, 0, llvmType)); |
| } |
| |
| // Next, all the block captures. |
| for (BlockDecl::capture_const_iterator ci = block->capture_begin(), |
| ce = block->capture_end(); ci != ce; ++ci) { |
| const VarDecl *variable = ci->getVariable(); |
| |
| if (ci->isByRef()) { |
| // We have to copy/dispose of the __block reference. |
| info.NeedsCopyDispose = true; |
| |
| // Just use void* instead of a pointer to the byref type. |
| QualType byRefPtrTy = C.VoidPtrTy; |
| |
| llvm::Type *llvmType = CGM.getTypes().ConvertType(byRefPtrTy); |
| std::pair<CharUnits,CharUnits> tinfo |
| = CGM.getContext().getTypeInfoInChars(byRefPtrTy); |
| maxFieldAlign = std::max(maxFieldAlign, tinfo.second); |
| |
| layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first, |
| &*ci, llvmType)); |
| continue; |
| } |
| |
| // Otherwise, build a layout chunk with the size and alignment of |
| // the declaration. |
| if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) { |
| info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant); |
| continue; |
| } |
| |
| // If we have a lifetime qualifier, honor it for capture purposes. |
| // That includes *not* copying it if it's __unsafe_unretained. |
| if (Qualifiers::ObjCLifetime lifetime |
| = variable->getType().getObjCLifetime()) { |
| switch (lifetime) { |
| case Qualifiers::OCL_None: llvm_unreachable("impossible"); |
| case Qualifiers::OCL_ExplicitNone: |
| case Qualifiers::OCL_Autoreleasing: |
| break; |
| |
| case Qualifiers::OCL_Strong: |
| case Qualifiers::OCL_Weak: |
| info.NeedsCopyDispose = true; |
| } |
| |
| // Block pointers require copy/dispose. So do Objective-C pointers. |
| } else if (variable->getType()->isObjCRetainableType()) { |
| info.NeedsCopyDispose = true; |
| |
| // So do types that require non-trivial copy construction. |
| } else if (ci->hasCopyExpr()) { |
| info.NeedsCopyDispose = true; |
| info.HasCXXObject = true; |
| |
| // And so do types with destructors. |
| } else if (CGM.getLangOpts().CPlusPlus) { |
| if (const CXXRecordDecl *record = |
| variable->getType()->getAsCXXRecordDecl()) { |
| if (!record->hasTrivialDestructor()) { |
| info.HasCXXObject = true; |
| info.NeedsCopyDispose = true; |
| } |
| } |
| } |
| |
| QualType VT = variable->getType(); |
| CharUnits size = C.getTypeSizeInChars(VT); |
| CharUnits align = C.getDeclAlign(variable); |
| |
| maxFieldAlign = std::max(maxFieldAlign, align); |
| |
| llvm::Type *llvmType = |
| CGM.getTypes().ConvertTypeForMem(VT); |
| |
| layout.push_back(BlockLayoutChunk(align, size, &*ci, llvmType)); |
| } |
| |
| // If that was everything, we're done here. |
| if (layout.empty()) { |
| info.StructureType = |
| llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); |
| info.CanBeGlobal = true; |
| return; |
| } |
| |
| // Sort the layout by alignment. We have to use a stable sort here |
| // to get reproducible results. There should probably be an |
| // llvm::array_pod_stable_sort. |
| std::stable_sort(layout.begin(), layout.end()); |
| |
| CharUnits &blockSize = info.BlockSize; |
| info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign); |
| |
| // Assuming that the first byte in the header is maximally aligned, |
| // get the alignment of the first byte following the header. |
| CharUnits endAlign = getLowBit(blockSize); |
| |
| // If the end of the header isn't satisfactorily aligned for the |
| // maximum thing, look for things that are okay with the header-end |
| // alignment, and keep appending them until we get something that's |
| // aligned right. This algorithm is only guaranteed optimal if |
| // that condition is satisfied at some point; otherwise we can get |
| // things like: |
| // header // next byte has alignment 4 |
| // something_with_size_5; // next byte has alignment 1 |
| // something_with_alignment_8; |
| // which has 7 bytes of padding, as opposed to the naive solution |
| // which might have less (?). |
| if (endAlign < maxFieldAlign) { |
| SmallVectorImpl<BlockLayoutChunk>::iterator |
| li = layout.begin() + 1, le = layout.end(); |
| |
| // Look for something that the header end is already |
| // satisfactorily aligned for. |
| for (; li != le && endAlign < li->Alignment; ++li) |
| ; |
| |
| // If we found something that's naturally aligned for the end of |
| // the header, keep adding things... |
| if (li != le) { |
| SmallVectorImpl<BlockLayoutChunk>::iterator first = li; |
| for (; li != le; ++li) { |
| assert(endAlign >= li->Alignment); |
| |
| li->setIndex(info, elementTypes.size()); |
| elementTypes.push_back(li->Type); |
| blockSize += li->Size; |
| endAlign = getLowBit(blockSize); |
| |
| // ...until we get to the alignment of the maximum field. |
| if (endAlign >= maxFieldAlign) |
| break; |
| } |
| |
| // Don't re-append everything we just appended. |
| layout.erase(first, li); |
| } |
| } |
| |
| assert(endAlign == getLowBit(blockSize)); |
| |
| // At this point, we just have to add padding if the end align still |
| // isn't aligned right. |
| if (endAlign < maxFieldAlign) { |
| CharUnits newBlockSize = blockSize.RoundUpToAlignment(maxFieldAlign); |
| CharUnits padding = newBlockSize - blockSize; |
| |
| elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty, |
| padding.getQuantity())); |
| blockSize = newBlockSize; |
| endAlign = getLowBit(blockSize); // might be > maxFieldAlign |
| } |
| |
| assert(endAlign >= maxFieldAlign); |
| assert(endAlign == getLowBit(blockSize)); |
| |
| // Slam everything else on now. This works because they have |
| // strictly decreasing alignment and we expect that size is always a |
| // multiple of alignment. |
| for (SmallVectorImpl<BlockLayoutChunk>::iterator |
| li = layout.begin(), le = layout.end(); li != le; ++li) { |
| assert(endAlign >= li->Alignment); |
| li->setIndex(info, elementTypes.size()); |
| elementTypes.push_back(li->Type); |
| blockSize += li->Size; |
| endAlign = getLowBit(blockSize); |
| } |
| |
| info.StructureType = |
| llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true); |
| } |
| |
| /// Enter the scope of a block. This should be run at the entrance to |
| /// a full-expression so that the block's cleanups are pushed at the |
| /// right place in the stack. |
| static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) { |
| assert(CGF.HaveInsertPoint()); |
| |
| // Allocate the block info and place it at the head of the list. |
| CGBlockInfo &blockInfo = |
| *new CGBlockInfo(block, CGF.CurFn->getName()); |
| blockInfo.NextBlockInfo = CGF.FirstBlockInfo; |
| CGF.FirstBlockInfo = &blockInfo; |
| |
| // Compute information about the layout, etc., of this block, |
| // pushing cleanups as necessary. |
| computeBlockInfo(CGF.CGM, &CGF, blockInfo); |
| |
| // Nothing else to do if it can be global. |
| if (blockInfo.CanBeGlobal) return; |
| |
| // Make the allocation for the block. |
| blockInfo.Address = |
| CGF.CreateTempAlloca(blockInfo.StructureType, "block"); |
| blockInfo.Address->setAlignment(blockInfo.BlockAlign.getQuantity()); |
| |
| // If there are cleanups to emit, enter them (but inactive). |
| if (!blockInfo.NeedsCopyDispose) return; |
| |
| // Walk through the captures (in order) and find the ones not |
| // captured by constant. |
| for (BlockDecl::capture_const_iterator ci = block->capture_begin(), |
| ce = block->capture_end(); ci != ce; ++ci) { |
| // Ignore __block captures; there's nothing special in the |
| // on-stack block that we need to do for them. |
| if (ci->isByRef()) continue; |
| |
| // Ignore variables that are constant-captured. |
| const VarDecl *variable = ci->getVariable(); |
| CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); |
| if (capture.isConstant()) continue; |
| |
| // Ignore objects that aren't destructed. |
| QualType::DestructionKind dtorKind = |
| variable->getType().isDestructedType(); |
| if (dtorKind == QualType::DK_none) continue; |
| |
| CodeGenFunction::Destroyer *destroyer; |
| |
| // Block captures count as local values and have imprecise semantics. |
| // They also can't be arrays, so need to worry about that. |
| if (dtorKind == QualType::DK_objc_strong_lifetime) { |
| destroyer = CodeGenFunction::destroyARCStrongImprecise; |
| } else { |
| destroyer = CGF.getDestroyer(dtorKind); |
| } |
| |
| // GEP down to the address. |
| llvm::Value *addr = CGF.Builder.CreateStructGEP(blockInfo.Address, |
| capture.getIndex()); |
| |
| // We can use that GEP as the dominating IP. |
| if (!blockInfo.DominatingIP) |
| blockInfo.DominatingIP = cast<llvm::Instruction>(addr); |
| |
| CleanupKind cleanupKind = InactiveNormalCleanup; |
| bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind); |
| if (useArrayEHCleanup) |
| cleanupKind = InactiveNormalAndEHCleanup; |
| |
| CGF.pushDestroy(cleanupKind, addr, variable->getType(), |
| destroyer, useArrayEHCleanup); |
| |
| // Remember where that cleanup was. |
| capture.setCleanup(CGF.EHStack.stable_begin()); |
| } |
| } |
| |
| /// Enter a full-expression with a non-trivial number of objects to |
| /// clean up. This is in this file because, at the moment, the only |
| /// kind of cleanup object is a BlockDecl*. |
| void CodeGenFunction::enterNonTrivialFullExpression(const ExprWithCleanups *E) { |
| assert(E->getNumObjects() != 0); |
| ArrayRef<ExprWithCleanups::CleanupObject> cleanups = E->getObjects(); |
| for (ArrayRef<ExprWithCleanups::CleanupObject>::iterator |
| i = cleanups.begin(), e = cleanups.end(); i != e; ++i) { |
| enterBlockScope(*this, *i); |
| } |
| } |
| |
| /// Find the layout for the given block in a linked list and remove it. |
| static CGBlockInfo *findAndRemoveBlockInfo(CGBlockInfo **head, |
| const BlockDecl *block) { |
| while (true) { |
| assert(head && *head); |
| CGBlockInfo *cur = *head; |
| |
| // If this is the block we're looking for, splice it out of the list. |
| if (cur->getBlockDecl() == block) { |
| *head = cur->NextBlockInfo; |
| return cur; |
| } |
| |
| head = &cur->NextBlockInfo; |
| } |
| } |
| |
| /// Destroy a chain of block layouts. |
| void CodeGenFunction::destroyBlockInfos(CGBlockInfo *head) { |
| assert(head && "destroying an empty chain"); |
| do { |
| CGBlockInfo *cur = head; |
| head = cur->NextBlockInfo; |
| delete cur; |
| } while (head != 0); |
| } |
| |
| /// Emit a block literal expression in the current function. |
| llvm::Value *CodeGenFunction::EmitBlockLiteral(const BlockExpr *blockExpr) { |
| // If the block has no captures, we won't have a pre-computed |
| // layout for it. |
| if (!blockExpr->getBlockDecl()->hasCaptures()) { |
| CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName()); |
| computeBlockInfo(CGM, this, blockInfo); |
| blockInfo.BlockExpression = blockExpr; |
| return EmitBlockLiteral(blockInfo); |
| } |
| |
| // Find the block info for this block and take ownership of it. |
| OwningPtr<CGBlockInfo> blockInfo; |
| blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo, |
| blockExpr->getBlockDecl())); |
| |
| blockInfo->BlockExpression = blockExpr; |
| return EmitBlockLiteral(*blockInfo); |
| } |
| |
| llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) { |
| // Using the computed layout, generate the actual block function. |
| bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda(); |
| llvm::Constant *blockFn |
| = CodeGenFunction(CGM).GenerateBlockFunction(CurGD, blockInfo, |
| CurFuncDecl, LocalDeclMap, |
| isLambdaConv); |
| blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy); |
| |
| // If there is nothing to capture, we can emit this as a global block. |
| if (blockInfo.CanBeGlobal) |
| return buildGlobalBlock(CGM, blockInfo, blockFn); |
| |
| // Otherwise, we have to emit this as a local block. |
| |
| llvm::Constant *isa = CGM.getNSConcreteStackBlock(); |
| isa = llvm::ConstantExpr::getBitCast(isa, VoidPtrTy); |
| |
| // Build the block descriptor. |
| llvm::Constant *descriptor = buildBlockDescriptor(CGM, blockInfo); |
| |
| llvm::AllocaInst *blockAddr = blockInfo.Address; |
| assert(blockAddr && "block has no address!"); |
| |
| // Compute the initial on-stack block flags. |
| BlockFlags flags = BLOCK_HAS_SIGNATURE; |
| if (blockInfo.NeedsCopyDispose) flags |= BLOCK_HAS_COPY_DISPOSE; |
| if (blockInfo.HasCXXObject) flags |= BLOCK_HAS_CXX_OBJ; |
| if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET; |
| |
| // Initialize the block literal. |
| Builder.CreateStore(isa, Builder.CreateStructGEP(blockAddr, 0, "block.isa")); |
| Builder.CreateStore(llvm::ConstantInt::get(IntTy, flags.getBitMask()), |
| Builder.CreateStructGEP(blockAddr, 1, "block.flags")); |
| Builder.CreateStore(llvm::ConstantInt::get(IntTy, 0), |
| Builder.CreateStructGEP(blockAddr, 2, "block.reserved")); |
| Builder.CreateStore(blockFn, Builder.CreateStructGEP(blockAddr, 3, |
| "block.invoke")); |
| Builder.CreateStore(descriptor, Builder.CreateStructGEP(blockAddr, 4, |
| "block.descriptor")); |
| |
| // Finally, capture all the values into the block. |
| const BlockDecl *blockDecl = blockInfo.getBlockDecl(); |
| |
| // First, 'this'. |
| if (blockDecl->capturesCXXThis()) { |
| llvm::Value *addr = Builder.CreateStructGEP(blockAddr, |
| blockInfo.CXXThisIndex, |
| "block.captured-this.addr"); |
| Builder.CreateStore(LoadCXXThis(), addr); |
| } |
| |
| // Next, captured variables. |
| for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), |
| ce = blockDecl->capture_end(); ci != ce; ++ci) { |
| const VarDecl *variable = ci->getVariable(); |
| const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); |
| |
| // Ignore constant captures. |
| if (capture.isConstant()) continue; |
| |
| QualType type = variable->getType(); |
| |
| // This will be a [[type]]*, except that a byref entry will just be |
| // an i8**. |
| llvm::Value *blockField = |
| Builder.CreateStructGEP(blockAddr, capture.getIndex(), |
| "block.captured"); |
| |
| // Compute the address of the thing we're going to move into the |
| // block literal. |
| llvm::Value *src; |
| if (BlockInfo && ci->isNested()) { |
| // We need to use the capture from the enclosing block. |
| const CGBlockInfo::Capture &enclosingCapture = |
| BlockInfo->getCapture(variable); |
| |
| // This is a [[type]]*, except that a byref entry wil just be an i8**. |
| src = Builder.CreateStructGEP(LoadBlockStruct(), |
| enclosingCapture.getIndex(), |
| "block.capture.addr"); |
| } else if (blockDecl->isConversionFromLambda()) { |
| // The lambda capture in a lambda's conversion-to-block-pointer is |
| // special; we'll simply emit it directly. |
| src = 0; |
| } else { |
| // This is a [[type]]*. |
| src = LocalDeclMap[variable]; |
| } |
| |
| // For byrefs, we just write the pointer to the byref struct into |
| // the block field. There's no need to chase the forwarding |
| // pointer at this point, since we're building something that will |
| // live a shorter life than the stack byref anyway. |
| if (ci->isByRef()) { |
| // Get a void* that points to the byref struct. |
| if (ci->isNested()) |
| src = Builder.CreateLoad(src, "byref.capture"); |
| else |
| src = Builder.CreateBitCast(src, VoidPtrTy); |
| |
| // Write that void* into the capture field. |
| Builder.CreateStore(src, blockField); |
| |
| // If we have a copy constructor, evaluate that into the block field. |
| } else if (const Expr *copyExpr = ci->getCopyExpr()) { |
| if (blockDecl->isConversionFromLambda()) { |
| // If we have a lambda conversion, emit the expression |
| // directly into the block instead. |
| CharUnits Align = getContext().getTypeAlignInChars(type); |
| AggValueSlot Slot = |
| AggValueSlot::forAddr(blockField, Align, Qualifiers(), |
| AggValueSlot::IsDestructed, |
| AggValueSlot::DoesNotNeedGCBarriers, |
| AggValueSlot::IsNotAliased); |
| EmitAggExpr(copyExpr, Slot); |
| } else { |
| EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr); |
| } |
| |
| // If it's a reference variable, copy the reference into the block field. |
| } else if (type->isReferenceType()) { |
| Builder.CreateStore(Builder.CreateLoad(src, "ref.val"), blockField); |
| |
| // Otherwise, fake up a POD copy into the block field. |
| } else { |
| // Fake up a new variable so that EmitScalarInit doesn't think |
| // we're referring to the variable in its own initializer. |
| ImplicitParamDecl blockFieldPseudoVar(/*DC*/ 0, SourceLocation(), |
| /*name*/ 0, type); |
| |
| // We use one of these or the other depending on whether the |
| // reference is nested. |
| DeclRefExpr declRef(const_cast<VarDecl*>(variable), |
| /*refersToEnclosing*/ ci->isNested(), type, |
| VK_LValue, SourceLocation()); |
| |
| ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue, |
| &declRef, VK_RValue); |
| EmitExprAsInit(&l2r, &blockFieldPseudoVar, |
| MakeAddrLValue(blockField, type, |
| getContext().getDeclAlign(variable)), |
| /*captured by init*/ false); |
| } |
| |
| // Activate the cleanup if layout pushed one. |
| if (!ci->isByRef()) { |
| EHScopeStack::stable_iterator cleanup = capture.getCleanup(); |
| if (cleanup.isValid()) |
| ActivateCleanupBlock(cleanup, blockInfo.DominatingIP); |
| } |
| } |
| |
| // Cast to the converted block-pointer type, which happens (somewhat |
| // unfortunately) to be a pointer to function type. |
| llvm::Value *result = |
| Builder.CreateBitCast(blockAddr, |
| ConvertType(blockInfo.getBlockExpr()->getType())); |
| |
| return result; |
| } |
| |
| |
| llvm::Type *CodeGenModule::getBlockDescriptorType() { |
| if (BlockDescriptorType) |
| return BlockDescriptorType; |
| |
| llvm::Type *UnsignedLongTy = |
| getTypes().ConvertType(getContext().UnsignedLongTy); |
| |
| // struct __block_descriptor { |
| // unsigned long reserved; |
| // unsigned long block_size; |
| // |
| // // later, the following will be added |
| // |
| // struct { |
| // void (*copyHelper)(); |
| // void (*copyHelper)(); |
| // } helpers; // !!! optional |
| // |
| // const char *signature; // the block signature |
| // const char *layout; // reserved |
| // }; |
| BlockDescriptorType = |
| llvm::StructType::create("struct.__block_descriptor", |
| UnsignedLongTy, UnsignedLongTy, NULL); |
| |
| // Now form a pointer to that. |
| BlockDescriptorType = llvm::PointerType::getUnqual(BlockDescriptorType); |
| return BlockDescriptorType; |
| } |
| |
| llvm::Type *CodeGenModule::getGenericBlockLiteralType() { |
| if (GenericBlockLiteralType) |
| return GenericBlockLiteralType; |
| |
| llvm::Type *BlockDescPtrTy = getBlockDescriptorType(); |
| |
| // struct __block_literal_generic { |
| // void *__isa; |
| // int __flags; |
| // int __reserved; |
| // void (*__invoke)(void *); |
| // struct __block_descriptor *__descriptor; |
| // }; |
| GenericBlockLiteralType = |
| llvm::StructType::create("struct.__block_literal_generic", |
| VoidPtrTy, IntTy, IntTy, VoidPtrTy, |
| BlockDescPtrTy, NULL); |
| |
| return GenericBlockLiteralType; |
| } |
| |
| |
| RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr* E, |
| ReturnValueSlot ReturnValue) { |
| const BlockPointerType *BPT = |
| E->getCallee()->getType()->getAs<BlockPointerType>(); |
| |
| llvm::Value *Callee = EmitScalarExpr(E->getCallee()); |
| |
| // Get a pointer to the generic block literal. |
| llvm::Type *BlockLiteralTy = |
| llvm::PointerType::getUnqual(CGM.getGenericBlockLiteralType()); |
| |
| // Bitcast the callee to a block literal. |
| llvm::Value *BlockLiteral = |
| Builder.CreateBitCast(Callee, BlockLiteralTy, "block.literal"); |
| |
| // Get the function pointer from the literal. |
| llvm::Value *FuncPtr = Builder.CreateStructGEP(BlockLiteral, 3); |
| |
| BlockLiteral = Builder.CreateBitCast(BlockLiteral, VoidPtrTy); |
| |
| // Add the block literal. |
| CallArgList Args; |
| Args.add(RValue::get(BlockLiteral), getContext().VoidPtrTy); |
| |
| QualType FnType = BPT->getPointeeType(); |
| |
| // And the rest of the arguments. |
| EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), |
| E->arg_begin(), E->arg_end()); |
| |
| // Load the function. |
| llvm::Value *Func = Builder.CreateLoad(FuncPtr); |
| |
| const FunctionType *FuncTy = FnType->castAs<FunctionType>(); |
| const CGFunctionInfo &FnInfo = |
| CGM.getTypes().arrangeFunctionCall(Args, FuncTy); |
| |
| // Cast the function pointer to the right type. |
| llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo); |
| |
| llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy); |
| Func = Builder.CreateBitCast(Func, BlockFTyPtr); |
| |
| // And call the block. |
| return EmitCall(FnInfo, Func, ReturnValue, Args); |
| } |
| |
| llvm::Value *CodeGenFunction::GetAddrOfBlockDecl(const VarDecl *variable, |
| bool isByRef) { |
| assert(BlockInfo && "evaluating block ref without block information?"); |
| const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable); |
| |
| // Handle constant captures. |
| if (capture.isConstant()) return LocalDeclMap[variable]; |
| |
| llvm::Value *addr = |
| Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(), |
| "block.capture.addr"); |
| |
| if (isByRef) { |
| // addr should be a void** right now. Load, then cast the result |
| // to byref*. |
| |
| addr = Builder.CreateLoad(addr); |
| llvm::PointerType *byrefPointerType |
| = llvm::PointerType::get(BuildByRefType(variable), 0); |
| addr = Builder.CreateBitCast(addr, byrefPointerType, |
| "byref.addr"); |
| |
| // Follow the forwarding pointer. |
| addr = Builder.CreateStructGEP(addr, 1, "byref.forwarding"); |
| addr = Builder.CreateLoad(addr, "byref.addr.forwarded"); |
| |
| // Cast back to byref* and GEP over to the actual object. |
| addr = Builder.CreateBitCast(addr, byrefPointerType); |
| addr = Builder.CreateStructGEP(addr, getByRefValueLLVMField(variable), |
| variable->getNameAsString()); |
| } |
| |
| if (variable->getType()->isReferenceType()) |
| addr = Builder.CreateLoad(addr, "ref.tmp"); |
| |
| return addr; |
| } |
| |
| llvm::Constant * |
| CodeGenModule::GetAddrOfGlobalBlock(const BlockExpr *blockExpr, |
| const char *name) { |
| CGBlockInfo blockInfo(blockExpr->getBlockDecl(), name); |
| blockInfo.BlockExpression = blockExpr; |
| |
| // Compute information about the layout, etc., of this block. |
| computeBlockInfo(*this, 0, blockInfo); |
| |
| // Using that metadata, generate the actual block function. |
| llvm::Constant *blockFn; |
| { |
| llvm::DenseMap<const Decl*, llvm::Value*> LocalDeclMap; |
| blockFn = CodeGenFunction(*this).GenerateBlockFunction(GlobalDecl(), |
| blockInfo, |
| 0, LocalDeclMap, |
| false); |
| } |
| blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy); |
| |
| return buildGlobalBlock(*this, blockInfo, blockFn); |
| } |
| |
| static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM, |
| const CGBlockInfo &blockInfo, |
| llvm::Constant *blockFn) { |
| assert(blockInfo.CanBeGlobal); |
| |
| // Generate the constants for the block literal initializer. |
| llvm::Constant *fields[BlockHeaderSize]; |
| |
| // isa |
| fields[0] = CGM.getNSConcreteGlobalBlock(); |
| |
| // __flags |
| BlockFlags flags = BLOCK_IS_GLOBAL | BLOCK_HAS_SIGNATURE; |
| if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET; |
| |
| fields[1] = llvm::ConstantInt::get(CGM.IntTy, flags.getBitMask()); |
| |
| // Reserved |
| fields[2] = llvm::Constant::getNullValue(CGM.IntTy); |
| |
| // Function |
| fields[3] = blockFn; |
| |
| // Descriptor |
| fields[4] = buildBlockDescriptor(CGM, blockInfo); |
| |
| llvm::Constant *init = llvm::ConstantStruct::getAnon(fields); |
| |
| llvm::GlobalVariable *literal = |
| new llvm::GlobalVariable(CGM.getModule(), |
| init->getType(), |
| /*constant*/ true, |
| llvm::GlobalVariable::InternalLinkage, |
| init, |
| "__block_literal_global"); |
| literal->setAlignment(blockInfo.BlockAlign.getQuantity()); |
| |
| // Return a constant of the appropriately-casted type. |
| llvm::Type *requiredType = |
| CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType()); |
| return llvm::ConstantExpr::getBitCast(literal, requiredType); |
| } |
| |
| llvm::Function * |
| CodeGenFunction::GenerateBlockFunction(GlobalDecl GD, |
| const CGBlockInfo &blockInfo, |
| const Decl *outerFnDecl, |
| const DeclMapTy &ldm, |
| bool IsLambdaConversionToBlock) { |
| const BlockDecl *blockDecl = blockInfo.getBlockDecl(); |
| |
| // Check if we should generate debug info for this block function. |
| if (CGM.getModuleDebugInfo()) |
| DebugInfo = CGM.getModuleDebugInfo(); |
| |
| BlockInfo = &blockInfo; |
| |
| // Arrange for local static and local extern declarations to appear |
| // to be local to this function as well, in case they're directly |
| // referenced in a block. |
| for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) { |
| const VarDecl *var = dyn_cast<VarDecl>(i->first); |
| if (var && !var->hasLocalStorage()) |
| LocalDeclMap[var] = i->second; |
| } |
| |
| // Begin building the function declaration. |
| |
| // Build the argument list. |
| FunctionArgList args; |
| |
| // The first argument is the block pointer. Just take it as a void* |
| // and cast it later. |
| QualType selfTy = getContext().VoidPtrTy; |
| IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor"); |
| |
| ImplicitParamDecl selfDecl(const_cast<BlockDecl*>(blockDecl), |
| SourceLocation(), II, selfTy); |
| args.push_back(&selfDecl); |
| |
| // Now add the rest of the parameters. |
| for (BlockDecl::param_const_iterator i = blockDecl->param_begin(), |
| e = blockDecl->param_end(); i != e; ++i) |
| args.push_back(*i); |
| |
| // Create the function declaration. |
| const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType(); |
| const CGFunctionInfo &fnInfo = |
| CGM.getTypes().arrangeFunctionDeclaration(fnType->getResultType(), args, |
| fnType->getExtInfo(), |
| fnType->isVariadic()); |
| if (CGM.ReturnTypeUsesSRet(fnInfo)) |
| blockInfo.UsesStret = true; |
| |
| llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo); |
| |
| MangleBuffer name; |
| CGM.getBlockMangledName(GD, name, blockDecl); |
| llvm::Function *fn = |
| llvm::Function::Create(fnLLVMType, llvm::GlobalValue::InternalLinkage, |
| name.getString(), &CGM.getModule()); |
| CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo); |
| |
| // Begin generating the function. |
| StartFunction(blockDecl, fnType->getResultType(), fn, fnInfo, args, |
| blockInfo.getBlockExpr()->getBody()->getLocStart()); |
| CurFuncDecl = outerFnDecl; // StartFunction sets this to blockDecl |
| |
| // Okay. Undo some of what StartFunction did. |
| |
| // Pull the 'self' reference out of the local decl map. |
| llvm::Value *blockAddr = LocalDeclMap[&selfDecl]; |
| LocalDeclMap.erase(&selfDecl); |
| BlockPointer = Builder.CreateBitCast(blockAddr, |
| blockInfo.StructureType->getPointerTo(), |
| "block"); |
| |
| // If we have a C++ 'this' reference, go ahead and force it into |
| // existence now. |
| if (blockDecl->capturesCXXThis()) { |
| llvm::Value *addr = Builder.CreateStructGEP(BlockPointer, |
| blockInfo.CXXThisIndex, |
| "block.captured-this"); |
| CXXThisValue = Builder.CreateLoad(addr, "this"); |
| } |
| |
| // LoadObjCSelf() expects there to be an entry for 'self' in LocalDeclMap; |
| // appease it. |
| if (const ObjCMethodDecl *method |
| = dyn_cast_or_null<ObjCMethodDecl>(CurFuncDecl)) { |
| const VarDecl *self = method->getSelfDecl(); |
| |
| // There might not be a capture for 'self', but if there is... |
| if (blockInfo.Captures.count(self)) { |
| const CGBlockInfo::Capture &capture = blockInfo.getCapture(self); |
| llvm::Value *selfAddr = Builder.CreateStructGEP(BlockPointer, |
| capture.getIndex(), |
| "block.captured-self"); |
| LocalDeclMap[self] = selfAddr; |
| } |
| } |
| |
| // Also force all the constant captures. |
| for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), |
| ce = blockDecl->capture_end(); ci != ce; ++ci) { |
| const VarDecl *variable = ci->getVariable(); |
| const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); |
| if (!capture.isConstant()) continue; |
| |
| unsigned align = getContext().getDeclAlign(variable).getQuantity(); |
| |
| llvm::AllocaInst *alloca = |
| CreateMemTemp(variable->getType(), "block.captured-const"); |
| alloca->setAlignment(align); |
| |
| Builder.CreateStore(capture.getConstant(), alloca, align); |
| |
| LocalDeclMap[variable] = alloca; |
| } |
| |
| // Save a spot to insert the debug information for all the DeclRefExprs. |
| llvm::BasicBlock *entry = Builder.GetInsertBlock(); |
| llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint(); |
| --entry_ptr; |
| |
| if (IsLambdaConversionToBlock) |
| EmitLambdaBlockInvokeBody(); |
| else |
| EmitStmt(blockDecl->getBody()); |
| |
| // Remember where we were... |
| llvm::BasicBlock *resume = Builder.GetInsertBlock(); |
| |
| // Go back to the entry. |
| ++entry_ptr; |
| Builder.SetInsertPoint(entry, entry_ptr); |
| |
| // Emit debug information for all the DeclRefExprs. |
| // FIXME: also for 'this' |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), |
| ce = blockDecl->capture_end(); ci != ce; ++ci) { |
| const VarDecl *variable = ci->getVariable(); |
| DI->EmitLocation(Builder, variable->getLocation()); |
| |
| if (CGM.getCodeGenOpts().DebugInfo >= CodeGenOptions::LimitedDebugInfo) { |
| const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); |
| if (capture.isConstant()) { |
| DI->EmitDeclareOfAutoVariable(variable, LocalDeclMap[variable], |
| Builder); |
| continue; |
| } |
| |
| DI->EmitDeclareOfBlockDeclRefVariable(variable, BlockPointer, |
| Builder, blockInfo); |
| } |
| } |
| } |
| |
| // And resume where we left off. |
| if (resume == 0) |
| Builder.ClearInsertionPoint(); |
| else |
| Builder.SetInsertPoint(resume); |
| |
| FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc()); |
| |
| return fn; |
| } |
| |
| /* |
| notes.push_back(HelperInfo()); |
| HelperInfo ¬e = notes.back(); |
| note.index = capture.getIndex(); |
| note.RequiresCopying = (ci->hasCopyExpr() || BlockRequiresCopying(type)); |
| note.cxxbar_import = ci->getCopyExpr(); |
| |
| if (ci->isByRef()) { |
| note.flag = BLOCK_FIELD_IS_BYREF; |
| if (type.isObjCGCWeak()) |
| note.flag |= BLOCK_FIELD_IS_WEAK; |
| } else if (type->isBlockPointerType()) { |
| note.flag = BLOCK_FIELD_IS_BLOCK; |
| } else { |
| note.flag = BLOCK_FIELD_IS_OBJECT; |
| } |
| */ |
| |
| |
| |
| llvm::Constant * |
| CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) { |
| ASTContext &C = getContext(); |
| |
| FunctionArgList args; |
| ImplicitParamDecl dstDecl(0, SourceLocation(), 0, C.VoidPtrTy); |
| args.push_back(&dstDecl); |
| ImplicitParamDecl srcDecl(0, SourceLocation(), 0, C.VoidPtrTy); |
| args.push_back(&srcDecl); |
| |
| const CGFunctionInfo &FI = |
| CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, |
| FunctionType::ExtInfo(), |
| /*variadic*/ false); |
| |
| // FIXME: it would be nice if these were mergeable with things with |
| // identical semantics. |
| llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); |
| |
| llvm::Function *Fn = |
| llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, |
| "__copy_helper_block_", &CGM.getModule()); |
| |
| IdentifierInfo *II |
| = &CGM.getContext().Idents.get("__copy_helper_block_"); |
| |
| // Check if we should generate debug info for this block helper function. |
| if (CGM.getModuleDebugInfo()) |
| DebugInfo = CGM.getModuleDebugInfo(); |
| |
| FunctionDecl *FD = FunctionDecl::Create(C, |
| C.getTranslationUnitDecl(), |
| SourceLocation(), |
| SourceLocation(), II, C.VoidTy, 0, |
| SC_Static, |
| SC_None, |
| false, |
| false); |
| StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); |
| |
| llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo(); |
| |
| llvm::Value *src = GetAddrOfLocalVar(&srcDecl); |
| src = Builder.CreateLoad(src); |
| src = Builder.CreateBitCast(src, structPtrTy, "block.source"); |
| |
| llvm::Value *dst = GetAddrOfLocalVar(&dstDecl); |
| dst = Builder.CreateLoad(dst); |
| dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest"); |
| |
| const BlockDecl *blockDecl = blockInfo.getBlockDecl(); |
| |
| for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), |
| ce = blockDecl->capture_end(); ci != ce; ++ci) { |
| const VarDecl *variable = ci->getVariable(); |
| QualType type = variable->getType(); |
| |
| const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); |
| if (capture.isConstant()) continue; |
| |
| const Expr *copyExpr = ci->getCopyExpr(); |
| BlockFieldFlags flags; |
| |
| bool isARCWeakCapture = false; |
| |
| if (copyExpr) { |
| assert(!ci->isByRef()); |
| // don't bother computing flags |
| |
| } else if (ci->isByRef()) { |
| flags = BLOCK_FIELD_IS_BYREF; |
| if (type.isObjCGCWeak()) |
| flags |= BLOCK_FIELD_IS_WEAK; |
| |
| } else if (type->isObjCRetainableType()) { |
| flags = BLOCK_FIELD_IS_OBJECT; |
| if (type->isBlockPointerType()) |
| flags = BLOCK_FIELD_IS_BLOCK; |
| |
| // Special rules for ARC captures: |
| if (getLangOpts().ObjCAutoRefCount) { |
| Qualifiers qs = type.getQualifiers(); |
| |
| // Don't generate special copy logic for a captured object |
| // unless it's __strong or __weak. |
| if (!qs.hasStrongOrWeakObjCLifetime()) |
| continue; |
| |
| // Support __weak direct captures. |
| if (qs.getObjCLifetime() == Qualifiers::OCL_Weak) |
| isARCWeakCapture = true; |
| } |
| } else { |
| continue; |
| } |
| |
| unsigned index = capture.getIndex(); |
| llvm::Value *srcField = Builder.CreateStructGEP(src, index); |
| llvm::Value *dstField = Builder.CreateStructGEP(dst, index); |
| |
| // If there's an explicit copy expression, we do that. |
| if (copyExpr) { |
| EmitSynthesizedCXXCopyCtor(dstField, srcField, copyExpr); |
| } else if (isARCWeakCapture) { |
| EmitARCCopyWeak(dstField, srcField); |
| } else { |
| llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src"); |
| srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy); |
| llvm::Value *dstAddr = Builder.CreateBitCast(dstField, VoidPtrTy); |
| Builder.CreateCall3(CGM.getBlockObjectAssign(), dstAddr, srcValue, |
| llvm::ConstantInt::get(Int32Ty, flags.getBitMask())); |
| } |
| } |
| |
| FinishFunction(); |
| |
| return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); |
| } |
| |
| llvm::Constant * |
| CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) { |
| ASTContext &C = getContext(); |
| |
| FunctionArgList args; |
| ImplicitParamDecl srcDecl(0, SourceLocation(), 0, C.VoidPtrTy); |
| args.push_back(&srcDecl); |
| |
| const CGFunctionInfo &FI = |
| CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, |
| FunctionType::ExtInfo(), |
| /*variadic*/ false); |
| |
| // FIXME: We'd like to put these into a mergable by content, with |
| // internal linkage. |
| llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); |
| |
| llvm::Function *Fn = |
| llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, |
| "__destroy_helper_block_", &CGM.getModule()); |
| |
| // Check if we should generate debug info for this block destroy function. |
| if (CGM.getModuleDebugInfo()) |
| DebugInfo = CGM.getModuleDebugInfo(); |
| |
| IdentifierInfo *II |
| = &CGM.getContext().Idents.get("__destroy_helper_block_"); |
| |
| FunctionDecl *FD = FunctionDecl::Create(C, C.getTranslationUnitDecl(), |
| SourceLocation(), |
| SourceLocation(), II, C.VoidTy, 0, |
| SC_Static, |
| SC_None, |
| false, false); |
| StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); |
| |
| llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo(); |
| |
| llvm::Value *src = GetAddrOfLocalVar(&srcDecl); |
| src = Builder.CreateLoad(src); |
| src = Builder.CreateBitCast(src, structPtrTy, "block"); |
| |
| const BlockDecl *blockDecl = blockInfo.getBlockDecl(); |
| |
| CodeGenFunction::RunCleanupsScope cleanups(*this); |
| |
| for (BlockDecl::capture_const_iterator ci = blockDecl->capture_begin(), |
| ce = blockDecl->capture_end(); ci != ce; ++ci) { |
| const VarDecl *variable = ci->getVariable(); |
| QualType type = variable->getType(); |
| |
| const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); |
| if (capture.isConstant()) continue; |
| |
| BlockFieldFlags flags; |
| const CXXDestructorDecl *dtor = 0; |
| |
| bool isARCWeakCapture = false; |
| |
| if (ci->isByRef()) { |
| flags = BLOCK_FIELD_IS_BYREF; |
| if (type.isObjCGCWeak()) |
| flags |= BLOCK_FIELD_IS_WEAK; |
| } else if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) { |
| if (record->hasTrivialDestructor()) |
| continue; |
| dtor = record->getDestructor(); |
| } else if (type->isObjCRetainableType()) { |
| flags = BLOCK_FIELD_IS_OBJECT; |
| if (type->isBlockPointerType()) |
| flags = BLOCK_FIELD_IS_BLOCK; |
| |
| // Special rules for ARC captures. |
| if (getLangOpts().ObjCAutoRefCount) { |
| Qualifiers qs = type.getQualifiers(); |
| |
| // Don't generate special dispose logic for a captured object |
| // unless it's __strong or __weak. |
| if (!qs.hasStrongOrWeakObjCLifetime()) |
| continue; |
| |
| // Support __weak direct captures. |
| if (qs.getObjCLifetime() == Qualifiers::OCL_Weak) |
| isARCWeakCapture = true; |
| } |
| } else { |
| continue; |
| } |
| |
| unsigned index = capture.getIndex(); |
| llvm::Value *srcField = Builder.CreateStructGEP(src, index); |
| |
| // If there's an explicit copy expression, we do that. |
| if (dtor) { |
| PushDestructorCleanup(dtor, srcField); |
| |
| // If this is a __weak capture, emit the release directly. |
| } else if (isARCWeakCapture) { |
| EmitARCDestroyWeak(srcField); |
| |
| // Otherwise we call _Block_object_dispose. It wouldn't be too |
| // hard to just emit this as a cleanup if we wanted to make sure |
| // that things were done in reverse. |
| } else { |
| llvm::Value *value = Builder.CreateLoad(srcField); |
| value = Builder.CreateBitCast(value, VoidPtrTy); |
| BuildBlockRelease(value, flags); |
| } |
| } |
| |
| cleanups.ForceCleanup(); |
| |
| FinishFunction(); |
| |
| return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); |
| } |
| |
| namespace { |
| |
| /// Emits the copy/dispose helper functions for a __block object of id type. |
| class ObjectByrefHelpers : public CodeGenModule::ByrefHelpers { |
| BlockFieldFlags Flags; |
| |
| public: |
| ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags) |
| : ByrefHelpers(alignment), Flags(flags) {} |
| |
| void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, |
| llvm::Value *srcField) { |
| destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy); |
| |
| srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy); |
| llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField); |
| |
| unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask(); |
| |
| llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags); |
| llvm::Value *fn = CGF.CGM.getBlockObjectAssign(); |
| CGF.Builder.CreateCall3(fn, destField, srcValue, flagsVal); |
| } |
| |
| void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { |
| field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0)); |
| llvm::Value *value = CGF.Builder.CreateLoad(field); |
| |
| CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER); |
| } |
| |
| void profileImpl(llvm::FoldingSetNodeID &id) const { |
| id.AddInteger(Flags.getBitMask()); |
| } |
| }; |
| |
| /// Emits the copy/dispose helpers for an ARC __block __weak variable. |
| class ARCWeakByrefHelpers : public CodeGenModule::ByrefHelpers { |
| public: |
| ARCWeakByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} |
| |
| void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, |
| llvm::Value *srcField) { |
| CGF.EmitARCMoveWeak(destField, srcField); |
| } |
| |
| void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { |
| CGF.EmitARCDestroyWeak(field); |
| } |
| |
| void profileImpl(llvm::FoldingSetNodeID &id) const { |
| // 0 is distinguishable from all pointers and byref flags |
| id.AddInteger(0); |
| } |
| }; |
| |
| /// Emits the copy/dispose helpers for an ARC __block __strong variable |
| /// that's not of block-pointer type. |
| class ARCStrongByrefHelpers : public CodeGenModule::ByrefHelpers { |
| public: |
| ARCStrongByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} |
| |
| void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, |
| llvm::Value *srcField) { |
| // Do a "move" by copying the value and then zeroing out the old |
| // variable. |
| |
| llvm::LoadInst *value = CGF.Builder.CreateLoad(srcField); |
| value->setAlignment(Alignment.getQuantity()); |
| |
| llvm::Value *null = |
| llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType())); |
| |
| llvm::StoreInst *store = CGF.Builder.CreateStore(value, destField); |
| store->setAlignment(Alignment.getQuantity()); |
| |
| store = CGF.Builder.CreateStore(null, srcField); |
| store->setAlignment(Alignment.getQuantity()); |
| } |
| |
| void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { |
| llvm::LoadInst *value = CGF.Builder.CreateLoad(field); |
| value->setAlignment(Alignment.getQuantity()); |
| |
| CGF.EmitARCRelease(value, /*precise*/ false); |
| } |
| |
| void profileImpl(llvm::FoldingSetNodeID &id) const { |
| // 1 is distinguishable from all pointers and byref flags |
| id.AddInteger(1); |
| } |
| }; |
| |
| /// Emits the copy/dispose helpers for an ARC __block __strong |
| /// variable that's of block-pointer type. |
| class ARCStrongBlockByrefHelpers : public CodeGenModule::ByrefHelpers { |
| public: |
| ARCStrongBlockByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {} |
| |
| void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, |
| llvm::Value *srcField) { |
| // Do the copy with objc_retainBlock; that's all that |
| // _Block_object_assign would do anyway, and we'd have to pass the |
| // right arguments to make sure it doesn't get no-op'ed. |
| llvm::LoadInst *oldValue = CGF.Builder.CreateLoad(srcField); |
| oldValue->setAlignment(Alignment.getQuantity()); |
| |
| llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true); |
| |
| llvm::StoreInst *store = CGF.Builder.CreateStore(copy, destField); |
| store->setAlignment(Alignment.getQuantity()); |
| } |
| |
| void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { |
| llvm::LoadInst *value = CGF.Builder.CreateLoad(field); |
| value->setAlignment(Alignment.getQuantity()); |
| |
| CGF.EmitARCRelease(value, /*precise*/ false); |
| } |
| |
| void profileImpl(llvm::FoldingSetNodeID &id) const { |
| // 2 is distinguishable from all pointers and byref flags |
| id.AddInteger(2); |
| } |
| }; |
| |
| /// Emits the copy/dispose helpers for a __block variable with a |
| /// nontrivial copy constructor or destructor. |
| class CXXByrefHelpers : public CodeGenModule::ByrefHelpers { |
| QualType VarType; |
| const Expr *CopyExpr; |
| |
| public: |
| CXXByrefHelpers(CharUnits alignment, QualType type, |
| const Expr *copyExpr) |
| : ByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {} |
| |
| bool needsCopy() const { return CopyExpr != 0; } |
| void emitCopy(CodeGenFunction &CGF, llvm::Value *destField, |
| llvm::Value *srcField) { |
| if (!CopyExpr) return; |
| CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr); |
| } |
| |
| void emitDispose(CodeGenFunction &CGF, llvm::Value *field) { |
| EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin(); |
| CGF.PushDestructorCleanup(VarType, field); |
| CGF.PopCleanupBlocks(cleanupDepth); |
| } |
| |
| void profileImpl(llvm::FoldingSetNodeID &id) const { |
| id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr()); |
| } |
| }; |
| } // end anonymous namespace |
| |
| static llvm::Constant * |
| generateByrefCopyHelper(CodeGenFunction &CGF, |
| llvm::StructType &byrefType, |
| CodeGenModule::ByrefHelpers &byrefInfo) { |
| ASTContext &Context = CGF.getContext(); |
| |
| QualType R = Context.VoidTy; |
| |
| FunctionArgList args; |
| ImplicitParamDecl dst(0, SourceLocation(), 0, Context.VoidPtrTy); |
| args.push_back(&dst); |
| |
| ImplicitParamDecl src(0, SourceLocation(), 0, Context.VoidPtrTy); |
| args.push_back(&src); |
| |
| const CGFunctionInfo &FI = |
| CGF.CGM.getTypes().arrangeFunctionDeclaration(R, args, |
| FunctionType::ExtInfo(), |
| /*variadic*/ false); |
| |
| CodeGenTypes &Types = CGF.CGM.getTypes(); |
| llvm::FunctionType *LTy = Types.GetFunctionType(FI); |
| |
| // FIXME: We'd like to put these into a mergable by content, with |
| // internal linkage. |
| llvm::Function *Fn = |
| llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, |
| "__Block_byref_object_copy_", &CGF.CGM.getModule()); |
| |
| IdentifierInfo *II |
| = &Context.Idents.get("__Block_byref_object_copy_"); |
| |
| FunctionDecl *FD = FunctionDecl::Create(Context, |
| Context.getTranslationUnitDecl(), |
| SourceLocation(), |
| SourceLocation(), II, R, 0, |
| SC_Static, |
| SC_None, |
| false, false); |
| |
| CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation()); |
| |
| if (byrefInfo.needsCopy()) { |
| llvm::Type *byrefPtrType = byrefType.getPointerTo(0); |
| |
| // dst->x |
| llvm::Value *destField = CGF.GetAddrOfLocalVar(&dst); |
| destField = CGF.Builder.CreateLoad(destField); |
| destField = CGF.Builder.CreateBitCast(destField, byrefPtrType); |
| destField = CGF.Builder.CreateStructGEP(destField, 6, "x"); |
| |
| // src->x |
| llvm::Value *srcField = CGF.GetAddrOfLocalVar(&src); |
| srcField = CGF.Builder.CreateLoad(srcField); |
| srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType); |
| srcField = CGF.Builder.CreateStructGEP(srcField, 6, "x"); |
| |
| byrefInfo.emitCopy(CGF, destField, srcField); |
| } |
| |
| CGF.FinishFunction(); |
| |
| return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy); |
| } |
| |
| /// Build the copy helper for a __block variable. |
| static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM, |
| llvm::StructType &byrefType, |
| CodeGenModule::ByrefHelpers &info) { |
| CodeGenFunction CGF(CGM); |
| return generateByrefCopyHelper(CGF, byrefType, info); |
| } |
| |
| /// Generate code for a __block variable's dispose helper. |
| static llvm::Constant * |
| generateByrefDisposeHelper(CodeGenFunction &CGF, |
| llvm::StructType &byrefType, |
| CodeGenModule::ByrefHelpers &byrefInfo) { |
| ASTContext &Context = CGF.getContext(); |
| QualType R = Context.VoidTy; |
| |
| FunctionArgList args; |
| ImplicitParamDecl src(0, SourceLocation(), 0, Context.VoidPtrTy); |
| args.push_back(&src); |
| |
| const CGFunctionInfo &FI = |
| CGF.CGM.getTypes().arrangeFunctionDeclaration(R, args, |
| FunctionType::ExtInfo(), |
| /*variadic*/ false); |
| |
| CodeGenTypes &Types = CGF.CGM.getTypes(); |
| llvm::FunctionType *LTy = Types.GetFunctionType(FI); |
| |
| // FIXME: We'd like to put these into a mergable by content, with |
| // internal linkage. |
| llvm::Function *Fn = |
| llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, |
| "__Block_byref_object_dispose_", |
| &CGF.CGM.getModule()); |
| |
| IdentifierInfo *II |
| = &Context.Idents.get("__Block_byref_object_dispose_"); |
| |
| FunctionDecl *FD = FunctionDecl::Create(Context, |
| Context.getTranslationUnitDecl(), |
| SourceLocation(), |
| SourceLocation(), II, R, 0, |
| SC_Static, |
| SC_None, |
| false, false); |
| CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation()); |
| |
| if (byrefInfo.needsDispose()) { |
| llvm::Value *V = CGF.GetAddrOfLocalVar(&src); |
| V = CGF.Builder.CreateLoad(V); |
| V = CGF.Builder.CreateBitCast(V, byrefType.getPointerTo(0)); |
| V = CGF.Builder.CreateStructGEP(V, 6, "x"); |
| |
| byrefInfo.emitDispose(CGF, V); |
| } |
| |
| CGF.FinishFunction(); |
| |
| return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy); |
| } |
| |
| /// Build the dispose helper for a __block variable. |
| static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM, |
| llvm::StructType &byrefType, |
| CodeGenModule::ByrefHelpers &info) { |
| CodeGenFunction CGF(CGM); |
| return generateByrefDisposeHelper(CGF, byrefType, info); |
| } |
| |
| /// |
| template <class T> static T *buildByrefHelpers(CodeGenModule &CGM, |
| llvm::StructType &byrefTy, |
| T &byrefInfo) { |
| // Increase the field's alignment to be at least pointer alignment, |
| // since the layout of the byref struct will guarantee at least that. |
| byrefInfo.Alignment = std::max(byrefInfo.Alignment, |
| CharUnits::fromQuantity(CGM.PointerAlignInBytes)); |
| |
| llvm::FoldingSetNodeID id; |
| byrefInfo.Profile(id); |
| |
| void *insertPos; |
| CodeGenModule::ByrefHelpers *node |
| = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos); |
| if (node) return static_cast<T*>(node); |
| |
| byrefInfo.CopyHelper = buildByrefCopyHelper(CGM, byrefTy, byrefInfo); |
| byrefInfo.DisposeHelper = buildByrefDisposeHelper(CGM, byrefTy, byrefInfo); |
| |
| T *copy = new (CGM.getContext()) T(byrefInfo); |
| CGM.ByrefHelpersCache.InsertNode(copy, insertPos); |
| return copy; |
| } |
| |
| CodeGenModule::ByrefHelpers * |
| CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType, |
| const AutoVarEmission &emission) { |
| const VarDecl &var = *emission.Variable; |
| QualType type = var.getType(); |
| |
| if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) { |
| const Expr *copyExpr = CGM.getContext().getBlockVarCopyInits(&var); |
| if (!copyExpr && record->hasTrivialDestructor()) return 0; |
| |
| CXXByrefHelpers byrefInfo(emission.Alignment, type, copyExpr); |
| return ::buildByrefHelpers(CGM, byrefType, byrefInfo); |
| } |
| |
| // Otherwise, if we don't have a retainable type, there's nothing to do. |
| // that the runtime does extra copies. |
| if (!type->isObjCRetainableType()) return 0; |
| |
| Qualifiers qs = type.getQualifiers(); |
| |
| // If we have lifetime, that dominates. |
| if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) { |
| assert(getLangOpts().ObjCAutoRefCount); |
| |
| switch (lifetime) { |
| case Qualifiers::OCL_None: llvm_unreachable("impossible"); |
| |
| // These are just bits as far as the runtime is concerned. |
| case Qualifiers::OCL_ExplicitNone: |
| case Qualifiers::OCL_Autoreleasing: |
| return 0; |
| |
| // Tell the runtime that this is ARC __weak, called by the |
| // byref routines. |
| case Qualifiers::OCL_Weak: { |
| ARCWeakByrefHelpers byrefInfo(emission.Alignment); |
| return ::buildByrefHelpers(CGM, byrefType, byrefInfo); |
| } |
| |
| // ARC __strong __block variables need to be retained. |
| case Qualifiers::OCL_Strong: |
| // Block pointers need to be copied, and there's no direct |
| // transfer possible. |
| if (type->isBlockPointerType()) { |
| ARCStrongBlockByrefHelpers byrefInfo(emission.Alignment); |
| return ::buildByrefHelpers(CGM, byrefType, byrefInfo); |
| |
| // Otherwise, we transfer ownership of the retain from the stack |
| // to the heap. |
| } else { |
| ARCStrongByrefHelpers byrefInfo(emission.Alignment); |
| return ::buildByrefHelpers(CGM, byrefType, byrefInfo); |
| } |
| } |
| llvm_unreachable("fell out of lifetime switch!"); |
| } |
| |
| BlockFieldFlags flags; |
| if (type->isBlockPointerType()) { |
| flags |= BLOCK_FIELD_IS_BLOCK; |
| } else if (CGM.getContext().isObjCNSObjectType(type) || |
| type->isObjCObjectPointerType()) { |
| flags |= BLOCK_FIELD_IS_OBJECT; |
| } else { |
| return 0; |
| } |
| |
| if (type.isObjCGCWeak()) |
| flags |= BLOCK_FIELD_IS_WEAK; |
| |
| ObjectByrefHelpers byrefInfo(emission.Alignment, flags); |
| return ::buildByrefHelpers(CGM, byrefType, byrefInfo); |
| } |
| |
| unsigned CodeGenFunction::getByRefValueLLVMField(const ValueDecl *VD) const { |
| assert(ByRefValueInfo.count(VD) && "Did not find value!"); |
| |
| return ByRefValueInfo.find(VD)->second.second; |
| } |
| |
| llvm::Value *CodeGenFunction::BuildBlockByrefAddress(llvm::Value *BaseAddr, |
| const VarDecl *V) { |
| llvm::Value *Loc = Builder.CreateStructGEP(BaseAddr, 1, "forwarding"); |
| Loc = Builder.CreateLoad(Loc); |
| Loc = Builder.CreateStructGEP(Loc, getByRefValueLLVMField(V), |
| V->getNameAsString()); |
| return Loc; |
| } |
| |
| /// BuildByRefType - This routine changes a __block variable declared as T x |
| /// into: |
| /// |
| /// struct { |
| /// void *__isa; |
| /// void *__forwarding; |
| /// int32_t __flags; |
| /// int32_t __size; |
| /// void *__copy_helper; // only if needed |
| /// void *__destroy_helper; // only if needed |
| /// char padding[X]; // only if needed |
| /// T x; |
| /// } x |
| /// |
| llvm::Type *CodeGenFunction::BuildByRefType(const VarDecl *D) { |
| std::pair<llvm::Type *, unsigned> &Info = ByRefValueInfo[D]; |
| if (Info.first) |
| return Info.first; |
| |
| QualType Ty = D->getType(); |
| |
| SmallVector<llvm::Type *, 8> types; |
| |
| llvm::StructType *ByRefType = |
| llvm::StructType::create(getLLVMContext(), |
| "struct.__block_byref_" + D->getNameAsString()); |
| |
| // void *__isa; |
| types.push_back(Int8PtrTy); |
| |
| // void *__forwarding; |
| types.push_back(llvm::PointerType::getUnqual(ByRefType)); |
| |
| // int32_t __flags; |
| types.push_back(Int32Ty); |
| |
| // int32_t __size; |
| types.push_back(Int32Ty); |
| |
| bool HasCopyAndDispose = |
| (Ty->isObjCRetainableType()) || getContext().getBlockVarCopyInits(D); |
| if (HasCopyAndDispose) { |
| /// void *__copy_helper; |
| types.push_back(Int8PtrTy); |
| |
| /// void *__destroy_helper; |
| types.push_back(Int8PtrTy); |
| } |
| |
| bool Packed = false; |
| CharUnits Align = getContext().getDeclAlign(D); |
| if (Align > getContext().toCharUnitsFromBits(Target.getPointerAlign(0))) { |
| // We have to insert padding. |
| |
| // The struct above has 2 32-bit integers. |
| unsigned CurrentOffsetInBytes = 4 * 2; |
| |
| // And either 2 or 4 pointers. |
| CurrentOffsetInBytes += (HasCopyAndDispose ? 4 : 2) * |
| CGM.getTargetData().getTypeAllocSize(Int8PtrTy); |
| |
| // Align the offset. |
| unsigned AlignedOffsetInBytes = |
| llvm::RoundUpToAlignment(CurrentOffsetInBytes, Align.getQuantity()); |
| |
| unsigned NumPaddingBytes = AlignedOffsetInBytes - CurrentOffsetInBytes; |
| if (NumPaddingBytes > 0) { |
| llvm::Type *Ty = Int8Ty; |
| // FIXME: We need a sema error for alignment larger than the minimum of |
| // the maximal stack alignment and the alignment of malloc on the system. |
| if (NumPaddingBytes > 1) |
| Ty = llvm::ArrayType::get(Ty, NumPaddingBytes); |
| |
| types.push_back(Ty); |
| |
| // We want a packed struct. |
| Packed = true; |
| } |
| } |
| |
| // T x; |
| types.push_back(ConvertTypeForMem(Ty)); |
| |
| ByRefType->setBody(types, Packed); |
| |
| Info.first = ByRefType; |
| |
| Info.second = types.size() - 1; |
| |
| return Info.first; |
| } |
| |
| /// Initialize the structural components of a __block variable, i.e. |
| /// everything but the actual object. |
| void CodeGenFunction::emitByrefStructureInit(const AutoVarEmission &emission) { |
| // Find the address of the local. |
| llvm::Value *addr = emission.Address; |
| |
| // That's an alloca of the byref structure type. |
| llvm::StructType *byrefType = cast<llvm::StructType>( |
| cast<llvm::PointerType>(addr->getType())->getElementType()); |
| |
| // Build the byref helpers if necessary. This is null if we don't need any. |
| CodeGenModule::ByrefHelpers *helpers = |
| buildByrefHelpers(*byrefType, emission); |
| |
| const VarDecl &D = *emission.Variable; |
| QualType type = D.getType(); |
| |
| llvm::Value *V; |
| |
| // Initialize the 'isa', which is just 0 or 1. |
| int isa = 0; |
| if (type.isObjCGCWeak()) |
| isa = 1; |
| V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa"); |
| Builder.CreateStore(V, Builder.CreateStructGEP(addr, 0, "byref.isa")); |
| |
| // Store the address of the variable into its own forwarding pointer. |
| Builder.CreateStore(addr, |
| Builder.CreateStructGEP(addr, 1, "byref.forwarding")); |
| |
| // Blocks ABI: |
| // c) the flags field is set to either 0 if no helper functions are |
| // needed or BLOCK_HAS_COPY_DISPOSE if they are, |
| BlockFlags flags; |
| if (helpers) flags |= BLOCK_HAS_COPY_DISPOSE; |
| Builder.CreateStore(llvm::ConstantInt::get(IntTy, flags.getBitMask()), |
| Builder.CreateStructGEP(addr, 2, "byref.flags")); |
| |
| CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType); |
| V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity()); |
| Builder.CreateStore(V, Builder.CreateStructGEP(addr, 3, "byref.size")); |
| |
| if (helpers) { |
| llvm::Value *copy_helper = Builder.CreateStructGEP(addr, 4); |
| Builder.CreateStore(helpers->CopyHelper, copy_helper); |
| |
| llvm::Value *destroy_helper = Builder.CreateStructGEP(addr, 5); |
| Builder.CreateStore(helpers->DisposeHelper, destroy_helper); |
| } |
| } |
| |
| void CodeGenFunction::BuildBlockRelease(llvm::Value *V, BlockFieldFlags flags) { |
| llvm::Value *F = CGM.getBlockObjectDispose(); |
| llvm::Value *N; |
| V = Builder.CreateBitCast(V, Int8PtrTy); |
| N = llvm::ConstantInt::get(Int32Ty, flags.getBitMask()); |
| Builder.CreateCall2(F, V, N); |
| } |
| |
| namespace { |
| struct CallBlockRelease : EHScopeStack::Cleanup { |
| llvm::Value *Addr; |
| CallBlockRelease(llvm::Value *Addr) : Addr(Addr) {} |
| |
| void Emit(CodeGenFunction &CGF, Flags flags) { |
| // Should we be passing FIELD_IS_WEAK here? |
| CGF.BuildBlockRelease(Addr, BLOCK_FIELD_IS_BYREF); |
| } |
| }; |
| } |
| |
| /// Enter a cleanup to destroy a __block variable. Note that this |
| /// cleanup should be a no-op if the variable hasn't left the stack |
| /// yet; if a cleanup is required for the variable itself, that needs |
| /// to be done externally. |
| void CodeGenFunction::enterByrefCleanup(const AutoVarEmission &emission) { |
| // We don't enter this cleanup if we're in pure-GC mode. |
| if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) |
| return; |
| |
| EHStack.pushCleanup<CallBlockRelease>(NormalAndEHCleanup, emission.Address); |
| } |
| |
| /// Adjust the declaration of something from the blocks API. |
| static void configureBlocksRuntimeObject(CodeGenModule &CGM, |
| llvm::Constant *C) { |
| if (!CGM.getLangOpts().BlocksRuntimeOptional) return; |
| |
| llvm::GlobalValue *GV = cast<llvm::GlobalValue>(C->stripPointerCasts()); |
| if (GV->isDeclaration() && |
| GV->getLinkage() == llvm::GlobalValue::ExternalLinkage) |
| GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); |
| } |
| |
| llvm::Constant *CodeGenModule::getBlockObjectDispose() { |
| if (BlockObjectDispose) |
| return BlockObjectDispose; |
| |
| llvm::Type *args[] = { Int8PtrTy, Int32Ty }; |
| llvm::FunctionType *fty |
| = llvm::FunctionType::get(VoidTy, args, false); |
| BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose"); |
| configureBlocksRuntimeObject(*this, BlockObjectDispose); |
| return BlockObjectDispose; |
| } |
| |
| llvm::Constant *CodeGenModule::getBlockObjectAssign() { |
| if (BlockObjectAssign) |
| return BlockObjectAssign; |
| |
| llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty }; |
| llvm::FunctionType *fty |
| = llvm::FunctionType::get(VoidTy, args, false); |
| BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign"); |
| configureBlocksRuntimeObject(*this, BlockObjectAssign); |
| return BlockObjectAssign; |
| } |
| |
| llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() { |
| if (NSConcreteGlobalBlock) |
| return NSConcreteGlobalBlock; |
| |
| NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock", |
| Int8PtrTy->getPointerTo(), 0); |
| configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock); |
| return NSConcreteGlobalBlock; |
| } |
| |
| llvm::Constant *CodeGenModule::getNSConcreteStackBlock() { |
| if (NSConcreteStackBlock) |
| return NSConcreteStackBlock; |
| |
| NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock", |
| Int8PtrTy->getPointerTo(), 0); |
| configureBlocksRuntimeObject(*this, NSConcreteStackBlock); |
| return NSConcreteStackBlock; |
| } |