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Diffstat (limited to 'clang/lib/CodeGen/CGBlocks.cpp')
| -rw-r--r-- | clang/lib/CodeGen/CGBlocks.cpp | 2044 |
1 files changed, 2044 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/CGBlocks.cpp b/clang/lib/CodeGen/CGBlocks.cpp new file mode 100644 index 0000000..f8c7bcd --- /dev/null +++ b/clang/lib/CodeGen/CGBlocks.cpp @@ -0,0 +1,2044 @@ +//===--- 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); + } + } + + // At this point, we just have to add padding if the end align still + // isn't aligned right. + if (endAlign < maxFieldAlign) { + CharUnits padding = maxFieldAlign - endAlign; + + elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty, + padding.getQuantity())); + blockSize += padding; + + endAlign = getLowBit(blockSize); + assert(endAlign >= maxFieldAlign); + } + + // 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 (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()); + + 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; +} |