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Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CGBlocks.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CGBlocks.cpp | 1421 |
1 files changed, 1421 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGBlocks.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGBlocks.cpp new file mode 100644 index 0000000..a35648d --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CGBlocks.cpp @@ -0,0 +1,1421 @@ +//===--- 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 BlockExpr *blockExpr, const char *N) + : Name(N), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false), + HasCXXObject(false), StructureType(0), Block(blockExpr) { + + // Skip asm prefix, if any. + if (Name && Name[0] == '\01') + ++Name; +} + +/// 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(); + + const llvm::Type *ulong = CGM.getTypes().ConvertType(C.UnsignedLongTy); + const llvm::Type *i8p = CGM.getTypes().ConvertType(C.VoidPtrTy); + + llvm::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.getLangOptions().ObjC1) + elements.push_back(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo)); + else + elements.push_back(llvm::Constant::getNullValue(i8p)); + + llvm::Constant *init = + llvm::ConstantStruct::get(CGM.getLLVMContext(), elements.data(), + elements.size(), false); + + 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()); +} + +static BlockFlags computeBlockFlag(CodeGenModule &CGM, + const BlockExpr *BE, + BlockFlags flags) { + const FunctionType *ftype = BE->getFunctionType(); + + // This is a bit overboard. + CallArgList args; + const CGFunctionInfo &fnInfo = + CGM.getTypes().getFunctionInfo(ftype->getResultType(), args, + ftype->getExtInfo()); + + if (CGM.ReturnTypeUsesSRet(fnInfo)) + flags |= BLOCK_USE_STRET; + + return flags; +} + +/* + 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' + const llvm::Type *Type; + + BlockLayoutChunk(CharUnits align, CharUnits size, + const BlockDecl::Capture *capture, + const 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 record type has a mutable field. +static bool hasMutableField(const CXXRecordDecl *record) { + for (CXXRecordDecl::field_iterator + i = record->field_begin(), e = record->field_end(); i != e; ++i) + if ((*i)->isMutable()) + return true; + + for (CXXRecordDecl::base_class_const_iterator + i = record->bases_begin(), e = record->bases_end(); i != e; ++i) { + const RecordType *record = i->getType()->castAs<RecordType>(); + if (hasMutableField(cast<CXXRecordDecl>(record->getDecl()))) + return true; + } + + return false; +} + +/// 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 !hasMutableField(record); +} + +/// 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, + 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.getLangOptions().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.EmitConstantExpr(init, var->getType()); +} + +/// 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, + std::vector<const 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()); + const llvm::Type *i8p = CGM.getTypes().ConvertType(C.VoidPtrTy); + const 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, CGBlockInfo &info) { + ASTContext &C = CGM.getContext(); + const BlockDecl *block = info.getBlockDecl(); + + std::vector<const llvm::Type*> 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. + llvm::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 = cast<CXXMethodDecl>(DC)->getThisType(C); + + const 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; + + const 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, variable)) { + info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant); + continue; + } + + // Block pointers require copy/dispose. + if (variable->getType()->isBlockPointerType()) { + info.NeedsCopyDispose = true; + + // So do Objective-C pointers. + } else if (variable->getType()->isObjCObjectPointerType() || + C.isObjCNSObjectType(variable->getType())) { + 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.getLangOptions().CPlusPlus) { + if (const CXXRecordDecl *record = + variable->getType()->getAsCXXRecordDecl()) { + if (!record->hasTrivialDestructor()) { + info.HasCXXObject = true; + info.NeedsCopyDispose = true; + } + } + } + + CharUnits size = C.getTypeSizeInChars(variable->getType()); + CharUnits align = C.getDeclAlign(variable); + maxFieldAlign = std::max(maxFieldAlign, align); + + const llvm::Type *llvmType = + CGM.getTypes().ConvertTypeForMem(variable->getType()); + + 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) { + llvm::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) { + llvm::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 (llvm::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); +} + +/// Emit a block literal expression in the current function. +llvm::Value *CodeGenFunction::EmitBlockLiteral(const BlockExpr *blockExpr) { + std::string Name = CurFn->getName(); + CGBlockInfo blockInfo(blockExpr, Name.c_str()); + + // Compute information about the layout, etc., of this block. + computeBlockInfo(CGM, blockInfo); + + // Using that metadata, generate the actual block function. + llvm::Constant *blockFn + = CodeGenFunction(CGM).GenerateBlockFunction(CurGD, blockInfo, + CurFuncDecl, LocalDeclMap); + 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); + + const llvm::Type *intTy = ConvertType(getContext().IntTy); + + llvm::AllocaInst *blockAddr = + CreateTempAlloca(blockInfo.StructureType, "block"); + blockAddr->setAlignment(blockInfo.BlockAlign.getQuantity()); + + // 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; + flags = computeBlockFlag(CGM, blockInfo.getBlockExpr(), flags); + + // 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 { + // 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()) { + 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 { + // We use one of these or the other depending on whether the + // reference is nested. + DeclRefExpr notNested(const_cast<VarDecl*>(variable), type, VK_LValue, + SourceLocation()); + BlockDeclRefExpr nested(const_cast<VarDecl*>(variable), type, + VK_LValue, SourceLocation(), /*byref*/ false); + + Expr *declRef = + (ci->isNested() ? static_cast<Expr*>(&nested) : ¬Nested); + + ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue, + declRef, VK_RValue); + EmitAnyExprToMem(&l2r, blockField, /*volatile*/ false, /*init*/ true); + } + + // Push a destructor if necessary. The semantics for when this + // actually gets run are really obscure. + if (!ci->isByRef() && CGM.getLangOptions().CPlusPlus) + PushDestructorCleanup(type, blockField); + } + + // 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; +} + + +const llvm::Type *CodeGenModule::getBlockDescriptorType() { + if (BlockDescriptorType) + return BlockDescriptorType; + + const 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::get(UnsignedLongTy->getContext(), + UnsignedLongTy, + UnsignedLongTy, + NULL); + + getModule().addTypeName("struct.__block_descriptor", + BlockDescriptorType); + + // Now form a pointer to that. + BlockDescriptorType = llvm::PointerType::getUnqual(BlockDescriptorType); + return BlockDescriptorType; +} + +const llvm::Type *CodeGenModule::getGenericBlockLiteralType() { + if (GenericBlockLiteralType) + return GenericBlockLiteralType; + + const llvm::Type *BlockDescPtrTy = getBlockDescriptorType(); + + // struct __block_literal_generic { + // void *__isa; + // int __flags; + // int __reserved; + // void (*__invoke)(void *); + // struct __block_descriptor *__descriptor; + // }; + GenericBlockLiteralType = llvm::StructType::get(getLLVMContext(), + VoidPtrTy, + IntTy, + IntTy, + VoidPtrTy, + BlockDescPtrTy, + NULL); + + getModule().addTypeName("struct.__block_literal_generic", + GenericBlockLiteralType); + + 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. + const 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, "tmp"); + + BlockLiteral = Builder.CreateBitCast(BlockLiteral, VoidPtrTy, "tmp"); + + // Add the block literal. + QualType VoidPtrTy = getContext().getPointerType(getContext().VoidTy); + CallArgList Args; + Args.push_back(std::make_pair(RValue::get(BlockLiteral), 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, "tmp"); + + const FunctionType *FuncTy = FnType->getAs<FunctionType>(); + QualType ResultType = FuncTy->getResultType(); + + const CGFunctionInfo &FnInfo = + CGM.getTypes().getFunctionInfo(ResultType, Args, + FuncTy->getExtInfo()); + + // Cast the function pointer to the right type. + const llvm::Type *BlockFTy = + CGM.getTypes().GetFunctionType(FnInfo, false); + + const 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); + const 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, name); + + // Compute information about the layout, etc., of this block. + computeBlockInfo(*this, 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); + } + 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 = computeBlockFlag(CGM, blockInfo.getBlockExpr(), + BLOCK_IS_GLOBAL | BLOCK_HAS_SIGNATURE); + 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::get(CGM.getLLVMContext(), fields, BlockHeaderSize, + /*packed*/ false); + + 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. + const 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) { + const BlockDecl *blockDecl = blockInfo.getBlockDecl(); + + DebugInfo = CGM.getDebugInfo(); + 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"); + + // FIXME: this leaks, and we only need it very temporarily. + ImplicitParamDecl *selfDecl = + ImplicitParamDecl::Create(getContext(), + const_cast<BlockDecl*>(blockDecl), + SourceLocation(), II, selfTy); + args.push_back(std::make_pair(selfDecl, selfTy)); + + // 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(std::make_pair(*i, (*i)->getType())); + + // Create the function declaration. + const FunctionProtoType *fnType = + cast<FunctionProtoType>(blockInfo.getBlockExpr()->getFunctionType()); + const CGFunctionInfo &fnInfo = + CGM.getTypes().getFunctionInfo(fnType->getResultType(), args, + fnType->getExtInfo()); + const llvm::FunctionType *fnLLVMType = + CGM.getTypes().GetFunctionType(fnInfo, fnType->isVariadic()); + + 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, args, + blockInfo.getBlockExpr()->getBody()->getLocEnd()); + CurFuncDecl = outerFnDecl; // StartFunction sets this to blockDecl + + // Okay. Undo some of what StartFunction did. We really don't need + // an alloca for the block address; in theory we could remove it, + // but that might do unpleasant things to debug info. + llvm::AllocaInst *blockAddrAlloca + = cast<llvm::AllocaInst>(LocalDeclMap[selfDecl]); + llvm::Value *blockAddr = Builder.CreateLoad(blockAddrAlloca); + 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 BlockDeclRefDecls. + llvm::BasicBlock *entry = Builder.GetInsertBlock(); + llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint(); + --entry_ptr; + + 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 BlockDeclRefDecls. + // 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->setLocation(variable->getLocation()); + + const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable); + if (capture.isConstant()) { + DI->EmitDeclareOfAutoVariable(variable, LocalDeclMap[variable], + Builder); + continue; + } + + DI->EmitDeclareOfBlockDeclRefVariable(variable, blockAddrAlloca, + 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; + // FIXME: This leaks + ImplicitParamDecl *dstDecl = + ImplicitParamDecl::Create(C, 0, SourceLocation(), 0, C.VoidPtrTy); + args.push_back(std::make_pair(dstDecl, dstDecl->getType())); + ImplicitParamDecl *srcDecl = + ImplicitParamDecl::Create(C, 0, SourceLocation(), 0, C.VoidPtrTy); + args.push_back(std::make_pair(srcDecl, srcDecl->getType())); + + const CGFunctionInfo &FI = + CGM.getTypes().getFunctionInfo(C.VoidTy, args, FunctionType::ExtInfo()); + + // FIXME: it would be nice if these were mergeable with things with + // identical semantics. + const llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI, false); + + llvm::Function *Fn = + llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, + "__copy_helper_block_", &CGM.getModule()); + + IdentifierInfo *II + = &CGM.getContext().Idents.get("__copy_helper_block_"); + + FunctionDecl *FD = FunctionDecl::Create(C, + C.getTranslationUnitDecl(), + SourceLocation(), II, C.VoidTy, 0, + SC_Static, + SC_None, + false, + true); + StartFunction(FD, C.VoidTy, Fn, args, SourceLocation()); + + const 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(); + unsigned flags = 0; + + 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->isBlockPointerType()) { + flags = BLOCK_FIELD_IS_BLOCK; + } else if (type->isObjCObjectPointerType() || C.isObjCNSObjectType(type)) { + flags = BLOCK_FIELD_IS_OBJECT; + } + + if (!copyExpr && !flags) 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 { + 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)); + } + } + + FinishFunction(); + + return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); +} + +llvm::Constant * +CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) { + ASTContext &C = getContext(); + + FunctionArgList args; + // FIXME: This leaks + ImplicitParamDecl *srcDecl = + ImplicitParamDecl::Create(C, 0, SourceLocation(), 0, C.VoidPtrTy); + args.push_back(std::make_pair(srcDecl, srcDecl->getType())); + + const CGFunctionInfo &FI = + CGM.getTypes().getFunctionInfo(C.VoidTy, args, FunctionType::ExtInfo()); + + // FIXME: We'd like to put these into a mergable by content, with + // internal linkage. + const llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI, false); + + llvm::Function *Fn = + llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, + "__destroy_helper_block_", &CGM.getModule()); + + IdentifierInfo *II + = &CGM.getContext().Idents.get("__destroy_helper_block_"); + + FunctionDecl *FD = FunctionDecl::Create(C, C.getTranslationUnitDecl(), + SourceLocation(), II, C.VoidTy, 0, + SC_Static, + SC_None, + false, true); + StartFunction(FD, C.VoidTy, Fn, args, SourceLocation()); + + const 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; + + if (ci->isByRef()) { + flags = BLOCK_FIELD_IS_BYREF; + if (type.isObjCGCWeak()) flags |= BLOCK_FIELD_IS_WEAK; + } else if (type->isBlockPointerType()) { + flags = BLOCK_FIELD_IS_BLOCK; + } else if (type->isObjCObjectPointerType() || C.isObjCNSObjectType(type)) { + flags = BLOCK_FIELD_IS_OBJECT; + } else if (C.getLangOptions().CPlusPlus) { + if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) + if (!record->hasTrivialDestructor()) + dtor = record->getDestructor(); + } + + if (!dtor && flags.empty()) 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); + + // 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); +} + +llvm::Constant *CodeGenFunction:: +GeneratebyrefCopyHelperFunction(const llvm::Type *T, BlockFieldFlags flags, + const VarDecl *variable) { + QualType R = getContext().VoidTy; + + FunctionArgList Args; + // FIXME: This leaks + ImplicitParamDecl *Dst = + ImplicitParamDecl::Create(getContext(), 0, + SourceLocation(), 0, + getContext().getPointerType(getContext().VoidTy)); + Args.push_back(std::make_pair(Dst, Dst->getType())); + + // FIXME: This leaks + ImplicitParamDecl *Src = + ImplicitParamDecl::Create(getContext(), 0, + SourceLocation(), 0, + getContext().getPointerType(getContext().VoidTy)); + Args.push_back(std::make_pair(Src, Src->getType())); + + const CGFunctionInfo &FI = + CGM.getTypes().getFunctionInfo(R, Args, FunctionType::ExtInfo()); + + CodeGenTypes &Types = CGM.getTypes(); + const llvm::FunctionType *LTy = Types.GetFunctionType(FI, false); + + // 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_", &CGM.getModule()); + + IdentifierInfo *II + = &CGM.getContext().Idents.get("__Block_byref_object_copy_"); + + FunctionDecl *FD = FunctionDecl::Create(getContext(), + getContext().getTranslationUnitDecl(), + SourceLocation(), II, R, 0, + SC_Static, + SC_None, + false, true); + StartFunction(FD, R, Fn, Args, SourceLocation()); + + // dst->x + llvm::Value *V = GetAddrOfLocalVar(Dst); + V = Builder.CreateBitCast(V, llvm::PointerType::get(T, 0)); + V = Builder.CreateLoad(V); + V = Builder.CreateStructGEP(V, 6, "x"); + llvm::Value *DstObj = V; + + // src->x + V = GetAddrOfLocalVar(Src); + V = Builder.CreateLoad(V); + V = Builder.CreateBitCast(V, T); + V = Builder.CreateStructGEP(V, 6, "x"); + + if (Expr *copyExpr = getContext().getBlockVarCopyInits(variable)) { + llvm::Value *SrcObj = V; + EmitSynthesizedCXXCopyCtor(DstObj, SrcObj, copyExpr); + } else { + DstObj = Builder.CreateBitCast(DstObj, VoidPtrTy); + V = Builder.CreateBitCast(V, VoidPtrPtrTy); + llvm::Value *SrcObj = Builder.CreateLoad(V); + flags |= BLOCK_BYREF_CALLER; + llvm::Value *N = llvm::ConstantInt::get(Int32Ty, flags.getBitMask()); + llvm::Value *F = CGM.getBlockObjectAssign(); + Builder.CreateCall3(F, DstObj, SrcObj, N); + } + + FinishFunction(); + + return llvm::ConstantExpr::getBitCast(Fn, Int8PtrTy); +} + +llvm::Constant * +CodeGenFunction::GeneratebyrefDestroyHelperFunction(const llvm::Type *T, + BlockFieldFlags flags, + const VarDecl *variable) { + QualType R = getContext().VoidTy; + + FunctionArgList Args; + // FIXME: This leaks + ImplicitParamDecl *Src = + ImplicitParamDecl::Create(getContext(), 0, + SourceLocation(), 0, + getContext().getPointerType(getContext().VoidTy)); + + Args.push_back(std::make_pair(Src, Src->getType())); + + const CGFunctionInfo &FI = + CGM.getTypes().getFunctionInfo(R, Args, FunctionType::ExtInfo()); + + CodeGenTypes &Types = CGM.getTypes(); + const llvm::FunctionType *LTy = Types.GetFunctionType(FI, false); + + // 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_", + &CGM.getModule()); + + IdentifierInfo *II + = &CGM.getContext().Idents.get("__Block_byref_object_dispose_"); + + FunctionDecl *FD = FunctionDecl::Create(getContext(), + getContext().getTranslationUnitDecl(), + SourceLocation(), II, R, 0, + SC_Static, + SC_None, + false, true); + StartFunction(FD, R, Fn, Args, SourceLocation()); + + llvm::Value *V = GetAddrOfLocalVar(Src); + V = Builder.CreateBitCast(V, llvm::PointerType::get(T, 0)); + V = Builder.CreateLoad(V); + V = Builder.CreateStructGEP(V, 6, "x"); + + // If it's not any kind of special object, it must have a destructor + // or something. + if (!flags.isSpecialPointer()) { + EHScopeStack::stable_iterator CleanupDepth = EHStack.stable_begin(); + PushDestructorCleanup(variable->getType(), V); + PopCleanupBlocks(CleanupDepth); + + // Otherwise, call _Block_object_dispose. + } else { + V = Builder.CreateBitCast(V, llvm::PointerType::get(Int8PtrTy, 0)); + V = Builder.CreateLoad(V); + + flags |= BLOCK_BYREF_CALLER; + BuildBlockRelease(V, flags); + } + + FinishFunction(); + + return llvm::ConstantExpr::getBitCast(Fn, Int8PtrTy); +} + +llvm::Constant *CodeGenModule::BuildbyrefCopyHelper(const llvm::Type *T, + BlockFieldFlags flags, + unsigned align, + const VarDecl *var) { + // All alignments below that of pointer alignment collapse down to just + // pointer alignment, as we always have at least that much alignment to begin + // with. + align /= unsigned(getTarget().getPointerAlign(0) / 8); + + // As an optimization, we only generate a single function of each kind we + // might need. We need a different one for each alignment and for each + // setting of flags. We mix Align and flag to get the kind. + uint64_t Kind = (uint64_t)align*BLOCK_BYREF_CURRENT_MAX + flags.getBitMask(); + llvm::Constant *&Entry = AssignCache[Kind]; + if (!Entry) + Entry = CodeGenFunction(*this). + GeneratebyrefCopyHelperFunction(T, flags, var); + return Entry; +} + +llvm::Constant *CodeGenModule::BuildbyrefDestroyHelper(const llvm::Type *T, + BlockFieldFlags flags, + unsigned align, + const VarDecl *var) { + // All alignments below that of pointer alignment collpase down to just + // pointer alignment, as we always have at least that much alignment to begin + // with. + align /= unsigned(getTarget().getPointerAlign(0) / 8); + + // As an optimization, we only generate a single function of each kind we + // might need. We need a different one for each alignment and for each + // setting of flags. We mix Align and flag to get the kind. + uint64_t Kind = (uint64_t)align*BLOCK_BYREF_CURRENT_MAX + flags.getBitMask(); + llvm::Constant *&Entry = DestroyCache[Kind]; + if (!Entry) + Entry = CodeGenFunction(*this). + GeneratebyrefDestroyHelperFunction(T, flags, var); + return Entry; +} + +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); +} |
