1 //===--- CGBlocks.cpp - Emit LLVM Code for declarations ---------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This contains code to emit blocks.
12 //===----------------------------------------------------------------------===//
15 #include "CGDebugInfo.h"
16 #include "CGObjCRuntime.h"
17 #include "CodeGenFunction.h"
18 #include "CodeGenModule.h"
19 #include "clang/CodeGen/ConstantInitBuilder.h"
20 #include "clang/AST/DeclObjC.h"
21 #include "llvm/ADT/SmallSet.h"
22 #include "llvm/IR/CallSite.h"
23 #include "llvm/IR/DataLayout.h"
24 #include "llvm/IR/Module.h"
28 using namespace clang;
29 using namespace CodeGen;
31 CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
32 : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
33 HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
34 LocalAddress(Address::invalid()), StructureType(nullptr), Block(block),
35 DominatingIP(nullptr) {
37 // Skip asm prefix, if any. 'name' is usually taken directly from
38 // the mangled name of the enclosing function.
39 if (!name.empty() && name[0] == '\01')
40 name = name.substr(1);
43 // Anchor the vtable to this translation unit.
44 BlockByrefHelpers::~BlockByrefHelpers() {}
46 /// Build the given block as a global block.
47 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
48 const CGBlockInfo &blockInfo,
49 llvm::Constant *blockFn);
51 /// Build the helper function to copy a block.
52 static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
53 const CGBlockInfo &blockInfo) {
54 return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
57 /// Build the helper function to dispose of a block.
58 static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
59 const CGBlockInfo &blockInfo) {
60 return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
63 /// buildBlockDescriptor - Build the block descriptor meta-data for a block.
64 /// buildBlockDescriptor is accessed from 5th field of the Block_literal
65 /// meta-data and contains stationary information about the block literal.
66 /// Its definition will have 4 (or optinally 6) words.
68 /// struct Block_descriptor {
69 /// unsigned long reserved;
70 /// unsigned long size; // size of Block_literal metadata in bytes.
71 /// void *copy_func_helper_decl; // optional copy helper.
72 /// void *destroy_func_decl; // optioanl destructor helper.
73 /// void *block_method_encoding_address; // @encode for block literal signature.
74 /// void *block_layout_info; // encoding of captured block variables.
77 static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
78 const CGBlockInfo &blockInfo) {
79 ASTContext &C = CGM.getContext();
81 llvm::IntegerType *ulong =
82 cast<llvm::IntegerType>(CGM.getTypes().ConvertType(C.UnsignedLongTy));
83 llvm::PointerType *i8p = nullptr;
84 if (CGM.getLangOpts().OpenCL)
86 llvm::Type::getInt8PtrTy(
87 CGM.getLLVMContext(), C.getTargetAddressSpace(LangAS::opencl_constant));
91 ConstantInitBuilder builder(CGM);
92 auto elements = builder.beginStruct();
95 elements.addInt(ulong, 0);
98 // FIXME: What is the right way to say this doesn't fit? We should give
99 // a user diagnostic in that case. Better fix would be to change the
101 elements.addInt(ulong, blockInfo.BlockSize.getQuantity());
103 // Optional copy/dispose helpers.
104 if (blockInfo.NeedsCopyDispose) {
105 // copy_func_helper_decl
106 elements.add(buildCopyHelper(CGM, blockInfo));
109 elements.add(buildDisposeHelper(CGM, blockInfo));
112 // Signature. Mandatory ObjC-style method descriptor @encode sequence.
113 std::string typeAtEncoding =
114 CGM.getContext().getObjCEncodingForBlock(blockInfo.getBlockExpr());
115 elements.add(llvm::ConstantExpr::getBitCast(
116 CGM.GetAddrOfConstantCString(typeAtEncoding).getPointer(), i8p));
119 if (C.getLangOpts().ObjC1) {
120 if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
121 elements.add(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
123 elements.add(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
126 elements.addNullPointer(i8p);
128 unsigned AddrSpace = 0;
129 if (C.getLangOpts().OpenCL)
130 AddrSpace = C.getTargetAddressSpace(LangAS::opencl_constant);
132 llvm::GlobalVariable *global =
133 elements.finishAndCreateGlobal("__block_descriptor_tmp",
134 CGM.getPointerAlign(),
136 llvm::GlobalValue::InternalLinkage,
139 return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
143 Purely notional variadic template describing the layout of a block.
145 template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
146 struct Block_literal {
147 /// Initialized to one of:
148 /// extern void *_NSConcreteStackBlock[];
149 /// extern void *_NSConcreteGlobalBlock[];
151 /// In theory, we could start one off malloc'ed by setting
152 /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
154 /// extern void *_NSConcreteMallocBlock[];
155 struct objc_class *isa;
157 /// These are the flags (with corresponding bit number) that the
158 /// compiler is actually supposed to know about.
159 /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
160 /// descriptor provides copy and dispose helper functions
161 /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
162 /// object with a nontrivial destructor or copy constructor
163 /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
165 /// 29. BLOCK_USE_STRET - indicates that the block function
166 /// uses stret, which objc_msgSend needs to know about
167 /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
168 /// @encoded signature string
169 /// And we're not supposed to manipulate these:
170 /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
171 /// to malloc'ed memory
172 /// 27. BLOCK_IS_GC - indicates that the block has been moved to
173 /// to GC-allocated memory
174 /// Additionally, the bottom 16 bits are a reference count which
175 /// should be zero on the stack.
178 /// Reserved; should be zero-initialized.
181 /// Function pointer generated from block literal.
182 _ResultType (*invoke)(Block_literal *, _ParamTypes...);
184 /// Block description metadata generated from block literal.
185 struct Block_descriptor *block_descriptor;
187 /// Captured values follow.
188 _CapturesTypes captures...;
193 /// A chunk of data that we actually have to capture in the block.
194 struct BlockLayoutChunk {
197 Qualifiers::ObjCLifetime Lifetime;
198 const BlockDecl::Capture *Capture; // null for 'this'
202 BlockLayoutChunk(CharUnits align, CharUnits size,
203 Qualifiers::ObjCLifetime lifetime,
204 const BlockDecl::Capture *capture,
205 llvm::Type *type, QualType fieldType)
206 : Alignment(align), Size(size), Lifetime(lifetime),
207 Capture(capture), Type(type), FieldType(fieldType) {}
209 /// Tell the block info that this chunk has the given field index.
210 void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
212 info.CXXThisIndex = index;
213 info.CXXThisOffset = offset;
215 auto C = CGBlockInfo::Capture::makeIndex(index, offset, FieldType);
216 info.Captures.insert({Capture->getVariable(), C});
221 /// Order by 1) all __strong together 2) next, all byfref together 3) next,
222 /// all __weak together. Preserve descending alignment in all situations.
223 bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
224 if (left.Alignment != right.Alignment)
225 return left.Alignment > right.Alignment;
227 auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
228 if (chunk.Capture && chunk.Capture->isByRef())
230 if (chunk.Lifetime == Qualifiers::OCL_Strong)
232 if (chunk.Lifetime == Qualifiers::OCL_Weak)
237 return getPrefOrder(left) < getPrefOrder(right);
239 } // end anonymous namespace
241 /// Determines if the given type is safe for constant capture in C++.
242 static bool isSafeForCXXConstantCapture(QualType type) {
243 const RecordType *recordType =
244 type->getBaseElementTypeUnsafe()->getAs<RecordType>();
246 // Only records can be unsafe.
247 if (!recordType) return true;
249 const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
251 // Maintain semantics for classes with non-trivial dtors or copy ctors.
252 if (!record->hasTrivialDestructor()) return false;
253 if (record->hasNonTrivialCopyConstructor()) return false;
255 // Otherwise, we just have to make sure there aren't any mutable
256 // fields that might have changed since initialization.
257 return !record->hasMutableFields();
260 /// It is illegal to modify a const object after initialization.
261 /// Therefore, if a const object has a constant initializer, we don't
262 /// actually need to keep storage for it in the block; we'll just
263 /// rematerialize it at the start of the block function. This is
264 /// acceptable because we make no promises about address stability of
265 /// captured variables.
266 static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
267 CodeGenFunction *CGF,
268 const VarDecl *var) {
269 // Return if this is a function parameter. We shouldn't try to
270 // rematerialize default arguments of function parameters.
271 if (isa<ParmVarDecl>(var))
274 QualType type = var->getType();
276 // We can only do this if the variable is const.
277 if (!type.isConstQualified()) return nullptr;
279 // Furthermore, in C++ we have to worry about mutable fields:
280 // C++ [dcl.type.cv]p4:
281 // Except that any class member declared mutable can be
282 // modified, any attempt to modify a const object during its
283 // lifetime results in undefined behavior.
284 if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
287 // If the variable doesn't have any initializer (shouldn't this be
288 // invalid?), it's not clear what we should do. Maybe capture as
290 const Expr *init = var->getInit();
291 if (!init) return nullptr;
293 return CGM.EmitConstantInit(*var, CGF);
296 /// Get the low bit of a nonzero character count. This is the
297 /// alignment of the nth byte if the 0th byte is universally aligned.
298 static CharUnits getLowBit(CharUnits v) {
299 return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
302 static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info,
303 SmallVectorImpl<llvm::Type*> &elementTypes) {
304 // The header is basically 'struct { void *; int; int; void *; void *; }'.
305 // Assert that that struct is packed.
306 assert(CGM.getIntSize() <= CGM.getPointerSize());
307 assert(CGM.getIntAlign() <= CGM.getPointerAlign());
308 assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()));
310 info.BlockAlign = CGM.getPointerAlign();
311 info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
313 assert(elementTypes.empty());
314 elementTypes.push_back(CGM.VoidPtrTy);
315 elementTypes.push_back(CGM.IntTy);
316 elementTypes.push_back(CGM.IntTy);
317 elementTypes.push_back(CGM.VoidPtrTy);
318 elementTypes.push_back(CGM.getBlockDescriptorType());
321 static QualType getCaptureFieldType(const CodeGenFunction &CGF,
322 const BlockDecl::Capture &CI) {
323 const VarDecl *VD = CI.getVariable();
325 // If the variable is captured by an enclosing block or lambda expression,
326 // use the type of the capture field.
327 if (CGF.BlockInfo && CI.isNested())
328 return CGF.BlockInfo->getCapture(VD).fieldType();
329 if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
330 return FD->getType();
331 return VD->getType();
334 /// Compute the layout of the given block. Attempts to lay the block
335 /// out with minimal space requirements.
336 static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF,
338 ASTContext &C = CGM.getContext();
339 const BlockDecl *block = info.getBlockDecl();
341 SmallVector<llvm::Type*, 8> elementTypes;
342 initializeForBlockHeader(CGM, info, elementTypes);
344 if (!block->hasCaptures()) {
346 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
347 info.CanBeGlobal = true;
350 else if (C.getLangOpts().ObjC1 &&
351 CGM.getLangOpts().getGC() == LangOptions::NonGC)
352 info.HasCapturedVariableLayout = true;
354 // Collect the layout chunks.
355 SmallVector<BlockLayoutChunk, 16> layout;
356 layout.reserve(block->capturesCXXThis() +
357 (block->capture_end() - block->capture_begin()));
359 CharUnits maxFieldAlign;
362 if (block->capturesCXXThis()) {
363 assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&
364 "Can't capture 'this' outside a method");
365 QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType(C);
367 // Theoretically, this could be in a different address space, so
368 // don't assume standard pointer size/align.
369 llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
370 std::pair<CharUnits,CharUnits> tinfo
371 = CGM.getContext().getTypeInfoInChars(thisType);
372 maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
374 layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
375 Qualifiers::OCL_None,
376 nullptr, llvmType, thisType));
379 // Next, all the block captures.
380 for (const auto &CI : block->captures()) {
381 const VarDecl *variable = CI.getVariable();
384 // We have to copy/dispose of the __block reference.
385 info.NeedsCopyDispose = true;
387 // Just use void* instead of a pointer to the byref type.
388 CharUnits align = CGM.getPointerAlign();
389 maxFieldAlign = std::max(maxFieldAlign, align);
391 layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
392 Qualifiers::OCL_None, &CI,
393 CGM.VoidPtrTy, variable->getType()));
397 // Otherwise, build a layout chunk with the size and alignment of
399 if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
400 info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
404 // If we have a lifetime qualifier, honor it for capture purposes.
405 // That includes *not* copying it if it's __unsafe_unretained.
406 Qualifiers::ObjCLifetime lifetime =
407 variable->getType().getObjCLifetime();
410 case Qualifiers::OCL_None: llvm_unreachable("impossible");
411 case Qualifiers::OCL_ExplicitNone:
412 case Qualifiers::OCL_Autoreleasing:
415 case Qualifiers::OCL_Strong:
416 case Qualifiers::OCL_Weak:
417 info.NeedsCopyDispose = true;
420 // Block pointers require copy/dispose. So do Objective-C pointers.
421 } else if (variable->getType()->isObjCRetainableType()) {
422 // But honor the inert __unsafe_unretained qualifier, which doesn't
423 // actually make it into the type system.
424 if (variable->getType()->isObjCInertUnsafeUnretainedType()) {
425 lifetime = Qualifiers::OCL_ExplicitNone;
427 info.NeedsCopyDispose = true;
428 // used for mrr below.
429 lifetime = Qualifiers::OCL_Strong;
432 // So do types that require non-trivial copy construction.
433 } else if (CI.hasCopyExpr()) {
434 info.NeedsCopyDispose = true;
435 info.HasCXXObject = true;
437 // And so do types with destructors.
438 } else if (CGM.getLangOpts().CPlusPlus) {
439 if (const CXXRecordDecl *record =
440 variable->getType()->getAsCXXRecordDecl()) {
441 if (!record->hasTrivialDestructor()) {
442 info.HasCXXObject = true;
443 info.NeedsCopyDispose = true;
448 QualType VT = getCaptureFieldType(*CGF, CI);
449 CharUnits size = C.getTypeSizeInChars(VT);
450 CharUnits align = C.getDeclAlign(variable);
452 maxFieldAlign = std::max(maxFieldAlign, align);
454 llvm::Type *llvmType =
455 CGM.getTypes().ConvertTypeForMem(VT);
458 BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
461 // If that was everything, we're done here.
462 if (layout.empty()) {
464 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
465 info.CanBeGlobal = true;
469 // Sort the layout by alignment. We have to use a stable sort here
470 // to get reproducible results. There should probably be an
471 // llvm::array_pod_stable_sort.
472 std::stable_sort(layout.begin(), layout.end());
474 // Needed for blocks layout info.
475 info.BlockHeaderForcedGapOffset = info.BlockSize;
476 info.BlockHeaderForcedGapSize = CharUnits::Zero();
478 CharUnits &blockSize = info.BlockSize;
479 info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
481 // Assuming that the first byte in the header is maximally aligned,
482 // get the alignment of the first byte following the header.
483 CharUnits endAlign = getLowBit(blockSize);
485 // If the end of the header isn't satisfactorily aligned for the
486 // maximum thing, look for things that are okay with the header-end
487 // alignment, and keep appending them until we get something that's
488 // aligned right. This algorithm is only guaranteed optimal if
489 // that condition is satisfied at some point; otherwise we can get
491 // header // next byte has alignment 4
492 // something_with_size_5; // next byte has alignment 1
493 // something_with_alignment_8;
494 // which has 7 bytes of padding, as opposed to the naive solution
495 // which might have less (?).
496 if (endAlign < maxFieldAlign) {
497 SmallVectorImpl<BlockLayoutChunk>::iterator
498 li = layout.begin() + 1, le = layout.end();
500 // Look for something that the header end is already
501 // satisfactorily aligned for.
502 for (; li != le && endAlign < li->Alignment; ++li)
505 // If we found something that's naturally aligned for the end of
506 // the header, keep adding things...
508 SmallVectorImpl<BlockLayoutChunk>::iterator first = li;
509 for (; li != le; ++li) {
510 assert(endAlign >= li->Alignment);
512 li->setIndex(info, elementTypes.size(), blockSize);
513 elementTypes.push_back(li->Type);
514 blockSize += li->Size;
515 endAlign = getLowBit(blockSize);
517 // ...until we get to the alignment of the maximum field.
518 if (endAlign >= maxFieldAlign) {
522 // Don't re-append everything we just appended.
523 layout.erase(first, li);
527 assert(endAlign == getLowBit(blockSize));
529 // At this point, we just have to add padding if the end align still
530 // isn't aligned right.
531 if (endAlign < maxFieldAlign) {
532 CharUnits newBlockSize = blockSize.alignTo(maxFieldAlign);
533 CharUnits padding = newBlockSize - blockSize;
535 // If we haven't yet added any fields, remember that there was an
536 // initial gap; this need to go into the block layout bit map.
537 if (blockSize == info.BlockHeaderForcedGapOffset) {
538 info.BlockHeaderForcedGapSize = padding;
541 elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
542 padding.getQuantity()));
543 blockSize = newBlockSize;
544 endAlign = getLowBit(blockSize); // might be > maxFieldAlign
547 assert(endAlign >= maxFieldAlign);
548 assert(endAlign == getLowBit(blockSize));
549 // Slam everything else on now. This works because they have
550 // strictly decreasing alignment and we expect that size is always a
551 // multiple of alignment.
552 for (SmallVectorImpl<BlockLayoutChunk>::iterator
553 li = layout.begin(), le = layout.end(); li != le; ++li) {
554 if (endAlign < li->Alignment) {
555 // size may not be multiple of alignment. This can only happen with
556 // an over-aligned variable. We will be adding a padding field to
557 // make the size be multiple of alignment.
558 CharUnits padding = li->Alignment - endAlign;
559 elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
560 padding.getQuantity()));
561 blockSize += padding;
562 endAlign = getLowBit(blockSize);
564 assert(endAlign >= li->Alignment);
565 li->setIndex(info, elementTypes.size(), blockSize);
566 elementTypes.push_back(li->Type);
567 blockSize += li->Size;
568 endAlign = getLowBit(blockSize);
572 llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
575 /// Enter the scope of a block. This should be run at the entrance to
576 /// a full-expression so that the block's cleanups are pushed at the
577 /// right place in the stack.
578 static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
579 assert(CGF.HaveInsertPoint());
581 // Allocate the block info and place it at the head of the list.
582 CGBlockInfo &blockInfo =
583 *new CGBlockInfo(block, CGF.CurFn->getName());
584 blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
585 CGF.FirstBlockInfo = &blockInfo;
587 // Compute information about the layout, etc., of this block,
588 // pushing cleanups as necessary.
589 computeBlockInfo(CGF.CGM, &CGF, blockInfo);
591 // Nothing else to do if it can be global.
592 if (blockInfo.CanBeGlobal) return;
594 // Make the allocation for the block.
595 blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
596 blockInfo.BlockAlign, "block");
598 // If there are cleanups to emit, enter them (but inactive).
599 if (!blockInfo.NeedsCopyDispose) return;
601 // Walk through the captures (in order) and find the ones not
602 // captured by constant.
603 for (const auto &CI : block->captures()) {
604 // Ignore __block captures; there's nothing special in the
605 // on-stack block that we need to do for them.
606 if (CI.isByRef()) continue;
608 // Ignore variables that are constant-captured.
609 const VarDecl *variable = CI.getVariable();
610 CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
611 if (capture.isConstant()) continue;
613 // Ignore objects that aren't destructed.
614 QualType VT = getCaptureFieldType(CGF, CI);
615 QualType::DestructionKind dtorKind = VT.isDestructedType();
616 if (dtorKind == QualType::DK_none) continue;
618 CodeGenFunction::Destroyer *destroyer;
620 // Block captures count as local values and have imprecise semantics.
621 // They also can't be arrays, so need to worry about that.
623 // For const-qualified captures, emit clang.arc.use to ensure the captured
624 // object doesn't get released while we are still depending on its validity
626 if (VT.isConstQualified() &&
627 VT.getObjCLifetime() == Qualifiers::OCL_Strong &&
628 CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
629 assert(CGF.CGM.getLangOpts().ObjCAutoRefCount &&
630 "expected ObjC ARC to be enabled");
631 destroyer = CodeGenFunction::emitARCIntrinsicUse;
632 } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
633 destroyer = CodeGenFunction::destroyARCStrongImprecise;
635 destroyer = CGF.getDestroyer(dtorKind);
638 // GEP down to the address.
639 Address addr = CGF.Builder.CreateStructGEP(blockInfo.LocalAddress,
641 capture.getOffset());
643 // We can use that GEP as the dominating IP.
644 if (!blockInfo.DominatingIP)
645 blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
647 CleanupKind cleanupKind = InactiveNormalCleanup;
648 bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
649 if (useArrayEHCleanup)
650 cleanupKind = InactiveNormalAndEHCleanup;
652 CGF.pushDestroy(cleanupKind, addr, VT,
653 destroyer, useArrayEHCleanup);
655 // Remember where that cleanup was.
656 capture.setCleanup(CGF.EHStack.stable_begin());
660 /// Enter a full-expression with a non-trivial number of objects to
661 /// clean up. This is in this file because, at the moment, the only
662 /// kind of cleanup object is a BlockDecl*.
663 void CodeGenFunction::enterNonTrivialFullExpression(const ExprWithCleanups *E) {
664 assert(E->getNumObjects() != 0);
665 ArrayRef<ExprWithCleanups::CleanupObject> cleanups = E->getObjects();
666 for (ArrayRef<ExprWithCleanups::CleanupObject>::iterator
667 i = cleanups.begin(), e = cleanups.end(); i != e; ++i) {
668 enterBlockScope(*this, *i);
672 /// Find the layout for the given block in a linked list and remove it.
673 static CGBlockInfo *findAndRemoveBlockInfo(CGBlockInfo **head,
674 const BlockDecl *block) {
676 assert(head && *head);
677 CGBlockInfo *cur = *head;
679 // If this is the block we're looking for, splice it out of the list.
680 if (cur->getBlockDecl() == block) {
681 *head = cur->NextBlockInfo;
685 head = &cur->NextBlockInfo;
689 /// Destroy a chain of block layouts.
690 void CodeGenFunction::destroyBlockInfos(CGBlockInfo *head) {
691 assert(head && "destroying an empty chain");
693 CGBlockInfo *cur = head;
694 head = cur->NextBlockInfo;
696 } while (head != nullptr);
699 /// Emit a block literal expression in the current function.
700 llvm::Value *CodeGenFunction::EmitBlockLiteral(const BlockExpr *blockExpr) {
701 // If the block has no captures, we won't have a pre-computed
703 if (!blockExpr->getBlockDecl()->hasCaptures()) {
704 if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr))
706 CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
707 computeBlockInfo(CGM, this, blockInfo);
708 blockInfo.BlockExpression = blockExpr;
709 return EmitBlockLiteral(blockInfo);
712 // Find the block info for this block and take ownership of it.
713 std::unique_ptr<CGBlockInfo> blockInfo;
714 blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
715 blockExpr->getBlockDecl()));
717 blockInfo->BlockExpression = blockExpr;
718 return EmitBlockLiteral(*blockInfo);
721 llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) {
722 // Using the computed layout, generate the actual block function.
723 bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
724 llvm::Constant *blockFn
725 = CodeGenFunction(CGM, true).GenerateBlockFunction(CurGD, blockInfo,
728 blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy);
730 // If there is nothing to capture, we can emit this as a global block.
731 if (blockInfo.CanBeGlobal)
732 return buildGlobalBlock(CGM, blockInfo, blockFn);
734 // Otherwise, we have to emit this as a local block.
736 llvm::Constant *isa =
737 (!CGM.getContext().getLangOpts().OpenCL)
738 ? CGM.getNSConcreteStackBlock()
739 : CGM.getNullPointer(VoidPtrPtrTy,
740 CGM.getContext().getPointerType(
741 QualType(CGM.getContext().VoidPtrTy)));
742 isa = llvm::ConstantExpr::getBitCast(isa, VoidPtrTy);
744 // Build the block descriptor.
745 llvm::Constant *descriptor = buildBlockDescriptor(CGM, blockInfo);
747 Address blockAddr = blockInfo.LocalAddress;
748 assert(blockAddr.isValid() && "block has no address!");
750 // Compute the initial on-stack block flags.
751 BlockFlags flags = BLOCK_HAS_SIGNATURE;
752 if (blockInfo.HasCapturedVariableLayout) flags |= BLOCK_HAS_EXTENDED_LAYOUT;
753 if (blockInfo.NeedsCopyDispose) flags |= BLOCK_HAS_COPY_DISPOSE;
754 if (blockInfo.HasCXXObject) flags |= BLOCK_HAS_CXX_OBJ;
755 if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET;
758 [&](unsigned index, CharUnits offset, const Twine &name) -> Address {
759 return Builder.CreateStructGEP(blockAddr, index, offset, name);
762 [&](llvm::Value *value, unsigned index, CharUnits offset,
764 Builder.CreateStore(value, projectField(index, offset, name));
767 // Initialize the block header.
769 // We assume all the header fields are densely packed.
772 auto addHeaderField =
773 [&](llvm::Value *value, CharUnits size, const Twine &name) {
774 storeField(value, index, offset, name);
779 addHeaderField(isa, getPointerSize(), "block.isa");
780 addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
781 getIntSize(), "block.flags");
782 addHeaderField(llvm::ConstantInt::get(IntTy, 0),
783 getIntSize(), "block.reserved");
784 addHeaderField(blockFn, getPointerSize(), "block.invoke");
785 addHeaderField(descriptor, getPointerSize(), "block.descriptor");
788 // Finally, capture all the values into the block.
789 const BlockDecl *blockDecl = blockInfo.getBlockDecl();
792 if (blockDecl->capturesCXXThis()) {
793 Address addr = projectField(blockInfo.CXXThisIndex, blockInfo.CXXThisOffset,
794 "block.captured-this.addr");
795 Builder.CreateStore(LoadCXXThis(), addr);
798 // Next, captured variables.
799 for (const auto &CI : blockDecl->captures()) {
800 const VarDecl *variable = CI.getVariable();
801 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
803 // Ignore constant captures.
804 if (capture.isConstant()) continue;
806 QualType type = capture.fieldType();
808 // This will be a [[type]]*, except that a byref entry will just be
811 projectField(capture.getIndex(), capture.getOffset(), "block.captured");
813 // Compute the address of the thing we're going to move into the
815 Address src = Address::invalid();
817 if (blockDecl->isConversionFromLambda()) {
818 // The lambda capture in a lambda's conversion-to-block-pointer is
819 // special; we'll simply emit it directly.
820 src = Address::invalid();
821 } else if (CI.isByRef()) {
822 if (BlockInfo && CI.isNested()) {
823 // We need to use the capture from the enclosing block.
824 const CGBlockInfo::Capture &enclosingCapture =
825 BlockInfo->getCapture(variable);
827 // This is a [[type]]*, except that a byref entry wil just be an i8**.
828 src = Builder.CreateStructGEP(LoadBlockStruct(),
829 enclosingCapture.getIndex(),
830 enclosingCapture.getOffset(),
831 "block.capture.addr");
833 auto I = LocalDeclMap.find(variable);
834 assert(I != LocalDeclMap.end());
838 DeclRefExpr declRef(const_cast<VarDecl *>(variable),
839 /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
840 type.getNonReferenceType(), VK_LValue,
842 src = EmitDeclRefLValue(&declRef).getAddress();
845 // For byrefs, we just write the pointer to the byref struct into
846 // the block field. There's no need to chase the forwarding
847 // pointer at this point, since we're building something that will
848 // live a shorter life than the stack byref anyway.
850 // Get a void* that points to the byref struct.
851 llvm::Value *byrefPointer;
853 byrefPointer = Builder.CreateLoad(src, "byref.capture");
855 byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
857 // Write that void* into the capture field.
858 Builder.CreateStore(byrefPointer, blockField);
860 // If we have a copy constructor, evaluate that into the block field.
861 } else if (const Expr *copyExpr = CI.getCopyExpr()) {
862 if (blockDecl->isConversionFromLambda()) {
863 // If we have a lambda conversion, emit the expression
864 // directly into the block instead.
866 AggValueSlot::forAddr(blockField, Qualifiers(),
867 AggValueSlot::IsDestructed,
868 AggValueSlot::DoesNotNeedGCBarriers,
869 AggValueSlot::IsNotAliased);
870 EmitAggExpr(copyExpr, Slot);
872 EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
875 // If it's a reference variable, copy the reference into the block field.
876 } else if (type->isReferenceType()) {
877 Builder.CreateStore(src.getPointer(), blockField);
879 // If type is const-qualified, copy the value into the block field.
880 } else if (type.isConstQualified() &&
881 type.getObjCLifetime() == Qualifiers::OCL_Strong &&
882 CGM.getCodeGenOpts().OptimizationLevel != 0) {
883 llvm::Value *value = Builder.CreateLoad(src, "captured");
884 Builder.CreateStore(value, blockField);
886 // If this is an ARC __strong block-pointer variable, don't do a
889 // TODO: this can be generalized into the normal initialization logic:
890 // we should never need to do a block-copy when initializing a local
891 // variable, because the local variable's lifetime should be strictly
892 // contained within the stack block's.
893 } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
894 type->isBlockPointerType()) {
895 // Load the block and do a simple retain.
896 llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
897 value = EmitARCRetainNonBlock(value);
899 // Do a primitive store to the block field.
900 Builder.CreateStore(value, blockField);
902 // Otherwise, fake up a POD copy into the block field.
904 // Fake up a new variable so that EmitScalarInit doesn't think
905 // we're referring to the variable in its own initializer.
906 ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
907 ImplicitParamDecl::Other);
909 // We use one of these or the other depending on whether the
910 // reference is nested.
911 DeclRefExpr declRef(const_cast<VarDecl *>(variable),
912 /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
913 type, VK_LValue, SourceLocation());
915 ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
916 &declRef, VK_RValue);
917 // FIXME: Pass a specific location for the expr init so that the store is
918 // attributed to a reasonable location - otherwise it may be attributed to
919 // locations of subexpressions in the initialization.
920 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
921 EmitExprAsInit(&l2r, &BlockFieldPseudoVar,
922 MakeAddrLValue(blockField, type, BaseInfo),
923 /*captured by init*/ false);
926 // Activate the cleanup if layout pushed one.
928 EHScopeStack::stable_iterator cleanup = capture.getCleanup();
929 if (cleanup.isValid())
930 ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
934 // Cast to the converted block-pointer type, which happens (somewhat
935 // unfortunately) to be a pointer to function type.
936 llvm::Value *result = Builder.CreatePointerCast(
937 blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
943 llvm::Type *CodeGenModule::getBlockDescriptorType() {
944 if (BlockDescriptorType)
945 return BlockDescriptorType;
947 llvm::Type *UnsignedLongTy =
948 getTypes().ConvertType(getContext().UnsignedLongTy);
950 // struct __block_descriptor {
951 // unsigned long reserved;
952 // unsigned long block_size;
954 // // later, the following will be added
957 // void (*copyHelper)();
958 // void (*copyHelper)();
959 // } helpers; // !!! optional
961 // const char *signature; // the block signature
962 // const char *layout; // reserved
964 BlockDescriptorType = llvm::StructType::create(
965 "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
967 // Now form a pointer to that.
968 unsigned AddrSpace = 0;
969 if (getLangOpts().OpenCL)
970 AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
971 BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
972 return BlockDescriptorType;
975 llvm::Type *CodeGenModule::getGenericBlockLiteralType() {
976 if (GenericBlockLiteralType)
977 return GenericBlockLiteralType;
979 llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
981 // struct __block_literal_generic {
985 // void (*__invoke)(void *);
986 // struct __block_descriptor *__descriptor;
988 GenericBlockLiteralType =
989 llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
990 IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
992 return GenericBlockLiteralType;
995 RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr *E,
996 ReturnValueSlot ReturnValue) {
997 const BlockPointerType *BPT =
998 E->getCallee()->getType()->getAs<BlockPointerType>();
1000 llvm::Value *BlockPtr = EmitScalarExpr(E->getCallee());
1002 // Get a pointer to the generic block literal.
1003 // For OpenCL we generate generic AS void ptr to be able to reuse the same
1004 // block definition for blocks with captures generated as private AS local
1005 // variables and without captures generated as global AS program scope
1007 unsigned AddrSpace = 0;
1008 if (getLangOpts().OpenCL)
1009 AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_generic);
1011 llvm::Type *BlockLiteralTy =
1012 llvm::PointerType::get(CGM.getGenericBlockLiteralType(), AddrSpace);
1014 // Bitcast the callee to a block literal.
1016 Builder.CreatePointerCast(BlockPtr, BlockLiteralTy, "block.literal");
1018 // Get the function pointer from the literal.
1019 llvm::Value *FuncPtr =
1020 Builder.CreateStructGEP(CGM.getGenericBlockLiteralType(), BlockPtr, 3);
1023 // Add the block literal.
1026 QualType VoidPtrQualTy = getContext().VoidPtrTy;
1027 llvm::Type *GenericVoidPtrTy = VoidPtrTy;
1028 if (getLangOpts().OpenCL) {
1029 GenericVoidPtrTy = Builder.getInt8PtrTy(
1030 getContext().getTargetAddressSpace(LangAS::opencl_generic));
1032 getContext().getPointerType(getContext().getAddrSpaceQualType(
1033 getContext().VoidTy, LangAS::opencl_generic));
1036 BlockPtr = Builder.CreatePointerCast(BlockPtr, GenericVoidPtrTy);
1037 Args.add(RValue::get(BlockPtr), VoidPtrQualTy);
1039 QualType FnType = BPT->getPointeeType();
1041 // And the rest of the arguments.
1042 EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1044 // Load the function.
1045 llvm::Value *Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1047 const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1048 const CGFunctionInfo &FnInfo =
1049 CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
1051 // Cast the function pointer to the right type.
1052 llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
1054 llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
1055 Func = Builder.CreateBitCast(Func, BlockFTyPtr);
1057 // Prepare the callee.
1058 CGCallee Callee(CGCalleeInfo(), Func);
1060 // And call the block.
1061 return EmitCall(FnInfo, Callee, ReturnValue, Args);
1064 Address CodeGenFunction::GetAddrOfBlockDecl(const VarDecl *variable,
1066 assert(BlockInfo && "evaluating block ref without block information?");
1067 const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1069 // Handle constant captures.
1070 if (capture.isConstant()) return LocalDeclMap.find(variable)->second;
1073 Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(),
1074 capture.getOffset(), "block.capture.addr");
1077 // addr should be a void** right now. Load, then cast the result
1080 auto &byrefInfo = getBlockByrefInfo(variable);
1081 addr = Address(Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
1083 auto byrefPointerType = llvm::PointerType::get(byrefInfo.Type, 0);
1084 addr = Builder.CreateBitCast(addr, byrefPointerType, "byref.addr");
1086 addr = emitBlockByrefAddress(addr, byrefInfo, /*follow*/ true,
1087 variable->getName());
1090 if (auto refType = capture.fieldType()->getAs<ReferenceType>())
1091 addr = EmitLoadOfReference(addr, refType);
1096 void CodeGenModule::setAddrOfGlobalBlock(const BlockExpr *BE,
1097 llvm::Constant *Addr) {
1098 bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
1100 assert(Ok && "Trying to replace an already-existing global block!");
1104 CodeGenModule::GetAddrOfGlobalBlock(const BlockExpr *BE,
1106 if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1109 CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1110 blockInfo.BlockExpression = BE;
1112 // Compute information about the layout, etc., of this block.
1113 computeBlockInfo(*this, nullptr, blockInfo);
1115 // Using that metadata, generate the actual block function.
1116 llvm::Constant *blockFn;
1118 CodeGenFunction::DeclMapTy LocalDeclMap;
1119 blockFn = CodeGenFunction(*this).GenerateBlockFunction(GlobalDecl(),
1124 blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy);
1126 return buildGlobalBlock(*this, blockInfo, blockFn);
1129 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1130 const CGBlockInfo &blockInfo,
1131 llvm::Constant *blockFn) {
1132 assert(blockInfo.CanBeGlobal);
1133 // Callers should detect this case on their own: calling this function
1134 // generally requires computing layout information, which is a waste of time
1135 // if we've already emitted this block.
1136 assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&
1137 "Refusing to re-emit a global block.");
1139 // Generate the constants for the block literal initializer.
1140 ConstantInitBuilder builder(CGM);
1141 auto fields = builder.beginStruct();
1144 fields.add((!CGM.getContext().getLangOpts().OpenCL)
1145 ? CGM.getNSConcreteGlobalBlock()
1146 : CGM.getNullPointer(CGM.VoidPtrPtrTy,
1147 CGM.getContext().getPointerType(QualType(
1148 CGM.getContext().VoidPtrTy))));
1151 BlockFlags flags = BLOCK_IS_GLOBAL | BLOCK_HAS_SIGNATURE;
1152 if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET;
1154 fields.addInt(CGM.IntTy, flags.getBitMask());
1157 fields.addInt(CGM.IntTy, 0);
1160 fields.add(blockFn);
1163 fields.add(buildBlockDescriptor(CGM, blockInfo));
1165 unsigned AddrSpace = 0;
1166 if (CGM.getContext().getLangOpts().OpenCL)
1167 AddrSpace = CGM.getContext().getTargetAddressSpace(LangAS::opencl_global);
1169 llvm::Constant *literal = fields.finishAndCreateGlobal(
1170 "__block_literal_global", blockInfo.BlockAlign,
1171 /*constant*/ true, llvm::GlobalVariable::InternalLinkage, AddrSpace);
1173 // Return a constant of the appropriately-casted type.
1174 llvm::Type *RequiredType =
1175 CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1176 llvm::Constant *Result =
1177 llvm::ConstantExpr::getPointerCast(literal, RequiredType);
1178 CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
1182 void CodeGenFunction::setBlockContextParameter(const ImplicitParamDecl *D,
1185 assert(BlockInfo && "not emitting prologue of block invocation function?!");
1187 llvm::Value *localAddr = nullptr;
1188 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1189 // Allocate a stack slot to let the debug info survive the RA.
1190 Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr");
1191 Builder.CreateStore(arg, alloc);
1192 localAddr = Builder.CreateLoad(alloc);
1195 if (CGDebugInfo *DI = getDebugInfo()) {
1196 if (CGM.getCodeGenOpts().getDebugInfo() >=
1197 codegenoptions::LimitedDebugInfo) {
1198 DI->setLocation(D->getLocation());
1199 DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, arg, argNum,
1200 localAddr, Builder);
1204 SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getLocStart();
1205 ApplyDebugLocation Scope(*this, StartLoc);
1207 // Instead of messing around with LocalDeclMap, just set the value
1208 // directly as BlockPointer.
1209 BlockPointer = Builder.CreatePointerCast(
1211 BlockInfo->StructureType->getPointerTo(
1212 getContext().getLangOpts().OpenCL
1213 ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1218 Address CodeGenFunction::LoadBlockStruct() {
1219 assert(BlockInfo && "not in a block invocation function!");
1220 assert(BlockPointer && "no block pointer set!");
1221 return Address(BlockPointer, BlockInfo->BlockAlign);
1225 CodeGenFunction::GenerateBlockFunction(GlobalDecl GD,
1226 const CGBlockInfo &blockInfo,
1227 const DeclMapTy &ldm,
1228 bool IsLambdaConversionToBlock) {
1229 const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1233 CurEHLocation = blockInfo.getBlockExpr()->getLocEnd();
1235 BlockInfo = &blockInfo;
1237 // Arrange for local static and local extern declarations to appear
1238 // to be local to this function as well, in case they're directly
1239 // referenced in a block.
1240 for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1241 const auto *var = dyn_cast<VarDecl>(i->first);
1242 if (var && !var->hasLocalStorage())
1243 setAddrOfLocalVar(var, i->second);
1246 // Begin building the function declaration.
1248 // Build the argument list.
1249 FunctionArgList args;
1251 // The first argument is the block pointer. Just take it as a void*
1252 // and cast it later.
1253 QualType selfTy = getContext().VoidPtrTy;
1255 // For OpenCL passed block pointer can be private AS local variable or
1256 // global AS program scope variable (for the case with and without captures).
1257 // Generic AS is used therefore to be able to accommodate both private and
1258 // generic AS in one implementation.
1259 if (getLangOpts().OpenCL)
1260 selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1261 getContext().VoidTy, LangAS::opencl_generic));
1263 IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1265 ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1266 SourceLocation(), II, selfTy,
1267 ImplicitParamDecl::ObjCSelf);
1268 args.push_back(&SelfDecl);
1270 // Now add the rest of the parameters.
1271 args.append(blockDecl->param_begin(), blockDecl->param_end());
1273 // Create the function declaration.
1274 const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1275 const CGFunctionInfo &fnInfo =
1276 CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1277 if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1278 blockInfo.UsesStret = true;
1280 llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1282 StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1283 llvm::Function *fn = llvm::Function::Create(
1284 fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1285 CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1287 // Begin generating the function.
1288 StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1289 blockDecl->getLocation(),
1290 blockInfo.getBlockExpr()->getBody()->getLocStart());
1292 // Okay. Undo some of what StartFunction did.
1294 // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1295 // won't delete the dbg.declare intrinsics for captured variables.
1296 llvm::Value *BlockPointerDbgLoc = BlockPointer;
1297 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1298 // Allocate a stack slot for it, so we can point the debugger to it
1299 Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1302 // Set the DebugLocation to empty, so the store is recognized as a
1303 // frame setup instruction by llvm::DwarfDebug::beginFunction().
1304 auto NL = ApplyDebugLocation::CreateEmpty(*this);
1305 Builder.CreateStore(BlockPointer, Alloca);
1306 BlockPointerDbgLoc = Alloca.getPointer();
1309 // If we have a C++ 'this' reference, go ahead and force it into
1311 if (blockDecl->capturesCXXThis()) {
1313 Builder.CreateStructGEP(LoadBlockStruct(), blockInfo.CXXThisIndex,
1314 blockInfo.CXXThisOffset, "block.captured-this");
1315 CXXThisValue = Builder.CreateLoad(addr, "this");
1318 // Also force all the constant captures.
1319 for (const auto &CI : blockDecl->captures()) {
1320 const VarDecl *variable = CI.getVariable();
1321 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1322 if (!capture.isConstant()) continue;
1324 CharUnits align = getContext().getDeclAlign(variable);
1326 CreateMemTemp(variable->getType(), align, "block.captured-const");
1328 Builder.CreateStore(capture.getConstant(), alloca);
1330 setAddrOfLocalVar(variable, alloca);
1333 // Save a spot to insert the debug information for all the DeclRefExprs.
1334 llvm::BasicBlock *entry = Builder.GetInsertBlock();
1335 llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1338 if (IsLambdaConversionToBlock)
1339 EmitLambdaBlockInvokeBody();
1341 PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1342 incrementProfileCounter(blockDecl->getBody());
1343 EmitStmt(blockDecl->getBody());
1346 // Remember where we were...
1347 llvm::BasicBlock *resume = Builder.GetInsertBlock();
1349 // Go back to the entry.
1351 Builder.SetInsertPoint(entry, entry_ptr);
1353 // Emit debug information for all the DeclRefExprs.
1354 // FIXME: also for 'this'
1355 if (CGDebugInfo *DI = getDebugInfo()) {
1356 for (const auto &CI : blockDecl->captures()) {
1357 const VarDecl *variable = CI.getVariable();
1358 DI->EmitLocation(Builder, variable->getLocation());
1360 if (CGM.getCodeGenOpts().getDebugInfo() >=
1361 codegenoptions::LimitedDebugInfo) {
1362 const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1363 if (capture.isConstant()) {
1364 auto addr = LocalDeclMap.find(variable)->second;
1365 DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1370 DI->EmitDeclareOfBlockDeclRefVariable(
1371 variable, BlockPointerDbgLoc, Builder, blockInfo,
1372 entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1375 // Recover location if it was changed in the above loop.
1376 DI->EmitLocation(Builder,
1377 cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1380 // And resume where we left off.
1381 if (resume == nullptr)
1382 Builder.ClearInsertionPoint();
1384 Builder.SetInsertPoint(resume);
1386 FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1393 /// Represents a type of copy/destroy operation that should be performed for an
1394 /// entity that's captured by a block.
1395 enum class BlockCaptureEntityKind {
1396 CXXRecord, // Copy or destroy
1399 BlockObject, // Assign or release
1403 /// Represents a captured entity that requires extra operations in order for
1404 /// this entity to be copied or destroyed correctly.
1405 struct BlockCaptureManagedEntity {
1406 BlockCaptureEntityKind Kind;
1407 BlockFieldFlags Flags;
1408 const BlockDecl::Capture &CI;
1409 const CGBlockInfo::Capture &Capture;
1411 BlockCaptureManagedEntity(BlockCaptureEntityKind Type, BlockFieldFlags Flags,
1412 const BlockDecl::Capture &CI,
1413 const CGBlockInfo::Capture &Capture)
1414 : Kind(Type), Flags(Flags), CI(CI), Capture(Capture) {}
1417 } // end anonymous namespace
1419 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1420 computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
1421 const LangOptions &LangOpts) {
1422 if (CI.getCopyExpr()) {
1423 assert(!CI.isByRef());
1424 // don't bother computing flags
1425 return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1427 BlockFieldFlags Flags;
1429 Flags = BLOCK_FIELD_IS_BYREF;
1430 if (T.isObjCGCWeak())
1431 Flags |= BLOCK_FIELD_IS_WEAK;
1432 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1434 if (!T->isObjCRetainableType())
1435 // For all other types, the memcpy is fine.
1436 return std::make_pair(BlockCaptureEntityKind::None, Flags);
1438 Flags = BLOCK_FIELD_IS_OBJECT;
1439 bool isBlockPointer = T->isBlockPointerType();
1441 Flags = BLOCK_FIELD_IS_BLOCK;
1443 // Special rules for ARC captures:
1444 Qualifiers QS = T.getQualifiers();
1446 // We need to register __weak direct captures with the runtime.
1447 if (QS.getObjCLifetime() == Qualifiers::OCL_Weak)
1448 return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1450 // We need to retain the copied value for __strong direct captures.
1451 if (QS.getObjCLifetime() == Qualifiers::OCL_Strong) {
1452 // If it's a block pointer, we have to copy the block and
1453 // assign that to the destination pointer, so we might as
1454 // well use _Block_object_assign. Otherwise we can avoid that.
1455 return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1456 : BlockCaptureEntityKind::BlockObject,
1460 // Non-ARC captures of retainable pointers are strong and
1461 // therefore require a call to _Block_object_assign.
1462 if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1463 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1465 // Otherwise the memcpy is fine.
1466 return std::make_pair(BlockCaptureEntityKind::None, Flags);
1469 /// Find the set of block captures that need to be explicitly copied or destroy.
1470 static void findBlockCapturedManagedEntities(
1471 const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1472 SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures,
1473 llvm::function_ref<std::pair<BlockCaptureEntityKind, BlockFieldFlags>(
1474 const BlockDecl::Capture &, QualType, const LangOptions &)>
1476 for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1477 const VarDecl *Variable = CI.getVariable();
1478 const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1479 if (Capture.isConstant())
1482 auto Info = Predicate(CI, Variable->getType(), LangOpts);
1483 if (Info.first != BlockCaptureEntityKind::None)
1484 ManagedCaptures.emplace_back(Info.first, Info.second, CI, Capture);
1488 /// Generate the copy-helper function for a block closure object:
1489 /// static void block_copy_helper(block_t *dst, block_t *src);
1490 /// The runtime will have previously initialized 'dst' by doing a
1491 /// bit-copy of 'src'.
1493 /// Note that this copies an entire block closure object to the heap;
1494 /// it should not be confused with a 'byref copy helper', which moves
1495 /// the contents of an individual __block variable to the heap.
1497 CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) {
1498 ASTContext &C = getContext();
1500 FunctionArgList args;
1501 ImplicitParamDecl DstDecl(getContext(), C.VoidPtrTy,
1502 ImplicitParamDecl::Other);
1503 args.push_back(&DstDecl);
1504 ImplicitParamDecl SrcDecl(getContext(), C.VoidPtrTy,
1505 ImplicitParamDecl::Other);
1506 args.push_back(&SrcDecl);
1508 const CGFunctionInfo &FI =
1509 CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, args);
1511 // FIXME: it would be nice if these were mergeable with things with
1512 // identical semantics.
1513 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1515 llvm::Function *Fn =
1516 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
1517 "__copy_helper_block_", &CGM.getModule());
1520 = &CGM.getContext().Idents.get("__copy_helper_block_");
1522 FunctionDecl *FD = FunctionDecl::Create(C,
1523 C.getTranslationUnitDecl(),
1525 SourceLocation(), II, C.VoidTy,
1530 CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
1532 auto NL = ApplyDebugLocation::CreateEmpty(*this);
1533 StartFunction(FD, C.VoidTy, Fn, FI, args);
1534 // Create a scope with an artificial location for the body of this function.
1535 auto AL = ApplyDebugLocation::CreateArtificial(*this);
1536 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1538 Address src = GetAddrOfLocalVar(&SrcDecl);
1539 src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
1540 src = Builder.CreateBitCast(src, structPtrTy, "block.source");
1542 Address dst = GetAddrOfLocalVar(&DstDecl);
1543 dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
1544 dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
1546 SmallVector<BlockCaptureManagedEntity, 4> CopiedCaptures;
1547 findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures,
1548 computeCopyInfoForBlockCapture);
1550 for (const auto &CopiedCapture : CopiedCaptures) {
1551 const BlockDecl::Capture &CI = CopiedCapture.CI;
1552 const CGBlockInfo::Capture &capture = CopiedCapture.Capture;
1553 BlockFieldFlags flags = CopiedCapture.Flags;
1555 unsigned index = capture.getIndex();
1556 Address srcField = Builder.CreateStructGEP(src, index, capture.getOffset());
1557 Address dstField = Builder.CreateStructGEP(dst, index, capture.getOffset());
1559 // If there's an explicit copy expression, we do that.
1560 if (CI.getCopyExpr()) {
1561 assert(CopiedCapture.Kind == BlockCaptureEntityKind::CXXRecord);
1562 EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
1563 } else if (CopiedCapture.Kind == BlockCaptureEntityKind::ARCWeak) {
1564 EmitARCCopyWeak(dstField, srcField);
1566 llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
1567 if (CopiedCapture.Kind == BlockCaptureEntityKind::ARCStrong) {
1568 // At -O0, store null into the destination field (so that the
1569 // storeStrong doesn't over-release) and then call storeStrong.
1570 // This is a workaround to not having an initStrong call.
1571 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1572 auto *ty = cast<llvm::PointerType>(srcValue->getType());
1573 llvm::Value *null = llvm::ConstantPointerNull::get(ty);
1574 Builder.CreateStore(null, dstField);
1575 EmitARCStoreStrongCall(dstField, srcValue, true);
1577 // With optimization enabled, take advantage of the fact that
1578 // the blocks runtime guarantees a memcpy of the block data, and
1579 // just emit a retain of the src field.
1581 EmitARCRetainNonBlock(srcValue);
1583 // We don't need this anymore, so kill it. It's not quite
1584 // worth the annoyance to avoid creating it in the first place.
1585 cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
1588 assert(CopiedCapture.Kind == BlockCaptureEntityKind::BlockObject);
1589 srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
1590 llvm::Value *dstAddr =
1591 Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
1592 llvm::Value *args[] = {
1593 dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
1596 const VarDecl *variable = CI.getVariable();
1597 bool copyCanThrow = false;
1598 if (CI.isByRef() && variable->getType()->getAsCXXRecordDecl()) {
1599 const Expr *copyExpr =
1600 CGM.getContext().getBlockVarCopyInits(variable);
1602 copyCanThrow = true; // FIXME: reuse the noexcept logic
1607 EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
1609 EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
1617 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1620 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1621 computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
1622 const LangOptions &LangOpts) {
1623 BlockFieldFlags Flags;
1625 Flags = BLOCK_FIELD_IS_BYREF;
1626 if (T.isObjCGCWeak())
1627 Flags |= BLOCK_FIELD_IS_WEAK;
1628 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1631 if (const CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1632 if (Record->hasTrivialDestructor())
1633 return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1634 return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1637 // Other types don't need to be destroy explicitly.
1638 if (!T->isObjCRetainableType())
1639 return std::make_pair(BlockCaptureEntityKind::None, Flags);
1641 Flags = BLOCK_FIELD_IS_OBJECT;
1642 if (T->isBlockPointerType())
1643 Flags = BLOCK_FIELD_IS_BLOCK;
1645 // Special rules for ARC captures.
1646 Qualifiers QS = T.getQualifiers();
1648 // Use objc_storeStrong for __strong direct captures; the
1649 // dynamic tools really like it when we do this.
1650 if (QS.getObjCLifetime() == Qualifiers::OCL_Strong)
1651 return std::make_pair(BlockCaptureEntityKind::ARCStrong, Flags);
1653 // Support __weak direct captures.
1654 if (QS.getObjCLifetime() == Qualifiers::OCL_Weak)
1655 return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1657 // Non-ARC captures are strong, and we need to use
1658 // _Block_object_dispose.
1659 if (!QS.hasObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1660 return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1662 // Otherwise, we have nothing to do.
1663 return std::make_pair(BlockCaptureEntityKind::None, Flags);
1666 /// Generate the destroy-helper function for a block closure object:
1667 /// static void block_destroy_helper(block_t *theBlock);
1669 /// Note that this destroys a heap-allocated block closure object;
1670 /// it should not be confused with a 'byref destroy helper', which
1671 /// destroys the heap-allocated contents of an individual __block
1674 CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) {
1675 ASTContext &C = getContext();
1677 FunctionArgList args;
1678 ImplicitParamDecl SrcDecl(getContext(), C.VoidPtrTy,
1679 ImplicitParamDecl::Other);
1680 args.push_back(&SrcDecl);
1682 const CGFunctionInfo &FI =
1683 CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, args);
1685 // FIXME: We'd like to put these into a mergable by content, with
1686 // internal linkage.
1687 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1689 llvm::Function *Fn =
1690 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
1691 "__destroy_helper_block_", &CGM.getModule());
1694 = &CGM.getContext().Idents.get("__destroy_helper_block_");
1696 FunctionDecl *FD = FunctionDecl::Create(C, C.getTranslationUnitDecl(),
1698 SourceLocation(), II, C.VoidTy,
1702 CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
1704 // Create a scope with an artificial location for the body of this function.
1705 auto NL = ApplyDebugLocation::CreateEmpty(*this);
1706 StartFunction(FD, C.VoidTy, Fn, FI, args);
1707 auto AL = ApplyDebugLocation::CreateArtificial(*this);
1709 llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1711 Address src = GetAddrOfLocalVar(&SrcDecl);
1712 src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
1713 src = Builder.CreateBitCast(src, structPtrTy, "block");
1715 CodeGenFunction::RunCleanupsScope cleanups(*this);
1717 SmallVector<BlockCaptureManagedEntity, 4> DestroyedCaptures;
1718 findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures,
1719 computeDestroyInfoForBlockCapture);
1721 for (const auto &DestroyedCapture : DestroyedCaptures) {
1722 const BlockDecl::Capture &CI = DestroyedCapture.CI;
1723 const CGBlockInfo::Capture &capture = DestroyedCapture.Capture;
1724 BlockFieldFlags flags = DestroyedCapture.Flags;
1727 Builder.CreateStructGEP(src, capture.getIndex(), capture.getOffset());
1729 // If the captured record has a destructor then call it.
1730 if (DestroyedCapture.Kind == BlockCaptureEntityKind::CXXRecord) {
1732 CI.getVariable()->getType()->getAsCXXRecordDecl()->getDestructor();
1733 PushDestructorCleanup(Dtor, srcField);
1735 // If this is a __weak capture, emit the release directly.
1736 } else if (DestroyedCapture.Kind == BlockCaptureEntityKind::ARCWeak) {
1737 EmitARCDestroyWeak(srcField);
1739 // Destroy strong objects with a call if requested.
1740 } else if (DestroyedCapture.Kind == BlockCaptureEntityKind::ARCStrong) {
1741 EmitARCDestroyStrong(srcField, ARCImpreciseLifetime);
1743 // Otherwise we call _Block_object_dispose. It wouldn't be too
1744 // hard to just emit this as a cleanup if we wanted to make sure
1745 // that things were done in reverse.
1747 assert(DestroyedCapture.Kind == BlockCaptureEntityKind::BlockObject);
1748 llvm::Value *value = Builder.CreateLoad(srcField);
1749 value = Builder.CreateBitCast(value, VoidPtrTy);
1750 BuildBlockRelease(value, flags);
1754 cleanups.ForceCleanup();
1758 return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1763 /// Emits the copy/dispose helper functions for a __block object of id type.
1764 class ObjectByrefHelpers final : public BlockByrefHelpers {
1765 BlockFieldFlags Flags;
1768 ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
1769 : BlockByrefHelpers(alignment), Flags(flags) {}
1771 void emitCopy(CodeGenFunction &CGF, Address destField,
1772 Address srcField) override {
1773 destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
1775 srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
1776 llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
1778 unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
1780 llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
1781 llvm::Value *fn = CGF.CGM.getBlockObjectAssign();
1783 llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
1784 CGF.EmitNounwindRuntimeCall(fn, args);
1787 void emitDispose(CodeGenFunction &CGF, Address field) override {
1788 field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
1789 llvm::Value *value = CGF.Builder.CreateLoad(field);
1791 CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER);
1794 void profileImpl(llvm::FoldingSetNodeID &id) const override {
1795 id.AddInteger(Flags.getBitMask());
1799 /// Emits the copy/dispose helpers for an ARC __block __weak variable.
1800 class ARCWeakByrefHelpers final : public BlockByrefHelpers {
1802 ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
1804 void emitCopy(CodeGenFunction &CGF, Address destField,
1805 Address srcField) override {
1806 CGF.EmitARCMoveWeak(destField, srcField);
1809 void emitDispose(CodeGenFunction &CGF, Address field) override {
1810 CGF.EmitARCDestroyWeak(field);
1813 void profileImpl(llvm::FoldingSetNodeID &id) const override {
1814 // 0 is distinguishable from all pointers and byref flags
1819 /// Emits the copy/dispose helpers for an ARC __block __strong variable
1820 /// that's not of block-pointer type.
1821 class ARCStrongByrefHelpers final : public BlockByrefHelpers {
1823 ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
1825 void emitCopy(CodeGenFunction &CGF, Address destField,
1826 Address srcField) override {
1827 // Do a "move" by copying the value and then zeroing out the old
1830 llvm::Value *value = CGF.Builder.CreateLoad(srcField);
1833 llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
1835 if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
1836 CGF.Builder.CreateStore(null, destField);
1837 CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
1838 CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
1841 CGF.Builder.CreateStore(value, destField);
1842 CGF.Builder.CreateStore(null, srcField);
1845 void emitDispose(CodeGenFunction &CGF, Address field) override {
1846 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime);
1849 void profileImpl(llvm::FoldingSetNodeID &id) const override {
1850 // 1 is distinguishable from all pointers and byref flags
1855 /// Emits the copy/dispose helpers for an ARC __block __strong
1856 /// variable that's of block-pointer type.
1857 class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
1859 ARCStrongBlockByrefHelpers(CharUnits alignment)
1860 : BlockByrefHelpers(alignment) {}
1862 void emitCopy(CodeGenFunction &CGF, Address destField,
1863 Address srcField) override {
1864 // Do the copy with objc_retainBlock; that's all that
1865 // _Block_object_assign would do anyway, and we'd have to pass the
1866 // right arguments to make sure it doesn't get no-op'ed.
1867 llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
1868 llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
1869 CGF.Builder.CreateStore(copy, destField);
1872 void emitDispose(CodeGenFunction &CGF, Address field) override {
1873 CGF.EmitARCDestroyStrong(field, ARCImpreciseLifetime);
1876 void profileImpl(llvm::FoldingSetNodeID &id) const override {
1877 // 2 is distinguishable from all pointers and byref flags
1882 /// Emits the copy/dispose helpers for a __block variable with a
1883 /// nontrivial copy constructor or destructor.
1884 class CXXByrefHelpers final : public BlockByrefHelpers {
1886 const Expr *CopyExpr;
1889 CXXByrefHelpers(CharUnits alignment, QualType type,
1890 const Expr *copyExpr)
1891 : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
1893 bool needsCopy() const override { return CopyExpr != nullptr; }
1894 void emitCopy(CodeGenFunction &CGF, Address destField,
1895 Address srcField) override {
1896 if (!CopyExpr) return;
1897 CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
1900 void emitDispose(CodeGenFunction &CGF, Address field) override {
1901 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
1902 CGF.PushDestructorCleanup(VarType, field);
1903 CGF.PopCleanupBlocks(cleanupDepth);
1906 void profileImpl(llvm::FoldingSetNodeID &id) const override {
1907 id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
1910 } // end anonymous namespace
1912 static llvm::Constant *
1913 generateByrefCopyHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo,
1914 BlockByrefHelpers &generator) {
1915 ASTContext &Context = CGF.getContext();
1917 QualType R = Context.VoidTy;
1919 FunctionArgList args;
1920 ImplicitParamDecl Dst(CGF.getContext(), Context.VoidPtrTy,
1921 ImplicitParamDecl::Other);
1922 args.push_back(&Dst);
1924 ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
1925 ImplicitParamDecl::Other);
1926 args.push_back(&Src);
1928 const CGFunctionInfo &FI =
1929 CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(R, args);
1931 llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
1933 // FIXME: We'd like to put these into a mergable by content, with
1934 // internal linkage.
1935 llvm::Function *Fn =
1936 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
1937 "__Block_byref_object_copy_", &CGF.CGM.getModule());
1940 = &Context.Idents.get("__Block_byref_object_copy_");
1942 FunctionDecl *FD = FunctionDecl::Create(Context,
1943 Context.getTranslationUnitDecl(),
1945 SourceLocation(), II, R, nullptr,
1949 CGF.CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
1951 CGF.StartFunction(FD, R, Fn, FI, args);
1953 if (generator.needsCopy()) {
1954 llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
1957 Address destField = CGF.GetAddrOfLocalVar(&Dst);
1958 destField = Address(CGF.Builder.CreateLoad(destField),
1959 byrefInfo.ByrefAlignment);
1960 destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
1961 destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
1965 Address srcField = CGF.GetAddrOfLocalVar(&Src);
1966 srcField = Address(CGF.Builder.CreateLoad(srcField),
1967 byrefInfo.ByrefAlignment);
1968 srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
1969 srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
1972 generator.emitCopy(CGF, destField, srcField);
1975 CGF.FinishFunction();
1977 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
1980 /// Build the copy helper for a __block variable.
1981 static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
1982 const BlockByrefInfo &byrefInfo,
1983 BlockByrefHelpers &generator) {
1984 CodeGenFunction CGF(CGM);
1985 return generateByrefCopyHelper(CGF, byrefInfo, generator);
1988 /// Generate code for a __block variable's dispose helper.
1989 static llvm::Constant *
1990 generateByrefDisposeHelper(CodeGenFunction &CGF,
1991 const BlockByrefInfo &byrefInfo,
1992 BlockByrefHelpers &generator) {
1993 ASTContext &Context = CGF.getContext();
1994 QualType R = Context.VoidTy;
1996 FunctionArgList args;
1997 ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
1998 ImplicitParamDecl::Other);
1999 args.push_back(&Src);
2001 const CGFunctionInfo &FI =
2002 CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(R, args);
2004 llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2006 // FIXME: We'd like to put these into a mergable by content, with
2007 // internal linkage.
2008 llvm::Function *Fn =
2009 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
2010 "__Block_byref_object_dispose_",
2011 &CGF.CGM.getModule());
2014 = &Context.Idents.get("__Block_byref_object_dispose_");
2016 FunctionDecl *FD = FunctionDecl::Create(Context,
2017 Context.getTranslationUnitDecl(),
2019 SourceLocation(), II, R, nullptr,
2023 CGF.CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
2025 CGF.StartFunction(FD, R, Fn, FI, args);
2027 if (generator.needsDispose()) {
2028 Address addr = CGF.GetAddrOfLocalVar(&Src);
2029 addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2030 auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2031 addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2032 addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2034 generator.emitDispose(CGF, addr);
2037 CGF.FinishFunction();
2039 return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2042 /// Build the dispose helper for a __block variable.
2043 static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2044 const BlockByrefInfo &byrefInfo,
2045 BlockByrefHelpers &generator) {
2046 CodeGenFunction CGF(CGM);
2047 return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2050 /// Lazily build the copy and dispose helpers for a __block variable
2051 /// with the given information.
2053 static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2055 llvm::FoldingSetNodeID id;
2056 generator.Profile(id);
2059 BlockByrefHelpers *node
2060 = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2061 if (node) return static_cast<T*>(node);
2063 generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2064 generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2066 T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2067 CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2071 /// Build the copy and dispose helpers for the given __block variable
2072 /// emission. Places the helpers in the global cache. Returns null
2073 /// if no helpers are required.
2075 CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2076 const AutoVarEmission &emission) {
2077 const VarDecl &var = *emission.Variable;
2078 QualType type = var.getType();
2080 auto &byrefInfo = getBlockByrefInfo(&var);
2082 // The alignment we care about for the purposes of uniquing byref
2083 // helpers is the alignment of the actual byref value field.
2084 CharUnits valueAlignment =
2085 byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2087 if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2088 const Expr *copyExpr = CGM.getContext().getBlockVarCopyInits(&var);
2089 if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2091 return ::buildByrefHelpers(
2092 CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2095 // Otherwise, if we don't have a retainable type, there's nothing to do.
2096 // that the runtime does extra copies.
2097 if (!type->isObjCRetainableType()) return nullptr;
2099 Qualifiers qs = type.getQualifiers();
2101 // If we have lifetime, that dominates.
2102 if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2104 case Qualifiers::OCL_None: llvm_unreachable("impossible");
2106 // These are just bits as far as the runtime is concerned.
2107 case Qualifiers::OCL_ExplicitNone:
2108 case Qualifiers::OCL_Autoreleasing:
2111 // Tell the runtime that this is ARC __weak, called by the
2113 case Qualifiers::OCL_Weak:
2114 return ::buildByrefHelpers(CGM, byrefInfo,
2115 ARCWeakByrefHelpers(valueAlignment));
2117 // ARC __strong __block variables need to be retained.
2118 case Qualifiers::OCL_Strong:
2119 // Block pointers need to be copied, and there's no direct
2120 // transfer possible.
2121 if (type->isBlockPointerType()) {
2122 return ::buildByrefHelpers(CGM, byrefInfo,
2123 ARCStrongBlockByrefHelpers(valueAlignment));
2125 // Otherwise, we transfer ownership of the retain from the stack
2128 return ::buildByrefHelpers(CGM, byrefInfo,
2129 ARCStrongByrefHelpers(valueAlignment));
2132 llvm_unreachable("fell out of lifetime switch!");
2135 BlockFieldFlags flags;
2136 if (type->isBlockPointerType()) {
2137 flags |= BLOCK_FIELD_IS_BLOCK;
2138 } else if (CGM.getContext().isObjCNSObjectType(type) ||
2139 type->isObjCObjectPointerType()) {
2140 flags |= BLOCK_FIELD_IS_OBJECT;
2145 if (type.isObjCGCWeak())
2146 flags |= BLOCK_FIELD_IS_WEAK;
2148 return ::buildByrefHelpers(CGM, byrefInfo,
2149 ObjectByrefHelpers(valueAlignment, flags));
2152 Address CodeGenFunction::emitBlockByrefAddress(Address baseAddr,
2154 bool followForward) {
2155 auto &info = getBlockByrefInfo(var);
2156 return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2159 Address CodeGenFunction::emitBlockByrefAddress(Address baseAddr,
2160 const BlockByrefInfo &info,
2162 const llvm::Twine &name) {
2163 // Chase the forwarding address if requested.
2164 if (followForward) {
2165 Address forwardingAddr =
2166 Builder.CreateStructGEP(baseAddr, 1, getPointerSize(), "forwarding");
2167 baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2170 return Builder.CreateStructGEP(baseAddr, info.FieldIndex,
2171 info.FieldOffset, name);
2174 /// BuildByrefInfo - This routine changes a __block variable declared as T x
2179 /// void *__forwarding;
2180 /// int32_t __flags;
2182 /// void *__copy_helper; // only if needed
2183 /// void *__destroy_helper; // only if needed
2184 /// void *__byref_variable_layout;// only if needed
2185 /// char padding[X]; // only if needed
2189 const BlockByrefInfo &CodeGenFunction::getBlockByrefInfo(const VarDecl *D) {
2190 auto it = BlockByrefInfos.find(D);
2191 if (it != BlockByrefInfos.end())
2194 llvm::StructType *byrefType =
2195 llvm::StructType::create(getLLVMContext(),
2196 "struct.__block_byref_" + D->getNameAsString());
2198 QualType Ty = D->getType();
2201 SmallVector<llvm::Type *, 8> types;
2204 types.push_back(Int8PtrTy);
2205 size += getPointerSize();
2207 // void *__forwarding;
2208 types.push_back(llvm::PointerType::getUnqual(byrefType));
2209 size += getPointerSize();
2212 types.push_back(Int32Ty);
2213 size += CharUnits::fromQuantity(4);
2216 types.push_back(Int32Ty);
2217 size += CharUnits::fromQuantity(4);
2219 // Note that this must match *exactly* the logic in buildByrefHelpers.
2220 bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2221 if (hasCopyAndDispose) {
2222 /// void *__copy_helper;
2223 types.push_back(Int8PtrTy);
2224 size += getPointerSize();
2226 /// void *__destroy_helper;
2227 types.push_back(Int8PtrTy);
2228 size += getPointerSize();
2231 bool HasByrefExtendedLayout = false;
2232 Qualifiers::ObjCLifetime Lifetime;
2233 if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2234 HasByrefExtendedLayout) {
2235 /// void *__byref_variable_layout;
2236 types.push_back(Int8PtrTy);
2237 size += CharUnits::fromQuantity(PointerSizeInBytes);
2241 llvm::Type *varTy = ConvertTypeForMem(Ty);
2243 bool packed = false;
2244 CharUnits varAlign = getContext().getDeclAlign(D);
2245 CharUnits varOffset = size.alignTo(varAlign);
2247 // We may have to insert padding.
2248 if (varOffset != size) {
2249 llvm::Type *paddingTy =
2250 llvm::ArrayType::get(Int8Ty, (varOffset - size).getQuantity());
2252 types.push_back(paddingTy);
2255 // Conversely, we might have to prevent LLVM from inserting padding.
2256 } else if (CGM.getDataLayout().getABITypeAlignment(varTy)
2257 > varAlign.getQuantity()) {
2260 types.push_back(varTy);
2262 byrefType->setBody(types, packed);
2264 BlockByrefInfo info;
2265 info.Type = byrefType;
2266 info.FieldIndex = types.size() - 1;
2267 info.FieldOffset = varOffset;
2268 info.ByrefAlignment = std::max(varAlign, getPointerAlign());
2270 auto pair = BlockByrefInfos.insert({D, info});
2271 assert(pair.second && "info was inserted recursively?");
2272 return pair.first->second;
2275 /// Initialize the structural components of a __block variable, i.e.
2276 /// everything but the actual object.
2277 void CodeGenFunction::emitByrefStructureInit(const AutoVarEmission &emission) {
2278 // Find the address of the local.
2279 Address addr = emission.Addr;
2281 // That's an alloca of the byref structure type.
2282 llvm::StructType *byrefType = cast<llvm::StructType>(
2283 cast<llvm::PointerType>(addr.getPointer()->getType())->getElementType());
2285 unsigned nextHeaderIndex = 0;
2286 CharUnits nextHeaderOffset;
2287 auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2288 const Twine &name) {
2289 auto fieldAddr = Builder.CreateStructGEP(addr, nextHeaderIndex,
2290 nextHeaderOffset, name);
2291 Builder.CreateStore(value, fieldAddr);
2294 nextHeaderOffset += fieldSize;
2297 // Build the byref helpers if necessary. This is null if we don't need any.
2298 BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2300 const VarDecl &D = *emission.Variable;
2301 QualType type = D.getType();
2303 bool HasByrefExtendedLayout;
2304 Qualifiers::ObjCLifetime ByrefLifetime;
2305 bool ByRefHasLifetime =
2306 getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2310 // Initialize the 'isa', which is just 0 or 1.
2312 if (type.isObjCGCWeak())
2314 V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2315 storeHeaderField(V, getPointerSize(), "byref.isa");
2317 // Store the address of the variable into its own forwarding pointer.
2318 storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2321 // c) the flags field is set to either 0 if no helper functions are
2322 // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2324 if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2325 if (ByRefHasLifetime) {
2326 if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2327 else switch (ByrefLifetime) {
2328 case Qualifiers::OCL_Strong:
2329 flags |= BLOCK_BYREF_LAYOUT_STRONG;
2331 case Qualifiers::OCL_Weak:
2332 flags |= BLOCK_BYREF_LAYOUT_WEAK;
2334 case Qualifiers::OCL_ExplicitNone:
2335 flags |= BLOCK_BYREF_LAYOUT_UNRETAINED;
2337 case Qualifiers::OCL_None:
2338 if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2339 flags |= BLOCK_BYREF_LAYOUT_NON_OBJECT;
2344 if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2345 printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2346 if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2347 printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2348 if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2349 BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2350 if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2351 printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2352 if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2353 printf(" BLOCK_BYREF_LAYOUT_STRONG");
2354 if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2355 printf(" BLOCK_BYREF_LAYOUT_WEAK");
2356 if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2357 printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2358 if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2359 printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2364 storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2365 getIntSize(), "byref.flags");
2367 CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2368 V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2369 storeHeaderField(V, getIntSize(), "byref.size");
2372 storeHeaderField(helpers->CopyHelper, getPointerSize(),
2373 "byref.copyHelper");
2374 storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2375 "byref.disposeHelper");
2378 if (ByRefHasLifetime && HasByrefExtendedLayout) {
2379 auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2380 storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2384 void CodeGenFunction::BuildBlockRelease(llvm::Value *V, BlockFieldFlags flags) {
2385 llvm::Value *F = CGM.getBlockObjectDispose();
2386 llvm::Value *args[] = {
2387 Builder.CreateBitCast(V, Int8PtrTy),
2388 llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2390 EmitNounwindRuntimeCall(F, args); // FIXME: throwing destructors?
2394 /// Release a __block variable.
2395 struct CallBlockRelease final : EHScopeStack::Cleanup {
2397 CallBlockRelease(llvm::Value *Addr) : Addr(Addr) {}
2399 void Emit(CodeGenFunction &CGF, Flags flags) override {
2400 // Should we be passing FIELD_IS_WEAK here?
2401 CGF.BuildBlockRelease(Addr, BLOCK_FIELD_IS_BYREF);
2404 } // end anonymous namespace
2406 /// Enter a cleanup to destroy a __block variable. Note that this
2407 /// cleanup should be a no-op if the variable hasn't left the stack
2408 /// yet; if a cleanup is required for the variable itself, that needs
2409 /// to be done externally.
2410 void CodeGenFunction::enterByrefCleanup(const AutoVarEmission &emission) {
2411 // We don't enter this cleanup if we're in pure-GC mode.
2412 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly)
2415 EHStack.pushCleanup<CallBlockRelease>(NormalAndEHCleanup,
2416 emission.Addr.getPointer());
2419 /// Adjust the declaration of something from the blocks API.
2420 static void configureBlocksRuntimeObject(CodeGenModule &CGM,
2421 llvm::Constant *C) {
2422 auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2424 if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2425 IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2426 TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
2427 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
2429 assert((isa<llvm::Function>(C->stripPointerCasts()) ||
2430 isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&
2431 "expected Function or GlobalVariable");
2433 const NamedDecl *ND = nullptr;
2434 for (const auto &Result : DC->lookup(&II))
2435 if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2436 (ND = dyn_cast<VarDecl>(Result)))
2439 // TODO: support static blocks runtime
2440 if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2441 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2442 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2444 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2445 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2449 if (!CGM.getLangOpts().BlocksRuntimeOptional)
2452 if (GV->isDeclaration() && GV->hasExternalLinkage())
2453 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2456 llvm::Constant *CodeGenModule::getBlockObjectDispose() {
2457 if (BlockObjectDispose)
2458 return BlockObjectDispose;
2460 llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2461 llvm::FunctionType *fty
2462 = llvm::FunctionType::get(VoidTy, args, false);
2463 BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2464 configureBlocksRuntimeObject(*this, BlockObjectDispose);
2465 return BlockObjectDispose;
2468 llvm::Constant *CodeGenModule::getBlockObjectAssign() {
2469 if (BlockObjectAssign)
2470 return BlockObjectAssign;
2472 llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
2473 llvm::FunctionType *fty
2474 = llvm::FunctionType::get(VoidTy, args, false);
2475 BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
2476 configureBlocksRuntimeObject(*this, BlockObjectAssign);
2477 return BlockObjectAssign;
2480 llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() {
2481 if (NSConcreteGlobalBlock)
2482 return NSConcreteGlobalBlock;
2484 NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
2485 Int8PtrTy->getPointerTo(),
2487 configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
2488 return NSConcreteGlobalBlock;
2491 llvm::Constant *CodeGenModule::getNSConcreteStackBlock() {
2492 if (NSConcreteStackBlock)
2493 return NSConcreteStackBlock;
2495 NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
2496 Int8PtrTy->getPointerTo(),
2498 configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
2499 return NSConcreteStackBlock;