1//===--- CGBlocks.cpp - Emit LLVM Code for declarations ---------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This contains code to emit blocks.
10//
11//===----------------------------------------------------------------------===//
12
13#include "CGBlocks.h"
14#include "CGCXXABI.h"
15#include "CGDebugInfo.h"
16#include "CGObjCRuntime.h"
17#include "CGOpenCLRuntime.h"
18#include "CodeGenFunction.h"
19#include "CodeGenModule.h"
20#include "ConstantEmitter.h"
21#include "TargetInfo.h"
22#include "clang/AST/Attr.h"
23#include "clang/AST/DeclObjC.h"
24#include "clang/CodeGen/ConstantInitBuilder.h"
25#include "llvm/ADT/SmallSet.h"
26#include "llvm/IR/DataLayout.h"
27#include "llvm/IR/Module.h"
28#include "llvm/Support/ScopedPrinter.h"
29#include <algorithm>
30#include <cstdio>
31
32using namespace clang;
33using namespace CodeGen;
34
35CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
36 : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
37 NoEscape(false), HasCXXObject(false), UsesStret(false),
38 HasCapturedVariableLayout(false), CapturesNonExternalType(false),
39 LocalAddress(RawAddress::invalid()), StructureType(nullptr),
40 Block(block) {
41
42 // Skip asm prefix, if any. 'name' is usually taken directly from
43 // the mangled name of the enclosing function.
44 if (!name.empty() && name[0] == '\01')
45 name = name.substr(Start: 1);
46}
47
48// Anchor the vtable to this translation unit.
49BlockByrefHelpers::~BlockByrefHelpers() {}
50
51/// Build the given block as a global block.
52static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
53 const CGBlockInfo &blockInfo,
54 llvm::Constant *blockFn);
55
56/// Build the helper function to copy a block.
57static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
58 const CGBlockInfo &blockInfo) {
59 return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
60}
61
62/// Build the helper function to dispose of a block.
63static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
64 const CGBlockInfo &blockInfo) {
65 return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
66}
67
68namespace {
69
70enum class CaptureStrKind {
71 // String for the copy helper.
72 CopyHelper,
73 // String for the dispose helper.
74 DisposeHelper,
75 // Merge the strings for the copy helper and dispose helper.
76 Merged
77};
78
79} // end anonymous namespace
80
81static std::string getBlockCaptureStr(const CGBlockInfo::Capture &Cap,
82 CaptureStrKind StrKind,
83 CharUnits BlockAlignment,
84 CodeGenModule &CGM);
85
86static std::string getBlockDescriptorName(const CGBlockInfo &BlockInfo,
87 CodeGenModule &CGM) {
88 std::string Name = "__block_descriptor_";
89 Name += llvm::to_string(Value: BlockInfo.BlockSize.getQuantity()) + "_";
90
91 if (BlockInfo.NeedsCopyDispose) {
92 if (CGM.getLangOpts().Exceptions)
93 Name += "e";
94 if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
95 Name += "a";
96 Name += llvm::to_string(Value: BlockInfo.BlockAlign.getQuantity()) + "_";
97
98 for (auto &Cap : BlockInfo.SortedCaptures) {
99 if (Cap.isConstantOrTrivial())
100 continue;
101
102 Name += llvm::to_string(Value: Cap.getOffset().getQuantity());
103
104 if (Cap.CopyKind == Cap.DisposeKind) {
105 // If CopyKind and DisposeKind are the same, merge the capture
106 // information.
107 assert(Cap.CopyKind != BlockCaptureEntityKind::None &&
108 "shouldn't see BlockCaptureManagedEntity that is None");
109 Name += getBlockCaptureStr(Cap, StrKind: CaptureStrKind::Merged,
110 BlockAlignment: BlockInfo.BlockAlign, CGM);
111 } else {
112 // If CopyKind and DisposeKind are not the same, which can happen when
113 // either Kind is None or the captured object is a __strong block,
114 // concatenate the copy and dispose strings.
115 Name += getBlockCaptureStr(Cap, StrKind: CaptureStrKind::CopyHelper,
116 BlockAlignment: BlockInfo.BlockAlign, CGM);
117 Name += getBlockCaptureStr(Cap, StrKind: CaptureStrKind::DisposeHelper,
118 BlockAlignment: BlockInfo.BlockAlign, CGM);
119 }
120 }
121 Name += "_";
122 }
123
124 std::string TypeAtEncoding;
125
126 if (!CGM.getCodeGenOpts().DisableBlockSignatureString) {
127 TypeAtEncoding =
128 CGM.getContext().getObjCEncodingForBlock(blockExpr: BlockInfo.getBlockExpr());
129 /// Replace occurrences of '@' with '\1'. '@' is reserved on ELF platforms
130 /// as a separator between symbol name and symbol version.
131 std::replace(first: TypeAtEncoding.begin(), last: TypeAtEncoding.end(), old_value: '@', new_value: '\1');
132 }
133 Name += "e" + llvm::to_string(Value: TypeAtEncoding.size()) + "_" + TypeAtEncoding;
134 Name += "l" + CGM.getObjCRuntime().getRCBlockLayoutStr(CGM, blockInfo: BlockInfo);
135 return Name;
136}
137
138/// buildBlockDescriptor - Build the block descriptor meta-data for a block.
139/// buildBlockDescriptor is accessed from 5th field of the Block_literal
140/// meta-data and contains stationary information about the block literal.
141/// Its definition will have 4 (or optionally 6) words.
142/// \code
143/// struct Block_descriptor {
144/// unsigned long reserved;
145/// unsigned long size; // size of Block_literal metadata in bytes.
146/// void *copy_func_helper_decl; // optional copy helper.
147/// void *destroy_func_decl; // optional destructor helper.
148/// void *block_method_encoding_address; // @encode for block literal signature.
149/// void *block_layout_info; // encoding of captured block variables.
150/// };
151/// \endcode
152static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
153 const CGBlockInfo &blockInfo) {
154 ASTContext &C = CGM.getContext();
155
156 llvm::IntegerType *ulong =
157 cast<llvm::IntegerType>(Val: CGM.getTypes().ConvertType(T: C.UnsignedLongTy));
158 llvm::PointerType *i8p = nullptr;
159 if (CGM.getLangOpts().OpenCL)
160 i8p = llvm::PointerType::get(
161 C&: CGM.getLLVMContext(), AddressSpace: C.getTargetAddressSpace(AS: LangAS::opencl_constant));
162 else
163 i8p = CGM.VoidPtrTy;
164
165 std::string descName;
166
167 // If an equivalent block descriptor global variable exists, return it.
168 if (C.getLangOpts().ObjC &&
169 CGM.getLangOpts().getGC() == LangOptions::NonGC) {
170 descName = getBlockDescriptorName(BlockInfo: blockInfo, CGM);
171 if (llvm::GlobalValue *desc = CGM.getModule().getNamedValue(Name: descName))
172 return desc;
173 }
174
175 // If there isn't an equivalent block descriptor global variable, create a new
176 // one.
177 ConstantInitBuilder builder(CGM);
178 auto elements = builder.beginStruct();
179
180 // reserved
181 elements.addInt(intTy: ulong, value: 0);
182
183 // Size
184 // FIXME: What is the right way to say this doesn't fit? We should give
185 // a user diagnostic in that case. Better fix would be to change the
186 // API to size_t.
187 elements.addInt(intTy: ulong, value: blockInfo.BlockSize.getQuantity());
188
189 // Optional copy/dispose helpers.
190 bool hasInternalHelper = false;
191 if (blockInfo.NeedsCopyDispose) {
192 // copy_func_helper_decl
193 llvm::Constant *copyHelper = buildCopyHelper(CGM, blockInfo);
194 elements.add(value: copyHelper);
195
196 // destroy_func_decl
197 llvm::Constant *disposeHelper = buildDisposeHelper(CGM, blockInfo);
198 elements.add(value: disposeHelper);
199
200 if (cast<llvm::Function>(Val: copyHelper->stripPointerCasts())
201 ->hasInternalLinkage() ||
202 cast<llvm::Function>(Val: disposeHelper->stripPointerCasts())
203 ->hasInternalLinkage())
204 hasInternalHelper = true;
205 }
206
207 // Signature. Mandatory ObjC-style method descriptor @encode sequence.
208 if (CGM.getCodeGenOpts().DisableBlockSignatureString) {
209 elements.addNullPointer(ptrTy: i8p);
210 } else {
211 std::string typeAtEncoding =
212 CGM.getContext().getObjCEncodingForBlock(blockExpr: blockInfo.getBlockExpr());
213 elements.add(value: CGM.GetAddrOfConstantCString(Str: typeAtEncoding).getPointer());
214 }
215
216 // GC layout.
217 if (C.getLangOpts().ObjC) {
218 if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
219 elements.add(value: CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
220 else
221 elements.add(value: CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
222 }
223 else
224 elements.addNullPointer(ptrTy: i8p);
225
226 unsigned AddrSpace = 0;
227 if (C.getLangOpts().OpenCL)
228 AddrSpace = C.getTargetAddressSpace(AS: LangAS::opencl_constant);
229
230 llvm::GlobalValue::LinkageTypes linkage;
231 if (descName.empty()) {
232 linkage = llvm::GlobalValue::InternalLinkage;
233 descName = "__block_descriptor_tmp";
234 } else if (hasInternalHelper) {
235 // If either the copy helper or the dispose helper has internal linkage,
236 // the block descriptor must have internal linkage too.
237 linkage = llvm::GlobalValue::InternalLinkage;
238 } else {
239 linkage = llvm::GlobalValue::LinkOnceODRLinkage;
240 }
241
242 llvm::GlobalVariable *global =
243 elements.finishAndCreateGlobal(args&: descName, args: CGM.getPointerAlign(),
244 /*constant*/ args: true, args&: linkage, args&: AddrSpace);
245
246 if (linkage == llvm::GlobalValue::LinkOnceODRLinkage) {
247 if (CGM.supportsCOMDAT())
248 global->setComdat(CGM.getModule().getOrInsertComdat(Name: descName));
249 global->setVisibility(llvm::GlobalValue::HiddenVisibility);
250 global->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
251 }
252
253 return global;
254}
255
256/*
257 Purely notional variadic template describing the layout of a block.
258
259 template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
260 struct Block_literal {
261 /// Initialized to one of:
262 /// extern void *_NSConcreteStackBlock[];
263 /// extern void *_NSConcreteGlobalBlock[];
264 ///
265 /// In theory, we could start one off malloc'ed by setting
266 /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
267 /// this isa:
268 /// extern void *_NSConcreteMallocBlock[];
269 struct objc_class *isa;
270
271 /// These are the flags (with corresponding bit number) that the
272 /// compiler is actually supposed to know about.
273 /// 23. BLOCK_IS_NOESCAPE - indicates that the block is non-escaping
274 /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
275 /// descriptor provides copy and dispose helper functions
276 /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
277 /// object with a nontrivial destructor or copy constructor
278 /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
279 /// as global memory
280 /// 29. BLOCK_USE_STRET - indicates that the block function
281 /// uses stret, which objc_msgSend needs to know about
282 /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
283 /// @encoded signature string
284 /// And we're not supposed to manipulate these:
285 /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
286 /// to malloc'ed memory
287 /// 27. BLOCK_IS_GC - indicates that the block has been moved to
288 /// to GC-allocated memory
289 /// Additionally, the bottom 16 bits are a reference count which
290 /// should be zero on the stack.
291 int flags;
292
293 /// Reserved; should be zero-initialized.
294 int reserved;
295
296 /// Function pointer generated from block literal.
297 _ResultType (*invoke)(Block_literal *, _ParamTypes...);
298
299 /// Block description metadata generated from block literal.
300 struct Block_descriptor *block_descriptor;
301
302 /// Captured values follow.
303 _CapturesTypes captures...;
304 };
305 */
306
307namespace {
308 /// A chunk of data that we actually have to capture in the block.
309 struct BlockLayoutChunk {
310 CharUnits Alignment;
311 CharUnits Size;
312 const BlockDecl::Capture *Capture; // null for 'this'
313 llvm::Type *Type;
314 QualType FieldType;
315 BlockCaptureEntityKind CopyKind, DisposeKind;
316 BlockFieldFlags CopyFlags, DisposeFlags;
317
318 BlockLayoutChunk(CharUnits align, CharUnits size,
319 const BlockDecl::Capture *capture, llvm::Type *type,
320 QualType fieldType, BlockCaptureEntityKind CopyKind,
321 BlockFieldFlags CopyFlags,
322 BlockCaptureEntityKind DisposeKind,
323 BlockFieldFlags DisposeFlags)
324 : Alignment(align), Size(size), Capture(capture), Type(type),
325 FieldType(fieldType), CopyKind(CopyKind), DisposeKind(DisposeKind),
326 CopyFlags(CopyFlags), DisposeFlags(DisposeFlags) {}
327
328 /// Tell the block info that this chunk has the given field index.
329 void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
330 if (!Capture) {
331 info.CXXThisIndex = index;
332 info.CXXThisOffset = offset;
333 } else {
334 info.SortedCaptures.push_back(Elt: CGBlockInfo::Capture::makeIndex(
335 index, offset, FieldType, CopyKind, CopyFlags, DisposeKind,
336 DisposeFlags, Cap: Capture));
337 }
338 }
339
340 bool isTrivial() const {
341 return CopyKind == BlockCaptureEntityKind::None &&
342 DisposeKind == BlockCaptureEntityKind::None;
343 }
344 };
345
346 /// Order by 1) all __strong together 2) next, all block together 3) next,
347 /// all byref together 4) next, all __weak together. Preserve descending
348 /// alignment in all situations.
349 bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
350 if (left.Alignment != right.Alignment)
351 return left.Alignment > right.Alignment;
352
353 auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
354 switch (chunk.CopyKind) {
355 case BlockCaptureEntityKind::ARCStrong:
356 return 0;
357 case BlockCaptureEntityKind::BlockObject:
358 switch (chunk.CopyFlags.getBitMask()) {
359 case BLOCK_FIELD_IS_OBJECT:
360 return 0;
361 case BLOCK_FIELD_IS_BLOCK:
362 return 1;
363 case BLOCK_FIELD_IS_BYREF:
364 return 2;
365 default:
366 break;
367 }
368 break;
369 case BlockCaptureEntityKind::ARCWeak:
370 return 3;
371 default:
372 break;
373 }
374 return 4;
375 };
376
377 return getPrefOrder(left) < getPrefOrder(right);
378 }
379} // end anonymous namespace
380
381static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
382computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
383 const LangOptions &LangOpts);
384
385static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
386computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
387 const LangOptions &LangOpts);
388
389static void addBlockLayout(CharUnits align, CharUnits size,
390 const BlockDecl::Capture *capture, llvm::Type *type,
391 QualType fieldType,
392 SmallVectorImpl<BlockLayoutChunk> &Layout,
393 CGBlockInfo &Info, CodeGenModule &CGM) {
394 if (!capture) {
395 // 'this' capture.
396 Layout.push_back(Elt: BlockLayoutChunk(
397 align, size, capture, type, fieldType, BlockCaptureEntityKind::None,
398 BlockFieldFlags(), BlockCaptureEntityKind::None, BlockFieldFlags()));
399 return;
400 }
401
402 const LangOptions &LangOpts = CGM.getLangOpts();
403 BlockCaptureEntityKind CopyKind, DisposeKind;
404 BlockFieldFlags CopyFlags, DisposeFlags;
405
406 std::tie(args&: CopyKind, args&: CopyFlags) =
407 computeCopyInfoForBlockCapture(CI: *capture, T: fieldType, LangOpts);
408 std::tie(args&: DisposeKind, args&: DisposeFlags) =
409 computeDestroyInfoForBlockCapture(CI: *capture, T: fieldType, LangOpts);
410 Layout.push_back(Elt: BlockLayoutChunk(align, size, capture, type, fieldType,
411 CopyKind, CopyFlags, DisposeKind,
412 DisposeFlags));
413
414 if (Info.NoEscape)
415 return;
416
417 if (!Layout.back().isTrivial())
418 Info.NeedsCopyDispose = true;
419}
420
421/// Determines if the given type is safe for constant capture in C++.
422static bool isSafeForCXXConstantCapture(QualType type) {
423 const RecordType *recordType =
424 type->getBaseElementTypeUnsafe()->getAs<RecordType>();
425
426 // Only records can be unsafe.
427 if (!recordType) return true;
428
429 const auto *record = cast<CXXRecordDecl>(Val: recordType->getDecl());
430
431 // Maintain semantics for classes with non-trivial dtors or copy ctors.
432 if (!record->hasTrivialDestructor()) return false;
433 if (record->hasNonTrivialCopyConstructor()) return false;
434
435 // Otherwise, we just have to make sure there aren't any mutable
436 // fields that might have changed since initialization.
437 return !record->hasMutableFields();
438}
439
440/// It is illegal to modify a const object after initialization.
441/// Therefore, if a const object has a constant initializer, we don't
442/// actually need to keep storage for it in the block; we'll just
443/// rematerialize it at the start of the block function. This is
444/// acceptable because we make no promises about address stability of
445/// captured variables.
446static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
447 CodeGenFunction *CGF,
448 const VarDecl *var) {
449 // Return if this is a function parameter. We shouldn't try to
450 // rematerialize default arguments of function parameters.
451 if (isa<ParmVarDecl>(Val: var))
452 return nullptr;
453
454 QualType type = var->getType();
455
456 // We can only do this if the variable is const.
457 if (!type.isConstQualified()) return nullptr;
458
459 // Furthermore, in C++ we have to worry about mutable fields:
460 // C++ [dcl.type.cv]p4:
461 // Except that any class member declared mutable can be
462 // modified, any attempt to modify a const object during its
463 // lifetime results in undefined behavior.
464 if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
465 return nullptr;
466
467 // If the variable doesn't have any initializer (shouldn't this be
468 // invalid?), it's not clear what we should do. Maybe capture as
469 // zero?
470 const Expr *init = var->getInit();
471 if (!init) return nullptr;
472
473 return ConstantEmitter(CGM, CGF).tryEmitAbstractForInitializer(D: *var);
474}
475
476/// Get the low bit of a nonzero character count. This is the
477/// alignment of the nth byte if the 0th byte is universally aligned.
478static CharUnits getLowBit(CharUnits v) {
479 return CharUnits::fromQuantity(Quantity: v.getQuantity() & (~v.getQuantity() + 1));
480}
481
482static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info,
483 SmallVectorImpl<llvm::Type*> &elementTypes) {
484
485 assert(elementTypes.empty());
486 if (CGM.getLangOpts().OpenCL) {
487 // The header is basically 'struct { int; int; generic void *;
488 // custom_fields; }'. Assert that struct is packed.
489 auto GenPtrAlign = CharUnits::fromQuantity(
490 Quantity: CGM.getTarget().getPointerAlign(AddrSpace: LangAS::opencl_generic) / 8);
491 auto GenPtrSize = CharUnits::fromQuantity(
492 Quantity: CGM.getTarget().getPointerWidth(AddrSpace: LangAS::opencl_generic) / 8);
493 assert(CGM.getIntSize() <= GenPtrSize);
494 assert(CGM.getIntAlign() <= GenPtrAlign);
495 assert((2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign));
496 elementTypes.push_back(Elt: CGM.IntTy); /* total size */
497 elementTypes.push_back(Elt: CGM.IntTy); /* align */
498 elementTypes.push_back(
499 Elt: CGM.getOpenCLRuntime()
500 .getGenericVoidPointerType()); /* invoke function */
501 unsigned Offset =
502 2 * CGM.getIntSize().getQuantity() + GenPtrSize.getQuantity();
503 unsigned BlockAlign = GenPtrAlign.getQuantity();
504 if (auto *Helper =
505 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
506 for (auto *I : Helper->getCustomFieldTypes()) /* custom fields */ {
507 // TargetOpenCLBlockHelp needs to make sure the struct is packed.
508 // If necessary, add padding fields to the custom fields.
509 unsigned Align = CGM.getDataLayout().getABITypeAlign(Ty: I).value();
510 if (BlockAlign < Align)
511 BlockAlign = Align;
512 assert(Offset % Align == 0);
513 Offset += CGM.getDataLayout().getTypeAllocSize(Ty: I);
514 elementTypes.push_back(Elt: I);
515 }
516 }
517 info.BlockAlign = CharUnits::fromQuantity(Quantity: BlockAlign);
518 info.BlockSize = CharUnits::fromQuantity(Quantity: Offset);
519 } else {
520 // The header is basically 'struct { void *; int; int; void *; void *; }'.
521 // Assert that the struct is packed.
522 assert(CGM.getIntSize() <= CGM.getPointerSize());
523 assert(CGM.getIntAlign() <= CGM.getPointerAlign());
524 assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()));
525 info.BlockAlign = CGM.getPointerAlign();
526 info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
527 elementTypes.push_back(Elt: CGM.VoidPtrTy);
528 elementTypes.push_back(Elt: CGM.IntTy);
529 elementTypes.push_back(Elt: CGM.IntTy);
530 elementTypes.push_back(Elt: CGM.VoidPtrTy);
531 elementTypes.push_back(Elt: CGM.getBlockDescriptorType());
532 }
533}
534
535static QualType getCaptureFieldType(const CodeGenFunction &CGF,
536 const BlockDecl::Capture &CI) {
537 const VarDecl *VD = CI.getVariable();
538
539 // If the variable is captured by an enclosing block or lambda expression,
540 // use the type of the capture field.
541 if (CGF.BlockInfo && CI.isNested())
542 return CGF.BlockInfo->getCapture(var: VD).fieldType();
543 if (auto *FD = CGF.LambdaCaptureFields.lookup(Val: VD))
544 return FD->getType();
545 // If the captured variable is a non-escaping __block variable, the field
546 // type is the reference type. If the variable is a __block variable that
547 // already has a reference type, the field type is the variable's type.
548 return VD->isNonEscapingByref() ?
549 CGF.getContext().getLValueReferenceType(T: VD->getType()) : VD->getType();
550}
551
552/// Compute the layout of the given block. Attempts to lay the block
553/// out with minimal space requirements.
554static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF,
555 CGBlockInfo &info) {
556 ASTContext &C = CGM.getContext();
557 const BlockDecl *block = info.getBlockDecl();
558
559 SmallVector<llvm::Type*, 8> elementTypes;
560 initializeForBlockHeader(CGM, info, elementTypes);
561 bool hasNonConstantCustomFields = false;
562 if (auto *OpenCLHelper =
563 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper())
564 hasNonConstantCustomFields =
565 !OpenCLHelper->areAllCustomFieldValuesConstant(Info: info);
566 if (!block->hasCaptures() && !hasNonConstantCustomFields) {
567 info.StructureType =
568 llvm::StructType::get(Context&: CGM.getLLVMContext(), Elements: elementTypes, isPacked: true);
569 info.CanBeGlobal = true;
570 return;
571 }
572 else if (C.getLangOpts().ObjC &&
573 CGM.getLangOpts().getGC() == LangOptions::NonGC)
574 info.HasCapturedVariableLayout = true;
575
576 if (block->doesNotEscape())
577 info.NoEscape = true;
578
579 // Collect the layout chunks.
580 SmallVector<BlockLayoutChunk, 16> layout;
581 layout.reserve(N: block->capturesCXXThis() +
582 (block->capture_end() - block->capture_begin()));
583
584 CharUnits maxFieldAlign;
585
586 // First, 'this'.
587 if (block->capturesCXXThis()) {
588 assert(CGF && isa_and_nonnull<CXXMethodDecl>(CGF->CurFuncDecl) &&
589 "Can't capture 'this' outside a method");
590 QualType thisType = cast<CXXMethodDecl>(Val: CGF->CurFuncDecl)->getThisType();
591
592 // Theoretically, this could be in a different address space, so
593 // don't assume standard pointer size/align.
594 llvm::Type *llvmType = CGM.getTypes().ConvertType(T: thisType);
595 auto TInfo = CGM.getContext().getTypeInfoInChars(T: thisType);
596 maxFieldAlign = std::max(a: maxFieldAlign, b: TInfo.Align);
597
598 addBlockLayout(align: TInfo.Align, size: TInfo.Width, capture: nullptr, type: llvmType, fieldType: thisType,
599 Layout&: layout, Info&: info, CGM);
600 }
601
602 // Next, all the block captures.
603 for (const auto &CI : block->captures()) {
604 const VarDecl *variable = CI.getVariable();
605
606 if (CI.isEscapingByref()) {
607 // Just use void* instead of a pointer to the byref type.
608 CharUnits align = CGM.getPointerAlign();
609 maxFieldAlign = std::max(a: maxFieldAlign, b: align);
610
611 // Since a __block variable cannot be captured by lambdas, its type and
612 // the capture field type should always match.
613 assert(CGF && getCaptureFieldType(*CGF, CI) == variable->getType() &&
614 "capture type differs from the variable type");
615 addBlockLayout(align, size: CGM.getPointerSize(), capture: &CI, type: CGM.VoidPtrTy,
616 fieldType: variable->getType(), Layout&: layout, Info&: info, CGM);
617 continue;
618 }
619
620 // Otherwise, build a layout chunk with the size and alignment of
621 // the declaration.
622 if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, var: variable)) {
623 info.SortedCaptures.push_back(
624 Elt: CGBlockInfo::Capture::makeConstant(value: constant, Cap: &CI));
625 continue;
626 }
627
628 QualType VT = getCaptureFieldType(CGF: *CGF, CI);
629
630 if (CGM.getLangOpts().CPlusPlus)
631 if (const CXXRecordDecl *record = VT->getAsCXXRecordDecl())
632 if (CI.hasCopyExpr() || !record->hasTrivialDestructor()) {
633 info.HasCXXObject = true;
634 if (!record->isExternallyVisible())
635 info.CapturesNonExternalType = true;
636 }
637
638 CharUnits size = C.getTypeSizeInChars(T: VT);
639 CharUnits align = C.getDeclAlign(D: variable);
640
641 maxFieldAlign = std::max(a: maxFieldAlign, b: align);
642
643 llvm::Type *llvmType =
644 CGM.getTypes().ConvertTypeForMem(T: VT);
645
646 addBlockLayout(align, size, capture: &CI, type: llvmType, fieldType: VT, Layout&: layout, Info&: info, CGM);
647 }
648
649 // If that was everything, we're done here.
650 if (layout.empty()) {
651 info.StructureType =
652 llvm::StructType::get(Context&: CGM.getLLVMContext(), Elements: elementTypes, isPacked: true);
653 info.CanBeGlobal = true;
654 info.buildCaptureMap();
655 return;
656 }
657
658 // Sort the layout by alignment. We have to use a stable sort here
659 // to get reproducible results. There should probably be an
660 // llvm::array_pod_stable_sort.
661 llvm::stable_sort(Range&: layout);
662
663 // Needed for blocks layout info.
664 info.BlockHeaderForcedGapOffset = info.BlockSize;
665 info.BlockHeaderForcedGapSize = CharUnits::Zero();
666
667 CharUnits &blockSize = info.BlockSize;
668 info.BlockAlign = std::max(a: maxFieldAlign, b: info.BlockAlign);
669
670 // Assuming that the first byte in the header is maximally aligned,
671 // get the alignment of the first byte following the header.
672 CharUnits endAlign = getLowBit(v: blockSize);
673
674 // If the end of the header isn't satisfactorily aligned for the
675 // maximum thing, look for things that are okay with the header-end
676 // alignment, and keep appending them until we get something that's
677 // aligned right. This algorithm is only guaranteed optimal if
678 // that condition is satisfied at some point; otherwise we can get
679 // things like:
680 // header // next byte has alignment 4
681 // something_with_size_5; // next byte has alignment 1
682 // something_with_alignment_8;
683 // which has 7 bytes of padding, as opposed to the naive solution
684 // which might have less (?).
685 if (endAlign < maxFieldAlign) {
686 SmallVectorImpl<BlockLayoutChunk>::iterator
687 li = layout.begin() + 1, le = layout.end();
688
689 // Look for something that the header end is already
690 // satisfactorily aligned for.
691 for (; li != le && endAlign < li->Alignment; ++li)
692 ;
693
694 // If we found something that's naturally aligned for the end of
695 // the header, keep adding things...
696 if (li != le) {
697 SmallVectorImpl<BlockLayoutChunk>::iterator first = li;
698 for (; li != le; ++li) {
699 assert(endAlign >= li->Alignment);
700
701 li->setIndex(info, index: elementTypes.size(), offset: blockSize);
702 elementTypes.push_back(Elt: li->Type);
703 blockSize += li->Size;
704 endAlign = getLowBit(v: blockSize);
705
706 // ...until we get to the alignment of the maximum field.
707 if (endAlign >= maxFieldAlign) {
708 ++li;
709 break;
710 }
711 }
712 // Don't re-append everything we just appended.
713 layout.erase(CS: first, CE: li);
714 }
715 }
716
717 assert(endAlign == getLowBit(blockSize));
718
719 // At this point, we just have to add padding if the end align still
720 // isn't aligned right.
721 if (endAlign < maxFieldAlign) {
722 CharUnits newBlockSize = blockSize.alignTo(Align: maxFieldAlign);
723 CharUnits padding = newBlockSize - blockSize;
724
725 // If we haven't yet added any fields, remember that there was an
726 // initial gap; this need to go into the block layout bit map.
727 if (blockSize == info.BlockHeaderForcedGapOffset) {
728 info.BlockHeaderForcedGapSize = padding;
729 }
730
731 elementTypes.push_back(Elt: llvm::ArrayType::get(ElementType: CGM.Int8Ty,
732 NumElements: padding.getQuantity()));
733 blockSize = newBlockSize;
734 endAlign = getLowBit(v: blockSize); // might be > maxFieldAlign
735 }
736
737 assert(endAlign >= maxFieldAlign);
738 assert(endAlign == getLowBit(blockSize));
739 // Slam everything else on now. This works because they have
740 // strictly decreasing alignment and we expect that size is always a
741 // multiple of alignment.
742 for (SmallVectorImpl<BlockLayoutChunk>::iterator
743 li = layout.begin(), le = layout.end(); li != le; ++li) {
744 if (endAlign < li->Alignment) {
745 // size may not be multiple of alignment. This can only happen with
746 // an over-aligned variable. We will be adding a padding field to
747 // make the size be multiple of alignment.
748 CharUnits padding = li->Alignment - endAlign;
749 elementTypes.push_back(Elt: llvm::ArrayType::get(ElementType: CGM.Int8Ty,
750 NumElements: padding.getQuantity()));
751 blockSize += padding;
752 endAlign = getLowBit(v: blockSize);
753 }
754 assert(endAlign >= li->Alignment);
755 li->setIndex(info, index: elementTypes.size(), offset: blockSize);
756 elementTypes.push_back(Elt: li->Type);
757 blockSize += li->Size;
758 endAlign = getLowBit(v: blockSize);
759 }
760
761 info.buildCaptureMap();
762 info.StructureType =
763 llvm::StructType::get(Context&: CGM.getLLVMContext(), Elements: elementTypes, isPacked: true);
764}
765
766/// Emit a block literal expression in the current function.
767llvm::Value *CodeGenFunction::EmitBlockLiteral(const BlockExpr *blockExpr) {
768 // If the block has no captures, we won't have a pre-computed
769 // layout for it.
770 if (!blockExpr->getBlockDecl()->hasCaptures())
771 // The block literal is emitted as a global variable, and the block invoke
772 // function has to be extracted from its initializer.
773 if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(BE: blockExpr))
774 return Block;
775
776 CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
777 computeBlockInfo(CGM, CGF: this, info&: blockInfo);
778 blockInfo.BlockExpression = blockExpr;
779 if (!blockInfo.CanBeGlobal)
780 blockInfo.LocalAddress = CreateTempAlloca(Ty: blockInfo.StructureType,
781 align: blockInfo.BlockAlign, Name: "block");
782 return EmitBlockLiteral(Info: blockInfo);
783}
784
785llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) {
786 bool IsOpenCL = CGM.getContext().getLangOpts().OpenCL;
787 auto GenVoidPtrTy =
788 IsOpenCL ? CGM.getOpenCLRuntime().getGenericVoidPointerType() : VoidPtrTy;
789 LangAS GenVoidPtrAddr = IsOpenCL ? LangAS::opencl_generic : LangAS::Default;
790 auto GenVoidPtrSize = CharUnits::fromQuantity(
791 Quantity: CGM.getTarget().getPointerWidth(AddrSpace: GenVoidPtrAddr) / 8);
792 // Using the computed layout, generate the actual block function.
793 bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
794 CodeGenFunction BlockCGF{CGM, true};
795 BlockCGF.SanOpts = SanOpts;
796 auto *InvokeFn = BlockCGF.GenerateBlockFunction(
797 GD: CurGD, Info: blockInfo, ldm: LocalDeclMap, IsLambdaConversionToBlock: isLambdaConv, BuildGlobalBlock: blockInfo.CanBeGlobal);
798 auto *blockFn = llvm::ConstantExpr::getPointerCast(C: InvokeFn, Ty: GenVoidPtrTy);
799
800 // If there is nothing to capture, we can emit this as a global block.
801 if (blockInfo.CanBeGlobal)
802 return CGM.getAddrOfGlobalBlockIfEmitted(BE: blockInfo.BlockExpression);
803
804 // Otherwise, we have to emit this as a local block.
805
806 RawAddress blockAddr = blockInfo.LocalAddress;
807 assert(blockAddr.isValid() && "block has no address!");
808
809 llvm::Constant *isa;
810 llvm::Constant *descriptor;
811 BlockFlags flags;
812 if (!IsOpenCL) {
813 // If the block is non-escaping, set field 'isa 'to NSConcreteGlobalBlock
814 // and set the BLOCK_IS_GLOBAL bit of field 'flags'. Copying a non-escaping
815 // block just returns the original block and releasing it is a no-op.
816 llvm::Constant *blockISA = blockInfo.NoEscape
817 ? CGM.getNSConcreteGlobalBlock()
818 : CGM.getNSConcreteStackBlock();
819 isa = blockISA;
820
821 // Build the block descriptor.
822 descriptor = buildBlockDescriptor(CGM, blockInfo);
823
824 // Compute the initial on-stack block flags.
825 if (!CGM.getCodeGenOpts().DisableBlockSignatureString)
826 flags = BLOCK_HAS_SIGNATURE;
827 if (blockInfo.HasCapturedVariableLayout)
828 flags |= BLOCK_HAS_EXTENDED_LAYOUT;
829 if (blockInfo.NeedsCopyDispose)
830 flags |= BLOCK_HAS_COPY_DISPOSE;
831 if (blockInfo.HasCXXObject)
832 flags |= BLOCK_HAS_CXX_OBJ;
833 if (blockInfo.UsesStret)
834 flags |= BLOCK_USE_STRET;
835 if (blockInfo.NoEscape)
836 flags |= BLOCK_IS_NOESCAPE | BLOCK_IS_GLOBAL;
837 }
838
839 auto projectField = [&](unsigned index, const Twine &name) -> Address {
840 return Builder.CreateStructGEP(Addr: blockAddr, Index: index, Name: name);
841 };
842 auto storeField = [&](llvm::Value *value, unsigned index, const Twine &name) {
843 Builder.CreateStore(Val: value, Addr: projectField(index, name));
844 };
845
846 // Initialize the block header.
847 {
848 // We assume all the header fields are densely packed.
849 unsigned index = 0;
850 CharUnits offset;
851 auto addHeaderField = [&](llvm::Value *value, CharUnits size,
852 const Twine &name) {
853 storeField(value, index, name);
854 offset += size;
855 index++;
856 };
857
858 if (!IsOpenCL) {
859 addHeaderField(isa, getPointerSize(), "block.isa");
860 addHeaderField(llvm::ConstantInt::get(Ty: IntTy, V: flags.getBitMask()),
861 getIntSize(), "block.flags");
862 addHeaderField(llvm::ConstantInt::get(Ty: IntTy, V: 0), getIntSize(),
863 "block.reserved");
864 } else {
865 addHeaderField(
866 llvm::ConstantInt::get(Ty: IntTy, V: blockInfo.BlockSize.getQuantity()),
867 getIntSize(), "block.size");
868 addHeaderField(
869 llvm::ConstantInt::get(Ty: IntTy, V: blockInfo.BlockAlign.getQuantity()),
870 getIntSize(), "block.align");
871 }
872 addHeaderField(blockFn, GenVoidPtrSize, "block.invoke");
873 if (!IsOpenCL)
874 addHeaderField(descriptor, getPointerSize(), "block.descriptor");
875 else if (auto *Helper =
876 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
877 for (auto I : Helper->getCustomFieldValues(CGF&: *this, Info: blockInfo)) {
878 addHeaderField(
879 I.first,
880 CharUnits::fromQuantity(
881 Quantity: CGM.getDataLayout().getTypeAllocSize(Ty: I.first->getType())),
882 I.second);
883 }
884 }
885 }
886
887 // Finally, capture all the values into the block.
888 const BlockDecl *blockDecl = blockInfo.getBlockDecl();
889
890 // First, 'this'.
891 if (blockDecl->capturesCXXThis()) {
892 Address addr =
893 projectField(blockInfo.CXXThisIndex, "block.captured-this.addr");
894 Builder.CreateStore(Val: LoadCXXThis(), Addr: addr);
895 }
896
897 // Next, captured variables.
898 for (const auto &CI : blockDecl->captures()) {
899 const VarDecl *variable = CI.getVariable();
900 const CGBlockInfo::Capture &capture = blockInfo.getCapture(var: variable);
901
902 // Ignore constant captures.
903 if (capture.isConstant()) continue;
904
905 QualType type = capture.fieldType();
906
907 // This will be a [[type]]*, except that a byref entry will just be
908 // an i8**.
909 Address blockField = projectField(capture.getIndex(), "block.captured");
910
911 // Compute the address of the thing we're going to move into the
912 // block literal.
913 Address src = Address::invalid();
914
915 if (blockDecl->isConversionFromLambda()) {
916 // The lambda capture in a lambda's conversion-to-block-pointer is
917 // special; we'll simply emit it directly.
918 src = Address::invalid();
919 } else if (CI.isEscapingByref()) {
920 if (BlockInfo && CI.isNested()) {
921 // We need to use the capture from the enclosing block.
922 const CGBlockInfo::Capture &enclosingCapture =
923 BlockInfo->getCapture(var: variable);
924
925 // This is a [[type]]*, except that a byref entry will just be an i8**.
926 src = Builder.CreateStructGEP(Addr: LoadBlockStruct(),
927 Index: enclosingCapture.getIndex(),
928 Name: "block.capture.addr");
929 } else {
930 auto I = LocalDeclMap.find(Val: variable);
931 assert(I != LocalDeclMap.end());
932 src = I->second;
933 }
934 } else {
935 DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
936 /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
937 type.getNonReferenceType(), VK_LValue,
938 SourceLocation());
939 src = EmitDeclRefLValue(E: &declRef).getAddress();
940 };
941
942 // For byrefs, we just write the pointer to the byref struct into
943 // the block field. There's no need to chase the forwarding
944 // pointer at this point, since we're building something that will
945 // live a shorter life than the stack byref anyway.
946 if (CI.isEscapingByref()) {
947 // Get a void* that points to the byref struct.
948 llvm::Value *byrefPointer;
949 if (CI.isNested())
950 byrefPointer = Builder.CreateLoad(Addr: src, Name: "byref.capture");
951 else
952 byrefPointer = src.emitRawPointer(CGF&: *this);
953
954 // Write that void* into the capture field.
955 Builder.CreateStore(Val: byrefPointer, Addr: blockField);
956
957 // If we have a copy constructor, evaluate that into the block field.
958 } else if (const Expr *copyExpr = CI.getCopyExpr()) {
959 if (blockDecl->isConversionFromLambda()) {
960 // If we have a lambda conversion, emit the expression
961 // directly into the block instead.
962 AggValueSlot Slot =
963 AggValueSlot::forAddr(addr: blockField, quals: Qualifiers(),
964 isDestructed: AggValueSlot::IsDestructed,
965 needsGC: AggValueSlot::DoesNotNeedGCBarriers,
966 isAliased: AggValueSlot::IsNotAliased,
967 mayOverlap: AggValueSlot::DoesNotOverlap);
968 EmitAggExpr(E: copyExpr, AS: Slot);
969 } else {
970 EmitSynthesizedCXXCopyCtor(Dest: blockField, Src: src, Exp: copyExpr);
971 }
972
973 // If it's a reference variable, copy the reference into the block field.
974 } else if (type->getAs<ReferenceType>()) {
975 Builder.CreateStore(Val: src.emitRawPointer(CGF&: *this), Addr: blockField);
976
977 // If type is const-qualified, copy the value into the block field.
978 } else if (type.isConstQualified() &&
979 type.getObjCLifetime() == Qualifiers::OCL_Strong &&
980 CGM.getCodeGenOpts().OptimizationLevel != 0) {
981 llvm::Value *value = Builder.CreateLoad(Addr: src, Name: "captured");
982 Builder.CreateStore(Val: value, Addr: blockField);
983
984 // If this is an ARC __strong block-pointer variable, don't do a
985 // block copy.
986 //
987 // TODO: this can be generalized into the normal initialization logic:
988 // we should never need to do a block-copy when initializing a local
989 // variable, because the local variable's lifetime should be strictly
990 // contained within the stack block's.
991 } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
992 type->isBlockPointerType()) {
993 // Load the block and do a simple retain.
994 llvm::Value *value = Builder.CreateLoad(Addr: src, Name: "block.captured_block");
995 value = EmitARCRetainNonBlock(value);
996
997 // Do a primitive store to the block field.
998 Builder.CreateStore(Val: value, Addr: blockField);
999
1000 // Otherwise, fake up a POD copy into the block field.
1001 } else {
1002 // Fake up a new variable so that EmitScalarInit doesn't think
1003 // we're referring to the variable in its own initializer.
1004 ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
1005 ImplicitParamKind::Other);
1006
1007 // We use one of these or the other depending on whether the
1008 // reference is nested.
1009 DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1010 /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1011 type, VK_LValue, SourceLocation());
1012
1013 ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
1014 &declRef, VK_PRValue, FPOptionsOverride());
1015 // FIXME: Pass a specific location for the expr init so that the store is
1016 // attributed to a reasonable location - otherwise it may be attributed to
1017 // locations of subexpressions in the initialization.
1018 EmitExprAsInit(init: &l2r, D: &BlockFieldPseudoVar,
1019 lvalue: MakeAddrLValue(Addr: blockField, T: type, Source: AlignmentSource::Decl),
1020 /*captured by init*/ capturedByInit: false);
1021 }
1022
1023 // Push a cleanup for the capture if necessary.
1024 if (!blockInfo.NoEscape && !blockInfo.NeedsCopyDispose)
1025 continue;
1026
1027 // Ignore __block captures; there's nothing special in the on-stack block
1028 // that we need to do for them.
1029 if (CI.isByRef())
1030 continue;
1031
1032 // Ignore objects that aren't destructed.
1033 QualType::DestructionKind dtorKind = type.isDestructedType();
1034 if (dtorKind == QualType::DK_none)
1035 continue;
1036
1037 CodeGenFunction::Destroyer *destroyer;
1038
1039 // Block captures count as local values and have imprecise semantics.
1040 // They also can't be arrays, so need to worry about that.
1041 //
1042 // For const-qualified captures, emit clang.arc.use to ensure the captured
1043 // object doesn't get released while we are still depending on its validity
1044 // within the block.
1045 if (type.isConstQualified() &&
1046 type.getObjCLifetime() == Qualifiers::OCL_Strong &&
1047 CGM.getCodeGenOpts().OptimizationLevel != 0) {
1048 assert(CGM.getLangOpts().ObjCAutoRefCount &&
1049 "expected ObjC ARC to be enabled");
1050 destroyer = emitARCIntrinsicUse;
1051 } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
1052 destroyer = destroyARCStrongImprecise;
1053 } else {
1054 destroyer = getDestroyer(destructionKind: dtorKind);
1055 }
1056
1057 CleanupKind cleanupKind = NormalCleanup;
1058 bool useArrayEHCleanup = needsEHCleanup(kind: dtorKind);
1059 if (useArrayEHCleanup)
1060 cleanupKind = NormalAndEHCleanup;
1061
1062 // Extend the lifetime of the capture to the end of the scope enclosing the
1063 // block expression except when the block decl is in the list of RetExpr's
1064 // cleanup objects, in which case its lifetime ends after the full
1065 // expression.
1066 auto IsBlockDeclInRetExpr = [&]() {
1067 auto *EWC = llvm::dyn_cast_or_null<ExprWithCleanups>(Val: RetExpr);
1068 if (EWC)
1069 for (auto &C : EWC->getObjects())
1070 if (auto *BD = C.dyn_cast<BlockDecl *>())
1071 if (BD == blockDecl)
1072 return true;
1073 return false;
1074 };
1075
1076 if (IsBlockDeclInRetExpr())
1077 pushDestroy(kind: cleanupKind, addr: blockField, type, destroyer, useEHCleanupForArray: useArrayEHCleanup);
1078 else
1079 pushLifetimeExtendedDestroy(kind: cleanupKind, addr: blockField, type, destroyer,
1080 useEHCleanupForArray: useArrayEHCleanup);
1081 }
1082
1083 // Cast to the converted block-pointer type, which happens (somewhat
1084 // unfortunately) to be a pointer to function type.
1085 llvm::Value *result = Builder.CreatePointerCast(
1086 V: blockAddr.getPointer(), DestTy: ConvertType(T: blockInfo.getBlockExpr()->getType()));
1087
1088 if (IsOpenCL) {
1089 CGM.getOpenCLRuntime().recordBlockInfo(E: blockInfo.BlockExpression, InvokeF: InvokeFn,
1090 Block: result, BlockTy: blockInfo.StructureType);
1091 }
1092
1093 return result;
1094}
1095
1096
1097llvm::Type *CodeGenModule::getBlockDescriptorType() {
1098 if (BlockDescriptorType)
1099 return BlockDescriptorType;
1100
1101 llvm::Type *UnsignedLongTy =
1102 getTypes().ConvertType(T: getContext().UnsignedLongTy);
1103
1104 // struct __block_descriptor {
1105 // unsigned long reserved;
1106 // unsigned long block_size;
1107 //
1108 // // later, the following will be added
1109 //
1110 // struct {
1111 // void (*copyHelper)();
1112 // void (*copyHelper)();
1113 // } helpers; // !!! optional
1114 //
1115 // const char *signature; // the block signature
1116 // const char *layout; // reserved
1117 // };
1118 BlockDescriptorType = llvm::StructType::create(
1119 Name: "struct.__block_descriptor", elt1: UnsignedLongTy, elts: UnsignedLongTy);
1120
1121 // Now form a pointer to that.
1122 unsigned AddrSpace = 0;
1123 if (getLangOpts().OpenCL)
1124 AddrSpace = getContext().getTargetAddressSpace(AS: LangAS::opencl_constant);
1125 BlockDescriptorType = llvm::PointerType::get(ElementType: BlockDescriptorType, AddressSpace: AddrSpace);
1126 return BlockDescriptorType;
1127}
1128
1129llvm::Type *CodeGenModule::getGenericBlockLiteralType() {
1130 if (GenericBlockLiteralType)
1131 return GenericBlockLiteralType;
1132
1133 llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
1134
1135 if (getLangOpts().OpenCL) {
1136 // struct __opencl_block_literal_generic {
1137 // int __size;
1138 // int __align;
1139 // __generic void *__invoke;
1140 // /* custom fields */
1141 // };
1142 SmallVector<llvm::Type *, 8> StructFields(
1143 {IntTy, IntTy, getOpenCLRuntime().getGenericVoidPointerType()});
1144 if (auto *Helper = getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1145 llvm::append_range(C&: StructFields, R: Helper->getCustomFieldTypes());
1146 }
1147 GenericBlockLiteralType = llvm::StructType::create(
1148 Elements: StructFields, Name: "struct.__opencl_block_literal_generic");
1149 } else {
1150 // struct __block_literal_generic {
1151 // void *__isa;
1152 // int __flags;
1153 // int __reserved;
1154 // void (*__invoke)(void *);
1155 // struct __block_descriptor *__descriptor;
1156 // };
1157 GenericBlockLiteralType =
1158 llvm::StructType::create(Name: "struct.__block_literal_generic", elt1: VoidPtrTy,
1159 elts: IntTy, elts: IntTy, elts: VoidPtrTy, elts: BlockDescPtrTy);
1160 }
1161
1162 return GenericBlockLiteralType;
1163}
1164
1165RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr *E,
1166 ReturnValueSlot ReturnValue) {
1167 const auto *BPT = E->getCallee()->getType()->castAs<BlockPointerType>();
1168 llvm::Value *BlockPtr = EmitScalarExpr(E: E->getCallee());
1169 llvm::Type *GenBlockTy = CGM.getGenericBlockLiteralType();
1170 llvm::Value *Func = nullptr;
1171 QualType FnType = BPT->getPointeeType();
1172 ASTContext &Ctx = getContext();
1173 CallArgList Args;
1174
1175 if (getLangOpts().OpenCL) {
1176 // For OpenCL, BlockPtr is already casted to generic block literal.
1177
1178 // First argument of a block call is a generic block literal casted to
1179 // generic void pointer, i.e. i8 addrspace(4)*
1180 llvm::Type *GenericVoidPtrTy =
1181 CGM.getOpenCLRuntime().getGenericVoidPointerType();
1182 llvm::Value *BlockDescriptor = Builder.CreatePointerCast(
1183 V: BlockPtr, DestTy: GenericVoidPtrTy);
1184 QualType VoidPtrQualTy = Ctx.getPointerType(
1185 T: Ctx.getAddrSpaceQualType(T: Ctx.VoidTy, AddressSpace: LangAS::opencl_generic));
1186 Args.add(rvalue: RValue::get(V: BlockDescriptor), type: VoidPtrQualTy);
1187 // And the rest of the arguments.
1188 EmitCallArgs(Args, Prototype: FnType->getAs<FunctionProtoType>(), ArgRange: E->arguments());
1189
1190 // We *can* call the block directly unless it is a function argument.
1191 if (!isa<ParmVarDecl>(Val: E->getCalleeDecl()))
1192 Func = CGM.getOpenCLRuntime().getInvokeFunction(E: E->getCallee());
1193 else {
1194 llvm::Value *FuncPtr = Builder.CreateStructGEP(Ty: GenBlockTy, Ptr: BlockPtr, Idx: 2);
1195 Func = Builder.CreateAlignedLoad(Ty: GenericVoidPtrTy, Addr: FuncPtr,
1196 Align: getPointerAlign());
1197 }
1198 } else {
1199 // Bitcast the block literal to a generic block literal.
1200 BlockPtr =
1201 Builder.CreatePointerCast(V: BlockPtr, DestTy: UnqualPtrTy, Name: "block.literal");
1202 // Get pointer to the block invoke function
1203 llvm::Value *FuncPtr = Builder.CreateStructGEP(Ty: GenBlockTy, Ptr: BlockPtr, Idx: 3);
1204
1205 // First argument is a block literal casted to a void pointer
1206 BlockPtr = Builder.CreatePointerCast(V: BlockPtr, DestTy: VoidPtrTy);
1207 Args.add(rvalue: RValue::get(V: BlockPtr), type: Ctx.VoidPtrTy);
1208 // And the rest of the arguments.
1209 EmitCallArgs(Args, Prototype: FnType->getAs<FunctionProtoType>(), ArgRange: E->arguments());
1210
1211 // Load the function.
1212 Func = Builder.CreateAlignedLoad(Ty: VoidPtrTy, Addr: FuncPtr, Align: getPointerAlign());
1213 }
1214
1215 const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1216 const CGFunctionInfo &FnInfo =
1217 CGM.getTypes().arrangeBlockFunctionCall(args: Args, type: FuncTy);
1218
1219 // Prepare the callee.
1220 CGCallee Callee(CGCalleeInfo(), Func);
1221
1222 // And call the block.
1223 return EmitCall(CallInfo: FnInfo, Callee, ReturnValue, Args);
1224}
1225
1226Address CodeGenFunction::GetAddrOfBlockDecl(const VarDecl *variable) {
1227 assert(BlockInfo && "evaluating block ref without block information?");
1228 const CGBlockInfo::Capture &capture = BlockInfo->getCapture(var: variable);
1229
1230 // Handle constant captures.
1231 if (capture.isConstant()) return LocalDeclMap.find(Val: variable)->second;
1232
1233 Address addr = Builder.CreateStructGEP(Addr: LoadBlockStruct(), Index: capture.getIndex(),
1234 Name: "block.capture.addr");
1235
1236 if (variable->isEscapingByref()) {
1237 // addr should be a void** right now. Load, then cast the result
1238 // to byref*.
1239
1240 auto &byrefInfo = getBlockByrefInfo(var: variable);
1241 addr = Address(Builder.CreateLoad(Addr: addr), byrefInfo.Type,
1242 byrefInfo.ByrefAlignment);
1243
1244 addr = emitBlockByrefAddress(baseAddr: addr, info: byrefInfo, /*follow*/ followForward: true,
1245 name: variable->getName());
1246 }
1247
1248 assert((!variable->isNonEscapingByref() ||
1249 capture.fieldType()->isReferenceType()) &&
1250 "the capture field of a non-escaping variable should have a "
1251 "reference type");
1252 if (capture.fieldType()->isReferenceType())
1253 addr = EmitLoadOfReference(RefLVal: MakeAddrLValue(Addr: addr, T: capture.fieldType()));
1254
1255 return addr;
1256}
1257
1258void CodeGenModule::setAddrOfGlobalBlock(const BlockExpr *BE,
1259 llvm::Constant *Addr) {
1260 bool Ok = EmittedGlobalBlocks.insert(KV: std::make_pair(x&: BE, y&: Addr)).second;
1261 (void)Ok;
1262 assert(Ok && "Trying to replace an already-existing global block!");
1263}
1264
1265llvm::Constant *
1266CodeGenModule::GetAddrOfGlobalBlock(const BlockExpr *BE,
1267 StringRef Name) {
1268 if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1269 return Block;
1270
1271 CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1272 blockInfo.BlockExpression = BE;
1273
1274 // Compute information about the layout, etc., of this block.
1275 computeBlockInfo(CGM&: *this, CGF: nullptr, info&: blockInfo);
1276
1277 // Using that metadata, generate the actual block function.
1278 {
1279 CodeGenFunction::DeclMapTy LocalDeclMap;
1280 CodeGenFunction(*this).GenerateBlockFunction(
1281 GD: GlobalDecl(), Info: blockInfo, ldm: LocalDeclMap,
1282 /*IsLambdaConversionToBlock*/ false, /*BuildGlobalBlock*/ true);
1283 }
1284
1285 return getAddrOfGlobalBlockIfEmitted(BE);
1286}
1287
1288static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1289 const CGBlockInfo &blockInfo,
1290 llvm::Constant *blockFn) {
1291 assert(blockInfo.CanBeGlobal);
1292 // Callers should detect this case on their own: calling this function
1293 // generally requires computing layout information, which is a waste of time
1294 // if we've already emitted this block.
1295 assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&
1296 "Refusing to re-emit a global block.");
1297
1298 // Generate the constants for the block literal initializer.
1299 ConstantInitBuilder builder(CGM);
1300 auto fields = builder.beginStruct();
1301
1302 bool IsOpenCL = CGM.getLangOpts().OpenCL;
1303 bool IsWindows = CGM.getTarget().getTriple().isOSWindows();
1304 if (!IsOpenCL) {
1305 // isa
1306 if (IsWindows)
1307 fields.addNullPointer(ptrTy: CGM.Int8PtrPtrTy);
1308 else
1309 fields.add(value: CGM.getNSConcreteGlobalBlock());
1310
1311 // __flags
1312 BlockFlags flags = BLOCK_IS_GLOBAL;
1313 if (!CGM.getCodeGenOpts().DisableBlockSignatureString)
1314 flags |= BLOCK_HAS_SIGNATURE;
1315 if (blockInfo.UsesStret)
1316 flags |= BLOCK_USE_STRET;
1317
1318 fields.addInt(intTy: CGM.IntTy, value: flags.getBitMask());
1319
1320 // Reserved
1321 fields.addInt(intTy: CGM.IntTy, value: 0);
1322 } else {
1323 fields.addInt(intTy: CGM.IntTy, value: blockInfo.BlockSize.getQuantity());
1324 fields.addInt(intTy: CGM.IntTy, value: blockInfo.BlockAlign.getQuantity());
1325 }
1326
1327 // Function
1328 fields.add(value: blockFn);
1329
1330 if (!IsOpenCL) {
1331 // Descriptor
1332 fields.add(value: buildBlockDescriptor(CGM, blockInfo));
1333 } else if (auto *Helper =
1334 CGM.getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1335 for (auto *I : Helper->getCustomFieldValues(CGM, Info: blockInfo)) {
1336 fields.add(value: I);
1337 }
1338 }
1339
1340 unsigned AddrSpace = 0;
1341 if (CGM.getContext().getLangOpts().OpenCL)
1342 AddrSpace = CGM.getContext().getTargetAddressSpace(AS: LangAS::opencl_global);
1343
1344 llvm::GlobalVariable *literal = fields.finishAndCreateGlobal(
1345 args: "__block_literal_global", args: blockInfo.BlockAlign,
1346 /*constant*/ args: !IsWindows, args: llvm::GlobalVariable::InternalLinkage, args&: AddrSpace);
1347
1348 literal->addAttribute(Kind: "objc_arc_inert");
1349
1350 // Windows does not allow globals to be initialised to point to globals in
1351 // different DLLs. Any such variables must run code to initialise them.
1352 if (IsWindows) {
1353 auto *Init = llvm::Function::Create(Ty: llvm::FunctionType::get(Result: CGM.VoidTy,
1354 isVarArg: {}), Linkage: llvm::GlobalValue::InternalLinkage, N: ".block_isa_init",
1355 M: &CGM.getModule());
1356 llvm::IRBuilder<> b(llvm::BasicBlock::Create(Context&: CGM.getLLVMContext(), Name: "entry",
1357 Parent: Init));
1358 b.CreateAlignedStore(Val: CGM.getNSConcreteGlobalBlock(),
1359 Ptr: b.CreateStructGEP(Ty: literal->getValueType(), Ptr: literal, Idx: 0),
1360 Align: CGM.getPointerAlign().getAsAlign());
1361 b.CreateRetVoid();
1362 // We can't use the normal LLVM global initialisation array, because we
1363 // need to specify that this runs early in library initialisation.
1364 auto *InitVar = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
1365 /*isConstant*/true, llvm::GlobalValue::InternalLinkage,
1366 Init, ".block_isa_init_ptr");
1367 InitVar->setSection(".CRT$XCLa");
1368 CGM.addUsedGlobal(GV: InitVar);
1369 }
1370
1371 // Return a constant of the appropriately-casted type.
1372 llvm::Type *RequiredType =
1373 CGM.getTypes().ConvertType(T: blockInfo.getBlockExpr()->getType());
1374 llvm::Constant *Result =
1375 llvm::ConstantExpr::getPointerCast(C: literal, Ty: RequiredType);
1376 CGM.setAddrOfGlobalBlock(BE: blockInfo.BlockExpression, Addr: Result);
1377 if (CGM.getContext().getLangOpts().OpenCL)
1378 CGM.getOpenCLRuntime().recordBlockInfo(
1379 E: blockInfo.BlockExpression,
1380 InvokeF: cast<llvm::Function>(Val: blockFn->stripPointerCasts()), Block: Result,
1381 BlockTy: literal->getValueType());
1382 return Result;
1383}
1384
1385void CodeGenFunction::setBlockContextParameter(const ImplicitParamDecl *D,
1386 unsigned argNum,
1387 llvm::Value *arg) {
1388 assert(BlockInfo && "not emitting prologue of block invocation function?!");
1389
1390 // Allocate a stack slot like for any local variable to guarantee optimal
1391 // debug info at -O0. The mem2reg pass will eliminate it when optimizing.
1392 RawAddress alloc = CreateMemTemp(T: D->getType(), Name: D->getName() + ".addr");
1393 Builder.CreateStore(Val: arg, Addr: alloc);
1394 if (CGDebugInfo *DI = getDebugInfo()) {
1395 if (CGM.getCodeGenOpts().hasReducedDebugInfo()) {
1396 DI->setLocation(D->getLocation());
1397 DI->EmitDeclareOfBlockLiteralArgVariable(
1398 block: *BlockInfo, Name: D->getName(), ArgNo: argNum,
1399 LocalAddr: cast<llvm::AllocaInst>(Val: alloc.getPointer()), Builder);
1400 }
1401 }
1402
1403 SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getBeginLoc();
1404 ApplyDebugLocation Scope(*this, StartLoc);
1405
1406 // Instead of messing around with LocalDeclMap, just set the value
1407 // directly as BlockPointer.
1408 BlockPointer = Builder.CreatePointerCast(
1409 V: arg,
1410 DestTy: llvm::PointerType::get(
1411 C&: getLLVMContext(),
1412 AddressSpace: getContext().getLangOpts().OpenCL
1413 ? getContext().getTargetAddressSpace(AS: LangAS::opencl_generic)
1414 : 0),
1415 Name: "block");
1416}
1417
1418Address CodeGenFunction::LoadBlockStruct() {
1419 assert(BlockInfo && "not in a block invocation function!");
1420 assert(BlockPointer && "no block pointer set!");
1421 return Address(BlockPointer, BlockInfo->StructureType, BlockInfo->BlockAlign);
1422}
1423
1424llvm::Function *CodeGenFunction::GenerateBlockFunction(
1425 GlobalDecl GD, const CGBlockInfo &blockInfo, const DeclMapTy &ldm,
1426 bool IsLambdaConversionToBlock, bool BuildGlobalBlock) {
1427 const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1428
1429 CurGD = GD;
1430
1431 CurEHLocation = blockInfo.getBlockExpr()->getEndLoc();
1432
1433 BlockInfo = &blockInfo;
1434
1435 // Arrange for local static and local extern declarations to appear
1436 // to be local to this function as well, in case they're directly
1437 // referenced in a block.
1438 for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1439 const auto *var = dyn_cast<VarDecl>(Val: i->first);
1440 if (var && !var->hasLocalStorage())
1441 setAddrOfLocalVar(VD: var, Addr: i->second);
1442 }
1443
1444 // Begin building the function declaration.
1445
1446 // Build the argument list.
1447 FunctionArgList args;
1448
1449 // The first argument is the block pointer. Just take it as a void*
1450 // and cast it later.
1451 QualType selfTy = getContext().VoidPtrTy;
1452
1453 // For OpenCL passed block pointer can be private AS local variable or
1454 // global AS program scope variable (for the case with and without captures).
1455 // Generic AS is used therefore to be able to accommodate both private and
1456 // generic AS in one implementation.
1457 if (getLangOpts().OpenCL)
1458 selfTy = getContext().getPointerType(T: getContext().getAddrSpaceQualType(
1459 T: getContext().VoidTy, AddressSpace: LangAS::opencl_generic));
1460
1461 const IdentifierInfo *II = &CGM.getContext().Idents.get(Name: ".block_descriptor");
1462
1463 ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1464 SourceLocation(), II, selfTy,
1465 ImplicitParamKind::ObjCSelf);
1466 args.push_back(Elt: &SelfDecl);
1467
1468 // Now add the rest of the parameters.
1469 args.append(in_start: blockDecl->param_begin(), in_end: blockDecl->param_end());
1470
1471 // Create the function declaration.
1472 const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1473 const CGFunctionInfo &fnInfo =
1474 CGM.getTypes().arrangeBlockFunctionDeclaration(type: fnType, args);
1475 if (CGM.ReturnSlotInterferesWithArgs(FI: fnInfo))
1476 blockInfo.UsesStret = true;
1477
1478 llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(Info: fnInfo);
1479
1480 StringRef name = CGM.getBlockMangledName(GD, BD: blockDecl);
1481 llvm::Function *fn = llvm::Function::Create(
1482 Ty: fnLLVMType, Linkage: llvm::GlobalValue::InternalLinkage, N: name, M: &CGM.getModule());
1483 CGM.SetInternalFunctionAttributes(GD: blockDecl, F: fn, FI: fnInfo);
1484
1485 if (BuildGlobalBlock) {
1486 auto GenVoidPtrTy = getContext().getLangOpts().OpenCL
1487 ? CGM.getOpenCLRuntime().getGenericVoidPointerType()
1488 : VoidPtrTy;
1489 buildGlobalBlock(CGM, blockInfo,
1490 blockFn: llvm::ConstantExpr::getPointerCast(C: fn, Ty: GenVoidPtrTy));
1491 }
1492
1493 // Begin generating the function.
1494 StartFunction(GD: blockDecl, RetTy: fnType->getReturnType(), Fn: fn, FnInfo: fnInfo, Args: args,
1495 Loc: blockDecl->getLocation(),
1496 StartLoc: blockInfo.getBlockExpr()->getBody()->getBeginLoc());
1497
1498 // Okay. Undo some of what StartFunction did.
1499
1500 // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1501 // won't delete the dbg.declare intrinsics for captured variables.
1502 llvm::Value *BlockPointerDbgLoc = BlockPointer;
1503 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1504 // Allocate a stack slot for it, so we can point the debugger to it
1505 Address Alloca = CreateTempAlloca(Ty: BlockPointer->getType(),
1506 align: getPointerAlign(),
1507 Name: "block.addr");
1508 // Set the DebugLocation to empty, so the store is recognized as a
1509 // frame setup instruction by llvm::DwarfDebug::beginFunction().
1510 auto NL = ApplyDebugLocation::CreateEmpty(CGF&: *this);
1511 Builder.CreateStore(Val: BlockPointer, Addr: Alloca);
1512 BlockPointerDbgLoc = Alloca.emitRawPointer(CGF&: *this);
1513 }
1514
1515 // If we have a C++ 'this' reference, go ahead and force it into
1516 // existence now.
1517 if (blockDecl->capturesCXXThis()) {
1518 Address addr = Builder.CreateStructGEP(
1519 Addr: LoadBlockStruct(), Index: blockInfo.CXXThisIndex, Name: "block.captured-this");
1520 CXXThisValue = Builder.CreateLoad(Addr: addr, Name: "this");
1521 }
1522
1523 // Also force all the constant captures.
1524 for (const auto &CI : blockDecl->captures()) {
1525 const VarDecl *variable = CI.getVariable();
1526 const CGBlockInfo::Capture &capture = blockInfo.getCapture(var: variable);
1527 if (!capture.isConstant()) continue;
1528
1529 CharUnits align = getContext().getDeclAlign(D: variable);
1530 Address alloca =
1531 CreateMemTemp(T: variable->getType(), Align: align, Name: "block.captured-const");
1532
1533 Builder.CreateStore(Val: capture.getConstant(), Addr: alloca);
1534
1535 setAddrOfLocalVar(VD: variable, Addr: alloca);
1536 }
1537
1538 // Save a spot to insert the debug information for all the DeclRefExprs.
1539 llvm::BasicBlock *entry = Builder.GetInsertBlock();
1540 llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1541 --entry_ptr;
1542
1543 if (IsLambdaConversionToBlock)
1544 EmitLambdaBlockInvokeBody();
1545 else {
1546 PGO.assignRegionCounters(GD: GlobalDecl(blockDecl), Fn: fn);
1547 incrementProfileCounter(S: blockDecl->getBody());
1548 EmitStmt(S: blockDecl->getBody());
1549 }
1550
1551 // Remember where we were...
1552 llvm::BasicBlock *resume = Builder.GetInsertBlock();
1553
1554 // Go back to the entry.
1555 if (entry_ptr->getNextNonDebugInstruction())
1556 entry_ptr = entry_ptr->getNextNonDebugInstruction()->getIterator();
1557 else
1558 entry_ptr = entry->end();
1559 Builder.SetInsertPoint(TheBB: entry, IP: entry_ptr);
1560
1561 // Emit debug information for all the DeclRefExprs.
1562 // FIXME: also for 'this'
1563 if (CGDebugInfo *DI = getDebugInfo()) {
1564 for (const auto &CI : blockDecl->captures()) {
1565 const VarDecl *variable = CI.getVariable();
1566 DI->EmitLocation(Builder, Loc: variable->getLocation());
1567
1568 if (CGM.getCodeGenOpts().hasReducedDebugInfo()) {
1569 const CGBlockInfo::Capture &capture = blockInfo.getCapture(var: variable);
1570 if (capture.isConstant()) {
1571 auto addr = LocalDeclMap.find(Val: variable)->second;
1572 (void)DI->EmitDeclareOfAutoVariable(
1573 Decl: variable, AI: addr.emitRawPointer(CGF&: *this), Builder);
1574 continue;
1575 }
1576
1577 DI->EmitDeclareOfBlockDeclRefVariable(
1578 variable, storage: BlockPointerDbgLoc, Builder, blockInfo,
1579 InsertPoint: entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1580 }
1581 }
1582 // Recover location if it was changed in the above loop.
1583 DI->EmitLocation(Builder,
1584 Loc: cast<CompoundStmt>(Val: blockDecl->getBody())->getRBracLoc());
1585 }
1586
1587 // And resume where we left off.
1588 if (resume == nullptr)
1589 Builder.ClearInsertionPoint();
1590 else
1591 Builder.SetInsertPoint(resume);
1592
1593 FinishFunction(EndLoc: cast<CompoundStmt>(Val: blockDecl->getBody())->getRBracLoc());
1594
1595 return fn;
1596}
1597
1598static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1599computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
1600 const LangOptions &LangOpts) {
1601 if (CI.getCopyExpr()) {
1602 assert(!CI.isByRef());
1603 // don't bother computing flags
1604 return std::make_pair(x: BlockCaptureEntityKind::CXXRecord, y: BlockFieldFlags());
1605 }
1606 BlockFieldFlags Flags;
1607 if (CI.isEscapingByref()) {
1608 Flags = BLOCK_FIELD_IS_BYREF;
1609 if (T.isObjCGCWeak())
1610 Flags |= BLOCK_FIELD_IS_WEAK;
1611 return std::make_pair(x: BlockCaptureEntityKind::BlockObject, y&: Flags);
1612 }
1613
1614 Flags = BLOCK_FIELD_IS_OBJECT;
1615 bool isBlockPointer = T->isBlockPointerType();
1616 if (isBlockPointer)
1617 Flags = BLOCK_FIELD_IS_BLOCK;
1618
1619 switch (T.isNonTrivialToPrimitiveCopy()) {
1620 case QualType::PCK_Struct:
1621 return std::make_pair(x: BlockCaptureEntityKind::NonTrivialCStruct,
1622 y: BlockFieldFlags());
1623 case QualType::PCK_ARCWeak:
1624 // We need to register __weak direct captures with the runtime.
1625 return std::make_pair(x: BlockCaptureEntityKind::ARCWeak, y&: Flags);
1626 case QualType::PCK_ARCStrong:
1627 // We need to retain the copied value for __strong direct captures.
1628 // If it's a block pointer, we have to copy the block and assign that to
1629 // the destination pointer, so we might as well use _Block_object_assign.
1630 // Otherwise we can avoid that.
1631 return std::make_pair(x: !isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1632 : BlockCaptureEntityKind::BlockObject,
1633 y&: Flags);
1634 case QualType::PCK_Trivial:
1635 case QualType::PCK_VolatileTrivial: {
1636 if (!T->isObjCRetainableType())
1637 // For all other types, the memcpy is fine.
1638 return std::make_pair(x: BlockCaptureEntityKind::None, y: BlockFieldFlags());
1639
1640 // Honor the inert __unsafe_unretained qualifier, which doesn't actually
1641 // make it into the type system.
1642 if (T->isObjCInertUnsafeUnretainedType())
1643 return std::make_pair(x: BlockCaptureEntityKind::None, y: BlockFieldFlags());
1644
1645 // Special rules for ARC captures:
1646 Qualifiers QS = T.getQualifiers();
1647
1648 // Non-ARC captures of retainable pointers are strong and
1649 // therefore require a call to _Block_object_assign.
1650 if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1651 return std::make_pair(x: BlockCaptureEntityKind::BlockObject, y&: Flags);
1652
1653 // Otherwise the memcpy is fine.
1654 return std::make_pair(x: BlockCaptureEntityKind::None, y: BlockFieldFlags());
1655 }
1656 }
1657 llvm_unreachable("after exhaustive PrimitiveCopyKind switch");
1658}
1659
1660namespace {
1661/// Release a __block variable.
1662struct CallBlockRelease final : EHScopeStack::Cleanup {
1663 Address Addr;
1664 BlockFieldFlags FieldFlags;
1665 bool LoadBlockVarAddr, CanThrow;
1666
1667 CallBlockRelease(Address Addr, BlockFieldFlags Flags, bool LoadValue,
1668 bool CT)
1669 : Addr(Addr), FieldFlags(Flags), LoadBlockVarAddr(LoadValue),
1670 CanThrow(CT) {}
1671
1672 void Emit(CodeGenFunction &CGF, Flags flags) override {
1673 llvm::Value *BlockVarAddr;
1674 if (LoadBlockVarAddr) {
1675 BlockVarAddr = CGF.Builder.CreateLoad(Addr);
1676 } else {
1677 BlockVarAddr = Addr.emitRawPointer(CGF);
1678 }
1679
1680 CGF.BuildBlockRelease(DeclPtr: BlockVarAddr, flags: FieldFlags, CanThrow);
1681 }
1682};
1683} // end anonymous namespace
1684
1685/// Check if \p T is a C++ class that has a destructor that can throw.
1686bool CodeGenFunction::cxxDestructorCanThrow(QualType T) {
1687 if (const auto *RD = T->getAsCXXRecordDecl())
1688 if (const CXXDestructorDecl *DD = RD->getDestructor())
1689 return DD->getType()->castAs<FunctionProtoType>()->canThrow();
1690 return false;
1691}
1692
1693// Return a string that has the information about a capture.
1694static std::string getBlockCaptureStr(const CGBlockInfo::Capture &Cap,
1695 CaptureStrKind StrKind,
1696 CharUnits BlockAlignment,
1697 CodeGenModule &CGM) {
1698 std::string Str;
1699 ASTContext &Ctx = CGM.getContext();
1700 const BlockDecl::Capture &CI = *Cap.Cap;
1701 QualType CaptureTy = CI.getVariable()->getType();
1702
1703 BlockCaptureEntityKind Kind;
1704 BlockFieldFlags Flags;
1705
1706 // CaptureStrKind::Merged should be passed only when the operations and the
1707 // flags are the same for copy and dispose.
1708 assert((StrKind != CaptureStrKind::Merged ||
1709 (Cap.CopyKind == Cap.DisposeKind &&
1710 Cap.CopyFlags == Cap.DisposeFlags)) &&
1711 "different operations and flags");
1712
1713 if (StrKind == CaptureStrKind::DisposeHelper) {
1714 Kind = Cap.DisposeKind;
1715 Flags = Cap.DisposeFlags;
1716 } else {
1717 Kind = Cap.CopyKind;
1718 Flags = Cap.CopyFlags;
1719 }
1720
1721 switch (Kind) {
1722 case BlockCaptureEntityKind::CXXRecord: {
1723 Str += "c";
1724 SmallString<256> TyStr;
1725 llvm::raw_svector_ostream Out(TyStr);
1726 CGM.getCXXABI().getMangleContext().mangleCanonicalTypeName(T: CaptureTy, Out);
1727 Str += llvm::to_string(Value: TyStr.size()) + TyStr.c_str();
1728 break;
1729 }
1730 case BlockCaptureEntityKind::ARCWeak:
1731 Str += "w";
1732 break;
1733 case BlockCaptureEntityKind::ARCStrong:
1734 Str += "s";
1735 break;
1736 case BlockCaptureEntityKind::BlockObject: {
1737 const VarDecl *Var = CI.getVariable();
1738 unsigned F = Flags.getBitMask();
1739 if (F & BLOCK_FIELD_IS_BYREF) {
1740 Str += "r";
1741 if (F & BLOCK_FIELD_IS_WEAK)
1742 Str += "w";
1743 else {
1744 // If CaptureStrKind::Merged is passed, check both the copy expression
1745 // and the destructor.
1746 if (StrKind != CaptureStrKind::DisposeHelper) {
1747 if (Ctx.getBlockVarCopyInit(VD: Var).canThrow())
1748 Str += "c";
1749 }
1750 if (StrKind != CaptureStrKind::CopyHelper) {
1751 if (CodeGenFunction::cxxDestructorCanThrow(T: CaptureTy))
1752 Str += "d";
1753 }
1754 }
1755 } else {
1756 assert((F & BLOCK_FIELD_IS_OBJECT) && "unexpected flag value");
1757 if (F == BLOCK_FIELD_IS_BLOCK)
1758 Str += "b";
1759 else
1760 Str += "o";
1761 }
1762 break;
1763 }
1764 case BlockCaptureEntityKind::NonTrivialCStruct: {
1765 bool IsVolatile = CaptureTy.isVolatileQualified();
1766 CharUnits Alignment = BlockAlignment.alignmentAtOffset(offset: Cap.getOffset());
1767
1768 Str += "n";
1769 std::string FuncStr;
1770 if (StrKind == CaptureStrKind::DisposeHelper)
1771 FuncStr = CodeGenFunction::getNonTrivialDestructorStr(
1772 QT: CaptureTy, Alignment, IsVolatile, Ctx);
1773 else
1774 // If CaptureStrKind::Merged is passed, use the copy constructor string.
1775 // It has all the information that the destructor string has.
1776 FuncStr = CodeGenFunction::getNonTrivialCopyConstructorStr(
1777 QT: CaptureTy, Alignment, IsVolatile, Ctx);
1778 // The underscore is necessary here because non-trivial copy constructor
1779 // and destructor strings can start with a number.
1780 Str += llvm::to_string(Value: FuncStr.size()) + "_" + FuncStr;
1781 break;
1782 }
1783 case BlockCaptureEntityKind::None:
1784 break;
1785 }
1786
1787 return Str;
1788}
1789
1790static std::string getCopyDestroyHelperFuncName(
1791 const SmallVectorImpl<CGBlockInfo::Capture> &Captures,
1792 CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM) {
1793 assert((StrKind == CaptureStrKind::CopyHelper ||
1794 StrKind == CaptureStrKind::DisposeHelper) &&
1795 "unexpected CaptureStrKind");
1796 std::string Name = StrKind == CaptureStrKind::CopyHelper
1797 ? "__copy_helper_block_"
1798 : "__destroy_helper_block_";
1799 if (CGM.getLangOpts().Exceptions)
1800 Name += "e";
1801 if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
1802 Name += "a";
1803 Name += llvm::to_string(Value: BlockAlignment.getQuantity()) + "_";
1804
1805 for (auto &Cap : Captures) {
1806 if (Cap.isConstantOrTrivial())
1807 continue;
1808 Name += llvm::to_string(Value: Cap.getOffset().getQuantity());
1809 Name += getBlockCaptureStr(Cap, StrKind, BlockAlignment, CGM);
1810 }
1811
1812 return Name;
1813}
1814
1815static void pushCaptureCleanup(BlockCaptureEntityKind CaptureKind,
1816 Address Field, QualType CaptureType,
1817 BlockFieldFlags Flags, bool ForCopyHelper,
1818 VarDecl *Var, CodeGenFunction &CGF) {
1819 bool EHOnly = ForCopyHelper;
1820
1821 switch (CaptureKind) {
1822 case BlockCaptureEntityKind::CXXRecord:
1823 case BlockCaptureEntityKind::ARCWeak:
1824 case BlockCaptureEntityKind::NonTrivialCStruct:
1825 case BlockCaptureEntityKind::ARCStrong: {
1826 if (CaptureType.isDestructedType() &&
1827 (!EHOnly || CGF.needsEHCleanup(kind: CaptureType.isDestructedType()))) {
1828 CodeGenFunction::Destroyer *Destroyer =
1829 CaptureKind == BlockCaptureEntityKind::ARCStrong
1830 ? CodeGenFunction::destroyARCStrongImprecise
1831 : CGF.getDestroyer(destructionKind: CaptureType.isDestructedType());
1832 CleanupKind Kind =
1833 EHOnly ? EHCleanup
1834 : CGF.getCleanupKind(kind: CaptureType.isDestructedType());
1835 CGF.pushDestroy(kind: Kind, addr: Field, type: CaptureType, destroyer: Destroyer, useEHCleanupForArray: Kind & EHCleanup);
1836 }
1837 break;
1838 }
1839 case BlockCaptureEntityKind::BlockObject: {
1840 if (!EHOnly || CGF.getLangOpts().Exceptions) {
1841 CleanupKind Kind = EHOnly ? EHCleanup : NormalAndEHCleanup;
1842 // Calls to _Block_object_dispose along the EH path in the copy helper
1843 // function don't throw as newly-copied __block variables always have a
1844 // reference count of 2.
1845 bool CanThrow =
1846 !ForCopyHelper && CGF.cxxDestructorCanThrow(T: CaptureType);
1847 CGF.enterByrefCleanup(Kind, Addr: Field, Flags, /*LoadBlockVarAddr*/ true,
1848 CanThrow);
1849 }
1850 break;
1851 }
1852 case BlockCaptureEntityKind::None:
1853 break;
1854 }
1855}
1856
1857static void setBlockHelperAttributesVisibility(bool CapturesNonExternalType,
1858 llvm::Function *Fn,
1859 const CGFunctionInfo &FI,
1860 CodeGenModule &CGM) {
1861 if (CapturesNonExternalType) {
1862 CGM.SetInternalFunctionAttributes(GD: GlobalDecl(), F: Fn, FI);
1863 } else {
1864 Fn->setVisibility(llvm::GlobalValue::HiddenVisibility);
1865 Fn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1866 CGM.SetLLVMFunctionAttributes(GD: GlobalDecl(), Info: FI, F: Fn, /*IsThunk=*/false);
1867 CGM.SetLLVMFunctionAttributesForDefinition(D: nullptr, F: Fn);
1868 }
1869}
1870/// Generate the copy-helper function for a block closure object:
1871/// static void block_copy_helper(block_t *dst, block_t *src);
1872/// The runtime will have previously initialized 'dst' by doing a
1873/// bit-copy of 'src'.
1874///
1875/// Note that this copies an entire block closure object to the heap;
1876/// it should not be confused with a 'byref copy helper', which moves
1877/// the contents of an individual __block variable to the heap.
1878llvm::Constant *
1879CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) {
1880 std::string FuncName = getCopyDestroyHelperFuncName(
1881 Captures: blockInfo.SortedCaptures, BlockAlignment: blockInfo.BlockAlign,
1882 StrKind: CaptureStrKind::CopyHelper, CGM);
1883
1884 if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(Name: FuncName))
1885 return Func;
1886
1887 ASTContext &C = getContext();
1888
1889 QualType ReturnTy = C.VoidTy;
1890
1891 FunctionArgList args;
1892 ImplicitParamDecl DstDecl(C, C.VoidPtrTy, ImplicitParamKind::Other);
1893 args.push_back(Elt: &DstDecl);
1894 ImplicitParamDecl SrcDecl(C, C.VoidPtrTy, ImplicitParamKind::Other);
1895 args.push_back(Elt: &SrcDecl);
1896
1897 const CGFunctionInfo &FI =
1898 CGM.getTypes().arrangeBuiltinFunctionDeclaration(resultType: ReturnTy, args);
1899
1900 // FIXME: it would be nice if these were mergeable with things with
1901 // identical semantics.
1902 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(Info: FI);
1903
1904 llvm::Function *Fn =
1905 llvm::Function::Create(Ty: LTy, Linkage: llvm::GlobalValue::LinkOnceODRLinkage,
1906 N: FuncName, M: &CGM.getModule());
1907 if (CGM.supportsCOMDAT())
1908 Fn->setComdat(CGM.getModule().getOrInsertComdat(Name: FuncName));
1909
1910 SmallVector<QualType, 2> ArgTys;
1911 ArgTys.push_back(Elt: C.VoidPtrTy);
1912 ArgTys.push_back(Elt: C.VoidPtrTy);
1913
1914 setBlockHelperAttributesVisibility(CapturesNonExternalType: blockInfo.CapturesNonExternalType, Fn, FI,
1915 CGM);
1916 StartFunction(GD: GlobalDecl(), RetTy: ReturnTy, Fn, FnInfo: FI, Args: args);
1917 auto AL = ApplyDebugLocation::CreateArtificial(CGF&: *this);
1918
1919 Address src = GetAddrOfLocalVar(VD: &SrcDecl);
1920 src = Address(Builder.CreateLoad(Addr: src), blockInfo.StructureType,
1921 blockInfo.BlockAlign);
1922
1923 Address dst = GetAddrOfLocalVar(VD: &DstDecl);
1924 dst = Address(Builder.CreateLoad(Addr: dst), blockInfo.StructureType,
1925 blockInfo.BlockAlign);
1926
1927 for (auto &capture : blockInfo.SortedCaptures) {
1928 if (capture.isConstantOrTrivial())
1929 continue;
1930
1931 const BlockDecl::Capture &CI = *capture.Cap;
1932 QualType captureType = CI.getVariable()->getType();
1933 BlockFieldFlags flags = capture.CopyFlags;
1934
1935 unsigned index = capture.getIndex();
1936 Address srcField = Builder.CreateStructGEP(Addr: src, Index: index);
1937 Address dstField = Builder.CreateStructGEP(Addr: dst, Index: index);
1938
1939 switch (capture.CopyKind) {
1940 case BlockCaptureEntityKind::CXXRecord:
1941 // If there's an explicit copy expression, we do that.
1942 assert(CI.getCopyExpr() && "copy expression for variable is missing");
1943 EmitSynthesizedCXXCopyCtor(Dest: dstField, Src: srcField, Exp: CI.getCopyExpr());
1944 break;
1945 case BlockCaptureEntityKind::ARCWeak:
1946 EmitARCCopyWeak(dst: dstField, src: srcField);
1947 break;
1948 case BlockCaptureEntityKind::NonTrivialCStruct: {
1949 // If this is a C struct that requires non-trivial copy construction,
1950 // emit a call to its copy constructor.
1951 QualType varType = CI.getVariable()->getType();
1952 callCStructCopyConstructor(Dst: MakeAddrLValue(Addr: dstField, T: varType),
1953 Src: MakeAddrLValue(Addr: srcField, T: varType));
1954 break;
1955 }
1956 case BlockCaptureEntityKind::ARCStrong: {
1957 llvm::Value *srcValue = Builder.CreateLoad(Addr: srcField, Name: "blockcopy.src");
1958 // At -O0, store null into the destination field (so that the
1959 // storeStrong doesn't over-release) and then call storeStrong.
1960 // This is a workaround to not having an initStrong call.
1961 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1962 auto *ty = cast<llvm::PointerType>(Val: srcValue->getType());
1963 llvm::Value *null = llvm::ConstantPointerNull::get(T: ty);
1964 Builder.CreateStore(Val: null, Addr: dstField);
1965 EmitARCStoreStrongCall(addr: dstField, value: srcValue, resultIgnored: true);
1966
1967 // With optimization enabled, take advantage of the fact that
1968 // the blocks runtime guarantees a memcpy of the block data, and
1969 // just emit a retain of the src field.
1970 } else {
1971 EmitARCRetainNonBlock(value: srcValue);
1972
1973 // Unless EH cleanup is required, we don't need this anymore, so kill
1974 // it. It's not quite worth the annoyance to avoid creating it in the
1975 // first place.
1976 if (!needsEHCleanup(kind: captureType.isDestructedType()))
1977 if (auto *I =
1978 cast_or_null<llvm::Instruction>(Val: dstField.getBasePointer()))
1979 I->eraseFromParent();
1980 }
1981 break;
1982 }
1983 case BlockCaptureEntityKind::BlockObject: {
1984 llvm::Value *srcValue = Builder.CreateLoad(Addr: srcField, Name: "blockcopy.src");
1985 llvm::Value *dstAddr = dstField.emitRawPointer(CGF&: *this);
1986 llvm::Value *args[] = {
1987 dstAddr, srcValue, llvm::ConstantInt::get(Ty: Int32Ty, V: flags.getBitMask())
1988 };
1989
1990 if (CI.isByRef() && C.getBlockVarCopyInit(VD: CI.getVariable()).canThrow())
1991 EmitRuntimeCallOrInvoke(callee: CGM.getBlockObjectAssign(), args);
1992 else
1993 EmitNounwindRuntimeCall(callee: CGM.getBlockObjectAssign(), args);
1994 break;
1995 }
1996 case BlockCaptureEntityKind::None:
1997 continue;
1998 }
1999
2000 // Ensure that we destroy the copied object if an exception is thrown later
2001 // in the helper function.
2002 pushCaptureCleanup(CaptureKind: capture.CopyKind, Field: dstField, CaptureType: captureType, Flags: flags,
2003 /*ForCopyHelper*/ true, Var: CI.getVariable(), CGF&: *this);
2004 }
2005
2006 FinishFunction();
2007
2008 return Fn;
2009}
2010
2011static BlockFieldFlags
2012getBlockFieldFlagsForObjCObjectPointer(const BlockDecl::Capture &CI,
2013 QualType T) {
2014 BlockFieldFlags Flags = BLOCK_FIELD_IS_OBJECT;
2015 if (T->isBlockPointerType())
2016 Flags = BLOCK_FIELD_IS_BLOCK;
2017 return Flags;
2018}
2019
2020static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
2021computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
2022 const LangOptions &LangOpts) {
2023 if (CI.isEscapingByref()) {
2024 BlockFieldFlags Flags = BLOCK_FIELD_IS_BYREF;
2025 if (T.isObjCGCWeak())
2026 Flags |= BLOCK_FIELD_IS_WEAK;
2027 return std::make_pair(x: BlockCaptureEntityKind::BlockObject, y&: Flags);
2028 }
2029
2030 switch (T.isDestructedType()) {
2031 case QualType::DK_cxx_destructor:
2032 return std::make_pair(x: BlockCaptureEntityKind::CXXRecord, y: BlockFieldFlags());
2033 case QualType::DK_objc_strong_lifetime:
2034 // Use objc_storeStrong for __strong direct captures; the
2035 // dynamic tools really like it when we do this.
2036 return std::make_pair(x: BlockCaptureEntityKind::ARCStrong,
2037 y: getBlockFieldFlagsForObjCObjectPointer(CI, T));
2038 case QualType::DK_objc_weak_lifetime:
2039 // Support __weak direct captures.
2040 return std::make_pair(x: BlockCaptureEntityKind::ARCWeak,
2041 y: getBlockFieldFlagsForObjCObjectPointer(CI, T));
2042 case QualType::DK_nontrivial_c_struct:
2043 return std::make_pair(x: BlockCaptureEntityKind::NonTrivialCStruct,
2044 y: BlockFieldFlags());
2045 case QualType::DK_none: {
2046 // Non-ARC captures are strong, and we need to use _Block_object_dispose.
2047 // But honor the inert __unsafe_unretained qualifier, which doesn't actually
2048 // make it into the type system.
2049 if (T->isObjCRetainableType() && !T.getQualifiers().hasObjCLifetime() &&
2050 !LangOpts.ObjCAutoRefCount && !T->isObjCInertUnsafeUnretainedType())
2051 return std::make_pair(x: BlockCaptureEntityKind::BlockObject,
2052 y: getBlockFieldFlagsForObjCObjectPointer(CI, T));
2053 // Otherwise, we have nothing to do.
2054 return std::make_pair(x: BlockCaptureEntityKind::None, y: BlockFieldFlags());
2055 }
2056 }
2057 llvm_unreachable("after exhaustive DestructionKind switch");
2058}
2059
2060/// Generate the destroy-helper function for a block closure object:
2061/// static void block_destroy_helper(block_t *theBlock);
2062///
2063/// Note that this destroys a heap-allocated block closure object;
2064/// it should not be confused with a 'byref destroy helper', which
2065/// destroys the heap-allocated contents of an individual __block
2066/// variable.
2067llvm::Constant *
2068CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) {
2069 std::string FuncName = getCopyDestroyHelperFuncName(
2070 Captures: blockInfo.SortedCaptures, BlockAlignment: blockInfo.BlockAlign,
2071 StrKind: CaptureStrKind::DisposeHelper, CGM);
2072
2073 if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(Name: FuncName))
2074 return Func;
2075
2076 ASTContext &C = getContext();
2077
2078 QualType ReturnTy = C.VoidTy;
2079
2080 FunctionArgList args;
2081 ImplicitParamDecl SrcDecl(C, C.VoidPtrTy, ImplicitParamKind::Other);
2082 args.push_back(Elt: &SrcDecl);
2083
2084 const CGFunctionInfo &FI =
2085 CGM.getTypes().arrangeBuiltinFunctionDeclaration(resultType: ReturnTy, args);
2086
2087 // FIXME: We'd like to put these into a mergable by content, with
2088 // internal linkage.
2089 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(Info: FI);
2090
2091 llvm::Function *Fn =
2092 llvm::Function::Create(Ty: LTy, Linkage: llvm::GlobalValue::LinkOnceODRLinkage,
2093 N: FuncName, M: &CGM.getModule());
2094 if (CGM.supportsCOMDAT())
2095 Fn->setComdat(CGM.getModule().getOrInsertComdat(Name: FuncName));
2096
2097 SmallVector<QualType, 1> ArgTys;
2098 ArgTys.push_back(Elt: C.VoidPtrTy);
2099
2100 setBlockHelperAttributesVisibility(CapturesNonExternalType: blockInfo.CapturesNonExternalType, Fn, FI,
2101 CGM);
2102 StartFunction(GD: GlobalDecl(), RetTy: ReturnTy, Fn, FnInfo: FI, Args: args);
2103 markAsIgnoreThreadCheckingAtRuntime(Fn);
2104
2105 auto AL = ApplyDebugLocation::CreateArtificial(CGF&: *this);
2106
2107 Address src = GetAddrOfLocalVar(VD: &SrcDecl);
2108 src = Address(Builder.CreateLoad(Addr: src), blockInfo.StructureType,
2109 blockInfo.BlockAlign);
2110
2111 CodeGenFunction::RunCleanupsScope cleanups(*this);
2112
2113 for (auto &capture : blockInfo.SortedCaptures) {
2114 if (capture.isConstantOrTrivial())
2115 continue;
2116
2117 const BlockDecl::Capture &CI = *capture.Cap;
2118 BlockFieldFlags flags = capture.DisposeFlags;
2119
2120 Address srcField = Builder.CreateStructGEP(Addr: src, Index: capture.getIndex());
2121
2122 pushCaptureCleanup(CaptureKind: capture.DisposeKind, Field: srcField,
2123 CaptureType: CI.getVariable()->getType(), Flags: flags,
2124 /*ForCopyHelper*/ false, Var: CI.getVariable(), CGF&: *this);
2125 }
2126
2127 cleanups.ForceCleanup();
2128
2129 FinishFunction();
2130
2131 return Fn;
2132}
2133
2134namespace {
2135
2136/// Emits the copy/dispose helper functions for a __block object of id type.
2137class ObjectByrefHelpers final : public BlockByrefHelpers {
2138 BlockFieldFlags Flags;
2139
2140public:
2141 ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
2142 : BlockByrefHelpers(alignment), Flags(flags) {}
2143
2144 void emitCopy(CodeGenFunction &CGF, Address destField,
2145 Address srcField) override {
2146 destField = destField.withElementType(ElemTy: CGF.Int8Ty);
2147
2148 srcField = srcField.withElementType(ElemTy: CGF.Int8PtrTy);
2149 llvm::Value *srcValue = CGF.Builder.CreateLoad(Addr: srcField);
2150
2151 unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
2152
2153 llvm::Value *flagsVal = llvm::ConstantInt::get(Ty: CGF.Int32Ty, V: flags);
2154 llvm::FunctionCallee fn = CGF.CGM.getBlockObjectAssign();
2155
2156 llvm::Value *args[] = {destField.emitRawPointer(CGF), srcValue, flagsVal};
2157 CGF.EmitNounwindRuntimeCall(callee: fn, args);
2158 }
2159
2160 void emitDispose(CodeGenFunction &CGF, Address field) override {
2161 field = field.withElementType(ElemTy: CGF.Int8PtrTy);
2162 llvm::Value *value = CGF.Builder.CreateLoad(Addr: field);
2163
2164 CGF.BuildBlockRelease(DeclPtr: value, flags: Flags | BLOCK_BYREF_CALLER, CanThrow: false);
2165 }
2166
2167 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2168 id.AddInteger(I: Flags.getBitMask());
2169 }
2170};
2171
2172/// Emits the copy/dispose helpers for an ARC __block __weak variable.
2173class ARCWeakByrefHelpers final : public BlockByrefHelpers {
2174public:
2175 ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2176
2177 void emitCopy(CodeGenFunction &CGF, Address destField,
2178 Address srcField) override {
2179 CGF.EmitARCMoveWeak(dst: destField, src: srcField);
2180 }
2181
2182 void emitDispose(CodeGenFunction &CGF, Address field) override {
2183 CGF.EmitARCDestroyWeak(addr: field);
2184 }
2185
2186 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2187 // 0 is distinguishable from all pointers and byref flags
2188 id.AddInteger(I: 0);
2189 }
2190};
2191
2192/// Emits the copy/dispose helpers for an ARC __block __strong variable
2193/// that's not of block-pointer type.
2194class ARCStrongByrefHelpers final : public BlockByrefHelpers {
2195public:
2196 ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2197
2198 void emitCopy(CodeGenFunction &CGF, Address destField,
2199 Address srcField) override {
2200 // Do a "move" by copying the value and then zeroing out the old
2201 // variable.
2202
2203 llvm::Value *value = CGF.Builder.CreateLoad(Addr: srcField);
2204
2205 llvm::Value *null =
2206 llvm::ConstantPointerNull::get(T: cast<llvm::PointerType>(Val: value->getType()));
2207
2208 if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
2209 CGF.Builder.CreateStore(Val: null, Addr: destField);
2210 CGF.EmitARCStoreStrongCall(addr: destField, value, /*ignored*/ resultIgnored: true);
2211 CGF.EmitARCStoreStrongCall(addr: srcField, value: null, /*ignored*/ resultIgnored: true);
2212 return;
2213 }
2214 CGF.Builder.CreateStore(Val: value, Addr: destField);
2215 CGF.Builder.CreateStore(Val: null, Addr: srcField);
2216 }
2217
2218 void emitDispose(CodeGenFunction &CGF, Address field) override {
2219 CGF.EmitARCDestroyStrong(addr: field, precise: ARCImpreciseLifetime);
2220 }
2221
2222 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2223 // 1 is distinguishable from all pointers and byref flags
2224 id.AddInteger(I: 1);
2225 }
2226};
2227
2228/// Emits the copy/dispose helpers for an ARC __block __strong
2229/// variable that's of block-pointer type.
2230class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
2231public:
2232 ARCStrongBlockByrefHelpers(CharUnits alignment)
2233 : BlockByrefHelpers(alignment) {}
2234
2235 void emitCopy(CodeGenFunction &CGF, Address destField,
2236 Address srcField) override {
2237 // Do the copy with objc_retainBlock; that's all that
2238 // _Block_object_assign would do anyway, and we'd have to pass the
2239 // right arguments to make sure it doesn't get no-op'ed.
2240 llvm::Value *oldValue = CGF.Builder.CreateLoad(Addr: srcField);
2241 llvm::Value *copy = CGF.EmitARCRetainBlock(value: oldValue, /*mandatory*/ true);
2242 CGF.Builder.CreateStore(Val: copy, Addr: destField);
2243 }
2244
2245 void emitDispose(CodeGenFunction &CGF, Address field) override {
2246 CGF.EmitARCDestroyStrong(addr: field, precise: ARCImpreciseLifetime);
2247 }
2248
2249 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2250 // 2 is distinguishable from all pointers and byref flags
2251 id.AddInteger(I: 2);
2252 }
2253};
2254
2255/// Emits the copy/dispose helpers for a __block variable with a
2256/// nontrivial copy constructor or destructor.
2257class CXXByrefHelpers final : public BlockByrefHelpers {
2258 QualType VarType;
2259 const Expr *CopyExpr;
2260
2261public:
2262 CXXByrefHelpers(CharUnits alignment, QualType type,
2263 const Expr *copyExpr)
2264 : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
2265
2266 bool needsCopy() const override { return CopyExpr != nullptr; }
2267 void emitCopy(CodeGenFunction &CGF, Address destField,
2268 Address srcField) override {
2269 if (!CopyExpr) return;
2270 CGF.EmitSynthesizedCXXCopyCtor(Dest: destField, Src: srcField, Exp: CopyExpr);
2271 }
2272
2273 void emitDispose(CodeGenFunction &CGF, Address field) override {
2274 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2275 CGF.PushDestructorCleanup(T: VarType, Addr: field);
2276 CGF.PopCleanupBlocks(OldCleanupStackSize: cleanupDepth);
2277 }
2278
2279 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2280 id.AddPointer(Ptr: VarType.getCanonicalType().getAsOpaquePtr());
2281 }
2282};
2283
2284/// Emits the copy/dispose helpers for a __block variable that is a non-trivial
2285/// C struct.
2286class NonTrivialCStructByrefHelpers final : public BlockByrefHelpers {
2287 QualType VarType;
2288
2289public:
2290 NonTrivialCStructByrefHelpers(CharUnits alignment, QualType type)
2291 : BlockByrefHelpers(alignment), VarType(type) {}
2292
2293 void emitCopy(CodeGenFunction &CGF, Address destField,
2294 Address srcField) override {
2295 CGF.callCStructMoveConstructor(Dst: CGF.MakeAddrLValue(Addr: destField, T: VarType),
2296 Src: CGF.MakeAddrLValue(Addr: srcField, T: VarType));
2297 }
2298
2299 bool needsDispose() const override {
2300 return VarType.isDestructedType();
2301 }
2302
2303 void emitDispose(CodeGenFunction &CGF, Address field) override {
2304 EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2305 CGF.pushDestroy(dtorKind: VarType.isDestructedType(), addr: field, type: VarType);
2306 CGF.PopCleanupBlocks(OldCleanupStackSize: cleanupDepth);
2307 }
2308
2309 void profileImpl(llvm::FoldingSetNodeID &id) const override {
2310 id.AddPointer(Ptr: VarType.getCanonicalType().getAsOpaquePtr());
2311 }
2312};
2313} // end anonymous namespace
2314
2315static llvm::Constant *
2316generateByrefCopyHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo,
2317 BlockByrefHelpers &generator) {
2318 ASTContext &Context = CGF.getContext();
2319
2320 QualType ReturnTy = Context.VoidTy;
2321
2322 FunctionArgList args;
2323 ImplicitParamDecl Dst(Context, Context.VoidPtrTy, ImplicitParamKind::Other);
2324 args.push_back(Elt: &Dst);
2325
2326 ImplicitParamDecl Src(Context, Context.VoidPtrTy, ImplicitParamKind::Other);
2327 args.push_back(Elt: &Src);
2328
2329 const CGFunctionInfo &FI =
2330 CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(resultType: ReturnTy, args);
2331
2332 llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(Info: FI);
2333
2334 // FIXME: We'd like to put these into a mergable by content, with
2335 // internal linkage.
2336 llvm::Function *Fn =
2337 llvm::Function::Create(Ty: LTy, Linkage: llvm::GlobalValue::InternalLinkage,
2338 N: "__Block_byref_object_copy_", M: &CGF.CGM.getModule());
2339
2340 SmallVector<QualType, 2> ArgTys;
2341 ArgTys.push_back(Elt: Context.VoidPtrTy);
2342 ArgTys.push_back(Elt: Context.VoidPtrTy);
2343
2344 CGF.CGM.SetInternalFunctionAttributes(GD: GlobalDecl(), F: Fn, FI);
2345
2346 CGF.StartFunction(GD: GlobalDecl(), RetTy: ReturnTy, Fn, FnInfo: FI, Args: args);
2347 // Create a scope with an artificial location for the body of this function.
2348 auto AL = ApplyDebugLocation::CreateArtificial(CGF);
2349
2350 if (generator.needsCopy()) {
2351 // dst->x
2352 Address destField = CGF.GetAddrOfLocalVar(VD: &Dst);
2353 destField = Address(CGF.Builder.CreateLoad(Addr: destField), byrefInfo.Type,
2354 byrefInfo.ByrefAlignment);
2355 destField =
2356 CGF.emitBlockByrefAddress(baseAddr: destField, info: byrefInfo, followForward: false, name: "dest-object");
2357
2358 // src->x
2359 Address srcField = CGF.GetAddrOfLocalVar(VD: &Src);
2360 srcField = Address(CGF.Builder.CreateLoad(Addr: srcField), byrefInfo.Type,
2361 byrefInfo.ByrefAlignment);
2362 srcField =
2363 CGF.emitBlockByrefAddress(baseAddr: srcField, info: byrefInfo, followForward: false, name: "src-object");
2364
2365 generator.emitCopy(CGF, dest: destField, src: srcField);
2366 }
2367
2368 CGF.FinishFunction();
2369
2370 return Fn;
2371}
2372
2373/// Build the copy helper for a __block variable.
2374static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
2375 const BlockByrefInfo &byrefInfo,
2376 BlockByrefHelpers &generator) {
2377 CodeGenFunction CGF(CGM);
2378 return generateByrefCopyHelper(CGF, byrefInfo, generator);
2379}
2380
2381/// Generate code for a __block variable's dispose helper.
2382static llvm::Constant *
2383generateByrefDisposeHelper(CodeGenFunction &CGF,
2384 const BlockByrefInfo &byrefInfo,
2385 BlockByrefHelpers &generator) {
2386 ASTContext &Context = CGF.getContext();
2387 QualType R = Context.VoidTy;
2388
2389 FunctionArgList args;
2390 ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2391 ImplicitParamKind::Other);
2392 args.push_back(Elt: &Src);
2393
2394 const CGFunctionInfo &FI =
2395 CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(resultType: R, args);
2396
2397 llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(Info: FI);
2398
2399 // FIXME: We'd like to put these into a mergable by content, with
2400 // internal linkage.
2401 llvm::Function *Fn =
2402 llvm::Function::Create(Ty: LTy, Linkage: llvm::GlobalValue::InternalLinkage,
2403 N: "__Block_byref_object_dispose_",
2404 M: &CGF.CGM.getModule());
2405
2406 SmallVector<QualType, 1> ArgTys;
2407 ArgTys.push_back(Elt: Context.VoidPtrTy);
2408
2409 CGF.CGM.SetInternalFunctionAttributes(GD: GlobalDecl(), F: Fn, FI);
2410
2411 CGF.StartFunction(GD: GlobalDecl(), RetTy: R, Fn, FnInfo: FI, Args: args);
2412 // Create a scope with an artificial location for the body of this function.
2413 auto AL = ApplyDebugLocation::CreateArtificial(CGF);
2414
2415 if (generator.needsDispose()) {
2416 Address addr = CGF.GetAddrOfLocalVar(VD: &Src);
2417 addr = Address(CGF.Builder.CreateLoad(Addr: addr), byrefInfo.Type,
2418 byrefInfo.ByrefAlignment);
2419 addr = CGF.emitBlockByrefAddress(baseAddr: addr, info: byrefInfo, followForward: false, name: "object");
2420
2421 generator.emitDispose(CGF, field: addr);
2422 }
2423
2424 CGF.FinishFunction();
2425
2426 return Fn;
2427}
2428
2429/// Build the dispose helper for a __block variable.
2430static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2431 const BlockByrefInfo &byrefInfo,
2432 BlockByrefHelpers &generator) {
2433 CodeGenFunction CGF(CGM);
2434 return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2435}
2436
2437/// Lazily build the copy and dispose helpers for a __block variable
2438/// with the given information.
2439template <class T>
2440static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2441 T &&generator) {
2442 llvm::FoldingSetNodeID id;
2443 generator.Profile(id);
2444
2445 void *insertPos;
2446 BlockByrefHelpers *node
2447 = CGM.ByrefHelpersCache.FindNodeOrInsertPos(ID: id, InsertPos&: insertPos);
2448 if (node) return static_cast<T*>(node);
2449
2450 generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2451 generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2452
2453 T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2454 CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2455 return copy;
2456}
2457
2458/// Build the copy and dispose helpers for the given __block variable
2459/// emission. Places the helpers in the global cache. Returns null
2460/// if no helpers are required.
2461BlockByrefHelpers *
2462CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2463 const AutoVarEmission &emission) {
2464 const VarDecl &var = *emission.Variable;
2465 assert(var.isEscapingByref() &&
2466 "only escaping __block variables need byref helpers");
2467
2468 QualType type = var.getType();
2469
2470 auto &byrefInfo = getBlockByrefInfo(var: &var);
2471
2472 // The alignment we care about for the purposes of uniquing byref
2473 // helpers is the alignment of the actual byref value field.
2474 CharUnits valueAlignment =
2475 byrefInfo.ByrefAlignment.alignmentAtOffset(offset: byrefInfo.FieldOffset);
2476
2477 if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2478 const Expr *copyExpr =
2479 CGM.getContext().getBlockVarCopyInit(VD: &var).getCopyExpr();
2480 if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2481
2482 return ::buildByrefHelpers(
2483 CGM, byrefInfo, generator: CXXByrefHelpers(valueAlignment, type, copyExpr));
2484 }
2485
2486 // If type is a non-trivial C struct type that is non-trivial to
2487 // destructly move or destroy, build the copy and dispose helpers.
2488 if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct ||
2489 type.isDestructedType() == QualType::DK_nontrivial_c_struct)
2490 return ::buildByrefHelpers(
2491 CGM, byrefInfo, generator: NonTrivialCStructByrefHelpers(valueAlignment, type));
2492
2493 // Otherwise, if we don't have a retainable type, there's nothing to do.
2494 // that the runtime does extra copies.
2495 if (!type->isObjCRetainableType()) return nullptr;
2496
2497 Qualifiers qs = type.getQualifiers();
2498
2499 // If we have lifetime, that dominates.
2500 if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2501 switch (lifetime) {
2502 case Qualifiers::OCL_None: llvm_unreachable("impossible");
2503
2504 // These are just bits as far as the runtime is concerned.
2505 case Qualifiers::OCL_ExplicitNone:
2506 case Qualifiers::OCL_Autoreleasing:
2507 return nullptr;
2508
2509 // Tell the runtime that this is ARC __weak, called by the
2510 // byref routines.
2511 case Qualifiers::OCL_Weak:
2512 return ::buildByrefHelpers(CGM, byrefInfo,
2513 generator: ARCWeakByrefHelpers(valueAlignment));
2514
2515 // ARC __strong __block variables need to be retained.
2516 case Qualifiers::OCL_Strong:
2517 // Block pointers need to be copied, and there's no direct
2518 // transfer possible.
2519 if (type->isBlockPointerType()) {
2520 return ::buildByrefHelpers(CGM, byrefInfo,
2521 generator: ARCStrongBlockByrefHelpers(valueAlignment));
2522
2523 // Otherwise, we transfer ownership of the retain from the stack
2524 // to the heap.
2525 } else {
2526 return ::buildByrefHelpers(CGM, byrefInfo,
2527 generator: ARCStrongByrefHelpers(valueAlignment));
2528 }
2529 }
2530 llvm_unreachable("fell out of lifetime switch!");
2531 }
2532
2533 BlockFieldFlags flags;
2534 if (type->isBlockPointerType()) {
2535 flags |= BLOCK_FIELD_IS_BLOCK;
2536 } else if (CGM.getContext().isObjCNSObjectType(Ty: type) ||
2537 type->isObjCObjectPointerType()) {
2538 flags |= BLOCK_FIELD_IS_OBJECT;
2539 } else {
2540 return nullptr;
2541 }
2542
2543 if (type.isObjCGCWeak())
2544 flags |= BLOCK_FIELD_IS_WEAK;
2545
2546 return ::buildByrefHelpers(CGM, byrefInfo,
2547 generator: ObjectByrefHelpers(valueAlignment, flags));
2548}
2549
2550Address CodeGenFunction::emitBlockByrefAddress(Address baseAddr,
2551 const VarDecl *var,
2552 bool followForward) {
2553 auto &info = getBlockByrefInfo(var);
2554 return emitBlockByrefAddress(baseAddr, info, followForward, name: var->getName());
2555}
2556
2557Address CodeGenFunction::emitBlockByrefAddress(Address baseAddr,
2558 const BlockByrefInfo &info,
2559 bool followForward,
2560 const llvm::Twine &name) {
2561 // Chase the forwarding address if requested.
2562 if (followForward) {
2563 Address forwardingAddr = Builder.CreateStructGEP(Addr: baseAddr, Index: 1, Name: "forwarding");
2564 baseAddr = Address(Builder.CreateLoad(Addr: forwardingAddr), info.Type,
2565 info.ByrefAlignment);
2566 }
2567
2568 return Builder.CreateStructGEP(Addr: baseAddr, Index: info.FieldIndex, Name: name);
2569}
2570
2571/// BuildByrefInfo - This routine changes a __block variable declared as T x
2572/// into:
2573///
2574/// struct {
2575/// void *__isa;
2576/// void *__forwarding;
2577/// int32_t __flags;
2578/// int32_t __size;
2579/// void *__copy_helper; // only if needed
2580/// void *__destroy_helper; // only if needed
2581/// void *__byref_variable_layout;// only if needed
2582/// char padding[X]; // only if needed
2583/// T x;
2584/// } x
2585///
2586const BlockByrefInfo &CodeGenFunction::getBlockByrefInfo(const VarDecl *D) {
2587 auto it = BlockByrefInfos.find(Val: D);
2588 if (it != BlockByrefInfos.end())
2589 return it->second;
2590
2591 llvm::StructType *byrefType =
2592 llvm::StructType::create(Context&: getLLVMContext(),
2593 Name: "struct.__block_byref_" + D->getNameAsString());
2594
2595 QualType Ty = D->getType();
2596
2597 CharUnits size;
2598 SmallVector<llvm::Type *, 8> types;
2599
2600 // void *__isa;
2601 types.push_back(Elt: VoidPtrTy);
2602 size += getPointerSize();
2603
2604 // void *__forwarding;
2605 types.push_back(Elt: VoidPtrTy);
2606 size += getPointerSize();
2607
2608 // int32_t __flags;
2609 types.push_back(Elt: Int32Ty);
2610 size += CharUnits::fromQuantity(Quantity: 4);
2611
2612 // int32_t __size;
2613 types.push_back(Elt: Int32Ty);
2614 size += CharUnits::fromQuantity(Quantity: 4);
2615
2616 // Note that this must match *exactly* the logic in buildByrefHelpers.
2617 bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2618 if (hasCopyAndDispose) {
2619 /// void *__copy_helper;
2620 types.push_back(Elt: VoidPtrTy);
2621 size += getPointerSize();
2622
2623 /// void *__destroy_helper;
2624 types.push_back(Elt: VoidPtrTy);
2625 size += getPointerSize();
2626 }
2627
2628 bool HasByrefExtendedLayout = false;
2629 Qualifiers::ObjCLifetime Lifetime = Qualifiers::OCL_None;
2630 if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2631 HasByrefExtendedLayout) {
2632 /// void *__byref_variable_layout;
2633 types.push_back(Elt: VoidPtrTy);
2634 size += CharUnits::fromQuantity(Quantity: PointerSizeInBytes);
2635 }
2636
2637 // T x;
2638 llvm::Type *varTy = ConvertTypeForMem(T: Ty);
2639
2640 bool packed = false;
2641 CharUnits varAlign = getContext().getDeclAlign(D);
2642 CharUnits varOffset = size.alignTo(Align: varAlign);
2643
2644 // We may have to insert padding.
2645 if (varOffset != size) {
2646 llvm::Type *paddingTy =
2647 llvm::ArrayType::get(ElementType: Int8Ty, NumElements: (varOffset - size).getQuantity());
2648
2649 types.push_back(Elt: paddingTy);
2650 size = varOffset;
2651
2652 // Conversely, we might have to prevent LLVM from inserting padding.
2653 } else if (CGM.getDataLayout().getABITypeAlign(Ty: varTy) >
2654 uint64_t(varAlign.getQuantity())) {
2655 packed = true;
2656 }
2657 types.push_back(Elt: varTy);
2658
2659 byrefType->setBody(Elements: types, isPacked: packed);
2660
2661 BlockByrefInfo info;
2662 info.Type = byrefType;
2663 info.FieldIndex = types.size() - 1;
2664 info.FieldOffset = varOffset;
2665 info.ByrefAlignment = std::max(a: varAlign, b: getPointerAlign());
2666
2667 auto pair = BlockByrefInfos.insert(KV: {D, info});
2668 assert(pair.second && "info was inserted recursively?");
2669 return pair.first->second;
2670}
2671
2672/// Initialize the structural components of a __block variable, i.e.
2673/// everything but the actual object.
2674void CodeGenFunction::emitByrefStructureInit(const AutoVarEmission &emission) {
2675 // Find the address of the local.
2676 Address addr = emission.Addr;
2677
2678 // That's an alloca of the byref structure type.
2679 llvm::StructType *byrefType = cast<llvm::StructType>(Val: addr.getElementType());
2680
2681 unsigned nextHeaderIndex = 0;
2682 CharUnits nextHeaderOffset;
2683 auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2684 const Twine &name) {
2685 auto fieldAddr = Builder.CreateStructGEP(Addr: addr, Index: nextHeaderIndex, Name: name);
2686 Builder.CreateStore(Val: value, Addr: fieldAddr);
2687
2688 nextHeaderIndex++;
2689 nextHeaderOffset += fieldSize;
2690 };
2691
2692 // Build the byref helpers if necessary. This is null if we don't need any.
2693 BlockByrefHelpers *helpers = buildByrefHelpers(byrefType&: *byrefType, emission);
2694
2695 const VarDecl &D = *emission.Variable;
2696 QualType type = D.getType();
2697
2698 bool HasByrefExtendedLayout = false;
2699 Qualifiers::ObjCLifetime ByrefLifetime = Qualifiers::OCL_None;
2700 bool ByRefHasLifetime =
2701 getContext().getByrefLifetime(Ty: type, Lifetime&: ByrefLifetime, HasByrefExtendedLayout);
2702
2703 llvm::Value *V;
2704
2705 // Initialize the 'isa', which is just 0 or 1.
2706 int isa = 0;
2707 if (type.isObjCGCWeak())
2708 isa = 1;
2709 V = Builder.CreateIntToPtr(V: Builder.getInt32(C: isa), DestTy: Int8PtrTy, Name: "isa");
2710 storeHeaderField(V, getPointerSize(), "byref.isa");
2711
2712 // Store the address of the variable into its own forwarding pointer.
2713 storeHeaderField(addr.emitRawPointer(CGF&: *this), getPointerSize(),
2714 "byref.forwarding");
2715
2716 // Blocks ABI:
2717 // c) the flags field is set to either 0 if no helper functions are
2718 // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2719 BlockFlags flags;
2720 if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2721 if (ByRefHasLifetime) {
2722 if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2723 else switch (ByrefLifetime) {
2724 case Qualifiers::OCL_Strong:
2725 flags |= BLOCK_BYREF_LAYOUT_STRONG;
2726 break;
2727 case Qualifiers::OCL_Weak:
2728 flags |= BLOCK_BYREF_LAYOUT_WEAK;
2729 break;
2730 case Qualifiers::OCL_ExplicitNone:
2731 flags |= BLOCK_BYREF_LAYOUT_UNRETAINED;
2732 break;
2733 case Qualifiers::OCL_None:
2734 if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2735 flags |= BLOCK_BYREF_LAYOUT_NON_OBJECT;
2736 break;
2737 default:
2738 break;
2739 }
2740 if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2741 printf(format: "\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2742 if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2743 printf(format: " BLOCK_BYREF_HAS_COPY_DISPOSE");
2744 if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2745 BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2746 if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2747 printf(format: " BLOCK_BYREF_LAYOUT_EXTENDED");
2748 if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2749 printf(format: " BLOCK_BYREF_LAYOUT_STRONG");
2750 if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2751 printf(format: " BLOCK_BYREF_LAYOUT_WEAK");
2752 if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2753 printf(format: " BLOCK_BYREF_LAYOUT_UNRETAINED");
2754 if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2755 printf(format: " BLOCK_BYREF_LAYOUT_NON_OBJECT");
2756 }
2757 printf(format: "\n");
2758 }
2759 }
2760 storeHeaderField(llvm::ConstantInt::get(Ty: IntTy, V: flags.getBitMask()),
2761 getIntSize(), "byref.flags");
2762
2763 CharUnits byrefSize = CGM.GetTargetTypeStoreSize(Ty: byrefType);
2764 V = llvm::ConstantInt::get(Ty: IntTy, V: byrefSize.getQuantity());
2765 storeHeaderField(V, getIntSize(), "byref.size");
2766
2767 if (helpers) {
2768 storeHeaderField(helpers->CopyHelper, getPointerSize(),
2769 "byref.copyHelper");
2770 storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2771 "byref.disposeHelper");
2772 }
2773
2774 if (ByRefHasLifetime && HasByrefExtendedLayout) {
2775 auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, T: type);
2776 storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2777 }
2778}
2779
2780void CodeGenFunction::BuildBlockRelease(llvm::Value *V, BlockFieldFlags flags,
2781 bool CanThrow) {
2782 llvm::FunctionCallee F = CGM.getBlockObjectDispose();
2783 llvm::Value *args[] = {V,
2784 llvm::ConstantInt::get(Ty: Int32Ty, V: flags.getBitMask())};
2785
2786 if (CanThrow)
2787 EmitRuntimeCallOrInvoke(callee: F, args);
2788 else
2789 EmitNounwindRuntimeCall(callee: F, args);
2790}
2791
2792void CodeGenFunction::enterByrefCleanup(CleanupKind Kind, Address Addr,
2793 BlockFieldFlags Flags,
2794 bool LoadBlockVarAddr, bool CanThrow) {
2795 EHStack.pushCleanup<CallBlockRelease>(Kind, A: Addr, A: Flags, A: LoadBlockVarAddr,
2796 A: CanThrow);
2797}
2798
2799/// Adjust the declaration of something from the blocks API.
2800static void configureBlocksRuntimeObject(CodeGenModule &CGM,
2801 llvm::Constant *C) {
2802 auto *GV = cast<llvm::GlobalValue>(Val: C->stripPointerCasts());
2803
2804 if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2805 const IdentifierInfo &II = CGM.getContext().Idents.get(Name: C->getName());
2806 TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
2807 DeclContext *DC = TranslationUnitDecl::castToDeclContext(D: TUDecl);
2808
2809 assert((isa<llvm::Function>(C->stripPointerCasts()) ||
2810 isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&
2811 "expected Function or GlobalVariable");
2812
2813 const NamedDecl *ND = nullptr;
2814 for (const auto *Result : DC->lookup(Name: &II))
2815 if ((ND = dyn_cast<FunctionDecl>(Val: Result)) ||
2816 (ND = dyn_cast<VarDecl>(Val: Result)))
2817 break;
2818
2819 // TODO: support static blocks runtime
2820 if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2821 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2822 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2823 } else {
2824 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2825 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2826 }
2827 }
2828
2829 if (CGM.getLangOpts().BlocksRuntimeOptional && GV->isDeclaration() &&
2830 GV->hasExternalLinkage())
2831 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2832
2833 CGM.setDSOLocal(GV);
2834}
2835
2836llvm::FunctionCallee CodeGenModule::getBlockObjectDispose() {
2837 if (BlockObjectDispose)
2838 return BlockObjectDispose;
2839
2840 llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2841 llvm::FunctionType *fty
2842 = llvm::FunctionType::get(Result: VoidTy, Params: args, isVarArg: false);
2843 BlockObjectDispose = CreateRuntimeFunction(Ty: fty, Name: "_Block_object_dispose");
2844 configureBlocksRuntimeObject(
2845 CGM&: *this, C: cast<llvm::Constant>(Val: BlockObjectDispose.getCallee()));
2846 return BlockObjectDispose;
2847}
2848
2849llvm::FunctionCallee CodeGenModule::getBlockObjectAssign() {
2850 if (BlockObjectAssign)
2851 return BlockObjectAssign;
2852
2853 llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
2854 llvm::FunctionType *fty
2855 = llvm::FunctionType::get(Result: VoidTy, Params: args, isVarArg: false);
2856 BlockObjectAssign = CreateRuntimeFunction(Ty: fty, Name: "_Block_object_assign");
2857 configureBlocksRuntimeObject(
2858 CGM&: *this, C: cast<llvm::Constant>(Val: BlockObjectAssign.getCallee()));
2859 return BlockObjectAssign;
2860}
2861
2862llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() {
2863 if (NSConcreteGlobalBlock)
2864 return NSConcreteGlobalBlock;
2865
2866 NSConcreteGlobalBlock = GetOrCreateLLVMGlobal(
2867 MangledName: "_NSConcreteGlobalBlock", Ty: Int8PtrTy, AddrSpace: LangAS::Default, D: nullptr);
2868 configureBlocksRuntimeObject(CGM&: *this, C: NSConcreteGlobalBlock);
2869 return NSConcreteGlobalBlock;
2870}
2871
2872llvm::Constant *CodeGenModule::getNSConcreteStackBlock() {
2873 if (NSConcreteStackBlock)
2874 return NSConcreteStackBlock;
2875
2876 NSConcreteStackBlock = GetOrCreateLLVMGlobal(
2877 MangledName: "_NSConcreteStackBlock", Ty: Int8PtrTy, AddrSpace: LangAS::Default, D: nullptr);
2878 configureBlocksRuntimeObject(CGM&: *this, C: NSConcreteStackBlock);
2879 return NSConcreteStackBlock;
2880}
2881