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CGBlocks.cpp
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1 //===--- CGBlocks.cpp - Emit LLVM Code for declarations ---------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This contains code to emit blocks.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CGBlocks.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/DeclObjC.h"
24 #include "llvm/ADT/SmallSet.h"
25 #include "llvm/IR/CallSite.h"
26 #include "llvm/IR/DataLayout.h"
27 #include "llvm/IR/Module.h"
28 #include <algorithm>
29 #include <cstdio>
30 
31 using namespace clang;
32 using namespace CodeGen;
33 
34 CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
35  : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
36  HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
37  LocalAddress(Address::invalid()), StructureType(nullptr), Block(block),
38  DominatingIP(nullptr) {
39 
40  // Skip asm prefix, if any. 'name' is usually taken directly from
41  // the mangled name of the enclosing function.
42  if (!name.empty() && name[0] == '\01')
43  name = name.substr(1);
44 }
45 
46 // Anchor the vtable to this translation unit.
48 
49 /// Build the given block as a global block.
50 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
51  const CGBlockInfo &blockInfo,
52  llvm::Constant *blockFn);
53 
54 /// Build the helper function to copy a block.
55 static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
56  const CGBlockInfo &blockInfo) {
57  return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
58 }
59 
60 /// Build the helper function to dispose of a block.
61 static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
62  const CGBlockInfo &blockInfo) {
63  return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
64 }
65 
66 /// buildBlockDescriptor - Build the block descriptor meta-data for a block.
67 /// buildBlockDescriptor is accessed from 5th field of the Block_literal
68 /// meta-data and contains stationary information about the block literal.
69 /// Its definition will have 4 (or optinally 6) words.
70 /// \code
71 /// struct Block_descriptor {
72 /// unsigned long reserved;
73 /// unsigned long size; // size of Block_literal metadata in bytes.
74 /// void *copy_func_helper_decl; // optional copy helper.
75 /// void *destroy_func_decl; // optioanl destructor helper.
76 /// void *block_method_encoding_address; // @encode for block literal signature.
77 /// void *block_layout_info; // encoding of captured block variables.
78 /// };
79 /// \endcode
80 static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
81  const CGBlockInfo &blockInfo) {
82  ASTContext &C = CGM.getContext();
83 
84  llvm::IntegerType *ulong =
85  cast<llvm::IntegerType>(CGM.getTypes().ConvertType(C.UnsignedLongTy));
86  llvm::PointerType *i8p = nullptr;
87  if (CGM.getLangOpts().OpenCL)
88  i8p =
89  llvm::Type::getInt8PtrTy(
91  else
92  i8p = CGM.VoidPtrTy;
93 
94  ConstantInitBuilder builder(CGM);
95  auto elements = builder.beginStruct();
96 
97  // reserved
98  elements.addInt(ulong, 0);
99 
100  // Size
101  // FIXME: What is the right way to say this doesn't fit? We should give
102  // a user diagnostic in that case. Better fix would be to change the
103  // API to size_t.
104  elements.addInt(ulong, blockInfo.BlockSize.getQuantity());
105 
106  // Optional copy/dispose helpers.
107  if (blockInfo.NeedsCopyDispose) {
108  // copy_func_helper_decl
109  elements.add(buildCopyHelper(CGM, blockInfo));
110 
111  // destroy_func_decl
112  elements.add(buildDisposeHelper(CGM, blockInfo));
113  }
114 
115  // Signature. Mandatory ObjC-style method descriptor @encode sequence.
116  std::string typeAtEncoding =
118  elements.add(llvm::ConstantExpr::getBitCast(
119  CGM.GetAddrOfConstantCString(typeAtEncoding).getPointer(), i8p));
120 
121  // GC layout.
122  if (C.getLangOpts().ObjC1) {
123  if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
124  elements.add(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
125  else
126  elements.add(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
127  }
128  else
129  elements.addNullPointer(i8p);
130 
131  unsigned AddrSpace = 0;
132  if (C.getLangOpts().OpenCL)
134 
135  llvm::GlobalVariable *global =
136  elements.finishAndCreateGlobal("__block_descriptor_tmp",
137  CGM.getPointerAlign(),
138  /*constant*/ true,
140  AddrSpace);
141 
142  return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
143 }
144 
145 /*
146  Purely notional variadic template describing the layout of a block.
147 
148  template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
149  struct Block_literal {
150  /// Initialized to one of:
151  /// extern void *_NSConcreteStackBlock[];
152  /// extern void *_NSConcreteGlobalBlock[];
153  ///
154  /// In theory, we could start one off malloc'ed by setting
155  /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
156  /// this isa:
157  /// extern void *_NSConcreteMallocBlock[];
158  struct objc_class *isa;
159 
160  /// These are the flags (with corresponding bit number) that the
161  /// compiler is actually supposed to know about.
162  /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
163  /// descriptor provides copy and dispose helper functions
164  /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
165  /// object with a nontrivial destructor or copy constructor
166  /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
167  /// as global memory
168  /// 29. BLOCK_USE_STRET - indicates that the block function
169  /// uses stret, which objc_msgSend needs to know about
170  /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
171  /// @encoded signature string
172  /// And we're not supposed to manipulate these:
173  /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
174  /// to malloc'ed memory
175  /// 27. BLOCK_IS_GC - indicates that the block has been moved to
176  /// to GC-allocated memory
177  /// Additionally, the bottom 16 bits are a reference count which
178  /// should be zero on the stack.
179  int flags;
180 
181  /// Reserved; should be zero-initialized.
182  int reserved;
183 
184  /// Function pointer generated from block literal.
185  _ResultType (*invoke)(Block_literal *, _ParamTypes...);
186 
187  /// Block description metadata generated from block literal.
188  struct Block_descriptor *block_descriptor;
189 
190  /// Captured values follow.
191  _CapturesTypes captures...;
192  };
193  */
194 
195 namespace {
196  /// A chunk of data that we actually have to capture in the block.
197  struct BlockLayoutChunk {
198  CharUnits Alignment;
199  CharUnits Size;
200  Qualifiers::ObjCLifetime Lifetime;
201  const BlockDecl::Capture *Capture; // null for 'this'
202  llvm::Type *Type;
203  QualType FieldType;
204 
205  BlockLayoutChunk(CharUnits align, CharUnits size,
206  Qualifiers::ObjCLifetime lifetime,
207  const BlockDecl::Capture *capture,
208  llvm::Type *type, QualType fieldType)
209  : Alignment(align), Size(size), Lifetime(lifetime),
210  Capture(capture), Type(type), FieldType(fieldType) {}
211 
212  /// Tell the block info that this chunk has the given field index.
213  void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
214  if (!Capture) {
215  info.CXXThisIndex = index;
216  info.CXXThisOffset = offset;
217  } else {
218  auto C = CGBlockInfo::Capture::makeIndex(index, offset, FieldType);
219  info.Captures.insert({Capture->getVariable(), C});
220  }
221  }
222  };
223 
224  /// Order by 1) all __strong together 2) next, all byfref together 3) next,
225  /// all __weak together. Preserve descending alignment in all situations.
226  bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
227  if (left.Alignment != right.Alignment)
228  return left.Alignment > right.Alignment;
229 
230  auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
231  if (chunk.Capture && chunk.Capture->isByRef())
232  return 1;
233  if (chunk.Lifetime == Qualifiers::OCL_Strong)
234  return 0;
235  if (chunk.Lifetime == Qualifiers::OCL_Weak)
236  return 2;
237  return 3;
238  };
239 
240  return getPrefOrder(left) < getPrefOrder(right);
241  }
242 } // end anonymous namespace
243 
244 /// Determines if the given type is safe for constant capture in C++.
246  const RecordType *recordType =
248 
249  // Only records can be unsafe.
250  if (!recordType) return true;
251 
252  const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
253 
254  // Maintain semantics for classes with non-trivial dtors or copy ctors.
255  if (!record->hasTrivialDestructor()) return false;
256  if (record->hasNonTrivialCopyConstructor()) return false;
257 
258  // Otherwise, we just have to make sure there aren't any mutable
259  // fields that might have changed since initialization.
260  return !record->hasMutableFields();
261 }
262 
263 /// It is illegal to modify a const object after initialization.
264 /// Therefore, if a const object has a constant initializer, we don't
265 /// actually need to keep storage for it in the block; we'll just
266 /// rematerialize it at the start of the block function. This is
267 /// acceptable because we make no promises about address stability of
268 /// captured variables.
269 static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
270  CodeGenFunction *CGF,
271  const VarDecl *var) {
272  // Return if this is a function parameter. We shouldn't try to
273  // rematerialize default arguments of function parameters.
274  if (isa<ParmVarDecl>(var))
275  return nullptr;
276 
277  QualType type = var->getType();
278 
279  // We can only do this if the variable is const.
280  if (!type.isConstQualified()) return nullptr;
281 
282  // Furthermore, in C++ we have to worry about mutable fields:
283  // C++ [dcl.type.cv]p4:
284  // Except that any class member declared mutable can be
285  // modified, any attempt to modify a const object during its
286  // lifetime results in undefined behavior.
287  if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
288  return nullptr;
289 
290  // If the variable doesn't have any initializer (shouldn't this be
291  // invalid?), it's not clear what we should do. Maybe capture as
292  // zero?
293  const Expr *init = var->getInit();
294  if (!init) return nullptr;
295 
296  return ConstantEmitter(CGM, CGF).tryEmitAbstractForInitializer(*var);
297 }
298 
299 /// Get the low bit of a nonzero character count. This is the
300 /// alignment of the nth byte if the 0th byte is universally aligned.
302  return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
303 }
304 
306  SmallVectorImpl<llvm::Type*> &elementTypes) {
307 
308  assert(elementTypes.empty());
309  if (CGM.getLangOpts().OpenCL) {
310  // The header is basically 'struct { int; int; generic void *;
311  // custom_fields; }'. Assert that struct is packed.
312  auto GenericAS =
314  auto GenPtrAlign =
315  CharUnits::fromQuantity(CGM.getTarget().getPointerAlign(GenericAS) / 8);
316  auto GenPtrSize =
317  CharUnits::fromQuantity(CGM.getTarget().getPointerWidth(GenericAS) / 8);
318  assert(CGM.getIntSize() <= GenPtrSize);
319  assert(CGM.getIntAlign() <= GenPtrAlign);
320  assert((2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign));
321  elementTypes.push_back(CGM.IntTy); /* total size */
322  elementTypes.push_back(CGM.IntTy); /* align */
323  elementTypes.push_back(
324  CGM.getOpenCLRuntime()
325  .getGenericVoidPointerType()); /* invoke function */
326  unsigned Offset =
327  2 * CGM.getIntSize().getQuantity() + GenPtrSize.getQuantity();
328  unsigned BlockAlign = GenPtrAlign.getQuantity();
329  if (auto *Helper =
331  for (auto I : Helper->getCustomFieldTypes()) /* custom fields */ {
332  // TargetOpenCLBlockHelp needs to make sure the struct is packed.
333  // If necessary, add padding fields to the custom fields.
334  unsigned Align = CGM.getDataLayout().getABITypeAlignment(I);
335  if (BlockAlign < Align)
336  BlockAlign = Align;
337  assert(Offset % Align == 0);
338  Offset += CGM.getDataLayout().getTypeAllocSize(I);
339  elementTypes.push_back(I);
340  }
341  }
342  info.BlockAlign = CharUnits::fromQuantity(BlockAlign);
343  info.BlockSize = CharUnits::fromQuantity(Offset);
344  } else {
345  // The header is basically 'struct { void *; int; int; void *; void *; }'.
346  // Assert that that struct is packed.
347  assert(CGM.getIntSize() <= CGM.getPointerSize());
348  assert(CGM.getIntAlign() <= CGM.getPointerAlign());
349  assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()));
350  info.BlockAlign = CGM.getPointerAlign();
351  info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
352  elementTypes.push_back(CGM.VoidPtrTy);
353  elementTypes.push_back(CGM.IntTy);
354  elementTypes.push_back(CGM.IntTy);
355  elementTypes.push_back(CGM.VoidPtrTy);
356  elementTypes.push_back(CGM.getBlockDescriptorType());
357  }
358 }
359 
361  const BlockDecl::Capture &CI) {
362  const VarDecl *VD = CI.getVariable();
363 
364  // If the variable is captured by an enclosing block or lambda expression,
365  // use the type of the capture field.
366  if (CGF.BlockInfo && CI.isNested())
367  return CGF.BlockInfo->getCapture(VD).fieldType();
368  if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
369  return FD->getType();
370  return VD->getType();
371 }
372 
373 /// Compute the layout of the given block. Attempts to lay the block
374 /// out with minimal space requirements.
376  CGBlockInfo &info) {
377  ASTContext &C = CGM.getContext();
378  const BlockDecl *block = info.getBlockDecl();
379 
380  SmallVector<llvm::Type*, 8> elementTypes;
381  initializeForBlockHeader(CGM, info, elementTypes);
382  bool hasNonConstantCustomFields = false;
383  if (auto *OpenCLHelper =
385  hasNonConstantCustomFields =
386  !OpenCLHelper->areAllCustomFieldValuesConstant(info);
387  if (!block->hasCaptures() && !hasNonConstantCustomFields) {
388  info.StructureType =
389  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
390  info.CanBeGlobal = true;
391  return;
392  }
393  else if (C.getLangOpts().ObjC1 &&
394  CGM.getLangOpts().getGC() == LangOptions::NonGC)
395  info.HasCapturedVariableLayout = true;
396 
397  // Collect the layout chunks.
399  layout.reserve(block->capturesCXXThis() +
400  (block->capture_end() - block->capture_begin()));
401 
402  CharUnits maxFieldAlign;
403 
404  // First, 'this'.
405  if (block->capturesCXXThis()) {
406  assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&
407  "Can't capture 'this' outside a method");
408  QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType(C);
409 
410  // Theoretically, this could be in a different address space, so
411  // don't assume standard pointer size/align.
412  llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
413  std::pair<CharUnits,CharUnits> tinfo
414  = CGM.getContext().getTypeInfoInChars(thisType);
415  maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
416 
417  layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
419  nullptr, llvmType, thisType));
420  }
421 
422  // Next, all the block captures.
423  for (const auto &CI : block->captures()) {
424  const VarDecl *variable = CI.getVariable();
425 
426  if (CI.isByRef()) {
427  // We have to copy/dispose of the __block reference.
428  info.NeedsCopyDispose = true;
429 
430  // Just use void* instead of a pointer to the byref type.
431  CharUnits align = CGM.getPointerAlign();
432  maxFieldAlign = std::max(maxFieldAlign, align);
433 
434  layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
436  CGM.VoidPtrTy, variable->getType()));
437  continue;
438  }
439 
440  // Otherwise, build a layout chunk with the size and alignment of
441  // the declaration.
442  if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
443  info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
444  continue;
445  }
446 
447  // If we have a lifetime qualifier, honor it for capture purposes.
448  // That includes *not* copying it if it's __unsafe_unretained.
449  Qualifiers::ObjCLifetime lifetime =
450  variable->getType().getObjCLifetime();
451  if (lifetime) {
452  switch (lifetime) {
453  case Qualifiers::OCL_None: llvm_unreachable("impossible");
456  break;
457 
460  info.NeedsCopyDispose = true;
461  }
462 
463  // Block pointers require copy/dispose. So do Objective-C pointers.
464  } else if (variable->getType()->isObjCRetainableType()) {
465  // But honor the inert __unsafe_unretained qualifier, which doesn't
466  // actually make it into the type system.
467  if (variable->getType()->isObjCInertUnsafeUnretainedType()) {
468  lifetime = Qualifiers::OCL_ExplicitNone;
469  } else {
470  info.NeedsCopyDispose = true;
471  // used for mrr below.
472  lifetime = Qualifiers::OCL_Strong;
473  }
474 
475  // So do types that require non-trivial copy construction.
476  } else if (CI.hasCopyExpr()) {
477  info.NeedsCopyDispose = true;
478  info.HasCXXObject = true;
479 
480  // And so do types with destructors.
481  } else if (CGM.getLangOpts().CPlusPlus) {
482  if (const CXXRecordDecl *record =
483  variable->getType()->getAsCXXRecordDecl()) {
484  if (!record->hasTrivialDestructor()) {
485  info.HasCXXObject = true;
486  info.NeedsCopyDispose = true;
487  }
488  }
489  }
490 
491  QualType VT = getCaptureFieldType(*CGF, CI);
492  CharUnits size = C.getTypeSizeInChars(VT);
493  CharUnits align = C.getDeclAlign(variable);
494 
495  maxFieldAlign = std::max(maxFieldAlign, align);
496 
497  llvm::Type *llvmType =
498  CGM.getTypes().ConvertTypeForMem(VT);
499 
500  layout.push_back(
501  BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
502  }
503 
504  // If that was everything, we're done here.
505  if (layout.empty()) {
506  info.StructureType =
507  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
508  info.CanBeGlobal = true;
509  return;
510  }
511 
512  // Sort the layout by alignment. We have to use a stable sort here
513  // to get reproducible results. There should probably be an
514  // llvm::array_pod_stable_sort.
515  std::stable_sort(layout.begin(), layout.end());
516 
517  // Needed for blocks layout info.
520 
521  CharUnits &blockSize = info.BlockSize;
522  info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
523 
524  // Assuming that the first byte in the header is maximally aligned,
525  // get the alignment of the first byte following the header.
526  CharUnits endAlign = getLowBit(blockSize);
527 
528  // If the end of the header isn't satisfactorily aligned for the
529  // maximum thing, look for things that are okay with the header-end
530  // alignment, and keep appending them until we get something that's
531  // aligned right. This algorithm is only guaranteed optimal if
532  // that condition is satisfied at some point; otherwise we can get
533  // things like:
534  // header // next byte has alignment 4
535  // something_with_size_5; // next byte has alignment 1
536  // something_with_alignment_8;
537  // which has 7 bytes of padding, as opposed to the naive solution
538  // which might have less (?).
539  if (endAlign < maxFieldAlign) {
541  li = layout.begin() + 1, le = layout.end();
542 
543  // Look for something that the header end is already
544  // satisfactorily aligned for.
545  for (; li != le && endAlign < li->Alignment; ++li)
546  ;
547 
548  // If we found something that's naturally aligned for the end of
549  // the header, keep adding things...
550  if (li != le) {
552  for (; li != le; ++li) {
553  assert(endAlign >= li->Alignment);
554 
555  li->setIndex(info, elementTypes.size(), blockSize);
556  elementTypes.push_back(li->Type);
557  blockSize += li->Size;
558  endAlign = getLowBit(blockSize);
559 
560  // ...until we get to the alignment of the maximum field.
561  if (endAlign >= maxFieldAlign) {
562  break;
563  }
564  }
565  // Don't re-append everything we just appended.
566  layout.erase(first, li);
567  }
568  }
569 
570  assert(endAlign == getLowBit(blockSize));
571 
572  // At this point, we just have to add padding if the end align still
573  // isn't aligned right.
574  if (endAlign < maxFieldAlign) {
575  CharUnits newBlockSize = blockSize.alignTo(maxFieldAlign);
576  CharUnits padding = newBlockSize - blockSize;
577 
578  // If we haven't yet added any fields, remember that there was an
579  // initial gap; this need to go into the block layout bit map.
580  if (blockSize == info.BlockHeaderForcedGapOffset) {
581  info.BlockHeaderForcedGapSize = padding;
582  }
583 
584  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
585  padding.getQuantity()));
586  blockSize = newBlockSize;
587  endAlign = getLowBit(blockSize); // might be > maxFieldAlign
588  }
589 
590  assert(endAlign >= maxFieldAlign);
591  assert(endAlign == getLowBit(blockSize));
592  // Slam everything else on now. This works because they have
593  // strictly decreasing alignment and we expect that size is always a
594  // multiple of alignment.
596  li = layout.begin(), le = layout.end(); li != le; ++li) {
597  if (endAlign < li->Alignment) {
598  // size may not be multiple of alignment. This can only happen with
599  // an over-aligned variable. We will be adding a padding field to
600  // make the size be multiple of alignment.
601  CharUnits padding = li->Alignment - endAlign;
602  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
603  padding.getQuantity()));
604  blockSize += padding;
605  endAlign = getLowBit(blockSize);
606  }
607  assert(endAlign >= li->Alignment);
608  li->setIndex(info, elementTypes.size(), blockSize);
609  elementTypes.push_back(li->Type);
610  blockSize += li->Size;
611  endAlign = getLowBit(blockSize);
612  }
613 
614  info.StructureType =
615  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
616 }
617 
618 /// Enter the scope of a block. This should be run at the entrance to
619 /// a full-expression so that the block's cleanups are pushed at the
620 /// right place in the stack.
621 static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
622  assert(CGF.HaveInsertPoint());
623 
624  // Allocate the block info and place it at the head of the list.
625  CGBlockInfo &blockInfo =
626  *new CGBlockInfo(block, CGF.CurFn->getName());
627  blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
628  CGF.FirstBlockInfo = &blockInfo;
629 
630  // Compute information about the layout, etc., of this block,
631  // pushing cleanups as necessary.
632  computeBlockInfo(CGF.CGM, &CGF, blockInfo);
633 
634  // Nothing else to do if it can be global.
635  if (blockInfo.CanBeGlobal) return;
636 
637  // Make the allocation for the block.
638  blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
639  blockInfo.BlockAlign, "block");
640 
641  // If there are cleanups to emit, enter them (but inactive).
642  if (!blockInfo.NeedsCopyDispose) return;
643 
644  // Walk through the captures (in order) and find the ones not
645  // captured by constant.
646  for (const auto &CI : block->captures()) {
647  // Ignore __block captures; there's nothing special in the
648  // on-stack block that we need to do for them.
649  if (CI.isByRef()) continue;
650 
651  // Ignore variables that are constant-captured.
652  const VarDecl *variable = CI.getVariable();
653  CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
654  if (capture.isConstant()) continue;
655 
656  // Ignore objects that aren't destructed.
657  QualType VT = getCaptureFieldType(CGF, CI);
659  if (dtorKind == QualType::DK_none) continue;
660 
661  CodeGenFunction::Destroyer *destroyer;
662 
663  // Block captures count as local values and have imprecise semantics.
664  // They also can't be arrays, so need to worry about that.
665  //
666  // For const-qualified captures, emit clang.arc.use to ensure the captured
667  // object doesn't get released while we are still depending on its validity
668  // within the block.
669  if (VT.isConstQualified() &&
671  CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
672  assert(CGF.CGM.getLangOpts().ObjCAutoRefCount &&
673  "expected ObjC ARC to be enabled");
675  } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
677  } else {
678  destroyer = CGF.getDestroyer(dtorKind);
679  }
680 
681  // GEP down to the address.
682  Address addr = CGF.Builder.CreateStructGEP(blockInfo.LocalAddress,
683  capture.getIndex(),
684  capture.getOffset());
685 
686  // We can use that GEP as the dominating IP.
687  if (!blockInfo.DominatingIP)
688  blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
689 
690  CleanupKind cleanupKind = InactiveNormalCleanup;
691  bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
692  if (useArrayEHCleanup)
693  cleanupKind = InactiveNormalAndEHCleanup;
694 
695  CGF.pushDestroy(cleanupKind, addr, VT,
696  destroyer, useArrayEHCleanup);
697 
698  // Remember where that cleanup was.
699  capture.setCleanup(CGF.EHStack.stable_begin());
700  }
701 }
702 
703 /// Enter a full-expression with a non-trivial number of objects to
704 /// clean up. This is in this file because, at the moment, the only
705 /// kind of cleanup object is a BlockDecl*.
707  assert(E->getNumObjects() != 0);
710  i = cleanups.begin(), e = cleanups.end(); i != e; ++i) {
711  enterBlockScope(*this, *i);
712  }
713 }
714 
715 /// Find the layout for the given block in a linked list and remove it.
717  const BlockDecl *block) {
718  while (true) {
719  assert(head && *head);
720  CGBlockInfo *cur = *head;
721 
722  // If this is the block we're looking for, splice it out of the list.
723  if (cur->getBlockDecl() == block) {
724  *head = cur->NextBlockInfo;
725  return cur;
726  }
727 
728  head = &cur->NextBlockInfo;
729  }
730 }
731 
732 /// Destroy a chain of block layouts.
734  assert(head && "destroying an empty chain");
735  do {
736  CGBlockInfo *cur = head;
737  head = cur->NextBlockInfo;
738  delete cur;
739  } while (head != nullptr);
740 }
741 
742 /// Emit a block literal expression in the current function.
744  llvm::Function **InvokeF) {
745  // If the block has no captures, we won't have a pre-computed
746  // layout for it.
747  if (!blockExpr->getBlockDecl()->hasCaptures()) {
748  // The block literal is emitted as a global variable, and the block invoke
749  // function has to be extracted from its initializer.
750  if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr)) {
751  if (InvokeF) {
752  auto *GV = cast<llvm::GlobalVariable>(
753  cast<llvm::Constant>(Block)->stripPointerCasts());
754  auto *BlockInit = cast<llvm::ConstantStruct>(GV->getInitializer());
755  *InvokeF = cast<llvm::Function>(
756  BlockInit->getAggregateElement(2)->stripPointerCasts());
757  }
758  return Block;
759  }
760  CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
761  computeBlockInfo(CGM, this, blockInfo);
762  blockInfo.BlockExpression = blockExpr;
763  return EmitBlockLiteral(blockInfo, InvokeF);
764  }
765 
766  // Find the block info for this block and take ownership of it.
767  std::unique_ptr<CGBlockInfo> blockInfo;
768  blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
769  blockExpr->getBlockDecl()));
770 
771  blockInfo->BlockExpression = blockExpr;
772  return EmitBlockLiteral(*blockInfo, InvokeF);
773 }
774 
776  llvm::Function **InvokeF) {
777  bool IsOpenCL = CGM.getContext().getLangOpts().OpenCL;
778  auto GenVoidPtrTy =
779  IsOpenCL ? CGM.getOpenCLRuntime().getGenericVoidPointerType() : VoidPtrTy;
780  LangAS GenVoidPtrAddr = IsOpenCL ? LangAS::opencl_generic : LangAS::Default;
781  auto GenVoidPtrSize = CharUnits::fromQuantity(
783  CGM.getContext().getTargetAddressSpace(GenVoidPtrAddr)) /
784  8);
785  // Using the computed layout, generate the actual block function.
786  bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
787  auto *InvokeFn = CodeGenFunction(CGM, true).GenerateBlockFunction(
788  CurGD, blockInfo, LocalDeclMap, isLambdaConv, blockInfo.CanBeGlobal);
789  if (InvokeF)
790  *InvokeF = InvokeFn;
791  auto *blockFn = llvm::ConstantExpr::getPointerCast(InvokeFn, GenVoidPtrTy);
792 
793  // If there is nothing to capture, we can emit this as a global block.
794  if (blockInfo.CanBeGlobal)
795  return CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression);
796 
797  // Otherwise, we have to emit this as a local block.
798 
799  Address blockAddr = blockInfo.LocalAddress;
800  assert(blockAddr.isValid() && "block has no address!");
801 
802  llvm::Constant *isa;
803  llvm::Constant *descriptor;
804  BlockFlags flags;
805  if (!IsOpenCL) {
806  isa = llvm::ConstantExpr::getBitCast(CGM.getNSConcreteStackBlock(),
807  VoidPtrTy);
808 
809  // Build the block descriptor.
810  descriptor = buildBlockDescriptor(CGM, blockInfo);
811 
812  // Compute the initial on-stack block flags.
813  flags = BLOCK_HAS_SIGNATURE;
814  if (blockInfo.HasCapturedVariableLayout)
815  flags |= BLOCK_HAS_EXTENDED_LAYOUT;
816  if (blockInfo.NeedsCopyDispose)
817  flags |= BLOCK_HAS_COPY_DISPOSE;
818  if (blockInfo.HasCXXObject)
819  flags |= BLOCK_HAS_CXX_OBJ;
820  if (blockInfo.UsesStret)
821  flags |= BLOCK_USE_STRET;
822  }
823 
824  auto projectField =
825  [&](unsigned index, CharUnits offset, const Twine &name) -> Address {
826  return Builder.CreateStructGEP(blockAddr, index, offset, name);
827  };
828  auto storeField =
829  [&](llvm::Value *value, unsigned index, CharUnits offset,
830  const Twine &name) {
831  Builder.CreateStore(value, projectField(index, offset, name));
832  };
833 
834  // Initialize the block header.
835  {
836  // We assume all the header fields are densely packed.
837  unsigned index = 0;
838  CharUnits offset;
839  auto addHeaderField =
840  [&](llvm::Value *value, CharUnits size, const Twine &name) {
841  storeField(value, index, offset, name);
842  offset += size;
843  index++;
844  };
845 
846  if (!IsOpenCL) {
847  addHeaderField(isa, getPointerSize(), "block.isa");
848  addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
849  getIntSize(), "block.flags");
850  addHeaderField(llvm::ConstantInt::get(IntTy, 0), getIntSize(),
851  "block.reserved");
852  } else {
853  addHeaderField(
854  llvm::ConstantInt::get(IntTy, blockInfo.BlockSize.getQuantity()),
855  getIntSize(), "block.size");
856  addHeaderField(
857  llvm::ConstantInt::get(IntTy, blockInfo.BlockAlign.getQuantity()),
858  getIntSize(), "block.align");
859  }
860  addHeaderField(blockFn, GenVoidPtrSize, "block.invoke");
861  if (!IsOpenCL)
862  addHeaderField(descriptor, getPointerSize(), "block.descriptor");
863  else if (auto *Helper =
865  for (auto I : Helper->getCustomFieldValues(*this, blockInfo)) {
866  addHeaderField(
867  I.first,
869  CGM.getDataLayout().getTypeAllocSize(I.first->getType())),
870  I.second);
871  }
872  }
873  }
874 
875  // Finally, capture all the values into the block.
876  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
877 
878  // First, 'this'.
879  if (blockDecl->capturesCXXThis()) {
880  Address addr = projectField(blockInfo.CXXThisIndex, blockInfo.CXXThisOffset,
881  "block.captured-this.addr");
882  Builder.CreateStore(LoadCXXThis(), addr);
883  }
884 
885  // Next, captured variables.
886  for (const auto &CI : blockDecl->captures()) {
887  const VarDecl *variable = CI.getVariable();
888  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
889 
890  // Ignore constant captures.
891  if (capture.isConstant()) continue;
892 
893  QualType type = capture.fieldType();
894 
895  // This will be a [[type]]*, except that a byref entry will just be
896  // an i8**.
897  Address blockField =
898  projectField(capture.getIndex(), capture.getOffset(), "block.captured");
899 
900  // Compute the address of the thing we're going to move into the
901  // block literal.
902  Address src = Address::invalid();
903 
904  if (blockDecl->isConversionFromLambda()) {
905  // The lambda capture in a lambda's conversion-to-block-pointer is
906  // special; we'll simply emit it directly.
907  src = Address::invalid();
908  } else if (CI.isByRef()) {
909  if (BlockInfo && CI.isNested()) {
910  // We need to use the capture from the enclosing block.
911  const CGBlockInfo::Capture &enclosingCapture =
912  BlockInfo->getCapture(variable);
913 
914  // This is a [[type]]*, except that a byref entry wil just be an i8**.
915  src = Builder.CreateStructGEP(LoadBlockStruct(),
916  enclosingCapture.getIndex(),
917  enclosingCapture.getOffset(),
918  "block.capture.addr");
919  } else {
920  auto I = LocalDeclMap.find(variable);
921  assert(I != LocalDeclMap.end());
922  src = I->second;
923  }
924  } else {
925  DeclRefExpr declRef(const_cast<VarDecl *>(variable),
926  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
928  SourceLocation());
929  src = EmitDeclRefLValue(&declRef).getAddress();
930  };
931 
932  // For byrefs, we just write the pointer to the byref struct into
933  // the block field. There's no need to chase the forwarding
934  // pointer at this point, since we're building something that will
935  // live a shorter life than the stack byref anyway.
936  if (CI.isByRef()) {
937  // Get a void* that points to the byref struct.
938  llvm::Value *byrefPointer;
939  if (CI.isNested())
940  byrefPointer = Builder.CreateLoad(src, "byref.capture");
941  else
942  byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
943 
944  // Write that void* into the capture field.
945  Builder.CreateStore(byrefPointer, blockField);
946 
947  // If we have a copy constructor, evaluate that into the block field.
948  } else if (const Expr *copyExpr = CI.getCopyExpr()) {
949  if (blockDecl->isConversionFromLambda()) {
950  // If we have a lambda conversion, emit the expression
951  // directly into the block instead.
952  AggValueSlot Slot =
953  AggValueSlot::forAddr(blockField, Qualifiers(),
957  EmitAggExpr(copyExpr, Slot);
958  } else {
959  EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
960  }
961 
962  // If it's a reference variable, copy the reference into the block field.
963  } else if (type->isReferenceType()) {
964  Builder.CreateStore(src.getPointer(), blockField);
965 
966  // If type is const-qualified, copy the value into the block field.
967  } else if (type.isConstQualified() &&
969  CGM.getCodeGenOpts().OptimizationLevel != 0) {
970  llvm::Value *value = Builder.CreateLoad(src, "captured");
971  Builder.CreateStore(value, blockField);
972 
973  // If this is an ARC __strong block-pointer variable, don't do a
974  // block copy.
975  //
976  // TODO: this can be generalized into the normal initialization logic:
977  // we should never need to do a block-copy when initializing a local
978  // variable, because the local variable's lifetime should be strictly
979  // contained within the stack block's.
980  } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
981  type->isBlockPointerType()) {
982  // Load the block and do a simple retain.
983  llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
984  value = EmitARCRetainNonBlock(value);
985 
986  // Do a primitive store to the block field.
987  Builder.CreateStore(value, blockField);
988 
989  // Otherwise, fake up a POD copy into the block field.
990  } else {
991  // Fake up a new variable so that EmitScalarInit doesn't think
992  // we're referring to the variable in its own initializer.
993  ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
995 
996  // We use one of these or the other depending on whether the
997  // reference is nested.
998  DeclRefExpr declRef(const_cast<VarDecl *>(variable),
999  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1001 
1002  ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
1003  &declRef, VK_RValue);
1004  // FIXME: Pass a specific location for the expr init so that the store is
1005  // attributed to a reasonable location - otherwise it may be attributed to
1006  // locations of subexpressions in the initialization.
1007  EmitExprAsInit(&l2r, &BlockFieldPseudoVar,
1008  MakeAddrLValue(blockField, type, AlignmentSource::Decl),
1009  /*captured by init*/ false);
1010  }
1011 
1012  // Activate the cleanup if layout pushed one.
1013  if (!CI.isByRef()) {
1015  if (cleanup.isValid())
1016  ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
1017  }
1018  }
1019 
1020  // Cast to the converted block-pointer type, which happens (somewhat
1021  // unfortunately) to be a pointer to function type.
1022  llvm::Value *result = Builder.CreatePointerCast(
1023  blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
1024 
1025  return result;
1026 }
1027 
1028 
1030  if (BlockDescriptorType)
1031  return BlockDescriptorType;
1032 
1033  llvm::Type *UnsignedLongTy =
1034  getTypes().ConvertType(getContext().UnsignedLongTy);
1035 
1036  // struct __block_descriptor {
1037  // unsigned long reserved;
1038  // unsigned long block_size;
1039  //
1040  // // later, the following will be added
1041  //
1042  // struct {
1043  // void (*copyHelper)();
1044  // void (*copyHelper)();
1045  // } helpers; // !!! optional
1046  //
1047  // const char *signature; // the block signature
1048  // const char *layout; // reserved
1049  // };
1050  BlockDescriptorType = llvm::StructType::create(
1051  "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
1052 
1053  // Now form a pointer to that.
1054  unsigned AddrSpace = 0;
1055  if (getLangOpts().OpenCL)
1056  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
1057  BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
1058  return BlockDescriptorType;
1059 }
1060 
1062  if (GenericBlockLiteralType)
1063  return GenericBlockLiteralType;
1064 
1065  llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
1066 
1067  if (getLangOpts().OpenCL) {
1068  // struct __opencl_block_literal_generic {
1069  // int __size;
1070  // int __align;
1071  // __generic void *__invoke;
1072  // /* custom fields */
1073  // };
1074  SmallVector<llvm::Type *, 8> StructFields(
1075  {IntTy, IntTy, getOpenCLRuntime().getGenericVoidPointerType()});
1076  if (auto *Helper = getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1077  for (auto I : Helper->getCustomFieldTypes())
1078  StructFields.push_back(I);
1079  }
1080  GenericBlockLiteralType = llvm::StructType::create(
1081  StructFields, "struct.__opencl_block_literal_generic");
1082  } else {
1083  // struct __block_literal_generic {
1084  // void *__isa;
1085  // int __flags;
1086  // int __reserved;
1087  // void (*__invoke)(void *);
1088  // struct __block_descriptor *__descriptor;
1089  // };
1090  GenericBlockLiteralType =
1091  llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
1092  IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
1093  }
1094 
1095  return GenericBlockLiteralType;
1096 }
1097 
1099  ReturnValueSlot ReturnValue) {
1100  const BlockPointerType *BPT =
1102 
1103  llvm::Value *BlockPtr = EmitScalarExpr(E->getCallee());
1104 
1105  // Get a pointer to the generic block literal.
1106  // For OpenCL we generate generic AS void ptr to be able to reuse the same
1107  // block definition for blocks with captures generated as private AS local
1108  // variables and without captures generated as global AS program scope
1109  // variables.
1110  unsigned AddrSpace = 0;
1111  if (getLangOpts().OpenCL)
1112  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_generic);
1113 
1114  llvm::Type *BlockLiteralTy =
1115  llvm::PointerType::get(CGM.getGenericBlockLiteralType(), AddrSpace);
1116 
1117  // Bitcast the callee to a block literal.
1118  BlockPtr =
1119  Builder.CreatePointerCast(BlockPtr, BlockLiteralTy, "block.literal");
1120 
1121  // Get the function pointer from the literal.
1122  llvm::Value *FuncPtr =
1123  Builder.CreateStructGEP(CGM.getGenericBlockLiteralType(), BlockPtr,
1124  CGM.getLangOpts().OpenCL ? 2 : 3);
1125 
1126  // Add the block literal.
1127  CallArgList Args;
1128 
1129  QualType VoidPtrQualTy = getContext().VoidPtrTy;
1130  llvm::Type *GenericVoidPtrTy = VoidPtrTy;
1131  if (getLangOpts().OpenCL) {
1132  GenericVoidPtrTy = CGM.getOpenCLRuntime().getGenericVoidPointerType();
1133  VoidPtrQualTy =
1134  getContext().getPointerType(getContext().getAddrSpaceQualType(
1135  getContext().VoidTy, LangAS::opencl_generic));
1136  }
1137 
1138  BlockPtr = Builder.CreatePointerCast(BlockPtr, GenericVoidPtrTy);
1139  Args.add(RValue::get(BlockPtr), VoidPtrQualTy);
1140 
1141  QualType FnType = BPT->getPointeeType();
1142 
1143  // And the rest of the arguments.
1144  EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1145 
1146  // Load the function.
1147  llvm::Value *Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1148 
1149  const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1150  const CGFunctionInfo &FnInfo =
1151  CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
1152 
1153  // Cast the function pointer to the right type.
1154  llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
1155 
1156  llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
1157  Func = Builder.CreatePointerCast(Func, BlockFTyPtr);
1158 
1159  // Prepare the callee.
1160  CGCallee Callee(CGCalleeInfo(), Func);
1161 
1162  // And call the block.
1163  return EmitCall(FnInfo, Callee, ReturnValue, Args);
1164 }
1165 
1167  bool isByRef) {
1168  assert(BlockInfo && "evaluating block ref without block information?");
1169  const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1170 
1171  // Handle constant captures.
1172  if (capture.isConstant()) return LocalDeclMap.find(variable)->second;
1173 
1174  Address addr =
1175  Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(),
1176  capture.getOffset(), "block.capture.addr");
1177 
1178  if (isByRef) {
1179  // addr should be a void** right now. Load, then cast the result
1180  // to byref*.
1181 
1182  auto &byrefInfo = getBlockByrefInfo(variable);
1183  addr = Address(Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
1184 
1185  auto byrefPointerType = llvm::PointerType::get(byrefInfo.Type, 0);
1186  addr = Builder.CreateBitCast(addr, byrefPointerType, "byref.addr");
1187 
1188  addr = emitBlockByrefAddress(addr, byrefInfo, /*follow*/ true,
1189  variable->getName());
1190  }
1191 
1192  if (capture.fieldType()->isReferenceType())
1193  addr = EmitLoadOfReference(MakeAddrLValue(addr, capture.fieldType()));
1194 
1195  return addr;
1196 }
1197 
1199  llvm::Constant *Addr) {
1200  bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
1201  (void)Ok;
1202  assert(Ok && "Trying to replace an already-existing global block!");
1203 }
1204 
1205 llvm::Constant *
1207  StringRef Name) {
1208  if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1209  return Block;
1210 
1211  CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1212  blockInfo.BlockExpression = BE;
1213 
1214  // Compute information about the layout, etc., of this block.
1215  computeBlockInfo(*this, nullptr, blockInfo);
1216 
1217  // Using that metadata, generate the actual block function.
1218  {
1219  CodeGenFunction::DeclMapTy LocalDeclMap;
1221  GlobalDecl(), blockInfo, LocalDeclMap,
1222  /*IsLambdaConversionToBlock*/ false, /*BuildGlobalBlock*/ true);
1223  }
1224 
1225  return getAddrOfGlobalBlockIfEmitted(BE);
1226 }
1227 
1228 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1229  const CGBlockInfo &blockInfo,
1230  llvm::Constant *blockFn) {
1231  assert(blockInfo.CanBeGlobal);
1232  // Callers should detect this case on their own: calling this function
1233  // generally requires computing layout information, which is a waste of time
1234  // if we've already emitted this block.
1235  assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&
1236  "Refusing to re-emit a global block.");
1237 
1238  // Generate the constants for the block literal initializer.
1239  ConstantInitBuilder builder(CGM);
1240  auto fields = builder.beginStruct();
1241 
1242  bool IsOpenCL = CGM.getLangOpts().OpenCL;
1243  if (!IsOpenCL) {
1244  // isa
1245  fields.add(CGM.getNSConcreteGlobalBlock());
1246 
1247  // __flags
1249  if (blockInfo.UsesStret)
1250  flags |= BLOCK_USE_STRET;
1251 
1252  fields.addInt(CGM.IntTy, flags.getBitMask());
1253 
1254  // Reserved
1255  fields.addInt(CGM.IntTy, 0);
1256  } else {
1257  fields.addInt(CGM.IntTy, blockInfo.BlockSize.getQuantity());
1258  fields.addInt(CGM.IntTy, blockInfo.BlockAlign.getQuantity());
1259  }
1260 
1261  // Function
1262  fields.add(blockFn);
1263 
1264  if (!IsOpenCL) {
1265  // Descriptor
1266  fields.add(buildBlockDescriptor(CGM, blockInfo));
1267  } else if (auto *Helper =
1269  for (auto I : Helper->getCustomFieldValues(CGM, blockInfo)) {
1270  fields.add(I);
1271  }
1272  }
1273 
1274  unsigned AddrSpace = 0;
1275  if (CGM.getContext().getLangOpts().OpenCL)
1277 
1278  llvm::Constant *literal = fields.finishAndCreateGlobal(
1279  "__block_literal_global", blockInfo.BlockAlign,
1280  /*constant*/ true, llvm::GlobalVariable::InternalLinkage, AddrSpace);
1281 
1282  // Return a constant of the appropriately-casted type.
1283  llvm::Type *RequiredType =
1284  CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1285  llvm::Constant *Result =
1286  llvm::ConstantExpr::getPointerCast(literal, RequiredType);
1287  CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
1288  return Result;
1289 }
1290 
1292  unsigned argNum,
1293  llvm::Value *arg) {
1294  assert(BlockInfo && "not emitting prologue of block invocation function?!");
1295 
1296  // Allocate a stack slot like for any local variable to guarantee optimal
1297  // debug info at -O0. The mem2reg pass will eliminate it when optimizing.
1298  Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr");
1299  Builder.CreateStore(arg, alloc);
1300  if (CGDebugInfo *DI = getDebugInfo()) {
1301  if (CGM.getCodeGenOpts().getDebugInfo() >=
1303  DI->setLocation(D->getLocation());
1304  DI->EmitDeclareOfBlockLiteralArgVariable(
1305  *BlockInfo, D->getName(), argNum,
1306  cast<llvm::AllocaInst>(alloc.getPointer()), Builder);
1307  }
1308  }
1309 
1310  SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getLocStart();
1311  ApplyDebugLocation Scope(*this, StartLoc);
1312 
1313  // Instead of messing around with LocalDeclMap, just set the value
1314  // directly as BlockPointer.
1315  BlockPointer = Builder.CreatePointerCast(
1316  arg,
1317  BlockInfo->StructureType->getPointerTo(
1318  getContext().getLangOpts().OpenCL
1319  ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1320  : 0),
1321  "block");
1322 }
1323 
1325  assert(BlockInfo && "not in a block invocation function!");
1326  assert(BlockPointer && "no block pointer set!");
1327  return Address(BlockPointer, BlockInfo->BlockAlign);
1328 }
1329 
1330 llvm::Function *
1332  const CGBlockInfo &blockInfo,
1333  const DeclMapTy &ldm,
1334  bool IsLambdaConversionToBlock,
1335  bool BuildGlobalBlock) {
1336  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1337 
1338  CurGD = GD;
1339 
1340  CurEHLocation = blockInfo.getBlockExpr()->getLocEnd();
1341 
1342  BlockInfo = &blockInfo;
1343 
1344  // Arrange for local static and local extern declarations to appear
1345  // to be local to this function as well, in case they're directly
1346  // referenced in a block.
1347  for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1348  const auto *var = dyn_cast<VarDecl>(i->first);
1349  if (var && !var->hasLocalStorage())
1350  setAddrOfLocalVar(var, i->second);
1351  }
1352 
1353  // Begin building the function declaration.
1354 
1355  // Build the argument list.
1356  FunctionArgList args;
1357 
1358  // The first argument is the block pointer. Just take it as a void*
1359  // and cast it later.
1360  QualType selfTy = getContext().VoidPtrTy;
1361 
1362  // For OpenCL passed block pointer can be private AS local variable or
1363  // global AS program scope variable (for the case with and without captures).
1364  // Generic AS is used therefore to be able to accommodate both private and
1365  // generic AS in one implementation.
1366  if (getLangOpts().OpenCL)
1367  selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1368  getContext().VoidTy, LangAS::opencl_generic));
1369 
1370  IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1371 
1372  ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1373  SourceLocation(), II, selfTy,
1375  args.push_back(&SelfDecl);
1376 
1377  // Now add the rest of the parameters.
1378  args.append(blockDecl->param_begin(), blockDecl->param_end());
1379 
1380  // Create the function declaration.
1381  const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1382  const CGFunctionInfo &fnInfo =
1383  CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1384  if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1385  blockInfo.UsesStret = true;
1386 
1387  llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1388 
1389  StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1390  llvm::Function *fn = llvm::Function::Create(
1391  fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1392  CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1393 
1394  if (BuildGlobalBlock) {
1395  auto GenVoidPtrTy = getContext().getLangOpts().OpenCL
1397  : VoidPtrTy;
1398  buildGlobalBlock(CGM, blockInfo,
1399  llvm::ConstantExpr::getPointerCast(fn, GenVoidPtrTy));
1400  }
1401 
1402  // Begin generating the function.
1403  StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1404  blockDecl->getLocation(),
1405  blockInfo.getBlockExpr()->getBody()->getLocStart());
1406 
1407  // Okay. Undo some of what StartFunction did.
1408 
1409  // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1410  // won't delete the dbg.declare intrinsics for captured variables.
1411  llvm::Value *BlockPointerDbgLoc = BlockPointer;
1412  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1413  // Allocate a stack slot for it, so we can point the debugger to it
1414  Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1415  getPointerAlign(),
1416  "block.addr");
1417  // Set the DebugLocation to empty, so the store is recognized as a
1418  // frame setup instruction by llvm::DwarfDebug::beginFunction().
1419  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1420  Builder.CreateStore(BlockPointer, Alloca);
1421  BlockPointerDbgLoc = Alloca.getPointer();
1422  }
1423 
1424  // If we have a C++ 'this' reference, go ahead and force it into
1425  // existence now.
1426  if (blockDecl->capturesCXXThis()) {
1427  Address addr =
1428  Builder.CreateStructGEP(LoadBlockStruct(), blockInfo.CXXThisIndex,
1429  blockInfo.CXXThisOffset, "block.captured-this");
1430  CXXThisValue = Builder.CreateLoad(addr, "this");
1431  }
1432 
1433  // Also force all the constant captures.
1434  for (const auto &CI : blockDecl->captures()) {
1435  const VarDecl *variable = CI.getVariable();
1436  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1437  if (!capture.isConstant()) continue;
1438 
1439  CharUnits align = getContext().getDeclAlign(variable);
1440  Address alloca =
1441  CreateMemTemp(variable->getType(), align, "block.captured-const");
1442 
1443  Builder.CreateStore(capture.getConstant(), alloca);
1444 
1445  setAddrOfLocalVar(variable, alloca);
1446  }
1447 
1448  // Save a spot to insert the debug information for all the DeclRefExprs.
1449  llvm::BasicBlock *entry = Builder.GetInsertBlock();
1450  llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1451  --entry_ptr;
1452 
1453  if (IsLambdaConversionToBlock)
1454  EmitLambdaBlockInvokeBody();
1455  else {
1456  PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1457  incrementProfileCounter(blockDecl->getBody());
1458  EmitStmt(blockDecl->getBody());
1459  }
1460 
1461  // Remember where we were...
1462  llvm::BasicBlock *resume = Builder.GetInsertBlock();
1463 
1464  // Go back to the entry.
1465  ++entry_ptr;
1466  Builder.SetInsertPoint(entry, entry_ptr);
1467 
1468  // Emit debug information for all the DeclRefExprs.
1469  // FIXME: also for 'this'
1470  if (CGDebugInfo *DI = getDebugInfo()) {
1471  for (const auto &CI : blockDecl->captures()) {
1472  const VarDecl *variable = CI.getVariable();
1473  DI->EmitLocation(Builder, variable->getLocation());
1474 
1475  if (CGM.getCodeGenOpts().getDebugInfo() >=
1477  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1478  if (capture.isConstant()) {
1479  auto addr = LocalDeclMap.find(variable)->second;
1480  DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1481  Builder);
1482  continue;
1483  }
1484 
1485  DI->EmitDeclareOfBlockDeclRefVariable(
1486  variable, BlockPointerDbgLoc, Builder, blockInfo,
1487  entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1488  }
1489  }
1490  // Recover location if it was changed in the above loop.
1491  DI->EmitLocation(Builder,
1492  cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1493  }
1494 
1495  // And resume where we left off.
1496  if (resume == nullptr)
1497  Builder.ClearInsertionPoint();
1498  else
1499  Builder.SetInsertPoint(resume);
1500 
1501  FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1502 
1503  return fn;
1504 }
1505 
1506 namespace {
1507 
1508 /// Represents a type of copy/destroy operation that should be performed for an
1509 /// entity that's captured by a block.
1511  CXXRecord, // Copy or destroy
1512  ARCWeak,
1513  ARCStrong,
1514  BlockObject, // Assign or release
1515  None
1516 };
1517 
1518 /// Represents a captured entity that requires extra operations in order for
1519 /// this entity to be copied or destroyed correctly.
1520 struct BlockCaptureManagedEntity {
1522  BlockFieldFlags Flags;
1523  const BlockDecl::Capture &CI;
1524  const CGBlockInfo::Capture &Capture;
1525 
1526  BlockCaptureManagedEntity(BlockCaptureEntityKind Type, BlockFieldFlags Flags,
1527  const BlockDecl::Capture &CI,
1528  const CGBlockInfo::Capture &Capture)
1529  : Kind(Type), Flags(Flags), CI(CI), Capture(Capture) {}
1530 };
1531 
1532 } // end anonymous namespace
1533 
1534 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1536  const LangOptions &LangOpts) {
1537  if (CI.getCopyExpr()) {
1538  assert(!CI.isByRef());
1539  // don't bother computing flags
1540  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1541  }
1542  BlockFieldFlags Flags;
1543  if (CI.isByRef()) {
1544  Flags = BLOCK_FIELD_IS_BYREF;
1545  if (T.isObjCGCWeak())
1546  Flags |= BLOCK_FIELD_IS_WEAK;
1547  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1548  }
1549  if (!T->isObjCRetainableType())
1550  // For all other types, the memcpy is fine.
1551  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1552 
1553  Flags = BLOCK_FIELD_IS_OBJECT;
1554  bool isBlockPointer = T->isBlockPointerType();
1555  if (isBlockPointer)
1556  Flags = BLOCK_FIELD_IS_BLOCK;
1557 
1558  // Special rules for ARC captures:
1559  Qualifiers QS = T.getQualifiers();
1560 
1561  // We need to register __weak direct captures with the runtime.
1563  return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1564 
1565  // We need to retain the copied value for __strong direct captures.
1567  // If it's a block pointer, we have to copy the block and
1568  // assign that to the destination pointer, so we might as
1569  // well use _Block_object_assign. Otherwise we can avoid that.
1570  return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1571  : BlockCaptureEntityKind::BlockObject,
1572  Flags);
1573  }
1574 
1575  // Non-ARC captures of retainable pointers are strong and
1576  // therefore require a call to _Block_object_assign.
1577  if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1578  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1579 
1580  // Otherwise the memcpy is fine.
1581  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1582 }
1583 
1584 /// Find the set of block captures that need to be explicitly copied or destroy.
1586  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1588  llvm::function_ref<std::pair<BlockCaptureEntityKind, BlockFieldFlags>(
1589  const BlockDecl::Capture &, QualType, const LangOptions &)>
1590  Predicate) {
1591  for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1592  const VarDecl *Variable = CI.getVariable();
1593  const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1594  if (Capture.isConstant())
1595  continue;
1596 
1597  auto Info = Predicate(CI, Variable->getType(), LangOpts);
1598  if (Info.first != BlockCaptureEntityKind::None)
1599  ManagedCaptures.emplace_back(Info.first, Info.second, CI, Capture);
1600  }
1601 }
1602 
1603 /// Generate the copy-helper function for a block closure object:
1604 /// static void block_copy_helper(block_t *dst, block_t *src);
1605 /// The runtime will have previously initialized 'dst' by doing a
1606 /// bit-copy of 'src'.
1607 ///
1608 /// Note that this copies an entire block closure object to the heap;
1609 /// it should not be confused with a 'byref copy helper', which moves
1610 /// the contents of an individual __block variable to the heap.
1611 llvm::Constant *
1613  ASTContext &C = getContext();
1614 
1615  FunctionArgList args;
1616  ImplicitParamDecl DstDecl(getContext(), C.VoidPtrTy,
1618  args.push_back(&DstDecl);
1619  ImplicitParamDecl SrcDecl(getContext(), C.VoidPtrTy,
1621  args.push_back(&SrcDecl);
1622 
1623  const CGFunctionInfo &FI =
1625 
1626  // FIXME: it would be nice if these were mergeable with things with
1627  // identical semantics.
1628  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1629 
1630  llvm::Function *Fn =
1632  "__copy_helper_block_", &CGM.getModule());
1633 
1634  IdentifierInfo *II
1635  = &CGM.getContext().Idents.get("__copy_helper_block_");
1636 
1639  SourceLocation(),
1640  SourceLocation(), II, C.VoidTy,
1641  nullptr, SC_Static,
1642  false,
1643  false);
1644 
1645  CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
1646 
1647  StartFunction(FD, C.VoidTy, Fn, FI, args);
1648  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getLocStart()};
1649  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1650 
1651  Address src = GetAddrOfLocalVar(&SrcDecl);
1652  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
1653  src = Builder.CreateBitCast(src, structPtrTy, "block.source");
1654 
1655  Address dst = GetAddrOfLocalVar(&DstDecl);
1656  dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
1657  dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
1658 
1660  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures,
1662 
1663  for (const auto &CopiedCapture : CopiedCaptures) {
1664  const BlockDecl::Capture &CI = CopiedCapture.CI;
1665  const CGBlockInfo::Capture &capture = CopiedCapture.Capture;
1666  BlockFieldFlags flags = CopiedCapture.Flags;
1667 
1668  unsigned index = capture.getIndex();
1669  Address srcField = Builder.CreateStructGEP(src, index, capture.getOffset());
1670  Address dstField = Builder.CreateStructGEP(dst, index, capture.getOffset());
1671 
1672  // If there's an explicit copy expression, we do that.
1673  if (CI.getCopyExpr()) {
1674  assert(CopiedCapture.Kind == BlockCaptureEntityKind::CXXRecord);
1675  EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
1676  } else if (CopiedCapture.Kind == BlockCaptureEntityKind::ARCWeak) {
1677  EmitARCCopyWeak(dstField, srcField);
1678  } else {
1679  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
1680  if (CopiedCapture.Kind == BlockCaptureEntityKind::ARCStrong) {
1681  // At -O0, store null into the destination field (so that the
1682  // storeStrong doesn't over-release) and then call storeStrong.
1683  // This is a workaround to not having an initStrong call.
1684  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1685  auto *ty = cast<llvm::PointerType>(srcValue->getType());
1686  llvm::Value *null = llvm::ConstantPointerNull::get(ty);
1687  Builder.CreateStore(null, dstField);
1688  EmitARCStoreStrongCall(dstField, srcValue, true);
1689 
1690  // With optimization enabled, take advantage of the fact that
1691  // the blocks runtime guarantees a memcpy of the block data, and
1692  // just emit a retain of the src field.
1693  } else {
1694  EmitARCRetainNonBlock(srcValue);
1695 
1696  // We don't need this anymore, so kill it. It's not quite
1697  // worth the annoyance to avoid creating it in the first place.
1698  cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
1699  }
1700  } else {
1701  assert(CopiedCapture.Kind == BlockCaptureEntityKind::BlockObject);
1702  srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
1703  llvm::Value *dstAddr =
1704  Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
1705  llvm::Value *args[] = {
1706  dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
1707  };
1708 
1709  const VarDecl *variable = CI.getVariable();
1710  bool copyCanThrow = false;
1711  if (CI.isByRef() && variable->getType()->getAsCXXRecordDecl()) {
1712  const Expr *copyExpr =
1713  CGM.getContext().getBlockVarCopyInits(variable);
1714  if (copyExpr) {
1715  copyCanThrow = true; // FIXME: reuse the noexcept logic
1716  }
1717  }
1718 
1719  if (copyCanThrow) {
1720  EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
1721  } else {
1722  EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
1723  }
1724  }
1725  }
1726  }
1727 
1728  FinishFunction();
1729 
1730  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1731 }
1732 
1733 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1735  const LangOptions &LangOpts) {
1736  BlockFieldFlags Flags;
1737  if (CI.isByRef()) {
1738  Flags = BLOCK_FIELD_IS_BYREF;
1739  if (T.isObjCGCWeak())
1740  Flags |= BLOCK_FIELD_IS_WEAK;
1741  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1742  }
1743 
1744  if (const CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1745  if (Record->hasTrivialDestructor())
1746  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1747  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1748  }
1749 
1750  // Other types don't need to be destroy explicitly.
1751  if (!T->isObjCRetainableType())
1752  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1753 
1754  Flags = BLOCK_FIELD_IS_OBJECT;
1755  if (T->isBlockPointerType())
1756  Flags = BLOCK_FIELD_IS_BLOCK;
1757 
1758  // Special rules for ARC captures.
1759  Qualifiers QS = T.getQualifiers();
1760 
1761  // Use objc_storeStrong for __strong direct captures; the
1762  // dynamic tools really like it when we do this.
1764  return std::make_pair(BlockCaptureEntityKind::ARCStrong, Flags);
1765 
1766  // Support __weak direct captures.
1768  return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1769 
1770  // Non-ARC captures are strong, and we need to use
1771  // _Block_object_dispose.
1772  if (!QS.hasObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1773  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1774 
1775  // Otherwise, we have nothing to do.
1776  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1777 }
1778 
1779 /// Generate the destroy-helper function for a block closure object:
1780 /// static void block_destroy_helper(block_t *theBlock);
1781 ///
1782 /// Note that this destroys a heap-allocated block closure object;
1783 /// it should not be confused with a 'byref destroy helper', which
1784 /// destroys the heap-allocated contents of an individual __block
1785 /// variable.
1786 llvm::Constant *
1788  ASTContext &C = getContext();
1789 
1790  FunctionArgList args;
1791  ImplicitParamDecl SrcDecl(getContext(), C.VoidPtrTy,
1793  args.push_back(&SrcDecl);
1794 
1795  const CGFunctionInfo &FI =
1797 
1798  // FIXME: We'd like to put these into a mergable by content, with
1799  // internal linkage.
1800  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1801 
1802  llvm::Function *Fn =
1804  "__destroy_helper_block_", &CGM.getModule());
1805 
1806  IdentifierInfo *II
1807  = &CGM.getContext().Idents.get("__destroy_helper_block_");
1808 
1810  SourceLocation(),
1811  SourceLocation(), II, C.VoidTy,
1812  nullptr, SC_Static,
1813  false, false);
1814 
1815  CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
1816 
1817  StartFunction(FD, C.VoidTy, Fn, FI, args);
1818  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getLocStart()};
1819 
1820  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1821 
1822  Address src = GetAddrOfLocalVar(&SrcDecl);
1823  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
1824  src = Builder.CreateBitCast(src, structPtrTy, "block");
1825 
1826  CodeGenFunction::RunCleanupsScope cleanups(*this);
1827 
1829  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures,
1831 
1832  for (const auto &DestroyedCapture : DestroyedCaptures) {
1833  const BlockDecl::Capture &CI = DestroyedCapture.CI;
1834  const CGBlockInfo::Capture &capture = DestroyedCapture.Capture;
1835  BlockFieldFlags flags = DestroyedCapture.Flags;
1836 
1837  Address srcField =
1838  Builder.CreateStructGEP(src, capture.getIndex(), capture.getOffset());
1839 
1840  // If the captured record has a destructor then call it.
1841  if (DestroyedCapture.Kind == BlockCaptureEntityKind::CXXRecord) {
1842  const auto *Dtor =
1844  PushDestructorCleanup(Dtor, srcField);
1845 
1846  // If this is a __weak capture, emit the release directly.
1847  } else if (DestroyedCapture.Kind == BlockCaptureEntityKind::ARCWeak) {
1848  EmitARCDestroyWeak(srcField);
1849 
1850  // Destroy strong objects with a call if requested.
1851  } else if (DestroyedCapture.Kind == BlockCaptureEntityKind::ARCStrong) {
1852  EmitARCDestroyStrong(srcField, ARCImpreciseLifetime);
1853 
1854  // Otherwise we call _Block_object_dispose. It wouldn't be too
1855  // hard to just emit this as a cleanup if we wanted to make sure
1856  // that things were done in reverse.
1857  } else {
1858  assert(DestroyedCapture.Kind == BlockCaptureEntityKind::BlockObject);
1859  llvm::Value *value = Builder.CreateLoad(srcField);
1860  value = Builder.CreateBitCast(value, VoidPtrTy);
1861  BuildBlockRelease(value, flags);
1862  }
1863  }
1864 
1865  cleanups.ForceCleanup();
1866 
1867  FinishFunction();
1868 
1869  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1870 }
1871 
1872 namespace {
1873 
1874 /// Emits the copy/dispose helper functions for a __block object of id type.
1875 class ObjectByrefHelpers final : public BlockByrefHelpers {
1876  BlockFieldFlags Flags;
1877 
1878 public:
1879  ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
1880  : BlockByrefHelpers(alignment), Flags(flags) {}
1881 
1882  void emitCopy(CodeGenFunction &CGF, Address destField,
1883  Address srcField) override {
1884  destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
1885 
1886  srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
1887  llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
1888 
1889  unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
1890 
1891  llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
1892  llvm::Value *fn = CGF.CGM.getBlockObjectAssign();
1893 
1894  llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
1895  CGF.EmitNounwindRuntimeCall(fn, args);
1896  }
1897 
1898  void emitDispose(CodeGenFunction &CGF, Address field) override {
1899  field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
1900  llvm::Value *value = CGF.Builder.CreateLoad(field);
1901 
1902  CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER);
1903  }
1904 
1905  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1906  id.AddInteger(Flags.getBitMask());
1907  }
1908 };
1909 
1910 /// Emits the copy/dispose helpers for an ARC __block __weak variable.
1911 class ARCWeakByrefHelpers final : public BlockByrefHelpers {
1912 public:
1913  ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
1914 
1915  void emitCopy(CodeGenFunction &CGF, Address destField,
1916  Address srcField) override {
1917  CGF.EmitARCMoveWeak(destField, srcField);
1918  }
1919 
1920  void emitDispose(CodeGenFunction &CGF, Address field) override {
1921  CGF.EmitARCDestroyWeak(field);
1922  }
1923 
1924  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1925  // 0 is distinguishable from all pointers and byref flags
1926  id.AddInteger(0);
1927  }
1928 };
1929 
1930 /// Emits the copy/dispose helpers for an ARC __block __strong variable
1931 /// that's not of block-pointer type.
1932 class ARCStrongByrefHelpers final : public BlockByrefHelpers {
1933 public:
1934  ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
1935 
1936  void emitCopy(CodeGenFunction &CGF, Address destField,
1937  Address srcField) override {
1938  // Do a "move" by copying the value and then zeroing out the old
1939  // variable.
1940 
1941  llvm::Value *value = CGF.Builder.CreateLoad(srcField);
1942 
1943  llvm::Value *null =
1944  llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
1945 
1946  if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
1947  CGF.Builder.CreateStore(null, destField);
1948  CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
1949  CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
1950  return;
1951  }
1952  CGF.Builder.CreateStore(value, destField);
1953  CGF.Builder.CreateStore(null, srcField);
1954  }
1955 
1956  void emitDispose(CodeGenFunction &CGF, Address field) override {
1958  }
1959 
1960  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1961  // 1 is distinguishable from all pointers and byref flags
1962  id.AddInteger(1);
1963  }
1964 };
1965 
1966 /// Emits the copy/dispose helpers for an ARC __block __strong
1967 /// variable that's of block-pointer type.
1968 class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
1969 public:
1970  ARCStrongBlockByrefHelpers(CharUnits alignment)
1971  : BlockByrefHelpers(alignment) {}
1972 
1973  void emitCopy(CodeGenFunction &CGF, Address destField,
1974  Address srcField) override {
1975  // Do the copy with objc_retainBlock; that's all that
1976  // _Block_object_assign would do anyway, and we'd have to pass the
1977  // right arguments to make sure it doesn't get no-op'ed.
1978  llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
1979  llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
1980  CGF.Builder.CreateStore(copy, destField);
1981  }
1982 
1983  void emitDispose(CodeGenFunction &CGF, Address field) override {
1985  }
1986 
1987  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1988  // 2 is distinguishable from all pointers and byref flags
1989  id.AddInteger(2);
1990  }
1991 };
1992 
1993 /// Emits the copy/dispose helpers for a __block variable with a
1994 /// nontrivial copy constructor or destructor.
1995 class CXXByrefHelpers final : public BlockByrefHelpers {
1996  QualType VarType;
1997  const Expr *CopyExpr;
1998 
1999 public:
2000  CXXByrefHelpers(CharUnits alignment, QualType type,
2001  const Expr *copyExpr)
2002  : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
2003 
2004  bool needsCopy() const override { return CopyExpr != nullptr; }
2005  void emitCopy(CodeGenFunction &CGF, Address destField,
2006  Address srcField) override {
2007  if (!CopyExpr) return;
2008  CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
2009  }
2010 
2011  void emitDispose(CodeGenFunction &CGF, Address field) override {
2012  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2013  CGF.PushDestructorCleanup(VarType, field);
2014  CGF.PopCleanupBlocks(cleanupDepth);
2015  }
2016 
2017  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2018  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2019  }
2020 };
2021 } // end anonymous namespace
2022 
2023 static llvm::Constant *
2025  BlockByrefHelpers &generator) {
2026  ASTContext &Context = CGF.getContext();
2027 
2028  QualType R = Context.VoidTy;
2029 
2030  FunctionArgList args;
2031  ImplicitParamDecl Dst(CGF.getContext(), Context.VoidPtrTy,
2033  args.push_back(&Dst);
2034 
2035  ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2037  args.push_back(&Src);
2038 
2039  const CGFunctionInfo &FI =
2041 
2042  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2043 
2044  // FIXME: We'd like to put these into a mergable by content, with
2045  // internal linkage.
2046  llvm::Function *Fn =
2048  "__Block_byref_object_copy_", &CGF.CGM.getModule());
2049 
2050  IdentifierInfo *II
2051  = &Context.Idents.get("__Block_byref_object_copy_");
2052 
2053  FunctionDecl *FD = FunctionDecl::Create(Context,
2054  Context.getTranslationUnitDecl(),
2055  SourceLocation(),
2056  SourceLocation(), II, R, nullptr,
2057  SC_Static,
2058  false, false);
2059 
2060  CGF.CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
2061 
2062  CGF.StartFunction(FD, R, Fn, FI, args);
2063 
2064  if (generator.needsCopy()) {
2065  llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
2066 
2067  // dst->x
2068  Address destField = CGF.GetAddrOfLocalVar(&Dst);
2069  destField = Address(CGF.Builder.CreateLoad(destField),
2070  byrefInfo.ByrefAlignment);
2071  destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
2072  destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
2073  "dest-object");
2074 
2075  // src->x
2076  Address srcField = CGF.GetAddrOfLocalVar(&Src);
2077  srcField = Address(CGF.Builder.CreateLoad(srcField),
2078  byrefInfo.ByrefAlignment);
2079  srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
2080  srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
2081  "src-object");
2082 
2083  generator.emitCopy(CGF, destField, srcField);
2084  }
2085 
2086  CGF.FinishFunction();
2087 
2088  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2089 }
2090 
2091 /// Build the copy helper for a __block variable.
2092 static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
2093  const BlockByrefInfo &byrefInfo,
2094  BlockByrefHelpers &generator) {
2095  CodeGenFunction CGF(CGM);
2096  return generateByrefCopyHelper(CGF, byrefInfo, generator);
2097 }
2098 
2099 /// Generate code for a __block variable's dispose helper.
2100 static llvm::Constant *
2102  const BlockByrefInfo &byrefInfo,
2103  BlockByrefHelpers &generator) {
2104  ASTContext &Context = CGF.getContext();
2105  QualType R = Context.VoidTy;
2106 
2107  FunctionArgList args;
2108  ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2110  args.push_back(&Src);
2111 
2112  const CGFunctionInfo &FI =
2114 
2115  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2116 
2117  // FIXME: We'd like to put these into a mergable by content, with
2118  // internal linkage.
2119  llvm::Function *Fn =
2121  "__Block_byref_object_dispose_",
2122  &CGF.CGM.getModule());
2123 
2124  IdentifierInfo *II
2125  = &Context.Idents.get("__Block_byref_object_dispose_");
2126 
2127  FunctionDecl *FD = FunctionDecl::Create(Context,
2128  Context.getTranslationUnitDecl(),
2129  SourceLocation(),
2130  SourceLocation(), II, R, nullptr,
2131  SC_Static,
2132  false, false);
2133 
2134  CGF.CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
2135 
2136  CGF.StartFunction(FD, R, Fn, FI, args);
2137 
2138  if (generator.needsDispose()) {
2139  Address addr = CGF.GetAddrOfLocalVar(&Src);
2140  addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2141  auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2142  addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2143  addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2144 
2145  generator.emitDispose(CGF, addr);
2146  }
2147 
2148  CGF.FinishFunction();
2149 
2150  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2151 }
2152 
2153 /// Build the dispose helper for a __block variable.
2154 static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2155  const BlockByrefInfo &byrefInfo,
2156  BlockByrefHelpers &generator) {
2157  CodeGenFunction CGF(CGM);
2158  return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2159 }
2160 
2161 /// Lazily build the copy and dispose helpers for a __block variable
2162 /// with the given information.
2163 template <class T>
2164 static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2165  T &&generator) {
2166  llvm::FoldingSetNodeID id;
2167  generator.Profile(id);
2168 
2169  void *insertPos;
2170  BlockByrefHelpers *node
2171  = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2172  if (node) return static_cast<T*>(node);
2173 
2174  generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2175  generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2176 
2177  T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2178  CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2179  return copy;
2180 }
2181 
2182 /// Build the copy and dispose helpers for the given __block variable
2183 /// emission. Places the helpers in the global cache. Returns null
2184 /// if no helpers are required.
2186 CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2187  const AutoVarEmission &emission) {
2188  const VarDecl &var = *emission.Variable;
2189  QualType type = var.getType();
2190 
2191  auto &byrefInfo = getBlockByrefInfo(&var);
2192 
2193  // The alignment we care about for the purposes of uniquing byref
2194  // helpers is the alignment of the actual byref value field.
2195  CharUnits valueAlignment =
2196  byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2197 
2198  if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2199  const Expr *copyExpr = CGM.getContext().getBlockVarCopyInits(&var);
2200  if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2201 
2203  CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2204  }
2205 
2206  // Otherwise, if we don't have a retainable type, there's nothing to do.
2207  // that the runtime does extra copies.
2208  if (!type->isObjCRetainableType()) return nullptr;
2209 
2210  Qualifiers qs = type.getQualifiers();
2211 
2212  // If we have lifetime, that dominates.
2213  if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2214  switch (lifetime) {
2215  case Qualifiers::OCL_None: llvm_unreachable("impossible");
2216 
2217  // These are just bits as far as the runtime is concerned.
2220  return nullptr;
2221 
2222  // Tell the runtime that this is ARC __weak, called by the
2223  // byref routines.
2224  case Qualifiers::OCL_Weak:
2225  return ::buildByrefHelpers(CGM, byrefInfo,
2226  ARCWeakByrefHelpers(valueAlignment));
2227 
2228  // ARC __strong __block variables need to be retained.
2230  // Block pointers need to be copied, and there's no direct
2231  // transfer possible.
2232  if (type->isBlockPointerType()) {
2233  return ::buildByrefHelpers(CGM, byrefInfo,
2234  ARCStrongBlockByrefHelpers(valueAlignment));
2235 
2236  // Otherwise, we transfer ownership of the retain from the stack
2237  // to the heap.
2238  } else {
2239  return ::buildByrefHelpers(CGM, byrefInfo,
2240  ARCStrongByrefHelpers(valueAlignment));
2241  }
2242  }
2243  llvm_unreachable("fell out of lifetime switch!");
2244  }
2245 
2246  BlockFieldFlags flags;
2247  if (type->isBlockPointerType()) {
2248  flags |= BLOCK_FIELD_IS_BLOCK;
2249  } else if (CGM.getContext().isObjCNSObjectType(type) ||
2250  type->isObjCObjectPointerType()) {
2251  flags |= BLOCK_FIELD_IS_OBJECT;
2252  } else {
2253  return nullptr;
2254  }
2255 
2256  if (type.isObjCGCWeak())
2257  flags |= BLOCK_FIELD_IS_WEAK;
2258 
2259  return ::buildByrefHelpers(CGM, byrefInfo,
2260  ObjectByrefHelpers(valueAlignment, flags));
2261 }
2262 
2264  const VarDecl *var,
2265  bool followForward) {
2266  auto &info = getBlockByrefInfo(var);
2267  return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2268 }
2269 
2271  const BlockByrefInfo &info,
2272  bool followForward,
2273  const llvm::Twine &name) {
2274  // Chase the forwarding address if requested.
2275  if (followForward) {
2276  Address forwardingAddr =
2277  Builder.CreateStructGEP(baseAddr, 1, getPointerSize(), "forwarding");
2278  baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2279  }
2280 
2281  return Builder.CreateStructGEP(baseAddr, info.FieldIndex,
2282  info.FieldOffset, name);
2283 }
2284 
2285 /// BuildByrefInfo - This routine changes a __block variable declared as T x
2286 /// into:
2287 ///
2288 /// struct {
2289 /// void *__isa;
2290 /// void *__forwarding;
2291 /// int32_t __flags;
2292 /// int32_t __size;
2293 /// void *__copy_helper; // only if needed
2294 /// void *__destroy_helper; // only if needed
2295 /// void *__byref_variable_layout;// only if needed
2296 /// char padding[X]; // only if needed
2297 /// T x;
2298 /// } x
2299 ///
2301  auto it = BlockByrefInfos.find(D);
2302  if (it != BlockByrefInfos.end())
2303  return it->second;
2304 
2305  llvm::StructType *byrefType =
2306  llvm::StructType::create(getLLVMContext(),
2307  "struct.__block_byref_" + D->getNameAsString());
2308 
2309  QualType Ty = D->getType();
2310 
2311  CharUnits size;
2313 
2314  // void *__isa;
2315  types.push_back(Int8PtrTy);
2316  size += getPointerSize();
2317 
2318  // void *__forwarding;
2319  types.push_back(llvm::PointerType::getUnqual(byrefType));
2320  size += getPointerSize();
2321 
2322  // int32_t __flags;
2323  types.push_back(Int32Ty);
2324  size += CharUnits::fromQuantity(4);
2325 
2326  // int32_t __size;
2327  types.push_back(Int32Ty);
2328  size += CharUnits::fromQuantity(4);
2329 
2330  // Note that this must match *exactly* the logic in buildByrefHelpers.
2331  bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2332  if (hasCopyAndDispose) {
2333  /// void *__copy_helper;
2334  types.push_back(Int8PtrTy);
2335  size += getPointerSize();
2336 
2337  /// void *__destroy_helper;
2338  types.push_back(Int8PtrTy);
2339  size += getPointerSize();
2340  }
2341 
2342  bool HasByrefExtendedLayout = false;
2343  Qualifiers::ObjCLifetime Lifetime;
2344  if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2345  HasByrefExtendedLayout) {
2346  /// void *__byref_variable_layout;
2347  types.push_back(Int8PtrTy);
2348  size += CharUnits::fromQuantity(PointerSizeInBytes);
2349  }
2350 
2351  // T x;
2352  llvm::Type *varTy = ConvertTypeForMem(Ty);
2353 
2354  bool packed = false;
2355  CharUnits varAlign = getContext().getDeclAlign(D);
2356  CharUnits varOffset = size.alignTo(varAlign);
2357 
2358  // We may have to insert padding.
2359  if (varOffset != size) {
2360  llvm::Type *paddingTy =
2361  llvm::ArrayType::get(Int8Ty, (varOffset - size).getQuantity());
2362 
2363  types.push_back(paddingTy);
2364  size = varOffset;
2365 
2366  // Conversely, we might have to prevent LLVM from inserting padding.
2367  } else if (CGM.getDataLayout().getABITypeAlignment(varTy)
2368  > varAlign.getQuantity()) {
2369  packed = true;
2370  }
2371  types.push_back(varTy);
2372 
2373  byrefType->setBody(types, packed);
2374 
2375  BlockByrefInfo info;
2376  info.Type = byrefType;
2377  info.FieldIndex = types.size() - 1;
2378  info.FieldOffset = varOffset;
2379  info.ByrefAlignment = std::max(varAlign, getPointerAlign());
2380 
2381  auto pair = BlockByrefInfos.insert({D, info});
2382  assert(pair.second && "info was inserted recursively?");
2383  return pair.first->second;
2384 }
2385 
2386 /// Initialize the structural components of a __block variable, i.e.
2387 /// everything but the actual object.
2389  // Find the address of the local.
2390  Address addr = emission.Addr;
2391 
2392  // That's an alloca of the byref structure type.
2393  llvm::StructType *byrefType = cast<llvm::StructType>(
2394  cast<llvm::PointerType>(addr.getPointer()->getType())->getElementType());
2395 
2396  unsigned nextHeaderIndex = 0;
2397  CharUnits nextHeaderOffset;
2398  auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2399  const Twine &name) {
2400  auto fieldAddr = Builder.CreateStructGEP(addr, nextHeaderIndex,
2401  nextHeaderOffset, name);
2402  Builder.CreateStore(value, fieldAddr);
2403 
2404  nextHeaderIndex++;
2405  nextHeaderOffset += fieldSize;
2406  };
2407 
2408  // Build the byref helpers if necessary. This is null if we don't need any.
2409  BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2410 
2411  const VarDecl &D = *emission.Variable;
2412  QualType type = D.getType();
2413 
2414  bool HasByrefExtendedLayout;
2415  Qualifiers::ObjCLifetime ByrefLifetime;
2416  bool ByRefHasLifetime =
2417  getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2418 
2419  llvm::Value *V;
2420 
2421  // Initialize the 'isa', which is just 0 or 1.
2422  int isa = 0;
2423  if (type.isObjCGCWeak())
2424  isa = 1;
2425  V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2426  storeHeaderField(V, getPointerSize(), "byref.isa");
2427 
2428  // Store the address of the variable into its own forwarding pointer.
2429  storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2430 
2431  // Blocks ABI:
2432  // c) the flags field is set to either 0 if no helper functions are
2433  // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2434  BlockFlags flags;
2435  if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2436  if (ByRefHasLifetime) {
2437  if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2438  else switch (ByrefLifetime) {
2440  flags |= BLOCK_BYREF_LAYOUT_STRONG;
2441  break;
2442  case Qualifiers::OCL_Weak:
2443  flags |= BLOCK_BYREF_LAYOUT_WEAK;
2444  break;
2447  break;
2448  case Qualifiers::OCL_None:
2449  if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2451  break;
2452  default:
2453  break;
2454  }
2455  if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2456  printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2457  if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2458  printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2459  if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2460  BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2461  if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2462  printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2463  if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2464  printf(" BLOCK_BYREF_LAYOUT_STRONG");
2465  if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2466  printf(" BLOCK_BYREF_LAYOUT_WEAK");
2467  if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2468  printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2469  if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2470  printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2471  }
2472  printf("\n");
2473  }
2474  }
2475  storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2476  getIntSize(), "byref.flags");
2477 
2478  CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2479  V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2480  storeHeaderField(V, getIntSize(), "byref.size");
2481 
2482  if (helpers) {
2483  storeHeaderField(helpers->CopyHelper, getPointerSize(),
2484  "byref.copyHelper");
2485  storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2486  "byref.disposeHelper");
2487  }
2488 
2489  if (ByRefHasLifetime && HasByrefExtendedLayout) {
2490  auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2491  storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2492  }
2493 }
2494 
2497  llvm::Value *args[] = {
2498  Builder.CreateBitCast(V, Int8PtrTy),
2499  llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2500  };
2501  EmitNounwindRuntimeCall(F, args); // FIXME: throwing destructors?
2502 }
2503 
2504 namespace {
2505  /// Release a __block variable.
2506  struct CallBlockRelease final : EHScopeStack::Cleanup {
2507  llvm::Value *Addr;
2508  CallBlockRelease(llvm::Value *Addr) : Addr(Addr) {}
2509 
2510  void Emit(CodeGenFunction &CGF, Flags flags) override {
2511  // Should we be passing FIELD_IS_WEAK here?
2513  }
2514  };
2515 } // end anonymous namespace
2516 
2517 /// Enter a cleanup to destroy a __block variable. Note that this
2518 /// cleanup should be a no-op if the variable hasn't left the stack
2519 /// yet; if a cleanup is required for the variable itself, that needs
2520 /// to be done externally.
2522  // We don't enter this cleanup if we're in pure-GC mode.
2523  if (CGM.getLangOpts().getGC() == LangOptions::GCOnly)
2524  return;
2525 
2526  EHStack.pushCleanup<CallBlockRelease>(NormalAndEHCleanup,
2527  emission.Addr.getPointer());
2528 }
2529 
2530 /// Adjust the declaration of something from the blocks API.
2532  llvm::Constant *C) {
2533  auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2534 
2535  if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2536  IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2539 
2540  assert((isa<llvm::Function>(C->stripPointerCasts()) ||
2541  isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&
2542  "expected Function or GlobalVariable");
2543 
2544  const NamedDecl *ND = nullptr;
2545  for (const auto &Result : DC->lookup(&II))
2546  if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2547  (ND = dyn_cast<VarDecl>(Result)))
2548  break;
2549 
2550  // TODO: support static blocks runtime
2551  if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2552  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2553  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2554  } else {
2555  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2556  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2557  }
2558  }
2559 
2560  if (!CGM.getLangOpts().BlocksRuntimeOptional)
2561  return;
2562 
2563  if (GV->isDeclaration() && GV->hasExternalLinkage())
2564  GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2565 }
2566 
2568  if (BlockObjectDispose)
2569  return BlockObjectDispose;
2570 
2571  llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2572  llvm::FunctionType *fty
2573  = llvm::FunctionType::get(VoidTy, args, false);
2574  BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2575  configureBlocksRuntimeObject(*this, BlockObjectDispose);
2576  return BlockObjectDispose;
2577 }
2578 
2580  if (BlockObjectAssign)
2581  return BlockObjectAssign;
2582 
2583  llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
2584  llvm::FunctionType *fty
2585  = llvm::FunctionType::get(VoidTy, args, false);
2586  BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
2587  configureBlocksRuntimeObject(*this, BlockObjectAssign);
2588  return BlockObjectAssign;
2589 }
2590 
2592  if (NSConcreteGlobalBlock)
2593  return NSConcreteGlobalBlock;
2594 
2595  NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
2596  Int8PtrTy->getPointerTo(),
2597  nullptr);
2598  configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
2599  return NSConcreteGlobalBlock;
2600 }
2601 
2603  if (NSConcreteStackBlock)
2604  return NSConcreteStackBlock;
2605 
2606  NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
2607  Int8PtrTy->getPointerTo(),
2608  nullptr);
2609  configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
2610  return NSConcreteStackBlock;
2611 }
const CGFunctionInfo & arrangeBuiltinFunctionDeclaration(QualType resultType, const FunctionArgList &args)
A builtin function is a freestanding function using the default C conventions.
Definition: CGCall.cpp:640
void enterNonTrivialFullExpression(const ExprWithCleanups *E)
Enter a full-expression with a non-trivial number of objects to clean up.
Definition: CGBlocks.cpp:706
const llvm::DataLayout & getDataLayout() const
CGOpenCLRuntime & getOpenCLRuntime()
Return a reference to the configured OpenCL runtime.
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:281
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
const BlockDecl * getBlockDecl() const
Definition: Expr.h:4866
Information about the layout of a __block variable.
Definition: CGBlocks.h:140
CharUnits alignTo(const CharUnits &Align) const
alignTo - Returns the next integer (mod 2**64) that is greater than or equal to this quantity and is ...
Definition: CharUnits.h:184
const Capture & getCapture(const VarDecl *var) const
Definition: CGBlocks.h:261
llvm::Constant * GenerateCopyHelperFunction(const CGBlockInfo &blockInfo)
Generate the copy-helper function for a block closure object: static void block_copy_helper(block_t *...
Definition: CGBlocks.cpp:1612
static llvm::Constant * generateByrefDisposeHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Generate code for a __block variable&#39;s dispose helper.
Definition: CGBlocks.cpp:2101
FunctionDecl - An instance of this class is created to represent a function declaration or definition...
Definition: Decl.h:1698
llvm::IntegerType * IntTy
int
llvm::Type * getGenericBlockLiteralType()
The type of a generic block literal.
Definition: CGBlocks.cpp:1061
const CGFunctionInfo & arrangeBlockFunctionDeclaration(const FunctionProtoType *type, const FunctionArgList &args)
Block invocation functions are C functions with an implicit parameter.
Definition: CGCall.cpp:614
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:61
Other implicit parameter.
Definition: Decl.h:1474
CharUnits BlockHeaderForcedGapOffset
Definition: CGBlocks.h:246
const FunctionProtoType * getFunctionType() const
getFunctionType - Return the underlying function type for this block.
Definition: Expr.cpp:2003
Expr * getCopyExpr() const
Definition: Decl.h:3725
static llvm::Constant * buildByrefDisposeHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the dispose helper for a __block variable.
Definition: CGBlocks.cpp:2154
A class which contains all the information about a particular captured value.
Definition: Decl.h:3693
CanQualType VoidPtrTy
Definition: ASTContext.h:981
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:1461
A (possibly-)qualified type.
Definition: Type.h:653
bool isBlockPointerType() const
Definition: Type.h:5960
const CodeGenOptions & getCodeGenOpts() const
bool hasCaptures() const
hasCaptures - True if this block (or its nested blocks) captures anything of local storage from its e...
Definition: Decl.h:3807
bool HaveInsertPoint() const
HaveInsertPoint - True if an insertion point is defined.
capture_const_iterator capture_begin() const
Definition: Decl.h:3817
llvm::LLVMContext & getLLVMContext()
void EmitARCDestroyWeak(Address addr)
void @objc_destroyWeak(i8** addr) Essentially objc_storeWeak(addr, nil).
Definition: CGObjC.cpp:2296
The standard implementation of ConstantInitBuilder used in Clang.
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3065
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:783
static T * buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, T &&generator)
Lazily build the copy and dispose helpers for a __block variable with the given information.
Definition: CGBlocks.cpp:2164
tooling::Replacements cleanup(const FormatStyle &Style, StringRef Code, ArrayRef< tooling::Range > Ranges, StringRef FileName="<stdin>")
Clean up any erroneous/redundant code in the given Ranges in Code.
Definition: Format.cpp:2007
ArrayRef< CleanupObject > getObjects() const
Definition: ExprCXX.h:3028
param_iterator param_end()
Definition: Decl.h:3787
static llvm::Constant * buildBlockDescriptor(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
buildBlockDescriptor - Build the block descriptor meta-data for a block.
Definition: CGBlocks.cpp:80
QualType getNonReferenceType() const
If Type is a reference type (e.g., const int&), returns the type that the reference refers to ("const...
Definition: Type.h:5901
The base class of the type hierarchy.
Definition: Type.h:1360
stable_iterator stable_begin() const
Create a stable reference to the top of the EH stack.
Definition: EHScopeStack.h:379
The l-value was an access to a declared entity or something equivalently strong, like the address of ...
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
capture_const_iterator capture_end() const
Definition: Decl.h:3818
Address GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
VarDecl - An instance of this class is created to represent a variable declaration or definition...
Definition: Decl.h:807
CGBlockInfo(const BlockDecl *blockDecl, StringRef Name)
Definition: CGBlocks.cpp:34
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6315
EHScopeStack::stable_iterator getCleanup() const
Definition: CGBlocks.h:179
LangAS
Defines the address space values used by the address space qualifier of QualType. ...
Definition: AddressSpaces.h:26
This class gathers all debug information during compilation and is responsible for emitting to llvm g...
Definition: CGDebugInfo.h:53
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:1535
virtual llvm::Constant * BuildRCBlockLayout(CodeGen::CodeGenModule &CGM, const CodeGen::CGBlockInfo &blockInfo)=0
llvm::Value * getPointer() const
Definition: Address.h:38
llvm::Type * ConvertTypeForMem(QualType T)
ConvertTypeForMem - Convert type T into a llvm::Type.
Represents an expression – generally a full-expression – that introduces cleanups to be run at the ...
Definition: ExprCXX.h:3000
static void destroyBlockInfos(CGBlockInfo *info)
Destroy a chain of block layouts.
Definition: CGBlocks.cpp:733
SourceLocation getLocStart() const LLVM_READONLY
Definition: Expr.h:4875
The collection of all-type qualifiers we support.
Definition: Type.h:152
const AstTypeMatcher< RecordType > recordType
Matches record types (e.g.
const BlockDecl * Block
Definition: CGBlocks.h:237
llvm::DenseMap< const VarDecl *, FieldDecl * > LambdaCaptureFields
uint64_t getPointerWidth(unsigned AddrSpace) const
Return the width of pointers on this target, for the specified address space.
Definition: TargetInfo.h:312
One of these records is kept for each identifier that is lexed.
void emitByrefStructureInit(const AutoVarEmission &emission)
Initialize the structural components of a __block variable, i.e.
Definition: CGBlocks.cpp:2388
CGBlockInfo * FirstBlockInfo
FirstBlockInfo - The head of a singly-linked-list of block layouts.
QualType getPointeeType() const
Definition: Type.h:2409
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
llvm::Type * ConvertType(QualType T)
ConvertType - Convert type T into a llvm::Type.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:128
llvm::Constant * tryEmitAbstractForInitializer(const VarDecl &D)
Try to emit the initializer of the given declaration as an abstract constant.
bool HasCapturedVariableLayout
HasCapturedVariableLayout : True if block has captured variables and their layout meta-data has been ...
Definition: CGBlocks.h:230
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:1734
bool isReferenceType() const
Definition: Type.h:5964
static void findBlockCapturedManagedEntities(const CGBlockInfo &BlockInfo, const LangOptions &LangOpts, SmallVectorImpl< BlockCaptureManagedEntity > &ManagedCaptures, llvm::function_ref< std::pair< BlockCaptureEntityKind, BlockFieldFlags >(const BlockDecl::Capture &, QualType, const LangOptions &)> Predicate)
Find the set of block captures that need to be explicitly copied or destroy.
Definition: CGBlocks.cpp:1585
std::string getObjCEncodingForBlock(const BlockExpr *blockExpr) const
Return the encoded type for this block declaration.
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:53
static llvm::Constant * generateByrefCopyHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Definition: CGBlocks.cpp:2024
Stmt * getBody() const override
getBody - If this Decl represents a declaration for a body of code, such as a function or method defi...
Definition: Decl.h:3767
static bool isSafeForCXXConstantCapture(QualType type)
Determines if the given type is safe for constant capture in C++.
Definition: CGBlocks.cpp:245
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:48
IdentifierTable & Idents
Definition: ASTContext.h:515
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:107
CharUnits GetTargetTypeStoreSize(llvm::Type *Ty) const
Return the store size, in character units, of the given LLVM type.
llvm::Value * EmitARCStoreStrongCall(Address addr, llvm::Value *value, bool resultIgnored)
Store into a strong object.
Definition: CGObjC.cpp:2134
Address GetAddrOfBlockDecl(const VarDecl *var, bool ByRef)
Definition: CGBlocks.cpp:1166
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:38
void EmitARCDestroyStrong(Address addr, ARCPreciseLifetime_t precise)
Destroy a __strong variable.
Definition: CGObjC.cpp:2120
const BlockDecl * getBlockDecl() const
Definition: CGBlocks.h:271
uint32_t Offset
Definition: CacheTokens.cpp:43
virtual TargetOpenCLBlockHelper * getTargetOpenCLBlockHelper() const
Definition: TargetInfo.h:287
bool HasCXXObject
HasCXXObject - True if the block&#39;s custom copy/dispose functions need to be run even in GC mode...
Definition: CGBlocks.h:222
uint32_t getBitMask() const
Definition: CGBlocks.h:117
bool isByRef() const
Whether this is a "by ref" capture, i.e.
Definition: Decl.h:3718
bool needsEHCleanup(QualType::DestructionKind kind)
Determines whether an EH cleanup is required to destroy a type with the given destruction kind...
llvm::Constant * getAddrOfGlobalBlockIfEmitted(const BlockExpr *BE)
Returns the address of a block which requires no caputres, or null if we&#39;ve yet to emit the block for...
CharUnits getDeclAlign(const Decl *D, bool ForAlignof=false) const
Return a conservative estimate of the alignment of the specified decl D.
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:39
void ForceCleanup(std::initializer_list< llvm::Value **> ValuesToReload={})
Force the emission of cleanups now, instead of waiting until this object is destroyed.
static Capture makeConstant(llvm::Value *value)
Definition: CGBlocks.h:206
CXXDestructorDecl * getDestructor() const
Returns the destructor decl for this class.
Definition: DeclCXX.cpp:1458
llvm::AllocaInst * CreateTempAlloca(llvm::Type *Ty, const Twine &Name="tmp", llvm::Value *ArraySize=nullptr)
CreateTempAlloca - This creates an alloca and inserts it into the entry block if ArraySize is nullptr...
Definition: CGExpr.cpp:94
llvm::Value * EmitBlockLiteral(const BlockExpr *, llvm::Function **InvokeF=nullptr)
Emit block literal.
Definition: CGBlocks.cpp:743
const Stmt * getBody() const
Definition: Expr.cpp:2012
llvm::Constant * getNSConcreteStackBlock()
Definition: CGBlocks.cpp:2602
static FunctionDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation NLoc, DeclarationName N, QualType T, TypeSourceInfo *TInfo, StorageClass SC, bool isInlineSpecified=false, bool hasWrittenPrototype=true, bool isConstexprSpecified=false)
Definition: Decl.h:1876
This object can be modified without requiring retains or releases.
Definition: Type.h:173
StringRef Name
Name - The name of the block, kindof.
Definition: CGBlocks.h:152
bool NeedsCopyDispose
True if the block needs a custom copy or dispose function.
Definition: CGBlocks.h:218
lookup_result lookup(DeclarationName Name) const
lookup - Find the declarations (if any) with the given Name in this context.
Definition: DeclBase.cpp:1521
const BlockExpr * BlockExpression
Definition: CGBlocks.h:238
static llvm::Constant * buildCopyHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to copy a block.
Definition: CGBlocks.cpp:55
bool isValid() const
Definition: Address.h:36
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1590
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3277
llvm::CallInst * EmitNounwindRuntimeCall(llvm::Value *callee, const Twine &name="")
uint32_t getBitMask() const
Definition: CGBlocks.h:73
const CodeGen::CGBlockInfo * BlockInfo
const TargetCodeGenInfo & getTargetCodeGenInfo()
CGBlockInfo - Information to generate a block literal.
Definition: CGBlocks.h:149
virtual void emitCopy(CodeGenFunction &CGF, Address dest, Address src)=0
RValue - This trivial value class is used to represent the result of an expression that is evaluated...
Definition: CGValue.h:39
bool CanBeGlobal
CanBeGlobal - True if the block can be global, i.e.
Definition: CGBlocks.h:215
SourceLocation getLocEnd() const LLVM_READONLY
Definition: Expr.h:4876
StringRef getBlockMangledName(GlobalDecl GD, const BlockDecl *BD)
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info, SmallVectorImpl< llvm::Type *> &elementTypes)
Definition: CGBlocks.cpp:305
CGBlockInfo * NextBlockInfo
The next block in the block-info chain.
Definition: CGBlocks.h:259
CGObjCRuntime & getObjCRuntime()
Return a reference to the configured Objective-C runtime.
BlockDecl - This represents a block literal declaration, which is like an unnamed FunctionDecl...
Definition: Decl.h:3689
Expr - This represents one expression.
Definition: Expr.h:106
void EmitARCMoveWeak(Address dst, Address src)
void @objc_moveWeak(i8** dest, i8** src) Disregards the current value in dest.
Definition: CGObjC.cpp:2313
Emit only debug info necessary for generating line number tables (-gline-tables-only).
static Address invalid()
Definition: Address.h:35
Enters a new scope for capturing cleanups, all of which will be executed once the scope is exited...
const FunctionProtoType * T
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6378
void SetInternalFunctionAttributes(const Decl *D, llvm::Function *F, const CGFunctionInfo &FI)
Set the attributes on the LLVM function for the given decl and function info.
bool isObjCRetainableType() const
Definition: Type.cpp:3968
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:4852
BlockCaptureEntityKind
Represents a type of copy/destroy operation that should be performed for an entity that&#39;s captured by...
Definition: CGBlocks.cpp:1510
static llvm::Constant * buildGlobalBlock(CodeGenModule &CGM, const CGBlockInfo &blockInfo, llvm::Constant *blockFn)
Build the given block as a global block.
Definition: CGBlocks.cpp:1228
llvm::Constant * GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo)
Generate the destroy-helper function for a block closure object: static void block_destroy_helper(blo...
Definition: CGBlocks.cpp:1787
const Expr * getCallee() const
Definition: Expr.h:2249
ObjCLifetime getObjCLifetime() const
Definition: Type.h:341
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:63
internal::Matcher< T > id(StringRef ID, const internal::BindableMatcher< T > &InnerMatcher)
If the provided matcher matches a node, binds the node to ID.
Definition: ASTMatchers.h:137
void add(RValue rvalue, QualType type, bool needscopy=false)
Definition: CGCall.h:207
bool ReturnSlotInterferesWithArgs(const CGFunctionInfo &FI)
Return true iff the given type uses an argument slot when &#39;sret&#39; is used as a return type...
Definition: CGCall.cpp:1485
static Capture makeIndex(unsigned index, CharUnits offset, QualType FieldType)
Definition: CGBlocks.h:197
QualType getType() const
Definition: Expr.h:128
bool isa(CodeGen::Address addr)
Definition: Address.h:112
bool isObjCInertUnsafeUnretainedType() const
Was this type written with the special inert-in-MRC __unsafe_unretained qualifier?
Definition: Type.cpp:560
static CharUnits getLowBit(CharUnits v)
Get the low bit of a nonzero character count.
Definition: CGBlocks.cpp:301
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:6273
const TargetInfo & getTarget() const
const LangOptions & getLangOpts() const
ASTContext & getContext() const
static AggValueSlot forAddr(Address addr, Qualifiers quals, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, IsZeroed_t isZeroed=IsNotZeroed)
forAddr - Make a slot for an aggregate value.
Definition: CGValue.h:495
do v
Definition: arm_acle.h:78
static QualType getCaptureFieldType(const CodeGenFunction &CGF, const BlockDecl::Capture &CI)
Definition: CGBlocks.cpp:360
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:29
virtual bool needsCopy() const
virtual llvm::Constant * BuildByrefLayout(CodeGen::CodeGenModule &CGM, QualType T)=0
Returns an i8* which points to the byref layout information.
bool isConstQualified() const
Determine whether this type is const-qualified.
Definition: Type.h:5787
param_iterator param_begin()
Definition: Decl.h:3786
The l-value was considered opaque, so the alignment was determined from a type.
RecordDecl * getDecl() const
Definition: Type.h:3995
void setBlockContextParameter(const ImplicitParamDecl *D, unsigned argNum, llvm::Value *ptr)
Definition: CGBlocks.cpp:1291
void PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize, std::initializer_list< llvm::Value **> ValuesToReload={})
Takes the old cleanup stack size and emits the cleanup blocks that have been added.
Definition: CGCleanup.cpp:420
bool UsesStret
UsesStret : True if the block uses an stret return.
Definition: CGBlocks.h:226
void enterByrefCleanup(const AutoVarEmission &emission)
Enter a cleanup to destroy a __block variable.
Definition: CGBlocks.cpp:2521
There is no lifetime qualification on this type.
Definition: Type.h:169
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:142
#define false
Definition: stdbool.h:33
Assigning into this object requires the old value to be released and the new value to be retained...
Definition: Type.h:180
Kind
Expr * getBlockVarCopyInits(const VarDecl *VD)
Get the copy initialization expression of the VarDecl VD, or NULL if none exists. ...
void PushDestructorCleanup(QualType T, Address Addr)
PushDestructorCleanup - Push a cleanup to call the complete-object destructor of an object of the giv...
Definition: CGClass.cpp:2373
void pushDestroy(QualType::DestructionKind dtorKind, Address addr, QualType type)
pushDestroy - Push the standard destructor for the given type as at least a normal cleanup...
Definition: CGDecl.cpp:1486
Encodes a location in the source.
static DeclContext * castToDeclContext(const TranslationUnitDecl *D)
Definition: Decl.h:129
QualType getReturnType() const
Definition: Type.h:3210
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
A saved depth on the scope stack.
Definition: EHScopeStack.h:107
llvm::StructType * StructureType
Definition: CGBlocks.h:236
std::string getNameAsString() const
getNameAsString - Get a human-readable name for the declaration, even if it is one of the special kin...
Definition: Decl.h:285
static void configureBlocksRuntimeObject(CodeGenModule &CGM, llvm::Constant *C)
Adjust the declaration of something from the blocks API.
Definition: CGBlocks.cpp:2531
An aggregate value slot.
Definition: CGValue.h:434
const BlockByrefInfo & getBlockByrefInfo(const VarDecl *var)
BuildByrefInfo - This routine changes a __block variable declared as T x into:
Definition: CGBlocks.cpp:2300
A scoped helper to set the current debug location to the specified location or preferred location of ...
Definition: CGDebugInfo.h:620
bool isConversionFromLambda() const
Definition: Decl.h:3824
CanQualType VoidTy
Definition: ASTContext.h:965
llvm::DenseMap< const VarDecl *, Capture > Captures
The mapping of allocated indexes within the block.
Definition: CGBlocks.h:233
arg_range arguments()
Definition: Expr.h:2303
bool isObjCObjectPointerType() const
Definition: Type.h:6049
static bool isBlockPointer(Expr *Arg)
llvm::Constant * getBlockObjectDispose()
Definition: CGBlocks.cpp:2567
An aligned address.
Definition: Address.h:25
void StartFunction(GlobalDecl GD, QualType RetTy, llvm::Function *Fn, const CGFunctionInfo &FnInfo, const FunctionArgList &Args, SourceLocation Loc=SourceLocation(), SourceLocation StartLoc=SourceLocation())
Emit code for the start of a function.
ImplicitCastExpr - Allows us to explicitly represent implicit type conversions, which have no direct ...
Definition: Expr.h:2823
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1102
llvm::Value * getConstant() const
Definition: CGBlocks.h:188
const BlockExpr * getBlockExpr() const
Definition: CGBlocks.h:272
All available information about a concrete callee.
Definition: CGCall.h:66
virtual bool needsDispose() const
bool operator<(DeclarationName LHS, DeclarationName RHS)
Ordering on two declaration names.
VarDecl * getVariable() const
The variable being captured.
Definition: Decl.h:3714
unsigned CXXThisIndex
The field index of &#39;this&#39; within the block, if there is one.
Definition: CGBlocks.h:155
Assigning into this object requires a lifetime extension.
Definition: Type.h:186
static Destroyer destroyARCStrongImprecise
void FinishFunction(SourceLocation EndLoc=SourceLocation())
FinishFunction - Complete IR generation of the current function.
const CGFunctionInfo & arrangeBlockFunctionCall(const CallArgList &args, const FunctionType *type)
A block function is essentially a free function with an extra implicit argument.
Definition: CGCall.cpp:607
std::pair< CharUnits, CharUnits > getTypeInfoInChars(const Type *T) const
ConstantAddress GetAddrOfConstantCString(const std::string &Str, const char *GlobalName=nullptr)
Returns a pointer to a character array containing the literal and a terminating &#39;\0&#39; character...
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:276
bool isObjCGCWeak() const
true when Type is objc&#39;s weak.
Definition: Type.h:1066
static llvm::Constant * tryCaptureAsConstant(CodeGenModule &CGM, CodeGenFunction *CGF, const VarDecl *var)
It is illegal to modify a const object after initialization.
Definition: CGBlocks.cpp:269
CGFunctionInfo - Class to encapsulate the information about a function definition.
This class organizes the cross-function state that is used while generating LLVM code.
CharUnits alignmentAtOffset(CharUnits offset) const
Given that this is a non-zero alignment value, what is the alignment at the given offset...
Definition: CharUnits.h:190
Dataflow Directional Tag Classes.
virtual llvm::Constant * BuildGCBlockLayout(CodeGen::CodeGenModule &CGM, const CodeGen::CGBlockInfo &blockInfo)=0
static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF, CGBlockInfo &info)
Compute the layout of the given block.
Definition: CGBlocks.cpp:375
llvm::FoldingSet< BlockByrefHelpers > ByrefHelpersCache
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1252
ArrayRef< Capture > captures() const
Definition: Decl.h:3815
bool isNested() const
Whether this is a nested capture, i.e.
Definition: Decl.h:3722
Address CreateStructGEP(Address Addr, unsigned Index, CharUnits Offset, const llvm::Twine &Name="")
Definition: CGBuilder.h:172
Parameter for Objective-C &#39;self&#39; argument.
Definition: Decl.h:1459
static llvm::Constant * buildDisposeHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to dispose of a block.
Definition: CGBlocks.cpp:61
const Expr * getInit() const
Definition: Decl.h:1213
llvm::Constant * getPointer() const
Definition: Address.h:84
std::unique_ptr< DiagnosticConsumer > create(StringRef OutputFile, DiagnosticOptions *Diags, bool MergeChildRecords=false)
Returns a DiagnosticConsumer that serializes diagnostics to a bitcode file.
llvm::LoadInst * CreateLoad(Address Addr, const llvm::Twine &Name="")
Definition: CGBuilder.h:70
int printf(__constant const char *st,...)
bool hasObjCLifetime() const
Definition: Type.h:340
llvm::StoreInst * CreateStore(llvm::Value *Val, Address Addr, bool IsVolatile=false)
Definition: CGBuilder.h:108
llvm::Module & getModule() const
llvm::StructType * Type
Definition: CGBlocks.h:142
llvm::DenseMap< const Decl *, Address > DeclMapTy
static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block)
Enter the scope of a block.
Definition: CGBlocks.cpp:621
Pointer to a block type.
Definition: Type.h:2394
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:3985
StructBuilder beginStruct(llvm::StructType *structTy=nullptr)
CanQualType UnsignedLongTy
Definition: ASTContext.h:974
unsigned getNumObjects() const
Definition: ExprCXX.h:3033
static llvm::Constant * buildByrefCopyHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the copy helper for a __block variable.
Definition: CGBlocks.cpp:2092
void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp)
Definition: CGExprCXX.cpp:626
static CGBlockInfo * findAndRemoveBlockInfo(CGBlockInfo **head, const BlockDecl *block)
Find the layout for the given block in a linked list and remove it.
Definition: CGBlocks.cpp:716
virtual void emitDispose(CodeGenFunction &CGF, Address field)=0
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:33
llvm::Constant * getBlockObjectAssign()
Definition: CGBlocks.cpp:2579
char __ovld __cnfn max(char x, char y)
Returns y if x < y, otherwise it returns x.
const Decl * CurFuncDecl
CurFuncDecl - Holds the Decl for the current outermost non-closure context.
A pair of helper functions for a __block variable.
bool capturesCXXThis() const
Definition: Decl.h:3820
Reading or writing from this object requires a barrier call.
Definition: Type.h:183
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:958
Represents a C++ struct/union/class.
Definition: DeclCXX.h:299
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:5755
void setAddrOfGlobalBlock(const BlockExpr *BE, llvm::Constant *Addr)
Notes that BE&#39;s global block is available via Addr.
Definition: CGBlocks.cpp:1198
CharUnits BlockHeaderForcedGapSize
Definition: CGBlocks.h:249
llvm::Value * EmitARCRetainBlock(llvm::Value *value, bool mandatory)
Retain the given block, with _Block_copy semantics.
Definition: CGObjC.cpp:1993
uint64_t getPointerAlign(unsigned AddrSpace) const
Definition: TargetInfo.h:315
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2209
StringRef getName() const
getName - Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:270
llvm::Function * GenerateBlockFunction(GlobalDecl GD, const CGBlockInfo &Info, const DeclMapTy &ldm, bool IsLambdaConversionToBlock, bool BuildGlobalBlock)
Definition: CGBlocks.cpp:1331
TranslationUnitDecl - The top declaration context.
Definition: Decl.h:107
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:956
static RValue get(llvm::Value *V)
Definition: CGValue.h:86
RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue)
Definition: CGBlocks.cpp:1098
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF)
Set the IRBuilder to not attach debug locations.
Definition: CGDebugInfo.h:668
llvm::Constant * getNSConcreteGlobalBlock()
Definition: CGBlocks.cpp:2591
llvm::Type * getBlockDescriptorType()
Fetches the type of a generic block descriptor.
Definition: CGBlocks.cpp:1029
llvm::Constant * GetAddrOfGlobalBlock(const BlockExpr *BE, StringRef Name)
Gets the address of a block which requires no captures.
Definition: CGBlocks.cpp:1206
QualType getType() const
Definition: Decl.h:639
An l-value expression is a reference to an object with independent storage.
Definition: Specifiers.h:111
llvm::PointerType * getGenericVoidPointerType()
Information for lazily generating a cleanup.
Definition: EHScopeStack.h:147
NamedDecl - This represents a decl with a name.
Definition: Decl.h:245
llvm::Instruction * DominatingIP
An instruction which dominates the full-expression that the block is inside.
Definition: CGBlocks.h:253
unsigned long ulong
An unsigned 64-bit integer.
Definition: opencl-c.h:52
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2358
static bool isObjCNSObjectType(QualType Ty)
Return true if this is an NSObject object with its NSObject attribute set.
Definition: ASTContext.h:1941
SourceLocation getLocStart() const LLVM_READONLY
Definition: Stmt.cpp:277
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:182
const LangOptions & getLangOpts() const
Definition: ASTContext.h:661
Address emitBlockByrefAddress(Address baseAddr, const VarDecl *V, bool followForward=true)
BuildBlockByrefAddress - Computes the location of the data in a variable which is declared as __block...
Definition: CGBlocks.cpp:2263
Abstract information about a function or function prototype.
Definition: CGCall.h:44
SourceLocation getLocation() const
Definition: DeclBase.h:416
void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags)
Definition: CGBlocks.cpp:2495
void setCleanup(EHScopeStack::stable_iterator cleanup)
Definition: CGBlocks.h:183
static OMPLinearClause * Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc, OpenMPLinearClauseKind Modifier, SourceLocation ModifierLoc, SourceLocation ColonLoc, SourceLocation EndLoc, ArrayRef< Expr *> VL, ArrayRef< Expr *> PL, ArrayRef< Expr *> IL, Expr *Step, Expr *CalcStep, Stmt *PreInit, Expr *PostUpdate)
Creates clause with a list of variables VL and a linear step Step.
void Destroyer(CodeGenFunction &CGF, Address addr, QualType ty)
Qualifiers::ObjCLifetime getObjCLifetime() const
Returns lifetime attribute of this type.
Definition: Type.h:1076
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1524