clang  7.0.0svn
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 optionally 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;
311  // custom_fields; }'. Assert that struct is packed.
312  elementTypes.push_back(CGM.IntTy); /* total size */
313  elementTypes.push_back(CGM.IntTy); /* align */
314  unsigned Offset = 2 * CGM.getIntSize().getQuantity();
315  unsigned BlockAlign = CGM.getIntAlign().getQuantity();
316  if (auto *Helper =
318  for (auto I : Helper->getCustomFieldTypes()) /* custom fields */ {
319  // TargetOpenCLBlockHelp needs to make sure the struct is packed.
320  // If necessary, add padding fields to the custom fields.
321  unsigned Align = CGM.getDataLayout().getABITypeAlignment(I);
322  if (BlockAlign < Align)
323  BlockAlign = Align;
324  assert(Offset % Align == 0);
325  Offset += CGM.getDataLayout().getTypeAllocSize(I);
326  elementTypes.push_back(I);
327  }
328  }
329  info.BlockAlign = CharUnits::fromQuantity(BlockAlign);
330  info.BlockSize = CharUnits::fromQuantity(Offset);
331  } else {
332  // The header is basically 'struct { void *; int; int; void *; void *; }'.
333  // Assert that the struct is packed.
334  assert(CGM.getIntSize() <= CGM.getPointerSize());
335  assert(CGM.getIntAlign() <= CGM.getPointerAlign());
336  assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()));
337  info.BlockAlign = CGM.getPointerAlign();
338  info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
339  elementTypes.push_back(CGM.VoidPtrTy);
340  elementTypes.push_back(CGM.IntTy);
341  elementTypes.push_back(CGM.IntTy);
342  elementTypes.push_back(CGM.VoidPtrTy);
343  elementTypes.push_back(CGM.getBlockDescriptorType());
344  }
345 }
346 
348  const BlockDecl::Capture &CI) {
349  const VarDecl *VD = CI.getVariable();
350 
351  // If the variable is captured by an enclosing block or lambda expression,
352  // use the type of the capture field.
353  if (CGF.BlockInfo && CI.isNested())
354  return CGF.BlockInfo->getCapture(VD).fieldType();
355  if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
356  return FD->getType();
357  return VD->getType();
358 }
359 
360 /// Compute the layout of the given block. Attempts to lay the block
361 /// out with minimal space requirements.
363  CGBlockInfo &info) {
364  ASTContext &C = CGM.getContext();
365  const BlockDecl *block = info.getBlockDecl();
366 
367  SmallVector<llvm::Type*, 8> elementTypes;
368  initializeForBlockHeader(CGM, info, elementTypes);
369  bool hasNonConstantCustomFields = false;
370  if (auto *OpenCLHelper =
372  hasNonConstantCustomFields =
373  !OpenCLHelper->areAllCustomFieldValuesConstant(info);
374  if (!block->hasCaptures() && !hasNonConstantCustomFields) {
375  info.StructureType =
376  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
377  info.CanBeGlobal = true;
378  return;
379  }
380  else if (C.getLangOpts().ObjC1 &&
381  CGM.getLangOpts().getGC() == LangOptions::NonGC)
382  info.HasCapturedVariableLayout = true;
383 
384  // Collect the layout chunks.
386  layout.reserve(block->capturesCXXThis() +
387  (block->capture_end() - block->capture_begin()));
388 
389  CharUnits maxFieldAlign;
390 
391  // First, 'this'.
392  if (block->capturesCXXThis()) {
393  assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&
394  "Can't capture 'this' outside a method");
395  QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType(C);
396 
397  // Theoretically, this could be in a different address space, so
398  // don't assume standard pointer size/align.
399  llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
400  std::pair<CharUnits,CharUnits> tinfo
401  = CGM.getContext().getTypeInfoInChars(thisType);
402  maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
403 
404  layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
406  nullptr, llvmType, thisType));
407  }
408 
409  // Next, all the block captures.
410  for (const auto &CI : block->captures()) {
411  const VarDecl *variable = CI.getVariable();
412 
413  if (CI.isByRef()) {
414  // We have to copy/dispose of the __block reference.
415  info.NeedsCopyDispose = true;
416 
417  // Just use void* instead of a pointer to the byref type.
418  CharUnits align = CGM.getPointerAlign();
419  maxFieldAlign = std::max(maxFieldAlign, align);
420 
421  layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
423  CGM.VoidPtrTy, variable->getType()));
424  continue;
425  }
426 
427  // Otherwise, build a layout chunk with the size and alignment of
428  // the declaration.
429  if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
430  info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
431  continue;
432  }
433 
434  // If we have a lifetime qualifier, honor it for capture purposes.
435  // That includes *not* copying it if it's __unsafe_unretained.
436  Qualifiers::ObjCLifetime lifetime =
437  variable->getType().getObjCLifetime();
438  if (lifetime) {
439  switch (lifetime) {
440  case Qualifiers::OCL_None: llvm_unreachable("impossible");
443  break;
444 
447  info.NeedsCopyDispose = true;
448  }
449 
450  // Block pointers require copy/dispose. So do Objective-C pointers.
451  } else if (variable->getType()->isObjCRetainableType()) {
452  // But honor the inert __unsafe_unretained qualifier, which doesn't
453  // actually make it into the type system.
454  if (variable->getType()->isObjCInertUnsafeUnretainedType()) {
455  lifetime = Qualifiers::OCL_ExplicitNone;
456  } else {
457  info.NeedsCopyDispose = true;
458  // used for mrr below.
459  lifetime = Qualifiers::OCL_Strong;
460  }
461 
462  // So do types that require non-trivial copy construction.
463  } else if (CI.hasCopyExpr()) {
464  info.NeedsCopyDispose = true;
465  info.HasCXXObject = true;
466 
467  // So do C structs that require non-trivial copy construction or
468  // destruction.
469  } else if (variable->getType().isNonTrivialToPrimitiveCopy() ==
471  variable->getType().isDestructedType() ==
473  info.NeedsCopyDispose = true;
474 
475  // And so do types with destructors.
476  } else if (CGM.getLangOpts().CPlusPlus) {
477  if (const CXXRecordDecl *record =
478  variable->getType()->getAsCXXRecordDecl()) {
479  if (!record->hasTrivialDestructor()) {
480  info.HasCXXObject = true;
481  info.NeedsCopyDispose = true;
482  }
483  }
484  }
485 
486  QualType VT = getCaptureFieldType(*CGF, CI);
487  CharUnits size = C.getTypeSizeInChars(VT);
488  CharUnits align = C.getDeclAlign(variable);
489 
490  maxFieldAlign = std::max(maxFieldAlign, align);
491 
492  llvm::Type *llvmType =
493  CGM.getTypes().ConvertTypeForMem(VT);
494 
495  layout.push_back(
496  BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
497  }
498 
499  // If that was everything, we're done here.
500  if (layout.empty()) {
501  info.StructureType =
502  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
503  info.CanBeGlobal = true;
504  return;
505  }
506 
507  // Sort the layout by alignment. We have to use a stable sort here
508  // to get reproducible results. There should probably be an
509  // llvm::array_pod_stable_sort.
510  std::stable_sort(layout.begin(), layout.end());
511 
512  // Needed for blocks layout info.
515 
516  CharUnits &blockSize = info.BlockSize;
517  info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
518 
519  // Assuming that the first byte in the header is maximally aligned,
520  // get the alignment of the first byte following the header.
521  CharUnits endAlign = getLowBit(blockSize);
522 
523  // If the end of the header isn't satisfactorily aligned for the
524  // maximum thing, look for things that are okay with the header-end
525  // alignment, and keep appending them until we get something that's
526  // aligned right. This algorithm is only guaranteed optimal if
527  // that condition is satisfied at some point; otherwise we can get
528  // things like:
529  // header // next byte has alignment 4
530  // something_with_size_5; // next byte has alignment 1
531  // something_with_alignment_8;
532  // which has 7 bytes of padding, as opposed to the naive solution
533  // which might have less (?).
534  if (endAlign < maxFieldAlign) {
536  li = layout.begin() + 1, le = layout.end();
537 
538  // Look for something that the header end is already
539  // satisfactorily aligned for.
540  for (; li != le && endAlign < li->Alignment; ++li)
541  ;
542 
543  // If we found something that's naturally aligned for the end of
544  // the header, keep adding things...
545  if (li != le) {
547  for (; li != le; ++li) {
548  assert(endAlign >= li->Alignment);
549 
550  li->setIndex(info, elementTypes.size(), blockSize);
551  elementTypes.push_back(li->Type);
552  blockSize += li->Size;
553  endAlign = getLowBit(blockSize);
554 
555  // ...until we get to the alignment of the maximum field.
556  if (endAlign >= maxFieldAlign) {
557  break;
558  }
559  }
560  // Don't re-append everything we just appended.
561  layout.erase(first, li);
562  }
563  }
564 
565  assert(endAlign == getLowBit(blockSize));
566 
567  // At this point, we just have to add padding if the end align still
568  // isn't aligned right.
569  if (endAlign < maxFieldAlign) {
570  CharUnits newBlockSize = blockSize.alignTo(maxFieldAlign);
571  CharUnits padding = newBlockSize - blockSize;
572 
573  // If we haven't yet added any fields, remember that there was an
574  // initial gap; this need to go into the block layout bit map.
575  if (blockSize == info.BlockHeaderForcedGapOffset) {
576  info.BlockHeaderForcedGapSize = padding;
577  }
578 
579  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
580  padding.getQuantity()));
581  blockSize = newBlockSize;
582  endAlign = getLowBit(blockSize); // might be > maxFieldAlign
583  }
584 
585  assert(endAlign >= maxFieldAlign);
586  assert(endAlign == getLowBit(blockSize));
587  // Slam everything else on now. This works because they have
588  // strictly decreasing alignment and we expect that size is always a
589  // multiple of alignment.
591  li = layout.begin(), le = layout.end(); li != le; ++li) {
592  if (endAlign < li->Alignment) {
593  // size may not be multiple of alignment. This can only happen with
594  // an over-aligned variable. We will be adding a padding field to
595  // make the size be multiple of alignment.
596  CharUnits padding = li->Alignment - endAlign;
597  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
598  padding.getQuantity()));
599  blockSize += padding;
600  endAlign = getLowBit(blockSize);
601  }
602  assert(endAlign >= li->Alignment);
603  li->setIndex(info, elementTypes.size(), blockSize);
604  elementTypes.push_back(li->Type);
605  blockSize += li->Size;
606  endAlign = getLowBit(blockSize);
607  }
608 
609  info.StructureType =
610  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
611 }
612 
613 /// Enter the scope of a block. This should be run at the entrance to
614 /// a full-expression so that the block's cleanups are pushed at the
615 /// right place in the stack.
616 static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
617  assert(CGF.HaveInsertPoint());
618 
619  // Allocate the block info and place it at the head of the list.
620  CGBlockInfo &blockInfo =
621  *new CGBlockInfo(block, CGF.CurFn->getName());
622  blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
623  CGF.FirstBlockInfo = &blockInfo;
624 
625  // Compute information about the layout, etc., of this block,
626  // pushing cleanups as necessary.
627  computeBlockInfo(CGF.CGM, &CGF, blockInfo);
628 
629  // Nothing else to do if it can be global.
630  if (blockInfo.CanBeGlobal) return;
631 
632  // Make the allocation for the block.
633  blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
634  blockInfo.BlockAlign, "block");
635 
636  // If there are cleanups to emit, enter them (but inactive).
637  if (!blockInfo.NeedsCopyDispose) return;
638 
639  // Walk through the captures (in order) and find the ones not
640  // captured by constant.
641  for (const auto &CI : block->captures()) {
642  // Ignore __block captures; there's nothing special in the
643  // on-stack block that we need to do for them.
644  if (CI.isByRef()) continue;
645 
646  // Ignore variables that are constant-captured.
647  const VarDecl *variable = CI.getVariable();
648  CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
649  if (capture.isConstant()) continue;
650 
651  // Ignore objects that aren't destructed.
652  QualType VT = getCaptureFieldType(CGF, CI);
654  if (dtorKind == QualType::DK_none) continue;
655 
656  CodeGenFunction::Destroyer *destroyer;
657 
658  // Block captures count as local values and have imprecise semantics.
659  // They also can't be arrays, so need to worry about that.
660  //
661  // For const-qualified captures, emit clang.arc.use to ensure the captured
662  // object doesn't get released while we are still depending on its validity
663  // within the block.
664  if (VT.isConstQualified() &&
666  CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
667  assert(CGF.CGM.getLangOpts().ObjCAutoRefCount &&
668  "expected ObjC ARC to be enabled");
670  } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
672  } else {
673  destroyer = CGF.getDestroyer(dtorKind);
674  }
675 
676  // GEP down to the address.
677  Address addr = CGF.Builder.CreateStructGEP(blockInfo.LocalAddress,
678  capture.getIndex(),
679  capture.getOffset());
680 
681  // We can use that GEP as the dominating IP.
682  if (!blockInfo.DominatingIP)
683  blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
684 
685  CleanupKind cleanupKind = InactiveNormalCleanup;
686  bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
687  if (useArrayEHCleanup)
688  cleanupKind = InactiveNormalAndEHCleanup;
689 
690  CGF.pushDestroy(cleanupKind, addr, VT,
691  destroyer, useArrayEHCleanup);
692 
693  // Remember where that cleanup was.
694  capture.setCleanup(CGF.EHStack.stable_begin());
695  }
696 }
697 
698 /// Enter a full-expression with a non-trivial number of objects to
699 /// clean up. This is in this file because, at the moment, the only
700 /// kind of cleanup object is a BlockDecl*.
702  assert(E->getNumObjects() != 0);
703  for (const ExprWithCleanups::CleanupObject &C : E->getObjects())
704  enterBlockScope(*this, C);
705 }
706 
707 /// Find the layout for the given block in a linked list and remove it.
709  const BlockDecl *block) {
710  while (true) {
711  assert(head && *head);
712  CGBlockInfo *cur = *head;
713 
714  // If this is the block we're looking for, splice it out of the list.
715  if (cur->getBlockDecl() == block) {
716  *head = cur->NextBlockInfo;
717  return cur;
718  }
719 
720  head = &cur->NextBlockInfo;
721  }
722 }
723 
724 /// Destroy a chain of block layouts.
726  assert(head && "destroying an empty chain");
727  do {
728  CGBlockInfo *cur = head;
729  head = cur->NextBlockInfo;
730  delete cur;
731  } while (head != nullptr);
732 }
733 
734 /// Emit a block literal expression in the current function.
736  // If the block has no captures, we won't have a pre-computed
737  // layout for it.
738  if (!blockExpr->getBlockDecl()->hasCaptures()) {
739  // The block literal is emitted as a global variable, and the block invoke
740  // function has to be extracted from its initializer.
741  if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr)) {
742  return Block;
743  }
744  CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
745  computeBlockInfo(CGM, this, blockInfo);
746  blockInfo.BlockExpression = blockExpr;
747  return EmitBlockLiteral(blockInfo);
748  }
749 
750  // Find the block info for this block and take ownership of it.
751  std::unique_ptr<CGBlockInfo> blockInfo;
752  blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
753  blockExpr->getBlockDecl()));
754 
755  blockInfo->BlockExpression = blockExpr;
756  return EmitBlockLiteral(*blockInfo);
757 }
758 
760  bool IsOpenCL = CGM.getContext().getLangOpts().OpenCL;
761  // Using the computed layout, generate the actual block function.
762  bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
763  CodeGenFunction BlockCGF{CGM, true};
764  BlockCGF.SanOpts = SanOpts;
765  auto *InvokeFn = BlockCGF.GenerateBlockFunction(
766  CurGD, blockInfo, LocalDeclMap, isLambdaConv, blockInfo.CanBeGlobal);
767 
768  // If there is nothing to capture, we can emit this as a global block.
769  if (blockInfo.CanBeGlobal)
770  return CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression);
771 
772  // Otherwise, we have to emit this as a local block.
773 
774  Address blockAddr = blockInfo.LocalAddress;
775  assert(blockAddr.isValid() && "block has no address!");
776 
777  llvm::Constant *isa;
778  llvm::Constant *descriptor;
779  BlockFlags flags;
780  if (!IsOpenCL) {
781  isa = llvm::ConstantExpr::getBitCast(CGM.getNSConcreteStackBlock(),
782  VoidPtrTy);
783 
784  // Build the block descriptor.
785  descriptor = buildBlockDescriptor(CGM, blockInfo);
786 
787  // Compute the initial on-stack block flags.
788  flags = BLOCK_HAS_SIGNATURE;
789  if (blockInfo.HasCapturedVariableLayout)
790  flags |= BLOCK_HAS_EXTENDED_LAYOUT;
791  if (blockInfo.NeedsCopyDispose)
792  flags |= BLOCK_HAS_COPY_DISPOSE;
793  if (blockInfo.HasCXXObject)
794  flags |= BLOCK_HAS_CXX_OBJ;
795  if (blockInfo.UsesStret)
796  flags |= BLOCK_USE_STRET;
797  }
798 
799  auto projectField =
800  [&](unsigned index, CharUnits offset, const Twine &name) -> Address {
801  return Builder.CreateStructGEP(blockAddr, index, offset, name);
802  };
803  auto storeField =
804  [&](llvm::Value *value, unsigned index, CharUnits offset,
805  const Twine &name) {
806  Builder.CreateStore(value, projectField(index, offset, name));
807  };
808 
809  // Initialize the block header.
810  {
811  // We assume all the header fields are densely packed.
812  unsigned index = 0;
813  CharUnits offset;
814  auto addHeaderField =
815  [&](llvm::Value *value, CharUnits size, const Twine &name) {
816  storeField(value, index, offset, name);
817  offset += size;
818  index++;
819  };
820 
821  if (!IsOpenCL) {
822  addHeaderField(isa, getPointerSize(), "block.isa");
823  addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
824  getIntSize(), "block.flags");
825  addHeaderField(llvm::ConstantInt::get(IntTy, 0), getIntSize(),
826  "block.reserved");
827  } else {
828  addHeaderField(
829  llvm::ConstantInt::get(IntTy, blockInfo.BlockSize.getQuantity()),
830  getIntSize(), "block.size");
831  addHeaderField(
832  llvm::ConstantInt::get(IntTy, blockInfo.BlockAlign.getQuantity()),
833  getIntSize(), "block.align");
834  }
835  if (!IsOpenCL) {
836  addHeaderField(llvm::ConstantExpr::getBitCast(InvokeFn, VoidPtrTy),
837  getPointerSize(), "block.invoke");
838  addHeaderField(descriptor, getPointerSize(), "block.descriptor");
839  } else if (auto *Helper =
841  for (auto I : Helper->getCustomFieldValues(*this, blockInfo)) {
842  addHeaderField(
843  I.first,
845  CGM.getDataLayout().getTypeAllocSize(I.first->getType())),
846  I.second);
847  }
848  }
849  }
850 
851  // Finally, capture all the values into the block.
852  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
853 
854  // First, 'this'.
855  if (blockDecl->capturesCXXThis()) {
856  Address addr = projectField(blockInfo.CXXThisIndex, blockInfo.CXXThisOffset,
857  "block.captured-this.addr");
858  Builder.CreateStore(LoadCXXThis(), addr);
859  }
860 
861  // Next, captured variables.
862  for (const auto &CI : blockDecl->captures()) {
863  const VarDecl *variable = CI.getVariable();
864  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
865 
866  // Ignore constant captures.
867  if (capture.isConstant()) continue;
868 
869  QualType type = capture.fieldType();
870 
871  // This will be a [[type]]*, except that a byref entry will just be
872  // an i8**.
873  Address blockField =
874  projectField(capture.getIndex(), capture.getOffset(), "block.captured");
875 
876  // Compute the address of the thing we're going to move into the
877  // block literal.
878  Address src = Address::invalid();
879 
880  if (blockDecl->isConversionFromLambda()) {
881  // The lambda capture in a lambda's conversion-to-block-pointer is
882  // special; we'll simply emit it directly.
883  src = Address::invalid();
884  } else if (CI.isByRef()) {
885  if (BlockInfo && CI.isNested()) {
886  // We need to use the capture from the enclosing block.
887  const CGBlockInfo::Capture &enclosingCapture =
888  BlockInfo->getCapture(variable);
889 
890  // This is a [[type]]*, except that a byref entry will just be an i8**.
891  src = Builder.CreateStructGEP(LoadBlockStruct(),
892  enclosingCapture.getIndex(),
893  enclosingCapture.getOffset(),
894  "block.capture.addr");
895  } else {
896  auto I = LocalDeclMap.find(variable);
897  assert(I != LocalDeclMap.end());
898  src = I->second;
899  }
900  } else {
901  DeclRefExpr declRef(const_cast<VarDecl *>(variable),
902  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
904  SourceLocation());
905  src = EmitDeclRefLValue(&declRef).getAddress();
906  };
907 
908  // For byrefs, we just write the pointer to the byref struct into
909  // the block field. There's no need to chase the forwarding
910  // pointer at this point, since we're building something that will
911  // live a shorter life than the stack byref anyway.
912  if (CI.isByRef()) {
913  // Get a void* that points to the byref struct.
914  llvm::Value *byrefPointer;
915  if (CI.isNested())
916  byrefPointer = Builder.CreateLoad(src, "byref.capture");
917  else
918  byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
919 
920  // Write that void* into the capture field.
921  Builder.CreateStore(byrefPointer, blockField);
922 
923  // If we have a copy constructor, evaluate that into the block field.
924  } else if (const Expr *copyExpr = CI.getCopyExpr()) {
925  if (blockDecl->isConversionFromLambda()) {
926  // If we have a lambda conversion, emit the expression
927  // directly into the block instead.
928  AggValueSlot Slot =
929  AggValueSlot::forAddr(blockField, Qualifiers(),
934  EmitAggExpr(copyExpr, Slot);
935  } else {
936  EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
937  }
938 
939  // If it's a reference variable, copy the reference into the block field.
940  } else if (type->isReferenceType()) {
941  Builder.CreateStore(src.getPointer(), blockField);
942 
943  // If type is const-qualified, copy the value into the block field.
944  } else if (type.isConstQualified() &&
946  CGM.getCodeGenOpts().OptimizationLevel != 0) {
947  llvm::Value *value = Builder.CreateLoad(src, "captured");
948  Builder.CreateStore(value, blockField);
949 
950  // If this is an ARC __strong block-pointer variable, don't do a
951  // block copy.
952  //
953  // TODO: this can be generalized into the normal initialization logic:
954  // we should never need to do a block-copy when initializing a local
955  // variable, because the local variable's lifetime should be strictly
956  // contained within the stack block's.
957  } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
958  type->isBlockPointerType()) {
959  // Load the block and do a simple retain.
960  llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
961  value = EmitARCRetainNonBlock(value);
962 
963  // Do a primitive store to the block field.
964  Builder.CreateStore(value, blockField);
965 
966  // Otherwise, fake up a POD copy into the block field.
967  } else {
968  // Fake up a new variable so that EmitScalarInit doesn't think
969  // we're referring to the variable in its own initializer.
970  ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
972 
973  // We use one of these or the other depending on whether the
974  // reference is nested.
975  DeclRefExpr declRef(const_cast<VarDecl *>(variable),
976  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
978 
979  ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
980  &declRef, VK_RValue);
981  // FIXME: Pass a specific location for the expr init so that the store is
982  // attributed to a reasonable location - otherwise it may be attributed to
983  // locations of subexpressions in the initialization.
984  EmitExprAsInit(&l2r, &BlockFieldPseudoVar,
985  MakeAddrLValue(blockField, type, AlignmentSource::Decl),
986  /*captured by init*/ false);
987  }
988 
989  // Activate the cleanup if layout pushed one.
990  if (!CI.isByRef()) {
992  if (cleanup.isValid())
993  ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
994  }
995  }
996 
997  // Cast to the converted block-pointer type, which happens (somewhat
998  // unfortunately) to be a pointer to function type.
999  llvm::Value *result = Builder.CreatePointerCast(
1000  blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
1001 
1002  if (IsOpenCL) {
1003  CGM.getOpenCLRuntime().recordBlockInfo(blockInfo.BlockExpression, InvokeFn,
1004  result);
1005  }
1006 
1007  return result;
1008 }
1009 
1010 
1012  if (BlockDescriptorType)
1013  return BlockDescriptorType;
1014 
1015  llvm::Type *UnsignedLongTy =
1016  getTypes().ConvertType(getContext().UnsignedLongTy);
1017 
1018  // struct __block_descriptor {
1019  // unsigned long reserved;
1020  // unsigned long block_size;
1021  //
1022  // // later, the following will be added
1023  //
1024  // struct {
1025  // void (*copyHelper)();
1026  // void (*copyHelper)();
1027  // } helpers; // !!! optional
1028  //
1029  // const char *signature; // the block signature
1030  // const char *layout; // reserved
1031  // };
1032  BlockDescriptorType = llvm::StructType::create(
1033  "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
1034 
1035  // Now form a pointer to that.
1036  unsigned AddrSpace = 0;
1037  if (getLangOpts().OpenCL)
1038  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
1039  BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
1040  return BlockDescriptorType;
1041 }
1042 
1044  assert(!getLangOpts().OpenCL && "OpenCL does not need this");
1045 
1046  if (GenericBlockLiteralType)
1047  return GenericBlockLiteralType;
1048 
1049  llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
1050 
1051  // struct __block_literal_generic {
1052  // void *__isa;
1053  // int __flags;
1054  // int __reserved;
1055  // void (*__invoke)(void *);
1056  // struct __block_descriptor *__descriptor;
1057  // };
1058  GenericBlockLiteralType =
1059  llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
1060  IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
1061 
1062  return GenericBlockLiteralType;
1063 }
1064 
1066  ReturnValueSlot ReturnValue) {
1067  const BlockPointerType *BPT =
1069 
1070  llvm::Value *BlockPtr = EmitScalarExpr(E->getCallee());
1071  llvm::Value *FuncPtr;
1072 
1073  if (!CGM.getLangOpts().OpenCL) {
1074  // Get a pointer to the generic block literal.
1075  llvm::Type *BlockLiteralTy =
1076  llvm::PointerType::get(CGM.getGenericBlockLiteralType(), 0);
1077 
1078  // Bitcast the callee to a block literal.
1079  BlockPtr =
1080  Builder.CreatePointerCast(BlockPtr, BlockLiteralTy, "block.literal");
1081 
1082  // Get the function pointer from the literal.
1083  FuncPtr =
1084  Builder.CreateStructGEP(CGM.getGenericBlockLiteralType(), BlockPtr, 3);
1085  }
1086 
1087  // Add the block literal.
1088  CallArgList Args;
1089 
1090  QualType VoidPtrQualTy = getContext().VoidPtrTy;
1091  llvm::Type *GenericVoidPtrTy = VoidPtrTy;
1092  if (getLangOpts().OpenCL) {
1093  GenericVoidPtrTy = CGM.getOpenCLRuntime().getGenericVoidPointerType();
1094  VoidPtrQualTy =
1095  getContext().getPointerType(getContext().getAddrSpaceQualType(
1096  getContext().VoidTy, LangAS::opencl_generic));
1097  }
1098 
1099  BlockPtr = Builder.CreatePointerCast(BlockPtr, GenericVoidPtrTy);
1100  Args.add(RValue::get(BlockPtr), VoidPtrQualTy);
1101 
1102  QualType FnType = BPT->getPointeeType();
1103 
1104  // And the rest of the arguments.
1105  EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1106 
1107  // Load the function.
1108  llvm::Value *Func;
1109  if (CGM.getLangOpts().OpenCL)
1110  Func = CGM.getOpenCLRuntime().getInvokeFunction(E->getCallee());
1111  else
1112  Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1113 
1114  const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1115  const CGFunctionInfo &FnInfo =
1116  CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
1117 
1118  // Cast the function pointer to the right type.
1119  llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
1120 
1121  llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
1122  Func = Builder.CreatePointerCast(Func, BlockFTyPtr);
1123 
1124  // Prepare the callee.
1125  CGCallee Callee(CGCalleeInfo(), Func);
1126 
1127  // And call the block.
1128  return EmitCall(FnInfo, Callee, ReturnValue, Args);
1129 }
1130 
1132  bool isByRef) {
1133  assert(BlockInfo && "evaluating block ref without block information?");
1134  const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1135 
1136  // Handle constant captures.
1137  if (capture.isConstant()) return LocalDeclMap.find(variable)->second;
1138 
1139  Address addr =
1140  Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(),
1141  capture.getOffset(), "block.capture.addr");
1142 
1143  if (isByRef) {
1144  // addr should be a void** right now. Load, then cast the result
1145  // to byref*.
1146 
1147  auto &byrefInfo = getBlockByrefInfo(variable);
1148  addr = Address(Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
1149 
1150  auto byrefPointerType = llvm::PointerType::get(byrefInfo.Type, 0);
1151  addr = Builder.CreateBitCast(addr, byrefPointerType, "byref.addr");
1152 
1153  addr = emitBlockByrefAddress(addr, byrefInfo, /*follow*/ true,
1154  variable->getName());
1155  }
1156 
1157  if (capture.fieldType()->isReferenceType())
1158  addr = EmitLoadOfReference(MakeAddrLValue(addr, capture.fieldType()));
1159 
1160  return addr;
1161 }
1162 
1164  llvm::Constant *Addr) {
1165  bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
1166  (void)Ok;
1167  assert(Ok && "Trying to replace an already-existing global block!");
1168 }
1169 
1170 llvm::Constant *
1172  StringRef Name) {
1173  if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1174  return Block;
1175 
1176  CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1177  blockInfo.BlockExpression = BE;
1178 
1179  // Compute information about the layout, etc., of this block.
1180  computeBlockInfo(*this, nullptr, blockInfo);
1181 
1182  // Using that metadata, generate the actual block function.
1183  {
1184  CodeGenFunction::DeclMapTy LocalDeclMap;
1186  GlobalDecl(), blockInfo, LocalDeclMap,
1187  /*IsLambdaConversionToBlock*/ false, /*BuildGlobalBlock*/ true);
1188  }
1189 
1190  return getAddrOfGlobalBlockIfEmitted(BE);
1191 }
1192 
1193 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1194  const CGBlockInfo &blockInfo,
1195  llvm::Constant *blockFn) {
1196  assert(blockInfo.CanBeGlobal);
1197  // Callers should detect this case on their own: calling this function
1198  // generally requires computing layout information, which is a waste of time
1199  // if we've already emitted this block.
1200  assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&
1201  "Refusing to re-emit a global block.");
1202 
1203  // Generate the constants for the block literal initializer.
1204  ConstantInitBuilder builder(CGM);
1205  auto fields = builder.beginStruct();
1206 
1207  bool IsOpenCL = CGM.getLangOpts().OpenCL;
1208  if (!IsOpenCL) {
1209  // isa
1210  fields.add(CGM.getNSConcreteGlobalBlock());
1211 
1212  // __flags
1214  if (blockInfo.UsesStret)
1215  flags |= BLOCK_USE_STRET;
1216 
1217  fields.addInt(CGM.IntTy, flags.getBitMask());
1218 
1219  // Reserved
1220  fields.addInt(CGM.IntTy, 0);
1221 
1222  // Function
1223  fields.add(blockFn);
1224  } else {
1225  fields.addInt(CGM.IntTy, blockInfo.BlockSize.getQuantity());
1226  fields.addInt(CGM.IntTy, blockInfo.BlockAlign.getQuantity());
1227  }
1228 
1229  if (!IsOpenCL) {
1230  // Descriptor
1231  fields.add(buildBlockDescriptor(CGM, blockInfo));
1232  } else if (auto *Helper =
1234  for (auto I : Helper->getCustomFieldValues(CGM, blockInfo)) {
1235  fields.add(I);
1236  }
1237  }
1238 
1239  unsigned AddrSpace = 0;
1240  if (CGM.getContext().getLangOpts().OpenCL)
1242 
1243  llvm::Constant *literal = fields.finishAndCreateGlobal(
1244  "__block_literal_global", blockInfo.BlockAlign,
1245  /*constant*/ true, llvm::GlobalVariable::InternalLinkage, AddrSpace);
1246 
1247  // Return a constant of the appropriately-casted type.
1248  llvm::Type *RequiredType =
1249  CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1250  llvm::Constant *Result =
1251  llvm::ConstantExpr::getPointerCast(literal, RequiredType);
1252  CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
1253  if (CGM.getContext().getLangOpts().OpenCL)
1255  blockInfo.BlockExpression,
1256  cast<llvm::Function>(blockFn->stripPointerCasts()), Result);
1257  return Result;
1258 }
1259 
1261  unsigned argNum,
1262  llvm::Value *arg) {
1263  assert(BlockInfo && "not emitting prologue of block invocation function?!");
1264 
1265  // Allocate a stack slot like for any local variable to guarantee optimal
1266  // debug info at -O0. The mem2reg pass will eliminate it when optimizing.
1267  Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr");
1268  Builder.CreateStore(arg, alloc);
1269  if (CGDebugInfo *DI = getDebugInfo()) {
1270  if (CGM.getCodeGenOpts().getDebugInfo() >=
1272  DI->setLocation(D->getLocation());
1273  DI->EmitDeclareOfBlockLiteralArgVariable(
1274  *BlockInfo, D->getName(), argNum,
1275  cast<llvm::AllocaInst>(alloc.getPointer()), Builder);
1276  }
1277  }
1278 
1279  SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getLocStart();
1280  ApplyDebugLocation Scope(*this, StartLoc);
1281 
1282  // Instead of messing around with LocalDeclMap, just set the value
1283  // directly as BlockPointer.
1284  BlockPointer = Builder.CreatePointerCast(
1285  arg,
1286  BlockInfo->StructureType->getPointerTo(
1287  getContext().getLangOpts().OpenCL
1288  ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1289  : 0),
1290  "block");
1291 }
1292 
1294  assert(BlockInfo && "not in a block invocation function!");
1295  assert(BlockPointer && "no block pointer set!");
1296  return Address(BlockPointer, BlockInfo->BlockAlign);
1297 }
1298 
1299 llvm::Function *
1301  const CGBlockInfo &blockInfo,
1302  const DeclMapTy &ldm,
1303  bool IsLambdaConversionToBlock,
1304  bool BuildGlobalBlock) {
1305  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1306 
1307  CurGD = GD;
1308 
1309  CurEHLocation = blockInfo.getBlockExpr()->getLocEnd();
1310 
1311  BlockInfo = &blockInfo;
1312 
1313  // Arrange for local static and local extern declarations to appear
1314  // to be local to this function as well, in case they're directly
1315  // referenced in a block.
1316  for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1317  const auto *var = dyn_cast<VarDecl>(i->first);
1318  if (var && !var->hasLocalStorage())
1319  setAddrOfLocalVar(var, i->second);
1320  }
1321 
1322  // Begin building the function declaration.
1323 
1324  // Build the argument list.
1325  FunctionArgList args;
1326 
1327  // The first argument is the block pointer. Just take it as a void*
1328  // and cast it later.
1329  QualType selfTy = getContext().VoidPtrTy;
1330 
1331  // For OpenCL passed block pointer can be private AS local variable or
1332  // global AS program scope variable (for the case with and without captures).
1333  // Generic AS is used therefore to be able to accommodate both private and
1334  // generic AS in one implementation.
1335  if (getLangOpts().OpenCL)
1336  selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1337  getContext().VoidTy, LangAS::opencl_generic));
1338 
1339  IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1340 
1341  ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1342  SourceLocation(), II, selfTy,
1344  args.push_back(&SelfDecl);
1345 
1346  // Now add the rest of the parameters.
1347  args.append(blockDecl->param_begin(), blockDecl->param_end());
1348 
1349  // Create the function declaration.
1350  const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1351  const CGFunctionInfo &fnInfo =
1352  CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1353  if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1354  blockInfo.UsesStret = true;
1355 
1356  llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1357 
1358  StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1359  llvm::Function *fn = llvm::Function::Create(
1360  fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1361  CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1362 
1363  if (BuildGlobalBlock) {
1364  auto GenVoidPtrTy = getContext().getLangOpts().OpenCL
1366  : VoidPtrTy;
1367  buildGlobalBlock(CGM, blockInfo,
1368  llvm::ConstantExpr::getPointerCast(fn, GenVoidPtrTy));
1369  }
1370 
1371  // Begin generating the function.
1372  StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1373  blockDecl->getLocation(),
1374  blockInfo.getBlockExpr()->getBody()->getLocStart());
1375 
1376  // Okay. Undo some of what StartFunction did.
1377 
1378  // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1379  // won't delete the dbg.declare intrinsics for captured variables.
1380  llvm::Value *BlockPointerDbgLoc = BlockPointer;
1381  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1382  // Allocate a stack slot for it, so we can point the debugger to it
1383  Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1384  getPointerAlign(),
1385  "block.addr");
1386  // Set the DebugLocation to empty, so the store is recognized as a
1387  // frame setup instruction by llvm::DwarfDebug::beginFunction().
1388  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1389  Builder.CreateStore(BlockPointer, Alloca);
1390  BlockPointerDbgLoc = Alloca.getPointer();
1391  }
1392 
1393  // If we have a C++ 'this' reference, go ahead and force it into
1394  // existence now.
1395  if (blockDecl->capturesCXXThis()) {
1396  Address addr =
1397  Builder.CreateStructGEP(LoadBlockStruct(), blockInfo.CXXThisIndex,
1398  blockInfo.CXXThisOffset, "block.captured-this");
1399  CXXThisValue = Builder.CreateLoad(addr, "this");
1400  }
1401 
1402  // Also force all the constant captures.
1403  for (const auto &CI : blockDecl->captures()) {
1404  const VarDecl *variable = CI.getVariable();
1405  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1406  if (!capture.isConstant()) continue;
1407 
1408  CharUnits align = getContext().getDeclAlign(variable);
1409  Address alloca =
1410  CreateMemTemp(variable->getType(), align, "block.captured-const");
1411 
1412  Builder.CreateStore(capture.getConstant(), alloca);
1413 
1414  setAddrOfLocalVar(variable, alloca);
1415  }
1416 
1417  // Save a spot to insert the debug information for all the DeclRefExprs.
1418  llvm::BasicBlock *entry = Builder.GetInsertBlock();
1419  llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1420  --entry_ptr;
1421 
1422  if (IsLambdaConversionToBlock)
1423  EmitLambdaBlockInvokeBody();
1424  else {
1425  PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1426  incrementProfileCounter(blockDecl->getBody());
1427  EmitStmt(blockDecl->getBody());
1428  }
1429 
1430  // Remember where we were...
1431  llvm::BasicBlock *resume = Builder.GetInsertBlock();
1432 
1433  // Go back to the entry.
1434  ++entry_ptr;
1435  Builder.SetInsertPoint(entry, entry_ptr);
1436 
1437  // Emit debug information for all the DeclRefExprs.
1438  // FIXME: also for 'this'
1439  if (CGDebugInfo *DI = getDebugInfo()) {
1440  for (const auto &CI : blockDecl->captures()) {
1441  const VarDecl *variable = CI.getVariable();
1442  DI->EmitLocation(Builder, variable->getLocation());
1443 
1444  if (CGM.getCodeGenOpts().getDebugInfo() >=
1446  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1447  if (capture.isConstant()) {
1448  auto addr = LocalDeclMap.find(variable)->second;
1449  (void)DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1450  Builder);
1451  continue;
1452  }
1453 
1454  DI->EmitDeclareOfBlockDeclRefVariable(
1455  variable, BlockPointerDbgLoc, Builder, blockInfo,
1456  entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1457  }
1458  }
1459  // Recover location if it was changed in the above loop.
1460  DI->EmitLocation(Builder,
1461  cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1462  }
1463 
1464  // And resume where we left off.
1465  if (resume == nullptr)
1466  Builder.ClearInsertionPoint();
1467  else
1468  Builder.SetInsertPoint(resume);
1469 
1470  FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1471 
1472  return fn;
1473 }
1474 
1475 namespace {
1476 
1477 /// Represents a type of copy/destroy operation that should be performed for an
1478 /// entity that's captured by a block.
1480  CXXRecord, // Copy or destroy
1481  ARCWeak,
1482  ARCStrong,
1483  NonTrivialCStruct,
1484  BlockObject, // Assign or release
1485  None
1486 };
1487 
1488 /// Represents a captured entity that requires extra operations in order for
1489 /// this entity to be copied or destroyed correctly.
1490 struct BlockCaptureManagedEntity {
1492  BlockFieldFlags Flags;
1493  const BlockDecl::Capture &CI;
1495 
1496  BlockCaptureManagedEntity(BlockCaptureEntityKind Type, BlockFieldFlags Flags,
1497  const BlockDecl::Capture &CI,
1498  const CGBlockInfo::Capture &Capture)
1499  : Kind(Type), Flags(Flags), CI(CI), Capture(Capture) {}
1500 };
1501 
1502 } // end anonymous namespace
1503 
1504 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1506  const LangOptions &LangOpts) {
1507  if (CI.getCopyExpr()) {
1508  assert(!CI.isByRef());
1509  // don't bother computing flags
1510  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1511  }
1512  BlockFieldFlags Flags;
1513  if (CI.isByRef()) {
1514  Flags = BLOCK_FIELD_IS_BYREF;
1515  if (T.isObjCGCWeak())
1516  Flags |= BLOCK_FIELD_IS_WEAK;
1517  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1518  }
1519 
1520  Flags = BLOCK_FIELD_IS_OBJECT;
1521  bool isBlockPointer = T->isBlockPointerType();
1522  if (isBlockPointer)
1523  Flags = BLOCK_FIELD_IS_BLOCK;
1524 
1525  switch (T.isNonTrivialToPrimitiveCopy()) {
1526  case QualType::PCK_Struct:
1527  return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
1528  BlockFieldFlags());
1529  case QualType::PCK_ARCWeak:
1530  // We need to register __weak direct captures with the runtime.
1531  return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1533  // We need to retain the copied value for __strong direct captures.
1534  // If it's a block pointer, we have to copy the block and assign that to
1535  // the destination pointer, so we might as well use _Block_object_assign.
1536  // Otherwise we can avoid that.
1537  return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1538  : BlockCaptureEntityKind::BlockObject,
1539  Flags);
1540  case QualType::PCK_Trivial:
1542  if (!T->isObjCRetainableType())
1543  // For all other types, the memcpy is fine.
1544  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1545 
1546  // Special rules for ARC captures:
1547  Qualifiers QS = T.getQualifiers();
1548 
1549  // Non-ARC captures of retainable pointers are strong and
1550  // therefore require a call to _Block_object_assign.
1551  if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1552  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1553 
1554  // Otherwise the memcpy is fine.
1555  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1556  }
1557  }
1558  llvm_unreachable("after exhaustive PrimitiveCopyKind switch");
1559 }
1560 
1561 /// Find the set of block captures that need to be explicitly copied or destroy.
1563  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1565  llvm::function_ref<std::pair<BlockCaptureEntityKind, BlockFieldFlags>(
1566  const BlockDecl::Capture &, QualType, const LangOptions &)>
1567  Predicate) {
1568  for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1569  const VarDecl *Variable = CI.getVariable();
1570  const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1571  if (Capture.isConstant())
1572  continue;
1573 
1574  auto Info = Predicate(CI, Variable->getType(), LangOpts);
1575  if (Info.first != BlockCaptureEntityKind::None)
1576  ManagedCaptures.emplace_back(Info.first, Info.second, CI, Capture);
1577  }
1578 }
1579 
1580 /// Generate the copy-helper function for a block closure object:
1581 /// static void block_copy_helper(block_t *dst, block_t *src);
1582 /// The runtime will have previously initialized 'dst' by doing a
1583 /// bit-copy of 'src'.
1584 ///
1585 /// Note that this copies an entire block closure object to the heap;
1586 /// it should not be confused with a 'byref copy helper', which moves
1587 /// the contents of an individual __block variable to the heap.
1588 llvm::Constant *
1590  ASTContext &C = getContext();
1591 
1592  FunctionArgList args;
1593  ImplicitParamDecl DstDecl(getContext(), C.VoidPtrTy,
1595  args.push_back(&DstDecl);
1596  ImplicitParamDecl SrcDecl(getContext(), C.VoidPtrTy,
1598  args.push_back(&SrcDecl);
1599 
1600  const CGFunctionInfo &FI =
1602 
1603  // FIXME: it would be nice if these were mergeable with things with
1604  // identical semantics.
1605  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1606 
1607  llvm::Function *Fn =
1609  "__copy_helper_block_", &CGM.getModule());
1610 
1611  IdentifierInfo *II
1612  = &CGM.getContext().Idents.get("__copy_helper_block_");
1613 
1616  SourceLocation(),
1617  SourceLocation(), II, C.VoidTy,
1618  nullptr, SC_Static,
1619  false,
1620  false);
1621 
1623 
1624  StartFunction(FD, C.VoidTy, Fn, FI, args);
1625  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getLocStart()};
1626  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1627 
1628  Address src = GetAddrOfLocalVar(&SrcDecl);
1629  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
1630  src = Builder.CreateBitCast(src, structPtrTy, "block.source");
1631 
1632  Address dst = GetAddrOfLocalVar(&DstDecl);
1633  dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
1634  dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
1635 
1637  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures,
1639 
1640  for (const auto &CopiedCapture : CopiedCaptures) {
1641  const BlockDecl::Capture &CI = CopiedCapture.CI;
1642  const CGBlockInfo::Capture &capture = CopiedCapture.Capture;
1643  BlockFieldFlags flags = CopiedCapture.Flags;
1644 
1645  unsigned index = capture.getIndex();
1646  Address srcField = Builder.CreateStructGEP(src, index, capture.getOffset());
1647  Address dstField = Builder.CreateStructGEP(dst, index, capture.getOffset());
1648 
1649  // If there's an explicit copy expression, we do that.
1650  if (CI.getCopyExpr()) {
1651  assert(CopiedCapture.Kind == BlockCaptureEntityKind::CXXRecord);
1652  EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
1653  } else if (CopiedCapture.Kind == BlockCaptureEntityKind::ARCWeak) {
1654  EmitARCCopyWeak(dstField, srcField);
1655  // If this is a C struct that requires non-trivial copy construction, emit a
1656  // call to its copy constructor.
1657  } else if (CopiedCapture.Kind ==
1658  BlockCaptureEntityKind::NonTrivialCStruct) {
1659  QualType varType = CI.getVariable()->getType();
1660  callCStructCopyConstructor(MakeAddrLValue(dstField, varType),
1661  MakeAddrLValue(srcField, varType));
1662  } else {
1663  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
1664  if (CopiedCapture.Kind == BlockCaptureEntityKind::ARCStrong) {
1665  // At -O0, store null into the destination field (so that the
1666  // storeStrong doesn't over-release) and then call storeStrong.
1667  // This is a workaround to not having an initStrong call.
1668  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1669  auto *ty = cast<llvm::PointerType>(srcValue->getType());
1670  llvm::Value *null = llvm::ConstantPointerNull::get(ty);
1671  Builder.CreateStore(null, dstField);
1672  EmitARCStoreStrongCall(dstField, srcValue, true);
1673 
1674  // With optimization enabled, take advantage of the fact that
1675  // the blocks runtime guarantees a memcpy of the block data, and
1676  // just emit a retain of the src field.
1677  } else {
1678  EmitARCRetainNonBlock(srcValue);
1679 
1680  // We don't need this anymore, so kill it. It's not quite
1681  // worth the annoyance to avoid creating it in the first place.
1682  cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
1683  }
1684  } else {
1685  assert(CopiedCapture.Kind == BlockCaptureEntityKind::BlockObject);
1686  srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
1687  llvm::Value *dstAddr =
1688  Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
1689  llvm::Value *args[] = {
1690  dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
1691  };
1692 
1693  const VarDecl *variable = CI.getVariable();
1694  bool copyCanThrow = false;
1695  if (CI.isByRef() && variable->getType()->getAsCXXRecordDecl()) {
1696  const Expr *copyExpr =
1697  CGM.getContext().getBlockVarCopyInits(variable);
1698  if (copyExpr) {
1699  copyCanThrow = true; // FIXME: reuse the noexcept logic
1700  }
1701  }
1702 
1703  if (copyCanThrow) {
1704  EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
1705  } else {
1706  EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
1707  }
1708  }
1709  }
1710  }
1711 
1712  FinishFunction();
1713 
1714  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1715 }
1716 
1717 static BlockFieldFlags
1719  QualType T) {
1721  if (T->isBlockPointerType())
1722  Flags = BLOCK_FIELD_IS_BLOCK;
1723  return Flags;
1724 }
1725 
1726 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1728  const LangOptions &LangOpts) {
1729  if (CI.isByRef()) {
1731  if (T.isObjCGCWeak())
1732  Flags |= BLOCK_FIELD_IS_WEAK;
1733  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1734  }
1735 
1736  switch (T.isDestructedType()) {
1738  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1740  // Use objc_storeStrong for __strong direct captures; the
1741  // dynamic tools really like it when we do this.
1742  return std::make_pair(BlockCaptureEntityKind::ARCStrong,
1745  // Support __weak direct captures.
1746  return std::make_pair(BlockCaptureEntityKind::ARCWeak,
1749  return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
1750  BlockFieldFlags());
1751  case QualType::DK_none: {
1752  // Non-ARC captures are strong, and we need to use _Block_object_dispose.
1753  if (T->isObjCRetainableType() && !T.getQualifiers().hasObjCLifetime() &&
1754  !LangOpts.ObjCAutoRefCount)
1755  return std::make_pair(BlockCaptureEntityKind::BlockObject,
1757  // Otherwise, we have nothing to do.
1758  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1759  }
1760  }
1761  llvm_unreachable("after exhaustive DestructionKind switch");
1762 }
1763 
1764 /// Generate the destroy-helper function for a block closure object:
1765 /// static void block_destroy_helper(block_t *theBlock);
1766 ///
1767 /// Note that this destroys a heap-allocated block closure object;
1768 /// it should not be confused with a 'byref destroy helper', which
1769 /// destroys the heap-allocated contents of an individual __block
1770 /// variable.
1771 llvm::Constant *
1773  ASTContext &C = getContext();
1774 
1775  FunctionArgList args;
1776  ImplicitParamDecl SrcDecl(getContext(), C.VoidPtrTy,
1778  args.push_back(&SrcDecl);
1779 
1780  const CGFunctionInfo &FI =
1782 
1783  // FIXME: We'd like to put these into a mergable by content, with
1784  // internal linkage.
1785  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1786 
1787  llvm::Function *Fn =
1789  "__destroy_helper_block_", &CGM.getModule());
1790 
1791  IdentifierInfo *II
1792  = &CGM.getContext().Idents.get("__destroy_helper_block_");
1793 
1795  SourceLocation(),
1796  SourceLocation(), II, C.VoidTy,
1797  nullptr, SC_Static,
1798  false, false);
1799 
1801 
1802  StartFunction(FD, C.VoidTy, Fn, FI, args);
1803  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getLocStart()};
1804 
1805  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1806 
1807  Address src = GetAddrOfLocalVar(&SrcDecl);
1808  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
1809  src = Builder.CreateBitCast(src, structPtrTy, "block");
1810 
1811  CodeGenFunction::RunCleanupsScope cleanups(*this);
1812 
1814  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures,
1816 
1817  for (const auto &DestroyedCapture : DestroyedCaptures) {
1818  const BlockDecl::Capture &CI = DestroyedCapture.CI;
1819  const CGBlockInfo::Capture &capture = DestroyedCapture.Capture;
1820  BlockFieldFlags flags = DestroyedCapture.Flags;
1821 
1822  Address srcField =
1823  Builder.CreateStructGEP(src, capture.getIndex(), capture.getOffset());
1824 
1825  // If the captured record has a destructor then call it.
1826  if (DestroyedCapture.Kind == BlockCaptureEntityKind::CXXRecord) {
1827  const auto *Dtor =
1829  PushDestructorCleanup(Dtor, srcField);
1830 
1831  // If this is a __weak capture, emit the release directly.
1832  } else if (DestroyedCapture.Kind == BlockCaptureEntityKind::ARCWeak) {
1833  EmitARCDestroyWeak(srcField);
1834 
1835  // Destroy strong objects with a call if requested.
1836  } else if (DestroyedCapture.Kind == BlockCaptureEntityKind::ARCStrong) {
1837  EmitARCDestroyStrong(srcField, ARCImpreciseLifetime);
1838 
1839  // If this is a C struct that requires non-trivial destruction, emit a call
1840  // to its destructor.
1841  } else if (DestroyedCapture.Kind ==
1842  BlockCaptureEntityKind::NonTrivialCStruct) {
1843  QualType varType = CI.getVariable()->getType();
1844  pushDestroy(varType.isDestructedType(), srcField, varType);
1845 
1846  // Otherwise we call _Block_object_dispose. It wouldn't be too
1847  // hard to just emit this as a cleanup if we wanted to make sure
1848  // that things were done in reverse.
1849  } else {
1850  assert(DestroyedCapture.Kind == BlockCaptureEntityKind::BlockObject);
1851  llvm::Value *value = Builder.CreateLoad(srcField);
1852  value = Builder.CreateBitCast(value, VoidPtrTy);
1853  BuildBlockRelease(value, flags);
1854  }
1855  }
1856 
1857  cleanups.ForceCleanup();
1858 
1859  FinishFunction();
1860 
1861  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1862 }
1863 
1864 namespace {
1865 
1866 /// Emits the copy/dispose helper functions for a __block object of id type.
1867 class ObjectByrefHelpers final : public BlockByrefHelpers {
1868  BlockFieldFlags Flags;
1869 
1870 public:
1871  ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
1872  : BlockByrefHelpers(alignment), Flags(flags) {}
1873 
1874  void emitCopy(CodeGenFunction &CGF, Address destField,
1875  Address srcField) override {
1876  destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
1877 
1878  srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
1879  llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
1880 
1881  unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
1882 
1883  llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
1884  llvm::Value *fn = CGF.CGM.getBlockObjectAssign();
1885 
1886  llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
1887  CGF.EmitNounwindRuntimeCall(fn, args);
1888  }
1889 
1890  void emitDispose(CodeGenFunction &CGF, Address field) override {
1891  field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
1892  llvm::Value *value = CGF.Builder.CreateLoad(field);
1893 
1894  CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER);
1895  }
1896 
1897  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1898  id.AddInteger(Flags.getBitMask());
1899  }
1900 };
1901 
1902 /// Emits the copy/dispose helpers for an ARC __block __weak variable.
1903 class ARCWeakByrefHelpers final : public BlockByrefHelpers {
1904 public:
1905  ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
1906 
1907  void emitCopy(CodeGenFunction &CGF, Address destField,
1908  Address srcField) override {
1909  CGF.EmitARCMoveWeak(destField, srcField);
1910  }
1911 
1912  void emitDispose(CodeGenFunction &CGF, Address field) override {
1913  CGF.EmitARCDestroyWeak(field);
1914  }
1915 
1916  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1917  // 0 is distinguishable from all pointers and byref flags
1918  id.AddInteger(0);
1919  }
1920 };
1921 
1922 /// Emits the copy/dispose helpers for an ARC __block __strong variable
1923 /// that's not of block-pointer type.
1924 class ARCStrongByrefHelpers final : public BlockByrefHelpers {
1925 public:
1926  ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
1927 
1928  void emitCopy(CodeGenFunction &CGF, Address destField,
1929  Address srcField) override {
1930  // Do a "move" by copying the value and then zeroing out the old
1931  // variable.
1932 
1933  llvm::Value *value = CGF.Builder.CreateLoad(srcField);
1934 
1935  llvm::Value *null =
1936  llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
1937 
1938  if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
1939  CGF.Builder.CreateStore(null, destField);
1940  CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
1941  CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
1942  return;
1943  }
1944  CGF.Builder.CreateStore(value, destField);
1945  CGF.Builder.CreateStore(null, srcField);
1946  }
1947 
1948  void emitDispose(CodeGenFunction &CGF, Address field) override {
1950  }
1951 
1952  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1953  // 1 is distinguishable from all pointers and byref flags
1954  id.AddInteger(1);
1955  }
1956 };
1957 
1958 /// Emits the copy/dispose helpers for an ARC __block __strong
1959 /// variable that's of block-pointer type.
1960 class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
1961 public:
1962  ARCStrongBlockByrefHelpers(CharUnits alignment)
1963  : BlockByrefHelpers(alignment) {}
1964 
1965  void emitCopy(CodeGenFunction &CGF, Address destField,
1966  Address srcField) override {
1967  // Do the copy with objc_retainBlock; that's all that
1968  // _Block_object_assign would do anyway, and we'd have to pass the
1969  // right arguments to make sure it doesn't get no-op'ed.
1970  llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
1971  llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
1972  CGF.Builder.CreateStore(copy, destField);
1973  }
1974 
1975  void emitDispose(CodeGenFunction &CGF, Address field) override {
1977  }
1978 
1979  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1980  // 2 is distinguishable from all pointers and byref flags
1981  id.AddInteger(2);
1982  }
1983 };
1984 
1985 /// Emits the copy/dispose helpers for a __block variable with a
1986 /// nontrivial copy constructor or destructor.
1987 class CXXByrefHelpers final : public BlockByrefHelpers {
1988  QualType VarType;
1989  const Expr *CopyExpr;
1990 
1991 public:
1992  CXXByrefHelpers(CharUnits alignment, QualType type,
1993  const Expr *copyExpr)
1994  : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
1995 
1996  bool needsCopy() const override { return CopyExpr != nullptr; }
1997  void emitCopy(CodeGenFunction &CGF, Address destField,
1998  Address srcField) override {
1999  if (!CopyExpr) return;
2000  CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
2001  }
2002 
2003  void emitDispose(CodeGenFunction &CGF, Address field) override {
2004  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2005  CGF.PushDestructorCleanup(VarType, field);
2006  CGF.PopCleanupBlocks(cleanupDepth);
2007  }
2008 
2009  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2010  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2011  }
2012 };
2013 
2014 /// Emits the copy/dispose helpers for a __block variable that is a non-trivial
2015 /// C struct.
2016 class NonTrivialCStructByrefHelpers final : public BlockByrefHelpers {
2017  QualType VarType;
2018 
2019 public:
2020  NonTrivialCStructByrefHelpers(CharUnits alignment, QualType type)
2021  : BlockByrefHelpers(alignment), VarType(type) {}
2022 
2023  void emitCopy(CodeGenFunction &CGF, Address destField,
2024  Address srcField) override {
2025  CGF.callCStructMoveConstructor(CGF.MakeAddrLValue(destField, VarType),
2026  CGF.MakeAddrLValue(srcField, VarType));
2027  }
2028 
2029  bool needsDispose() const override {
2030  return VarType.isDestructedType();
2031  }
2032 
2033  void emitDispose(CodeGenFunction &CGF, Address field) override {
2034  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2035  CGF.pushDestroy(VarType.isDestructedType(), field, VarType);
2036  CGF.PopCleanupBlocks(cleanupDepth);
2037  }
2038 
2039  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2040  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2041  }
2042 };
2043 } // end anonymous namespace
2044 
2045 static llvm::Constant *
2047  BlockByrefHelpers &generator) {
2048  ASTContext &Context = CGF.getContext();
2049 
2050  QualType R = Context.VoidTy;
2051 
2052  FunctionArgList args;
2053  ImplicitParamDecl Dst(CGF.getContext(), Context.VoidPtrTy,
2055  args.push_back(&Dst);
2056 
2057  ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2059  args.push_back(&Src);
2060 
2061  const CGFunctionInfo &FI =
2063 
2064  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2065 
2066  // FIXME: We'd like to put these into a mergable by content, with
2067  // internal linkage.
2068  llvm::Function *Fn =
2070  "__Block_byref_object_copy_", &CGF.CGM.getModule());
2071 
2072  IdentifierInfo *II
2073  = &Context.Idents.get("__Block_byref_object_copy_");
2074 
2075  FunctionDecl *FD = FunctionDecl::Create(Context,
2076  Context.getTranslationUnitDecl(),
2077  SourceLocation(),
2078  SourceLocation(), II, R, nullptr,
2079  SC_Static,
2080  false, false);
2081 
2083 
2084  CGF.StartFunction(FD, R, Fn, FI, args);
2085 
2086  if (generator.needsCopy()) {
2087  llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
2088 
2089  // dst->x
2090  Address destField = CGF.GetAddrOfLocalVar(&Dst);
2091  destField = Address(CGF.Builder.CreateLoad(destField),
2092  byrefInfo.ByrefAlignment);
2093  destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
2094  destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
2095  "dest-object");
2096 
2097  // src->x
2098  Address srcField = CGF.GetAddrOfLocalVar(&Src);
2099  srcField = Address(CGF.Builder.CreateLoad(srcField),
2100  byrefInfo.ByrefAlignment);
2101  srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
2102  srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
2103  "src-object");
2104 
2105  generator.emitCopy(CGF, destField, srcField);
2106  }
2107 
2108  CGF.FinishFunction();
2109 
2110  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2111 }
2112 
2113 /// Build the copy helper for a __block variable.
2114 static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
2115  const BlockByrefInfo &byrefInfo,
2116  BlockByrefHelpers &generator) {
2117  CodeGenFunction CGF(CGM);
2118  return generateByrefCopyHelper(CGF, byrefInfo, generator);
2119 }
2120 
2121 /// Generate code for a __block variable's dispose helper.
2122 static llvm::Constant *
2124  const BlockByrefInfo &byrefInfo,
2125  BlockByrefHelpers &generator) {
2126  ASTContext &Context = CGF.getContext();
2127  QualType R = Context.VoidTy;
2128 
2129  FunctionArgList args;
2130  ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2132  args.push_back(&Src);
2133 
2134  const CGFunctionInfo &FI =
2136 
2137  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2138 
2139  // FIXME: We'd like to put these into a mergable by content, with
2140  // internal linkage.
2141  llvm::Function *Fn =
2143  "__Block_byref_object_dispose_",
2144  &CGF.CGM.getModule());
2145 
2146  IdentifierInfo *II
2147  = &Context.Idents.get("__Block_byref_object_dispose_");
2148 
2149  FunctionDecl *FD = FunctionDecl::Create(Context,
2150  Context.getTranslationUnitDecl(),
2151  SourceLocation(),
2152  SourceLocation(), II, R, nullptr,
2153  SC_Static,
2154  false, false);
2155 
2157 
2158  CGF.StartFunction(FD, R, Fn, FI, args);
2159 
2160  if (generator.needsDispose()) {
2161  Address addr = CGF.GetAddrOfLocalVar(&Src);
2162  addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2163  auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2164  addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2165  addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2166 
2167  generator.emitDispose(CGF, addr);
2168  }
2169 
2170  CGF.FinishFunction();
2171 
2172  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2173 }
2174 
2175 /// Build the dispose helper for a __block variable.
2176 static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2177  const BlockByrefInfo &byrefInfo,
2178  BlockByrefHelpers &generator) {
2179  CodeGenFunction CGF(CGM);
2180  return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2181 }
2182 
2183 /// Lazily build the copy and dispose helpers for a __block variable
2184 /// with the given information.
2185 template <class T>
2186 static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2187  T &&generator) {
2188  llvm::FoldingSetNodeID id;
2189  generator.Profile(id);
2190 
2191  void *insertPos;
2192  BlockByrefHelpers *node
2193  = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2194  if (node) return static_cast<T*>(node);
2195 
2196  generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2197  generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2198 
2199  T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2200  CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2201  return copy;
2202 }
2203 
2204 /// Build the copy and dispose helpers for the given __block variable
2205 /// emission. Places the helpers in the global cache. Returns null
2206 /// if no helpers are required.
2208 CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2209  const AutoVarEmission &emission) {
2210  const VarDecl &var = *emission.Variable;
2211  QualType type = var.getType();
2212 
2213  auto &byrefInfo = getBlockByrefInfo(&var);
2214 
2215  // The alignment we care about for the purposes of uniquing byref
2216  // helpers is the alignment of the actual byref value field.
2217  CharUnits valueAlignment =
2218  byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2219 
2220  if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2221  const Expr *copyExpr = CGM.getContext().getBlockVarCopyInits(&var);
2222  if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2223 
2225  CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2226  }
2227 
2228  // If type is a non-trivial C struct type that is non-trivial to
2229  // destructly move or destroy, build the copy and dispose helpers.
2233  CGM, byrefInfo, NonTrivialCStructByrefHelpers(valueAlignment, type));
2234 
2235  // Otherwise, if we don't have a retainable type, there's nothing to do.
2236  // that the runtime does extra copies.
2237  if (!type->isObjCRetainableType()) return nullptr;
2238 
2239  Qualifiers qs = type.getQualifiers();
2240 
2241  // If we have lifetime, that dominates.
2242  if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2243  switch (lifetime) {
2244  case Qualifiers::OCL_None: llvm_unreachable("impossible");
2245 
2246  // These are just bits as far as the runtime is concerned.
2249  return nullptr;
2250 
2251  // Tell the runtime that this is ARC __weak, called by the
2252  // byref routines.
2253  case Qualifiers::OCL_Weak:
2254  return ::buildByrefHelpers(CGM, byrefInfo,
2255  ARCWeakByrefHelpers(valueAlignment));
2256 
2257  // ARC __strong __block variables need to be retained.
2259  // Block pointers need to be copied, and there's no direct
2260  // transfer possible.
2261  if (type->isBlockPointerType()) {
2262  return ::buildByrefHelpers(CGM, byrefInfo,
2263  ARCStrongBlockByrefHelpers(valueAlignment));
2264 
2265  // Otherwise, we transfer ownership of the retain from the stack
2266  // to the heap.
2267  } else {
2268  return ::buildByrefHelpers(CGM, byrefInfo,
2269  ARCStrongByrefHelpers(valueAlignment));
2270  }
2271  }
2272  llvm_unreachable("fell out of lifetime switch!");
2273  }
2274 
2275  BlockFieldFlags flags;
2276  if (type->isBlockPointerType()) {
2277  flags |= BLOCK_FIELD_IS_BLOCK;
2278  } else if (CGM.getContext().isObjCNSObjectType(type) ||
2279  type->isObjCObjectPointerType()) {
2280  flags |= BLOCK_FIELD_IS_OBJECT;
2281  } else {
2282  return nullptr;
2283  }
2284 
2285  if (type.isObjCGCWeak())
2286  flags |= BLOCK_FIELD_IS_WEAK;
2287 
2288  return ::buildByrefHelpers(CGM, byrefInfo,
2289  ObjectByrefHelpers(valueAlignment, flags));
2290 }
2291 
2293  const VarDecl *var,
2294  bool followForward) {
2295  auto &info = getBlockByrefInfo(var);
2296  return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2297 }
2298 
2300  const BlockByrefInfo &info,
2301  bool followForward,
2302  const llvm::Twine &name) {
2303  // Chase the forwarding address if requested.
2304  if (followForward) {
2305  Address forwardingAddr =
2306  Builder.CreateStructGEP(baseAddr, 1, getPointerSize(), "forwarding");
2307  baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2308  }
2309 
2310  return Builder.CreateStructGEP(baseAddr, info.FieldIndex,
2311  info.FieldOffset, name);
2312 }
2313 
2314 /// BuildByrefInfo - This routine changes a __block variable declared as T x
2315 /// into:
2316 ///
2317 /// struct {
2318 /// void *__isa;
2319 /// void *__forwarding;
2320 /// int32_t __flags;
2321 /// int32_t __size;
2322 /// void *__copy_helper; // only if needed
2323 /// void *__destroy_helper; // only if needed
2324 /// void *__byref_variable_layout;// only if needed
2325 /// char padding[X]; // only if needed
2326 /// T x;
2327 /// } x
2328 ///
2330  auto it = BlockByrefInfos.find(D);
2331  if (it != BlockByrefInfos.end())
2332  return it->second;
2333 
2334  llvm::StructType *byrefType =
2335  llvm::StructType::create(getLLVMContext(),
2336  "struct.__block_byref_" + D->getNameAsString());
2337 
2338  QualType Ty = D->getType();
2339 
2340  CharUnits size;
2342 
2343  // void *__isa;
2344  types.push_back(Int8PtrTy);
2345  size += getPointerSize();
2346 
2347  // void *__forwarding;
2348  types.push_back(llvm::PointerType::getUnqual(byrefType));
2349  size += getPointerSize();
2350 
2351  // int32_t __flags;
2352  types.push_back(Int32Ty);
2353  size += CharUnits::fromQuantity(4);
2354 
2355  // int32_t __size;
2356  types.push_back(Int32Ty);
2357  size += CharUnits::fromQuantity(4);
2358 
2359  // Note that this must match *exactly* the logic in buildByrefHelpers.
2360  bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2361  if (hasCopyAndDispose) {
2362  /// void *__copy_helper;
2363  types.push_back(Int8PtrTy);
2364  size += getPointerSize();
2365 
2366  /// void *__destroy_helper;
2367  types.push_back(Int8PtrTy);
2368  size += getPointerSize();
2369  }
2370 
2371  bool HasByrefExtendedLayout = false;
2372  Qualifiers::ObjCLifetime Lifetime;
2373  if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2374  HasByrefExtendedLayout) {
2375  /// void *__byref_variable_layout;
2376  types.push_back(Int8PtrTy);
2377  size += CharUnits::fromQuantity(PointerSizeInBytes);
2378  }
2379 
2380  // T x;
2381  llvm::Type *varTy = ConvertTypeForMem(Ty);
2382 
2383  bool packed = false;
2384  CharUnits varAlign = getContext().getDeclAlign(D);
2385  CharUnits varOffset = size.alignTo(varAlign);
2386 
2387  // We may have to insert padding.
2388  if (varOffset != size) {
2389  llvm::Type *paddingTy =
2390  llvm::ArrayType::get(Int8Ty, (varOffset - size).getQuantity());
2391 
2392  types.push_back(paddingTy);
2393  size = varOffset;
2394 
2395  // Conversely, we might have to prevent LLVM from inserting padding.
2396  } else if (CGM.getDataLayout().getABITypeAlignment(varTy)
2397  > varAlign.getQuantity()) {
2398  packed = true;
2399  }
2400  types.push_back(varTy);
2401 
2402  byrefType->setBody(types, packed);
2403 
2404  BlockByrefInfo info;
2405  info.Type = byrefType;
2406  info.FieldIndex = types.size() - 1;
2407  info.FieldOffset = varOffset;
2408  info.ByrefAlignment = std::max(varAlign, getPointerAlign());
2409 
2410  auto pair = BlockByrefInfos.insert({D, info});
2411  assert(pair.second && "info was inserted recursively?");
2412  return pair.first->second;
2413 }
2414 
2415 /// Initialize the structural components of a __block variable, i.e.
2416 /// everything but the actual object.
2418  // Find the address of the local.
2419  Address addr = emission.Addr;
2420 
2421  // That's an alloca of the byref structure type.
2422  llvm::StructType *byrefType = cast<llvm::StructType>(
2423  cast<llvm::PointerType>(addr.getPointer()->getType())->getElementType());
2424 
2425  unsigned nextHeaderIndex = 0;
2426  CharUnits nextHeaderOffset;
2427  auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2428  const Twine &name) {
2429  auto fieldAddr = Builder.CreateStructGEP(addr, nextHeaderIndex,
2430  nextHeaderOffset, name);
2431  Builder.CreateStore(value, fieldAddr);
2432 
2433  nextHeaderIndex++;
2434  nextHeaderOffset += fieldSize;
2435  };
2436 
2437  // Build the byref helpers if necessary. This is null if we don't need any.
2438  BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2439 
2440  const VarDecl &D = *emission.Variable;
2441  QualType type = D.getType();
2442 
2443  bool HasByrefExtendedLayout;
2444  Qualifiers::ObjCLifetime ByrefLifetime;
2445  bool ByRefHasLifetime =
2446  getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2447 
2448  llvm::Value *V;
2449 
2450  // Initialize the 'isa', which is just 0 or 1.
2451  int isa = 0;
2452  if (type.isObjCGCWeak())
2453  isa = 1;
2454  V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2455  storeHeaderField(V, getPointerSize(), "byref.isa");
2456 
2457  // Store the address of the variable into its own forwarding pointer.
2458  storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2459 
2460  // Blocks ABI:
2461  // c) the flags field is set to either 0 if no helper functions are
2462  // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2463  BlockFlags flags;
2464  if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2465  if (ByRefHasLifetime) {
2466  if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2467  else switch (ByrefLifetime) {
2469  flags |= BLOCK_BYREF_LAYOUT_STRONG;
2470  break;
2471  case Qualifiers::OCL_Weak:
2472  flags |= BLOCK_BYREF_LAYOUT_WEAK;
2473  break;
2476  break;
2477  case Qualifiers::OCL_None:
2478  if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2480  break;
2481  default:
2482  break;
2483  }
2484  if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2485  printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2486  if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2487  printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2488  if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2489  BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2490  if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2491  printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2492  if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2493  printf(" BLOCK_BYREF_LAYOUT_STRONG");
2494  if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2495  printf(" BLOCK_BYREF_LAYOUT_WEAK");
2496  if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2497  printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2498  if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2499  printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2500  }
2501  printf("\n");
2502  }
2503  }
2504  storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2505  getIntSize(), "byref.flags");
2506 
2507  CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2508  V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2509  storeHeaderField(V, getIntSize(), "byref.size");
2510 
2511  if (helpers) {
2512  storeHeaderField(helpers->CopyHelper, getPointerSize(),
2513  "byref.copyHelper");
2514  storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2515  "byref.disposeHelper");
2516  }
2517 
2518  if (ByRefHasLifetime && HasByrefExtendedLayout) {
2519  auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2520  storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2521  }
2522 }
2523 
2526  llvm::Value *args[] = {
2527  Builder.CreateBitCast(V, Int8PtrTy),
2528  llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2529  };
2530  EmitNounwindRuntimeCall(F, args); // FIXME: throwing destructors?
2531 }
2532 
2533 namespace {
2534  /// Release a __block variable.
2535  struct CallBlockRelease final : EHScopeStack::Cleanup {
2536  llvm::Value *Addr;
2537  CallBlockRelease(llvm::Value *Addr) : Addr(Addr) {}
2538 
2539  void Emit(CodeGenFunction &CGF, Flags flags) override {
2540  // Should we be passing FIELD_IS_WEAK here?
2542  }
2543  };
2544 } // end anonymous namespace
2545 
2546 /// Enter a cleanup to destroy a __block variable. Note that this
2547 /// cleanup should be a no-op if the variable hasn't left the stack
2548 /// yet; if a cleanup is required for the variable itself, that needs
2549 /// to be done externally.
2551  // We don't enter this cleanup if we're in pure-GC mode.
2552  if (CGM.getLangOpts().getGC() == LangOptions::GCOnly)
2553  return;
2554 
2555  EHStack.pushCleanup<CallBlockRelease>(NormalAndEHCleanup,
2556  emission.Addr.getPointer());
2557 }
2558 
2559 /// Adjust the declaration of something from the blocks API.
2561  llvm::Constant *C) {
2562  auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2563 
2564  if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2565  IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2568 
2569  assert((isa<llvm::Function>(C->stripPointerCasts()) ||
2570  isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&
2571  "expected Function or GlobalVariable");
2572 
2573  const NamedDecl *ND = nullptr;
2574  for (const auto &Result : DC->lookup(&II))
2575  if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2576  (ND = dyn_cast<VarDecl>(Result)))
2577  break;
2578 
2579  // TODO: support static blocks runtime
2580  if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2581  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2582  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2583  } else {
2584  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2585  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2586  }
2587  }
2588 
2589  if (CGM.getLangOpts().BlocksRuntimeOptional && GV->isDeclaration() &&
2590  GV->hasExternalLinkage())
2591  GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2592 
2593  CGM.setDSOLocal(GV);
2594 }
2595 
2597  if (BlockObjectDispose)
2598  return BlockObjectDispose;
2599 
2600  llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2601  llvm::FunctionType *fty
2602  = llvm::FunctionType::get(VoidTy, args, false);
2603  BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2604  configureBlocksRuntimeObject(*this, BlockObjectDispose);
2605  return BlockObjectDispose;
2606 }
2607 
2609  if (BlockObjectAssign)
2610  return BlockObjectAssign;
2611 
2612  llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
2613  llvm::FunctionType *fty
2614  = llvm::FunctionType::get(VoidTy, args, false);
2615  BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
2616  configureBlocksRuntimeObject(*this, BlockObjectAssign);
2617  return BlockObjectAssign;
2618 }
2619 
2621  if (NSConcreteGlobalBlock)
2622  return NSConcreteGlobalBlock;
2623 
2624  NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
2625  Int8PtrTy->getPointerTo(),
2626  nullptr);
2627  configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
2628  return NSConcreteGlobalBlock;
2629 }
2630 
2632  if (NSConcreteStackBlock)
2633  return NSConcreteStackBlock;
2634 
2635  NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
2636  Int8PtrTy->getPointerTo(),
2637  nullptr);
2638  configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
2639  return NSConcreteStackBlock;
2640 }
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:701
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:361
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
const BlockDecl * getBlockDecl() const
Definition: Expr.h:4887
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:1589
static llvm::Constant * generateByrefDisposeHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Generate code for a __block variable&#39;s dispose helper.
Definition: CGBlocks.cpp:2123
Represents a function declaration or definition.
Definition: Decl.h:1709
llvm::IntegerType * IntTy
int
llvm::Type * getGenericBlockLiteralType()
The type of a generic block literal.
Definition: CGBlocks.cpp:1043
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:60
Other implicit parameter.
Definition: Decl.h:1488
CharUnits BlockHeaderForcedGapOffset
Definition: CGBlocks.h:246
const FunctionProtoType * getFunctionType() const
getFunctionType - Return the underlying function type for this block.
Definition: Expr.cpp:2005
Expr * getCopyExpr() const
Definition: Decl.h:3871
static llvm::Constant * buildByrefDisposeHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the dispose helper for a __block variable.
Definition: CGBlocks.cpp:2176
A class which contains all the information about a particular captured value.
Definition: Decl.h:3839
CanQualType VoidPtrTy
Definition: ASTContext.h:1012
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:1582
A (possibly-)qualified type.
Definition: Type.h:653
bool isBlockPointerType() const
Definition: Type.h:6029
const CodeGenOptions & getCodeGenOpts() const
bool hasCaptures() const
True if this block (or its nested blocks) captures anything of local storage from its enclosing scope...
Definition: Decl.h:3957
bool HaveInsertPoint() const
HaveInsertPoint - True if an insertion point is defined.
capture_const_iterator capture_begin() const
Definition: Decl.h:3967
llvm::LLVMContext & getLLVMContext()
void EmitARCDestroyWeak(Address addr)
void @objc_destroyWeak(i8** addr) Essentially objc_storeWeak(addr, nil).
Definition: CGObjC.cpp:2280
The standard implementation of ConstantInitBuilder used in Clang.
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3125
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:795
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:2186
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:2236
ArrayRef< CleanupObject > getObjects() const
Definition: ExprCXX.h:3031
param_iterator param_end()
Definition: Decl.h:3937
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:5970
The base class of the type hierarchy.
Definition: Type.h:1419
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:3968
The type would be trivial except that it is volatile-qualified.
Definition: Type.h:1120
Address GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
Represents a variable declaration or definition.
Definition: Decl.h:812
CGBlockInfo(const BlockDecl *blockDecl, StringRef Name)
Definition: CGBlocks.cpp:34
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6390
EHScopeStack::stable_iterator getCleanup() const
Definition: CGBlocks.h:179
This class gathers all debug information during compilation and is responsible for emitting to llvm g...
Definition: CGDebugInfo.h:54
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:1505
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:3003
static void destroyBlockInfos(CGBlockInfo *info)
Destroy a chain of block layouts.
Definition: CGBlocks.cpp:725
SourceLocation getLocStart() const LLVM_READONLY
Definition: Expr.h:4896
The collection of all-type qualifiers we support.
Definition: Type.h:152
void add(RValue rvalue, QualType type)
Definition: CGCall.h:285
const AstTypeMatcher< RecordType > recordType
Matches record types (e.g.
const BlockDecl * Block
Definition: CGBlocks.h:237
llvm::DenseMap< const VarDecl *, FieldDecl * > LambdaCaptureFields
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:2417
CGBlockInfo * FirstBlockInfo
FirstBlockInfo - The head of a singly-linked-list of block layouts.
QualType getPointeeType() const
Definition: Type.h:2469
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:149
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:1727
bool isReferenceType() const
Definition: Type.h:6033
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:1562
std::string getObjCEncodingForBlock(const BlockExpr *blockExpr) const
Return the encoded type for this block declaration.
void recordBlockInfo(const BlockExpr *E, llvm::Function *InvokeF, llvm::Value *Block)
Record invoke function and block literal emitted during normal codegen for a block expression...
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:2046
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:3917
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:50
IdentifierTable & Idents
Definition: ASTContext.h:537
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:2118
Address GetAddrOfBlockDecl(const VarDecl *var, bool ByRef)
Definition: CGBlocks.cpp:1131
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:2104
const BlockDecl * getBlockDecl() const
Definition: CGBlocks.h:271
uint32_t Offset
Definition: CacheTokens.cpp:43
void setDSOLocal(llvm::GlobalValue *GV) const
virtual TargetOpenCLBlockHelper * getTargetOpenCLBlockHelper() const
Definition: TargetInfo.h:286
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
llvm::Value * EmitBlockLiteral(const BlockExpr *)
Emit block literal.
Definition: CGBlocks.cpp:735
uint32_t getBitMask() const
Definition: CGBlocks.h:117
bool isByRef() const
Whether this is a "by ref" capture, i.e.
Definition: Decl.h:3864
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...
The type is an Objective-C retainable pointer type that is qualified with the ARC __strong qualifier...
Definition: Type.h:1124
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:40
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:1655
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
void callCStructMoveConstructor(LValue Dst, LValue Src)
const Stmt * getBody() const
Definition: Expr.cpp:2014
llvm::Constant * getNSConcreteStackBlock()
Definition: CGBlocks.cpp:2631
The type does not fall into any of the following categories.
Definition: Type.h:1115
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:1904
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:1531
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:3346
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:4897
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.
PrimitiveCopyKind isNonTrivialToPrimitiveDestructiveMove() const
Check if this is a non-trivial type that would cause a C struct transitively containing this type to ...
Definition: Type.cpp:2238
Pepresents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:3835
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:2297
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:6453
bool isObjCRetainableType() const
Definition: Type.cpp:3851
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:4873
BlockCaptureEntityKind
Represents a type of copy/destroy operation that should be performed for an entity that&#39;s captured by...
Definition: CGBlocks.cpp:1479
static llvm::Constant * buildGlobalBlock(CodeGenModule &CGM, const CGBlockInfo &blockInfo, llvm::Constant *blockFn)
Build the given block as a global block.
Definition: CGBlocks.cpp:1193
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:1772
const Expr * getCallee() const
Definition: Expr.h:2267
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
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:1492
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:564
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:6348
const TargetInfo & getTarget() const
const LangOptions & getLangOpts() const
ASTContext & getContext() const
static BlockFieldFlags getBlockFieldFlagsForObjCObjectPointer(const BlockDecl::Capture &CI, QualType T)
Definition: CGBlocks.cpp:1718
do v
Definition: arm_acle.h:78
static QualType getCaptureFieldType(const CodeGenFunction &CGF, const BlockDecl::Capture &CI)
Definition: CGBlocks.cpp:347
llvm::Function * getInvokeFunction(const Expr *E)
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:35
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:5856
param_iterator param_begin()
Definition: Decl.h:3936
The l-value was considered opaque, so the alignment was determined from a type.
RecordDecl * getDecl() const
Definition: Type.h:4064
void setBlockContextParameter(const ImplicitParamDecl *D, unsigned argNum, llvm::Value *ptr)
Definition: CGBlocks.cpp:1260
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:2550
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
static AggValueSlot forAddr(Address addr, Qualifiers quals, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, Overlap_t mayOverlap, IsZeroed_t isZeroed=IsNotZeroed)
forAddr - Make a slot for an aggregate value.
Definition: CGValue.h:506
#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 nullptr 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:2393
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:1609
Encodes a location in the source.
static DeclContext * castToDeclContext(const TranslationUnitDecl *D)
Definition: Decl.h:129
QualType getReturnType() const
Definition: Type.h:3279
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
Get a human-readable name for the declaration, even if it is one of the special kinds of names (C++ c...
Definition: Decl.h:291
static void configureBlocksRuntimeObject(CodeGenModule &CGM, llvm::Constant *C)
Adjust the declaration of something from the blocks API.
Definition: CGBlocks.cpp:2560
The type is a struct containing a field whose type is neither PCK_Trivial nor PCK_VolatileTrivial.
Definition: Type.h:1136
An aggregate value slot.
Definition: CGValue.h:437
const BlockByrefInfo & getBlockByrefInfo(const VarDecl *var)
BuildByrefInfo - This routine changes a __block variable declared as T x into:
Definition: CGBlocks.cpp:2329
A scoped helper to set the current debug location to the specified location or preferred location of ...
Definition: CGDebugInfo.h:641
bool isConversionFromLambda() const
Definition: Decl.h:3974
CanQualType VoidTy
Definition: ASTContext.h:996
llvm::DenseMap< const VarDecl *, Capture > Captures
The mapping of allocated indexes within the block.
Definition: CGBlocks.h:233
arg_range arguments()
Definition: Expr.h:2321
bool isObjCObjectPointerType() const
Definition: Type.h:6118
static bool isBlockPointer(Expr *Arg)
llvm::Constant * getBlockObjectDispose()
Definition: CGBlocks.cpp:2596
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:2844
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1164
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:67
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:3860
PrimitiveCopyKind isNonTrivialToPrimitiveCopy() const
Check if this is a non-trivial type that would cause a C struct transitively containing this type to ...
Definition: Type.cpp:2220
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.
The type is an Objective-C retainable pointer type that is qualified with the ARC __weak qualifier...
Definition: Type.h:1128
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:356
bool isObjCGCWeak() const
true when Type is objc&#39;s weak.
Definition: Type.h:1060
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:362
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:1256
ArrayRef< Capture > captures() const
Definition: Decl.h:3965
bool isNested() const
Whether this is a nested capture, i.e.
Definition: Decl.h:3868
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:1473
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:1217
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
LValue MakeAddrLValue(Address Addr, QualType T, AlignmentSource Source=AlignmentSource::Type)
llvm::DenseMap< const Decl *, Address > DeclMapTy
static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block)
Enter the scope of a block.
Definition: CGBlocks.cpp:616
Pointer to a block type.
Definition: Type.h:2454
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:4054
StructBuilder beginStruct(llvm::StructType *structTy=nullptr)
CanQualType UnsignedLongTy
Definition: ASTContext.h:1005
unsigned getNumObjects() const
Definition: ExprCXX.h:3036
static llvm::Constant * buildByrefCopyHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the copy helper for a __block variable.
Definition: CGBlocks.cpp:2114
void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp)
Definition: CGExprCXX.cpp:641
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:708
void SetInternalFunctionAttributes(GlobalDecl GD, llvm::Function *F, const CGFunctionInfo &FI)
Set the attributes on the LLVM function for the given decl and function info.
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:32
llvm::Constant * getBlockObjectAssign()
Definition: CGBlocks.cpp:2608
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:3970
Reading or writing from this object requires a barrier call.
Definition: Type.h:183
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:989
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:5824
void setAddrOfGlobalBlock(const BlockExpr *BE, llvm::Constant *Addr)
Notes that BE&#39;s global block is available via Addr.
Definition: CGBlocks.cpp:1163
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:1977
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2227
StringRef getName() const
Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:275
__DEVICE__ int max(int __a, int __b)
llvm::Function * GenerateBlockFunction(GlobalDecl GD, const CGBlockInfo &Info, const DeclMapTy &ldm, bool IsLambdaConversionToBlock, bool BuildGlobalBlock)
Definition: CGBlocks.cpp:1300
The top declaration context.
Definition: Decl.h:107
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:965
static RValue get(llvm::Value *V)
Definition: CGValue.h:86
RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue)
Definition: CGBlocks.cpp:1065
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:689
llvm::Constant * getNSConcreteGlobalBlock()
Definition: CGBlocks.cpp:2620
llvm::Type * getBlockDescriptorType()
Fetches the type of a generic block descriptor.
Definition: CGBlocks.cpp:1011
llvm::Constant * GetAddrOfGlobalBlock(const BlockExpr *BE, StringRef Name)
Gets the address of a block which requires no captures.
Definition: CGBlocks.cpp:1171
QualType getType() const
Definition: Decl.h:647
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
This represents a decl that may have a name.
Definition: Decl.h:248
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:2422
static bool isObjCNSObjectType(QualType Ty)
Return true if this is an NSObject object with its NSObject attribute set.
Definition: ASTContext.h:2002
SourceLocation getLocStart() const LLVM_READONLY
Definition: Stmt.cpp:278
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:260
const LangOptions & getLangOpts() const
Definition: ASTContext.h:688
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:2292
Abstract information about a function or function prototype.
Definition: CGCall.h:45
SourceLocation getLocation() const
Definition: DeclBase.h:416
void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags)
Definition: CGBlocks.cpp:2524
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:1070
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1531