clang  3.7.0
CGBlocks.cpp
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1 //===--- CGBlocks.cpp - Emit LLVM Code for declarations -------------------===//
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 "CodeGenFunction.h"
18 #include "CodeGenModule.h"
19 #include "clang/AST/DeclObjC.h"
20 #include "llvm/ADT/SmallSet.h"
21 #include "llvm/IR/CallSite.h"
22 #include "llvm/IR/DataLayout.h"
23 #include "llvm/IR/Module.h"
24 #include <algorithm>
25 #include <cstdio>
26 
27 using namespace clang;
28 using namespace CodeGen;
29 
30 CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
31  : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
32  HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
33  StructureType(nullptr), Block(block),
34  DominatingIP(nullptr) {
35 
36  // Skip asm prefix, if any. 'name' is usually taken directly from
37  // the mangled name of the enclosing function.
38  if (!name.empty() && name[0] == '\01')
39  name = name.substr(1);
40 }
41 
42 // Anchor the vtable to this translation unit.
44 
45 /// Build the given block as a global block.
46 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
47  const CGBlockInfo &blockInfo,
48  llvm::Constant *blockFn);
49 
50 /// Build the helper function to copy a block.
51 static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
52  const CGBlockInfo &blockInfo) {
53  return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
54 }
55 
56 /// Build the helper function to dispose of a block.
57 static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
58  const CGBlockInfo &blockInfo) {
59  return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
60 }
61 
62 /// buildBlockDescriptor - Build the block descriptor meta-data for a block.
63 /// buildBlockDescriptor is accessed from 5th field of the Block_literal
64 /// meta-data and contains stationary information about the block literal.
65 /// Its definition will have 4 (or optinally 6) words.
66 /// \code
67 /// struct Block_descriptor {
68 /// unsigned long reserved;
69 /// unsigned long size; // size of Block_literal metadata in bytes.
70 /// void *copy_func_helper_decl; // optional copy helper.
71 /// void *destroy_func_decl; // optioanl destructor helper.
72 /// void *block_method_encoding_address; // @encode for block literal signature.
73 /// void *block_layout_info; // encoding of captured block variables.
74 /// };
75 /// \endcode
76 static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
77  const CGBlockInfo &blockInfo) {
78  ASTContext &C = CGM.getContext();
79 
80  llvm::Type *ulong = CGM.getTypes().ConvertType(C.UnsignedLongTy);
81  llvm::Type *i8p = NULL;
82  if (CGM.getLangOpts().OpenCL)
83  i8p =
84  llvm::Type::getInt8PtrTy(
86  else
87  i8p = CGM.getTypes().ConvertType(C.VoidPtrTy);
88 
90 
91  // reserved
92  elements.push_back(llvm::ConstantInt::get(ulong, 0));
93 
94  // Size
95  // FIXME: What is the right way to say this doesn't fit? We should give
96  // a user diagnostic in that case. Better fix would be to change the
97  // API to size_t.
98  elements.push_back(llvm::ConstantInt::get(ulong,
99  blockInfo.BlockSize.getQuantity()));
100 
101  // Optional copy/dispose helpers.
102  if (blockInfo.NeedsCopyDispose) {
103  // copy_func_helper_decl
104  elements.push_back(buildCopyHelper(CGM, blockInfo));
105 
106  // destroy_func_decl
107  elements.push_back(buildDisposeHelper(CGM, blockInfo));
108  }
109 
110  // Signature. Mandatory ObjC-style method descriptor @encode sequence.
111  std::string typeAtEncoding =
113  elements.push_back(llvm::ConstantExpr::getBitCast(
114  CGM.GetAddrOfConstantCString(typeAtEncoding), i8p));
115 
116  // GC layout.
117  if (C.getLangOpts().ObjC1) {
118  if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
119  elements.push_back(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
120  else
121  elements.push_back(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
122  }
123  else
124  elements.push_back(llvm::Constant::getNullValue(i8p));
125 
126  llvm::Constant *init = llvm::ConstantStruct::getAnon(elements);
127 
128  llvm::GlobalVariable *global =
129  new llvm::GlobalVariable(CGM.getModule(), init->getType(), true,
131  init, "__block_descriptor_tmp");
132 
133  return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
134 }
135 
136 /*
137  Purely notional variadic template describing the layout of a block.
138 
139  template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
140  struct Block_literal {
141  /// Initialized to one of:
142  /// extern void *_NSConcreteStackBlock[];
143  /// extern void *_NSConcreteGlobalBlock[];
144  ///
145  /// In theory, we could start one off malloc'ed by setting
146  /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
147  /// this isa:
148  /// extern void *_NSConcreteMallocBlock[];
149  struct objc_class *isa;
150 
151  /// These are the flags (with corresponding bit number) that the
152  /// compiler is actually supposed to know about.
153  /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
154  /// descriptor provides copy and dispose helper functions
155  /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
156  /// object with a nontrivial destructor or copy constructor
157  /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
158  /// as global memory
159  /// 29. BLOCK_USE_STRET - indicates that the block function
160  /// uses stret, which objc_msgSend needs to know about
161  /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
162  /// @encoded signature string
163  /// And we're not supposed to manipulate these:
164  /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
165  /// to malloc'ed memory
166  /// 27. BLOCK_IS_GC - indicates that the block has been moved to
167  /// to GC-allocated memory
168  /// Additionally, the bottom 16 bits are a reference count which
169  /// should be zero on the stack.
170  int flags;
171 
172  /// Reserved; should be zero-initialized.
173  int reserved;
174 
175  /// Function pointer generated from block literal.
176  _ResultType (*invoke)(Block_literal *, _ParamTypes...);
177 
178  /// Block description metadata generated from block literal.
179  struct Block_descriptor *block_descriptor;
180 
181  /// Captured values follow.
182  _CapturesTypes captures...;
183  };
184  */
185 
186 /// The number of fields in a block header.
187 const unsigned BlockHeaderSize = 5;
188 
189 namespace {
190  /// A chunk of data that we actually have to capture in the block.
191  struct BlockLayoutChunk {
192  CharUnits Alignment;
193  CharUnits Size;
194  Qualifiers::ObjCLifetime Lifetime;
195  const BlockDecl::Capture *Capture; // null for 'this'
196  llvm::Type *Type;
197 
198  BlockLayoutChunk(CharUnits align, CharUnits size,
199  Qualifiers::ObjCLifetime lifetime,
200  const BlockDecl::Capture *capture,
201  llvm::Type *type)
202  : Alignment(align), Size(size), Lifetime(lifetime),
203  Capture(capture), Type(type) {}
204 
205  /// Tell the block info that this chunk has the given field index.
206  void setIndex(CGBlockInfo &info, unsigned index) {
207  if (!Capture)
208  info.CXXThisIndex = index;
209  else
210  info.Captures[Capture->getVariable()]
212  }
213  };
214 
215  /// Order by 1) all __strong together 2) next, all byfref together 3) next,
216  /// all __weak together. Preserve descending alignment in all situations.
217  bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
218  CharUnits LeftValue, RightValue;
219  bool LeftByref = left.Capture ? left.Capture->isByRef() : false;
220  bool RightByref = right.Capture ? right.Capture->isByRef() : false;
221 
222  if (left.Lifetime == Qualifiers::OCL_Strong &&
223  left.Alignment >= right.Alignment)
224  LeftValue = CharUnits::fromQuantity(64);
225  else if (LeftByref && left.Alignment >= right.Alignment)
226  LeftValue = CharUnits::fromQuantity(32);
227  else if (left.Lifetime == Qualifiers::OCL_Weak &&
228  left.Alignment >= right.Alignment)
229  LeftValue = CharUnits::fromQuantity(16);
230  else
231  LeftValue = left.Alignment;
232  if (right.Lifetime == Qualifiers::OCL_Strong &&
233  right.Alignment >= left.Alignment)
234  RightValue = CharUnits::fromQuantity(64);
235  else if (RightByref && right.Alignment >= left.Alignment)
236  RightValue = CharUnits::fromQuantity(32);
237  else if (right.Lifetime == Qualifiers::OCL_Weak &&
238  right.Alignment >= left.Alignment)
239  RightValue = CharUnits::fromQuantity(16);
240  else
241  RightValue = right.Alignment;
242 
243  return LeftValue > RightValue;
244  }
245 }
246 
247 /// Determines if the given type is safe for constant capture in C++.
249  const RecordType *recordType =
251 
252  // Only records can be unsafe.
253  if (!recordType) return true;
254 
255  const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
256 
257  // Maintain semantics for classes with non-trivial dtors or copy ctors.
258  if (!record->hasTrivialDestructor()) return false;
259  if (record->hasNonTrivialCopyConstructor()) return false;
260 
261  // Otherwise, we just have to make sure there aren't any mutable
262  // fields that might have changed since initialization.
263  return !record->hasMutableFields();
264 }
265 
266 /// It is illegal to modify a const object after initialization.
267 /// Therefore, if a const object has a constant initializer, we don't
268 /// actually need to keep storage for it in the block; we'll just
269 /// rematerialize it at the start of the block function. This is
270 /// acceptable because we make no promises about address stability of
271 /// captured variables.
272 static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
273  CodeGenFunction *CGF,
274  const VarDecl *var) {
275  QualType type = var->getType();
276 
277  // We can only do this if the variable is const.
278  if (!type.isConstQualified()) return nullptr;
279 
280  // Furthermore, in C++ we have to worry about mutable fields:
281  // C++ [dcl.type.cv]p4:
282  // Except that any class member declared mutable can be
283  // modified, any attempt to modify a const object during its
284  // lifetime results in undefined behavior.
285  if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
286  return nullptr;
287 
288  // If the variable doesn't have any initializer (shouldn't this be
289  // invalid?), it's not clear what we should do. Maybe capture as
290  // zero?
291  const Expr *init = var->getInit();
292  if (!init) return nullptr;
293 
294  return CGM.EmitConstantInit(*var, CGF);
295 }
296 
297 /// Get the low bit of a nonzero character count. This is the
298 /// alignment of the nth byte if the 0th byte is universally aligned.
300  return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
301 }
302 
304  SmallVectorImpl<llvm::Type*> &elementTypes) {
305  ASTContext &C = CGM.getContext();
306 
307  // The header is basically a 'struct { void *; int; int; void *; void *; }'.
308  CharUnits ptrSize, ptrAlign, intSize, intAlign;
309  std::tie(ptrSize, ptrAlign) = C.getTypeInfoInChars(C.VoidPtrTy);
310  std::tie(intSize, intAlign) = C.getTypeInfoInChars(C.IntTy);
311 
312  // Are there crazy embedded platforms where this isn't true?
313  assert(intSize <= ptrSize && "layout assumptions horribly violated");
314 
315  CharUnits headerSize = ptrSize;
316  if (2 * intSize < ptrAlign) headerSize += ptrSize;
317  else headerSize += 2 * intSize;
318  headerSize += 2 * ptrSize;
319 
320  info.BlockAlign = ptrAlign;
321  info.BlockSize = headerSize;
322 
323  assert(elementTypes.empty());
324  llvm::Type *i8p = CGM.getTypes().ConvertType(C.VoidPtrTy);
325  llvm::Type *intTy = CGM.getTypes().ConvertType(C.IntTy);
326  elementTypes.push_back(i8p);
327  elementTypes.push_back(intTy);
328  elementTypes.push_back(intTy);
329  elementTypes.push_back(i8p);
330  elementTypes.push_back(CGM.getBlockDescriptorType());
331 
332  assert(elementTypes.size() == BlockHeaderSize);
333 }
334 
335 /// Compute the layout of the given block. Attempts to lay the block
336 /// out with minimal space requirements.
338  CGBlockInfo &info) {
339  ASTContext &C = CGM.getContext();
340  const BlockDecl *block = info.getBlockDecl();
341 
342  SmallVector<llvm::Type*, 8> elementTypes;
343  initializeForBlockHeader(CGM, info, elementTypes);
344 
345  if (!block->hasCaptures()) {
346  info.StructureType =
347  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
348  info.CanBeGlobal = true;
349  return;
350  }
351  else if (C.getLangOpts().ObjC1 &&
352  CGM.getLangOpts().getGC() == LangOptions::NonGC)
353  info.HasCapturedVariableLayout = true;
354 
355  // Collect the layout chunks.
357  layout.reserve(block->capturesCXXThis() +
358  (block->capture_end() - block->capture_begin()));
359 
360  CharUnits maxFieldAlign;
361 
362  // First, 'this'.
363  if (block->capturesCXXThis()) {
364  assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&
365  "Can't capture 'this' outside a method");
366  QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType(C);
367 
368  llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
369  std::pair<CharUnits,CharUnits> tinfo
370  = CGM.getContext().getTypeInfoInChars(thisType);
371  maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
372 
373  layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
375  nullptr, llvmType));
376  }
377 
378  // Next, all the block captures.
379  for (const auto &CI : block->captures()) {
380  const VarDecl *variable = CI.getVariable();
381 
382  if (CI.isByRef()) {
383  // We have to copy/dispose of the __block reference.
384  info.NeedsCopyDispose = true;
385 
386  // Just use void* instead of a pointer to the byref type.
387  QualType byRefPtrTy = C.VoidPtrTy;
388 
389  llvm::Type *llvmType = CGM.getTypes().ConvertType(byRefPtrTy);
390  std::pair<CharUnits,CharUnits> tinfo
391  = CGM.getContext().getTypeInfoInChars(byRefPtrTy);
392  maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
393 
394  layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
395  Qualifiers::OCL_None, &CI, llvmType));
396  continue;
397  }
398 
399  // Otherwise, build a layout chunk with the size and alignment of
400  // the declaration.
401  if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
402  info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
403  continue;
404  }
405 
406  // If we have a lifetime qualifier, honor it for capture purposes.
407  // That includes *not* copying it if it's __unsafe_unretained.
408  Qualifiers::ObjCLifetime lifetime =
409  variable->getType().getObjCLifetime();
410  if (lifetime) {
411  switch (lifetime) {
412  case Qualifiers::OCL_None: llvm_unreachable("impossible");
415  break;
416 
419  info.NeedsCopyDispose = true;
420  }
421 
422  // Block pointers require copy/dispose. So do Objective-C pointers.
423  } else if (variable->getType()->isObjCRetainableType()) {
424  info.NeedsCopyDispose = true;
425  // used for mrr below.
426  lifetime = Qualifiers::OCL_Strong;
427 
428  // So do types that require non-trivial copy construction.
429  } else if (CI.hasCopyExpr()) {
430  info.NeedsCopyDispose = true;
431  info.HasCXXObject = true;
432 
433  // And so do types with destructors.
434  } else if (CGM.getLangOpts().CPlusPlus) {
435  if (const CXXRecordDecl *record =
436  variable->getType()->getAsCXXRecordDecl()) {
437  if (!record->hasTrivialDestructor()) {
438  info.HasCXXObject = true;
439  info.NeedsCopyDispose = true;
440  }
441  }
442  }
443 
444  QualType VT = variable->getType();
445  CharUnits size = C.getTypeSizeInChars(VT);
446  CharUnits align = C.getDeclAlign(variable);
447 
448  maxFieldAlign = std::max(maxFieldAlign, align);
449 
450  llvm::Type *llvmType =
451  CGM.getTypes().ConvertTypeForMem(VT);
452 
453  layout.push_back(BlockLayoutChunk(align, size, lifetime, &CI, llvmType));
454  }
455 
456  // If that was everything, we're done here.
457  if (layout.empty()) {
458  info.StructureType =
459  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
460  info.CanBeGlobal = true;
461  return;
462  }
463 
464  // Sort the layout by alignment. We have to use a stable sort here
465  // to get reproducible results. There should probably be an
466  // llvm::array_pod_stable_sort.
467  std::stable_sort(layout.begin(), layout.end());
468 
469  // Needed for blocks layout info.
472 
473  CharUnits &blockSize = info.BlockSize;
474  info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
475 
476  // Assuming that the first byte in the header is maximally aligned,
477  // get the alignment of the first byte following the header.
478  CharUnits endAlign = getLowBit(blockSize);
479 
480  // If the end of the header isn't satisfactorily aligned for the
481  // maximum thing, look for things that are okay with the header-end
482  // alignment, and keep appending them until we get something that's
483  // aligned right. This algorithm is only guaranteed optimal if
484  // that condition is satisfied at some point; otherwise we can get
485  // things like:
486  // header // next byte has alignment 4
487  // something_with_size_5; // next byte has alignment 1
488  // something_with_alignment_8;
489  // which has 7 bytes of padding, as opposed to the naive solution
490  // which might have less (?).
491  if (endAlign < maxFieldAlign) {
493  li = layout.begin() + 1, le = layout.end();
494 
495  // Look for something that the header end is already
496  // satisfactorily aligned for.
497  for (; li != le && endAlign < li->Alignment; ++li)
498  ;
499 
500  // If we found something that's naturally aligned for the end of
501  // the header, keep adding things...
502  if (li != le) {
504  for (; li != le; ++li) {
505  assert(endAlign >= li->Alignment);
506 
507  li->setIndex(info, elementTypes.size());
508  elementTypes.push_back(li->Type);
509  blockSize += li->Size;
510  endAlign = getLowBit(blockSize);
511 
512  // ...until we get to the alignment of the maximum field.
513  if (endAlign >= maxFieldAlign) {
514  if (li == first) {
515  // No user field was appended. So, a gap was added.
516  // Save total gap size for use in block layout bit map.
517  info.BlockHeaderForcedGapSize = li->Size;
518  }
519  break;
520  }
521  }
522  // Don't re-append everything we just appended.
523  layout.erase(first, li);
524  }
525  }
526 
527  assert(endAlign == getLowBit(blockSize));
528 
529  // At this point, we just have to add padding if the end align still
530  // isn't aligned right.
531  if (endAlign < maxFieldAlign) {
532  CharUnits newBlockSize = blockSize.RoundUpToAlignment(maxFieldAlign);
533  CharUnits padding = newBlockSize - blockSize;
534 
535  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
536  padding.getQuantity()));
537  blockSize = newBlockSize;
538  endAlign = getLowBit(blockSize); // might be > maxFieldAlign
539  }
540 
541  assert(endAlign >= maxFieldAlign);
542  assert(endAlign == getLowBit(blockSize));
543  // Slam everything else on now. This works because they have
544  // strictly decreasing alignment and we expect that size is always a
545  // multiple of alignment.
547  li = layout.begin(), le = layout.end(); li != le; ++li) {
548  if (endAlign < li->Alignment) {
549  // size may not be multiple of alignment. This can only happen with
550  // an over-aligned variable. We will be adding a padding field to
551  // make the size be multiple of alignment.
552  CharUnits padding = li->Alignment - endAlign;
553  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
554  padding.getQuantity()));
555  blockSize += padding;
556  endAlign = getLowBit(blockSize);
557  }
558  assert(endAlign >= li->Alignment);
559  li->setIndex(info, elementTypes.size());
560  elementTypes.push_back(li->Type);
561  blockSize += li->Size;
562  endAlign = getLowBit(blockSize);
563  }
564 
565  info.StructureType =
566  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
567 }
568 
569 /// Enter the scope of a block. This should be run at the entrance to
570 /// a full-expression so that the block's cleanups are pushed at the
571 /// right place in the stack.
572 static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
573  assert(CGF.HaveInsertPoint());
574 
575  // Allocate the block info and place it at the head of the list.
576  CGBlockInfo &blockInfo =
577  *new CGBlockInfo(block, CGF.CurFn->getName());
578  blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
579  CGF.FirstBlockInfo = &blockInfo;
580 
581  // Compute information about the layout, etc., of this block,
582  // pushing cleanups as necessary.
583  computeBlockInfo(CGF.CGM, &CGF, blockInfo);
584 
585  // Nothing else to do if it can be global.
586  if (blockInfo.CanBeGlobal) return;
587 
588  // Make the allocation for the block.
589  blockInfo.Address =
590  CGF.CreateTempAlloca(blockInfo.StructureType, "block");
591  blockInfo.Address->setAlignment(blockInfo.BlockAlign.getQuantity());
592 
593  // If there are cleanups to emit, enter them (but inactive).
594  if (!blockInfo.NeedsCopyDispose) return;
595 
596  // Walk through the captures (in order) and find the ones not
597  // captured by constant.
598  for (const auto &CI : block->captures()) {
599  // Ignore __block captures; there's nothing special in the
600  // on-stack block that we need to do for them.
601  if (CI.isByRef()) continue;
602 
603  // Ignore variables that are constant-captured.
604  const VarDecl *variable = CI.getVariable();
605  CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
606  if (capture.isConstant()) continue;
607 
608  // Ignore objects that aren't destructed.
609  QualType::DestructionKind dtorKind =
610  variable->getType().isDestructedType();
611  if (dtorKind == QualType::DK_none) continue;
612 
613  CodeGenFunction::Destroyer *destroyer;
614 
615  // Block captures count as local values and have imprecise semantics.
616  // They also can't be arrays, so need to worry about that.
617  if (dtorKind == QualType::DK_objc_strong_lifetime) {
619  } else {
620  destroyer = CGF.getDestroyer(dtorKind);
621  }
622 
623  // GEP down to the address.
624  llvm::Value *addr = CGF.Builder.CreateStructGEP(
625  blockInfo.StructureType, blockInfo.Address, capture.getIndex());
626 
627  // We can use that GEP as the dominating IP.
628  if (!blockInfo.DominatingIP)
629  blockInfo.DominatingIP = cast<llvm::Instruction>(addr);
630 
631  CleanupKind cleanupKind = InactiveNormalCleanup;
632  bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
633  if (useArrayEHCleanup)
634  cleanupKind = InactiveNormalAndEHCleanup;
635 
636  CGF.pushDestroy(cleanupKind, addr, variable->getType(),
637  destroyer, useArrayEHCleanup);
638 
639  // Remember where that cleanup was.
640  capture.setCleanup(CGF.EHStack.stable_begin());
641  }
642 }
643 
644 /// Enter a full-expression with a non-trivial number of objects to
645 /// clean up. This is in this file because, at the moment, the only
646 /// kind of cleanup object is a BlockDecl*.
648  assert(E->getNumObjects() != 0);
651  i = cleanups.begin(), e = cleanups.end(); i != e; ++i) {
652  enterBlockScope(*this, *i);
653  }
654 }
655 
656 /// Find the layout for the given block in a linked list and remove it.
658  const BlockDecl *block) {
659  while (true) {
660  assert(head && *head);
661  CGBlockInfo *cur = *head;
662 
663  // If this is the block we're looking for, splice it out of the list.
664  if (cur->getBlockDecl() == block) {
665  *head = cur->NextBlockInfo;
666  return cur;
667  }
668 
669  head = &cur->NextBlockInfo;
670  }
671 }
672 
673 /// Destroy a chain of block layouts.
675  assert(head && "destroying an empty chain");
676  do {
677  CGBlockInfo *cur = head;
678  head = cur->NextBlockInfo;
679  delete cur;
680  } while (head != nullptr);
681 }
682 
683 /// Emit a block literal expression in the current function.
685  // If the block has no captures, we won't have a pre-computed
686  // layout for it.
687  if (!blockExpr->getBlockDecl()->hasCaptures()) {
688  CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
689  computeBlockInfo(CGM, this, blockInfo);
690  blockInfo.BlockExpression = blockExpr;
691  return EmitBlockLiteral(blockInfo);
692  }
693 
694  // Find the block info for this block and take ownership of it.
695  std::unique_ptr<CGBlockInfo> blockInfo;
696  blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
697  blockExpr->getBlockDecl()));
698 
699  blockInfo->BlockExpression = blockExpr;
700  return EmitBlockLiteral(*blockInfo);
701 }
702 
704  // Using the computed layout, generate the actual block function.
705  bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
706  llvm::Constant *blockFn
707  = CodeGenFunction(CGM, true).GenerateBlockFunction(CurGD, blockInfo,
708  LocalDeclMap,
709  isLambdaConv);
710  blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy);
711 
712  // If there is nothing to capture, we can emit this as a global block.
713  if (blockInfo.CanBeGlobal)
714  return buildGlobalBlock(CGM, blockInfo, blockFn);
715 
716  // Otherwise, we have to emit this as a local block.
717 
718  llvm::Constant *isa = CGM.getNSConcreteStackBlock();
719  isa = llvm::ConstantExpr::getBitCast(isa, VoidPtrTy);
720 
721  // Build the block descriptor.
722  llvm::Constant *descriptor = buildBlockDescriptor(CGM, blockInfo);
723 
724  llvm::Type *blockTy = blockInfo.StructureType;
725  llvm::AllocaInst *blockAddr = blockInfo.Address;
726  assert(blockAddr && "block has no address!");
727 
728  // Compute the initial on-stack block flags.
731  if (blockInfo.NeedsCopyDispose) flags |= BLOCK_HAS_COPY_DISPOSE;
732  if (blockInfo.HasCXXObject) flags |= BLOCK_HAS_CXX_OBJ;
733  if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET;
734 
735  // Initialize the block literal.
736  Builder.CreateStore(
737  isa, Builder.CreateStructGEP(blockTy, blockAddr, 0, "block.isa"));
738  Builder.CreateStore(
739  llvm::ConstantInt::get(IntTy, flags.getBitMask()),
740  Builder.CreateStructGEP(blockTy, blockAddr, 1, "block.flags"));
741  Builder.CreateStore(
742  llvm::ConstantInt::get(IntTy, 0),
743  Builder.CreateStructGEP(blockTy, blockAddr, 2, "block.reserved"));
744  Builder.CreateStore(
745  blockFn, Builder.CreateStructGEP(blockTy, blockAddr, 3, "block.invoke"));
746  Builder.CreateStore(descriptor, Builder.CreateStructGEP(blockTy, blockAddr, 4,
747  "block.descriptor"));
748 
749  // Finally, capture all the values into the block.
750  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
751 
752  // First, 'this'.
753  if (blockDecl->capturesCXXThis()) {
754  llvm::Value *addr = Builder.CreateStructGEP(
755  blockTy, blockAddr, blockInfo.CXXThisIndex, "block.captured-this.addr");
756  Builder.CreateStore(LoadCXXThis(), addr);
757  }
758 
759  // Next, captured variables.
760  for (const auto &CI : blockDecl->captures()) {
761  const VarDecl *variable = CI.getVariable();
762  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
763 
764  // Ignore constant captures.
765  if (capture.isConstant()) continue;
766 
767  QualType type = variable->getType();
768  CharUnits align = getContext().getDeclAlign(variable);
769 
770  // This will be a [[type]]*, except that a byref entry will just be
771  // an i8**.
772  llvm::Value *blockField = Builder.CreateStructGEP(
773  blockTy, blockAddr, capture.getIndex(), "block.captured");
774 
775  // Compute the address of the thing we're going to move into the
776  // block literal.
777  llvm::Value *src;
778  if (BlockInfo && CI.isNested()) {
779  // We need to use the capture from the enclosing block.
780  const CGBlockInfo::Capture &enclosingCapture =
781  BlockInfo->getCapture(variable);
782 
783  // This is a [[type]]*, except that a byref entry wil just be an i8**.
784  src = Builder.CreateStructGEP(BlockInfo->StructureType, LoadBlockStruct(),
785  enclosingCapture.getIndex(),
786  "block.capture.addr");
787  } else if (blockDecl->isConversionFromLambda()) {
788  // The lambda capture in a lambda's conversion-to-block-pointer is
789  // special; we'll simply emit it directly.
790  src = nullptr;
791  } else {
792  // Just look it up in the locals map, which will give us back a
793  // [[type]]*. If that doesn't work, do the more elaborate DRE
794  // emission.
795  src = LocalDeclMap.lookup(variable);
796  if (!src) {
797  DeclRefExpr declRef(
798  const_cast<VarDecl *>(variable),
799  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(), type,
801  src = EmitDeclRefLValue(&declRef).getAddress();
802  }
803  }
804 
805  // For byrefs, we just write the pointer to the byref struct into
806  // the block field. There's no need to chase the forwarding
807  // pointer at this point, since we're building something that will
808  // live a shorter life than the stack byref anyway.
809  if (CI.isByRef()) {
810  // Get a void* that points to the byref struct.
811  if (CI.isNested())
812  src = Builder.CreateAlignedLoad(src, align.getQuantity(),
813  "byref.capture");
814  else
815  src = Builder.CreateBitCast(src, VoidPtrTy);
816 
817  // Write that void* into the capture field.
818  Builder.CreateAlignedStore(src, blockField, align.getQuantity());
819 
820  // If we have a copy constructor, evaluate that into the block field.
821  } else if (const Expr *copyExpr = CI.getCopyExpr()) {
822  if (blockDecl->isConversionFromLambda()) {
823  // If we have a lambda conversion, emit the expression
824  // directly into the block instead.
825  AggValueSlot Slot =
826  AggValueSlot::forAddr(blockField, align, Qualifiers(),
830  EmitAggExpr(copyExpr, Slot);
831  } else {
832  EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
833  }
834 
835  // If it's a reference variable, copy the reference into the block field.
836  } else if (type->isReferenceType()) {
837  llvm::Value *ref =
838  Builder.CreateAlignedLoad(src, align.getQuantity(), "ref.val");
839  Builder.CreateAlignedStore(ref, blockField, align.getQuantity());
840 
841  // If this is an ARC __strong block-pointer variable, don't do a
842  // block copy.
843  //
844  // TODO: this can be generalized into the normal initialization logic:
845  // we should never need to do a block-copy when initializing a local
846  // variable, because the local variable's lifetime should be strictly
847  // contained within the stack block's.
848  } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
849  type->isBlockPointerType()) {
850  // Load the block and do a simple retain.
851  LValue srcLV = MakeAddrLValue(src, type, align);
852  llvm::Value *value = EmitLoadOfScalar(srcLV, SourceLocation());
853  value = EmitARCRetainNonBlock(value);
854 
855  // Do a primitive store to the block field.
856  LValue destLV = MakeAddrLValue(blockField, type, align);
857  EmitStoreOfScalar(value, destLV, /*init*/ true);
858 
859  // Otherwise, fake up a POD copy into the block field.
860  } else {
861  // Fake up a new variable so that EmitScalarInit doesn't think
862  // we're referring to the variable in its own initializer.
863  ImplicitParamDecl blockFieldPseudoVar(getContext(), /*DC*/ nullptr,
864  SourceLocation(), /*name*/ nullptr,
865  type);
866 
867  // We use one of these or the other depending on whether the
868  // reference is nested.
869  DeclRefExpr declRef(const_cast<VarDecl *>(variable),
870  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
872 
874  &declRef, VK_RValue);
875  // FIXME: Pass a specific location for the expr init so that the store is
876  // attributed to a reasonable location - otherwise it may be attributed to
877  // locations of subexpressions in the initialization.
878  EmitExprAsInit(&l2r, &blockFieldPseudoVar,
879  MakeAddrLValue(blockField, type, align),
880  /*captured by init*/ false);
881  }
882 
883  // Activate the cleanup if layout pushed one.
884  if (!CI.isByRef()) {
885  EHScopeStack::stable_iterator cleanup = capture.getCleanup();
886  if (cleanup.isValid())
887  ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
888  }
889  }
890 
891  // Cast to the converted block-pointer type, which happens (somewhat
892  // unfortunately) to be a pointer to function type.
893  llvm::Value *result =
894  Builder.CreateBitCast(blockAddr,
895  ConvertType(blockInfo.getBlockExpr()->getType()));
896 
897  return result;
898 }
899 
900 
902  if (BlockDescriptorType)
903  return BlockDescriptorType;
904 
905  llvm::Type *UnsignedLongTy =
906  getTypes().ConvertType(getContext().UnsignedLongTy);
907 
908  // struct __block_descriptor {
909  // unsigned long reserved;
910  // unsigned long block_size;
911  //
912  // // later, the following will be added
913  //
914  // struct {
915  // void (*copyHelper)();
916  // void (*copyHelper)();
917  // } helpers; // !!! optional
918  //
919  // const char *signature; // the block signature
920  // const char *layout; // reserved
921  // };
922  BlockDescriptorType =
923  llvm::StructType::create("struct.__block_descriptor",
924  UnsignedLongTy, UnsignedLongTy, nullptr);
925 
926  // Now form a pointer to that.
927  BlockDescriptorType = llvm::PointerType::getUnqual(BlockDescriptorType);
928  return BlockDescriptorType;
929 }
930 
932  if (GenericBlockLiteralType)
933  return GenericBlockLiteralType;
934 
935  llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
936 
937  // struct __block_literal_generic {
938  // void *__isa;
939  // int __flags;
940  // int __reserved;
941  // void (*__invoke)(void *);
942  // struct __block_descriptor *__descriptor;
943  // };
944  GenericBlockLiteralType =
945  llvm::StructType::create("struct.__block_literal_generic",
947  BlockDescPtrTy, nullptr);
948 
949  return GenericBlockLiteralType;
950 }
951 
952 
954  ReturnValueSlot ReturnValue) {
955  const BlockPointerType *BPT =
957 
958  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
959 
960  // Get a pointer to the generic block literal.
961  llvm::Type *BlockLiteralTy =
962  llvm::PointerType::getUnqual(CGM.getGenericBlockLiteralType());
963 
964  // Bitcast the callee to a block literal.
965  llvm::Value *BlockLiteral =
966  Builder.CreateBitCast(Callee, BlockLiteralTy, "block.literal");
967 
968  // Get the function pointer from the literal.
969  llvm::Value *FuncPtr = Builder.CreateStructGEP(
970  CGM.getGenericBlockLiteralType(), BlockLiteral, 3);
971 
972  BlockLiteral = Builder.CreateBitCast(BlockLiteral, VoidPtrTy);
973 
974  // Add the block literal.
975  CallArgList Args;
976  Args.add(RValue::get(BlockLiteral), getContext().VoidPtrTy);
977 
978  QualType FnType = BPT->getPointeeType();
979 
980  // And the rest of the arguments.
981  EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(),
982  E->arg_begin(), E->arg_end());
983 
984  // Load the function.
985  llvm::Value *Func = Builder.CreateLoad(FuncPtr);
986 
987  const FunctionType *FuncTy = FnType->castAs<FunctionType>();
988  const CGFunctionInfo &FnInfo =
989  CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
990 
991  // Cast the function pointer to the right type.
992  llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
993 
994  llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
995  Func = Builder.CreateBitCast(Func, BlockFTyPtr);
996 
997  // And call the block.
998  return EmitCall(FnInfo, Func, ReturnValue, Args);
999 }
1000 
1002  bool isByRef) {
1003  assert(BlockInfo && "evaluating block ref without block information?");
1004  const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1005 
1006  // Handle constant captures.
1007  if (capture.isConstant()) return LocalDeclMap[variable];
1008 
1009  llvm::Value *addr =
1010  Builder.CreateStructGEP(BlockInfo->StructureType, LoadBlockStruct(),
1011  capture.getIndex(), "block.capture.addr");
1012 
1013  if (isByRef) {
1014  // addr should be a void** right now. Load, then cast the result
1015  // to byref*.
1016 
1017  addr = Builder.CreateLoad(addr);
1018  auto *byrefType = BuildByRefType(variable);
1019  llvm::PointerType *byrefPointerType = llvm::PointerType::get(byrefType, 0);
1020  addr = Builder.CreateBitCast(addr, byrefPointerType,
1021  "byref.addr");
1022 
1023  // Follow the forwarding pointer.
1024  addr = Builder.CreateStructGEP(byrefType, addr, 1, "byref.forwarding");
1025  addr = Builder.CreateLoad(addr, "byref.addr.forwarded");
1026 
1027  // Cast back to byref* and GEP over to the actual object.
1028  addr = Builder.CreateBitCast(addr, byrefPointerType);
1029  addr = Builder.CreateStructGEP(byrefType, addr,
1030  getByRefValueLLVMField(variable).second,
1031  variable->getNameAsString());
1032  }
1033 
1034  if (variable->getType()->isReferenceType())
1035  addr = Builder.CreateLoad(addr, "ref.tmp");
1036 
1037  return addr;
1038 }
1039 
1040 llvm::Constant *
1042  const char *name) {
1043  CGBlockInfo blockInfo(blockExpr->getBlockDecl(), name);
1044  blockInfo.BlockExpression = blockExpr;
1045 
1046  // Compute information about the layout, etc., of this block.
1047  computeBlockInfo(*this, nullptr, blockInfo);
1048 
1049  // Using that metadata, generate the actual block function.
1050  llvm::Constant *blockFn;
1051  {
1052  llvm::DenseMap<const Decl*, llvm::Value*> LocalDeclMap;
1054  blockInfo,
1055  LocalDeclMap,
1056  false);
1057  }
1058  blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy);
1059 
1060  return buildGlobalBlock(*this, blockInfo, blockFn);
1061 }
1062 
1063 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1064  const CGBlockInfo &blockInfo,
1065  llvm::Constant *blockFn) {
1066  assert(blockInfo.CanBeGlobal);
1067 
1068  // Generate the constants for the block literal initializer.
1069  llvm::Constant *fields[BlockHeaderSize];
1070 
1071  // isa
1072  fields[0] = CGM.getNSConcreteGlobalBlock();
1073 
1074  // __flags
1076  if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET;
1077 
1078  fields[1] = llvm::ConstantInt::get(CGM.IntTy, flags.getBitMask());
1079 
1080  // Reserved
1081  fields[2] = llvm::Constant::getNullValue(CGM.IntTy);
1082 
1083  // Function
1084  fields[3] = blockFn;
1085 
1086  // Descriptor
1087  fields[4] = buildBlockDescriptor(CGM, blockInfo);
1088 
1089  llvm::Constant *init = llvm::ConstantStruct::getAnon(fields);
1090 
1091  llvm::GlobalVariable *literal =
1092  new llvm::GlobalVariable(CGM.getModule(),
1093  init->getType(),
1094  /*constant*/ true,
1096  init,
1097  "__block_literal_global");
1098  literal->setAlignment(blockInfo.BlockAlign.getQuantity());
1099 
1100  // Return a constant of the appropriately-casted type.
1101  llvm::Type *requiredType =
1102  CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1103  return llvm::ConstantExpr::getBitCast(literal, requiredType);
1104 }
1105 
1106 llvm::Function *
1108  const CGBlockInfo &blockInfo,
1109  const DeclMapTy &ldm,
1110  bool IsLambdaConversionToBlock) {
1111  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1112 
1113  CurGD = GD;
1114 
1115  CurEHLocation = blockInfo.getBlockExpr()->getLocEnd();
1116 
1117  BlockInfo = &blockInfo;
1118 
1119  // Arrange for local static and local extern declarations to appear
1120  // to be local to this function as well, in case they're directly
1121  // referenced in a block.
1122  for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1123  const auto *var = dyn_cast<VarDecl>(i->first);
1124  if (var && !var->hasLocalStorage())
1125  LocalDeclMap[var] = i->second;
1126  }
1127 
1128  // Begin building the function declaration.
1129 
1130  // Build the argument list.
1131  FunctionArgList args;
1132 
1133  // The first argument is the block pointer. Just take it as a void*
1134  // and cast it later.
1135  QualType selfTy = getContext().VoidPtrTy;
1136  IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1137 
1138  ImplicitParamDecl selfDecl(getContext(), const_cast<BlockDecl*>(blockDecl),
1139  SourceLocation(), II, selfTy);
1140  args.push_back(&selfDecl);
1141 
1142  // Now add the rest of the parameters.
1143  args.append(blockDecl->param_begin(), blockDecl->param_end());
1144 
1145  // Create the function declaration.
1146  const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1147  const CGFunctionInfo &fnInfo = CGM.getTypes().arrangeFreeFunctionDeclaration(
1148  fnType->getReturnType(), args, fnType->getExtInfo(),
1149  fnType->isVariadic());
1150  if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1151  blockInfo.UsesStret = true;
1152 
1153  llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1154 
1155  StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1156  llvm::Function *fn = llvm::Function::Create(
1157  fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1158  CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1159 
1160  // Begin generating the function.
1161  StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1162  blockDecl->getLocation(),
1163  blockInfo.getBlockExpr()->getBody()->getLocStart());
1164 
1165  // Okay. Undo some of what StartFunction did.
1166 
1167  // Pull the 'self' reference out of the local decl map.
1168  llvm::Value *blockAddr = LocalDeclMap[&selfDecl];
1169  LocalDeclMap.erase(&selfDecl);
1170  BlockPointer = Builder.CreateBitCast(blockAddr,
1171  blockInfo.StructureType->getPointerTo(),
1172  "block");
1173  // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1174  // won't delete the dbg.declare intrinsics for captured variables.
1175  llvm::Value *BlockPointerDbgLoc = BlockPointer;
1176  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1177  // Allocate a stack slot for it, so we can point the debugger to it
1178  llvm::AllocaInst *Alloca = CreateTempAlloca(BlockPointer->getType(),
1179  "block.addr");
1180  unsigned Align = getContext().getDeclAlign(&selfDecl).getQuantity();
1181  Alloca->setAlignment(Align);
1182  // Set the DebugLocation to empty, so the store is recognized as a
1183  // frame setup instruction by llvm::DwarfDebug::beginFunction().
1184  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1185  Builder.CreateAlignedStore(BlockPointer, Alloca, Align);
1186  BlockPointerDbgLoc = Alloca;
1187  }
1188 
1189  // If we have a C++ 'this' reference, go ahead and force it into
1190  // existence now.
1191  if (blockDecl->capturesCXXThis()) {
1192  llvm::Value *addr =
1193  Builder.CreateStructGEP(blockInfo.StructureType, BlockPointer,
1194  blockInfo.CXXThisIndex, "block.captured-this");
1195  CXXThisValue = Builder.CreateLoad(addr, "this");
1196  }
1197 
1198  // Also force all the constant captures.
1199  for (const auto &CI : blockDecl->captures()) {
1200  const VarDecl *variable = CI.getVariable();
1201  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1202  if (!capture.isConstant()) continue;
1203 
1204  unsigned align = getContext().getDeclAlign(variable).getQuantity();
1205 
1206  llvm::AllocaInst *alloca =
1207  CreateMemTemp(variable->getType(), "block.captured-const");
1208  alloca->setAlignment(align);
1209 
1210  Builder.CreateAlignedStore(capture.getConstant(), alloca, align);
1211 
1212  LocalDeclMap[variable] = alloca;
1213  }
1214 
1215  // Save a spot to insert the debug information for all the DeclRefExprs.
1216  llvm::BasicBlock *entry = Builder.GetInsertBlock();
1217  llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1218  --entry_ptr;
1219 
1220  if (IsLambdaConversionToBlock)
1221  EmitLambdaBlockInvokeBody();
1222  else {
1223  PGO.assignRegionCounters(blockDecl, fn);
1224  incrementProfileCounter(blockDecl->getBody());
1225  EmitStmt(blockDecl->getBody());
1226  }
1227 
1228  // Remember where we were...
1229  llvm::BasicBlock *resume = Builder.GetInsertBlock();
1230 
1231  // Go back to the entry.
1232  ++entry_ptr;
1233  Builder.SetInsertPoint(entry, entry_ptr);
1234 
1235  // Emit debug information for all the DeclRefExprs.
1236  // FIXME: also for 'this'
1237  if (CGDebugInfo *DI = getDebugInfo()) {
1238  for (const auto &CI : blockDecl->captures()) {
1239  const VarDecl *variable = CI.getVariable();
1240  DI->EmitLocation(Builder, variable->getLocation());
1241 
1242  if (CGM.getCodeGenOpts().getDebugInfo()
1244  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1245  if (capture.isConstant()) {
1246  DI->EmitDeclareOfAutoVariable(variable, LocalDeclMap[variable],
1247  Builder);
1248  continue;
1249  }
1250 
1251  DI->EmitDeclareOfBlockDeclRefVariable(variable, BlockPointerDbgLoc,
1252  Builder, blockInfo,
1253  entry_ptr == entry->end()
1254  ? nullptr : entry_ptr);
1255  }
1256  }
1257  // Recover location if it was changed in the above loop.
1258  DI->EmitLocation(Builder,
1259  cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1260  }
1261 
1262  // And resume where we left off.
1263  if (resume == nullptr)
1264  Builder.ClearInsertionPoint();
1265  else
1266  Builder.SetInsertPoint(resume);
1267 
1268  FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1269 
1270  return fn;
1271 }
1272 
1273 /*
1274  notes.push_back(HelperInfo());
1275  HelperInfo &note = notes.back();
1276  note.index = capture.getIndex();
1277  note.RequiresCopying = (ci->hasCopyExpr() || BlockRequiresCopying(type));
1278  note.cxxbar_import = ci->getCopyExpr();
1279 
1280  if (ci->isByRef()) {
1281  note.flag = BLOCK_FIELD_IS_BYREF;
1282  if (type.isObjCGCWeak())
1283  note.flag |= BLOCK_FIELD_IS_WEAK;
1284  } else if (type->isBlockPointerType()) {
1285  note.flag = BLOCK_FIELD_IS_BLOCK;
1286  } else {
1287  note.flag = BLOCK_FIELD_IS_OBJECT;
1288  }
1289  */
1290 
1291 
1292 /// Generate the copy-helper function for a block closure object:
1293 /// static void block_copy_helper(block_t *dst, block_t *src);
1294 /// The runtime will have previously initialized 'dst' by doing a
1295 /// bit-copy of 'src'.
1296 ///
1297 /// Note that this copies an entire block closure object to the heap;
1298 /// it should not be confused with a 'byref copy helper', which moves
1299 /// the contents of an individual __block variable to the heap.
1300 llvm::Constant *
1302  ASTContext &C = getContext();
1303 
1304  FunctionArgList args;
1305  ImplicitParamDecl dstDecl(getContext(), nullptr, SourceLocation(), nullptr,
1306  C.VoidPtrTy);
1307  args.push_back(&dstDecl);
1308  ImplicitParamDecl srcDecl(getContext(), nullptr, SourceLocation(), nullptr,
1309  C.VoidPtrTy);
1310  args.push_back(&srcDecl);
1311 
1312  const CGFunctionInfo &FI = CGM.getTypes().arrangeFreeFunctionDeclaration(
1313  C.VoidTy, args, FunctionType::ExtInfo(), /*variadic=*/false);
1314 
1315  // FIXME: it would be nice if these were mergeable with things with
1316  // identical semantics.
1317  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1318 
1319  llvm::Function *Fn =
1321  "__copy_helper_block_", &CGM.getModule());
1322 
1323  IdentifierInfo *II
1324  = &CGM.getContext().Idents.get("__copy_helper_block_");
1325 
1328  SourceLocation(),
1329  SourceLocation(), II, C.VoidTy,
1330  nullptr, SC_Static,
1331  false,
1332  false);
1333  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1334  StartFunction(FD, C.VoidTy, Fn, FI, args);
1335  // Create a scope with an artificial location for the body of this function.
1336  auto AL = ApplyDebugLocation::CreateArtificial(*this);
1337  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1338 
1339  llvm::Value *src = GetAddrOfLocalVar(&srcDecl);
1340  src = Builder.CreateLoad(src);
1341  src = Builder.CreateBitCast(src, structPtrTy, "block.source");
1342 
1343  llvm::Value *dst = GetAddrOfLocalVar(&dstDecl);
1344  dst = Builder.CreateLoad(dst);
1345  dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
1346 
1347  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1348 
1349  for (const auto &CI : blockDecl->captures()) {
1350  const VarDecl *variable = CI.getVariable();
1351  QualType type = variable->getType();
1352 
1353  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1354  if (capture.isConstant()) continue;
1355 
1356  const Expr *copyExpr = CI.getCopyExpr();
1357  BlockFieldFlags flags;
1358 
1359  bool useARCWeakCopy = false;
1360  bool useARCStrongCopy = false;
1361 
1362  if (copyExpr) {
1363  assert(!CI.isByRef());
1364  // don't bother computing flags
1365 
1366  } else if (CI.isByRef()) {
1367  flags = BLOCK_FIELD_IS_BYREF;
1368  if (type.isObjCGCWeak())
1369  flags |= BLOCK_FIELD_IS_WEAK;
1370 
1371  } else if (type->isObjCRetainableType()) {
1372  flags = BLOCK_FIELD_IS_OBJECT;
1373  bool isBlockPointer = type->isBlockPointerType();
1374  if (isBlockPointer)
1375  flags = BLOCK_FIELD_IS_BLOCK;
1376 
1377  // Special rules for ARC captures:
1378  if (getLangOpts().ObjCAutoRefCount) {
1379  Qualifiers qs = type.getQualifiers();
1380 
1381  // We need to register __weak direct captures with the runtime.
1382  if (qs.getObjCLifetime() == Qualifiers::OCL_Weak) {
1383  useARCWeakCopy = true;
1384 
1385  // We need to retain the copied value for __strong direct captures.
1386  } else if (qs.getObjCLifetime() == Qualifiers::OCL_Strong) {
1387  // If it's a block pointer, we have to copy the block and
1388  // assign that to the destination pointer, so we might as
1389  // well use _Block_object_assign. Otherwise we can avoid that.
1390  if (!isBlockPointer)
1391  useARCStrongCopy = true;
1392 
1393  // Otherwise the memcpy is fine.
1394  } else {
1395  continue;
1396  }
1397 
1398  // Non-ARC captures of retainable pointers are strong and
1399  // therefore require a call to _Block_object_assign.
1400  } else {
1401  // fall through
1402  }
1403  } else {
1404  continue;
1405  }
1406 
1407  unsigned index = capture.getIndex();
1408  llvm::Value *srcField =
1409  Builder.CreateStructGEP(blockInfo.StructureType, src, index);
1410  llvm::Value *dstField =
1411  Builder.CreateStructGEP(blockInfo.StructureType, dst, index);
1412 
1413  // If there's an explicit copy expression, we do that.
1414  if (copyExpr) {
1415  EmitSynthesizedCXXCopyCtor(dstField, srcField, copyExpr);
1416  } else if (useARCWeakCopy) {
1417  EmitARCCopyWeak(dstField, srcField);
1418  } else {
1419  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
1420  if (useARCStrongCopy) {
1421  // At -O0, store null into the destination field (so that the
1422  // storeStrong doesn't over-release) and then call storeStrong.
1423  // This is a workaround to not having an initStrong call.
1424  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1425  auto *ty = cast<llvm::PointerType>(srcValue->getType());
1426  llvm::Value *null = llvm::ConstantPointerNull::get(ty);
1427  Builder.CreateStore(null, dstField);
1428  EmitARCStoreStrongCall(dstField, srcValue, true);
1429 
1430  // With optimization enabled, take advantage of the fact that
1431  // the blocks runtime guarantees a memcpy of the block data, and
1432  // just emit a retain of the src field.
1433  } else {
1434  EmitARCRetainNonBlock(srcValue);
1435 
1436  // We don't need this anymore, so kill it. It's not quite
1437  // worth the annoyance to avoid creating it in the first place.
1438  cast<llvm::Instruction>(dstField)->eraseFromParent();
1439  }
1440  } else {
1441  srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
1442  llvm::Value *dstAddr = Builder.CreateBitCast(dstField, VoidPtrTy);
1443  llvm::Value *args[] = {
1444  dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
1445  };
1446 
1447  bool copyCanThrow = false;
1448  if (CI.isByRef() && variable->getType()->getAsCXXRecordDecl()) {
1449  const Expr *copyExpr =
1450  CGM.getContext().getBlockVarCopyInits(variable);
1451  if (copyExpr) {
1452  copyCanThrow = true; // FIXME: reuse the noexcept logic
1453  }
1454  }
1455 
1456  if (copyCanThrow) {
1457  EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
1458  } else {
1459  EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
1460  }
1461  }
1462  }
1463  }
1464 
1465  FinishFunction();
1466 
1467  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1468 }
1469 
1470 /// Generate the destroy-helper function for a block closure object:
1471 /// static void block_destroy_helper(block_t *theBlock);
1472 ///
1473 /// Note that this destroys a heap-allocated block closure object;
1474 /// it should not be confused with a 'byref destroy helper', which
1475 /// destroys the heap-allocated contents of an individual __block
1476 /// variable.
1477 llvm::Constant *
1479  ASTContext &C = getContext();
1480 
1481  FunctionArgList args;
1482  ImplicitParamDecl srcDecl(getContext(), nullptr, SourceLocation(), nullptr,
1483  C.VoidPtrTy);
1484  args.push_back(&srcDecl);
1485 
1486  const CGFunctionInfo &FI = CGM.getTypes().arrangeFreeFunctionDeclaration(
1487  C.VoidTy, args, FunctionType::ExtInfo(), /*variadic=*/false);
1488 
1489  // FIXME: We'd like to put these into a mergable by content, with
1490  // internal linkage.
1491  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1492 
1493  llvm::Function *Fn =
1495  "__destroy_helper_block_", &CGM.getModule());
1496 
1497  IdentifierInfo *II
1498  = &CGM.getContext().Idents.get("__destroy_helper_block_");
1499 
1501  SourceLocation(),
1502  SourceLocation(), II, C.VoidTy,
1503  nullptr, SC_Static,
1504  false, false);
1505  // Create a scope with an artificial location for the body of this function.
1506  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1507  StartFunction(FD, C.VoidTy, Fn, FI, args);
1508  auto AL = ApplyDebugLocation::CreateArtificial(*this);
1509 
1510  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1511 
1512  llvm::Value *src = GetAddrOfLocalVar(&srcDecl);
1513  src = Builder.CreateLoad(src);
1514  src = Builder.CreateBitCast(src, structPtrTy, "block");
1515 
1516  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1517 
1518  CodeGenFunction::RunCleanupsScope cleanups(*this);
1519 
1520  for (const auto &CI : blockDecl->captures()) {
1521  const VarDecl *variable = CI.getVariable();
1522  QualType type = variable->getType();
1523 
1524  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1525  if (capture.isConstant()) continue;
1526 
1527  BlockFieldFlags flags;
1528  const CXXDestructorDecl *dtor = nullptr;
1529 
1530  bool useARCWeakDestroy = false;
1531  bool useARCStrongDestroy = false;
1532 
1533  if (CI.isByRef()) {
1534  flags = BLOCK_FIELD_IS_BYREF;
1535  if (type.isObjCGCWeak())
1536  flags |= BLOCK_FIELD_IS_WEAK;
1537  } else if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
1538  if (record->hasTrivialDestructor())
1539  continue;
1540  dtor = record->getDestructor();
1541  } else if (type->isObjCRetainableType()) {
1542  flags = BLOCK_FIELD_IS_OBJECT;
1543  if (type->isBlockPointerType())
1544  flags = BLOCK_FIELD_IS_BLOCK;
1545 
1546  // Special rules for ARC captures.
1547  if (getLangOpts().ObjCAutoRefCount) {
1548  Qualifiers qs = type.getQualifiers();
1549 
1550  // Don't generate special dispose logic for a captured object
1551  // unless it's __strong or __weak.
1552  if (!qs.hasStrongOrWeakObjCLifetime())
1553  continue;
1554 
1555  // Support __weak direct captures.
1557  useARCWeakDestroy = true;
1558 
1559  // Tools really want us to use objc_storeStrong here.
1560  else
1561  useARCStrongDestroy = true;
1562  }
1563  } else {
1564  continue;
1565  }
1566 
1567  unsigned index = capture.getIndex();
1568  llvm::Value *srcField =
1569  Builder.CreateStructGEP(blockInfo.StructureType, src, index);
1570 
1571  // If there's an explicit copy expression, we do that.
1572  if (dtor) {
1573  PushDestructorCleanup(dtor, srcField);
1574 
1575  // If this is a __weak capture, emit the release directly.
1576  } else if (useARCWeakDestroy) {
1577  EmitARCDestroyWeak(srcField);
1578 
1579  // Destroy strong objects with a call if requested.
1580  } else if (useARCStrongDestroy) {
1581  EmitARCDestroyStrong(srcField, ARCImpreciseLifetime);
1582 
1583  // Otherwise we call _Block_object_dispose. It wouldn't be too
1584  // hard to just emit this as a cleanup if we wanted to make sure
1585  // that things were done in reverse.
1586  } else {
1587  llvm::Value *value = Builder.CreateLoad(srcField);
1588  value = Builder.CreateBitCast(value, VoidPtrTy);
1589  BuildBlockRelease(value, flags);
1590  }
1591  }
1592 
1593  cleanups.ForceCleanup();
1594 
1595  FinishFunction();
1596 
1597  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1598 }
1599 
1600 namespace {
1601 
1602 /// Emits the copy/dispose helper functions for a __block object of id type.
1603 class ObjectByrefHelpers : public CodeGenModule::ByrefHelpers {
1604  BlockFieldFlags Flags;
1605 
1606 public:
1607  ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
1608  : ByrefHelpers(alignment), Flags(flags) {}
1609 
1610  void emitCopy(CodeGenFunction &CGF, llvm::Value *destField,
1611  llvm::Value *srcField) override {
1612  destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
1613 
1614  srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
1615  llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
1616 
1617  unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
1618 
1619  llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
1620  llvm::Value *fn = CGF.CGM.getBlockObjectAssign();
1621 
1622  llvm::Value *args[] = { destField, srcValue, flagsVal };
1623  CGF.EmitNounwindRuntimeCall(fn, args);
1624  }
1625 
1626  void emitDispose(CodeGenFunction &CGF, llvm::Value *field) override {
1627  field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
1628  llvm::Value *value = CGF.Builder.CreateLoad(field);
1629 
1630  CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER);
1631  }
1632 
1633  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1634  id.AddInteger(Flags.getBitMask());
1635  }
1636 };
1637 
1638 /// Emits the copy/dispose helpers for an ARC __block __weak variable.
1639 class ARCWeakByrefHelpers : public CodeGenModule::ByrefHelpers {
1640 public:
1641  ARCWeakByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {}
1642 
1643  void emitCopy(CodeGenFunction &CGF, llvm::Value *destField,
1644  llvm::Value *srcField) override {
1645  CGF.EmitARCMoveWeak(destField, srcField);
1646  }
1647 
1648  void emitDispose(CodeGenFunction &CGF, llvm::Value *field) override {
1649  CGF.EmitARCDestroyWeak(field);
1650  }
1651 
1652  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1653  // 0 is distinguishable from all pointers and byref flags
1654  id.AddInteger(0);
1655  }
1656 };
1657 
1658 /// Emits the copy/dispose helpers for an ARC __block __strong variable
1659 /// that's not of block-pointer type.
1660 class ARCStrongByrefHelpers : public CodeGenModule::ByrefHelpers {
1661 public:
1662  ARCStrongByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {}
1663 
1664  void emitCopy(CodeGenFunction &CGF, llvm::Value *destField,
1665  llvm::Value *srcField) override {
1666  // Do a "move" by copying the value and then zeroing out the old
1667  // variable.
1668 
1669  llvm::LoadInst *value = CGF.Builder.CreateLoad(srcField);
1670  value->setAlignment(Alignment.getQuantity());
1671 
1672  llvm::Value *null =
1673  llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
1674 
1675  if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
1676  llvm::StoreInst *store = CGF.Builder.CreateStore(null, destField);
1677  store->setAlignment(Alignment.getQuantity());
1678  CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
1679  CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
1680  return;
1681  }
1682  llvm::StoreInst *store = CGF.Builder.CreateStore(value, destField);
1683  store->setAlignment(Alignment.getQuantity());
1684 
1685  store = CGF.Builder.CreateStore(null, srcField);
1686  store->setAlignment(Alignment.getQuantity());
1687  }
1688 
1689  void emitDispose(CodeGenFunction &CGF, llvm::Value *field) override {
1691  }
1692 
1693  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1694  // 1 is distinguishable from all pointers and byref flags
1695  id.AddInteger(1);
1696  }
1697 };
1698 
1699 /// Emits the copy/dispose helpers for an ARC __block __strong
1700 /// variable that's of block-pointer type.
1701 class ARCStrongBlockByrefHelpers : public CodeGenModule::ByrefHelpers {
1702 public:
1703  ARCStrongBlockByrefHelpers(CharUnits alignment) : ByrefHelpers(alignment) {}
1704 
1705  void emitCopy(CodeGenFunction &CGF, llvm::Value *destField,
1706  llvm::Value *srcField) override {
1707  // Do the copy with objc_retainBlock; that's all that
1708  // _Block_object_assign would do anyway, and we'd have to pass the
1709  // right arguments to make sure it doesn't get no-op'ed.
1710  llvm::LoadInst *oldValue = CGF.Builder.CreateLoad(srcField);
1711  oldValue->setAlignment(Alignment.getQuantity());
1712 
1713  llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
1714 
1715  llvm::StoreInst *store = CGF.Builder.CreateStore(copy, destField);
1716  store->setAlignment(Alignment.getQuantity());
1717  }
1718 
1719  void emitDispose(CodeGenFunction &CGF, llvm::Value *field) override {
1721  }
1722 
1723  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1724  // 2 is distinguishable from all pointers and byref flags
1725  id.AddInteger(2);
1726  }
1727 };
1728 
1729 /// Emits the copy/dispose helpers for a __block variable with a
1730 /// nontrivial copy constructor or destructor.
1731 class CXXByrefHelpers : public CodeGenModule::ByrefHelpers {
1732  QualType VarType;
1733  const Expr *CopyExpr;
1734 
1735 public:
1736  CXXByrefHelpers(CharUnits alignment, QualType type,
1737  const Expr *copyExpr)
1738  : ByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
1739 
1740  bool needsCopy() const override { return CopyExpr != nullptr; }
1741  void emitCopy(CodeGenFunction &CGF, llvm::Value *destField,
1742  llvm::Value *srcField) override {
1743  if (!CopyExpr) return;
1744  CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
1745  }
1746 
1747  void emitDispose(CodeGenFunction &CGF, llvm::Value *field) override {
1748  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
1749  CGF.PushDestructorCleanup(VarType, field);
1750  CGF.PopCleanupBlocks(cleanupDepth);
1751  }
1752 
1753  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1754  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
1755  }
1756 };
1757 } // end anonymous namespace
1758 
1759 static llvm::Constant *
1761  llvm::StructType &byrefType,
1762  unsigned valueFieldIndex,
1763  CodeGenModule::ByrefHelpers &byrefInfo) {
1764  ASTContext &Context = CGF.getContext();
1765 
1766  QualType R = Context.VoidTy;
1767 
1768  FunctionArgList args;
1769  ImplicitParamDecl dst(CGF.getContext(), nullptr, SourceLocation(), nullptr,
1770  Context.VoidPtrTy);
1771  args.push_back(&dst);
1772 
1773  ImplicitParamDecl src(CGF.getContext(), nullptr, SourceLocation(), nullptr,
1774  Context.VoidPtrTy);
1775  args.push_back(&src);
1776 
1778  R, args, FunctionType::ExtInfo(), /*variadic=*/false);
1779 
1780  CodeGenTypes &Types = CGF.CGM.getTypes();
1781  llvm::FunctionType *LTy = Types.GetFunctionType(FI);
1782 
1783  // FIXME: We'd like to put these into a mergable by content, with
1784  // internal linkage.
1785  llvm::Function *Fn =
1787  "__Block_byref_object_copy_", &CGF.CGM.getModule());
1788 
1789  IdentifierInfo *II
1790  = &Context.Idents.get("__Block_byref_object_copy_");
1791 
1792  FunctionDecl *FD = FunctionDecl::Create(Context,
1793  Context.getTranslationUnitDecl(),
1794  SourceLocation(),
1795  SourceLocation(), II, R, nullptr,
1796  SC_Static,
1797  false, false);
1798 
1799  CGF.StartFunction(FD, R, Fn, FI, args);
1800 
1801  if (byrefInfo.needsCopy()) {
1802  llvm::Type *byrefPtrType = byrefType.getPointerTo(0);
1803 
1804  // dst->x
1805  llvm::Value *destField = CGF.GetAddrOfLocalVar(&dst);
1806  destField = CGF.Builder.CreateLoad(destField);
1807  destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
1808  destField = CGF.Builder.CreateStructGEP(&byrefType, destField,
1809  valueFieldIndex, "x");
1810 
1811  // src->x
1812  llvm::Value *srcField = CGF.GetAddrOfLocalVar(&src);
1813  srcField = CGF.Builder.CreateLoad(srcField);
1814  srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
1815  srcField =
1816  CGF.Builder.CreateStructGEP(&byrefType, srcField, valueFieldIndex, "x");
1817 
1818  byrefInfo.emitCopy(CGF, destField, srcField);
1819  }
1820 
1821  CGF.FinishFunction();
1822 
1823  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
1824 }
1825 
1826 /// Build the copy helper for a __block variable.
1827 static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
1828  llvm::StructType &byrefType,
1829  unsigned byrefValueIndex,
1831  CodeGenFunction CGF(CGM);
1832  return generateByrefCopyHelper(CGF, byrefType, byrefValueIndex, info);
1833 }
1834 
1835 /// Generate code for a __block variable's dispose helper.
1836 static llvm::Constant *
1838  llvm::StructType &byrefType,
1839  unsigned byrefValueIndex,
1840  CodeGenModule::ByrefHelpers &byrefInfo) {
1841  ASTContext &Context = CGF.getContext();
1842  QualType R = Context.VoidTy;
1843 
1844  FunctionArgList args;
1845  ImplicitParamDecl src(CGF.getContext(), nullptr, SourceLocation(), nullptr,
1846  Context.VoidPtrTy);
1847  args.push_back(&src);
1848 
1850  R, args, FunctionType::ExtInfo(), /*variadic=*/false);
1851 
1852  CodeGenTypes &Types = CGF.CGM.getTypes();
1853  llvm::FunctionType *LTy = Types.GetFunctionType(FI);
1854 
1855  // FIXME: We'd like to put these into a mergable by content, with
1856  // internal linkage.
1857  llvm::Function *Fn =
1859  "__Block_byref_object_dispose_",
1860  &CGF.CGM.getModule());
1861 
1862  IdentifierInfo *II
1863  = &Context.Idents.get("__Block_byref_object_dispose_");
1864 
1865  FunctionDecl *FD = FunctionDecl::Create(Context,
1866  Context.getTranslationUnitDecl(),
1867  SourceLocation(),
1868  SourceLocation(), II, R, nullptr,
1869  SC_Static,
1870  false, false);
1871  CGF.StartFunction(FD, R, Fn, FI, args);
1872 
1873  if (byrefInfo.needsDispose()) {
1874  llvm::Value *V = CGF.GetAddrOfLocalVar(&src);
1875  V = CGF.Builder.CreateLoad(V);
1876  V = CGF.Builder.CreateBitCast(V, byrefType.getPointerTo(0));
1877  V = CGF.Builder.CreateStructGEP(&byrefType, V, byrefValueIndex, "x");
1878 
1879  byrefInfo.emitDispose(CGF, V);
1880  }
1881 
1882  CGF.FinishFunction();
1883 
1884  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
1885 }
1886 
1887 /// Build the dispose helper for a __block variable.
1888 static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
1889  llvm::StructType &byrefType,
1890  unsigned byrefValueIndex,
1892  CodeGenFunction CGF(CGM);
1893  return generateByrefDisposeHelper(CGF, byrefType, byrefValueIndex, info);
1894 }
1895 
1896 /// Lazily build the copy and dispose helpers for a __block variable
1897 /// with the given information.
1898 template <class T> static T *buildByrefHelpers(CodeGenModule &CGM,
1899  llvm::StructType &byrefTy,
1900  unsigned byrefValueIndex,
1901  T &byrefInfo) {
1902  // Increase the field's alignment to be at least pointer alignment,
1903  // since the layout of the byref struct will guarantee at least that.
1904  byrefInfo.Alignment = std::max(byrefInfo.Alignment,
1906 
1907  llvm::FoldingSetNodeID id;
1908  byrefInfo.Profile(id);
1909 
1910  void *insertPos;
1912  = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
1913  if (node) return static_cast<T*>(node);
1914 
1915  byrefInfo.CopyHelper =
1916  buildByrefCopyHelper(CGM, byrefTy, byrefValueIndex, byrefInfo);
1917  byrefInfo.DisposeHelper =
1918  buildByrefDisposeHelper(CGM, byrefTy, byrefValueIndex,byrefInfo);
1919 
1920  T *copy = new (CGM.getContext()) T(byrefInfo);
1921  CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
1922  return copy;
1923 }
1924 
1925 /// Build the copy and dispose helpers for the given __block variable
1926 /// emission. Places the helpers in the global cache. Returns null
1927 /// if no helpers are required.
1929 CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
1930  const AutoVarEmission &emission) {
1931  const VarDecl &var = *emission.Variable;
1932  QualType type = var.getType();
1933 
1934  unsigned byrefValueIndex = getByRefValueLLVMField(&var).second;
1935 
1936  if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
1937  const Expr *copyExpr = CGM.getContext().getBlockVarCopyInits(&var);
1938  if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
1939 
1940  CXXByrefHelpers byrefInfo(emission.Alignment, type, copyExpr);
1941  return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo);
1942  }
1943 
1944  // Otherwise, if we don't have a retainable type, there's nothing to do.
1945  // that the runtime does extra copies.
1946  if (!type->isObjCRetainableType()) return nullptr;
1947 
1948  Qualifiers qs = type.getQualifiers();
1949 
1950  // If we have lifetime, that dominates.
1951  if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
1952  assert(getLangOpts().ObjCAutoRefCount);
1953 
1954  switch (lifetime) {
1955  case Qualifiers::OCL_None: llvm_unreachable("impossible");
1956 
1957  // These are just bits as far as the runtime is concerned.
1960  return nullptr;
1961 
1962  // Tell the runtime that this is ARC __weak, called by the
1963  // byref routines.
1964  case Qualifiers::OCL_Weak: {
1965  ARCWeakByrefHelpers byrefInfo(emission.Alignment);
1966  return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo);
1967  }
1968 
1969  // ARC __strong __block variables need to be retained.
1971  // Block pointers need to be copied, and there's no direct
1972  // transfer possible.
1973  if (type->isBlockPointerType()) {
1974  ARCStrongBlockByrefHelpers byrefInfo(emission.Alignment);
1975  return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo);
1976 
1977  // Otherwise, we transfer ownership of the retain from the stack
1978  // to the heap.
1979  } else {
1980  ARCStrongByrefHelpers byrefInfo(emission.Alignment);
1981  return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo);
1982  }
1983  }
1984  llvm_unreachable("fell out of lifetime switch!");
1985  }
1986 
1987  BlockFieldFlags flags;
1988  if (type->isBlockPointerType()) {
1989  flags |= BLOCK_FIELD_IS_BLOCK;
1990  } else if (CGM.getContext().isObjCNSObjectType(type) ||
1991  type->isObjCObjectPointerType()) {
1992  flags |= BLOCK_FIELD_IS_OBJECT;
1993  } else {
1994  return nullptr;
1995  }
1996 
1997  if (type.isObjCGCWeak())
1998  flags |= BLOCK_FIELD_IS_WEAK;
1999 
2000  ObjectByrefHelpers byrefInfo(emission.Alignment, flags);
2001  return ::buildByrefHelpers(CGM, byrefType, byrefValueIndex, byrefInfo);
2002 }
2003 
2004 std::pair<llvm::Type *, unsigned>
2006  assert(ByRefValueInfo.count(VD) && "Did not find value!");
2007 
2008  return ByRefValueInfo.find(VD)->second;
2009 }
2010 
2012  const VarDecl *V) {
2013  auto P = getByRefValueLLVMField(V);
2014  llvm::Value *Loc =
2015  Builder.CreateStructGEP(P.first, BaseAddr, 1, "forwarding");
2016  Loc = Builder.CreateLoad(Loc);
2017  Loc = Builder.CreateStructGEP(P.first, Loc, P.second, V->getNameAsString());
2018  return Loc;
2019 }
2020 
2021 /// BuildByRefType - This routine changes a __block variable declared as T x
2022 /// into:
2023 ///
2024 /// struct {
2025 /// void *__isa;
2026 /// void *__forwarding;
2027 /// int32_t __flags;
2028 /// int32_t __size;
2029 /// void *__copy_helper; // only if needed
2030 /// void *__destroy_helper; // only if needed
2031 /// void *__byref_variable_layout;// only if needed
2032 /// char padding[X]; // only if needed
2033 /// T x;
2034 /// } x
2035 ///
2037  std::pair<llvm::Type *, unsigned> &Info = ByRefValueInfo[D];
2038  if (Info.first)
2039  return Info.first;
2040 
2041  QualType Ty = D->getType();
2042 
2044 
2045  llvm::StructType *ByRefType =
2047  "struct.__block_byref_" + D->getNameAsString());
2048 
2049  // void *__isa;
2050  types.push_back(Int8PtrTy);
2051 
2052  // void *__forwarding;
2053  types.push_back(llvm::PointerType::getUnqual(ByRefType));
2054 
2055  // int32_t __flags;
2056  types.push_back(Int32Ty);
2057 
2058  // int32_t __size;
2059  types.push_back(Int32Ty);
2060  // Note that this must match *exactly* the logic in buildByrefHelpers.
2061  bool HasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2062  if (HasCopyAndDispose) {
2063  /// void *__copy_helper;
2064  types.push_back(Int8PtrTy);
2065 
2066  /// void *__destroy_helper;
2067  types.push_back(Int8PtrTy);
2068  }
2069  bool HasByrefExtendedLayout = false;
2070  Qualifiers::ObjCLifetime Lifetime;
2071  if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2072  HasByrefExtendedLayout)
2073  /// void *__byref_variable_layout;
2074  types.push_back(Int8PtrTy);
2075 
2076  bool Packed = false;
2077  CharUnits Align = getContext().getDeclAlign(D);
2078  if (Align >
2079  getContext().toCharUnitsFromBits(getTarget().getPointerAlign(0))) {
2080  // We have to insert padding.
2081 
2082  // The struct above has 2 32-bit integers.
2083  unsigned CurrentOffsetInBytes = 4 * 2;
2084 
2085  // And either 2, 3, 4 or 5 pointers.
2086  unsigned noPointers = 2;
2087  if (HasCopyAndDispose)
2088  noPointers += 2;
2089  if (HasByrefExtendedLayout)
2090  noPointers += 1;
2091 
2092  CurrentOffsetInBytes += noPointers * CGM.getDataLayout().getTypeAllocSize(Int8PtrTy);
2093 
2094  // Align the offset.
2095  unsigned AlignedOffsetInBytes =
2096  llvm::RoundUpToAlignment(CurrentOffsetInBytes, Align.getQuantity());
2097 
2098  unsigned NumPaddingBytes = AlignedOffsetInBytes - CurrentOffsetInBytes;
2099  if (NumPaddingBytes > 0) {
2100  llvm::Type *Ty = Int8Ty;
2101  // FIXME: We need a sema error for alignment larger than the minimum of
2102  // the maximal stack alignment and the alignment of malloc on the system.
2103  if (NumPaddingBytes > 1)
2104  Ty = llvm::ArrayType::get(Ty, NumPaddingBytes);
2105 
2106  types.push_back(Ty);
2107 
2108  // We want a packed struct.
2109  Packed = true;
2110  }
2111  }
2112 
2113  // T x;
2114  types.push_back(ConvertTypeForMem(Ty));
2115 
2116  ByRefType->setBody(types, Packed);
2117 
2118  Info.first = ByRefType;
2119 
2120  Info.second = types.size() - 1;
2121 
2122  return Info.first;
2123 }
2124 
2125 /// Initialize the structural components of a __block variable, i.e.
2126 /// everything but the actual object.
2128  // Find the address of the local.
2129  llvm::Value *addr = emission.Address;
2130 
2131  // That's an alloca of the byref structure type.
2132  llvm::StructType *byrefType = cast<llvm::StructType>(
2133  cast<llvm::PointerType>(addr->getType())->getElementType());
2134 
2135  // Build the byref helpers if necessary. This is null if we don't need any.
2136  CodeGenModule::ByrefHelpers *helpers =
2137  buildByrefHelpers(*byrefType, emission);
2138 
2139  const VarDecl &D = *emission.Variable;
2140  QualType type = D.getType();
2141 
2142  bool HasByrefExtendedLayout;
2143  Qualifiers::ObjCLifetime ByrefLifetime;
2144  bool ByRefHasLifetime =
2145  getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2146 
2147  llvm::Value *V;
2148 
2149  // Initialize the 'isa', which is just 0 or 1.
2150  int isa = 0;
2151  if (type.isObjCGCWeak())
2152  isa = 1;
2153  V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2154  Builder.CreateStore(V,
2155  Builder.CreateStructGEP(nullptr, addr, 0, "byref.isa"));
2156 
2157  // Store the address of the variable into its own forwarding pointer.
2158  Builder.CreateStore(
2159  addr, Builder.CreateStructGEP(nullptr, addr, 1, "byref.forwarding"));
2160 
2161  // Blocks ABI:
2162  // c) the flags field is set to either 0 if no helper functions are
2163  // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2164  BlockFlags flags;
2165  if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2166  if (ByRefHasLifetime) {
2167  if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2168  else switch (ByrefLifetime) {
2170  flags |= BLOCK_BYREF_LAYOUT_STRONG;
2171  break;
2172  case Qualifiers::OCL_Weak:
2173  flags |= BLOCK_BYREF_LAYOUT_WEAK;
2174  break;
2177  break;
2178  case Qualifiers::OCL_None:
2179  if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2181  break;
2182  default:
2183  break;
2184  }
2185  if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2186  printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2187  if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2188  printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2189  if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2190  BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2191  if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2192  printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2193  if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2194  printf(" BLOCK_BYREF_LAYOUT_STRONG");
2195  if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2196  printf(" BLOCK_BYREF_LAYOUT_WEAK");
2197  if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2198  printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2199  if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2200  printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2201  }
2202  printf("\n");
2203  }
2204  }
2205 
2206  Builder.CreateStore(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2207  Builder.CreateStructGEP(nullptr, addr, 2, "byref.flags"));
2208 
2209  CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2210  V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2211  Builder.CreateStore(V,
2212  Builder.CreateStructGEP(nullptr, addr, 3, "byref.size"));
2213 
2214  if (helpers) {
2215  llvm::Value *copy_helper = Builder.CreateStructGEP(nullptr, addr, 4);
2216  Builder.CreateStore(helpers->CopyHelper, copy_helper);
2217 
2218  llvm::Value *destroy_helper = Builder.CreateStructGEP(nullptr, addr, 5);
2219  Builder.CreateStore(helpers->DisposeHelper, destroy_helper);
2220  }
2221  if (ByRefHasLifetime && HasByrefExtendedLayout) {
2222  llvm::Constant* ByrefLayoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2223  llvm::Value *ByrefInfoAddr =
2224  Builder.CreateStructGEP(nullptr, addr, helpers ? 6 : 4, "byref.layout");
2225  // cast destination to pointer to source type.
2226  llvm::Type *DesTy = ByrefLayoutInfo->getType();
2227  DesTy = DesTy->getPointerTo();
2228  llvm::Value *BC = Builder.CreatePointerCast(ByrefInfoAddr, DesTy);
2229  Builder.CreateStore(ByrefLayoutInfo, BC);
2230  }
2231 }
2232 
2234  llvm::Value *F = CGM.getBlockObjectDispose();
2235  llvm::Value *args[] = {
2236  Builder.CreateBitCast(V, Int8PtrTy),
2237  llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2238  };
2239  EmitNounwindRuntimeCall(F, args); // FIXME: throwing destructors?
2240 }
2241 
2242 namespace {
2243  struct CallBlockRelease : EHScopeStack::Cleanup {
2244  llvm::Value *Addr;
2245  CallBlockRelease(llvm::Value *Addr) : Addr(Addr) {}
2246 
2247  void Emit(CodeGenFunction &CGF, Flags flags) override {
2248  // Should we be passing FIELD_IS_WEAK here?
2250  }
2251  };
2252 }
2253 
2254 /// Enter a cleanup to destroy a __block variable. Note that this
2255 /// cleanup should be a no-op if the variable hasn't left the stack
2256 /// yet; if a cleanup is required for the variable itself, that needs
2257 /// to be done externally.
2259  // We don't enter this cleanup if we're in pure-GC mode.
2260  if (CGM.getLangOpts().getGC() == LangOptions::GCOnly)
2261  return;
2262 
2263  EHStack.pushCleanup<CallBlockRelease>(NormalAndEHCleanup, emission.Address);
2264 }
2265 
2266 /// Adjust the declaration of something from the blocks API.
2268  llvm::Constant *C) {
2269  if (!CGM.getLangOpts().BlocksRuntimeOptional) return;
2270 
2271  auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2272  if (GV->isDeclaration() && GV->hasExternalLinkage())
2273  GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2274 }
2275 
2277  if (BlockObjectDispose)
2278  return BlockObjectDispose;
2279 
2280  llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2281  llvm::FunctionType *fty
2282  = llvm::FunctionType::get(VoidTy, args, false);
2283  BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2284  configureBlocksRuntimeObject(*this, BlockObjectDispose);
2285  return BlockObjectDispose;
2286 }
2287 
2289  if (BlockObjectAssign)
2290  return BlockObjectAssign;
2291 
2292  llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
2293  llvm::FunctionType *fty
2294  = llvm::FunctionType::get(VoidTy, args, false);
2295  BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
2296  configureBlocksRuntimeObject(*this, BlockObjectAssign);
2297  return BlockObjectAssign;
2298 }
2299 
2301  if (NSConcreteGlobalBlock)
2302  return NSConcreteGlobalBlock;
2303 
2304  NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
2305  Int8PtrTy->getPointerTo(),
2306  nullptr);
2307  configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
2308  return NSConcreteGlobalBlock;
2309 }
2310 
2312  if (NSConcreteStackBlock)
2313  return NSConcreteStackBlock;
2314 
2315  NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
2316  Int8PtrTy->getPointerTo(),
2317  nullptr);
2318  configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
2319  return NSConcreteStackBlock;
2320 }
void enterNonTrivialFullExpression(const ExprWithCleanups *E)
Definition: CGBlocks.cpp:647
llvm::Value * GetAddrOfBlockDecl(const VarDecl *var, bool ByRef)
Definition: CGBlocks.cpp:1001
llvm::Constant * GenerateCopyHelperFunction(const CGBlockInfo &blockInfo)
Definition: CGBlocks.cpp:1301
llvm::IntegerType * IntTy
int
bool isVariadic() const
Definition: Type.h:3228
llvm::Type * getGenericBlockLiteralType()
The type of a generic block literal.
Definition: CGBlocks.cpp:931
CharUnits BlockHeaderForcedGapOffset
Definition: CGBlocks.h:218
virtual void emitDispose(CodeGenFunction &CGF, llvm::Value *field)=0
void EmitARCMoveWeak(llvm::Value *dst, llvm::Value *src)
Definition: CGObjC.cpp:2249
CanQualType VoidPtrTy
Definition: ASTContext.h:831
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:1356
A pair of helper functions for a __block variable.
CharUnits getDeclAlign(const Decl *D, bool ForAlignof=false) const
Return a conservative estimate of the alignment of the specified decl D.
DestructionKind isDestructedType() const
Definition: Type.h:999
llvm::Module & getModule() const
llvm::LLVMContext & getLLVMContext()
llvm::AllocaInst * CreateTempAlloca(llvm::Type *Ty, const Twine &Name="tmp")
Definition: CGExpr.cpp:57
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:163
static Capture makeIndex(unsigned index)
Definition: CGBlocks.h:173
param_iterator param_end()
Definition: Decl.h:3525
std::string getObjCEncodingForBlock(const BlockExpr *blockExpr) const
Return the encoded type for this block declaration.
static llvm::Constant * buildBlockDescriptor(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Definition: CGBlocks.cpp:76
const Expr * getInit() const
Definition: Decl.h:1068
bool isBlockPointerType() const
Definition: Type.h:5238
const CGFunctionInfo & arrangeFreeFunctionDeclaration(QualType ResTy, const FunctionArgList &Args, const FunctionType::ExtInfo &Info, bool isVariadic)
Definition: CGCall.cpp:460
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
bool hasStrongOrWeakObjCLifetime() const
True if the lifetime is either strong or weak.
Definition: Type.h:307
uint32_t getBitMask() const
Definition: CGBlocks.h:121
CGBlockInfo(const BlockDecl *blockDecl, StringRef Name)
Definition: CGBlocks.cpp:30
bool capturesCXXThis() const
Definition: Decl.h:3575
const Expr * getCallee() const
Definition: Expr.h:2188
ObjCLifetime getObjCLifetime() const
Definition: Type.h:287
bool hasCaptures() const
Definition: Decl.h:3552
const FunctionProtoType * getFunctionType() const
getFunctionType - Return the underlying function type for this block.
Definition: Expr.cpp:1987
virtual llvm::Constant * BuildRCBlockLayout(CodeGen::CodeGenModule &CGM, const CodeGen::CGBlockInfo &blockInfo)=0
capture_range captures()
Definition: Decl.h:3563
llvm::Type * ConvertTypeForMem(QualType T)
capture_iterator capture_begin()
Definition: Decl.h:3570
bool isObjCRetainableType() const
Definition: Type.cpp:3542
static void destroyBlockInfos(CGBlockInfo *info)
Destroy a chain of block layouts.
Definition: CGBlocks.cpp:674
void emitByrefStructureInit(const AutoVarEmission &emission)
Definition: CGBlocks.cpp:2127
CGBlockInfo * FirstBlockInfo
FirstBlockInfo - The head of a singly-linked-list of block layouts.
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:89
bool isReferenceType() const
Definition: Type.h:5241
const Stmt * getBody() const
Definition: Expr.cpp:1996
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:53
Stmt * getBody() const override
Definition: Decl.h:3503
static bool isSafeForCXXConstantCapture(QualType type)
Determines if the given type is safe for constant capture in C++.
Definition: CGBlocks.cpp:248
IdentifierTable & Idents
Definition: ASTContext.h:439
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:95
static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF)
Apply TemporaryLocation if it is valid. Otherwise switch to an artificial debug location that has a v...
Definition: CGDebugInfo.h:525
void EmitARCDestroyStrong(llvm::Value *addr, ARCPreciseLifetime_t precise)
Definition: CGObjC.cpp:2053
static T * buildByrefHelpers(CodeGenModule &CGM, llvm::StructType &byrefTy, unsigned byrefValueIndex, T &byrefInfo)
Definition: CGBlocks.cpp:1898
const Capture & getCapture(const VarDecl *var) const
Definition: CGBlocks.h:233
void EmitSynthesizedCXXCopyCtor(llvm::Value *Dest, llvm::Value *Src, const Expr *Exp)
Definition: CGExprCXX.cpp:466
void Destroyer(CodeGenFunction &CGF, llvm::Value *addr, QualType ty)
const LangOptions & getLangOpts() const
Definition: ASTContext.h:533
QualType getReturnType() const
Definition: Type.h:2952
llvm::GlobalVariable * GetAddrOfConstantCString(const std::string &Str, const char *GlobalName=nullptr, unsigned Alignment=0)
llvm::Value * EmitBlockLiteral(const BlockExpr *)
Emit a block literal expression in the current function.
Definition: CGBlocks.cpp:684
bool getByrefLifetime(QualType Ty, Qualifiers::ObjCLifetime &Lifetime, bool &HasByrefExtendedLayout) const
bool needsEHCleanup(QualType::DestructionKind kind)
RecordDecl * getDecl() const
Definition: Type.h:3527
void pushDestroy(QualType::DestructionKind dtorKind, llvm::Value *addr, QualType type)
Definition: CGDecl.cpp:1381
static OMPLinearClause * Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation ColonLoc, SourceLocation EndLoc, ArrayRef< Expr * > VL, ArrayRef< Expr * > IL, Expr *Step, Expr *CalcStep)
Creates clause with a list of variables VL and a linear step Step.
std::string getNameAsString() const
Definition: Decl.h:183
llvm::PointerType * VoidPtrPtrTy
static Capture makeConstant(llvm::Value *value)
Definition: CGBlocks.h:179
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
llvm::Type * BuildByRefType(const VarDecl *var)
Definition: CGBlocks.cpp:2036
llvm::Constant * getNSConcreteStackBlock()
Definition: CGBlocks.cpp:2311
std::pair< CharUnits, CharUnits > getTypeInfoInChars(const Type *T) const
QualType getType() const
Definition: Decl.h:538
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:1683
arg_iterator arg_end()
Definition: Expr.h:2247
bool NeedsCopyDispose
True if the block needs a custom copy or dispose function.
Definition: CGBlocks.h:191
const BlockExpr * BlockExpression
Definition: CGBlocks.h:211
AnnotatingParser & P
static llvm::Constant * buildCopyHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to copy a block.
Definition: CGBlocks.cpp:51
ExtInfo getExtInfo() const
Definition: Type.h:2961
bool isConversionFromLambda() const
Definition: Decl.h:3579
llvm::CallInst * EmitNounwindRuntimeCall(llvm::Value *callee, const Twine &name="")
llvm::Function * GenerateBlockFunction(GlobalDecl GD, const CGBlockInfo &Info, const DeclMapTy &ldm, bool IsLambdaConversionToBlock)
Definition: CGBlocks.cpp:1107
void PushDestructorCleanup(QualType T, llvm::Value *Addr)
Definition: CGClass.cpp:1980
Qualifiers::ObjCLifetime getObjCLifetime() const
getObjCLifetime - Returns lifetime attribute of this type.
Definition: Type.h:976
CGBlockInfo - Information to generate a block literal.
Definition: CGBlocks.h:144
unsigned getNumObjects() const
Definition: ExprCXX.h:2799
const TargetInfo & getTarget() const
SourceLocation getLocEnd() const LLVM_READONLY
Definition: Expr.h:4626
static llvm::Constant * buildByrefCopyHelper(CodeGenModule &CGM, llvm::StructType &byrefType, unsigned byrefValueIndex, CodeGenModule::ByrefHelpers &info)
Build the copy helper for a __block variable.
Definition: CGBlocks.cpp:1827
capture_iterator capture_end()
Definition: Decl.h:3571
CGBlockInfo * NextBlockInfo
Definition: CGBlocks.h:231
CGObjCRuntime & getObjCRuntime()
Return a reference to the configured Objective-C runtime.
QualType getPointeeType() const
Definition: Type.h:2246
Enters a new scope for capturing cleanups, all of which will be executed once the scope is exited...
llvm::Value * GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
#define NULL
Definition: stddef.h:105
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2358
static llvm::Constant * buildGlobalBlock(CodeGenModule &CGM, const CGBlockInfo &blockInfo, llvm::Constant *blockFn)
Build the given block as a global block.
Definition: CGBlocks.cpp:1063
llvm::Constant * GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo)
Definition: CGBlocks.cpp:1478
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:812
bool isObjCGCWeak() const
isObjCGCWeak true when Type is objc's weak.
Definition: Type.h:966
llvm::FoldingSet< ByrefHelpers > ByrefHelpersCache
ASTContext & getContext() const
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:115
void add(RValue rvalue, QualType type, bool needscopy=false)
Definition: CGCall.h:81
stable_iterator stable_begin() const
Definition: EHScopeStack.h:364
std::pair< llvm::Type *, unsigned > getByRefValueLLVMField(const ValueDecl *VD) const
Definition: CGBlocks.cpp:2005
static CharUnits getLowBit(CharUnits v)
Definition: CGBlocks.cpp:299
do v
Definition: arm_acle.h:77
EHScopeStack::stable_iterator getCleanup() const
Definition: CGBlocks.h:164
param_iterator param_begin()
Definition: Decl.h:3524
void enterByrefCleanup(const AutoVarEmission &emission)
Definition: CGBlocks.cpp:2258
There is no lifetime qualification on this type.
Definition: Type.h:130
ArrayRef< CleanupObject > getObjects() const
Definition: ExprCXX.h:2795
#define false
Definition: stdbool.h:33
llvm::Constant * CreateRuntimeFunction(llvm::FunctionType *Ty, StringRef Name, llvm::AttributeSet ExtraAttrs=llvm::AttributeSet())
Create a new runtime function with the specified type and name.
ASTContext & getContext() const
Encodes a location in the source. The SourceManager can decode this to get at the full include stack...
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
llvm::StructType * StructureType
Definition: CGBlocks.h:209
static void configureBlocksRuntimeObject(CodeGenModule &CGM, llvm::Constant *C)
Adjust the declaration of something from the blocks API.
Definition: CGBlocks.cpp:2267
An aggregate value slot.
Definition: CGValue.h:363
CanQualType VoidTy
Definition: ASTContext.h:817
llvm::DenseMap< const VarDecl *, Capture > Captures
The mapping of allocated indexes within the block.
Definition: CGBlocks.h:206
const CodeGenOptions & getCodeGenOpts() const
const Type * getBaseElementTypeUnsafe() const
Definition: Type.h:5520
llvm::Constant * getBlockObjectDispose()
Definition: CGBlocks.cpp:2276
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.
const LangOptions & getLangOpts() const
const T * castAs() const
Definition: Type.h:5586
bool operator<(DeclarationName LHS, DeclarationName RHS)
unsigned CXXThisIndex
The field index of 'this' within the block, if there is one.
Definition: CGBlocks.h:150
Assigning into this object requires a lifetime extension.
Definition: Type.h:147
const BlockDecl * getBlockDecl() const
Definition: Expr.h:4616
static Destroyer destroyARCStrongImprecise
void FinishFunction(SourceLocation EndLoc=SourceLocation())
void EmitARCDestroyWeak(llvm::Value *addr)
Definition: CGObjC.cpp:2232
static llvm::Constant * tryCaptureAsConstant(CodeGenModule &CGM, CodeGenFunction *CGF, const VarDecl *var)
Definition: CGBlocks.cpp:272
QualType getType() const
Definition: Expr.h:125
const unsigned BlockHeaderSize
The number of fields in a block header.
Definition: CGBlocks.cpp:187
llvm::AllocaInst * Address
Definition: CGBlocks.h:208
static const Type * getElementType(const Expr *BaseExpr)
virtual llvm::Constant * BuildGCBlockLayout(CodeGen::CodeGenModule &CGM, const CodeGen::CGBlockInfo &blockInfo)=0
static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF, CGBlockInfo &info)
Definition: CGBlocks.cpp:337
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Definition: ASTMatchers.h:1639
llvm::Value * getConstant() const
Definition: CGBlocks.h:160
static llvm::Constant * buildDisposeHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to dispose of a block.
Definition: CGBlocks.cpp:57
std::unique_ptr< DiagnosticConsumer > create(StringRef OutputFile, DiagnosticOptions *Diags, bool MergeChildRecords=false)
Returns a DiagnosticConsumer that serializes diagnostics to a bitcode file.
static llvm::Constant * generateByrefCopyHelper(CodeGenFunction &CGF, llvm::StructType &byrefType, unsigned valueFieldIndex, CodeGenModule::ByrefHelpers &byrefInfo)
Definition: CGBlocks.cpp:1760
static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block)
Definition: CGBlocks.cpp:572
const T * getAs() const
Definition: Type.h:5555
CanQualType UnsignedLongTy
Definition: ASTContext.h:826
arg_iterator arg_begin()
Definition: Expr.h:2246
llvm::Value * BuildBlockByrefAddress(llvm::Value *BaseAddr, const VarDecl *V)
Definition: CGBlocks.cpp:2011
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:657
llvm::Constant * GetAddrOfGlobalBlock(const BlockExpr *BE, const char *)
Gets the address of a block which requires no captures.
Definition: CGBlocks.cpp:1041
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1505
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:33
llvm::Constant * getBlockObjectAssign()
Definition: CGBlocks.cpp:2288
llvm::Constant * EmitConstantInit(const VarDecl &D, CodeGenFunction *CGF=nullptr)
Reading or writing from this object requires a barrier call.
Definition: Type.h:144
static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info, SmallVectorImpl< llvm::Type * > &elementTypes)
Definition: CGBlocks.cpp:303
Represents a C++ struct/union/class.
Definition: DeclCXX.h:285
BoundNodesTreeBuilder *const Builder
bool isObjCObjectPointerType() const
Definition: Type.h:5304
uint32_t getBitMask() const
Definition: CGBlocks.h:77
void PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize)
Takes the old cleanup stack size and emits the cleanup blocks that have been added.
Definition: CGCleanup.cpp:388
const BlockDecl * getBlockDecl() const
Definition: CGBlocks.h:243
CharUnits BlockHeaderForcedGapSize
Definition: CGBlocks.h:221
llvm::Value * EmitARCRetainBlock(llvm::Value *value, bool mandatory)
Definition: CGObjC.cpp:1945
llvm::Value * EmitARCStoreStrongCall(llvm::Value *addr, llvm::Value *value, bool resultIgnored)
Definition: CGObjC.cpp:2069
void ForceCleanup()
Force the emission of cleanups now, instead of waiting until this object is destroyed.
CanQualType IntTy
Definition: ASTContext.h:825
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2089
A reference to a declared variable, function, enum, etc. [C99 6.5.1p2].
Definition: Expr.h:899
static RValue get(llvm::Value *V)
Definition: CGValue.h:71
RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue)
Definition: CGBlocks.cpp:953
virtual void emitCopy(CodeGenFunction &CGF, llvm::Value *dest, llvm::Value *src)=0
static AggValueSlot forAddr(llvm::Value *addr, CharUnits align, Qualifiers quals, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, IsZeroed_t isZeroed=IsNotZeroed)
Definition: CGValue.h:424
static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF)
Definition: CGDebugInfo.h:542
llvm::Constant * getNSConcreteGlobalBlock()
Definition: CGBlocks.cpp:2300
llvm::Type * getBlockDescriptorType()
Fetches the type of a generic block descriptor.
Definition: CGBlocks.cpp:901
An l-value expression is a reference to an object with independent storage.
Definition: Specifiers.h:99
const BlockExpr * getBlockExpr() const
Definition: CGBlocks.h:244
SourceLocation getLocation() const
Definition: DeclBase.h:372
llvm::Instruction * DominatingIP
Definition: CGBlocks.h:225
static llvm::Constant * buildByrefDisposeHelper(CodeGenModule &CGM, llvm::StructType &byrefType, unsigned byrefValueIndex, CodeGenModule::ByrefHelpers &info)
Build the dispose helper for a __block variable.
Definition: CGBlocks.cpp:1888
bool isConstQualified() const
Determine whether this type is const-qualified.
Definition: Type.h:5075
CharUnits RoundUpToAlignment(const CharUnits &Align) const
Definition: CharUnits.h:168
static llvm::Constant * generateByrefDisposeHelper(CodeGenFunction &CGF, llvm::StructType &byrefType, unsigned byrefValueIndex, CodeGenModule::ByrefHelpers &byrefInfo)
Generate code for a __block variable's dispose helper.
Definition: CGBlocks.cpp:1837
bool BlockRequiresCopying(QualType Ty, const VarDecl *D)
Returns true iff we need copy/dispose helpers for the given type.
void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags)
Definition: CGBlocks.cpp:2233
void setCleanup(EHScopeStack::stable_iterator cleanup)
Definition: CGBlocks.h:168
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:5043
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1253