clang  5.0.0svn
CGBlocks.cpp
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1 //===--- CGBlocks.cpp - Emit LLVM Code for declarations ---------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This contains code to emit blocks.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CGBlocks.h"
15 #include "CGDebugInfo.h"
16 #include "CGObjCRuntime.h"
17 #include "CodeGenFunction.h"
18 #include "CodeGenModule.h"
20 #include "clang/AST/DeclObjC.h"
21 #include "llvm/ADT/SmallSet.h"
22 #include "llvm/IR/CallSite.h"
23 #include "llvm/IR/DataLayout.h"
24 #include "llvm/IR/Module.h"
25 #include <algorithm>
26 #include <cstdio>
27 
28 using namespace clang;
29 using namespace CodeGen;
30 
31 CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
32  : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
33  HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
34  LocalAddress(Address::invalid()), StructureType(nullptr), Block(block),
35  DominatingIP(nullptr) {
36 
37  // Skip asm prefix, if any. 'name' is usually taken directly from
38  // the mangled name of the enclosing function.
39  if (!name.empty() && name[0] == '\01')
40  name = name.substr(1);
41 }
42 
43 // Anchor the vtable to this translation unit.
45 
46 /// Build the given block as a global block.
47 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
48  const CGBlockInfo &blockInfo,
49  llvm::Constant *blockFn);
50 
51 /// Build the helper function to copy a block.
52 static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
53  const CGBlockInfo &blockInfo) {
54  return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
55 }
56 
57 /// Build the helper function to dispose of a block.
58 static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
59  const CGBlockInfo &blockInfo) {
60  return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
61 }
62 
63 /// buildBlockDescriptor - Build the block descriptor meta-data for a block.
64 /// buildBlockDescriptor is accessed from 5th field of the Block_literal
65 /// meta-data and contains stationary information about the block literal.
66 /// Its definition will have 4 (or optinally 6) words.
67 /// \code
68 /// struct Block_descriptor {
69 /// unsigned long reserved;
70 /// unsigned long size; // size of Block_literal metadata in bytes.
71 /// void *copy_func_helper_decl; // optional copy helper.
72 /// void *destroy_func_decl; // optioanl destructor helper.
73 /// void *block_method_encoding_address; // @encode for block literal signature.
74 /// void *block_layout_info; // encoding of captured block variables.
75 /// };
76 /// \endcode
77 static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
78  const CGBlockInfo &blockInfo) {
79  ASTContext &C = CGM.getContext();
80 
81  llvm::IntegerType *ulong =
82  cast<llvm::IntegerType>(CGM.getTypes().ConvertType(C.UnsignedLongTy));
83  llvm::PointerType *i8p = nullptr;
84  if (CGM.getLangOpts().OpenCL)
85  i8p =
86  llvm::Type::getInt8PtrTy(
88  else
89  i8p = CGM.VoidPtrTy;
90 
91  ConstantInitBuilder builder(CGM);
92  auto elements = builder.beginStruct();
93 
94  // reserved
95  elements.addInt(ulong, 0);
96 
97  // Size
98  // FIXME: What is the right way to say this doesn't fit? We should give
99  // a user diagnostic in that case. Better fix would be to change the
100  // API to size_t.
101  elements.addInt(ulong, blockInfo.BlockSize.getQuantity());
102 
103  // Optional copy/dispose helpers.
104  if (blockInfo.NeedsCopyDispose) {
105  // copy_func_helper_decl
106  elements.add(buildCopyHelper(CGM, blockInfo));
107 
108  // destroy_func_decl
109  elements.add(buildDisposeHelper(CGM, blockInfo));
110  }
111 
112  // Signature. Mandatory ObjC-style method descriptor @encode sequence.
113  std::string typeAtEncoding =
115  elements.add(llvm::ConstantExpr::getBitCast(
116  CGM.GetAddrOfConstantCString(typeAtEncoding).getPointer(), i8p));
117 
118  // GC layout.
119  if (C.getLangOpts().ObjC1) {
120  if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
121  elements.add(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
122  else
123  elements.add(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
124  }
125  else
126  elements.addNullPointer(i8p);
127 
128  unsigned AddrSpace = 0;
129  if (C.getLangOpts().OpenCL)
131 
132  llvm::GlobalVariable *global =
133  elements.finishAndCreateGlobal("__block_descriptor_tmp",
134  CGM.getPointerAlign(),
135  /*constant*/ true,
137  AddrSpace);
138 
139  return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
140 }
141 
142 /*
143  Purely notional variadic template describing the layout of a block.
144 
145  template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
146  struct Block_literal {
147  /// Initialized to one of:
148  /// extern void *_NSConcreteStackBlock[];
149  /// extern void *_NSConcreteGlobalBlock[];
150  ///
151  /// In theory, we could start one off malloc'ed by setting
152  /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
153  /// this isa:
154  /// extern void *_NSConcreteMallocBlock[];
155  struct objc_class *isa;
156 
157  /// These are the flags (with corresponding bit number) that the
158  /// compiler is actually supposed to know about.
159  /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
160  /// descriptor provides copy and dispose helper functions
161  /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
162  /// object with a nontrivial destructor or copy constructor
163  /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
164  /// as global memory
165  /// 29. BLOCK_USE_STRET - indicates that the block function
166  /// uses stret, which objc_msgSend needs to know about
167  /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
168  /// @encoded signature string
169  /// And we're not supposed to manipulate these:
170  /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
171  /// to malloc'ed memory
172  /// 27. BLOCK_IS_GC - indicates that the block has been moved to
173  /// to GC-allocated memory
174  /// Additionally, the bottom 16 bits are a reference count which
175  /// should be zero on the stack.
176  int flags;
177 
178  /// Reserved; should be zero-initialized.
179  int reserved;
180 
181  /// Function pointer generated from block literal.
182  _ResultType (*invoke)(Block_literal *, _ParamTypes...);
183 
184  /// Block description metadata generated from block literal.
185  struct Block_descriptor *block_descriptor;
186 
187  /// Captured values follow.
188  _CapturesTypes captures...;
189  };
190  */
191 
192 namespace {
193  /// A chunk of data that we actually have to capture in the block.
194  struct BlockLayoutChunk {
195  CharUnits Alignment;
196  CharUnits Size;
197  Qualifiers::ObjCLifetime Lifetime;
198  const BlockDecl::Capture *Capture; // null for 'this'
199  llvm::Type *Type;
200  QualType FieldType;
201 
202  BlockLayoutChunk(CharUnits align, CharUnits size,
203  Qualifiers::ObjCLifetime lifetime,
204  const BlockDecl::Capture *capture,
205  llvm::Type *type, QualType fieldType)
206  : Alignment(align), Size(size), Lifetime(lifetime),
207  Capture(capture), Type(type), FieldType(fieldType) {}
208 
209  /// Tell the block info that this chunk has the given field index.
210  void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
211  if (!Capture) {
212  info.CXXThisIndex = index;
213  info.CXXThisOffset = offset;
214  } else {
215  auto C = CGBlockInfo::Capture::makeIndex(index, offset, FieldType);
216  info.Captures.insert({Capture->getVariable(), C});
217  }
218  }
219  };
220 
221  /// Order by 1) all __strong together 2) next, all byfref together 3) next,
222  /// all __weak together. Preserve descending alignment in all situations.
223  bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
224  if (left.Alignment != right.Alignment)
225  return left.Alignment > right.Alignment;
226 
227  auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
228  if (chunk.Capture && chunk.Capture->isByRef())
229  return 1;
230  if (chunk.Lifetime == Qualifiers::OCL_Strong)
231  return 0;
232  if (chunk.Lifetime == Qualifiers::OCL_Weak)
233  return 2;
234  return 3;
235  };
236 
237  return getPrefOrder(left) < getPrefOrder(right);
238  }
239 } // end anonymous namespace
240 
241 /// Determines if the given type is safe for constant capture in C++.
243  const RecordType *recordType =
245 
246  // Only records can be unsafe.
247  if (!recordType) return true;
248 
249  const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
250 
251  // Maintain semantics for classes with non-trivial dtors or copy ctors.
252  if (!record->hasTrivialDestructor()) return false;
253  if (record->hasNonTrivialCopyConstructor()) return false;
254 
255  // Otherwise, we just have to make sure there aren't any mutable
256  // fields that might have changed since initialization.
257  return !record->hasMutableFields();
258 }
259 
260 /// It is illegal to modify a const object after initialization.
261 /// Therefore, if a const object has a constant initializer, we don't
262 /// actually need to keep storage for it in the block; we'll just
263 /// rematerialize it at the start of the block function. This is
264 /// acceptable because we make no promises about address stability of
265 /// captured variables.
266 static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
267  CodeGenFunction *CGF,
268  const VarDecl *var) {
269  // Return if this is a function parameter. We shouldn't try to
270  // rematerialize default arguments of function parameters.
271  if (isa<ParmVarDecl>(var))
272  return nullptr;
273 
274  QualType type = var->getType();
275 
276  // We can only do this if the variable is const.
277  if (!type.isConstQualified()) return nullptr;
278 
279  // Furthermore, in C++ we have to worry about mutable fields:
280  // C++ [dcl.type.cv]p4:
281  // Except that any class member declared mutable can be
282  // modified, any attempt to modify a const object during its
283  // lifetime results in undefined behavior.
284  if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
285  return nullptr;
286 
287  // If the variable doesn't have any initializer (shouldn't this be
288  // invalid?), it's not clear what we should do. Maybe capture as
289  // zero?
290  const Expr *init = var->getInit();
291  if (!init) return nullptr;
292 
293  return CGM.EmitConstantInit(*var, CGF);
294 }
295 
296 /// Get the low bit of a nonzero character count. This is the
297 /// alignment of the nth byte if the 0th byte is universally aligned.
299  return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
300 }
301 
303  SmallVectorImpl<llvm::Type*> &elementTypes) {
304  // The header is basically 'struct { void *; int; int; void *; void *; }'.
305  // Assert that that struct is packed.
306  assert(CGM.getIntSize() <= CGM.getPointerSize());
307  assert(CGM.getIntAlign() <= CGM.getPointerAlign());
308  assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()));
309 
310  info.BlockAlign = CGM.getPointerAlign();
311  info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
312 
313  assert(elementTypes.empty());
314  elementTypes.push_back(CGM.VoidPtrTy);
315  elementTypes.push_back(CGM.IntTy);
316  elementTypes.push_back(CGM.IntTy);
317  elementTypes.push_back(CGM.VoidPtrTy);
318  elementTypes.push_back(CGM.getBlockDescriptorType());
319 }
320 
322  const BlockDecl::Capture &CI) {
323  const VarDecl *VD = CI.getVariable();
324 
325  // If the variable is captured by an enclosing block or lambda expression,
326  // use the type of the capture field.
327  if (CGF.BlockInfo && CI.isNested())
328  return CGF.BlockInfo->getCapture(VD).fieldType();
329  if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
330  return FD->getType();
331  return VD->getType();
332 }
333 
334 /// Compute the layout of the given block. Attempts to lay the block
335 /// out with minimal space requirements.
337  CGBlockInfo &info) {
338  ASTContext &C = CGM.getContext();
339  const BlockDecl *block = info.getBlockDecl();
340 
341  SmallVector<llvm::Type*, 8> elementTypes;
342  initializeForBlockHeader(CGM, info, elementTypes);
343 
344  if (!block->hasCaptures()) {
345  info.StructureType =
346  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
347  info.CanBeGlobal = true;
348  return;
349  }
350  else if (C.getLangOpts().ObjC1 &&
351  CGM.getLangOpts().getGC() == LangOptions::NonGC)
352  info.HasCapturedVariableLayout = true;
353 
354  // Collect the layout chunks.
356  layout.reserve(block->capturesCXXThis() +
357  (block->capture_end() - block->capture_begin()));
358 
359  CharUnits maxFieldAlign;
360 
361  // First, 'this'.
362  if (block->capturesCXXThis()) {
363  assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&
364  "Can't capture 'this' outside a method");
365  QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType(C);
366 
367  // Theoretically, this could be in a different address space, so
368  // don't assume standard pointer size/align.
369  llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
370  std::pair<CharUnits,CharUnits> tinfo
371  = CGM.getContext().getTypeInfoInChars(thisType);
372  maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
373 
374  layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
376  nullptr, llvmType, thisType));
377  }
378 
379  // Next, all the block captures.
380  for (const auto &CI : block->captures()) {
381  const VarDecl *variable = CI.getVariable();
382 
383  if (CI.isByRef()) {
384  // We have to copy/dispose of the __block reference.
385  info.NeedsCopyDispose = true;
386 
387  // Just use void* instead of a pointer to the byref type.
388  CharUnits align = CGM.getPointerAlign();
389  maxFieldAlign = std::max(maxFieldAlign, align);
390 
391  layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
393  CGM.VoidPtrTy, variable->getType()));
394  continue;
395  }
396 
397  // Otherwise, build a layout chunk with the size and alignment of
398  // the declaration.
399  if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
400  info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
401  continue;
402  }
403 
404  // If we have a lifetime qualifier, honor it for capture purposes.
405  // That includes *not* copying it if it's __unsafe_unretained.
406  Qualifiers::ObjCLifetime lifetime =
407  variable->getType().getObjCLifetime();
408  if (lifetime) {
409  switch (lifetime) {
410  case Qualifiers::OCL_None: llvm_unreachable("impossible");
413  break;
414 
417  info.NeedsCopyDispose = true;
418  }
419 
420  // Block pointers require copy/dispose. So do Objective-C pointers.
421  } else if (variable->getType()->isObjCRetainableType()) {
422  // But honor the inert __unsafe_unretained qualifier, which doesn't
423  // actually make it into the type system.
424  if (variable->getType()->isObjCInertUnsafeUnretainedType()) {
425  lifetime = Qualifiers::OCL_ExplicitNone;
426  } else {
427  info.NeedsCopyDispose = true;
428  // used for mrr below.
429  lifetime = Qualifiers::OCL_Strong;
430  }
431 
432  // So do types that require non-trivial copy construction.
433  } else if (CI.hasCopyExpr()) {
434  info.NeedsCopyDispose = true;
435  info.HasCXXObject = true;
436 
437  // And so do types with destructors.
438  } else if (CGM.getLangOpts().CPlusPlus) {
439  if (const CXXRecordDecl *record =
440  variable->getType()->getAsCXXRecordDecl()) {
441  if (!record->hasTrivialDestructor()) {
442  info.HasCXXObject = true;
443  info.NeedsCopyDispose = true;
444  }
445  }
446  }
447 
448  QualType VT = getCaptureFieldType(*CGF, CI);
449  CharUnits size = C.getTypeSizeInChars(VT);
450  CharUnits align = C.getDeclAlign(variable);
451 
452  maxFieldAlign = std::max(maxFieldAlign, align);
453 
454  llvm::Type *llvmType =
455  CGM.getTypes().ConvertTypeForMem(VT);
456 
457  layout.push_back(
458  BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
459  }
460 
461  // If that was everything, we're done here.
462  if (layout.empty()) {
463  info.StructureType =
464  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
465  info.CanBeGlobal = true;
466  return;
467  }
468 
469  // Sort the layout by alignment. We have to use a stable sort here
470  // to get reproducible results. There should probably be an
471  // llvm::array_pod_stable_sort.
472  std::stable_sort(layout.begin(), layout.end());
473 
474  // Needed for blocks layout info.
477 
478  CharUnits &blockSize = info.BlockSize;
479  info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
480 
481  // Assuming that the first byte in the header is maximally aligned,
482  // get the alignment of the first byte following the header.
483  CharUnits endAlign = getLowBit(blockSize);
484 
485  // If the end of the header isn't satisfactorily aligned for the
486  // maximum thing, look for things that are okay with the header-end
487  // alignment, and keep appending them until we get something that's
488  // aligned right. This algorithm is only guaranteed optimal if
489  // that condition is satisfied at some point; otherwise we can get
490  // things like:
491  // header // next byte has alignment 4
492  // something_with_size_5; // next byte has alignment 1
493  // something_with_alignment_8;
494  // which has 7 bytes of padding, as opposed to the naive solution
495  // which might have less (?).
496  if (endAlign < maxFieldAlign) {
498  li = layout.begin() + 1, le = layout.end();
499 
500  // Look for something that the header end is already
501  // satisfactorily aligned for.
502  for (; li != le && endAlign < li->Alignment; ++li)
503  ;
504 
505  // If we found something that's naturally aligned for the end of
506  // the header, keep adding things...
507  if (li != le) {
509  for (; li != le; ++li) {
510  assert(endAlign >= li->Alignment);
511 
512  li->setIndex(info, elementTypes.size(), blockSize);
513  elementTypes.push_back(li->Type);
514  blockSize += li->Size;
515  endAlign = getLowBit(blockSize);
516 
517  // ...until we get to the alignment of the maximum field.
518  if (endAlign >= maxFieldAlign) {
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.alignTo(maxFieldAlign);
533  CharUnits padding = newBlockSize - blockSize;
534 
535  // If we haven't yet added any fields, remember that there was an
536  // initial gap; this need to go into the block layout bit map.
537  if (blockSize == info.BlockHeaderForcedGapOffset) {
538  info.BlockHeaderForcedGapSize = padding;
539  }
540 
541  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
542  padding.getQuantity()));
543  blockSize = newBlockSize;
544  endAlign = getLowBit(blockSize); // might be > maxFieldAlign
545  }
546 
547  assert(endAlign >= maxFieldAlign);
548  assert(endAlign == getLowBit(blockSize));
549  // Slam everything else on now. This works because they have
550  // strictly decreasing alignment and we expect that size is always a
551  // multiple of alignment.
553  li = layout.begin(), le = layout.end(); li != le; ++li) {
554  if (endAlign < li->Alignment) {
555  // size may not be multiple of alignment. This can only happen with
556  // an over-aligned variable. We will be adding a padding field to
557  // make the size be multiple of alignment.
558  CharUnits padding = li->Alignment - endAlign;
559  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
560  padding.getQuantity()));
561  blockSize += padding;
562  endAlign = getLowBit(blockSize);
563  }
564  assert(endAlign >= li->Alignment);
565  li->setIndex(info, elementTypes.size(), blockSize);
566  elementTypes.push_back(li->Type);
567  blockSize += li->Size;
568  endAlign = getLowBit(blockSize);
569  }
570 
571  info.StructureType =
572  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
573 }
574 
575 /// Enter the scope of a block. This should be run at the entrance to
576 /// a full-expression so that the block's cleanups are pushed at the
577 /// right place in the stack.
578 static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
579  assert(CGF.HaveInsertPoint());
580 
581  // Allocate the block info and place it at the head of the list.
582  CGBlockInfo &blockInfo =
583  *new CGBlockInfo(block, CGF.CurFn->getName());
584  blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
585  CGF.FirstBlockInfo = &blockInfo;
586 
587  // Compute information about the layout, etc., of this block,
588  // pushing cleanups as necessary.
589  computeBlockInfo(CGF.CGM, &CGF, blockInfo);
590 
591  // Nothing else to do if it can be global.
592  if (blockInfo.CanBeGlobal) return;
593 
594  // Make the allocation for the block.
595  blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
596  blockInfo.BlockAlign, "block");
597 
598  // If there are cleanups to emit, enter them (but inactive).
599  if (!blockInfo.NeedsCopyDispose) return;
600 
601  // Walk through the captures (in order) and find the ones not
602  // captured by constant.
603  for (const auto &CI : block->captures()) {
604  // Ignore __block captures; there's nothing special in the
605  // on-stack block that we need to do for them.
606  if (CI.isByRef()) continue;
607 
608  // Ignore variables that are constant-captured.
609  const VarDecl *variable = CI.getVariable();
610  CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
611  if (capture.isConstant()) continue;
612 
613  // Ignore objects that aren't destructed.
614  QualType VT = getCaptureFieldType(CGF, CI);
616  if (dtorKind == QualType::DK_none) continue;
617 
618  CodeGenFunction::Destroyer *destroyer;
619 
620  // Block captures count as local values and have imprecise semantics.
621  // They also can't be arrays, so need to worry about that.
622  //
623  // For const-qualified captures, emit clang.arc.use to ensure the captured
624  // object doesn't get released while we are still depending on its validity
625  // within the block.
626  if (VT.isConstQualified() &&
628  CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
629  assert(CGF.CGM.getLangOpts().ObjCAutoRefCount &&
630  "expected ObjC ARC to be enabled");
632  } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
634  } else {
635  destroyer = CGF.getDestroyer(dtorKind);
636  }
637 
638  // GEP down to the address.
639  Address addr = CGF.Builder.CreateStructGEP(blockInfo.LocalAddress,
640  capture.getIndex(),
641  capture.getOffset());
642 
643  // We can use that GEP as the dominating IP.
644  if (!blockInfo.DominatingIP)
645  blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
646 
647  CleanupKind cleanupKind = InactiveNormalCleanup;
648  bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
649  if (useArrayEHCleanup)
650  cleanupKind = InactiveNormalAndEHCleanup;
651 
652  CGF.pushDestroy(cleanupKind, addr, VT,
653  destroyer, useArrayEHCleanup);
654 
655  // Remember where that cleanup was.
656  capture.setCleanup(CGF.EHStack.stable_begin());
657  }
658 }
659 
660 /// Enter a full-expression with a non-trivial number of objects to
661 /// clean up. This is in this file because, at the moment, the only
662 /// kind of cleanup object is a BlockDecl*.
664  assert(E->getNumObjects() != 0);
667  i = cleanups.begin(), e = cleanups.end(); i != e; ++i) {
668  enterBlockScope(*this, *i);
669  }
670 }
671 
672 /// Find the layout for the given block in a linked list and remove it.
674  const BlockDecl *block) {
675  while (true) {
676  assert(head && *head);
677  CGBlockInfo *cur = *head;
678 
679  // If this is the block we're looking for, splice it out of the list.
680  if (cur->getBlockDecl() == block) {
681  *head = cur->NextBlockInfo;
682  return cur;
683  }
684 
685  head = &cur->NextBlockInfo;
686  }
687 }
688 
689 /// Destroy a chain of block layouts.
691  assert(head && "destroying an empty chain");
692  do {
693  CGBlockInfo *cur = head;
694  head = cur->NextBlockInfo;
695  delete cur;
696  } while (head != nullptr);
697 }
698 
699 /// Emit a block literal expression in the current function.
701  // If the block has no captures, we won't have a pre-computed
702  // layout for it.
703  if (!blockExpr->getBlockDecl()->hasCaptures()) {
704  if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr))
705  return Block;
706  CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
707  computeBlockInfo(CGM, this, blockInfo);
708  blockInfo.BlockExpression = blockExpr;
709  return EmitBlockLiteral(blockInfo);
710  }
711 
712  // Find the block info for this block and take ownership of it.
713  std::unique_ptr<CGBlockInfo> blockInfo;
714  blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
715  blockExpr->getBlockDecl()));
716 
717  blockInfo->BlockExpression = blockExpr;
718  return EmitBlockLiteral(*blockInfo);
719 }
720 
722  // Using the computed layout, generate the actual block function.
723  bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
724  llvm::Constant *blockFn
725  = CodeGenFunction(CGM, true).GenerateBlockFunction(CurGD, blockInfo,
726  LocalDeclMap,
727  isLambdaConv);
728  blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy);
729 
730  // If there is nothing to capture, we can emit this as a global block.
731  if (blockInfo.CanBeGlobal)
732  return buildGlobalBlock(CGM, blockInfo, blockFn);
733 
734  // Otherwise, we have to emit this as a local block.
735 
736  llvm::Constant *isa =
737  (!CGM.getContext().getLangOpts().OpenCL)
739  : CGM.getNullPointer(cast<llvm::PointerType>(
740  CGM.getNSConcreteStackBlock()->getType()),
741  QualType(getContext().VoidPtrTy));
742  isa = llvm::ConstantExpr::getBitCast(isa, VoidPtrTy);
743 
744  // Build the block descriptor.
745  llvm::Constant *descriptor = buildBlockDescriptor(CGM, blockInfo);
746 
747  Address blockAddr = blockInfo.LocalAddress;
748  assert(blockAddr.isValid() && "block has no address!");
749 
750  // Compute the initial on-stack block flags.
753  if (blockInfo.NeedsCopyDispose) flags |= BLOCK_HAS_COPY_DISPOSE;
754  if (blockInfo.HasCXXObject) flags |= BLOCK_HAS_CXX_OBJ;
755  if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET;
756 
757  auto projectField =
758  [&](unsigned index, CharUnits offset, const Twine &name) -> Address {
759  return Builder.CreateStructGEP(blockAddr, index, offset, name);
760  };
761  auto storeField =
762  [&](llvm::Value *value, unsigned index, CharUnits offset,
763  const Twine &name) {
764  Builder.CreateStore(value, projectField(index, offset, name));
765  };
766 
767  // Initialize the block header.
768  {
769  // We assume all the header fields are densely packed.
770  unsigned index = 0;
771  CharUnits offset;
772  auto addHeaderField =
773  [&](llvm::Value *value, CharUnits size, const Twine &name) {
774  storeField(value, index, offset, name);
775  offset += size;
776  index++;
777  };
778 
779  addHeaderField(isa, getPointerSize(), "block.isa");
780  addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
781  getIntSize(), "block.flags");
782  addHeaderField(llvm::ConstantInt::get(IntTy, 0),
783  getIntSize(), "block.reserved");
784  addHeaderField(blockFn, getPointerSize(), "block.invoke");
785  addHeaderField(descriptor, getPointerSize(), "block.descriptor");
786  }
787 
788  // Finally, capture all the values into the block.
789  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
790 
791  // First, 'this'.
792  if (blockDecl->capturesCXXThis()) {
793  Address addr = projectField(blockInfo.CXXThisIndex, blockInfo.CXXThisOffset,
794  "block.captured-this.addr");
795  Builder.CreateStore(LoadCXXThis(), addr);
796  }
797 
798  // Next, captured variables.
799  for (const auto &CI : blockDecl->captures()) {
800  const VarDecl *variable = CI.getVariable();
801  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
802 
803  // Ignore constant captures.
804  if (capture.isConstant()) continue;
805 
806  QualType type = capture.fieldType();
807 
808  // This will be a [[type]]*, except that a byref entry will just be
809  // an i8**.
810  Address blockField =
811  projectField(capture.getIndex(), capture.getOffset(), "block.captured");
812 
813  // Compute the address of the thing we're going to move into the
814  // block literal.
815  Address src = Address::invalid();
816 
817  if (blockDecl->isConversionFromLambda()) {
818  // The lambda capture in a lambda's conversion-to-block-pointer is
819  // special; we'll simply emit it directly.
820  src = Address::invalid();
821  } else if (CI.isByRef()) {
822  if (BlockInfo && CI.isNested()) {
823  // We need to use the capture from the enclosing block.
824  const CGBlockInfo::Capture &enclosingCapture =
825  BlockInfo->getCapture(variable);
826 
827  // This is a [[type]]*, except that a byref entry wil just be an i8**.
828  src = Builder.CreateStructGEP(LoadBlockStruct(),
829  enclosingCapture.getIndex(),
830  enclosingCapture.getOffset(),
831  "block.capture.addr");
832  } else {
833  auto I = LocalDeclMap.find(variable);
834  assert(I != LocalDeclMap.end());
835  src = I->second;
836  }
837  } else {
838  DeclRefExpr declRef(const_cast<VarDecl *>(variable),
839  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
841  SourceLocation());
842  src = EmitDeclRefLValue(&declRef).getAddress();
843  };
844 
845  // For byrefs, we just write the pointer to the byref struct into
846  // the block field. There's no need to chase the forwarding
847  // pointer at this point, since we're building something that will
848  // live a shorter life than the stack byref anyway.
849  if (CI.isByRef()) {
850  // Get a void* that points to the byref struct.
851  llvm::Value *byrefPointer;
852  if (CI.isNested())
853  byrefPointer = Builder.CreateLoad(src, "byref.capture");
854  else
855  byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
856 
857  // Write that void* into the capture field.
858  Builder.CreateStore(byrefPointer, blockField);
859 
860  // If we have a copy constructor, evaluate that into the block field.
861  } else if (const Expr *copyExpr = CI.getCopyExpr()) {
862  if (blockDecl->isConversionFromLambda()) {
863  // If we have a lambda conversion, emit the expression
864  // directly into the block instead.
865  AggValueSlot Slot =
866  AggValueSlot::forAddr(blockField, Qualifiers(),
870  EmitAggExpr(copyExpr, Slot);
871  } else {
872  EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
873  }
874 
875  // If it's a reference variable, copy the reference into the block field.
876  } else if (type->isReferenceType()) {
877  Builder.CreateStore(src.getPointer(), blockField);
878 
879  // If type is const-qualified, copy the value into the block field.
880  } else if (type.isConstQualified() &&
882  CGM.getCodeGenOpts().OptimizationLevel != 0) {
883  llvm::Value *value = Builder.CreateLoad(src, "captured");
884  Builder.CreateStore(value, blockField);
885 
886  // If this is an ARC __strong block-pointer variable, don't do a
887  // block copy.
888  //
889  // TODO: this can be generalized into the normal initialization logic:
890  // we should never need to do a block-copy when initializing a local
891  // variable, because the local variable's lifetime should be strictly
892  // contained within the stack block's.
893  } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
894  type->isBlockPointerType()) {
895  // Load the block and do a simple retain.
896  llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
897  value = EmitARCRetainNonBlock(value);
898 
899  // Do a primitive store to the block field.
900  Builder.CreateStore(value, blockField);
901 
902  // Otherwise, fake up a POD copy into the block field.
903  } else {
904  // Fake up a new variable so that EmitScalarInit doesn't think
905  // we're referring to the variable in its own initializer.
906  ImplicitParamDecl blockFieldPseudoVar(getContext(), /*DC*/ nullptr,
907  SourceLocation(), /*name*/ nullptr,
908  type);
909 
910  // We use one of these or the other depending on whether the
911  // reference is nested.
912  DeclRefExpr declRef(const_cast<VarDecl *>(variable),
913  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
915 
916  ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
917  &declRef, VK_RValue);
918  // FIXME: Pass a specific location for the expr init so that the store is
919  // attributed to a reasonable location - otherwise it may be attributed to
920  // locations of subexpressions in the initialization.
921  LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
922  EmitExprAsInit(&l2r, &blockFieldPseudoVar,
923  MakeAddrLValue(blockField, type, BaseInfo),
924  /*captured by init*/ false);
925  }
926 
927  // Activate the cleanup if layout pushed one.
928  if (!CI.isByRef()) {
930  if (cleanup.isValid())
931  ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
932  }
933  }
934 
935  // Cast to the converted block-pointer type, which happens (somewhat
936  // unfortunately) to be a pointer to function type.
937  llvm::Value *result = Builder.CreatePointerCast(
938  blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
939 
940  return result;
941 }
942 
943 
945  if (BlockDescriptorType)
946  return BlockDescriptorType;
947 
948  llvm::Type *UnsignedLongTy =
949  getTypes().ConvertType(getContext().UnsignedLongTy);
950 
951  // struct __block_descriptor {
952  // unsigned long reserved;
953  // unsigned long block_size;
954  //
955  // // later, the following will be added
956  //
957  // struct {
958  // void (*copyHelper)();
959  // void (*copyHelper)();
960  // } helpers; // !!! optional
961  //
962  // const char *signature; // the block signature
963  // const char *layout; // reserved
964  // };
965  BlockDescriptorType = llvm::StructType::create(
966  "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
967 
968  // Now form a pointer to that.
969  unsigned AddrSpace = 0;
970  if (getLangOpts().OpenCL)
971  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
972  BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
973  return BlockDescriptorType;
974 }
975 
977  if (GenericBlockLiteralType)
978  return GenericBlockLiteralType;
979 
980  llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
981 
982  // struct __block_literal_generic {
983  // void *__isa;
984  // int __flags;
985  // int __reserved;
986  // void (*__invoke)(void *);
987  // struct __block_descriptor *__descriptor;
988  // };
989  GenericBlockLiteralType =
990  llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
991  IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
992 
993  return GenericBlockLiteralType;
994 }
995 
997  ReturnValueSlot ReturnValue) {
998  const BlockPointerType *BPT =
1000 
1001  llvm::Value *BlockPtr = EmitScalarExpr(E->getCallee());
1002 
1003  // Get a pointer to the generic block literal.
1004  // For OpenCL we generate generic AS void ptr to be able to reuse the same
1005  // block definition for blocks with captures generated as private AS local
1006  // variables and without captures generated as global AS program scope
1007  // variables.
1008  unsigned AddrSpace = 0;
1009  if (getLangOpts().OpenCL)
1010  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_generic);
1011 
1012  llvm::Type *BlockLiteralTy =
1013  llvm::PointerType::get(CGM.getGenericBlockLiteralType(), AddrSpace);
1014 
1015  // Bitcast the callee to a block literal.
1016  BlockPtr =
1017  Builder.CreatePointerCast(BlockPtr, BlockLiteralTy, "block.literal");
1018 
1019  // Get the function pointer from the literal.
1020  llvm::Value *FuncPtr =
1021  Builder.CreateStructGEP(CGM.getGenericBlockLiteralType(), BlockPtr, 3);
1022 
1023 
1024  // Add the block literal.
1025  CallArgList Args;
1026 
1027  QualType VoidPtrQualTy = getContext().VoidPtrTy;
1028  llvm::Type *GenericVoidPtrTy = VoidPtrTy;
1029  if (getLangOpts().OpenCL) {
1030  GenericVoidPtrTy = Builder.getInt8PtrTy(
1031  getContext().getTargetAddressSpace(LangAS::opencl_generic));
1032  VoidPtrQualTy =
1033  getContext().getPointerType(getContext().getAddrSpaceQualType(
1034  getContext().VoidTy, LangAS::opencl_generic));
1035  }
1036 
1037  BlockPtr = Builder.CreatePointerCast(BlockPtr, GenericVoidPtrTy);
1038  Args.add(RValue::get(BlockPtr), VoidPtrQualTy);
1039 
1040  QualType FnType = BPT->getPointeeType();
1041 
1042  // And the rest of the arguments.
1043  EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1044 
1045  // Load the function.
1046  llvm::Value *Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1047 
1048  const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1049  const CGFunctionInfo &FnInfo =
1050  CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
1051 
1052  // Cast the function pointer to the right type.
1053  llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
1054 
1055  llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
1056  Func = Builder.CreateBitCast(Func, BlockFTyPtr);
1057 
1058  // Prepare the callee.
1059  CGCallee Callee(CGCalleeInfo(), Func);
1060 
1061  // And call the block.
1062  return EmitCall(FnInfo, Callee, ReturnValue, Args);
1063 }
1064 
1066  bool isByRef) {
1067  assert(BlockInfo && "evaluating block ref without block information?");
1068  const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1069 
1070  // Handle constant captures.
1071  if (capture.isConstant()) return LocalDeclMap.find(variable)->second;
1072 
1073  Address addr =
1074  Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(),
1075  capture.getOffset(), "block.capture.addr");
1076 
1077  if (isByRef) {
1078  // addr should be a void** right now. Load, then cast the result
1079  // to byref*.
1080 
1081  auto &byrefInfo = getBlockByrefInfo(variable);
1082  addr = Address(Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
1083 
1084  auto byrefPointerType = llvm::PointerType::get(byrefInfo.Type, 0);
1085  addr = Builder.CreateBitCast(addr, byrefPointerType, "byref.addr");
1086 
1087  addr = emitBlockByrefAddress(addr, byrefInfo, /*follow*/ true,
1088  variable->getName());
1089  }
1090 
1091  if (auto refType = capture.fieldType()->getAs<ReferenceType>())
1092  addr = EmitLoadOfReference(addr, refType);
1093 
1094  return addr;
1095 }
1096 
1098  llvm::Constant *Addr) {
1099  bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
1100  (void)Ok;
1101  assert(Ok && "Trying to replace an already-existing global block!");
1102 }
1103 
1104 llvm::Constant *
1106  StringRef Name) {
1107  if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1108  return Block;
1109 
1110  CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1111  blockInfo.BlockExpression = BE;
1112 
1113  // Compute information about the layout, etc., of this block.
1114  computeBlockInfo(*this, nullptr, blockInfo);
1115 
1116  // Using that metadata, generate the actual block function.
1117  llvm::Constant *blockFn;
1118  {
1119  CodeGenFunction::DeclMapTy LocalDeclMap;
1121  blockInfo,
1122  LocalDeclMap,
1123  false);
1124  }
1125  blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy);
1126 
1127  return buildGlobalBlock(*this, blockInfo, blockFn);
1128 }
1129 
1130 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1131  const CGBlockInfo &blockInfo,
1132  llvm::Constant *blockFn) {
1133  assert(blockInfo.CanBeGlobal);
1134  // Callers should detect this case on their own: calling this function
1135  // generally requires computing layout information, which is a waste of time
1136  // if we've already emitted this block.
1137  assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&
1138  "Refusing to re-emit a global block.");
1139 
1140  // Generate the constants for the block literal initializer.
1141  ConstantInitBuilder builder(CGM);
1142  auto fields = builder.beginStruct();
1143 
1144  // isa
1145  fields.add(
1146  (!CGM.getContext().getLangOpts().OpenCL)
1147  ? CGM.getNSConcreteGlobalBlock()
1148  : CGM.getNullPointer(cast<llvm::PointerType>(
1149  CGM.getNSConcreteGlobalBlock()->getType()),
1150  QualType(CGM.getContext().VoidPtrTy)));
1151 
1152  // __flags
1154  if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET;
1155 
1156  fields.addInt(CGM.IntTy, flags.getBitMask());
1157 
1158  // Reserved
1159  fields.addInt(CGM.IntTy, 0);
1160 
1161  // Function
1162  fields.add(blockFn);
1163 
1164  // Descriptor
1165  fields.add(buildBlockDescriptor(CGM, blockInfo));
1166 
1167  unsigned AddrSpace = 0;
1168  if (CGM.getContext().getLangOpts().OpenCL)
1170 
1171  llvm::Constant *literal = fields.finishAndCreateGlobal(
1172  "__block_literal_global", blockInfo.BlockAlign,
1173  /*constant*/ true, llvm::GlobalVariable::InternalLinkage, AddrSpace);
1174 
1175  // Return a constant of the appropriately-casted type.
1176  llvm::Type *RequiredType =
1177  CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1178  llvm::Constant *Result =
1179  llvm::ConstantExpr::getPointerCast(literal, RequiredType);
1180  CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
1181  return Result;
1182 }
1183 
1185  unsigned argNum,
1186  llvm::Value *arg) {
1187  assert(BlockInfo && "not emitting prologue of block invocation function?!");
1188 
1189  llvm::Value *localAddr = nullptr;
1190  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1191  // Allocate a stack slot to let the debug info survive the RA.
1192  Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr");
1193  Builder.CreateStore(arg, alloc);
1194  localAddr = Builder.CreateLoad(alloc);
1195  }
1196 
1197  if (CGDebugInfo *DI = getDebugInfo()) {
1198  if (CGM.getCodeGenOpts().getDebugInfo() >=
1200  DI->setLocation(D->getLocation());
1201  DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, arg, argNum,
1202  localAddr, Builder);
1203  }
1204  }
1205 
1206  SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getLocStart();
1207  ApplyDebugLocation Scope(*this, StartLoc);
1208 
1209  // Instead of messing around with LocalDeclMap, just set the value
1210  // directly as BlockPointer.
1211  BlockPointer = Builder.CreatePointerCast(
1212  arg,
1213  BlockInfo->StructureType->getPointerTo(
1214  getContext().getLangOpts().OpenCL
1215  ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1216  : 0),
1217  "block");
1218 }
1219 
1221  assert(BlockInfo && "not in a block invocation function!");
1222  assert(BlockPointer && "no block pointer set!");
1223  return Address(BlockPointer, BlockInfo->BlockAlign);
1224 }
1225 
1226 llvm::Function *
1228  const CGBlockInfo &blockInfo,
1229  const DeclMapTy &ldm,
1230  bool IsLambdaConversionToBlock) {
1231  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1232 
1233  CurGD = GD;
1234 
1235  CurEHLocation = blockInfo.getBlockExpr()->getLocEnd();
1236 
1237  BlockInfo = &blockInfo;
1238 
1239  // Arrange for local static and local extern declarations to appear
1240  // to be local to this function as well, in case they're directly
1241  // referenced in a block.
1242  for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1243  const auto *var = dyn_cast<VarDecl>(i->first);
1244  if (var && !var->hasLocalStorage())
1245  setAddrOfLocalVar(var, i->second);
1246  }
1247 
1248  // Begin building the function declaration.
1249 
1250  // Build the argument list.
1251  FunctionArgList args;
1252 
1253  // The first argument is the block pointer. Just take it as a void*
1254  // and cast it later.
1255  QualType selfTy = getContext().VoidPtrTy;
1256 
1257  // For OpenCL passed block pointer can be private AS local variable or
1258  // global AS program scope variable (for the case with and without captures).
1259  // Generic AS is used therefore to be able to accomodate both private and
1260  // generic AS in one implementation.
1261  if (getLangOpts().OpenCL)
1262  selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1263  getContext().VoidTy, LangAS::opencl_generic));
1264 
1265  IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1266 
1267  ImplicitParamDecl selfDecl(getContext(), const_cast<BlockDecl*>(blockDecl),
1268  SourceLocation(), II, selfTy);
1269  args.push_back(&selfDecl);
1270 
1271  // Now add the rest of the parameters.
1272  args.append(blockDecl->param_begin(), blockDecl->param_end());
1273 
1274  // Create the function declaration.
1275  const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1276  const CGFunctionInfo &fnInfo =
1277  CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1278  if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1279  blockInfo.UsesStret = true;
1280 
1281  llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1282 
1283  StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1284  llvm::Function *fn = llvm::Function::Create(
1285  fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1286  CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1287 
1288  // Begin generating the function.
1289  StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1290  blockDecl->getLocation(),
1291  blockInfo.getBlockExpr()->getBody()->getLocStart());
1292 
1293  // Okay. Undo some of what StartFunction did.
1294 
1295  // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1296  // won't delete the dbg.declare intrinsics for captured variables.
1297  llvm::Value *BlockPointerDbgLoc = BlockPointer;
1298  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1299  // Allocate a stack slot for it, so we can point the debugger to it
1300  Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1301  getPointerAlign(),
1302  "block.addr");
1303  // Set the DebugLocation to empty, so the store is recognized as a
1304  // frame setup instruction by llvm::DwarfDebug::beginFunction().
1305  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1306  Builder.CreateStore(BlockPointer, Alloca);
1307  BlockPointerDbgLoc = Alloca.getPointer();
1308  }
1309 
1310  // If we have a C++ 'this' reference, go ahead and force it into
1311  // existence now.
1312  if (blockDecl->capturesCXXThis()) {
1313  Address addr =
1314  Builder.CreateStructGEP(LoadBlockStruct(), blockInfo.CXXThisIndex,
1315  blockInfo.CXXThisOffset, "block.captured-this");
1316  CXXThisValue = Builder.CreateLoad(addr, "this");
1317  }
1318 
1319  // Also force all the constant captures.
1320  for (const auto &CI : blockDecl->captures()) {
1321  const VarDecl *variable = CI.getVariable();
1322  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1323  if (!capture.isConstant()) continue;
1324 
1325  CharUnits align = getContext().getDeclAlign(variable);
1326  Address alloca =
1327  CreateMemTemp(variable->getType(), align, "block.captured-const");
1328 
1329  Builder.CreateStore(capture.getConstant(), alloca);
1330 
1331  setAddrOfLocalVar(variable, alloca);
1332  }
1333 
1334  // Save a spot to insert the debug information for all the DeclRefExprs.
1335  llvm::BasicBlock *entry = Builder.GetInsertBlock();
1336  llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1337  --entry_ptr;
1338 
1339  if (IsLambdaConversionToBlock)
1340  EmitLambdaBlockInvokeBody();
1341  else {
1342  PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1343  incrementProfileCounter(blockDecl->getBody());
1344  EmitStmt(blockDecl->getBody());
1345  }
1346 
1347  // Remember where we were...
1348  llvm::BasicBlock *resume = Builder.GetInsertBlock();
1349 
1350  // Go back to the entry.
1351  ++entry_ptr;
1352  Builder.SetInsertPoint(entry, entry_ptr);
1353 
1354  // Emit debug information for all the DeclRefExprs.
1355  // FIXME: also for 'this'
1356  if (CGDebugInfo *DI = getDebugInfo()) {
1357  for (const auto &CI : blockDecl->captures()) {
1358  const VarDecl *variable = CI.getVariable();
1359  DI->EmitLocation(Builder, variable->getLocation());
1360 
1361  if (CGM.getCodeGenOpts().getDebugInfo() >=
1363  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1364  if (capture.isConstant()) {
1365  auto addr = LocalDeclMap.find(variable)->second;
1366  DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1367  Builder);
1368  continue;
1369  }
1370 
1371  DI->EmitDeclareOfBlockDeclRefVariable(
1372  variable, BlockPointerDbgLoc, Builder, blockInfo,
1373  entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1374  }
1375  }
1376  // Recover location if it was changed in the above loop.
1377  DI->EmitLocation(Builder,
1378  cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1379  }
1380 
1381  // And resume where we left off.
1382  if (resume == nullptr)
1383  Builder.ClearInsertionPoint();
1384  else
1385  Builder.SetInsertPoint(resume);
1386 
1387  FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1388 
1389  return fn;
1390 }
1391 
1392 namespace {
1393 
1394 /// Represents a type of copy/destroy operation that should be performed for an
1395 /// entity that's captured by a block.
1397  CXXRecord, // Copy or destroy
1398  ARCWeak,
1399  ARCStrong,
1400  BlockObject, // Assign or release
1401  None
1402 };
1403 
1404 /// Represents a captured entity that requires extra operations in order for
1405 /// this entity to be copied or destroyed correctly.
1406 struct BlockCaptureManagedEntity {
1408  BlockFieldFlags Flags;
1409  const BlockDecl::Capture &CI;
1410  const CGBlockInfo::Capture &Capture;
1411 
1412  BlockCaptureManagedEntity(BlockCaptureEntityKind Type, BlockFieldFlags Flags,
1413  const BlockDecl::Capture &CI,
1414  const CGBlockInfo::Capture &Capture)
1415  : Kind(Type), Flags(Flags), CI(CI), Capture(Capture) {}
1416 };
1417 
1418 } // end anonymous namespace
1419 
1420 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1422  const LangOptions &LangOpts) {
1423  if (CI.getCopyExpr()) {
1424  assert(!CI.isByRef());
1425  // don't bother computing flags
1426  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1427  }
1428  BlockFieldFlags Flags;
1429  if (CI.isByRef()) {
1430  Flags = BLOCK_FIELD_IS_BYREF;
1431  if (T.isObjCGCWeak())
1432  Flags |= BLOCK_FIELD_IS_WEAK;
1433  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1434  }
1435  if (!T->isObjCRetainableType())
1436  // For all other types, the memcpy is fine.
1437  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1438 
1439  Flags = BLOCK_FIELD_IS_OBJECT;
1440  bool isBlockPointer = T->isBlockPointerType();
1441  if (isBlockPointer)
1442  Flags = BLOCK_FIELD_IS_BLOCK;
1443 
1444  // Special rules for ARC captures:
1445  Qualifiers QS = T.getQualifiers();
1446 
1447  // We need to register __weak direct captures with the runtime.
1449  return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1450 
1451  // We need to retain the copied value for __strong direct captures.
1453  // If it's a block pointer, we have to copy the block and
1454  // assign that to the destination pointer, so we might as
1455  // well use _Block_object_assign. Otherwise we can avoid that.
1456  return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1457  : BlockCaptureEntityKind::BlockObject,
1458  Flags);
1459  }
1460 
1461  // Non-ARC captures of retainable pointers are strong and
1462  // therefore require a call to _Block_object_assign.
1463  if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1464  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1465 
1466  // Otherwise the memcpy is fine.
1467  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1468 }
1469 
1470 /// Find the set of block captures that need to be explicitly copied or destroy.
1472  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1474  llvm::function_ref<std::pair<BlockCaptureEntityKind, BlockFieldFlags>(
1475  const BlockDecl::Capture &, QualType, const LangOptions &)>
1476  Predicate) {
1477  for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1478  const VarDecl *Variable = CI.getVariable();
1479  const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1480  if (Capture.isConstant())
1481  continue;
1482 
1483  auto Info = Predicate(CI, Variable->getType(), LangOpts);
1484  if (Info.first != BlockCaptureEntityKind::None)
1485  ManagedCaptures.emplace_back(Info.first, Info.second, CI, Capture);
1486  }
1487 }
1488 
1489 /// Generate the copy-helper function for a block closure object:
1490 /// static void block_copy_helper(block_t *dst, block_t *src);
1491 /// The runtime will have previously initialized 'dst' by doing a
1492 /// bit-copy of 'src'.
1493 ///
1494 /// Note that this copies an entire block closure object to the heap;
1495 /// it should not be confused with a 'byref copy helper', which moves
1496 /// the contents of an individual __block variable to the heap.
1497 llvm::Constant *
1499  ASTContext &C = getContext();
1500 
1501  FunctionArgList args;
1502  ImplicitParamDecl dstDecl(getContext(), nullptr, SourceLocation(), nullptr,
1503  C.VoidPtrTy);
1504  args.push_back(&dstDecl);
1505  ImplicitParamDecl srcDecl(getContext(), nullptr, SourceLocation(), nullptr,
1506  C.VoidPtrTy);
1507  args.push_back(&srcDecl);
1508 
1509  const CGFunctionInfo &FI =
1511 
1512  // FIXME: it would be nice if these were mergeable with things with
1513  // identical semantics.
1514  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1515 
1516  llvm::Function *Fn =
1518  "__copy_helper_block_", &CGM.getModule());
1519 
1520  IdentifierInfo *II
1521  = &CGM.getContext().Idents.get("__copy_helper_block_");
1522 
1525  SourceLocation(),
1526  SourceLocation(), II, C.VoidTy,
1527  nullptr, SC_Static,
1528  false,
1529  false);
1530 
1531  CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
1532 
1533  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1534  StartFunction(FD, C.VoidTy, Fn, FI, args);
1535  // Create a scope with an artificial location for the body of this function.
1536  auto AL = ApplyDebugLocation::CreateArtificial(*this);
1537  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1538 
1539  Address src = GetAddrOfLocalVar(&srcDecl);
1540  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
1541  src = Builder.CreateBitCast(src, structPtrTy, "block.source");
1542 
1543  Address dst = GetAddrOfLocalVar(&dstDecl);
1544  dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
1545  dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
1546 
1548  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures,
1550 
1551  for (const auto &CopiedCapture : CopiedCaptures) {
1552  const BlockDecl::Capture &CI = CopiedCapture.CI;
1553  const CGBlockInfo::Capture &capture = CopiedCapture.Capture;
1554  BlockFieldFlags flags = CopiedCapture.Flags;
1555 
1556  unsigned index = capture.getIndex();
1557  Address srcField = Builder.CreateStructGEP(src, index, capture.getOffset());
1558  Address dstField = Builder.CreateStructGEP(dst, index, capture.getOffset());
1559 
1560  // If there's an explicit copy expression, we do that.
1561  if (CI.getCopyExpr()) {
1562  assert(CopiedCapture.Kind == BlockCaptureEntityKind::CXXRecord);
1563  EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
1564  } else if (CopiedCapture.Kind == BlockCaptureEntityKind::ARCWeak) {
1565  EmitARCCopyWeak(dstField, srcField);
1566  } else {
1567  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
1568  if (CopiedCapture.Kind == BlockCaptureEntityKind::ARCStrong) {
1569  // At -O0, store null into the destination field (so that the
1570  // storeStrong doesn't over-release) and then call storeStrong.
1571  // This is a workaround to not having an initStrong call.
1572  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1573  auto *ty = cast<llvm::PointerType>(srcValue->getType());
1574  llvm::Value *null = llvm::ConstantPointerNull::get(ty);
1575  Builder.CreateStore(null, dstField);
1576  EmitARCStoreStrongCall(dstField, srcValue, true);
1577 
1578  // With optimization enabled, take advantage of the fact that
1579  // the blocks runtime guarantees a memcpy of the block data, and
1580  // just emit a retain of the src field.
1581  } else {
1582  EmitARCRetainNonBlock(srcValue);
1583 
1584  // We don't need this anymore, so kill it. It's not quite
1585  // worth the annoyance to avoid creating it in the first place.
1586  cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
1587  }
1588  } else {
1589  assert(CopiedCapture.Kind == BlockCaptureEntityKind::BlockObject);
1590  srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
1591  llvm::Value *dstAddr =
1592  Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
1593  llvm::Value *args[] = {
1594  dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
1595  };
1596 
1597  const VarDecl *variable = CI.getVariable();
1598  bool copyCanThrow = false;
1599  if (CI.isByRef() && variable->getType()->getAsCXXRecordDecl()) {
1600  const Expr *copyExpr =
1601  CGM.getContext().getBlockVarCopyInits(variable);
1602  if (copyExpr) {
1603  copyCanThrow = true; // FIXME: reuse the noexcept logic
1604  }
1605  }
1606 
1607  if (copyCanThrow) {
1608  EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
1609  } else {
1610  EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
1611  }
1612  }
1613  }
1614  }
1615 
1616  FinishFunction();
1617 
1618  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1619 }
1620 
1621 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1623  const LangOptions &LangOpts) {
1624  BlockFieldFlags Flags;
1625  if (CI.isByRef()) {
1626  Flags = BLOCK_FIELD_IS_BYREF;
1627  if (T.isObjCGCWeak())
1628  Flags |= BLOCK_FIELD_IS_WEAK;
1629  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1630  }
1631 
1632  if (const CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1633  if (Record->hasTrivialDestructor())
1634  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1635  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1636  }
1637 
1638  // Other types don't need to be destroy explicitly.
1639  if (!T->isObjCRetainableType())
1640  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1641 
1642  Flags = BLOCK_FIELD_IS_OBJECT;
1643  if (T->isBlockPointerType())
1644  Flags = BLOCK_FIELD_IS_BLOCK;
1645 
1646  // Special rules for ARC captures.
1647  Qualifiers QS = T.getQualifiers();
1648 
1649  // Use objc_storeStrong for __strong direct captures; the
1650  // dynamic tools really like it when we do this.
1652  return std::make_pair(BlockCaptureEntityKind::ARCStrong, Flags);
1653 
1654  // Support __weak direct captures.
1656  return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1657 
1658  // Non-ARC captures are strong, and we need to use
1659  // _Block_object_dispose.
1660  if (!QS.hasObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1661  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1662 
1663  // Otherwise, we have nothing to do.
1664  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1665 }
1666 
1667 /// Generate the destroy-helper function for a block closure object:
1668 /// static void block_destroy_helper(block_t *theBlock);
1669 ///
1670 /// Note that this destroys a heap-allocated block closure object;
1671 /// it should not be confused with a 'byref destroy helper', which
1672 /// destroys the heap-allocated contents of an individual __block
1673 /// variable.
1674 llvm::Constant *
1676  ASTContext &C = getContext();
1677 
1678  FunctionArgList args;
1679  ImplicitParamDecl srcDecl(getContext(), nullptr, SourceLocation(), nullptr,
1680  C.VoidPtrTy);
1681  args.push_back(&srcDecl);
1682 
1683  const CGFunctionInfo &FI =
1685 
1686  // FIXME: We'd like to put these into a mergable by content, with
1687  // internal linkage.
1688  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1689 
1690  llvm::Function *Fn =
1692  "__destroy_helper_block_", &CGM.getModule());
1693 
1694  IdentifierInfo *II
1695  = &CGM.getContext().Idents.get("__destroy_helper_block_");
1696 
1698  SourceLocation(),
1699  SourceLocation(), II, C.VoidTy,
1700  nullptr, SC_Static,
1701  false, false);
1702 
1703  CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
1704 
1705  // Create a scope with an artificial location for the body of this function.
1706  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1707  StartFunction(FD, C.VoidTy, Fn, FI, args);
1708  auto AL = ApplyDebugLocation::CreateArtificial(*this);
1709 
1710  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1711 
1712  Address src = GetAddrOfLocalVar(&srcDecl);
1713  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
1714  src = Builder.CreateBitCast(src, structPtrTy, "block");
1715 
1716  CodeGenFunction::RunCleanupsScope cleanups(*this);
1717 
1719  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures,
1721 
1722  for (const auto &DestroyedCapture : DestroyedCaptures) {
1723  const BlockDecl::Capture &CI = DestroyedCapture.CI;
1724  const CGBlockInfo::Capture &capture = DestroyedCapture.Capture;
1725  BlockFieldFlags flags = DestroyedCapture.Flags;
1726 
1727  Address srcField =
1728  Builder.CreateStructGEP(src, capture.getIndex(), capture.getOffset());
1729 
1730  // If the captured record has a destructor then call it.
1731  if (DestroyedCapture.Kind == BlockCaptureEntityKind::CXXRecord) {
1732  const auto *Dtor =
1734  PushDestructorCleanup(Dtor, srcField);
1735 
1736  // If this is a __weak capture, emit the release directly.
1737  } else if (DestroyedCapture.Kind == BlockCaptureEntityKind::ARCWeak) {
1738  EmitARCDestroyWeak(srcField);
1739 
1740  // Destroy strong objects with a call if requested.
1741  } else if (DestroyedCapture.Kind == BlockCaptureEntityKind::ARCStrong) {
1742  EmitARCDestroyStrong(srcField, ARCImpreciseLifetime);
1743 
1744  // Otherwise we call _Block_object_dispose. It wouldn't be too
1745  // hard to just emit this as a cleanup if we wanted to make sure
1746  // that things were done in reverse.
1747  } else {
1748  assert(DestroyedCapture.Kind == BlockCaptureEntityKind::BlockObject);
1749  llvm::Value *value = Builder.CreateLoad(srcField);
1750  value = Builder.CreateBitCast(value, VoidPtrTy);
1751  BuildBlockRelease(value, flags);
1752  }
1753  }
1754 
1755  cleanups.ForceCleanup();
1756 
1757  FinishFunction();
1758 
1759  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1760 }
1761 
1762 namespace {
1763 
1764 /// Emits the copy/dispose helper functions for a __block object of id type.
1765 class ObjectByrefHelpers final : public BlockByrefHelpers {
1766  BlockFieldFlags Flags;
1767 
1768 public:
1769  ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
1770  : BlockByrefHelpers(alignment), Flags(flags) {}
1771 
1772  void emitCopy(CodeGenFunction &CGF, Address destField,
1773  Address srcField) override {
1774  destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
1775 
1776  srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
1777  llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
1778 
1779  unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
1780 
1781  llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
1782  llvm::Value *fn = CGF.CGM.getBlockObjectAssign();
1783 
1784  llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
1785  CGF.EmitNounwindRuntimeCall(fn, args);
1786  }
1787 
1788  void emitDispose(CodeGenFunction &CGF, Address field) override {
1789  field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
1790  llvm::Value *value = CGF.Builder.CreateLoad(field);
1791 
1792  CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER);
1793  }
1794 
1795  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1796  id.AddInteger(Flags.getBitMask());
1797  }
1798 };
1799 
1800 /// Emits the copy/dispose helpers for an ARC __block __weak variable.
1801 class ARCWeakByrefHelpers final : public BlockByrefHelpers {
1802 public:
1803  ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
1804 
1805  void emitCopy(CodeGenFunction &CGF, Address destField,
1806  Address srcField) override {
1807  CGF.EmitARCMoveWeak(destField, srcField);
1808  }
1809 
1810  void emitDispose(CodeGenFunction &CGF, Address field) override {
1811  CGF.EmitARCDestroyWeak(field);
1812  }
1813 
1814  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1815  // 0 is distinguishable from all pointers and byref flags
1816  id.AddInteger(0);
1817  }
1818 };
1819 
1820 /// Emits the copy/dispose helpers for an ARC __block __strong variable
1821 /// that's not of block-pointer type.
1822 class ARCStrongByrefHelpers final : public BlockByrefHelpers {
1823 public:
1824  ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
1825 
1826  void emitCopy(CodeGenFunction &CGF, Address destField,
1827  Address srcField) override {
1828  // Do a "move" by copying the value and then zeroing out the old
1829  // variable.
1830 
1831  llvm::Value *value = CGF.Builder.CreateLoad(srcField);
1832 
1833  llvm::Value *null =
1834  llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
1835 
1836  if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
1837  CGF.Builder.CreateStore(null, destField);
1838  CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
1839  CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
1840  return;
1841  }
1842  CGF.Builder.CreateStore(value, destField);
1843  CGF.Builder.CreateStore(null, srcField);
1844  }
1845 
1846  void emitDispose(CodeGenFunction &CGF, Address field) override {
1848  }
1849 
1850  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1851  // 1 is distinguishable from all pointers and byref flags
1852  id.AddInteger(1);
1853  }
1854 };
1855 
1856 /// Emits the copy/dispose helpers for an ARC __block __strong
1857 /// variable that's of block-pointer type.
1858 class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
1859 public:
1860  ARCStrongBlockByrefHelpers(CharUnits alignment)
1861  : BlockByrefHelpers(alignment) {}
1862 
1863  void emitCopy(CodeGenFunction &CGF, Address destField,
1864  Address srcField) override {
1865  // Do the copy with objc_retainBlock; that's all that
1866  // _Block_object_assign would do anyway, and we'd have to pass the
1867  // right arguments to make sure it doesn't get no-op'ed.
1868  llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
1869  llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
1870  CGF.Builder.CreateStore(copy, destField);
1871  }
1872 
1873  void emitDispose(CodeGenFunction &CGF, Address field) override {
1875  }
1876 
1877  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1878  // 2 is distinguishable from all pointers and byref flags
1879  id.AddInteger(2);
1880  }
1881 };
1882 
1883 /// Emits the copy/dispose helpers for a __block variable with a
1884 /// nontrivial copy constructor or destructor.
1885 class CXXByrefHelpers final : public BlockByrefHelpers {
1886  QualType VarType;
1887  const Expr *CopyExpr;
1888 
1889 public:
1890  CXXByrefHelpers(CharUnits alignment, QualType type,
1891  const Expr *copyExpr)
1892  : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
1893 
1894  bool needsCopy() const override { return CopyExpr != nullptr; }
1895  void emitCopy(CodeGenFunction &CGF, Address destField,
1896  Address srcField) override {
1897  if (!CopyExpr) return;
1898  CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
1899  }
1900 
1901  void emitDispose(CodeGenFunction &CGF, Address field) override {
1902  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
1903  CGF.PushDestructorCleanup(VarType, field);
1904  CGF.PopCleanupBlocks(cleanupDepth);
1905  }
1906 
1907  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1908  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
1909  }
1910 };
1911 } // end anonymous namespace
1912 
1913 static llvm::Constant *
1915  BlockByrefHelpers &generator) {
1916  ASTContext &Context = CGF.getContext();
1917 
1918  QualType R = Context.VoidTy;
1919 
1920  FunctionArgList args;
1921  ImplicitParamDecl dst(CGF.getContext(), nullptr, SourceLocation(), nullptr,
1922  Context.VoidPtrTy);
1923  args.push_back(&dst);
1924 
1925  ImplicitParamDecl src(CGF.getContext(), nullptr, SourceLocation(), nullptr,
1926  Context.VoidPtrTy);
1927  args.push_back(&src);
1928 
1929  const CGFunctionInfo &FI =
1931 
1932  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
1933 
1934  // FIXME: We'd like to put these into a mergable by content, with
1935  // internal linkage.
1936  llvm::Function *Fn =
1938  "__Block_byref_object_copy_", &CGF.CGM.getModule());
1939 
1940  IdentifierInfo *II
1941  = &Context.Idents.get("__Block_byref_object_copy_");
1942 
1943  FunctionDecl *FD = FunctionDecl::Create(Context,
1944  Context.getTranslationUnitDecl(),
1945  SourceLocation(),
1946  SourceLocation(), II, R, nullptr,
1947  SC_Static,
1948  false, false);
1949 
1950  CGF.CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
1951 
1952  CGF.StartFunction(FD, R, Fn, FI, args);
1953 
1954  if (generator.needsCopy()) {
1955  llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
1956 
1957  // dst->x
1958  Address destField = CGF.GetAddrOfLocalVar(&dst);
1959  destField = Address(CGF.Builder.CreateLoad(destField),
1960  byrefInfo.ByrefAlignment);
1961  destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
1962  destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
1963  "dest-object");
1964 
1965  // src->x
1966  Address srcField = CGF.GetAddrOfLocalVar(&src);
1967  srcField = Address(CGF.Builder.CreateLoad(srcField),
1968  byrefInfo.ByrefAlignment);
1969  srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
1970  srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
1971  "src-object");
1972 
1973  generator.emitCopy(CGF, destField, srcField);
1974  }
1975 
1976  CGF.FinishFunction();
1977 
1978  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
1979 }
1980 
1981 /// Build the copy helper for a __block variable.
1982 static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
1983  const BlockByrefInfo &byrefInfo,
1984  BlockByrefHelpers &generator) {
1985  CodeGenFunction CGF(CGM);
1986  return generateByrefCopyHelper(CGF, byrefInfo, generator);
1987 }
1988 
1989 /// Generate code for a __block variable's dispose helper.
1990 static llvm::Constant *
1992  const BlockByrefInfo &byrefInfo,
1993  BlockByrefHelpers &generator) {
1994  ASTContext &Context = CGF.getContext();
1995  QualType R = Context.VoidTy;
1996 
1997  FunctionArgList args;
1998  ImplicitParamDecl src(CGF.getContext(), nullptr, SourceLocation(), nullptr,
1999  Context.VoidPtrTy);
2000  args.push_back(&src);
2001 
2002  const CGFunctionInfo &FI =
2004 
2005  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2006 
2007  // FIXME: We'd like to put these into a mergable by content, with
2008  // internal linkage.
2009  llvm::Function *Fn =
2011  "__Block_byref_object_dispose_",
2012  &CGF.CGM.getModule());
2013 
2014  IdentifierInfo *II
2015  = &Context.Idents.get("__Block_byref_object_dispose_");
2016 
2017  FunctionDecl *FD = FunctionDecl::Create(Context,
2018  Context.getTranslationUnitDecl(),
2019  SourceLocation(),
2020  SourceLocation(), II, R, nullptr,
2021  SC_Static,
2022  false, false);
2023 
2024  CGF.CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
2025 
2026  CGF.StartFunction(FD, R, Fn, FI, args);
2027 
2028  if (generator.needsDispose()) {
2029  Address addr = CGF.GetAddrOfLocalVar(&src);
2030  addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2031  auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2032  addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2033  addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2034 
2035  generator.emitDispose(CGF, addr);
2036  }
2037 
2038  CGF.FinishFunction();
2039 
2040  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2041 }
2042 
2043 /// Build the dispose helper for a __block variable.
2044 static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2045  const BlockByrefInfo &byrefInfo,
2046  BlockByrefHelpers &generator) {
2047  CodeGenFunction CGF(CGM);
2048  return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2049 }
2050 
2051 /// Lazily build the copy and dispose helpers for a __block variable
2052 /// with the given information.
2053 template <class T>
2054 static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2055  T &&generator) {
2056  llvm::FoldingSetNodeID id;
2057  generator.Profile(id);
2058 
2059  void *insertPos;
2060  BlockByrefHelpers *node
2061  = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2062  if (node) return static_cast<T*>(node);
2063 
2064  generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2065  generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2066 
2067  T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2068  CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2069  return copy;
2070 }
2071 
2072 /// Build the copy and dispose helpers for the given __block variable
2073 /// emission. Places the helpers in the global cache. Returns null
2074 /// if no helpers are required.
2076 CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2077  const AutoVarEmission &emission) {
2078  const VarDecl &var = *emission.Variable;
2079  QualType type = var.getType();
2080 
2081  auto &byrefInfo = getBlockByrefInfo(&var);
2082 
2083  // The alignment we care about for the purposes of uniquing byref
2084  // helpers is the alignment of the actual byref value field.
2085  CharUnits valueAlignment =
2086  byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2087 
2088  if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2089  const Expr *copyExpr = CGM.getContext().getBlockVarCopyInits(&var);
2090  if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2091 
2093  CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2094  }
2095 
2096  // Otherwise, if we don't have a retainable type, there's nothing to do.
2097  // that the runtime does extra copies.
2098  if (!type->isObjCRetainableType()) return nullptr;
2099 
2100  Qualifiers qs = type.getQualifiers();
2101 
2102  // If we have lifetime, that dominates.
2103  if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2104  switch (lifetime) {
2105  case Qualifiers::OCL_None: llvm_unreachable("impossible");
2106 
2107  // These are just bits as far as the runtime is concerned.
2110  return nullptr;
2111 
2112  // Tell the runtime that this is ARC __weak, called by the
2113  // byref routines.
2114  case Qualifiers::OCL_Weak:
2115  return ::buildByrefHelpers(CGM, byrefInfo,
2116  ARCWeakByrefHelpers(valueAlignment));
2117 
2118  // ARC __strong __block variables need to be retained.
2120  // Block pointers need to be copied, and there's no direct
2121  // transfer possible.
2122  if (type->isBlockPointerType()) {
2123  return ::buildByrefHelpers(CGM, byrefInfo,
2124  ARCStrongBlockByrefHelpers(valueAlignment));
2125 
2126  // Otherwise, we transfer ownership of the retain from the stack
2127  // to the heap.
2128  } else {
2129  return ::buildByrefHelpers(CGM, byrefInfo,
2130  ARCStrongByrefHelpers(valueAlignment));
2131  }
2132  }
2133  llvm_unreachable("fell out of lifetime switch!");
2134  }
2135 
2136  BlockFieldFlags flags;
2137  if (type->isBlockPointerType()) {
2138  flags |= BLOCK_FIELD_IS_BLOCK;
2139  } else if (CGM.getContext().isObjCNSObjectType(type) ||
2140  type->isObjCObjectPointerType()) {
2141  flags |= BLOCK_FIELD_IS_OBJECT;
2142  } else {
2143  return nullptr;
2144  }
2145 
2146  if (type.isObjCGCWeak())
2147  flags |= BLOCK_FIELD_IS_WEAK;
2148 
2149  return ::buildByrefHelpers(CGM, byrefInfo,
2150  ObjectByrefHelpers(valueAlignment, flags));
2151 }
2152 
2154  const VarDecl *var,
2155  bool followForward) {
2156  auto &info = getBlockByrefInfo(var);
2157  return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2158 }
2159 
2161  const BlockByrefInfo &info,
2162  bool followForward,
2163  const llvm::Twine &name) {
2164  // Chase the forwarding address if requested.
2165  if (followForward) {
2166  Address forwardingAddr =
2167  Builder.CreateStructGEP(baseAddr, 1, getPointerSize(), "forwarding");
2168  baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2169  }
2170 
2171  return Builder.CreateStructGEP(baseAddr, info.FieldIndex,
2172  info.FieldOffset, name);
2173 }
2174 
2175 /// BuildByrefInfo - This routine changes a __block variable declared as T x
2176 /// into:
2177 ///
2178 /// struct {
2179 /// void *__isa;
2180 /// void *__forwarding;
2181 /// int32_t __flags;
2182 /// int32_t __size;
2183 /// void *__copy_helper; // only if needed
2184 /// void *__destroy_helper; // only if needed
2185 /// void *__byref_variable_layout;// only if needed
2186 /// char padding[X]; // only if needed
2187 /// T x;
2188 /// } x
2189 ///
2191  auto it = BlockByrefInfos.find(D);
2192  if (it != BlockByrefInfos.end())
2193  return it->second;
2194 
2195  llvm::StructType *byrefType =
2196  llvm::StructType::create(getLLVMContext(),
2197  "struct.__block_byref_" + D->getNameAsString());
2198 
2199  QualType Ty = D->getType();
2200 
2201  CharUnits size;
2203 
2204  // void *__isa;
2205  types.push_back(Int8PtrTy);
2206  size += getPointerSize();
2207 
2208  // void *__forwarding;
2209  types.push_back(llvm::PointerType::getUnqual(byrefType));
2210  size += getPointerSize();
2211 
2212  // int32_t __flags;
2213  types.push_back(Int32Ty);
2214  size += CharUnits::fromQuantity(4);
2215 
2216  // int32_t __size;
2217  types.push_back(Int32Ty);
2218  size += CharUnits::fromQuantity(4);
2219 
2220  // Note that this must match *exactly* the logic in buildByrefHelpers.
2221  bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2222  if (hasCopyAndDispose) {
2223  /// void *__copy_helper;
2224  types.push_back(Int8PtrTy);
2225  size += getPointerSize();
2226 
2227  /// void *__destroy_helper;
2228  types.push_back(Int8PtrTy);
2229  size += getPointerSize();
2230  }
2231 
2232  bool HasByrefExtendedLayout = false;
2233  Qualifiers::ObjCLifetime Lifetime;
2234  if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2235  HasByrefExtendedLayout) {
2236  /// void *__byref_variable_layout;
2237  types.push_back(Int8PtrTy);
2238  size += CharUnits::fromQuantity(PointerSizeInBytes);
2239  }
2240 
2241  // T x;
2242  llvm::Type *varTy = ConvertTypeForMem(Ty);
2243 
2244  bool packed = false;
2245  CharUnits varAlign = getContext().getDeclAlign(D);
2246  CharUnits varOffset = size.alignTo(varAlign);
2247 
2248  // We may have to insert padding.
2249  if (varOffset != size) {
2250  llvm::Type *paddingTy =
2251  llvm::ArrayType::get(Int8Ty, (varOffset - size).getQuantity());
2252 
2253  types.push_back(paddingTy);
2254  size = varOffset;
2255 
2256  // Conversely, we might have to prevent LLVM from inserting padding.
2257  } else if (CGM.getDataLayout().getABITypeAlignment(varTy)
2258  > varAlign.getQuantity()) {
2259  packed = true;
2260  }
2261  types.push_back(varTy);
2262 
2263  byrefType->setBody(types, packed);
2264 
2265  BlockByrefInfo info;
2266  info.Type = byrefType;
2267  info.FieldIndex = types.size() - 1;
2268  info.FieldOffset = varOffset;
2269  info.ByrefAlignment = std::max(varAlign, getPointerAlign());
2270 
2271  auto pair = BlockByrefInfos.insert({D, info});
2272  assert(pair.second && "info was inserted recursively?");
2273  return pair.first->second;
2274 }
2275 
2276 /// Initialize the structural components of a __block variable, i.e.
2277 /// everything but the actual object.
2279  // Find the address of the local.
2280  Address addr = emission.Addr;
2281 
2282  // That's an alloca of the byref structure type.
2283  llvm::StructType *byrefType = cast<llvm::StructType>(
2284  cast<llvm::PointerType>(addr.getPointer()->getType())->getElementType());
2285 
2286  unsigned nextHeaderIndex = 0;
2287  CharUnits nextHeaderOffset;
2288  auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2289  const Twine &name) {
2290  auto fieldAddr = Builder.CreateStructGEP(addr, nextHeaderIndex,
2291  nextHeaderOffset, name);
2292  Builder.CreateStore(value, fieldAddr);
2293 
2294  nextHeaderIndex++;
2295  nextHeaderOffset += fieldSize;
2296  };
2297 
2298  // Build the byref helpers if necessary. This is null if we don't need any.
2299  BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2300 
2301  const VarDecl &D = *emission.Variable;
2302  QualType type = D.getType();
2303 
2304  bool HasByrefExtendedLayout;
2305  Qualifiers::ObjCLifetime ByrefLifetime;
2306  bool ByRefHasLifetime =
2307  getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2308 
2309  llvm::Value *V;
2310 
2311  // Initialize the 'isa', which is just 0 or 1.
2312  int isa = 0;
2313  if (type.isObjCGCWeak())
2314  isa = 1;
2315  V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2316  storeHeaderField(V, getPointerSize(), "byref.isa");
2317 
2318  // Store the address of the variable into its own forwarding pointer.
2319  storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2320 
2321  // Blocks ABI:
2322  // c) the flags field is set to either 0 if no helper functions are
2323  // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2324  BlockFlags flags;
2325  if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2326  if (ByRefHasLifetime) {
2327  if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2328  else switch (ByrefLifetime) {
2330  flags |= BLOCK_BYREF_LAYOUT_STRONG;
2331  break;
2332  case Qualifiers::OCL_Weak:
2333  flags |= BLOCK_BYREF_LAYOUT_WEAK;
2334  break;
2337  break;
2338  case Qualifiers::OCL_None:
2339  if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2341  break;
2342  default:
2343  break;
2344  }
2345  if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2346  printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2347  if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2348  printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2349  if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2350  BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2351  if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2352  printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2353  if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2354  printf(" BLOCK_BYREF_LAYOUT_STRONG");
2355  if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2356  printf(" BLOCK_BYREF_LAYOUT_WEAK");
2357  if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2358  printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2359  if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2360  printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2361  }
2362  printf("\n");
2363  }
2364  }
2365  storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2366  getIntSize(), "byref.flags");
2367 
2368  CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2369  V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2370  storeHeaderField(V, getIntSize(), "byref.size");
2371 
2372  if (helpers) {
2373  storeHeaderField(helpers->CopyHelper, getPointerSize(),
2374  "byref.copyHelper");
2375  storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2376  "byref.disposeHelper");
2377  }
2378 
2379  if (ByRefHasLifetime && HasByrefExtendedLayout) {
2380  auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2381  storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2382  }
2383 }
2384 
2387  llvm::Value *args[] = {
2388  Builder.CreateBitCast(V, Int8PtrTy),
2389  llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2390  };
2391  EmitNounwindRuntimeCall(F, args); // FIXME: throwing destructors?
2392 }
2393 
2394 namespace {
2395  /// Release a __block variable.
2396  struct CallBlockRelease final : EHScopeStack::Cleanup {
2397  llvm::Value *Addr;
2398  CallBlockRelease(llvm::Value *Addr) : Addr(Addr) {}
2399 
2400  void Emit(CodeGenFunction &CGF, Flags flags) override {
2401  // Should we be passing FIELD_IS_WEAK here?
2403  }
2404  };
2405 } // end anonymous namespace
2406 
2407 /// Enter a cleanup to destroy a __block variable. Note that this
2408 /// cleanup should be a no-op if the variable hasn't left the stack
2409 /// yet; if a cleanup is required for the variable itself, that needs
2410 /// to be done externally.
2412  // We don't enter this cleanup if we're in pure-GC mode.
2413  if (CGM.getLangOpts().getGC() == LangOptions::GCOnly)
2414  return;
2415 
2416  EHStack.pushCleanup<CallBlockRelease>(NormalAndEHCleanup,
2417  emission.Addr.getPointer());
2418 }
2419 
2420 /// Adjust the declaration of something from the blocks API.
2422  llvm::Constant *C) {
2423  auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2424 
2425  if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2426  IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2429 
2430  assert((isa<llvm::Function>(C->stripPointerCasts()) ||
2431  isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&
2432  "expected Function or GlobalVariable");
2433 
2434  const NamedDecl *ND = nullptr;
2435  for (const auto &Result : DC->lookup(&II))
2436  if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2437  (ND = dyn_cast<VarDecl>(Result)))
2438  break;
2439 
2440  // TODO: support static blocks runtime
2441  if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2442  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2443  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2444  } else {
2445  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2446  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2447  }
2448  }
2449 
2450  if (!CGM.getLangOpts().BlocksRuntimeOptional)
2451  return;
2452 
2453  if (GV->isDeclaration() && GV->hasExternalLinkage())
2454  GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2455 }
2456 
2458  if (BlockObjectDispose)
2459  return BlockObjectDispose;
2460 
2461  llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2462  llvm::FunctionType *fty
2463  = llvm::FunctionType::get(VoidTy, args, false);
2464  BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2465  configureBlocksRuntimeObject(*this, BlockObjectDispose);
2466  return BlockObjectDispose;
2467 }
2468 
2470  if (BlockObjectAssign)
2471  return BlockObjectAssign;
2472 
2473  llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
2474  llvm::FunctionType *fty
2475  = llvm::FunctionType::get(VoidTy, args, false);
2476  BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
2477  configureBlocksRuntimeObject(*this, BlockObjectAssign);
2478  return BlockObjectAssign;
2479 }
2480 
2482  if (NSConcreteGlobalBlock)
2483  return NSConcreteGlobalBlock;
2484 
2485  NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
2486  Int8PtrTy->getPointerTo(),
2487  nullptr);
2488  configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
2489  return NSConcreteGlobalBlock;
2490 }
2491 
2493  if (NSConcreteStackBlock)
2494  return NSConcreteStackBlock;
2495 
2496  NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
2497  Int8PtrTy->getPointerTo(),
2498  nullptr);
2499  configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
2500  return NSConcreteStackBlock;
2501 }
const CGFunctionInfo & arrangeBuiltinFunctionDeclaration(QualType resultType, const FunctionArgList &args)
A builtin function is a freestanding function using the default C conventions.
Definition: CGCall.cpp:636
void enterNonTrivialFullExpression(const ExprWithCleanups *E)
Enter a full-expression with a non-trivial number of objects to clean up.
Definition: CGBlocks.cpp:663
const llvm::DataLayout & getDataLayout() const
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:281
const BlockDecl * getBlockDecl() const
Definition: Expr.h:4834
Information about the layout of a __block variable.
Definition: CGBlocks.h:140
CharUnits alignTo(const CharUnits &Align) const
alignTo - Returns the next integer (mod 2**64) that is greater than or equal to this quantity and is ...
Definition: CharUnits.h:184
const Capture & getCapture(const VarDecl *var) const
Definition: CGBlocks.h:261
llvm::Constant * GenerateCopyHelperFunction(const CGBlockInfo &blockInfo)
Generate the copy-helper function for a block closure object: static void block_copy_helper(block_t *...
Definition: CGBlocks.cpp:1498
static llvm::Constant * generateByrefDisposeHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Generate code for a __block variable&#39;s dispose helper.
Definition: CGBlocks.cpp:1991
FunctionDecl - An instance of this class is created to represent a function declaration or definition...
Definition: Decl.h:1583
llvm::IntegerType * IntTy
int
llvm::Type * getGenericBlockLiteralType()
The type of a generic block literal.
Definition: CGBlocks.cpp:976
const CGFunctionInfo & arrangeBlockFunctionDeclaration(const FunctionProtoType *type, const FunctionArgList &args)
Block invocation functions are C functions with an implicit parameter.
Definition: CGCall.cpp:610
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:50
CharUnits BlockHeaderForcedGapOffset
Definition: CGBlocks.h:246
const FunctionProtoType * getFunctionType() const
getFunctionType - Return the underlying function type for this block.
Definition: Expr.cpp:1932
Expr * getCopyExpr() const
Definition: Decl.h:3544
static llvm::Constant * buildByrefDisposeHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the dispose helper for a __block variable.
Definition: CGBlocks.cpp:2044
A class which contains all the information about a particular captured value.
Definition: Decl.h:3512
CanQualType VoidPtrTy
Definition: ASTContext.h:978
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:1464
A (possibly-)qualified type.
Definition: Type.h:616
bool isBlockPointerType() const
Definition: Type.h:5716
const CodeGenOptions & getCodeGenOpts() const
bool hasCaptures() const
hasCaptures - True if this block (or its nested blocks) captures anything of local storage from its e...
Definition: Decl.h:3625
bool HaveInsertPoint() const
HaveInsertPoint - True if an insertion point is defined.
capture_const_iterator capture_begin() const
Definition: Decl.h:3635
llvm::LLVMContext & getLLVMContext()
void EmitARCDestroyWeak(Address addr)
void @objc_destroyWeak(i8** addr) Essentially objc_storeWeak(addr, nil).
Definition: CGObjC.cpp:2298
The standard implementation of ConstantInitBuilder used in Clang.
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:2922
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:777
static T * buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, T &&generator)
Lazily build the copy and dispose helpers for a __block variable with the given information.
Definition: CGBlocks.cpp:2054
llvm::AllocaInst * CreateTempAlloca(llvm::Type *Ty, const Twine &Name="tmp")
CreateTempAlloca - This creates a alloca and inserts it into the entry block.
Definition: CGExpr.cpp:72
tooling::Replacements cleanup(const FormatStyle &Style, StringRef Code, ArrayRef< tooling::Range > Ranges, StringRef FileName="<stdin>")
Clean up any erroneous/redundant code in the given Ranges in Code.
Definition: Format.cpp:1910
ArrayRef< CleanupObject > getObjects() const
Definition: ExprCXX.h:2948
param_iterator param_end()
Definition: Decl.h:3607
static llvm::Constant * buildBlockDescriptor(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
buildBlockDescriptor - Build the block descriptor meta-data for a block.
Definition: CGBlocks.cpp:77
QualType getNonReferenceType() const
If Type is a reference type (e.g., const int&), returns the type that the reference refers to ("const...
Definition: Type.h:5660
The base class of the type hierarchy.
Definition: Type.h:1303
stable_iterator stable_begin() const
Create a stable reference to the top of the EH stack.
Definition: EHScopeStack.h:379
The l-value was an access to a declared entity or something equivalently strong, like the address of ...
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
capture_const_iterator capture_end() const
Definition: Decl.h:3636
Address GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
VarDecl - An instance of this class is created to represent a variable declaration or definition...
Definition: Decl.h:758
CGBlockInfo(const BlockDecl *blockDecl, StringRef Name)
Definition: CGBlocks.cpp:31
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6040
EHScopeStack::stable_iterator getCleanup() const
Definition: CGBlocks.h:179
This class gathers all debug information during compilation and is responsible for emitting to llvm g...
Definition: CGDebugInfo.h:53
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:1421
virtual llvm::Constant * BuildRCBlockLayout(CodeGen::CodeGenModule &CGM, const CodeGen::CGBlockInfo &blockInfo)=0
llvm::Value * getPointer() const
Definition: Address.h:38
llvm::Type * ConvertTypeForMem(QualType T)
ConvertTypeForMem - Convert type T into a llvm::Type.
Represents an expression – generally a full-expression – that introduces cleanups to be run at the ...
Definition: ExprCXX.h:2920
static void destroyBlockInfos(CGBlockInfo *info)
Destroy a chain of block layouts.
Definition: CGBlocks.cpp:690
The collection of all-type qualifiers we support.
Definition: Type.h:118
const BlockDecl * Block
Definition: CGBlocks.h:237
llvm::DenseMap< const VarDecl *, FieldDecl * > LambdaCaptureFields
One of these records is kept for each identifier that is lexed.
void emitByrefStructureInit(const AutoVarEmission &emission)
Initialize the structural components of a __block variable, i.e.
Definition: CGBlocks.cpp:2278
CGBlockInfo * FirstBlockInfo
FirstBlockInfo - The head of a singly-linked-list of block layouts.
QualType getPointeeType() const
Definition: Type.h:2340
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
llvm::Type * ConvertType(QualType T)
ConvertType - Convert type T into a llvm::Type.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:128
bool HasCapturedVariableLayout
HasCapturedVariableLayout : True if block has captured variables and their layout meta-data has been ...
Definition: CGBlocks.h:230
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:1622
bool isReferenceType() const
Definition: Type.h:5719
static void findBlockCapturedManagedEntities(const CGBlockInfo &BlockInfo, const LangOptions &LangOpts, SmallVectorImpl< BlockCaptureManagedEntity > &ManagedCaptures, llvm::function_ref< std::pair< BlockCaptureEntityKind, BlockFieldFlags >(const BlockDecl::Capture &, QualType, const LangOptions &)> Predicate)
Find the set of block captures that need to be explicitly copied or destroy.
Definition: CGBlocks.cpp:1471
std::string getObjCEncodingForBlock(const BlockExpr *blockExpr) const
Return the encoded type for this block declaration.
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:53
static llvm::Constant * generateByrefCopyHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Definition: CGBlocks.cpp:1914
Stmt * getBody() const override
getBody - If this Decl represents a declaration for a body of code, such as a function or method defi...
Definition: Decl.h:3588
static bool isSafeForCXXConstantCapture(QualType type)
Determines if the given type is safe for constant capture in C++.
Definition: CGBlocks.cpp:242
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:48
IdentifierTable & Idents
Definition: ASTContext.h:513
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:106
CharUnits GetTargetTypeStoreSize(llvm::Type *Ty) const
Return the store size, in character units, of the given LLVM type.
static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF)
Apply TemporaryLocation if it is valid.
Definition: CGDebugInfo.h:648
llvm::Value * EmitARCStoreStrongCall(Address addr, llvm::Value *value, bool resultIgnored)
Store into a strong object.
Definition: CGObjC.cpp:2136
Address GetAddrOfBlockDecl(const VarDecl *var, bool ByRef)
Definition: CGBlocks.cpp:1065
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:38
void EmitARCDestroyStrong(Address addr, ARCPreciseLifetime_t precise)
Destroy a __strong variable.
Definition: CGObjC.cpp:2122
const BlockDecl * getBlockDecl() const
Definition: CGBlocks.h:271
bool HasCXXObject
HasCXXObject - True if the block&#39;s custom copy/dispose functions need to be run even in GC mode...
Definition: CGBlocks.h:222
llvm::Value * EmitBlockLiteral(const BlockExpr *)
Emit a block literal expression in the current function.
Definition: CGBlocks.cpp:700
uint32_t getBitMask() const
Definition: CGBlocks.h:117
bool isByRef() const
Whether this is a "by ref" capture, i.e.
Definition: Decl.h:3537
bool needsEHCleanup(QualType::DestructionKind kind)
Determines whether an EH cleanup is required to destroy a type with the given destruction kind...
llvm::Constant * getAddrOfGlobalBlockIfEmitted(const BlockExpr *BE)
Returns the address of a block which requires no caputres, or null if we&#39;ve yet to emit the block for...
CharUnits getDeclAlign(const Decl *D, bool ForAlignof=false) const
Return a conservative estimate of the alignment of the specified decl D.
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:39
void ForceCleanup(std::initializer_list< llvm::Value **> ValuesToReload={})
Force the emission of cleanups now, instead of waiting until this object is destroyed.
static Capture makeConstant(llvm::Value *value)
Definition: CGBlocks.h:206
CXXDestructorDecl * getDestructor() const
Returns the destructor decl for this class.
Definition: DeclCXX.cpp:1411
const Stmt * getBody() const
Definition: Expr.cpp:1941
llvm::Constant * getNSConcreteStackBlock()
Definition: CGBlocks.cpp:2492
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:1744
This object can be modified without requiring retains or releases.
Definition: Type.h:139
StringRef Name
Name - The name of the block, kindof.
Definition: CGBlocks.h:152
bool NeedsCopyDispose
True if the block needs a custom copy or dispose function.
Definition: CGBlocks.h:218
lookup_result lookup(DeclarationName Name) const
lookup - Find the declarations (if any) with the given Name in this context.
Definition: DeclBase.cpp:1505
const BlockExpr * BlockExpression
Definition: CGBlocks.h:238
static llvm::Constant * buildCopyHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to copy a block.
Definition: CGBlocks.cpp:52
bool isValid() const
Definition: Address.h:36
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1548
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3128
llvm::CallInst * EmitNounwindRuntimeCall(llvm::Value *callee, const Twine &name="")
uint32_t getBitMask() const
Definition: CGBlocks.h:73
const CodeGen::CGBlockInfo * BlockInfo
llvm::Function * GenerateBlockFunction(GlobalDecl GD, const CGBlockInfo &Info, const DeclMapTy &ldm, bool IsLambdaConversionToBlock)
Definition: CGBlocks.cpp:1227
CGBlockInfo - Information to generate a block literal.
Definition: CGBlocks.h:149
virtual void emitCopy(CodeGenFunction &CGF, Address dest, Address src)=0
RValue - This trivial value class is used to represent the result of an expression that is evaluated...
Definition: CGValue.h:38
bool CanBeGlobal
CanBeGlobal - True if the block can be global, i.e.
Definition: CGBlocks.h:215
SourceLocation getLocEnd() const LLVM_READONLY
Definition: Expr.h:4844
StringRef getBlockMangledName(GlobalDecl GD, const BlockDecl *BD)
llvm::Constant * getNullPointer(llvm::PointerType *T, QualType QT)
Get target specific null pointer.
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info, SmallVectorImpl< llvm::Type *> &elementTypes)
Definition: CGBlocks.cpp:302
CGBlockInfo * NextBlockInfo
The next block in the block-info chain.
Definition: CGBlocks.h:259
CGObjCRuntime & getObjCRuntime()
Return a reference to the configured Objective-C runtime.
BlockDecl - This represents a block literal declaration, which is like an unnamed FunctionDecl...
Definition: Decl.h:3508
Expr - This represents one expression.
Definition: Expr.h:105
void EmitARCMoveWeak(Address dst, Address src)
void @objc_moveWeak(i8** dest, i8** src) Disregards the current value in dest.
Definition: CGObjC.cpp:2315
Emit only debug info necessary for generating line number tables (-gline-tables-only).
static Address invalid()
Definition: Address.h:35
Enters a new scope for capturing cleanups, all of which will be executed once the scope is exited...
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6103
void SetInternalFunctionAttributes(const Decl *D, llvm::Function *F, const CGFunctionInfo &FI)
Set the attributes on the LLVM function for the given decl and function info.
bool isObjCRetainableType() const
Definition: Type.cpp:3740
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:4820
BlockCaptureEntityKind
Represents a type of copy/destroy operation that should be performed for an entity that&#39;s captured by...
Definition: CGBlocks.cpp:1396
static llvm::Constant * buildGlobalBlock(CodeGenModule &CGM, const CGBlockInfo &blockInfo, llvm::Constant *blockFn)
Build the given block as a global block.
Definition: CGBlocks.cpp:1130
llvm::Constant * GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo)
Generate the destroy-helper function for a block closure object: static void block_destroy_helper(blo...
Definition: CGBlocks.cpp:1675
const Expr * getCallee() const
Definition: Expr.h:2246
ObjCLifetime getObjCLifetime() const
Definition: Type.h:309
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:102
void add(RValue rvalue, QualType type, bool needscopy=false)
Definition: CGCall.h:207
bool ReturnSlotInterferesWithArgs(const CGFunctionInfo &FI)
Return true iff the given type uses an argument slot when &#39;sret&#39; is used as a return type...
Definition: CGCall.cpp:1470
static Capture makeIndex(unsigned index, CharUnits offset, QualType FieldType)
Definition: CGBlocks.h:197
QualType getType() const
Definition: Expr.h:127
bool isa(CodeGen::Address addr)
Definition: Address.h:112
bool isObjCInertUnsafeUnretainedType() const
Was this type written with the special inert-in-MRC __unsafe_unretained qualifier?
Definition: Type.cpp:518
static CharUnits getLowBit(CharUnits v)
Get the low bit of a nonzero character count.
Definition: CGBlocks.cpp:298
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:5998
const TargetInfo & getTarget() const
The result type of a method or function.
const LangOptions & getLangOpts() const
ASTContext & getContext() const
static AggValueSlot forAddr(Address addr, Qualifiers quals, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, IsZeroed_t isZeroed=IsNotZeroed)
forAddr - Make a slot for an aggregate value.
Definition: CGValue.h:517
do v
Definition: arm_acle.h:78
static QualType getCaptureFieldType(const CodeGenFunction &CGF, const BlockDecl::Capture &CI)
Definition: CGBlocks.cpp:321
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:29
virtual bool needsCopy() const
virtual llvm::Constant * BuildByrefLayout(CodeGen::CodeGenModule &CGM, QualType T)=0
Returns an i8* which points to the byref layout information.
bool isConstQualified() const
Determine whether this type is const-qualified.
Definition: Type.h:5546
param_iterator param_begin()
Definition: Decl.h:3606
The l-value was considered opaque, so the alignment was determined from a type.
RecordDecl * getDecl() const
Definition: Type.h:3792
void setBlockContextParameter(const ImplicitParamDecl *D, unsigned argNum, llvm::Value *ptr)
Definition: CGBlocks.cpp:1184
void PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize, std::initializer_list< llvm::Value **> ValuesToReload={})
Takes the old cleanup stack size and emits the cleanup blocks that have been added.
Definition: CGCleanup.cpp:420
bool UsesStret
UsesStret : True if the block uses an stret return.
Definition: CGBlocks.h:226
void enterByrefCleanup(const AutoVarEmission &emission)
Enter a cleanup to destroy a __block variable.
Definition: CGBlocks.cpp:2411
There is no lifetime qualification on this type.
Definition: Type.h:135
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:142
#define false
Definition: stdbool.h:33
Assigning into this object requires the old value to be released and the new value to be retained...
Definition: Type.h:146
Kind
Expr * getBlockVarCopyInits(const VarDecl *VD)
Get the copy initialization expression of the VarDecl VD, or NULL if none exists. ...
void PushDestructorCleanup(QualType T, Address Addr)
PushDestructorCleanup - Push a cleanup to call the complete-object destructor of an object of the giv...
Definition: CGClass.cpp:2332
void pushDestroy(QualType::DestructionKind dtorKind, Address addr, QualType type)
pushDestroy - Push the standard destructor for the given type as at least a normal cleanup...
Definition: CGDecl.cpp:1489
Encodes a location in the source.
static DeclContext * castToDeclContext(const TranslationUnitDecl *D)
Definition: Decl.h:99
QualType getReturnType() const
Definition: Type.h:3064
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
A saved depth on the scope stack.
Definition: EHScopeStack.h:107
llvm::StructType * StructureType
Definition: CGBlocks.h:236
std::string getNameAsString() const
getNameAsString - Get a human-readable name for the declaration, even if it is one of the special kin...
Definition: Decl.h:252
static void configureBlocksRuntimeObject(CodeGenModule &CGM, llvm::Constant *C)
Adjust the declaration of something from the blocks API.
Definition: CGBlocks.cpp:2421
An aggregate value slot.
Definition: CGValue.h:456
const BlockByrefInfo & getBlockByrefInfo(const VarDecl *var)
BuildByrefInfo - This routine changes a __block variable declared as T x into:
Definition: CGBlocks.cpp:2190
A scoped helper to set the current debug location to the specified location or preferred location of ...
Definition: CGDebugInfo.h:617
bool isConversionFromLambda() const
Definition: Decl.h:3642
CanQualType VoidTy
Definition: ASTContext.h:963
llvm::DenseMap< const VarDecl *, Capture > Captures
The mapping of allocated indexes within the block.
Definition: CGBlocks.h:233
arg_range arguments()
Definition: Expr.h:2300
bool isObjCObjectPointerType() const
Definition: Type.h:5782
static bool isBlockPointer(Expr *Arg)
llvm::Constant * getBlockObjectDispose()
Definition: CGBlocks.cpp:2457
An aligned address.
Definition: Address.h:25
void StartFunction(GlobalDecl GD, QualType RetTy, llvm::Function *Fn, const CGFunctionInfo &FnInfo, const FunctionArgList &Args, SourceLocation Loc=SourceLocation(), SourceLocation StartLoc=SourceLocation())
Emit code for the start of a function.
ImplicitCastExpr - Allows us to explicitly represent implicit type conversions, which have no direct ...
Definition: Expr.h:2804
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1054
llvm::Value * getConstant() const
Definition: CGBlocks.h:188
const BlockExpr * getBlockExpr() const
Definition: CGBlocks.h:272
All available information about a concrete callee.
Definition: CGCall.h:66
virtual bool needsDispose() const
bool operator<(DeclarationName LHS, DeclarationName RHS)
Ordering on two declaration names.
VarDecl * getVariable() const
The variable being captured.
Definition: Decl.h:3533
unsigned CXXThisIndex
The field index of &#39;this&#39; within the block, if there is one.
Definition: CGBlocks.h:155
Assigning into this object requires a lifetime extension.
Definition: Type.h:152
static Destroyer destroyARCStrongImprecise
void FinishFunction(SourceLocation EndLoc=SourceLocation())
FinishFunction - Complete IR generation of the current function.
const CGFunctionInfo & arrangeBlockFunctionCall(const CallArgList &args, const FunctionType *type)
A block function is essentially a free function with an extra implicit argument.
Definition: CGCall.cpp:603
std::pair< CharUnits, CharUnits > getTypeInfoInChars(const Type *T) const
ConstantAddress GetAddrOfConstantCString(const std::string &Str, const char *GlobalName=nullptr)
Returns a pointer to a character array containing the literal and a terminating &#39;\0&#39; character...
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:276
bool isObjCGCWeak() const
true when Type is objc&#39;s weak.
Definition: Type.h:1018
static llvm::Constant * tryCaptureAsConstant(CodeGenModule &CGM, CodeGenFunction *CGF, const VarDecl *var)
It is illegal to modify a const object after initialization.
Definition: CGBlocks.cpp:266
CGFunctionInfo - Class to encapsulate the information about a function definition.
This class organizes the cross-function state that is used while generating LLVM code.
CharUnits alignmentAtOffset(CharUnits offset) const
Given that this is a non-zero alignment value, what is the alignment at the given offset...
Definition: CharUnits.h:190
/file This file defines classes for searching and anlyzing source code clones.
virtual llvm::Constant * BuildGCBlockLayout(CodeGen::CodeGenModule &CGM, const CodeGen::CGBlockInfo &blockInfo)=0
static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF, CGBlockInfo &info)
Compute the layout of the given block.
Definition: CGBlocks.cpp:336
llvm::FoldingSet< BlockByrefHelpers > ByrefHelpersCache
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1176
ArrayRef< Capture > captures() const
Definition: Decl.h:3633
bool isNested() const
Whether this is a nested capture, i.e.
Definition: Decl.h:3541
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Definition: ASTMatchers.h:2126
Address CreateStructGEP(Address Addr, unsigned Index, CharUnits Offset, const llvm::Twine &Name="")
Definition: CGBuilder.h:165
static llvm::Constant * buildDisposeHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to dispose of a block.
Definition: CGBlocks.cpp:58
const Expr * getInit() const
Definition: Decl.h:1141
llvm::Constant * getPointer() const
Definition: Address.h:84
std::unique_ptr< DiagnosticConsumer > create(StringRef OutputFile, DiagnosticOptions *Diags, bool MergeChildRecords=false)
Returns a DiagnosticConsumer that serializes diagnostics to a bitcode file.
llvm::LoadInst * CreateLoad(Address Addr, const llvm::Twine &Name="")
Definition: CGBuilder.h:70
int printf(__constant const char *st,...)
bool hasObjCLifetime() const
Definition: Type.h:308
llvm::StoreInst * CreateStore(llvm::Value *Val, Address Addr, bool IsVolatile=false)
Definition: CGBuilder.h:108
llvm::Module & getModule() const
llvm::StructType * Type
Definition: CGBlocks.h:142
llvm::DenseMap< const Decl *, Address > DeclMapTy
static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block)
Enter the scope of a block.
Definition: CGBlocks.cpp:578
Pointer to a block type.
Definition: Type.h:2326
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:3783
StructBuilder beginStruct(llvm::StructType *structTy=nullptr)
CanQualType UnsignedLongTy
Definition: ASTContext.h:972
unsigned getNumObjects() const
Definition: ExprCXX.h:2953
static llvm::Constant * buildByrefCopyHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the copy helper for a __block variable.
Definition: CGBlocks.cpp:1982
Base for LValueReferenceType and RValueReferenceType.
Definition: Type.h:2359
void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp)
Definition: CGExprCXX.cpp:624
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:673
virtual void emitDispose(CodeGenFunction &CGF, Address field)=0
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:33
llvm::Constant * getBlockObjectAssign()
Definition: CGBlocks.cpp:2469
llvm::Constant * EmitConstantInit(const VarDecl &D, CodeGenFunction *CGF=nullptr)
Try to emit the initializer for the given declaration as a constant; returns 0 if the expression cann...
char __ovld __cnfn max(char x, char y)
Returns y if x < y, otherwise it returns x.
const Decl * CurFuncDecl
CurFuncDecl - Holds the Decl for the current outermost non-closure context.
A pair of helper functions for a __block variable.
bool capturesCXXThis() const
Definition: Decl.h:3638
Reading or writing from this object requires a barrier call.
Definition: Type.h:149
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:956
Represents a C++ struct/union/class.
Definition: DeclCXX.h:267
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:5514
void setAddrOfGlobalBlock(const BlockExpr *BE, llvm::Constant *Addr)
Notes that BE&#39;s global block is available via Addr.
Definition: CGBlocks.cpp:1097
CharUnits BlockHeaderForcedGapSize
Definition: CGBlocks.h:249
llvm::Value * EmitARCRetainBlock(llvm::Value *value, bool mandatory)
Retain the given block, with _Block_copy semantics.
Definition: CGObjC.cpp:1995
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2206
StringRef getName() const
getName - Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:237
TranslationUnitDecl - The top declaration context.
Definition: Decl.h:80
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:953
static RValue get(llvm::Value *V)
Definition: CGValue.h:85
RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue)
Definition: CGBlocks.cpp:996
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF)
Set the IRBuilder to not attach debug locations.
Definition: CGDebugInfo.h:665
llvm::Constant * getNSConcreteGlobalBlock()
Definition: CGBlocks.cpp:2481
llvm::Type * getBlockDescriptorType()
Fetches the type of a generic block descriptor.
Definition: CGBlocks.cpp:944
llvm::Constant * GetAddrOfGlobalBlock(const BlockExpr *BE, StringRef Name)
Gets the address of a block which requires no captures.
Definition: CGBlocks.cpp:1105
QualType getType() const
Definition: Decl.h:589
An l-value expression is a reference to an object with independent storage.
Definition: Specifiers.h:110
Information for lazily generating a cleanup.
Definition: EHScopeStack.h:147
NamedDecl - This represents a decl with a name.
Definition: Decl.h:213
llvm::Instruction * DominatingIP
An instruction which dominates the full-expression that the block is inside.
Definition: CGBlocks.h:253
unsigned long ulong
An unsigned 64-bit integer.
Definition: opencl-c.h:52
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2312
static bool isObjCNSObjectType(QualType Ty)
Return true if this is an NSObject object with its NSObject attribute set.
Definition: ASTContext.h:1900
SourceLocation getLocStart() const LLVM_READONLY
Definition: Stmt.cpp:257
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:182
const LangOptions & getLangOpts() const
Definition: ASTContext.h:659
Address emitBlockByrefAddress(Address baseAddr, const VarDecl *V, bool followForward=true)
BuildBlockByrefAddress - Computes the location of the data in a variable which is declared as __block...
Definition: CGBlocks.cpp:2153
Abstract information about a function or function prototype.
Definition: CGCall.h:44
SourceLocation getLocation() const
Definition: DeclBase.h:388
void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags)
Definition: CGBlocks.cpp:2385
void setCleanup(EHScopeStack::stable_iterator cleanup)
Definition: CGBlocks.h:183
static OMPLinearClause * Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc, OpenMPLinearClauseKind Modifier, SourceLocation ModifierLoc, SourceLocation ColonLoc, SourceLocation EndLoc, ArrayRef< Expr *> VL, ArrayRef< Expr *> PL, ArrayRef< Expr *> IL, Expr *Step, Expr *CalcStep, Stmt *PreInit, Expr *PostUpdate)
Creates clause with a list of variables VL and a linear step Step.
void Destroyer(CodeGenFunction &CGF, Address addr, QualType ty)
Qualifiers::ObjCLifetime getObjCLifetime() const
Returns lifetime attribute of this type.
Definition: Type.h:1028
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1509