clang  6.0.0svn
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"
19 #include "ConstantEmitter.h"
21 #include "clang/AST/DeclObjC.h"
22 #include "llvm/ADT/SmallSet.h"
23 #include "llvm/IR/CallSite.h"
24 #include "llvm/IR/DataLayout.h"
25 #include "llvm/IR/Module.h"
26 #include <algorithm>
27 #include <cstdio>
28 
29 using namespace clang;
30 using namespace CodeGen;
31 
32 CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
33  : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
34  HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
35  LocalAddress(Address::invalid()), StructureType(nullptr), Block(block),
36  DominatingIP(nullptr) {
37 
38  // Skip asm prefix, if any. 'name' is usually taken directly from
39  // the mangled name of the enclosing function.
40  if (!name.empty() && name[0] == '\01')
41  name = name.substr(1);
42 }
43 
44 // Anchor the vtable to this translation unit.
46 
47 /// Build the given block as a global block.
48 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
49  const CGBlockInfo &blockInfo,
50  llvm::Constant *blockFn);
51 
52 /// Build the helper function to copy a block.
53 static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
54  const CGBlockInfo &blockInfo) {
55  return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
56 }
57 
58 /// Build the helper function to dispose of a block.
59 static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
60  const CGBlockInfo &blockInfo) {
61  return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
62 }
63 
64 /// buildBlockDescriptor - Build the block descriptor meta-data for a block.
65 /// buildBlockDescriptor is accessed from 5th field of the Block_literal
66 /// meta-data and contains stationary information about the block literal.
67 /// Its definition will have 4 (or optinally 6) words.
68 /// \code
69 /// struct Block_descriptor {
70 /// unsigned long reserved;
71 /// unsigned long size; // size of Block_literal metadata in bytes.
72 /// void *copy_func_helper_decl; // optional copy helper.
73 /// void *destroy_func_decl; // optioanl destructor helper.
74 /// void *block_method_encoding_address; // @encode for block literal signature.
75 /// void *block_layout_info; // encoding of captured block variables.
76 /// };
77 /// \endcode
78 static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
79  const CGBlockInfo &blockInfo) {
80  ASTContext &C = CGM.getContext();
81 
82  llvm::IntegerType *ulong =
83  cast<llvm::IntegerType>(CGM.getTypes().ConvertType(C.UnsignedLongTy));
84  llvm::PointerType *i8p = nullptr;
85  if (CGM.getLangOpts().OpenCL)
86  i8p =
87  llvm::Type::getInt8PtrTy(
89  else
90  i8p = CGM.VoidPtrTy;
91 
92  ConstantInitBuilder builder(CGM);
93  auto elements = builder.beginStruct();
94 
95  // reserved
96  elements.addInt(ulong, 0);
97 
98  // Size
99  // FIXME: What is the right way to say this doesn't fit? We should give
100  // a user diagnostic in that case. Better fix would be to change the
101  // API to size_t.
102  elements.addInt(ulong, blockInfo.BlockSize.getQuantity());
103 
104  // Optional copy/dispose helpers.
105  if (blockInfo.NeedsCopyDispose) {
106  // copy_func_helper_decl
107  elements.add(buildCopyHelper(CGM, blockInfo));
108 
109  // destroy_func_decl
110  elements.add(buildDisposeHelper(CGM, blockInfo));
111  }
112 
113  // Signature. Mandatory ObjC-style method descriptor @encode sequence.
114  std::string typeAtEncoding =
116  elements.add(llvm::ConstantExpr::getBitCast(
117  CGM.GetAddrOfConstantCString(typeAtEncoding).getPointer(), i8p));
118 
119  // GC layout.
120  if (C.getLangOpts().ObjC1) {
121  if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
122  elements.add(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
123  else
124  elements.add(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
125  }
126  else
127  elements.addNullPointer(i8p);
128 
129  unsigned AddrSpace = 0;
130  if (C.getLangOpts().OpenCL)
132 
133  llvm::GlobalVariable *global =
134  elements.finishAndCreateGlobal("__block_descriptor_tmp",
135  CGM.getPointerAlign(),
136  /*constant*/ true,
138  AddrSpace);
139 
140  return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
141 }
142 
143 /*
144  Purely notional variadic template describing the layout of a block.
145 
146  template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
147  struct Block_literal {
148  /// Initialized to one of:
149  /// extern void *_NSConcreteStackBlock[];
150  /// extern void *_NSConcreteGlobalBlock[];
151  ///
152  /// In theory, we could start one off malloc'ed by setting
153  /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
154  /// this isa:
155  /// extern void *_NSConcreteMallocBlock[];
156  struct objc_class *isa;
157 
158  /// These are the flags (with corresponding bit number) that the
159  /// compiler is actually supposed to know about.
160  /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
161  /// descriptor provides copy and dispose helper functions
162  /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
163  /// object with a nontrivial destructor or copy constructor
164  /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
165  /// as global memory
166  /// 29. BLOCK_USE_STRET - indicates that the block function
167  /// uses stret, which objc_msgSend needs to know about
168  /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
169  /// @encoded signature string
170  /// And we're not supposed to manipulate these:
171  /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
172  /// to malloc'ed memory
173  /// 27. BLOCK_IS_GC - indicates that the block has been moved to
174  /// to GC-allocated memory
175  /// Additionally, the bottom 16 bits are a reference count which
176  /// should be zero on the stack.
177  int flags;
178 
179  /// Reserved; should be zero-initialized.
180  int reserved;
181 
182  /// Function pointer generated from block literal.
183  _ResultType (*invoke)(Block_literal *, _ParamTypes...);
184 
185  /// Block description metadata generated from block literal.
186  struct Block_descriptor *block_descriptor;
187 
188  /// Captured values follow.
189  _CapturesTypes captures...;
190  };
191  */
192 
193 namespace {
194  /// A chunk of data that we actually have to capture in the block.
195  struct BlockLayoutChunk {
196  CharUnits Alignment;
197  CharUnits Size;
198  Qualifiers::ObjCLifetime Lifetime;
199  const BlockDecl::Capture *Capture; // null for 'this'
200  llvm::Type *Type;
201  QualType FieldType;
202 
203  BlockLayoutChunk(CharUnits align, CharUnits size,
204  Qualifiers::ObjCLifetime lifetime,
205  const BlockDecl::Capture *capture,
206  llvm::Type *type, QualType fieldType)
207  : Alignment(align), Size(size), Lifetime(lifetime),
208  Capture(capture), Type(type), FieldType(fieldType) {}
209 
210  /// Tell the block info that this chunk has the given field index.
211  void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
212  if (!Capture) {
213  info.CXXThisIndex = index;
214  info.CXXThisOffset = offset;
215  } else {
216  auto C = CGBlockInfo::Capture::makeIndex(index, offset, FieldType);
217  info.Captures.insert({Capture->getVariable(), C});
218  }
219  }
220  };
221 
222  /// Order by 1) all __strong together 2) next, all byfref together 3) next,
223  /// all __weak together. Preserve descending alignment in all situations.
224  bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
225  if (left.Alignment != right.Alignment)
226  return left.Alignment > right.Alignment;
227 
228  auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
229  if (chunk.Capture && chunk.Capture->isByRef())
230  return 1;
231  if (chunk.Lifetime == Qualifiers::OCL_Strong)
232  return 0;
233  if (chunk.Lifetime == Qualifiers::OCL_Weak)
234  return 2;
235  return 3;
236  };
237 
238  return getPrefOrder(left) < getPrefOrder(right);
239  }
240 } // end anonymous namespace
241 
242 /// Determines if the given type is safe for constant capture in C++.
244  const RecordType *recordType =
246 
247  // Only records can be unsafe.
248  if (!recordType) return true;
249 
250  const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
251 
252  // Maintain semantics for classes with non-trivial dtors or copy ctors.
253  if (!record->hasTrivialDestructor()) return false;
254  if (record->hasNonTrivialCopyConstructor()) return false;
255 
256  // Otherwise, we just have to make sure there aren't any mutable
257  // fields that might have changed since initialization.
258  return !record->hasMutableFields();
259 }
260 
261 /// It is illegal to modify a const object after initialization.
262 /// Therefore, if a const object has a constant initializer, we don't
263 /// actually need to keep storage for it in the block; we'll just
264 /// rematerialize it at the start of the block function. This is
265 /// acceptable because we make no promises about address stability of
266 /// captured variables.
267 static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
268  CodeGenFunction *CGF,
269  const VarDecl *var) {
270  // Return if this is a function parameter. We shouldn't try to
271  // rematerialize default arguments of function parameters.
272  if (isa<ParmVarDecl>(var))
273  return nullptr;
274 
275  QualType type = var->getType();
276 
277  // We can only do this if the variable is const.
278  if (!type.isConstQualified()) return nullptr;
279 
280  // Furthermore, in C++ we have to worry about mutable fields:
281  // C++ [dcl.type.cv]p4:
282  // Except that any class member declared mutable can be
283  // modified, any attempt to modify a const object during its
284  // lifetime results in undefined behavior.
285  if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
286  return nullptr;
287 
288  // If the variable doesn't have any initializer (shouldn't this be
289  // invalid?), it's not clear what we should do. Maybe capture as
290  // zero?
291  const Expr *init = var->getInit();
292  if (!init) return nullptr;
293 
294  return ConstantEmitter(CGM, CGF).tryEmitAbstractForInitializer(*var);
295 }
296 
297 /// Get the low bit of a nonzero character count. This is the
298 /// alignment of the nth byte if the 0th byte is universally aligned.
300  return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
301 }
302 
304  SmallVectorImpl<llvm::Type*> &elementTypes) {
305  // The header is basically 'struct { void *; int; int; void *; void *; }'.
306  // Assert that that struct is packed.
307  assert(CGM.getIntSize() <= CGM.getPointerSize());
308  assert(CGM.getIntAlign() <= CGM.getPointerAlign());
309  assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()));
310 
311  info.BlockAlign = CGM.getPointerAlign();
312  info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
313 
314  assert(elementTypes.empty());
315  elementTypes.push_back(CGM.VoidPtrTy);
316  elementTypes.push_back(CGM.IntTy);
317  elementTypes.push_back(CGM.IntTy);
318  elementTypes.push_back(CGM.VoidPtrTy);
319  elementTypes.push_back(CGM.getBlockDescriptorType());
320 }
321 
323  const BlockDecl::Capture &CI) {
324  const VarDecl *VD = CI.getVariable();
325 
326  // If the variable is captured by an enclosing block or lambda expression,
327  // use the type of the capture field.
328  if (CGF.BlockInfo && CI.isNested())
329  return CGF.BlockInfo->getCapture(VD).fieldType();
330  if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
331  return FD->getType();
332  return VD->getType();
333 }
334 
335 /// Compute the layout of the given block. Attempts to lay the block
336 /// out with minimal space requirements.
338  CGBlockInfo &info) {
339  ASTContext &C = CGM.getContext();
340  const BlockDecl *block = info.getBlockDecl();
341 
342  SmallVector<llvm::Type*, 8> elementTypes;
343  initializeForBlockHeader(CGM, info, elementTypes);
344 
345  if (!block->hasCaptures()) {
346  info.StructureType =
347  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
348  info.CanBeGlobal = true;
349  return;
350  }
351  else if (C.getLangOpts().ObjC1 &&
352  CGM.getLangOpts().getGC() == LangOptions::NonGC)
353  info.HasCapturedVariableLayout = true;
354 
355  // Collect the layout chunks.
357  layout.reserve(block->capturesCXXThis() +
358  (block->capture_end() - block->capture_begin()));
359 
360  CharUnits maxFieldAlign;
361 
362  // First, 'this'.
363  if (block->capturesCXXThis()) {
364  assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&
365  "Can't capture 'this' outside a method");
366  QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType(C);
367 
368  // Theoretically, this could be in a different address space, so
369  // don't assume standard pointer size/align.
370  llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
371  std::pair<CharUnits,CharUnits> tinfo
372  = CGM.getContext().getTypeInfoInChars(thisType);
373  maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
374 
375  layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
377  nullptr, llvmType, thisType));
378  }
379 
380  // Next, all the block captures.
381  for (const auto &CI : block->captures()) {
382  const VarDecl *variable = CI.getVariable();
383 
384  if (CI.isByRef()) {
385  // We have to copy/dispose of the __block reference.
386  info.NeedsCopyDispose = true;
387 
388  // Just use void* instead of a pointer to the byref type.
389  CharUnits align = CGM.getPointerAlign();
390  maxFieldAlign = std::max(maxFieldAlign, align);
391 
392  layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
394  CGM.VoidPtrTy, variable->getType()));
395  continue;
396  }
397 
398  // Otherwise, build a layout chunk with the size and alignment of
399  // the declaration.
400  if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
401  info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
402  continue;
403  }
404 
405  // If we have a lifetime qualifier, honor it for capture purposes.
406  // That includes *not* copying it if it's __unsafe_unretained.
407  Qualifiers::ObjCLifetime lifetime =
408  variable->getType().getObjCLifetime();
409  if (lifetime) {
410  switch (lifetime) {
411  case Qualifiers::OCL_None: llvm_unreachable("impossible");
414  break;
415 
418  info.NeedsCopyDispose = true;
419  }
420 
421  // Block pointers require copy/dispose. So do Objective-C pointers.
422  } else if (variable->getType()->isObjCRetainableType()) {
423  // But honor the inert __unsafe_unretained qualifier, which doesn't
424  // actually make it into the type system.
425  if (variable->getType()->isObjCInertUnsafeUnretainedType()) {
426  lifetime = Qualifiers::OCL_ExplicitNone;
427  } else {
428  info.NeedsCopyDispose = true;
429  // used for mrr below.
430  lifetime = Qualifiers::OCL_Strong;
431  }
432 
433  // So do types that require non-trivial copy construction.
434  } else if (CI.hasCopyExpr()) {
435  info.NeedsCopyDispose = true;
436  info.HasCXXObject = true;
437 
438  // And so do types with destructors.
439  } else if (CGM.getLangOpts().CPlusPlus) {
440  if (const CXXRecordDecl *record =
441  variable->getType()->getAsCXXRecordDecl()) {
442  if (!record->hasTrivialDestructor()) {
443  info.HasCXXObject = true;
444  info.NeedsCopyDispose = true;
445  }
446  }
447  }
448 
449  QualType VT = getCaptureFieldType(*CGF, CI);
450  CharUnits size = C.getTypeSizeInChars(VT);
451  CharUnits align = C.getDeclAlign(variable);
452 
453  maxFieldAlign = std::max(maxFieldAlign, align);
454 
455  llvm::Type *llvmType =
456  CGM.getTypes().ConvertTypeForMem(VT);
457 
458  layout.push_back(
459  BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
460  }
461 
462  // If that was everything, we're done here.
463  if (layout.empty()) {
464  info.StructureType =
465  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
466  info.CanBeGlobal = true;
467  return;
468  }
469 
470  // Sort the layout by alignment. We have to use a stable sort here
471  // to get reproducible results. There should probably be an
472  // llvm::array_pod_stable_sort.
473  std::stable_sort(layout.begin(), layout.end());
474 
475  // Needed for blocks layout info.
478 
479  CharUnits &blockSize = info.BlockSize;
480  info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
481 
482  // Assuming that the first byte in the header is maximally aligned,
483  // get the alignment of the first byte following the header.
484  CharUnits endAlign = getLowBit(blockSize);
485 
486  // If the end of the header isn't satisfactorily aligned for the
487  // maximum thing, look for things that are okay with the header-end
488  // alignment, and keep appending them until we get something that's
489  // aligned right. This algorithm is only guaranteed optimal if
490  // that condition is satisfied at some point; otherwise we can get
491  // things like:
492  // header // next byte has alignment 4
493  // something_with_size_5; // next byte has alignment 1
494  // something_with_alignment_8;
495  // which has 7 bytes of padding, as opposed to the naive solution
496  // which might have less (?).
497  if (endAlign < maxFieldAlign) {
499  li = layout.begin() + 1, le = layout.end();
500 
501  // Look for something that the header end is already
502  // satisfactorily aligned for.
503  for (; li != le && endAlign < li->Alignment; ++li)
504  ;
505 
506  // If we found something that's naturally aligned for the end of
507  // the header, keep adding things...
508  if (li != le) {
510  for (; li != le; ++li) {
511  assert(endAlign >= li->Alignment);
512 
513  li->setIndex(info, elementTypes.size(), blockSize);
514  elementTypes.push_back(li->Type);
515  blockSize += li->Size;
516  endAlign = getLowBit(blockSize);
517 
518  // ...until we get to the alignment of the maximum field.
519  if (endAlign >= maxFieldAlign) {
520  break;
521  }
522  }
523  // Don't re-append everything we just appended.
524  layout.erase(first, li);
525  }
526  }
527 
528  assert(endAlign == getLowBit(blockSize));
529 
530  // At this point, we just have to add padding if the end align still
531  // isn't aligned right.
532  if (endAlign < maxFieldAlign) {
533  CharUnits newBlockSize = blockSize.alignTo(maxFieldAlign);
534  CharUnits padding = newBlockSize - blockSize;
535 
536  // If we haven't yet added any fields, remember that there was an
537  // initial gap; this need to go into the block layout bit map.
538  if (blockSize == info.BlockHeaderForcedGapOffset) {
539  info.BlockHeaderForcedGapSize = padding;
540  }
541 
542  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
543  padding.getQuantity()));
544  blockSize = newBlockSize;
545  endAlign = getLowBit(blockSize); // might be > maxFieldAlign
546  }
547 
548  assert(endAlign >= maxFieldAlign);
549  assert(endAlign == getLowBit(blockSize));
550  // Slam everything else on now. This works because they have
551  // strictly decreasing alignment and we expect that size is always a
552  // multiple of alignment.
554  li = layout.begin(), le = layout.end(); li != le; ++li) {
555  if (endAlign < li->Alignment) {
556  // size may not be multiple of alignment. This can only happen with
557  // an over-aligned variable. We will be adding a padding field to
558  // make the size be multiple of alignment.
559  CharUnits padding = li->Alignment - endAlign;
560  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
561  padding.getQuantity()));
562  blockSize += padding;
563  endAlign = getLowBit(blockSize);
564  }
565  assert(endAlign >= li->Alignment);
566  li->setIndex(info, elementTypes.size(), blockSize);
567  elementTypes.push_back(li->Type);
568  blockSize += li->Size;
569  endAlign = getLowBit(blockSize);
570  }
571 
572  info.StructureType =
573  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
574 }
575 
576 /// Enter the scope of a block. This should be run at the entrance to
577 /// a full-expression so that the block's cleanups are pushed at the
578 /// right place in the stack.
579 static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
580  assert(CGF.HaveInsertPoint());
581 
582  // Allocate the block info and place it at the head of the list.
583  CGBlockInfo &blockInfo =
584  *new CGBlockInfo(block, CGF.CurFn->getName());
585  blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
586  CGF.FirstBlockInfo = &blockInfo;
587 
588  // Compute information about the layout, etc., of this block,
589  // pushing cleanups as necessary.
590  computeBlockInfo(CGF.CGM, &CGF, blockInfo);
591 
592  // Nothing else to do if it can be global.
593  if (blockInfo.CanBeGlobal) return;
594 
595  // Make the allocation for the block.
596  blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
597  blockInfo.BlockAlign, "block");
598 
599  // If there are cleanups to emit, enter them (but inactive).
600  if (!blockInfo.NeedsCopyDispose) return;
601 
602  // Walk through the captures (in order) and find the ones not
603  // captured by constant.
604  for (const auto &CI : block->captures()) {
605  // Ignore __block captures; there's nothing special in the
606  // on-stack block that we need to do for them.
607  if (CI.isByRef()) continue;
608 
609  // Ignore variables that are constant-captured.
610  const VarDecl *variable = CI.getVariable();
611  CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
612  if (capture.isConstant()) continue;
613 
614  // Ignore objects that aren't destructed.
615  QualType VT = getCaptureFieldType(CGF, CI);
617  if (dtorKind == QualType::DK_none) continue;
618 
619  CodeGenFunction::Destroyer *destroyer;
620 
621  // Block captures count as local values and have imprecise semantics.
622  // They also can't be arrays, so need to worry about that.
623  //
624  // For const-qualified captures, emit clang.arc.use to ensure the captured
625  // object doesn't get released while we are still depending on its validity
626  // within the block.
627  if (VT.isConstQualified() &&
629  CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
630  assert(CGF.CGM.getLangOpts().ObjCAutoRefCount &&
631  "expected ObjC ARC to be enabled");
633  } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
635  } else {
636  destroyer = CGF.getDestroyer(dtorKind);
637  }
638 
639  // GEP down to the address.
640  Address addr = CGF.Builder.CreateStructGEP(blockInfo.LocalAddress,
641  capture.getIndex(),
642  capture.getOffset());
643 
644  // We can use that GEP as the dominating IP.
645  if (!blockInfo.DominatingIP)
646  blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
647 
648  CleanupKind cleanupKind = InactiveNormalCleanup;
649  bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
650  if (useArrayEHCleanup)
651  cleanupKind = InactiveNormalAndEHCleanup;
652 
653  CGF.pushDestroy(cleanupKind, addr, VT,
654  destroyer, useArrayEHCleanup);
655 
656  // Remember where that cleanup was.
657  capture.setCleanup(CGF.EHStack.stable_begin());
658  }
659 }
660 
661 /// Enter a full-expression with a non-trivial number of objects to
662 /// clean up. This is in this file because, at the moment, the only
663 /// kind of cleanup object is a BlockDecl*.
665  assert(E->getNumObjects() != 0);
668  i = cleanups.begin(), e = cleanups.end(); i != e; ++i) {
669  enterBlockScope(*this, *i);
670  }
671 }
672 
673 /// Find the layout for the given block in a linked list and remove it.
675  const BlockDecl *block) {
676  while (true) {
677  assert(head && *head);
678  CGBlockInfo *cur = *head;
679 
680  // If this is the block we're looking for, splice it out of the list.
681  if (cur->getBlockDecl() == block) {
682  *head = cur->NextBlockInfo;
683  return cur;
684  }
685 
686  head = &cur->NextBlockInfo;
687  }
688 }
689 
690 /// Destroy a chain of block layouts.
692  assert(head && "destroying an empty chain");
693  do {
694  CGBlockInfo *cur = head;
695  head = cur->NextBlockInfo;
696  delete cur;
697  } while (head != nullptr);
698 }
699 
700 /// Emit a block literal expression in the current function.
702  // If the block has no captures, we won't have a pre-computed
703  // layout for it.
704  if (!blockExpr->getBlockDecl()->hasCaptures()) {
705  if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr))
706  return Block;
707  CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
708  computeBlockInfo(CGM, this, blockInfo);
709  blockInfo.BlockExpression = blockExpr;
710  return EmitBlockLiteral(blockInfo);
711  }
712 
713  // Find the block info for this block and take ownership of it.
714  std::unique_ptr<CGBlockInfo> blockInfo;
715  blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
716  blockExpr->getBlockDecl()));
717 
718  blockInfo->BlockExpression = blockExpr;
719  return EmitBlockLiteral(*blockInfo);
720 }
721 
723  // Using the computed layout, generate the actual block function.
724  bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
725  llvm::Constant *blockFn
726  = CodeGenFunction(CGM, true).GenerateBlockFunction(CurGD, blockInfo,
727  LocalDeclMap,
728  isLambdaConv,
729  blockInfo.CanBeGlobal);
730  blockFn = llvm::ConstantExpr::getBitCast(blockFn, VoidPtrTy);
731 
732  // If there is nothing to capture, we can emit this as a global block.
733  if (blockInfo.CanBeGlobal)
734  return CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression);
735 
736  // Otherwise, we have to emit this as a local block.
737 
738  llvm::Constant *isa =
739  (!CGM.getContext().getLangOpts().OpenCL)
741  : CGM.getNullPointer(VoidPtrPtrTy,
743  QualType(CGM.getContext().VoidPtrTy)));
744  isa = llvm::ConstantExpr::getBitCast(isa, VoidPtrTy);
745 
746  // Build the block descriptor.
747  llvm::Constant *descriptor = buildBlockDescriptor(CGM, blockInfo);
748 
749  Address blockAddr = blockInfo.LocalAddress;
750  assert(blockAddr.isValid() && "block has no address!");
751 
752  // Compute the initial on-stack block flags.
755  if (blockInfo.NeedsCopyDispose) flags |= BLOCK_HAS_COPY_DISPOSE;
756  if (blockInfo.HasCXXObject) flags |= BLOCK_HAS_CXX_OBJ;
757  if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET;
758 
759  auto projectField =
760  [&](unsigned index, CharUnits offset, const Twine &name) -> Address {
761  return Builder.CreateStructGEP(blockAddr, index, offset, name);
762  };
763  auto storeField =
764  [&](llvm::Value *value, unsigned index, CharUnits offset,
765  const Twine &name) {
766  Builder.CreateStore(value, projectField(index, offset, name));
767  };
768 
769  // Initialize the block header.
770  {
771  // We assume all the header fields are densely packed.
772  unsigned index = 0;
773  CharUnits offset;
774  auto addHeaderField =
775  [&](llvm::Value *value, CharUnits size, const Twine &name) {
776  storeField(value, index, offset, name);
777  offset += size;
778  index++;
779  };
780 
781  addHeaderField(isa, getPointerSize(), "block.isa");
782  addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
783  getIntSize(), "block.flags");
784  addHeaderField(llvm::ConstantInt::get(IntTy, 0),
785  getIntSize(), "block.reserved");
786  addHeaderField(blockFn, getPointerSize(), "block.invoke");
787  addHeaderField(descriptor, getPointerSize(), "block.descriptor");
788  }
789 
790  // Finally, capture all the values into the block.
791  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
792 
793  // First, 'this'.
794  if (blockDecl->capturesCXXThis()) {
795  Address addr = projectField(blockInfo.CXXThisIndex, blockInfo.CXXThisOffset,
796  "block.captured-this.addr");
797  Builder.CreateStore(LoadCXXThis(), addr);
798  }
799 
800  // Next, captured variables.
801  for (const auto &CI : blockDecl->captures()) {
802  const VarDecl *variable = CI.getVariable();
803  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
804 
805  // Ignore constant captures.
806  if (capture.isConstant()) continue;
807 
808  QualType type = capture.fieldType();
809 
810  // This will be a [[type]]*, except that a byref entry will just be
811  // an i8**.
812  Address blockField =
813  projectField(capture.getIndex(), capture.getOffset(), "block.captured");
814 
815  // Compute the address of the thing we're going to move into the
816  // block literal.
817  Address src = Address::invalid();
818 
819  if (blockDecl->isConversionFromLambda()) {
820  // The lambda capture in a lambda's conversion-to-block-pointer is
821  // special; we'll simply emit it directly.
822  src = Address::invalid();
823  } else if (CI.isByRef()) {
824  if (BlockInfo && CI.isNested()) {
825  // We need to use the capture from the enclosing block.
826  const CGBlockInfo::Capture &enclosingCapture =
827  BlockInfo->getCapture(variable);
828 
829  // This is a [[type]]*, except that a byref entry wil just be an i8**.
830  src = Builder.CreateStructGEP(LoadBlockStruct(),
831  enclosingCapture.getIndex(),
832  enclosingCapture.getOffset(),
833  "block.capture.addr");
834  } else {
835  auto I = LocalDeclMap.find(variable);
836  assert(I != LocalDeclMap.end());
837  src = I->second;
838  }
839  } else {
840  DeclRefExpr declRef(const_cast<VarDecl *>(variable),
841  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
843  SourceLocation());
844  src = EmitDeclRefLValue(&declRef).getAddress();
845  };
846 
847  // For byrefs, we just write the pointer to the byref struct into
848  // the block field. There's no need to chase the forwarding
849  // pointer at this point, since we're building something that will
850  // live a shorter life than the stack byref anyway.
851  if (CI.isByRef()) {
852  // Get a void* that points to the byref struct.
853  llvm::Value *byrefPointer;
854  if (CI.isNested())
855  byrefPointer = Builder.CreateLoad(src, "byref.capture");
856  else
857  byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
858 
859  // Write that void* into the capture field.
860  Builder.CreateStore(byrefPointer, blockField);
861 
862  // If we have a copy constructor, evaluate that into the block field.
863  } else if (const Expr *copyExpr = CI.getCopyExpr()) {
864  if (blockDecl->isConversionFromLambda()) {
865  // If we have a lambda conversion, emit the expression
866  // directly into the block instead.
867  AggValueSlot Slot =
868  AggValueSlot::forAddr(blockField, Qualifiers(),
872  EmitAggExpr(copyExpr, Slot);
873  } else {
874  EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
875  }
876 
877  // If it's a reference variable, copy the reference into the block field.
878  } else if (type->isReferenceType()) {
879  Builder.CreateStore(src.getPointer(), blockField);
880 
881  // If type is const-qualified, copy the value into the block field.
882  } else if (type.isConstQualified() &&
884  CGM.getCodeGenOpts().OptimizationLevel != 0) {
885  llvm::Value *value = Builder.CreateLoad(src, "captured");
886  Builder.CreateStore(value, blockField);
887 
888  // If this is an ARC __strong block-pointer variable, don't do a
889  // block copy.
890  //
891  // TODO: this can be generalized into the normal initialization logic:
892  // we should never need to do a block-copy when initializing a local
893  // variable, because the local variable's lifetime should be strictly
894  // contained within the stack block's.
895  } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
896  type->isBlockPointerType()) {
897  // Load the block and do a simple retain.
898  llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
899  value = EmitARCRetainNonBlock(value);
900 
901  // Do a primitive store to the block field.
902  Builder.CreateStore(value, blockField);
903 
904  // Otherwise, fake up a POD copy into the block field.
905  } else {
906  // Fake up a new variable so that EmitScalarInit doesn't think
907  // we're referring to the variable in its own initializer.
908  ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
910 
911  // We use one of these or the other depending on whether the
912  // reference is nested.
913  DeclRefExpr declRef(const_cast<VarDecl *>(variable),
914  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
916 
917  ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
918  &declRef, VK_RValue);
919  // FIXME: Pass a specific location for the expr init so that the store is
920  // attributed to a reasonable location - otherwise it may be attributed to
921  // locations of subexpressions in the initialization.
922  LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
923  EmitExprAsInit(&l2r, &BlockFieldPseudoVar,
924  MakeAddrLValue(blockField, type, BaseInfo),
925  /*captured by init*/ false);
926  }
927 
928  // Activate the cleanup if layout pushed one.
929  if (!CI.isByRef()) {
931  if (cleanup.isValid())
932  ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
933  }
934  }
935 
936  // Cast to the converted block-pointer type, which happens (somewhat
937  // unfortunately) to be a pointer to function type.
938  llvm::Value *result = Builder.CreatePointerCast(
939  blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
940 
941  return result;
942 }
943 
944 
946  if (BlockDescriptorType)
947  return BlockDescriptorType;
948 
949  llvm::Type *UnsignedLongTy =
950  getTypes().ConvertType(getContext().UnsignedLongTy);
951 
952  // struct __block_descriptor {
953  // unsigned long reserved;
954  // unsigned long block_size;
955  //
956  // // later, the following will be added
957  //
958  // struct {
959  // void (*copyHelper)();
960  // void (*copyHelper)();
961  // } helpers; // !!! optional
962  //
963  // const char *signature; // the block signature
964  // const char *layout; // reserved
965  // };
966  BlockDescriptorType = llvm::StructType::create(
967  "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
968 
969  // Now form a pointer to that.
970  unsigned AddrSpace = 0;
971  if (getLangOpts().OpenCL)
972  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
973  BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
974  return BlockDescriptorType;
975 }
976 
978  if (GenericBlockLiteralType)
979  return GenericBlockLiteralType;
980 
981  llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
982 
983  // struct __block_literal_generic {
984  // void *__isa;
985  // int __flags;
986  // int __reserved;
987  // void (*__invoke)(void *);
988  // struct __block_descriptor *__descriptor;
989  // };
990  GenericBlockLiteralType =
991  llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
992  IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
993 
994  return GenericBlockLiteralType;
995 }
996 
998  ReturnValueSlot ReturnValue) {
999  const BlockPointerType *BPT =
1001 
1002  llvm::Value *BlockPtr = EmitScalarExpr(E->getCallee());
1003 
1004  // Get a pointer to the generic block literal.
1005  // For OpenCL we generate generic AS void ptr to be able to reuse the same
1006  // block definition for blocks with captures generated as private AS local
1007  // variables and without captures generated as global AS program scope
1008  // variables.
1009  unsigned AddrSpace = 0;
1010  if (getLangOpts().OpenCL)
1011  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_generic);
1012 
1013  llvm::Type *BlockLiteralTy =
1014  llvm::PointerType::get(CGM.getGenericBlockLiteralType(), AddrSpace);
1015 
1016  // Bitcast the callee to a block literal.
1017  BlockPtr =
1018  Builder.CreatePointerCast(BlockPtr, BlockLiteralTy, "block.literal");
1019 
1020  // Get the function pointer from the literal.
1021  llvm::Value *FuncPtr =
1022  Builder.CreateStructGEP(CGM.getGenericBlockLiteralType(), BlockPtr, 3);
1023 
1024 
1025  // Add the block literal.
1026  CallArgList Args;
1027 
1028  QualType VoidPtrQualTy = getContext().VoidPtrTy;
1029  llvm::Type *GenericVoidPtrTy = VoidPtrTy;
1030  if (getLangOpts().OpenCL) {
1031  GenericVoidPtrTy = Builder.getInt8PtrTy(
1032  getContext().getTargetAddressSpace(LangAS::opencl_generic));
1033  VoidPtrQualTy =
1034  getContext().getPointerType(getContext().getAddrSpaceQualType(
1035  getContext().VoidTy, LangAS::opencl_generic));
1036  }
1037 
1038  BlockPtr = Builder.CreatePointerCast(BlockPtr, GenericVoidPtrTy);
1039  Args.add(RValue::get(BlockPtr), VoidPtrQualTy);
1040 
1041  QualType FnType = BPT->getPointeeType();
1042 
1043  // And the rest of the arguments.
1044  EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1045 
1046  // Load the function.
1047  llvm::Value *Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1048 
1049  const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1050  const CGFunctionInfo &FnInfo =
1051  CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
1052 
1053  // Cast the function pointer to the right type.
1054  llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
1055 
1056  llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
1057  Func = Builder.CreateBitCast(Func, BlockFTyPtr);
1058 
1059  // Prepare the callee.
1060  CGCallee Callee(CGCalleeInfo(), Func);
1061 
1062  // And call the block.
1063  return EmitCall(FnInfo, Callee, ReturnValue, Args);
1064 }
1065 
1067  bool isByRef) {
1068  assert(BlockInfo && "evaluating block ref without block information?");
1069  const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1070 
1071  // Handle constant captures.
1072  if (capture.isConstant()) return LocalDeclMap.find(variable)->second;
1073 
1074  Address addr =
1075  Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(),
1076  capture.getOffset(), "block.capture.addr");
1077 
1078  if (isByRef) {
1079  // addr should be a void** right now. Load, then cast the result
1080  // to byref*.
1081 
1082  auto &byrefInfo = getBlockByrefInfo(variable);
1083  addr = Address(Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
1084 
1085  auto byrefPointerType = llvm::PointerType::get(byrefInfo.Type, 0);
1086  addr = Builder.CreateBitCast(addr, byrefPointerType, "byref.addr");
1087 
1088  addr = emitBlockByrefAddress(addr, byrefInfo, /*follow*/ true,
1089  variable->getName());
1090  }
1091 
1092  if (auto refType = capture.fieldType()->getAs<ReferenceType>())
1093  addr = EmitLoadOfReference(addr, refType);
1094 
1095  return addr;
1096 }
1097 
1099  llvm::Constant *Addr) {
1100  bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
1101  (void)Ok;
1102  assert(Ok && "Trying to replace an already-existing global block!");
1103 }
1104 
1105 llvm::Constant *
1107  StringRef Name) {
1108  if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1109  return Block;
1110 
1111  CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1112  blockInfo.BlockExpression = BE;
1113 
1114  // Compute information about the layout, etc., of this block.
1115  computeBlockInfo(*this, nullptr, blockInfo);
1116 
1117  // Using that metadata, generate the actual block function.
1118  {
1119  CodeGenFunction::DeclMapTy LocalDeclMap;
1121  GlobalDecl(), blockInfo, LocalDeclMap,
1122  /*IsLambdaConversionToBlock*/ false, /*BuildGlobalBlock*/ true);
1123  }
1124 
1125  return getAddrOfGlobalBlockIfEmitted(BE);
1126 }
1127 
1128 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1129  const CGBlockInfo &blockInfo,
1130  llvm::Constant *blockFn) {
1131  assert(blockInfo.CanBeGlobal);
1132  // Callers should detect this case on their own: calling this function
1133  // generally requires computing layout information, which is a waste of time
1134  // if we've already emitted this block.
1135  assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&
1136  "Refusing to re-emit a global block.");
1137 
1138  // Generate the constants for the block literal initializer.
1139  ConstantInitBuilder builder(CGM);
1140  auto fields = builder.beginStruct();
1141 
1142  // isa
1143  fields.add((!CGM.getContext().getLangOpts().OpenCL)
1144  ? CGM.getNSConcreteGlobalBlock()
1145  : CGM.getNullPointer(CGM.VoidPtrPtrTy,
1147  CGM.getContext().VoidPtrTy))));
1148 
1149  // __flags
1151  if (blockInfo.UsesStret) flags |= BLOCK_USE_STRET;
1152 
1153  fields.addInt(CGM.IntTy, flags.getBitMask());
1154 
1155  // Reserved
1156  fields.addInt(CGM.IntTy, 0);
1157 
1158  // Function
1159  fields.add(blockFn);
1160 
1161  // Descriptor
1162  fields.add(buildBlockDescriptor(CGM, blockInfo));
1163 
1164  unsigned AddrSpace = 0;
1165  if (CGM.getContext().getLangOpts().OpenCL)
1167 
1168  llvm::Constant *literal = fields.finishAndCreateGlobal(
1169  "__block_literal_global", blockInfo.BlockAlign,
1170  /*constant*/ true, llvm::GlobalVariable::InternalLinkage, AddrSpace);
1171 
1172  // Return a constant of the appropriately-casted type.
1173  llvm::Type *RequiredType =
1174  CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1175  llvm::Constant *Result =
1176  llvm::ConstantExpr::getPointerCast(literal, RequiredType);
1177  CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
1178  return Result;
1179 }
1180 
1182  unsigned argNum,
1183  llvm::Value *arg) {
1184  assert(BlockInfo && "not emitting prologue of block invocation function?!");
1185 
1186  llvm::Value *localAddr = nullptr;
1187  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1188  // Allocate a stack slot to let the debug info survive the RA.
1189  Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr");
1190  Builder.CreateStore(arg, alloc);
1191  localAddr = Builder.CreateLoad(alloc);
1192  }
1193 
1194  if (CGDebugInfo *DI = getDebugInfo()) {
1195  if (CGM.getCodeGenOpts().getDebugInfo() >=
1197  DI->setLocation(D->getLocation());
1198  DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, arg, argNum,
1199  localAddr, Builder);
1200  }
1201  }
1202 
1203  SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getLocStart();
1204  ApplyDebugLocation Scope(*this, StartLoc);
1205 
1206  // Instead of messing around with LocalDeclMap, just set the value
1207  // directly as BlockPointer.
1208  BlockPointer = Builder.CreatePointerCast(
1209  arg,
1210  BlockInfo->StructureType->getPointerTo(
1211  getContext().getLangOpts().OpenCL
1212  ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1213  : 0),
1214  "block");
1215 }
1216 
1218  assert(BlockInfo && "not in a block invocation function!");
1219  assert(BlockPointer && "no block pointer set!");
1220  return Address(BlockPointer, BlockInfo->BlockAlign);
1221 }
1222 
1223 llvm::Function *
1225  const CGBlockInfo &blockInfo,
1226  const DeclMapTy &ldm,
1227  bool IsLambdaConversionToBlock,
1228  bool BuildGlobalBlock) {
1229  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1230 
1231  CurGD = GD;
1232 
1233  CurEHLocation = blockInfo.getBlockExpr()->getLocEnd();
1234 
1235  BlockInfo = &blockInfo;
1236 
1237  // Arrange for local static and local extern declarations to appear
1238  // to be local to this function as well, in case they're directly
1239  // referenced in a block.
1240  for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1241  const auto *var = dyn_cast<VarDecl>(i->first);
1242  if (var && !var->hasLocalStorage())
1243  setAddrOfLocalVar(var, i->second);
1244  }
1245 
1246  // Begin building the function declaration.
1247 
1248  // Build the argument list.
1249  FunctionArgList args;
1250 
1251  // The first argument is the block pointer. Just take it as a void*
1252  // and cast it later.
1253  QualType selfTy = getContext().VoidPtrTy;
1254 
1255  // For OpenCL passed block pointer can be private AS local variable or
1256  // global AS program scope variable (for the case with and without captures).
1257  // Generic AS is used therefore to be able to accommodate both private and
1258  // generic AS in one implementation.
1259  if (getLangOpts().OpenCL)
1260  selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1261  getContext().VoidTy, LangAS::opencl_generic));
1262 
1263  IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1264 
1265  ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1266  SourceLocation(), II, selfTy,
1268  args.push_back(&SelfDecl);
1269 
1270  // Now add the rest of the parameters.
1271  args.append(blockDecl->param_begin(), blockDecl->param_end());
1272 
1273  // Create the function declaration.
1274  const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1275  const CGFunctionInfo &fnInfo =
1276  CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1277  if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1278  blockInfo.UsesStret = true;
1279 
1280  llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1281 
1282  StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1283  llvm::Function *fn = llvm::Function::Create(
1284  fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1285  CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1286 
1287  if (BuildGlobalBlock)
1288  buildGlobalBlock(CGM, blockInfo,
1289  llvm::ConstantExpr::getBitCast(fn, VoidPtrTy));
1290 
1291  // Begin generating the function.
1292  StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1293  blockDecl->getLocation(),
1294  blockInfo.getBlockExpr()->getBody()->getLocStart());
1295 
1296  // Okay. Undo some of what StartFunction did.
1297 
1298  // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1299  // won't delete the dbg.declare intrinsics for captured variables.
1300  llvm::Value *BlockPointerDbgLoc = BlockPointer;
1301  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1302  // Allocate a stack slot for it, so we can point the debugger to it
1303  Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1304  getPointerAlign(),
1305  "block.addr");
1306  // Set the DebugLocation to empty, so the store is recognized as a
1307  // frame setup instruction by llvm::DwarfDebug::beginFunction().
1308  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1309  Builder.CreateStore(BlockPointer, Alloca);
1310  BlockPointerDbgLoc = Alloca.getPointer();
1311  }
1312 
1313  // If we have a C++ 'this' reference, go ahead and force it into
1314  // existence now.
1315  if (blockDecl->capturesCXXThis()) {
1316  Address addr =
1317  Builder.CreateStructGEP(LoadBlockStruct(), blockInfo.CXXThisIndex,
1318  blockInfo.CXXThisOffset, "block.captured-this");
1319  CXXThisValue = Builder.CreateLoad(addr, "this");
1320  }
1321 
1322  // Also force all the constant captures.
1323  for (const auto &CI : blockDecl->captures()) {
1324  const VarDecl *variable = CI.getVariable();
1325  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1326  if (!capture.isConstant()) continue;
1327 
1328  CharUnits align = getContext().getDeclAlign(variable);
1329  Address alloca =
1330  CreateMemTemp(variable->getType(), align, "block.captured-const");
1331 
1332  Builder.CreateStore(capture.getConstant(), alloca);
1333 
1334  setAddrOfLocalVar(variable, alloca);
1335  }
1336 
1337  // Save a spot to insert the debug information for all the DeclRefExprs.
1338  llvm::BasicBlock *entry = Builder.GetInsertBlock();
1339  llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1340  --entry_ptr;
1341 
1342  if (IsLambdaConversionToBlock)
1343  EmitLambdaBlockInvokeBody();
1344  else {
1345  PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1346  incrementProfileCounter(blockDecl->getBody());
1347  EmitStmt(blockDecl->getBody());
1348  }
1349 
1350  // Remember where we were...
1351  llvm::BasicBlock *resume = Builder.GetInsertBlock();
1352 
1353  // Go back to the entry.
1354  ++entry_ptr;
1355  Builder.SetInsertPoint(entry, entry_ptr);
1356 
1357  // Emit debug information for all the DeclRefExprs.
1358  // FIXME: also for 'this'
1359  if (CGDebugInfo *DI = getDebugInfo()) {
1360  for (const auto &CI : blockDecl->captures()) {
1361  const VarDecl *variable = CI.getVariable();
1362  DI->EmitLocation(Builder, variable->getLocation());
1363 
1364  if (CGM.getCodeGenOpts().getDebugInfo() >=
1366  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1367  if (capture.isConstant()) {
1368  auto addr = LocalDeclMap.find(variable)->second;
1369  DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1370  Builder);
1371  continue;
1372  }
1373 
1374  DI->EmitDeclareOfBlockDeclRefVariable(
1375  variable, BlockPointerDbgLoc, Builder, blockInfo,
1376  entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1377  }
1378  }
1379  // Recover location if it was changed in the above loop.
1380  DI->EmitLocation(Builder,
1381  cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1382  }
1383 
1384  // And resume where we left off.
1385  if (resume == nullptr)
1386  Builder.ClearInsertionPoint();
1387  else
1388  Builder.SetInsertPoint(resume);
1389 
1390  FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1391 
1392  return fn;
1393 }
1394 
1395 namespace {
1396 
1397 /// Represents a type of copy/destroy operation that should be performed for an
1398 /// entity that's captured by a block.
1400  CXXRecord, // Copy or destroy
1401  ARCWeak,
1402  ARCStrong,
1403  BlockObject, // Assign or release
1404  None
1405 };
1406 
1407 /// Represents a captured entity that requires extra operations in order for
1408 /// this entity to be copied or destroyed correctly.
1409 struct BlockCaptureManagedEntity {
1411  BlockFieldFlags Flags;
1412  const BlockDecl::Capture &CI;
1413  const CGBlockInfo::Capture &Capture;
1414 
1415  BlockCaptureManagedEntity(BlockCaptureEntityKind Type, BlockFieldFlags Flags,
1416  const BlockDecl::Capture &CI,
1417  const CGBlockInfo::Capture &Capture)
1418  : Kind(Type), Flags(Flags), CI(CI), Capture(Capture) {}
1419 };
1420 
1421 } // end anonymous namespace
1422 
1423 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1425  const LangOptions &LangOpts) {
1426  if (CI.getCopyExpr()) {
1427  assert(!CI.isByRef());
1428  // don't bother computing flags
1429  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1430  }
1431  BlockFieldFlags Flags;
1432  if (CI.isByRef()) {
1433  Flags = BLOCK_FIELD_IS_BYREF;
1434  if (T.isObjCGCWeak())
1435  Flags |= BLOCK_FIELD_IS_WEAK;
1436  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1437  }
1438  if (!T->isObjCRetainableType())
1439  // For all other types, the memcpy is fine.
1440  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1441 
1442  Flags = BLOCK_FIELD_IS_OBJECT;
1443  bool isBlockPointer = T->isBlockPointerType();
1444  if (isBlockPointer)
1445  Flags = BLOCK_FIELD_IS_BLOCK;
1446 
1447  // Special rules for ARC captures:
1448  Qualifiers QS = T.getQualifiers();
1449 
1450  // We need to register __weak direct captures with the runtime.
1452  return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1453 
1454  // We need to retain the copied value for __strong direct captures.
1456  // If it's a block pointer, we have to copy the block and
1457  // assign that to the destination pointer, so we might as
1458  // well use _Block_object_assign. Otherwise we can avoid that.
1459  return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1460  : BlockCaptureEntityKind::BlockObject,
1461  Flags);
1462  }
1463 
1464  // Non-ARC captures of retainable pointers are strong and
1465  // therefore require a call to _Block_object_assign.
1466  if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1467  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1468 
1469  // Otherwise the memcpy is fine.
1470  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1471 }
1472 
1473 /// Find the set of block captures that need to be explicitly copied or destroy.
1475  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1477  llvm::function_ref<std::pair<BlockCaptureEntityKind, BlockFieldFlags>(
1478  const BlockDecl::Capture &, QualType, const LangOptions &)>
1479  Predicate) {
1480  for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1481  const VarDecl *Variable = CI.getVariable();
1482  const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1483  if (Capture.isConstant())
1484  continue;
1485 
1486  auto Info = Predicate(CI, Variable->getType(), LangOpts);
1487  if (Info.first != BlockCaptureEntityKind::None)
1488  ManagedCaptures.emplace_back(Info.first, Info.second, CI, Capture);
1489  }
1490 }
1491 
1492 /// Generate the copy-helper function for a block closure object:
1493 /// static void block_copy_helper(block_t *dst, block_t *src);
1494 /// The runtime will have previously initialized 'dst' by doing a
1495 /// bit-copy of 'src'.
1496 ///
1497 /// Note that this copies an entire block closure object to the heap;
1498 /// it should not be confused with a 'byref copy helper', which moves
1499 /// the contents of an individual __block variable to the heap.
1500 llvm::Constant *
1502  ASTContext &C = getContext();
1503 
1504  FunctionArgList args;
1505  ImplicitParamDecl DstDecl(getContext(), C.VoidPtrTy,
1507  args.push_back(&DstDecl);
1508  ImplicitParamDecl SrcDecl(getContext(), C.VoidPtrTy,
1510  args.push_back(&SrcDecl);
1511 
1512  const CGFunctionInfo &FI =
1514 
1515  // FIXME: it would be nice if these were mergeable with things with
1516  // identical semantics.
1517  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1518 
1519  llvm::Function *Fn =
1521  "__copy_helper_block_", &CGM.getModule());
1522 
1523  IdentifierInfo *II
1524  = &CGM.getContext().Idents.get("__copy_helper_block_");
1525 
1528  SourceLocation(),
1529  SourceLocation(), II, C.VoidTy,
1530  nullptr, SC_Static,
1531  false,
1532  false);
1533 
1534  CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
1535 
1536  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1537  StartFunction(FD, C.VoidTy, Fn, FI, args);
1538  // Create a scope with an artificial location for the body of this function.
1539  auto AL = ApplyDebugLocation::CreateArtificial(*this);
1540  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1541 
1542  Address src = GetAddrOfLocalVar(&SrcDecl);
1543  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
1544  src = Builder.CreateBitCast(src, structPtrTy, "block.source");
1545 
1546  Address dst = GetAddrOfLocalVar(&DstDecl);
1547  dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
1548  dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
1549 
1551  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures,
1553 
1554  for (const auto &CopiedCapture : CopiedCaptures) {
1555  const BlockDecl::Capture &CI = CopiedCapture.CI;
1556  const CGBlockInfo::Capture &capture = CopiedCapture.Capture;
1557  BlockFieldFlags flags = CopiedCapture.Flags;
1558 
1559  unsigned index = capture.getIndex();
1560  Address srcField = Builder.CreateStructGEP(src, index, capture.getOffset());
1561  Address dstField = Builder.CreateStructGEP(dst, index, capture.getOffset());
1562 
1563  // If there's an explicit copy expression, we do that.
1564  if (CI.getCopyExpr()) {
1565  assert(CopiedCapture.Kind == BlockCaptureEntityKind::CXXRecord);
1566  EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
1567  } else if (CopiedCapture.Kind == BlockCaptureEntityKind::ARCWeak) {
1568  EmitARCCopyWeak(dstField, srcField);
1569  } else {
1570  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
1571  if (CopiedCapture.Kind == BlockCaptureEntityKind::ARCStrong) {
1572  // At -O0, store null into the destination field (so that the
1573  // storeStrong doesn't over-release) and then call storeStrong.
1574  // This is a workaround to not having an initStrong call.
1575  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1576  auto *ty = cast<llvm::PointerType>(srcValue->getType());
1577  llvm::Value *null = llvm::ConstantPointerNull::get(ty);
1578  Builder.CreateStore(null, dstField);
1579  EmitARCStoreStrongCall(dstField, srcValue, true);
1580 
1581  // With optimization enabled, take advantage of the fact that
1582  // the blocks runtime guarantees a memcpy of the block data, and
1583  // just emit a retain of the src field.
1584  } else {
1585  EmitARCRetainNonBlock(srcValue);
1586 
1587  // We don't need this anymore, so kill it. It's not quite
1588  // worth the annoyance to avoid creating it in the first place.
1589  cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
1590  }
1591  } else {
1592  assert(CopiedCapture.Kind == BlockCaptureEntityKind::BlockObject);
1593  srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
1594  llvm::Value *dstAddr =
1595  Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
1596  llvm::Value *args[] = {
1597  dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
1598  };
1599 
1600  const VarDecl *variable = CI.getVariable();
1601  bool copyCanThrow = false;
1602  if (CI.isByRef() && variable->getType()->getAsCXXRecordDecl()) {
1603  const Expr *copyExpr =
1604  CGM.getContext().getBlockVarCopyInits(variable);
1605  if (copyExpr) {
1606  copyCanThrow = true; // FIXME: reuse the noexcept logic
1607  }
1608  }
1609 
1610  if (copyCanThrow) {
1611  EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
1612  } else {
1613  EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
1614  }
1615  }
1616  }
1617  }
1618 
1619  FinishFunction();
1620 
1621  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1622 }
1623 
1624 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1626  const LangOptions &LangOpts) {
1627  BlockFieldFlags Flags;
1628  if (CI.isByRef()) {
1629  Flags = BLOCK_FIELD_IS_BYREF;
1630  if (T.isObjCGCWeak())
1631  Flags |= BLOCK_FIELD_IS_WEAK;
1632  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1633  }
1634 
1635  if (const CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
1636  if (Record->hasTrivialDestructor())
1637  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1638  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1639  }
1640 
1641  // Other types don't need to be destroy explicitly.
1642  if (!T->isObjCRetainableType())
1643  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1644 
1645  Flags = BLOCK_FIELD_IS_OBJECT;
1646  if (T->isBlockPointerType())
1647  Flags = BLOCK_FIELD_IS_BLOCK;
1648 
1649  // Special rules for ARC captures.
1650  Qualifiers QS = T.getQualifiers();
1651 
1652  // Use objc_storeStrong for __strong direct captures; the
1653  // dynamic tools really like it when we do this.
1655  return std::make_pair(BlockCaptureEntityKind::ARCStrong, Flags);
1656 
1657  // Support __weak direct captures.
1659  return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1660 
1661  // Non-ARC captures are strong, and we need to use
1662  // _Block_object_dispose.
1663  if (!QS.hasObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1664  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1665 
1666  // Otherwise, we have nothing to do.
1667  return std::make_pair(BlockCaptureEntityKind::None, Flags);
1668 }
1669 
1670 /// Generate the destroy-helper function for a block closure object:
1671 /// static void block_destroy_helper(block_t *theBlock);
1672 ///
1673 /// Note that this destroys a heap-allocated block closure object;
1674 /// it should not be confused with a 'byref destroy helper', which
1675 /// destroys the heap-allocated contents of an individual __block
1676 /// variable.
1677 llvm::Constant *
1679  ASTContext &C = getContext();
1680 
1681  FunctionArgList args;
1682  ImplicitParamDecl SrcDecl(getContext(), C.VoidPtrTy,
1684  args.push_back(&SrcDecl);
1685 
1686  const CGFunctionInfo &FI =
1688 
1689  // FIXME: We'd like to put these into a mergable by content, with
1690  // internal linkage.
1691  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
1692 
1693  llvm::Function *Fn =
1695  "__destroy_helper_block_", &CGM.getModule());
1696 
1697  IdentifierInfo *II
1698  = &CGM.getContext().Idents.get("__destroy_helper_block_");
1699 
1701  SourceLocation(),
1702  SourceLocation(), II, C.VoidTy,
1703  nullptr, SC_Static,
1704  false, false);
1705 
1706  CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
1707 
1708  // Create a scope with an artificial location for the body of this function.
1709  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1710  StartFunction(FD, C.VoidTy, Fn, FI, args);
1711  auto AL = ApplyDebugLocation::CreateArtificial(*this);
1712 
1713  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
1714 
1715  Address src = GetAddrOfLocalVar(&SrcDecl);
1716  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
1717  src = Builder.CreateBitCast(src, structPtrTy, "block");
1718 
1719  CodeGenFunction::RunCleanupsScope cleanups(*this);
1720 
1722  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures,
1724 
1725  for (const auto &DestroyedCapture : DestroyedCaptures) {
1726  const BlockDecl::Capture &CI = DestroyedCapture.CI;
1727  const CGBlockInfo::Capture &capture = DestroyedCapture.Capture;
1728  BlockFieldFlags flags = DestroyedCapture.Flags;
1729 
1730  Address srcField =
1731  Builder.CreateStructGEP(src, capture.getIndex(), capture.getOffset());
1732 
1733  // If the captured record has a destructor then call it.
1734  if (DestroyedCapture.Kind == BlockCaptureEntityKind::CXXRecord) {
1735  const auto *Dtor =
1737  PushDestructorCleanup(Dtor, srcField);
1738 
1739  // If this is a __weak capture, emit the release directly.
1740  } else if (DestroyedCapture.Kind == BlockCaptureEntityKind::ARCWeak) {
1741  EmitARCDestroyWeak(srcField);
1742 
1743  // Destroy strong objects with a call if requested.
1744  } else if (DestroyedCapture.Kind == BlockCaptureEntityKind::ARCStrong) {
1745  EmitARCDestroyStrong(srcField, ARCImpreciseLifetime);
1746 
1747  // Otherwise we call _Block_object_dispose. It wouldn't be too
1748  // hard to just emit this as a cleanup if we wanted to make sure
1749  // that things were done in reverse.
1750  } else {
1751  assert(DestroyedCapture.Kind == BlockCaptureEntityKind::BlockObject);
1752  llvm::Value *value = Builder.CreateLoad(srcField);
1753  value = Builder.CreateBitCast(value, VoidPtrTy);
1754  BuildBlockRelease(value, flags);
1755  }
1756  }
1757 
1758  cleanups.ForceCleanup();
1759 
1760  FinishFunction();
1761 
1762  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
1763 }
1764 
1765 namespace {
1766 
1767 /// Emits the copy/dispose helper functions for a __block object of id type.
1768 class ObjectByrefHelpers final : public BlockByrefHelpers {
1769  BlockFieldFlags Flags;
1770 
1771 public:
1772  ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
1773  : BlockByrefHelpers(alignment), Flags(flags) {}
1774 
1775  void emitCopy(CodeGenFunction &CGF, Address destField,
1776  Address srcField) override {
1777  destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
1778 
1779  srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
1780  llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
1781 
1782  unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
1783 
1784  llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
1785  llvm::Value *fn = CGF.CGM.getBlockObjectAssign();
1786 
1787  llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
1788  CGF.EmitNounwindRuntimeCall(fn, args);
1789  }
1790 
1791  void emitDispose(CodeGenFunction &CGF, Address field) override {
1792  field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
1793  llvm::Value *value = CGF.Builder.CreateLoad(field);
1794 
1795  CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER);
1796  }
1797 
1798  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1799  id.AddInteger(Flags.getBitMask());
1800  }
1801 };
1802 
1803 /// Emits the copy/dispose helpers for an ARC __block __weak variable.
1804 class ARCWeakByrefHelpers final : public BlockByrefHelpers {
1805 public:
1806  ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
1807 
1808  void emitCopy(CodeGenFunction &CGF, Address destField,
1809  Address srcField) override {
1810  CGF.EmitARCMoveWeak(destField, srcField);
1811  }
1812 
1813  void emitDispose(CodeGenFunction &CGF, Address field) override {
1814  CGF.EmitARCDestroyWeak(field);
1815  }
1816 
1817  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1818  // 0 is distinguishable from all pointers and byref flags
1819  id.AddInteger(0);
1820  }
1821 };
1822 
1823 /// Emits the copy/dispose helpers for an ARC __block __strong variable
1824 /// that's not of block-pointer type.
1825 class ARCStrongByrefHelpers final : public BlockByrefHelpers {
1826 public:
1827  ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
1828 
1829  void emitCopy(CodeGenFunction &CGF, Address destField,
1830  Address srcField) override {
1831  // Do a "move" by copying the value and then zeroing out the old
1832  // variable.
1833 
1834  llvm::Value *value = CGF.Builder.CreateLoad(srcField);
1835 
1836  llvm::Value *null =
1837  llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
1838 
1839  if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
1840  CGF.Builder.CreateStore(null, destField);
1841  CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
1842  CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
1843  return;
1844  }
1845  CGF.Builder.CreateStore(value, destField);
1846  CGF.Builder.CreateStore(null, srcField);
1847  }
1848 
1849  void emitDispose(CodeGenFunction &CGF, Address field) override {
1851  }
1852 
1853  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1854  // 1 is distinguishable from all pointers and byref flags
1855  id.AddInteger(1);
1856  }
1857 };
1858 
1859 /// Emits the copy/dispose helpers for an ARC __block __strong
1860 /// variable that's of block-pointer type.
1861 class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
1862 public:
1863  ARCStrongBlockByrefHelpers(CharUnits alignment)
1864  : BlockByrefHelpers(alignment) {}
1865 
1866  void emitCopy(CodeGenFunction &CGF, Address destField,
1867  Address srcField) override {
1868  // Do the copy with objc_retainBlock; that's all that
1869  // _Block_object_assign would do anyway, and we'd have to pass the
1870  // right arguments to make sure it doesn't get no-op'ed.
1871  llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
1872  llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
1873  CGF.Builder.CreateStore(copy, destField);
1874  }
1875 
1876  void emitDispose(CodeGenFunction &CGF, Address field) override {
1878  }
1879 
1880  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1881  // 2 is distinguishable from all pointers and byref flags
1882  id.AddInteger(2);
1883  }
1884 };
1885 
1886 /// Emits the copy/dispose helpers for a __block variable with a
1887 /// nontrivial copy constructor or destructor.
1888 class CXXByrefHelpers final : public BlockByrefHelpers {
1889  QualType VarType;
1890  const Expr *CopyExpr;
1891 
1892 public:
1893  CXXByrefHelpers(CharUnits alignment, QualType type,
1894  const Expr *copyExpr)
1895  : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
1896 
1897  bool needsCopy() const override { return CopyExpr != nullptr; }
1898  void emitCopy(CodeGenFunction &CGF, Address destField,
1899  Address srcField) override {
1900  if (!CopyExpr) return;
1901  CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
1902  }
1903 
1904  void emitDispose(CodeGenFunction &CGF, Address field) override {
1905  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
1906  CGF.PushDestructorCleanup(VarType, field);
1907  CGF.PopCleanupBlocks(cleanupDepth);
1908  }
1909 
1910  void profileImpl(llvm::FoldingSetNodeID &id) const override {
1911  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
1912  }
1913 };
1914 } // end anonymous namespace
1915 
1916 static llvm::Constant *
1918  BlockByrefHelpers &generator) {
1919  ASTContext &Context = CGF.getContext();
1920 
1921  QualType R = Context.VoidTy;
1922 
1923  FunctionArgList args;
1924  ImplicitParamDecl Dst(CGF.getContext(), Context.VoidPtrTy,
1926  args.push_back(&Dst);
1927 
1928  ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
1930  args.push_back(&Src);
1931 
1932  const CGFunctionInfo &FI =
1934 
1935  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
1936 
1937  // FIXME: We'd like to put these into a mergable by content, with
1938  // internal linkage.
1939  llvm::Function *Fn =
1941  "__Block_byref_object_copy_", &CGF.CGM.getModule());
1942 
1943  IdentifierInfo *II
1944  = &Context.Idents.get("__Block_byref_object_copy_");
1945 
1946  FunctionDecl *FD = FunctionDecl::Create(Context,
1947  Context.getTranslationUnitDecl(),
1948  SourceLocation(),
1949  SourceLocation(), II, R, nullptr,
1950  SC_Static,
1951  false, false);
1952 
1953  CGF.CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
1954 
1955  CGF.StartFunction(FD, R, Fn, FI, args);
1956 
1957  if (generator.needsCopy()) {
1958  llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
1959 
1960  // dst->x
1961  Address destField = CGF.GetAddrOfLocalVar(&Dst);
1962  destField = Address(CGF.Builder.CreateLoad(destField),
1963  byrefInfo.ByrefAlignment);
1964  destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
1965  destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
1966  "dest-object");
1967 
1968  // src->x
1969  Address srcField = CGF.GetAddrOfLocalVar(&Src);
1970  srcField = Address(CGF.Builder.CreateLoad(srcField),
1971  byrefInfo.ByrefAlignment);
1972  srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
1973  srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
1974  "src-object");
1975 
1976  generator.emitCopy(CGF, destField, srcField);
1977  }
1978 
1979  CGF.FinishFunction();
1980 
1981  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
1982 }
1983 
1984 /// Build the copy helper for a __block variable.
1985 static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
1986  const BlockByrefInfo &byrefInfo,
1987  BlockByrefHelpers &generator) {
1988  CodeGenFunction CGF(CGM);
1989  return generateByrefCopyHelper(CGF, byrefInfo, generator);
1990 }
1991 
1992 /// Generate code for a __block variable's dispose helper.
1993 static llvm::Constant *
1995  const BlockByrefInfo &byrefInfo,
1996  BlockByrefHelpers &generator) {
1997  ASTContext &Context = CGF.getContext();
1998  QualType R = Context.VoidTy;
1999 
2000  FunctionArgList args;
2001  ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2003  args.push_back(&Src);
2004 
2005  const CGFunctionInfo &FI =
2007 
2008  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2009 
2010  // FIXME: We'd like to put these into a mergable by content, with
2011  // internal linkage.
2012  llvm::Function *Fn =
2014  "__Block_byref_object_dispose_",
2015  &CGF.CGM.getModule());
2016 
2017  IdentifierInfo *II
2018  = &Context.Idents.get("__Block_byref_object_dispose_");
2019 
2020  FunctionDecl *FD = FunctionDecl::Create(Context,
2021  Context.getTranslationUnitDecl(),
2022  SourceLocation(),
2023  SourceLocation(), II, R, nullptr,
2024  SC_Static,
2025  false, false);
2026 
2027  CGF.CGM.SetInternalFunctionAttributes(nullptr, Fn, FI);
2028 
2029  CGF.StartFunction(FD, R, Fn, FI, args);
2030 
2031  if (generator.needsDispose()) {
2032  Address addr = CGF.GetAddrOfLocalVar(&Src);
2033  addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2034  auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2035  addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2036  addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2037 
2038  generator.emitDispose(CGF, addr);
2039  }
2040 
2041  CGF.FinishFunction();
2042 
2043  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2044 }
2045 
2046 /// Build the dispose helper for a __block variable.
2047 static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2048  const BlockByrefInfo &byrefInfo,
2049  BlockByrefHelpers &generator) {
2050  CodeGenFunction CGF(CGM);
2051  return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2052 }
2053 
2054 /// Lazily build the copy and dispose helpers for a __block variable
2055 /// with the given information.
2056 template <class T>
2057 static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2058  T &&generator) {
2059  llvm::FoldingSetNodeID id;
2060  generator.Profile(id);
2061 
2062  void *insertPos;
2063  BlockByrefHelpers *node
2064  = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2065  if (node) return static_cast<T*>(node);
2066 
2067  generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2068  generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2069 
2070  T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2071  CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2072  return copy;
2073 }
2074 
2075 /// Build the copy and dispose helpers for the given __block variable
2076 /// emission. Places the helpers in the global cache. Returns null
2077 /// if no helpers are required.
2079 CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2080  const AutoVarEmission &emission) {
2081  const VarDecl &var = *emission.Variable;
2082  QualType type = var.getType();
2083 
2084  auto &byrefInfo = getBlockByrefInfo(&var);
2085 
2086  // The alignment we care about for the purposes of uniquing byref
2087  // helpers is the alignment of the actual byref value field.
2088  CharUnits valueAlignment =
2089  byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2090 
2091  if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2092  const Expr *copyExpr = CGM.getContext().getBlockVarCopyInits(&var);
2093  if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2094 
2096  CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2097  }
2098 
2099  // Otherwise, if we don't have a retainable type, there's nothing to do.
2100  // that the runtime does extra copies.
2101  if (!type->isObjCRetainableType()) return nullptr;
2102 
2103  Qualifiers qs = type.getQualifiers();
2104 
2105  // If we have lifetime, that dominates.
2106  if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2107  switch (lifetime) {
2108  case Qualifiers::OCL_None: llvm_unreachable("impossible");
2109 
2110  // These are just bits as far as the runtime is concerned.
2113  return nullptr;
2114 
2115  // Tell the runtime that this is ARC __weak, called by the
2116  // byref routines.
2117  case Qualifiers::OCL_Weak:
2118  return ::buildByrefHelpers(CGM, byrefInfo,
2119  ARCWeakByrefHelpers(valueAlignment));
2120 
2121  // ARC __strong __block variables need to be retained.
2123  // Block pointers need to be copied, and there's no direct
2124  // transfer possible.
2125  if (type->isBlockPointerType()) {
2126  return ::buildByrefHelpers(CGM, byrefInfo,
2127  ARCStrongBlockByrefHelpers(valueAlignment));
2128 
2129  // Otherwise, we transfer ownership of the retain from the stack
2130  // to the heap.
2131  } else {
2132  return ::buildByrefHelpers(CGM, byrefInfo,
2133  ARCStrongByrefHelpers(valueAlignment));
2134  }
2135  }
2136  llvm_unreachable("fell out of lifetime switch!");
2137  }
2138 
2139  BlockFieldFlags flags;
2140  if (type->isBlockPointerType()) {
2141  flags |= BLOCK_FIELD_IS_BLOCK;
2142  } else if (CGM.getContext().isObjCNSObjectType(type) ||
2143  type->isObjCObjectPointerType()) {
2144  flags |= BLOCK_FIELD_IS_OBJECT;
2145  } else {
2146  return nullptr;
2147  }
2148 
2149  if (type.isObjCGCWeak())
2150  flags |= BLOCK_FIELD_IS_WEAK;
2151 
2152  return ::buildByrefHelpers(CGM, byrefInfo,
2153  ObjectByrefHelpers(valueAlignment, flags));
2154 }
2155 
2157  const VarDecl *var,
2158  bool followForward) {
2159  auto &info = getBlockByrefInfo(var);
2160  return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2161 }
2162 
2164  const BlockByrefInfo &info,
2165  bool followForward,
2166  const llvm::Twine &name) {
2167  // Chase the forwarding address if requested.
2168  if (followForward) {
2169  Address forwardingAddr =
2170  Builder.CreateStructGEP(baseAddr, 1, getPointerSize(), "forwarding");
2171  baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2172  }
2173 
2174  return Builder.CreateStructGEP(baseAddr, info.FieldIndex,
2175  info.FieldOffset, name);
2176 }
2177 
2178 /// BuildByrefInfo - This routine changes a __block variable declared as T x
2179 /// into:
2180 ///
2181 /// struct {
2182 /// void *__isa;
2183 /// void *__forwarding;
2184 /// int32_t __flags;
2185 /// int32_t __size;
2186 /// void *__copy_helper; // only if needed
2187 /// void *__destroy_helper; // only if needed
2188 /// void *__byref_variable_layout;// only if needed
2189 /// char padding[X]; // only if needed
2190 /// T x;
2191 /// } x
2192 ///
2194  auto it = BlockByrefInfos.find(D);
2195  if (it != BlockByrefInfos.end())
2196  return it->second;
2197 
2198  llvm::StructType *byrefType =
2199  llvm::StructType::create(getLLVMContext(),
2200  "struct.__block_byref_" + D->getNameAsString());
2201 
2202  QualType Ty = D->getType();
2203 
2204  CharUnits size;
2206 
2207  // void *__isa;
2208  types.push_back(Int8PtrTy);
2209  size += getPointerSize();
2210 
2211  // void *__forwarding;
2212  types.push_back(llvm::PointerType::getUnqual(byrefType));
2213  size += getPointerSize();
2214 
2215  // int32_t __flags;
2216  types.push_back(Int32Ty);
2217  size += CharUnits::fromQuantity(4);
2218 
2219  // int32_t __size;
2220  types.push_back(Int32Ty);
2221  size += CharUnits::fromQuantity(4);
2222 
2223  // Note that this must match *exactly* the logic in buildByrefHelpers.
2224  bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2225  if (hasCopyAndDispose) {
2226  /// void *__copy_helper;
2227  types.push_back(Int8PtrTy);
2228  size += getPointerSize();
2229 
2230  /// void *__destroy_helper;
2231  types.push_back(Int8PtrTy);
2232  size += getPointerSize();
2233  }
2234 
2235  bool HasByrefExtendedLayout = false;
2236  Qualifiers::ObjCLifetime Lifetime;
2237  if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2238  HasByrefExtendedLayout) {
2239  /// void *__byref_variable_layout;
2240  types.push_back(Int8PtrTy);
2241  size += CharUnits::fromQuantity(PointerSizeInBytes);
2242  }
2243 
2244  // T x;
2245  llvm::Type *varTy = ConvertTypeForMem(Ty);
2246 
2247  bool packed = false;
2248  CharUnits varAlign = getContext().getDeclAlign(D);
2249  CharUnits varOffset = size.alignTo(varAlign);
2250 
2251  // We may have to insert padding.
2252  if (varOffset != size) {
2253  llvm::Type *paddingTy =
2254  llvm::ArrayType::get(Int8Ty, (varOffset - size).getQuantity());
2255 
2256  types.push_back(paddingTy);
2257  size = varOffset;
2258 
2259  // Conversely, we might have to prevent LLVM from inserting padding.
2260  } else if (CGM.getDataLayout().getABITypeAlignment(varTy)
2261  > varAlign.getQuantity()) {
2262  packed = true;
2263  }
2264  types.push_back(varTy);
2265 
2266  byrefType->setBody(types, packed);
2267 
2268  BlockByrefInfo info;
2269  info.Type = byrefType;
2270  info.FieldIndex = types.size() - 1;
2271  info.FieldOffset = varOffset;
2272  info.ByrefAlignment = std::max(varAlign, getPointerAlign());
2273 
2274  auto pair = BlockByrefInfos.insert({D, info});
2275  assert(pair.second && "info was inserted recursively?");
2276  return pair.first->second;
2277 }
2278 
2279 /// Initialize the structural components of a __block variable, i.e.
2280 /// everything but the actual object.
2282  // Find the address of the local.
2283  Address addr = emission.Addr;
2284 
2285  // That's an alloca of the byref structure type.
2286  llvm::StructType *byrefType = cast<llvm::StructType>(
2287  cast<llvm::PointerType>(addr.getPointer()->getType())->getElementType());
2288 
2289  unsigned nextHeaderIndex = 0;
2290  CharUnits nextHeaderOffset;
2291  auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2292  const Twine &name) {
2293  auto fieldAddr = Builder.CreateStructGEP(addr, nextHeaderIndex,
2294  nextHeaderOffset, name);
2295  Builder.CreateStore(value, fieldAddr);
2296 
2297  nextHeaderIndex++;
2298  nextHeaderOffset += fieldSize;
2299  };
2300 
2301  // Build the byref helpers if necessary. This is null if we don't need any.
2302  BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2303 
2304  const VarDecl &D = *emission.Variable;
2305  QualType type = D.getType();
2306 
2307  bool HasByrefExtendedLayout;
2308  Qualifiers::ObjCLifetime ByrefLifetime;
2309  bool ByRefHasLifetime =
2310  getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2311 
2312  llvm::Value *V;
2313 
2314  // Initialize the 'isa', which is just 0 or 1.
2315  int isa = 0;
2316  if (type.isObjCGCWeak())
2317  isa = 1;
2318  V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2319  storeHeaderField(V, getPointerSize(), "byref.isa");
2320 
2321  // Store the address of the variable into its own forwarding pointer.
2322  storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2323 
2324  // Blocks ABI:
2325  // c) the flags field is set to either 0 if no helper functions are
2326  // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2327  BlockFlags flags;
2328  if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2329  if (ByRefHasLifetime) {
2330  if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2331  else switch (ByrefLifetime) {
2333  flags |= BLOCK_BYREF_LAYOUT_STRONG;
2334  break;
2335  case Qualifiers::OCL_Weak:
2336  flags |= BLOCK_BYREF_LAYOUT_WEAK;
2337  break;
2340  break;
2341  case Qualifiers::OCL_None:
2342  if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2344  break;
2345  default:
2346  break;
2347  }
2348  if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2349  printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2350  if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2351  printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2352  if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2353  BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2354  if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2355  printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2356  if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2357  printf(" BLOCK_BYREF_LAYOUT_STRONG");
2358  if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2359  printf(" BLOCK_BYREF_LAYOUT_WEAK");
2360  if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2361  printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2362  if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2363  printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2364  }
2365  printf("\n");
2366  }
2367  }
2368  storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2369  getIntSize(), "byref.flags");
2370 
2371  CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2372  V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2373  storeHeaderField(V, getIntSize(), "byref.size");
2374 
2375  if (helpers) {
2376  storeHeaderField(helpers->CopyHelper, getPointerSize(),
2377  "byref.copyHelper");
2378  storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2379  "byref.disposeHelper");
2380  }
2381 
2382  if (ByRefHasLifetime && HasByrefExtendedLayout) {
2383  auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2384  storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2385  }
2386 }
2387 
2390  llvm::Value *args[] = {
2391  Builder.CreateBitCast(V, Int8PtrTy),
2392  llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2393  };
2394  EmitNounwindRuntimeCall(F, args); // FIXME: throwing destructors?
2395 }
2396 
2397 namespace {
2398  /// Release a __block variable.
2399  struct CallBlockRelease final : EHScopeStack::Cleanup {
2400  llvm::Value *Addr;
2401  CallBlockRelease(llvm::Value *Addr) : Addr(Addr) {}
2402 
2403  void Emit(CodeGenFunction &CGF, Flags flags) override {
2404  // Should we be passing FIELD_IS_WEAK here?
2406  }
2407  };
2408 } // end anonymous namespace
2409 
2410 /// Enter a cleanup to destroy a __block variable. Note that this
2411 /// cleanup should be a no-op if the variable hasn't left the stack
2412 /// yet; if a cleanup is required for the variable itself, that needs
2413 /// to be done externally.
2415  // We don't enter this cleanup if we're in pure-GC mode.
2416  if (CGM.getLangOpts().getGC() == LangOptions::GCOnly)
2417  return;
2418 
2419  EHStack.pushCleanup<CallBlockRelease>(NormalAndEHCleanup,
2420  emission.Addr.getPointer());
2421 }
2422 
2423 /// Adjust the declaration of something from the blocks API.
2425  llvm::Constant *C) {
2426  auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2427 
2428  if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2429  IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2432 
2433  assert((isa<llvm::Function>(C->stripPointerCasts()) ||
2434  isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&
2435  "expected Function or GlobalVariable");
2436 
2437  const NamedDecl *ND = nullptr;
2438  for (const auto &Result : DC->lookup(&II))
2439  if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2440  (ND = dyn_cast<VarDecl>(Result)))
2441  break;
2442 
2443  // TODO: support static blocks runtime
2444  if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2445  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2446  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2447  } else {
2448  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2449  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2450  }
2451  }
2452 
2453  if (!CGM.getLangOpts().BlocksRuntimeOptional)
2454  return;
2455 
2456  if (GV->isDeclaration() && GV->hasExternalLinkage())
2457  GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2458 }
2459 
2461  if (BlockObjectDispose)
2462  return BlockObjectDispose;
2463 
2464  llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2465  llvm::FunctionType *fty
2466  = llvm::FunctionType::get(VoidTy, args, false);
2467  BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2468  configureBlocksRuntimeObject(*this, BlockObjectDispose);
2469  return BlockObjectDispose;
2470 }
2471 
2473  if (BlockObjectAssign)
2474  return BlockObjectAssign;
2475 
2476  llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
2477  llvm::FunctionType *fty
2478  = llvm::FunctionType::get(VoidTy, args, false);
2479  BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
2480  configureBlocksRuntimeObject(*this, BlockObjectAssign);
2481  return BlockObjectAssign;
2482 }
2483 
2485  if (NSConcreteGlobalBlock)
2486  return NSConcreteGlobalBlock;
2487 
2488  NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
2489  Int8PtrTy->getPointerTo(),
2490  nullptr);
2491  configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
2492  return NSConcreteGlobalBlock;
2493 }
2494 
2496  if (NSConcreteStackBlock)
2497  return NSConcreteStackBlock;
2498 
2499  NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
2500  Int8PtrTy->getPointerTo(),
2501  nullptr);
2502  configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
2503  return NSConcreteStackBlock;
2504 }
const CGFunctionInfo & arrangeBuiltinFunctionDeclaration(QualType resultType, const FunctionArgList &args)
A builtin function is a freestanding function using the default C conventions.
Definition: CGCall.cpp:640
void enterNonTrivialFullExpression(const ExprWithCleanups *E)
Enter a full-expression with a non-trivial number of objects to clean up.
Definition: CGBlocks.cpp:664
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:4853
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:1501
static llvm::Constant * generateByrefDisposeHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Generate code for a __block variable&#39;s dispose helper.
Definition: CGBlocks.cpp:1994
FunctionDecl - An instance of this class is created to represent a function declaration or definition...
Definition: Decl.h:1629
llvm::IntegerType * IntTy
int
llvm::Type * getGenericBlockLiteralType()
The type of a generic block literal.
Definition: CGBlocks.cpp:977
const CGFunctionInfo & arrangeBlockFunctionDeclaration(const FunctionProtoType *type, const FunctionArgList &args)
Block invocation functions are C functions with an implicit parameter.
Definition: CGCall.cpp:614
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:61
Parameter for captured context.
Definition: Decl.h:1406
CharUnits BlockHeaderForcedGapOffset
Definition: CGBlocks.h:246
const FunctionProtoType * getFunctionType() const
getFunctionType - Return the underlying function type for this block.
Definition: Expr.cpp:1992
Expr * getCopyExpr() const
Definition: Decl.h:3618
static llvm::Constant * buildByrefDisposeHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the dispose helper for a __block variable.
Definition: CGBlocks.cpp:2047
A class which contains all the information about a particular captured value.
Definition: Decl.h:3586
CanQualType VoidPtrTy
Definition: ASTContext.h:979
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:1455
A (possibly-)qualified type.
Definition: Type.h:614
bool isBlockPointerType() const
Definition: Type.h:5728
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:3699
bool HaveInsertPoint() const
HaveInsertPoint - True if an insertion point is defined.
capture_const_iterator capture_begin() const
Definition: Decl.h:3709
llvm::LLVMContext & getLLVMContext()
void EmitARCDestroyWeak(Address addr)
void @objc_destroyWeak(i8** addr) Essentially objc_storeWeak(addr, nil).
Definition: CGObjC.cpp:2296
The standard implementation of ConstantInitBuilder used in Clang.
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:2920
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:781
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:2057
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:1968
ArrayRef< CleanupObject > getObjects() const
Definition: ExprCXX.h:2948
param_iterator param_end()
Definition: Decl.h:3681
static llvm::Constant * buildBlockDescriptor(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
buildBlockDescriptor - Build the block descriptor meta-data for a block.
Definition: CGBlocks.cpp:78
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:5672
The base class of the type hierarchy.
Definition: Type.h:1300
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:3710
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:769
CGBlockInfo(const BlockDecl *blockDecl, StringRef Name)
Definition: CGBlocks.cpp:32
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6052
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:1424
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:691
The collection of all-type qualifiers we support.
Definition: Type.h:116
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:2281
CGBlockInfo * FirstBlockInfo
FirstBlockInfo - The head of a singly-linked-list of block layouts.
QualType getPointeeType() const
Definition: Type.h:2338
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
llvm::Type * ConvertType(QualType T)
ConvertType - Convert type T into a llvm::Type.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:128
llvm::Constant * tryEmitAbstractForInitializer(const VarDecl &D)
Try to emit the initializer of the given declaration as an abstract constant.
bool HasCapturedVariableLayout
HasCapturedVariableLayout : True if block has captured variables and their layout meta-data has been ...
Definition: CGBlocks.h:230
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:1625
bool isReferenceType() const
Definition: Type.h:5731
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:1474
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:1917
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:3662
static bool isSafeForCXXConstantCapture(QualType type)
Determines if the given type is safe for constant capture in C++.
Definition: CGBlocks.cpp:243
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:107
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:651
llvm::Value * EmitARCStoreStrongCall(Address addr, llvm::Value *value, bool resultIgnored)
Store into a strong object.
Definition: CGObjC.cpp:2134
Address GetAddrOfBlockDecl(const VarDecl *var, bool ByRef)
Definition: CGBlocks.cpp:1066
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:38
void EmitARCDestroyStrong(Address addr, ARCPreciseLifetime_t precise)
Destroy a __strong variable.
Definition: CGObjC.cpp:2120
const BlockDecl * getBlockDecl() const
Definition: CGBlocks.h:271
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:701
uint32_t getBitMask() const
Definition: CGBlocks.h:117
bool isByRef() const
Whether this is a "by ref" capture, i.e.
Definition: Decl.h:3611
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:1437
llvm::AllocaInst * CreateTempAlloca(llvm::Type *Ty, const Twine &Name="tmp", llvm::Value *ArraySize=nullptr)
CreateTempAlloca - This creates an alloca and inserts it into the entry block if ArraySize is nullptr...
Definition: CGExpr.cpp:91
const Stmt * getBody() const
Definition: Expr.cpp:2001
llvm::Constant * getNSConcreteStackBlock()
Definition: CGBlocks.cpp:2495
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:1791
This object can be modified without requiring retains or releases.
Definition: Type.h:137
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:1507
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:53
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:1549
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3126
llvm::CallInst * EmitNounwindRuntimeCall(llvm::Value *callee, const Twine &name="")
uint32_t getBitMask() const
Definition: CGBlocks.h:73
const CodeGen::CGBlockInfo * BlockInfo
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:4863
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:303
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:3582
Expr - This represents one expression.
Definition: Expr.h:106
void EmitARCMoveWeak(Address dst, Address src)
void @objc_moveWeak(i8** dest, i8** src) Disregards the current value in dest.
Definition: CGObjC.cpp:2313
Emit only debug info necessary for generating line number tables (-gline-tables-only).
static Address invalid()
Definition: Address.h:35
Enters a new scope for capturing cleanups, all of which will be executed once the scope is exited...
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6115
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:3768
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:4839
BlockCaptureEntityKind
Represents a type of copy/destroy operation that should be performed for an entity that&#39;s captured by...
Definition: CGBlocks.cpp:1399
static llvm::Constant * buildGlobalBlock(CodeGenModule &CGM, const CGBlockInfo &blockInfo, llvm::Constant *blockFn)
Build the given block as a global block.
Definition: CGBlocks.cpp:1128
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:1678
const Expr * getCallee() const
Definition: Expr.h:2249
ObjCLifetime getObjCLifetime() const
Definition: Type.h:307
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:1485
static Capture makeIndex(unsigned index, CharUnits offset, QualType FieldType)
Definition: CGBlocks.h:197
QualType getType() const
Definition: Expr.h:128
bool isa(CodeGen::Address addr)
Definition: Address.h:112
bool isObjCInertUnsafeUnretainedType() const
Was this type written with the special inert-in-MRC __unsafe_unretained qualifier?
Definition: Type.cpp:519
static CharUnits getLowBit(CharUnits v)
Get the low bit of a nonzero character count.
Definition: CGBlocks.cpp:299
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:6010
const TargetInfo & getTarget() const
const LangOptions & getLangOpts() const
ASTContext & getContext() const
static AggValueSlot forAddr(Address addr, Qualifiers quals, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, IsZeroed_t isZeroed=IsNotZeroed)
forAddr - Make a slot for an aggregate value.
Definition: CGValue.h:517
do v
Definition: arm_acle.h:78
static QualType getCaptureFieldType(const CodeGenFunction &CGF, const BlockDecl::Capture &CI)
Definition: CGBlocks.cpp:322
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:5558
param_iterator param_begin()
Definition: Decl.h:3680
The l-value was considered opaque, so the alignment was determined from a type.
RecordDecl * getDecl() const
Definition: Type.h:3804
void setBlockContextParameter(const ImplicitParamDecl *D, unsigned argNum, llvm::Value *ptr)
Definition: CGBlocks.cpp:1181
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:2414
There is no lifetime qualification on this type.
Definition: Type.h:133
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:144
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:2333
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:1480
Encodes a location in the source.
static DeclContext * castToDeclContext(const TranslationUnitDecl *D)
Definition: Decl.h:99
QualType getReturnType() const
Definition: Type.h:3062
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:2424
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:2193
A scoped helper to set the current debug location to the specified location or preferred location of ...
Definition: CGDebugInfo.h:620
bool isConversionFromLambda() const
Definition: Decl.h:3716
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:2303
bool isObjCObjectPointerType() const
Definition: Type.h:5794
static bool isBlockPointer(Expr *Arg)
llvm::Constant * getBlockObjectDispose()
Definition: CGBlocks.cpp:2460
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:2817
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1052
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:3607
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:150
static Destroyer destroyARCStrongImprecise
void FinishFunction(SourceLocation EndLoc=SourceLocation())
FinishFunction - Complete IR generation of the current function.
const CGFunctionInfo & arrangeBlockFunctionCall(const CallArgList &args, const FunctionType *type)
A block function is essentially a free function with an extra implicit argument.
Definition: CGCall.cpp:607
std::pair< CharUnits, CharUnits > getTypeInfoInChars(const Type *T) const
ConstantAddress GetAddrOfConstantCString(const std::string &Str, const char *GlobalName=nullptr)
Returns a pointer to a character array containing the literal and a terminating &#39;\0&#39; character...
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:276
bool isObjCGCWeak() const
true when Type is objc&#39;s weak.
Definition: Type.h:1016
static llvm::Constant * tryCaptureAsConstant(CodeGenModule &CGM, CodeGenFunction *CGF, const VarDecl *var)
It is illegal to modify a const object after initialization.
Definition: CGBlocks.cpp:267
CGFunctionInfo - Class to encapsulate the information about a function definition.
This class organizes the cross-function state that is used while generating LLVM code.
CharUnits alignmentAtOffset(CharUnits offset) const
Given that this is a non-zero alignment value, what is the alignment at the given offset...
Definition: CharUnits.h:190
Dataflow Directional Tag Classes.
virtual llvm::Constant * BuildGCBlockLayout(CodeGen::CodeGenModule &CGM, const CodeGen::CGBlockInfo &blockInfo)=0
static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF, CGBlockInfo &info)
Compute the layout of the given block.
Definition: CGBlocks.cpp:337
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:1217
ArrayRef< Capture > captures() const
Definition: Decl.h:3707
bool isNested() const
Whether this is a nested capture, i.e.
Definition: Decl.h:3615
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Definition: ASTMatchers.h:2154
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:59
const Expr * getInit() const
Definition: Decl.h:1157
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:306
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:579
Pointer to a block type.
Definition: Type.h:2324
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:3795
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:1985
Base for LValueReferenceType and RValueReferenceType.
Definition: Type.h:2357
void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp)
Definition: CGExprCXX.cpp:626
static CGBlockInfo * findAndRemoveBlockInfo(CGBlockInfo **head, const BlockDecl *block)
Find the layout for the given block in a linked list and remove it.
Definition: CGBlocks.cpp:674
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:2472
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:3712
Reading or writing from this object requires a barrier call.
Definition: Type.h:147
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:956
Represents a C++ struct/union/class.
Definition: DeclCXX.h:266
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:5526
void setAddrOfGlobalBlock(const BlockExpr *BE, llvm::Constant *Addr)
Notes that BE&#39;s global block is available via Addr.
Definition: CGBlocks.cpp:1098
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
CharUnits BlockHeaderForcedGapSize
Definition: CGBlocks.h:249
llvm::Value * EmitARCRetainBlock(llvm::Value *value, bool mandatory)
Retain the given block, with _Block_copy semantics.
Definition: CGObjC.cpp:1993
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2209
StringRef getName() const
getName - Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:237
llvm::Function * GenerateBlockFunction(GlobalDecl GD, const CGBlockInfo &Info, const DeclMapTy &ldm, bool IsLambdaConversionToBlock, bool BuildGlobalBlock)
Definition: CGBlocks.cpp:1224
TranslationUnitDecl - The top declaration context.
Definition: Decl.h:80
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:956
static RValue get(llvm::Value *V)
Definition: CGValue.h:85
RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue)
Definition: CGBlocks.cpp:997
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF)
Set the IRBuilder to not attach debug locations.
Definition: CGDebugInfo.h:668
llvm::Constant * getNSConcreteGlobalBlock()
Definition: CGBlocks.cpp:2484
llvm::Type * getBlockDescriptorType()
Fetches the type of a generic block descriptor.
Definition: CGBlocks.cpp:945
llvm::Constant * GetAddrOfGlobalBlock(const BlockExpr *BE, StringRef Name)
Gets the address of a block which requires no captures.
Definition: CGBlocks.cpp:1106
QualType getType() const
Definition: Decl.h:600
An l-value expression is a reference to an object with independent storage.
Definition: Specifiers.h:111
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:2340
static bool isObjCNSObjectType(QualType Ty)
Return true if this is an NSObject object with its NSObject attribute set.
Definition: ASTContext.h:1923
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:2156
Abstract information about a function or function prototype.
Definition: CGCall.h:44
SourceLocation getLocation() const
Definition: DeclBase.h:407
void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags)
Definition: CGBlocks.cpp:2388
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:1026
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1524