clang  8.0.0
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 "CGCXXABI.h"
16 #include "CGDebugInfo.h"
17 #include "CGObjCRuntime.h"
18 #include "CGOpenCLRuntime.h"
19 #include "CodeGenFunction.h"
20 #include "CodeGenModule.h"
21 #include "ConstantEmitter.h"
22 #include "TargetInfo.h"
23 #include "clang/AST/DeclObjC.h"
25 #include "llvm/ADT/SmallSet.h"
26 #include "llvm/IR/CallSite.h"
27 #include "llvm/IR/DataLayout.h"
28 #include "llvm/IR/Module.h"
29 #include "llvm/Support/ScopedPrinter.h"
30 #include <algorithm>
31 #include <cstdio>
32 
33 using namespace clang;
34 using namespace CodeGen;
35 
36 CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
37  : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
38  HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
39  CapturesNonExternalType(false), LocalAddress(Address::invalid()),
40  StructureType(nullptr), Block(block), DominatingIP(nullptr) {
41 
42  // Skip asm prefix, if any. 'name' is usually taken directly from
43  // the mangled name of the enclosing function.
44  if (!name.empty() && name[0] == '\01')
45  name = name.substr(1);
46 }
47 
48 // Anchor the vtable to this translation unit.
50 
51 /// Build the given block as a global block.
52 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
53  const CGBlockInfo &blockInfo,
54  llvm::Constant *blockFn);
55 
56 /// Build the helper function to copy a block.
57 static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
58  const CGBlockInfo &blockInfo) {
59  return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
60 }
61 
62 /// Build the helper function to dispose of a block.
63 static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
64  const CGBlockInfo &blockInfo) {
65  return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
66 }
67 
68 namespace {
69 
70 /// Represents a type of copy/destroy operation that should be performed for an
71 /// entity that's captured by a block.
73  CXXRecord, // Copy or destroy
74  ARCWeak,
75  ARCStrong,
76  NonTrivialCStruct,
77  BlockObject, // Assign or release
78  None
79 };
80 
81 /// Represents a captured entity that requires extra operations in order for
82 /// this entity to be copied or destroyed correctly.
83 struct BlockCaptureManagedEntity {
84  BlockCaptureEntityKind CopyKind, DisposeKind;
85  BlockFieldFlags CopyFlags, DisposeFlags;
86  const BlockDecl::Capture *CI;
88 
89  BlockCaptureManagedEntity(BlockCaptureEntityKind CopyType,
90  BlockCaptureEntityKind DisposeType,
91  BlockFieldFlags CopyFlags,
92  BlockFieldFlags DisposeFlags,
93  const BlockDecl::Capture &CI,
94  const CGBlockInfo::Capture &Capture)
95  : CopyKind(CopyType), DisposeKind(DisposeType), CopyFlags(CopyFlags),
96  DisposeFlags(DisposeFlags), CI(&CI), Capture(&Capture) {}
97 
98  bool operator<(const BlockCaptureManagedEntity &Other) const {
99  return Capture->getOffset() < Other.Capture->getOffset();
100  }
101 };
102 
103 enum class CaptureStrKind {
104  // String for the copy helper.
105  CopyHelper,
106  // String for the dispose helper.
107  DisposeHelper,
108  // Merge the strings for the copy helper and dispose helper.
109  Merged
110 };
111 
112 } // end anonymous namespace
113 
115  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
116  SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures);
117 
118 static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
119  CaptureStrKind StrKind,
120  CharUnits BlockAlignment,
121  CodeGenModule &CGM);
122 
123 static std::string getBlockDescriptorName(const CGBlockInfo &BlockInfo,
124  CodeGenModule &CGM) {
125  std::string Name = "__block_descriptor_";
126  Name += llvm::to_string(BlockInfo.BlockSize.getQuantity()) + "_";
127 
128  if (BlockInfo.needsCopyDisposeHelpers()) {
129  if (CGM.getLangOpts().Exceptions)
130  Name += "e";
131  if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
132  Name += "a";
133  Name += llvm::to_string(BlockInfo.BlockAlign.getQuantity()) + "_";
134 
137  ManagedCaptures);
138 
139  for (const BlockCaptureManagedEntity &E : ManagedCaptures) {
140  Name += llvm::to_string(E.Capture->getOffset().getQuantity());
141 
142  if (E.CopyKind == E.DisposeKind) {
143  // If CopyKind and DisposeKind are the same, merge the capture
144  // information.
145  assert(E.CopyKind != BlockCaptureEntityKind::None &&
146  "shouldn't see BlockCaptureManagedEntity that is None");
147  Name += getBlockCaptureStr(E, CaptureStrKind::Merged,
148  BlockInfo.BlockAlign, CGM);
149  } else {
150  // If CopyKind and DisposeKind are not the same, which can happen when
151  // either Kind is None or the captured object is a __strong block,
152  // concatenate the copy and dispose strings.
153  Name += getBlockCaptureStr(E, CaptureStrKind::CopyHelper,
154  BlockInfo.BlockAlign, CGM);
155  Name += getBlockCaptureStr(E, CaptureStrKind::DisposeHelper,
156  BlockInfo.BlockAlign, CGM);
157  }
158  }
159  Name += "_";
160  }
161 
162  std::string TypeAtEncoding =
164  /// Replace occurrences of '@' with '\1'. '@' is reserved on ELF platforms as
165  /// a separator between symbol name and symbol version.
166  std::replace(TypeAtEncoding.begin(), TypeAtEncoding.end(), '@', '\1');
167  Name += "e" + llvm::to_string(TypeAtEncoding.size()) + "_" + TypeAtEncoding;
168  Name += "l" + CGM.getObjCRuntime().getRCBlockLayoutStr(CGM, BlockInfo);
169  return Name;
170 }
171 
172 /// buildBlockDescriptor - Build the block descriptor meta-data for a block.
173 /// buildBlockDescriptor is accessed from 5th field of the Block_literal
174 /// meta-data and contains stationary information about the block literal.
175 /// Its definition will have 4 (or optionally 6) words.
176 /// \code
177 /// struct Block_descriptor {
178 /// unsigned long reserved;
179 /// unsigned long size; // size of Block_literal metadata in bytes.
180 /// void *copy_func_helper_decl; // optional copy helper.
181 /// void *destroy_func_decl; // optional destructor helper.
182 /// void *block_method_encoding_address; // @encode for block literal signature.
183 /// void *block_layout_info; // encoding of captured block variables.
184 /// };
185 /// \endcode
186 static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
187  const CGBlockInfo &blockInfo) {
188  ASTContext &C = CGM.getContext();
189 
190  llvm::IntegerType *ulong =
191  cast<llvm::IntegerType>(CGM.getTypes().ConvertType(C.UnsignedLongTy));
192  llvm::PointerType *i8p = nullptr;
193  if (CGM.getLangOpts().OpenCL)
194  i8p =
195  llvm::Type::getInt8PtrTy(
197  else
198  i8p = CGM.VoidPtrTy;
199 
200  std::string descName;
201 
202  // If an equivalent block descriptor global variable exists, return it.
203  if (C.getLangOpts().ObjC &&
204  CGM.getLangOpts().getGC() == LangOptions::NonGC) {
205  descName = getBlockDescriptorName(blockInfo, CGM);
206  if (llvm::GlobalValue *desc = CGM.getModule().getNamedValue(descName))
207  return llvm::ConstantExpr::getBitCast(desc,
208  CGM.getBlockDescriptorType());
209  }
210 
211  // If there isn't an equivalent block descriptor global variable, create a new
212  // one.
213  ConstantInitBuilder builder(CGM);
214  auto elements = builder.beginStruct();
215 
216  // reserved
217  elements.addInt(ulong, 0);
218 
219  // Size
220  // FIXME: What is the right way to say this doesn't fit? We should give
221  // a user diagnostic in that case. Better fix would be to change the
222  // API to size_t.
223  elements.addInt(ulong, blockInfo.BlockSize.getQuantity());
224 
225  // Optional copy/dispose helpers.
226  bool hasInternalHelper = false;
227  if (blockInfo.needsCopyDisposeHelpers()) {
228  // copy_func_helper_decl
229  llvm::Constant *copyHelper = buildCopyHelper(CGM, blockInfo);
230  elements.add(copyHelper);
231 
232  // destroy_func_decl
233  llvm::Constant *disposeHelper = buildDisposeHelper(CGM, blockInfo);
234  elements.add(disposeHelper);
235 
236  if (cast<llvm::Function>(copyHelper->getOperand(0))->hasInternalLinkage() ||
237  cast<llvm::Function>(disposeHelper->getOperand(0))
238  ->hasInternalLinkage())
239  hasInternalHelper = true;
240  }
241 
242  // Signature. Mandatory ObjC-style method descriptor @encode sequence.
243  std::string typeAtEncoding =
245  elements.add(llvm::ConstantExpr::getBitCast(
246  CGM.GetAddrOfConstantCString(typeAtEncoding).getPointer(), i8p));
247 
248  // GC layout.
249  if (C.getLangOpts().ObjC) {
250  if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
251  elements.add(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
252  else
253  elements.add(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
254  }
255  else
256  elements.addNullPointer(i8p);
257 
258  unsigned AddrSpace = 0;
259  if (C.getLangOpts().OpenCL)
261 
262  llvm::GlobalValue::LinkageTypes linkage;
263  if (descName.empty()) {
265  descName = "__block_descriptor_tmp";
266  } else if (hasInternalHelper) {
267  // If either the copy helper or the dispose helper has internal linkage,
268  // the block descriptor must have internal linkage too.
270  } else {
271  linkage = llvm::GlobalValue::LinkOnceODRLinkage;
272  }
273 
274  llvm::GlobalVariable *global =
275  elements.finishAndCreateGlobal(descName, CGM.getPointerAlign(),
276  /*constant*/ true, linkage, AddrSpace);
277 
278  if (linkage == llvm::GlobalValue::LinkOnceODRLinkage) {
279  global->setVisibility(llvm::GlobalValue::HiddenVisibility);
280  global->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
281  }
282 
283  return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
284 }
285 
286 /*
287  Purely notional variadic template describing the layout of a block.
288 
289  template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
290  struct Block_literal {
291  /// Initialized to one of:
292  /// extern void *_NSConcreteStackBlock[];
293  /// extern void *_NSConcreteGlobalBlock[];
294  ///
295  /// In theory, we could start one off malloc'ed by setting
296  /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
297  /// this isa:
298  /// extern void *_NSConcreteMallocBlock[];
299  struct objc_class *isa;
300 
301  /// These are the flags (with corresponding bit number) that the
302  /// compiler is actually supposed to know about.
303  /// 23. BLOCK_IS_NOESCAPE - indicates that the block is non-escaping
304  /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
305  /// descriptor provides copy and dispose helper functions
306  /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
307  /// object with a nontrivial destructor or copy constructor
308  /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
309  /// as global memory
310  /// 29. BLOCK_USE_STRET - indicates that the block function
311  /// uses stret, which objc_msgSend needs to know about
312  /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
313  /// @encoded signature string
314  /// And we're not supposed to manipulate these:
315  /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
316  /// to malloc'ed memory
317  /// 27. BLOCK_IS_GC - indicates that the block has been moved to
318  /// to GC-allocated memory
319  /// Additionally, the bottom 16 bits are a reference count which
320  /// should be zero on the stack.
321  int flags;
322 
323  /// Reserved; should be zero-initialized.
324  int reserved;
325 
326  /// Function pointer generated from block literal.
327  _ResultType (*invoke)(Block_literal *, _ParamTypes...);
328 
329  /// Block description metadata generated from block literal.
330  struct Block_descriptor *block_descriptor;
331 
332  /// Captured values follow.
333  _CapturesTypes captures...;
334  };
335  */
336 
337 namespace {
338  /// A chunk of data that we actually have to capture in the block.
339  struct BlockLayoutChunk {
340  CharUnits Alignment;
341  CharUnits Size;
342  Qualifiers::ObjCLifetime Lifetime;
343  const BlockDecl::Capture *Capture; // null for 'this'
344  llvm::Type *Type;
345  QualType FieldType;
346 
347  BlockLayoutChunk(CharUnits align, CharUnits size,
348  Qualifiers::ObjCLifetime lifetime,
349  const BlockDecl::Capture *capture,
350  llvm::Type *type, QualType fieldType)
351  : Alignment(align), Size(size), Lifetime(lifetime),
352  Capture(capture), Type(type), FieldType(fieldType) {}
353 
354  /// Tell the block info that this chunk has the given field index.
355  void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
356  if (!Capture) {
357  info.CXXThisIndex = index;
358  info.CXXThisOffset = offset;
359  } else {
360  auto C = CGBlockInfo::Capture::makeIndex(index, offset, FieldType);
361  info.Captures.insert({Capture->getVariable(), C});
362  }
363  }
364  };
365 
366  /// Order by 1) all __strong together 2) next, all byfref together 3) next,
367  /// all __weak together. Preserve descending alignment in all situations.
368  bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
369  if (left.Alignment != right.Alignment)
370  return left.Alignment > right.Alignment;
371 
372  auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
373  if (chunk.Capture && chunk.Capture->isByRef())
374  return 1;
375  if (chunk.Lifetime == Qualifiers::OCL_Strong)
376  return 0;
377  if (chunk.Lifetime == Qualifiers::OCL_Weak)
378  return 2;
379  return 3;
380  };
381 
382  return getPrefOrder(left) < getPrefOrder(right);
383  }
384 } // end anonymous namespace
385 
386 /// Determines if the given type is safe for constant capture in C++.
388  const RecordType *recordType =
390 
391  // Only records can be unsafe.
392  if (!recordType) return true;
393 
394  const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
395 
396  // Maintain semantics for classes with non-trivial dtors or copy ctors.
397  if (!record->hasTrivialDestructor()) return false;
398  if (record->hasNonTrivialCopyConstructor()) return false;
399 
400  // Otherwise, we just have to make sure there aren't any mutable
401  // fields that might have changed since initialization.
402  return !record->hasMutableFields();
403 }
404 
405 /// It is illegal to modify a const object after initialization.
406 /// Therefore, if a const object has a constant initializer, we don't
407 /// actually need to keep storage for it in the block; we'll just
408 /// rematerialize it at the start of the block function. This is
409 /// acceptable because we make no promises about address stability of
410 /// captured variables.
411 static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
412  CodeGenFunction *CGF,
413  const VarDecl *var) {
414  // Return if this is a function parameter. We shouldn't try to
415  // rematerialize default arguments of function parameters.
416  if (isa<ParmVarDecl>(var))
417  return nullptr;
418 
419  QualType type = var->getType();
420 
421  // We can only do this if the variable is const.
422  if (!type.isConstQualified()) return nullptr;
423 
424  // Furthermore, in C++ we have to worry about mutable fields:
425  // C++ [dcl.type.cv]p4:
426  // Except that any class member declared mutable can be
427  // modified, any attempt to modify a const object during its
428  // lifetime results in undefined behavior.
429  if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
430  return nullptr;
431 
432  // If the variable doesn't have any initializer (shouldn't this be
433  // invalid?), it's not clear what we should do. Maybe capture as
434  // zero?
435  const Expr *init = var->getInit();
436  if (!init) return nullptr;
437 
438  return ConstantEmitter(CGM, CGF).tryEmitAbstractForInitializer(*var);
439 }
440 
441 /// Get the low bit of a nonzero character count. This is the
442 /// alignment of the nth byte if the 0th byte is universally aligned.
444  return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
445 }
446 
448  SmallVectorImpl<llvm::Type*> &elementTypes) {
449 
450  assert(elementTypes.empty());
451  if (CGM.getLangOpts().OpenCL) {
452  // The header is basically 'struct { int; int; generic void *;
453  // custom_fields; }'. Assert that struct is packed.
454  auto GenericAS =
456  auto GenPtrAlign =
457  CharUnits::fromQuantity(CGM.getTarget().getPointerAlign(GenericAS) / 8);
458  auto GenPtrSize =
459  CharUnits::fromQuantity(CGM.getTarget().getPointerWidth(GenericAS) / 8);
460  assert(CGM.getIntSize() <= GenPtrSize);
461  assert(CGM.getIntAlign() <= GenPtrAlign);
462  assert((2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign));
463  elementTypes.push_back(CGM.IntTy); /* total size */
464  elementTypes.push_back(CGM.IntTy); /* align */
465  elementTypes.push_back(
466  CGM.getOpenCLRuntime()
467  .getGenericVoidPointerType()); /* invoke function */
468  unsigned Offset =
469  2 * CGM.getIntSize().getQuantity() + GenPtrSize.getQuantity();
470  unsigned BlockAlign = GenPtrAlign.getQuantity();
471  if (auto *Helper =
473  for (auto I : Helper->getCustomFieldTypes()) /* custom fields */ {
474  // TargetOpenCLBlockHelp needs to make sure the struct is packed.
475  // If necessary, add padding fields to the custom fields.
476  unsigned Align = CGM.getDataLayout().getABITypeAlignment(I);
477  if (BlockAlign < Align)
478  BlockAlign = Align;
479  assert(Offset % Align == 0);
480  Offset += CGM.getDataLayout().getTypeAllocSize(I);
481  elementTypes.push_back(I);
482  }
483  }
484  info.BlockAlign = CharUnits::fromQuantity(BlockAlign);
485  info.BlockSize = CharUnits::fromQuantity(Offset);
486  } else {
487  // The header is basically 'struct { void *; int; int; void *; void *; }'.
488  // Assert that the struct is packed.
489  assert(CGM.getIntSize() <= CGM.getPointerSize());
490  assert(CGM.getIntAlign() <= CGM.getPointerAlign());
491  assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()));
492  info.BlockAlign = CGM.getPointerAlign();
493  info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
494  elementTypes.push_back(CGM.VoidPtrTy);
495  elementTypes.push_back(CGM.IntTy);
496  elementTypes.push_back(CGM.IntTy);
497  elementTypes.push_back(CGM.VoidPtrTy);
498  elementTypes.push_back(CGM.getBlockDescriptorType());
499  }
500 }
501 
503  const BlockDecl::Capture &CI) {
504  const VarDecl *VD = CI.getVariable();
505 
506  // If the variable is captured by an enclosing block or lambda expression,
507  // use the type of the capture field.
508  if (CGF.BlockInfo && CI.isNested())
509  return CGF.BlockInfo->getCapture(VD).fieldType();
510  if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
511  return FD->getType();
512  // If the captured variable is a non-escaping __block variable, the field
513  // type is the reference type. If the variable is a __block variable that
514  // already has a reference type, the field type is the variable's type.
515  return VD->isNonEscapingByref() ?
516  CGF.getContext().getLValueReferenceType(VD->getType()) : VD->getType();
517 }
518 
519 /// Compute the layout of the given block. Attempts to lay the block
520 /// out with minimal space requirements.
522  CGBlockInfo &info) {
523  ASTContext &C = CGM.getContext();
524  const BlockDecl *block = info.getBlockDecl();
525 
526  SmallVector<llvm::Type*, 8> elementTypes;
527  initializeForBlockHeader(CGM, info, elementTypes);
528  bool hasNonConstantCustomFields = false;
529  if (auto *OpenCLHelper =
531  hasNonConstantCustomFields =
532  !OpenCLHelper->areAllCustomFieldValuesConstant(info);
533  if (!block->hasCaptures() && !hasNonConstantCustomFields) {
534  info.StructureType =
535  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
536  info.CanBeGlobal = true;
537  return;
538  }
539  else if (C.getLangOpts().ObjC &&
540  CGM.getLangOpts().getGC() == LangOptions::NonGC)
541  info.HasCapturedVariableLayout = true;
542 
543  // Collect the layout chunks.
545  layout.reserve(block->capturesCXXThis() +
546  (block->capture_end() - block->capture_begin()));
547 
548  CharUnits maxFieldAlign;
549 
550  // First, 'this'.
551  if (block->capturesCXXThis()) {
552  assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&
553  "Can't capture 'this' outside a method");
554  QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType();
555 
556  // Theoretically, this could be in a different address space, so
557  // don't assume standard pointer size/align.
558  llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
559  std::pair<CharUnits,CharUnits> tinfo
560  = CGM.getContext().getTypeInfoInChars(thisType);
561  maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
562 
563  layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
565  nullptr, llvmType, thisType));
566  }
567 
568  // Next, all the block captures.
569  for (const auto &CI : block->captures()) {
570  const VarDecl *variable = CI.getVariable();
571 
572  if (CI.isEscapingByref()) {
573  // We have to copy/dispose of the __block reference.
574  info.NeedsCopyDispose = true;
575 
576  // Just use void* instead of a pointer to the byref type.
577  CharUnits align = CGM.getPointerAlign();
578  maxFieldAlign = std::max(maxFieldAlign, align);
579 
580  // Since a __block variable cannot be captured by lambdas, its type and
581  // the capture field type should always match.
582  assert(getCaptureFieldType(*CGF, CI) == variable->getType() &&
583  "capture type differs from the variable type");
584  layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
586  CGM.VoidPtrTy, variable->getType()));
587  continue;
588  }
589 
590  // Otherwise, build a layout chunk with the size and alignment of
591  // the declaration.
592  if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
593  info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
594  continue;
595  }
596 
597  QualType VT = getCaptureFieldType(*CGF, CI);
598 
599  // If we have a lifetime qualifier, honor it for capture purposes.
600  // That includes *not* copying it if it's __unsafe_unretained.
602  if (lifetime) {
603  switch (lifetime) {
604  case Qualifiers::OCL_None: llvm_unreachable("impossible");
607  break;
608 
611  info.NeedsCopyDispose = true;
612  }
613 
614  // Block pointers require copy/dispose. So do Objective-C pointers.
615  } else if (VT->isObjCRetainableType()) {
616  // But honor the inert __unsafe_unretained qualifier, which doesn't
617  // actually make it into the type system.
619  lifetime = Qualifiers::OCL_ExplicitNone;
620  } else {
621  info.NeedsCopyDispose = true;
622  // used for mrr below.
623  lifetime = Qualifiers::OCL_Strong;
624  }
625 
626  // So do types that require non-trivial copy construction.
627  } else if (CI.hasCopyExpr()) {
628  info.NeedsCopyDispose = true;
629  info.HasCXXObject = true;
631  info.CapturesNonExternalType = true;
632 
633  // So do C structs that require non-trivial copy construction or
634  // destruction.
637  info.NeedsCopyDispose = true;
638 
639  // And so do types with destructors.
640  } else if (CGM.getLangOpts().CPlusPlus) {
641  if (const CXXRecordDecl *record = VT->getAsCXXRecordDecl()) {
642  if (!record->hasTrivialDestructor()) {
643  info.HasCXXObject = true;
644  info.NeedsCopyDispose = true;
645  if (!record->isExternallyVisible())
646  info.CapturesNonExternalType = true;
647  }
648  }
649  }
650 
651  CharUnits size = C.getTypeSizeInChars(VT);
652  CharUnits align = C.getDeclAlign(variable);
653 
654  maxFieldAlign = std::max(maxFieldAlign, align);
655 
656  llvm::Type *llvmType =
657  CGM.getTypes().ConvertTypeForMem(VT);
658 
659  layout.push_back(
660  BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
661  }
662 
663  // If that was everything, we're done here.
664  if (layout.empty()) {
665  info.StructureType =
666  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
667  info.CanBeGlobal = true;
668  return;
669  }
670 
671  // Sort the layout by alignment. We have to use a stable sort here
672  // to get reproducible results. There should probably be an
673  // llvm::array_pod_stable_sort.
674  std::stable_sort(layout.begin(), layout.end());
675 
676  // Needed for blocks layout info.
679 
680  CharUnits &blockSize = info.BlockSize;
681  info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
682 
683  // Assuming that the first byte in the header is maximally aligned,
684  // get the alignment of the first byte following the header.
685  CharUnits endAlign = getLowBit(blockSize);
686 
687  // If the end of the header isn't satisfactorily aligned for the
688  // maximum thing, look for things that are okay with the header-end
689  // alignment, and keep appending them until we get something that's
690  // aligned right. This algorithm is only guaranteed optimal if
691  // that condition is satisfied at some point; otherwise we can get
692  // things like:
693  // header // next byte has alignment 4
694  // something_with_size_5; // next byte has alignment 1
695  // something_with_alignment_8;
696  // which has 7 bytes of padding, as opposed to the naive solution
697  // which might have less (?).
698  if (endAlign < maxFieldAlign) {
699  SmallVectorImpl<BlockLayoutChunk>::iterator
700  li = layout.begin() + 1, le = layout.end();
701 
702  // Look for something that the header end is already
703  // satisfactorily aligned for.
704  for (; li != le && endAlign < li->Alignment; ++li)
705  ;
706 
707  // If we found something that's naturally aligned for the end of
708  // the header, keep adding things...
709  if (li != le) {
710  SmallVectorImpl<BlockLayoutChunk>::iterator first = li;
711  for (; li != le; ++li) {
712  assert(endAlign >= li->Alignment);
713 
714  li->setIndex(info, elementTypes.size(), blockSize);
715  elementTypes.push_back(li->Type);
716  blockSize += li->Size;
717  endAlign = getLowBit(blockSize);
718 
719  // ...until we get to the alignment of the maximum field.
720  if (endAlign >= maxFieldAlign) {
721  break;
722  }
723  }
724  // Don't re-append everything we just appended.
725  layout.erase(first, li);
726  }
727  }
728 
729  assert(endAlign == getLowBit(blockSize));
730 
731  // At this point, we just have to add padding if the end align still
732  // isn't aligned right.
733  if (endAlign < maxFieldAlign) {
734  CharUnits newBlockSize = blockSize.alignTo(maxFieldAlign);
735  CharUnits padding = newBlockSize - blockSize;
736 
737  // If we haven't yet added any fields, remember that there was an
738  // initial gap; this need to go into the block layout bit map.
739  if (blockSize == info.BlockHeaderForcedGapOffset) {
740  info.BlockHeaderForcedGapSize = padding;
741  }
742 
743  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
744  padding.getQuantity()));
745  blockSize = newBlockSize;
746  endAlign = getLowBit(blockSize); // might be > maxFieldAlign
747  }
748 
749  assert(endAlign >= maxFieldAlign);
750  assert(endAlign == getLowBit(blockSize));
751  // Slam everything else on now. This works because they have
752  // strictly decreasing alignment and we expect that size is always a
753  // multiple of alignment.
754  for (SmallVectorImpl<BlockLayoutChunk>::iterator
755  li = layout.begin(), le = layout.end(); li != le; ++li) {
756  if (endAlign < li->Alignment) {
757  // size may not be multiple of alignment. This can only happen with
758  // an over-aligned variable. We will be adding a padding field to
759  // make the size be multiple of alignment.
760  CharUnits padding = li->Alignment - endAlign;
761  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
762  padding.getQuantity()));
763  blockSize += padding;
764  endAlign = getLowBit(blockSize);
765  }
766  assert(endAlign >= li->Alignment);
767  li->setIndex(info, elementTypes.size(), blockSize);
768  elementTypes.push_back(li->Type);
769  blockSize += li->Size;
770  endAlign = getLowBit(blockSize);
771  }
772 
773  info.StructureType =
774  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
775 }
776 
777 /// Enter the scope of a block. This should be run at the entrance to
778 /// a full-expression so that the block's cleanups are pushed at the
779 /// right place in the stack.
780 static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
781  assert(CGF.HaveInsertPoint());
782 
783  // Allocate the block info and place it at the head of the list.
784  CGBlockInfo &blockInfo =
785  *new CGBlockInfo(block, CGF.CurFn->getName());
786  blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
787  CGF.FirstBlockInfo = &blockInfo;
788 
789  // Compute information about the layout, etc., of this block,
790  // pushing cleanups as necessary.
791  computeBlockInfo(CGF.CGM, &CGF, blockInfo);
792 
793  // Nothing else to do if it can be global.
794  if (blockInfo.CanBeGlobal) return;
795 
796  // Make the allocation for the block.
797  blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
798  blockInfo.BlockAlign, "block");
799 
800  // If there are cleanups to emit, enter them (but inactive).
801  if (!blockInfo.NeedsCopyDispose) return;
802 
803  // Walk through the captures (in order) and find the ones not
804  // captured by constant.
805  for (const auto &CI : block->captures()) {
806  // Ignore __block captures; there's nothing special in the
807  // on-stack block that we need to do for them.
808  if (CI.isByRef()) continue;
809 
810  // Ignore variables that are constant-captured.
811  const VarDecl *variable = CI.getVariable();
812  CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
813  if (capture.isConstant()) continue;
814 
815  // Ignore objects that aren't destructed.
816  QualType VT = getCaptureFieldType(CGF, CI);
818  if (dtorKind == QualType::DK_none) continue;
819 
820  CodeGenFunction::Destroyer *destroyer;
821 
822  // Block captures count as local values and have imprecise semantics.
823  // They also can't be arrays, so need to worry about that.
824  //
825  // For const-qualified captures, emit clang.arc.use to ensure the captured
826  // object doesn't get released while we are still depending on its validity
827  // within the block.
828  if (VT.isConstQualified() &&
830  CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
831  assert(CGF.CGM.getLangOpts().ObjCAutoRefCount &&
832  "expected ObjC ARC to be enabled");
834  } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
836  } else {
837  destroyer = CGF.getDestroyer(dtorKind);
838  }
839 
840  // GEP down to the address.
841  Address addr = CGF.Builder.CreateStructGEP(blockInfo.LocalAddress,
842  capture.getIndex(),
843  capture.getOffset());
844 
845  // We can use that GEP as the dominating IP.
846  if (!blockInfo.DominatingIP)
847  blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
848 
849  CleanupKind cleanupKind = InactiveNormalCleanup;
850  bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
851  if (useArrayEHCleanup)
852  cleanupKind = InactiveNormalAndEHCleanup;
853 
854  CGF.pushDestroy(cleanupKind, addr, VT,
855  destroyer, useArrayEHCleanup);
856 
857  // Remember where that cleanup was.
858  capture.setCleanup(CGF.EHStack.stable_begin());
859  }
860 }
861 
862 /// Enter a full-expression with a non-trivial number of objects to
863 /// clean up. This is in this file because, at the moment, the only
864 /// kind of cleanup object is a BlockDecl*.
866  if (const auto EWC = dyn_cast<ExprWithCleanups>(E)) {
867  assert(EWC->getNumObjects() != 0);
868  for (const ExprWithCleanups::CleanupObject &C : EWC->getObjects())
869  enterBlockScope(*this, C);
870  }
871 }
872 
873 /// Find the layout for the given block in a linked list and remove it.
875  const BlockDecl *block) {
876  while (true) {
877  assert(head && *head);
878  CGBlockInfo *cur = *head;
879 
880  // If this is the block we're looking for, splice it out of the list.
881  if (cur->getBlockDecl() == block) {
882  *head = cur->NextBlockInfo;
883  return cur;
884  }
885 
886  head = &cur->NextBlockInfo;
887  }
888 }
889 
890 /// Destroy a chain of block layouts.
892  assert(head && "destroying an empty chain");
893  do {
894  CGBlockInfo *cur = head;
895  head = cur->NextBlockInfo;
896  delete cur;
897  } while (head != nullptr);
898 }
899 
900 /// Emit a block literal expression in the current function.
902  // If the block has no captures, we won't have a pre-computed
903  // layout for it.
904  if (!blockExpr->getBlockDecl()->hasCaptures()) {
905  // The block literal is emitted as a global variable, and the block invoke
906  // function has to be extracted from its initializer.
907  if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr)) {
908  return Block;
909  }
910  CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
911  computeBlockInfo(CGM, this, blockInfo);
912  blockInfo.BlockExpression = blockExpr;
913  return EmitBlockLiteral(blockInfo);
914  }
915 
916  // Find the block info for this block and take ownership of it.
917  std::unique_ptr<CGBlockInfo> blockInfo;
918  blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
919  blockExpr->getBlockDecl()));
920 
921  blockInfo->BlockExpression = blockExpr;
922  return EmitBlockLiteral(*blockInfo);
923 }
924 
926  bool IsOpenCL = CGM.getContext().getLangOpts().OpenCL;
927  auto GenVoidPtrTy =
928  IsOpenCL ? CGM.getOpenCLRuntime().getGenericVoidPointerType() : VoidPtrTy;
929  LangAS GenVoidPtrAddr = IsOpenCL ? LangAS::opencl_generic : LangAS::Default;
930  auto GenVoidPtrSize = CharUnits::fromQuantity(
932  CGM.getContext().getTargetAddressSpace(GenVoidPtrAddr)) /
933  8);
934  // Using the computed layout, generate the actual block function.
935  bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
936  CodeGenFunction BlockCGF{CGM, true};
937  BlockCGF.SanOpts = SanOpts;
938  auto *InvokeFn = BlockCGF.GenerateBlockFunction(
939  CurGD, blockInfo, LocalDeclMap, isLambdaConv, blockInfo.CanBeGlobal);
940  auto *blockFn = llvm::ConstantExpr::getPointerCast(InvokeFn, GenVoidPtrTy);
941 
942  // If there is nothing to capture, we can emit this as a global block.
943  if (blockInfo.CanBeGlobal)
944  return CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression);
945 
946  // Otherwise, we have to emit this as a local block.
947 
948  Address blockAddr = blockInfo.LocalAddress;
949  assert(blockAddr.isValid() && "block has no address!");
950 
951  llvm::Constant *isa;
952  llvm::Constant *descriptor;
953  BlockFlags flags;
954  if (!IsOpenCL) {
955  // If the block is non-escaping, set field 'isa 'to NSConcreteGlobalBlock
956  // and set the BLOCK_IS_GLOBAL bit of field 'flags'. Copying a non-escaping
957  // block just returns the original block and releasing it is a no-op.
958  llvm::Constant *blockISA = blockInfo.getBlockDecl()->doesNotEscape()
960  : CGM.getNSConcreteStackBlock();
961  isa = llvm::ConstantExpr::getBitCast(blockISA, VoidPtrTy);
962 
963  // Build the block descriptor.
964  descriptor = buildBlockDescriptor(CGM, blockInfo);
965 
966  // Compute the initial on-stack block flags.
967  flags = BLOCK_HAS_SIGNATURE;
968  if (blockInfo.HasCapturedVariableLayout)
969  flags |= BLOCK_HAS_EXTENDED_LAYOUT;
970  if (blockInfo.needsCopyDisposeHelpers())
971  flags |= BLOCK_HAS_COPY_DISPOSE;
972  if (blockInfo.HasCXXObject)
973  flags |= BLOCK_HAS_CXX_OBJ;
974  if (blockInfo.UsesStret)
975  flags |= BLOCK_USE_STRET;
976  if (blockInfo.getBlockDecl()->doesNotEscape())
978  }
979 
980  auto projectField =
981  [&](unsigned index, CharUnits offset, const Twine &name) -> Address {
982  return Builder.CreateStructGEP(blockAddr, index, offset, name);
983  };
984  auto storeField =
985  [&](llvm::Value *value, unsigned index, CharUnits offset,
986  const Twine &name) {
987  Builder.CreateStore(value, projectField(index, offset, name));
988  };
989 
990  // Initialize the block header.
991  {
992  // We assume all the header fields are densely packed.
993  unsigned index = 0;
994  CharUnits offset;
995  auto addHeaderField =
996  [&](llvm::Value *value, CharUnits size, const Twine &name) {
997  storeField(value, index, offset, name);
998  offset += size;
999  index++;
1000  };
1001 
1002  if (!IsOpenCL) {
1003  addHeaderField(isa, getPointerSize(), "block.isa");
1004  addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
1005  getIntSize(), "block.flags");
1006  addHeaderField(llvm::ConstantInt::get(IntTy, 0), getIntSize(),
1007  "block.reserved");
1008  } else {
1009  addHeaderField(
1010  llvm::ConstantInt::get(IntTy, blockInfo.BlockSize.getQuantity()),
1011  getIntSize(), "block.size");
1012  addHeaderField(
1013  llvm::ConstantInt::get(IntTy, blockInfo.BlockAlign.getQuantity()),
1014  getIntSize(), "block.align");
1015  }
1016  addHeaderField(blockFn, GenVoidPtrSize, "block.invoke");
1017  if (!IsOpenCL)
1018  addHeaderField(descriptor, getPointerSize(), "block.descriptor");
1019  else if (auto *Helper =
1021  for (auto I : Helper->getCustomFieldValues(*this, blockInfo)) {
1022  addHeaderField(
1023  I.first,
1025  CGM.getDataLayout().getTypeAllocSize(I.first->getType())),
1026  I.second);
1027  }
1028  }
1029  }
1030 
1031  // Finally, capture all the values into the block.
1032  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1033 
1034  // First, 'this'.
1035  if (blockDecl->capturesCXXThis()) {
1036  Address addr = projectField(blockInfo.CXXThisIndex, blockInfo.CXXThisOffset,
1037  "block.captured-this.addr");
1038  Builder.CreateStore(LoadCXXThis(), addr);
1039  }
1040 
1041  // Next, captured variables.
1042  for (const auto &CI : blockDecl->captures()) {
1043  const VarDecl *variable = CI.getVariable();
1044  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1045 
1046  // Ignore constant captures.
1047  if (capture.isConstant()) continue;
1048 
1049  QualType type = capture.fieldType();
1050 
1051  // This will be a [[type]]*, except that a byref entry will just be
1052  // an i8**.
1053  Address blockField =
1054  projectField(capture.getIndex(), capture.getOffset(), "block.captured");
1055 
1056  // Compute the address of the thing we're going to move into the
1057  // block literal.
1058  Address src = Address::invalid();
1059 
1060  if (blockDecl->isConversionFromLambda()) {
1061  // The lambda capture in a lambda's conversion-to-block-pointer is
1062  // special; we'll simply emit it directly.
1063  src = Address::invalid();
1064  } else if (CI.isEscapingByref()) {
1065  if (BlockInfo && CI.isNested()) {
1066  // We need to use the capture from the enclosing block.
1067  const CGBlockInfo::Capture &enclosingCapture =
1068  BlockInfo->getCapture(variable);
1069 
1070  // This is a [[type]]*, except that a byref entry will just be an i8**.
1071  src = Builder.CreateStructGEP(LoadBlockStruct(),
1072  enclosingCapture.getIndex(),
1073  enclosingCapture.getOffset(),
1074  "block.capture.addr");
1075  } else {
1076  auto I = LocalDeclMap.find(variable);
1077  assert(I != LocalDeclMap.end());
1078  src = I->second;
1079  }
1080  } else {
1081  DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1082  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1084  SourceLocation());
1085  src = EmitDeclRefLValue(&declRef).getAddress();
1086  };
1087 
1088  // For byrefs, we just write the pointer to the byref struct into
1089  // the block field. There's no need to chase the forwarding
1090  // pointer at this point, since we're building something that will
1091  // live a shorter life than the stack byref anyway.
1092  if (CI.isEscapingByref()) {
1093  // Get a void* that points to the byref struct.
1094  llvm::Value *byrefPointer;
1095  if (CI.isNested())
1096  byrefPointer = Builder.CreateLoad(src, "byref.capture");
1097  else
1098  byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
1099 
1100  // Write that void* into the capture field.
1101  Builder.CreateStore(byrefPointer, blockField);
1102 
1103  // If we have a copy constructor, evaluate that into the block field.
1104  } else if (const Expr *copyExpr = CI.getCopyExpr()) {
1105  if (blockDecl->isConversionFromLambda()) {
1106  // If we have a lambda conversion, emit the expression
1107  // directly into the block instead.
1108  AggValueSlot Slot =
1109  AggValueSlot::forAddr(blockField, Qualifiers(),
1114  EmitAggExpr(copyExpr, Slot);
1115  } else {
1116  EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
1117  }
1118 
1119  // If it's a reference variable, copy the reference into the block field.
1120  } else if (type->isReferenceType()) {
1121  Builder.CreateStore(src.getPointer(), blockField);
1122 
1123  // If type is const-qualified, copy the value into the block field.
1124  } else if (type.isConstQualified() &&
1126  CGM.getCodeGenOpts().OptimizationLevel != 0) {
1127  llvm::Value *value = Builder.CreateLoad(src, "captured");
1128  Builder.CreateStore(value, blockField);
1129 
1130  // If this is an ARC __strong block-pointer variable, don't do a
1131  // block copy.
1132  //
1133  // TODO: this can be generalized into the normal initialization logic:
1134  // we should never need to do a block-copy when initializing a local
1135  // variable, because the local variable's lifetime should be strictly
1136  // contained within the stack block's.
1137  } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
1138  type->isBlockPointerType()) {
1139  // Load the block and do a simple retain.
1140  llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
1141  value = EmitARCRetainNonBlock(value);
1142 
1143  // Do a primitive store to the block field.
1144  Builder.CreateStore(value, blockField);
1145 
1146  // Otherwise, fake up a POD copy into the block field.
1147  } else {
1148  // Fake up a new variable so that EmitScalarInit doesn't think
1149  // we're referring to the variable in its own initializer.
1150  ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
1152 
1153  // We use one of these or the other depending on whether the
1154  // reference is nested.
1155  DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1156  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1158 
1159  ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
1160  &declRef, VK_RValue);
1161  // FIXME: Pass a specific location for the expr init so that the store is
1162  // attributed to a reasonable location - otherwise it may be attributed to
1163  // locations of subexpressions in the initialization.
1164  EmitExprAsInit(&l2r, &BlockFieldPseudoVar,
1165  MakeAddrLValue(blockField, type, AlignmentSource::Decl),
1166  /*captured by init*/ false);
1167  }
1168 
1169  // Activate the cleanup if layout pushed one.
1170  if (!CI.isByRef()) {
1172  if (cleanup.isValid())
1173  ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
1174  }
1175  }
1176 
1177  // Cast to the converted block-pointer type, which happens (somewhat
1178  // unfortunately) to be a pointer to function type.
1179  llvm::Value *result = Builder.CreatePointerCast(
1180  blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
1181 
1182  if (IsOpenCL) {
1183  CGM.getOpenCLRuntime().recordBlockInfo(blockInfo.BlockExpression, InvokeFn,
1184  result);
1185  }
1186 
1187  return result;
1188 }
1189 
1190 
1192  if (BlockDescriptorType)
1193  return BlockDescriptorType;
1194 
1195  llvm::Type *UnsignedLongTy =
1196  getTypes().ConvertType(getContext().UnsignedLongTy);
1197 
1198  // struct __block_descriptor {
1199  // unsigned long reserved;
1200  // unsigned long block_size;
1201  //
1202  // // later, the following will be added
1203  //
1204  // struct {
1205  // void (*copyHelper)();
1206  // void (*copyHelper)();
1207  // } helpers; // !!! optional
1208  //
1209  // const char *signature; // the block signature
1210  // const char *layout; // reserved
1211  // };
1212  BlockDescriptorType = llvm::StructType::create(
1213  "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
1214 
1215  // Now form a pointer to that.
1216  unsigned AddrSpace = 0;
1217  if (getLangOpts().OpenCL)
1218  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
1219  BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
1220  return BlockDescriptorType;
1221 }
1222 
1224  if (GenericBlockLiteralType)
1225  return GenericBlockLiteralType;
1226 
1227  llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
1228 
1229  if (getLangOpts().OpenCL) {
1230  // struct __opencl_block_literal_generic {
1231  // int __size;
1232  // int __align;
1233  // __generic void *__invoke;
1234  // /* custom fields */
1235  // };
1236  SmallVector<llvm::Type *, 8> StructFields(
1237  {IntTy, IntTy, getOpenCLRuntime().getGenericVoidPointerType()});
1238  if (auto *Helper = getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1239  for (auto I : Helper->getCustomFieldTypes())
1240  StructFields.push_back(I);
1241  }
1242  GenericBlockLiteralType = llvm::StructType::create(
1243  StructFields, "struct.__opencl_block_literal_generic");
1244  } else {
1245  // struct __block_literal_generic {
1246  // void *__isa;
1247  // int __flags;
1248  // int __reserved;
1249  // void (*__invoke)(void *);
1250  // struct __block_descriptor *__descriptor;
1251  // };
1252  GenericBlockLiteralType =
1253  llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
1254  IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
1255  }
1256 
1257  return GenericBlockLiteralType;
1258 }
1259 
1261  ReturnValueSlot ReturnValue) {
1262  const BlockPointerType *BPT =
1264 
1265  llvm::Value *BlockPtr = EmitScalarExpr(E->getCallee());
1266 
1267  // Get a pointer to the generic block literal.
1268  // For OpenCL we generate generic AS void ptr to be able to reuse the same
1269  // block definition for blocks with captures generated as private AS local
1270  // variables and without captures generated as global AS program scope
1271  // variables.
1272  unsigned AddrSpace = 0;
1273  if (getLangOpts().OpenCL)
1274  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_generic);
1275 
1276  llvm::Type *BlockLiteralTy =
1277  llvm::PointerType::get(CGM.getGenericBlockLiteralType(), AddrSpace);
1278 
1279  // Bitcast the callee to a block literal.
1280  BlockPtr =
1281  Builder.CreatePointerCast(BlockPtr, BlockLiteralTy, "block.literal");
1282 
1283  // Get the function pointer from the literal.
1284  llvm::Value *FuncPtr =
1285  Builder.CreateStructGEP(CGM.getGenericBlockLiteralType(), BlockPtr,
1286  CGM.getLangOpts().OpenCL ? 2 : 3);
1287 
1288  // Add the block literal.
1289  CallArgList Args;
1290 
1291  QualType VoidPtrQualTy = getContext().VoidPtrTy;
1292  llvm::Type *GenericVoidPtrTy = VoidPtrTy;
1293  if (getLangOpts().OpenCL) {
1294  GenericVoidPtrTy = CGM.getOpenCLRuntime().getGenericVoidPointerType();
1295  VoidPtrQualTy =
1296  getContext().getPointerType(getContext().getAddrSpaceQualType(
1297  getContext().VoidTy, LangAS::opencl_generic));
1298  }
1299 
1300  BlockPtr = Builder.CreatePointerCast(BlockPtr, GenericVoidPtrTy);
1301  Args.add(RValue::get(BlockPtr), VoidPtrQualTy);
1302 
1303  QualType FnType = BPT->getPointeeType();
1304 
1305  // And the rest of the arguments.
1306  EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1307 
1308  // Load the function.
1309  llvm::Value *Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1310 
1311  const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1312  const CGFunctionInfo &FnInfo =
1313  CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
1314 
1315  // Cast the function pointer to the right type.
1316  llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
1317 
1318  llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
1319  Func = Builder.CreatePointerCast(Func, BlockFTyPtr);
1320 
1321  // Prepare the callee.
1322  CGCallee Callee(CGCalleeInfo(), Func);
1323 
1324  // And call the block.
1325  return EmitCall(FnInfo, Callee, ReturnValue, Args);
1326 }
1327 
1329  assert(BlockInfo && "evaluating block ref without block information?");
1330  const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1331 
1332  // Handle constant captures.
1333  if (capture.isConstant()) return LocalDeclMap.find(variable)->second;
1334 
1335  Address addr =
1336  Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(),
1337  capture.getOffset(), "block.capture.addr");
1338 
1339  if (variable->isEscapingByref()) {
1340  // addr should be a void** right now. Load, then cast the result
1341  // to byref*.
1342 
1343  auto &byrefInfo = getBlockByrefInfo(variable);
1344  addr = Address(Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
1345 
1346  auto byrefPointerType = llvm::PointerType::get(byrefInfo.Type, 0);
1347  addr = Builder.CreateBitCast(addr, byrefPointerType, "byref.addr");
1348 
1349  addr = emitBlockByrefAddress(addr, byrefInfo, /*follow*/ true,
1350  variable->getName());
1351  }
1352 
1353  assert((!variable->isNonEscapingByref() ||
1354  capture.fieldType()->isReferenceType()) &&
1355  "the capture field of a non-escaping variable should have a "
1356  "reference type");
1357  if (capture.fieldType()->isReferenceType())
1358  addr = EmitLoadOfReference(MakeAddrLValue(addr, capture.fieldType()));
1359 
1360  return addr;
1361 }
1362 
1364  llvm::Constant *Addr) {
1365  bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
1366  (void)Ok;
1367  assert(Ok && "Trying to replace an already-existing global block!");
1368 }
1369 
1370 llvm::Constant *
1372  StringRef Name) {
1373  if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1374  return Block;
1375 
1376  CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1377  blockInfo.BlockExpression = BE;
1378 
1379  // Compute information about the layout, etc., of this block.
1380  computeBlockInfo(*this, nullptr, blockInfo);
1381 
1382  // Using that metadata, generate the actual block function.
1383  {
1384  CodeGenFunction::DeclMapTy LocalDeclMap;
1386  GlobalDecl(), blockInfo, LocalDeclMap,
1387  /*IsLambdaConversionToBlock*/ false, /*BuildGlobalBlock*/ true);
1388  }
1389 
1390  return getAddrOfGlobalBlockIfEmitted(BE);
1391 }
1392 
1393 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1394  const CGBlockInfo &blockInfo,
1395  llvm::Constant *blockFn) {
1396  assert(blockInfo.CanBeGlobal);
1397  // Callers should detect this case on their own: calling this function
1398  // generally requires computing layout information, which is a waste of time
1399  // if we've already emitted this block.
1400  assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&
1401  "Refusing to re-emit a global block.");
1402 
1403  // Generate the constants for the block literal initializer.
1404  ConstantInitBuilder builder(CGM);
1405  auto fields = builder.beginStruct();
1406 
1407  bool IsOpenCL = CGM.getLangOpts().OpenCL;
1408  bool IsWindows = CGM.getTarget().getTriple().isOSWindows();
1409  if (!IsOpenCL) {
1410  // isa
1411  if (IsWindows)
1412  fields.addNullPointer(CGM.Int8PtrPtrTy);
1413  else
1414  fields.add(CGM.getNSConcreteGlobalBlock());
1415 
1416  // __flags
1418  if (blockInfo.UsesStret)
1419  flags |= BLOCK_USE_STRET;
1420 
1421  fields.addInt(CGM.IntTy, flags.getBitMask());
1422 
1423  // Reserved
1424  fields.addInt(CGM.IntTy, 0);
1425  } else {
1426  fields.addInt(CGM.IntTy, blockInfo.BlockSize.getQuantity());
1427  fields.addInt(CGM.IntTy, blockInfo.BlockAlign.getQuantity());
1428  }
1429 
1430  // Function
1431  fields.add(blockFn);
1432 
1433  if (!IsOpenCL) {
1434  // Descriptor
1435  fields.add(buildBlockDescriptor(CGM, blockInfo));
1436  } else if (auto *Helper =
1438  for (auto I : Helper->getCustomFieldValues(CGM, blockInfo)) {
1439  fields.add(I);
1440  }
1441  }
1442 
1443  unsigned AddrSpace = 0;
1444  if (CGM.getContext().getLangOpts().OpenCL)
1446 
1447  llvm::Constant *literal = fields.finishAndCreateGlobal(
1448  "__block_literal_global", blockInfo.BlockAlign,
1449  /*constant*/ !IsWindows, llvm::GlobalVariable::InternalLinkage, AddrSpace);
1450 
1451  // Windows does not allow globals to be initialised to point to globals in
1452  // different DLLs. Any such variables must run code to initialise them.
1453  if (IsWindows) {
1454  auto *Init = llvm::Function::Create(llvm::FunctionType::get(CGM.VoidTy,
1455  {}), llvm::GlobalValue::InternalLinkage, ".block_isa_init",
1456  &CGM.getModule());
1457  llvm::IRBuilder<> b(llvm::BasicBlock::Create(CGM.getLLVMContext(), "entry",
1458  Init));
1459  b.CreateAlignedStore(CGM.getNSConcreteGlobalBlock(),
1460  b.CreateStructGEP(literal, 0), CGM.getPointerAlign().getQuantity());
1461  b.CreateRetVoid();
1462  // We can't use the normal LLVM global initialisation array, because we
1463  // need to specify that this runs early in library initialisation.
1464  auto *InitVar = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
1465  /*isConstant*/true, llvm::GlobalValue::InternalLinkage,
1466  Init, ".block_isa_init_ptr");
1467  InitVar->setSection(".CRT$XCLa");
1468  CGM.addUsedGlobal(InitVar);
1469  }
1470 
1471  // Return a constant of the appropriately-casted type.
1472  llvm::Type *RequiredType =
1473  CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1474  llvm::Constant *Result =
1475  llvm::ConstantExpr::getPointerCast(literal, RequiredType);
1476  CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
1477  if (CGM.getContext().getLangOpts().OpenCL)
1479  blockInfo.BlockExpression,
1480  cast<llvm::Function>(blockFn->stripPointerCasts()), Result);
1481  return Result;
1482 }
1483 
1485  unsigned argNum,
1486  llvm::Value *arg) {
1487  assert(BlockInfo && "not emitting prologue of block invocation function?!");
1488 
1489  // Allocate a stack slot like for any local variable to guarantee optimal
1490  // debug info at -O0. The mem2reg pass will eliminate it when optimizing.
1491  Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr");
1492  Builder.CreateStore(arg, alloc);
1493  if (CGDebugInfo *DI = getDebugInfo()) {
1494  if (CGM.getCodeGenOpts().getDebugInfo() >=
1496  DI->setLocation(D->getLocation());
1497  DI->EmitDeclareOfBlockLiteralArgVariable(
1498  *BlockInfo, D->getName(), argNum,
1499  cast<llvm::AllocaInst>(alloc.getPointer()), Builder);
1500  }
1501  }
1502 
1503  SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getBeginLoc();
1504  ApplyDebugLocation Scope(*this, StartLoc);
1505 
1506  // Instead of messing around with LocalDeclMap, just set the value
1507  // directly as BlockPointer.
1508  BlockPointer = Builder.CreatePointerCast(
1509  arg,
1510  BlockInfo->StructureType->getPointerTo(
1511  getContext().getLangOpts().OpenCL
1512  ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1513  : 0),
1514  "block");
1515 }
1516 
1518  assert(BlockInfo && "not in a block invocation function!");
1519  assert(BlockPointer && "no block pointer set!");
1520  return Address(BlockPointer, BlockInfo->BlockAlign);
1521 }
1522 
1523 llvm::Function *
1525  const CGBlockInfo &blockInfo,
1526  const DeclMapTy &ldm,
1527  bool IsLambdaConversionToBlock,
1528  bool BuildGlobalBlock) {
1529  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1530 
1531  CurGD = GD;
1532 
1533  CurEHLocation = blockInfo.getBlockExpr()->getEndLoc();
1534 
1535  BlockInfo = &blockInfo;
1536 
1537  // Arrange for local static and local extern declarations to appear
1538  // to be local to this function as well, in case they're directly
1539  // referenced in a block.
1540  for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1541  const auto *var = dyn_cast<VarDecl>(i->first);
1542  if (var && !var->hasLocalStorage())
1543  setAddrOfLocalVar(var, i->second);
1544  }
1545 
1546  // Begin building the function declaration.
1547 
1548  // Build the argument list.
1549  FunctionArgList args;
1550 
1551  // The first argument is the block pointer. Just take it as a void*
1552  // and cast it later.
1553  QualType selfTy = getContext().VoidPtrTy;
1554 
1555  // For OpenCL passed block pointer can be private AS local variable or
1556  // global AS program scope variable (for the case with and without captures).
1557  // Generic AS is used therefore to be able to accommodate both private and
1558  // generic AS in one implementation.
1559  if (getLangOpts().OpenCL)
1560  selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1561  getContext().VoidTy, LangAS::opencl_generic));
1562 
1563  IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1564 
1565  ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1566  SourceLocation(), II, selfTy,
1568  args.push_back(&SelfDecl);
1569 
1570  // Now add the rest of the parameters.
1571  args.append(blockDecl->param_begin(), blockDecl->param_end());
1572 
1573  // Create the function declaration.
1574  const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1575  const CGFunctionInfo &fnInfo =
1576  CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1577  if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1578  blockInfo.UsesStret = true;
1579 
1580  llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1581 
1582  StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1583  llvm::Function *fn = llvm::Function::Create(
1584  fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1585  CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1586 
1587  if (BuildGlobalBlock) {
1588  auto GenVoidPtrTy = getContext().getLangOpts().OpenCL
1590  : VoidPtrTy;
1591  buildGlobalBlock(CGM, blockInfo,
1592  llvm::ConstantExpr::getPointerCast(fn, GenVoidPtrTy));
1593  }
1594 
1595  // Begin generating the function.
1596  StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1597  blockDecl->getLocation(),
1598  blockInfo.getBlockExpr()->getBody()->getBeginLoc());
1599 
1600  // Okay. Undo some of what StartFunction did.
1601 
1602  // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1603  // won't delete the dbg.declare intrinsics for captured variables.
1604  llvm::Value *BlockPointerDbgLoc = BlockPointer;
1605  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1606  // Allocate a stack slot for it, so we can point the debugger to it
1607  Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1608  getPointerAlign(),
1609  "block.addr");
1610  // Set the DebugLocation to empty, so the store is recognized as a
1611  // frame setup instruction by llvm::DwarfDebug::beginFunction().
1612  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1613  Builder.CreateStore(BlockPointer, Alloca);
1614  BlockPointerDbgLoc = Alloca.getPointer();
1615  }
1616 
1617  // If we have a C++ 'this' reference, go ahead and force it into
1618  // existence now.
1619  if (blockDecl->capturesCXXThis()) {
1620  Address addr =
1621  Builder.CreateStructGEP(LoadBlockStruct(), blockInfo.CXXThisIndex,
1622  blockInfo.CXXThisOffset, "block.captured-this");
1623  CXXThisValue = Builder.CreateLoad(addr, "this");
1624  }
1625 
1626  // Also force all the constant captures.
1627  for (const auto &CI : blockDecl->captures()) {
1628  const VarDecl *variable = CI.getVariable();
1629  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1630  if (!capture.isConstant()) continue;
1631 
1632  CharUnits align = getContext().getDeclAlign(variable);
1633  Address alloca =
1634  CreateMemTemp(variable->getType(), align, "block.captured-const");
1635 
1636  Builder.CreateStore(capture.getConstant(), alloca);
1637 
1638  setAddrOfLocalVar(variable, alloca);
1639  }
1640 
1641  // Save a spot to insert the debug information for all the DeclRefExprs.
1642  llvm::BasicBlock *entry = Builder.GetInsertBlock();
1643  llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1644  --entry_ptr;
1645 
1646  if (IsLambdaConversionToBlock)
1647  EmitLambdaBlockInvokeBody();
1648  else {
1649  PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1650  incrementProfileCounter(blockDecl->getBody());
1651  EmitStmt(blockDecl->getBody());
1652  }
1653 
1654  // Remember where we were...
1655  llvm::BasicBlock *resume = Builder.GetInsertBlock();
1656 
1657  // Go back to the entry.
1658  ++entry_ptr;
1659  Builder.SetInsertPoint(entry, entry_ptr);
1660 
1661  // Emit debug information for all the DeclRefExprs.
1662  // FIXME: also for 'this'
1663  if (CGDebugInfo *DI = getDebugInfo()) {
1664  for (const auto &CI : blockDecl->captures()) {
1665  const VarDecl *variable = CI.getVariable();
1666  DI->EmitLocation(Builder, variable->getLocation());
1667 
1668  if (CGM.getCodeGenOpts().getDebugInfo() >=
1670  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1671  if (capture.isConstant()) {
1672  auto addr = LocalDeclMap.find(variable)->second;
1673  (void)DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1674  Builder);
1675  continue;
1676  }
1677 
1678  DI->EmitDeclareOfBlockDeclRefVariable(
1679  variable, BlockPointerDbgLoc, Builder, blockInfo,
1680  entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1681  }
1682  }
1683  // Recover location if it was changed in the above loop.
1684  DI->EmitLocation(Builder,
1685  cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1686  }
1687 
1688  // And resume where we left off.
1689  if (resume == nullptr)
1690  Builder.ClearInsertionPoint();
1691  else
1692  Builder.SetInsertPoint(resume);
1693 
1694  FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1695 
1696  return fn;
1697 }
1698 
1699 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1701  const LangOptions &LangOpts) {
1702  if (CI.getCopyExpr()) {
1703  assert(!CI.isByRef());
1704  // don't bother computing flags
1705  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1706  }
1707  BlockFieldFlags Flags;
1708  if (CI.isEscapingByref()) {
1709  Flags = BLOCK_FIELD_IS_BYREF;
1710  if (T.isObjCGCWeak())
1711  Flags |= BLOCK_FIELD_IS_WEAK;
1712  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1713  }
1714 
1715  Flags = BLOCK_FIELD_IS_OBJECT;
1716  bool isBlockPointer = T->isBlockPointerType();
1717  if (isBlockPointer)
1718  Flags = BLOCK_FIELD_IS_BLOCK;
1719 
1720  switch (T.isNonTrivialToPrimitiveCopy()) {
1721  case QualType::PCK_Struct:
1722  return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
1723  BlockFieldFlags());
1724  case QualType::PCK_ARCWeak:
1725  // We need to register __weak direct captures with the runtime.
1726  return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1728  // We need to retain the copied value for __strong direct captures.
1729  // If it's a block pointer, we have to copy the block and assign that to
1730  // the destination pointer, so we might as well use _Block_object_assign.
1731  // Otherwise we can avoid that.
1732  return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1733  : BlockCaptureEntityKind::BlockObject,
1734  Flags);
1735  case QualType::PCK_Trivial:
1737  if (!T->isObjCRetainableType())
1738  // For all other types, the memcpy is fine.
1739  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1740 
1741  // Special rules for ARC captures:
1742  Qualifiers QS = T.getQualifiers();
1743 
1744  // Non-ARC captures of retainable pointers are strong and
1745  // therefore require a call to _Block_object_assign.
1746  if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1747  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1748 
1749  // Otherwise the memcpy is fine.
1750  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1751  }
1752  }
1753  llvm_unreachable("after exhaustive PrimitiveCopyKind switch");
1754 }
1755 
1756 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1758  const LangOptions &LangOpts);
1759 
1760 /// Find the set of block captures that need to be explicitly copied or destroy.
1762  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1763  SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures) {
1764  for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1765  const VarDecl *Variable = CI.getVariable();
1766  const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1767  if (Capture.isConstant())
1768  continue;
1769 
1770  QualType VT = Capture.fieldType();
1771  auto CopyInfo = computeCopyInfoForBlockCapture(CI, VT, LangOpts);
1772  auto DisposeInfo = computeDestroyInfoForBlockCapture(CI, VT, LangOpts);
1773  if (CopyInfo.first != BlockCaptureEntityKind::None ||
1774  DisposeInfo.first != BlockCaptureEntityKind::None)
1775  ManagedCaptures.emplace_back(CopyInfo.first, DisposeInfo.first,
1776  CopyInfo.second, DisposeInfo.second, CI,
1777  Capture);
1778  }
1779 
1780  // Sort the captures by offset.
1781  llvm::sort(ManagedCaptures);
1782 }
1783 
1784 namespace {
1785 /// Release a __block variable.
1786 struct CallBlockRelease final : EHScopeStack::Cleanup {
1787  Address Addr;
1788  BlockFieldFlags FieldFlags;
1789  bool LoadBlockVarAddr, CanThrow;
1790 
1791  CallBlockRelease(Address Addr, BlockFieldFlags Flags, bool LoadValue,
1792  bool CT)
1793  : Addr(Addr), FieldFlags(Flags), LoadBlockVarAddr(LoadValue),
1794  CanThrow(CT) {}
1795 
1796  void Emit(CodeGenFunction &CGF, Flags flags) override {
1797  llvm::Value *BlockVarAddr;
1798  if (LoadBlockVarAddr) {
1799  BlockVarAddr = CGF.Builder.CreateLoad(Addr);
1800  BlockVarAddr = CGF.Builder.CreateBitCast(BlockVarAddr, CGF.VoidPtrTy);
1801  } else {
1802  BlockVarAddr = Addr.getPointer();
1803  }
1804 
1805  CGF.BuildBlockRelease(BlockVarAddr, FieldFlags, CanThrow);
1806  }
1807 };
1808 } // end anonymous namespace
1809 
1810 /// Check if \p T is a C++ class that has a destructor that can throw.
1812  if (const auto *RD = T->getAsCXXRecordDecl())
1813  if (const CXXDestructorDecl *DD = RD->getDestructor())
1814  return DD->getType()->getAs<FunctionProtoType>()->canThrow();
1815  return false;
1816 }
1817 
1818 // Return a string that has the information about a capture.
1819 static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
1820  CaptureStrKind StrKind,
1821  CharUnits BlockAlignment,
1822  CodeGenModule &CGM) {
1823  std::string Str;
1824  ASTContext &Ctx = CGM.getContext();
1825  const BlockDecl::Capture &CI = *E.CI;
1826  QualType CaptureTy = CI.getVariable()->getType();
1827 
1829  BlockFieldFlags Flags;
1830 
1831  // CaptureStrKind::Merged should be passed only when the operations and the
1832  // flags are the same for copy and dispose.
1833  assert((StrKind != CaptureStrKind::Merged ||
1834  (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) &&
1835  "different operations and flags");
1836 
1837  if (StrKind == CaptureStrKind::DisposeHelper) {
1838  Kind = E.DisposeKind;
1839  Flags = E.DisposeFlags;
1840  } else {
1841  Kind = E.CopyKind;
1842  Flags = E.CopyFlags;
1843  }
1844 
1845  switch (Kind) {
1846  case BlockCaptureEntityKind::CXXRecord: {
1847  Str += "c";
1848  SmallString<256> TyStr;
1849  llvm::raw_svector_ostream Out(TyStr);
1850  CGM.getCXXABI().getMangleContext().mangleTypeName(CaptureTy, Out);
1851  Str += llvm::to_string(TyStr.size()) + TyStr.c_str();
1852  break;
1853  }
1854  case BlockCaptureEntityKind::ARCWeak:
1855  Str += "w";
1856  break;
1857  case BlockCaptureEntityKind::ARCStrong:
1858  Str += "s";
1859  break;
1860  case BlockCaptureEntityKind::BlockObject: {
1861  const VarDecl *Var = CI.getVariable();
1862  unsigned F = Flags.getBitMask();
1863  if (F & BLOCK_FIELD_IS_BYREF) {
1864  Str += "r";
1865  if (F & BLOCK_FIELD_IS_WEAK)
1866  Str += "w";
1867  else {
1868  // If CaptureStrKind::Merged is passed, check both the copy expression
1869  // and the destructor.
1870  if (StrKind != CaptureStrKind::DisposeHelper) {
1871  if (Ctx.getBlockVarCopyInit(Var).canThrow())
1872  Str += "c";
1873  }
1874  if (StrKind != CaptureStrKind::CopyHelper) {
1876  Str += "d";
1877  }
1878  }
1879  } else {
1880  assert((F & BLOCK_FIELD_IS_OBJECT) && "unexpected flag value");
1881  if (F == BLOCK_FIELD_IS_BLOCK)
1882  Str += "b";
1883  else
1884  Str += "o";
1885  }
1886  break;
1887  }
1888  case BlockCaptureEntityKind::NonTrivialCStruct: {
1889  bool IsVolatile = CaptureTy.isVolatileQualified();
1890  CharUnits Alignment =
1891  BlockAlignment.alignmentAtOffset(E.Capture->getOffset());
1892 
1893  Str += "n";
1894  std::string FuncStr;
1895  if (StrKind == CaptureStrKind::DisposeHelper)
1897  CaptureTy, Alignment, IsVolatile, Ctx);
1898  else
1899  // If CaptureStrKind::Merged is passed, use the copy constructor string.
1900  // It has all the information that the destructor string has.
1902  CaptureTy, Alignment, IsVolatile, Ctx);
1903  // The underscore is necessary here because non-trivial copy constructor
1904  // and destructor strings can start with a number.
1905  Str += llvm::to_string(FuncStr.size()) + "_" + FuncStr;
1906  break;
1907  }
1909  break;
1910  }
1911 
1912  return Str;
1913 }
1914 
1915 static std::string getCopyDestroyHelperFuncName(
1916  const SmallVectorImpl<BlockCaptureManagedEntity> &Captures,
1917  CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM) {
1918  assert((StrKind == CaptureStrKind::CopyHelper ||
1919  StrKind == CaptureStrKind::DisposeHelper) &&
1920  "unexpected CaptureStrKind");
1921  std::string Name = StrKind == CaptureStrKind::CopyHelper
1922  ? "__copy_helper_block_"
1923  : "__destroy_helper_block_";
1924  if (CGM.getLangOpts().Exceptions)
1925  Name += "e";
1926  if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
1927  Name += "a";
1928  Name += llvm::to_string(BlockAlignment.getQuantity()) + "_";
1929 
1930  for (const BlockCaptureManagedEntity &E : Captures) {
1931  Name += llvm::to_string(E.Capture->getOffset().getQuantity());
1932  Name += getBlockCaptureStr(E, StrKind, BlockAlignment, CGM);
1933  }
1934 
1935  return Name;
1936 }
1937 
1939  Address Field, QualType CaptureType,
1940  BlockFieldFlags Flags, bool ForCopyHelper,
1941  VarDecl *Var, CodeGenFunction &CGF) {
1942  bool EHOnly = ForCopyHelper;
1943 
1944  switch (CaptureKind) {
1945  case BlockCaptureEntityKind::CXXRecord:
1946  case BlockCaptureEntityKind::ARCWeak:
1947  case BlockCaptureEntityKind::NonTrivialCStruct:
1948  case BlockCaptureEntityKind::ARCStrong: {
1949  if (CaptureType.isDestructedType() &&
1950  (!EHOnly || CGF.needsEHCleanup(CaptureType.isDestructedType()))) {
1951  CodeGenFunction::Destroyer *Destroyer =
1952  CaptureKind == BlockCaptureEntityKind::ARCStrong
1954  : CGF.getDestroyer(CaptureType.isDestructedType());
1955  CleanupKind Kind =
1956  EHOnly ? EHCleanup
1957  : CGF.getCleanupKind(CaptureType.isDestructedType());
1958  CGF.pushDestroy(Kind, Field, CaptureType, Destroyer, Kind & EHCleanup);
1959  }
1960  break;
1961  }
1962  case BlockCaptureEntityKind::BlockObject: {
1963  if (!EHOnly || CGF.getLangOpts().Exceptions) {
1965  // Calls to _Block_object_dispose along the EH path in the copy helper
1966  // function don't throw as newly-copied __block variables always have a
1967  // reference count of 2.
1968  bool CanThrow =
1969  !ForCopyHelper && CGF.cxxDestructorCanThrow(CaptureType);
1970  CGF.enterByrefCleanup(Kind, Field, Flags, /*LoadBlockVarAddr*/ true,
1971  CanThrow);
1972  }
1973  break;
1974  }
1976  break;
1977  }
1978 }
1979 
1981  llvm::Function *Fn,
1982  const CGFunctionInfo &FI,
1983  CodeGenModule &CGM) {
1984  if (CapturesNonExternalType) {
1986  } else {
1987  Fn->setVisibility(llvm::GlobalValue::HiddenVisibility);
1988  Fn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1989  CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, Fn);
1990  CGM.SetLLVMFunctionAttributesForDefinition(nullptr, Fn);
1991  }
1992 }
1993 /// Generate the copy-helper function for a block closure object:
1994 /// static void block_copy_helper(block_t *dst, block_t *src);
1995 /// The runtime will have previously initialized 'dst' by doing a
1996 /// bit-copy of 'src'.
1997 ///
1998 /// Note that this copies an entire block closure object to the heap;
1999 /// it should not be confused with a 'byref copy helper', which moves
2000 /// the contents of an individual __block variable to the heap.
2001 llvm::Constant *
2004  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures);
2005  std::string FuncName =
2006  getCopyDestroyHelperFuncName(CopiedCaptures, blockInfo.BlockAlign,
2007  CaptureStrKind::CopyHelper, CGM);
2008 
2009  if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2010  return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2011 
2012  ASTContext &C = getContext();
2013 
2014  QualType ReturnTy = C.VoidTy;
2015 
2016  FunctionArgList args;
2018  args.push_back(&DstDecl);
2020  args.push_back(&SrcDecl);
2021 
2022  const CGFunctionInfo &FI =
2023  CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2024 
2025  // FIXME: it would be nice if these were mergeable with things with
2026  // identical semantics.
2027  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2028 
2029  llvm::Function *Fn =
2030  llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2031  FuncName, &CGM.getModule());
2032 
2033  IdentifierInfo *II = &C.Idents.get(FuncName);
2034 
2035  SmallVector<QualType, 2> ArgTys;
2036  ArgTys.push_back(C.VoidPtrTy);
2037  ArgTys.push_back(C.VoidPtrTy);
2038  QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2039 
2042  FunctionTy, nullptr, SC_Static, false, false);
2043 
2045  CGM);
2046  StartFunction(FD, ReturnTy, Fn, FI, args);
2047  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2048  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2049 
2050  Address src = GetAddrOfLocalVar(&SrcDecl);
2051  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2052  src = Builder.CreateBitCast(src, structPtrTy, "block.source");
2053 
2054  Address dst = GetAddrOfLocalVar(&DstDecl);
2055  dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
2056  dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
2057 
2058  for (const auto &CopiedCapture : CopiedCaptures) {
2059  const BlockDecl::Capture &CI = *CopiedCapture.CI;
2060  const CGBlockInfo::Capture &capture = *CopiedCapture.Capture;
2061  QualType captureType = CI.getVariable()->getType();
2062  BlockFieldFlags flags = CopiedCapture.CopyFlags;
2063 
2064  unsigned index = capture.getIndex();
2065  Address srcField = Builder.CreateStructGEP(src, index, capture.getOffset());
2066  Address dstField = Builder.CreateStructGEP(dst, index, capture.getOffset());
2067 
2068  switch (CopiedCapture.CopyKind) {
2069  case BlockCaptureEntityKind::CXXRecord:
2070  // If there's an explicit copy expression, we do that.
2071  assert(CI.getCopyExpr() && "copy expression for variable is missing");
2072  EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
2073  break;
2074  case BlockCaptureEntityKind::ARCWeak:
2075  EmitARCCopyWeak(dstField, srcField);
2076  break;
2077  case BlockCaptureEntityKind::NonTrivialCStruct: {
2078  // If this is a C struct that requires non-trivial copy construction,
2079  // emit a call to its copy constructor.
2080  QualType varType = CI.getVariable()->getType();
2081  callCStructCopyConstructor(MakeAddrLValue(dstField, varType),
2082  MakeAddrLValue(srcField, varType));
2083  break;
2084  }
2085  case BlockCaptureEntityKind::ARCStrong: {
2086  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2087  // At -O0, store null into the destination field (so that the
2088  // storeStrong doesn't over-release) and then call storeStrong.
2089  // This is a workaround to not having an initStrong call.
2090  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2091  auto *ty = cast<llvm::PointerType>(srcValue->getType());
2092  llvm::Value *null = llvm::ConstantPointerNull::get(ty);
2093  Builder.CreateStore(null, dstField);
2094  EmitARCStoreStrongCall(dstField, srcValue, true);
2095 
2096  // With optimization enabled, take advantage of the fact that
2097  // the blocks runtime guarantees a memcpy of the block data, and
2098  // just emit a retain of the src field.
2099  } else {
2100  EmitARCRetainNonBlock(srcValue);
2101 
2102  // Unless EH cleanup is required, we don't need this anymore, so kill
2103  // it. It's not quite worth the annoyance to avoid creating it in the
2104  // first place.
2105  if (!needsEHCleanup(captureType.isDestructedType()))
2106  cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
2107  }
2108  break;
2109  }
2110  case BlockCaptureEntityKind::BlockObject: {
2111  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2112  srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
2113  llvm::Value *dstAddr =
2114  Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
2115  llvm::Value *args[] = {
2116  dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2117  };
2118 
2119  if (CI.isByRef() && C.getBlockVarCopyInit(CI.getVariable()).canThrow())
2120  EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
2121  else
2122  EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
2123  break;
2124  }
2126  continue;
2127  }
2128 
2129  // Ensure that we destroy the copied object if an exception is thrown later
2130  // in the helper function.
2131  pushCaptureCleanup(CopiedCapture.CopyKind, dstField, captureType, flags,
2132  /*ForCopyHelper*/ true, CI.getVariable(), *this);
2133  }
2134 
2135  FinishFunction();
2136 
2137  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2138 }
2139 
2140 static BlockFieldFlags
2142  QualType T) {
2144  if (T->isBlockPointerType())
2145  Flags = BLOCK_FIELD_IS_BLOCK;
2146  return Flags;
2147 }
2148 
2149 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
2151  const LangOptions &LangOpts) {
2152  if (CI.isEscapingByref()) {
2154  if (T.isObjCGCWeak())
2155  Flags |= BLOCK_FIELD_IS_WEAK;
2156  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
2157  }
2158 
2159  switch (T.isDestructedType()) {
2161  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
2163  // Use objc_storeStrong for __strong direct captures; the
2164  // dynamic tools really like it when we do this.
2165  return std::make_pair(BlockCaptureEntityKind::ARCStrong,
2168  // Support __weak direct captures.
2169  return std::make_pair(BlockCaptureEntityKind::ARCWeak,
2172  return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
2173  BlockFieldFlags());
2174  case QualType::DK_none: {
2175  // Non-ARC captures are strong, and we need to use _Block_object_dispose.
2176  if (T->isObjCRetainableType() && !T.getQualifiers().hasObjCLifetime() &&
2177  !LangOpts.ObjCAutoRefCount)
2178  return std::make_pair(BlockCaptureEntityKind::BlockObject,
2180  // Otherwise, we have nothing to do.
2181  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
2182  }
2183  }
2184  llvm_unreachable("after exhaustive DestructionKind switch");
2185 }
2186 
2187 /// Generate the destroy-helper function for a block closure object:
2188 /// static void block_destroy_helper(block_t *theBlock);
2189 ///
2190 /// Note that this destroys a heap-allocated block closure object;
2191 /// it should not be confused with a 'byref destroy helper', which
2192 /// destroys the heap-allocated contents of an individual __block
2193 /// variable.
2194 llvm::Constant *
2197  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures);
2198  std::string FuncName =
2199  getCopyDestroyHelperFuncName(DestroyedCaptures, blockInfo.BlockAlign,
2200  CaptureStrKind::DisposeHelper, CGM);
2201 
2202  if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2203  return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2204 
2205  ASTContext &C = getContext();
2206 
2207  QualType ReturnTy = C.VoidTy;
2208 
2209  FunctionArgList args;
2211  args.push_back(&SrcDecl);
2212 
2213  const CGFunctionInfo &FI =
2214  CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2215 
2216  // FIXME: We'd like to put these into a mergable by content, with
2217  // internal linkage.
2218  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2219 
2220  llvm::Function *Fn =
2221  llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2222  FuncName, &CGM.getModule());
2223 
2224  IdentifierInfo *II = &C.Idents.get(FuncName);
2225 
2226  SmallVector<QualType, 1> ArgTys;
2227  ArgTys.push_back(C.VoidPtrTy);
2228  QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2229 
2232  FunctionTy, nullptr, SC_Static, false, false);
2233 
2235  CGM);
2236  StartFunction(FD, ReturnTy, Fn, FI, args);
2237  markAsIgnoreThreadCheckingAtRuntime(Fn);
2238 
2239  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2240 
2241  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2242 
2243  Address src = GetAddrOfLocalVar(&SrcDecl);
2244  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2245  src = Builder.CreateBitCast(src, structPtrTy, "block");
2246 
2247  CodeGenFunction::RunCleanupsScope cleanups(*this);
2248 
2249  for (const auto &DestroyedCapture : DestroyedCaptures) {
2250  const BlockDecl::Capture &CI = *DestroyedCapture.CI;
2251  const CGBlockInfo::Capture &capture = *DestroyedCapture.Capture;
2252  BlockFieldFlags flags = DestroyedCapture.DisposeFlags;
2253 
2254  Address srcField =
2255  Builder.CreateStructGEP(src, capture.getIndex(), capture.getOffset());
2256 
2257  pushCaptureCleanup(DestroyedCapture.DisposeKind, srcField,
2258  CI.getVariable()->getType(), flags,
2259  /*ForCopyHelper*/ false, CI.getVariable(), *this);
2260  }
2261 
2262  cleanups.ForceCleanup();
2263 
2264  FinishFunction();
2265 
2266  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2267 }
2268 
2269 namespace {
2270 
2271 /// Emits the copy/dispose helper functions for a __block object of id type.
2272 class ObjectByrefHelpers final : public BlockByrefHelpers {
2273  BlockFieldFlags Flags;
2274 
2275 public:
2276  ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
2277  : BlockByrefHelpers(alignment), Flags(flags) {}
2278 
2279  void emitCopy(CodeGenFunction &CGF, Address destField,
2280  Address srcField) override {
2281  destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
2282 
2283  srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
2284  llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
2285 
2286  unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
2287 
2288  llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
2289  llvm::Value *fn = CGF.CGM.getBlockObjectAssign();
2290 
2291  llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
2292  CGF.EmitNounwindRuntimeCall(fn, args);
2293  }
2294 
2295  void emitDispose(CodeGenFunction &CGF, Address field) override {
2296  field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
2297  llvm::Value *value = CGF.Builder.CreateLoad(field);
2298 
2299  CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER, false);
2300  }
2301 
2302  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2303  id.AddInteger(Flags.getBitMask());
2304  }
2305 };
2306 
2307 /// Emits the copy/dispose helpers for an ARC __block __weak variable.
2308 class ARCWeakByrefHelpers final : public BlockByrefHelpers {
2309 public:
2310  ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2311 
2312  void emitCopy(CodeGenFunction &CGF, Address destField,
2313  Address srcField) override {
2314  CGF.EmitARCMoveWeak(destField, srcField);
2315  }
2316 
2317  void emitDispose(CodeGenFunction &CGF, Address field) override {
2318  CGF.EmitARCDestroyWeak(field);
2319  }
2320 
2321  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2322  // 0 is distinguishable from all pointers and byref flags
2323  id.AddInteger(0);
2324  }
2325 };
2326 
2327 /// Emits the copy/dispose helpers for an ARC __block __strong variable
2328 /// that's not of block-pointer type.
2329 class ARCStrongByrefHelpers final : public BlockByrefHelpers {
2330 public:
2331  ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2332 
2333  void emitCopy(CodeGenFunction &CGF, Address destField,
2334  Address srcField) override {
2335  // Do a "move" by copying the value and then zeroing out the old
2336  // variable.
2337 
2338  llvm::Value *value = CGF.Builder.CreateLoad(srcField);
2339 
2340  llvm::Value *null =
2341  llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
2342 
2343  if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
2344  CGF.Builder.CreateStore(null, destField);
2345  CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
2346  CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
2347  return;
2348  }
2349  CGF.Builder.CreateStore(value, destField);
2350  CGF.Builder.CreateStore(null, srcField);
2351  }
2352 
2353  void emitDispose(CodeGenFunction &CGF, Address field) override {
2355  }
2356 
2357  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2358  // 1 is distinguishable from all pointers and byref flags
2359  id.AddInteger(1);
2360  }
2361 };
2362 
2363 /// Emits the copy/dispose helpers for an ARC __block __strong
2364 /// variable that's of block-pointer type.
2365 class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
2366 public:
2367  ARCStrongBlockByrefHelpers(CharUnits alignment)
2368  : BlockByrefHelpers(alignment) {}
2369 
2370  void emitCopy(CodeGenFunction &CGF, Address destField,
2371  Address srcField) override {
2372  // Do the copy with objc_retainBlock; that's all that
2373  // _Block_object_assign would do anyway, and we'd have to pass the
2374  // right arguments to make sure it doesn't get no-op'ed.
2375  llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
2376  llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
2377  CGF.Builder.CreateStore(copy, destField);
2378  }
2379 
2380  void emitDispose(CodeGenFunction &CGF, Address field) override {
2382  }
2383 
2384  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2385  // 2 is distinguishable from all pointers and byref flags
2386  id.AddInteger(2);
2387  }
2388 };
2389 
2390 /// Emits the copy/dispose helpers for a __block variable with a
2391 /// nontrivial copy constructor or destructor.
2392 class CXXByrefHelpers final : public BlockByrefHelpers {
2393  QualType VarType;
2394  const Expr *CopyExpr;
2395 
2396 public:
2397  CXXByrefHelpers(CharUnits alignment, QualType type,
2398  const Expr *copyExpr)
2399  : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
2400 
2401  bool needsCopy() const override { return CopyExpr != nullptr; }
2402  void emitCopy(CodeGenFunction &CGF, Address destField,
2403  Address srcField) override {
2404  if (!CopyExpr) return;
2405  CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
2406  }
2407 
2408  void emitDispose(CodeGenFunction &CGF, Address field) override {
2409  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2410  CGF.PushDestructorCleanup(VarType, field);
2411  CGF.PopCleanupBlocks(cleanupDepth);
2412  }
2413 
2414  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2415  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2416  }
2417 };
2418 
2419 /// Emits the copy/dispose helpers for a __block variable that is a non-trivial
2420 /// C struct.
2421 class NonTrivialCStructByrefHelpers final : public BlockByrefHelpers {
2422  QualType VarType;
2423 
2424 public:
2425  NonTrivialCStructByrefHelpers(CharUnits alignment, QualType type)
2426  : BlockByrefHelpers(alignment), VarType(type) {}
2427 
2428  void emitCopy(CodeGenFunction &CGF, Address destField,
2429  Address srcField) override {
2430  CGF.callCStructMoveConstructor(CGF.MakeAddrLValue(destField, VarType),
2431  CGF.MakeAddrLValue(srcField, VarType));
2432  }
2433 
2434  bool needsDispose() const override {
2435  return VarType.isDestructedType();
2436  }
2437 
2438  void emitDispose(CodeGenFunction &CGF, Address field) override {
2439  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2440  CGF.pushDestroy(VarType.isDestructedType(), field, VarType);
2441  CGF.PopCleanupBlocks(cleanupDepth);
2442  }
2443 
2444  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2445  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2446  }
2447 };
2448 } // end anonymous namespace
2449 
2450 static llvm::Constant *
2452  BlockByrefHelpers &generator) {
2453  ASTContext &Context = CGF.getContext();
2454 
2455  QualType ReturnTy = Context.VoidTy;
2456 
2457  FunctionArgList args;
2458  ImplicitParamDecl Dst(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2459  args.push_back(&Dst);
2460 
2461  ImplicitParamDecl Src(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2462  args.push_back(&Src);
2463 
2464  const CGFunctionInfo &FI =
2465  CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2466 
2467  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2468 
2469  // FIXME: We'd like to put these into a mergable by content, with
2470  // internal linkage.
2471  llvm::Function *Fn =
2473  "__Block_byref_object_copy_", &CGF.CGM.getModule());
2474 
2475  IdentifierInfo *II
2476  = &Context.Idents.get("__Block_byref_object_copy_");
2477 
2478  SmallVector<QualType, 2> ArgTys;
2479  ArgTys.push_back(Context.VoidPtrTy);
2480  ArgTys.push_back(Context.VoidPtrTy);
2481  QualType FunctionTy = Context.getFunctionType(ReturnTy, ArgTys, {});
2482 
2484  Context, Context.getTranslationUnitDecl(), SourceLocation(),
2485  SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2486 
2488 
2489  CGF.StartFunction(FD, ReturnTy, Fn, FI, args);
2490 
2491  if (generator.needsCopy()) {
2492  llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
2493 
2494  // dst->x
2495  Address destField = CGF.GetAddrOfLocalVar(&Dst);
2496  destField = Address(CGF.Builder.CreateLoad(destField),
2497  byrefInfo.ByrefAlignment);
2498  destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
2499  destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
2500  "dest-object");
2501 
2502  // src->x
2503  Address srcField = CGF.GetAddrOfLocalVar(&Src);
2504  srcField = Address(CGF.Builder.CreateLoad(srcField),
2505  byrefInfo.ByrefAlignment);
2506  srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
2507  srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
2508  "src-object");
2509 
2510  generator.emitCopy(CGF, destField, srcField);
2511  }
2512 
2513  CGF.FinishFunction();
2514 
2515  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2516 }
2517 
2518 /// Build the copy helper for a __block variable.
2519 static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
2520  const BlockByrefInfo &byrefInfo,
2521  BlockByrefHelpers &generator) {
2522  CodeGenFunction CGF(CGM);
2523  return generateByrefCopyHelper(CGF, byrefInfo, generator);
2524 }
2525 
2526 /// Generate code for a __block variable's dispose helper.
2527 static llvm::Constant *
2529  const BlockByrefInfo &byrefInfo,
2530  BlockByrefHelpers &generator) {
2531  ASTContext &Context = CGF.getContext();
2532  QualType R = Context.VoidTy;
2533 
2534  FunctionArgList args;
2535  ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2537  args.push_back(&Src);
2538 
2539  const CGFunctionInfo &FI =
2541 
2542  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2543 
2544  // FIXME: We'd like to put these into a mergable by content, with
2545  // internal linkage.
2546  llvm::Function *Fn =
2548  "__Block_byref_object_dispose_",
2549  &CGF.CGM.getModule());
2550 
2551  IdentifierInfo *II
2552  = &Context.Idents.get("__Block_byref_object_dispose_");
2553 
2554  SmallVector<QualType, 1> ArgTys;
2555  ArgTys.push_back(Context.VoidPtrTy);
2556  QualType FunctionTy = Context.getFunctionType(R, ArgTys, {});
2557 
2559  Context, Context.getTranslationUnitDecl(), SourceLocation(),
2560  SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2561 
2563 
2564  CGF.StartFunction(FD, R, Fn, FI, args);
2565 
2566  if (generator.needsDispose()) {
2567  Address addr = CGF.GetAddrOfLocalVar(&Src);
2568  addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2569  auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2570  addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2571  addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2572 
2573  generator.emitDispose(CGF, addr);
2574  }
2575 
2576  CGF.FinishFunction();
2577 
2578  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2579 }
2580 
2581 /// Build the dispose helper for a __block variable.
2582 static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2583  const BlockByrefInfo &byrefInfo,
2584  BlockByrefHelpers &generator) {
2585  CodeGenFunction CGF(CGM);
2586  return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2587 }
2588 
2589 /// Lazily build the copy and dispose helpers for a __block variable
2590 /// with the given information.
2591 template <class T>
2592 static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2593  T &&generator) {
2594  llvm::FoldingSetNodeID id;
2595  generator.Profile(id);
2596 
2597  void *insertPos;
2598  BlockByrefHelpers *node
2599  = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2600  if (node) return static_cast<T*>(node);
2601 
2602  generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2603  generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2604 
2605  T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2606  CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2607  return copy;
2608 }
2609 
2610 /// Build the copy and dispose helpers for the given __block variable
2611 /// emission. Places the helpers in the global cache. Returns null
2612 /// if no helpers are required.
2614 CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2615  const AutoVarEmission &emission) {
2616  const VarDecl &var = *emission.Variable;
2617  assert(var.isEscapingByref() &&
2618  "only escaping __block variables need byref helpers");
2619 
2620  QualType type = var.getType();
2621 
2622  auto &byrefInfo = getBlockByrefInfo(&var);
2623 
2624  // The alignment we care about for the purposes of uniquing byref
2625  // helpers is the alignment of the actual byref value field.
2626  CharUnits valueAlignment =
2627  byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2628 
2629  if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2630  const Expr *copyExpr =
2632  if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2633 
2635  CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2636  }
2637 
2638  // If type is a non-trivial C struct type that is non-trivial to
2639  // destructly move or destroy, build the copy and dispose helpers.
2640  if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct ||
2641  type.isDestructedType() == QualType::DK_nontrivial_c_struct)
2643  CGM, byrefInfo, NonTrivialCStructByrefHelpers(valueAlignment, type));
2644 
2645  // Otherwise, if we don't have a retainable type, there's nothing to do.
2646  // that the runtime does extra copies.
2647  if (!type->isObjCRetainableType()) return nullptr;
2648 
2649  Qualifiers qs = type.getQualifiers();
2650 
2651  // If we have lifetime, that dominates.
2652  if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2653  switch (lifetime) {
2654  case Qualifiers::OCL_None: llvm_unreachable("impossible");
2655 
2656  // These are just bits as far as the runtime is concerned.
2659  return nullptr;
2660 
2661  // Tell the runtime that this is ARC __weak, called by the
2662  // byref routines.
2663  case Qualifiers::OCL_Weak:
2664  return ::buildByrefHelpers(CGM, byrefInfo,
2665  ARCWeakByrefHelpers(valueAlignment));
2666 
2667  // ARC __strong __block variables need to be retained.
2669  // Block pointers need to be copied, and there's no direct
2670  // transfer possible.
2671  if (type->isBlockPointerType()) {
2672  return ::buildByrefHelpers(CGM, byrefInfo,
2673  ARCStrongBlockByrefHelpers(valueAlignment));
2674 
2675  // Otherwise, we transfer ownership of the retain from the stack
2676  // to the heap.
2677  } else {
2678  return ::buildByrefHelpers(CGM, byrefInfo,
2679  ARCStrongByrefHelpers(valueAlignment));
2680  }
2681  }
2682  llvm_unreachable("fell out of lifetime switch!");
2683  }
2684 
2685  BlockFieldFlags flags;
2686  if (type->isBlockPointerType()) {
2687  flags |= BLOCK_FIELD_IS_BLOCK;
2688  } else if (CGM.getContext().isObjCNSObjectType(type) ||
2689  type->isObjCObjectPointerType()) {
2690  flags |= BLOCK_FIELD_IS_OBJECT;
2691  } else {
2692  return nullptr;
2693  }
2694 
2695  if (type.isObjCGCWeak())
2696  flags |= BLOCK_FIELD_IS_WEAK;
2697 
2698  return ::buildByrefHelpers(CGM, byrefInfo,
2699  ObjectByrefHelpers(valueAlignment, flags));
2700 }
2701 
2703  const VarDecl *var,
2704  bool followForward) {
2705  auto &info = getBlockByrefInfo(var);
2706  return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2707 }
2708 
2710  const BlockByrefInfo &info,
2711  bool followForward,
2712  const llvm::Twine &name) {
2713  // Chase the forwarding address if requested.
2714  if (followForward) {
2715  Address forwardingAddr =
2716  Builder.CreateStructGEP(baseAddr, 1, getPointerSize(), "forwarding");
2717  baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2718  }
2719 
2720  return Builder.CreateStructGEP(baseAddr, info.FieldIndex,
2721  info.FieldOffset, name);
2722 }
2723 
2724 /// BuildByrefInfo - This routine changes a __block variable declared as T x
2725 /// into:
2726 ///
2727 /// struct {
2728 /// void *__isa;
2729 /// void *__forwarding;
2730 /// int32_t __flags;
2731 /// int32_t __size;
2732 /// void *__copy_helper; // only if needed
2733 /// void *__destroy_helper; // only if needed
2734 /// void *__byref_variable_layout;// only if needed
2735 /// char padding[X]; // only if needed
2736 /// T x;
2737 /// } x
2738 ///
2740  auto it = BlockByrefInfos.find(D);
2741  if (it != BlockByrefInfos.end())
2742  return it->second;
2743 
2744  llvm::StructType *byrefType =
2745  llvm::StructType::create(getLLVMContext(),
2746  "struct.__block_byref_" + D->getNameAsString());
2747 
2748  QualType Ty = D->getType();
2749 
2750  CharUnits size;
2752 
2753  // void *__isa;
2754  types.push_back(Int8PtrTy);
2755  size += getPointerSize();
2756 
2757  // void *__forwarding;
2758  types.push_back(llvm::PointerType::getUnqual(byrefType));
2759  size += getPointerSize();
2760 
2761  // int32_t __flags;
2762  types.push_back(Int32Ty);
2763  size += CharUnits::fromQuantity(4);
2764 
2765  // int32_t __size;
2766  types.push_back(Int32Ty);
2767  size += CharUnits::fromQuantity(4);
2768 
2769  // Note that this must match *exactly* the logic in buildByrefHelpers.
2770  bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2771  if (hasCopyAndDispose) {
2772  /// void *__copy_helper;
2773  types.push_back(Int8PtrTy);
2774  size += getPointerSize();
2775 
2776  /// void *__destroy_helper;
2777  types.push_back(Int8PtrTy);
2778  size += getPointerSize();
2779  }
2780 
2781  bool HasByrefExtendedLayout = false;
2782  Qualifiers::ObjCLifetime Lifetime;
2783  if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2784  HasByrefExtendedLayout) {
2785  /// void *__byref_variable_layout;
2786  types.push_back(Int8PtrTy);
2787  size += CharUnits::fromQuantity(PointerSizeInBytes);
2788  }
2789 
2790  // T x;
2791  llvm::Type *varTy = ConvertTypeForMem(Ty);
2792 
2793  bool packed = false;
2794  CharUnits varAlign = getContext().getDeclAlign(D);
2795  CharUnits varOffset = size.alignTo(varAlign);
2796 
2797  // We may have to insert padding.
2798  if (varOffset != size) {
2799  llvm::Type *paddingTy =
2800  llvm::ArrayType::get(Int8Ty, (varOffset - size).getQuantity());
2801 
2802  types.push_back(paddingTy);
2803  size = varOffset;
2804 
2805  // Conversely, we might have to prevent LLVM from inserting padding.
2806  } else if (CGM.getDataLayout().getABITypeAlignment(varTy)
2807  > varAlign.getQuantity()) {
2808  packed = true;
2809  }
2810  types.push_back(varTy);
2811 
2812  byrefType->setBody(types, packed);
2813 
2814  BlockByrefInfo info;
2815  info.Type = byrefType;
2816  info.FieldIndex = types.size() - 1;
2817  info.FieldOffset = varOffset;
2818  info.ByrefAlignment = std::max(varAlign, getPointerAlign());
2819 
2820  auto pair = BlockByrefInfos.insert({D, info});
2821  assert(pair.second && "info was inserted recursively?");
2822  return pair.first->second;
2823 }
2824 
2825 /// Initialize the structural components of a __block variable, i.e.
2826 /// everything but the actual object.
2828  // Find the address of the local.
2829  Address addr = emission.Addr;
2830 
2831  // That's an alloca of the byref structure type.
2832  llvm::StructType *byrefType = cast<llvm::StructType>(
2833  cast<llvm::PointerType>(addr.getPointer()->getType())->getElementType());
2834 
2835  unsigned nextHeaderIndex = 0;
2836  CharUnits nextHeaderOffset;
2837  auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2838  const Twine &name) {
2839  auto fieldAddr = Builder.CreateStructGEP(addr, nextHeaderIndex,
2840  nextHeaderOffset, name);
2841  Builder.CreateStore(value, fieldAddr);
2842 
2843  nextHeaderIndex++;
2844  nextHeaderOffset += fieldSize;
2845  };
2846 
2847  // Build the byref helpers if necessary. This is null if we don't need any.
2848  BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2849 
2850  const VarDecl &D = *emission.Variable;
2851  QualType type = D.getType();
2852 
2853  bool HasByrefExtendedLayout;
2854  Qualifiers::ObjCLifetime ByrefLifetime;
2855  bool ByRefHasLifetime =
2856  getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2857 
2858  llvm::Value *V;
2859 
2860  // Initialize the 'isa', which is just 0 or 1.
2861  int isa = 0;
2862  if (type.isObjCGCWeak())
2863  isa = 1;
2864  V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2865  storeHeaderField(V, getPointerSize(), "byref.isa");
2866 
2867  // Store the address of the variable into its own forwarding pointer.
2868  storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2869 
2870  // Blocks ABI:
2871  // c) the flags field is set to either 0 if no helper functions are
2872  // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2873  BlockFlags flags;
2874  if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2875  if (ByRefHasLifetime) {
2876  if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2877  else switch (ByrefLifetime) {
2879  flags |= BLOCK_BYREF_LAYOUT_STRONG;
2880  break;
2881  case Qualifiers::OCL_Weak:
2882  flags |= BLOCK_BYREF_LAYOUT_WEAK;
2883  break;
2886  break;
2887  case Qualifiers::OCL_None:
2888  if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2890  break;
2891  default:
2892  break;
2893  }
2894  if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2895  printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2896  if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2897  printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2898  if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2899  BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2900  if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2901  printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2902  if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2903  printf(" BLOCK_BYREF_LAYOUT_STRONG");
2904  if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2905  printf(" BLOCK_BYREF_LAYOUT_WEAK");
2906  if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2907  printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2908  if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2909  printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2910  }
2911  printf("\n");
2912  }
2913  }
2914  storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2915  getIntSize(), "byref.flags");
2916 
2917  CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2918  V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2919  storeHeaderField(V, getIntSize(), "byref.size");
2920 
2921  if (helpers) {
2922  storeHeaderField(helpers->CopyHelper, getPointerSize(),
2923  "byref.copyHelper");
2924  storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2925  "byref.disposeHelper");
2926  }
2927 
2928  if (ByRefHasLifetime && HasByrefExtendedLayout) {
2929  auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2930  storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2931  }
2932 }
2933 
2935  bool CanThrow) {
2937  llvm::Value *args[] = {
2938  Builder.CreateBitCast(V, Int8PtrTy),
2939  llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2940  };
2941 
2942  if (CanThrow)
2943  EmitRuntimeCallOrInvoke(F, args);
2944  else
2945  EmitNounwindRuntimeCall(F, args);
2946 }
2947 
2949  BlockFieldFlags Flags,
2950  bool LoadBlockVarAddr, bool CanThrow) {
2951  EHStack.pushCleanup<CallBlockRelease>(Kind, Addr, Flags, LoadBlockVarAddr,
2952  CanThrow);
2953 }
2954 
2955 /// Adjust the declaration of something from the blocks API.
2957  llvm::Constant *C) {
2958  auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2959 
2960  if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2961  IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2964 
2965  assert((isa<llvm::Function>(C->stripPointerCasts()) ||
2966  isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&
2967  "expected Function or GlobalVariable");
2968 
2969  const NamedDecl *ND = nullptr;
2970  for (const auto &Result : DC->lookup(&II))
2971  if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2972  (ND = dyn_cast<VarDecl>(Result)))
2973  break;
2974 
2975  // TODO: support static blocks runtime
2976  if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2977  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2978  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2979  } else {
2980  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2981  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2982  }
2983  }
2984 
2985  if (CGM.getLangOpts().BlocksRuntimeOptional && GV->isDeclaration() &&
2986  GV->hasExternalLinkage())
2987  GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2988 
2989  CGM.setDSOLocal(GV);
2990 }
2991 
2993  if (BlockObjectDispose)
2994  return BlockObjectDispose;
2995 
2996  llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2997  llvm::FunctionType *fty
2998  = llvm::FunctionType::get(VoidTy, args, false);
2999  BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
3000  configureBlocksRuntimeObject(*this, BlockObjectDispose);
3001  return BlockObjectDispose;
3002 }
3003 
3005  if (BlockObjectAssign)
3006  return BlockObjectAssign;
3007 
3008  llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
3009  llvm::FunctionType *fty
3010  = llvm::FunctionType::get(VoidTy, args, false);
3011  BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
3012  configureBlocksRuntimeObject(*this, BlockObjectAssign);
3013  return BlockObjectAssign;
3014 }
3015 
3017  if (NSConcreteGlobalBlock)
3018  return NSConcreteGlobalBlock;
3019 
3020  NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
3021  Int8PtrTy->getPointerTo(),
3022  nullptr);
3023  configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
3024  return NSConcreteGlobalBlock;
3025 }
3026 
3028  if (NSConcreteStackBlock)
3029  return NSConcreteStackBlock;
3030 
3031  NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
3032  Int8PtrTy->getPointerTo(),
3033  nullptr);
3034  configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
3035  return NSConcreteStackBlock;
3036 }
const CGFunctionInfo & arrangeBuiltinFunctionDeclaration(QualType resultType, const FunctionArgList &args)
A builtin function is a freestanding function using the default C conventions.
Definition: CGCall.cpp:659
const llvm::DataLayout & getDataLayout() const
CGOpenCLRuntime & getOpenCLRuntime()
Return a reference to the configured OpenCL runtime.
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:361
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
const BlockDecl * getBlockDecl() const
Definition: Expr.h:5196
Information about the layout of a __block variable.
Definition: CGBlocks.h:144
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
CaptureStrKind
Definition: CGBlocks.cpp:103
const Capture & getCapture(const VarDecl *var) const
Definition: CGBlocks.h:271
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:2002
static llvm::Constant * generateByrefDisposeHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Generate code for a __block variable&#39;s dispose helper.
Definition: CGBlocks.cpp:2528
Represents a function declaration or definition.
Definition: Decl.h:1738
llvm::IntegerType * IntTy
int
llvm::Type * getGenericBlockLiteralType()
The type of a generic block literal.
Definition: CGBlocks.cpp:1223
const CGFunctionInfo & arrangeBlockFunctionDeclaration(const FunctionProtoType *type, const FunctionArgList &args)
Block invocation functions are C functions with an implicit parameter.
Definition: CGCall.cpp:633
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:60
Other implicit parameter.
Definition: Decl.h:1510
CharUnits BlockHeaderForcedGapOffset
Definition: CGBlocks.h:256
const FunctionProtoType * getFunctionType() const
getFunctionType - Return the underlying function type for this block.
Definition: Expr.cpp:2131
Expr * getCopyExpr() const
Definition: Decl.h:3904
static llvm::Constant * buildByrefDisposeHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the dispose helper for a __block variable.
Definition: CGBlocks.cpp:2582
void SetLLVMFunctionAttributes(GlobalDecl GD, const CGFunctionInfo &Info, llvm::Function *F)
Set the LLVM function attributes (sext, zext, etc).
A class which contains all the information about a particular captured value.
Definition: Decl.h:3864
CanQualType VoidPtrTy
Definition: ASTContext.h:1044
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:1925
A (possibly-)qualified type.
Definition: Type.h:638
bool isBlockPointerType() const
Definition: Type.h:6304
const CodeGenOptions & getCodeGenOpts() const
bool hasCaptures() const
True if this block (or its nested blocks) captures anything of local storage from its enclosing scope...
Definition: Decl.h:3977
bool HaveInsertPoint() const
HaveInsertPoint - True if an insertion point is defined.
capture_const_iterator capture_begin() const
Definition: Decl.h:3987
llvm::LLVMContext & getLLVMContext()
void EmitARCDestroyWeak(Address addr)
void @objc_destroyWeak(i8** addr) Essentially objc_storeWeak(addr, nil).
Definition: CGObjC.cpp:2377
The standard implementation of ConstantInitBuilder used in Clang.
BlockVarCopyInit getBlockVarCopyInit(const VarDecl *VD) const
Get the copy initialization expression of the VarDecl VD, or nullptr if none exists.
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3355
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:955
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:2592
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:2228
QualType getLValueReferenceType(QualType T, bool SpelledAsLValue=true) const
Return the uniqued reference to the type for an lvalue reference to the specified type...
param_iterator param_end()
Definition: Decl.h:3957
static llvm::Constant * buildBlockDescriptor(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
buildBlockDescriptor - Build the block descriptor meta-data for a block.
Definition: CGBlocks.cpp:186
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:6245
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:3988
The type would be trivial except that it is volatile-qualified.
Definition: Type.h:1108
Address GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
Represents a variable declaration or definition.
Definition: Decl.h:813
Objects with "hidden" visibility are not seen by the dynamic linker.
Definition: Visibility.h:37
CGBlockInfo(const BlockDecl *blockDecl, StringRef Name)
Definition: CGBlocks.cpp:36
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6748
EHScopeStack::stable_iterator getCleanup() const
Definition: CGBlocks.h:183
static void setBlockHelperAttributesVisibility(bool CapturesNonExternalType, llvm::Function *Fn, const CGFunctionInfo &FI, CodeGenModule &CGM)
Definition: CGBlocks.cpp:1980
LangAS
Defines the address space values used by the address space qualifier of QualType. ...
Definition: AddressSpaces.h:26
This class gathers all debug information during compilation and is responsible for emitting to llvm g...
Definition: CGDebugInfo.h:54
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:1700
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.
const internal::VariadicDynCastAllOfMatcher< Stmt, BlockExpr > blockExpr
Matches a reference to a block.
static void pushCaptureCleanup(BlockCaptureEntityKind CaptureKind, Address Field, QualType CaptureType, BlockFieldFlags Flags, bool ForCopyHelper, VarDecl *Var, CodeGenFunction &CGF)
Definition: CGBlocks.cpp:1938
static void destroyBlockInfos(CGBlockInfo *info)
Destroy a chain of block layouts.
Definition: CGBlocks.cpp:891
The collection of all-type qualifiers we support.
Definition: Type.h:141
void add(RValue rvalue, QualType type)
Definition: CGCall.h:285
const AstTypeMatcher< RecordType > recordType
Matches record types (e.g.
const BlockDecl * Block
Definition: CGBlocks.h:247
llvm::DenseMap< const VarDecl *, FieldDecl * > LambdaCaptureFields
uint64_t getPointerWidth(unsigned AddrSpace) const
Return the width of pointers on this target, for the specified address space.
Definition: TargetInfo.h:349
static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E, CaptureStrKind StrKind, CharUnits BlockAlignment, CodeGenModule &CGM)
Definition: CGBlocks.cpp:1819
One of these records is kept for each identifier that is lexed.
bool doesNotEscape() const
Definition: Decl.h:4009
void emitByrefStructureInit(const AutoVarEmission &emission)
Initialize the structural components of a __block variable, i.e.
Definition: CGBlocks.cpp:2827
CGBlockInfo * FirstBlockInfo
FirstBlockInfo - The head of a singly-linked-list of block layouts.
QualType getPointeeType() const
Definition: Type.h:2654
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:155
llvm::Constant * tryEmitAbstractForInitializer(const VarDecl &D)
Try to emit the initializer of the given declaration as an abstract constant.
bool isObjCInertUnsafeUnretainedType() const
Was this type written with the special inert-in-ARC __unsafe_unretained qualifier?
Definition: Type.h:1996
bool HasCapturedVariableLayout
HasCapturedVariableLayout : True if block has captured variables and their layout meta-data has been ...
Definition: CGBlocks.h:235
FullExpr - Represents a "full-expression" node.
Definition: Expr.h:877
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:288
bool isReferenceType() const
Definition: Type.h:6308
Denotes a cleanup that should run when a scope is exited using exceptional control flow (a throw stat...
Definition: EHScopeStack.h:81
std::string getObjCEncodingForBlock(const BlockExpr *blockExpr) const
Return the encoded type for this block declaration.
void recordBlockInfo(const BlockExpr *E, llvm::Function *InvokeF, llvm::Value *Block)
Record invoke function and block literal emitted during normal codegen for a block expression...
static AggValueSlot forAddr(Address addr, Qualifiers quals, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, Overlap_t mayOverlap, IsZeroed_t isZeroed=IsNotZeroed, IsSanitizerChecked_t isChecked=IsNotSanitizerChecked)
forAddr - Make a slot for an aggregate value.
Definition: CGValue.h:514
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:2451
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:3937
static bool isSafeForCXXConstantCapture(QualType type)
Determines if the given type is safe for constant capture in C++.
Definition: CGBlocks.cpp:387
CleanupKind getCleanupKind(QualType::DestructionKind kind)
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:50
IdentifierTable & Idents
Definition: ASTContext.h:566
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:110
CharUnits GetTargetTypeStoreSize(llvm::Type *Ty) const
Return the store size, in character units, of the given LLVM type.
llvm::Value * EmitARCStoreStrongCall(Address addr, llvm::Value *value, bool resultIgnored)
Store into a strong object.
Definition: CGObjC.cpp:2217
virtual std::string getRCBlockLayoutStr(CodeGen::CodeGenModule &CGM, const CGBlockInfo &blockInfo)
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:2203
const BlockDecl * getBlockDecl() const
Definition: CGBlocks.h:281
void setDSOLocal(llvm::GlobalValue *GV) const
virtual TargetOpenCLBlockHelper * getTargetOpenCLBlockHelper() const
Definition: TargetInfo.h:286
bool HasCXXObject
HasCXXObject - True if the block&#39;s custom copy/dispose functions need to be run even in GC mode...
Definition: CGBlocks.h:227
llvm::Value * EmitBlockLiteral(const BlockExpr *)
Emit block literal.
Definition: CGBlocks.cpp:901
uint32_t getBitMask() const
Definition: CGBlocks.h:118
bool isByRef() const
Whether this is a "by ref" capture, i.e.
Definition: Decl.h:3889
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6142
bool needsEHCleanup(QualType::DestructionKind kind)
Determines whether an EH cleanup is required to destroy a type with the given destruction kind...
llvm::Constant * getAddrOfGlobalBlockIfEmitted(const BlockExpr *BE)
Returns the address of a block which requires no caputres, or null if we&#39;ve yet to emit the block for...
The type is an Objective-C retainable pointer type that is qualified with the ARC __strong qualifier...
Definition: Type.h:1112
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:41
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:210
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:106
void callCStructMoveConstructor(LValue Dst, LValue Src)
const Stmt * getBody() const
Definition: Expr.cpp:2140
llvm::Constant * getNSConcreteStackBlock()
Definition: CGBlocks.cpp:3027
static std::string getNonTrivialCopyConstructorStr(QualType QT, CharUnits Alignment, bool IsVolatile, ASTContext &Ctx)
The type does not fall into any of the following categories.
Definition: Type.h:1103
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:1875
This object can be modified without requiring retains or releases.
Definition: Type.h:162
StringRef Name
Name - The name of the block, kindof.
Definition: CGBlocks.h:156
bool isEscapingByref() const
Definition: Decl.h:3891
bool NeedsCopyDispose
True if the block has captures that would necessitate custom copy or dispose helper functions if the ...
Definition: CGBlocks.h:223
lookup_result lookup(DeclarationName Name) const
lookup - Find the declarations (if any) with the given Name in this context.
Definition: DeclBase.cpp:1595
const BlockExpr * BlockExpression
Definition: CGBlocks.h:248
static llvm::Constant * buildCopyHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to copy a block.
Definition: CGBlocks.cpp:57
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:1613
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3687
llvm::CallInst * EmitNounwindRuntimeCall(llvm::Value *callee, const Twine &name="")
uint32_t getBitMask() const
Definition: CGBlocks.h:74
const CodeGen::CGBlockInfo * BlockInfo
const TargetCodeGenInfo & getTargetCodeGenInfo()
CGBlockInfo - Information to generate a block literal.
Definition: CGBlocks.h:153
virtual void emitCopy(CodeGenFunction &CGF, Address dest, Address src)=0
RValue - This trivial value class is used to represent the result of an expression that is evaluated...
Definition: CGValue.h:39
bool CanBeGlobal
CanBeGlobal - True if the block can be global, i.e.
Definition: CGBlocks.h:219
StringRef getBlockMangledName(GlobalDecl GD, const BlockDecl *BD)
static void findBlockCapturedManagedEntities(const CGBlockInfo &BlockInfo, const LangOptions &LangOpts, SmallVectorImpl< BlockCaptureManagedEntity > &ManagedCaptures)
Find the set of block captures that need to be explicitly copied or destroy.
Definition: CGBlocks.cpp:1761
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
unsigned Offset
Definition: Format.cpp:1631
static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info, SmallVectorImpl< llvm::Type *> &elementTypes)
Definition: CGBlocks.cpp:447
CGBlockInfo * NextBlockInfo
The next block in the block-info chain.
Definition: CGBlocks.h:269
CGObjCRuntime & getObjCRuntime()
Return a reference to the configured Objective-C runtime.
Pepresents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:3858
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:2393
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:6811
bool isObjCRetainableType() const
Definition: Type.cpp:3921
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5182
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2706
BlockCaptureEntityKind
Represents a type of copy/destroy operation that should be performed for an entity that&#39;s captured by...
Definition: CGBlocks.cpp:72
static llvm::Constant * buildGlobalBlock(CodeGenModule &CGM, const CGBlockInfo &blockInfo, llvm::Constant *blockFn)
Build the given block as a global block.
Definition: CGBlocks.cpp:1393
Expr * getCallee()
Definition: Expr.h:2514
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:2195
ObjCLifetime getObjCLifetime() const
Definition: Type.h:326
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:63
internal::Matcher< T > id(StringRef ID, const internal::BindableMatcher< T > &InnerMatcher)
If the provided matcher matches a node, binds the node to ID.
Definition: ASTMatchers.h:137
bool needsCopyDisposeHelpers() const
Definition: CGBlocks.h:291
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:1511
static Capture makeIndex(unsigned index, CharUnits offset, QualType FieldType)
Definition: CGBlocks.h:201
QualType getType() const
Definition: Expr.h:128
bool isa(CodeGen::Address addr)
Definition: Address.h:112
QualType getFunctionType(QualType ResultTy, ArrayRef< QualType > Args, const FunctionProtoType::ExtProtoInfo &EPI) const
Return a normal function type with a typed argument list.
Definition: ASTContext.h:1380
static bool CanThrow(Expr *E, ASTContext &Ctx)
Definition: CFG.cpp:2407
static CharUnits getLowBit(CharUnits v)
Get the low bit of a nonzero character count.
Definition: CGBlocks.cpp:443
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:6688
const TargetInfo & getTarget() const
const LangOptions & getLangOpts() const
ASTContext & getContext() const
static BlockFieldFlags getBlockFieldFlagsForObjCObjectPointer(const BlockDecl::Capture &CI, QualType T)
Definition: CGBlocks.cpp:2141
do v
Definition: arm_acle.h:78
Address GetAddrOfBlockDecl(const VarDecl *var)
Definition: CGBlocks.cpp:1328
static QualType getCaptureFieldType(const CodeGenFunction &CGF, const BlockDecl::Capture &CI)
Definition: CGBlocks.cpp:502
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:35
static std::string getBlockDescriptorName(const CGBlockInfo &BlockInfo, CodeGenModule &CGM)
Definition: CGBlocks.cpp:123
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:6131
param_iterator param_begin()
Definition: Decl.h:3956
The l-value was considered opaque, so the alignment was determined from a type.
RecordDecl * getDecl() const
Definition: Type.h:4380
void setBlockContextParameter(const ImplicitParamDecl *D, unsigned argNum, llvm::Value *ptr)
Definition: CGBlocks.cpp:1484
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:424
bool UsesStret
UsesStret : True if the block uses an stret return.
Definition: CGBlocks.h:231
There is no lifetime qualification on this type.
Definition: Type.h:158
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:169
Kind
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:2419
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:1952
Encodes a location in the source.
static DeclContext * castToDeclContext(const TranslationUnitDecl *D)
Definition: Decl.h:130
void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags, bool CanThrow)
Definition: CGBlocks.cpp:2934
QualType getReturnType() const
Definition: Type.h:3613
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Expr.h:5205
A saved depth on the scope stack.
Definition: EHScopeStack.h:107
llvm::StructType * StructureType
Definition: CGBlocks.h:246
std::string getNameAsString() const
Get a human-readable name for the declaration, even if it is one of the special kinds of names (C++ c...
Definition: Decl.h:292
static std::string getCopyDestroyHelperFuncName(const SmallVectorImpl< BlockCaptureManagedEntity > &Captures, CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM)
Definition: CGBlocks.cpp:1915
static void configureBlocksRuntimeObject(CodeGenModule &CGM, llvm::Constant *C)
Adjust the declaration of something from the blocks API.
Definition: CGBlocks.cpp:2956
The type is a struct containing a field whose type is neither PCK_Trivial nor PCK_VolatileTrivial.
Definition: Type.h:1124
An aggregate value slot.
Definition: CGValue.h:437
const BlockByrefInfo & getBlockByrefInfo(const VarDecl *var)
BuildByrefInfo - This routine changes a __block variable declared as T x into:
Definition: CGBlocks.cpp:2739
A scoped helper to set the current debug location to the specified location or preferred location of ...
Definition: CGDebugInfo.h:684
bool CapturesNonExternalType
Indicates whether an object of a non-external C++ class is captured.
Definition: CGBlocks.h:240
static bool cxxDestructorCanThrow(QualType T)
Check if T is a C++ class that has a destructor that can throw.
Definition: CGBlocks.cpp:1811
bool isConversionFromLambda() const
Definition: Decl.h:4001
void enterNonTrivialFullExpression(const FullExpr *E)
Enter a full-expression with a non-trivial number of objects to clean up.
Definition: CGBlocks.cpp:865
CanQualType VoidTy
Definition: ASTContext.h:1016
llvm::DenseMap< const VarDecl *, Capture > Captures
The mapping of allocated indexes within the block.
Definition: CGBlocks.h:243
bool isNonEscapingByref() const
Indicates the capture is a __block variable that is never captured by an escaping block...
Definition: Decl.cpp:2378
arg_range arguments()
Definition: Expr.h:2590
bool isObjCObjectPointerType() const
Definition: Type.h:6393
static bool isBlockPointer(Expr *Arg)
llvm::Constant * getBlockObjectDispose()
Definition: CGBlocks.cpp:2992
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.
void SetLLVMFunctionAttributesForDefinition(const Decl *D, llvm::Function *F)
Set the LLVM function attributes which only apply to a function definition.
ImplicitCastExpr - Allows us to explicitly represent implicit type conversions, which have no direct ...
Definition: Expr.h:3120
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1152
llvm::Value * getConstant() const
Definition: CGBlocks.h:192
const BlockExpr * getBlockExpr() const
Definition: CGBlocks.h:282
All available information about a concrete callee.
Definition: CGCall.h:67
MangleContext & getMangleContext()
Gets the mangle context.
Definition: CGCXXABI.h:97
void enterByrefCleanup(CleanupKind Kind, Address Addr, BlockFieldFlags Flags, bool LoadBlockVarAddr, bool CanThrow)
Enter a cleanup to destroy a __block variable.
Definition: CGBlocks.cpp:2948
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:3885
PrimitiveCopyKind isNonTrivialToPrimitiveCopy() const
Check if this is a non-trivial type that would cause a C struct transitively containing this type to ...
Definition: Type.cpp:2265
unsigned CXXThisIndex
The field index of &#39;this&#39; within the block, if there is one.
Definition: CGBlocks.h:159
Assigning into this object requires a lifetime extension.
Definition: Type.h:175
static Destroyer destroyARCStrongImprecise
void FinishFunction(SourceLocation EndLoc=SourceLocation())
FinishFunction - Complete IR generation of the current function.
virtual void mangleTypeName(QualType T, raw_ostream &)=0
Generates a unique string for an externally visible type for use with TBAA or type uniquing...
The type is an Objective-C retainable pointer type that is qualified with the ARC __weak qualifier...
Definition: Type.h:1116
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:626
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...
void addUsedGlobal(llvm::GlobalValue *GV)
Add a global to a list to be added to the llvm.used metadata.
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:356
bool isObjCGCWeak() const
true when Type is objc&#39;s weak.
Definition: Type.h:1048
static llvm::Constant * tryCaptureAsConstant(CodeGenModule &CGM, CodeGenFunction *CGF, const VarDecl *var)
It is illegal to modify a const object after initialization.
Definition: CGBlocks.cpp:411
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:521
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:1262
ArrayRef< Capture > captures() const
Definition: Decl.h:3985
bool isNested() const
Whether this is a nested capture, i.e.
Definition: Decl.h:3901
Address CreateStructGEP(Address Addr, unsigned Index, CharUnits Offset, const llvm::Twine &Name="")
Definition: CGBuilder.h:172
Parameter for Objective-C &#39;self&#39; argument.
Definition: Decl.h:1495
static llvm::Constant * buildDisposeHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to dispose of a block.
Definition: CGBlocks.cpp:63
const Expr * getInit() const
Definition: Decl.h:1220
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:325
llvm::StoreInst * CreateStore(llvm::Value *Val, Address Addr, bool IsVolatile=false)
Definition: CGBuilder.h:108
bool isEscapingByref() const
Indicates the capture is a __block variable that is captured by a block that can potentially escape (...
Definition: Decl.cpp:2374
llvm::Module & getModule() const
llvm::StructType * Type
Definition: CGBlocks.h:146
LValue MakeAddrLValue(Address Addr, QualType T, AlignmentSource Source=AlignmentSource::Type)
llvm::DenseMap< const Decl *, Address > DeclMapTy
static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block)
Enter the scope of a block.
Definition: CGBlocks.cpp:780
Pointer to a block type.
Definition: Type.h:2639
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:4370
StructBuilder beginStruct(llvm::StructType *structTy=nullptr)
CanQualType UnsignedLongTy
Definition: ASTContext.h:1026
static llvm::Constant * buildByrefCopyHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the copy helper for a __block variable.
Definition: CGBlocks.cpp:2519
void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp)
Definition: CGExprCXX.cpp:645
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:874
void SetInternalFunctionAttributes(GlobalDecl GD, llvm::Function *F, const CGFunctionInfo &FI)
Set the attributes on the LLVM function for the given decl and function info.
virtual void emitDispose(CodeGenFunction &CGF, Address field)=0
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:32
llvm::Constant * getBlockObjectAssign()
Definition: CGBlocks.cpp:3004
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:3990
Reading or writing from this object requires a barrier call.
Definition: Type.h:172
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:1009
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
static std::string getNonTrivialDestructorStr(QualType QT, CharUnits Alignment, bool IsVolatile, ASTContext &Ctx)
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:6099
void setAddrOfGlobalBlock(const BlockExpr *BE, llvm::Constant *Addr)
Notes that BE&#39;s global block is available via Addr.
Definition: CGBlocks.cpp:1363
CharUnits BlockHeaderForcedGapSize
Definition: CGBlocks.h:259
SourceLocation getEndLoc() const LLVM_READONLY
Definition: Expr.h:5208
llvm::Value * EmitARCRetainBlock(llvm::Value *value, bool mandatory)
Retain the given block, with _Block_copy semantics.
Definition: CGObjC.cpp:2077
uint64_t getPointerAlign(unsigned AddrSpace) const
Definition: TargetInfo.h:352
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2396
StringRef getName() const
Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:276
CGCXXABI & getCXXABI() const
__DEVICE__ int max(int __a, int __b)
llvm::Function * GenerateBlockFunction(GlobalDecl GD, const CGBlockInfo &Info, const DeclMapTy &ldm, bool IsLambdaConversionToBlock, bool BuildGlobalBlock)
Definition: CGBlocks.cpp:1524
The top declaration context.
Definition: Decl.h:108
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1041
static RValue get(llvm::Value *V)
Definition: CGValue.h:86
RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue)
Definition: CGBlocks.cpp:1260
const internal::VariadicDynCastAllOfMatcher< Decl, BlockDecl > blockDecl
Matches block declarations.
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:732
llvm::Constant * getNSConcreteGlobalBlock()
Definition: CGBlocks.cpp:3016
llvm::Type * getBlockDescriptorType()
Fetches the type of a generic block descriptor.
Definition: CGBlocks.cpp:1191
llvm::Constant * GetAddrOfGlobalBlock(const BlockExpr *BE, StringRef Name)
Gets the address of a block which requires no captures.
Definition: CGBlocks.cpp:1371
QualType getType() const
Definition: Decl.h:648
An l-value expression is a reference to an object with independent storage.
Definition: Specifiers.h:114
llvm::PointerType * getGenericVoidPointerType()
Information for lazily generating a cleanup.
Definition: EHScopeStack.h:147
This represents a decl that may have a name.
Definition: Decl.h:249
llvm::Instruction * DominatingIP
An instruction which dominates the full-expression that the block is inside.
Definition: CGBlocks.h:263
unsigned long ulong
An unsigned 64-bit integer.
Definition: opencl-c.h:60
const LangOptions & getLangOpts() const
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2499
static bool isObjCNSObjectType(QualType Ty)
Return true if this is an NSObject object with its NSObject attribute set.
Definition: ASTContext.h:2050
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:260
const LangOptions & getLangOpts() const
Definition: ASTContext.h:707
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:2702
Abstract information about a function or function prototype.
Definition: CGCall.h:45
SourceLocation getLocation() const
Definition: DeclBase.h:418
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:2150
bool isExternallyVisible() const
Definition: Decl.h:380
void setCleanup(EHScopeStack::stable_iterator cleanup)
Definition: CGBlocks.h:187
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:1058
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1550