clang  9.0.0svn
CGBlocks.cpp
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1 //===--- CGBlocks.cpp - Emit LLVM Code for declarations ---------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This contains code to emit blocks.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "CGBlocks.h"
14 #include "CGCXXABI.h"
15 #include "CGDebugInfo.h"
16 #include "CGObjCRuntime.h"
17 #include "CGOpenCLRuntime.h"
18 #include "CodeGenFunction.h"
19 #include "CodeGenModule.h"
20 #include "ConstantEmitter.h"
21 #include "TargetInfo.h"
22 #include "clang/AST/DeclObjC.h"
24 #include "llvm/ADT/SmallSet.h"
25 #include "llvm/IR/DataLayout.h"
26 #include "llvm/IR/Module.h"
27 #include "llvm/Support/ScopedPrinter.h"
28 #include <algorithm>
29 #include <cstdio>
30 
31 using namespace clang;
32 using namespace CodeGen;
33 
34 CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
35  : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
36  HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
37  CapturesNonExternalType(false), LocalAddress(Address::invalid()),
38  StructureType(nullptr), Block(block), DominatingIP(nullptr) {
39 
40  // Skip asm prefix, if any. 'name' is usually taken directly from
41  // the mangled name of the enclosing function.
42  if (!name.empty() && name[0] == '\01')
43  name = name.substr(1);
44 }
45 
46 // Anchor the vtable to this translation unit.
48 
49 /// Build the given block as a global block.
50 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
51  const CGBlockInfo &blockInfo,
52  llvm::Constant *blockFn);
53 
54 /// Build the helper function to copy a block.
55 static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
56  const CGBlockInfo &blockInfo) {
57  return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
58 }
59 
60 /// Build the helper function to dispose of a block.
61 static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
62  const CGBlockInfo &blockInfo) {
63  return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
64 }
65 
66 namespace {
67 
68 /// Represents a type of copy/destroy operation that should be performed for an
69 /// entity that's captured by a block.
71  CXXRecord, // Copy or destroy
72  ARCWeak,
73  ARCStrong,
74  NonTrivialCStruct,
75  BlockObject, // Assign or release
76  None
77 };
78 
79 /// Represents a captured entity that requires extra operations in order for
80 /// this entity to be copied or destroyed correctly.
81 struct BlockCaptureManagedEntity {
82  BlockCaptureEntityKind CopyKind, DisposeKind;
83  BlockFieldFlags CopyFlags, DisposeFlags;
84  const BlockDecl::Capture *CI;
86 
87  BlockCaptureManagedEntity(BlockCaptureEntityKind CopyType,
88  BlockCaptureEntityKind DisposeType,
89  BlockFieldFlags CopyFlags,
90  BlockFieldFlags DisposeFlags,
91  const BlockDecl::Capture &CI,
92  const CGBlockInfo::Capture &Capture)
93  : CopyKind(CopyType), DisposeKind(DisposeType), CopyFlags(CopyFlags),
94  DisposeFlags(DisposeFlags), CI(&CI), Capture(&Capture) {}
95 
96  bool operator<(const BlockCaptureManagedEntity &Other) const {
97  return Capture->getOffset() < Other.Capture->getOffset();
98  }
99 };
100 
101 enum class CaptureStrKind {
102  // String for the copy helper.
103  CopyHelper,
104  // String for the dispose helper.
105  DisposeHelper,
106  // Merge the strings for the copy helper and dispose helper.
107  Merged
108 };
109 
110 } // end anonymous namespace
111 
113  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
114  SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures);
115 
116 static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
117  CaptureStrKind StrKind,
118  CharUnits BlockAlignment,
119  CodeGenModule &CGM);
120 
121 static std::string getBlockDescriptorName(const CGBlockInfo &BlockInfo,
122  CodeGenModule &CGM) {
123  std::string Name = "__block_descriptor_";
124  Name += llvm::to_string(BlockInfo.BlockSize.getQuantity()) + "_";
125 
126  if (BlockInfo.needsCopyDisposeHelpers()) {
127  if (CGM.getLangOpts().Exceptions)
128  Name += "e";
129  if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
130  Name += "a";
131  Name += llvm::to_string(BlockInfo.BlockAlign.getQuantity()) + "_";
132 
135  ManagedCaptures);
136 
137  for (const BlockCaptureManagedEntity &E : ManagedCaptures) {
138  Name += llvm::to_string(E.Capture->getOffset().getQuantity());
139 
140  if (E.CopyKind == E.DisposeKind) {
141  // If CopyKind and DisposeKind are the same, merge the capture
142  // information.
143  assert(E.CopyKind != BlockCaptureEntityKind::None &&
144  "shouldn't see BlockCaptureManagedEntity that is None");
145  Name += getBlockCaptureStr(E, CaptureStrKind::Merged,
146  BlockInfo.BlockAlign, CGM);
147  } else {
148  // If CopyKind and DisposeKind are not the same, which can happen when
149  // either Kind is None or the captured object is a __strong block,
150  // concatenate the copy and dispose strings.
151  Name += getBlockCaptureStr(E, CaptureStrKind::CopyHelper,
152  BlockInfo.BlockAlign, CGM);
153  Name += getBlockCaptureStr(E, CaptureStrKind::DisposeHelper,
154  BlockInfo.BlockAlign, CGM);
155  }
156  }
157  Name += "_";
158  }
159 
160  std::string TypeAtEncoding =
162  /// Replace occurrences of '@' with '\1'. '@' is reserved on ELF platforms as
163  /// a separator between symbol name and symbol version.
164  std::replace(TypeAtEncoding.begin(), TypeAtEncoding.end(), '@', '\1');
165  Name += "e" + llvm::to_string(TypeAtEncoding.size()) + "_" + TypeAtEncoding;
166  Name += "l" + CGM.getObjCRuntime().getRCBlockLayoutStr(CGM, BlockInfo);
167  return Name;
168 }
169 
170 /// buildBlockDescriptor - Build the block descriptor meta-data for a block.
171 /// buildBlockDescriptor is accessed from 5th field of the Block_literal
172 /// meta-data and contains stationary information about the block literal.
173 /// Its definition will have 4 (or optionally 6) words.
174 /// \code
175 /// struct Block_descriptor {
176 /// unsigned long reserved;
177 /// unsigned long size; // size of Block_literal metadata in bytes.
178 /// void *copy_func_helper_decl; // optional copy helper.
179 /// void *destroy_func_decl; // optional destructor helper.
180 /// void *block_method_encoding_address; // @encode for block literal signature.
181 /// void *block_layout_info; // encoding of captured block variables.
182 /// };
183 /// \endcode
184 static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
185  const CGBlockInfo &blockInfo) {
186  ASTContext &C = CGM.getContext();
187 
188  llvm::IntegerType *ulong =
189  cast<llvm::IntegerType>(CGM.getTypes().ConvertType(C.UnsignedLongTy));
190  llvm::PointerType *i8p = nullptr;
191  if (CGM.getLangOpts().OpenCL)
192  i8p =
193  llvm::Type::getInt8PtrTy(
195  else
196  i8p = CGM.VoidPtrTy;
197 
198  std::string descName;
199 
200  // If an equivalent block descriptor global variable exists, return it.
201  if (C.getLangOpts().ObjC &&
202  CGM.getLangOpts().getGC() == LangOptions::NonGC) {
203  descName = getBlockDescriptorName(blockInfo, CGM);
204  if (llvm::GlobalValue *desc = CGM.getModule().getNamedValue(descName))
205  return llvm::ConstantExpr::getBitCast(desc,
206  CGM.getBlockDescriptorType());
207  }
208 
209  // If there isn't an equivalent block descriptor global variable, create a new
210  // one.
211  ConstantInitBuilder builder(CGM);
212  auto elements = builder.beginStruct();
213 
214  // reserved
215  elements.addInt(ulong, 0);
216 
217  // Size
218  // FIXME: What is the right way to say this doesn't fit? We should give
219  // a user diagnostic in that case. Better fix would be to change the
220  // API to size_t.
221  elements.addInt(ulong, blockInfo.BlockSize.getQuantity());
222 
223  // Optional copy/dispose helpers.
224  bool hasInternalHelper = false;
225  if (blockInfo.needsCopyDisposeHelpers()) {
226  // copy_func_helper_decl
227  llvm::Constant *copyHelper = buildCopyHelper(CGM, blockInfo);
228  elements.add(copyHelper);
229 
230  // destroy_func_decl
231  llvm::Constant *disposeHelper = buildDisposeHelper(CGM, blockInfo);
232  elements.add(disposeHelper);
233 
234  if (cast<llvm::Function>(copyHelper->getOperand(0))->hasInternalLinkage() ||
235  cast<llvm::Function>(disposeHelper->getOperand(0))
236  ->hasInternalLinkage())
237  hasInternalHelper = true;
238  }
239 
240  // Signature. Mandatory ObjC-style method descriptor @encode sequence.
241  std::string typeAtEncoding =
243  elements.add(llvm::ConstantExpr::getBitCast(
244  CGM.GetAddrOfConstantCString(typeAtEncoding).getPointer(), i8p));
245 
246  // GC layout.
247  if (C.getLangOpts().ObjC) {
248  if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
249  elements.add(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
250  else
251  elements.add(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
252  }
253  else
254  elements.addNullPointer(i8p);
255 
256  unsigned AddrSpace = 0;
257  if (C.getLangOpts().OpenCL)
259 
260  llvm::GlobalValue::LinkageTypes linkage;
261  if (descName.empty()) {
263  descName = "__block_descriptor_tmp";
264  } else if (hasInternalHelper) {
265  // If either the copy helper or the dispose helper has internal linkage,
266  // the block descriptor must have internal linkage too.
268  } else {
269  linkage = llvm::GlobalValue::LinkOnceODRLinkage;
270  }
271 
272  llvm::GlobalVariable *global =
273  elements.finishAndCreateGlobal(descName, CGM.getPointerAlign(),
274  /*constant*/ true, linkage, AddrSpace);
275 
276  if (linkage == llvm::GlobalValue::LinkOnceODRLinkage) {
277  global->setVisibility(llvm::GlobalValue::HiddenVisibility);
278  global->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
279  }
280 
281  return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
282 }
283 
284 /*
285  Purely notional variadic template describing the layout of a block.
286 
287  template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
288  struct Block_literal {
289  /// Initialized to one of:
290  /// extern void *_NSConcreteStackBlock[];
291  /// extern void *_NSConcreteGlobalBlock[];
292  ///
293  /// In theory, we could start one off malloc'ed by setting
294  /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
295  /// this isa:
296  /// extern void *_NSConcreteMallocBlock[];
297  struct objc_class *isa;
298 
299  /// These are the flags (with corresponding bit number) that the
300  /// compiler is actually supposed to know about.
301  /// 23. BLOCK_IS_NOESCAPE - indicates that the block is non-escaping
302  /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
303  /// descriptor provides copy and dispose helper functions
304  /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
305  /// object with a nontrivial destructor or copy constructor
306  /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
307  /// as global memory
308  /// 29. BLOCK_USE_STRET - indicates that the block function
309  /// uses stret, which objc_msgSend needs to know about
310  /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
311  /// @encoded signature string
312  /// And we're not supposed to manipulate these:
313  /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
314  /// to malloc'ed memory
315  /// 27. BLOCK_IS_GC - indicates that the block has been moved to
316  /// to GC-allocated memory
317  /// Additionally, the bottom 16 bits are a reference count which
318  /// should be zero on the stack.
319  int flags;
320 
321  /// Reserved; should be zero-initialized.
322  int reserved;
323 
324  /// Function pointer generated from block literal.
325  _ResultType (*invoke)(Block_literal *, _ParamTypes...);
326 
327  /// Block description metadata generated from block literal.
328  struct Block_descriptor *block_descriptor;
329 
330  /// Captured values follow.
331  _CapturesTypes captures...;
332  };
333  */
334 
335 namespace {
336  /// A chunk of data that we actually have to capture in the block.
337  struct BlockLayoutChunk {
338  CharUnits Alignment;
339  CharUnits Size;
340  Qualifiers::ObjCLifetime Lifetime;
341  const BlockDecl::Capture *Capture; // null for 'this'
342  llvm::Type *Type;
343  QualType FieldType;
344 
345  BlockLayoutChunk(CharUnits align, CharUnits size,
346  Qualifiers::ObjCLifetime lifetime,
347  const BlockDecl::Capture *capture,
348  llvm::Type *type, QualType fieldType)
349  : Alignment(align), Size(size), Lifetime(lifetime),
350  Capture(capture), Type(type), FieldType(fieldType) {}
351 
352  /// Tell the block info that this chunk has the given field index.
353  void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
354  if (!Capture) {
355  info.CXXThisIndex = index;
356  info.CXXThisOffset = offset;
357  } else {
358  auto C = CGBlockInfo::Capture::makeIndex(index, offset, FieldType);
359  info.Captures.insert({Capture->getVariable(), C});
360  }
361  }
362  };
363 
364  /// Order by 1) all __strong together 2) next, all byfref together 3) next,
365  /// all __weak together. Preserve descending alignment in all situations.
366  bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
367  if (left.Alignment != right.Alignment)
368  return left.Alignment > right.Alignment;
369 
370  auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
371  if (chunk.Capture && chunk.Capture->isByRef())
372  return 1;
373  if (chunk.Lifetime == Qualifiers::OCL_Strong)
374  return 0;
375  if (chunk.Lifetime == Qualifiers::OCL_Weak)
376  return 2;
377  return 3;
378  };
379 
380  return getPrefOrder(left) < getPrefOrder(right);
381  }
382 } // end anonymous namespace
383 
384 /// Determines if the given type is safe for constant capture in C++.
386  const RecordType *recordType =
388 
389  // Only records can be unsafe.
390  if (!recordType) return true;
391 
392  const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
393 
394  // Maintain semantics for classes with non-trivial dtors or copy ctors.
395  if (!record->hasTrivialDestructor()) return false;
396  if (record->hasNonTrivialCopyConstructor()) return false;
397 
398  // Otherwise, we just have to make sure there aren't any mutable
399  // fields that might have changed since initialization.
400  return !record->hasMutableFields();
401 }
402 
403 /// It is illegal to modify a const object after initialization.
404 /// Therefore, if a const object has a constant initializer, we don't
405 /// actually need to keep storage for it in the block; we'll just
406 /// rematerialize it at the start of the block function. This is
407 /// acceptable because we make no promises about address stability of
408 /// captured variables.
409 static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
410  CodeGenFunction *CGF,
411  const VarDecl *var) {
412  // Return if this is a function parameter. We shouldn't try to
413  // rematerialize default arguments of function parameters.
414  if (isa<ParmVarDecl>(var))
415  return nullptr;
416 
417  QualType type = var->getType();
418 
419  // We can only do this if the variable is const.
420  if (!type.isConstQualified()) return nullptr;
421 
422  // Furthermore, in C++ we have to worry about mutable fields:
423  // C++ [dcl.type.cv]p4:
424  // Except that any class member declared mutable can be
425  // modified, any attempt to modify a const object during its
426  // lifetime results in undefined behavior.
427  if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
428  return nullptr;
429 
430  // If the variable doesn't have any initializer (shouldn't this be
431  // invalid?), it's not clear what we should do. Maybe capture as
432  // zero?
433  const Expr *init = var->getInit();
434  if (!init) return nullptr;
435 
436  return ConstantEmitter(CGM, CGF).tryEmitAbstractForInitializer(*var);
437 }
438 
439 /// Get the low bit of a nonzero character count. This is the
440 /// alignment of the nth byte if the 0th byte is universally aligned.
442  return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
443 }
444 
446  SmallVectorImpl<llvm::Type*> &elementTypes) {
447 
448  assert(elementTypes.empty());
449  if (CGM.getLangOpts().OpenCL) {
450  // The header is basically 'struct { int; int; generic void *;
451  // custom_fields; }'. Assert that struct is packed.
452  auto GenericAS =
454  auto GenPtrAlign =
455  CharUnits::fromQuantity(CGM.getTarget().getPointerAlign(GenericAS) / 8);
456  auto GenPtrSize =
457  CharUnits::fromQuantity(CGM.getTarget().getPointerWidth(GenericAS) / 8);
458  assert(CGM.getIntSize() <= GenPtrSize);
459  assert(CGM.getIntAlign() <= GenPtrAlign);
460  assert((2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign));
461  elementTypes.push_back(CGM.IntTy); /* total size */
462  elementTypes.push_back(CGM.IntTy); /* align */
463  elementTypes.push_back(
464  CGM.getOpenCLRuntime()
465  .getGenericVoidPointerType()); /* invoke function */
466  unsigned Offset =
467  2 * CGM.getIntSize().getQuantity() + GenPtrSize.getQuantity();
468  unsigned BlockAlign = GenPtrAlign.getQuantity();
469  if (auto *Helper =
471  for (auto I : Helper->getCustomFieldTypes()) /* custom fields */ {
472  // TargetOpenCLBlockHelp needs to make sure the struct is packed.
473  // If necessary, add padding fields to the custom fields.
474  unsigned Align = CGM.getDataLayout().getABITypeAlignment(I);
475  if (BlockAlign < Align)
476  BlockAlign = Align;
477  assert(Offset % Align == 0);
478  Offset += CGM.getDataLayout().getTypeAllocSize(I);
479  elementTypes.push_back(I);
480  }
481  }
482  info.BlockAlign = CharUnits::fromQuantity(BlockAlign);
483  info.BlockSize = CharUnits::fromQuantity(Offset);
484  } else {
485  // The header is basically 'struct { void *; int; int; void *; void *; }'.
486  // Assert that the struct is packed.
487  assert(CGM.getIntSize() <= CGM.getPointerSize());
488  assert(CGM.getIntAlign() <= CGM.getPointerAlign());
489  assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()));
490  info.BlockAlign = CGM.getPointerAlign();
491  info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
492  elementTypes.push_back(CGM.VoidPtrTy);
493  elementTypes.push_back(CGM.IntTy);
494  elementTypes.push_back(CGM.IntTy);
495  elementTypes.push_back(CGM.VoidPtrTy);
496  elementTypes.push_back(CGM.getBlockDescriptorType());
497  }
498 }
499 
501  const BlockDecl::Capture &CI) {
502  const VarDecl *VD = CI.getVariable();
503 
504  // If the variable is captured by an enclosing block or lambda expression,
505  // use the type of the capture field.
506  if (CGF.BlockInfo && CI.isNested())
507  return CGF.BlockInfo->getCapture(VD).fieldType();
508  if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
509  return FD->getType();
510  // If the captured variable is a non-escaping __block variable, the field
511  // type is the reference type. If the variable is a __block variable that
512  // already has a reference type, the field type is the variable's type.
513  return VD->isNonEscapingByref() ?
514  CGF.getContext().getLValueReferenceType(VD->getType()) : VD->getType();
515 }
516 
517 /// Compute the layout of the given block. Attempts to lay the block
518 /// out with minimal space requirements.
520  CGBlockInfo &info) {
521  ASTContext &C = CGM.getContext();
522  const BlockDecl *block = info.getBlockDecl();
523 
524  SmallVector<llvm::Type*, 8> elementTypes;
525  initializeForBlockHeader(CGM, info, elementTypes);
526  bool hasNonConstantCustomFields = false;
527  if (auto *OpenCLHelper =
529  hasNonConstantCustomFields =
530  !OpenCLHelper->areAllCustomFieldValuesConstant(info);
531  if (!block->hasCaptures() && !hasNonConstantCustomFields) {
532  info.StructureType =
533  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
534  info.CanBeGlobal = true;
535  return;
536  }
537  else if (C.getLangOpts().ObjC &&
538  CGM.getLangOpts().getGC() == LangOptions::NonGC)
539  info.HasCapturedVariableLayout = true;
540 
541  // Collect the layout chunks.
543  layout.reserve(block->capturesCXXThis() +
544  (block->capture_end() - block->capture_begin()));
545 
546  CharUnits maxFieldAlign;
547 
548  // First, 'this'.
549  if (block->capturesCXXThis()) {
550  assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&
551  "Can't capture 'this' outside a method");
552  QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType();
553 
554  // Theoretically, this could be in a different address space, so
555  // don't assume standard pointer size/align.
556  llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
557  std::pair<CharUnits,CharUnits> tinfo
558  = CGM.getContext().getTypeInfoInChars(thisType);
559  maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
560 
561  layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
563  nullptr, llvmType, thisType));
564  }
565 
566  // Next, all the block captures.
567  for (const auto &CI : block->captures()) {
568  const VarDecl *variable = CI.getVariable();
569 
570  if (CI.isEscapingByref()) {
571  // We have to copy/dispose of the __block reference.
572  info.NeedsCopyDispose = true;
573 
574  // Just use void* instead of a pointer to the byref type.
575  CharUnits align = CGM.getPointerAlign();
576  maxFieldAlign = std::max(maxFieldAlign, align);
577 
578  // Since a __block variable cannot be captured by lambdas, its type and
579  // the capture field type should always match.
580  assert(getCaptureFieldType(*CGF, CI) == variable->getType() &&
581  "capture type differs from the variable type");
582  layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
584  CGM.VoidPtrTy, variable->getType()));
585  continue;
586  }
587 
588  // Otherwise, build a layout chunk with the size and alignment of
589  // the declaration.
590  if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
591  info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
592  continue;
593  }
594 
595  QualType VT = getCaptureFieldType(*CGF, CI);
596 
597  // If we have a lifetime qualifier, honor it for capture purposes.
598  // That includes *not* copying it if it's __unsafe_unretained.
600  if (lifetime) {
601  switch (lifetime) {
602  case Qualifiers::OCL_None: llvm_unreachable("impossible");
605  break;
606 
609  info.NeedsCopyDispose = true;
610  }
611 
612  // Block pointers require copy/dispose. So do Objective-C pointers.
613  } else if (VT->isObjCRetainableType()) {
614  // But honor the inert __unsafe_unretained qualifier, which doesn't
615  // actually make it into the type system.
617  lifetime = Qualifiers::OCL_ExplicitNone;
618  } else {
619  info.NeedsCopyDispose = true;
620  // used for mrr below.
621  lifetime = Qualifiers::OCL_Strong;
622  }
623 
624  // So do types that require non-trivial copy construction.
625  } else if (CI.hasCopyExpr()) {
626  info.NeedsCopyDispose = true;
627  info.HasCXXObject = true;
629  info.CapturesNonExternalType = true;
630 
631  // So do C structs that require non-trivial copy construction or
632  // destruction.
635  info.NeedsCopyDispose = true;
636 
637  // And so do types with destructors.
638  } else if (CGM.getLangOpts().CPlusPlus) {
639  if (const CXXRecordDecl *record = VT->getAsCXXRecordDecl()) {
640  if (!record->hasTrivialDestructor()) {
641  info.HasCXXObject = true;
642  info.NeedsCopyDispose = true;
643  if (!record->isExternallyVisible())
644  info.CapturesNonExternalType = true;
645  }
646  }
647  }
648 
649  CharUnits size = C.getTypeSizeInChars(VT);
650  CharUnits align = C.getDeclAlign(variable);
651 
652  maxFieldAlign = std::max(maxFieldAlign, align);
653 
654  llvm::Type *llvmType =
655  CGM.getTypes().ConvertTypeForMem(VT);
656 
657  layout.push_back(
658  BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
659  }
660 
661  // If that was everything, we're done here.
662  if (layout.empty()) {
663  info.StructureType =
664  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
665  info.CanBeGlobal = true;
666  return;
667  }
668 
669  // Sort the layout by alignment. We have to use a stable sort here
670  // to get reproducible results. There should probably be an
671  // llvm::array_pod_stable_sort.
672  std::stable_sort(layout.begin(), layout.end());
673 
674  // Needed for blocks layout info.
677 
678  CharUnits &blockSize = info.BlockSize;
679  info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
680 
681  // Assuming that the first byte in the header is maximally aligned,
682  // get the alignment of the first byte following the header.
683  CharUnits endAlign = getLowBit(blockSize);
684 
685  // If the end of the header isn't satisfactorily aligned for the
686  // maximum thing, look for things that are okay with the header-end
687  // alignment, and keep appending them until we get something that's
688  // aligned right. This algorithm is only guaranteed optimal if
689  // that condition is satisfied at some point; otherwise we can get
690  // things like:
691  // header // next byte has alignment 4
692  // something_with_size_5; // next byte has alignment 1
693  // something_with_alignment_8;
694  // which has 7 bytes of padding, as opposed to the naive solution
695  // which might have less (?).
696  if (endAlign < maxFieldAlign) {
697  SmallVectorImpl<BlockLayoutChunk>::iterator
698  li = layout.begin() + 1, le = layout.end();
699 
700  // Look for something that the header end is already
701  // satisfactorily aligned for.
702  for (; li != le && endAlign < li->Alignment; ++li)
703  ;
704 
705  // If we found something that's naturally aligned for the end of
706  // the header, keep adding things...
707  if (li != le) {
708  SmallVectorImpl<BlockLayoutChunk>::iterator first = li;
709  for (; li != le; ++li) {
710  assert(endAlign >= li->Alignment);
711 
712  li->setIndex(info, elementTypes.size(), blockSize);
713  elementTypes.push_back(li->Type);
714  blockSize += li->Size;
715  endAlign = getLowBit(blockSize);
716 
717  // ...until we get to the alignment of the maximum field.
718  if (endAlign >= maxFieldAlign) {
719  break;
720  }
721  }
722  // Don't re-append everything we just appended.
723  layout.erase(first, li);
724  }
725  }
726 
727  assert(endAlign == getLowBit(blockSize));
728 
729  // At this point, we just have to add padding if the end align still
730  // isn't aligned right.
731  if (endAlign < maxFieldAlign) {
732  CharUnits newBlockSize = blockSize.alignTo(maxFieldAlign);
733  CharUnits padding = newBlockSize - blockSize;
734 
735  // If we haven't yet added any fields, remember that there was an
736  // initial gap; this need to go into the block layout bit map.
737  if (blockSize == info.BlockHeaderForcedGapOffset) {
738  info.BlockHeaderForcedGapSize = padding;
739  }
740 
741  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
742  padding.getQuantity()));
743  blockSize = newBlockSize;
744  endAlign = getLowBit(blockSize); // might be > maxFieldAlign
745  }
746 
747  assert(endAlign >= maxFieldAlign);
748  assert(endAlign == getLowBit(blockSize));
749  // Slam everything else on now. This works because they have
750  // strictly decreasing alignment and we expect that size is always a
751  // multiple of alignment.
752  for (SmallVectorImpl<BlockLayoutChunk>::iterator
753  li = layout.begin(), le = layout.end(); li != le; ++li) {
754  if (endAlign < li->Alignment) {
755  // size may not be multiple of alignment. This can only happen with
756  // an over-aligned variable. We will be adding a padding field to
757  // make the size be multiple of alignment.
758  CharUnits padding = li->Alignment - endAlign;
759  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
760  padding.getQuantity()));
761  blockSize += padding;
762  endAlign = getLowBit(blockSize);
763  }
764  assert(endAlign >= li->Alignment);
765  li->setIndex(info, elementTypes.size(), blockSize);
766  elementTypes.push_back(li->Type);
767  blockSize += li->Size;
768  endAlign = getLowBit(blockSize);
769  }
770 
771  info.StructureType =
772  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
773 }
774 
775 /// Enter the scope of a block. This should be run at the entrance to
776 /// a full-expression so that the block's cleanups are pushed at the
777 /// right place in the stack.
778 static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
779  assert(CGF.HaveInsertPoint());
780 
781  // Allocate the block info and place it at the head of the list.
782  CGBlockInfo &blockInfo =
783  *new CGBlockInfo(block, CGF.CurFn->getName());
784  blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
785  CGF.FirstBlockInfo = &blockInfo;
786 
787  // Compute information about the layout, etc., of this block,
788  // pushing cleanups as necessary.
789  computeBlockInfo(CGF.CGM, &CGF, blockInfo);
790 
791  // Nothing else to do if it can be global.
792  if (blockInfo.CanBeGlobal) return;
793 
794  // Make the allocation for the block.
795  blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
796  blockInfo.BlockAlign, "block");
797 
798  // If there are cleanups to emit, enter them (but inactive).
799  if (!blockInfo.NeedsCopyDispose) return;
800 
801  // Walk through the captures (in order) and find the ones not
802  // captured by constant.
803  for (const auto &CI : block->captures()) {
804  // Ignore __block captures; there's nothing special in the
805  // on-stack block that we need to do for them.
806  if (CI.isByRef()) continue;
807 
808  // Ignore variables that are constant-captured.
809  const VarDecl *variable = CI.getVariable();
810  CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
811  if (capture.isConstant()) continue;
812 
813  // Ignore objects that aren't destructed.
814  QualType VT = getCaptureFieldType(CGF, CI);
816  if (dtorKind == QualType::DK_none) continue;
817 
818  CodeGenFunction::Destroyer *destroyer;
819 
820  // Block captures count as local values and have imprecise semantics.
821  // They also can't be arrays, so need to worry about that.
822  //
823  // For const-qualified captures, emit clang.arc.use to ensure the captured
824  // object doesn't get released while we are still depending on its validity
825  // within the block.
826  if (VT.isConstQualified() &&
828  CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
829  assert(CGF.CGM.getLangOpts().ObjCAutoRefCount &&
830  "expected ObjC ARC to be enabled");
832  } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
834  } else {
835  destroyer = CGF.getDestroyer(dtorKind);
836  }
837 
838  // GEP down to the address.
839  Address addr =
840  CGF.Builder.CreateStructGEP(blockInfo.LocalAddress, capture.getIndex());
841 
842  // We can use that GEP as the dominating IP.
843  if (!blockInfo.DominatingIP)
844  blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
845 
846  CleanupKind cleanupKind = InactiveNormalCleanup;
847  bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
848  if (useArrayEHCleanup)
849  cleanupKind = InactiveNormalAndEHCleanup;
850 
851  CGF.pushDestroy(cleanupKind, addr, VT,
852  destroyer, useArrayEHCleanup);
853 
854  // Remember where that cleanup was.
855  capture.setCleanup(CGF.EHStack.stable_begin());
856  }
857 }
858 
859 /// Enter a full-expression with a non-trivial number of objects to
860 /// clean up. This is in this file because, at the moment, the only
861 /// kind of cleanup object is a BlockDecl*.
863  if (const auto EWC = dyn_cast<ExprWithCleanups>(E)) {
864  assert(EWC->getNumObjects() != 0);
865  for (const ExprWithCleanups::CleanupObject &C : EWC->getObjects())
866  enterBlockScope(*this, C);
867  }
868 }
869 
870 /// Find the layout for the given block in a linked list and remove it.
872  const BlockDecl *block) {
873  while (true) {
874  assert(head && *head);
875  CGBlockInfo *cur = *head;
876 
877  // If this is the block we're looking for, splice it out of the list.
878  if (cur->getBlockDecl() == block) {
879  *head = cur->NextBlockInfo;
880  return cur;
881  }
882 
883  head = &cur->NextBlockInfo;
884  }
885 }
886 
887 /// Destroy a chain of block layouts.
889  assert(head && "destroying an empty chain");
890  do {
891  CGBlockInfo *cur = head;
892  head = cur->NextBlockInfo;
893  delete cur;
894  } while (head != nullptr);
895 }
896 
897 /// Emit a block literal expression in the current function.
899  // If the block has no captures, we won't have a pre-computed
900  // layout for it.
901  if (!blockExpr->getBlockDecl()->hasCaptures()) {
902  // The block literal is emitted as a global variable, and the block invoke
903  // function has to be extracted from its initializer.
904  if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr)) {
905  return Block;
906  }
907  CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
908  computeBlockInfo(CGM, this, blockInfo);
909  blockInfo.BlockExpression = blockExpr;
910  return EmitBlockLiteral(blockInfo);
911  }
912 
913  // Find the block info for this block and take ownership of it.
914  std::unique_ptr<CGBlockInfo> blockInfo;
915  blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
916  blockExpr->getBlockDecl()));
917 
918  blockInfo->BlockExpression = blockExpr;
919  return EmitBlockLiteral(*blockInfo);
920 }
921 
923  bool IsOpenCL = CGM.getContext().getLangOpts().OpenCL;
924  auto GenVoidPtrTy =
925  IsOpenCL ? CGM.getOpenCLRuntime().getGenericVoidPointerType() : VoidPtrTy;
926  LangAS GenVoidPtrAddr = IsOpenCL ? LangAS::opencl_generic : LangAS::Default;
927  auto GenVoidPtrSize = CharUnits::fromQuantity(
929  CGM.getContext().getTargetAddressSpace(GenVoidPtrAddr)) /
930  8);
931  // Using the computed layout, generate the actual block function.
932  bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
933  CodeGenFunction BlockCGF{CGM, true};
934  BlockCGF.SanOpts = SanOpts;
935  auto *InvokeFn = BlockCGF.GenerateBlockFunction(
936  CurGD, blockInfo, LocalDeclMap, isLambdaConv, blockInfo.CanBeGlobal);
937  auto *blockFn = llvm::ConstantExpr::getPointerCast(InvokeFn, GenVoidPtrTy);
938 
939  // If there is nothing to capture, we can emit this as a global block.
940  if (blockInfo.CanBeGlobal)
941  return CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression);
942 
943  // Otherwise, we have to emit this as a local block.
944 
945  Address blockAddr = blockInfo.LocalAddress;
946  assert(blockAddr.isValid() && "block has no address!");
947 
948  llvm::Constant *isa;
949  llvm::Constant *descriptor;
950  BlockFlags flags;
951  if (!IsOpenCL) {
952  // If the block is non-escaping, set field 'isa 'to NSConcreteGlobalBlock
953  // and set the BLOCK_IS_GLOBAL bit of field 'flags'. Copying a non-escaping
954  // block just returns the original block and releasing it is a no-op.
955  llvm::Constant *blockISA = blockInfo.getBlockDecl()->doesNotEscape()
957  : CGM.getNSConcreteStackBlock();
958  isa = llvm::ConstantExpr::getBitCast(blockISA, VoidPtrTy);
959 
960  // Build the block descriptor.
961  descriptor = buildBlockDescriptor(CGM, blockInfo);
962 
963  // Compute the initial on-stack block flags.
964  flags = BLOCK_HAS_SIGNATURE;
965  if (blockInfo.HasCapturedVariableLayout)
966  flags |= BLOCK_HAS_EXTENDED_LAYOUT;
967  if (blockInfo.needsCopyDisposeHelpers())
968  flags |= BLOCK_HAS_COPY_DISPOSE;
969  if (blockInfo.HasCXXObject)
970  flags |= BLOCK_HAS_CXX_OBJ;
971  if (blockInfo.UsesStret)
972  flags |= BLOCK_USE_STRET;
973  if (blockInfo.getBlockDecl()->doesNotEscape())
975  }
976 
977  auto projectField = [&](unsigned index, const Twine &name) -> Address {
978  return Builder.CreateStructGEP(blockAddr, index, name);
979  };
980  auto storeField = [&](llvm::Value *value, unsigned index, const Twine &name) {
981  Builder.CreateStore(value, projectField(index, name));
982  };
983 
984  // Initialize the block header.
985  {
986  // We assume all the header fields are densely packed.
987  unsigned index = 0;
988  CharUnits offset;
989  auto addHeaderField = [&](llvm::Value *value, CharUnits size,
990  const Twine &name) {
991  storeField(value, index, name);
992  offset += size;
993  index++;
994  };
995 
996  if (!IsOpenCL) {
997  addHeaderField(isa, getPointerSize(), "block.isa");
998  addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
999  getIntSize(), "block.flags");
1000  addHeaderField(llvm::ConstantInt::get(IntTy, 0), getIntSize(),
1001  "block.reserved");
1002  } else {
1003  addHeaderField(
1004  llvm::ConstantInt::get(IntTy, blockInfo.BlockSize.getQuantity()),
1005  getIntSize(), "block.size");
1006  addHeaderField(
1007  llvm::ConstantInt::get(IntTy, blockInfo.BlockAlign.getQuantity()),
1008  getIntSize(), "block.align");
1009  }
1010  addHeaderField(blockFn, GenVoidPtrSize, "block.invoke");
1011  if (!IsOpenCL)
1012  addHeaderField(descriptor, getPointerSize(), "block.descriptor");
1013  else if (auto *Helper =
1015  for (auto I : Helper->getCustomFieldValues(*this, blockInfo)) {
1016  addHeaderField(
1017  I.first,
1019  CGM.getDataLayout().getTypeAllocSize(I.first->getType())),
1020  I.second);
1021  }
1022  }
1023  }
1024 
1025  // Finally, capture all the values into the block.
1026  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1027 
1028  // First, 'this'.
1029  if (blockDecl->capturesCXXThis()) {
1030  Address addr =
1031  projectField(blockInfo.CXXThisIndex, "block.captured-this.addr");
1032  Builder.CreateStore(LoadCXXThis(), addr);
1033  }
1034 
1035  // Next, captured variables.
1036  for (const auto &CI : blockDecl->captures()) {
1037  const VarDecl *variable = CI.getVariable();
1038  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1039 
1040  // Ignore constant captures.
1041  if (capture.isConstant()) continue;
1042 
1043  QualType type = capture.fieldType();
1044 
1045  // This will be a [[type]]*, except that a byref entry will just be
1046  // an i8**.
1047  Address blockField = projectField(capture.getIndex(), "block.captured");
1048 
1049  // Compute the address of the thing we're going to move into the
1050  // block literal.
1051  Address src = Address::invalid();
1052 
1053  if (blockDecl->isConversionFromLambda()) {
1054  // The lambda capture in a lambda's conversion-to-block-pointer is
1055  // special; we'll simply emit it directly.
1056  src = Address::invalid();
1057  } else if (CI.isEscapingByref()) {
1058  if (BlockInfo && CI.isNested()) {
1059  // We need to use the capture from the enclosing block.
1060  const CGBlockInfo::Capture &enclosingCapture =
1061  BlockInfo->getCapture(variable);
1062 
1063  // This is a [[type]]*, except that a byref entry will just be an i8**.
1064  src = Builder.CreateStructGEP(LoadBlockStruct(),
1065  enclosingCapture.getIndex(),
1066  "block.capture.addr");
1067  } else {
1068  auto I = LocalDeclMap.find(variable);
1069  assert(I != LocalDeclMap.end());
1070  src = I->second;
1071  }
1072  } else {
1073  DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1074  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1076  SourceLocation());
1077  src = EmitDeclRefLValue(&declRef).getAddress();
1078  };
1079 
1080  // For byrefs, we just write the pointer to the byref struct into
1081  // the block field. There's no need to chase the forwarding
1082  // pointer at this point, since we're building something that will
1083  // live a shorter life than the stack byref anyway.
1084  if (CI.isEscapingByref()) {
1085  // Get a void* that points to the byref struct.
1086  llvm::Value *byrefPointer;
1087  if (CI.isNested())
1088  byrefPointer = Builder.CreateLoad(src, "byref.capture");
1089  else
1090  byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
1091 
1092  // Write that void* into the capture field.
1093  Builder.CreateStore(byrefPointer, blockField);
1094 
1095  // If we have a copy constructor, evaluate that into the block field.
1096  } else if (const Expr *copyExpr = CI.getCopyExpr()) {
1097  if (blockDecl->isConversionFromLambda()) {
1098  // If we have a lambda conversion, emit the expression
1099  // directly into the block instead.
1100  AggValueSlot Slot =
1101  AggValueSlot::forAddr(blockField, Qualifiers(),
1106  EmitAggExpr(copyExpr, Slot);
1107  } else {
1108  EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
1109  }
1110 
1111  // If it's a reference variable, copy the reference into the block field.
1112  } else if (type->isReferenceType()) {
1113  Builder.CreateStore(src.getPointer(), blockField);
1114 
1115  // If type is const-qualified, copy the value into the block field.
1116  } else if (type.isConstQualified() &&
1118  CGM.getCodeGenOpts().OptimizationLevel != 0) {
1119  llvm::Value *value = Builder.CreateLoad(src, "captured");
1120  Builder.CreateStore(value, blockField);
1121 
1122  // If this is an ARC __strong block-pointer variable, don't do a
1123  // block copy.
1124  //
1125  // TODO: this can be generalized into the normal initialization logic:
1126  // we should never need to do a block-copy when initializing a local
1127  // variable, because the local variable's lifetime should be strictly
1128  // contained within the stack block's.
1129  } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
1130  type->isBlockPointerType()) {
1131  // Load the block and do a simple retain.
1132  llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
1133  value = EmitARCRetainNonBlock(value);
1134 
1135  // Do a primitive store to the block field.
1136  Builder.CreateStore(value, blockField);
1137 
1138  // Otherwise, fake up a POD copy into the block field.
1139  } else {
1140  // Fake up a new variable so that EmitScalarInit doesn't think
1141  // we're referring to the variable in its own initializer.
1142  ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
1144 
1145  // We use one of these or the other depending on whether the
1146  // reference is nested.
1147  DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1148  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1150 
1151  ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
1152  &declRef, VK_RValue);
1153  // FIXME: Pass a specific location for the expr init so that the store is
1154  // attributed to a reasonable location - otherwise it may be attributed to
1155  // locations of subexpressions in the initialization.
1156  EmitExprAsInit(&l2r, &BlockFieldPseudoVar,
1157  MakeAddrLValue(blockField, type, AlignmentSource::Decl),
1158  /*captured by init*/ false);
1159  }
1160 
1161  // Activate the cleanup if layout pushed one.
1162  if (!CI.isByRef()) {
1164  if (cleanup.isValid())
1165  ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
1166  }
1167  }
1168 
1169  // Cast to the converted block-pointer type, which happens (somewhat
1170  // unfortunately) to be a pointer to function type.
1171  llvm::Value *result = Builder.CreatePointerCast(
1172  blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
1173 
1174  if (IsOpenCL) {
1175  CGM.getOpenCLRuntime().recordBlockInfo(blockInfo.BlockExpression, InvokeFn,
1176  result);
1177  }
1178 
1179  return result;
1180 }
1181 
1182 
1184  if (BlockDescriptorType)
1185  return BlockDescriptorType;
1186 
1187  llvm::Type *UnsignedLongTy =
1188  getTypes().ConvertType(getContext().UnsignedLongTy);
1189 
1190  // struct __block_descriptor {
1191  // unsigned long reserved;
1192  // unsigned long block_size;
1193  //
1194  // // later, the following will be added
1195  //
1196  // struct {
1197  // void (*copyHelper)();
1198  // void (*copyHelper)();
1199  // } helpers; // !!! optional
1200  //
1201  // const char *signature; // the block signature
1202  // const char *layout; // reserved
1203  // };
1204  BlockDescriptorType = llvm::StructType::create(
1205  "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
1206 
1207  // Now form a pointer to that.
1208  unsigned AddrSpace = 0;
1209  if (getLangOpts().OpenCL)
1210  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
1211  BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
1212  return BlockDescriptorType;
1213 }
1214 
1216  if (GenericBlockLiteralType)
1217  return GenericBlockLiteralType;
1218 
1219  llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
1220 
1221  if (getLangOpts().OpenCL) {
1222  // struct __opencl_block_literal_generic {
1223  // int __size;
1224  // int __align;
1225  // __generic void *__invoke;
1226  // /* custom fields */
1227  // };
1228  SmallVector<llvm::Type *, 8> StructFields(
1229  {IntTy, IntTy, getOpenCLRuntime().getGenericVoidPointerType()});
1230  if (auto *Helper = getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1231  for (auto I : Helper->getCustomFieldTypes())
1232  StructFields.push_back(I);
1233  }
1234  GenericBlockLiteralType = llvm::StructType::create(
1235  StructFields, "struct.__opencl_block_literal_generic");
1236  } else {
1237  // struct __block_literal_generic {
1238  // void *__isa;
1239  // int __flags;
1240  // int __reserved;
1241  // void (*__invoke)(void *);
1242  // struct __block_descriptor *__descriptor;
1243  // };
1244  GenericBlockLiteralType =
1245  llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
1246  IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
1247  }
1248 
1249  return GenericBlockLiteralType;
1250 }
1251 
1253  ReturnValueSlot ReturnValue) {
1254  const BlockPointerType *BPT =
1256  llvm::Value *BlockPtr = EmitScalarExpr(E->getCallee());
1257  llvm::Type *GenBlockTy = CGM.getGenericBlockLiteralType();
1258  llvm::Value *Func = nullptr;
1259  QualType FnType = BPT->getPointeeType();
1260  ASTContext &Ctx = getContext();
1261  CallArgList Args;
1262 
1263  if (getLangOpts().OpenCL) {
1264  // For OpenCL, BlockPtr is already casted to generic block literal.
1265 
1266  // First argument of a block call is a generic block literal casted to
1267  // generic void pointer, i.e. i8 addrspace(4)*
1268  llvm::Value *BlockDescriptor = Builder.CreatePointerCast(
1269  BlockPtr, CGM.getOpenCLRuntime().getGenericVoidPointerType());
1270  QualType VoidPtrQualTy = Ctx.getPointerType(
1272  Args.add(RValue::get(BlockDescriptor), VoidPtrQualTy);
1273  // And the rest of the arguments.
1274  EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1275 
1276  // We *can* call the block directly unless it is a function argument.
1277  if (!isa<ParmVarDecl>(E->getCalleeDecl()))
1278  Func = CGM.getOpenCLRuntime().getInvokeFunction(E->getCallee());
1279  else {
1280  llvm::Value *FuncPtr = Builder.CreateStructGEP(GenBlockTy, BlockPtr, 2);
1281  Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1282  }
1283  } else {
1284  // Bitcast the block literal to a generic block literal.
1285  BlockPtr = Builder.CreatePointerCast(
1286  BlockPtr, llvm::PointerType::get(GenBlockTy, 0), "block.literal");
1287  // Get pointer to the block invoke function
1288  llvm::Value *FuncPtr = Builder.CreateStructGEP(GenBlockTy, BlockPtr, 3);
1289 
1290  // First argument is a block literal casted to a void pointer
1291  BlockPtr = Builder.CreatePointerCast(BlockPtr, VoidPtrTy);
1292  Args.add(RValue::get(BlockPtr), Ctx.VoidPtrTy);
1293  // And the rest of the arguments.
1294  EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1295 
1296  // Load the function.
1297  Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1298  }
1299 
1300  const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1301  const CGFunctionInfo &FnInfo =
1302  CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
1303 
1304  // Cast the function pointer to the right type.
1305  llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
1306 
1307  llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
1308  Func = Builder.CreatePointerCast(Func, BlockFTyPtr);
1309 
1310  // Prepare the callee.
1311  CGCallee Callee(CGCalleeInfo(), Func);
1312 
1313  // And call the block.
1314  return EmitCall(FnInfo, Callee, ReturnValue, Args);
1315 }
1316 
1318  assert(BlockInfo && "evaluating block ref without block information?");
1319  const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1320 
1321  // Handle constant captures.
1322  if (capture.isConstant()) return LocalDeclMap.find(variable)->second;
1323 
1324  Address addr = Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(),
1325  "block.capture.addr");
1326 
1327  if (variable->isEscapingByref()) {
1328  // addr should be a void** right now. Load, then cast the result
1329  // to byref*.
1330 
1331  auto &byrefInfo = getBlockByrefInfo(variable);
1332  addr = Address(Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
1333 
1334  auto byrefPointerType = llvm::PointerType::get(byrefInfo.Type, 0);
1335  addr = Builder.CreateBitCast(addr, byrefPointerType, "byref.addr");
1336 
1337  addr = emitBlockByrefAddress(addr, byrefInfo, /*follow*/ true,
1338  variable->getName());
1339  }
1340 
1341  assert((!variable->isNonEscapingByref() ||
1342  capture.fieldType()->isReferenceType()) &&
1343  "the capture field of a non-escaping variable should have a "
1344  "reference type");
1345  if (capture.fieldType()->isReferenceType())
1346  addr = EmitLoadOfReference(MakeAddrLValue(addr, capture.fieldType()));
1347 
1348  return addr;
1349 }
1350 
1352  llvm::Constant *Addr) {
1353  bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
1354  (void)Ok;
1355  assert(Ok && "Trying to replace an already-existing global block!");
1356 }
1357 
1358 llvm::Constant *
1360  StringRef Name) {
1361  if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1362  return Block;
1363 
1364  CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1365  blockInfo.BlockExpression = BE;
1366 
1367  // Compute information about the layout, etc., of this block.
1368  computeBlockInfo(*this, nullptr, blockInfo);
1369 
1370  // Using that metadata, generate the actual block function.
1371  {
1372  CodeGenFunction::DeclMapTy LocalDeclMap;
1374  GlobalDecl(), blockInfo, LocalDeclMap,
1375  /*IsLambdaConversionToBlock*/ false, /*BuildGlobalBlock*/ true);
1376  }
1377 
1378  return getAddrOfGlobalBlockIfEmitted(BE);
1379 }
1380 
1381 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1382  const CGBlockInfo &blockInfo,
1383  llvm::Constant *blockFn) {
1384  assert(blockInfo.CanBeGlobal);
1385  // Callers should detect this case on their own: calling this function
1386  // generally requires computing layout information, which is a waste of time
1387  // if we've already emitted this block.
1388  assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&
1389  "Refusing to re-emit a global block.");
1390 
1391  // Generate the constants for the block literal initializer.
1392  ConstantInitBuilder builder(CGM);
1393  auto fields = builder.beginStruct();
1394 
1395  bool IsOpenCL = CGM.getLangOpts().OpenCL;
1396  bool IsWindows = CGM.getTarget().getTriple().isOSWindows();
1397  if (!IsOpenCL) {
1398  // isa
1399  if (IsWindows)
1400  fields.addNullPointer(CGM.Int8PtrPtrTy);
1401  else
1402  fields.add(CGM.getNSConcreteGlobalBlock());
1403 
1404  // __flags
1406  if (blockInfo.UsesStret)
1407  flags |= BLOCK_USE_STRET;
1408 
1409  fields.addInt(CGM.IntTy, flags.getBitMask());
1410 
1411  // Reserved
1412  fields.addInt(CGM.IntTy, 0);
1413  } else {
1414  fields.addInt(CGM.IntTy, blockInfo.BlockSize.getQuantity());
1415  fields.addInt(CGM.IntTy, blockInfo.BlockAlign.getQuantity());
1416  }
1417 
1418  // Function
1419  fields.add(blockFn);
1420 
1421  if (!IsOpenCL) {
1422  // Descriptor
1423  fields.add(buildBlockDescriptor(CGM, blockInfo));
1424  } else if (auto *Helper =
1426  for (auto I : Helper->getCustomFieldValues(CGM, blockInfo)) {
1427  fields.add(I);
1428  }
1429  }
1430 
1431  unsigned AddrSpace = 0;
1432  if (CGM.getContext().getLangOpts().OpenCL)
1434 
1435  llvm::Constant *literal = fields.finishAndCreateGlobal(
1436  "__block_literal_global", blockInfo.BlockAlign,
1437  /*constant*/ !IsWindows, llvm::GlobalVariable::InternalLinkage, AddrSpace);
1438 
1439  // Windows does not allow globals to be initialised to point to globals in
1440  // different DLLs. Any such variables must run code to initialise them.
1441  if (IsWindows) {
1442  auto *Init = llvm::Function::Create(llvm::FunctionType::get(CGM.VoidTy,
1443  {}), llvm::GlobalValue::InternalLinkage, ".block_isa_init",
1444  &CGM.getModule());
1445  llvm::IRBuilder<> b(llvm::BasicBlock::Create(CGM.getLLVMContext(), "entry",
1446  Init));
1447  b.CreateAlignedStore(CGM.getNSConcreteGlobalBlock(),
1448  b.CreateStructGEP(literal, 0), CGM.getPointerAlign().getQuantity());
1449  b.CreateRetVoid();
1450  // We can't use the normal LLVM global initialisation array, because we
1451  // need to specify that this runs early in library initialisation.
1452  auto *InitVar = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
1453  /*isConstant*/true, llvm::GlobalValue::InternalLinkage,
1454  Init, ".block_isa_init_ptr");
1455  InitVar->setSection(".CRT$XCLa");
1456  CGM.addUsedGlobal(InitVar);
1457  }
1458 
1459  // Return a constant of the appropriately-casted type.
1460  llvm::Type *RequiredType =
1461  CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1462  llvm::Constant *Result =
1463  llvm::ConstantExpr::getPointerCast(literal, RequiredType);
1464  CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
1465  if (CGM.getContext().getLangOpts().OpenCL)
1467  blockInfo.BlockExpression,
1468  cast<llvm::Function>(blockFn->stripPointerCasts()), Result);
1469  return Result;
1470 }
1471 
1473  unsigned argNum,
1474  llvm::Value *arg) {
1475  assert(BlockInfo && "not emitting prologue of block invocation function?!");
1476 
1477  // Allocate a stack slot like for any local variable to guarantee optimal
1478  // debug info at -O0. The mem2reg pass will eliminate it when optimizing.
1479  Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr");
1480  Builder.CreateStore(arg, alloc);
1481  if (CGDebugInfo *DI = getDebugInfo()) {
1482  if (CGM.getCodeGenOpts().getDebugInfo() >=
1484  DI->setLocation(D->getLocation());
1485  DI->EmitDeclareOfBlockLiteralArgVariable(
1486  *BlockInfo, D->getName(), argNum,
1487  cast<llvm::AllocaInst>(alloc.getPointer()), Builder);
1488  }
1489  }
1490 
1491  SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getBeginLoc();
1492  ApplyDebugLocation Scope(*this, StartLoc);
1493 
1494  // Instead of messing around with LocalDeclMap, just set the value
1495  // directly as BlockPointer.
1496  BlockPointer = Builder.CreatePointerCast(
1497  arg,
1498  BlockInfo->StructureType->getPointerTo(
1499  getContext().getLangOpts().OpenCL
1500  ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1501  : 0),
1502  "block");
1503 }
1504 
1506  assert(BlockInfo && "not in a block invocation function!");
1507  assert(BlockPointer && "no block pointer set!");
1508  return Address(BlockPointer, BlockInfo->BlockAlign);
1509 }
1510 
1511 llvm::Function *
1513  const CGBlockInfo &blockInfo,
1514  const DeclMapTy &ldm,
1515  bool IsLambdaConversionToBlock,
1516  bool BuildGlobalBlock) {
1517  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1518 
1519  CurGD = GD;
1520 
1521  CurEHLocation = blockInfo.getBlockExpr()->getEndLoc();
1522 
1523  BlockInfo = &blockInfo;
1524 
1525  // Arrange for local static and local extern declarations to appear
1526  // to be local to this function as well, in case they're directly
1527  // referenced in a block.
1528  for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1529  const auto *var = dyn_cast<VarDecl>(i->first);
1530  if (var && !var->hasLocalStorage())
1531  setAddrOfLocalVar(var, i->second);
1532  }
1533 
1534  // Begin building the function declaration.
1535 
1536  // Build the argument list.
1537  FunctionArgList args;
1538 
1539  // The first argument is the block pointer. Just take it as a void*
1540  // and cast it later.
1541  QualType selfTy = getContext().VoidPtrTy;
1542 
1543  // For OpenCL passed block pointer can be private AS local variable or
1544  // global AS program scope variable (for the case with and without captures).
1545  // Generic AS is used therefore to be able to accommodate both private and
1546  // generic AS in one implementation.
1547  if (getLangOpts().OpenCL)
1548  selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1549  getContext().VoidTy, LangAS::opencl_generic));
1550 
1551  IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1552 
1553  ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1554  SourceLocation(), II, selfTy,
1556  args.push_back(&SelfDecl);
1557 
1558  // Now add the rest of the parameters.
1559  args.append(blockDecl->param_begin(), blockDecl->param_end());
1560 
1561  // Create the function declaration.
1562  const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1563  const CGFunctionInfo &fnInfo =
1564  CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1565  if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1566  blockInfo.UsesStret = true;
1567 
1568  llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1569 
1570  StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1571  llvm::Function *fn = llvm::Function::Create(
1572  fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1573  CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1574 
1575  if (BuildGlobalBlock) {
1576  auto GenVoidPtrTy = getContext().getLangOpts().OpenCL
1578  : VoidPtrTy;
1579  buildGlobalBlock(CGM, blockInfo,
1580  llvm::ConstantExpr::getPointerCast(fn, GenVoidPtrTy));
1581  }
1582 
1583  // Begin generating the function.
1584  StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1585  blockDecl->getLocation(),
1586  blockInfo.getBlockExpr()->getBody()->getBeginLoc());
1587 
1588  // Okay. Undo some of what StartFunction did.
1589 
1590  // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1591  // won't delete the dbg.declare intrinsics for captured variables.
1592  llvm::Value *BlockPointerDbgLoc = BlockPointer;
1593  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1594  // Allocate a stack slot for it, so we can point the debugger to it
1595  Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1596  getPointerAlign(),
1597  "block.addr");
1598  // Set the DebugLocation to empty, so the store is recognized as a
1599  // frame setup instruction by llvm::DwarfDebug::beginFunction().
1600  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1601  Builder.CreateStore(BlockPointer, Alloca);
1602  BlockPointerDbgLoc = Alloca.getPointer();
1603  }
1604 
1605  // If we have a C++ 'this' reference, go ahead and force it into
1606  // existence now.
1607  if (blockDecl->capturesCXXThis()) {
1608  Address addr = Builder.CreateStructGEP(
1609  LoadBlockStruct(), blockInfo.CXXThisIndex, "block.captured-this");
1610  CXXThisValue = Builder.CreateLoad(addr, "this");
1611  }
1612 
1613  // Also force all the constant captures.
1614  for (const auto &CI : blockDecl->captures()) {
1615  const VarDecl *variable = CI.getVariable();
1616  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1617  if (!capture.isConstant()) continue;
1618 
1619  CharUnits align = getContext().getDeclAlign(variable);
1620  Address alloca =
1621  CreateMemTemp(variable->getType(), align, "block.captured-const");
1622 
1623  Builder.CreateStore(capture.getConstant(), alloca);
1624 
1625  setAddrOfLocalVar(variable, alloca);
1626  }
1627 
1628  // Save a spot to insert the debug information for all the DeclRefExprs.
1629  llvm::BasicBlock *entry = Builder.GetInsertBlock();
1630  llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1631  --entry_ptr;
1632 
1633  if (IsLambdaConversionToBlock)
1634  EmitLambdaBlockInvokeBody();
1635  else {
1636  PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1637  incrementProfileCounter(blockDecl->getBody());
1638  EmitStmt(blockDecl->getBody());
1639  }
1640 
1641  // Remember where we were...
1642  llvm::BasicBlock *resume = Builder.GetInsertBlock();
1643 
1644  // Go back to the entry.
1645  ++entry_ptr;
1646  Builder.SetInsertPoint(entry, entry_ptr);
1647 
1648  // Emit debug information for all the DeclRefExprs.
1649  // FIXME: also for 'this'
1650  if (CGDebugInfo *DI = getDebugInfo()) {
1651  for (const auto &CI : blockDecl->captures()) {
1652  const VarDecl *variable = CI.getVariable();
1653  DI->EmitLocation(Builder, variable->getLocation());
1654 
1655  if (CGM.getCodeGenOpts().getDebugInfo() >=
1657  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1658  if (capture.isConstant()) {
1659  auto addr = LocalDeclMap.find(variable)->second;
1660  (void)DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1661  Builder);
1662  continue;
1663  }
1664 
1665  DI->EmitDeclareOfBlockDeclRefVariable(
1666  variable, BlockPointerDbgLoc, Builder, blockInfo,
1667  entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1668  }
1669  }
1670  // Recover location if it was changed in the above loop.
1671  DI->EmitLocation(Builder,
1672  cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1673  }
1674 
1675  // And resume where we left off.
1676  if (resume == nullptr)
1677  Builder.ClearInsertionPoint();
1678  else
1679  Builder.SetInsertPoint(resume);
1680 
1681  FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1682 
1683  return fn;
1684 }
1685 
1686 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1688  const LangOptions &LangOpts) {
1689  if (CI.getCopyExpr()) {
1690  assert(!CI.isByRef());
1691  // don't bother computing flags
1692  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1693  }
1694  BlockFieldFlags Flags;
1695  if (CI.isEscapingByref()) {
1696  Flags = BLOCK_FIELD_IS_BYREF;
1697  if (T.isObjCGCWeak())
1698  Flags |= BLOCK_FIELD_IS_WEAK;
1699  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1700  }
1701 
1702  Flags = BLOCK_FIELD_IS_OBJECT;
1703  bool isBlockPointer = T->isBlockPointerType();
1704  if (isBlockPointer)
1705  Flags = BLOCK_FIELD_IS_BLOCK;
1706 
1707  switch (T.isNonTrivialToPrimitiveCopy()) {
1708  case QualType::PCK_Struct:
1709  return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
1710  BlockFieldFlags());
1711  case QualType::PCK_ARCWeak:
1712  // We need to register __weak direct captures with the runtime.
1713  return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1715  // We need to retain the copied value for __strong direct captures.
1716  // If it's a block pointer, we have to copy the block and assign that to
1717  // the destination pointer, so we might as well use _Block_object_assign.
1718  // Otherwise we can avoid that.
1719  return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1720  : BlockCaptureEntityKind::BlockObject,
1721  Flags);
1722  case QualType::PCK_Trivial:
1724  if (!T->isObjCRetainableType())
1725  // For all other types, the memcpy is fine.
1726  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1727 
1728  // Special rules for ARC captures:
1729  Qualifiers QS = T.getQualifiers();
1730 
1731  // Non-ARC captures of retainable pointers are strong and
1732  // therefore require a call to _Block_object_assign.
1733  if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1734  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1735 
1736  // Otherwise the memcpy is fine.
1737  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1738  }
1739  }
1740  llvm_unreachable("after exhaustive PrimitiveCopyKind switch");
1741 }
1742 
1743 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1745  const LangOptions &LangOpts);
1746 
1747 /// Find the set of block captures that need to be explicitly copied or destroy.
1749  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1750  SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures) {
1751  for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1752  const VarDecl *Variable = CI.getVariable();
1753  const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1754  if (Capture.isConstant())
1755  continue;
1756 
1757  QualType VT = Capture.fieldType();
1758  auto CopyInfo = computeCopyInfoForBlockCapture(CI, VT, LangOpts);
1759  auto DisposeInfo = computeDestroyInfoForBlockCapture(CI, VT, LangOpts);
1760  if (CopyInfo.first != BlockCaptureEntityKind::None ||
1761  DisposeInfo.first != BlockCaptureEntityKind::None)
1762  ManagedCaptures.emplace_back(CopyInfo.first, DisposeInfo.first,
1763  CopyInfo.second, DisposeInfo.second, CI,
1764  Capture);
1765  }
1766 
1767  // Sort the captures by offset.
1768  llvm::sort(ManagedCaptures);
1769 }
1770 
1771 namespace {
1772 /// Release a __block variable.
1773 struct CallBlockRelease final : EHScopeStack::Cleanup {
1774  Address Addr;
1775  BlockFieldFlags FieldFlags;
1776  bool LoadBlockVarAddr, CanThrow;
1777 
1778  CallBlockRelease(Address Addr, BlockFieldFlags Flags, bool LoadValue,
1779  bool CT)
1780  : Addr(Addr), FieldFlags(Flags), LoadBlockVarAddr(LoadValue),
1781  CanThrow(CT) {}
1782 
1783  void Emit(CodeGenFunction &CGF, Flags flags) override {
1784  llvm::Value *BlockVarAddr;
1785  if (LoadBlockVarAddr) {
1786  BlockVarAddr = CGF.Builder.CreateLoad(Addr);
1787  BlockVarAddr = CGF.Builder.CreateBitCast(BlockVarAddr, CGF.VoidPtrTy);
1788  } else {
1789  BlockVarAddr = Addr.getPointer();
1790  }
1791 
1792  CGF.BuildBlockRelease(BlockVarAddr, FieldFlags, CanThrow);
1793  }
1794 };
1795 } // end anonymous namespace
1796 
1797 /// Check if \p T is a C++ class that has a destructor that can throw.
1799  if (const auto *RD = T->getAsCXXRecordDecl())
1800  if (const CXXDestructorDecl *DD = RD->getDestructor())
1801  return DD->getType()->getAs<FunctionProtoType>()->canThrow();
1802  return false;
1803 }
1804 
1805 // Return a string that has the information about a capture.
1806 static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
1807  CaptureStrKind StrKind,
1808  CharUnits BlockAlignment,
1809  CodeGenModule &CGM) {
1810  std::string Str;
1811  ASTContext &Ctx = CGM.getContext();
1812  const BlockDecl::Capture &CI = *E.CI;
1813  QualType CaptureTy = CI.getVariable()->getType();
1814 
1816  BlockFieldFlags Flags;
1817 
1818  // CaptureStrKind::Merged should be passed only when the operations and the
1819  // flags are the same for copy and dispose.
1820  assert((StrKind != CaptureStrKind::Merged ||
1821  (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) &&
1822  "different operations and flags");
1823 
1824  if (StrKind == CaptureStrKind::DisposeHelper) {
1825  Kind = E.DisposeKind;
1826  Flags = E.DisposeFlags;
1827  } else {
1828  Kind = E.CopyKind;
1829  Flags = E.CopyFlags;
1830  }
1831 
1832  switch (Kind) {
1833  case BlockCaptureEntityKind::CXXRecord: {
1834  Str += "c";
1835  SmallString<256> TyStr;
1836  llvm::raw_svector_ostream Out(TyStr);
1837  CGM.getCXXABI().getMangleContext().mangleTypeName(CaptureTy, Out);
1838  Str += llvm::to_string(TyStr.size()) + TyStr.c_str();
1839  break;
1840  }
1841  case BlockCaptureEntityKind::ARCWeak:
1842  Str += "w";
1843  break;
1844  case BlockCaptureEntityKind::ARCStrong:
1845  Str += "s";
1846  break;
1847  case BlockCaptureEntityKind::BlockObject: {
1848  const VarDecl *Var = CI.getVariable();
1849  unsigned F = Flags.getBitMask();
1850  if (F & BLOCK_FIELD_IS_BYREF) {
1851  Str += "r";
1852  if (F & BLOCK_FIELD_IS_WEAK)
1853  Str += "w";
1854  else {
1855  // If CaptureStrKind::Merged is passed, check both the copy expression
1856  // and the destructor.
1857  if (StrKind != CaptureStrKind::DisposeHelper) {
1858  if (Ctx.getBlockVarCopyInit(Var).canThrow())
1859  Str += "c";
1860  }
1861  if (StrKind != CaptureStrKind::CopyHelper) {
1863  Str += "d";
1864  }
1865  }
1866  } else {
1867  assert((F & BLOCK_FIELD_IS_OBJECT) && "unexpected flag value");
1868  if (F == BLOCK_FIELD_IS_BLOCK)
1869  Str += "b";
1870  else
1871  Str += "o";
1872  }
1873  break;
1874  }
1875  case BlockCaptureEntityKind::NonTrivialCStruct: {
1876  bool IsVolatile = CaptureTy.isVolatileQualified();
1877  CharUnits Alignment =
1878  BlockAlignment.alignmentAtOffset(E.Capture->getOffset());
1879 
1880  Str += "n";
1881  std::string FuncStr;
1882  if (StrKind == CaptureStrKind::DisposeHelper)
1884  CaptureTy, Alignment, IsVolatile, Ctx);
1885  else
1886  // If CaptureStrKind::Merged is passed, use the copy constructor string.
1887  // It has all the information that the destructor string has.
1889  CaptureTy, Alignment, IsVolatile, Ctx);
1890  // The underscore is necessary here because non-trivial copy constructor
1891  // and destructor strings can start with a number.
1892  Str += llvm::to_string(FuncStr.size()) + "_" + FuncStr;
1893  break;
1894  }
1896  break;
1897  }
1898 
1899  return Str;
1900 }
1901 
1902 static std::string getCopyDestroyHelperFuncName(
1903  const SmallVectorImpl<BlockCaptureManagedEntity> &Captures,
1904  CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM) {
1905  assert((StrKind == CaptureStrKind::CopyHelper ||
1906  StrKind == CaptureStrKind::DisposeHelper) &&
1907  "unexpected CaptureStrKind");
1908  std::string Name = StrKind == CaptureStrKind::CopyHelper
1909  ? "__copy_helper_block_"
1910  : "__destroy_helper_block_";
1911  if (CGM.getLangOpts().Exceptions)
1912  Name += "e";
1913  if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
1914  Name += "a";
1915  Name += llvm::to_string(BlockAlignment.getQuantity()) + "_";
1916 
1917  for (const BlockCaptureManagedEntity &E : Captures) {
1918  Name += llvm::to_string(E.Capture->getOffset().getQuantity());
1919  Name += getBlockCaptureStr(E, StrKind, BlockAlignment, CGM);
1920  }
1921 
1922  return Name;
1923 }
1924 
1926  Address Field, QualType CaptureType,
1927  BlockFieldFlags Flags, bool ForCopyHelper,
1928  VarDecl *Var, CodeGenFunction &CGF) {
1929  bool EHOnly = ForCopyHelper;
1930 
1931  switch (CaptureKind) {
1932  case BlockCaptureEntityKind::CXXRecord:
1933  case BlockCaptureEntityKind::ARCWeak:
1934  case BlockCaptureEntityKind::NonTrivialCStruct:
1935  case BlockCaptureEntityKind::ARCStrong: {
1936  if (CaptureType.isDestructedType() &&
1937  (!EHOnly || CGF.needsEHCleanup(CaptureType.isDestructedType()))) {
1938  CodeGenFunction::Destroyer *Destroyer =
1939  CaptureKind == BlockCaptureEntityKind::ARCStrong
1941  : CGF.getDestroyer(CaptureType.isDestructedType());
1942  CleanupKind Kind =
1943  EHOnly ? EHCleanup
1944  : CGF.getCleanupKind(CaptureType.isDestructedType());
1945  CGF.pushDestroy(Kind, Field, CaptureType, Destroyer, Kind & EHCleanup);
1946  }
1947  break;
1948  }
1949  case BlockCaptureEntityKind::BlockObject: {
1950  if (!EHOnly || CGF.getLangOpts().Exceptions) {
1952  // Calls to _Block_object_dispose along the EH path in the copy helper
1953  // function don't throw as newly-copied __block variables always have a
1954  // reference count of 2.
1955  bool CanThrow =
1956  !ForCopyHelper && CGF.cxxDestructorCanThrow(CaptureType);
1957  CGF.enterByrefCleanup(Kind, Field, Flags, /*LoadBlockVarAddr*/ true,
1958  CanThrow);
1959  }
1960  break;
1961  }
1963  break;
1964  }
1965 }
1966 
1968  llvm::Function *Fn,
1969  const CGFunctionInfo &FI,
1970  CodeGenModule &CGM) {
1971  if (CapturesNonExternalType) {
1973  } else {
1974  Fn->setVisibility(llvm::GlobalValue::HiddenVisibility);
1975  Fn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1976  CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, Fn);
1977  CGM.SetLLVMFunctionAttributesForDefinition(nullptr, Fn);
1978  }
1979 }
1980 /// Generate the copy-helper function for a block closure object:
1981 /// static void block_copy_helper(block_t *dst, block_t *src);
1982 /// The runtime will have previously initialized 'dst' by doing a
1983 /// bit-copy of 'src'.
1984 ///
1985 /// Note that this copies an entire block closure object to the heap;
1986 /// it should not be confused with a 'byref copy helper', which moves
1987 /// the contents of an individual __block variable to the heap.
1988 llvm::Constant *
1991  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures);
1992  std::string FuncName =
1993  getCopyDestroyHelperFuncName(CopiedCaptures, blockInfo.BlockAlign,
1994  CaptureStrKind::CopyHelper, CGM);
1995 
1996  if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
1997  return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
1998 
1999  ASTContext &C = getContext();
2000 
2001  QualType ReturnTy = C.VoidTy;
2002 
2003  FunctionArgList args;
2005  args.push_back(&DstDecl);
2007  args.push_back(&SrcDecl);
2008 
2009  const CGFunctionInfo &FI =
2010  CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2011 
2012  // FIXME: it would be nice if these were mergeable with things with
2013  // identical semantics.
2014  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2015 
2016  llvm::Function *Fn =
2017  llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2018  FuncName, &CGM.getModule());
2019  if (CGM.supportsCOMDAT())
2020  Fn->setComdat(CGM.getModule().getOrInsertComdat(FuncName));
2021 
2022  IdentifierInfo *II = &C.Idents.get(FuncName);
2023 
2024  SmallVector<QualType, 2> ArgTys;
2025  ArgTys.push_back(C.VoidPtrTy);
2026  ArgTys.push_back(C.VoidPtrTy);
2027  QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2028 
2031  FunctionTy, nullptr, SC_Static, false, false);
2032 
2034  CGM);
2035  StartFunction(FD, ReturnTy, Fn, FI, args);
2036  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2037  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2038 
2039  Address src = GetAddrOfLocalVar(&SrcDecl);
2040  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2041  src = Builder.CreateBitCast(src, structPtrTy, "block.source");
2042 
2043  Address dst = GetAddrOfLocalVar(&DstDecl);
2044  dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
2045  dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
2046 
2047  for (const auto &CopiedCapture : CopiedCaptures) {
2048  const BlockDecl::Capture &CI = *CopiedCapture.CI;
2049  const CGBlockInfo::Capture &capture = *CopiedCapture.Capture;
2050  QualType captureType = CI.getVariable()->getType();
2051  BlockFieldFlags flags = CopiedCapture.CopyFlags;
2052 
2053  unsigned index = capture.getIndex();
2054  Address srcField = Builder.CreateStructGEP(src, index);
2055  Address dstField = Builder.CreateStructGEP(dst, index);
2056 
2057  switch (CopiedCapture.CopyKind) {
2058  case BlockCaptureEntityKind::CXXRecord:
2059  // If there's an explicit copy expression, we do that.
2060  assert(CI.getCopyExpr() && "copy expression for variable is missing");
2061  EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
2062  break;
2063  case BlockCaptureEntityKind::ARCWeak:
2064  EmitARCCopyWeak(dstField, srcField);
2065  break;
2066  case BlockCaptureEntityKind::NonTrivialCStruct: {
2067  // If this is a C struct that requires non-trivial copy construction,
2068  // emit a call to its copy constructor.
2069  QualType varType = CI.getVariable()->getType();
2070  callCStructCopyConstructor(MakeAddrLValue(dstField, varType),
2071  MakeAddrLValue(srcField, varType));
2072  break;
2073  }
2074  case BlockCaptureEntityKind::ARCStrong: {
2075  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2076  // At -O0, store null into the destination field (so that the
2077  // storeStrong doesn't over-release) and then call storeStrong.
2078  // This is a workaround to not having an initStrong call.
2079  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2080  auto *ty = cast<llvm::PointerType>(srcValue->getType());
2081  llvm::Value *null = llvm::ConstantPointerNull::get(ty);
2082  Builder.CreateStore(null, dstField);
2083  EmitARCStoreStrongCall(dstField, srcValue, true);
2084 
2085  // With optimization enabled, take advantage of the fact that
2086  // the blocks runtime guarantees a memcpy of the block data, and
2087  // just emit a retain of the src field.
2088  } else {
2089  EmitARCRetainNonBlock(srcValue);
2090 
2091  // Unless EH cleanup is required, we don't need this anymore, so kill
2092  // it. It's not quite worth the annoyance to avoid creating it in the
2093  // first place.
2094  if (!needsEHCleanup(captureType.isDestructedType()))
2095  cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
2096  }
2097  break;
2098  }
2099  case BlockCaptureEntityKind::BlockObject: {
2100  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2101  srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
2102  llvm::Value *dstAddr =
2103  Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
2104  llvm::Value *args[] = {
2105  dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2106  };
2107 
2108  if (CI.isByRef() && C.getBlockVarCopyInit(CI.getVariable()).canThrow())
2109  EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
2110  else
2111  EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
2112  break;
2113  }
2115  continue;
2116  }
2117 
2118  // Ensure that we destroy the copied object if an exception is thrown later
2119  // in the helper function.
2120  pushCaptureCleanup(CopiedCapture.CopyKind, dstField, captureType, flags,
2121  /*ForCopyHelper*/ true, CI.getVariable(), *this);
2122  }
2123 
2124  FinishFunction();
2125 
2126  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2127 }
2128 
2129 static BlockFieldFlags
2131  QualType T) {
2133  if (T->isBlockPointerType())
2134  Flags = BLOCK_FIELD_IS_BLOCK;
2135  return Flags;
2136 }
2137 
2138 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
2140  const LangOptions &LangOpts) {
2141  if (CI.isEscapingByref()) {
2143  if (T.isObjCGCWeak())
2144  Flags |= BLOCK_FIELD_IS_WEAK;
2145  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
2146  }
2147 
2148  switch (T.isDestructedType()) {
2150  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
2152  // Use objc_storeStrong for __strong direct captures; the
2153  // dynamic tools really like it when we do this.
2154  return std::make_pair(BlockCaptureEntityKind::ARCStrong,
2157  // Support __weak direct captures.
2158  return std::make_pair(BlockCaptureEntityKind::ARCWeak,
2161  return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
2162  BlockFieldFlags());
2163  case QualType::DK_none: {
2164  // Non-ARC captures are strong, and we need to use _Block_object_dispose.
2165  if (T->isObjCRetainableType() && !T.getQualifiers().hasObjCLifetime() &&
2166  !LangOpts.ObjCAutoRefCount)
2167  return std::make_pair(BlockCaptureEntityKind::BlockObject,
2169  // Otherwise, we have nothing to do.
2170  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
2171  }
2172  }
2173  llvm_unreachable("after exhaustive DestructionKind switch");
2174 }
2175 
2176 /// Generate the destroy-helper function for a block closure object:
2177 /// static void block_destroy_helper(block_t *theBlock);
2178 ///
2179 /// Note that this destroys a heap-allocated block closure object;
2180 /// it should not be confused with a 'byref destroy helper', which
2181 /// destroys the heap-allocated contents of an individual __block
2182 /// variable.
2183 llvm::Constant *
2186  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures);
2187  std::string FuncName =
2188  getCopyDestroyHelperFuncName(DestroyedCaptures, blockInfo.BlockAlign,
2189  CaptureStrKind::DisposeHelper, CGM);
2190 
2191  if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2192  return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2193 
2194  ASTContext &C = getContext();
2195 
2196  QualType ReturnTy = C.VoidTy;
2197 
2198  FunctionArgList args;
2200  args.push_back(&SrcDecl);
2201 
2202  const CGFunctionInfo &FI =
2203  CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2204 
2205  // FIXME: We'd like to put these into a mergable by content, with
2206  // internal linkage.
2207  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2208 
2209  llvm::Function *Fn =
2210  llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2211  FuncName, &CGM.getModule());
2212  if (CGM.supportsCOMDAT())
2213  Fn->setComdat(CGM.getModule().getOrInsertComdat(FuncName));
2214 
2215  IdentifierInfo *II = &C.Idents.get(FuncName);
2216 
2217  SmallVector<QualType, 1> ArgTys;
2218  ArgTys.push_back(C.VoidPtrTy);
2219  QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2220 
2223  FunctionTy, nullptr, SC_Static, false, false);
2224 
2226  CGM);
2227  StartFunction(FD, ReturnTy, Fn, FI, args);
2228  markAsIgnoreThreadCheckingAtRuntime(Fn);
2229 
2230  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2231 
2232  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2233 
2234  Address src = GetAddrOfLocalVar(&SrcDecl);
2235  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2236  src = Builder.CreateBitCast(src, structPtrTy, "block");
2237 
2238  CodeGenFunction::RunCleanupsScope cleanups(*this);
2239 
2240  for (const auto &DestroyedCapture : DestroyedCaptures) {
2241  const BlockDecl::Capture &CI = *DestroyedCapture.CI;
2242  const CGBlockInfo::Capture &capture = *DestroyedCapture.Capture;
2243  BlockFieldFlags flags = DestroyedCapture.DisposeFlags;
2244 
2245  Address srcField = Builder.CreateStructGEP(src, capture.getIndex());
2246 
2247  pushCaptureCleanup(DestroyedCapture.DisposeKind, srcField,
2248  CI.getVariable()->getType(), flags,
2249  /*ForCopyHelper*/ false, CI.getVariable(), *this);
2250  }
2251 
2252  cleanups.ForceCleanup();
2253 
2254  FinishFunction();
2255 
2256  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2257 }
2258 
2259 namespace {
2260 
2261 /// Emits the copy/dispose helper functions for a __block object of id type.
2262 class ObjectByrefHelpers final : public BlockByrefHelpers {
2263  BlockFieldFlags Flags;
2264 
2265 public:
2266  ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
2267  : BlockByrefHelpers(alignment), Flags(flags) {}
2268 
2269  void emitCopy(CodeGenFunction &CGF, Address destField,
2270  Address srcField) override {
2271  destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
2272 
2273  srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
2274  llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
2275 
2276  unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
2277 
2278  llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
2279  llvm::FunctionCallee fn = CGF.CGM.getBlockObjectAssign();
2280 
2281  llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
2282  CGF.EmitNounwindRuntimeCall(fn, args);
2283  }
2284 
2285  void emitDispose(CodeGenFunction &CGF, Address field) override {
2286  field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
2287  llvm::Value *value = CGF.Builder.CreateLoad(field);
2288 
2289  CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER, false);
2290  }
2291 
2292  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2293  id.AddInteger(Flags.getBitMask());
2294  }
2295 };
2296 
2297 /// Emits the copy/dispose helpers for an ARC __block __weak variable.
2298 class ARCWeakByrefHelpers final : public BlockByrefHelpers {
2299 public:
2300  ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2301 
2302  void emitCopy(CodeGenFunction &CGF, Address destField,
2303  Address srcField) override {
2304  CGF.EmitARCMoveWeak(destField, srcField);
2305  }
2306 
2307  void emitDispose(CodeGenFunction &CGF, Address field) override {
2308  CGF.EmitARCDestroyWeak(field);
2309  }
2310 
2311  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2312  // 0 is distinguishable from all pointers and byref flags
2313  id.AddInteger(0);
2314  }
2315 };
2316 
2317 /// Emits the copy/dispose helpers for an ARC __block __strong variable
2318 /// that's not of block-pointer type.
2319 class ARCStrongByrefHelpers final : public BlockByrefHelpers {
2320 public:
2321  ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2322 
2323  void emitCopy(CodeGenFunction &CGF, Address destField,
2324  Address srcField) override {
2325  // Do a "move" by copying the value and then zeroing out the old
2326  // variable.
2327 
2328  llvm::Value *value = CGF.Builder.CreateLoad(srcField);
2329 
2330  llvm::Value *null =
2331  llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
2332 
2333  if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
2334  CGF.Builder.CreateStore(null, destField);
2335  CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
2336  CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
2337  return;
2338  }
2339  CGF.Builder.CreateStore(value, destField);
2340  CGF.Builder.CreateStore(null, srcField);
2341  }
2342 
2343  void emitDispose(CodeGenFunction &CGF, Address field) override {
2345  }
2346 
2347  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2348  // 1 is distinguishable from all pointers and byref flags
2349  id.AddInteger(1);
2350  }
2351 };
2352 
2353 /// Emits the copy/dispose helpers for an ARC __block __strong
2354 /// variable that's of block-pointer type.
2355 class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
2356 public:
2357  ARCStrongBlockByrefHelpers(CharUnits alignment)
2358  : BlockByrefHelpers(alignment) {}
2359 
2360  void emitCopy(CodeGenFunction &CGF, Address destField,
2361  Address srcField) override {
2362  // Do the copy with objc_retainBlock; that's all that
2363  // _Block_object_assign would do anyway, and we'd have to pass the
2364  // right arguments to make sure it doesn't get no-op'ed.
2365  llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
2366  llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
2367  CGF.Builder.CreateStore(copy, destField);
2368  }
2369 
2370  void emitDispose(CodeGenFunction &CGF, Address field) override {
2372  }
2373 
2374  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2375  // 2 is distinguishable from all pointers and byref flags
2376  id.AddInteger(2);
2377  }
2378 };
2379 
2380 /// Emits the copy/dispose helpers for a __block variable with a
2381 /// nontrivial copy constructor or destructor.
2382 class CXXByrefHelpers final : public BlockByrefHelpers {
2383  QualType VarType;
2384  const Expr *CopyExpr;
2385 
2386 public:
2387  CXXByrefHelpers(CharUnits alignment, QualType type,
2388  const Expr *copyExpr)
2389  : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
2390 
2391  bool needsCopy() const override { return CopyExpr != nullptr; }
2392  void emitCopy(CodeGenFunction &CGF, Address destField,
2393  Address srcField) override {
2394  if (!CopyExpr) return;
2395  CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
2396  }
2397 
2398  void emitDispose(CodeGenFunction &CGF, Address field) override {
2399  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2400  CGF.PushDestructorCleanup(VarType, field);
2401  CGF.PopCleanupBlocks(cleanupDepth);
2402  }
2403 
2404  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2405  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2406  }
2407 };
2408 
2409 /// Emits the copy/dispose helpers for a __block variable that is a non-trivial
2410 /// C struct.
2411 class NonTrivialCStructByrefHelpers final : public BlockByrefHelpers {
2412  QualType VarType;
2413 
2414 public:
2415  NonTrivialCStructByrefHelpers(CharUnits alignment, QualType type)
2416  : BlockByrefHelpers(alignment), VarType(type) {}
2417 
2418  void emitCopy(CodeGenFunction &CGF, Address destField,
2419  Address srcField) override {
2420  CGF.callCStructMoveConstructor(CGF.MakeAddrLValue(destField, VarType),
2421  CGF.MakeAddrLValue(srcField, VarType));
2422  }
2423 
2424  bool needsDispose() const override {
2425  return VarType.isDestructedType();
2426  }
2427 
2428  void emitDispose(CodeGenFunction &CGF, Address field) override {
2429  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2430  CGF.pushDestroy(VarType.isDestructedType(), field, VarType);
2431  CGF.PopCleanupBlocks(cleanupDepth);
2432  }
2433 
2434  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2435  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2436  }
2437 };
2438 } // end anonymous namespace
2439 
2440 static llvm::Constant *
2442  BlockByrefHelpers &generator) {
2443  ASTContext &Context = CGF.getContext();
2444 
2445  QualType ReturnTy = Context.VoidTy;
2446 
2447  FunctionArgList args;
2448  ImplicitParamDecl Dst(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2449  args.push_back(&Dst);
2450 
2451  ImplicitParamDecl Src(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2452  args.push_back(&Src);
2453 
2454  const CGFunctionInfo &FI =
2455  CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2456 
2457  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2458 
2459  // FIXME: We'd like to put these into a mergable by content, with
2460  // internal linkage.
2461  llvm::Function *Fn =
2463  "__Block_byref_object_copy_", &CGF.CGM.getModule());
2464 
2465  IdentifierInfo *II
2466  = &Context.Idents.get("__Block_byref_object_copy_");
2467 
2468  SmallVector<QualType, 2> ArgTys;
2469  ArgTys.push_back(Context.VoidPtrTy);
2470  ArgTys.push_back(Context.VoidPtrTy);
2471  QualType FunctionTy = Context.getFunctionType(ReturnTy, ArgTys, {});
2472 
2474  Context, Context.getTranslationUnitDecl(), SourceLocation(),
2475  SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2476 
2478 
2479  CGF.StartFunction(FD, ReturnTy, Fn, FI, args);
2480 
2481  if (generator.needsCopy()) {
2482  llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
2483 
2484  // dst->x
2485  Address destField = CGF.GetAddrOfLocalVar(&Dst);
2486  destField = Address(CGF.Builder.CreateLoad(destField),
2487  byrefInfo.ByrefAlignment);
2488  destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
2489  destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
2490  "dest-object");
2491 
2492  // src->x
2493  Address srcField = CGF.GetAddrOfLocalVar(&Src);
2494  srcField = Address(CGF.Builder.CreateLoad(srcField),
2495  byrefInfo.ByrefAlignment);
2496  srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
2497  srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
2498  "src-object");
2499 
2500  generator.emitCopy(CGF, destField, srcField);
2501  }
2502 
2503  CGF.FinishFunction();
2504 
2505  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2506 }
2507 
2508 /// Build the copy helper for a __block variable.
2509 static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
2510  const BlockByrefInfo &byrefInfo,
2511  BlockByrefHelpers &generator) {
2512  CodeGenFunction CGF(CGM);
2513  return generateByrefCopyHelper(CGF, byrefInfo, generator);
2514 }
2515 
2516 /// Generate code for a __block variable's dispose helper.
2517 static llvm::Constant *
2519  const BlockByrefInfo &byrefInfo,
2520  BlockByrefHelpers &generator) {
2521  ASTContext &Context = CGF.getContext();
2522  QualType R = Context.VoidTy;
2523 
2524  FunctionArgList args;
2525  ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2527  args.push_back(&Src);
2528 
2529  const CGFunctionInfo &FI =
2531 
2532  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2533 
2534  // FIXME: We'd like to put these into a mergable by content, with
2535  // internal linkage.
2536  llvm::Function *Fn =
2538  "__Block_byref_object_dispose_",
2539  &CGF.CGM.getModule());
2540 
2541  IdentifierInfo *II
2542  = &Context.Idents.get("__Block_byref_object_dispose_");
2543 
2544  SmallVector<QualType, 1> ArgTys;
2545  ArgTys.push_back(Context.VoidPtrTy);
2546  QualType FunctionTy = Context.getFunctionType(R, ArgTys, {});
2547 
2549  Context, Context.getTranslationUnitDecl(), SourceLocation(),
2550  SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2551 
2553 
2554  CGF.StartFunction(FD, R, Fn, FI, args);
2555 
2556  if (generator.needsDispose()) {
2557  Address addr = CGF.GetAddrOfLocalVar(&Src);
2558  addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2559  auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2560  addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2561  addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2562 
2563  generator.emitDispose(CGF, addr);
2564  }
2565 
2566  CGF.FinishFunction();
2567 
2568  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2569 }
2570 
2571 /// Build the dispose helper for a __block variable.
2572 static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2573  const BlockByrefInfo &byrefInfo,
2574  BlockByrefHelpers &generator) {
2575  CodeGenFunction CGF(CGM);
2576  return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2577 }
2578 
2579 /// Lazily build the copy and dispose helpers for a __block variable
2580 /// with the given information.
2581 template <class T>
2582 static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2583  T &&generator) {
2584  llvm::FoldingSetNodeID id;
2585  generator.Profile(id);
2586 
2587  void *insertPos;
2588  BlockByrefHelpers *node
2589  = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2590  if (node) return static_cast<T*>(node);
2591 
2592  generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2593  generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2594 
2595  T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2596  CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2597  return copy;
2598 }
2599 
2600 /// Build the copy and dispose helpers for the given __block variable
2601 /// emission. Places the helpers in the global cache. Returns null
2602 /// if no helpers are required.
2604 CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2605  const AutoVarEmission &emission) {
2606  const VarDecl &var = *emission.Variable;
2607  assert(var.isEscapingByref() &&
2608  "only escaping __block variables need byref helpers");
2609 
2610  QualType type = var.getType();
2611 
2612  auto &byrefInfo = getBlockByrefInfo(&var);
2613 
2614  // The alignment we care about for the purposes of uniquing byref
2615  // helpers is the alignment of the actual byref value field.
2616  CharUnits valueAlignment =
2617  byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2618 
2619  if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2620  const Expr *copyExpr =
2622  if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2623 
2625  CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2626  }
2627 
2628  // If type is a non-trivial C struct type that is non-trivial to
2629  // destructly move or destroy, build the copy and dispose helpers.
2630  if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct ||
2631  type.isDestructedType() == QualType::DK_nontrivial_c_struct)
2633  CGM, byrefInfo, NonTrivialCStructByrefHelpers(valueAlignment, type));
2634 
2635  // Otherwise, if we don't have a retainable type, there's nothing to do.
2636  // that the runtime does extra copies.
2637  if (!type->isObjCRetainableType()) return nullptr;
2638 
2639  Qualifiers qs = type.getQualifiers();
2640 
2641  // If we have lifetime, that dominates.
2642  if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2643  switch (lifetime) {
2644  case Qualifiers::OCL_None: llvm_unreachable("impossible");
2645 
2646  // These are just bits as far as the runtime is concerned.
2649  return nullptr;
2650 
2651  // Tell the runtime that this is ARC __weak, called by the
2652  // byref routines.
2653  case Qualifiers::OCL_Weak:
2654  return ::buildByrefHelpers(CGM, byrefInfo,
2655  ARCWeakByrefHelpers(valueAlignment));
2656 
2657  // ARC __strong __block variables need to be retained.
2659  // Block pointers need to be copied, and there's no direct
2660  // transfer possible.
2661  if (type->isBlockPointerType()) {
2662  return ::buildByrefHelpers(CGM, byrefInfo,
2663  ARCStrongBlockByrefHelpers(valueAlignment));
2664 
2665  // Otherwise, we transfer ownership of the retain from the stack
2666  // to the heap.
2667  } else {
2668  return ::buildByrefHelpers(CGM, byrefInfo,
2669  ARCStrongByrefHelpers(valueAlignment));
2670  }
2671  }
2672  llvm_unreachable("fell out of lifetime switch!");
2673  }
2674 
2675  BlockFieldFlags flags;
2676  if (type->isBlockPointerType()) {
2677  flags |= BLOCK_FIELD_IS_BLOCK;
2678  } else if (CGM.getContext().isObjCNSObjectType(type) ||
2679  type->isObjCObjectPointerType()) {
2680  flags |= BLOCK_FIELD_IS_OBJECT;
2681  } else {
2682  return nullptr;
2683  }
2684 
2685  if (type.isObjCGCWeak())
2686  flags |= BLOCK_FIELD_IS_WEAK;
2687 
2688  return ::buildByrefHelpers(CGM, byrefInfo,
2689  ObjectByrefHelpers(valueAlignment, flags));
2690 }
2691 
2693  const VarDecl *var,
2694  bool followForward) {
2695  auto &info = getBlockByrefInfo(var);
2696  return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2697 }
2698 
2700  const BlockByrefInfo &info,
2701  bool followForward,
2702  const llvm::Twine &name) {
2703  // Chase the forwarding address if requested.
2704  if (followForward) {
2705  Address forwardingAddr = Builder.CreateStructGEP(baseAddr, 1, "forwarding");
2706  baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2707  }
2708 
2709  return Builder.CreateStructGEP(baseAddr, info.FieldIndex, name);
2710 }
2711 
2712 /// BuildByrefInfo - This routine changes a __block variable declared as T x
2713 /// into:
2714 ///
2715 /// struct {
2716 /// void *__isa;
2717 /// void *__forwarding;
2718 /// int32_t __flags;
2719 /// int32_t __size;
2720 /// void *__copy_helper; // only if needed
2721 /// void *__destroy_helper; // only if needed
2722 /// void *__byref_variable_layout;// only if needed
2723 /// char padding[X]; // only if needed
2724 /// T x;
2725 /// } x
2726 ///
2728  auto it = BlockByrefInfos.find(D);
2729  if (it != BlockByrefInfos.end())
2730  return it->second;
2731 
2732  llvm::StructType *byrefType =
2733  llvm::StructType::create(getLLVMContext(),
2734  "struct.__block_byref_" + D->getNameAsString());
2735 
2736  QualType Ty = D->getType();
2737 
2738  CharUnits size;
2740 
2741  // void *__isa;
2742  types.push_back(Int8PtrTy);
2743  size += getPointerSize();
2744 
2745  // void *__forwarding;
2746  types.push_back(llvm::PointerType::getUnqual(byrefType));
2747  size += getPointerSize();
2748 
2749  // int32_t __flags;
2750  types.push_back(Int32Ty);
2751  size += CharUnits::fromQuantity(4);
2752 
2753  // int32_t __size;
2754  types.push_back(Int32Ty);
2755  size += CharUnits::fromQuantity(4);
2756 
2757  // Note that this must match *exactly* the logic in buildByrefHelpers.
2758  bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2759  if (hasCopyAndDispose) {
2760  /// void *__copy_helper;
2761  types.push_back(Int8PtrTy);
2762  size += getPointerSize();
2763 
2764  /// void *__destroy_helper;
2765  types.push_back(Int8PtrTy);
2766  size += getPointerSize();
2767  }
2768 
2769  bool HasByrefExtendedLayout = false;
2770  Qualifiers::ObjCLifetime Lifetime;
2771  if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2772  HasByrefExtendedLayout) {
2773  /// void *__byref_variable_layout;
2774  types.push_back(Int8PtrTy);
2775  size += CharUnits::fromQuantity(PointerSizeInBytes);
2776  }
2777 
2778  // T x;
2779  llvm::Type *varTy = ConvertTypeForMem(Ty);
2780 
2781  bool packed = false;
2782  CharUnits varAlign = getContext().getDeclAlign(D);
2783  CharUnits varOffset = size.alignTo(varAlign);
2784 
2785  // We may have to insert padding.
2786  if (varOffset != size) {
2787  llvm::Type *paddingTy =
2788  llvm::ArrayType::get(Int8Ty, (varOffset - size).getQuantity());
2789 
2790  types.push_back(paddingTy);
2791  size = varOffset;
2792 
2793  // Conversely, we might have to prevent LLVM from inserting padding.
2794  } else if (CGM.getDataLayout().getABITypeAlignment(varTy)
2795  > varAlign.getQuantity()) {
2796  packed = true;
2797  }
2798  types.push_back(varTy);
2799 
2800  byrefType->setBody(types, packed);
2801 
2802  BlockByrefInfo info;
2803  info.Type = byrefType;
2804  info.FieldIndex = types.size() - 1;
2805  info.FieldOffset = varOffset;
2806  info.ByrefAlignment = std::max(varAlign, getPointerAlign());
2807 
2808  auto pair = BlockByrefInfos.insert({D, info});
2809  assert(pair.second && "info was inserted recursively?");
2810  return pair.first->second;
2811 }
2812 
2813 /// Initialize the structural components of a __block variable, i.e.
2814 /// everything but the actual object.
2816  // Find the address of the local.
2817  Address addr = emission.Addr;
2818 
2819  // That's an alloca of the byref structure type.
2820  llvm::StructType *byrefType = cast<llvm::StructType>(
2821  cast<llvm::PointerType>(addr.getPointer()->getType())->getElementType());
2822 
2823  unsigned nextHeaderIndex = 0;
2824  CharUnits nextHeaderOffset;
2825  auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2826  const Twine &name) {
2827  auto fieldAddr = Builder.CreateStructGEP(addr, nextHeaderIndex, name);
2828  Builder.CreateStore(value, fieldAddr);
2829 
2830  nextHeaderIndex++;
2831  nextHeaderOffset += fieldSize;
2832  };
2833 
2834  // Build the byref helpers if necessary. This is null if we don't need any.
2835  BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2836 
2837  const VarDecl &D = *emission.Variable;
2838  QualType type = D.getType();
2839 
2840  bool HasByrefExtendedLayout;
2841  Qualifiers::ObjCLifetime ByrefLifetime;
2842  bool ByRefHasLifetime =
2843  getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2844 
2845  llvm::Value *V;
2846 
2847  // Initialize the 'isa', which is just 0 or 1.
2848  int isa = 0;
2849  if (type.isObjCGCWeak())
2850  isa = 1;
2851  V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2852  storeHeaderField(V, getPointerSize(), "byref.isa");
2853 
2854  // Store the address of the variable into its own forwarding pointer.
2855  storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2856 
2857  // Blocks ABI:
2858  // c) the flags field is set to either 0 if no helper functions are
2859  // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2860  BlockFlags flags;
2861  if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2862  if (ByRefHasLifetime) {
2863  if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2864  else switch (ByrefLifetime) {
2866  flags |= BLOCK_BYREF_LAYOUT_STRONG;
2867  break;
2868  case Qualifiers::OCL_Weak:
2869  flags |= BLOCK_BYREF_LAYOUT_WEAK;
2870  break;
2873  break;
2874  case Qualifiers::OCL_None:
2875  if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2877  break;
2878  default:
2879  break;
2880  }
2881  if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2882  printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2883  if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2884  printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2885  if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2886  BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2887  if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2888  printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2889  if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2890  printf(" BLOCK_BYREF_LAYOUT_STRONG");
2891  if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2892  printf(" BLOCK_BYREF_LAYOUT_WEAK");
2893  if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2894  printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2895  if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2896  printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2897  }
2898  printf("\n");
2899  }
2900  }
2901  storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2902  getIntSize(), "byref.flags");
2903 
2904  CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2905  V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2906  storeHeaderField(V, getIntSize(), "byref.size");
2907 
2908  if (helpers) {
2909  storeHeaderField(helpers->CopyHelper, getPointerSize(),
2910  "byref.copyHelper");
2911  storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2912  "byref.disposeHelper");
2913  }
2914 
2915  if (ByRefHasLifetime && HasByrefExtendedLayout) {
2916  auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2917  storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2918  }
2919 }
2920 
2922  bool CanThrow) {
2923  llvm::FunctionCallee F = CGM.getBlockObjectDispose();
2924  llvm::Value *args[] = {
2925  Builder.CreateBitCast(V, Int8PtrTy),
2926  llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2927  };
2928 
2929  if (CanThrow)
2930  EmitRuntimeCallOrInvoke(F, args);
2931  else
2932  EmitNounwindRuntimeCall(F, args);
2933 }
2934 
2936  BlockFieldFlags Flags,
2937  bool LoadBlockVarAddr, bool CanThrow) {
2938  EHStack.pushCleanup<CallBlockRelease>(Kind, Addr, Flags, LoadBlockVarAddr,
2939  CanThrow);
2940 }
2941 
2942 /// Adjust the declaration of something from the blocks API.
2944  llvm::Constant *C) {
2945  auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2946 
2947  if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2948  IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2951 
2952  assert((isa<llvm::Function>(C->stripPointerCasts()) ||
2953  isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&
2954  "expected Function or GlobalVariable");
2955 
2956  const NamedDecl *ND = nullptr;
2957  for (const auto &Result : DC->lookup(&II))
2958  if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2959  (ND = dyn_cast<VarDecl>(Result)))
2960  break;
2961 
2962  // TODO: support static blocks runtime
2963  if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2964  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2965  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2966  } else {
2967  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2968  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2969  }
2970  }
2971 
2972  if (CGM.getLangOpts().BlocksRuntimeOptional && GV->isDeclaration() &&
2973  GV->hasExternalLinkage())
2974  GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2975 
2976  CGM.setDSOLocal(GV);
2977 }
2978 
2980  if (BlockObjectDispose)
2981  return BlockObjectDispose;
2982 
2983  llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2984  llvm::FunctionType *fty
2985  = llvm::FunctionType::get(VoidTy, args, false);
2986  BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2988  *this, cast<llvm::Constant>(BlockObjectDispose.getCallee()));
2989  return BlockObjectDispose;
2990 }
2991 
2992 llvm::FunctionCallee CodeGenModule::getBlockObjectAssign() {
2993  if (BlockObjectAssign)
2994  return BlockObjectAssign;
2995 
2996  llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
2997  llvm::FunctionType *fty
2998  = llvm::FunctionType::get(VoidTy, args, false);
2999  BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
3001  *this, cast<llvm::Constant>(BlockObjectAssign.getCallee()));
3002  return BlockObjectAssign;
3003 }
3004 
3006  if (NSConcreteGlobalBlock)
3007  return NSConcreteGlobalBlock;
3008 
3009  NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
3010  Int8PtrTy->getPointerTo(),
3011  nullptr);
3012  configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
3013  return NSConcreteGlobalBlock;
3014 }
3015 
3017  if (NSConcreteStackBlock)
3018  return NSConcreteStackBlock;
3019 
3020  NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
3021  Int8PtrTy->getPointerTo(),
3022  nullptr);
3023  configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
3024  return NSConcreteStackBlock;
3025 }
const CGFunctionInfo & arrangeBuiltinFunctionDeclaration(QualType resultType, const FunctionArgList &args)
A builtin function is a freestanding function using the default C conventions.
Definition: CGCall.cpp:660
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:363
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Address CreateStructGEP(Address Addr, unsigned Index, const llvm::Twine &Name="")
Definition: CGBuilder.h:178
QualType getAddrSpaceQualType(QualType T, LangAS AddressSpace) const
Return the uniqued reference to the type for an address space qualified type with the specified type ...
const BlockDecl * getBlockDecl() const
Definition: Expr.h:5395
Information about the layout of a __block variable.
Definition: CGBlocks.h:143
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:183
CaptureStrKind
Definition: CGBlocks.cpp:101
const Capture & getCapture(const VarDecl *var) const
Definition: CGBlocks.h:270
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:1989
static llvm::Constant * generateByrefDisposeHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Generate code for a __block variable&#39;s dispose helper.
Definition: CGBlocks.cpp:2518
Represents a function declaration or definition.
Definition: Decl.h:1737
llvm::IntegerType * IntTy
int
llvm::Type * getGenericBlockLiteralType()
The type of a generic block literal.
Definition: CGBlocks.cpp:1215
const CGFunctionInfo & arrangeBlockFunctionDeclaration(const FunctionProtoType *type, const FunctionArgList &args)
Block invocation functions are C functions with an implicit parameter.
Definition: CGCall.cpp:635
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:59
Other implicit parameter.
Definition: Decl.h:1509
CharUnits BlockHeaderForcedGapOffset
Definition: CGBlocks.h:255
const FunctionProtoType * getFunctionType() const
getFunctionType - Return the underlying function type for this block.
Definition: Expr.cpp:2130
Expr * getCopyExpr() const
Definition: Decl.h:3903
static llvm::Constant * buildByrefDisposeHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the dispose helper for a __block variable.
Definition: CGBlocks.cpp:2572
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:3863
CanQualType VoidPtrTy
Definition: ASTContext.h:1043
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:1924
A (possibly-)qualified type.
Definition: Type.h:634
bool isBlockPointerType() const
Definition: Type.h:6309
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:3976
bool HaveInsertPoint() const
HaveInsertPoint - True if an insertion point is defined.
capture_const_iterator capture_begin() const
Definition: Decl.h:3986
llvm::LLVMContext & getLLVMContext()
void EmitARCDestroyWeak(Address addr)
void @objc_destroyWeak(i8** addr) Essentially objc_storeWeak(addr, nil).
Definition: CGObjC.cpp:2410
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:3360
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:962
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:2582
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:2233
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:3956
static llvm::Constant * buildBlockDescriptor(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
buildBlockDescriptor - Build the block descriptor meta-data for a block.
Definition: CGBlocks.cpp:184
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:6250
stable_iterator stable_begin() const
Create a stable reference to the top of the EH stack.
Definition: EHScopeStack.h:378
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:3987
The type would be trivial except that it is volatile-qualified.
Definition: Type.h:1104
Address GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
Represents a variable declaration or definition.
Definition: Decl.h:812
Objects with "hidden" visibility are not seen by the dynamic linker.
Definition: Visibility.h:36
CGBlockInfo(const BlockDecl *blockDecl, StringRef Name)
Definition: CGBlocks.cpp:34
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6761
EHScopeStack::stable_iterator getCleanup() const
Definition: CGBlocks.h:182
static void setBlockHelperAttributesVisibility(bool CapturesNonExternalType, llvm::Function *Fn, const CGFunctionInfo &FI, CodeGenModule &CGM)
Definition: CGBlocks.cpp:1967
LangAS
Defines the address space values used by the address space qualifier of QualType. ...
Definition: AddressSpaces.h:25
This class gathers all debug information during compilation and is responsible for emitting to llvm g...
Definition: CGDebugInfo.h:53
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:1687
virtual llvm::Constant * BuildRCBlockLayout(CodeGen::CodeGenModule &CGM, const CodeGen::CGBlockInfo &blockInfo)=0
llvm::Value * getPointer() const
Definition: Address.h:37
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:1925
static void destroyBlockInfos(CGBlockInfo *info)
Destroy a chain of block layouts.
Definition: CGBlocks.cpp:888
The collection of all-type qualifiers we support.
Definition: Type.h:137
void add(RValue rvalue, QualType type)
Definition: CGCall.h:287
const AstTypeMatcher< RecordType > recordType
Matches record types (e.g.
const BlockDecl * Block
Definition: CGBlocks.h:246
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:358
static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E, CaptureStrKind StrKind, CharUnits BlockAlignment, CodeGenModule &CGM)
Definition: CGBlocks.cpp:1806
One of these records is kept for each identifier that is lexed.
bool doesNotEscape() const
Definition: Decl.h:4008
void emitByrefStructureInit(const AutoVarEmission &emission)
Initialize the structural components of a __block variable, i.e.
Definition: CGBlocks.cpp:2815
CGBlockInfo * FirstBlockInfo
FirstBlockInfo - The head of a singly-linked-list of block layouts.
QualType getPointeeType() const
Definition: Type.h:2659
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:154
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:1998
bool HasCapturedVariableLayout
HasCapturedVariableLayout : True if block has captured variables and their layout meta-data has been ...
Definition: CGBlocks.h:234
FullExpr - Represents a "full-expression" node.
Definition: Expr.h:910
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:263
bool isReferenceType() const
Definition: Type.h:6313
Denotes a cleanup that should run when a scope is exited using exceptional control flow (a throw stat...
Definition: EHScopeStack.h:80
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:513
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:52
static llvm::Constant * generateByrefCopyHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Definition: CGBlocks.cpp:2441
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:3936
static bool isSafeForCXXConstantCapture(QualType type)
Determines if the given type is safe for constant capture in C++.
Definition: CGBlocks.cpp:385
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:49
IdentifierTable & Idents
Definition: ASTContext.h:565
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:109
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:2250
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:37
void EmitARCDestroyStrong(Address addr, ARCPreciseLifetime_t precise)
Destroy a __strong variable.
Definition: CGObjC.cpp:2236
const BlockDecl * getBlockDecl() const
Definition: CGBlocks.h:280
void setDSOLocal(llvm::GlobalValue *GV) const
virtual TargetOpenCLBlockHelper * getTargetOpenCLBlockHelper() const
Definition: TargetInfo.h:285
bool HasCXXObject
HasCXXObject - True if the block&#39;s custom copy/dispose functions need to be run even in GC mode...
Definition: CGBlocks.h:226
llvm::Value * EmitBlockLiteral(const BlockExpr *)
Emit block literal.
Definition: CGBlocks.cpp:898
uint32_t getBitMask() const
Definition: CGBlocks.h:117
bool isByRef() const
Whether this is a "by ref" capture, i.e.
Definition: Decl.h:3888
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6147
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:1108
CharUnits getDeclAlign(const Decl *D, bool ForAlignof=false) const
Return a conservative estimate of the alignment of the specified decl D.
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:40
void ForceCleanup(std::initializer_list< llvm::Value **> ValuesToReload={})
Force the emission of cleanups now, instead of waiting until this object is destroyed.
static Capture makeConstant(llvm::Value *value)
Definition: CGBlocks.h:209
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:105
void callCStructMoveConstructor(LValue Dst, LValue Src)
const Stmt * getBody() const
Definition: Expr.cpp:2139
llvm::Constant * getNSConcreteStackBlock()
Definition: CGBlocks.cpp:3016
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:1099
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:1874
This object can be modified without requiring retains or releases.
Definition: Type.h:158
StringRef Name
Name - The name of the block, kindof.
Definition: CGBlocks.h:155
bool isEscapingByref() const
Definition: Decl.h:3890
bool NeedsCopyDispose
True if the block has captures that would necessitate custom copy or dispose helper functions if the ...
Definition: CGBlocks.h:222
lookup_result lookup(DeclarationName Name) const
lookup - Find the declarations (if any) with the given Name in this context.
Definition: DeclBase.cpp:1598
const BlockExpr * BlockExpression
Definition: CGBlocks.h:247
static llvm::Constant * buildCopyHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to copy a block.
Definition: CGBlocks.cpp:55
bool isValid() const
Definition: Address.h:35
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1635
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3692
uint32_t getBitMask() const
Definition: CGBlocks.h:73
const CodeGen::CGBlockInfo * BlockInfo
const TargetCodeGenInfo & getTargetCodeGenInfo()
CGBlockInfo - Information to generate a block literal.
Definition: CGBlocks.h:152
virtual void emitCopy(CodeGenFunction &CGF, Address dest, Address src)=0
RValue - This trivial value class is used to represent the result of an expression that is evaluated...
Definition: CGValue.h:38
bool CanBeGlobal
CanBeGlobal - True if the block can be global, i.e.
Definition: CGBlocks.h:218
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:1748
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:178
unsigned Offset
Definition: Format.cpp:1630
static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info, SmallVectorImpl< llvm::Type *> &elementTypes)
Definition: CGBlocks.cpp:445
CGBlockInfo * NextBlockInfo
The next block in the block-info chain.
Definition: CGBlocks.h:268
CGObjCRuntime & getObjCRuntime()
Return a reference to the configured Objective-C runtime.
Represents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:3857
This represents one expression.
Definition: Expr.h:108
void EmitARCMoveWeak(Address dst, Address src)
void @objc_moveWeak(i8** dest, i8** src) Disregards the current value in dest.
Definition: CGObjC.cpp:2426
Emit only debug info necessary for generating line number tables (-gline-tables-only).
static Address invalid()
Definition: Address.h:34
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:6824
bool isObjCRetainableType() const
Definition: Type.cpp:4000
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5381
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2713
BlockCaptureEntityKind
Represents a type of copy/destroy operation that should be performed for an entity that&#39;s captured by...
Definition: CGBlocks.cpp:70
static llvm::Constant * buildGlobalBlock(CodeGenModule &CGM, const CGBlockInfo &blockInfo, llvm::Constant *blockFn)
Build the given block as a global block.
Definition: CGBlocks.cpp:1381
Expr * getCallee()
Definition: Expr.h:2547
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:2184
ObjCLifetime getObjCLifetime() const
Definition: Type.h:322
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:62
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:136
bool needsCopyDisposeHelpers() const
Definition: CGBlocks.h:290
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:1510
static Capture makeIndex(unsigned index, CharUnits offset, QualType FieldType)
Definition: CGBlocks.h:200
QualType getType() const
Definition: Expr.h:130
llvm::FunctionCallee getBlockObjectAssign()
Definition: CGBlocks.cpp:2992
bool isa(CodeGen::Address addr)
Definition: Address.h:111
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:1379
static bool CanThrow(Expr *E, ASTContext &Ctx)
Definition: CFG.cpp:2406
static CharUnits getLowBit(CharUnits v)
Get the low bit of a nonzero character count.
Definition: CGBlocks.cpp:441
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:6701
const TargetInfo & getTarget() const
const LangOptions & getLangOpts() const
ASTContext & getContext() const
static BlockFieldFlags getBlockFieldFlagsForObjCObjectPointer(const BlockDecl::Capture &CI, QualType T)
Definition: CGBlocks.cpp:2130
do v
Definition: arm_acle.h:78
Address GetAddrOfBlockDecl(const VarDecl *var)
Definition: CGBlocks.cpp:1317
static QualType getCaptureFieldType(const CodeGenFunction &CGF, const BlockDecl::Capture &CI)
Definition: CGBlocks.cpp:500
llvm::Function * getInvokeFunction(const Expr *E)
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:34
static std::string getBlockDescriptorName(const CGBlockInfo &BlockInfo, CodeGenModule &CGM)
Definition: CGBlocks.cpp:121
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:6136
param_iterator param_begin()
Definition: Decl.h:3955
The l-value was considered opaque, so the alignment was determined from a type.
RecordDecl * getDecl() const
Definition: Type.h:4385
void setBlockContextParameter(const ImplicitParamDecl *D, unsigned argNum, llvm::Value *ptr)
Definition: CGBlocks.cpp:1472
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:417
bool UsesStret
UsesStret : True if the block uses an stret return.
Definition: CGBlocks.h:230
There is no lifetime qualification on this type.
Definition: Type.h:154
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:141
llvm::FunctionCallee getBlockObjectDispose()
Definition: CGBlocks.cpp:2979
#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:165
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:2418
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:1951
Encodes a location in the source.
static DeclContext * castToDeclContext(const TranslationUnitDecl *D)
Definition: Decl.h:129
void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags, bool CanThrow)
Definition: CGBlocks.cpp:2921
QualType getReturnType() const
Definition: Type.h:3618
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Expr.h:5404
A saved depth on the scope stack.
Definition: EHScopeStack.h:106
llvm::StructType * StructureType
Definition: CGBlocks.h:245
std::string getNameAsString() const
Get a human-readable name for the declaration, even if it is one of the special kinds of names (C++ c...
Definition: Decl.h:291
static std::string getCopyDestroyHelperFuncName(const SmallVectorImpl< BlockCaptureManagedEntity > &Captures, CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM)
Definition: CGBlocks.cpp:1902
static void configureBlocksRuntimeObject(CodeGenModule &CGM, llvm::Constant *C)
Adjust the declaration of something from the blocks API.
Definition: CGBlocks.cpp:2943
The type is a struct containing a field whose type is neither PCK_Trivial nor PCK_VolatileTrivial.
Definition: Type.h:1120
An aggregate value slot.
Definition: CGValue.h:436
const BlockByrefInfo & getBlockByrefInfo(const VarDecl *var)
BuildByrefInfo - This routine changes a __block variable declared as T x into:
Definition: CGBlocks.cpp:2727
A scoped helper to set the current debug location to the specified location or preferred location of ...
Definition: CGDebugInfo.h:686
bool CapturesNonExternalType
Indicates whether an object of a non-external C++ class is captured.
Definition: CGBlocks.h:239
static bool cxxDestructorCanThrow(QualType T)
Check if T is a C++ class that has a destructor that can throw.
Definition: CGBlocks.cpp:1798
bool isConversionFromLambda() const
Definition: Decl.h:4000
void enterNonTrivialFullExpression(const FullExpr *E)
Enter a full-expression with a non-trivial number of objects to clean up.
Definition: CGBlocks.cpp:862
CanQualType VoidTy
Definition: ASTContext.h:1015
llvm::DenseMap< const VarDecl *, Capture > Captures
The mapping of allocated indexes within the block.
Definition: CGBlocks.h:242
bool isNonEscapingByref() const
Indicates the capture is a __block variable that is never captured by an escaping block...
Definition: Decl.cpp:2377
arg_range arguments()
Definition: Expr.h:2623
bool isObjCObjectPointerType() const
Definition: Type.h:6398
static bool isBlockPointer(Expr *Arg)
An aligned address.
Definition: Address.h:24
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:3153
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1154
llvm::Value * getConstant() const
Definition: CGBlocks.h:191
const BlockExpr * getBlockExpr() const
Definition: CGBlocks.h:281
All available information about a concrete callee.
Definition: CGCall.h:66
MangleContext & getMangleContext()
Gets the mangle context.
Definition: CGCXXABI.h:96
void enterByrefCleanup(CleanupKind Kind, Address Addr, BlockFieldFlags Flags, bool LoadBlockVarAddr, bool CanThrow)
Enter a cleanup to destroy a __block variable.
Definition: CGBlocks.cpp:2935
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:3884
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:2343
unsigned CXXThisIndex
The field index of &#39;this&#39; within the block, if there is one.
Definition: CGBlocks.h:158
Assigning into this object requires a lifetime extension.
Definition: Type.h:171
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:1112
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:628
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:358
bool isObjCGCWeak() const
true when Type is objc&#39;s weak.
Definition: Type.h:1044
static llvm::Constant * tryCaptureAsConstant(CodeGenModule &CGM, CodeGenFunction *CGF, const VarDecl *var)
It is illegal to modify a const object after initialization.
Definition: CGBlocks.cpp:409
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:189
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:519
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:1265
ArrayRef< Capture > captures() const
Definition: Decl.h:3984
bool isNested() const
Whether this is a nested capture, i.e.
Definition: Decl.h:3900
Parameter for Objective-C &#39;self&#39; argument.
Definition: Decl.h:1494
static llvm::Constant * buildDisposeHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to dispose of a block.
Definition: CGBlocks.cpp:61
const Expr * getInit() const
Definition: Decl.h:1219
llvm::Constant * getPointer() const
Definition: Address.h:83
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:69
int printf(__constant const char *st,...) __attribute__((format(printf
bool hasObjCLifetime() const
Definition: Type.h:321
llvm::StoreInst * CreateStore(llvm::Value *Val, Address Addr, bool IsVolatile=false)
Definition: CGBuilder.h:107
bool isEscapingByref() const
Indicates the capture is a __block variable that is captured by a block that can potentially escape (...
Definition: Decl.cpp:2373
llvm::Module & getModule() const
llvm::StructType * Type
Definition: CGBlocks.h:145
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:778
Pointer to a block type.
Definition: Type.h:2644
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:4375
StructBuilder beginStruct(llvm::StructType *structTy=nullptr)
CanQualType UnsignedLongTy
Definition: ASTContext.h:1025
static llvm::Constant * buildByrefCopyHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the copy helper for a __block variable.
Definition: CGBlocks.cpp:2509
void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp)
Definition: CGExprCXX.cpp:629
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:871
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:31
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:3989
Reading or writing from this object requires a barrier call.
Definition: Type.h:168
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:1008
Represents a C++ struct/union/class.
Definition: DeclCXX.h:299
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:6104
void setAddrOfGlobalBlock(const BlockExpr *BE, llvm::Constant *Addr)
Notes that BE&#39;s global block is available via Addr.
Definition: CGBlocks.cpp:1351
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
CharUnits BlockHeaderForcedGapSize
Definition: CGBlocks.h:258
SourceLocation getEndLoc() const LLVM_READONLY
Definition: Expr.h:5407
llvm::Value * EmitARCRetainBlock(llvm::Value *value, bool mandatory)
Retain the given block, with _Block_copy semantics.
Definition: CGObjC.cpp:2110
uint64_t getPointerAlign(unsigned AddrSpace) const
Definition: TargetInfo.h:361
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2429
StringRef getName() const
Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:275
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:1512
The top declaration context.
Definition: Decl.h:107
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1074
static RValue get(llvm::Value *V)
Definition: CGValue.h:85
RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue)
Definition: CGBlocks.cpp:1252
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:734
llvm::Constant * getNSConcreteGlobalBlock()
Definition: CGBlocks.cpp:3005
llvm::Type * getBlockDescriptorType()
Fetches the type of a generic block descriptor.
Definition: CGBlocks.cpp:1183
llvm::Constant * GetAddrOfGlobalBlock(const BlockExpr *BE, StringRef Name)
Gets the address of a block which requires no captures.
Definition: CGBlocks.cpp:1359
QualType getType() const
Definition: Decl.h:647
An l-value expression is a reference to an object with independent storage.
Definition: Specifiers.h:113
llvm::PointerType * getGenericVoidPointerType()
Information for lazily generating a cleanup.
Definition: EHScopeStack.h:146
This represents a decl that may have a name.
Definition: Decl.h:248
llvm::Instruction * DominatingIP
An instruction which dominates the full-expression that the block is inside.
Definition: CGBlocks.h:262
unsigned long ulong
An unsigned 64-bit integer.
Definition: opencl-c.h:59
const LangOptions & getLangOpts() const
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2517
llvm::CallInst * EmitNounwindRuntimeCall(llvm::FunctionCallee callee, const Twine &name="")
static bool isObjCNSObjectType(QualType Ty)
Return true if this is an NSObject object with its NSObject attribute set.
Definition: ASTContext.h:2052
Decl * getCalleeDecl()
Definition: Expr.h:2559
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:262
const LangOptions & getLangOpts() const
Definition: ASTContext.h:706
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:2692
Abstract information about a function or function prototype.
Definition: CGCall.h:44
SourceLocation getLocation() const
Definition: DeclBase.h:420
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:2139
bool isExternallyVisible() const
Definition: Decl.h:379
void setCleanup(EHScopeStack::stable_iterator cleanup)
Definition: CGBlocks.h:186
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:1054
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1549