clang  10.0.0git
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/Attr.h"
23 #include "clang/AST/DeclObjC.h"
25 #include "llvm/ADT/SmallSet.h"
26 #include "llvm/IR/DataLayout.h"
27 #include "llvm/IR/Module.h"
28 #include "llvm/Support/ScopedPrinter.h"
29 #include <algorithm>
30 #include <cstdio>
31 
32 using namespace clang;
33 using namespace CodeGen;
34 
35 CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
36  : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
37  HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
38  CapturesNonExternalType(false), LocalAddress(Address::invalid()),
39  StructureType(nullptr), Block(block), DominatingIP(nullptr) {
40 
41  // Skip asm prefix, if any. 'name' is usually taken directly from
42  // the mangled name of the enclosing function.
43  if (!name.empty() && name[0] == '\01')
44  name = name.substr(1);
45 }
46 
47 // Anchor the vtable to this translation unit.
49 
50 /// Build the given block as a global block.
51 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
52  const CGBlockInfo &blockInfo,
53  llvm::Constant *blockFn);
54 
55 /// Build the helper function to copy a block.
56 static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
57  const CGBlockInfo &blockInfo) {
58  return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
59 }
60 
61 /// Build the helper function to dispose of a block.
62 static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
63  const CGBlockInfo &blockInfo) {
64  return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
65 }
66 
67 namespace {
68 
69 /// Represents a type of copy/destroy operation that should be performed for an
70 /// entity that's captured by a block.
72  CXXRecord, // Copy or destroy
73  ARCWeak,
74  ARCStrong,
75  NonTrivialCStruct,
76  BlockObject, // Assign or release
77  None
78 };
79 
80 /// Represents a captured entity that requires extra operations in order for
81 /// this entity to be copied or destroyed correctly.
82 struct BlockCaptureManagedEntity {
83  BlockCaptureEntityKind CopyKind, DisposeKind;
84  BlockFieldFlags CopyFlags, DisposeFlags;
85  const BlockDecl::Capture *CI;
87 
88  BlockCaptureManagedEntity(BlockCaptureEntityKind CopyType,
89  BlockCaptureEntityKind DisposeType,
90  BlockFieldFlags CopyFlags,
91  BlockFieldFlags DisposeFlags,
92  const BlockDecl::Capture &CI,
93  const CGBlockInfo::Capture &Capture)
94  : CopyKind(CopyType), DisposeKind(DisposeType), CopyFlags(CopyFlags),
95  DisposeFlags(DisposeFlags), CI(&CI), Capture(&Capture) {}
96 
97  bool operator<(const BlockCaptureManagedEntity &Other) const {
98  return Capture->getOffset() < Other.Capture->getOffset();
99  }
100 };
101 
102 enum class CaptureStrKind {
103  // String for the copy helper.
104  CopyHelper,
105  // String for the dispose helper.
106  DisposeHelper,
107  // Merge the strings for the copy helper and dispose helper.
108  Merged
109 };
110 
111 } // end anonymous namespace
112 
114  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
115  SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures);
116 
117 static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
118  CaptureStrKind StrKind,
119  CharUnits BlockAlignment,
120  CodeGenModule &CGM);
121 
122 static std::string getBlockDescriptorName(const CGBlockInfo &BlockInfo,
123  CodeGenModule &CGM) {
124  std::string Name = "__block_descriptor_";
125  Name += llvm::to_string(BlockInfo.BlockSize.getQuantity()) + "_";
126 
127  if (BlockInfo.needsCopyDisposeHelpers()) {
128  if (CGM.getLangOpts().Exceptions)
129  Name += "e";
130  if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
131  Name += "a";
132  Name += llvm::to_string(BlockInfo.BlockAlign.getQuantity()) + "_";
133 
136  ManagedCaptures);
137 
138  for (const BlockCaptureManagedEntity &E : ManagedCaptures) {
139  Name += llvm::to_string(E.Capture->getOffset().getQuantity());
140 
141  if (E.CopyKind == E.DisposeKind) {
142  // If CopyKind and DisposeKind are the same, merge the capture
143  // information.
144  assert(E.CopyKind != BlockCaptureEntityKind::None &&
145  "shouldn't see BlockCaptureManagedEntity that is None");
146  Name += getBlockCaptureStr(E, CaptureStrKind::Merged,
147  BlockInfo.BlockAlign, CGM);
148  } else {
149  // If CopyKind and DisposeKind are not the same, which can happen when
150  // either Kind is None or the captured object is a __strong block,
151  // concatenate the copy and dispose strings.
152  Name += getBlockCaptureStr(E, CaptureStrKind::CopyHelper,
153  BlockInfo.BlockAlign, CGM);
154  Name += getBlockCaptureStr(E, CaptureStrKind::DisposeHelper,
155  BlockInfo.BlockAlign, CGM);
156  }
157  }
158  Name += "_";
159  }
160 
161  std::string TypeAtEncoding =
163  /// Replace occurrences of '@' with '\1'. '@' is reserved on ELF platforms as
164  /// a separator between symbol name and symbol version.
165  std::replace(TypeAtEncoding.begin(), TypeAtEncoding.end(), '@', '\1');
166  Name += "e" + llvm::to_string(TypeAtEncoding.size()) + "_" + TypeAtEncoding;
167  Name += "l" + CGM.getObjCRuntime().getRCBlockLayoutStr(CGM, BlockInfo);
168  return Name;
169 }
170 
171 /// buildBlockDescriptor - Build the block descriptor meta-data for a block.
172 /// buildBlockDescriptor is accessed from 5th field of the Block_literal
173 /// meta-data and contains stationary information about the block literal.
174 /// Its definition will have 4 (or optionally 6) words.
175 /// \code
176 /// struct Block_descriptor {
177 /// unsigned long reserved;
178 /// unsigned long size; // size of Block_literal metadata in bytes.
179 /// void *copy_func_helper_decl; // optional copy helper.
180 /// void *destroy_func_decl; // optional destructor helper.
181 /// void *block_method_encoding_address; // @encode for block literal signature.
182 /// void *block_layout_info; // encoding of captured block variables.
183 /// };
184 /// \endcode
185 static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
186  const CGBlockInfo &blockInfo) {
187  ASTContext &C = CGM.getContext();
188 
189  llvm::IntegerType *ulong =
190  cast<llvm::IntegerType>(CGM.getTypes().ConvertType(C.UnsignedLongTy));
191  llvm::PointerType *i8p = nullptr;
192  if (CGM.getLangOpts().OpenCL)
193  i8p =
194  llvm::Type::getInt8PtrTy(
196  else
197  i8p = CGM.VoidPtrTy;
198 
199  std::string descName;
200 
201  // If an equivalent block descriptor global variable exists, return it.
202  if (C.getLangOpts().ObjC &&
203  CGM.getLangOpts().getGC() == LangOptions::NonGC) {
204  descName = getBlockDescriptorName(blockInfo, CGM);
205  if (llvm::GlobalValue *desc = CGM.getModule().getNamedValue(descName))
206  return llvm::ConstantExpr::getBitCast(desc,
207  CGM.getBlockDescriptorType());
208  }
209 
210  // If there isn't an equivalent block descriptor global variable, create a new
211  // one.
212  ConstantInitBuilder builder(CGM);
213  auto elements = builder.beginStruct();
214 
215  // reserved
216  elements.addInt(ulong, 0);
217 
218  // Size
219  // FIXME: What is the right way to say this doesn't fit? We should give
220  // a user diagnostic in that case. Better fix would be to change the
221  // API to size_t.
222  elements.addInt(ulong, blockInfo.BlockSize.getQuantity());
223 
224  // Optional copy/dispose helpers.
225  bool hasInternalHelper = false;
226  if (blockInfo.needsCopyDisposeHelpers()) {
227  // copy_func_helper_decl
228  llvm::Constant *copyHelper = buildCopyHelper(CGM, blockInfo);
229  elements.add(copyHelper);
230 
231  // destroy_func_decl
232  llvm::Constant *disposeHelper = buildDisposeHelper(CGM, blockInfo);
233  elements.add(disposeHelper);
234 
235  if (cast<llvm::Function>(copyHelper->getOperand(0))->hasInternalLinkage() ||
236  cast<llvm::Function>(disposeHelper->getOperand(0))
237  ->hasInternalLinkage())
238  hasInternalHelper = true;
239  }
240 
241  // Signature. Mandatory ObjC-style method descriptor @encode sequence.
242  std::string typeAtEncoding =
244  elements.add(llvm::ConstantExpr::getBitCast(
245  CGM.GetAddrOfConstantCString(typeAtEncoding).getPointer(), i8p));
246 
247  // GC layout.
248  if (C.getLangOpts().ObjC) {
249  if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
250  elements.add(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
251  else
252  elements.add(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
253  }
254  else
255  elements.addNullPointer(i8p);
256 
257  unsigned AddrSpace = 0;
258  if (C.getLangOpts().OpenCL)
260 
261  llvm::GlobalValue::LinkageTypes linkage;
262  if (descName.empty()) {
264  descName = "__block_descriptor_tmp";
265  } else if (hasInternalHelper) {
266  // If either the copy helper or the dispose helper has internal linkage,
267  // the block descriptor must have internal linkage too.
269  } else {
270  linkage = llvm::GlobalValue::LinkOnceODRLinkage;
271  }
272 
273  llvm::GlobalVariable *global =
274  elements.finishAndCreateGlobal(descName, CGM.getPointerAlign(),
275  /*constant*/ true, linkage, AddrSpace);
276 
277  if (linkage == llvm::GlobalValue::LinkOnceODRLinkage) {
278  if (CGM.supportsCOMDAT())
279  global->setComdat(CGM.getModule().getOrInsertComdat(descName));
280  global->setVisibility(llvm::GlobalValue::HiddenVisibility);
281  global->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
282  }
283 
284  return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
285 }
286 
287 /*
288  Purely notional variadic template describing the layout of a block.
289 
290  template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
291  struct Block_literal {
292  /// Initialized to one of:
293  /// extern void *_NSConcreteStackBlock[];
294  /// extern void *_NSConcreteGlobalBlock[];
295  ///
296  /// In theory, we could start one off malloc'ed by setting
297  /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
298  /// this isa:
299  /// extern void *_NSConcreteMallocBlock[];
300  struct objc_class *isa;
301 
302  /// These are the flags (with corresponding bit number) that the
303  /// compiler is actually supposed to know about.
304  /// 23. BLOCK_IS_NOESCAPE - indicates that the block is non-escaping
305  /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
306  /// descriptor provides copy and dispose helper functions
307  /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
308  /// object with a nontrivial destructor or copy constructor
309  /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
310  /// as global memory
311  /// 29. BLOCK_USE_STRET - indicates that the block function
312  /// uses stret, which objc_msgSend needs to know about
313  /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
314  /// @encoded signature string
315  /// And we're not supposed to manipulate these:
316  /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
317  /// to malloc'ed memory
318  /// 27. BLOCK_IS_GC - indicates that the block has been moved to
319  /// to GC-allocated memory
320  /// Additionally, the bottom 16 bits are a reference count which
321  /// should be zero on the stack.
322  int flags;
323 
324  /// Reserved; should be zero-initialized.
325  int reserved;
326 
327  /// Function pointer generated from block literal.
328  _ResultType (*invoke)(Block_literal *, _ParamTypes...);
329 
330  /// Block description metadata generated from block literal.
331  struct Block_descriptor *block_descriptor;
332 
333  /// Captured values follow.
334  _CapturesTypes captures...;
335  };
336  */
337 
338 namespace {
339  /// A chunk of data that we actually have to capture in the block.
340  struct BlockLayoutChunk {
341  CharUnits Alignment;
342  CharUnits Size;
343  Qualifiers::ObjCLifetime Lifetime;
344  const BlockDecl::Capture *Capture; // null for 'this'
345  llvm::Type *Type;
346  QualType FieldType;
347 
348  BlockLayoutChunk(CharUnits align, CharUnits size,
349  Qualifiers::ObjCLifetime lifetime,
350  const BlockDecl::Capture *capture,
351  llvm::Type *type, QualType fieldType)
352  : Alignment(align), Size(size), Lifetime(lifetime),
353  Capture(capture), Type(type), FieldType(fieldType) {}
354 
355  /// Tell the block info that this chunk has the given field index.
356  void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
357  if (!Capture) {
358  info.CXXThisIndex = index;
359  info.CXXThisOffset = offset;
360  } else {
361  auto C = CGBlockInfo::Capture::makeIndex(index, offset, FieldType);
362  info.Captures.insert({Capture->getVariable(), C});
363  }
364  }
365  };
366 
367  /// Order by 1) all __strong together 2) next, all byfref together 3) next,
368  /// all __weak together. Preserve descending alignment in all situations.
369  bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
370  if (left.Alignment != right.Alignment)
371  return left.Alignment > right.Alignment;
372 
373  auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
374  if (chunk.Capture && chunk.Capture->isByRef())
375  return 1;
376  if (chunk.Lifetime == Qualifiers::OCL_Strong)
377  return 0;
378  if (chunk.Lifetime == Qualifiers::OCL_Weak)
379  return 2;
380  return 3;
381  };
382 
383  return getPrefOrder(left) < getPrefOrder(right);
384  }
385 } // end anonymous namespace
386 
387 /// Determines if the given type is safe for constant capture in C++.
389  const RecordType *recordType =
391 
392  // Only records can be unsafe.
393  if (!recordType) return true;
394 
395  const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
396 
397  // Maintain semantics for classes with non-trivial dtors or copy ctors.
398  if (!record->hasTrivialDestructor()) return false;
399  if (record->hasNonTrivialCopyConstructor()) return false;
400 
401  // Otherwise, we just have to make sure there aren't any mutable
402  // fields that might have changed since initialization.
403  return !record->hasMutableFields();
404 }
405 
406 /// It is illegal to modify a const object after initialization.
407 /// Therefore, if a const object has a constant initializer, we don't
408 /// actually need to keep storage for it in the block; we'll just
409 /// rematerialize it at the start of the block function. This is
410 /// acceptable because we make no promises about address stability of
411 /// captured variables.
412 static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
413  CodeGenFunction *CGF,
414  const VarDecl *var) {
415  // Return if this is a function parameter. We shouldn't try to
416  // rematerialize default arguments of function parameters.
417  if (isa<ParmVarDecl>(var))
418  return nullptr;
419 
420  QualType type = var->getType();
421 
422  // We can only do this if the variable is const.
423  if (!type.isConstQualified()) return nullptr;
424 
425  // Furthermore, in C++ we have to worry about mutable fields:
426  // C++ [dcl.type.cv]p4:
427  // Except that any class member declared mutable can be
428  // modified, any attempt to modify a const object during its
429  // lifetime results in undefined behavior.
430  if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
431  return nullptr;
432 
433  // If the variable doesn't have any initializer (shouldn't this be
434  // invalid?), it's not clear what we should do. Maybe capture as
435  // zero?
436  const Expr *init = var->getInit();
437  if (!init) return nullptr;
438 
439  return ConstantEmitter(CGM, CGF).tryEmitAbstractForInitializer(*var);
440 }
441 
442 /// Get the low bit of a nonzero character count. This is the
443 /// alignment of the nth byte if the 0th byte is universally aligned.
445  return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
446 }
447 
449  SmallVectorImpl<llvm::Type*> &elementTypes) {
450 
451  assert(elementTypes.empty());
452  if (CGM.getLangOpts().OpenCL) {
453  // The header is basically 'struct { int; int; generic void *;
454  // custom_fields; }'. Assert that struct is packed.
455  auto GenericAS =
457  auto GenPtrAlign =
458  CharUnits::fromQuantity(CGM.getTarget().getPointerAlign(GenericAS) / 8);
459  auto GenPtrSize =
460  CharUnits::fromQuantity(CGM.getTarget().getPointerWidth(GenericAS) / 8);
461  assert(CGM.getIntSize() <= GenPtrSize);
462  assert(CGM.getIntAlign() <= GenPtrAlign);
463  assert((2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign));
464  elementTypes.push_back(CGM.IntTy); /* total size */
465  elementTypes.push_back(CGM.IntTy); /* align */
466  elementTypes.push_back(
467  CGM.getOpenCLRuntime()
468  .getGenericVoidPointerType()); /* invoke function */
469  unsigned Offset =
470  2 * CGM.getIntSize().getQuantity() + GenPtrSize.getQuantity();
471  unsigned BlockAlign = GenPtrAlign.getQuantity();
472  if (auto *Helper =
474  for (auto I : Helper->getCustomFieldTypes()) /* custom fields */ {
475  // TargetOpenCLBlockHelp needs to make sure the struct is packed.
476  // If necessary, add padding fields to the custom fields.
477  unsigned Align = CGM.getDataLayout().getABITypeAlignment(I);
478  if (BlockAlign < Align)
479  BlockAlign = Align;
480  assert(Offset % Align == 0);
481  Offset += CGM.getDataLayout().getTypeAllocSize(I);
482  elementTypes.push_back(I);
483  }
484  }
485  info.BlockAlign = CharUnits::fromQuantity(BlockAlign);
486  info.BlockSize = CharUnits::fromQuantity(Offset);
487  } else {
488  // The header is basically 'struct { void *; int; int; void *; void *; }'.
489  // Assert that the struct is packed.
490  assert(CGM.getIntSize() <= CGM.getPointerSize());
491  assert(CGM.getIntAlign() <= CGM.getPointerAlign());
492  assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()));
493  info.BlockAlign = CGM.getPointerAlign();
494  info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
495  elementTypes.push_back(CGM.VoidPtrTy);
496  elementTypes.push_back(CGM.IntTy);
497  elementTypes.push_back(CGM.IntTy);
498  elementTypes.push_back(CGM.VoidPtrTy);
499  elementTypes.push_back(CGM.getBlockDescriptorType());
500  }
501 }
502 
504  const BlockDecl::Capture &CI) {
505  const VarDecl *VD = CI.getVariable();
506 
507  // If the variable is captured by an enclosing block or lambda expression,
508  // use the type of the capture field.
509  if (CGF.BlockInfo && CI.isNested())
510  return CGF.BlockInfo->getCapture(VD).fieldType();
511  if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
512  return FD->getType();
513  // If the captured variable is a non-escaping __block variable, the field
514  // type is the reference type. If the variable is a __block variable that
515  // already has a reference type, the field type is the variable's type.
516  return VD->isNonEscapingByref() ?
517  CGF.getContext().getLValueReferenceType(VD->getType()) : VD->getType();
518 }
519 
520 /// Compute the layout of the given block. Attempts to lay the block
521 /// out with minimal space requirements.
523  CGBlockInfo &info) {
524  ASTContext &C = CGM.getContext();
525  const BlockDecl *block = info.getBlockDecl();
526 
527  SmallVector<llvm::Type*, 8> elementTypes;
528  initializeForBlockHeader(CGM, info, elementTypes);
529  bool hasNonConstantCustomFields = false;
530  if (auto *OpenCLHelper =
532  hasNonConstantCustomFields =
533  !OpenCLHelper->areAllCustomFieldValuesConstant(info);
534  if (!block->hasCaptures() && !hasNonConstantCustomFields) {
535  info.StructureType =
536  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
537  info.CanBeGlobal = true;
538  return;
539  }
540  else if (C.getLangOpts().ObjC &&
541  CGM.getLangOpts().getGC() == LangOptions::NonGC)
542  info.HasCapturedVariableLayout = true;
543 
544  // Collect the layout chunks.
546  layout.reserve(block->capturesCXXThis() +
547  (block->capture_end() - block->capture_begin()));
548 
549  CharUnits maxFieldAlign;
550 
551  // First, 'this'.
552  if (block->capturesCXXThis()) {
553  assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&
554  "Can't capture 'this' outside a method");
555  QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType();
556 
557  // Theoretically, this could be in a different address space, so
558  // don't assume standard pointer size/align.
559  llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
560  std::pair<CharUnits,CharUnits> tinfo
561  = CGM.getContext().getTypeInfoInChars(thisType);
562  maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
563 
564  layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
566  nullptr, llvmType, thisType));
567  }
568 
569  // Next, all the block captures.
570  for (const auto &CI : block->captures()) {
571  const VarDecl *variable = CI.getVariable();
572 
573  if (CI.isEscapingByref()) {
574  // We have to copy/dispose of the __block reference.
575  info.NeedsCopyDispose = true;
576 
577  // Just use void* instead of a pointer to the byref type.
579  maxFieldAlign = std::max(maxFieldAlign, align);
580 
581  // Since a __block variable cannot be captured by lambdas, its type and
582  // the capture field type should always match.
583  assert(getCaptureFieldType(*CGF, CI) == variable->getType() &&
584  "capture type differs from the variable type");
585  layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
587  CGM.VoidPtrTy, variable->getType()));
588  continue;
589  }
590 
591  // Otherwise, build a layout chunk with the size and alignment of
592  // the declaration.
593  if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
594  info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
595  continue;
596  }
597 
598  QualType VT = getCaptureFieldType(*CGF, CI);
599 
600  // If we have a lifetime qualifier, honor it for capture purposes.
601  // That includes *not* copying it if it's __unsafe_unretained.
603  if (lifetime) {
604  switch (lifetime) {
605  case Qualifiers::OCL_None: llvm_unreachable("impossible");
608  break;
609 
612  info.NeedsCopyDispose = true;
613  }
614 
615  // Block pointers require copy/dispose. So do Objective-C pointers.
616  } else if (VT->isObjCRetainableType()) {
617  // But honor the inert __unsafe_unretained qualifier, which doesn't
618  // actually make it into the type system.
620  lifetime = Qualifiers::OCL_ExplicitNone;
621  } else {
622  info.NeedsCopyDispose = true;
623  // used for mrr below.
624  lifetime = Qualifiers::OCL_Strong;
625  }
626 
627  // So do types that require non-trivial copy construction.
628  } else if (CI.hasCopyExpr()) {
629  info.NeedsCopyDispose = true;
630  info.HasCXXObject = true;
632  info.CapturesNonExternalType = true;
633 
634  // So do C structs that require non-trivial copy construction or
635  // destruction.
638  info.NeedsCopyDispose = true;
639 
640  // And so do types with destructors.
641  } else if (CGM.getLangOpts().CPlusPlus) {
642  if (const CXXRecordDecl *record = VT->getAsCXXRecordDecl()) {
643  if (!record->hasTrivialDestructor()) {
644  info.HasCXXObject = true;
645  info.NeedsCopyDispose = true;
646  if (!record->isExternallyVisible())
647  info.CapturesNonExternalType = true;
648  }
649  }
650  }
651 
652  CharUnits size = C.getTypeSizeInChars(VT);
653  CharUnits align = C.getDeclAlign(variable);
654 
655  maxFieldAlign = std::max(maxFieldAlign, align);
656 
657  llvm::Type *llvmType =
658  CGM.getTypes().ConvertTypeForMem(VT);
659 
660  layout.push_back(
661  BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
662  }
663 
664  // If that was everything, we're done here.
665  if (layout.empty()) {
666  info.StructureType =
667  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
668  info.CanBeGlobal = true;
669  return;
670  }
671 
672  // Sort the layout by alignment. We have to use a stable sort here
673  // to get reproducible results. There should probably be an
674  // llvm::array_pod_stable_sort.
675  llvm::stable_sort(layout);
676 
677  // Needed for blocks layout info.
680 
681  CharUnits &blockSize = info.BlockSize;
682  info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
683 
684  // Assuming that the first byte in the header is maximally aligned,
685  // get the alignment of the first byte following the header.
686  CharUnits endAlign = getLowBit(blockSize);
687 
688  // If the end of the header isn't satisfactorily aligned for the
689  // maximum thing, look for things that are okay with the header-end
690  // alignment, and keep appending them until we get something that's
691  // aligned right. This algorithm is only guaranteed optimal if
692  // that condition is satisfied at some point; otherwise we can get
693  // things like:
694  // header // next byte has alignment 4
695  // something_with_size_5; // next byte has alignment 1
696  // something_with_alignment_8;
697  // which has 7 bytes of padding, as opposed to the naive solution
698  // which might have less (?).
699  if (endAlign < maxFieldAlign) {
700  SmallVectorImpl<BlockLayoutChunk>::iterator
701  li = layout.begin() + 1, le = layout.end();
702 
703  // Look for something that the header end is already
704  // satisfactorily aligned for.
705  for (; li != le && endAlign < li->Alignment; ++li)
706  ;
707 
708  // If we found something that's naturally aligned for the end of
709  // the header, keep adding things...
710  if (li != le) {
711  SmallVectorImpl<BlockLayoutChunk>::iterator first = li;
712  for (; li != le; ++li) {
713  assert(endAlign >= li->Alignment);
714 
715  li->setIndex(info, elementTypes.size(), blockSize);
716  elementTypes.push_back(li->Type);
717  blockSize += li->Size;
718  endAlign = getLowBit(blockSize);
719 
720  // ...until we get to the alignment of the maximum field.
721  if (endAlign >= maxFieldAlign) {
722  break;
723  }
724  }
725  // Don't re-append everything we just appended.
726  layout.erase(first, li);
727  }
728  }
729 
730  assert(endAlign == getLowBit(blockSize));
731 
732  // At this point, we just have to add padding if the end align still
733  // isn't aligned right.
734  if (endAlign < maxFieldAlign) {
735  CharUnits newBlockSize = blockSize.alignTo(maxFieldAlign);
736  CharUnits padding = newBlockSize - blockSize;
737 
738  // If we haven't yet added any fields, remember that there was an
739  // initial gap; this need to go into the block layout bit map.
740  if (blockSize == info.BlockHeaderForcedGapOffset) {
741  info.BlockHeaderForcedGapSize = padding;
742  }
743 
744  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
745  padding.getQuantity()));
746  blockSize = newBlockSize;
747  endAlign = getLowBit(blockSize); // might be > maxFieldAlign
748  }
749 
750  assert(endAlign >= maxFieldAlign);
751  assert(endAlign == getLowBit(blockSize));
752  // Slam everything else on now. This works because they have
753  // strictly decreasing alignment and we expect that size is always a
754  // multiple of alignment.
755  for (SmallVectorImpl<BlockLayoutChunk>::iterator
756  li = layout.begin(), le = layout.end(); li != le; ++li) {
757  if (endAlign < li->Alignment) {
758  // size may not be multiple of alignment. This can only happen with
759  // an over-aligned variable. We will be adding a padding field to
760  // make the size be multiple of alignment.
761  CharUnits padding = li->Alignment - endAlign;
762  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
763  padding.getQuantity()));
764  blockSize += padding;
765  endAlign = getLowBit(blockSize);
766  }
767  assert(endAlign >= li->Alignment);
768  li->setIndex(info, elementTypes.size(), blockSize);
769  elementTypes.push_back(li->Type);
770  blockSize += li->Size;
771  endAlign = getLowBit(blockSize);
772  }
773 
774  info.StructureType =
775  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
776 }
777 
778 /// Enter the scope of a block. This should be run at the entrance to
779 /// a full-expression so that the block's cleanups are pushed at the
780 /// right place in the stack.
781 static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
782  assert(CGF.HaveInsertPoint());
783 
784  // Allocate the block info and place it at the head of the list.
785  CGBlockInfo &blockInfo =
786  *new CGBlockInfo(block, CGF.CurFn->getName());
787  blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
788  CGF.FirstBlockInfo = &blockInfo;
789 
790  // Compute information about the layout, etc., of this block,
791  // pushing cleanups as necessary.
792  computeBlockInfo(CGF.CGM, &CGF, blockInfo);
793 
794  // Nothing else to do if it can be global.
795  if (blockInfo.CanBeGlobal) return;
796 
797  // Make the allocation for the block.
798  blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
799  blockInfo.BlockAlign, "block");
800 
801  // If there are cleanups to emit, enter them (but inactive).
802  if (!blockInfo.NeedsCopyDispose) return;
803 
804  // Walk through the captures (in order) and find the ones not
805  // captured by constant.
806  for (const auto &CI : block->captures()) {
807  // Ignore __block captures; there's nothing special in the
808  // on-stack block that we need to do for them.
809  if (CI.isByRef()) continue;
810 
811  // Ignore variables that are constant-captured.
812  const VarDecl *variable = CI.getVariable();
813  CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
814  if (capture.isConstant()) continue;
815 
816  // Ignore objects that aren't destructed.
817  QualType VT = getCaptureFieldType(CGF, CI);
819  if (dtorKind == QualType::DK_none) continue;
820 
821  CodeGenFunction::Destroyer *destroyer;
822 
823  // Block captures count as local values and have imprecise semantics.
824  // They also can't be arrays, so need to worry about that.
825  //
826  // For const-qualified captures, emit clang.arc.use to ensure the captured
827  // object doesn't get released while we are still depending on its validity
828  // within the block.
829  if (VT.isConstQualified() &&
831  CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
832  assert(CGF.CGM.getLangOpts().ObjCAutoRefCount &&
833  "expected ObjC ARC to be enabled");
835  } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
837  } else {
838  destroyer = CGF.getDestroyer(dtorKind);
839  }
840 
841  // GEP down to the address.
842  Address addr =
843  CGF.Builder.CreateStructGEP(blockInfo.LocalAddress, capture.getIndex());
844 
845  // We can use that GEP as the dominating IP.
846  if (!blockInfo.DominatingIP)
847  blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
848 
849  CleanupKind cleanupKind = InactiveNormalCleanup;
850  bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
851  if (useArrayEHCleanup)
852  cleanupKind = InactiveNormalAndEHCleanup;
853 
854  CGF.pushDestroy(cleanupKind, addr, VT,
855  destroyer, useArrayEHCleanup);
856 
857  // Remember where that cleanup was.
858  capture.setCleanup(CGF.EHStack.stable_begin());
859  }
860 }
861 
862 /// Enter a full-expression with a non-trivial number of objects to
863 /// clean up. This is in this file because, at the moment, the only
864 /// kind of cleanup object is a BlockDecl*.
866  if (const auto EWC = dyn_cast<ExprWithCleanups>(E)) {
867  assert(EWC->getNumObjects() != 0);
868  for (const ExprWithCleanups::CleanupObject &C : EWC->getObjects())
869  enterBlockScope(*this, C);
870  }
871 }
872 
873 /// Find the layout for the given block in a linked list and remove it.
875  const BlockDecl *block) {
876  while (true) {
877  assert(head && *head);
878  CGBlockInfo *cur = *head;
879 
880  // If this is the block we're looking for, splice it out of the list.
881  if (cur->getBlockDecl() == block) {
882  *head = cur->NextBlockInfo;
883  return cur;
884  }
885 
886  head = &cur->NextBlockInfo;
887  }
888 }
889 
890 /// Destroy a chain of block layouts.
892  assert(head && "destroying an empty chain");
893  do {
894  CGBlockInfo *cur = head;
895  head = cur->NextBlockInfo;
896  delete cur;
897  } while (head != nullptr);
898 }
899 
900 /// Emit a block literal expression in the current function.
902  // If the block has no captures, we won't have a pre-computed
903  // layout for it.
904  if (!blockExpr->getBlockDecl()->hasCaptures()) {
905  // The block literal is emitted as a global variable, and the block invoke
906  // function has to be extracted from its initializer.
907  if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr)) {
908  return Block;
909  }
910  CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
911  computeBlockInfo(CGM, this, blockInfo);
912  blockInfo.BlockExpression = blockExpr;
913  return EmitBlockLiteral(blockInfo);
914  }
915 
916  // Find the block info for this block and take ownership of it.
917  std::unique_ptr<CGBlockInfo> blockInfo;
918  blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
919  blockExpr->getBlockDecl()));
920 
921  blockInfo->BlockExpression = blockExpr;
922  return EmitBlockLiteral(*blockInfo);
923 }
924 
926  bool IsOpenCL = CGM.getContext().getLangOpts().OpenCL;
927  auto GenVoidPtrTy =
928  IsOpenCL ? CGM.getOpenCLRuntime().getGenericVoidPointerType() : VoidPtrTy;
929  LangAS GenVoidPtrAddr = IsOpenCL ? LangAS::opencl_generic : LangAS::Default;
930  auto GenVoidPtrSize = CharUnits::fromQuantity(
932  CGM.getContext().getTargetAddressSpace(GenVoidPtrAddr)) /
933  8);
934  // Using the computed layout, generate the actual block function.
935  bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
936  CodeGenFunction BlockCGF{CGM, true};
937  BlockCGF.SanOpts = SanOpts;
938  auto *InvokeFn = BlockCGF.GenerateBlockFunction(
939  CurGD, blockInfo, LocalDeclMap, isLambdaConv, blockInfo.CanBeGlobal);
940  auto *blockFn = llvm::ConstantExpr::getPointerCast(InvokeFn, GenVoidPtrTy);
941 
942  // If there is nothing to capture, we can emit this as a global block.
943  if (blockInfo.CanBeGlobal)
944  return CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression);
945 
946  // Otherwise, we have to emit this as a local block.
947 
948  Address blockAddr = blockInfo.LocalAddress;
949  assert(blockAddr.isValid() && "block has no address!");
950 
951  llvm::Constant *isa;
952  llvm::Constant *descriptor;
953  BlockFlags flags;
954  if (!IsOpenCL) {
955  // If the block is non-escaping, set field 'isa 'to NSConcreteGlobalBlock
956  // and set the BLOCK_IS_GLOBAL bit of field 'flags'. Copying a non-escaping
957  // block just returns the original block and releasing it is a no-op.
958  llvm::Constant *blockISA = blockInfo.getBlockDecl()->doesNotEscape()
960  : CGM.getNSConcreteStackBlock();
961  isa = llvm::ConstantExpr::getBitCast(blockISA, VoidPtrTy);
962 
963  // Build the block descriptor.
964  descriptor = buildBlockDescriptor(CGM, blockInfo);
965 
966  // Compute the initial on-stack block flags.
967  flags = BLOCK_HAS_SIGNATURE;
968  if (blockInfo.HasCapturedVariableLayout)
969  flags |= BLOCK_HAS_EXTENDED_LAYOUT;
970  if (blockInfo.needsCopyDisposeHelpers())
971  flags |= BLOCK_HAS_COPY_DISPOSE;
972  if (blockInfo.HasCXXObject)
973  flags |= BLOCK_HAS_CXX_OBJ;
974  if (blockInfo.UsesStret)
975  flags |= BLOCK_USE_STRET;
976  if (blockInfo.getBlockDecl()->doesNotEscape())
978  }
979 
980  auto projectField = [&](unsigned index, const Twine &name) -> Address {
981  return Builder.CreateStructGEP(blockAddr, index, name);
982  };
983  auto storeField = [&](llvm::Value *value, unsigned index, const Twine &name) {
984  Builder.CreateStore(value, projectField(index, name));
985  };
986 
987  // Initialize the block header.
988  {
989  // We assume all the header fields are densely packed.
990  unsigned index = 0;
991  CharUnits offset;
992  auto addHeaderField = [&](llvm::Value *value, CharUnits size,
993  const Twine &name) {
994  storeField(value, index, name);
995  offset += size;
996  index++;
997  };
998 
999  if (!IsOpenCL) {
1000  addHeaderField(isa, getPointerSize(), "block.isa");
1001  addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
1002  getIntSize(), "block.flags");
1003  addHeaderField(llvm::ConstantInt::get(IntTy, 0), getIntSize(),
1004  "block.reserved");
1005  } else {
1006  addHeaderField(
1007  llvm::ConstantInt::get(IntTy, blockInfo.BlockSize.getQuantity()),
1008  getIntSize(), "block.size");
1009  addHeaderField(
1010  llvm::ConstantInt::get(IntTy, blockInfo.BlockAlign.getQuantity()),
1011  getIntSize(), "block.align");
1012  }
1013  addHeaderField(blockFn, GenVoidPtrSize, "block.invoke");
1014  if (!IsOpenCL)
1015  addHeaderField(descriptor, getPointerSize(), "block.descriptor");
1016  else if (auto *Helper =
1018  for (auto I : Helper->getCustomFieldValues(*this, blockInfo)) {
1019  addHeaderField(
1020  I.first,
1022  CGM.getDataLayout().getTypeAllocSize(I.first->getType())),
1023  I.second);
1024  }
1025  }
1026  }
1027 
1028  // Finally, capture all the values into the block.
1029  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1030 
1031  // First, 'this'.
1032  if (blockDecl->capturesCXXThis()) {
1033  Address addr =
1034  projectField(blockInfo.CXXThisIndex, "block.captured-this.addr");
1035  Builder.CreateStore(LoadCXXThis(), addr);
1036  }
1037 
1038  // Next, captured variables.
1039  for (const auto &CI : blockDecl->captures()) {
1040  const VarDecl *variable = CI.getVariable();
1041  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1042 
1043  // Ignore constant captures.
1044  if (capture.isConstant()) continue;
1045 
1046  QualType type = capture.fieldType();
1047 
1048  // This will be a [[type]]*, except that a byref entry will just be
1049  // an i8**.
1050  Address blockField = projectField(capture.getIndex(), "block.captured");
1051 
1052  // Compute the address of the thing we're going to move into the
1053  // block literal.
1054  Address src = Address::invalid();
1055 
1056  if (blockDecl->isConversionFromLambda()) {
1057  // The lambda capture in a lambda's conversion-to-block-pointer is
1058  // special; we'll simply emit it directly.
1059  src = Address::invalid();
1060  } else if (CI.isEscapingByref()) {
1061  if (BlockInfo && CI.isNested()) {
1062  // We need to use the capture from the enclosing block.
1063  const CGBlockInfo::Capture &enclosingCapture =
1064  BlockInfo->getCapture(variable);
1065 
1066  // This is a [[type]]*, except that a byref entry will just be an i8**.
1067  src = Builder.CreateStructGEP(LoadBlockStruct(),
1068  enclosingCapture.getIndex(),
1069  "block.capture.addr");
1070  } else {
1071  auto I = LocalDeclMap.find(variable);
1072  assert(I != LocalDeclMap.end());
1073  src = I->second;
1074  }
1075  } else {
1076  DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1077  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1079  SourceLocation());
1080  src = EmitDeclRefLValue(&declRef).getAddress(*this);
1081  };
1082 
1083  // For byrefs, we just write the pointer to the byref struct into
1084  // the block field. There's no need to chase the forwarding
1085  // pointer at this point, since we're building something that will
1086  // live a shorter life than the stack byref anyway.
1087  if (CI.isEscapingByref()) {
1088  // Get a void* that points to the byref struct.
1089  llvm::Value *byrefPointer;
1090  if (CI.isNested())
1091  byrefPointer = Builder.CreateLoad(src, "byref.capture");
1092  else
1093  byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
1094 
1095  // Write that void* into the capture field.
1096  Builder.CreateStore(byrefPointer, blockField);
1097 
1098  // If we have a copy constructor, evaluate that into the block field.
1099  } else if (const Expr *copyExpr = CI.getCopyExpr()) {
1100  if (blockDecl->isConversionFromLambda()) {
1101  // If we have a lambda conversion, emit the expression
1102  // directly into the block instead.
1103  AggValueSlot Slot =
1104  AggValueSlot::forAddr(blockField, Qualifiers(),
1109  EmitAggExpr(copyExpr, Slot);
1110  } else {
1111  EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
1112  }
1113 
1114  // If it's a reference variable, copy the reference into the block field.
1115  } else if (type->isReferenceType()) {
1116  Builder.CreateStore(src.getPointer(), blockField);
1117 
1118  // If type is const-qualified, copy the value into the block field.
1119  } else if (type.isConstQualified() &&
1121  CGM.getCodeGenOpts().OptimizationLevel != 0) {
1122  llvm::Value *value = Builder.CreateLoad(src, "captured");
1123  Builder.CreateStore(value, blockField);
1124 
1125  // If this is an ARC __strong block-pointer variable, don't do a
1126  // block copy.
1127  //
1128  // TODO: this can be generalized into the normal initialization logic:
1129  // we should never need to do a block-copy when initializing a local
1130  // variable, because the local variable's lifetime should be strictly
1131  // contained within the stack block's.
1132  } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
1133  type->isBlockPointerType()) {
1134  // Load the block and do a simple retain.
1135  llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
1136  value = EmitARCRetainNonBlock(value);
1137 
1138  // Do a primitive store to the block field.
1139  Builder.CreateStore(value, blockField);
1140 
1141  // Otherwise, fake up a POD copy into the block field.
1142  } else {
1143  // Fake up a new variable so that EmitScalarInit doesn't think
1144  // we're referring to the variable in its own initializer.
1145  ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
1147 
1148  // We use one of these or the other depending on whether the
1149  // reference is nested.
1150  DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1151  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1153 
1154  ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
1155  &declRef, VK_RValue);
1156  // FIXME: Pass a specific location for the expr init so that the store is
1157  // attributed to a reasonable location - otherwise it may be attributed to
1158  // locations of subexpressions in the initialization.
1159  EmitExprAsInit(&l2r, &BlockFieldPseudoVar,
1160  MakeAddrLValue(blockField, type, AlignmentSource::Decl),
1161  /*captured by init*/ false);
1162  }
1163 
1164  // Activate the cleanup if layout pushed one.
1165  if (!CI.isByRef()) {
1167  if (cleanup.isValid())
1168  ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
1169  }
1170  }
1171 
1172  // Cast to the converted block-pointer type, which happens (somewhat
1173  // unfortunately) to be a pointer to function type.
1174  llvm::Value *result = Builder.CreatePointerCast(
1175  blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
1176 
1177  if (IsOpenCL) {
1178  CGM.getOpenCLRuntime().recordBlockInfo(blockInfo.BlockExpression, InvokeFn,
1179  result);
1180  }
1181 
1182  return result;
1183 }
1184 
1185 
1187  if (BlockDescriptorType)
1188  return BlockDescriptorType;
1189 
1190  llvm::Type *UnsignedLongTy =
1191  getTypes().ConvertType(getContext().UnsignedLongTy);
1192 
1193  // struct __block_descriptor {
1194  // unsigned long reserved;
1195  // unsigned long block_size;
1196  //
1197  // // later, the following will be added
1198  //
1199  // struct {
1200  // void (*copyHelper)();
1201  // void (*copyHelper)();
1202  // } helpers; // !!! optional
1203  //
1204  // const char *signature; // the block signature
1205  // const char *layout; // reserved
1206  // };
1207  BlockDescriptorType = llvm::StructType::create(
1208  "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
1209 
1210  // Now form a pointer to that.
1211  unsigned AddrSpace = 0;
1212  if (getLangOpts().OpenCL)
1213  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
1214  BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
1215  return BlockDescriptorType;
1216 }
1217 
1219  if (GenericBlockLiteralType)
1220  return GenericBlockLiteralType;
1221 
1222  llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
1223 
1224  if (getLangOpts().OpenCL) {
1225  // struct __opencl_block_literal_generic {
1226  // int __size;
1227  // int __align;
1228  // __generic void *__invoke;
1229  // /* custom fields */
1230  // };
1231  SmallVector<llvm::Type *, 8> StructFields(
1232  {IntTy, IntTy, getOpenCLRuntime().getGenericVoidPointerType()});
1233  if (auto *Helper = getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1234  for (auto I : Helper->getCustomFieldTypes())
1235  StructFields.push_back(I);
1236  }
1237  GenericBlockLiteralType = llvm::StructType::create(
1238  StructFields, "struct.__opencl_block_literal_generic");
1239  } else {
1240  // struct __block_literal_generic {
1241  // void *__isa;
1242  // int __flags;
1243  // int __reserved;
1244  // void (*__invoke)(void *);
1245  // struct __block_descriptor *__descriptor;
1246  // };
1247  GenericBlockLiteralType =
1248  llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
1249  IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
1250  }
1251 
1252  return GenericBlockLiteralType;
1253 }
1254 
1257  const auto *BPT = E->getCallee()->getType()->castAs<BlockPointerType>();
1258  llvm::Value *BlockPtr = EmitScalarExpr(E->getCallee());
1259  llvm::Type *GenBlockTy = CGM.getGenericBlockLiteralType();
1260  llvm::Value *Func = nullptr;
1261  QualType FnType = BPT->getPointeeType();
1262  ASTContext &Ctx = getContext();
1263  CallArgList Args;
1264 
1265  if (getLangOpts().OpenCL) {
1266  // For OpenCL, BlockPtr is already casted to generic block literal.
1267 
1268  // First argument of a block call is a generic block literal casted to
1269  // generic void pointer, i.e. i8 addrspace(4)*
1270  llvm::Value *BlockDescriptor = Builder.CreatePointerCast(
1271  BlockPtr, CGM.getOpenCLRuntime().getGenericVoidPointerType());
1272  QualType VoidPtrQualTy = Ctx.getPointerType(
1274  Args.add(RValue::get(BlockDescriptor), VoidPtrQualTy);
1275  // And the rest of the arguments.
1276  EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1277 
1278  // We *can* call the block directly unless it is a function argument.
1279  if (!isa<ParmVarDecl>(E->getCalleeDecl()))
1280  Func = CGM.getOpenCLRuntime().getInvokeFunction(E->getCallee());
1281  else {
1282  llvm::Value *FuncPtr = Builder.CreateStructGEP(GenBlockTy, BlockPtr, 2);
1283  Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1284  }
1285  } else {
1286  // Bitcast the block literal to a generic block literal.
1287  BlockPtr = Builder.CreatePointerCast(
1288  BlockPtr, llvm::PointerType::get(GenBlockTy, 0), "block.literal");
1289  // Get pointer to the block invoke function
1290  llvm::Value *FuncPtr = Builder.CreateStructGEP(GenBlockTy, BlockPtr, 3);
1291 
1292  // First argument is a block literal casted to a void pointer
1293  BlockPtr = Builder.CreatePointerCast(BlockPtr, VoidPtrTy);
1294  Args.add(RValue::get(BlockPtr), Ctx.VoidPtrTy);
1295  // And the rest of the arguments.
1296  EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(), E->arguments());
1297 
1298  // Load the function.
1299  Func = Builder.CreateAlignedLoad(FuncPtr, getPointerAlign());
1300  }
1301 
1302  const FunctionType *FuncTy = FnType->castAs<FunctionType>();
1303  const CGFunctionInfo &FnInfo =
1304  CGM.getTypes().arrangeBlockFunctionCall(Args, FuncTy);
1305 
1306  // Cast the function pointer to the right type.
1307  llvm::Type *BlockFTy = CGM.getTypes().GetFunctionType(FnInfo);
1308 
1309  llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
1310  Func = Builder.CreatePointerCast(Func, BlockFTyPtr);
1311 
1312  // Prepare the callee.
1313  CGCallee Callee(CGCalleeInfo(), Func);
1314 
1315  // And call the block.
1316  return EmitCall(FnInfo, Callee, ReturnValue, Args);
1317 }
1318 
1320  assert(BlockInfo && "evaluating block ref without block information?");
1321  const CGBlockInfo::Capture &capture = BlockInfo->getCapture(variable);
1322 
1323  // Handle constant captures.
1324  if (capture.isConstant()) return LocalDeclMap.find(variable)->second;
1325 
1326  Address addr = Builder.CreateStructGEP(LoadBlockStruct(), capture.getIndex(),
1327  "block.capture.addr");
1328 
1329  if (variable->isEscapingByref()) {
1330  // addr should be a void** right now. Load, then cast the result
1331  // to byref*.
1332 
1333  auto &byrefInfo = getBlockByrefInfo(variable);
1334  addr = Address(Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
1335 
1336  auto byrefPointerType = llvm::PointerType::get(byrefInfo.Type, 0);
1337  addr = Builder.CreateBitCast(addr, byrefPointerType, "byref.addr");
1338 
1339  addr = emitBlockByrefAddress(addr, byrefInfo, /*follow*/ true,
1340  variable->getName());
1341  }
1342 
1343  assert((!variable->isNonEscapingByref() ||
1344  capture.fieldType()->isReferenceType()) &&
1345  "the capture field of a non-escaping variable should have a "
1346  "reference type");
1347  if (capture.fieldType()->isReferenceType())
1348  addr = EmitLoadOfReference(MakeAddrLValue(addr, capture.fieldType()));
1349 
1350  return addr;
1351 }
1352 
1354  llvm::Constant *Addr) {
1355  bool Ok = EmittedGlobalBlocks.insert(std::make_pair(BE, Addr)).second;
1356  (void)Ok;
1357  assert(Ok && "Trying to replace an already-existing global block!");
1358 }
1359 
1360 llvm::Constant *
1362  StringRef Name) {
1363  if (llvm::Constant *Block = getAddrOfGlobalBlockIfEmitted(BE))
1364  return Block;
1365 
1366  CGBlockInfo blockInfo(BE->getBlockDecl(), Name);
1367  blockInfo.BlockExpression = BE;
1368 
1369  // Compute information about the layout, etc., of this block.
1370  computeBlockInfo(*this, nullptr, blockInfo);
1371 
1372  // Using that metadata, generate the actual block function.
1373  {
1374  CodeGenFunction::DeclMapTy LocalDeclMap;
1376  GlobalDecl(), blockInfo, LocalDeclMap,
1377  /*IsLambdaConversionToBlock*/ false, /*BuildGlobalBlock*/ true);
1378  }
1379 
1380  return getAddrOfGlobalBlockIfEmitted(BE);
1381 }
1382 
1383 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
1384  const CGBlockInfo &blockInfo,
1385  llvm::Constant *blockFn) {
1386  assert(blockInfo.CanBeGlobal);
1387  // Callers should detect this case on their own: calling this function
1388  // generally requires computing layout information, which is a waste of time
1389  // if we've already emitted this block.
1390  assert(!CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression) &&
1391  "Refusing to re-emit a global block.");
1392 
1393  // Generate the constants for the block literal initializer.
1394  ConstantInitBuilder builder(CGM);
1395  auto fields = builder.beginStruct();
1396 
1397  bool IsOpenCL = CGM.getLangOpts().OpenCL;
1398  bool IsWindows = CGM.getTarget().getTriple().isOSWindows();
1399  if (!IsOpenCL) {
1400  // isa
1401  if (IsWindows)
1402  fields.addNullPointer(CGM.Int8PtrPtrTy);
1403  else
1404  fields.add(CGM.getNSConcreteGlobalBlock());
1405 
1406  // __flags
1408  if (blockInfo.UsesStret)
1409  flags |= BLOCK_USE_STRET;
1410 
1411  fields.addInt(CGM.IntTy, flags.getBitMask());
1412 
1413  // Reserved
1414  fields.addInt(CGM.IntTy, 0);
1415  } else {
1416  fields.addInt(CGM.IntTy, blockInfo.BlockSize.getQuantity());
1417  fields.addInt(CGM.IntTy, blockInfo.BlockAlign.getQuantity());
1418  }
1419 
1420  // Function
1421  fields.add(blockFn);
1422 
1423  if (!IsOpenCL) {
1424  // Descriptor
1425  fields.add(buildBlockDescriptor(CGM, blockInfo));
1426  } else if (auto *Helper =
1428  for (auto I : Helper->getCustomFieldValues(CGM, blockInfo)) {
1429  fields.add(I);
1430  }
1431  }
1432 
1433  unsigned AddrSpace = 0;
1434  if (CGM.getContext().getLangOpts().OpenCL)
1436 
1437  llvm::GlobalVariable *literal = fields.finishAndCreateGlobal(
1438  "__block_literal_global", blockInfo.BlockAlign,
1439  /*constant*/ !IsWindows, llvm::GlobalVariable::InternalLinkage, AddrSpace);
1440 
1441  literal->addAttribute("objc_arc_inert");
1442 
1443  // Windows does not allow globals to be initialised to point to globals in
1444  // different DLLs. Any such variables must run code to initialise them.
1445  if (IsWindows) {
1446  auto *Init = llvm::Function::Create(llvm::FunctionType::get(CGM.VoidTy,
1447  {}), llvm::GlobalValue::InternalLinkage, ".block_isa_init",
1448  &CGM.getModule());
1449  llvm::IRBuilder<> b(llvm::BasicBlock::Create(CGM.getLLVMContext(), "entry",
1450  Init));
1451  b.CreateAlignedStore(CGM.getNSConcreteGlobalBlock(),
1452  b.CreateStructGEP(literal, 0), CGM.getPointerAlign().getQuantity());
1453  b.CreateRetVoid();
1454  // We can't use the normal LLVM global initialisation array, because we
1455  // need to specify that this runs early in library initialisation.
1456  auto *InitVar = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
1457  /*isConstant*/true, llvm::GlobalValue::InternalLinkage,
1458  Init, ".block_isa_init_ptr");
1459  InitVar->setSection(".CRT$XCLa");
1460  CGM.addUsedGlobal(InitVar);
1461  }
1462 
1463  // Return a constant of the appropriately-casted type.
1464  llvm::Type *RequiredType =
1465  CGM.getTypes().ConvertType(blockInfo.getBlockExpr()->getType());
1466  llvm::Constant *Result =
1467  llvm::ConstantExpr::getPointerCast(literal, RequiredType);
1468  CGM.setAddrOfGlobalBlock(blockInfo.BlockExpression, Result);
1469  if (CGM.getContext().getLangOpts().OpenCL)
1471  blockInfo.BlockExpression,
1472  cast<llvm::Function>(blockFn->stripPointerCasts()), Result);
1473  return Result;
1474 }
1475 
1477  unsigned argNum,
1478  llvm::Value *arg) {
1479  assert(BlockInfo && "not emitting prologue of block invocation function?!");
1480 
1481  // Allocate a stack slot like for any local variable to guarantee optimal
1482  // debug info at -O0. The mem2reg pass will eliminate it when optimizing.
1483  Address alloc = CreateMemTemp(D->getType(), D->getName() + ".addr");
1484  Builder.CreateStore(arg, alloc);
1485  if (CGDebugInfo *DI = getDebugInfo()) {
1486  if (CGM.getCodeGenOpts().hasReducedDebugInfo()) {
1487  DI->setLocation(D->getLocation());
1488  DI->EmitDeclareOfBlockLiteralArgVariable(
1489  *BlockInfo, D->getName(), argNum,
1490  cast<llvm::AllocaInst>(alloc.getPointer()), Builder);
1491  }
1492  }
1493 
1494  SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getBeginLoc();
1495  ApplyDebugLocation Scope(*this, StartLoc);
1496 
1497  // Instead of messing around with LocalDeclMap, just set the value
1498  // directly as BlockPointer.
1499  BlockPointer = Builder.CreatePointerCast(
1500  arg,
1501  BlockInfo->StructureType->getPointerTo(
1502  getContext().getLangOpts().OpenCL
1503  ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1504  : 0),
1505  "block");
1506 }
1507 
1509  assert(BlockInfo && "not in a block invocation function!");
1510  assert(BlockPointer && "no block pointer set!");
1511  return Address(BlockPointer, BlockInfo->BlockAlign);
1512 }
1513 
1514 llvm::Function *
1516  const CGBlockInfo &blockInfo,
1517  const DeclMapTy &ldm,
1518  bool IsLambdaConversionToBlock,
1519  bool BuildGlobalBlock) {
1520  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1521 
1522  CurGD = GD;
1523 
1524  CurEHLocation = blockInfo.getBlockExpr()->getEndLoc();
1525 
1526  BlockInfo = &blockInfo;
1527 
1528  // Arrange for local static and local extern declarations to appear
1529  // to be local to this function as well, in case they're directly
1530  // referenced in a block.
1531  for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1532  const auto *var = dyn_cast<VarDecl>(i->first);
1533  if (var && !var->hasLocalStorage())
1534  setAddrOfLocalVar(var, i->second);
1535  }
1536 
1537  // Begin building the function declaration.
1538 
1539  // Build the argument list.
1540  FunctionArgList args;
1541 
1542  // The first argument is the block pointer. Just take it as a void*
1543  // and cast it later.
1544  QualType selfTy = getContext().VoidPtrTy;
1545 
1546  // For OpenCL passed block pointer can be private AS local variable or
1547  // global AS program scope variable (for the case with and without captures).
1548  // Generic AS is used therefore to be able to accommodate both private and
1549  // generic AS in one implementation.
1550  if (getLangOpts().OpenCL)
1551  selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1552  getContext().VoidTy, LangAS::opencl_generic));
1553 
1554  IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1555 
1556  ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1557  SourceLocation(), II, selfTy,
1559  args.push_back(&SelfDecl);
1560 
1561  // Now add the rest of the parameters.
1562  args.append(blockDecl->param_begin(), blockDecl->param_end());
1563 
1564  // Create the function declaration.
1565  const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1566  const CGFunctionInfo &fnInfo =
1567  CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1568  if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1569  blockInfo.UsesStret = true;
1570 
1571  llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1572 
1573  StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1574  llvm::Function *fn = llvm::Function::Create(
1575  fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1576  CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1577 
1578  if (BuildGlobalBlock) {
1579  auto GenVoidPtrTy = getContext().getLangOpts().OpenCL
1581  : VoidPtrTy;
1582  buildGlobalBlock(CGM, blockInfo,
1583  llvm::ConstantExpr::getPointerCast(fn, GenVoidPtrTy));
1584  }
1585 
1586  // Begin generating the function.
1587  StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1588  blockDecl->getLocation(),
1589  blockInfo.getBlockExpr()->getBody()->getBeginLoc());
1590 
1591  // Okay. Undo some of what StartFunction did.
1592 
1593  // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1594  // won't delete the dbg.declare intrinsics for captured variables.
1595  llvm::Value *BlockPointerDbgLoc = BlockPointer;
1596  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1597  // Allocate a stack slot for it, so we can point the debugger to it
1598  Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1599  getPointerAlign(),
1600  "block.addr");
1601  // Set the DebugLocation to empty, so the store is recognized as a
1602  // frame setup instruction by llvm::DwarfDebug::beginFunction().
1603  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1604  Builder.CreateStore(BlockPointer, Alloca);
1605  BlockPointerDbgLoc = Alloca.getPointer();
1606  }
1607 
1608  // If we have a C++ 'this' reference, go ahead and force it into
1609  // existence now.
1610  if (blockDecl->capturesCXXThis()) {
1611  Address addr = Builder.CreateStructGEP(
1612  LoadBlockStruct(), blockInfo.CXXThisIndex, "block.captured-this");
1613  CXXThisValue = Builder.CreateLoad(addr, "this");
1614  }
1615 
1616  // Also force all the constant captures.
1617  for (const auto &CI : blockDecl->captures()) {
1618  const VarDecl *variable = CI.getVariable();
1619  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1620  if (!capture.isConstant()) continue;
1621 
1622  CharUnits align = getContext().getDeclAlign(variable);
1623  Address alloca =
1624  CreateMemTemp(variable->getType(), align, "block.captured-const");
1625 
1626  Builder.CreateStore(capture.getConstant(), alloca);
1627 
1628  setAddrOfLocalVar(variable, alloca);
1629  }
1630 
1631  // Save a spot to insert the debug information for all the DeclRefExprs.
1632  llvm::BasicBlock *entry = Builder.GetInsertBlock();
1633  llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1634  --entry_ptr;
1635 
1636  if (IsLambdaConversionToBlock)
1637  EmitLambdaBlockInvokeBody();
1638  else {
1639  PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1640  incrementProfileCounter(blockDecl->getBody());
1641  EmitStmt(blockDecl->getBody());
1642  }
1643 
1644  // Remember where we were...
1645  llvm::BasicBlock *resume = Builder.GetInsertBlock();
1646 
1647  // Go back to the entry.
1648  ++entry_ptr;
1649  Builder.SetInsertPoint(entry, entry_ptr);
1650 
1651  // Emit debug information for all the DeclRefExprs.
1652  // FIXME: also for 'this'
1653  if (CGDebugInfo *DI = getDebugInfo()) {
1654  for (const auto &CI : blockDecl->captures()) {
1655  const VarDecl *variable = CI.getVariable();
1656  DI->EmitLocation(Builder, variable->getLocation());
1657 
1658  if (CGM.getCodeGenOpts().hasReducedDebugInfo()) {
1659  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1660  if (capture.isConstant()) {
1661  auto addr = LocalDeclMap.find(variable)->second;
1662  (void)DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1663  Builder);
1664  continue;
1665  }
1666 
1667  DI->EmitDeclareOfBlockDeclRefVariable(
1668  variable, BlockPointerDbgLoc, Builder, blockInfo,
1669  entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1670  }
1671  }
1672  // Recover location if it was changed in the above loop.
1673  DI->EmitLocation(Builder,
1674  cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1675  }
1676 
1677  // And resume where we left off.
1678  if (resume == nullptr)
1679  Builder.ClearInsertionPoint();
1680  else
1681  Builder.SetInsertPoint(resume);
1682 
1683  FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1684 
1685  return fn;
1686 }
1687 
1688 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1690  const LangOptions &LangOpts) {
1691  if (CI.getCopyExpr()) {
1692  assert(!CI.isByRef());
1693  // don't bother computing flags
1694  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1695  }
1696  BlockFieldFlags Flags;
1697  if (CI.isEscapingByref()) {
1698  Flags = BLOCK_FIELD_IS_BYREF;
1699  if (T.isObjCGCWeak())
1700  Flags |= BLOCK_FIELD_IS_WEAK;
1701  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1702  }
1703 
1704  Flags = BLOCK_FIELD_IS_OBJECT;
1705  bool isBlockPointer = T->isBlockPointerType();
1706  if (isBlockPointer)
1707  Flags = BLOCK_FIELD_IS_BLOCK;
1708 
1709  switch (T.isNonTrivialToPrimitiveCopy()) {
1710  case QualType::PCK_Struct:
1711  return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
1712  BlockFieldFlags());
1713  case QualType::PCK_ARCWeak:
1714  // We need to register __weak direct captures with the runtime.
1715  return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1717  // We need to retain the copied value for __strong direct captures.
1718  // If it's a block pointer, we have to copy the block and assign that to
1719  // the destination pointer, so we might as well use _Block_object_assign.
1720  // Otherwise we can avoid that.
1721  return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1722  : BlockCaptureEntityKind::BlockObject,
1723  Flags);
1724  case QualType::PCK_Trivial:
1726  if (!T->isObjCRetainableType())
1727  // For all other types, the memcpy is fine.
1728  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1729 
1730  // Special rules for ARC captures:
1731  Qualifiers QS = T.getQualifiers();
1732 
1733  // Non-ARC captures of retainable pointers are strong and
1734  // therefore require a call to _Block_object_assign.
1735  if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1736  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1737 
1738  // Otherwise the memcpy is fine.
1739  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1740  }
1741  }
1742  llvm_unreachable("after exhaustive PrimitiveCopyKind switch");
1743 }
1744 
1745 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1747  const LangOptions &LangOpts);
1748 
1749 /// Find the set of block captures that need to be explicitly copied or destroy.
1751  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1752  SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures) {
1753  for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1754  const VarDecl *Variable = CI.getVariable();
1755  const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1756  if (Capture.isConstant())
1757  continue;
1758 
1759  QualType VT = Capture.fieldType();
1760  auto CopyInfo = computeCopyInfoForBlockCapture(CI, VT, LangOpts);
1761  auto DisposeInfo = computeDestroyInfoForBlockCapture(CI, VT, LangOpts);
1762  if (CopyInfo.first != BlockCaptureEntityKind::None ||
1763  DisposeInfo.first != BlockCaptureEntityKind::None)
1764  ManagedCaptures.emplace_back(CopyInfo.first, DisposeInfo.first,
1765  CopyInfo.second, DisposeInfo.second, CI,
1766  Capture);
1767  }
1768 
1769  // Sort the captures by offset.
1770  llvm::sort(ManagedCaptures);
1771 }
1772 
1773 namespace {
1774 /// Release a __block variable.
1775 struct CallBlockRelease final : EHScopeStack::Cleanup {
1776  Address Addr;
1777  BlockFieldFlags FieldFlags;
1778  bool LoadBlockVarAddr, CanThrow;
1779 
1780  CallBlockRelease(Address Addr, BlockFieldFlags Flags, bool LoadValue,
1781  bool CT)
1782  : Addr(Addr), FieldFlags(Flags), LoadBlockVarAddr(LoadValue),
1783  CanThrow(CT) {}
1784 
1785  void Emit(CodeGenFunction &CGF, Flags flags) override {
1786  llvm::Value *BlockVarAddr;
1787  if (LoadBlockVarAddr) {
1788  BlockVarAddr = CGF.Builder.CreateLoad(Addr);
1789  BlockVarAddr = CGF.Builder.CreateBitCast(BlockVarAddr, CGF.VoidPtrTy);
1790  } else {
1791  BlockVarAddr = Addr.getPointer();
1792  }
1793 
1794  CGF.BuildBlockRelease(BlockVarAddr, FieldFlags, CanThrow);
1795  }
1796 };
1797 } // end anonymous namespace
1798 
1799 /// Check if \p T is a C++ class that has a destructor that can throw.
1801  if (const auto *RD = T->getAsCXXRecordDecl())
1802  if (const CXXDestructorDecl *DD = RD->getDestructor())
1803  return DD->getType()->castAs<FunctionProtoType>()->canThrow();
1804  return false;
1805 }
1806 
1807 // Return a string that has the information about a capture.
1808 static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
1809  CaptureStrKind StrKind,
1810  CharUnits BlockAlignment,
1811  CodeGenModule &CGM) {
1812  std::string Str;
1813  ASTContext &Ctx = CGM.getContext();
1814  const BlockDecl::Capture &CI = *E.CI;
1815  QualType CaptureTy = CI.getVariable()->getType();
1816 
1818  BlockFieldFlags Flags;
1819 
1820  // CaptureStrKind::Merged should be passed only when the operations and the
1821  // flags are the same for copy and dispose.
1822  assert((StrKind != CaptureStrKind::Merged ||
1823  (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) &&
1824  "different operations and flags");
1825 
1826  if (StrKind == CaptureStrKind::DisposeHelper) {
1827  Kind = E.DisposeKind;
1828  Flags = E.DisposeFlags;
1829  } else {
1830  Kind = E.CopyKind;
1831  Flags = E.CopyFlags;
1832  }
1833 
1834  switch (Kind) {
1835  case BlockCaptureEntityKind::CXXRecord: {
1836  Str += "c";
1837  SmallString<256> TyStr;
1838  llvm::raw_svector_ostream Out(TyStr);
1839  CGM.getCXXABI().getMangleContext().mangleTypeName(CaptureTy, Out);
1840  Str += llvm::to_string(TyStr.size()) + TyStr.c_str();
1841  break;
1842  }
1843  case BlockCaptureEntityKind::ARCWeak:
1844  Str += "w";
1845  break;
1846  case BlockCaptureEntityKind::ARCStrong:
1847  Str += "s";
1848  break;
1849  case BlockCaptureEntityKind::BlockObject: {
1850  const VarDecl *Var = CI.getVariable();
1851  unsigned F = Flags.getBitMask();
1852  if (F & BLOCK_FIELD_IS_BYREF) {
1853  Str += "r";
1854  if (F & BLOCK_FIELD_IS_WEAK)
1855  Str += "w";
1856  else {
1857  // If CaptureStrKind::Merged is passed, check both the copy expression
1858  // and the destructor.
1859  if (StrKind != CaptureStrKind::DisposeHelper) {
1860  if (Ctx.getBlockVarCopyInit(Var).canThrow())
1861  Str += "c";
1862  }
1863  if (StrKind != CaptureStrKind::CopyHelper) {
1865  Str += "d";
1866  }
1867  }
1868  } else {
1869  assert((F & BLOCK_FIELD_IS_OBJECT) && "unexpected flag value");
1870  if (F == BLOCK_FIELD_IS_BLOCK)
1871  Str += "b";
1872  else
1873  Str += "o";
1874  }
1875  break;
1876  }
1877  case BlockCaptureEntityKind::NonTrivialCStruct: {
1878  bool IsVolatile = CaptureTy.isVolatileQualified();
1879  CharUnits Alignment =
1880  BlockAlignment.alignmentAtOffset(E.Capture->getOffset());
1881 
1882  Str += "n";
1883  std::string FuncStr;
1884  if (StrKind == CaptureStrKind::DisposeHelper)
1886  CaptureTy, Alignment, IsVolatile, Ctx);
1887  else
1888  // If CaptureStrKind::Merged is passed, use the copy constructor string.
1889  // It has all the information that the destructor string has.
1891  CaptureTy, Alignment, IsVolatile, Ctx);
1892  // The underscore is necessary here because non-trivial copy constructor
1893  // and destructor strings can start with a number.
1894  Str += llvm::to_string(FuncStr.size()) + "_" + FuncStr;
1895  break;
1896  }
1898  break;
1899  }
1900 
1901  return Str;
1902 }
1903 
1904 static std::string getCopyDestroyHelperFuncName(
1905  const SmallVectorImpl<BlockCaptureManagedEntity> &Captures,
1906  CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM) {
1907  assert((StrKind == CaptureStrKind::CopyHelper ||
1908  StrKind == CaptureStrKind::DisposeHelper) &&
1909  "unexpected CaptureStrKind");
1910  std::string Name = StrKind == CaptureStrKind::CopyHelper
1911  ? "__copy_helper_block_"
1912  : "__destroy_helper_block_";
1913  if (CGM.getLangOpts().Exceptions)
1914  Name += "e";
1915  if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
1916  Name += "a";
1917  Name += llvm::to_string(BlockAlignment.getQuantity()) + "_";
1918 
1919  for (const BlockCaptureManagedEntity &E : Captures) {
1920  Name += llvm::to_string(E.Capture->getOffset().getQuantity());
1921  Name += getBlockCaptureStr(E, StrKind, BlockAlignment, CGM);
1922  }
1923 
1924  return Name;
1925 }
1926 
1928  Address Field, QualType CaptureType,
1929  BlockFieldFlags Flags, bool ForCopyHelper,
1930  VarDecl *Var, CodeGenFunction &CGF) {
1931  bool EHOnly = ForCopyHelper;
1932 
1933  switch (CaptureKind) {
1934  case BlockCaptureEntityKind::CXXRecord:
1935  case BlockCaptureEntityKind::ARCWeak:
1936  case BlockCaptureEntityKind::NonTrivialCStruct:
1937  case BlockCaptureEntityKind::ARCStrong: {
1938  if (CaptureType.isDestructedType() &&
1939  (!EHOnly || CGF.needsEHCleanup(CaptureType.isDestructedType()))) {
1940  CodeGenFunction::Destroyer *Destroyer =
1941  CaptureKind == BlockCaptureEntityKind::ARCStrong
1943  : CGF.getDestroyer(CaptureType.isDestructedType());
1944  CleanupKind Kind =
1945  EHOnly ? EHCleanup
1946  : CGF.getCleanupKind(CaptureType.isDestructedType());
1947  CGF.pushDestroy(Kind, Field, CaptureType, Destroyer, Kind & EHCleanup);
1948  }
1949  break;
1950  }
1951  case BlockCaptureEntityKind::BlockObject: {
1952  if (!EHOnly || CGF.getLangOpts().Exceptions) {
1954  // Calls to _Block_object_dispose along the EH path in the copy helper
1955  // function don't throw as newly-copied __block variables always have a
1956  // reference count of 2.
1957  bool CanThrow =
1958  !ForCopyHelper && CGF.cxxDestructorCanThrow(CaptureType);
1959  CGF.enterByrefCleanup(Kind, Field, Flags, /*LoadBlockVarAddr*/ true,
1960  CanThrow);
1961  }
1962  break;
1963  }
1965  break;
1966  }
1967 }
1968 
1970  llvm::Function *Fn,
1971  const CGFunctionInfo &FI,
1972  CodeGenModule &CGM) {
1973  if (CapturesNonExternalType) {
1975  } else {
1976  Fn->setVisibility(llvm::GlobalValue::HiddenVisibility);
1977  Fn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1978  CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, Fn);
1979  CGM.SetLLVMFunctionAttributesForDefinition(nullptr, Fn);
1980  }
1981 }
1982 /// Generate the copy-helper function for a block closure object:
1983 /// static void block_copy_helper(block_t *dst, block_t *src);
1984 /// The runtime will have previously initialized 'dst' by doing a
1985 /// bit-copy of 'src'.
1986 ///
1987 /// Note that this copies an entire block closure object to the heap;
1988 /// it should not be confused with a 'byref copy helper', which moves
1989 /// the contents of an individual __block variable to the heap.
1990 llvm::Constant *
1993  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures);
1994  std::string FuncName =
1995  getCopyDestroyHelperFuncName(CopiedCaptures, blockInfo.BlockAlign,
1996  CaptureStrKind::CopyHelper, CGM);
1997 
1998  if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
1999  return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2000 
2001  ASTContext &C = getContext();
2002 
2003  QualType ReturnTy = C.VoidTy;
2004 
2005  FunctionArgList args;
2007  args.push_back(&DstDecl);
2009  args.push_back(&SrcDecl);
2010 
2011  const CGFunctionInfo &FI =
2012  CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2013 
2014  // FIXME: it would be nice if these were mergeable with things with
2015  // identical semantics.
2016  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2017 
2018  llvm::Function *Fn =
2019  llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2020  FuncName, &CGM.getModule());
2021  if (CGM.supportsCOMDAT())
2022  Fn->setComdat(CGM.getModule().getOrInsertComdat(FuncName));
2023 
2024  IdentifierInfo *II = &C.Idents.get(FuncName);
2025 
2026  SmallVector<QualType, 2> ArgTys;
2027  ArgTys.push_back(C.VoidPtrTy);
2028  ArgTys.push_back(C.VoidPtrTy);
2029  QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2030 
2033  FunctionTy, nullptr, SC_Static, false, false);
2034 
2036  CGM);
2037  StartFunction(FD, ReturnTy, Fn, FI, args);
2038  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2039  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2040 
2041  Address src = GetAddrOfLocalVar(&SrcDecl);
2042  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2043  src = Builder.CreateBitCast(src, structPtrTy, "block.source");
2044 
2045  Address dst = GetAddrOfLocalVar(&DstDecl);
2046  dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
2047  dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
2048 
2049  for (const auto &CopiedCapture : CopiedCaptures) {
2050  const BlockDecl::Capture &CI = *CopiedCapture.CI;
2051  const CGBlockInfo::Capture &capture = *CopiedCapture.Capture;
2052  QualType captureType = CI.getVariable()->getType();
2053  BlockFieldFlags flags = CopiedCapture.CopyFlags;
2054 
2055  unsigned index = capture.getIndex();
2056  Address srcField = Builder.CreateStructGEP(src, index);
2057  Address dstField = Builder.CreateStructGEP(dst, index);
2058 
2059  switch (CopiedCapture.CopyKind) {
2060  case BlockCaptureEntityKind::CXXRecord:
2061  // If there's an explicit copy expression, we do that.
2062  assert(CI.getCopyExpr() && "copy expression for variable is missing");
2063  EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
2064  break;
2065  case BlockCaptureEntityKind::ARCWeak:
2066  EmitARCCopyWeak(dstField, srcField);
2067  break;
2068  case BlockCaptureEntityKind::NonTrivialCStruct: {
2069  // If this is a C struct that requires non-trivial copy construction,
2070  // emit a call to its copy constructor.
2071  QualType varType = CI.getVariable()->getType();
2072  callCStructCopyConstructor(MakeAddrLValue(dstField, varType),
2073  MakeAddrLValue(srcField, varType));
2074  break;
2075  }
2076  case BlockCaptureEntityKind::ARCStrong: {
2077  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2078  // At -O0, store null into the destination field (so that the
2079  // storeStrong doesn't over-release) and then call storeStrong.
2080  // This is a workaround to not having an initStrong call.
2081  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2082  auto *ty = cast<llvm::PointerType>(srcValue->getType());
2083  llvm::Value *null = llvm::ConstantPointerNull::get(ty);
2084  Builder.CreateStore(null, dstField);
2085  EmitARCStoreStrongCall(dstField, srcValue, true);
2086 
2087  // With optimization enabled, take advantage of the fact that
2088  // the blocks runtime guarantees a memcpy of the block data, and
2089  // just emit a retain of the src field.
2090  } else {
2091  EmitARCRetainNonBlock(srcValue);
2092 
2093  // Unless EH cleanup is required, we don't need this anymore, so kill
2094  // it. It's not quite worth the annoyance to avoid creating it in the
2095  // first place.
2096  if (!needsEHCleanup(captureType.isDestructedType()))
2097  cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
2098  }
2099  break;
2100  }
2101  case BlockCaptureEntityKind::BlockObject: {
2102  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2103  srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
2104  llvm::Value *dstAddr =
2105  Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
2106  llvm::Value *args[] = {
2107  dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2108  };
2109 
2110  if (CI.isByRef() && C.getBlockVarCopyInit(CI.getVariable()).canThrow())
2111  EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
2112  else
2113  EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
2114  break;
2115  }
2117  continue;
2118  }
2119 
2120  // Ensure that we destroy the copied object if an exception is thrown later
2121  // in the helper function.
2122  pushCaptureCleanup(CopiedCapture.CopyKind, dstField, captureType, flags,
2123  /*ForCopyHelper*/ true, CI.getVariable(), *this);
2124  }
2125 
2126  FinishFunction();
2127 
2128  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2129 }
2130 
2131 static BlockFieldFlags
2133  QualType T) {
2135  if (T->isBlockPointerType())
2136  Flags = BLOCK_FIELD_IS_BLOCK;
2137  return Flags;
2138 }
2139 
2140 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
2142  const LangOptions &LangOpts) {
2143  if (CI.isEscapingByref()) {
2145  if (T.isObjCGCWeak())
2146  Flags |= BLOCK_FIELD_IS_WEAK;
2147  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
2148  }
2149 
2150  switch (T.isDestructedType()) {
2152  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
2154  // Use objc_storeStrong for __strong direct captures; the
2155  // dynamic tools really like it when we do this.
2156  return std::make_pair(BlockCaptureEntityKind::ARCStrong,
2159  // Support __weak direct captures.
2160  return std::make_pair(BlockCaptureEntityKind::ARCWeak,
2163  return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
2164  BlockFieldFlags());
2165  case QualType::DK_none: {
2166  // Non-ARC captures are strong, and we need to use _Block_object_dispose.
2167  if (T->isObjCRetainableType() && !T.getQualifiers().hasObjCLifetime() &&
2168  !LangOpts.ObjCAutoRefCount)
2169  return std::make_pair(BlockCaptureEntityKind::BlockObject,
2171  // Otherwise, we have nothing to do.
2172  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
2173  }
2174  }
2175  llvm_unreachable("after exhaustive DestructionKind switch");
2176 }
2177 
2178 /// Generate the destroy-helper function for a block closure object:
2179 /// static void block_destroy_helper(block_t *theBlock);
2180 ///
2181 /// Note that this destroys a heap-allocated block closure object;
2182 /// it should not be confused with a 'byref destroy helper', which
2183 /// destroys the heap-allocated contents of an individual __block
2184 /// variable.
2185 llvm::Constant *
2188  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures);
2189  std::string FuncName =
2190  getCopyDestroyHelperFuncName(DestroyedCaptures, blockInfo.BlockAlign,
2191  CaptureStrKind::DisposeHelper, CGM);
2192 
2193  if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2194  return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2195 
2196  ASTContext &C = getContext();
2197 
2198  QualType ReturnTy = C.VoidTy;
2199 
2200  FunctionArgList args;
2202  args.push_back(&SrcDecl);
2203 
2204  const CGFunctionInfo &FI =
2205  CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2206 
2207  // FIXME: We'd like to put these into a mergable by content, with
2208  // internal linkage.
2209  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2210 
2211  llvm::Function *Fn =
2212  llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2213  FuncName, &CGM.getModule());
2214  if (CGM.supportsCOMDAT())
2215  Fn->setComdat(CGM.getModule().getOrInsertComdat(FuncName));
2216 
2217  IdentifierInfo *II = &C.Idents.get(FuncName);
2218 
2219  SmallVector<QualType, 1> ArgTys;
2220  ArgTys.push_back(C.VoidPtrTy);
2221  QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2222 
2225  FunctionTy, nullptr, SC_Static, false, false);
2226 
2228  CGM);
2229  StartFunction(FD, ReturnTy, Fn, FI, args);
2230  markAsIgnoreThreadCheckingAtRuntime(Fn);
2231 
2232  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2233 
2234  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2235 
2236  Address src = GetAddrOfLocalVar(&SrcDecl);
2237  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2238  src = Builder.CreateBitCast(src, structPtrTy, "block");
2239 
2240  CodeGenFunction::RunCleanupsScope cleanups(*this);
2241 
2242  for (const auto &DestroyedCapture : DestroyedCaptures) {
2243  const BlockDecl::Capture &CI = *DestroyedCapture.CI;
2244  const CGBlockInfo::Capture &capture = *DestroyedCapture.Capture;
2245  BlockFieldFlags flags = DestroyedCapture.DisposeFlags;
2246 
2247  Address srcField = Builder.CreateStructGEP(src, capture.getIndex());
2248 
2249  pushCaptureCleanup(DestroyedCapture.DisposeKind, srcField,
2250  CI.getVariable()->getType(), flags,
2251  /*ForCopyHelper*/ false, CI.getVariable(), *this);
2252  }
2253 
2254  cleanups.ForceCleanup();
2255 
2256  FinishFunction();
2257 
2258  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2259 }
2260 
2261 namespace {
2262 
2263 /// Emits the copy/dispose helper functions for a __block object of id type.
2264 class ObjectByrefHelpers final : public BlockByrefHelpers {
2265  BlockFieldFlags Flags;
2266 
2267 public:
2268  ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
2269  : BlockByrefHelpers(alignment), Flags(flags) {}
2270 
2271  void emitCopy(CodeGenFunction &CGF, Address destField,
2272  Address srcField) override {
2273  destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
2274 
2275  srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
2276  llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
2277 
2278  unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
2279 
2280  llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
2281  llvm::FunctionCallee fn = CGF.CGM.getBlockObjectAssign();
2282 
2283  llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
2284  CGF.EmitNounwindRuntimeCall(fn, args);
2285  }
2286 
2287  void emitDispose(CodeGenFunction &CGF, Address field) override {
2288  field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
2289  llvm::Value *value = CGF.Builder.CreateLoad(field);
2290 
2291  CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER, false);
2292  }
2293 
2294  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2295  id.AddInteger(Flags.getBitMask());
2296  }
2297 };
2298 
2299 /// Emits the copy/dispose helpers for an ARC __block __weak variable.
2300 class ARCWeakByrefHelpers final : public BlockByrefHelpers {
2301 public:
2302  ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2303 
2304  void emitCopy(CodeGenFunction &CGF, Address destField,
2305  Address srcField) override {
2306  CGF.EmitARCMoveWeak(destField, srcField);
2307  }
2308 
2309  void emitDispose(CodeGenFunction &CGF, Address field) override {
2310  CGF.EmitARCDestroyWeak(field);
2311  }
2312 
2313  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2314  // 0 is distinguishable from all pointers and byref flags
2315  id.AddInteger(0);
2316  }
2317 };
2318 
2319 /// Emits the copy/dispose helpers for an ARC __block __strong variable
2320 /// that's not of block-pointer type.
2321 class ARCStrongByrefHelpers final : public BlockByrefHelpers {
2322 public:
2323  ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2324 
2325  void emitCopy(CodeGenFunction &CGF, Address destField,
2326  Address srcField) override {
2327  // Do a "move" by copying the value and then zeroing out the old
2328  // variable.
2329 
2330  llvm::Value *value = CGF.Builder.CreateLoad(srcField);
2331 
2332  llvm::Value *null =
2333  llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
2334 
2335  if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
2336  CGF.Builder.CreateStore(null, destField);
2337  CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
2338  CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
2339  return;
2340  }
2341  CGF.Builder.CreateStore(value, destField);
2342  CGF.Builder.CreateStore(null, srcField);
2343  }
2344 
2345  void emitDispose(CodeGenFunction &CGF, Address field) override {
2347  }
2348 
2349  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2350  // 1 is distinguishable from all pointers and byref flags
2351  id.AddInteger(1);
2352  }
2353 };
2354 
2355 /// Emits the copy/dispose helpers for an ARC __block __strong
2356 /// variable that's of block-pointer type.
2357 class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
2358 public:
2359  ARCStrongBlockByrefHelpers(CharUnits alignment)
2360  : BlockByrefHelpers(alignment) {}
2361 
2362  void emitCopy(CodeGenFunction &CGF, Address destField,
2363  Address srcField) override {
2364  // Do the copy with objc_retainBlock; that's all that
2365  // _Block_object_assign would do anyway, and we'd have to pass the
2366  // right arguments to make sure it doesn't get no-op'ed.
2367  llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
2368  llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
2369  CGF.Builder.CreateStore(copy, destField);
2370  }
2371 
2372  void emitDispose(CodeGenFunction &CGF, Address field) override {
2374  }
2375 
2376  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2377  // 2 is distinguishable from all pointers and byref flags
2378  id.AddInteger(2);
2379  }
2380 };
2381 
2382 /// Emits the copy/dispose helpers for a __block variable with a
2383 /// nontrivial copy constructor or destructor.
2384 class CXXByrefHelpers final : public BlockByrefHelpers {
2385  QualType VarType;
2386  const Expr *CopyExpr;
2387 
2388 public:
2389  CXXByrefHelpers(CharUnits alignment, QualType type,
2390  const Expr *copyExpr)
2391  : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
2392 
2393  bool needsCopy() const override { return CopyExpr != nullptr; }
2394  void emitCopy(CodeGenFunction &CGF, Address destField,
2395  Address srcField) override {
2396  if (!CopyExpr) return;
2397  CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
2398  }
2399 
2400  void emitDispose(CodeGenFunction &CGF, Address field) override {
2401  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2402  CGF.PushDestructorCleanup(VarType, field);
2403  CGF.PopCleanupBlocks(cleanupDepth);
2404  }
2405 
2406  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2407  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2408  }
2409 };
2410 
2411 /// Emits the copy/dispose helpers for a __block variable that is a non-trivial
2412 /// C struct.
2413 class NonTrivialCStructByrefHelpers final : public BlockByrefHelpers {
2414  QualType VarType;
2415 
2416 public:
2417  NonTrivialCStructByrefHelpers(CharUnits alignment, QualType type)
2418  : BlockByrefHelpers(alignment), VarType(type) {}
2419 
2420  void emitCopy(CodeGenFunction &CGF, Address destField,
2421  Address srcField) override {
2422  CGF.callCStructMoveConstructor(CGF.MakeAddrLValue(destField, VarType),
2423  CGF.MakeAddrLValue(srcField, VarType));
2424  }
2425 
2426  bool needsDispose() const override {
2427  return VarType.isDestructedType();
2428  }
2429 
2430  void emitDispose(CodeGenFunction &CGF, Address field) override {
2431  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2432  CGF.pushDestroy(VarType.isDestructedType(), field, VarType);
2433  CGF.PopCleanupBlocks(cleanupDepth);
2434  }
2435 
2436  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2437  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2438  }
2439 };
2440 } // end anonymous namespace
2441 
2442 static llvm::Constant *
2444  BlockByrefHelpers &generator) {
2445  ASTContext &Context = CGF.getContext();
2446 
2447  QualType ReturnTy = Context.VoidTy;
2448 
2449  FunctionArgList args;
2450  ImplicitParamDecl Dst(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2451  args.push_back(&Dst);
2452 
2453  ImplicitParamDecl Src(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2454  args.push_back(&Src);
2455 
2456  const CGFunctionInfo &FI =
2457  CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2458 
2459  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2460 
2461  // FIXME: We'd like to put these into a mergable by content, with
2462  // internal linkage.
2463  llvm::Function *Fn =
2465  "__Block_byref_object_copy_", &CGF.CGM.getModule());
2466 
2467  IdentifierInfo *II
2468  = &Context.Idents.get("__Block_byref_object_copy_");
2469 
2470  SmallVector<QualType, 2> ArgTys;
2471  ArgTys.push_back(Context.VoidPtrTy);
2472  ArgTys.push_back(Context.VoidPtrTy);
2473  QualType FunctionTy = Context.getFunctionType(ReturnTy, ArgTys, {});
2474 
2476  Context, Context.getTranslationUnitDecl(), SourceLocation(),
2477  SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2478 
2480 
2481  CGF.StartFunction(FD, ReturnTy, Fn, FI, args);
2482 
2483  if (generator.needsCopy()) {
2484  llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
2485 
2486  // dst->x
2487  Address destField = CGF.GetAddrOfLocalVar(&Dst);
2488  destField = Address(CGF.Builder.CreateLoad(destField),
2489  byrefInfo.ByrefAlignment);
2490  destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
2491  destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
2492  "dest-object");
2493 
2494  // src->x
2495  Address srcField = CGF.GetAddrOfLocalVar(&Src);
2496  srcField = Address(CGF.Builder.CreateLoad(srcField),
2497  byrefInfo.ByrefAlignment);
2498  srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
2499  srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
2500  "src-object");
2501 
2502  generator.emitCopy(CGF, destField, srcField);
2503  }
2504 
2505  CGF.FinishFunction();
2506 
2507  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2508 }
2509 
2510 /// Build the copy helper for a __block variable.
2511 static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
2512  const BlockByrefInfo &byrefInfo,
2513  BlockByrefHelpers &generator) {
2514  CodeGenFunction CGF(CGM);
2515  return generateByrefCopyHelper(CGF, byrefInfo, generator);
2516 }
2517 
2518 /// Generate code for a __block variable's dispose helper.
2519 static llvm::Constant *
2521  const BlockByrefInfo &byrefInfo,
2522  BlockByrefHelpers &generator) {
2523  ASTContext &Context = CGF.getContext();
2524  QualType R = Context.VoidTy;
2525 
2526  FunctionArgList args;
2527  ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2529  args.push_back(&Src);
2530 
2531  const CGFunctionInfo &FI =
2533 
2534  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2535 
2536  // FIXME: We'd like to put these into a mergable by content, with
2537  // internal linkage.
2538  llvm::Function *Fn =
2540  "__Block_byref_object_dispose_",
2541  &CGF.CGM.getModule());
2542 
2543  IdentifierInfo *II
2544  = &Context.Idents.get("__Block_byref_object_dispose_");
2545 
2546  SmallVector<QualType, 1> ArgTys;
2547  ArgTys.push_back(Context.VoidPtrTy);
2548  QualType FunctionTy = Context.getFunctionType(R, ArgTys, {});
2549 
2551  Context, Context.getTranslationUnitDecl(), SourceLocation(),
2552  SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2553 
2555 
2556  CGF.StartFunction(FD, R, Fn, FI, args);
2557 
2558  if (generator.needsDispose()) {
2559  Address addr = CGF.GetAddrOfLocalVar(&Src);
2560  addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2561  auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2562  addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2563  addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2564 
2565  generator.emitDispose(CGF, addr);
2566  }
2567 
2568  CGF.FinishFunction();
2569 
2570  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2571 }
2572 
2573 /// Build the dispose helper for a __block variable.
2574 static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2575  const BlockByrefInfo &byrefInfo,
2576  BlockByrefHelpers &generator) {
2577  CodeGenFunction CGF(CGM);
2578  return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2579 }
2580 
2581 /// Lazily build the copy and dispose helpers for a __block variable
2582 /// with the given information.
2583 template <class T>
2584 static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2585  T &&generator) {
2586  llvm::FoldingSetNodeID id;
2587  generator.Profile(id);
2588 
2589  void *insertPos;
2591  = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2592  if (node) return static_cast<T*>(node);
2593 
2594  generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2595  generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2596 
2597  T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2598  CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2599  return copy;
2600 }
2601 
2602 /// Build the copy and dispose helpers for the given __block variable
2603 /// emission. Places the helpers in the global cache. Returns null
2604 /// if no helpers are required.
2606 CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2607  const AutoVarEmission &emission) {
2608  const VarDecl &var = *emission.Variable;
2609  assert(var.isEscapingByref() &&
2610  "only escaping __block variables need byref helpers");
2611 
2612  QualType type = var.getType();
2613 
2614  auto &byrefInfo = getBlockByrefInfo(&var);
2615 
2616  // The alignment we care about for the purposes of uniquing byref
2617  // helpers is the alignment of the actual byref value field.
2618  CharUnits valueAlignment =
2619  byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2620 
2621  if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2622  const Expr *copyExpr =
2624  if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2625 
2627  CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2628  }
2629 
2630  // If type is a non-trivial C struct type that is non-trivial to
2631  // destructly move or destroy, build the copy and dispose helpers.
2632  if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct ||
2633  type.isDestructedType() == QualType::DK_nontrivial_c_struct)
2635  CGM, byrefInfo, NonTrivialCStructByrefHelpers(valueAlignment, type));
2636 
2637  // Otherwise, if we don't have a retainable type, there's nothing to do.
2638  // that the runtime does extra copies.
2639  if (!type->isObjCRetainableType()) return nullptr;
2640 
2641  Qualifiers qs = type.getQualifiers();
2642 
2643  // If we have lifetime, that dominates.
2644  if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2645  switch (lifetime) {
2646  case Qualifiers::OCL_None: llvm_unreachable("impossible");
2647 
2648  // These are just bits as far as the runtime is concerned.
2651  return nullptr;
2652 
2653  // Tell the runtime that this is ARC __weak, called by the
2654  // byref routines.
2655  case Qualifiers::OCL_Weak:
2656  return ::buildByrefHelpers(CGM, byrefInfo,
2657  ARCWeakByrefHelpers(valueAlignment));
2658 
2659  // ARC __strong __block variables need to be retained.
2661  // Block pointers need to be copied, and there's no direct
2662  // transfer possible.
2663  if (type->isBlockPointerType()) {
2664  return ::buildByrefHelpers(CGM, byrefInfo,
2665  ARCStrongBlockByrefHelpers(valueAlignment));
2666 
2667  // Otherwise, we transfer ownership of the retain from the stack
2668  // to the heap.
2669  } else {
2670  return ::buildByrefHelpers(CGM, byrefInfo,
2671  ARCStrongByrefHelpers(valueAlignment));
2672  }
2673  }
2674  llvm_unreachable("fell out of lifetime switch!");
2675  }
2676 
2677  BlockFieldFlags flags;
2678  if (type->isBlockPointerType()) {
2679  flags |= BLOCK_FIELD_IS_BLOCK;
2680  } else if (CGM.getContext().isObjCNSObjectType(type) ||
2681  type->isObjCObjectPointerType()) {
2682  flags |= BLOCK_FIELD_IS_OBJECT;
2683  } else {
2684  return nullptr;
2685  }
2686 
2687  if (type.isObjCGCWeak())
2688  flags |= BLOCK_FIELD_IS_WEAK;
2689 
2690  return ::buildByrefHelpers(CGM, byrefInfo,
2691  ObjectByrefHelpers(valueAlignment, flags));
2692 }
2693 
2695  const VarDecl *var,
2696  bool followForward) {
2697  auto &info = getBlockByrefInfo(var);
2698  return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2699 }
2700 
2702  const BlockByrefInfo &info,
2703  bool followForward,
2704  const llvm::Twine &name) {
2705  // Chase the forwarding address if requested.
2706  if (followForward) {
2707  Address forwardingAddr = Builder.CreateStructGEP(baseAddr, 1, "forwarding");
2708  baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2709  }
2710 
2711  return Builder.CreateStructGEP(baseAddr, info.FieldIndex, name);
2712 }
2713 
2714 /// BuildByrefInfo - This routine changes a __block variable declared as T x
2715 /// into:
2716 ///
2717 /// struct {
2718 /// void *__isa;
2719 /// void *__forwarding;
2720 /// int32_t __flags;
2721 /// int32_t __size;
2722 /// void *__copy_helper; // only if needed
2723 /// void *__destroy_helper; // only if needed
2724 /// void *__byref_variable_layout;// only if needed
2725 /// char padding[X]; // only if needed
2726 /// T x;
2727 /// } x
2728 ///
2730  auto it = BlockByrefInfos.find(D);
2731  if (it != BlockByrefInfos.end())
2732  return it->second;
2733 
2734  llvm::StructType *byrefType =
2735  llvm::StructType::create(getLLVMContext(),
2736  "struct.__block_byref_" + D->getNameAsString());
2737 
2738  QualType Ty = D->getType();
2739 
2740  CharUnits size;
2742 
2743  // void *__isa;
2744  types.push_back(Int8PtrTy);
2745  size += getPointerSize();
2746 
2747  // void *__forwarding;
2748  types.push_back(llvm::PointerType::getUnqual(byrefType));
2749  size += getPointerSize();
2750 
2751  // int32_t __flags;
2752  types.push_back(Int32Ty);
2753  size += CharUnits::fromQuantity(4);
2754 
2755  // int32_t __size;
2756  types.push_back(Int32Ty);
2757  size += CharUnits::fromQuantity(4);
2758 
2759  // Note that this must match *exactly* the logic in buildByrefHelpers.
2760  bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2761  if (hasCopyAndDispose) {
2762  /// void *__copy_helper;
2763  types.push_back(Int8PtrTy);
2764  size += getPointerSize();
2765 
2766  /// void *__destroy_helper;
2767  types.push_back(Int8PtrTy);
2768  size += getPointerSize();
2769  }
2770 
2771  bool HasByrefExtendedLayout = false;
2772  Qualifiers::ObjCLifetime Lifetime;
2773  if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2774  HasByrefExtendedLayout) {
2775  /// void *__byref_variable_layout;
2776  types.push_back(Int8PtrTy);
2777  size += CharUnits::fromQuantity(PointerSizeInBytes);
2778  }
2779 
2780  // T x;
2781  llvm::Type *varTy = ConvertTypeForMem(Ty);
2782 
2783  bool packed = false;
2784  CharUnits varAlign = getContext().getDeclAlign(D);
2785  CharUnits varOffset = size.alignTo(varAlign);
2786 
2787  // We may have to insert padding.
2788  if (varOffset != size) {
2789  llvm::Type *paddingTy =
2790  llvm::ArrayType::get(Int8Ty, (varOffset - size).getQuantity());
2791 
2792  types.push_back(paddingTy);
2793  size = varOffset;
2794 
2795  // Conversely, we might have to prevent LLVM from inserting padding.
2796  } else if (CGM.getDataLayout().getABITypeAlignment(varTy)
2797  > varAlign.getQuantity()) {
2798  packed = true;
2799  }
2800  types.push_back(varTy);
2801 
2802  byrefType->setBody(types, packed);
2803 
2804  BlockByrefInfo info;
2805  info.Type = byrefType;
2806  info.FieldIndex = types.size() - 1;
2807  info.FieldOffset = varOffset;
2808  info.ByrefAlignment = std::max(varAlign, getPointerAlign());
2809 
2810  auto pair = BlockByrefInfos.insert({D, info});
2811  assert(pair.second && "info was inserted recursively?");
2812  return pair.first->second;
2813 }
2814 
2815 /// Initialize the structural components of a __block variable, i.e.
2816 /// everything but the actual object.
2818  // Find the address of the local.
2819  Address addr = emission.Addr;
2820 
2821  // That's an alloca of the byref structure type.
2822  llvm::StructType *byrefType = cast<llvm::StructType>(
2823  cast<llvm::PointerType>(addr.getPointer()->getType())->getElementType());
2824 
2825  unsigned nextHeaderIndex = 0;
2826  CharUnits nextHeaderOffset;
2827  auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2828  const Twine &name) {
2829  auto fieldAddr = Builder.CreateStructGEP(addr, nextHeaderIndex, name);
2830  Builder.CreateStore(value, fieldAddr);
2831 
2832  nextHeaderIndex++;
2833  nextHeaderOffset += fieldSize;
2834  };
2835 
2836  // Build the byref helpers if necessary. This is null if we don't need any.
2837  BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2838 
2839  const VarDecl &D = *emission.Variable;
2840  QualType type = D.getType();
2841 
2842  bool HasByrefExtendedLayout;
2843  Qualifiers::ObjCLifetime ByrefLifetime;
2844  bool ByRefHasLifetime =
2845  getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2846 
2847  llvm::Value *V;
2848 
2849  // Initialize the 'isa', which is just 0 or 1.
2850  int isa = 0;
2851  if (type.isObjCGCWeak())
2852  isa = 1;
2853  V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2854  storeHeaderField(V, getPointerSize(), "byref.isa");
2855 
2856  // Store the address of the variable into its own forwarding pointer.
2857  storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2858 
2859  // Blocks ABI:
2860  // c) the flags field is set to either 0 if no helper functions are
2861  // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2862  BlockFlags flags;
2863  if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2864  if (ByRefHasLifetime) {
2865  if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2866  else switch (ByrefLifetime) {
2868  flags |= BLOCK_BYREF_LAYOUT_STRONG;
2869  break;
2870  case Qualifiers::OCL_Weak:
2871  flags |= BLOCK_BYREF_LAYOUT_WEAK;
2872  break;
2875  break;
2876  case Qualifiers::OCL_None:
2877  if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2879  break;
2880  default:
2881  break;
2882  }
2883  if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2884  printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2885  if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2886  printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2887  if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2888  BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2889  if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2890  printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2891  if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2892  printf(" BLOCK_BYREF_LAYOUT_STRONG");
2893  if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2894  printf(" BLOCK_BYREF_LAYOUT_WEAK");
2895  if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2896  printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2897  if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2898  printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2899  }
2900  printf("\n");
2901  }
2902  }
2903  storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2904  getIntSize(), "byref.flags");
2905 
2906  CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2907  V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2908  storeHeaderField(V, getIntSize(), "byref.size");
2909 
2910  if (helpers) {
2911  storeHeaderField(helpers->CopyHelper, getPointerSize(),
2912  "byref.copyHelper");
2913  storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2914  "byref.disposeHelper");
2915  }
2916 
2917  if (ByRefHasLifetime && HasByrefExtendedLayout) {
2918  auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2919  storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2920  }
2921 }
2922 
2924  bool CanThrow) {
2925  llvm::FunctionCallee F = CGM.getBlockObjectDispose();
2926  llvm::Value *args[] = {
2927  Builder.CreateBitCast(V, Int8PtrTy),
2928  llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2929  };
2930 
2931  if (CanThrow)
2932  EmitRuntimeCallOrInvoke(F, args);
2933  else
2934  EmitNounwindRuntimeCall(F, args);
2935 }
2936 
2938  BlockFieldFlags Flags,
2939  bool LoadBlockVarAddr, bool CanThrow) {
2940  EHStack.pushCleanup<CallBlockRelease>(Kind, Addr, Flags, LoadBlockVarAddr,
2941  CanThrow);
2942 }
2943 
2944 /// Adjust the declaration of something from the blocks API.
2946  llvm::Constant *C) {
2947  auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2948 
2949  if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2950  IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2953 
2954  assert((isa<llvm::Function>(C->stripPointerCasts()) ||
2955  isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&
2956  "expected Function or GlobalVariable");
2957 
2958  const NamedDecl *ND = nullptr;
2959  for (const auto &Result : DC->lookup(&II))
2960  if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2961  (ND = dyn_cast<VarDecl>(Result)))
2962  break;
2963 
2964  // TODO: support static blocks runtime
2965  if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2966  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2967  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2968  } else {
2969  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2970  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2971  }
2972  }
2973 
2974  if (CGM.getLangOpts().BlocksRuntimeOptional && GV->isDeclaration() &&
2975  GV->hasExternalLinkage())
2976  GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2977 
2978  CGM.setDSOLocal(GV);
2979 }
2980 
2982  if (BlockObjectDispose)
2983  return BlockObjectDispose;
2984 
2985  llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2986  llvm::FunctionType *fty
2987  = llvm::FunctionType::get(VoidTy, args, false);
2988  BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2990  *this, cast<llvm::Constant>(BlockObjectDispose.getCallee()));
2991  return BlockObjectDispose;
2992 }
2993 
2994 llvm::FunctionCallee CodeGenModule::getBlockObjectAssign() {
2995  if (BlockObjectAssign)
2996  return BlockObjectAssign;
2997 
2998  llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
2999  llvm::FunctionType *fty
3000  = llvm::FunctionType::get(VoidTy, args, false);
3001  BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
3003  *this, cast<llvm::Constant>(BlockObjectAssign.getCallee()));
3004  return BlockObjectAssign;
3005 }
3006 
3008  if (NSConcreteGlobalBlock)
3009  return NSConcreteGlobalBlock;
3010 
3011  NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
3012  Int8PtrTy->getPointerTo(),
3013  nullptr);
3014  configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
3015  return NSConcreteGlobalBlock;
3016 }
3017 
3019  if (NSConcreteStackBlock)
3020  return NSConcreteStackBlock;
3021 
3022  NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
3023  Int8PtrTy->getPointerTo(),
3024  nullptr);
3025  configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
3026  return NSConcreteStackBlock;
3027 }
const CGFunctionInfo & arrangeBuiltinFunctionDeclaration(QualType resultType, const FunctionArgList &args)
A builtin function is a freestanding function using the default C conventions.
Definition: CGCall.cpp:653
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:359
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:5593
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:188
CaptureStrKind
Definition: CGBlocks.cpp:102
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:1991
static llvm::Constant * generateByrefDisposeHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Generate code for a __block variable&#39;s dispose helper.
Definition: CGBlocks.cpp:2520
Represents a function declaration or definition.
Definition: Decl.h:1783
llvm::IntegerType * IntTy
int
llvm::Type * getGenericBlockLiteralType()
The type of a generic block literal.
Definition: CGBlocks.cpp:1218
const CGFunctionInfo & arrangeBlockFunctionDeclaration(const FunctionProtoType *type, const FunctionArgList &args)
Block invocation functions are C functions with an implicit parameter.
Definition: CGCall.cpp:628
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:1555
CharUnits BlockHeaderForcedGapOffset
Definition: CGBlocks.h:255
const FunctionProtoType * getFunctionType() const
getFunctionType - Return the underlying function type for this block.
Definition: Expr.cpp:2375
Expr * getCopyExpr() const
Definition: Decl.h:4083
static llvm::Constant * buildByrefDisposeHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the dispose helper for a __block variable.
Definition: CGBlocks.cpp:2574
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:4043
CanQualType VoidPtrTy
Definition: ASTContext.h:1044
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:2028
A (possibly-)qualified type.
Definition: Type.h:654
bool isBlockPointerType() const
Definition: Type.h:6512
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:4156
bool HaveInsertPoint() const
HaveInsertPoint - True if an insertion point is defined.
capture_const_iterator capture_begin() const
Definition: Decl.h:4166
llvm::LLVMContext & getLLVMContext()
void EmitARCDestroyWeak(Address addr)
void @objc_destroyWeak(i8** addr) Essentially objc_storeWeak(addr, nil).
Definition: CGObjC.cpp:2451
The standard implementation of ConstantInitBuilder used in Clang.
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3422
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:557
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:994
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:2584
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:2472
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:4136
static llvm::Constant * buildBlockDescriptor(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
buildBlockDescriptor - Build the block descriptor meta-data for a block.
Definition: CGBlocks.cpp:185
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:6452
constexpr size_t align(size_t Size)
Aligns a size to the pointer alignment.
Definition: PrimType.h:57
Expr * getCopyExpr() const
Definition: Expr.h:5634
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 ...
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, ConstexprSpecKind ConstexprKind=CSK_unspecified, Expr *TrailingRequiresClause=nullptr)
Definition: Decl.h:1955
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
capture_const_iterator capture_end() const
Definition: Decl.h:4167
The type would be trivial except that it is volatile-qualified.
Definition: Type.h:1130
Address GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
bool ReturnValue(const T &V, APValue &R)
Convers a value to an APValue.
Definition: Interp.h:41
Represents a variable declaration or definition.
Definition: Decl.h:820
Objects with "hidden" visibility are not seen by the dynamic linker.
Definition: Visibility.h:36
CGBlockInfo(const BlockDecl *blockDecl, StringRef Name)
Definition: CGBlocks.cpp:35
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:7002
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:1969
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:54
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:1689
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:1927
static void destroyBlockInfos(CGBlockInfo *info)
Destroy a chain of block layouts.
Definition: CGBlocks.cpp:891
The collection of all-type qualifiers we support.
Definition: Type.h:143
void add(RValue rvalue, QualType type)
Definition: CGCall.h:285
const AstTypeMatcher< RecordType > recordType
Matches record types (e.g.
const BlockDecl * Block
Definition: CGBlocks.h: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:361
static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E, CaptureStrKind StrKind, CharUnits BlockAlignment, CodeGenModule &CGM)
Definition: CGBlocks.cpp:1808
bool canThrow() const
Definition: Expr.h:5635
One of these records is kept for each identifier that is lexed.
bool doesNotEscape() const
Definition: Decl.h:4188
void emitByrefStructureInit(const AutoVarEmission &emission)
Initialize the structural components of a __block variable, i.e.
Definition: CGBlocks.cpp:2817
CGBlockInfo * FirstBlockInfo
FirstBlockInfo - The head of a singly-linked-list of block layouts.
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:168
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:2064
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:950
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:275
bool isReferenceType() const
Definition: Type.h:6516
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:516
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:53
static llvm::Constant * generateByrefCopyHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Definition: CGBlocks.cpp:2443
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:4116
static bool isSafeForCXXConstantCapture(QualType type)
Determines if the given type is safe for constant capture in C++.
Definition: CGBlocks.cpp:388
__DEVICE__ int max(int __a, int __b)
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:53
IdentifierTable & Idents
Definition: ASTContext.h:580
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:125
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:2291
virtual std::string getRCBlockLayoutStr(CodeGen::CodeGenModule &CGM, const CGBlockInfo &blockInfo)
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:38
void EmitARCDestroyStrong(Address addr, ARCPreciseLifetime_t precise)
Destroy a __strong variable.
Definition: CGObjC.cpp:2277
const BlockDecl * getBlockDecl() const
Definition: CGBlocks.h:280
void setDSOLocal(llvm::GlobalValue *GV) const
virtual TargetOpenCLBlockHelper * getTargetOpenCLBlockHelper() const
Definition: TargetInfo.h:298
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:901
uint32_t getBitMask() const
Definition: CGBlocks.h:117
bool isByRef() const
Whether this is a "by ref" capture, i.e.
Definition: Decl.h:4068
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6326
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...
RangeSelector name(std::string ID)
Given a node with a "name", (like NamedDecl, DeclRefExpr or CxxCtorInitializer) selects the name&#39;s to...
The type is an Objective-C retainable pointer type that is qualified with the ARC __strong qualifier...
Definition: Type.h:1134
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:106
void callCStructMoveConstructor(LValue Dst, LValue Src)
const Stmt * getBody() const
Definition: Expr.cpp:2384
llvm::Constant * getNSConcreteStackBlock()
Definition: CGBlocks.cpp:3018
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:1125
This object can be modified without requiring retains or releases.
Definition: Type.h:164
StringRef Name
Name - The name of the block, kindof.
Definition: CGBlocks.h:155
bool isEscapingByref() const
Definition: Decl.h:4070
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:1612
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:56
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:1690
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3754
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:39
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:1750
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
unsigned Offset
Definition: Format.cpp:1827
static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info, SmallVectorImpl< llvm::Type *> &elementTypes)
Definition: CGBlocks.cpp:448
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:4037
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:2467
static Address invalid()
Definition: Address.h:34
unsigned long ulong
An unsigned 64-bit integer.
Definition: opencl-c-base.h:32
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:7067
bool isObjCRetainableType() const
Definition: Type.cpp:4060
#define V(N, I)
Definition: ASTContext.h:2941
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5579
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2649
BlockCaptureEntityKind
Represents a type of copy/destroy operation that should be performed for an entity that&#39;s captured by...
Definition: CGBlocks.cpp:71
static llvm::Constant * buildGlobalBlock(CodeGenModule &CGM, const CGBlockInfo &blockInfo, llvm::Constant *blockFn)
Build the given block as a global block.
Definition: CGBlocks.cpp:1383
Expr * getCallee()
Definition: Expr.h:2663
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:2186
ObjCLifetime getObjCLifetime() const
Definition: Type.h:333
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:63
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:1517
static Capture makeIndex(unsigned index, CharUnits offset, QualType FieldType)
Definition: CGBlocks.h:200
QualType getType() const
Definition: Expr.h:137
llvm::FunctionCallee getBlockObjectAssign()
Definition: CGBlocks.cpp:2994
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:1401
static bool CanThrow(Expr *E, ASTContext &Ctx)
Definition: CFG.cpp:2580
static CharUnits getLowBit(CharUnits v)
Get the low bit of a nonzero character count.
Definition: CGBlocks.cpp:444
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:6925
const TargetInfo & getTarget() const
const LangOptions & getLangOpts() const
ASTContext & getContext() const
static BlockFieldFlags getBlockFieldFlagsForObjCObjectPointer(const BlockDecl::Capture &CI, QualType T)
Definition: CGBlocks.cpp:2132
do v
Definition: arm_acle.h:64
Address GetAddrOfBlockDecl(const VarDecl *var)
Definition: CGBlocks.cpp:1319
static QualType getCaptureFieldType(const CodeGenFunction &CGF, const BlockDecl::Capture &CI)
Definition: CGBlocks.cpp:503
llvm::Function * getInvokeFunction(const Expr *E)
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:40
static std::string getBlockDescriptorName(const CGBlockInfo &BlockInfo, CodeGenModule &CGM)
Definition: CGBlocks.cpp:122
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:6315
param_iterator param_begin()
Definition: Decl.h:4135
The l-value was considered opaque, so the alignment was determined from a type.
RecordDecl * getDecl() const
Definition: Type.h:4505
void setBlockContextParameter(const ImplicitParamDecl *D, unsigned argNum, llvm::Value *ptr)
Definition: CGBlocks.cpp:1476
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:160
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:141
llvm::FunctionCallee getBlockObjectDispose()
Definition: CGBlocks.cpp:2981
#define false
Definition: stdbool.h:17
Assigning into this object requires the old value to be released and the new value to be retained...
Definition: Type.h:171
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:2445
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:2055
Encodes a location in the source.
static DeclContext * castToDeclContext(const TranslationUnitDecl *D)
Definition: Decl.h:104
void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags, bool CanThrow)
Definition: CGBlocks.cpp:2923
QualType getReturnType() const
Definition: Type.h:3680
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Expr.h:5602
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:266
static std::string getCopyDestroyHelperFuncName(const SmallVectorImpl< BlockCaptureManagedEntity > &Captures, CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM)
Definition: CGBlocks.cpp:1904
static void configureBlocksRuntimeObject(CodeGenModule &CGM, llvm::Constant *C)
Adjust the declaration of something from the blocks API.
Definition: CGBlocks.cpp:2945
The type is a struct containing a field whose type is neither PCK_Trivial nor PCK_VolatileTrivial.
Definition: Type.h:1146
An aggregate value slot.
Definition: CGValue.h:439
const BlockByrefInfo & getBlockByrefInfo(const VarDecl *var)
BuildByrefInfo - This routine changes a __block variable declared as T x into:
Definition: CGBlocks.cpp:2729
A scoped helper to set the current debug location to the specified location or preferred location of ...
Definition: CGDebugInfo.h:737
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:1800
bool isConversionFromLambda() const
Definition: Decl.h:4180
void enterNonTrivialFullExpression(const FullExpr *E)
Enter a full-expression with a non-trivial number of objects to clean up.
Definition: CGBlocks.cpp:865
CanQualType VoidTy
Definition: ASTContext.h:1016
llvm::DenseMap< const VarDecl *, Capture > Captures
The mapping of allocated indexes within the block.
Definition: CGBlocks.h:242
bool isNonEscapingByref() const
Indicates the capture is a __block variable that is never captured by an escaping block...
Definition: Decl.cpp:2480
arg_range arguments()
Definition: Expr.h:2739
bool isObjCObjectPointerType() const
Definition: Type.h:6618
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:3274
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1174
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:2937
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:4064
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:2361
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:177
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:1138
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:621
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:355
bool isObjCGCWeak() const
true when Type is objc&#39;s weak.
Definition: Type.h:1070
static llvm::Constant * tryCaptureAsConstant(CodeGenModule &CGM, CodeGenFunction *CGF, const VarDecl *var)
It is illegal to modify a const object after initialization.
Definition: CGBlocks.cpp:412
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:194
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:522
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:1271
ArrayRef< Capture > captures() const
Definition: Decl.h:4164
bool isNested() const
Whether this is a nested capture, i.e.
Definition: Decl.h:4080
Parameter for Objective-C &#39;self&#39; argument.
Definition: Decl.h:1540
static llvm::Constant * buildDisposeHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to dispose of a block.
Definition: CGBlocks.cpp:62
const Expr * getInit() const
Definition: Decl.h:1229
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:332
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:2476
BlockVarCopyInit getBlockVarCopyInit(const VarDecl *VD) const
Get the copy initialization expression of the VarDecl VD, or nullptr if none exists.
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:781
Pointer to a block type.
Definition: Type.h:2716
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:4495
StructBuilder beginStruct(llvm::StructType *structTy=nullptr)
CanQualType UnsignedLongTy
Definition: ASTContext.h:1026
static llvm::Constant * buildByrefCopyHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the copy helper for a __block variable.
Definition: CGBlocks.cpp:2511
void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp)
Definition: CGExprCXX.cpp:653
static CGBlockInfo * findAndRemoveBlockInfo(CGBlockInfo **head, const BlockDecl *block)
Find the layout for the given block in a linked list and remove it.
Definition: CGBlocks.cpp:874
void SetInternalFunctionAttributes(GlobalDecl GD, llvm::Function *F, const CGFunctionInfo &FI)
Set the attributes on the LLVM function for the given decl and function info.
virtual void emitDispose(CodeGenFunction &CGF, Address field)=0
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:31
bool hasReducedDebugInfo() const
Check if type and variable info should be emitted.
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:4169
Reading or writing from this object requires a barrier call.
Definition: Type.h:174
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:1009
Represents a C++ struct/union/class.
Definition: DeclCXX.h:253
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:6283
void setAddrOfGlobalBlock(const BlockExpr *BE, llvm::Constant *Addr)
Notes that BE&#39;s global block is available via Addr.
Definition: CGBlocks.cpp:1353
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:5605
llvm::Value * EmitARCRetainBlock(llvm::Value *value, bool mandatory)
Retain the given block, with _Block_copy semantics.
Definition: CGObjC.cpp:2149
uint64_t getPointerAlign(unsigned AddrSpace) const
Definition: TargetInfo.h:364
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2546
StringRef getName() const
Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:250
CGCXXABI & getCXXABI() const
llvm::Function * GenerateBlockFunction(GlobalDecl GD, const CGBlockInfo &Info, const DeclMapTy &ldm, bool IsLambdaConversionToBlock, bool BuildGlobalBlock)
Definition: CGBlocks.cpp:1515
The top declaration context.
Definition: Decl.h:82
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1171
static RValue get(llvm::Value *V)
Definition: CGValue.h:86
RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue)
Definition: CGBlocks.cpp:1255
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:786
llvm::Constant * getNSConcreteGlobalBlock()
Definition: CGBlocks.cpp:3007
RangeSelector node(std::string ID)
Selects a node, including trailing semicolon (for non-expression statements).
llvm::Type * getBlockDescriptorType()
Fetches the type of a generic block descriptor.
Definition: CGBlocks.cpp:1186
llvm::Constant * GetAddrOfGlobalBlock(const BlockExpr *BE, StringRef Name)
Gets the address of a block which requires no captures.
Definition: CGBlocks.cpp:1361
QualType getType() const
Definition: Decl.h:630
An l-value expression is a reference to an object with independent storage.
Definition: Specifiers.h:129
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:223
llvm::Instruction * DominatingIP
An instruction which dominates the full-expression that the block is inside.
Definition: CGBlocks.h:262
const LangOptions & getLangOpts() const
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2557
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:2084
Decl * getCalleeDecl()
Definition: Expr.h:2675
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:261
const LangOptions & getLangOpts() const
Definition: ASTContext.h:724
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:2694
Abstract information about a function or function prototype.
Definition: CGCall.h:44
SourceLocation getLocation() const
Definition: DeclBase.h:429
static std::pair< BlockCaptureEntityKind, BlockFieldFlags > computeDestroyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T, const LangOptions &LangOpts)
Definition: CGBlocks.cpp:2141
bool isExternallyVisible() const
Definition: Decl.h:362
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:1080
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1556