clang  9.0.0svn
CGBlocks.cpp
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1 //===--- CGBlocks.cpp - Emit LLVM Code for declarations ---------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This contains code to emit blocks.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "CGBlocks.h"
14 #include "CGCXXABI.h"
15 #include "CGDebugInfo.h"
16 #include "CGObjCRuntime.h"
17 #include "CGOpenCLRuntime.h"
18 #include "CodeGenFunction.h"
19 #include "CodeGenModule.h"
20 #include "ConstantEmitter.h"
21 #include "TargetInfo.h"
22 #include "clang/AST/DeclObjC.h"
24 #include "llvm/ADT/SmallSet.h"
25 #include "llvm/IR/DataLayout.h"
26 #include "llvm/IR/Module.h"
27 #include "llvm/Support/ScopedPrinter.h"
28 #include <algorithm>
29 #include <cstdio>
30 
31 using namespace clang;
32 using namespace CodeGen;
33 
34 CGBlockInfo::CGBlockInfo(const BlockDecl *block, StringRef name)
35  : Name(name), CXXThisIndex(0), CanBeGlobal(false), NeedsCopyDispose(false),
36  HasCXXObject(false), UsesStret(false), HasCapturedVariableLayout(false),
37  CapturesNonExternalType(false), LocalAddress(Address::invalid()),
38  StructureType(nullptr), Block(block), DominatingIP(nullptr) {
39 
40  // Skip asm prefix, if any. 'name' is usually taken directly from
41  // the mangled name of the enclosing function.
42  if (!name.empty() && name[0] == '\01')
43  name = name.substr(1);
44 }
45 
46 // Anchor the vtable to this translation unit.
48 
49 /// Build the given block as a global block.
50 static llvm::Constant *buildGlobalBlock(CodeGenModule &CGM,
51  const CGBlockInfo &blockInfo,
52  llvm::Constant *blockFn);
53 
54 /// Build the helper function to copy a block.
55 static llvm::Constant *buildCopyHelper(CodeGenModule &CGM,
56  const CGBlockInfo &blockInfo) {
57  return CodeGenFunction(CGM).GenerateCopyHelperFunction(blockInfo);
58 }
59 
60 /// Build the helper function to dispose of a block.
61 static llvm::Constant *buildDisposeHelper(CodeGenModule &CGM,
62  const CGBlockInfo &blockInfo) {
63  return CodeGenFunction(CGM).GenerateDestroyHelperFunction(blockInfo);
64 }
65 
66 namespace {
67 
68 /// Represents a type of copy/destroy operation that should be performed for an
69 /// entity that's captured by a block.
71  CXXRecord, // Copy or destroy
72  ARCWeak,
73  ARCStrong,
74  NonTrivialCStruct,
75  BlockObject, // Assign or release
76  None
77 };
78 
79 /// Represents a captured entity that requires extra operations in order for
80 /// this entity to be copied or destroyed correctly.
81 struct BlockCaptureManagedEntity {
82  BlockCaptureEntityKind CopyKind, DisposeKind;
83  BlockFieldFlags CopyFlags, DisposeFlags;
84  const BlockDecl::Capture *CI;
86 
87  BlockCaptureManagedEntity(BlockCaptureEntityKind CopyType,
88  BlockCaptureEntityKind DisposeType,
89  BlockFieldFlags CopyFlags,
90  BlockFieldFlags DisposeFlags,
91  const BlockDecl::Capture &CI,
92  const CGBlockInfo::Capture &Capture)
93  : CopyKind(CopyType), DisposeKind(DisposeType), CopyFlags(CopyFlags),
94  DisposeFlags(DisposeFlags), CI(&CI), Capture(&Capture) {}
95 
96  bool operator<(const BlockCaptureManagedEntity &Other) const {
97  return Capture->getOffset() < Other.Capture->getOffset();
98  }
99 };
100 
101 enum class CaptureStrKind {
102  // String for the copy helper.
103  CopyHelper,
104  // String for the dispose helper.
105  DisposeHelper,
106  // Merge the strings for the copy helper and dispose helper.
107  Merged
108 };
109 
110 } // end anonymous namespace
111 
113  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
114  SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures);
115 
116 static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
117  CaptureStrKind StrKind,
118  CharUnits BlockAlignment,
119  CodeGenModule &CGM);
120 
121 static std::string getBlockDescriptorName(const CGBlockInfo &BlockInfo,
122  CodeGenModule &CGM) {
123  std::string Name = "__block_descriptor_";
124  Name += llvm::to_string(BlockInfo.BlockSize.getQuantity()) + "_";
125 
126  if (BlockInfo.needsCopyDisposeHelpers()) {
127  if (CGM.getLangOpts().Exceptions)
128  Name += "e";
129  if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
130  Name += "a";
131  Name += llvm::to_string(BlockInfo.BlockAlign.getQuantity()) + "_";
132 
135  ManagedCaptures);
136 
137  for (const BlockCaptureManagedEntity &E : ManagedCaptures) {
138  Name += llvm::to_string(E.Capture->getOffset().getQuantity());
139 
140  if (E.CopyKind == E.DisposeKind) {
141  // If CopyKind and DisposeKind are the same, merge the capture
142  // information.
143  assert(E.CopyKind != BlockCaptureEntityKind::None &&
144  "shouldn't see BlockCaptureManagedEntity that is None");
145  Name += getBlockCaptureStr(E, CaptureStrKind::Merged,
146  BlockInfo.BlockAlign, CGM);
147  } else {
148  // If CopyKind and DisposeKind are not the same, which can happen when
149  // either Kind is None or the captured object is a __strong block,
150  // concatenate the copy and dispose strings.
151  Name += getBlockCaptureStr(E, CaptureStrKind::CopyHelper,
152  BlockInfo.BlockAlign, CGM);
153  Name += getBlockCaptureStr(E, CaptureStrKind::DisposeHelper,
154  BlockInfo.BlockAlign, CGM);
155  }
156  }
157  Name += "_";
158  }
159 
160  std::string TypeAtEncoding =
162  /// Replace occurrences of '@' with '\1'. '@' is reserved on ELF platforms as
163  /// a separator between symbol name and symbol version.
164  std::replace(TypeAtEncoding.begin(), TypeAtEncoding.end(), '@', '\1');
165  Name += "e" + llvm::to_string(TypeAtEncoding.size()) + "_" + TypeAtEncoding;
166  Name += "l" + CGM.getObjCRuntime().getRCBlockLayoutStr(CGM, BlockInfo);
167  return Name;
168 }
169 
170 /// buildBlockDescriptor - Build the block descriptor meta-data for a block.
171 /// buildBlockDescriptor is accessed from 5th field of the Block_literal
172 /// meta-data and contains stationary information about the block literal.
173 /// Its definition will have 4 (or optionally 6) words.
174 /// \code
175 /// struct Block_descriptor {
176 /// unsigned long reserved;
177 /// unsigned long size; // size of Block_literal metadata in bytes.
178 /// void *copy_func_helper_decl; // optional copy helper.
179 /// void *destroy_func_decl; // optional destructor helper.
180 /// void *block_method_encoding_address; // @encode for block literal signature.
181 /// void *block_layout_info; // encoding of captured block variables.
182 /// };
183 /// \endcode
184 static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
185  const CGBlockInfo &blockInfo) {
186  ASTContext &C = CGM.getContext();
187 
188  llvm::IntegerType *ulong =
189  cast<llvm::IntegerType>(CGM.getTypes().ConvertType(C.UnsignedLongTy));
190  llvm::PointerType *i8p = nullptr;
191  if (CGM.getLangOpts().OpenCL)
192  i8p =
193  llvm::Type::getInt8PtrTy(
195  else
196  i8p = CGM.VoidPtrTy;
197 
198  std::string descName;
199 
200  // If an equivalent block descriptor global variable exists, return it.
201  if (C.getLangOpts().ObjC &&
202  CGM.getLangOpts().getGC() == LangOptions::NonGC) {
203  descName = getBlockDescriptorName(blockInfo, CGM);
204  if (llvm::GlobalValue *desc = CGM.getModule().getNamedValue(descName))
205  return llvm::ConstantExpr::getBitCast(desc,
206  CGM.getBlockDescriptorType());
207  }
208 
209  // If there isn't an equivalent block descriptor global variable, create a new
210  // one.
211  ConstantInitBuilder builder(CGM);
212  auto elements = builder.beginStruct();
213 
214  // reserved
215  elements.addInt(ulong, 0);
216 
217  // Size
218  // FIXME: What is the right way to say this doesn't fit? We should give
219  // a user diagnostic in that case. Better fix would be to change the
220  // API to size_t.
221  elements.addInt(ulong, blockInfo.BlockSize.getQuantity());
222 
223  // Optional copy/dispose helpers.
224  bool hasInternalHelper = false;
225  if (blockInfo.needsCopyDisposeHelpers()) {
226  // copy_func_helper_decl
227  llvm::Constant *copyHelper = buildCopyHelper(CGM, blockInfo);
228  elements.add(copyHelper);
229 
230  // destroy_func_decl
231  llvm::Constant *disposeHelper = buildDisposeHelper(CGM, blockInfo);
232  elements.add(disposeHelper);
233 
234  if (cast<llvm::Function>(copyHelper->getOperand(0))->hasInternalLinkage() ||
235  cast<llvm::Function>(disposeHelper->getOperand(0))
236  ->hasInternalLinkage())
237  hasInternalHelper = true;
238  }
239 
240  // Signature. Mandatory ObjC-style method descriptor @encode sequence.
241  std::string typeAtEncoding =
243  elements.add(llvm::ConstantExpr::getBitCast(
244  CGM.GetAddrOfConstantCString(typeAtEncoding).getPointer(), i8p));
245 
246  // GC layout.
247  if (C.getLangOpts().ObjC) {
248  if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
249  elements.add(CGM.getObjCRuntime().BuildGCBlockLayout(CGM, blockInfo));
250  else
251  elements.add(CGM.getObjCRuntime().BuildRCBlockLayout(CGM, blockInfo));
252  }
253  else
254  elements.addNullPointer(i8p);
255 
256  unsigned AddrSpace = 0;
257  if (C.getLangOpts().OpenCL)
259 
260  llvm::GlobalValue::LinkageTypes linkage;
261  if (descName.empty()) {
263  descName = "__block_descriptor_tmp";
264  } else if (hasInternalHelper) {
265  // If either the copy helper or the dispose helper has internal linkage,
266  // the block descriptor must have internal linkage too.
268  } else {
269  linkage = llvm::GlobalValue::LinkOnceODRLinkage;
270  }
271 
272  llvm::GlobalVariable *global =
273  elements.finishAndCreateGlobal(descName, CGM.getPointerAlign(),
274  /*constant*/ true, linkage, AddrSpace);
275 
276  if (linkage == llvm::GlobalValue::LinkOnceODRLinkage) {
277  if (CGM.supportsCOMDAT())
278  global->setComdat(CGM.getModule().getOrInsertComdat(descName));
279  global->setVisibility(llvm::GlobalValue::HiddenVisibility);
280  global->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
281  }
282 
283  return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
284 }
285 
286 /*
287  Purely notional variadic template describing the layout of a block.
288 
289  template <class _ResultType, class... _ParamTypes, class... _CaptureTypes>
290  struct Block_literal {
291  /// Initialized to one of:
292  /// extern void *_NSConcreteStackBlock[];
293  /// extern void *_NSConcreteGlobalBlock[];
294  ///
295  /// In theory, we could start one off malloc'ed by setting
296  /// BLOCK_NEEDS_FREE, giving it a refcount of 1, and using
297  /// this isa:
298  /// extern void *_NSConcreteMallocBlock[];
299  struct objc_class *isa;
300 
301  /// These are the flags (with corresponding bit number) that the
302  /// compiler is actually supposed to know about.
303  /// 23. BLOCK_IS_NOESCAPE - indicates that the block is non-escaping
304  /// 25. BLOCK_HAS_COPY_DISPOSE - indicates that the block
305  /// descriptor provides copy and dispose helper functions
306  /// 26. BLOCK_HAS_CXX_OBJ - indicates that there's a captured
307  /// object with a nontrivial destructor or copy constructor
308  /// 28. BLOCK_IS_GLOBAL - indicates that the block is allocated
309  /// as global memory
310  /// 29. BLOCK_USE_STRET - indicates that the block function
311  /// uses stret, which objc_msgSend needs to know about
312  /// 30. BLOCK_HAS_SIGNATURE - indicates that the block has an
313  /// @encoded signature string
314  /// And we're not supposed to manipulate these:
315  /// 24. BLOCK_NEEDS_FREE - indicates that the block has been moved
316  /// to malloc'ed memory
317  /// 27. BLOCK_IS_GC - indicates that the block has been moved to
318  /// to GC-allocated memory
319  /// Additionally, the bottom 16 bits are a reference count which
320  /// should be zero on the stack.
321  int flags;
322 
323  /// Reserved; should be zero-initialized.
324  int reserved;
325 
326  /// Function pointer generated from block literal.
327  _ResultType (*invoke)(Block_literal *, _ParamTypes...);
328 
329  /// Block description metadata generated from block literal.
330  struct Block_descriptor *block_descriptor;
331 
332  /// Captured values follow.
333  _CapturesTypes captures...;
334  };
335  */
336 
337 namespace {
338  /// A chunk of data that we actually have to capture in the block.
339  struct BlockLayoutChunk {
340  CharUnits Alignment;
341  CharUnits Size;
342  Qualifiers::ObjCLifetime Lifetime;
343  const BlockDecl::Capture *Capture; // null for 'this'
344  llvm::Type *Type;
345  QualType FieldType;
346 
347  BlockLayoutChunk(CharUnits align, CharUnits size,
348  Qualifiers::ObjCLifetime lifetime,
349  const BlockDecl::Capture *capture,
350  llvm::Type *type, QualType fieldType)
351  : Alignment(align), Size(size), Lifetime(lifetime),
352  Capture(capture), Type(type), FieldType(fieldType) {}
353 
354  /// Tell the block info that this chunk has the given field index.
355  void setIndex(CGBlockInfo &info, unsigned index, CharUnits offset) {
356  if (!Capture) {
357  info.CXXThisIndex = index;
358  info.CXXThisOffset = offset;
359  } else {
360  auto C = CGBlockInfo::Capture::makeIndex(index, offset, FieldType);
361  info.Captures.insert({Capture->getVariable(), C});
362  }
363  }
364  };
365 
366  /// Order by 1) all __strong together 2) next, all byfref together 3) next,
367  /// all __weak together. Preserve descending alignment in all situations.
368  bool operator<(const BlockLayoutChunk &left, const BlockLayoutChunk &right) {
369  if (left.Alignment != right.Alignment)
370  return left.Alignment > right.Alignment;
371 
372  auto getPrefOrder = [](const BlockLayoutChunk &chunk) {
373  if (chunk.Capture && chunk.Capture->isByRef())
374  return 1;
375  if (chunk.Lifetime == Qualifiers::OCL_Strong)
376  return 0;
377  if (chunk.Lifetime == Qualifiers::OCL_Weak)
378  return 2;
379  return 3;
380  };
381 
382  return getPrefOrder(left) < getPrefOrder(right);
383  }
384 } // end anonymous namespace
385 
386 /// Determines if the given type is safe for constant capture in C++.
388  const RecordType *recordType =
390 
391  // Only records can be unsafe.
392  if (!recordType) return true;
393 
394  const auto *record = cast<CXXRecordDecl>(recordType->getDecl());
395 
396  // Maintain semantics for classes with non-trivial dtors or copy ctors.
397  if (!record->hasTrivialDestructor()) return false;
398  if (record->hasNonTrivialCopyConstructor()) return false;
399 
400  // Otherwise, we just have to make sure there aren't any mutable
401  // fields that might have changed since initialization.
402  return !record->hasMutableFields();
403 }
404 
405 /// It is illegal to modify a const object after initialization.
406 /// Therefore, if a const object has a constant initializer, we don't
407 /// actually need to keep storage for it in the block; we'll just
408 /// rematerialize it at the start of the block function. This is
409 /// acceptable because we make no promises about address stability of
410 /// captured variables.
411 static llvm::Constant *tryCaptureAsConstant(CodeGenModule &CGM,
412  CodeGenFunction *CGF,
413  const VarDecl *var) {
414  // Return if this is a function parameter. We shouldn't try to
415  // rematerialize default arguments of function parameters.
416  if (isa<ParmVarDecl>(var))
417  return nullptr;
418 
419  QualType type = var->getType();
420 
421  // We can only do this if the variable is const.
422  if (!type.isConstQualified()) return nullptr;
423 
424  // Furthermore, in C++ we have to worry about mutable fields:
425  // C++ [dcl.type.cv]p4:
426  // Except that any class member declared mutable can be
427  // modified, any attempt to modify a const object during its
428  // lifetime results in undefined behavior.
429  if (CGM.getLangOpts().CPlusPlus && !isSafeForCXXConstantCapture(type))
430  return nullptr;
431 
432  // If the variable doesn't have any initializer (shouldn't this be
433  // invalid?), it's not clear what we should do. Maybe capture as
434  // zero?
435  const Expr *init = var->getInit();
436  if (!init) return nullptr;
437 
438  return ConstantEmitter(CGM, CGF).tryEmitAbstractForInitializer(*var);
439 }
440 
441 /// Get the low bit of a nonzero character count. This is the
442 /// alignment of the nth byte if the 0th byte is universally aligned.
444  return CharUnits::fromQuantity(v.getQuantity() & (~v.getQuantity() + 1));
445 }
446 
448  SmallVectorImpl<llvm::Type*> &elementTypes) {
449 
450  assert(elementTypes.empty());
451  if (CGM.getLangOpts().OpenCL) {
452  // The header is basically 'struct { int; int; generic void *;
453  // custom_fields; }'. Assert that struct is packed.
454  auto GenericAS =
456  auto GenPtrAlign =
457  CharUnits::fromQuantity(CGM.getTarget().getPointerAlign(GenericAS) / 8);
458  auto GenPtrSize =
459  CharUnits::fromQuantity(CGM.getTarget().getPointerWidth(GenericAS) / 8);
460  assert(CGM.getIntSize() <= GenPtrSize);
461  assert(CGM.getIntAlign() <= GenPtrAlign);
462  assert((2 * CGM.getIntSize()).isMultipleOf(GenPtrAlign));
463  elementTypes.push_back(CGM.IntTy); /* total size */
464  elementTypes.push_back(CGM.IntTy); /* align */
465  elementTypes.push_back(
466  CGM.getOpenCLRuntime()
467  .getGenericVoidPointerType()); /* invoke function */
468  unsigned Offset =
469  2 * CGM.getIntSize().getQuantity() + GenPtrSize.getQuantity();
470  unsigned BlockAlign = GenPtrAlign.getQuantity();
471  if (auto *Helper =
473  for (auto I : Helper->getCustomFieldTypes()) /* custom fields */ {
474  // TargetOpenCLBlockHelp needs to make sure the struct is packed.
475  // If necessary, add padding fields to the custom fields.
476  unsigned Align = CGM.getDataLayout().getABITypeAlignment(I);
477  if (BlockAlign < Align)
478  BlockAlign = Align;
479  assert(Offset % Align == 0);
480  Offset += CGM.getDataLayout().getTypeAllocSize(I);
481  elementTypes.push_back(I);
482  }
483  }
484  info.BlockAlign = CharUnits::fromQuantity(BlockAlign);
485  info.BlockSize = CharUnits::fromQuantity(Offset);
486  } else {
487  // The header is basically 'struct { void *; int; int; void *; void *; }'.
488  // Assert that the struct is packed.
489  assert(CGM.getIntSize() <= CGM.getPointerSize());
490  assert(CGM.getIntAlign() <= CGM.getPointerAlign());
491  assert((2 * CGM.getIntSize()).isMultipleOf(CGM.getPointerAlign()));
492  info.BlockAlign = CGM.getPointerAlign();
493  info.BlockSize = 3 * CGM.getPointerSize() + 2 * CGM.getIntSize();
494  elementTypes.push_back(CGM.VoidPtrTy);
495  elementTypes.push_back(CGM.IntTy);
496  elementTypes.push_back(CGM.IntTy);
497  elementTypes.push_back(CGM.VoidPtrTy);
498  elementTypes.push_back(CGM.getBlockDescriptorType());
499  }
500 }
501 
503  const BlockDecl::Capture &CI) {
504  const VarDecl *VD = CI.getVariable();
505 
506  // If the variable is captured by an enclosing block or lambda expression,
507  // use the type of the capture field.
508  if (CGF.BlockInfo && CI.isNested())
509  return CGF.BlockInfo->getCapture(VD).fieldType();
510  if (auto *FD = CGF.LambdaCaptureFields.lookup(VD))
511  return FD->getType();
512  // If the captured variable is a non-escaping __block variable, the field
513  // type is the reference type. If the variable is a __block variable that
514  // already has a reference type, the field type is the variable's type.
515  return VD->isNonEscapingByref() ?
516  CGF.getContext().getLValueReferenceType(VD->getType()) : VD->getType();
517 }
518 
519 /// Compute the layout of the given block. Attempts to lay the block
520 /// out with minimal space requirements.
522  CGBlockInfo &info) {
523  ASTContext &C = CGM.getContext();
524  const BlockDecl *block = info.getBlockDecl();
525 
526  SmallVector<llvm::Type*, 8> elementTypes;
527  initializeForBlockHeader(CGM, info, elementTypes);
528  bool hasNonConstantCustomFields = false;
529  if (auto *OpenCLHelper =
531  hasNonConstantCustomFields =
532  !OpenCLHelper->areAllCustomFieldValuesConstant(info);
533  if (!block->hasCaptures() && !hasNonConstantCustomFields) {
534  info.StructureType =
535  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
536  info.CanBeGlobal = true;
537  return;
538  }
539  else if (C.getLangOpts().ObjC &&
540  CGM.getLangOpts().getGC() == LangOptions::NonGC)
541  info.HasCapturedVariableLayout = true;
542 
543  // Collect the layout chunks.
545  layout.reserve(block->capturesCXXThis() +
546  (block->capture_end() - block->capture_begin()));
547 
548  CharUnits maxFieldAlign;
549 
550  // First, 'this'.
551  if (block->capturesCXXThis()) {
552  assert(CGF && CGF->CurFuncDecl && isa<CXXMethodDecl>(CGF->CurFuncDecl) &&
553  "Can't capture 'this' outside a method");
554  QualType thisType = cast<CXXMethodDecl>(CGF->CurFuncDecl)->getThisType();
555 
556  // Theoretically, this could be in a different address space, so
557  // don't assume standard pointer size/align.
558  llvm::Type *llvmType = CGM.getTypes().ConvertType(thisType);
559  std::pair<CharUnits,CharUnits> tinfo
560  = CGM.getContext().getTypeInfoInChars(thisType);
561  maxFieldAlign = std::max(maxFieldAlign, tinfo.second);
562 
563  layout.push_back(BlockLayoutChunk(tinfo.second, tinfo.first,
565  nullptr, llvmType, thisType));
566  }
567 
568  // Next, all the block captures.
569  for (const auto &CI : block->captures()) {
570  const VarDecl *variable = CI.getVariable();
571 
572  if (CI.isEscapingByref()) {
573  // We have to copy/dispose of the __block reference.
574  info.NeedsCopyDispose = true;
575 
576  // Just use void* instead of a pointer to the byref type.
577  CharUnits align = CGM.getPointerAlign();
578  maxFieldAlign = std::max(maxFieldAlign, align);
579 
580  // Since a __block variable cannot be captured by lambdas, its type and
581  // the capture field type should always match.
582  assert(getCaptureFieldType(*CGF, CI) == variable->getType() &&
583  "capture type differs from the variable type");
584  layout.push_back(BlockLayoutChunk(align, CGM.getPointerSize(),
586  CGM.VoidPtrTy, variable->getType()));
587  continue;
588  }
589 
590  // Otherwise, build a layout chunk with the size and alignment of
591  // the declaration.
592  if (llvm::Constant *constant = tryCaptureAsConstant(CGM, CGF, variable)) {
593  info.Captures[variable] = CGBlockInfo::Capture::makeConstant(constant);
594  continue;
595  }
596 
597  QualType VT = getCaptureFieldType(*CGF, CI);
598 
599  // If we have a lifetime qualifier, honor it for capture purposes.
600  // That includes *not* copying it if it's __unsafe_unretained.
602  if (lifetime) {
603  switch (lifetime) {
604  case Qualifiers::OCL_None: llvm_unreachable("impossible");
607  break;
608 
611  info.NeedsCopyDispose = true;
612  }
613 
614  // Block pointers require copy/dispose. So do Objective-C pointers.
615  } else if (VT->isObjCRetainableType()) {
616  // But honor the inert __unsafe_unretained qualifier, which doesn't
617  // actually make it into the type system.
619  lifetime = Qualifiers::OCL_ExplicitNone;
620  } else {
621  info.NeedsCopyDispose = true;
622  // used for mrr below.
623  lifetime = Qualifiers::OCL_Strong;
624  }
625 
626  // So do types that require non-trivial copy construction.
627  } else if (CI.hasCopyExpr()) {
628  info.NeedsCopyDispose = true;
629  info.HasCXXObject = true;
631  info.CapturesNonExternalType = true;
632 
633  // So do C structs that require non-trivial copy construction or
634  // destruction.
637  info.NeedsCopyDispose = true;
638 
639  // And so do types with destructors.
640  } else if (CGM.getLangOpts().CPlusPlus) {
641  if (const CXXRecordDecl *record = VT->getAsCXXRecordDecl()) {
642  if (!record->hasTrivialDestructor()) {
643  info.HasCXXObject = true;
644  info.NeedsCopyDispose = true;
645  if (!record->isExternallyVisible())
646  info.CapturesNonExternalType = true;
647  }
648  }
649  }
650 
651  CharUnits size = C.getTypeSizeInChars(VT);
652  CharUnits align = C.getDeclAlign(variable);
653 
654  maxFieldAlign = std::max(maxFieldAlign, align);
655 
656  llvm::Type *llvmType =
657  CGM.getTypes().ConvertTypeForMem(VT);
658 
659  layout.push_back(
660  BlockLayoutChunk(align, size, lifetime, &CI, llvmType, VT));
661  }
662 
663  // If that was everything, we're done here.
664  if (layout.empty()) {
665  info.StructureType =
666  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
667  info.CanBeGlobal = true;
668  return;
669  }
670 
671  // Sort the layout by alignment. We have to use a stable sort here
672  // to get reproducible results. There should probably be an
673  // llvm::array_pod_stable_sort.
674  llvm::stable_sort(layout);
675 
676  // Needed for blocks layout info.
679 
680  CharUnits &blockSize = info.BlockSize;
681  info.BlockAlign = std::max(maxFieldAlign, info.BlockAlign);
682 
683  // Assuming that the first byte in the header is maximally aligned,
684  // get the alignment of the first byte following the header.
685  CharUnits endAlign = getLowBit(blockSize);
686 
687  // If the end of the header isn't satisfactorily aligned for the
688  // maximum thing, look for things that are okay with the header-end
689  // alignment, and keep appending them until we get something that's
690  // aligned right. This algorithm is only guaranteed optimal if
691  // that condition is satisfied at some point; otherwise we can get
692  // things like:
693  // header // next byte has alignment 4
694  // something_with_size_5; // next byte has alignment 1
695  // something_with_alignment_8;
696  // which has 7 bytes of padding, as opposed to the naive solution
697  // which might have less (?).
698  if (endAlign < maxFieldAlign) {
699  SmallVectorImpl<BlockLayoutChunk>::iterator
700  li = layout.begin() + 1, le = layout.end();
701 
702  // Look for something that the header end is already
703  // satisfactorily aligned for.
704  for (; li != le && endAlign < li->Alignment; ++li)
705  ;
706 
707  // If we found something that's naturally aligned for the end of
708  // the header, keep adding things...
709  if (li != le) {
710  SmallVectorImpl<BlockLayoutChunk>::iterator first = li;
711  for (; li != le; ++li) {
712  assert(endAlign >= li->Alignment);
713 
714  li->setIndex(info, elementTypes.size(), blockSize);
715  elementTypes.push_back(li->Type);
716  blockSize += li->Size;
717  endAlign = getLowBit(blockSize);
718 
719  // ...until we get to the alignment of the maximum field.
720  if (endAlign >= maxFieldAlign) {
721  break;
722  }
723  }
724  // Don't re-append everything we just appended.
725  layout.erase(first, li);
726  }
727  }
728 
729  assert(endAlign == getLowBit(blockSize));
730 
731  // At this point, we just have to add padding if the end align still
732  // isn't aligned right.
733  if (endAlign < maxFieldAlign) {
734  CharUnits newBlockSize = blockSize.alignTo(maxFieldAlign);
735  CharUnits padding = newBlockSize - blockSize;
736 
737  // If we haven't yet added any fields, remember that there was an
738  // initial gap; this need to go into the block layout bit map.
739  if (blockSize == info.BlockHeaderForcedGapOffset) {
740  info.BlockHeaderForcedGapSize = padding;
741  }
742 
743  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
744  padding.getQuantity()));
745  blockSize = newBlockSize;
746  endAlign = getLowBit(blockSize); // might be > maxFieldAlign
747  }
748 
749  assert(endAlign >= maxFieldAlign);
750  assert(endAlign == getLowBit(blockSize));
751  // Slam everything else on now. This works because they have
752  // strictly decreasing alignment and we expect that size is always a
753  // multiple of alignment.
754  for (SmallVectorImpl<BlockLayoutChunk>::iterator
755  li = layout.begin(), le = layout.end(); li != le; ++li) {
756  if (endAlign < li->Alignment) {
757  // size may not be multiple of alignment. This can only happen with
758  // an over-aligned variable. We will be adding a padding field to
759  // make the size be multiple of alignment.
760  CharUnits padding = li->Alignment - endAlign;
761  elementTypes.push_back(llvm::ArrayType::get(CGM.Int8Ty,
762  padding.getQuantity()));
763  blockSize += padding;
764  endAlign = getLowBit(blockSize);
765  }
766  assert(endAlign >= li->Alignment);
767  li->setIndex(info, elementTypes.size(), blockSize);
768  elementTypes.push_back(li->Type);
769  blockSize += li->Size;
770  endAlign = getLowBit(blockSize);
771  }
772 
773  info.StructureType =
774  llvm::StructType::get(CGM.getLLVMContext(), elementTypes, true);
775 }
776 
777 /// Enter the scope of a block. This should be run at the entrance to
778 /// a full-expression so that the block's cleanups are pushed at the
779 /// right place in the stack.
780 static void enterBlockScope(CodeGenFunction &CGF, BlockDecl *block) {
781  assert(CGF.HaveInsertPoint());
782 
783  // Allocate the block info and place it at the head of the list.
784  CGBlockInfo &blockInfo =
785  *new CGBlockInfo(block, CGF.CurFn->getName());
786  blockInfo.NextBlockInfo = CGF.FirstBlockInfo;
787  CGF.FirstBlockInfo = &blockInfo;
788 
789  // Compute information about the layout, etc., of this block,
790  // pushing cleanups as necessary.
791  computeBlockInfo(CGF.CGM, &CGF, blockInfo);
792 
793  // Nothing else to do if it can be global.
794  if (blockInfo.CanBeGlobal) return;
795 
796  // Make the allocation for the block.
797  blockInfo.LocalAddress = CGF.CreateTempAlloca(blockInfo.StructureType,
798  blockInfo.BlockAlign, "block");
799 
800  // If there are cleanups to emit, enter them (but inactive).
801  if (!blockInfo.NeedsCopyDispose) return;
802 
803  // Walk through the captures (in order) and find the ones not
804  // captured by constant.
805  for (const auto &CI : block->captures()) {
806  // Ignore __block captures; there's nothing special in the
807  // on-stack block that we need to do for them.
808  if (CI.isByRef()) continue;
809 
810  // Ignore variables that are constant-captured.
811  const VarDecl *variable = CI.getVariable();
812  CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
813  if (capture.isConstant()) continue;
814 
815  // Ignore objects that aren't destructed.
816  QualType VT = getCaptureFieldType(CGF, CI);
818  if (dtorKind == QualType::DK_none) continue;
819 
820  CodeGenFunction::Destroyer *destroyer;
821 
822  // Block captures count as local values and have imprecise semantics.
823  // They also can't be arrays, so need to worry about that.
824  //
825  // For const-qualified captures, emit clang.arc.use to ensure the captured
826  // object doesn't get released while we are still depending on its validity
827  // within the block.
828  if (VT.isConstQualified() &&
830  CGF.CGM.getCodeGenOpts().OptimizationLevel != 0) {
831  assert(CGF.CGM.getLangOpts().ObjCAutoRefCount &&
832  "expected ObjC ARC to be enabled");
834  } else if (dtorKind == QualType::DK_objc_strong_lifetime) {
836  } else {
837  destroyer = CGF.getDestroyer(dtorKind);
838  }
839 
840  // GEP down to the address.
841  Address addr =
842  CGF.Builder.CreateStructGEP(blockInfo.LocalAddress, capture.getIndex());
843 
844  // We can use that GEP as the dominating IP.
845  if (!blockInfo.DominatingIP)
846  blockInfo.DominatingIP = cast<llvm::Instruction>(addr.getPointer());
847 
848  CleanupKind cleanupKind = InactiveNormalCleanup;
849  bool useArrayEHCleanup = CGF.needsEHCleanup(dtorKind);
850  if (useArrayEHCleanup)
851  cleanupKind = InactiveNormalAndEHCleanup;
852 
853  CGF.pushDestroy(cleanupKind, addr, VT,
854  destroyer, useArrayEHCleanup);
855 
856  // Remember where that cleanup was.
857  capture.setCleanup(CGF.EHStack.stable_begin());
858  }
859 }
860 
861 /// Enter a full-expression with a non-trivial number of objects to
862 /// clean up. This is in this file because, at the moment, the only
863 /// kind of cleanup object is a BlockDecl*.
865  if (const auto EWC = dyn_cast<ExprWithCleanups>(E)) {
866  assert(EWC->getNumObjects() != 0);
867  for (const ExprWithCleanups::CleanupObject &C : EWC->getObjects())
868  enterBlockScope(*this, C);
869  }
870 }
871 
872 /// Find the layout for the given block in a linked list and remove it.
874  const BlockDecl *block) {
875  while (true) {
876  assert(head && *head);
877  CGBlockInfo *cur = *head;
878 
879  // If this is the block we're looking for, splice it out of the list.
880  if (cur->getBlockDecl() == block) {
881  *head = cur->NextBlockInfo;
882  return cur;
883  }
884 
885  head = &cur->NextBlockInfo;
886  }
887 }
888 
889 /// Destroy a chain of block layouts.
891  assert(head && "destroying an empty chain");
892  do {
893  CGBlockInfo *cur = head;
894  head = cur->NextBlockInfo;
895  delete cur;
896  } while (head != nullptr);
897 }
898 
899 /// Emit a block literal expression in the current function.
901  // If the block has no captures, we won't have a pre-computed
902  // layout for it.
903  if (!blockExpr->getBlockDecl()->hasCaptures()) {
904  // The block literal is emitted as a global variable, and the block invoke
905  // function has to be extracted from its initializer.
906  if (llvm::Constant *Block = CGM.getAddrOfGlobalBlockIfEmitted(blockExpr)) {
907  return Block;
908  }
909  CGBlockInfo blockInfo(blockExpr->getBlockDecl(), CurFn->getName());
910  computeBlockInfo(CGM, this, blockInfo);
911  blockInfo.BlockExpression = blockExpr;
912  return EmitBlockLiteral(blockInfo);
913  }
914 
915  // Find the block info for this block and take ownership of it.
916  std::unique_ptr<CGBlockInfo> blockInfo;
917  blockInfo.reset(findAndRemoveBlockInfo(&FirstBlockInfo,
918  blockExpr->getBlockDecl()));
919 
920  blockInfo->BlockExpression = blockExpr;
921  return EmitBlockLiteral(*blockInfo);
922 }
923 
925  bool IsOpenCL = CGM.getContext().getLangOpts().OpenCL;
926  auto GenVoidPtrTy =
927  IsOpenCL ? CGM.getOpenCLRuntime().getGenericVoidPointerType() : VoidPtrTy;
928  LangAS GenVoidPtrAddr = IsOpenCL ? LangAS::opencl_generic : LangAS::Default;
929  auto GenVoidPtrSize = CharUnits::fromQuantity(
931  CGM.getContext().getTargetAddressSpace(GenVoidPtrAddr)) /
932  8);
933  // Using the computed layout, generate the actual block function.
934  bool isLambdaConv = blockInfo.getBlockDecl()->isConversionFromLambda();
935  CodeGenFunction BlockCGF{CGM, true};
936  BlockCGF.SanOpts = SanOpts;
937  auto *InvokeFn = BlockCGF.GenerateBlockFunction(
938  CurGD, blockInfo, LocalDeclMap, isLambdaConv, blockInfo.CanBeGlobal);
939  auto *blockFn = llvm::ConstantExpr::getPointerCast(InvokeFn, GenVoidPtrTy);
940 
941  // If there is nothing to capture, we can emit this as a global block.
942  if (blockInfo.CanBeGlobal)
943  return CGM.getAddrOfGlobalBlockIfEmitted(blockInfo.BlockExpression);
944 
945  // Otherwise, we have to emit this as a local block.
946 
947  Address blockAddr = blockInfo.LocalAddress;
948  assert(blockAddr.isValid() && "block has no address!");
949 
950  llvm::Constant *isa;
951  llvm::Constant *descriptor;
952  BlockFlags flags;
953  if (!IsOpenCL) {
954  // If the block is non-escaping, set field 'isa 'to NSConcreteGlobalBlock
955  // and set the BLOCK_IS_GLOBAL bit of field 'flags'. Copying a non-escaping
956  // block just returns the original block and releasing it is a no-op.
957  llvm::Constant *blockISA = blockInfo.getBlockDecl()->doesNotEscape()
959  : CGM.getNSConcreteStackBlock();
960  isa = llvm::ConstantExpr::getBitCast(blockISA, VoidPtrTy);
961 
962  // Build the block descriptor.
963  descriptor = buildBlockDescriptor(CGM, blockInfo);
964 
965  // Compute the initial on-stack block flags.
966  flags = BLOCK_HAS_SIGNATURE;
967  if (blockInfo.HasCapturedVariableLayout)
968  flags |= BLOCK_HAS_EXTENDED_LAYOUT;
969  if (blockInfo.needsCopyDisposeHelpers())
970  flags |= BLOCK_HAS_COPY_DISPOSE;
971  if (blockInfo.HasCXXObject)
972  flags |= BLOCK_HAS_CXX_OBJ;
973  if (blockInfo.UsesStret)
974  flags |= BLOCK_USE_STRET;
975  if (blockInfo.getBlockDecl()->doesNotEscape())
977  }
978 
979  auto projectField = [&](unsigned index, const Twine &name) -> Address {
980  return Builder.CreateStructGEP(blockAddr, index, name);
981  };
982  auto storeField = [&](llvm::Value *value, unsigned index, const Twine &name) {
983  Builder.CreateStore(value, projectField(index, name));
984  };
985 
986  // Initialize the block header.
987  {
988  // We assume all the header fields are densely packed.
989  unsigned index = 0;
990  CharUnits offset;
991  auto addHeaderField = [&](llvm::Value *value, CharUnits size,
992  const Twine &name) {
993  storeField(value, index, name);
994  offset += size;
995  index++;
996  };
997 
998  if (!IsOpenCL) {
999  addHeaderField(isa, getPointerSize(), "block.isa");
1000  addHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
1001  getIntSize(), "block.flags");
1002  addHeaderField(llvm::ConstantInt::get(IntTy, 0), getIntSize(),
1003  "block.reserved");
1004  } else {
1005  addHeaderField(
1006  llvm::ConstantInt::get(IntTy, blockInfo.BlockSize.getQuantity()),
1007  getIntSize(), "block.size");
1008  addHeaderField(
1009  llvm::ConstantInt::get(IntTy, blockInfo.BlockAlign.getQuantity()),
1010  getIntSize(), "block.align");
1011  }
1012  addHeaderField(blockFn, GenVoidPtrSize, "block.invoke");
1013  if (!IsOpenCL)
1014  addHeaderField(descriptor, getPointerSize(), "block.descriptor");
1015  else if (auto *Helper =
1017  for (auto I : Helper->getCustomFieldValues(*this, blockInfo)) {
1018  addHeaderField(
1019  I.first,
1021  CGM.getDataLayout().getTypeAllocSize(I.first->getType())),
1022  I.second);
1023  }
1024  }
1025  }
1026 
1027  // Finally, capture all the values into the block.
1028  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1029 
1030  // First, 'this'.
1031  if (blockDecl->capturesCXXThis()) {
1032  Address addr =
1033  projectField(blockInfo.CXXThisIndex, "block.captured-this.addr");
1034  Builder.CreateStore(LoadCXXThis(), addr);
1035  }
1036 
1037  // Next, captured variables.
1038  for (const auto &CI : blockDecl->captures()) {
1039  const VarDecl *variable = CI.getVariable();
1040  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1041 
1042  // Ignore constant captures.
1043  if (capture.isConstant()) continue;
1044 
1045  QualType type = capture.fieldType();
1046 
1047  // This will be a [[type]]*, except that a byref entry will just be
1048  // an i8**.
1049  Address blockField = projectField(capture.getIndex(), "block.captured");
1050 
1051  // Compute the address of the thing we're going to move into the
1052  // block literal.
1053  Address src = Address::invalid();
1054 
1055  if (blockDecl->isConversionFromLambda()) {
1056  // The lambda capture in a lambda's conversion-to-block-pointer is
1057  // special; we'll simply emit it directly.
1058  src = Address::invalid();
1059  } else if (CI.isEscapingByref()) {
1060  if (BlockInfo && CI.isNested()) {
1061  // We need to use the capture from the enclosing block.
1062  const CGBlockInfo::Capture &enclosingCapture =
1063  BlockInfo->getCapture(variable);
1064 
1065  // This is a [[type]]*, except that a byref entry will just be an i8**.
1066  src = Builder.CreateStructGEP(LoadBlockStruct(),
1067  enclosingCapture.getIndex(),
1068  "block.capture.addr");
1069  } else {
1070  auto I = LocalDeclMap.find(variable);
1071  assert(I != LocalDeclMap.end());
1072  src = I->second;
1073  }
1074  } else {
1075  DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1076  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1078  SourceLocation());
1079  src = EmitDeclRefLValue(&declRef).getAddress();
1080  };
1081 
1082  // For byrefs, we just write the pointer to the byref struct into
1083  // the block field. There's no need to chase the forwarding
1084  // pointer at this point, since we're building something that will
1085  // live a shorter life than the stack byref anyway.
1086  if (CI.isEscapingByref()) {
1087  // Get a void* that points to the byref struct.
1088  llvm::Value *byrefPointer;
1089  if (CI.isNested())
1090  byrefPointer = Builder.CreateLoad(src, "byref.capture");
1091  else
1092  byrefPointer = Builder.CreateBitCast(src.getPointer(), VoidPtrTy);
1093 
1094  // Write that void* into the capture field.
1095  Builder.CreateStore(byrefPointer, blockField);
1096 
1097  // If we have a copy constructor, evaluate that into the block field.
1098  } else if (const Expr *copyExpr = CI.getCopyExpr()) {
1099  if (blockDecl->isConversionFromLambda()) {
1100  // If we have a lambda conversion, emit the expression
1101  // directly into the block instead.
1102  AggValueSlot Slot =
1103  AggValueSlot::forAddr(blockField, Qualifiers(),
1108  EmitAggExpr(copyExpr, Slot);
1109  } else {
1110  EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
1111  }
1112 
1113  // If it's a reference variable, copy the reference into the block field.
1114  } else if (type->isReferenceType()) {
1115  Builder.CreateStore(src.getPointer(), blockField);
1116 
1117  // If type is const-qualified, copy the value into the block field.
1118  } else if (type.isConstQualified() &&
1120  CGM.getCodeGenOpts().OptimizationLevel != 0) {
1121  llvm::Value *value = Builder.CreateLoad(src, "captured");
1122  Builder.CreateStore(value, blockField);
1123 
1124  // If this is an ARC __strong block-pointer variable, don't do a
1125  // block copy.
1126  //
1127  // TODO: this can be generalized into the normal initialization logic:
1128  // we should never need to do a block-copy when initializing a local
1129  // variable, because the local variable's lifetime should be strictly
1130  // contained within the stack block's.
1131  } else if (type.getObjCLifetime() == Qualifiers::OCL_Strong &&
1132  type->isBlockPointerType()) {
1133  // Load the block and do a simple retain.
1134  llvm::Value *value = Builder.CreateLoad(src, "block.captured_block");
1135  value = EmitARCRetainNonBlock(value);
1136 
1137  // Do a primitive store to the block field.
1138  Builder.CreateStore(value, blockField);
1139 
1140  // Otherwise, fake up a POD copy into the block field.
1141  } else {
1142  // Fake up a new variable so that EmitScalarInit doesn't think
1143  // we're referring to the variable in its own initializer.
1144  ImplicitParamDecl BlockFieldPseudoVar(getContext(), type,
1146 
1147  // We use one of these or the other depending on whether the
1148  // reference is nested.
1149  DeclRefExpr declRef(getContext(), const_cast<VarDecl *>(variable),
1150  /*RefersToEnclosingVariableOrCapture*/ CI.isNested(),
1152 
1153  ImplicitCastExpr l2r(ImplicitCastExpr::OnStack, type, CK_LValueToRValue,
1154  &declRef, VK_RValue);
1155  // FIXME: Pass a specific location for the expr init so that the store is
1156  // attributed to a reasonable location - otherwise it may be attributed to
1157  // locations of subexpressions in the initialization.
1158  EmitExprAsInit(&l2r, &BlockFieldPseudoVar,
1159  MakeAddrLValue(blockField, type, AlignmentSource::Decl),
1160  /*captured by init*/ false);
1161  }
1162 
1163  // Activate the cleanup if layout pushed one.
1164  if (!CI.isByRef()) {
1166  if (cleanup.isValid())
1167  ActivateCleanupBlock(cleanup, blockInfo.DominatingIP);
1168  }
1169  }
1170 
1171  // Cast to the converted block-pointer type, which happens (somewhat
1172  // unfortunately) to be a pointer to function type.
1173  llvm::Value *result = Builder.CreatePointerCast(
1174  blockAddr.getPointer(), ConvertType(blockInfo.getBlockExpr()->getType()));
1175 
1176  if (IsOpenCL) {
1177  CGM.getOpenCLRuntime().recordBlockInfo(blockInfo.BlockExpression, InvokeFn,
1178  result);
1179  }
1180 
1181  return result;
1182 }
1183 
1184 
1186  if (BlockDescriptorType)
1187  return BlockDescriptorType;
1188 
1189  llvm::Type *UnsignedLongTy =
1190  getTypes().ConvertType(getContext().UnsignedLongTy);
1191 
1192  // struct __block_descriptor {
1193  // unsigned long reserved;
1194  // unsigned long block_size;
1195  //
1196  // // later, the following will be added
1197  //
1198  // struct {
1199  // void (*copyHelper)();
1200  // void (*copyHelper)();
1201  // } helpers; // !!! optional
1202  //
1203  // const char *signature; // the block signature
1204  // const char *layout; // reserved
1205  // };
1206  BlockDescriptorType = llvm::StructType::create(
1207  "struct.__block_descriptor", UnsignedLongTy, UnsignedLongTy);
1208 
1209  // Now form a pointer to that.
1210  unsigned AddrSpace = 0;
1211  if (getLangOpts().OpenCL)
1212  AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
1213  BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
1214  return BlockDescriptorType;
1215 }
1216 
1218  if (GenericBlockLiteralType)
1219  return GenericBlockLiteralType;
1220 
1221  llvm::Type *BlockDescPtrTy = getBlockDescriptorType();
1222 
1223  if (getLangOpts().OpenCL) {
1224  // struct __opencl_block_literal_generic {
1225  // int __size;
1226  // int __align;
1227  // __generic void *__invoke;
1228  // /* custom fields */
1229  // };
1230  SmallVector<llvm::Type *, 8> StructFields(
1231  {IntTy, IntTy, getOpenCLRuntime().getGenericVoidPointerType()});
1232  if (auto *Helper = getTargetCodeGenInfo().getTargetOpenCLBlockHelper()) {
1233  for (auto I : Helper->getCustomFieldTypes())
1234  StructFields.push_back(I);
1235  }
1236  GenericBlockLiteralType = llvm::StructType::create(
1237  StructFields, "struct.__opencl_block_literal_generic");
1238  } else {
1239  // struct __block_literal_generic {
1240  // void *__isa;
1241  // int __flags;
1242  // int __reserved;
1243  // void (*__invoke)(void *);
1244  // struct __block_descriptor *__descriptor;
1245  // };
1246  GenericBlockLiteralType =
1247  llvm::StructType::create("struct.__block_literal_generic", VoidPtrTy,
1248  IntTy, IntTy, VoidPtrTy, BlockDescPtrTy);
1249  }
1250 
1251  return GenericBlockLiteralType;
1252 }
1253 
1255  ReturnValueSlot ReturnValue) {
1256  const BlockPointerType *BPT =
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().getDebugInfo() >=
1488  DI->setLocation(D->getLocation());
1489  DI->EmitDeclareOfBlockLiteralArgVariable(
1490  *BlockInfo, D->getName(), argNum,
1491  cast<llvm::AllocaInst>(alloc.getPointer()), Builder);
1492  }
1493  }
1494 
1495  SourceLocation StartLoc = BlockInfo->getBlockExpr()->getBody()->getBeginLoc();
1496  ApplyDebugLocation Scope(*this, StartLoc);
1497 
1498  // Instead of messing around with LocalDeclMap, just set the value
1499  // directly as BlockPointer.
1500  BlockPointer = Builder.CreatePointerCast(
1501  arg,
1502  BlockInfo->StructureType->getPointerTo(
1503  getContext().getLangOpts().OpenCL
1504  ? getContext().getTargetAddressSpace(LangAS::opencl_generic)
1505  : 0),
1506  "block");
1507 }
1508 
1510  assert(BlockInfo && "not in a block invocation function!");
1511  assert(BlockPointer && "no block pointer set!");
1512  return Address(BlockPointer, BlockInfo->BlockAlign);
1513 }
1514 
1515 llvm::Function *
1517  const CGBlockInfo &blockInfo,
1518  const DeclMapTy &ldm,
1519  bool IsLambdaConversionToBlock,
1520  bool BuildGlobalBlock) {
1521  const BlockDecl *blockDecl = blockInfo.getBlockDecl();
1522 
1523  CurGD = GD;
1524 
1525  CurEHLocation = blockInfo.getBlockExpr()->getEndLoc();
1526 
1527  BlockInfo = &blockInfo;
1528 
1529  // Arrange for local static and local extern declarations to appear
1530  // to be local to this function as well, in case they're directly
1531  // referenced in a block.
1532  for (DeclMapTy::const_iterator i = ldm.begin(), e = ldm.end(); i != e; ++i) {
1533  const auto *var = dyn_cast<VarDecl>(i->first);
1534  if (var && !var->hasLocalStorage())
1535  setAddrOfLocalVar(var, i->second);
1536  }
1537 
1538  // Begin building the function declaration.
1539 
1540  // Build the argument list.
1541  FunctionArgList args;
1542 
1543  // The first argument is the block pointer. Just take it as a void*
1544  // and cast it later.
1545  QualType selfTy = getContext().VoidPtrTy;
1546 
1547  // For OpenCL passed block pointer can be private AS local variable or
1548  // global AS program scope variable (for the case with and without captures).
1549  // Generic AS is used therefore to be able to accommodate both private and
1550  // generic AS in one implementation.
1551  if (getLangOpts().OpenCL)
1552  selfTy = getContext().getPointerType(getContext().getAddrSpaceQualType(
1553  getContext().VoidTy, LangAS::opencl_generic));
1554 
1555  IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
1556 
1557  ImplicitParamDecl SelfDecl(getContext(), const_cast<BlockDecl *>(blockDecl),
1558  SourceLocation(), II, selfTy,
1560  args.push_back(&SelfDecl);
1561 
1562  // Now add the rest of the parameters.
1563  args.append(blockDecl->param_begin(), blockDecl->param_end());
1564 
1565  // Create the function declaration.
1566  const FunctionProtoType *fnType = blockInfo.getBlockExpr()->getFunctionType();
1567  const CGFunctionInfo &fnInfo =
1568  CGM.getTypes().arrangeBlockFunctionDeclaration(fnType, args);
1569  if (CGM.ReturnSlotInterferesWithArgs(fnInfo))
1570  blockInfo.UsesStret = true;
1571 
1572  llvm::FunctionType *fnLLVMType = CGM.getTypes().GetFunctionType(fnInfo);
1573 
1574  StringRef name = CGM.getBlockMangledName(GD, blockDecl);
1575  llvm::Function *fn = llvm::Function::Create(
1576  fnLLVMType, llvm::GlobalValue::InternalLinkage, name, &CGM.getModule());
1577  CGM.SetInternalFunctionAttributes(blockDecl, fn, fnInfo);
1578 
1579  if (BuildGlobalBlock) {
1580  auto GenVoidPtrTy = getContext().getLangOpts().OpenCL
1582  : VoidPtrTy;
1583  buildGlobalBlock(CGM, blockInfo,
1584  llvm::ConstantExpr::getPointerCast(fn, GenVoidPtrTy));
1585  }
1586 
1587  // Begin generating the function.
1588  StartFunction(blockDecl, fnType->getReturnType(), fn, fnInfo, args,
1589  blockDecl->getLocation(),
1590  blockInfo.getBlockExpr()->getBody()->getBeginLoc());
1591 
1592  // Okay. Undo some of what StartFunction did.
1593 
1594  // At -O0 we generate an explicit alloca for the BlockPointer, so the RA
1595  // won't delete the dbg.declare intrinsics for captured variables.
1596  llvm::Value *BlockPointerDbgLoc = BlockPointer;
1597  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
1598  // Allocate a stack slot for it, so we can point the debugger to it
1599  Address Alloca = CreateTempAlloca(BlockPointer->getType(),
1600  getPointerAlign(),
1601  "block.addr");
1602  // Set the DebugLocation to empty, so the store is recognized as a
1603  // frame setup instruction by llvm::DwarfDebug::beginFunction().
1604  auto NL = ApplyDebugLocation::CreateEmpty(*this);
1605  Builder.CreateStore(BlockPointer, Alloca);
1606  BlockPointerDbgLoc = Alloca.getPointer();
1607  }
1608 
1609  // If we have a C++ 'this' reference, go ahead and force it into
1610  // existence now.
1611  if (blockDecl->capturesCXXThis()) {
1612  Address addr = Builder.CreateStructGEP(
1613  LoadBlockStruct(), blockInfo.CXXThisIndex, "block.captured-this");
1614  CXXThisValue = Builder.CreateLoad(addr, "this");
1615  }
1616 
1617  // Also force all the constant captures.
1618  for (const auto &CI : blockDecl->captures()) {
1619  const VarDecl *variable = CI.getVariable();
1620  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1621  if (!capture.isConstant()) continue;
1622 
1623  CharUnits align = getContext().getDeclAlign(variable);
1624  Address alloca =
1625  CreateMemTemp(variable->getType(), align, "block.captured-const");
1626 
1627  Builder.CreateStore(capture.getConstant(), alloca);
1628 
1629  setAddrOfLocalVar(variable, alloca);
1630  }
1631 
1632  // Save a spot to insert the debug information for all the DeclRefExprs.
1633  llvm::BasicBlock *entry = Builder.GetInsertBlock();
1634  llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
1635  --entry_ptr;
1636 
1637  if (IsLambdaConversionToBlock)
1638  EmitLambdaBlockInvokeBody();
1639  else {
1640  PGO.assignRegionCounters(GlobalDecl(blockDecl), fn);
1641  incrementProfileCounter(blockDecl->getBody());
1642  EmitStmt(blockDecl->getBody());
1643  }
1644 
1645  // Remember where we were...
1646  llvm::BasicBlock *resume = Builder.GetInsertBlock();
1647 
1648  // Go back to the entry.
1649  ++entry_ptr;
1650  Builder.SetInsertPoint(entry, entry_ptr);
1651 
1652  // Emit debug information for all the DeclRefExprs.
1653  // FIXME: also for 'this'
1654  if (CGDebugInfo *DI = getDebugInfo()) {
1655  for (const auto &CI : blockDecl->captures()) {
1656  const VarDecl *variable = CI.getVariable();
1657  DI->EmitLocation(Builder, variable->getLocation());
1658 
1659  if (CGM.getCodeGenOpts().getDebugInfo() >=
1661  const CGBlockInfo::Capture &capture = blockInfo.getCapture(variable);
1662  if (capture.isConstant()) {
1663  auto addr = LocalDeclMap.find(variable)->second;
1664  (void)DI->EmitDeclareOfAutoVariable(variable, addr.getPointer(),
1665  Builder);
1666  continue;
1667  }
1668 
1669  DI->EmitDeclareOfBlockDeclRefVariable(
1670  variable, BlockPointerDbgLoc, Builder, blockInfo,
1671  entry_ptr == entry->end() ? nullptr : &*entry_ptr);
1672  }
1673  }
1674  // Recover location if it was changed in the above loop.
1675  DI->EmitLocation(Builder,
1676  cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1677  }
1678 
1679  // And resume where we left off.
1680  if (resume == nullptr)
1681  Builder.ClearInsertionPoint();
1682  else
1683  Builder.SetInsertPoint(resume);
1684 
1685  FinishFunction(cast<CompoundStmt>(blockDecl->getBody())->getRBracLoc());
1686 
1687  return fn;
1688 }
1689 
1690 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1692  const LangOptions &LangOpts) {
1693  if (CI.getCopyExpr()) {
1694  assert(!CI.isByRef());
1695  // don't bother computing flags
1696  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
1697  }
1698  BlockFieldFlags Flags;
1699  if (CI.isEscapingByref()) {
1700  Flags = BLOCK_FIELD_IS_BYREF;
1701  if (T.isObjCGCWeak())
1702  Flags |= BLOCK_FIELD_IS_WEAK;
1703  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1704  }
1705 
1706  Flags = BLOCK_FIELD_IS_OBJECT;
1707  bool isBlockPointer = T->isBlockPointerType();
1708  if (isBlockPointer)
1709  Flags = BLOCK_FIELD_IS_BLOCK;
1710 
1711  switch (T.isNonTrivialToPrimitiveCopy()) {
1712  case QualType::PCK_Struct:
1713  return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
1714  BlockFieldFlags());
1715  case QualType::PCK_ARCWeak:
1716  // We need to register __weak direct captures with the runtime.
1717  return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
1719  // We need to retain the copied value for __strong direct captures.
1720  // If it's a block pointer, we have to copy the block and assign that to
1721  // the destination pointer, so we might as well use _Block_object_assign.
1722  // Otherwise we can avoid that.
1723  return std::make_pair(!isBlockPointer ? BlockCaptureEntityKind::ARCStrong
1724  : BlockCaptureEntityKind::BlockObject,
1725  Flags);
1726  case QualType::PCK_Trivial:
1728  if (!T->isObjCRetainableType())
1729  // For all other types, the memcpy is fine.
1730  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1731 
1732  // Special rules for ARC captures:
1733  Qualifiers QS = T.getQualifiers();
1734 
1735  // Non-ARC captures of retainable pointers are strong and
1736  // therefore require a call to _Block_object_assign.
1737  if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
1738  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
1739 
1740  // Otherwise the memcpy is fine.
1741  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
1742  }
1743  }
1744  llvm_unreachable("after exhaustive PrimitiveCopyKind switch");
1745 }
1746 
1747 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
1749  const LangOptions &LangOpts);
1750 
1751 /// Find the set of block captures that need to be explicitly copied or destroy.
1753  const CGBlockInfo &BlockInfo, const LangOptions &LangOpts,
1754  SmallVectorImpl<BlockCaptureManagedEntity> &ManagedCaptures) {
1755  for (const auto &CI : BlockInfo.getBlockDecl()->captures()) {
1756  const VarDecl *Variable = CI.getVariable();
1757  const CGBlockInfo::Capture &Capture = BlockInfo.getCapture(Variable);
1758  if (Capture.isConstant())
1759  continue;
1760 
1761  QualType VT = Capture.fieldType();
1762  auto CopyInfo = computeCopyInfoForBlockCapture(CI, VT, LangOpts);
1763  auto DisposeInfo = computeDestroyInfoForBlockCapture(CI, VT, LangOpts);
1764  if (CopyInfo.first != BlockCaptureEntityKind::None ||
1765  DisposeInfo.first != BlockCaptureEntityKind::None)
1766  ManagedCaptures.emplace_back(CopyInfo.first, DisposeInfo.first,
1767  CopyInfo.second, DisposeInfo.second, CI,
1768  Capture);
1769  }
1770 
1771  // Sort the captures by offset.
1772  llvm::sort(ManagedCaptures);
1773 }
1774 
1775 namespace {
1776 /// Release a __block variable.
1777 struct CallBlockRelease final : EHScopeStack::Cleanup {
1778  Address Addr;
1779  BlockFieldFlags FieldFlags;
1780  bool LoadBlockVarAddr, CanThrow;
1781 
1782  CallBlockRelease(Address Addr, BlockFieldFlags Flags, bool LoadValue,
1783  bool CT)
1784  : Addr(Addr), FieldFlags(Flags), LoadBlockVarAddr(LoadValue),
1785  CanThrow(CT) {}
1786 
1787  void Emit(CodeGenFunction &CGF, Flags flags) override {
1788  llvm::Value *BlockVarAddr;
1789  if (LoadBlockVarAddr) {
1790  BlockVarAddr = CGF.Builder.CreateLoad(Addr);
1791  BlockVarAddr = CGF.Builder.CreateBitCast(BlockVarAddr, CGF.VoidPtrTy);
1792  } else {
1793  BlockVarAddr = Addr.getPointer();
1794  }
1795 
1796  CGF.BuildBlockRelease(BlockVarAddr, FieldFlags, CanThrow);
1797  }
1798 };
1799 } // end anonymous namespace
1800 
1801 /// Check if \p T is a C++ class that has a destructor that can throw.
1803  if (const auto *RD = T->getAsCXXRecordDecl())
1804  if (const CXXDestructorDecl *DD = RD->getDestructor())
1805  return DD->getType()->getAs<FunctionProtoType>()->canThrow();
1806  return false;
1807 }
1808 
1809 // Return a string that has the information about a capture.
1810 static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E,
1811  CaptureStrKind StrKind,
1812  CharUnits BlockAlignment,
1813  CodeGenModule &CGM) {
1814  std::string Str;
1815  ASTContext &Ctx = CGM.getContext();
1816  const BlockDecl::Capture &CI = *E.CI;
1817  QualType CaptureTy = CI.getVariable()->getType();
1818 
1820  BlockFieldFlags Flags;
1821 
1822  // CaptureStrKind::Merged should be passed only when the operations and the
1823  // flags are the same for copy and dispose.
1824  assert((StrKind != CaptureStrKind::Merged ||
1825  (E.CopyKind == E.DisposeKind && E.CopyFlags == E.DisposeFlags)) &&
1826  "different operations and flags");
1827 
1828  if (StrKind == CaptureStrKind::DisposeHelper) {
1829  Kind = E.DisposeKind;
1830  Flags = E.DisposeFlags;
1831  } else {
1832  Kind = E.CopyKind;
1833  Flags = E.CopyFlags;
1834  }
1835 
1836  switch (Kind) {
1837  case BlockCaptureEntityKind::CXXRecord: {
1838  Str += "c";
1839  SmallString<256> TyStr;
1840  llvm::raw_svector_ostream Out(TyStr);
1841  CGM.getCXXABI().getMangleContext().mangleTypeName(CaptureTy, Out);
1842  Str += llvm::to_string(TyStr.size()) + TyStr.c_str();
1843  break;
1844  }
1845  case BlockCaptureEntityKind::ARCWeak:
1846  Str += "w";
1847  break;
1848  case BlockCaptureEntityKind::ARCStrong:
1849  Str += "s";
1850  break;
1851  case BlockCaptureEntityKind::BlockObject: {
1852  const VarDecl *Var = CI.getVariable();
1853  unsigned F = Flags.getBitMask();
1854  if (F & BLOCK_FIELD_IS_BYREF) {
1855  Str += "r";
1856  if (F & BLOCK_FIELD_IS_WEAK)
1857  Str += "w";
1858  else {
1859  // If CaptureStrKind::Merged is passed, check both the copy expression
1860  // and the destructor.
1861  if (StrKind != CaptureStrKind::DisposeHelper) {
1862  if (Ctx.getBlockVarCopyInit(Var).canThrow())
1863  Str += "c";
1864  }
1865  if (StrKind != CaptureStrKind::CopyHelper) {
1867  Str += "d";
1868  }
1869  }
1870  } else {
1871  assert((F & BLOCK_FIELD_IS_OBJECT) && "unexpected flag value");
1872  if (F == BLOCK_FIELD_IS_BLOCK)
1873  Str += "b";
1874  else
1875  Str += "o";
1876  }
1877  break;
1878  }
1879  case BlockCaptureEntityKind::NonTrivialCStruct: {
1880  bool IsVolatile = CaptureTy.isVolatileQualified();
1881  CharUnits Alignment =
1882  BlockAlignment.alignmentAtOffset(E.Capture->getOffset());
1883 
1884  Str += "n";
1885  std::string FuncStr;
1886  if (StrKind == CaptureStrKind::DisposeHelper)
1888  CaptureTy, Alignment, IsVolatile, Ctx);
1889  else
1890  // If CaptureStrKind::Merged is passed, use the copy constructor string.
1891  // It has all the information that the destructor string has.
1893  CaptureTy, Alignment, IsVolatile, Ctx);
1894  // The underscore is necessary here because non-trivial copy constructor
1895  // and destructor strings can start with a number.
1896  Str += llvm::to_string(FuncStr.size()) + "_" + FuncStr;
1897  break;
1898  }
1900  break;
1901  }
1902 
1903  return Str;
1904 }
1905 
1906 static std::string getCopyDestroyHelperFuncName(
1907  const SmallVectorImpl<BlockCaptureManagedEntity> &Captures,
1908  CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM) {
1909  assert((StrKind == CaptureStrKind::CopyHelper ||
1910  StrKind == CaptureStrKind::DisposeHelper) &&
1911  "unexpected CaptureStrKind");
1912  std::string Name = StrKind == CaptureStrKind::CopyHelper
1913  ? "__copy_helper_block_"
1914  : "__destroy_helper_block_";
1915  if (CGM.getLangOpts().Exceptions)
1916  Name += "e";
1917  if (CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
1918  Name += "a";
1919  Name += llvm::to_string(BlockAlignment.getQuantity()) + "_";
1920 
1921  for (const BlockCaptureManagedEntity &E : Captures) {
1922  Name += llvm::to_string(E.Capture->getOffset().getQuantity());
1923  Name += getBlockCaptureStr(E, StrKind, BlockAlignment, CGM);
1924  }
1925 
1926  return Name;
1927 }
1928 
1930  Address Field, QualType CaptureType,
1931  BlockFieldFlags Flags, bool ForCopyHelper,
1932  VarDecl *Var, CodeGenFunction &CGF) {
1933  bool EHOnly = ForCopyHelper;
1934 
1935  switch (CaptureKind) {
1936  case BlockCaptureEntityKind::CXXRecord:
1937  case BlockCaptureEntityKind::ARCWeak:
1938  case BlockCaptureEntityKind::NonTrivialCStruct:
1939  case BlockCaptureEntityKind::ARCStrong: {
1940  if (CaptureType.isDestructedType() &&
1941  (!EHOnly || CGF.needsEHCleanup(CaptureType.isDestructedType()))) {
1942  CodeGenFunction::Destroyer *Destroyer =
1943  CaptureKind == BlockCaptureEntityKind::ARCStrong
1945  : CGF.getDestroyer(CaptureType.isDestructedType());
1946  CleanupKind Kind =
1947  EHOnly ? EHCleanup
1948  : CGF.getCleanupKind(CaptureType.isDestructedType());
1949  CGF.pushDestroy(Kind, Field, CaptureType, Destroyer, Kind & EHCleanup);
1950  }
1951  break;
1952  }
1953  case BlockCaptureEntityKind::BlockObject: {
1954  if (!EHOnly || CGF.getLangOpts().Exceptions) {
1956  // Calls to _Block_object_dispose along the EH path in the copy helper
1957  // function don't throw as newly-copied __block variables always have a
1958  // reference count of 2.
1959  bool CanThrow =
1960  !ForCopyHelper && CGF.cxxDestructorCanThrow(CaptureType);
1961  CGF.enterByrefCleanup(Kind, Field, Flags, /*LoadBlockVarAddr*/ true,
1962  CanThrow);
1963  }
1964  break;
1965  }
1967  break;
1968  }
1969 }
1970 
1972  llvm::Function *Fn,
1973  const CGFunctionInfo &FI,
1974  CodeGenModule &CGM) {
1975  if (CapturesNonExternalType) {
1977  } else {
1978  Fn->setVisibility(llvm::GlobalValue::HiddenVisibility);
1979  Fn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1980  CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, Fn);
1981  CGM.SetLLVMFunctionAttributesForDefinition(nullptr, Fn);
1982  }
1983 }
1984 /// Generate the copy-helper function for a block closure object:
1985 /// static void block_copy_helper(block_t *dst, block_t *src);
1986 /// The runtime will have previously initialized 'dst' by doing a
1987 /// bit-copy of 'src'.
1988 ///
1989 /// Note that this copies an entire block closure object to the heap;
1990 /// it should not be confused with a 'byref copy helper', which moves
1991 /// the contents of an individual __block variable to the heap.
1992 llvm::Constant *
1995  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), CopiedCaptures);
1996  std::string FuncName =
1997  getCopyDestroyHelperFuncName(CopiedCaptures, blockInfo.BlockAlign,
1998  CaptureStrKind::CopyHelper, CGM);
1999 
2000  if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2001  return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2002 
2003  ASTContext &C = getContext();
2004 
2005  QualType ReturnTy = C.VoidTy;
2006 
2007  FunctionArgList args;
2009  args.push_back(&DstDecl);
2011  args.push_back(&SrcDecl);
2012 
2013  const CGFunctionInfo &FI =
2014  CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2015 
2016  // FIXME: it would be nice if these were mergeable with things with
2017  // identical semantics.
2018  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2019 
2020  llvm::Function *Fn =
2021  llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2022  FuncName, &CGM.getModule());
2023  if (CGM.supportsCOMDAT())
2024  Fn->setComdat(CGM.getModule().getOrInsertComdat(FuncName));
2025 
2026  IdentifierInfo *II = &C.Idents.get(FuncName);
2027 
2028  SmallVector<QualType, 2> ArgTys;
2029  ArgTys.push_back(C.VoidPtrTy);
2030  ArgTys.push_back(C.VoidPtrTy);
2031  QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2032 
2035  FunctionTy, nullptr, SC_Static, false, false);
2036 
2038  CGM);
2039  StartFunction(FD, ReturnTy, Fn, FI, args);
2040  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2041  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2042 
2043  Address src = GetAddrOfLocalVar(&SrcDecl);
2044  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2045  src = Builder.CreateBitCast(src, structPtrTy, "block.source");
2046 
2047  Address dst = GetAddrOfLocalVar(&DstDecl);
2048  dst = Address(Builder.CreateLoad(dst), blockInfo.BlockAlign);
2049  dst = Builder.CreateBitCast(dst, structPtrTy, "block.dest");
2050 
2051  for (const auto &CopiedCapture : CopiedCaptures) {
2052  const BlockDecl::Capture &CI = *CopiedCapture.CI;
2053  const CGBlockInfo::Capture &capture = *CopiedCapture.Capture;
2054  QualType captureType = CI.getVariable()->getType();
2055  BlockFieldFlags flags = CopiedCapture.CopyFlags;
2056 
2057  unsigned index = capture.getIndex();
2058  Address srcField = Builder.CreateStructGEP(src, index);
2059  Address dstField = Builder.CreateStructGEP(dst, index);
2060 
2061  switch (CopiedCapture.CopyKind) {
2062  case BlockCaptureEntityKind::CXXRecord:
2063  // If there's an explicit copy expression, we do that.
2064  assert(CI.getCopyExpr() && "copy expression for variable is missing");
2065  EmitSynthesizedCXXCopyCtor(dstField, srcField, CI.getCopyExpr());
2066  break;
2067  case BlockCaptureEntityKind::ARCWeak:
2068  EmitARCCopyWeak(dstField, srcField);
2069  break;
2070  case BlockCaptureEntityKind::NonTrivialCStruct: {
2071  // If this is a C struct that requires non-trivial copy construction,
2072  // emit a call to its copy constructor.
2073  QualType varType = CI.getVariable()->getType();
2074  callCStructCopyConstructor(MakeAddrLValue(dstField, varType),
2075  MakeAddrLValue(srcField, varType));
2076  break;
2077  }
2078  case BlockCaptureEntityKind::ARCStrong: {
2079  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2080  // At -O0, store null into the destination field (so that the
2081  // storeStrong doesn't over-release) and then call storeStrong.
2082  // This is a workaround to not having an initStrong call.
2083  if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2084  auto *ty = cast<llvm::PointerType>(srcValue->getType());
2085  llvm::Value *null = llvm::ConstantPointerNull::get(ty);
2086  Builder.CreateStore(null, dstField);
2087  EmitARCStoreStrongCall(dstField, srcValue, true);
2088 
2089  // With optimization enabled, take advantage of the fact that
2090  // the blocks runtime guarantees a memcpy of the block data, and
2091  // just emit a retain of the src field.
2092  } else {
2093  EmitARCRetainNonBlock(srcValue);
2094 
2095  // Unless EH cleanup is required, we don't need this anymore, so kill
2096  // it. It's not quite worth the annoyance to avoid creating it in the
2097  // first place.
2098  if (!needsEHCleanup(captureType.isDestructedType()))
2099  cast<llvm::Instruction>(dstField.getPointer())->eraseFromParent();
2100  }
2101  break;
2102  }
2103  case BlockCaptureEntityKind::BlockObject: {
2104  llvm::Value *srcValue = Builder.CreateLoad(srcField, "blockcopy.src");
2105  srcValue = Builder.CreateBitCast(srcValue, VoidPtrTy);
2106  llvm::Value *dstAddr =
2107  Builder.CreateBitCast(dstField.getPointer(), VoidPtrTy);
2108  llvm::Value *args[] = {
2109  dstAddr, srcValue, llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2110  };
2111 
2112  if (CI.isByRef() && C.getBlockVarCopyInit(CI.getVariable()).canThrow())
2113  EmitRuntimeCallOrInvoke(CGM.getBlockObjectAssign(), args);
2114  else
2115  EmitNounwindRuntimeCall(CGM.getBlockObjectAssign(), args);
2116  break;
2117  }
2119  continue;
2120  }
2121 
2122  // Ensure that we destroy the copied object if an exception is thrown later
2123  // in the helper function.
2124  pushCaptureCleanup(CopiedCapture.CopyKind, dstField, captureType, flags,
2125  /*ForCopyHelper*/ true, CI.getVariable(), *this);
2126  }
2127 
2128  FinishFunction();
2129 
2130  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2131 }
2132 
2133 static BlockFieldFlags
2135  QualType T) {
2137  if (T->isBlockPointerType())
2138  Flags = BLOCK_FIELD_IS_BLOCK;
2139  return Flags;
2140 }
2141 
2142 static std::pair<BlockCaptureEntityKind, BlockFieldFlags>
2144  const LangOptions &LangOpts) {
2145  if (CI.isEscapingByref()) {
2147  if (T.isObjCGCWeak())
2148  Flags |= BLOCK_FIELD_IS_WEAK;
2149  return std::make_pair(BlockCaptureEntityKind::BlockObject, Flags);
2150  }
2151 
2152  switch (T.isDestructedType()) {
2154  return std::make_pair(BlockCaptureEntityKind::CXXRecord, BlockFieldFlags());
2156  // Use objc_storeStrong for __strong direct captures; the
2157  // dynamic tools really like it when we do this.
2158  return std::make_pair(BlockCaptureEntityKind::ARCStrong,
2161  // Support __weak direct captures.
2162  return std::make_pair(BlockCaptureEntityKind::ARCWeak,
2165  return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
2166  BlockFieldFlags());
2167  case QualType::DK_none: {
2168  // Non-ARC captures are strong, and we need to use _Block_object_dispose.
2169  if (T->isObjCRetainableType() && !T.getQualifiers().hasObjCLifetime() &&
2170  !LangOpts.ObjCAutoRefCount)
2171  return std::make_pair(BlockCaptureEntityKind::BlockObject,
2173  // Otherwise, we have nothing to do.
2174  return std::make_pair(BlockCaptureEntityKind::None, BlockFieldFlags());
2175  }
2176  }
2177  llvm_unreachable("after exhaustive DestructionKind switch");
2178 }
2179 
2180 /// Generate the destroy-helper function for a block closure object:
2181 /// static void block_destroy_helper(block_t *theBlock);
2182 ///
2183 /// Note that this destroys a heap-allocated block closure object;
2184 /// it should not be confused with a 'byref destroy helper', which
2185 /// destroys the heap-allocated contents of an individual __block
2186 /// variable.
2187 llvm::Constant *
2190  findBlockCapturedManagedEntities(blockInfo, getLangOpts(), DestroyedCaptures);
2191  std::string FuncName =
2192  getCopyDestroyHelperFuncName(DestroyedCaptures, blockInfo.BlockAlign,
2193  CaptureStrKind::DisposeHelper, CGM);
2194 
2195  if (llvm::GlobalValue *Func = CGM.getModule().getNamedValue(FuncName))
2196  return llvm::ConstantExpr::getBitCast(Func, VoidPtrTy);
2197 
2198  ASTContext &C = getContext();
2199 
2200  QualType ReturnTy = C.VoidTy;
2201 
2202  FunctionArgList args;
2204  args.push_back(&SrcDecl);
2205 
2206  const CGFunctionInfo &FI =
2207  CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2208 
2209  // FIXME: We'd like to put these into a mergable by content, with
2210  // internal linkage.
2211  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
2212 
2213  llvm::Function *Fn =
2214  llvm::Function::Create(LTy, llvm::GlobalValue::LinkOnceODRLinkage,
2215  FuncName, &CGM.getModule());
2216  if (CGM.supportsCOMDAT())
2217  Fn->setComdat(CGM.getModule().getOrInsertComdat(FuncName));
2218 
2219  IdentifierInfo *II = &C.Idents.get(FuncName);
2220 
2221  SmallVector<QualType, 1> ArgTys;
2222  ArgTys.push_back(C.VoidPtrTy);
2223  QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
2224 
2227  FunctionTy, nullptr, SC_Static, false, false);
2228 
2230  CGM);
2231  StartFunction(FD, ReturnTy, Fn, FI, args);
2232  markAsIgnoreThreadCheckingAtRuntime(Fn);
2233 
2234  ApplyDebugLocation NL{*this, blockInfo.getBlockExpr()->getBeginLoc()};
2235 
2236  llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
2237 
2238  Address src = GetAddrOfLocalVar(&SrcDecl);
2239  src = Address(Builder.CreateLoad(src), blockInfo.BlockAlign);
2240  src = Builder.CreateBitCast(src, structPtrTy, "block");
2241 
2242  CodeGenFunction::RunCleanupsScope cleanups(*this);
2243 
2244  for (const auto &DestroyedCapture : DestroyedCaptures) {
2245  const BlockDecl::Capture &CI = *DestroyedCapture.CI;
2246  const CGBlockInfo::Capture &capture = *DestroyedCapture.Capture;
2247  BlockFieldFlags flags = DestroyedCapture.DisposeFlags;
2248 
2249  Address srcField = Builder.CreateStructGEP(src, capture.getIndex());
2250 
2251  pushCaptureCleanup(DestroyedCapture.DisposeKind, srcField,
2252  CI.getVariable()->getType(), flags,
2253  /*ForCopyHelper*/ false, CI.getVariable(), *this);
2254  }
2255 
2256  cleanups.ForceCleanup();
2257 
2258  FinishFunction();
2259 
2260  return llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
2261 }
2262 
2263 namespace {
2264 
2265 /// Emits the copy/dispose helper functions for a __block object of id type.
2266 class ObjectByrefHelpers final : public BlockByrefHelpers {
2267  BlockFieldFlags Flags;
2268 
2269 public:
2270  ObjectByrefHelpers(CharUnits alignment, BlockFieldFlags flags)
2271  : BlockByrefHelpers(alignment), Flags(flags) {}
2272 
2273  void emitCopy(CodeGenFunction &CGF, Address destField,
2274  Address srcField) override {
2275  destField = CGF.Builder.CreateBitCast(destField, CGF.VoidPtrTy);
2276 
2277  srcField = CGF.Builder.CreateBitCast(srcField, CGF.VoidPtrPtrTy);
2278  llvm::Value *srcValue = CGF.Builder.CreateLoad(srcField);
2279 
2280  unsigned flags = (Flags | BLOCK_BYREF_CALLER).getBitMask();
2281 
2282  llvm::Value *flagsVal = llvm::ConstantInt::get(CGF.Int32Ty, flags);
2283  llvm::FunctionCallee fn = CGF.CGM.getBlockObjectAssign();
2284 
2285  llvm::Value *args[] = { destField.getPointer(), srcValue, flagsVal };
2286  CGF.EmitNounwindRuntimeCall(fn, args);
2287  }
2288 
2289  void emitDispose(CodeGenFunction &CGF, Address field) override {
2290  field = CGF.Builder.CreateBitCast(field, CGF.Int8PtrTy->getPointerTo(0));
2291  llvm::Value *value = CGF.Builder.CreateLoad(field);
2292 
2293  CGF.BuildBlockRelease(value, Flags | BLOCK_BYREF_CALLER, false);
2294  }
2295 
2296  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2297  id.AddInteger(Flags.getBitMask());
2298  }
2299 };
2300 
2301 /// Emits the copy/dispose helpers for an ARC __block __weak variable.
2302 class ARCWeakByrefHelpers final : public BlockByrefHelpers {
2303 public:
2304  ARCWeakByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2305 
2306  void emitCopy(CodeGenFunction &CGF, Address destField,
2307  Address srcField) override {
2308  CGF.EmitARCMoveWeak(destField, srcField);
2309  }
2310 
2311  void emitDispose(CodeGenFunction &CGF, Address field) override {
2312  CGF.EmitARCDestroyWeak(field);
2313  }
2314 
2315  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2316  // 0 is distinguishable from all pointers and byref flags
2317  id.AddInteger(0);
2318  }
2319 };
2320 
2321 /// Emits the copy/dispose helpers for an ARC __block __strong variable
2322 /// that's not of block-pointer type.
2323 class ARCStrongByrefHelpers final : public BlockByrefHelpers {
2324 public:
2325  ARCStrongByrefHelpers(CharUnits alignment) : BlockByrefHelpers(alignment) {}
2326 
2327  void emitCopy(CodeGenFunction &CGF, Address destField,
2328  Address srcField) override {
2329  // Do a "move" by copying the value and then zeroing out the old
2330  // variable.
2331 
2332  llvm::Value *value = CGF.Builder.CreateLoad(srcField);
2333 
2334  llvm::Value *null =
2335  llvm::ConstantPointerNull::get(cast<llvm::PointerType>(value->getType()));
2336 
2337  if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
2338  CGF.Builder.CreateStore(null, destField);
2339  CGF.EmitARCStoreStrongCall(destField, value, /*ignored*/ true);
2340  CGF.EmitARCStoreStrongCall(srcField, null, /*ignored*/ true);
2341  return;
2342  }
2343  CGF.Builder.CreateStore(value, destField);
2344  CGF.Builder.CreateStore(null, srcField);
2345  }
2346 
2347  void emitDispose(CodeGenFunction &CGF, Address field) override {
2349  }
2350 
2351  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2352  // 1 is distinguishable from all pointers and byref flags
2353  id.AddInteger(1);
2354  }
2355 };
2356 
2357 /// Emits the copy/dispose helpers for an ARC __block __strong
2358 /// variable that's of block-pointer type.
2359 class ARCStrongBlockByrefHelpers final : public BlockByrefHelpers {
2360 public:
2361  ARCStrongBlockByrefHelpers(CharUnits alignment)
2362  : BlockByrefHelpers(alignment) {}
2363 
2364  void emitCopy(CodeGenFunction &CGF, Address destField,
2365  Address srcField) override {
2366  // Do the copy with objc_retainBlock; that's all that
2367  // _Block_object_assign would do anyway, and we'd have to pass the
2368  // right arguments to make sure it doesn't get no-op'ed.
2369  llvm::Value *oldValue = CGF.Builder.CreateLoad(srcField);
2370  llvm::Value *copy = CGF.EmitARCRetainBlock(oldValue, /*mandatory*/ true);
2371  CGF.Builder.CreateStore(copy, destField);
2372  }
2373 
2374  void emitDispose(CodeGenFunction &CGF, Address field) override {
2376  }
2377 
2378  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2379  // 2 is distinguishable from all pointers and byref flags
2380  id.AddInteger(2);
2381  }
2382 };
2383 
2384 /// Emits the copy/dispose helpers for a __block variable with a
2385 /// nontrivial copy constructor or destructor.
2386 class CXXByrefHelpers final : public BlockByrefHelpers {
2387  QualType VarType;
2388  const Expr *CopyExpr;
2389 
2390 public:
2391  CXXByrefHelpers(CharUnits alignment, QualType type,
2392  const Expr *copyExpr)
2393  : BlockByrefHelpers(alignment), VarType(type), CopyExpr(copyExpr) {}
2394 
2395  bool needsCopy() const override { return CopyExpr != nullptr; }
2396  void emitCopy(CodeGenFunction &CGF, Address destField,
2397  Address srcField) override {
2398  if (!CopyExpr) return;
2399  CGF.EmitSynthesizedCXXCopyCtor(destField, srcField, CopyExpr);
2400  }
2401 
2402  void emitDispose(CodeGenFunction &CGF, Address field) override {
2403  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2404  CGF.PushDestructorCleanup(VarType, field);
2405  CGF.PopCleanupBlocks(cleanupDepth);
2406  }
2407 
2408  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2409  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2410  }
2411 };
2412 
2413 /// Emits the copy/dispose helpers for a __block variable that is a non-trivial
2414 /// C struct.
2415 class NonTrivialCStructByrefHelpers final : public BlockByrefHelpers {
2416  QualType VarType;
2417 
2418 public:
2419  NonTrivialCStructByrefHelpers(CharUnits alignment, QualType type)
2420  : BlockByrefHelpers(alignment), VarType(type) {}
2421 
2422  void emitCopy(CodeGenFunction &CGF, Address destField,
2423  Address srcField) override {
2424  CGF.callCStructMoveConstructor(CGF.MakeAddrLValue(destField, VarType),
2425  CGF.MakeAddrLValue(srcField, VarType));
2426  }
2427 
2428  bool needsDispose() const override {
2429  return VarType.isDestructedType();
2430  }
2431 
2432  void emitDispose(CodeGenFunction &CGF, Address field) override {
2433  EHScopeStack::stable_iterator cleanupDepth = CGF.EHStack.stable_begin();
2434  CGF.pushDestroy(VarType.isDestructedType(), field, VarType);
2435  CGF.PopCleanupBlocks(cleanupDepth);
2436  }
2437 
2438  void profileImpl(llvm::FoldingSetNodeID &id) const override {
2439  id.AddPointer(VarType.getCanonicalType().getAsOpaquePtr());
2440  }
2441 };
2442 } // end anonymous namespace
2443 
2444 static llvm::Constant *
2446  BlockByrefHelpers &generator) {
2447  ASTContext &Context = CGF.getContext();
2448 
2449  QualType ReturnTy = Context.VoidTy;
2450 
2451  FunctionArgList args;
2452  ImplicitParamDecl Dst(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2453  args.push_back(&Dst);
2454 
2455  ImplicitParamDecl Src(Context, Context.VoidPtrTy, ImplicitParamDecl::Other);
2456  args.push_back(&Src);
2457 
2458  const CGFunctionInfo &FI =
2459  CGF.CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
2460 
2461  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2462 
2463  // FIXME: We'd like to put these into a mergable by content, with
2464  // internal linkage.
2465  llvm::Function *Fn =
2467  "__Block_byref_object_copy_", &CGF.CGM.getModule());
2468 
2469  IdentifierInfo *II
2470  = &Context.Idents.get("__Block_byref_object_copy_");
2471 
2472  SmallVector<QualType, 2> ArgTys;
2473  ArgTys.push_back(Context.VoidPtrTy);
2474  ArgTys.push_back(Context.VoidPtrTy);
2475  QualType FunctionTy = Context.getFunctionType(ReturnTy, ArgTys, {});
2476 
2478  Context, Context.getTranslationUnitDecl(), SourceLocation(),
2479  SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2480 
2482 
2483  CGF.StartFunction(FD, ReturnTy, Fn, FI, args);
2484 
2485  if (generator.needsCopy()) {
2486  llvm::Type *byrefPtrType = byrefInfo.Type->getPointerTo(0);
2487 
2488  // dst->x
2489  Address destField = CGF.GetAddrOfLocalVar(&Dst);
2490  destField = Address(CGF.Builder.CreateLoad(destField),
2491  byrefInfo.ByrefAlignment);
2492  destField = CGF.Builder.CreateBitCast(destField, byrefPtrType);
2493  destField = CGF.emitBlockByrefAddress(destField, byrefInfo, false,
2494  "dest-object");
2495 
2496  // src->x
2497  Address srcField = CGF.GetAddrOfLocalVar(&Src);
2498  srcField = Address(CGF.Builder.CreateLoad(srcField),
2499  byrefInfo.ByrefAlignment);
2500  srcField = CGF.Builder.CreateBitCast(srcField, byrefPtrType);
2501  srcField = CGF.emitBlockByrefAddress(srcField, byrefInfo, false,
2502  "src-object");
2503 
2504  generator.emitCopy(CGF, destField, srcField);
2505  }
2506 
2507  CGF.FinishFunction();
2508 
2509  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2510 }
2511 
2512 /// Build the copy helper for a __block variable.
2513 static llvm::Constant *buildByrefCopyHelper(CodeGenModule &CGM,
2514  const BlockByrefInfo &byrefInfo,
2515  BlockByrefHelpers &generator) {
2516  CodeGenFunction CGF(CGM);
2517  return generateByrefCopyHelper(CGF, byrefInfo, generator);
2518 }
2519 
2520 /// Generate code for a __block variable's dispose helper.
2521 static llvm::Constant *
2523  const BlockByrefInfo &byrefInfo,
2524  BlockByrefHelpers &generator) {
2525  ASTContext &Context = CGF.getContext();
2526  QualType R = Context.VoidTy;
2527 
2528  FunctionArgList args;
2529  ImplicitParamDecl Src(CGF.getContext(), Context.VoidPtrTy,
2531  args.push_back(&Src);
2532 
2533  const CGFunctionInfo &FI =
2535 
2536  llvm::FunctionType *LTy = CGF.CGM.getTypes().GetFunctionType(FI);
2537 
2538  // FIXME: We'd like to put these into a mergable by content, with
2539  // internal linkage.
2540  llvm::Function *Fn =
2542  "__Block_byref_object_dispose_",
2543  &CGF.CGM.getModule());
2544 
2545  IdentifierInfo *II
2546  = &Context.Idents.get("__Block_byref_object_dispose_");
2547 
2548  SmallVector<QualType, 1> ArgTys;
2549  ArgTys.push_back(Context.VoidPtrTy);
2550  QualType FunctionTy = Context.getFunctionType(R, ArgTys, {});
2551 
2553  Context, Context.getTranslationUnitDecl(), SourceLocation(),
2554  SourceLocation(), II, FunctionTy, nullptr, SC_Static, false, false);
2555 
2557 
2558  CGF.StartFunction(FD, R, Fn, FI, args);
2559 
2560  if (generator.needsDispose()) {
2561  Address addr = CGF.GetAddrOfLocalVar(&Src);
2562  addr = Address(CGF.Builder.CreateLoad(addr), byrefInfo.ByrefAlignment);
2563  auto byrefPtrType = byrefInfo.Type->getPointerTo(0);
2564  addr = CGF.Builder.CreateBitCast(addr, byrefPtrType);
2565  addr = CGF.emitBlockByrefAddress(addr, byrefInfo, false, "object");
2566 
2567  generator.emitDispose(CGF, addr);
2568  }
2569 
2570  CGF.FinishFunction();
2571 
2572  return llvm::ConstantExpr::getBitCast(Fn, CGF.Int8PtrTy);
2573 }
2574 
2575 /// Build the dispose helper for a __block variable.
2576 static llvm::Constant *buildByrefDisposeHelper(CodeGenModule &CGM,
2577  const BlockByrefInfo &byrefInfo,
2578  BlockByrefHelpers &generator) {
2579  CodeGenFunction CGF(CGM);
2580  return generateByrefDisposeHelper(CGF, byrefInfo, generator);
2581 }
2582 
2583 /// Lazily build the copy and dispose helpers for a __block variable
2584 /// with the given information.
2585 template <class T>
2586 static T *buildByrefHelpers(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo,
2587  T &&generator) {
2588  llvm::FoldingSetNodeID id;
2589  generator.Profile(id);
2590 
2591  void *insertPos;
2593  = CGM.ByrefHelpersCache.FindNodeOrInsertPos(id, insertPos);
2594  if (node) return static_cast<T*>(node);
2595 
2596  generator.CopyHelper = buildByrefCopyHelper(CGM, byrefInfo, generator);
2597  generator.DisposeHelper = buildByrefDisposeHelper(CGM, byrefInfo, generator);
2598 
2599  T *copy = new (CGM.getContext()) T(std::forward<T>(generator));
2600  CGM.ByrefHelpersCache.InsertNode(copy, insertPos);
2601  return copy;
2602 }
2603 
2604 /// Build the copy and dispose helpers for the given __block variable
2605 /// emission. Places the helpers in the global cache. Returns null
2606 /// if no helpers are required.
2608 CodeGenFunction::buildByrefHelpers(llvm::StructType &byrefType,
2609  const AutoVarEmission &emission) {
2610  const VarDecl &var = *emission.Variable;
2611  assert(var.isEscapingByref() &&
2612  "only escaping __block variables need byref helpers");
2613 
2614  QualType type = var.getType();
2615 
2616  auto &byrefInfo = getBlockByrefInfo(&var);
2617 
2618  // The alignment we care about for the purposes of uniquing byref
2619  // helpers is the alignment of the actual byref value field.
2620  CharUnits valueAlignment =
2621  byrefInfo.ByrefAlignment.alignmentAtOffset(byrefInfo.FieldOffset);
2622 
2623  if (const CXXRecordDecl *record = type->getAsCXXRecordDecl()) {
2624  const Expr *copyExpr =
2626  if (!copyExpr && record->hasTrivialDestructor()) return nullptr;
2627 
2629  CGM, byrefInfo, CXXByrefHelpers(valueAlignment, type, copyExpr));
2630  }
2631 
2632  // If type is a non-trivial C struct type that is non-trivial to
2633  // destructly move or destroy, build the copy and dispose helpers.
2634  if (type.isNonTrivialToPrimitiveDestructiveMove() == QualType::PCK_Struct ||
2635  type.isDestructedType() == QualType::DK_nontrivial_c_struct)
2637  CGM, byrefInfo, NonTrivialCStructByrefHelpers(valueAlignment, type));
2638 
2639  // Otherwise, if we don't have a retainable type, there's nothing to do.
2640  // that the runtime does extra copies.
2641  if (!type->isObjCRetainableType()) return nullptr;
2642 
2643  Qualifiers qs = type.getQualifiers();
2644 
2645  // If we have lifetime, that dominates.
2646  if (Qualifiers::ObjCLifetime lifetime = qs.getObjCLifetime()) {
2647  switch (lifetime) {
2648  case Qualifiers::OCL_None: llvm_unreachable("impossible");
2649 
2650  // These are just bits as far as the runtime is concerned.
2653  return nullptr;
2654 
2655  // Tell the runtime that this is ARC __weak, called by the
2656  // byref routines.
2657  case Qualifiers::OCL_Weak:
2658  return ::buildByrefHelpers(CGM, byrefInfo,
2659  ARCWeakByrefHelpers(valueAlignment));
2660 
2661  // ARC __strong __block variables need to be retained.
2663  // Block pointers need to be copied, and there's no direct
2664  // transfer possible.
2665  if (type->isBlockPointerType()) {
2666  return ::buildByrefHelpers(CGM, byrefInfo,
2667  ARCStrongBlockByrefHelpers(valueAlignment));
2668 
2669  // Otherwise, we transfer ownership of the retain from the stack
2670  // to the heap.
2671  } else {
2672  return ::buildByrefHelpers(CGM, byrefInfo,
2673  ARCStrongByrefHelpers(valueAlignment));
2674  }
2675  }
2676  llvm_unreachable("fell out of lifetime switch!");
2677  }
2678 
2679  BlockFieldFlags flags;
2680  if (type->isBlockPointerType()) {
2681  flags |= BLOCK_FIELD_IS_BLOCK;
2682  } else if (CGM.getContext().isObjCNSObjectType(type) ||
2683  type->isObjCObjectPointerType()) {
2684  flags |= BLOCK_FIELD_IS_OBJECT;
2685  } else {
2686  return nullptr;
2687  }
2688 
2689  if (type.isObjCGCWeak())
2690  flags |= BLOCK_FIELD_IS_WEAK;
2691 
2692  return ::buildByrefHelpers(CGM, byrefInfo,
2693  ObjectByrefHelpers(valueAlignment, flags));
2694 }
2695 
2697  const VarDecl *var,
2698  bool followForward) {
2699  auto &info = getBlockByrefInfo(var);
2700  return emitBlockByrefAddress(baseAddr, info, followForward, var->getName());
2701 }
2702 
2704  const BlockByrefInfo &info,
2705  bool followForward,
2706  const llvm::Twine &name) {
2707  // Chase the forwarding address if requested.
2708  if (followForward) {
2709  Address forwardingAddr = Builder.CreateStructGEP(baseAddr, 1, "forwarding");
2710  baseAddr = Address(Builder.CreateLoad(forwardingAddr), info.ByrefAlignment);
2711  }
2712 
2713  return Builder.CreateStructGEP(baseAddr, info.FieldIndex, name);
2714 }
2715 
2716 /// BuildByrefInfo - This routine changes a __block variable declared as T x
2717 /// into:
2718 ///
2719 /// struct {
2720 /// void *__isa;
2721 /// void *__forwarding;
2722 /// int32_t __flags;
2723 /// int32_t __size;
2724 /// void *__copy_helper; // only if needed
2725 /// void *__destroy_helper; // only if needed
2726 /// void *__byref_variable_layout;// only if needed
2727 /// char padding[X]; // only if needed
2728 /// T x;
2729 /// } x
2730 ///
2732  auto it = BlockByrefInfos.find(D);
2733  if (it != BlockByrefInfos.end())
2734  return it->second;
2735 
2736  llvm::StructType *byrefType =
2737  llvm::StructType::create(getLLVMContext(),
2738  "struct.__block_byref_" + D->getNameAsString());
2739 
2740  QualType Ty = D->getType();
2741 
2742  CharUnits size;
2744 
2745  // void *__isa;
2746  types.push_back(Int8PtrTy);
2747  size += getPointerSize();
2748 
2749  // void *__forwarding;
2750  types.push_back(llvm::PointerType::getUnqual(byrefType));
2751  size += getPointerSize();
2752 
2753  // int32_t __flags;
2754  types.push_back(Int32Ty);
2755  size += CharUnits::fromQuantity(4);
2756 
2757  // int32_t __size;
2758  types.push_back(Int32Ty);
2759  size += CharUnits::fromQuantity(4);
2760 
2761  // Note that this must match *exactly* the logic in buildByrefHelpers.
2762  bool hasCopyAndDispose = getContext().BlockRequiresCopying(Ty, D);
2763  if (hasCopyAndDispose) {
2764  /// void *__copy_helper;
2765  types.push_back(Int8PtrTy);
2766  size += getPointerSize();
2767 
2768  /// void *__destroy_helper;
2769  types.push_back(Int8PtrTy);
2770  size += getPointerSize();
2771  }
2772 
2773  bool HasByrefExtendedLayout = false;
2774  Qualifiers::ObjCLifetime Lifetime;
2775  if (getContext().getByrefLifetime(Ty, Lifetime, HasByrefExtendedLayout) &&
2776  HasByrefExtendedLayout) {
2777  /// void *__byref_variable_layout;
2778  types.push_back(Int8PtrTy);
2779  size += CharUnits::fromQuantity(PointerSizeInBytes);
2780  }
2781 
2782  // T x;
2783  llvm::Type *varTy = ConvertTypeForMem(Ty);
2784 
2785  bool packed = false;
2786  CharUnits varAlign = getContext().getDeclAlign(D);
2787  CharUnits varOffset = size.alignTo(varAlign);
2788 
2789  // We may have to insert padding.
2790  if (varOffset != size) {
2791  llvm::Type *paddingTy =
2792  llvm::ArrayType::get(Int8Ty, (varOffset - size).getQuantity());
2793 
2794  types.push_back(paddingTy);
2795  size = varOffset;
2796 
2797  // Conversely, we might have to prevent LLVM from inserting padding.
2798  } else if (CGM.getDataLayout().getABITypeAlignment(varTy)
2799  > varAlign.getQuantity()) {
2800  packed = true;
2801  }
2802  types.push_back(varTy);
2803 
2804  byrefType->setBody(types, packed);
2805 
2806  BlockByrefInfo info;
2807  info.Type = byrefType;
2808  info.FieldIndex = types.size() - 1;
2809  info.FieldOffset = varOffset;
2810  info.ByrefAlignment = std::max(varAlign, getPointerAlign());
2811 
2812  auto pair = BlockByrefInfos.insert({D, info});
2813  assert(pair.second && "info was inserted recursively?");
2814  return pair.first->second;
2815 }
2816 
2817 /// Initialize the structural components of a __block variable, i.e.
2818 /// everything but the actual object.
2820  // Find the address of the local.
2821  Address addr = emission.Addr;
2822 
2823  // That's an alloca of the byref structure type.
2824  llvm::StructType *byrefType = cast<llvm::StructType>(
2825  cast<llvm::PointerType>(addr.getPointer()->getType())->getElementType());
2826 
2827  unsigned nextHeaderIndex = 0;
2828  CharUnits nextHeaderOffset;
2829  auto storeHeaderField = [&](llvm::Value *value, CharUnits fieldSize,
2830  const Twine &name) {
2831  auto fieldAddr = Builder.CreateStructGEP(addr, nextHeaderIndex, name);
2832  Builder.CreateStore(value, fieldAddr);
2833 
2834  nextHeaderIndex++;
2835  nextHeaderOffset += fieldSize;
2836  };
2837 
2838  // Build the byref helpers if necessary. This is null if we don't need any.
2839  BlockByrefHelpers *helpers = buildByrefHelpers(*byrefType, emission);
2840 
2841  const VarDecl &D = *emission.Variable;
2842  QualType type = D.getType();
2843 
2844  bool HasByrefExtendedLayout;
2845  Qualifiers::ObjCLifetime ByrefLifetime;
2846  bool ByRefHasLifetime =
2847  getContext().getByrefLifetime(type, ByrefLifetime, HasByrefExtendedLayout);
2848 
2849  llvm::Value *V;
2850 
2851  // Initialize the 'isa', which is just 0 or 1.
2852  int isa = 0;
2853  if (type.isObjCGCWeak())
2854  isa = 1;
2855  V = Builder.CreateIntToPtr(Builder.getInt32(isa), Int8PtrTy, "isa");
2856  storeHeaderField(V, getPointerSize(), "byref.isa");
2857 
2858  // Store the address of the variable into its own forwarding pointer.
2859  storeHeaderField(addr.getPointer(), getPointerSize(), "byref.forwarding");
2860 
2861  // Blocks ABI:
2862  // c) the flags field is set to either 0 if no helper functions are
2863  // needed or BLOCK_BYREF_HAS_COPY_DISPOSE if they are,
2864  BlockFlags flags;
2865  if (helpers) flags |= BLOCK_BYREF_HAS_COPY_DISPOSE;
2866  if (ByRefHasLifetime) {
2867  if (HasByrefExtendedLayout) flags |= BLOCK_BYREF_LAYOUT_EXTENDED;
2868  else switch (ByrefLifetime) {
2870  flags |= BLOCK_BYREF_LAYOUT_STRONG;
2871  break;
2872  case Qualifiers::OCL_Weak:
2873  flags |= BLOCK_BYREF_LAYOUT_WEAK;
2874  break;
2877  break;
2878  case Qualifiers::OCL_None:
2879  if (!type->isObjCObjectPointerType() && !type->isBlockPointerType())
2881  break;
2882  default:
2883  break;
2884  }
2885  if (CGM.getLangOpts().ObjCGCBitmapPrint) {
2886  printf("\n Inline flag for BYREF variable layout (%d):", flags.getBitMask());
2887  if (flags & BLOCK_BYREF_HAS_COPY_DISPOSE)
2888  printf(" BLOCK_BYREF_HAS_COPY_DISPOSE");
2889  if (flags & BLOCK_BYREF_LAYOUT_MASK) {
2890  BlockFlags ThisFlag(flags.getBitMask() & BLOCK_BYREF_LAYOUT_MASK);
2891  if (ThisFlag == BLOCK_BYREF_LAYOUT_EXTENDED)
2892  printf(" BLOCK_BYREF_LAYOUT_EXTENDED");
2893  if (ThisFlag == BLOCK_BYREF_LAYOUT_STRONG)
2894  printf(" BLOCK_BYREF_LAYOUT_STRONG");
2895  if (ThisFlag == BLOCK_BYREF_LAYOUT_WEAK)
2896  printf(" BLOCK_BYREF_LAYOUT_WEAK");
2897  if (ThisFlag == BLOCK_BYREF_LAYOUT_UNRETAINED)
2898  printf(" BLOCK_BYREF_LAYOUT_UNRETAINED");
2899  if (ThisFlag == BLOCK_BYREF_LAYOUT_NON_OBJECT)
2900  printf(" BLOCK_BYREF_LAYOUT_NON_OBJECT");
2901  }
2902  printf("\n");
2903  }
2904  }
2905  storeHeaderField(llvm::ConstantInt::get(IntTy, flags.getBitMask()),
2906  getIntSize(), "byref.flags");
2907 
2908  CharUnits byrefSize = CGM.GetTargetTypeStoreSize(byrefType);
2909  V = llvm::ConstantInt::get(IntTy, byrefSize.getQuantity());
2910  storeHeaderField(V, getIntSize(), "byref.size");
2911 
2912  if (helpers) {
2913  storeHeaderField(helpers->CopyHelper, getPointerSize(),
2914  "byref.copyHelper");
2915  storeHeaderField(helpers->DisposeHelper, getPointerSize(),
2916  "byref.disposeHelper");
2917  }
2918 
2919  if (ByRefHasLifetime && HasByrefExtendedLayout) {
2920  auto layoutInfo = CGM.getObjCRuntime().BuildByrefLayout(CGM, type);
2921  storeHeaderField(layoutInfo, getPointerSize(), "byref.layout");
2922  }
2923 }
2924 
2926  bool CanThrow) {
2927  llvm::FunctionCallee F = CGM.getBlockObjectDispose();
2928  llvm::Value *args[] = {
2929  Builder.CreateBitCast(V, Int8PtrTy),
2930  llvm::ConstantInt::get(Int32Ty, flags.getBitMask())
2931  };
2932 
2933  if (CanThrow)
2934  EmitRuntimeCallOrInvoke(F, args);
2935  else
2936  EmitNounwindRuntimeCall(F, args);
2937 }
2938 
2940  BlockFieldFlags Flags,
2941  bool LoadBlockVarAddr, bool CanThrow) {
2942  EHStack.pushCleanup<CallBlockRelease>(Kind, Addr, Flags, LoadBlockVarAddr,
2943  CanThrow);
2944 }
2945 
2946 /// Adjust the declaration of something from the blocks API.
2948  llvm::Constant *C) {
2949  auto *GV = cast<llvm::GlobalValue>(C->stripPointerCasts());
2950 
2951  if (CGM.getTarget().getTriple().isOSBinFormatCOFF()) {
2952  IdentifierInfo &II = CGM.getContext().Idents.get(C->getName());
2955 
2956  assert((isa<llvm::Function>(C->stripPointerCasts()) ||
2957  isa<llvm::GlobalVariable>(C->stripPointerCasts())) &&
2958  "expected Function or GlobalVariable");
2959 
2960  const NamedDecl *ND = nullptr;
2961  for (const auto &Result : DC->lookup(&II))
2962  if ((ND = dyn_cast<FunctionDecl>(Result)) ||
2963  (ND = dyn_cast<VarDecl>(Result)))
2964  break;
2965 
2966  // TODO: support static blocks runtime
2967  if (GV->isDeclaration() && (!ND || !ND->hasAttr<DLLExportAttr>())) {
2968  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2969  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2970  } else {
2971  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2972  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
2973  }
2974  }
2975 
2976  if (CGM.getLangOpts().BlocksRuntimeOptional && GV->isDeclaration() &&
2977  GV->hasExternalLinkage())
2978  GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2979 
2980  CGM.setDSOLocal(GV);
2981 }
2982 
2984  if (BlockObjectDispose)
2985  return BlockObjectDispose;
2986 
2987  llvm::Type *args[] = { Int8PtrTy, Int32Ty };
2988  llvm::FunctionType *fty
2989  = llvm::FunctionType::get(VoidTy, args, false);
2990  BlockObjectDispose = CreateRuntimeFunction(fty, "_Block_object_dispose");
2992  *this, cast<llvm::Constant>(BlockObjectDispose.getCallee()));
2993  return BlockObjectDispose;
2994 }
2995 
2996 llvm::FunctionCallee CodeGenModule::getBlockObjectAssign() {
2997  if (BlockObjectAssign)
2998  return BlockObjectAssign;
2999 
3000  llvm::Type *args[] = { Int8PtrTy, Int8PtrTy, Int32Ty };
3001  llvm::FunctionType *fty
3002  = llvm::FunctionType::get(VoidTy, args, false);
3003  BlockObjectAssign = CreateRuntimeFunction(fty, "_Block_object_assign");
3005  *this, cast<llvm::Constant>(BlockObjectAssign.getCallee()));
3006  return BlockObjectAssign;
3007 }
3008 
3010  if (NSConcreteGlobalBlock)
3011  return NSConcreteGlobalBlock;
3012 
3013  NSConcreteGlobalBlock = GetOrCreateLLVMGlobal("_NSConcreteGlobalBlock",
3014  Int8PtrTy->getPointerTo(),
3015  nullptr);
3016  configureBlocksRuntimeObject(*this, NSConcreteGlobalBlock);
3017  return NSConcreteGlobalBlock;
3018 }
3019 
3021  if (NSConcreteStackBlock)
3022  return NSConcreteStackBlock;
3023 
3024  NSConcreteStackBlock = GetOrCreateLLVMGlobal("_NSConcreteStackBlock",
3025  Int8PtrTy->getPointerTo(),
3026  nullptr);
3027  configureBlocksRuntimeObject(*this, NSConcreteStackBlock);
3028  return NSConcreteStackBlock;
3029 }
const CGFunctionInfo & arrangeBuiltinFunctionDeclaration(QualType resultType, const FunctionArgList &args)
A builtin function is a freestanding function using the default C conventions.
Definition: CGCall.cpp:652
const llvm::DataLayout & getDataLayout() const
CGOpenCLRuntime & getOpenCLRuntime()
Return a reference to the configured OpenCL runtime.
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:363
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Address CreateStructGEP(Address Addr, unsigned Index, const llvm::Twine &Name="")
Definition: CGBuilder.h:178
QualType getAddrSpaceQualType(QualType T, LangAS AddressSpace) const
Return the uniqued reference to the type for an address space qualified type with the specified type ...
const BlockDecl * getBlockDecl() const
Definition: Expr.h:5555
Information about the layout of a __block variable.
Definition: CGBlocks.h:143
CharUnits alignTo(const CharUnits &Align) const
alignTo - Returns the next integer (mod 2**64) that is greater than or equal to this quantity and is ...
Definition: CharUnits.h:183
CaptureStrKind
Definition: CGBlocks.cpp:101
const Capture & getCapture(const VarDecl *var) const
Definition: CGBlocks.h:270
llvm::Constant * GenerateCopyHelperFunction(const CGBlockInfo &blockInfo)
Generate the copy-helper function for a block closure object: static void block_copy_helper(block_t *...
Definition: CGBlocks.cpp:1993
static llvm::Constant * generateByrefDisposeHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Generate code for a __block variable&#39;s dispose helper.
Definition: CGBlocks.cpp:2522
Represents a function declaration or definition.
Definition: Decl.h:1748
llvm::IntegerType * IntTy
int
llvm::Type * getGenericBlockLiteralType()
The type of a generic block literal.
Definition: CGBlocks.cpp:1217
const CGFunctionInfo & arrangeBlockFunctionDeclaration(const FunctionProtoType *type, const FunctionArgList &args)
Block invocation functions are C functions with an implicit parameter.
Definition: CGCall.cpp:627
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:59
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)
Definition: Decl.h:1895
Other implicit parameter.
Definition: Decl.h:1524
CharUnits BlockHeaderForcedGapOffset
Definition: CGBlocks.h:255
const FunctionProtoType * getFunctionType() const
getFunctionType - Return the underlying function type for this block.
Definition: Expr.cpp:2352
Expr * getCopyExpr() const
Definition: Decl.h:3961
static llvm::Constant * buildByrefDisposeHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the dispose helper for a __block variable.
Definition: CGBlocks.cpp:2576
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:3921
CanQualType VoidPtrTy
Definition: ASTContext.h:1042
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:2033
A (possibly-)qualified type.
Definition: Type.h:643
bool isBlockPointerType() const
Definition: Type.h:6392
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:4034
bool HaveInsertPoint() const
HaveInsertPoint - True if an insertion point is defined.
capture_const_iterator capture_begin() const
Definition: Decl.h:4044
llvm::LLVMContext & getLLVMContext()
void EmitARCDestroyWeak(Address addr)
void @objc_destroyWeak(i8** addr) Essentially objc_storeWeak(addr, nil).
Definition: CGObjC.cpp:2436
The standard implementation of ConstantInitBuilder used in Clang.
BlockVarCopyInit getBlockVarCopyInit(const VarDecl *VD) const
Get the copy initialization expression of the VarDecl VD, or nullptr if none exists.
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3387
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:985
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:2586
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:2328
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:4014
static llvm::Constant * buildBlockDescriptor(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
buildBlockDescriptor - Build the block descriptor meta-data for a block.
Definition: CGBlocks.cpp:184
QualType getNonReferenceType() const
If Type is a reference type (e.g., const int&), returns the type that the reference refers to ("const...
Definition: Type.h:6333
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 ...
RangeSelector name(std::string ID)
Given a node with a "name", (like NamedDecl, DeclRefExpr or CxxCtorInitializer) selects the name&#39;s to...
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
capture_const_iterator capture_end() const
Definition: Decl.h:4045
The type would be trivial except that it is volatile-qualified.
Definition: Type.h:1113
Address GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
Represents a variable declaration or definition.
Definition: Decl.h:812
Objects with "hidden" visibility are not seen by the dynamic linker.
Definition: Visibility.h:36
CGBlockInfo(const BlockDecl *blockDecl, StringRef Name)
Definition: CGBlocks.cpp:34
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6851
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:1971
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:1691
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:1929
static void destroyBlockInfos(CGBlockInfo *info)
Destroy a chain of block layouts.
Definition: CGBlocks.cpp:890
long i
Definition: xmmintrin.h:1456
The collection of all-type qualifiers we support.
Definition: Type.h:137
void add(RValue rvalue, QualType type)
Definition: CGCall.h:287
const AstTypeMatcher< RecordType > recordType
Matches record types (e.g.
const BlockDecl * Block
Definition: CGBlocks.h:246
llvm::DenseMap< const VarDecl *, FieldDecl * > LambdaCaptureFields
uint64_t getPointerWidth(unsigned AddrSpace) const
Return the width of pointers on this target, for the specified address space.
Definition: TargetInfo.h:358
static std::string getBlockCaptureStr(const BlockCaptureManagedEntity &E, CaptureStrKind StrKind, CharUnits BlockAlignment, CodeGenModule &CGM)
Definition: CGBlocks.cpp:1810
One of these records is kept for each identifier that is lexed.
bool doesNotEscape() const
Definition: Decl.h:4066
void emitByrefStructureInit(const AutoVarEmission &emission)
Initialize the structural components of a __block variable, i.e.
Definition: CGBlocks.cpp:2819
CGBlockInfo * FirstBlockInfo
FirstBlockInfo - The head of a singly-linked-list of block layouts.
QualType getPointeeType() const
Definition: Type.h:2686
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
llvm::Type * ConvertType(QualType T)
ConvertType - Convert type T into a llvm::Type.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:154
llvm::Constant * tryEmitAbstractForInitializer(const VarDecl &D)
Try to emit the initializer of the given declaration as an abstract constant.
bool isObjCInertUnsafeUnretainedType() const
Was this type written with the special inert-in-ARC __unsafe_unretained qualifier?
Definition: Type.h:2025
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:920
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:263
bool isReferenceType() const
Definition: Type.h:6396
Denotes a cleanup that should run when a scope is exited using exceptional control flow (a throw stat...
Definition: EHScopeStack.h:80
std::string getObjCEncodingForBlock(const BlockExpr *blockExpr) const
Return the encoded type for this block declaration.
void recordBlockInfo(const BlockExpr *E, llvm::Function *InvokeF, llvm::Value *Block)
Record invoke function and block literal emitted during normal codegen for a block expression...
static AggValueSlot forAddr(Address addr, Qualifiers quals, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, Overlap_t mayOverlap, IsZeroed_t isZeroed=IsNotZeroed, IsSanitizerChecked_t isChecked=IsNotSanitizerChecked)
forAddr - Make a slot for an aggregate value.
Definition: CGValue.h:513
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:52
static llvm::Constant * generateByrefCopyHelper(CodeGenFunction &CGF, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Definition: CGBlocks.cpp:2445
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:3994
static bool isSafeForCXXConstantCapture(QualType type)
Determines if the given type is safe for constant capture in C++.
Definition: CGBlocks.cpp:387
__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:49
IdentifierTable & Idents
Definition: ASTContext.h:569
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:124
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:2276
virtual std::string getRCBlockLayoutStr(CodeGen::CodeGenModule &CGM, const CGBlockInfo &blockInfo)
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:37
void EmitARCDestroyStrong(Address addr, ARCPreciseLifetime_t precise)
Destroy a __strong variable.
Definition: CGObjC.cpp:2262
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:900
uint32_t getBitMask() const
Definition: CGBlocks.h:117
bool isByRef() const
Whether this is a "by ref" capture, i.e.
Definition: Decl.h:3946
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6212
bool needsEHCleanup(QualType::DestructionKind kind)
Determines whether an EH cleanup is required to destroy a type with the given destruction kind...
llvm::Constant * getAddrOfGlobalBlockIfEmitted(const BlockExpr *BE)
Returns the address of a block which requires no caputres, or null if we&#39;ve yet to emit the block for...
The type is an Objective-C retainable pointer type that is qualified with the ARC __strong qualifier...
Definition: Type.h:1117
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
b
Definition: emmintrin.h:321
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:2361
llvm::Constant * getNSConcreteStackBlock()
Definition: CGBlocks.cpp:3020
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:1108
RangeSelector node(std::string ID)
Selects a node, including trailing semicolon (for non-expression statements).
This object can be modified without requiring retains or releases.
Definition: Type.h:158
StringRef Name
Name - The name of the block, kindof.
Definition: CGBlocks.h:155
bool isEscapingByref() const
Definition: Decl.h:3948
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:1602
const BlockExpr * BlockExpression
Definition: CGBlocks.h:247
static llvm::Constant * buildCopyHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to copy a block.
Definition: CGBlocks.cpp:55
bool isValid() const
Definition: Address.h:35
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1636
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3719
uint32_t getBitMask() const
Definition: CGBlocks.h:73
const CodeGen::CGBlockInfo * BlockInfo
const TargetCodeGenInfo & getTargetCodeGenInfo()
CGBlockInfo - Information to generate a block literal.
Definition: CGBlocks.h:152
virtual void emitCopy(CodeGenFunction &CGF, Address dest, Address src)=0
RValue - This trivial value class is used to represent the result of an expression that is evaluated...
Definition: CGValue.h:38
bool CanBeGlobal
CanBeGlobal - True if the block can be global, i.e.
Definition: CGBlocks.h:218
StringRef getBlockMangledName(GlobalDecl GD, const BlockDecl *BD)
static void findBlockCapturedManagedEntities(const CGBlockInfo &BlockInfo, const LangOptions &LangOpts, SmallVectorImpl< BlockCaptureManagedEntity > &ManagedCaptures)
Find the set of block captures that need to be explicitly copied or destroy.
Definition: CGBlocks.cpp:1752
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:178
unsigned Offset
Definition: Format.cpp:1713
static void initializeForBlockHeader(CodeGenModule &CGM, CGBlockInfo &info, SmallVectorImpl< llvm::Type *> &elementTypes)
Definition: CGBlocks.cpp:447
CGBlockInfo * NextBlockInfo
The next block in the block-info chain.
Definition: CGBlocks.h: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:3915
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:2452
Emit only debug info necessary for generating line number tables (-gline-tables-only).
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:6916
bool isObjCRetainableType() const
Definition: Type.cpp:3984
#define V(N, I)
Definition: ASTContext.h:2907
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5541
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2830
BlockCaptureEntityKind
Represents a type of copy/destroy operation that should be performed for an entity that&#39;s captured by...
Definition: CGBlocks.cpp:70
static llvm::Constant * buildGlobalBlock(CodeGenModule &CGM, const CGBlockInfo &blockInfo, llvm::Constant *blockFn)
Build the given block as a global block.
Definition: CGBlocks.cpp:1383
Expr * getCallee()
Definition: Expr.h:2634
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:2188
ObjCLifetime getObjCLifetime() const
Definition: Type.h:327
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:62
internal::Matcher< T > id(StringRef ID, const internal::BindableMatcher< T > &InnerMatcher)
If the provided matcher matches a node, binds the node to ID.
Definition: ASTMatchers.h:138
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:1502
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:2996
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:1382
static bool CanThrow(Expr *E, ASTContext &Ctx)
Definition: CFG.cpp:2475
static CharUnits getLowBit(CharUnits v)
Get the low bit of a nonzero character count.
Definition: CGBlocks.cpp:443
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:6791
const TargetInfo & getTarget() const
const LangOptions & getLangOpts() const
ASTContext & getContext() const
static BlockFieldFlags getBlockFieldFlagsForObjCObjectPointer(const BlockDecl::Capture &CI, QualType T)
Definition: CGBlocks.cpp:2134
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:502
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:121
virtual bool needsCopy() const
virtual llvm::Constant * BuildByrefLayout(CodeGen::CodeGenModule &CGM, QualType T)=0
Returns an i8* which points to the byref layout information.
bool isConstQualified() const
Determine whether this type is const-qualified.
Definition: Type.h:6201
param_iterator param_begin()
Definition: Decl.h:4013
The l-value was considered opaque, so the alignment was determined from a type.
RecordDecl * getDecl() const
Definition: Type.h:4448
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:154
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:141
llvm::FunctionCallee getBlockObjectDispose()
Definition: CGBlocks.cpp:2983
#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:165
Kind
void PushDestructorCleanup(QualType T, Address Addr)
PushDestructorCleanup - Push a cleanup to call the complete-object destructor of an object of the giv...
Definition: CGClass.cpp:2432
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:2060
Encodes a location in the source.
static DeclContext * castToDeclContext(const TranslationUnitDecl *D)
Definition: Decl.h:129
void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags, bool CanThrow)
Definition: CGBlocks.cpp:2925
QualType getReturnType() const
Definition: Type.h:3645
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Expr.h:5564
A saved depth on the scope stack.
Definition: EHScopeStack.h:106
llvm::StructType * StructureType
Definition: CGBlocks.h:245
std::string getNameAsString() const
Get a human-readable name for the declaration, even if it is one of the special kinds of names (C++ c...
Definition: Decl.h:291
static std::string getCopyDestroyHelperFuncName(const SmallVectorImpl< BlockCaptureManagedEntity > &Captures, CharUnits BlockAlignment, CaptureStrKind StrKind, CodeGenModule &CGM)
Definition: CGBlocks.cpp:1906
static void configureBlocksRuntimeObject(CodeGenModule &CGM, llvm::Constant *C)
Adjust the declaration of something from the blocks API.
Definition: CGBlocks.cpp:2947
The type is a struct containing a field whose type is neither PCK_Trivial nor PCK_VolatileTrivial.
Definition: Type.h:1129
An aggregate value slot.
Definition: CGValue.h:436
const BlockByrefInfo & getBlockByrefInfo(const VarDecl *var)
BuildByrefInfo - This routine changes a __block variable declared as T x into:
Definition: CGBlocks.cpp:2731
A scoped helper to set the current debug location to the specified location or preferred location of ...
Definition: CGDebugInfo.h:711
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:1802
bool isConversionFromLambda() const
Definition: Decl.h:4058
void enterNonTrivialFullExpression(const FullExpr *E)
Enter a full-expression with a non-trivial number of objects to clean up.
Definition: CGBlocks.cpp:864
CanQualType VoidTy
Definition: ASTContext.h:1014
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:2436
arg_range arguments()
Definition: Expr.h:2710
bool isObjCObjectPointerType() const
Definition: Type.h:6488
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:3245
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1157
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:2939
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:3942
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:2308
unsigned CXXThisIndex
The field index of &#39;this&#39; within the block, if there is one.
Definition: CGBlocks.h:158
Assigning into this object requires a lifetime extension.
Definition: Type.h:171
static Destroyer destroyARCStrongImprecise
void FinishFunction(SourceLocation EndLoc=SourceLocation())
FinishFunction - Complete IR generation of the current function.
virtual void mangleTypeName(QualType T, raw_ostream &)=0
Generates a unique string for an externally visible type for use with TBAA or type uniquing...
The type is an Objective-C retainable pointer type that is qualified with the ARC __weak qualifier...
Definition: Type.h:1121
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:620
std::pair< CharUnits, CharUnits > getTypeInfoInChars(const Type *T) const
ConstantAddress GetAddrOfConstantCString(const std::string &Str, const char *GlobalName=nullptr)
Returns a pointer to a character array containing the literal and a terminating &#39;\0&#39; character...
void addUsedGlobal(llvm::GlobalValue *GV)
Add a global to a list to be added to the llvm.used metadata.
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:358
bool isObjCGCWeak() const
true when Type is objc&#39;s weak.
Definition: Type.h:1053
static llvm::Constant * tryCaptureAsConstant(CodeGenModule &CGM, CodeGenFunction *CGF, const VarDecl *var)
It is illegal to modify a const object after initialization.
Definition: CGBlocks.cpp:411
CGFunctionInfo - Class to encapsulate the information about a function definition.
This class organizes the cross-function state that is used while generating LLVM code.
CharUnits alignmentAtOffset(CharUnits offset) const
Given that this is a non-zero alignment value, what is the alignment at the given offset...
Definition: CharUnits.h:189
Dataflow Directional Tag Classes.
virtual llvm::Constant * BuildGCBlockLayout(CodeGen::CodeGenModule &CGM, const CodeGen::CGBlockInfo &blockInfo)=0
static void computeBlockInfo(CodeGenModule &CGM, CodeGenFunction *CGF, CGBlockInfo &info)
Compute the layout of the given block.
Definition: CGBlocks.cpp:521
llvm::FoldingSet< BlockByrefHelpers > ByrefHelpersCache
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1271
ArrayRef< Capture > captures() const
Definition: Decl.h:4042
bool isNested() const
Whether this is a nested capture, i.e.
Definition: Decl.h:3958
Parameter for Objective-C &#39;self&#39; argument.
Definition: Decl.h:1509
static llvm::Constant * buildDisposeHelper(CodeGenModule &CGM, const CGBlockInfo &blockInfo)
Build the helper function to dispose of a block.
Definition: CGBlocks.cpp:61
const Expr * getInit() const
Definition: Decl.h:1219
llvm::Constant * getPointer() const
Definition: Address.h:83
std::unique_ptr< DiagnosticConsumer > create(StringRef OutputFile, DiagnosticOptions *Diags, bool MergeChildRecords=false)
Returns a DiagnosticConsumer that serializes diagnostics to a bitcode file.
llvm::LoadInst * CreateLoad(Address Addr, const llvm::Twine &Name="")
Definition: CGBuilder.h:69
int printf(__constant const char *st,...) __attribute__((format(printf
bool hasObjCLifetime() const
Definition: Type.h:326
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:2432
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:780
Pointer to a block type.
Definition: Type.h:2671
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:4438
StructBuilder beginStruct(llvm::StructType *structTy=nullptr)
CanQualType UnsignedLongTy
Definition: ASTContext.h:1024
static llvm::Constant * buildByrefCopyHelper(CodeGenModule &CGM, const BlockByrefInfo &byrefInfo, BlockByrefHelpers &generator)
Build the copy helper for a __block variable.
Definition: CGBlocks.cpp:2513
void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp)
Definition: CGExprCXX.cpp:624
static CGBlockInfo * findAndRemoveBlockInfo(CGBlockInfo **head, const BlockDecl *block)
Find the layout for the given block in a linked list and remove it.
Definition: CGBlocks.cpp:873
void SetInternalFunctionAttributes(GlobalDecl GD, llvm::Function *F, const CGFunctionInfo &FI)
Set the attributes on the LLVM function for the given decl and function info.
virtual void emitDispose(CodeGenFunction &CGF, Address field)=0
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:31
const Decl * CurFuncDecl
CurFuncDecl - Holds the Decl for the current outermost non-closure context.
A pair of helper functions for a __block variable.
bool capturesCXXThis() const
Definition: Decl.h:4047
Reading or writing from this object requires a barrier call.
Definition: Type.h:168
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:1007
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
static std::string getNonTrivialDestructorStr(QualType QT, CharUnits Alignment, bool IsVolatile, ASTContext &Ctx)
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:6169
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:5567
llvm::Value * EmitARCRetainBlock(llvm::Value *value, bool mandatory)
Retain the given block, with _Block_copy semantics.
Definition: CGObjC.cpp:2134
uint64_t getPointerAlign(unsigned AddrSpace) const
Definition: TargetInfo.h:361
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2516
StringRef getName() const
Get the name of identifier for this declaration as a StringRef.
Definition: Decl.h:275
CGCXXABI & getCXXABI() const
llvm::Function * GenerateBlockFunction(GlobalDecl GD, const CGBlockInfo &Info, const DeclMapTy &ldm, bool IsLambdaConversionToBlock, bool BuildGlobalBlock)
Definition: CGBlocks.cpp:1516
The top declaration context.
Definition: Decl.h:107
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1141
static RValue get(llvm::Value *V)
Definition: CGValue.h:85
result[0]
Definition: emmintrin.h:120
RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue)
Definition: CGBlocks.cpp:1254
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:759
llvm::Constant * getNSConcreteGlobalBlock()
Definition: CGBlocks.cpp:3009
llvm::Type * getBlockDescriptorType()
Fetches the type of a generic block descriptor.
Definition: CGBlocks.cpp:1185
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:647
An l-value expression is a reference to an object with independent storage.
Definition: Specifiers.h:128
llvm::PointerType * getGenericVoidPointerType()
Information for lazily generating a cleanup.
Definition: EHScopeStack.h:146
This represents a decl that may have a name.
Definition: Decl.h:248
llvm::Instruction * DominatingIP
An instruction which dominates the full-expression that the block is inside.
Definition: CGBlocks.h:262
const LangOptions & getLangOpts() const
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2532
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:2059
Decl * getCalleeDecl()
Definition: Expr.h:2646
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:262
const LangOptions & getLangOpts() const
Definition: ASTContext.h:710
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:2696
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:2143
bool isExternallyVisible() const
Definition: Decl.h:379
void setCleanup(EHScopeStack::stable_iterator cleanup)
Definition: CGBlocks.h:186
static OMPLinearClause * Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc, OpenMPLinearClauseKind Modifier, SourceLocation ModifierLoc, SourceLocation ColonLoc, SourceLocation EndLoc, ArrayRef< Expr *> VL, ArrayRef< Expr *> PL, ArrayRef< Expr *> IL, Expr *Step, Expr *CalcStep, Stmt *PreInit, Expr *PostUpdate)
Creates clause with a list of variables VL and a linear step Step.
void Destroyer(CodeGenFunction &CGF, Address addr, QualType ty)
Qualifiers::ObjCLifetime getObjCLifetime() const
Returns lifetime attribute of this type.
Definition: Type.h:1063
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1541