clang  7.0.0svn
CGExprAgg.cpp
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1 //===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate Expressions --------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This contains code to emit Aggregate Expr nodes as LLVM code.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CodeGenFunction.h"
15 #include "CGCXXABI.h"
16 #include "CGObjCRuntime.h"
17 #include "CodeGenModule.h"
18 #include "ConstantEmitter.h"
19 #include "clang/AST/ASTContext.h"
20 #include "clang/AST/DeclCXX.h"
21 #include "clang/AST/DeclTemplate.h"
22 #include "clang/AST/StmtVisitor.h"
23 #include "llvm/IR/Constants.h"
24 #include "llvm/IR/Function.h"
25 #include "llvm/IR/GlobalVariable.h"
26 #include "llvm/IR/Intrinsics.h"
27 #include "llvm/IR/IntrinsicInst.h"
28 using namespace clang;
29 using namespace CodeGen;
30 
31 //===----------------------------------------------------------------------===//
32 // Aggregate Expression Emitter
33 //===----------------------------------------------------------------------===//
34 
35 namespace {
36 class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
37  CodeGenFunction &CGF;
38  CGBuilderTy &Builder;
39  AggValueSlot Dest;
40  bool IsResultUnused;
41 
42  AggValueSlot EnsureSlot(QualType T) {
43  if (!Dest.isIgnored()) return Dest;
44  return CGF.CreateAggTemp(T, "agg.tmp.ensured");
45  }
46  void EnsureDest(QualType T) {
47  if (!Dest.isIgnored()) return;
48  Dest = CGF.CreateAggTemp(T, "agg.tmp.ensured");
49  }
50 
51  // Calls `Fn` with a valid return value slot, potentially creating a temporary
52  // to do so. If a temporary is created, an appropriate copy into `Dest` will
53  // be emitted, as will lifetime markers.
54  //
55  // The given function should take a ReturnValueSlot, and return an RValue that
56  // points to said slot.
57  void withReturnValueSlot(const Expr *E,
58  llvm::function_ref<RValue(ReturnValueSlot)> Fn);
59 
60 public:
61  AggExprEmitter(CodeGenFunction &cgf, AggValueSlot Dest, bool IsResultUnused)
62  : CGF(cgf), Builder(CGF.Builder), Dest(Dest),
63  IsResultUnused(IsResultUnused) { }
64 
65  //===--------------------------------------------------------------------===//
66  // Utilities
67  //===--------------------------------------------------------------------===//
68 
69  /// EmitAggLoadOfLValue - Given an expression with aggregate type that
70  /// represents a value lvalue, this method emits the address of the lvalue,
71  /// then loads the result into DestPtr.
72  void EmitAggLoadOfLValue(const Expr *E);
73 
74  enum ExprValueKind {
75  EVK_RValue,
76  EVK_NonRValue
77  };
78 
79  /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
80  /// SrcIsRValue is true if source comes from an RValue.
81  void EmitFinalDestCopy(QualType type, const LValue &src,
82  ExprValueKind SrcValueKind = EVK_NonRValue);
83  void EmitFinalDestCopy(QualType type, RValue src);
84  void EmitCopy(QualType type, const AggValueSlot &dest,
85  const AggValueSlot &src);
86 
87  void EmitMoveFromReturnSlot(const Expr *E, RValue Src);
88 
89  void EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
90  QualType ArrayQTy, InitListExpr *E);
91 
93  if (CGF.getLangOpts().getGC() && TypeRequiresGCollection(T))
96  }
97 
98  bool TypeRequiresGCollection(QualType T);
99 
100  //===--------------------------------------------------------------------===//
101  // Visitor Methods
102  //===--------------------------------------------------------------------===//
103 
104  void Visit(Expr *E) {
105  ApplyDebugLocation DL(CGF, E);
107  }
108 
109  void VisitStmt(Stmt *S) {
110  CGF.ErrorUnsupported(S, "aggregate expression");
111  }
112  void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); }
113  void VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
114  Visit(GE->getResultExpr());
115  }
116  void VisitCoawaitExpr(CoawaitExpr *E) {
117  CGF.EmitCoawaitExpr(*E, Dest, IsResultUnused);
118  }
119  void VisitCoyieldExpr(CoyieldExpr *E) {
120  CGF.EmitCoyieldExpr(*E, Dest, IsResultUnused);
121  }
122  void VisitUnaryCoawait(UnaryOperator *E) { Visit(E->getSubExpr()); }
123  void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); }
124  void VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) {
125  return Visit(E->getReplacement());
126  }
127 
128  // l-values.
129  void VisitDeclRefExpr(DeclRefExpr *E) { EmitAggLoadOfLValue(E); }
130  void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); }
131  void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); }
132  void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); }
133  void VisitCompoundLiteralExpr(CompoundLiteralExpr *E);
134  void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
135  EmitAggLoadOfLValue(E);
136  }
137  void VisitPredefinedExpr(const PredefinedExpr *E) {
138  EmitAggLoadOfLValue(E);
139  }
140 
141  // Operators.
142  void VisitCastExpr(CastExpr *E);
143  void VisitCallExpr(const CallExpr *E);
144  void VisitStmtExpr(const StmtExpr *E);
145  void VisitBinaryOperator(const BinaryOperator *BO);
146  void VisitPointerToDataMemberBinaryOperator(const BinaryOperator *BO);
147  void VisitBinAssign(const BinaryOperator *E);
148  void VisitBinComma(const BinaryOperator *E);
149  void VisitBinCmp(const BinaryOperator *E);
150 
151  void VisitObjCMessageExpr(ObjCMessageExpr *E);
152  void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
153  EmitAggLoadOfLValue(E);
154  }
155 
156  void VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E);
157  void VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
158  void VisitChooseExpr(const ChooseExpr *CE);
159  void VisitInitListExpr(InitListExpr *E);
160  void VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E,
161  llvm::Value *outerBegin = nullptr);
162  void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E);
163  void VisitNoInitExpr(NoInitExpr *E) { } // Do nothing.
164  void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
165  Visit(DAE->getExpr());
166  }
167  void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
169  Visit(DIE->getExpr());
170  }
171  void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
172  void VisitCXXConstructExpr(const CXXConstructExpr *E);
173  void VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E);
174  void VisitLambdaExpr(LambdaExpr *E);
175  void VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E);
176  void VisitExprWithCleanups(ExprWithCleanups *E);
177  void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E);
178  void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); }
179  void VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E);
180  void VisitOpaqueValueExpr(OpaqueValueExpr *E);
181 
182  void VisitPseudoObjectExpr(PseudoObjectExpr *E) {
183  if (E->isGLValue()) {
184  LValue LV = CGF.EmitPseudoObjectLValue(E);
185  return EmitFinalDestCopy(E->getType(), LV);
186  }
187 
188  CGF.EmitPseudoObjectRValue(E, EnsureSlot(E->getType()));
189  }
190 
191  void VisitVAArgExpr(VAArgExpr *E);
192 
193  void EmitInitializationToLValue(Expr *E, LValue Address);
194  void EmitNullInitializationToLValue(LValue Address);
195  // case Expr::ChooseExprClass:
196  void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); }
197  void VisitAtomicExpr(AtomicExpr *E) {
198  RValue Res = CGF.EmitAtomicExpr(E);
199  EmitFinalDestCopy(E->getType(), Res);
200  }
201 };
202 } // end anonymous namespace.
203 
204 //===----------------------------------------------------------------------===//
205 // Utilities
206 //===----------------------------------------------------------------------===//
207 
208 /// EmitAggLoadOfLValue - Given an expression with aggregate type that
209 /// represents a value lvalue, this method emits the address of the lvalue,
210 /// then loads the result into DestPtr.
211 void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) {
212  LValue LV = CGF.EmitLValue(E);
213 
214  // If the type of the l-value is atomic, then do an atomic load.
215  if (LV.getType()->isAtomicType() || CGF.LValueIsSuitableForInlineAtomic(LV)) {
216  CGF.EmitAtomicLoad(LV, E->getExprLoc(), Dest);
217  return;
218  }
219 
220  EmitFinalDestCopy(E->getType(), LV);
221 }
222 
223 /// True if the given aggregate type requires special GC API calls.
224 bool AggExprEmitter::TypeRequiresGCollection(QualType T) {
225  // Only record types have members that might require garbage collection.
226  const RecordType *RecordTy = T->getAs<RecordType>();
227  if (!RecordTy) return false;
228 
229  // Don't mess with non-trivial C++ types.
230  RecordDecl *Record = RecordTy->getDecl();
231  if (isa<CXXRecordDecl>(Record) &&
232  (cast<CXXRecordDecl>(Record)->hasNonTrivialCopyConstructor() ||
233  !cast<CXXRecordDecl>(Record)->hasTrivialDestructor()))
234  return false;
235 
236  // Check whether the type has an object member.
237  return Record->hasObjectMember();
238 }
239 
240 void AggExprEmitter::withReturnValueSlot(
241  const Expr *E, llvm::function_ref<RValue(ReturnValueSlot)> EmitCall) {
242  QualType RetTy = E->getType();
243  bool RequiresDestruction =
244  Dest.isIgnored() &&
246 
247  // If it makes no observable difference, save a memcpy + temporary.
248  //
249  // We need to always provide our own temporary if destruction is required.
250  // Otherwise, EmitCall will emit its own, notice that it's "unused", and end
251  // its lifetime before we have the chance to emit a proper destructor call.
252  bool UseTemp = Dest.isPotentiallyAliased() || Dest.requiresGCollection() ||
253  (RequiresDestruction && !Dest.getAddress().isValid());
254 
255  Address RetAddr = Address::invalid();
256  Address RetAllocaAddr = Address::invalid();
257 
258  EHScopeStack::stable_iterator LifetimeEndBlock;
259  llvm::Value *LifetimeSizePtr = nullptr;
260  llvm::IntrinsicInst *LifetimeStartInst = nullptr;
261  if (!UseTemp) {
262  RetAddr = Dest.getAddress();
263  } else {
264  RetAddr = CGF.CreateMemTemp(RetTy, "tmp", &RetAllocaAddr);
265  uint64_t Size =
266  CGF.CGM.getDataLayout().getTypeAllocSize(CGF.ConvertTypeForMem(RetTy));
267  LifetimeSizePtr = CGF.EmitLifetimeStart(Size, RetAllocaAddr.getPointer());
268  if (LifetimeSizePtr) {
269  LifetimeStartInst =
270  cast<llvm::IntrinsicInst>(std::prev(Builder.GetInsertPoint()));
271  assert(LifetimeStartInst->getIntrinsicID() ==
272  llvm::Intrinsic::lifetime_start &&
273  "Last insertion wasn't a lifetime.start?");
274 
276  NormalEHLifetimeMarker, RetAllocaAddr, LifetimeSizePtr);
277  LifetimeEndBlock = CGF.EHStack.stable_begin();
278  }
279  }
280 
281  RValue Src =
282  EmitCall(ReturnValueSlot(RetAddr, Dest.isVolatile(), IsResultUnused));
283 
284  if (RequiresDestruction)
285  CGF.pushDestroy(RetTy.isDestructedType(), Src.getAggregateAddress(), RetTy);
286 
287  if (!UseTemp)
288  return;
289 
290  assert(Dest.getPointer() != Src.getAggregatePointer());
291  EmitFinalDestCopy(E->getType(), Src);
292 
293  if (!RequiresDestruction && LifetimeStartInst) {
294  // If there's no dtor to run, the copy was the last use of our temporary.
295  // Since we're not guaranteed to be in an ExprWithCleanups, clean up
296  // eagerly.
297  CGF.DeactivateCleanupBlock(LifetimeEndBlock, LifetimeStartInst);
298  CGF.EmitLifetimeEnd(LifetimeSizePtr, RetAllocaAddr.getPointer());
299  }
300 }
301 
302 /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
303 void AggExprEmitter::EmitFinalDestCopy(QualType type, RValue src) {
304  assert(src.isAggregate() && "value must be aggregate value!");
305  LValue srcLV = CGF.MakeAddrLValue(src.getAggregateAddress(), type);
306  EmitFinalDestCopy(type, srcLV, EVK_RValue);
307 }
308 
309 /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
310 void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src,
311  ExprValueKind SrcValueKind) {
312  // If Dest is ignored, then we're evaluating an aggregate expression
313  // in a context that doesn't care about the result. Note that loads
314  // from volatile l-values force the existence of a non-ignored
315  // destination.
316  if (Dest.isIgnored())
317  return;
318 
319  // Copy non-trivial C structs here.
320  LValue DstLV = CGF.MakeAddrLValue(
321  Dest.getAddress(), Dest.isVolatile() ? type.withVolatile() : type);
322 
323  if (SrcValueKind == EVK_RValue) {
325  if (Dest.isPotentiallyAliased())
326  CGF.callCStructMoveAssignmentOperator(DstLV, src);
327  else
328  CGF.callCStructMoveConstructor(DstLV, src);
329  return;
330  }
331  } else {
333  if (Dest.isPotentiallyAliased())
334  CGF.callCStructCopyAssignmentOperator(DstLV, src);
335  else
336  CGF.callCStructCopyConstructor(DstLV, src);
337  return;
338  }
339  }
340 
341  AggValueSlot srcAgg =
343  needsGC(type), AggValueSlot::IsAliased,
345  EmitCopy(type, Dest, srcAgg);
346 }
347 
348 /// Perform a copy from the source into the destination.
349 ///
350 /// \param type - the type of the aggregate being copied; qualifiers are
351 /// ignored
352 void AggExprEmitter::EmitCopy(QualType type, const AggValueSlot &dest,
353  const AggValueSlot &src) {
354  if (dest.requiresGCollection()) {
355  CharUnits sz = dest.getPreferredSize(CGF.getContext(), type);
356  llvm::Value *size = llvm::ConstantInt::get(CGF.SizeTy, sz.getQuantity());
358  dest.getAddress(),
359  src.getAddress(),
360  size);
361  return;
362  }
363 
364  // If the result of the assignment is used, copy the LHS there also.
365  // It's volatile if either side is. Use the minimum alignment of
366  // the two sides.
367  LValue DestLV = CGF.MakeAddrLValue(dest.getAddress(), type);
368  LValue SrcLV = CGF.MakeAddrLValue(src.getAddress(), type);
369  CGF.EmitAggregateCopy(DestLV, SrcLV, type, dest.mayOverlap(),
370  dest.isVolatile() || src.isVolatile());
371 }
372 
373 /// Emit the initializer for a std::initializer_list initialized with a
374 /// real initializer list.
375 void
376 AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
377  // Emit an array containing the elements. The array is externally destructed
378  // if the std::initializer_list object is.
379  ASTContext &Ctx = CGF.getContext();
380  LValue Array = CGF.EmitLValue(E->getSubExpr());
381  assert(Array.isSimple() && "initializer_list array not a simple lvalue");
382  Address ArrayPtr = Array.getAddress();
383 
386  assert(ArrayType && "std::initializer_list constructed from non-array");
387 
388  // FIXME: Perform the checks on the field types in SemaInit.
389  RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
391  if (Field == Record->field_end()) {
392  CGF.ErrorUnsupported(E, "weird std::initializer_list");
393  return;
394  }
395 
396  // Start pointer.
397  if (!Field->getType()->isPointerType() ||
398  !Ctx.hasSameType(Field->getType()->getPointeeType(),
399  ArrayType->getElementType())) {
400  CGF.ErrorUnsupported(E, "weird std::initializer_list");
401  return;
402  }
403 
404  AggValueSlot Dest = EnsureSlot(E->getType());
405  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
406  LValue Start = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
407  llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0);
408  llvm::Value *IdxStart[] = { Zero, Zero };
409  llvm::Value *ArrayStart =
410  Builder.CreateInBoundsGEP(ArrayPtr.getPointer(), IdxStart, "arraystart");
411  CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start);
412  ++Field;
413 
414  if (Field == Record->field_end()) {
415  CGF.ErrorUnsupported(E, "weird std::initializer_list");
416  return;
417  }
418 
419  llvm::Value *Size = Builder.getInt(ArrayType->getSize());
420  LValue EndOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
421  if (Field->getType()->isPointerType() &&
422  Ctx.hasSameType(Field->getType()->getPointeeType(),
423  ArrayType->getElementType())) {
424  // End pointer.
425  llvm::Value *IdxEnd[] = { Zero, Size };
426  llvm::Value *ArrayEnd =
427  Builder.CreateInBoundsGEP(ArrayPtr.getPointer(), IdxEnd, "arrayend");
428  CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength);
429  } else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) {
430  // Length.
431  CGF.EmitStoreThroughLValue(RValue::get(Size), EndOrLength);
432  } else {
433  CGF.ErrorUnsupported(E, "weird std::initializer_list");
434  return;
435  }
436 }
437 
438 /// Determine if E is a trivial array filler, that is, one that is
439 /// equivalent to zero-initialization.
440 static bool isTrivialFiller(Expr *E) {
441  if (!E)
442  return true;
443 
444  if (isa<ImplicitValueInitExpr>(E))
445  return true;
446 
447  if (auto *ILE = dyn_cast<InitListExpr>(E)) {
448  if (ILE->getNumInits())
449  return false;
450  return isTrivialFiller(ILE->getArrayFiller());
451  }
452 
453  if (auto *Cons = dyn_cast_or_null<CXXConstructExpr>(E))
454  return Cons->getConstructor()->isDefaultConstructor() &&
455  Cons->getConstructor()->isTrivial();
456 
457  // FIXME: Are there other cases where we can avoid emitting an initializer?
458  return false;
459 }
460 
461 /// Emit initialization of an array from an initializer list.
462 void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
463  QualType ArrayQTy, InitListExpr *E) {
464  uint64_t NumInitElements = E->getNumInits();
465 
466  uint64_t NumArrayElements = AType->getNumElements();
467  assert(NumInitElements <= NumArrayElements);
468 
469  QualType elementType =
470  CGF.getContext().getAsArrayType(ArrayQTy)->getElementType();
471 
472  // DestPtr is an array*. Construct an elementType* by drilling
473  // down a level.
474  llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
475  llvm::Value *indices[] = { zero, zero };
476  llvm::Value *begin =
477  Builder.CreateInBoundsGEP(DestPtr.getPointer(), indices, "arrayinit.begin");
478 
479  CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
480  CharUnits elementAlign =
481  DestPtr.getAlignment().alignmentOfArrayElement(elementSize);
482 
483  // Consider initializing the array by copying from a global. For this to be
484  // more efficient than per-element initialization, the size of the elements
485  // with explicit initializers should be large enough.
486  if (NumInitElements * elementSize.getQuantity() > 16 &&
487  elementType.isTriviallyCopyableType(CGF.getContext())) {
488  CodeGen::CodeGenModule &CGM = CGF.CGM;
489  ConstantEmitter Emitter(CGM);
490  LangAS AS = ArrayQTy.getAddressSpace();
491  if (llvm::Constant *C = Emitter.tryEmitForInitializer(E, AS, ArrayQTy)) {
492  auto GV = new llvm::GlobalVariable(
493  CGM.getModule(), C->getType(),
494  CGM.isTypeConstant(ArrayQTy, /* ExcludeCtorDtor= */ true),
495  llvm::GlobalValue::PrivateLinkage, C, "constinit",
496  /* InsertBefore= */ nullptr, llvm::GlobalVariable::NotThreadLocal,
498  Emitter.finalize(GV);
499  CharUnits Align = CGM.getContext().getTypeAlignInChars(ArrayQTy);
500  GV->setAlignment(Align.getQuantity());
501  EmitFinalDestCopy(ArrayQTy, CGF.MakeAddrLValue(GV, ArrayQTy, Align));
502  return;
503  }
504  }
505 
506  // Exception safety requires us to destroy all the
507  // already-constructed members if an initializer throws.
508  // For that, we'll need an EH cleanup.
509  QualType::DestructionKind dtorKind = elementType.isDestructedType();
510  Address endOfInit = Address::invalid();
512  llvm::Instruction *cleanupDominator = nullptr;
513  if (CGF.needsEHCleanup(dtorKind)) {
514  // In principle we could tell the cleanup where we are more
515  // directly, but the control flow can get so varied here that it
516  // would actually be quite complex. Therefore we go through an
517  // alloca.
518  endOfInit = CGF.CreateTempAlloca(begin->getType(), CGF.getPointerAlign(),
519  "arrayinit.endOfInit");
520  cleanupDominator = Builder.CreateStore(begin, endOfInit);
521  CGF.pushIrregularPartialArrayCleanup(begin, endOfInit, elementType,
522  elementAlign,
523  CGF.getDestroyer(dtorKind));
524  cleanup = CGF.EHStack.stable_begin();
525 
526  // Otherwise, remember that we didn't need a cleanup.
527  } else {
528  dtorKind = QualType::DK_none;
529  }
530 
531  llvm::Value *one = llvm::ConstantInt::get(CGF.SizeTy, 1);
532 
533  // The 'current element to initialize'. The invariants on this
534  // variable are complicated. Essentially, after each iteration of
535  // the loop, it points to the last initialized element, except
536  // that it points to the beginning of the array before any
537  // elements have been initialized.
538  llvm::Value *element = begin;
539 
540  // Emit the explicit initializers.
541  for (uint64_t i = 0; i != NumInitElements; ++i) {
542  // Advance to the next element.
543  if (i > 0) {
544  element = Builder.CreateInBoundsGEP(element, one, "arrayinit.element");
545 
546  // Tell the cleanup that it needs to destroy up to this
547  // element. TODO: some of these stores can be trivially
548  // observed to be unnecessary.
549  if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit);
550  }
551 
552  LValue elementLV =
553  CGF.MakeAddrLValue(Address(element, elementAlign), elementType);
554  EmitInitializationToLValue(E->getInit(i), elementLV);
555  }
556 
557  // Check whether there's a non-trivial array-fill expression.
558  Expr *filler = E->getArrayFiller();
559  bool hasTrivialFiller = isTrivialFiller(filler);
560 
561  // Any remaining elements need to be zero-initialized, possibly
562  // using the filler expression. We can skip this if the we're
563  // emitting to zeroed memory.
564  if (NumInitElements != NumArrayElements &&
565  !(Dest.isZeroed() && hasTrivialFiller &&
566  CGF.getTypes().isZeroInitializable(elementType))) {
567 
568  // Use an actual loop. This is basically
569  // do { *array++ = filler; } while (array != end);
570 
571  // Advance to the start of the rest of the array.
572  if (NumInitElements) {
573  element = Builder.CreateInBoundsGEP(element, one, "arrayinit.start");
574  if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit);
575  }
576 
577  // Compute the end of the array.
578  llvm::Value *end = Builder.CreateInBoundsGEP(begin,
579  llvm::ConstantInt::get(CGF.SizeTy, NumArrayElements),
580  "arrayinit.end");
581 
582  llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
583  llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body");
584 
585  // Jump into the body.
586  CGF.EmitBlock(bodyBB);
587  llvm::PHINode *currentElement =
588  Builder.CreatePHI(element->getType(), 2, "arrayinit.cur");
589  currentElement->addIncoming(element, entryBB);
590 
591  // Emit the actual filler expression.
592  {
593  // C++1z [class.temporary]p5:
594  // when a default constructor is called to initialize an element of
595  // an array with no corresponding initializer [...] the destruction of
596  // every temporary created in a default argument is sequenced before
597  // the construction of the next array element, if any
598  CodeGenFunction::RunCleanupsScope CleanupsScope(CGF);
599  LValue elementLV =
600  CGF.MakeAddrLValue(Address(currentElement, elementAlign), elementType);
601  if (filler)
602  EmitInitializationToLValue(filler, elementLV);
603  else
604  EmitNullInitializationToLValue(elementLV);
605  }
606 
607  // Move on to the next element.
608  llvm::Value *nextElement =
609  Builder.CreateInBoundsGEP(currentElement, one, "arrayinit.next");
610 
611  // Tell the EH cleanup that we finished with the last element.
612  if (endOfInit.isValid()) Builder.CreateStore(nextElement, endOfInit);
613 
614  // Leave the loop if we're done.
615  llvm::Value *done = Builder.CreateICmpEQ(nextElement, end,
616  "arrayinit.done");
617  llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end");
618  Builder.CreateCondBr(done, endBB, bodyBB);
619  currentElement->addIncoming(nextElement, Builder.GetInsertBlock());
620 
621  CGF.EmitBlock(endBB);
622  }
623 
624  // Leave the partial-array cleanup if we entered one.
625  if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, cleanupDominator);
626 }
627 
628 //===----------------------------------------------------------------------===//
629 // Visitor Methods
630 //===----------------------------------------------------------------------===//
631 
632 void AggExprEmitter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E){
633  Visit(E->GetTemporaryExpr());
634 }
635 
636 void AggExprEmitter::VisitOpaqueValueExpr(OpaqueValueExpr *e) {
637  // If this is a unique OVE, just visit its source expression.
638  if (e->isUnique())
639  Visit(e->getSourceExpr());
640  else
641  EmitFinalDestCopy(e->getType(), CGF.getOrCreateOpaqueLValueMapping(e));
642 }
643 
644 void
645 AggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
646  if (Dest.isPotentiallyAliased() &&
647  E->getType().isPODType(CGF.getContext())) {
648  // For a POD type, just emit a load of the lvalue + a copy, because our
649  // compound literal might alias the destination.
650  EmitAggLoadOfLValue(E);
651  return;
652  }
653 
654  AggValueSlot Slot = EnsureSlot(E->getType());
655  CGF.EmitAggExpr(E->getInitializer(), Slot);
656 }
657 
658 /// Attempt to look through various unimportant expressions to find a
659 /// cast of the given kind.
661  while (true) {
662  op = op->IgnoreParens();
663  if (CastExpr *castE = dyn_cast<CastExpr>(op)) {
664  if (castE->getCastKind() == kind)
665  return castE->getSubExpr();
666  if (castE->getCastKind() == CK_NoOp)
667  continue;
668  }
669  return nullptr;
670  }
671 }
672 
673 void AggExprEmitter::VisitCastExpr(CastExpr *E) {
674  if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
675  CGF.CGM.EmitExplicitCastExprType(ECE, &CGF);
676  switch (E->getCastKind()) {
677  case CK_Dynamic: {
678  // FIXME: Can this actually happen? We have no test coverage for it.
679  assert(isa<CXXDynamicCastExpr>(E) && "CK_Dynamic without a dynamic_cast?");
680  LValue LV = CGF.EmitCheckedLValue(E->getSubExpr(),
682  // FIXME: Do we also need to handle property references here?
683  if (LV.isSimple())
684  CGF.EmitDynamicCast(LV.getAddress(), cast<CXXDynamicCastExpr>(E));
685  else
686  CGF.CGM.ErrorUnsupported(E, "non-simple lvalue dynamic_cast");
687 
688  if (!Dest.isIgnored())
689  CGF.CGM.ErrorUnsupported(E, "lvalue dynamic_cast with a destination");
690  break;
691  }
692 
693  case CK_ToUnion: {
694  // Evaluate even if the destination is ignored.
695  if (Dest.isIgnored()) {
697  /*ignoreResult=*/true);
698  break;
699  }
700 
701  // GCC union extension
702  QualType Ty = E->getSubExpr()->getType();
703  Address CastPtr =
704  Builder.CreateElementBitCast(Dest.getAddress(), CGF.ConvertType(Ty));
705  EmitInitializationToLValue(E->getSubExpr(),
706  CGF.MakeAddrLValue(CastPtr, Ty));
707  break;
708  }
709 
710  case CK_DerivedToBase:
711  case CK_BaseToDerived:
712  case CK_UncheckedDerivedToBase: {
713  llvm_unreachable("cannot perform hierarchy conversion in EmitAggExpr: "
714  "should have been unpacked before we got here");
715  }
716 
717  case CK_NonAtomicToAtomic:
718  case CK_AtomicToNonAtomic: {
719  bool isToAtomic = (E->getCastKind() == CK_NonAtomicToAtomic);
720 
721  // Determine the atomic and value types.
723  QualType valueType = E->getType();
724  if (isToAtomic) std::swap(atomicType, valueType);
725 
726  assert(atomicType->isAtomicType());
727  assert(CGF.getContext().hasSameUnqualifiedType(valueType,
728  atomicType->castAs<AtomicType>()->getValueType()));
729 
730  // Just recurse normally if we're ignoring the result or the
731  // atomic type doesn't change representation.
732  if (Dest.isIgnored() || !CGF.CGM.isPaddedAtomicType(atomicType)) {
733  return Visit(E->getSubExpr());
734  }
735 
736  CastKind peepholeTarget =
737  (isToAtomic ? CK_AtomicToNonAtomic : CK_NonAtomicToAtomic);
738 
739  // These two cases are reverses of each other; try to peephole them.
740  if (Expr *op = findPeephole(E->getSubExpr(), peepholeTarget)) {
741  assert(CGF.getContext().hasSameUnqualifiedType(op->getType(),
742  E->getType()) &&
743  "peephole significantly changed types?");
744  return Visit(op);
745  }
746 
747  // If we're converting an r-value of non-atomic type to an r-value
748  // of atomic type, just emit directly into the relevant sub-object.
749  if (isToAtomic) {
750  AggValueSlot valueDest = Dest;
751  if (!valueDest.isIgnored() && CGF.CGM.isPaddedAtomicType(atomicType)) {
752  // Zero-initialize. (Strictly speaking, we only need to initialize
753  // the padding at the end, but this is simpler.)
754  if (!Dest.isZeroed())
756 
757  // Build a GEP to refer to the subobject.
758  Address valueAddr =
759  CGF.Builder.CreateStructGEP(valueDest.getAddress(), 0,
760  CharUnits());
761  valueDest = AggValueSlot::forAddr(valueAddr,
762  valueDest.getQualifiers(),
763  valueDest.isExternallyDestructed(),
764  valueDest.requiresGCollection(),
765  valueDest.isPotentiallyAliased(),
768  }
769 
770  CGF.EmitAggExpr(E->getSubExpr(), valueDest);
771  return;
772  }
773 
774  // Otherwise, we're converting an atomic type to a non-atomic type.
775  // Make an atomic temporary, emit into that, and then copy the value out.
776  AggValueSlot atomicSlot =
777  CGF.CreateAggTemp(atomicType, "atomic-to-nonatomic.temp");
778  CGF.EmitAggExpr(E->getSubExpr(), atomicSlot);
779 
780  Address valueAddr =
781  Builder.CreateStructGEP(atomicSlot.getAddress(), 0, CharUnits());
782  RValue rvalue = RValue::getAggregate(valueAddr, atomicSlot.isVolatile());
783  return EmitFinalDestCopy(valueType, rvalue);
784  }
785 
786  case CK_LValueToRValue:
787  // If we're loading from a volatile type, force the destination
788  // into existence.
789  if (E->getSubExpr()->getType().isVolatileQualified()) {
790  EnsureDest(E->getType());
791  return Visit(E->getSubExpr());
792  }
793 
794  LLVM_FALLTHROUGH;
795 
796  case CK_NoOp:
797  case CK_UserDefinedConversion:
798  case CK_ConstructorConversion:
800  E->getType()) &&
801  "Implicit cast types must be compatible");
802  Visit(E->getSubExpr());
803  break;
804 
805  case CK_LValueBitCast:
806  llvm_unreachable("should not be emitting lvalue bitcast as rvalue");
807 
808  case CK_Dependent:
809  case CK_BitCast:
810  case CK_ArrayToPointerDecay:
811  case CK_FunctionToPointerDecay:
812  case CK_NullToPointer:
813  case CK_NullToMemberPointer:
814  case CK_BaseToDerivedMemberPointer:
815  case CK_DerivedToBaseMemberPointer:
816  case CK_MemberPointerToBoolean:
817  case CK_ReinterpretMemberPointer:
818  case CK_IntegralToPointer:
819  case CK_PointerToIntegral:
820  case CK_PointerToBoolean:
821  case CK_ToVoid:
822  case CK_VectorSplat:
823  case CK_IntegralCast:
824  case CK_BooleanToSignedIntegral:
825  case CK_IntegralToBoolean:
826  case CK_IntegralToFloating:
827  case CK_FloatingToIntegral:
828  case CK_FloatingToBoolean:
829  case CK_FloatingCast:
830  case CK_CPointerToObjCPointerCast:
831  case CK_BlockPointerToObjCPointerCast:
832  case CK_AnyPointerToBlockPointerCast:
833  case CK_ObjCObjectLValueCast:
834  case CK_FloatingRealToComplex:
835  case CK_FloatingComplexToReal:
836  case CK_FloatingComplexToBoolean:
837  case CK_FloatingComplexCast:
838  case CK_FloatingComplexToIntegralComplex:
839  case CK_IntegralRealToComplex:
840  case CK_IntegralComplexToReal:
841  case CK_IntegralComplexToBoolean:
842  case CK_IntegralComplexCast:
843  case CK_IntegralComplexToFloatingComplex:
844  case CK_ARCProduceObject:
845  case CK_ARCConsumeObject:
846  case CK_ARCReclaimReturnedObject:
847  case CK_ARCExtendBlockObject:
848  case CK_CopyAndAutoreleaseBlockObject:
849  case CK_BuiltinFnToFnPtr:
850  case CK_ZeroToOCLEvent:
851  case CK_ZeroToOCLQueue:
852  case CK_AddressSpaceConversion:
853  case CK_IntToOCLSampler:
854  llvm_unreachable("cast kind invalid for aggregate types");
855  }
856 }
857 
858 void AggExprEmitter::VisitCallExpr(const CallExpr *E) {
859  if (E->getCallReturnType(CGF.getContext())->isReferenceType()) {
860  EmitAggLoadOfLValue(E);
861  return;
862  }
863 
864  withReturnValueSlot(E, [&](ReturnValueSlot Slot) {
865  return CGF.EmitCallExpr(E, Slot);
866  });
867 }
868 
869 void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) {
870  withReturnValueSlot(E, [&](ReturnValueSlot Slot) {
871  return CGF.EmitObjCMessageExpr(E, Slot);
872  });
873 }
874 
875 void AggExprEmitter::VisitBinComma(const BinaryOperator *E) {
876  CGF.EmitIgnoredExpr(E->getLHS());
877  Visit(E->getRHS());
878 }
879 
880 void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) {
882  CGF.EmitCompoundStmt(*E->getSubStmt(), true, Dest);
883 }
884 
889 };
890 
892  const BinaryOperator *E, llvm::Value *LHS,
894  const char *NameSuffix = "") {
895  QualType ArgTy = E->getLHS()->getType();
896  if (const ComplexType *CT = ArgTy->getAs<ComplexType>())
897  ArgTy = CT->getElementType();
898 
899  if (const auto *MPT = ArgTy->getAs<MemberPointerType>()) {
900  assert(Kind == CK_Equal &&
901  "member pointers may only be compared for equality");
903  CGF, LHS, RHS, MPT, /*IsInequality*/ false);
904  }
905 
906  // Compute the comparison instructions for the specified comparison kind.
907  struct CmpInstInfo {
908  const char *Name;
909  llvm::CmpInst::Predicate FCmp;
910  llvm::CmpInst::Predicate SCmp;
911  llvm::CmpInst::Predicate UCmp;
912  };
913  CmpInstInfo InstInfo = [&]() -> CmpInstInfo {
914  using FI = llvm::FCmpInst;
915  using II = llvm::ICmpInst;
916  switch (Kind) {
917  case CK_Less:
918  return {"cmp.lt", FI::FCMP_OLT, II::ICMP_SLT, II::ICMP_ULT};
919  case CK_Greater:
920  return {"cmp.gt", FI::FCMP_OGT, II::ICMP_SGT, II::ICMP_UGT};
921  case CK_Equal:
922  return {"cmp.eq", FI::FCMP_OEQ, II::ICMP_EQ, II::ICMP_EQ};
923  }
924  llvm_unreachable("Unrecognised CompareKind enum");
925  }();
926 
927  if (ArgTy->hasFloatingRepresentation())
928  return Builder.CreateFCmp(InstInfo.FCmp, LHS, RHS,
929  llvm::Twine(InstInfo.Name) + NameSuffix);
930  if (ArgTy->isIntegralOrEnumerationType() || ArgTy->isPointerType()) {
931  auto Inst =
932  ArgTy->hasSignedIntegerRepresentation() ? InstInfo.SCmp : InstInfo.UCmp;
933  return Builder.CreateICmp(Inst, LHS, RHS,
934  llvm::Twine(InstInfo.Name) + NameSuffix);
935  }
936 
937  llvm_unreachable("unsupported aggregate binary expression should have "
938  "already been handled");
939 }
940 
941 void AggExprEmitter::VisitBinCmp(const BinaryOperator *E) {
942  using llvm::BasicBlock;
943  using llvm::PHINode;
944  using llvm::Value;
945  assert(CGF.getContext().hasSameType(E->getLHS()->getType(),
946  E->getRHS()->getType()));
947  const ComparisonCategoryInfo &CmpInfo =
949  assert(CmpInfo.Record->isTriviallyCopyable() &&
950  "cannot copy non-trivially copyable aggregate");
951 
952  QualType ArgTy = E->getLHS()->getType();
953 
954  // TODO: Handle comparing these types.
955  if (ArgTy->isVectorType())
956  return CGF.ErrorUnsupported(
957  E, "aggregate three-way comparison with vector arguments");
958  if (!ArgTy->isIntegralOrEnumerationType() && !ArgTy->isRealFloatingType() &&
959  !ArgTy->isNullPtrType() && !ArgTy->isPointerType() &&
960  !ArgTy->isMemberPointerType() && !ArgTy->isAnyComplexType()) {
961  return CGF.ErrorUnsupported(E, "aggregate three-way comparison");
962  }
963  bool IsComplex = ArgTy->isAnyComplexType();
964 
965  // Evaluate the operands to the expression and extract their values.
966  auto EmitOperand = [&](Expr *E) -> std::pair<Value *, Value *> {
967  RValue RV = CGF.EmitAnyExpr(E);
968  if (RV.isScalar())
969  return {RV.getScalarVal(), nullptr};
970  if (RV.isAggregate())
971  return {RV.getAggregatePointer(), nullptr};
972  assert(RV.isComplex());
973  return RV.getComplexVal();
974  };
975  auto LHSValues = EmitOperand(E->getLHS()),
976  RHSValues = EmitOperand(E->getRHS());
977 
978  auto EmitCmp = [&](CompareKind K) {
979  Value *Cmp = EmitCompare(Builder, CGF, E, LHSValues.first, RHSValues.first,
980  K, IsComplex ? ".r" : "");
981  if (!IsComplex)
982  return Cmp;
983  assert(K == CompareKind::CK_Equal);
984  Value *CmpImag = EmitCompare(Builder, CGF, E, LHSValues.second,
985  RHSValues.second, K, ".i");
986  return Builder.CreateAnd(Cmp, CmpImag, "and.eq");
987  };
988  auto EmitCmpRes = [&](const ComparisonCategoryInfo::ValueInfo *VInfo) {
989  return Builder.getInt(VInfo->getIntValue());
990  };
991 
992  Value *Select;
993  if (ArgTy->isNullPtrType()) {
994  Select = EmitCmpRes(CmpInfo.getEqualOrEquiv());
995  } else if (CmpInfo.isEquality()) {
996  Select = Builder.CreateSelect(
997  EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()),
998  EmitCmpRes(CmpInfo.getNonequalOrNonequiv()), "sel.eq");
999  } else if (!CmpInfo.isPartial()) {
1000  Value *SelectOne =
1001  Builder.CreateSelect(EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()),
1002  EmitCmpRes(CmpInfo.getGreater()), "sel.lt");
1003  Select = Builder.CreateSelect(EmitCmp(CK_Equal),
1004  EmitCmpRes(CmpInfo.getEqualOrEquiv()),
1005  SelectOne, "sel.eq");
1006  } else {
1007  Value *SelectEq = Builder.CreateSelect(
1008  EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()),
1009  EmitCmpRes(CmpInfo.getUnordered()), "sel.eq");
1010  Value *SelectGT = Builder.CreateSelect(EmitCmp(CK_Greater),
1011  EmitCmpRes(CmpInfo.getGreater()),
1012  SelectEq, "sel.gt");
1013  Select = Builder.CreateSelect(
1014  EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()), SelectGT, "sel.lt");
1015  }
1016  // Create the return value in the destination slot.
1017  EnsureDest(E->getType());
1018  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
1019 
1020  // Emit the address of the first (and only) field in the comparison category
1021  // type, and initialize it from the constant integer value selected above.
1023  DestLV, *CmpInfo.Record->field_begin());
1024  CGF.EmitStoreThroughLValue(RValue::get(Select), FieldLV, /*IsInit*/ true);
1025 
1026  // All done! The result is in the Dest slot.
1027 }
1028 
1029 void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) {
1030  if (E->getOpcode() == BO_PtrMemD || E->getOpcode() == BO_PtrMemI)
1031  VisitPointerToDataMemberBinaryOperator(E);
1032  else
1033  CGF.ErrorUnsupported(E, "aggregate binary expression");
1034 }
1035 
1036 void AggExprEmitter::VisitPointerToDataMemberBinaryOperator(
1037  const BinaryOperator *E) {
1039  EmitFinalDestCopy(E->getType(), LV);
1040 }
1041 
1042 /// Is the value of the given expression possibly a reference to or
1043 /// into a __block variable?
1044 static bool isBlockVarRef(const Expr *E) {
1045  // Make sure we look through parens.
1046  E = E->IgnoreParens();
1047 
1048  // Check for a direct reference to a __block variable.
1049  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
1050  const VarDecl *var = dyn_cast<VarDecl>(DRE->getDecl());
1051  return (var && var->hasAttr<BlocksAttr>());
1052  }
1053 
1054  // More complicated stuff.
1055 
1056  // Binary operators.
1057  if (const BinaryOperator *op = dyn_cast<BinaryOperator>(E)) {
1058  // For an assignment or pointer-to-member operation, just care
1059  // about the LHS.
1060  if (op->isAssignmentOp() || op->isPtrMemOp())
1061  return isBlockVarRef(op->getLHS());
1062 
1063  // For a comma, just care about the RHS.
1064  if (op->getOpcode() == BO_Comma)
1065  return isBlockVarRef(op->getRHS());
1066 
1067  // FIXME: pointer arithmetic?
1068  return false;
1069 
1070  // Check both sides of a conditional operator.
1071  } else if (const AbstractConditionalOperator *op
1072  = dyn_cast<AbstractConditionalOperator>(E)) {
1073  return isBlockVarRef(op->getTrueExpr())
1074  || isBlockVarRef(op->getFalseExpr());
1075 
1076  // OVEs are required to support BinaryConditionalOperators.
1077  } else if (const OpaqueValueExpr *op
1078  = dyn_cast<OpaqueValueExpr>(E)) {
1079  if (const Expr *src = op->getSourceExpr())
1080  return isBlockVarRef(src);
1081 
1082  // Casts are necessary to get things like (*(int*)&var) = foo().
1083  // We don't really care about the kind of cast here, except
1084  // we don't want to look through l2r casts, because it's okay
1085  // to get the *value* in a __block variable.
1086  } else if (const CastExpr *cast = dyn_cast<CastExpr>(E)) {
1087  if (cast->getCastKind() == CK_LValueToRValue)
1088  return false;
1089  return isBlockVarRef(cast->getSubExpr());
1090 
1091  // Handle unary operators. Again, just aggressively look through
1092  // it, ignoring the operation.
1093  } else if (const UnaryOperator *uop = dyn_cast<UnaryOperator>(E)) {
1094  return isBlockVarRef(uop->getSubExpr());
1095 
1096  // Look into the base of a field access.
1097  } else if (const MemberExpr *mem = dyn_cast<MemberExpr>(E)) {
1098  return isBlockVarRef(mem->getBase());
1099 
1100  // Look into the base of a subscript.
1101  } else if (const ArraySubscriptExpr *sub = dyn_cast<ArraySubscriptExpr>(E)) {
1102  return isBlockVarRef(sub->getBase());
1103  }
1104 
1105  return false;
1106 }
1107 
1108 void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
1109  // For an assignment to work, the value on the right has
1110  // to be compatible with the value on the left.
1111  assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
1112  E->getRHS()->getType())
1113  && "Invalid assignment");
1114 
1115  // If the LHS might be a __block variable, and the RHS can
1116  // potentially cause a block copy, we need to evaluate the RHS first
1117  // so that the assignment goes the right place.
1118  // This is pretty semantically fragile.
1119  if (isBlockVarRef(E->getLHS()) &&
1120  E->getRHS()->HasSideEffects(CGF.getContext())) {
1121  // Ensure that we have a destination, and evaluate the RHS into that.
1122  EnsureDest(E->getRHS()->getType());
1123  Visit(E->getRHS());
1124 
1125  // Now emit the LHS and copy into it.
1127 
1128  // That copy is an atomic copy if the LHS is atomic.
1129  if (LHS.getType()->isAtomicType() ||
1131  CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false);
1132  return;
1133  }
1134 
1135  EmitCopy(E->getLHS()->getType(),
1137  needsGC(E->getLHS()->getType()),
1140  Dest);
1141  return;
1142  }
1143 
1144  LValue LHS = CGF.EmitLValue(E->getLHS());
1145 
1146  // If we have an atomic type, evaluate into the destination and then
1147  // do an atomic copy.
1148  if (LHS.getType()->isAtomicType() ||
1150  EnsureDest(E->getRHS()->getType());
1151  Visit(E->getRHS());
1152  CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false);
1153  return;
1154  }
1155 
1156  // Codegen the RHS so that it stores directly into the LHS.
1157  AggValueSlot LHSSlot =
1159  needsGC(E->getLHS()->getType()),
1162  // A non-volatile aggregate destination might have volatile member.
1163  if (!LHSSlot.isVolatile() &&
1164  CGF.hasVolatileMember(E->getLHS()->getType()))
1165  LHSSlot.setVolatile(true);
1166 
1167  CGF.EmitAggExpr(E->getRHS(), LHSSlot);
1168 
1169  // Copy into the destination if the assignment isn't ignored.
1170  EmitFinalDestCopy(E->getType(), LHS);
1171 }
1172 
1173 void AggExprEmitter::
1174 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
1175  llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
1176  llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
1177  llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
1178 
1179  // Bind the common expression if necessary.
1180  CodeGenFunction::OpaqueValueMapping binding(CGF, E);
1181 
1183  CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock,
1184  CGF.getProfileCount(E));
1185 
1186  // Save whether the destination's lifetime is externally managed.
1187  bool isExternallyDestructed = Dest.isExternallyDestructed();
1188 
1189  eval.begin(CGF);
1190  CGF.EmitBlock(LHSBlock);
1191  CGF.incrementProfileCounter(E);
1192  Visit(E->getTrueExpr());
1193  eval.end(CGF);
1194 
1195  assert(CGF.HaveInsertPoint() && "expression evaluation ended with no IP!");
1196  CGF.Builder.CreateBr(ContBlock);
1197 
1198  // If the result of an agg expression is unused, then the emission
1199  // of the LHS might need to create a destination slot. That's fine
1200  // with us, and we can safely emit the RHS into the same slot, but
1201  // we shouldn't claim that it's already being destructed.
1202  Dest.setExternallyDestructed(isExternallyDestructed);
1203 
1204  eval.begin(CGF);
1205  CGF.EmitBlock(RHSBlock);
1206  Visit(E->getFalseExpr());
1207  eval.end(CGF);
1208 
1209  CGF.EmitBlock(ContBlock);
1210 }
1211 
1212 void AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) {
1213  Visit(CE->getChosenSubExpr());
1214 }
1215 
1216 void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
1217  Address ArgValue = Address::invalid();
1218  Address ArgPtr = CGF.EmitVAArg(VE, ArgValue);
1219 
1220  // If EmitVAArg fails, emit an error.
1221  if (!ArgPtr.isValid()) {
1222  CGF.ErrorUnsupported(VE, "aggregate va_arg expression");
1223  return;
1224  }
1225 
1226  EmitFinalDestCopy(VE->getType(), CGF.MakeAddrLValue(ArgPtr, VE->getType()));
1227 }
1228 
1229 void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
1230  // Ensure that we have a slot, but if we already do, remember
1231  // whether it was externally destructed.
1232  bool wasExternallyDestructed = Dest.isExternallyDestructed();
1233  EnsureDest(E->getType());
1234 
1235  // We're going to push a destructor if there isn't already one.
1236  Dest.setExternallyDestructed();
1237 
1238  Visit(E->getSubExpr());
1239 
1240  // Push that destructor we promised.
1241  if (!wasExternallyDestructed)
1242  CGF.EmitCXXTemporary(E->getTemporary(), E->getType(), Dest.getAddress());
1243 }
1244 
1245 void
1246 AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) {
1247  AggValueSlot Slot = EnsureSlot(E->getType());
1248  CGF.EmitCXXConstructExpr(E, Slot);
1249 }
1250 
1251 void AggExprEmitter::VisitCXXInheritedCtorInitExpr(
1252  const CXXInheritedCtorInitExpr *E) {
1253  AggValueSlot Slot = EnsureSlot(E->getType());
1255  E->getConstructor(), E->constructsVBase(), Slot.getAddress(),
1256  E->inheritedFromVBase(), E);
1257 }
1258 
1259 void
1260 AggExprEmitter::VisitLambdaExpr(LambdaExpr *E) {
1261  AggValueSlot Slot = EnsureSlot(E->getType());
1262  CGF.EmitLambdaExpr(E, Slot);
1263 }
1264 
1265 void AggExprEmitter::VisitExprWithCleanups(ExprWithCleanups *E) {
1266  CGF.enterFullExpression(E);
1267  CodeGenFunction::RunCleanupsScope cleanups(CGF);
1268  Visit(E->getSubExpr());
1269 }
1270 
1271 void AggExprEmitter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
1272  QualType T = E->getType();
1273  AggValueSlot Slot = EnsureSlot(T);
1274  EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T));
1275 }
1276 
1277 void AggExprEmitter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
1278  QualType T = E->getType();
1279  AggValueSlot Slot = EnsureSlot(T);
1280  EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T));
1281 }
1282 
1283 /// isSimpleZero - If emitting this value will obviously just cause a store of
1284 /// zero to memory, return true. This can return false if uncertain, so it just
1285 /// handles simple cases.
1286 static bool isSimpleZero(const Expr *E, CodeGenFunction &CGF) {
1287  E = E->IgnoreParens();
1288 
1289  // 0
1290  if (const IntegerLiteral *IL = dyn_cast<IntegerLiteral>(E))
1291  return IL->getValue() == 0;
1292  // +0.0
1293  if (const FloatingLiteral *FL = dyn_cast<FloatingLiteral>(E))
1294  return FL->getValue().isPosZero();
1295  // int()
1296  if ((isa<ImplicitValueInitExpr>(E) || isa<CXXScalarValueInitExpr>(E)) &&
1297  CGF.getTypes().isZeroInitializable(E->getType()))
1298  return true;
1299  // (int*)0 - Null pointer expressions.
1300  if (const CastExpr *ICE = dyn_cast<CastExpr>(E))
1301  return ICE->getCastKind() == CK_NullToPointer &&
1303  // '\0'
1304  if (const CharacterLiteral *CL = dyn_cast<CharacterLiteral>(E))
1305  return CL->getValue() == 0;
1306 
1307  // Otherwise, hard case: conservatively return false.
1308  return false;
1309 }
1310 
1311 
1312 void
1313 AggExprEmitter::EmitInitializationToLValue(Expr *E, LValue LV) {
1314  QualType type = LV.getType();
1315  // FIXME: Ignore result?
1316  // FIXME: Are initializers affected by volatile?
1317  if (Dest.isZeroed() && isSimpleZero(E, CGF)) {
1318  // Storing "i32 0" to a zero'd memory location is a noop.
1319  return;
1320  } else if (isa<ImplicitValueInitExpr>(E) || isa<CXXScalarValueInitExpr>(E)) {
1321  return EmitNullInitializationToLValue(LV);
1322  } else if (isa<NoInitExpr>(E)) {
1323  // Do nothing.
1324  return;
1325  } else if (type->isReferenceType()) {
1326  RValue RV = CGF.EmitReferenceBindingToExpr(E);
1327  return CGF.EmitStoreThroughLValue(RV, LV);
1328  }
1329 
1330  switch (CGF.getEvaluationKind(type)) {
1331  case TEK_Complex:
1332  CGF.EmitComplexExprIntoLValue(E, LV, /*isInit*/ true);
1333  return;
1334  case TEK_Aggregate:
1340  Dest.isZeroed()));
1341  return;
1342  case TEK_Scalar:
1343  if (LV.isSimple()) {
1344  CGF.EmitScalarInit(E, /*D=*/nullptr, LV, /*Captured=*/false);
1345  } else {
1347  }
1348  return;
1349  }
1350  llvm_unreachable("bad evaluation kind");
1351 }
1352 
1353 void AggExprEmitter::EmitNullInitializationToLValue(LValue lv) {
1354  QualType type = lv.getType();
1355 
1356  // If the destination slot is already zeroed out before the aggregate is
1357  // copied into it, we don't have to emit any zeros here.
1358  if (Dest.isZeroed() && CGF.getTypes().isZeroInitializable(type))
1359  return;
1360 
1361  if (CGF.hasScalarEvaluationKind(type)) {
1362  // For non-aggregates, we can store the appropriate null constant.
1363  llvm::Value *null = CGF.CGM.EmitNullConstant(type);
1364  // Note that the following is not equivalent to
1365  // EmitStoreThroughBitfieldLValue for ARC types.
1366  if (lv.isBitField()) {
1368  } else {
1369  assert(lv.isSimple());
1370  CGF.EmitStoreOfScalar(null, lv, /* isInitialization */ true);
1371  }
1372  } else {
1373  // There's a potential optimization opportunity in combining
1374  // memsets; that would be easy for arrays, but relatively
1375  // difficult for structures with the current code.
1376  CGF.EmitNullInitialization(lv.getAddress(), lv.getType());
1377  }
1378 }
1379 
1380 void AggExprEmitter::VisitInitListExpr(InitListExpr *E) {
1381 #if 0
1382  // FIXME: Assess perf here? Figure out what cases are worth optimizing here
1383  // (Length of globals? Chunks of zeroed-out space?).
1384  //
1385  // If we can, prefer a copy from a global; this is a lot less code for long
1386  // globals, and it's easier for the current optimizers to analyze.
1387  if (llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, E->getType(), &CGF)) {
1388  llvm::GlobalVariable* GV =
1389  new llvm::GlobalVariable(CGF.CGM.getModule(), C->getType(), true,
1391  EmitFinalDestCopy(E->getType(), CGF.MakeAddrLValue(GV, E->getType()));
1392  return;
1393  }
1394 #endif
1395  if (E->hadArrayRangeDesignator())
1396  CGF.ErrorUnsupported(E, "GNU array range designator extension");
1397 
1398  if (E->isTransparent())
1399  return Visit(E->getInit(0));
1400 
1401  AggValueSlot Dest = EnsureSlot(E->getType());
1402 
1403  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
1404 
1405  // Handle initialization of an array.
1406  if (E->getType()->isArrayType()) {
1407  auto AType = cast<llvm::ArrayType>(Dest.getAddress().getElementType());
1408  EmitArrayInit(Dest.getAddress(), AType, E->getType(), E);
1409  return;
1410  }
1411 
1412  assert(E->getType()->isRecordType() && "Only support structs/unions here!");
1413 
1414  // Do struct initialization; this code just sets each individual member
1415  // to the approprate value. This makes bitfield support automatic;
1416  // the disadvantage is that the generated code is more difficult for
1417  // the optimizer, especially with bitfields.
1418  unsigned NumInitElements = E->getNumInits();
1419  RecordDecl *record = E->getType()->castAs<RecordType>()->getDecl();
1420 
1421  // We'll need to enter cleanup scopes in case any of the element
1422  // initializers throws an exception.
1424  llvm::Instruction *cleanupDominator = nullptr;
1425 
1426  unsigned curInitIndex = 0;
1427 
1428  // Emit initialization of base classes.
1429  if (auto *CXXRD = dyn_cast<CXXRecordDecl>(record)) {
1430  assert(E->getNumInits() >= CXXRD->getNumBases() &&
1431  "missing initializer for base class");
1432  for (auto &Base : CXXRD->bases()) {
1433  assert(!Base.isVirtual() && "should not see vbases here");
1434  auto *BaseRD = Base.getType()->getAsCXXRecordDecl();
1436  Dest.getAddress(), CXXRD, BaseRD,
1437  /*isBaseVirtual*/ false);
1439  V, Qualifiers(),
1443  CGF.overlapForBaseInit(CXXRD, BaseRD, Base.isVirtual()));
1444  CGF.EmitAggExpr(E->getInit(curInitIndex++), AggSlot);
1445 
1446  if (QualType::DestructionKind dtorKind =
1447  Base.getType().isDestructedType()) {
1448  CGF.pushDestroy(dtorKind, V, Base.getType());
1449  cleanups.push_back(CGF.EHStack.stable_begin());
1450  }
1451  }
1452  }
1453 
1454  // Prepare a 'this' for CXXDefaultInitExprs.
1456 
1457  if (record->isUnion()) {
1458  // Only initialize one field of a union. The field itself is
1459  // specified by the initializer list.
1460  if (!E->getInitializedFieldInUnion()) {
1461  // Empty union; we have nothing to do.
1462 
1463 #ifndef NDEBUG
1464  // Make sure that it's really an empty and not a failure of
1465  // semantic analysis.
1466  for (const auto *Field : record->fields())
1467  assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed");
1468 #endif
1469  return;
1470  }
1471 
1472  // FIXME: volatility
1473  FieldDecl *Field = E->getInitializedFieldInUnion();
1474 
1475  LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestLV, Field);
1476  if (NumInitElements) {
1477  // Store the initializer into the field
1478  EmitInitializationToLValue(E->getInit(0), FieldLoc);
1479  } else {
1480  // Default-initialize to null.
1481  EmitNullInitializationToLValue(FieldLoc);
1482  }
1483 
1484  return;
1485  }
1486 
1487  // Here we iterate over the fields; this makes it simpler to both
1488  // default-initialize fields and skip over unnamed fields.
1489  for (const auto *field : record->fields()) {
1490  // We're done once we hit the flexible array member.
1491  if (field->getType()->isIncompleteArrayType())
1492  break;
1493 
1494  // Always skip anonymous bitfields.
1495  if (field->isUnnamedBitfield())
1496  continue;
1497 
1498  // We're done if we reach the end of the explicit initializers, we
1499  // have a zeroed object, and the rest of the fields are
1500  // zero-initializable.
1501  if (curInitIndex == NumInitElements && Dest.isZeroed() &&
1502  CGF.getTypes().isZeroInitializable(E->getType()))
1503  break;
1504 
1505 
1506  LValue LV = CGF.EmitLValueForFieldInitialization(DestLV, field);
1507  // We never generate write-barries for initialized fields.
1508  LV.setNonGC(true);
1509 
1510  if (curInitIndex < NumInitElements) {
1511  // Store the initializer into the field.
1512  EmitInitializationToLValue(E->getInit(curInitIndex++), LV);
1513  } else {
1514  // We're out of initializers; default-initialize to null
1515  EmitNullInitializationToLValue(LV);
1516  }
1517 
1518  // Push a destructor if necessary.
1519  // FIXME: if we have an array of structures, all explicitly
1520  // initialized, we can end up pushing a linear number of cleanups.
1521  bool pushedCleanup = false;
1522  if (QualType::DestructionKind dtorKind
1523  = field->getType().isDestructedType()) {
1524  assert(LV.isSimple());
1525  if (CGF.needsEHCleanup(dtorKind)) {
1526  if (!cleanupDominator)
1527  cleanupDominator = CGF.Builder.CreateAlignedLoad(
1528  CGF.Int8Ty,
1529  llvm::Constant::getNullValue(CGF.Int8PtrTy),
1530  CharUnits::One()); // placeholder
1531 
1532  CGF.pushDestroy(EHCleanup, LV.getAddress(), field->getType(),
1533  CGF.getDestroyer(dtorKind), false);
1534  cleanups.push_back(CGF.EHStack.stable_begin());
1535  pushedCleanup = true;
1536  }
1537  }
1538 
1539  // If the GEP didn't get used because of a dead zero init or something
1540  // else, clean it up for -O0 builds and general tidiness.
1541  if (!pushedCleanup && LV.isSimple())
1542  if (llvm::GetElementPtrInst *GEP =
1543  dyn_cast<llvm::GetElementPtrInst>(LV.getPointer()))
1544  if (GEP->use_empty())
1545  GEP->eraseFromParent();
1546  }
1547 
1548  // Deactivate all the partial cleanups in reverse order, which
1549  // generally means popping them.
1550  for (unsigned i = cleanups.size(); i != 0; --i)
1551  CGF.DeactivateCleanupBlock(cleanups[i-1], cleanupDominator);
1552 
1553  // Destroy the placeholder if we made one.
1554  if (cleanupDominator)
1555  cleanupDominator->eraseFromParent();
1556 }
1557 
1558 void AggExprEmitter::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E,
1559  llvm::Value *outerBegin) {
1560  // Emit the common subexpression.
1562 
1563  Address destPtr = EnsureSlot(E->getType()).getAddress();
1564  uint64_t numElements = E->getArraySize().getZExtValue();
1565 
1566  if (!numElements)
1567  return;
1568 
1569  // destPtr is an array*. Construct an elementType* by drilling down a level.
1570  llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
1571  llvm::Value *indices[] = {zero, zero};
1572  llvm::Value *begin = Builder.CreateInBoundsGEP(destPtr.getPointer(), indices,
1573  "arrayinit.begin");
1574 
1575  // Prepare to special-case multidimensional array initialization: we avoid
1576  // emitting multiple destructor loops in that case.
1577  if (!outerBegin)
1578  outerBegin = begin;
1579  ArrayInitLoopExpr *InnerLoop = dyn_cast<ArrayInitLoopExpr>(E->getSubExpr());
1580 
1581  QualType elementType =
1582  CGF.getContext().getAsArrayType(E->getType())->getElementType();
1583  CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
1584  CharUnits elementAlign =
1585  destPtr.getAlignment().alignmentOfArrayElement(elementSize);
1586 
1587  llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
1588  llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body");
1589 
1590  // Jump into the body.
1591  CGF.EmitBlock(bodyBB);
1592  llvm::PHINode *index =
1593  Builder.CreatePHI(zero->getType(), 2, "arrayinit.index");
1594  index->addIncoming(zero, entryBB);
1595  llvm::Value *element = Builder.CreateInBoundsGEP(begin, index);
1596 
1597  // Prepare for a cleanup.
1598  QualType::DestructionKind dtorKind = elementType.isDestructedType();
1600  if (CGF.needsEHCleanup(dtorKind) && !InnerLoop) {
1601  if (outerBegin->getType() != element->getType())
1602  outerBegin = Builder.CreateBitCast(outerBegin, element->getType());
1603  CGF.pushRegularPartialArrayCleanup(outerBegin, element, elementType,
1604  elementAlign,
1605  CGF.getDestroyer(dtorKind));
1606  cleanup = CGF.EHStack.stable_begin();
1607  } else {
1608  dtorKind = QualType::DK_none;
1609  }
1610 
1611  // Emit the actual filler expression.
1612  {
1613  // Temporaries created in an array initialization loop are destroyed
1614  // at the end of each iteration.
1615  CodeGenFunction::RunCleanupsScope CleanupsScope(CGF);
1617  LValue elementLV =
1618  CGF.MakeAddrLValue(Address(element, elementAlign), elementType);
1619 
1620  if (InnerLoop) {
1621  // If the subexpression is an ArrayInitLoopExpr, share its cleanup.
1622  auto elementSlot = AggValueSlot::forLValue(
1623  elementLV, AggValueSlot::IsDestructed,
1627  AggExprEmitter(CGF, elementSlot, false)
1628  .VisitArrayInitLoopExpr(InnerLoop, outerBegin);
1629  } else
1630  EmitInitializationToLValue(E->getSubExpr(), elementLV);
1631  }
1632 
1633  // Move on to the next element.
1634  llvm::Value *nextIndex = Builder.CreateNUWAdd(
1635  index, llvm::ConstantInt::get(CGF.SizeTy, 1), "arrayinit.next");
1636  index->addIncoming(nextIndex, Builder.GetInsertBlock());
1637 
1638  // Leave the loop if we're done.
1639  llvm::Value *done = Builder.CreateICmpEQ(
1640  nextIndex, llvm::ConstantInt::get(CGF.SizeTy, numElements),
1641  "arrayinit.done");
1642  llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end");
1643  Builder.CreateCondBr(done, endBB, bodyBB);
1644 
1645  CGF.EmitBlock(endBB);
1646 
1647  // Leave the partial-array cleanup if we entered one.
1648  if (dtorKind)
1649  CGF.DeactivateCleanupBlock(cleanup, index);
1650 }
1651 
1652 void AggExprEmitter::VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E) {
1653  AggValueSlot Dest = EnsureSlot(E->getType());
1654 
1655  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
1656  EmitInitializationToLValue(E->getBase(), DestLV);
1657  VisitInitListExpr(E->getUpdater());
1658 }
1659 
1660 //===----------------------------------------------------------------------===//
1661 // Entry Points into this File
1662 //===----------------------------------------------------------------------===//
1663 
1664 /// GetNumNonZeroBytesInInit - Get an approximate count of the number of
1665 /// non-zero bytes that will be stored when outputting the initializer for the
1666 /// specified initializer expression.
1668  E = E->IgnoreParens();
1669 
1670  // 0 and 0.0 won't require any non-zero stores!
1671  if (isSimpleZero(E, CGF)) return CharUnits::Zero();
1672 
1673  // If this is an initlist expr, sum up the size of sizes of the (present)
1674  // elements. If this is something weird, assume the whole thing is non-zero.
1675  const InitListExpr *ILE = dyn_cast<InitListExpr>(E);
1676  while (ILE && ILE->isTransparent())
1677  ILE = dyn_cast<InitListExpr>(ILE->getInit(0));
1678  if (!ILE || !CGF.getTypes().isZeroInitializable(ILE->getType()))
1679  return CGF.getContext().getTypeSizeInChars(E->getType());
1680 
1681  // InitListExprs for structs have to be handled carefully. If there are
1682  // reference members, we need to consider the size of the reference, not the
1683  // referencee. InitListExprs for unions and arrays can't have references.
1684  if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
1685  if (!RT->isUnionType()) {
1686  RecordDecl *SD = E->getType()->getAs<RecordType>()->getDecl();
1687  CharUnits NumNonZeroBytes = CharUnits::Zero();
1688 
1689  unsigned ILEElement = 0;
1690  if (auto *CXXRD = dyn_cast<CXXRecordDecl>(SD))
1691  while (ILEElement != CXXRD->getNumBases())
1692  NumNonZeroBytes +=
1693  GetNumNonZeroBytesInInit(ILE->getInit(ILEElement++), CGF);
1694  for (const auto *Field : SD->fields()) {
1695  // We're done once we hit the flexible array member or run out of
1696  // InitListExpr elements.
1697  if (Field->getType()->isIncompleteArrayType() ||
1698  ILEElement == ILE->getNumInits())
1699  break;
1700  if (Field->isUnnamedBitfield())
1701  continue;
1702 
1703  const Expr *E = ILE->getInit(ILEElement++);
1704 
1705  // Reference values are always non-null and have the width of a pointer.
1706  if (Field->getType()->isReferenceType())
1707  NumNonZeroBytes += CGF.getContext().toCharUnitsFromBits(
1708  CGF.getTarget().getPointerWidth(0));
1709  else
1710  NumNonZeroBytes += GetNumNonZeroBytesInInit(E, CGF);
1711  }
1712 
1713  return NumNonZeroBytes;
1714  }
1715  }
1716 
1717 
1718  CharUnits NumNonZeroBytes = CharUnits::Zero();
1719  for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i)
1720  NumNonZeroBytes += GetNumNonZeroBytesInInit(ILE->getInit(i), CGF);
1721  return NumNonZeroBytes;
1722 }
1723 
1724 /// CheckAggExprForMemSetUse - If the initializer is large and has a lot of
1725 /// zeros in it, emit a memset and avoid storing the individual zeros.
1726 ///
1727 static void CheckAggExprForMemSetUse(AggValueSlot &Slot, const Expr *E,
1728  CodeGenFunction &CGF) {
1729  // If the slot is already known to be zeroed, nothing to do. Don't mess with
1730  // volatile stores.
1731  if (Slot.isZeroed() || Slot.isVolatile() || !Slot.getAddress().isValid())
1732  return;
1733 
1734  // C++ objects with a user-declared constructor don't need zero'ing.
1735  if (CGF.getLangOpts().CPlusPlus)
1736  if (const RecordType *RT = CGF.getContext()
1737  .getBaseElementType(E->getType())->getAs<RecordType>()) {
1738  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1739  if (RD->hasUserDeclaredConstructor())
1740  return;
1741  }
1742 
1743  // If the type is 16-bytes or smaller, prefer individual stores over memset.
1744  CharUnits Size = Slot.getPreferredSize(CGF.getContext(), E->getType());
1745  if (Size <= CharUnits::fromQuantity(16))
1746  return;
1747 
1748  // Check to see if over 3/4 of the initializer are known to be zero. If so,
1749  // we prefer to emit memset + individual stores for the rest.
1750  CharUnits NumNonZeroBytes = GetNumNonZeroBytesInInit(E, CGF);
1751  if (NumNonZeroBytes*4 > Size)
1752  return;
1753 
1754  // Okay, it seems like a good idea to use an initial memset, emit the call.
1755  llvm::Constant *SizeVal = CGF.Builder.getInt64(Size.getQuantity());
1756 
1757  Address Loc = Slot.getAddress();
1758  Loc = CGF.Builder.CreateElementBitCast(Loc, CGF.Int8Ty);
1759  CGF.Builder.CreateMemSet(Loc, CGF.Builder.getInt8(0), SizeVal, false);
1760 
1761  // Tell the AggExprEmitter that the slot is known zero.
1762  Slot.setZeroed();
1763 }
1764 
1765 
1766 
1767 
1768 /// EmitAggExpr - Emit the computation of the specified expression of aggregate
1769 /// type. The result is computed into DestPtr. Note that if DestPtr is null,
1770 /// the value of the aggregate expression is not needed. If VolatileDest is
1771 /// true, DestPtr cannot be 0.
1773  assert(E && hasAggregateEvaluationKind(E->getType()) &&
1774  "Invalid aggregate expression to emit");
1775  assert((Slot.getAddress().isValid() || Slot.isIgnored()) &&
1776  "slot has bits but no address");
1777 
1778  // Optimize the slot if possible.
1779  CheckAggExprForMemSetUse(Slot, E, *this);
1780 
1781  AggExprEmitter(*this, Slot, Slot.isIgnored()).Visit(const_cast<Expr*>(E));
1782 }
1783 
1785  assert(hasAggregateEvaluationKind(E->getType()) && "Invalid argument!");
1786  Address Temp = CreateMemTemp(E->getType());
1787  LValue LV = MakeAddrLValue(Temp, E->getType());
1792  return LV;
1793 }
1794 
1796  const CXXRecordDecl *RD, const CXXRecordDecl *BaseRD, bool IsVirtual) {
1797  // Virtual bases are initialized first, in address order, so there's never
1798  // any overlap during their initialization.
1799  //
1800  // FIXME: Under P0840, this is no longer true: the tail padding of a vbase
1801  // of a field could be reused by a vbase of a containing class.
1802  if (IsVirtual)
1804 
1805  // If the base class is laid out entirely within the nvsize of the derived
1806  // class, its tail padding cannot yet be initialized, so we can issue
1807  // stores at the full width of the base class.
1808  const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1809  if (Layout.getBaseClassOffset(BaseRD) +
1810  getContext().getASTRecordLayout(BaseRD).getSize() <=
1811  Layout.getNonVirtualSize())
1813 
1814  // The tail padding may contain values we need to preserve.
1815  return AggValueSlot::MayOverlap;
1816 }
1817 
1819  AggValueSlot::Overlap_t MayOverlap,
1820  bool isVolatile) {
1821  assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
1822 
1823  Address DestPtr = Dest.getAddress();
1824  Address SrcPtr = Src.getAddress();
1825 
1826  if (getLangOpts().CPlusPlus) {
1827  if (const RecordType *RT = Ty->getAs<RecordType>()) {
1828  CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl());
1829  assert((Record->hasTrivialCopyConstructor() ||
1830  Record->hasTrivialCopyAssignment() ||
1831  Record->hasTrivialMoveConstructor() ||
1832  Record->hasTrivialMoveAssignment() ||
1833  Record->isUnion()) &&
1834  "Trying to aggregate-copy a type without a trivial copy/move "
1835  "constructor or assignment operator");
1836  // Ignore empty classes in C++.
1837  if (Record->isEmpty())
1838  return;
1839  }
1840  }
1841 
1842  // Aggregate assignment turns into llvm.memcpy. This is almost valid per
1843  // C99 6.5.16.1p3, which states "If the value being stored in an object is
1844  // read from another object that overlaps in anyway the storage of the first
1845  // object, then the overlap shall be exact and the two objects shall have
1846  // qualified or unqualified versions of a compatible type."
1847  //
1848  // memcpy is not defined if the source and destination pointers are exactly
1849  // equal, but other compilers do this optimization, and almost every memcpy
1850  // implementation handles this case safely. If there is a libc that does not
1851  // safely handle this, we can add a target hook.
1852 
1853  // Get data size info for this aggregate. Don't copy the tail padding if this
1854  // might be a potentially-overlapping subobject, since the tail padding might
1855  // be occupied by a different object. Otherwise, copying it is fine.
1856  std::pair<CharUnits, CharUnits> TypeInfo;
1857  if (MayOverlap)
1858  TypeInfo = getContext().getTypeInfoDataSizeInChars(Ty);
1859  else
1860  TypeInfo = getContext().getTypeInfoInChars(Ty);
1861 
1862  llvm::Value *SizeVal = nullptr;
1863  if (TypeInfo.first.isZero()) {
1864  // But note that getTypeInfo returns 0 for a VLA.
1865  if (auto *VAT = dyn_cast_or_null<VariableArrayType>(
1866  getContext().getAsArrayType(Ty))) {
1867  QualType BaseEltTy;
1868  SizeVal = emitArrayLength(VAT, BaseEltTy, DestPtr);
1869  TypeInfo = getContext().getTypeInfoInChars(BaseEltTy);
1870  assert(!TypeInfo.first.isZero());
1871  SizeVal = Builder.CreateNUWMul(
1872  SizeVal,
1873  llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity()));
1874  }
1875  }
1876  if (!SizeVal) {
1877  SizeVal = llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity());
1878  }
1879 
1880  // FIXME: If we have a volatile struct, the optimizer can remove what might
1881  // appear to be `extra' memory ops:
1882  //
1883  // volatile struct { int i; } a, b;
1884  //
1885  // int main() {
1886  // a = b;
1887  // a = b;
1888  // }
1889  //
1890  // we need to use a different call here. We use isVolatile to indicate when
1891  // either the source or the destination is volatile.
1892 
1893  DestPtr = Builder.CreateElementBitCast(DestPtr, Int8Ty);
1894  SrcPtr = Builder.CreateElementBitCast(SrcPtr, Int8Ty);
1895 
1896  // Don't do any of the memmove_collectable tests if GC isn't set.
1897  if (CGM.getLangOpts().getGC() == LangOptions::NonGC) {
1898  // fall through
1899  } else if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
1900  RecordDecl *Record = RecordTy->getDecl();
1901  if (Record->hasObjectMember()) {
1902  CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
1903  SizeVal);
1904  return;
1905  }
1906  } else if (Ty->isArrayType()) {
1907  QualType BaseType = getContext().getBaseElementType(Ty);
1908  if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
1909  if (RecordTy->getDecl()->hasObjectMember()) {
1910  CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
1911  SizeVal);
1912  return;
1913  }
1914  }
1915  }
1916 
1917  auto Inst = Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, isVolatile);
1918 
1919  // Determine the metadata to describe the position of any padding in this
1920  // memcpy, as well as the TBAA tags for the members of the struct, in case
1921  // the optimizer wishes to expand it in to scalar memory operations.
1922  if (llvm::MDNode *TBAAStructTag = CGM.getTBAAStructInfo(Ty))
1923  Inst->setMetadata(llvm::LLVMContext::MD_tbaa_struct, TBAAStructTag);
1924 
1925  if (CGM.getCodeGenOpts().NewStructPathTBAA) {
1926  TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForMemoryTransfer(
1927  Dest.getTBAAInfo(), Src.getTBAAInfo());
1928  CGM.DecorateInstructionWithTBAA(Inst, TBAAInfo);
1929  }
1930 }
bool isAggregate() const
Definition: CGValue.h:54
const llvm::DataLayout & getDataLayout() const
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:361
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Defines the clang::ASTContext interface.
Expr * getChosenSubExpr() const
getChosenSubExpr - Return the subexpression chosen according to the condition.
Definition: Expr.h:3785
Address getAddress() const
Definition: CGValue.h:569
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:1604
A (possibly-)qualified type.
Definition: Type.h:655
bool isPODType(const ASTContext &Context) const
Determine whether this is a Plain Old Data (POD) type (C++ 3.9p10).
Definition: Type.cpp:2063
bool isArrayType() const
Definition: Type.h:6098
llvm::Type * ConvertTypeForMem(QualType T)
void EmitBranchOnBoolExpr(const Expr *Cond, llvm::BasicBlock *TrueBlock, llvm::BasicBlock *FalseBlock, uint64_t TrueCount)
EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g.
RValue EmitCoyieldExpr(const CoyieldExpr &E, AggValueSlot aggSlot=AggValueSlot::ignored(), bool ignoreResult=false)
Address CreateMemTemp(QualType T, const Twine &Name="tmp", Address *Alloca=nullptr)
CreateMemTemp - Create a temporary memory object of the given type, with appropriate alignmen and cas...
Definition: CGExpr.cpp:139
bool HaveInsertPoint() const
HaveInsertPoint - True if an insertion point is defined.
CompoundStmt * getSubStmt()
Definition: Expr.h:3584
const Expr * getInit(unsigned Init) const
Definition: Expr.h:4000
Stmt - This represents one statement.
Definition: Stmt.h:66
Address GetAddressOfDirectBaseInCompleteClass(Address Value, const CXXRecordDecl *Derived, const CXXRecordDecl *Base, bool BaseIsVirtual)
GetAddressOfBaseOfCompleteClass - Convert the given pointer to a complete class to the given direct b...
Definition: CGClass.cpp:199
llvm::Constant * tryEmitForInitializer(const VarDecl &D)
Try to emit the initiaizer of the given declaration as an abstract constant.
CharUnits getBaseClassOffset(const CXXRecordDecl *Base) const
getBaseClassOffset - Get the offset, in chars, for the given base class.
Definition: RecordLayout.h:223
NeedsGCBarriers_t requiresGCollection() const
Definition: CGValue.h:561
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:2043
llvm::Value * getPointer() const
Definition: CGValue.h:565
bool isRecordType() const
Definition: Type.h:6122
Address EmitVAArg(VAArgExpr *VE, Address &VAListAddr)
Generate code to get an argument from the passed in pointer and update it accordingly.
Definition: CGCall.cpp:4505
virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF, Address DestPtr, Address SrcPtr, llvm::Value *Size)=0
RValue EmitPseudoObjectRValue(const PseudoObjectExpr *e, AggValueSlot slot=AggValueSlot::ignored())
Definition: CGExpr.cpp:4860
RValue EmitCoawaitExpr(const CoawaitExpr &E, AggValueSlot aggSlot=AggValueSlot::ignored(), bool ignoreResult=false)
bool isTransparent() const
Is this a transparent initializer list (that is, an InitListExpr that is purely syntactic, and whose semantics are that of the sole contained initializer)?
Definition: Expr.cpp:1964
Defines the C++ template declaration subclasses.
Opcode getOpcode() const
Definition: Expr.h:3106
ParenExpr - This represents a parethesized expression, e.g.
Definition: Expr.h:1730
void EmitStoreThroughLValue(RValue Src, LValue Dst, bool isInit=false)
EmitStoreThroughLValue - Store the specified rvalue into the specified lvalue, where both are guarant...
Definition: CGExpr.cpp:1865
void EmitComplexExprIntoLValue(const Expr *E, LValue dest, bool isInit)
EmitComplexExprIntoLValue - Emit the given expression of complex type and place its result into the s...
Represents an array type, per C99 6.7.5.2 - Array Declarators.
Definition: Type.h:2650
Represents a call to a C++ constructor.
Definition: ExprCXX.h:1239
bool hasTrivialMoveConstructor() const
Determine whether this class has a trivial move constructor (C++11 [class.copy]p12) ...
Definition: DeclCXX.h:1413
stable_iterator stable_begin() const
Create a stable reference to the top of the EH stack.
Definition: EHScopeStack.h:379
void setZeroed(bool V=true)
Definition: CGValue.h:597
QualType getValueType() const
Gets the type contained by this atomic type, i.e.
Definition: Type.h:5736
LValue EmitLValueForFieldInitialization(LValue Base, const FieldDecl *Field)
EmitLValueForFieldInitialization - Like EmitLValueForField, except that if the Field is a reference...
Definition: CGExpr.cpp:3922
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
Represents a prvalue temporary that is written into memory so that a reference can bind to it...
Definition: ExprCXX.h:4039
IsAliased_t isPotentiallyAliased() const
Definition: CGValue.h:581
const Expr * getResultExpr() const
The generic selection&#39;s result expression.
Definition: Expr.h:4840
void EmitAtomicStore(RValue rvalue, LValue lvalue, bool isInit)
Definition: CGAtomic.cpp:1885
QualType getElementType() const
Definition: Type.h:2685
static bool isBlockVarRef(const Expr *E)
Is the value of the given expression possibly a reference to or into a __block variable?
Definition: CGExprAgg.cpp:1044
static Expr * findPeephole(Expr *op, CastKind kind)
Attempt to look through various unimportant expressions to find a cast of the given kind...
Definition: CGExprAgg.cpp:660
Represents a variable declaration or definition.
Definition: Decl.h:812
CompoundLiteralExpr - [C99 6.5.2.5].
Definition: Expr.h:2715
OpaqueValueExpr * getCommonExpr() const
Get the common subexpression shared by all initializations (the source array).
Definition: Expr.h:4587
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6456
uint64_t getProfileCount(const Stmt *S)
Get the profiler&#39;s count for the given statement.
static bool isSimpleZero(const Expr *E, CodeGenFunction &CGF)
isSimpleZero - If emitting this value will obviously just cause a store of zero to memory...
Definition: CGExprAgg.cpp:1286
LangAS
Defines the address space values used by the address space qualifier of QualType. ...
Definition: AddressSpaces.h:26
IsZeroed_t isZeroed() const
Definition: CGValue.h:598
Implicit construction of a std::initializer_list<T> object from an array temporary within list-initia...
Definition: ExprCXX.h:594
llvm::Value * getPointer() const
Definition: Address.h:38
CXXConstructorDecl * getConstructor() const
Get the constructor that this expression will call.
Definition: ExprCXX.h:1435
A C++ throw-expression (C++ [except.throw]).
Definition: ExprCXX.h:985
Represents an expression – generally a full-expression – that introduces cleanups to be run at the ...
Definition: ExprCXX.h:3003
void EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst, llvm::Value **Result=nullptr)
EmitStoreThroughBitfieldLValue - Store Src into Dst with same constraints as EmitStoreThroughLValue.
Definition: CGExpr.cpp:1962
The collection of all-type qualifiers we support.
Definition: Type.h:154
bool hasFloatingRepresentation() const
Determine whether this type has a floating-point representation of some sort, e.g., it is a floating-point type or a vector thereof.
Definition: Type.cpp:1893
static CharUnits GetNumNonZeroBytesInInit(const Expr *E, CodeGenFunction &CGF)
GetNumNonZeroBytesInInit - Get an approximate count of the number of non-zero bytes that will be stor...
Definition: CGExprAgg.cpp:1667
Represents a struct/union/class.
Definition: Decl.h:3548
bool isEmpty() const
Determine whether this is an empty class in the sense of (C++11 [meta.unary.prop]).
Definition: DeclCXX.h:1317
uint64_t getPointerWidth(unsigned AddrSpace) const
Return the width of pointers on this target, for the specified address space.
Definition: TargetInfo.h:339
const TargetInfo & getTarget() const
An object to manage conditionally-evaluated expressions.
AggValueSlot::Overlap_t overlapForBaseInit(const CXXRecordDecl *RD, const CXXRecordDecl *BaseRD, bool IsVirtual)
Determine whether a base class initialization may overlap some other object.
Definition: CGExprAgg.cpp:1795
IsDestructed_t isExternallyDestructed() const
Definition: CGValue.h:540
Expr * GetTemporaryExpr() const
Retrieve the temporary-generating subexpression whose value will be materialized into a glvalue...
Definition: ExprCXX.h:4080
Address getAddress() const
Definition: CGValue.h:327
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:150
llvm::Value * EmitDynamicCast(Address V, const CXXDynamicCastExpr *DCE)
Definition: CGExprCXX.cpp:2151
RValue EmitReferenceBindingToExpr(const Expr *E)
Emits a reference binding to the passed in expression.
Definition: CGExpr.cpp:556
field_range fields() const
Definition: Decl.h:3764
Represents a member of a struct/union/class.
Definition: Decl.h:2521
Represents a place-holder for an object not to be initialized by anything.
Definition: Expr.h:4480
An RAII object to set (and then clear) a mapping for an OpaqueValueExpr.
bool isReferenceType() const
Definition: Type.h:6061
bool hasTrivialMoveAssignment() const
Determine whether this class has a trivial move assignment operator (C++11 [class.copy]p25)
Definition: DeclCXX.h:1453
Denotes a cleanup that should run when a scope is exited using exceptional control flow (a throw stat...
Definition: EHScopeStack.h:81
Expr * getSourceExpr() const
The source expression of an opaque value expression is the expression which originally generated the ...
Definition: Expr.h:934
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:53
CharUnits getPreferredSize(ASTContext &Ctx, QualType Type) const
Get the preferred size to use when storing a value to this slot.
Definition: CGValue.h:605
Expr * getSubExpr()
Definition: Expr.h:2841
bool isPaddedAtomicType(QualType type)
static bool isTrivialFiller(Expr *E)
Determine if E is a trivial array filler, that is, one that is equivalent to zero-initialization.
Definition: CGExprAgg.cpp:440
bool isIntegralOrEnumerationType() const
Determine whether this type is an integral or enumeration type.
Definition: Type.h:6370
bool hadArrayRangeDesignator() const
Definition: Expr.h:4120
void EmitStoreOfScalar(llvm::Value *Value, Address Addr, bool Volatile, QualType Ty, AlignmentSource Source=AlignmentSource::Type, bool isInit=false, bool isNontemporal=false)
EmitStoreOfScalar - Store a scalar value to an address, taking care to appropriately convert from the...
void setNonGC(bool Value)
Definition: CGValue.h:277
RValue EmitAnyExpr(const Expr *E, AggValueSlot aggSlot=AggValueSlot::ignored(), bool ignoreResult=false)
EmitAnyExpr - Emit code to compute the specified expression which can have any type.
Definition: CGExpr.cpp:194
void pushFullExprCleanup(CleanupKind kind, As... A)
pushFullExprCleanup - Push a cleanup to be run at the end of the current full-expression.
bool isGLValue() const
Definition: Expr.h:252
void EmitInheritedCXXConstructorCall(const CXXConstructorDecl *D, bool ForVirtualBase, Address This, bool InheritedFromVBase, const CXXInheritedCtorInitExpr *E)
Emit a call to a constructor inherited from a base class, passing the current constructor&#39;s arguments...
Definition: CGClass.cpp:2140
Describes an C or C++ initializer list.
Definition: Expr.h:3952
A C++ typeid expression (C++ [expr.typeid]), which gets the type_info that corresponds to the supplie...
Definition: ExprCXX.h:638
void pushRegularPartialArrayCleanup(llvm::Value *arrayBegin, llvm::Value *arrayEnd, QualType elementType, CharUnits elementAlignment, Destroyer *destroyer)
pushRegularPartialArrayCleanup - Push an EH cleanup to destroy already-constructed elements of the gi...
Definition: CGDecl.cpp:1876
static bool hasScalarEvaluationKind(QualType T)
Address CreateElementBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Cast the element type of the given address to a different type, preserving information like the align...
Definition: CGBuilder.h:157
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:38
bool isPartial() const
True iff the comparison is not totally ordered.
bool isTriviallyCopyableType(const ASTContext &Context) const
Return true if this is a trivially copyable type (C++0x [basic.types]p9)
Definition: Type.cpp:2167
CharUnits getAlignment() const
Return the alignment of this pointer.
Definition: Address.h:67
bool isComplex() const
Definition: CGValue.h:53
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3065
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:5895
bool needsEHCleanup(QualType::DestructionKind kind)
Determines whether an EH cleanup is required to destroy a type with the given destruction kind...
bool constructsVBase() const
Determine whether this constructor is actually constructing a base class (rather than a complete obje...
Definition: ExprCXX.h:1439
llvm::CallInst * CreateMemCpy(Address Dest, Address Src, llvm::Value *Size, bool IsVolatile=false)
Definition: CGBuilder.h:259
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:40
field_iterator field_begin() const
Definition: Decl.cpp:4027
llvm::BasicBlock * createBasicBlock(const Twine &name="", llvm::Function *parent=nullptr, llvm::BasicBlock *before=nullptr)
createBasicBlock - Create an LLVM basic block.
void EmitIgnoredExpr(const Expr *E)
EmitIgnoredExpr - Emit an expression in a context which ignores the result.
Definition: CGExpr.cpp:182
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:2788
Represents binding an expression to a temporary.
Definition: ExprCXX.h:1196
bool isSimple() const
Definition: CGValue.h:252
RValue EmitAtomicExpr(AtomicExpr *E)
Definition: CGAtomic.cpp:745
CXXTemporary * getTemporary()
Definition: ExprCXX.h:1215
A C++ lambda expression, which produces a function object (of unspecified type) that can be invoked l...
Definition: ExprCXX.h:1583
bool isEquality() const
True iff the comparison category is an equality comparison.
void incrementProfileCounter(const Stmt *S, llvm::Value *StepV=nullptr)
Increment the profiler&#39;s counter for the given statement by StepV.
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
const ComparisonCategoryInfo & getInfoForType(QualType Ty) const
Return the comparison category information as specified by getCategoryForType(Ty).
void callCStructMoveConstructor(LValue Dst, LValue Src)
Address getAggregateAddress() const
getAggregateAddr() - Return the Value* of the address of the aggregate.
Definition: CGValue.h:71
A default argument (C++ [dcl.fct.default]).
Definition: ExprCXX.h:1042
Checking the operand of a load. Must be suitably sized and aligned.
bool isTypeConstant(QualType QTy, bool ExcludeCtorDtor)
isTypeConstant - Determine whether an object of this type can be emitted as a constant.
const Expr * getExpr() const
Get the initialization expression that will be used.
Definition: ExprCXX.h:1141
RValue EmitObjCMessageExpr(const ObjCMessageExpr *E, ReturnValueSlot Return=ReturnValueSlot())
Definition: CGObjC.cpp:355
bool hasAttr() const
Definition: DeclBase.h:536
bool isTriviallyCopyable() const
Determine whether this class is considered trivially copyable per (C++11 [class]p6).
Definition: DeclCXX.cpp:533
bool isValid() const
Definition: Address.h:36
void EmitCXXConstructExpr(const CXXConstructExpr *E, AggValueSlot Dest)
Definition: CGExprCXX.cpp:569
static CharUnits One()
One - Construct a CharUnits quantity of one.
Definition: CharUnits.h:58
CastKind
CastKind - The kind of operation required for a conversion.
RValue - This trivial value class is used to represent the result of an expression that is evaluated...
Definition: CGValue.h:39
InitListExpr * getUpdater() const
Definition: Expr.h:4538
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
Represents a call to the builtin function __builtin_va_arg.
Definition: Expr.h:3858
bool isPointerZeroInitializable(QualType T)
Check if the pointer type can be zero-initialized (in the C++ sense) with an LLVM zeroinitializer...
ASTRecordLayout - This class contains layout information for one RecordDecl, which is a struct/union/...
Definition: RecordLayout.h:39
bool HasSideEffects(const ASTContext &Ctx, bool IncludePossibleEffects=true) const
HasSideEffects - This routine returns true for all those expressions which have any effect other than...
Definition: Expr.cpp:2989
static TypeEvaluationKind getEvaluationKind(QualType T)
getEvaluationKind - Return the TypeEvaluationKind of QualType T.
CGObjCRuntime & getObjCRuntime()
Return a reference to the configured Objective-C runtime.
PrimitiveCopyKind isNonTrivialToPrimitiveDestructiveMove() const
Check if this is a non-trivial type that would cause a C struct transitively containing this type to ...
Definition: Type.cpp:2245
An expression "T()" which creates a value-initialized rvalue of type T, which is a non-class type...
Definition: ExprCXX.h:1805
void callCStructMoveAssignmentOperator(LValue Dst, LValue Src)
Expr - This represents one expression.
Definition: Expr.h:106
ExprValueKind
The categorization of expression values, currently following the C++11 scheme.
Definition: Specifiers.h:107
static Address invalid()
Definition: Address.h:35
Qualifiers getQualifiers() const
Definition: CGValue.h:547
Enters a new scope for capturing cleanups, all of which will be executed once the scope is exited...
const FunctionProtoType * T
std::pair< llvm::Value *, llvm::Value * > getComplexVal() const
getComplexVal - Return the real/imag components of this complex value.
Definition: CGValue.h:66
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6519
Address EmitCompoundStmt(const CompoundStmt &S, bool GetLast=false, AggValueSlot AVS=AggValueSlot::ignored())
EmitCompoundStmt - Emit a compound statement {..} node.
Definition: CGStmt.cpp:372
unsigned getNumInits() const
Definition: Expr.h:3982
Expr * getSubExpr() const
Get the initializer to use for each array element.
Definition: Expr.h:4592
AggValueSlot CreateAggTemp(QualType T, const Twine &Name="tmp")
CreateAggTemp - Create a temporary memory object for the given aggregate type.
field_iterator field_end() const
Definition: Decl.h:3767
llvm::PointerType * getType() const
Return the type of the pointer value.
Definition: Address.h:44
CharUnits getTypeAlignInChars(QualType T) const
Return the ABI-specified alignment of a (complete) type T, in characters.
bool isAnyComplexType() const
Definition: Type.h:6130
const ValueInfo * getNonequalOrNonequiv() const
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:63
QualType getType() const
Definition: Expr.h:128
void EmitLambdaExpr(const LambdaExpr *E, AggValueSlot Dest)
Definition: CGExprCXX.cpp:2242
An RAII object to record that we&#39;re evaluating a statement expression.
TBAAAccessInfo getTBAAInfo() const
Definition: CGValue.h:308
CharUnits alignmentOfArrayElement(CharUnits elementSize) const
Given that this is the alignment of the first element of an array, return the minimum alignment of an...
Definition: CharUnits.h:197
An expression that sends a message to the given Objective-C object or class.
Definition: ExprObjC.h:903
llvm::CallInst * CreateMemSet(Address Dest, llvm::Value *Value, llvm::Value *Size, bool IsVolatile=false)
Definition: CGBuilder.h:281
UnaryOperator - This represents the unary-expression&#39;s (except sizeof and alignof), the postinc/postdec operators from postfix-expression, and various extensions.
Definition: Expr.h:1782
const AstTypeMatcher< AtomicType > atomicType
Matches atomic types.
Represents a reference to a non-type template parameter that has been substituted with a template arg...
Definition: ExprCXX.h:3841
bool hasTrivialCopyConstructor() const
Determine whether this class has a trivial copy constructor (C++ [class.copy]p6, C++11 [class...
Definition: DeclCXX.h:1390
const Expr * getSubExpr() const
Definition: Expr.h:1746
const Expr * getSubExpr() const
Definition: ExprCXX.h:1219
ASTContext & getContext() const
RValue EmitAtomicLoad(LValue LV, SourceLocation SL, AggValueSlot Slot=AggValueSlot::ignored())
Definition: CGAtomic.cpp:1461
void callCStructCopyAssignmentOperator(LValue Dst, LValue Src)
RecordDecl * getDecl() const
Definition: Type.h:4082
const ValueInfo * getGreater() const
OpaqueValueExpr - An expression referring to an opaque object of a fixed type and value class...
Definition: Expr.h:875
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:142
static AggValueSlot forAddr(Address addr, Qualifiers quals, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, Overlap_t mayOverlap, IsZeroed_t isZeroed=IsNotZeroed)
forAddr - Make a slot for an aggregate value.
Definition: CGValue.h:506
Expr * getBase() const
Definition: Expr.h:4535
Kind
Represents a call to an inherited base class constructor from an inheriting constructor.
Definition: ExprCXX.h:1400
PseudoObjectExpr - An expression which accesses a pseudo-object l-value.
Definition: Expr.h:5049
bool inheritedFromVBase() const
Determine whether the inherited constructor is inherited from a virtual base of the object we constru...
Definition: ExprCXX.h:1449
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:1631
bool hasTrivialCopyAssignment() const
Determine whether this class has a trivial copy assignment operator (C++ [class.copy]p11, C++11 [class.copy]p25)
Definition: DeclCXX.h:1440
bool LValueIsSuitableForInlineAtomic(LValue Src)
An LValue is a candidate for having its loads and stores be made atomic if we are operating under /vo...
Definition: CGAtomic.cpp:1448
LangAS getAddressSpace() const
Return the address space of this type.
Definition: Type.h:5941
A saved depth on the scope stack.
Definition: EHScopeStack.h:107
Expr * getSubExpr() const
Definition: Expr.h:1809
LValue EmitCheckedLValue(const Expr *E, TypeCheckKind TCK)
Same as EmitLValue but additionally we generate checking code to guard against undefined behavior...
Definition: CGExpr.cpp:1163
CastKind getCastKind() const
Definition: Expr.h:2835
const ValueInfo * getLess() const
LValue EmitAggExprToLValue(const Expr *E)
EmitAggExprToLValue - Emit the computation of the specified expression of aggregate type into a tempo...
Definition: CGExprAgg.cpp:1784
void DeactivateCleanupBlock(EHScopeStack::stable_iterator Cleanup, llvm::Instruction *DominatingIP)
DeactivateCleanupBlock - Deactivates the given cleanup block.
Definition: CGCleanup.cpp:1235
The type is a struct containing a field whose type is neither PCK_Trivial nor PCK_VolatileTrivial.
Definition: Type.h:1138
An aggregate value slot.
Definition: CGValue.h:437
llvm::Value * EmitLifetimeStart(uint64_t Size, llvm::Value *Addr)
Emit a lifetime.begin marker if some criteria are satisfied.
Definition: CGDecl.cpp:963
A scoped helper to set the current debug location to the specified location or preferred location of ...
Definition: CGDebugInfo.h:641
QualType getBaseElementType(const ArrayType *VAT) const
Return the innermost element type of an array type.
const ConstantArrayType * getAsConstantArrayType(QualType T) const
Definition: ASTContext.h:2354
StmtVisitor - This class implements a simple visitor for Stmt subclasses.
Definition: StmtVisitor.h:186
const ArrayType * getAsArrayType(QualType T) const
Type Query functions.
AtomicExpr - Variadic atomic builtins: __atomic_exchange, __atomic_fetch_*, __atomic_load, __atomic_store, and __atomic_compare_exchange_*, for the similarly-named C++11 instructions, and __c11 variants for <stdatomic.h>, and corresponding __opencl_atomic_* for OpenCL 2.0.
Definition: Expr.h:5183
void EmitCXXTemporary(const CXXTemporary *Temporary, QualType TempType, Address Ptr)
Emits all the code to cause the given temporary to be cleaned up.
Definition: CGCleanup.cpp:1267
static void CheckAggExprForMemSetUse(AggValueSlot &Slot, const Expr *E, CodeGenFunction &CGF)
CheckAggExprForMemSetUse - If the initializer is large and has a lot of zeros in it, emit a memset and avoid storing the individual zeros.
Definition: CGExprAgg.cpp:1727
An aligned address.
Definition: Address.h:25
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1166
LValue EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E)
Definition: CGExpr.cpp:4731
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:2227
StmtExpr - This is the GNU Statement Expression extension: ({int X=4; X;}).
Definition: Expr.h:3568
static AggValueSlot forLValue(const LValue &LV, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, Overlap_t mayOverlap, IsZeroed_t isZeroed=IsNotZeroed)
Definition: CGValue.h:530
QualType getType() const
Definition: CGValue.h:264
RValue EmitCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue=ReturnValueSlot())
Definition: CGExpr.cpp:4280
Expr * getArrayFiller()
If this initializer list initializes an array with more elements than there are initializers in the l...
Definition: Expr.h:4046
void enterFullExpression(const ExprWithCleanups *E)
bool hasSameUnqualifiedType(QualType T1, QualType T2) const
Determine whether the given types are equivalent after cvr-qualifiers have been removed.
Definition: ASTContext.h:2247
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:216
const Expr * getInitializer() const
Definition: Expr.h:2741
Expr * getLHS() const
Definition: Expr.h:3109
void setExternallyDestructed(bool destructed=true)
Definition: CGValue.h:543
Represents a C11 generic selection.
Definition: Expr.h:4764
llvm::Value * EmitScalarExpr(const Expr *E, bool IgnoreResultAssign=false)
EmitScalarExpr - Emit the computation of the specified expression of LLVM scalar type, returning the result.
virtual llvm::Value * EmitMemberPointerComparison(CodeGenFunction &CGF, llvm::Value *L, llvm::Value *R, const MemberPointerType *MPT, bool Inequality)
Emit a comparison between two member pointers. Returns an i1.
Definition: CGCXXABI.cpp:87
llvm::Value * getScalarVal() const
getScalarVal() - Return the Value* of this scalar value.
Definition: CGValue.h:59
QualType withVolatile() const
Definition: Type.h:828
void ErrorUnsupported(const Stmt *S, const char *Type)
Print out an error that codegen doesn&#39;t support the specified stmt yet.
This class organizes the cross-function state that is used while generating LLVM code.
void setVolatile(bool flag)
Definition: CGValue.h:553
Dataflow Directional Tag Classes.
[C99 6.4.2.2] - A predefined identifier such as func.
Definition: Expr.h:1204
static AggValueSlot ignored()
ignored - Returns an aggregate value slot indicating that the aggregate value is being ignored...
Definition: CGValue.h:491
Address CreateStructGEP(Address Addr, unsigned Index, CharUnits Offset, const llvm::Twine &Name="")
Definition: CGBuilder.h:172
CompareKind
Definition: CGExprAgg.cpp:885
A scope within which we are constructing the fields of an object which might use a CXXDefaultInitExpr...
LValue getOrCreateOpaqueLValueMapping(const OpaqueValueExpr *e)
Given an opaque value expression, return its LValue mapping if it exists, otherwise create one...
Definition: CGExpr.cpp:4229
llvm::LoadInst * CreateAlignedLoad(llvm::Value *Addr, CharUnits Align, const llvm::Twine &Name="")
Definition: CGBuilder.h:91
LValue EmitPseudoObjectLValue(const PseudoObjectExpr *e)
Definition: CGExpr.cpp:4865
bool hasUserDeclaredConstructor() const
Determine whether this class has any user-declared constructors.
Definition: DeclCXX.h:974
Represents a &#39;co_yield&#39; expression.
Definition: ExprCXX.h:4391
const Expr * getExpr() const
Definition: ExprCXX.h:1077
U cast(CodeGen::Address addr)
Definition: Address.h:109
llvm::Constant * EmitNullConstant(QualType T)
Return the result of value-initializing the given type, i.e.
Checking the destination of a store. Must be suitably sized and aligned.
CXXRecordDecl * Record
The declaration for the comparison category type from the standard library.
A pointer to member type per C++ 8.3.3 - Pointers to members.
Definition: Type.h:2594
bool isBitField() const
Definition: CGValue.h:254
llvm::StoreInst * CreateStore(llvm::Value *Val, Address Addr, bool IsVolatile=false)
Definition: CGBuilder.h:108
llvm::Module & getModule() const
QualType getCallReturnType(const ASTContext &Ctx) const
getCallReturnType - Get the return type of the call expr.
Definition: Expr.cpp:1338
LValue MakeAddrLValue(Address Addr, QualType T, AlignmentSource Source=AlignmentSource::Type)
specific_decl_iterator - Iterates over a subrange of declarations stored in a DeclContext, providing only those that are of type SpecificDecl (or a class derived from it).
Definition: DeclBase.h:1606
void EmitAggExpr(const Expr *E, AggValueSlot AS)
EmitAggExpr - Emit the computation of the specified expression of aggregate type. ...
Definition: CGExprAgg.cpp:1772
void EmitExplicitCastExprType(const ExplicitCastExpr *E, CodeGenFunction *CGF=nullptr)
Emit type info if type of an expression is a variably modified type.
Definition: CGExpr.cpp:976
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:4072
Complex values, per C99 6.2.5p11.
Definition: Type.h:2315
ArraySubscriptExpr - [C99 6.5.2.1] Array Subscripting.
Definition: Expr.h:2195
CodeGenTypes & getTypes() const
AbstractConditionalOperator - An abstract base class for ConditionalOperator and BinaryConditionalOpe...
Definition: Expr.h:3307
llvm::Type * getElementType() const
Return the type of the values stored in this address.
Definition: Address.h:52
const llvm::APInt & getSize() const
Definition: Type.h:2728
bool isAtomicType() const
Definition: Type.h:6159
Represents a &#39;co_await&#39; expression.
Definition: ExprCXX.h:4308
bool isUnique() const
Definition: Expr.h:942
llvm::Value * getAggregatePointer() const
Definition: CGValue.h:76
void EmitScalarInit(const Expr *init, const ValueDecl *D, LValue lvalue, bool capturedByInit)
Definition: CGDecl.cpp:738
bool hasSameType(QualType T1, QualType T2) const
Determine whether the given types T1 and T2 are equivalent.
Definition: ASTContext.h:2223
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:32
void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false)
EmitBlock - Emit the given block.
Definition: CGStmt.cpp:445
ObjCIvarRefExpr - A reference to an ObjC instance variable.
Definition: ExprObjC.h:513
A use of a default initializer in a constructor or in aggregate initialization.
Definition: ExprCXX.h:1113
CharUnits toCharUnitsFromBits(int64_t BitSize) const
Convert a size in bits to a size in characters.
Overlap_t mayOverlap() const
Definition: CGValue.h:585
void callCStructCopyConstructor(LValue Dst, LValue Src)
static llvm::Value * EmitCompare(CGBuilderTy &Builder, CodeGenFunction &CGF, const BinaryOperator *E, llvm::Value *LHS, llvm::Value *RHS, CompareKind Kind, const char *NameSuffix="")
Definition: CGExprAgg.cpp:891
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
MemberExpr - [C99 6.5.2.3] Structure and Union Members.
Definition: Expr.h:2465
void ErrorUnsupported(const Stmt *S, const char *Type)
ErrorUnsupported - Print out an error that codegen doesn&#39;t support the specified stmt yet...
bool hasSignedIntegerRepresentation() const
Determine whether this type has an signed integer representation of some sort, e.g., it is an signed integer type or a vector.
Definition: Type.cpp:1837
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
Represents a loop initializing the elements of an array.
Definition: Expr.h:4570
ChooseExpr - GNU builtin-in function __builtin_choose_expr.
Definition: Expr.h:3744
llvm::Type * ConvertType(QualType T)
LValue EmitLValue(const Expr *E)
EmitLValue - Emit code to compute a designator that specifies the location of the expression...
Definition: CGExpr.cpp:1199
const ValueInfo * getEqualOrEquiv() const
CharUnits getNonVirtualSize() const
getNonVirtualSize - Get the non-virtual size (in chars) of an object, which is the size of the object...
Definition: RecordLayout.h:193
unsigned kind
All of the diagnostics that can be emitted by the frontend.
Definition: DiagnosticIDs.h:61
StringLiteral - This represents a string literal expression, e.g.
Definition: Expr.h:1566
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2283
void finalize(llvm::GlobalVariable *global)
CGCXXABI & getCXXABI() const
bool hasVolatileMember(QualType T)
hasVolatileMember - returns true if aggregate type has a volatile member.
void EmitAggregateCopy(LValue Dest, LValue Src, QualType EltTy, AggValueSlot::Overlap_t MayOverlap, bool isVolatile=false)
EmitAggregateCopy - Emit an aggregate copy.
Definition: CGExprAgg.cpp:1818
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:972
static RValue get(llvm::Value *V)
Definition: CGValue.h:86
bool isUnion() const
Definition: Decl.h:3225
Expr * getRHS() const
Definition: Expr.h:3111
bool isPointerType() const
Definition: Type.h:6049
bool hasObjectMember() const
Definition: Decl.h:3658
void EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr)
Definition: CGDecl.cpp:979
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
FieldDecl * getInitializedFieldInUnion()
If this initializes a union, specifies which field in the union to initialize.
Definition: Expr.h:4064
static RValue getAggregate(Address addr, bool isVolatile=false)
Definition: CGValue.h:107
LValue - This represents an lvalue references.
Definition: CGValue.h:167
RValue asRValue() const
Definition: CGValue.h:589
const LangOptions & getLangOpts() const
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2440
const ValueInfo * getUnordered() const
llvm::APInt getArraySize() const
Definition: Expr.h:4594
llvm::Value * getPointer() const
Definition: CGValue.h:323
Represents the canonical version of C arrays with a specified constant size.
Definition: Type.h:2710
bool isZeroInitializable(QualType T)
IsZeroInitializable - Return whether a type can be zero-initialized (in the C++ sense) with an LLVM z...
Represents an implicitly-generated value initialization of an object of a given type.
Definition: Expr.h:4660
void EmitCXXThrowExpr(const CXXThrowExpr *E, bool KeepInsertionPoint=true)
bool isScalar() const
Definition: CGValue.h:52
void pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin, Address arrayEndPointer, QualType elementType, CharUnits elementAlignment, Destroyer *destroyer)
pushIrregularPartialArrayCleanup - Push an EH cleanup to destroy already-constructed elements of the ...
Definition: CGDecl.cpp:1859
void EmitNullInitialization(Address DestPtr, QualType Ty)
EmitNullInitialization - Generate code to set a value of the given type to null, If the type contains...
Expr * IgnoreParens() LLVM_READONLY
IgnoreParens - Ignore parentheses.
Definition: Expr.cpp:2469
CanQualType getSizeType() const
Return the unique type for "size_t" (C99 7.17), defined in <stddef.h>.
ComparisonCategories CompCategories
Types and expressions required to build C++2a three-way comparisons using operator<=>, including the values return by builtin <=> operators.
Definition: ASTContext.h:1996