clang  3.8.0
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 "CGObjCRuntime.h"
16 #include "CodeGenModule.h"
17 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/DeclTemplate.h"
20 #include "clang/AST/StmtVisitor.h"
21 #include "llvm/IR/Constants.h"
22 #include "llvm/IR/Function.h"
23 #include "llvm/IR/GlobalVariable.h"
24 #include "llvm/IR/Intrinsics.h"
25 using namespace clang;
26 using namespace CodeGen;
27 
28 //===----------------------------------------------------------------------===//
29 // Aggregate Expression Emitter
30 //===----------------------------------------------------------------------===//
31 
32 namespace {
33 class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
34  CodeGenFunction &CGF;
36  AggValueSlot Dest;
37  bool IsResultUnused;
38 
39  /// We want to use 'dest' as the return slot except under two
40  /// conditions:
41  /// - The destination slot requires garbage collection, so we
42  /// need to use the GC API.
43  /// - The destination slot is potentially aliased.
44  bool shouldUseDestForReturnSlot() const {
45  return !(Dest.requiresGCollection() || Dest.isPotentiallyAliased());
46  }
47 
48  ReturnValueSlot getReturnValueSlot() const {
49  if (!shouldUseDestForReturnSlot())
50  return ReturnValueSlot();
51 
52  return ReturnValueSlot(Dest.getAddress(), Dest.isVolatile(),
53  IsResultUnused);
54  }
55 
56  AggValueSlot EnsureSlot(QualType T) {
57  if (!Dest.isIgnored()) return Dest;
58  return CGF.CreateAggTemp(T, "agg.tmp.ensured");
59  }
60  void EnsureDest(QualType T) {
61  if (!Dest.isIgnored()) return;
62  Dest = CGF.CreateAggTemp(T, "agg.tmp.ensured");
63  }
64 
65 public:
66  AggExprEmitter(CodeGenFunction &cgf, AggValueSlot Dest, bool IsResultUnused)
67  : CGF(cgf), Builder(CGF.Builder), Dest(Dest),
68  IsResultUnused(IsResultUnused) { }
69 
70  //===--------------------------------------------------------------------===//
71  // Utilities
72  //===--------------------------------------------------------------------===//
73 
74  /// EmitAggLoadOfLValue - Given an expression with aggregate type that
75  /// represents a value lvalue, this method emits the address of the lvalue,
76  /// then loads the result into DestPtr.
77  void EmitAggLoadOfLValue(const Expr *E);
78 
79  /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
80  void EmitFinalDestCopy(QualType type, const LValue &src);
81  void EmitFinalDestCopy(QualType type, RValue src);
82  void EmitCopy(QualType type, const AggValueSlot &dest,
83  const AggValueSlot &src);
84 
85  void EmitMoveFromReturnSlot(const Expr *E, RValue Src);
86 
87  void EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
88  QualType elementType, InitListExpr *E);
89 
91  if (CGF.getLangOpts().getGC() && TypeRequiresGCollection(T))
94  }
95 
96  bool TypeRequiresGCollection(QualType T);
97 
98  //===--------------------------------------------------------------------===//
99  // Visitor Methods
100  //===--------------------------------------------------------------------===//
101 
102  void Visit(Expr *E) {
103  ApplyDebugLocation DL(CGF, E);
105  }
106 
107  void VisitStmt(Stmt *S) {
108  CGF.ErrorUnsupported(S, "aggregate expression");
109  }
110  void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); }
111  void VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
112  Visit(GE->getResultExpr());
113  }
114  void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); }
115  void VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) {
116  return Visit(E->getReplacement());
117  }
118 
119  // l-values.
120  void VisitDeclRefExpr(DeclRefExpr *E) {
121  // For aggregates, we should always be able to emit the variable
122  // as an l-value unless it's a reference. This is due to the fact
123  // that we can't actually ever see a normal l2r conversion on an
124  // aggregate in C++, and in C there's no language standard
125  // actively preventing us from listing variables in the captures
126  // list of a block.
127  if (E->getDecl()->getType()->isReferenceType()) {
129  = CGF.tryEmitAsConstant(E)) {
130  EmitFinalDestCopy(E->getType(), result.getReferenceLValue(CGF, E));
131  return;
132  }
133  }
134 
135  EmitAggLoadOfLValue(E);
136  }
137 
138  void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); }
139  void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); }
140  void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); }
141  void VisitCompoundLiteralExpr(CompoundLiteralExpr *E);
142  void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
143  EmitAggLoadOfLValue(E);
144  }
145  void VisitPredefinedExpr(const PredefinedExpr *E) {
146  EmitAggLoadOfLValue(E);
147  }
148 
149  // Operators.
150  void VisitCastExpr(CastExpr *E);
151  void VisitCallExpr(const CallExpr *E);
152  void VisitStmtExpr(const StmtExpr *E);
153  void VisitBinaryOperator(const BinaryOperator *BO);
154  void VisitPointerToDataMemberBinaryOperator(const BinaryOperator *BO);
155  void VisitBinAssign(const BinaryOperator *E);
156  void VisitBinComma(const BinaryOperator *E);
157 
158  void VisitObjCMessageExpr(ObjCMessageExpr *E);
159  void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
160  EmitAggLoadOfLValue(E);
161  }
162 
163  void VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E);
164  void VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
165  void VisitChooseExpr(const ChooseExpr *CE);
166  void VisitInitListExpr(InitListExpr *E);
167  void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E);
168  void VisitNoInitExpr(NoInitExpr *E) { } // Do nothing.
169  void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
170  Visit(DAE->getExpr());
171  }
172  void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
174  Visit(DIE->getExpr());
175  }
176  void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
177  void VisitCXXConstructExpr(const CXXConstructExpr *E);
178  void VisitLambdaExpr(LambdaExpr *E);
179  void VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E);
180  void VisitExprWithCleanups(ExprWithCleanups *E);
181  void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E);
182  void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); }
183  void VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E);
184  void VisitOpaqueValueExpr(OpaqueValueExpr *E);
185 
186  void VisitPseudoObjectExpr(PseudoObjectExpr *E) {
187  if (E->isGLValue()) {
188  LValue LV = CGF.EmitPseudoObjectLValue(E);
189  return EmitFinalDestCopy(E->getType(), LV);
190  }
191 
192  CGF.EmitPseudoObjectRValue(E, EnsureSlot(E->getType()));
193  }
194 
195  void VisitVAArgExpr(VAArgExpr *E);
196 
197  void EmitInitializationToLValue(Expr *E, LValue Address);
198  void EmitNullInitializationToLValue(LValue Address);
199  // case Expr::ChooseExprClass:
200  void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); }
201  void VisitAtomicExpr(AtomicExpr *E) {
202  RValue Res = CGF.EmitAtomicExpr(E);
203  EmitFinalDestCopy(E->getType(), Res);
204  }
205 };
206 } // end anonymous namespace.
207 
208 //===----------------------------------------------------------------------===//
209 // Utilities
210 //===----------------------------------------------------------------------===//
211 
212 /// EmitAggLoadOfLValue - Given an expression with aggregate type that
213 /// represents a value lvalue, this method emits the address of the lvalue,
214 /// then loads the result into DestPtr.
215 void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) {
216  LValue LV = CGF.EmitLValue(E);
217 
218  // If the type of the l-value is atomic, then do an atomic load.
219  if (LV.getType()->isAtomicType() || CGF.LValueIsSuitableForInlineAtomic(LV)) {
220  CGF.EmitAtomicLoad(LV, E->getExprLoc(), Dest);
221  return;
222  }
223 
224  EmitFinalDestCopy(E->getType(), LV);
225 }
226 
227 /// \brief True if the given aggregate type requires special GC API calls.
228 bool AggExprEmitter::TypeRequiresGCollection(QualType T) {
229  // Only record types have members that might require garbage collection.
230  const RecordType *RecordTy = T->getAs<RecordType>();
231  if (!RecordTy) return false;
232 
233  // Don't mess with non-trivial C++ types.
234  RecordDecl *Record = RecordTy->getDecl();
235  if (isa<CXXRecordDecl>(Record) &&
236  (cast<CXXRecordDecl>(Record)->hasNonTrivialCopyConstructor() ||
237  !cast<CXXRecordDecl>(Record)->hasTrivialDestructor()))
238  return false;
239 
240  // Check whether the type has an object member.
241  return Record->hasObjectMember();
242 }
243 
244 /// \brief Perform the final move to DestPtr if for some reason
245 /// getReturnValueSlot() didn't use it directly.
246 ///
247 /// The idea is that you do something like this:
248 /// RValue Result = EmitSomething(..., getReturnValueSlot());
249 /// EmitMoveFromReturnSlot(E, Result);
250 ///
251 /// If nothing interferes, this will cause the result to be emitted
252 /// directly into the return value slot. Otherwise, a final move
253 /// will be performed.
254 void AggExprEmitter::EmitMoveFromReturnSlot(const Expr *E, RValue src) {
255  if (shouldUseDestForReturnSlot()) {
256  // Logically, Dest.getAddr() should equal Src.getAggregateAddr().
257  // The possibility of undef rvalues complicates that a lot,
258  // though, so we can't really assert.
259  return;
260  }
261 
262  // Otherwise, copy from there to the destination.
263  assert(Dest.getPointer() != src.getAggregatePointer());
264  EmitFinalDestCopy(E->getType(), src);
265 }
266 
267 /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
268 void AggExprEmitter::EmitFinalDestCopy(QualType type, RValue src) {
269  assert(src.isAggregate() && "value must be aggregate value!");
270  LValue srcLV = CGF.MakeAddrLValue(src.getAggregateAddress(), type);
271  EmitFinalDestCopy(type, srcLV);
272 }
273 
274 /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
275 void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src) {
276  // If Dest is ignored, then we're evaluating an aggregate expression
277  // in a context that doesn't care about the result. Note that loads
278  // from volatile l-values force the existence of a non-ignored
279  // destination.
280  if (Dest.isIgnored())
281  return;
282 
283  AggValueSlot srcAgg =
285  needsGC(type), AggValueSlot::IsAliased);
286  EmitCopy(type, Dest, srcAgg);
287 }
288 
289 /// Perform a copy from the source into the destination.
290 ///
291 /// \param type - the type of the aggregate being copied; qualifiers are
292 /// ignored
293 void AggExprEmitter::EmitCopy(QualType type, const AggValueSlot &dest,
294  const AggValueSlot &src) {
295  if (dest.requiresGCollection()) {
296  CharUnits sz = CGF.getContext().getTypeSizeInChars(type);
297  llvm::Value *size = llvm::ConstantInt::get(CGF.SizeTy, sz.getQuantity());
298  CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF,
299  dest.getAddress(),
300  src.getAddress(),
301  size);
302  return;
303  }
304 
305  // If the result of the assignment is used, copy the LHS there also.
306  // It's volatile if either side is. Use the minimum alignment of
307  // the two sides.
308  CGF.EmitAggregateCopy(dest.getAddress(), src.getAddress(), type,
309  dest.isVolatile() || src.isVolatile());
310 }
311 
312 /// \brief Emit the initializer for a std::initializer_list initialized with a
313 /// real initializer list.
314 void
315 AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
316  // Emit an array containing the elements. The array is externally destructed
317  // if the std::initializer_list object is.
318  ASTContext &Ctx = CGF.getContext();
319  LValue Array = CGF.EmitLValue(E->getSubExpr());
320  assert(Array.isSimple() && "initializer_list array not a simple lvalue");
321  Address ArrayPtr = Array.getAddress();
322 
325  assert(ArrayType && "std::initializer_list constructed from non-array");
326 
327  // FIXME: Perform the checks on the field types in SemaInit.
328  RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
329  RecordDecl::field_iterator Field = Record->field_begin();
330  if (Field == Record->field_end()) {
331  CGF.ErrorUnsupported(E, "weird std::initializer_list");
332  return;
333  }
334 
335  // Start pointer.
336  if (!Field->getType()->isPointerType() ||
337  !Ctx.hasSameType(Field->getType()->getPointeeType(),
338  ArrayType->getElementType())) {
339  CGF.ErrorUnsupported(E, "weird std::initializer_list");
340  return;
341  }
342 
343  AggValueSlot Dest = EnsureSlot(E->getType());
344  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
345  LValue Start = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
346  llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0);
347  llvm::Value *IdxStart[] = { Zero, Zero };
348  llvm::Value *ArrayStart =
349  Builder.CreateInBoundsGEP(ArrayPtr.getPointer(), IdxStart, "arraystart");
350  CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start);
351  ++Field;
352 
353  if (Field == Record->field_end()) {
354  CGF.ErrorUnsupported(E, "weird std::initializer_list");
355  return;
356  }
357 
358  llvm::Value *Size = Builder.getInt(ArrayType->getSize());
359  LValue EndOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
360  if (Field->getType()->isPointerType() &&
361  Ctx.hasSameType(Field->getType()->getPointeeType(),
362  ArrayType->getElementType())) {
363  // End pointer.
364  llvm::Value *IdxEnd[] = { Zero, Size };
365  llvm::Value *ArrayEnd =
366  Builder.CreateInBoundsGEP(ArrayPtr.getPointer(), IdxEnd, "arrayend");
367  CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength);
368  } else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) {
369  // Length.
370  CGF.EmitStoreThroughLValue(RValue::get(Size), EndOrLength);
371  } else {
372  CGF.ErrorUnsupported(E, "weird std::initializer_list");
373  return;
374  }
375 }
376 
377 /// \brief Determine if E is a trivial array filler, that is, one that is
378 /// equivalent to zero-initialization.
379 static bool isTrivialFiller(Expr *E) {
380  if (!E)
381  return true;
382 
383  if (isa<ImplicitValueInitExpr>(E))
384  return true;
385 
386  if (auto *ILE = dyn_cast<InitListExpr>(E)) {
387  if (ILE->getNumInits())
388  return false;
389  return isTrivialFiller(ILE->getArrayFiller());
390  }
391 
392  if (auto *Cons = dyn_cast_or_null<CXXConstructExpr>(E))
393  return Cons->getConstructor()->isDefaultConstructor() &&
394  Cons->getConstructor()->isTrivial();
395 
396  // FIXME: Are there other cases where we can avoid emitting an initializer?
397  return false;
398 }
399 
400 /// \brief Emit initialization of an array from an initializer list.
401 void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
402  QualType elementType, InitListExpr *E) {
403  uint64_t NumInitElements = E->getNumInits();
404 
405  uint64_t NumArrayElements = AType->getNumElements();
406  assert(NumInitElements <= NumArrayElements);
407 
408  // DestPtr is an array*. Construct an elementType* by drilling
409  // down a level.
410  llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
411  llvm::Value *indices[] = { zero, zero };
412  llvm::Value *begin =
413  Builder.CreateInBoundsGEP(DestPtr.getPointer(), indices, "arrayinit.begin");
414 
415  CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
416  CharUnits elementAlign =
417  DestPtr.getAlignment().alignmentOfArrayElement(elementSize);
418 
419  // Exception safety requires us to destroy all the
420  // already-constructed members if an initializer throws.
421  // For that, we'll need an EH cleanup.
422  QualType::DestructionKind dtorKind = elementType.isDestructedType();
423  Address endOfInit = Address::invalid();
425  llvm::Instruction *cleanupDominator = nullptr;
426  if (CGF.needsEHCleanup(dtorKind)) {
427  // In principle we could tell the cleanup where we are more
428  // directly, but the control flow can get so varied here that it
429  // would actually be quite complex. Therefore we go through an
430  // alloca.
431  endOfInit = CGF.CreateTempAlloca(begin->getType(), CGF.getPointerAlign(),
432  "arrayinit.endOfInit");
433  cleanupDominator = Builder.CreateStore(begin, endOfInit);
434  CGF.pushIrregularPartialArrayCleanup(begin, endOfInit, elementType,
435  elementAlign,
436  CGF.getDestroyer(dtorKind));
437  cleanup = CGF.EHStack.stable_begin();
438 
439  // Otherwise, remember that we didn't need a cleanup.
440  } else {
441  dtorKind = QualType::DK_none;
442  }
443 
444  llvm::Value *one = llvm::ConstantInt::get(CGF.SizeTy, 1);
445 
446  // The 'current element to initialize'. The invariants on this
447  // variable are complicated. Essentially, after each iteration of
448  // the loop, it points to the last initialized element, except
449  // that it points to the beginning of the array before any
450  // elements have been initialized.
451  llvm::Value *element = begin;
452 
453  // Emit the explicit initializers.
454  for (uint64_t i = 0; i != NumInitElements; ++i) {
455  // Advance to the next element.
456  if (i > 0) {
457  element = Builder.CreateInBoundsGEP(element, one, "arrayinit.element");
458 
459  // Tell the cleanup that it needs to destroy up to this
460  // element. TODO: some of these stores can be trivially
461  // observed to be unnecessary.
462  if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit);
463  }
464 
465  LValue elementLV =
466  CGF.MakeAddrLValue(Address(element, elementAlign), elementType);
467  EmitInitializationToLValue(E->getInit(i), elementLV);
468  }
469 
470  // Check whether there's a non-trivial array-fill expression.
471  Expr *filler = E->getArrayFiller();
472  bool hasTrivialFiller = isTrivialFiller(filler);
473 
474  // Any remaining elements need to be zero-initialized, possibly
475  // using the filler expression. We can skip this if the we're
476  // emitting to zeroed memory.
477  if (NumInitElements != NumArrayElements &&
478  !(Dest.isZeroed() && hasTrivialFiller &&
479  CGF.getTypes().isZeroInitializable(elementType))) {
480 
481  // Use an actual loop. This is basically
482  // do { *array++ = filler; } while (array != end);
483 
484  // Advance to the start of the rest of the array.
485  if (NumInitElements) {
486  element = Builder.CreateInBoundsGEP(element, one, "arrayinit.start");
487  if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit);
488  }
489 
490  // Compute the end of the array.
491  llvm::Value *end = Builder.CreateInBoundsGEP(begin,
492  llvm::ConstantInt::get(CGF.SizeTy, NumArrayElements),
493  "arrayinit.end");
494 
495  llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
496  llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body");
497 
498  // Jump into the body.
499  CGF.EmitBlock(bodyBB);
500  llvm::PHINode *currentElement =
501  Builder.CreatePHI(element->getType(), 2, "arrayinit.cur");
502  currentElement->addIncoming(element, entryBB);
503 
504  // Emit the actual filler expression.
505  LValue elementLV =
506  CGF.MakeAddrLValue(Address(currentElement, elementAlign), elementType);
507  if (filler)
508  EmitInitializationToLValue(filler, elementLV);
509  else
510  EmitNullInitializationToLValue(elementLV);
511 
512  // Move on to the next element.
513  llvm::Value *nextElement =
514  Builder.CreateInBoundsGEP(currentElement, one, "arrayinit.next");
515 
516  // Tell the EH cleanup that we finished with the last element.
517  if (endOfInit.isValid()) Builder.CreateStore(nextElement, endOfInit);
518 
519  // Leave the loop if we're done.
520  llvm::Value *done = Builder.CreateICmpEQ(nextElement, end,
521  "arrayinit.done");
522  llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end");
523  Builder.CreateCondBr(done, endBB, bodyBB);
524  currentElement->addIncoming(nextElement, Builder.GetInsertBlock());
525 
526  CGF.EmitBlock(endBB);
527  }
528 
529  // Leave the partial-array cleanup if we entered one.
530  if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, cleanupDominator);
531 }
532 
533 //===----------------------------------------------------------------------===//
534 // Visitor Methods
535 //===----------------------------------------------------------------------===//
536 
537 void AggExprEmitter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E){
538  Visit(E->GetTemporaryExpr());
539 }
540 
541 void AggExprEmitter::VisitOpaqueValueExpr(OpaqueValueExpr *e) {
542  EmitFinalDestCopy(e->getType(), CGF.getOpaqueLValueMapping(e));
543 }
544 
545 void
546 AggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
547  if (Dest.isPotentiallyAliased() &&
548  E->getType().isPODType(CGF.getContext())) {
549  // For a POD type, just emit a load of the lvalue + a copy, because our
550  // compound literal might alias the destination.
551  EmitAggLoadOfLValue(E);
552  return;
553  }
554 
555  AggValueSlot Slot = EnsureSlot(E->getType());
556  CGF.EmitAggExpr(E->getInitializer(), Slot);
557 }
558 
559 /// Attempt to look through various unimportant expressions to find a
560 /// cast of the given kind.
562  while (true) {
563  op = op->IgnoreParens();
564  if (CastExpr *castE = dyn_cast<CastExpr>(op)) {
565  if (castE->getCastKind() == kind)
566  return castE->getSubExpr();
567  if (castE->getCastKind() == CK_NoOp)
568  continue;
569  }
570  return nullptr;
571  }
572 }
573 
574 void AggExprEmitter::VisitCastExpr(CastExpr *E) {
575  if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
576  CGF.CGM.EmitExplicitCastExprType(ECE, &CGF);
577  switch (E->getCastKind()) {
578  case CK_Dynamic: {
579  // FIXME: Can this actually happen? We have no test coverage for it.
580  assert(isa<CXXDynamicCastExpr>(E) && "CK_Dynamic without a dynamic_cast?");
581  LValue LV = CGF.EmitCheckedLValue(E->getSubExpr(),
583  // FIXME: Do we also need to handle property references here?
584  if (LV.isSimple())
585  CGF.EmitDynamicCast(LV.getAddress(), cast<CXXDynamicCastExpr>(E));
586  else
587  CGF.CGM.ErrorUnsupported(E, "non-simple lvalue dynamic_cast");
588 
589  if (!Dest.isIgnored())
590  CGF.CGM.ErrorUnsupported(E, "lvalue dynamic_cast with a destination");
591  break;
592  }
593 
594  case CK_ToUnion: {
595  // Evaluate even if the destination is ignored.
596  if (Dest.isIgnored()) {
597  CGF.EmitAnyExpr(E->getSubExpr(), AggValueSlot::ignored(),
598  /*ignoreResult=*/true);
599  break;
600  }
601 
602  // GCC union extension
603  QualType Ty = E->getSubExpr()->getType();
604  Address CastPtr =
605  Builder.CreateElementBitCast(Dest.getAddress(), CGF.ConvertType(Ty));
606  EmitInitializationToLValue(E->getSubExpr(),
607  CGF.MakeAddrLValue(CastPtr, Ty));
608  break;
609  }
610 
611  case CK_DerivedToBase:
612  case CK_BaseToDerived:
614  llvm_unreachable("cannot perform hierarchy conversion in EmitAggExpr: "
615  "should have been unpacked before we got here");
616  }
617 
619  case CK_AtomicToNonAtomic: {
620  bool isToAtomic = (E->getCastKind() == CK_NonAtomicToAtomic);
621 
622  // Determine the atomic and value types.
623  QualType atomicType = E->getSubExpr()->getType();
624  QualType valueType = E->getType();
625  if (isToAtomic) std::swap(atomicType, valueType);
626 
627  assert(atomicType->isAtomicType());
628  assert(CGF.getContext().hasSameUnqualifiedType(valueType,
629  atomicType->castAs<AtomicType>()->getValueType()));
630 
631  // Just recurse normally if we're ignoring the result or the
632  // atomic type doesn't change representation.
633  if (Dest.isIgnored() || !CGF.CGM.isPaddedAtomicType(atomicType)) {
634  return Visit(E->getSubExpr());
635  }
636 
637  CastKind peepholeTarget =
639 
640  // These two cases are reverses of each other; try to peephole them.
641  if (Expr *op = findPeephole(E->getSubExpr(), peepholeTarget)) {
642  assert(CGF.getContext().hasSameUnqualifiedType(op->getType(),
643  E->getType()) &&
644  "peephole significantly changed types?");
645  return Visit(op);
646  }
647 
648  // If we're converting an r-value of non-atomic type to an r-value
649  // of atomic type, just emit directly into the relevant sub-object.
650  if (isToAtomic) {
651  AggValueSlot valueDest = Dest;
652  if (!valueDest.isIgnored() && CGF.CGM.isPaddedAtomicType(atomicType)) {
653  // Zero-initialize. (Strictly speaking, we only need to intialize
654  // the padding at the end, but this is simpler.)
655  if (!Dest.isZeroed())
656  CGF.EmitNullInitialization(Dest.getAddress(), atomicType);
657 
658  // Build a GEP to refer to the subobject.
659  Address valueAddr =
660  CGF.Builder.CreateStructGEP(valueDest.getAddress(), 0,
661  CharUnits());
662  valueDest = AggValueSlot::forAddr(valueAddr,
663  valueDest.getQualifiers(),
664  valueDest.isExternallyDestructed(),
665  valueDest.requiresGCollection(),
666  valueDest.isPotentiallyAliased(),
668  }
669 
670  CGF.EmitAggExpr(E->getSubExpr(), valueDest);
671  return;
672  }
673 
674  // Otherwise, we're converting an atomic type to a non-atomic type.
675  // Make an atomic temporary, emit into that, and then copy the value out.
676  AggValueSlot atomicSlot =
677  CGF.CreateAggTemp(atomicType, "atomic-to-nonatomic.temp");
678  CGF.EmitAggExpr(E->getSubExpr(), atomicSlot);
679 
680  Address valueAddr =
681  Builder.CreateStructGEP(atomicSlot.getAddress(), 0, CharUnits());
682  RValue rvalue = RValue::getAggregate(valueAddr, atomicSlot.isVolatile());
683  return EmitFinalDestCopy(valueType, rvalue);
684  }
685 
686  case CK_LValueToRValue:
687  // If we're loading from a volatile type, force the destination
688  // into existence.
689  if (E->getSubExpr()->getType().isVolatileQualified()) {
690  EnsureDest(E->getType());
691  return Visit(E->getSubExpr());
692  }
693 
694  // fallthrough
695 
696  case CK_NoOp:
699  assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(),
700  E->getType()) &&
701  "Implicit cast types must be compatible");
702  Visit(E->getSubExpr());
703  break;
704 
705  case CK_LValueBitCast:
706  llvm_unreachable("should not be emitting lvalue bitcast as rvalue");
707 
708  case CK_Dependent:
709  case CK_BitCast:
712  case CK_NullToPointer:
720  case CK_PointerToBoolean:
721  case CK_ToVoid:
722  case CK_VectorSplat:
723  case CK_IntegralCast:
729  case CK_FloatingCast:
744  case CK_ARCProduceObject:
745  case CK_ARCConsumeObject:
749  case CK_BuiltinFnToFnPtr:
750  case CK_ZeroToOCLEvent:
752  llvm_unreachable("cast kind invalid for aggregate types");
753  }
754 }
755 
756 void AggExprEmitter::VisitCallExpr(const CallExpr *E) {
757  if (E->getCallReturnType(CGF.getContext())->isReferenceType()) {
758  EmitAggLoadOfLValue(E);
759  return;
760  }
761 
762  RValue RV = CGF.EmitCallExpr(E, getReturnValueSlot());
763  EmitMoveFromReturnSlot(E, RV);
764 }
765 
766 void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) {
767  RValue RV = CGF.EmitObjCMessageExpr(E, getReturnValueSlot());
768  EmitMoveFromReturnSlot(E, RV);
769 }
770 
771 void AggExprEmitter::VisitBinComma(const BinaryOperator *E) {
772  CGF.EmitIgnoredExpr(E->getLHS());
773  Visit(E->getRHS());
774 }
775 
776 void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) {
778  CGF.EmitCompoundStmt(*E->getSubStmt(), true, Dest);
779 }
780 
781 void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) {
782  if (E->getOpcode() == BO_PtrMemD || E->getOpcode() == BO_PtrMemI)
783  VisitPointerToDataMemberBinaryOperator(E);
784  else
785  CGF.ErrorUnsupported(E, "aggregate binary expression");
786 }
787 
788 void AggExprEmitter::VisitPointerToDataMemberBinaryOperator(
789  const BinaryOperator *E) {
790  LValue LV = CGF.EmitPointerToDataMemberBinaryExpr(E);
791  EmitFinalDestCopy(E->getType(), LV);
792 }
793 
794 /// Is the value of the given expression possibly a reference to or
795 /// into a __block variable?
796 static bool isBlockVarRef(const Expr *E) {
797  // Make sure we look through parens.
798  E = E->IgnoreParens();
799 
800  // Check for a direct reference to a __block variable.
801  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
802  const VarDecl *var = dyn_cast<VarDecl>(DRE->getDecl());
803  return (var && var->hasAttr<BlocksAttr>());
804  }
805 
806  // More complicated stuff.
807 
808  // Binary operators.
809  if (const BinaryOperator *op = dyn_cast<BinaryOperator>(E)) {
810  // For an assignment or pointer-to-member operation, just care
811  // about the LHS.
812  if (op->isAssignmentOp() || op->isPtrMemOp())
813  return isBlockVarRef(op->getLHS());
814 
815  // For a comma, just care about the RHS.
816  if (op->getOpcode() == BO_Comma)
817  return isBlockVarRef(op->getRHS());
818 
819  // FIXME: pointer arithmetic?
820  return false;
821 
822  // Check both sides of a conditional operator.
823  } else if (const AbstractConditionalOperator *op
824  = dyn_cast<AbstractConditionalOperator>(E)) {
825  return isBlockVarRef(op->getTrueExpr())
826  || isBlockVarRef(op->getFalseExpr());
827 
828  // OVEs are required to support BinaryConditionalOperators.
829  } else if (const OpaqueValueExpr *op
830  = dyn_cast<OpaqueValueExpr>(E)) {
831  if (const Expr *src = op->getSourceExpr())
832  return isBlockVarRef(src);
833 
834  // Casts are necessary to get things like (*(int*)&var) = foo().
835  // We don't really care about the kind of cast here, except
836  // we don't want to look through l2r casts, because it's okay
837  // to get the *value* in a __block variable.
838  } else if (const CastExpr *cast = dyn_cast<CastExpr>(E)) {
839  if (cast->getCastKind() == CK_LValueToRValue)
840  return false;
841  return isBlockVarRef(cast->getSubExpr());
842 
843  // Handle unary operators. Again, just aggressively look through
844  // it, ignoring the operation.
845  } else if (const UnaryOperator *uop = dyn_cast<UnaryOperator>(E)) {
846  return isBlockVarRef(uop->getSubExpr());
847 
848  // Look into the base of a field access.
849  } else if (const MemberExpr *mem = dyn_cast<MemberExpr>(E)) {
850  return isBlockVarRef(mem->getBase());
851 
852  // Look into the base of a subscript.
853  } else if (const ArraySubscriptExpr *sub = dyn_cast<ArraySubscriptExpr>(E)) {
854  return isBlockVarRef(sub->getBase());
855  }
856 
857  return false;
858 }
859 
860 void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
861  // For an assignment to work, the value on the right has
862  // to be compatible with the value on the left.
863  assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
864  E->getRHS()->getType())
865  && "Invalid assignment");
866 
867  // If the LHS might be a __block variable, and the RHS can
868  // potentially cause a block copy, we need to evaluate the RHS first
869  // so that the assignment goes the right place.
870  // This is pretty semantically fragile.
871  if (isBlockVarRef(E->getLHS()) &&
872  E->getRHS()->HasSideEffects(CGF.getContext())) {
873  // Ensure that we have a destination, and evaluate the RHS into that.
874  EnsureDest(E->getRHS()->getType());
875  Visit(E->getRHS());
876 
877  // Now emit the LHS and copy into it.
878  LValue LHS = CGF.EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
879 
880  // That copy is an atomic copy if the LHS is atomic.
881  if (LHS.getType()->isAtomicType() ||
882  CGF.LValueIsSuitableForInlineAtomic(LHS)) {
883  CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false);
884  return;
885  }
886 
887  EmitCopy(E->getLHS()->getType(),
889  needsGC(E->getLHS()->getType()),
891  Dest);
892  return;
893  }
894 
895  LValue LHS = CGF.EmitLValue(E->getLHS());
896 
897  // If we have an atomic type, evaluate into the destination and then
898  // do an atomic copy.
899  if (LHS.getType()->isAtomicType() ||
900  CGF.LValueIsSuitableForInlineAtomic(LHS)) {
901  EnsureDest(E->getRHS()->getType());
902  Visit(E->getRHS());
903  CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false);
904  return;
905  }
906 
907  // Codegen the RHS so that it stores directly into the LHS.
908  AggValueSlot LHSSlot =
910  needsGC(E->getLHS()->getType()),
912  // A non-volatile aggregate destination might have volatile member.
913  if (!LHSSlot.isVolatile() &&
914  CGF.hasVolatileMember(E->getLHS()->getType()))
915  LHSSlot.setVolatile(true);
916 
917  CGF.EmitAggExpr(E->getRHS(), LHSSlot);
918 
919  // Copy into the destination if the assignment isn't ignored.
920  EmitFinalDestCopy(E->getType(), LHS);
921 }
922 
923 void AggExprEmitter::
924 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
925  llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
926  llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
927  llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
928 
929  // Bind the common expression if necessary.
930  CodeGenFunction::OpaqueValueMapping binding(CGF, E);
931 
933  CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock,
934  CGF.getProfileCount(E));
935 
936  // Save whether the destination's lifetime is externally managed.
937  bool isExternallyDestructed = Dest.isExternallyDestructed();
938 
939  eval.begin(CGF);
940  CGF.EmitBlock(LHSBlock);
941  CGF.incrementProfileCounter(E);
942  Visit(E->getTrueExpr());
943  eval.end(CGF);
944 
945  assert(CGF.HaveInsertPoint() && "expression evaluation ended with no IP!");
946  CGF.Builder.CreateBr(ContBlock);
947 
948  // If the result of an agg expression is unused, then the emission
949  // of the LHS might need to create a destination slot. That's fine
950  // with us, and we can safely emit the RHS into the same slot, but
951  // we shouldn't claim that it's already being destructed.
952  Dest.setExternallyDestructed(isExternallyDestructed);
953 
954  eval.begin(CGF);
955  CGF.EmitBlock(RHSBlock);
956  Visit(E->getFalseExpr());
957  eval.end(CGF);
958 
959  CGF.EmitBlock(ContBlock);
960 }
961 
962 void AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) {
963  Visit(CE->getChosenSubExpr());
964 }
965 
966 void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
967  Address ArgValue = Address::invalid();
968  Address ArgPtr = CGF.EmitVAArg(VE, ArgValue);
969 
970  if (!ArgPtr.isValid()) {
971  // If EmitVAArg fails, we fall back to the LLVM instruction.
972  llvm::Value *Val = Builder.CreateVAArg(ArgValue.getPointer(),
973  CGF.ConvertType(VE->getType()));
974  if (!Dest.isIgnored())
975  Builder.CreateStore(Val, Dest.getAddress());
976  return;
977  }
978 
979  EmitFinalDestCopy(VE->getType(), CGF.MakeAddrLValue(ArgPtr, VE->getType()));
980 }
981 
982 void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
983  // Ensure that we have a slot, but if we already do, remember
984  // whether it was externally destructed.
985  bool wasExternallyDestructed = Dest.isExternallyDestructed();
986  EnsureDest(E->getType());
987 
988  // We're going to push a destructor if there isn't already one.
990 
991  Visit(E->getSubExpr());
992 
993  // Push that destructor we promised.
994  if (!wasExternallyDestructed)
995  CGF.EmitCXXTemporary(E->getTemporary(), E->getType(), Dest.getAddress());
996 }
997 
998 void
999 AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) {
1000  AggValueSlot Slot = EnsureSlot(E->getType());
1001  CGF.EmitCXXConstructExpr(E, Slot);
1002 }
1003 
1004 void
1005 AggExprEmitter::VisitLambdaExpr(LambdaExpr *E) {
1006  AggValueSlot Slot = EnsureSlot(E->getType());
1007  CGF.EmitLambdaExpr(E, Slot);
1008 }
1009 
1010 void AggExprEmitter::VisitExprWithCleanups(ExprWithCleanups *E) {
1011  CGF.enterFullExpression(E);
1012  CodeGenFunction::RunCleanupsScope cleanups(CGF);
1013  Visit(E->getSubExpr());
1014 }
1015 
1016 void AggExprEmitter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
1017  QualType T = E->getType();
1018  AggValueSlot Slot = EnsureSlot(T);
1019  EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T));
1020 }
1021 
1022 void AggExprEmitter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
1023  QualType T = E->getType();
1024  AggValueSlot Slot = EnsureSlot(T);
1025  EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T));
1026 }
1027 
1028 /// isSimpleZero - If emitting this value will obviously just cause a store of
1029 /// zero to memory, return true. This can return false if uncertain, so it just
1030 /// handles simple cases.
1031 static bool isSimpleZero(const Expr *E, CodeGenFunction &CGF) {
1032  E = E->IgnoreParens();
1033 
1034  // 0
1035  if (const IntegerLiteral *IL = dyn_cast<IntegerLiteral>(E))
1036  return IL->getValue() == 0;
1037  // +0.0
1038  if (const FloatingLiteral *FL = dyn_cast<FloatingLiteral>(E))
1039  return FL->getValue().isPosZero();
1040  // int()
1041  if ((isa<ImplicitValueInitExpr>(E) || isa<CXXScalarValueInitExpr>(E)) &&
1042  CGF.getTypes().isZeroInitializable(E->getType()))
1043  return true;
1044  // (int*)0 - Null pointer expressions.
1045  if (const CastExpr *ICE = dyn_cast<CastExpr>(E))
1046  return ICE->getCastKind() == CK_NullToPointer;
1047  // '\0'
1048  if (const CharacterLiteral *CL = dyn_cast<CharacterLiteral>(E))
1049  return CL->getValue() == 0;
1050 
1051  // Otherwise, hard case: conservatively return false.
1052  return false;
1053 }
1054 
1055 
1056 void
1057 AggExprEmitter::EmitInitializationToLValue(Expr *E, LValue LV) {
1058  QualType type = LV.getType();
1059  // FIXME: Ignore result?
1060  // FIXME: Are initializers affected by volatile?
1061  if (Dest.isZeroed() && isSimpleZero(E, CGF)) {
1062  // Storing "i32 0" to a zero'd memory location is a noop.
1063  return;
1064  } else if (isa<ImplicitValueInitExpr>(E) || isa<CXXScalarValueInitExpr>(E)) {
1065  return EmitNullInitializationToLValue(LV);
1066  } else if (isa<NoInitExpr>(E)) {
1067  // Do nothing.
1068  return;
1069  } else if (type->isReferenceType()) {
1070  RValue RV = CGF.EmitReferenceBindingToExpr(E);
1071  return CGF.EmitStoreThroughLValue(RV, LV);
1072  }
1073 
1074  switch (CGF.getEvaluationKind(type)) {
1075  case TEK_Complex:
1076  CGF.EmitComplexExprIntoLValue(E, LV, /*isInit*/ true);
1077  return;
1078  case TEK_Aggregate:
1079  CGF.EmitAggExpr(E, AggValueSlot::forLValue(LV,
1083  Dest.isZeroed()));
1084  return;
1085  case TEK_Scalar:
1086  if (LV.isSimple()) {
1087  CGF.EmitScalarInit(E, /*D=*/nullptr, LV, /*Captured=*/false);
1088  } else {
1089  CGF.EmitStoreThroughLValue(RValue::get(CGF.EmitScalarExpr(E)), LV);
1090  }
1091  return;
1092  }
1093  llvm_unreachable("bad evaluation kind");
1094 }
1095 
1096 void AggExprEmitter::EmitNullInitializationToLValue(LValue lv) {
1097  QualType type = lv.getType();
1098 
1099  // If the destination slot is already zeroed out before the aggregate is
1100  // copied into it, we don't have to emit any zeros here.
1101  if (Dest.isZeroed() && CGF.getTypes().isZeroInitializable(type))
1102  return;
1103 
1104  if (CGF.hasScalarEvaluationKind(type)) {
1105  // For non-aggregates, we can store the appropriate null constant.
1106  llvm::Value *null = CGF.CGM.EmitNullConstant(type);
1107  // Note that the following is not equivalent to
1108  // EmitStoreThroughBitfieldLValue for ARC types.
1109  if (lv.isBitField()) {
1110  CGF.EmitStoreThroughBitfieldLValue(RValue::get(null), lv);
1111  } else {
1112  assert(lv.isSimple());
1113  CGF.EmitStoreOfScalar(null, lv, /* isInitialization */ true);
1114  }
1115  } else {
1116  // There's a potential optimization opportunity in combining
1117  // memsets; that would be easy for arrays, but relatively
1118  // difficult for structures with the current code.
1119  CGF.EmitNullInitialization(lv.getAddress(), lv.getType());
1120  }
1121 }
1122 
1123 void AggExprEmitter::VisitInitListExpr(InitListExpr *E) {
1124 #if 0
1125  // FIXME: Assess perf here? Figure out what cases are worth optimizing here
1126  // (Length of globals? Chunks of zeroed-out space?).
1127  //
1128  // If we can, prefer a copy from a global; this is a lot less code for long
1129  // globals, and it's easier for the current optimizers to analyze.
1130  if (llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, E->getType(), &CGF)) {
1131  llvm::GlobalVariable* GV =
1132  new llvm::GlobalVariable(CGF.CGM.getModule(), C->getType(), true,
1134  EmitFinalDestCopy(E->getType(), CGF.MakeAddrLValue(GV, E->getType()));
1135  return;
1136  }
1137 #endif
1138  if (E->hadArrayRangeDesignator())
1139  CGF.ErrorUnsupported(E, "GNU array range designator extension");
1140 
1141  AggValueSlot Dest = EnsureSlot(E->getType());
1142 
1143  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
1144 
1145  // Handle initialization of an array.
1146  if (E->getType()->isArrayType()) {
1147  if (E->isStringLiteralInit())
1148  return Visit(E->getInit(0));
1149 
1150  QualType elementType =
1151  CGF.getContext().getAsArrayType(E->getType())->getElementType();
1152 
1153  auto AType = cast<llvm::ArrayType>(Dest.getAddress().getElementType());
1154  EmitArrayInit(Dest.getAddress(), AType, elementType, E);
1155  return;
1156  }
1157 
1158  if (E->getType()->isAtomicType()) {
1159  // An _Atomic(T) object can be list-initialized from an expression
1160  // of the same type.
1161  assert(E->getNumInits() == 1 &&
1162  CGF.getContext().hasSameUnqualifiedType(E->getInit(0)->getType(),
1163  E->getType()) &&
1164  "unexpected list initialization for atomic object");
1165  return Visit(E->getInit(0));
1166  }
1167 
1168  assert(E->getType()->isRecordType() && "Only support structs/unions here!");
1169 
1170  // Do struct initialization; this code just sets each individual member
1171  // to the approprate value. This makes bitfield support automatic;
1172  // the disadvantage is that the generated code is more difficult for
1173  // the optimizer, especially with bitfields.
1174  unsigned NumInitElements = E->getNumInits();
1175  RecordDecl *record = E->getType()->castAs<RecordType>()->getDecl();
1176 
1177  // Prepare a 'this' for CXXDefaultInitExprs.
1179 
1180  if (record->isUnion()) {
1181  // Only initialize one field of a union. The field itself is
1182  // specified by the initializer list.
1183  if (!E->getInitializedFieldInUnion()) {
1184  // Empty union; we have nothing to do.
1185 
1186 #ifndef NDEBUG
1187  // Make sure that it's really an empty and not a failure of
1188  // semantic analysis.
1189  for (const auto *Field : record->fields())
1190  assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed");
1191 #endif
1192  return;
1193  }
1194 
1195  // FIXME: volatility
1196  FieldDecl *Field = E->getInitializedFieldInUnion();
1197 
1198  LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestLV, Field);
1199  if (NumInitElements) {
1200  // Store the initializer into the field
1201  EmitInitializationToLValue(E->getInit(0), FieldLoc);
1202  } else {
1203  // Default-initialize to null.
1204  EmitNullInitializationToLValue(FieldLoc);
1205  }
1206 
1207  return;
1208  }
1209 
1210  // We'll need to enter cleanup scopes in case any of the member
1211  // initializers throw an exception.
1213  llvm::Instruction *cleanupDominator = nullptr;
1214 
1215  // Here we iterate over the fields; this makes it simpler to both
1216  // default-initialize fields and skip over unnamed fields.
1217  unsigned curInitIndex = 0;
1218  for (const auto *field : record->fields()) {
1219  // We're done once we hit the flexible array member.
1220  if (field->getType()->isIncompleteArrayType())
1221  break;
1222 
1223  // Always skip anonymous bitfields.
1224  if (field->isUnnamedBitfield())
1225  continue;
1226 
1227  // We're done if we reach the end of the explicit initializers, we
1228  // have a zeroed object, and the rest of the fields are
1229  // zero-initializable.
1230  if (curInitIndex == NumInitElements && Dest.isZeroed() &&
1231  CGF.getTypes().isZeroInitializable(E->getType()))
1232  break;
1233 
1234 
1235  LValue LV = CGF.EmitLValueForFieldInitialization(DestLV, field);
1236  // We never generate write-barries for initialized fields.
1237  LV.setNonGC(true);
1238 
1239  if (curInitIndex < NumInitElements) {
1240  // Store the initializer into the field.
1241  EmitInitializationToLValue(E->getInit(curInitIndex++), LV);
1242  } else {
1243  // We're out of initalizers; default-initialize to null
1244  EmitNullInitializationToLValue(LV);
1245  }
1246 
1247  // Push a destructor if necessary.
1248  // FIXME: if we have an array of structures, all explicitly
1249  // initialized, we can end up pushing a linear number of cleanups.
1250  bool pushedCleanup = false;
1251  if (QualType::DestructionKind dtorKind
1252  = field->getType().isDestructedType()) {
1253  assert(LV.isSimple());
1254  if (CGF.needsEHCleanup(dtorKind)) {
1255  if (!cleanupDominator)
1256  cleanupDominator = CGF.Builder.CreateAlignedLoad(
1257  CGF.Int8Ty,
1258  llvm::Constant::getNullValue(CGF.Int8PtrTy),
1259  CharUnits::One()); // placeholder
1260 
1261  CGF.pushDestroy(EHCleanup, LV.getAddress(), field->getType(),
1262  CGF.getDestroyer(dtorKind), false);
1263  cleanups.push_back(CGF.EHStack.stable_begin());
1264  pushedCleanup = true;
1265  }
1266  }
1267 
1268  // If the GEP didn't get used because of a dead zero init or something
1269  // else, clean it up for -O0 builds and general tidiness.
1270  if (!pushedCleanup && LV.isSimple())
1271  if (llvm::GetElementPtrInst *GEP =
1272  dyn_cast<llvm::GetElementPtrInst>(LV.getPointer()))
1273  if (GEP->use_empty())
1274  GEP->eraseFromParent();
1275  }
1276 
1277  // Deactivate all the partial cleanups in reverse order, which
1278  // generally means popping them.
1279  for (unsigned i = cleanups.size(); i != 0; --i)
1280  CGF.DeactivateCleanupBlock(cleanups[i-1], cleanupDominator);
1281 
1282  // Destroy the placeholder if we made one.
1283  if (cleanupDominator)
1284  cleanupDominator->eraseFromParent();
1285 }
1286 
1287 void AggExprEmitter::VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E) {
1288  AggValueSlot Dest = EnsureSlot(E->getType());
1289 
1290  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
1291  EmitInitializationToLValue(E->getBase(), DestLV);
1292  VisitInitListExpr(E->getUpdater());
1293 }
1294 
1295 //===----------------------------------------------------------------------===//
1296 // Entry Points into this File
1297 //===----------------------------------------------------------------------===//
1298 
1299 /// GetNumNonZeroBytesInInit - Get an approximate count of the number of
1300 /// non-zero bytes that will be stored when outputting the initializer for the
1301 /// specified initializer expression.
1303  E = E->IgnoreParens();
1304 
1305  // 0 and 0.0 won't require any non-zero stores!
1306  if (isSimpleZero(E, CGF)) return CharUnits::Zero();
1307 
1308  // If this is an initlist expr, sum up the size of sizes of the (present)
1309  // elements. If this is something weird, assume the whole thing is non-zero.
1310  const InitListExpr *ILE = dyn_cast<InitListExpr>(E);
1311  if (!ILE || !CGF.getTypes().isZeroInitializable(ILE->getType()))
1312  return CGF.getContext().getTypeSizeInChars(E->getType());
1313 
1314  // InitListExprs for structs have to be handled carefully. If there are
1315  // reference members, we need to consider the size of the reference, not the
1316  // referencee. InitListExprs for unions and arrays can't have references.
1317  if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
1318  if (!RT->isUnionType()) {
1319  RecordDecl *SD = E->getType()->getAs<RecordType>()->getDecl();
1320  CharUnits NumNonZeroBytes = CharUnits::Zero();
1321 
1322  unsigned ILEElement = 0;
1323  for (const auto *Field : SD->fields()) {
1324  // We're done once we hit the flexible array member or run out of
1325  // InitListExpr elements.
1326  if (Field->getType()->isIncompleteArrayType() ||
1327  ILEElement == ILE->getNumInits())
1328  break;
1329  if (Field->isUnnamedBitfield())
1330  continue;
1331 
1332  const Expr *E = ILE->getInit(ILEElement++);
1333 
1334  // Reference values are always non-null and have the width of a pointer.
1335  if (Field->getType()->isReferenceType())
1336  NumNonZeroBytes += CGF.getContext().toCharUnitsFromBits(
1337  CGF.getTarget().getPointerWidth(0));
1338  else
1339  NumNonZeroBytes += GetNumNonZeroBytesInInit(E, CGF);
1340  }
1341 
1342  return NumNonZeroBytes;
1343  }
1344  }
1345 
1346 
1347  CharUnits NumNonZeroBytes = CharUnits::Zero();
1348  for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i)
1349  NumNonZeroBytes += GetNumNonZeroBytesInInit(ILE->getInit(i), CGF);
1350  return NumNonZeroBytes;
1351 }
1352 
1353 /// CheckAggExprForMemSetUse - If the initializer is large and has a lot of
1354 /// zeros in it, emit a memset and avoid storing the individual zeros.
1355 ///
1356 static void CheckAggExprForMemSetUse(AggValueSlot &Slot, const Expr *E,
1357  CodeGenFunction &CGF) {
1358  // If the slot is already known to be zeroed, nothing to do. Don't mess with
1359  // volatile stores.
1360  if (Slot.isZeroed() || Slot.isVolatile() || !Slot.getAddress().isValid())
1361  return;
1362 
1363  // C++ objects with a user-declared constructor don't need zero'ing.
1364  if (CGF.getLangOpts().CPlusPlus)
1365  if (const RecordType *RT = CGF.getContext()
1366  .getBaseElementType(E->getType())->getAs<RecordType>()) {
1367  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1368  if (RD->hasUserDeclaredConstructor())
1369  return;
1370  }
1371 
1372  // If the type is 16-bytes or smaller, prefer individual stores over memset.
1373  CharUnits Size = CGF.getContext().getTypeSizeInChars(E->getType());
1374  if (Size <= CharUnits::fromQuantity(16))
1375  return;
1376 
1377  // Check to see if over 3/4 of the initializer are known to be zero. If so,
1378  // we prefer to emit memset + individual stores for the rest.
1379  CharUnits NumNonZeroBytes = GetNumNonZeroBytesInInit(E, CGF);
1380  if (NumNonZeroBytes*4 > Size)
1381  return;
1382 
1383  // Okay, it seems like a good idea to use an initial memset, emit the call.
1384  llvm::Constant *SizeVal = CGF.Builder.getInt64(Size.getQuantity());
1385 
1386  Address Loc = Slot.getAddress();
1387  Loc = CGF.Builder.CreateElementBitCast(Loc, CGF.Int8Ty);
1388  CGF.Builder.CreateMemSet(Loc, CGF.Builder.getInt8(0), SizeVal, false);
1389 
1390  // Tell the AggExprEmitter that the slot is known zero.
1391  Slot.setZeroed();
1392 }
1393 
1394 
1395 
1396 
1397 /// EmitAggExpr - Emit the computation of the specified expression of aggregate
1398 /// type. The result is computed into DestPtr. Note that if DestPtr is null,
1399 /// the value of the aggregate expression is not needed. If VolatileDest is
1400 /// true, DestPtr cannot be 0.
1402  assert(E && hasAggregateEvaluationKind(E->getType()) &&
1403  "Invalid aggregate expression to emit");
1404  assert((Slot.getAddress().isValid() || Slot.isIgnored()) &&
1405  "slot has bits but no address");
1406 
1407  // Optimize the slot if possible.
1408  CheckAggExprForMemSetUse(Slot, E, *this);
1409 
1410  AggExprEmitter(*this, Slot, Slot.isIgnored()).Visit(const_cast<Expr*>(E));
1411 }
1412 
1414  assert(hasAggregateEvaluationKind(E->getType()) && "Invalid argument!");
1415  Address Temp = CreateMemTemp(E->getType());
1416  LValue LV = MakeAddrLValue(Temp, E->getType());
1420  return LV;
1421 }
1422 
1424  Address SrcPtr, QualType Ty,
1425  bool isVolatile,
1426  bool isAssignment) {
1427  assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
1428 
1429  if (getLangOpts().CPlusPlus) {
1430  if (const RecordType *RT = Ty->getAs<RecordType>()) {
1431  CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl());
1432  assert((Record->hasTrivialCopyConstructor() ||
1433  Record->hasTrivialCopyAssignment() ||
1434  Record->hasTrivialMoveConstructor() ||
1435  Record->hasTrivialMoveAssignment() ||
1436  Record->isUnion()) &&
1437  "Trying to aggregate-copy a type without a trivial copy/move "
1438  "constructor or assignment operator");
1439  // Ignore empty classes in C++.
1440  if (Record->isEmpty())
1441  return;
1442  }
1443  }
1444 
1445  // Aggregate assignment turns into llvm.memcpy. This is almost valid per
1446  // C99 6.5.16.1p3, which states "If the value being stored in an object is
1447  // read from another object that overlaps in anyway the storage of the first
1448  // object, then the overlap shall be exact and the two objects shall have
1449  // qualified or unqualified versions of a compatible type."
1450  //
1451  // memcpy is not defined if the source and destination pointers are exactly
1452  // equal, but other compilers do this optimization, and almost every memcpy
1453  // implementation handles this case safely. If there is a libc that does not
1454  // safely handle this, we can add a target hook.
1455 
1456  // Get data size info for this aggregate. If this is an assignment,
1457  // don't copy the tail padding, because we might be assigning into a
1458  // base subobject where the tail padding is claimed. Otherwise,
1459  // copying it is fine.
1460  std::pair<CharUnits, CharUnits> TypeInfo;
1461  if (isAssignment)
1462  TypeInfo = getContext().getTypeInfoDataSizeInChars(Ty);
1463  else
1464  TypeInfo = getContext().getTypeInfoInChars(Ty);
1465 
1466  llvm::Value *SizeVal = nullptr;
1467  if (TypeInfo.first.isZero()) {
1468  // But note that getTypeInfo returns 0 for a VLA.
1469  if (auto *VAT = dyn_cast_or_null<VariableArrayType>(
1470  getContext().getAsArrayType(Ty))) {
1471  QualType BaseEltTy;
1472  SizeVal = emitArrayLength(VAT, BaseEltTy, DestPtr);
1473  TypeInfo = getContext().getTypeInfoDataSizeInChars(BaseEltTy);
1474  std::pair<CharUnits, CharUnits> LastElementTypeInfo;
1475  if (!isAssignment)
1476  LastElementTypeInfo = getContext().getTypeInfoInChars(BaseEltTy);
1477  assert(!TypeInfo.first.isZero());
1478  SizeVal = Builder.CreateNUWMul(
1479  SizeVal,
1480  llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity()));
1481  if (!isAssignment) {
1482  SizeVal = Builder.CreateNUWSub(
1483  SizeVal,
1484  llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity()));
1485  SizeVal = Builder.CreateNUWAdd(
1486  SizeVal, llvm::ConstantInt::get(
1487  SizeTy, LastElementTypeInfo.first.getQuantity()));
1488  }
1489  }
1490  }
1491  if (!SizeVal) {
1492  SizeVal = llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity());
1493  }
1494 
1495  // FIXME: If we have a volatile struct, the optimizer can remove what might
1496  // appear to be `extra' memory ops:
1497  //
1498  // volatile struct { int i; } a, b;
1499  //
1500  // int main() {
1501  // a = b;
1502  // a = b;
1503  // }
1504  //
1505  // we need to use a different call here. We use isVolatile to indicate when
1506  // either the source or the destination is volatile.
1507 
1508  DestPtr = Builder.CreateElementBitCast(DestPtr, Int8Ty);
1509  SrcPtr = Builder.CreateElementBitCast(SrcPtr, Int8Ty);
1510 
1511  // Don't do any of the memmove_collectable tests if GC isn't set.
1512  if (CGM.getLangOpts().getGC() == LangOptions::NonGC) {
1513  // fall through
1514  } else if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
1515  RecordDecl *Record = RecordTy->getDecl();
1516  if (Record->hasObjectMember()) {
1517  CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
1518  SizeVal);
1519  return;
1520  }
1521  } else if (Ty->isArrayType()) {
1522  QualType BaseType = getContext().getBaseElementType(Ty);
1523  if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
1524  if (RecordTy->getDecl()->hasObjectMember()) {
1525  CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
1526  SizeVal);
1527  return;
1528  }
1529  }
1530  }
1531 
1532  auto Inst = Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, isVolatile);
1533 
1534  // Determine the metadata to describe the position of any padding in this
1535  // memcpy, as well as the TBAA tags for the members of the struct, in case
1536  // the optimizer wishes to expand it in to scalar memory operations.
1537  if (llvm::MDNode *TBAAStructTag = CGM.getTBAAStructInfo(Ty))
1538  Inst->setMetadata(llvm::LLVMContext::MD_tbaa_struct, TBAAStructTag);
1539 }
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:151
Defines the clang::ASTContext interface.
unsigned getNumInits() const
Definition: Expr.h:3754
CastKind getCastKind() const
Definition: Expr.h:2658
CK_LValueToRValue - A conversion which causes the extraction of an r-value from the operand gl-value...
A (possibly-)qualified type.
Definition: Type.h:575
llvm::Value * getPointer() const
Definition: CGValue.h:327
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1003
CompoundStmt * getSubStmt()
Definition: Expr.h:3374
static AggValueSlot forLValue(const LValue &LV, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, IsZeroed_t isZeroed=IsNotZeroed)
Definition: CGValue.h:524
const TargetInfo & getTarget() const
CanQualType getSizeType() const
Return the unique type for "size_t" (C99 7.17), defined in <stddef.h>.
Expr * GetTemporaryExpr() const
Retrieve the temporary-generating subexpression whose value will be materialized into a glvalue...
Definition: ExprCXX.h:3905
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:171
bool isRecordType() const
Definition: Type.h:5362
virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF, Address DestPtr, Address SrcPtr, llvm::Value *Size)=0
CK_ToUnion - The GCC cast-to-union extension.
llvm::MDNode * getTBAAStructInfo(QualType QTy)
Address getAddress() const
Definition: CGValue.h:331
Defines the C++ template declaration subclasses.
ParenExpr - This represents a parethesized expression, e.g.
Definition: Expr.h:1605
CK_BaseToDerivedMemberPointer - Member pointer in base class to member pointer in derived class...
Represents an array type, per C99 6.7.5.2 - Array Declarators.
Definition: Type.h:2424
const Expr * getResultExpr() const
The generic selection's result expression.
Definition: Expr.h:4494
Represents a call to a C++ constructor.
Definition: ExprCXX.h:1149
CK_FloatingToIntegral - Floating point to integral.
void setZeroed(bool V=true)
Definition: CGValue.h:586
const LangOptions & getLangOpts() const
[ARC] Consumes a retainable object pointer that has just been produced, e.g.
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
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:2940
Represents a prvalue temporary that is written into memory so that a reference can bind to it...
Definition: ExprCXX.h:3864
const llvm::APInt & getSize() const
Definition: Type.h:2495
bool isVolatile() const
Definition: CGValue.h:542
CK_IntegralToFloating - Integral to floating point.
bool hadArrayRangeDesignator() const
Definition: Expr.h:3871
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:796
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:561
VarDecl - An instance of this class is created to represent a variable declaration or definition...
Definition: Decl.h:699
CK_IntegralCast - A cast between integral types (other than to boolean).
llvm::Type * getElementType() const
Return the type of the values stored in this address.
Definition: Address.h:52
CompoundLiteralExpr - [C99 6.5.2.5].
Definition: Expr.h:2540
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:1031
field_iterator field_begin() const
Definition: Decl.cpp:3746
CK_Dynamic - A C++ dynamic_cast.
Implicit construction of a std::initializer_list<T> object from an array temporary within list-initia...
Definition: ExprCXX.h:517
CK_Dependent - A conversion which cannot yet be analyzed because either the expression or target type...
IsZeroed_t isZeroed() const
Definition: CGValue.h:587
A C++ throw-expression (C++ [except.throw]).
Definition: ExprCXX.h:900
Represents an expression – generally a full-expression – that introduces cleanups to be run at the en...
Definition: ExprCXX.h:2847
iterator begin() const
Definition: Type.h:4072
bool hasTrivialCopyConstructor() const
Determine whether this class has a trivial copy constructor (C++ [class.copy]p6, C++11 [class...
Definition: DeclCXX.h:1207
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:1302
RecordDecl - Represents a struct/union/class.
Definition: Decl.h:3166
An object to manage conditionally-evaluated expressions.
bool isEmpty() const
Determine whether this is an empty class in the sense of (C++11 [meta.unary.prop]).
Definition: DeclCXX.h:1144
bool hasAttr() const
Definition: DeclBase.h:498
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:91
Converts between different integral complex types.
bool isReferenceType() const
Definition: Type.h:5314
FieldDecl - An instance of this class is created by Sema::ActOnField to represent a member of a struc...
Definition: Decl.h:2209
Represents a place-holder for an object not to be initialized by anything.
Definition: Expr.h:4253
An RAII object to set (and then clear) a mapping for an OpaqueValueExpr.
Converting between two Objective-C object types, which can occur when performing reference binding to...
Denotes a cleanup that should run when a scope is exited using exceptional control flow (a throw stat...
Definition: EHScopeStack.h:81
bool hasSameType(QualType T1, QualType T2) const
Determine whether the given types T1 and T2 are equivalent.
Definition: ASTContext.h:1962
CK_FloatingCast - Casting between floating types of different size.
[ARC] Causes a value of block type to be copied to the heap, if it is not already there...
CK_VectorSplat - A conversion from an arithmetic type to a vector of that element type...
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:53
Expr * getSubExpr()
Definition: Expr.h:2662
CK_NullToPointer - Null pointer constant to pointer, ObjC pointer, or block pointer.
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:379
CK_PointerToIntegral - Pointer to integral.
CK_IntegralToPointer - Integral to pointer.
Expr * getLHS() const
Definition: Expr.h:2921
void setNonGC(bool Value)
Definition: CGValue.h:271
Converts a floating point complex to bool by comparing against 0+0i.
Describes an C or C++ initializer list.
Definition: Expr.h:3724
A C++ typeid expression (C++ [expr.typeid]), which gets the type_info that corresponds to the supplie...
Definition: ExprCXX.h:559
CK_IntegralToBoolean - Integral to boolean.
Expr * getChosenSubExpr() const
getChosenSubExpr - Return the subexpression chosen according to the condition.
Definition: Expr.h:3566
Expr * getTrueExpr() const
Definition: Expr.h:3304
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:176
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:38
field_range fields() const
Definition: Decl.h:3295
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:2875
RecordDecl * getDecl() const
Definition: Type.h:3553
llvm::CallInst * CreateMemCpy(Address Dest, Address Src, llvm::Value *Size, bool IsVolatile=false)
Definition: CGBuilder.h:272
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:38
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:2610
Represents binding an expression to a temporary.
Definition: ExprCXX.h:1106
CXXTemporary * getTemporary()
Definition: ExprCXX.h:1126
A C++ lambda expression, which produces a function object (of unspecified type) that can be invoked l...
Definition: ExprCXX.h:1422
iterator end() const
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
bool isValid() const
Definition: Address.h:36
std::pair< CharUnits, CharUnits > getTypeInfoInChars(const Type *T) const
A default argument (C++ [dcl.fct.default]).
Definition: ExprCXX.h:954
QualType getType() const
Definition: Decl.h:530
bool isUnnamedBitfield() const
Determines whether this is an unnamed bitfield.
Definition: Decl.h:2283
Checking the operand of a load. Must be suitably sized and aligned.
field_iterator field_end() const
Definition: Decl.h:3298
CK_AnyPointerToBlockPointerCast - Casting any non-block pointer to a block pointer.
LValue MakeAddrLValue(Address Addr, QualType T, AlignmentSource AlignSource=AlignmentSource::Type)
bool isUnion() const
Definition: Decl.h:2856
QualType getValueType() const
Gets the type contained by this atomic type, i.e.
Definition: Type.h:5003
static CharUnits One()
One - Construct a CharUnits quantity of one.
Definition: CharUnits.h:58
Causes a block literal to by copied to the heap and then autoreleased.
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:38
const Expr * getExpr() const
Get the initialization expression that will be used.
Definition: ExprCXX.h:1049
Represents a call to the builtin function __builtin_va_arg.
Definition: Expr.h:3633
CK_FunctionToPointerDecay - Function to pointer decay.
Converts between different floating point complex types.
std::pair< CharUnits, CharUnits > getTypeInfoDataSizeInChars(QualType T) const
CGObjCRuntime & getObjCRuntime()
Return a reference to the configured Objective-C runtime.
An expression "T()" which creates a value-initialized rvalue of type T, which is a non-class type...
Definition: ExprCXX.h:1683
llvm::Value * getPointer() const
Definition: Address.h:38
Expr - This represents one expression.
Definition: Expr.h:104
CK_PointerToBoolean - Pointer to boolean conversion.
Converts an integral complex to an integral real of the source's element type by discarding the imagi...
static Address invalid()
Definition: Address.h:35
bool isAggregate() const
Definition: CGValue.h:53
CK_BitCast - A conversion which causes a bit pattern of one type to be reinterpreted as a bit pattern...
bool isAnyComplexType() const
Definition: Type.h:5368
Enters a new scope for capturing cleanups, all of which will be executed once the scope is exited...
bool isAtomicType() const
Definition: Type.h:5387
RValue asRValue() const
Definition: CGValue.h:578
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:63
CharUnits toCharUnitsFromBits(int64_t BitSize) const
Convert a size in bits to a size in characters.
An RAII object to record that we're evaluating a statement expression.
Expr * getSubExpr() const
Definition: Expr.h:1681
CK_ConstructorConversion - Conversion by constructor.
An expression that sends a message to the given Objective-C object or class.
Definition: ExprObjC.h:860
llvm::CallInst * CreateMemSet(Address Dest, llvm::Value *Value, llvm::Value *Size, bool IsVolatile=false)
Definition: CGBuilder.h:294
Converts from an integral complex to a floating complex.
UnaryOperator - This represents the unary-expression's (except sizeof and alignof), the postinc/postdec operators from postfix-expression, and various extensions.
Definition: Expr.h:1654
Represents a reference to a non-type template parameter that has been substituted with a template arg...
Definition: ExprCXX.h:3669
ValueDecl * getDecl()
Definition: Expr.h:1007
bool isGLValue() const
Definition: Expr.h:249
static AggValueSlot forAddr(Address addr, Qualifiers quals, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, IsZeroed_t isZeroed=IsNotZeroed)
forAddr - Make a slot for an aggregate value.
Definition: CGValue.h:502
CK_ArrayToPointerDecay - Array to pointer decay.
InitListExpr * getUpdater() const
Definition: Expr.h:4308
CK_CPointerToObjCPointerCast - Casting a C pointer kind to an Objective-C pointer.
OpaqueValueExpr - An expression referring to an opaque object of a fixed type and value class...
Definition: Expr.h:840
PseudoObjectExpr - An expression which accesses a pseudo-object l-value.
Definition: Expr.h:4692
bool isSimple() const
Definition: CGValue.h:246
CK_UserDefinedConversion - Conversion using a user defined type conversion function.
ASTContext & getContext() const
A saved depth on the scope stack.
Definition: EHScopeStack.h:104
LValue EmitAggExprToLValue(const Expr *E)
EmitAggExprToLValue - Emit the computation of the specified expression of aggregate type into a tempo...
Definition: CGExprAgg.cpp:1413
CK_NullToMemberPointer - Null pointer constant to member pointer.
An aggregate value slot.
Definition: CGValue.h:441
A scoped helper to set the current debug location to the specified location or preferred location of ...
Definition: CGDebugInfo.h:531
StmtVisitor - This class implements a simple visitor for Stmt subclasses.
Definition: StmtVisitor.h:178
CK_ReinterpretMemberPointer - Reinterpret a member pointer as a different kind of member pointer...
CK_DerivedToBase - A conversion from a C++ class pointer to a base class pointer. ...
const ConstantArrayType * getAsConstantArrayType(QualType T) const
Definition: ASTContext.h:2094
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>.
Definition: Expr.h:4817
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:190
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:1356
An aligned address.
Definition: Address.h:25
Converts from an integral real to an integral complex whose element type matches the source...
const LangOptions & getLangOpts() const
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:5706
bool hasObjectMember() const
Definition: Decl.h:3238
StmtExpr - This is the GNU Statement Expression extension: ({int X=4; X;}).
Definition: Expr.h:3358
bool isBitField() const
Definition: CGValue.h:248
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:5159
Expr * getArrayFiller()
If this initializer list initializes an array with more elements than there are initializers in the l...
Definition: Expr.h:3809
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:193
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:1235
void setExternallyDestructed(bool destructed=true)
Definition: CGValue.h:536
Represents a C11 generic selection.
Definition: Expr.h:4426
QualType getCallReturnType(const ASTContext &Ctx) const
getCallReturnType - Get the return type of the call expr.
Definition: Expr.cpp:1273
QualType getType() const
Definition: Expr.h:125
Converts a floating point complex to floating point real of the source's element type.
CharUnits getAlignment() const
Return the alignment of this pointer.
Definition: Address.h:67
static const Type * getElementType(const Expr *BaseExpr)
void setVolatile(bool flag)
Definition: CGValue.h:546
llvm::Value * getAggregatePointer() const
Definition: CGValue.h:75
const Expr * getExpr() const
Definition: ExprCXX.h:985
[C99 6.4.2.2] - A predefined identifier such as func.
Definition: Expr.h:1146
Converts an integral complex to bool by comparing against 0+0i.
Address CreateMemTemp(QualType T, const Twine &Name="tmp")
CreateMemTemp - Create a temporary memory object of the given type, with appropriate alignment...
Definition: CGExpr.cpp:97
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Definition: ASTMatchers.h:1723
static AggValueSlot ignored()
ignored - Returns an aggregate value slot indicating that the aggregate value is being ignored...
Definition: CGValue.h:487
A scope within which we are constructing the fields of an object which might use a CXXDefaultInitExpr...
CK_BaseToDerived - A conversion from a C++ class pointer/reference to a derived class pointer/referen...
U cast(CodeGen::Address addr)
Definition: Address.h:109
IsAliased_t isPotentiallyAliased() const
Definition: CGValue.h:574
bool hasTrivialMoveConstructor() const
Determine whether this class has a trivial move constructor (C++11 [class.copy]p12) ...
Definition: DeclCXX.h:1220
Checking the destination of a store. Must be suitably sized and aligned.
CK_BlockPointerToObjCPointerCast - Casting a block pointer to an ObjC pointer.
detail::InMemoryDirectory::const_iterator E
void EmitAggregateCopy(Address DestPtr, Address SrcPtr, QualType EltTy, bool isVolatile=false, bool isAssignment=false)
EmitAggregateCopy - Emit an aggregate copy.
Definition: CGExprAgg.cpp:1423
IsDestructed_t isExternallyDestructed() const
Definition: CGValue.h:533
A conversion of a floating point real to a floating point complex of the original type...
CK_MemberPointerToBoolean - Member pointer to boolean.
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:1459
void EmitAggExpr(const Expr *E, AggValueSlot AS)
EmitAggExpr - Emit the computation of the specified expression of aggregate type. ...
Definition: CGExprAgg.cpp:1401
[ARC] Reclaim a retainable object pointer object that may have been produced and autoreleased as part...
static bool hasAggregateEvaluationKind(QualType T)
bool hasTrivialMoveAssignment() const
Determine whether this class has a trivial move assignment operator (C++11 [class.copy]p25)
Definition: DeclCXX.h:1248
llvm::PointerType * getType() const
Return the type of the pointer value.
Definition: Address.h:44
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:3544
const T * getAs() const
Member-template getAs<specific type>'.
Definition: Type.h:5675
Expr * getFalseExpr() const
Definition: Expr.h:3310
ArraySubscriptExpr - [C99 6.5.2.1] Array Subscripting.
Definition: Expr.h:2049
AbstractConditionalOperator - An abstract base class for ConditionalOperator and BinaryConditionalOpe...
Definition: Expr.h:3106
NeedsGCBarriers_t requiresGCollection() const
Definition: CGValue.h:554
[ARC] Produces a retainable object pointer so that it may be consumed, e.g.
CK_LValueBitCast - A conversion which reinterprets the address of an l-value as an l-value of a diffe...
Converts from T to _Atomic(T).
Address getAddress() const
Definition: CGValue.h:562
Converts from a floating complex to an integral complex.
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:33
const Expr * getInitializer() const
Definition: Expr.h:2566
CK_UncheckedDerivedToBase - A conversion from a C++ class pointer/reference to a base class that can ...
ObjCIvarRefExpr - A reference to an ObjC instance variable.
Definition: ExprObjC.h:479
uint64_t getPointerWidth(unsigned AddrSpace) const
Return the width of pointers on this target, for the specified address space.
A use of a default initializer in a constructor or in aggregate initialization.
Definition: ExprCXX.h:1024
bool isPODType(ASTContext &Context) const
Determine whether this is a Plain Old Data (POD) type (C++ 3.9p10).
Definition: Type.cpp:1961
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:2297
const Expr * getSubExpr() const
Definition: Expr.h:1621
Represents a C++ struct/union/class.
Definition: DeclCXX.h:285
BoundNodesTreeBuilder *const Builder
Opcode getOpcode() const
Definition: Expr.h:2918
ChooseExpr - GNU builtin-in function __builtin_choose_expr.
Definition: Expr.h:3525
unsigned kind
All of the diagnostics that can be emitted by the frontend.
Definition: DiagnosticIDs.h:43
Address getAggregateAddress() const
getAggregateAddr() - Return the Value* of the address of the aggregate.
Definition: CGValue.h:70
Converts from _Atomic(T) to T.
bool isArrayType() const
Definition: Type.h:5344
StringLiteral - This represents a string literal expression, e.g.
Definition: Expr.h:1452
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2134
Expr * getRHS() const
Definition: Expr.h:2923
QualType getType() const
Definition: CGValue.h:258
bool isIncompleteArrayType() const
Definition: Type.h:5350
bool isStringLiteralInit() const
Definition: Expr.cpp:1957
Expr * getBase() const
Definition: Expr.h:4305
CK_NoOp - A conversion which does not affect the type other than (possibly) adding qualifiers...
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:922
static RValue get(llvm::Value *V)
Definition: CGValue.h:85
CK_DerivedToBaseMemberPointer - Member pointer in derived class to member pointer in base class...
QualType getElementType() const
Definition: Type.h:2458
const Expr * getInit(unsigned Init) const
Definition: Expr.h:3763
const Expr * getSubExpr() const
Definition: ExprCXX.h:1130
FieldDecl * getInitializedFieldInUnion()
If this initializes a union, specifies which field in the union to initialize.
Definition: Expr.h:3827
static RValue getAggregate(Address addr, bool isVolatile=false)
Definition: CGValue.h:106
CodeGenTypes & getTypes() const
LValue - This represents an lvalue references.
Definition: CGValue.h:152
Qualifiers getQualifiers() const
Definition: CGValue.h:540
llvm::Value * emitArrayLength(const ArrayType *arrayType, QualType &baseType, Address &addr)
emitArrayLength - Compute the length of an array, even if it's a VLA, and drill down to the base elem...
CK_ToVoid - Cast to void, discarding the computed value.
bool isIgnored() const
Definition: CGValue.h:566
Represents the canonical version of C arrays with a specified constant size.
Definition: Type.h:2480
QualType getBaseElementType(const ArrayType *VAT) const
Return the innermost element type of an array type.
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:4328
bool hasUserDeclaredConstructor() const
Determine whether this class has any user-declared constructors.
Definition: DeclCXX.h:839
Expr * IgnoreParens() LLVM_READONLY
IgnoreParens - Ignore parentheses.
Definition: Expr.cpp:2433
CK_FloatingToBoolean - Floating point to boolean.