clang  8.0.0svn
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  void VisitConstantExpr(ConstantExpr *E) {
129  return Visit(E->getSubExpr());
130  }
131 
132  // l-values.
133  void VisitDeclRefExpr(DeclRefExpr *E) { EmitAggLoadOfLValue(E); }
134  void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); }
135  void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); }
136  void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); }
137  void VisitCompoundLiteralExpr(CompoundLiteralExpr *E);
138  void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
139  EmitAggLoadOfLValue(E);
140  }
141  void VisitPredefinedExpr(const PredefinedExpr *E) {
142  EmitAggLoadOfLValue(E);
143  }
144 
145  // Operators.
146  void VisitCastExpr(CastExpr *E);
147  void VisitCallExpr(const CallExpr *E);
148  void VisitStmtExpr(const StmtExpr *E);
149  void VisitBinaryOperator(const BinaryOperator *BO);
150  void VisitPointerToDataMemberBinaryOperator(const BinaryOperator *BO);
151  void VisitBinAssign(const BinaryOperator *E);
152  void VisitBinComma(const BinaryOperator *E);
153  void VisitBinCmp(const BinaryOperator *E);
154 
155  void VisitObjCMessageExpr(ObjCMessageExpr *E);
156  void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
157  EmitAggLoadOfLValue(E);
158  }
159 
160  void VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E);
161  void VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
162  void VisitChooseExpr(const ChooseExpr *CE);
163  void VisitInitListExpr(InitListExpr *E);
164  void VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E,
165  llvm::Value *outerBegin = nullptr);
166  void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E);
167  void VisitNoInitExpr(NoInitExpr *E) { } // Do nothing.
168  void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
169  Visit(DAE->getExpr());
170  }
171  void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
173  Visit(DIE->getExpr());
174  }
175  void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
176  void VisitCXXConstructExpr(const CXXConstructExpr *E);
177  void VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *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 /// 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 void AggExprEmitter::withReturnValueSlot(
245  const Expr *E, llvm::function_ref<RValue(ReturnValueSlot)> EmitCall) {
246  QualType RetTy = E->getType();
247  bool RequiresDestruction =
248  Dest.isIgnored() &&
250 
251  // If it makes no observable difference, save a memcpy + temporary.
252  //
253  // We need to always provide our own temporary if destruction is required.
254  // Otherwise, EmitCall will emit its own, notice that it's "unused", and end
255  // its lifetime before we have the chance to emit a proper destructor call.
256  bool UseTemp = Dest.isPotentiallyAliased() || Dest.requiresGCollection() ||
257  (RequiresDestruction && !Dest.getAddress().isValid());
258 
259  Address RetAddr = Address::invalid();
260  Address RetAllocaAddr = Address::invalid();
261 
262  EHScopeStack::stable_iterator LifetimeEndBlock;
263  llvm::Value *LifetimeSizePtr = nullptr;
264  llvm::IntrinsicInst *LifetimeStartInst = nullptr;
265  if (!UseTemp) {
266  RetAddr = Dest.getAddress();
267  } else {
268  RetAddr = CGF.CreateMemTemp(RetTy, "tmp", &RetAllocaAddr);
269  uint64_t Size =
270  CGF.CGM.getDataLayout().getTypeAllocSize(CGF.ConvertTypeForMem(RetTy));
271  LifetimeSizePtr = CGF.EmitLifetimeStart(Size, RetAllocaAddr.getPointer());
272  if (LifetimeSizePtr) {
273  LifetimeStartInst =
274  cast<llvm::IntrinsicInst>(std::prev(Builder.GetInsertPoint()));
275  assert(LifetimeStartInst->getIntrinsicID() ==
276  llvm::Intrinsic::lifetime_start &&
277  "Last insertion wasn't a lifetime.start?");
278 
280  NormalEHLifetimeMarker, RetAllocaAddr, LifetimeSizePtr);
281  LifetimeEndBlock = CGF.EHStack.stable_begin();
282  }
283  }
284 
285  RValue Src =
286  EmitCall(ReturnValueSlot(RetAddr, Dest.isVolatile(), IsResultUnused));
287 
288  if (RequiresDestruction)
289  CGF.pushDestroy(RetTy.isDestructedType(), Src.getAggregateAddress(), RetTy);
290 
291  if (!UseTemp)
292  return;
293 
294  assert(Dest.getPointer() != Src.getAggregatePointer());
295  EmitFinalDestCopy(E->getType(), Src);
296 
297  if (!RequiresDestruction && LifetimeStartInst) {
298  // If there's no dtor to run, the copy was the last use of our temporary.
299  // Since we're not guaranteed to be in an ExprWithCleanups, clean up
300  // eagerly.
301  CGF.DeactivateCleanupBlock(LifetimeEndBlock, LifetimeStartInst);
302  CGF.EmitLifetimeEnd(LifetimeSizePtr, RetAllocaAddr.getPointer());
303  }
304 }
305 
306 /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
307 void AggExprEmitter::EmitFinalDestCopy(QualType type, RValue src) {
308  assert(src.isAggregate() && "value must be aggregate value!");
309  LValue srcLV = CGF.MakeAddrLValue(src.getAggregateAddress(), type);
310  EmitFinalDestCopy(type, srcLV, EVK_RValue);
311 }
312 
313 /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
314 void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src,
315  ExprValueKind SrcValueKind) {
316  // If Dest is ignored, then we're evaluating an aggregate expression
317  // in a context that doesn't care about the result. Note that loads
318  // from volatile l-values force the existence of a non-ignored
319  // destination.
320  if (Dest.isIgnored())
321  return;
322 
323  // Copy non-trivial C structs here.
324  LValue DstLV = CGF.MakeAddrLValue(
325  Dest.getAddress(), Dest.isVolatile() ? type.withVolatile() : type);
326 
327  if (SrcValueKind == EVK_RValue) {
329  if (Dest.isPotentiallyAliased())
330  CGF.callCStructMoveAssignmentOperator(DstLV, src);
331  else
332  CGF.callCStructMoveConstructor(DstLV, src);
333  return;
334  }
335  } else {
337  if (Dest.isPotentiallyAliased())
338  CGF.callCStructCopyAssignmentOperator(DstLV, src);
339  else
340  CGF.callCStructCopyConstructor(DstLV, src);
341  return;
342  }
343  }
344 
345  AggValueSlot srcAgg =
347  needsGC(type), AggValueSlot::IsAliased,
349  EmitCopy(type, Dest, srcAgg);
350 }
351 
352 /// Perform a copy from the source into the destination.
353 ///
354 /// \param type - the type of the aggregate being copied; qualifiers are
355 /// ignored
356 void AggExprEmitter::EmitCopy(QualType type, const AggValueSlot &dest,
357  const AggValueSlot &src) {
358  if (dest.requiresGCollection()) {
359  CharUnits sz = dest.getPreferredSize(CGF.getContext(), type);
360  llvm::Value *size = llvm::ConstantInt::get(CGF.SizeTy, sz.getQuantity());
362  dest.getAddress(),
363  src.getAddress(),
364  size);
365  return;
366  }
367 
368  // If the result of the assignment is used, copy the LHS there also.
369  // It's volatile if either side is. Use the minimum alignment of
370  // the two sides.
371  LValue DestLV = CGF.MakeAddrLValue(dest.getAddress(), type);
372  LValue SrcLV = CGF.MakeAddrLValue(src.getAddress(), type);
373  CGF.EmitAggregateCopy(DestLV, SrcLV, type, dest.mayOverlap(),
374  dest.isVolatile() || src.isVolatile());
375 }
376 
377 /// Emit the initializer for a std::initializer_list initialized with a
378 /// real initializer list.
379 void
380 AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
381  // Emit an array containing the elements. The array is externally destructed
382  // if the std::initializer_list object is.
383  ASTContext &Ctx = CGF.getContext();
384  LValue Array = CGF.EmitLValue(E->getSubExpr());
385  assert(Array.isSimple() && "initializer_list array not a simple lvalue");
386  Address ArrayPtr = Array.getAddress();
387 
390  assert(ArrayType && "std::initializer_list constructed from non-array");
391 
392  // FIXME: Perform the checks on the field types in SemaInit.
393  RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
395  if (Field == Record->field_end()) {
396  CGF.ErrorUnsupported(E, "weird std::initializer_list");
397  return;
398  }
399 
400  // Start pointer.
401  if (!Field->getType()->isPointerType() ||
402  !Ctx.hasSameType(Field->getType()->getPointeeType(),
403  ArrayType->getElementType())) {
404  CGF.ErrorUnsupported(E, "weird std::initializer_list");
405  return;
406  }
407 
408  AggValueSlot Dest = EnsureSlot(E->getType());
409  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
410  LValue Start = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
411  llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0);
412  llvm::Value *IdxStart[] = { Zero, Zero };
413  llvm::Value *ArrayStart =
414  Builder.CreateInBoundsGEP(ArrayPtr.getPointer(), IdxStart, "arraystart");
415  CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start);
416  ++Field;
417 
418  if (Field == Record->field_end()) {
419  CGF.ErrorUnsupported(E, "weird std::initializer_list");
420  return;
421  }
422 
423  llvm::Value *Size = Builder.getInt(ArrayType->getSize());
424  LValue EndOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
425  if (Field->getType()->isPointerType() &&
426  Ctx.hasSameType(Field->getType()->getPointeeType(),
427  ArrayType->getElementType())) {
428  // End pointer.
429  llvm::Value *IdxEnd[] = { Zero, Size };
430  llvm::Value *ArrayEnd =
431  Builder.CreateInBoundsGEP(ArrayPtr.getPointer(), IdxEnd, "arrayend");
432  CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength);
433  } else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) {
434  // Length.
435  CGF.EmitStoreThroughLValue(RValue::get(Size), EndOrLength);
436  } else {
437  CGF.ErrorUnsupported(E, "weird std::initializer_list");
438  return;
439  }
440 }
441 
442 /// Determine if E is a trivial array filler, that is, one that is
443 /// equivalent to zero-initialization.
444 static bool isTrivialFiller(Expr *E) {
445  if (!E)
446  return true;
447 
448  if (isa<ImplicitValueInitExpr>(E))
449  return true;
450 
451  if (auto *ILE = dyn_cast<InitListExpr>(E)) {
452  if (ILE->getNumInits())
453  return false;
454  return isTrivialFiller(ILE->getArrayFiller());
455  }
456 
457  if (auto *Cons = dyn_cast_or_null<CXXConstructExpr>(E))
458  return Cons->getConstructor()->isDefaultConstructor() &&
459  Cons->getConstructor()->isTrivial();
460 
461  // FIXME: Are there other cases where we can avoid emitting an initializer?
462  return false;
463 }
464 
465 /// Emit initialization of an array from an initializer list.
466 void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
467  QualType ArrayQTy, InitListExpr *E) {
468  uint64_t NumInitElements = E->getNumInits();
469 
470  uint64_t NumArrayElements = AType->getNumElements();
471  assert(NumInitElements <= NumArrayElements);
472 
473  QualType elementType =
474  CGF.getContext().getAsArrayType(ArrayQTy)->getElementType();
475 
476  // DestPtr is an array*. Construct an elementType* by drilling
477  // down a level.
478  llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
479  llvm::Value *indices[] = { zero, zero };
480  llvm::Value *begin =
481  Builder.CreateInBoundsGEP(DestPtr.getPointer(), indices, "arrayinit.begin");
482 
483  CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
484  CharUnits elementAlign =
485  DestPtr.getAlignment().alignmentOfArrayElement(elementSize);
486 
487  // Consider initializing the array by copying from a global. For this to be
488  // more efficient than per-element initialization, the size of the elements
489  // with explicit initializers should be large enough.
490  if (NumInitElements * elementSize.getQuantity() > 16 &&
491  elementType.isTriviallyCopyableType(CGF.getContext())) {
492  CodeGen::CodeGenModule &CGM = CGF.CGM;
493  ConstantEmitter Emitter(CGM);
494  LangAS AS = ArrayQTy.getAddressSpace();
495  if (llvm::Constant *C = Emitter.tryEmitForInitializer(E, AS, ArrayQTy)) {
496  auto GV = new llvm::GlobalVariable(
497  CGM.getModule(), C->getType(),
498  CGM.isTypeConstant(ArrayQTy, /* ExcludeCtorDtor= */ true),
499  llvm::GlobalValue::PrivateLinkage, C, "constinit",
500  /* InsertBefore= */ nullptr, llvm::GlobalVariable::NotThreadLocal,
502  Emitter.finalize(GV);
503  CharUnits Align = CGM.getContext().getTypeAlignInChars(ArrayQTy);
504  GV->setAlignment(Align.getQuantity());
505  EmitFinalDestCopy(ArrayQTy, CGF.MakeAddrLValue(GV, ArrayQTy, Align));
506  return;
507  }
508  }
509 
510  // Exception safety requires us to destroy all the
511  // already-constructed members if an initializer throws.
512  // For that, we'll need an EH cleanup.
513  QualType::DestructionKind dtorKind = elementType.isDestructedType();
514  Address endOfInit = Address::invalid();
516  llvm::Instruction *cleanupDominator = nullptr;
517  if (CGF.needsEHCleanup(dtorKind)) {
518  // In principle we could tell the cleanup where we are more
519  // directly, but the control flow can get so varied here that it
520  // would actually be quite complex. Therefore we go through an
521  // alloca.
522  endOfInit = CGF.CreateTempAlloca(begin->getType(), CGF.getPointerAlign(),
523  "arrayinit.endOfInit");
524  cleanupDominator = Builder.CreateStore(begin, endOfInit);
525  CGF.pushIrregularPartialArrayCleanup(begin, endOfInit, elementType,
526  elementAlign,
527  CGF.getDestroyer(dtorKind));
528  cleanup = CGF.EHStack.stable_begin();
529 
530  // Otherwise, remember that we didn't need a cleanup.
531  } else {
532  dtorKind = QualType::DK_none;
533  }
534 
535  llvm::Value *one = llvm::ConstantInt::get(CGF.SizeTy, 1);
536 
537  // The 'current element to initialize'. The invariants on this
538  // variable are complicated. Essentially, after each iteration of
539  // the loop, it points to the last initialized element, except
540  // that it points to the beginning of the array before any
541  // elements have been initialized.
542  llvm::Value *element = begin;
543 
544  // Emit the explicit initializers.
545  for (uint64_t i = 0; i != NumInitElements; ++i) {
546  // Advance to the next element.
547  if (i > 0) {
548  element = Builder.CreateInBoundsGEP(element, one, "arrayinit.element");
549 
550  // Tell the cleanup that it needs to destroy up to this
551  // element. TODO: some of these stores can be trivially
552  // observed to be unnecessary.
553  if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit);
554  }
555 
556  LValue elementLV =
557  CGF.MakeAddrLValue(Address(element, elementAlign), elementType);
558  EmitInitializationToLValue(E->getInit(i), elementLV);
559  }
560 
561  // Check whether there's a non-trivial array-fill expression.
562  Expr *filler = E->getArrayFiller();
563  bool hasTrivialFiller = isTrivialFiller(filler);
564 
565  // Any remaining elements need to be zero-initialized, possibly
566  // using the filler expression. We can skip this if the we're
567  // emitting to zeroed memory.
568  if (NumInitElements != NumArrayElements &&
569  !(Dest.isZeroed() && hasTrivialFiller &&
570  CGF.getTypes().isZeroInitializable(elementType))) {
571 
572  // Use an actual loop. This is basically
573  // do { *array++ = filler; } while (array != end);
574 
575  // Advance to the start of the rest of the array.
576  if (NumInitElements) {
577  element = Builder.CreateInBoundsGEP(element, one, "arrayinit.start");
578  if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit);
579  }
580 
581  // Compute the end of the array.
582  llvm::Value *end = Builder.CreateInBoundsGEP(begin,
583  llvm::ConstantInt::get(CGF.SizeTy, NumArrayElements),
584  "arrayinit.end");
585 
586  llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
587  llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body");
588 
589  // Jump into the body.
590  CGF.EmitBlock(bodyBB);
591  llvm::PHINode *currentElement =
592  Builder.CreatePHI(element->getType(), 2, "arrayinit.cur");
593  currentElement->addIncoming(element, entryBB);
594 
595  // Emit the actual filler expression.
596  {
597  // C++1z [class.temporary]p5:
598  // when a default constructor is called to initialize an element of
599  // an array with no corresponding initializer [...] the destruction of
600  // every temporary created in a default argument is sequenced before
601  // the construction of the next array element, if any
602  CodeGenFunction::RunCleanupsScope CleanupsScope(CGF);
603  LValue elementLV =
604  CGF.MakeAddrLValue(Address(currentElement, elementAlign), elementType);
605  if (filler)
606  EmitInitializationToLValue(filler, elementLV);
607  else
608  EmitNullInitializationToLValue(elementLV);
609  }
610 
611  // Move on to the next element.
612  llvm::Value *nextElement =
613  Builder.CreateInBoundsGEP(currentElement, one, "arrayinit.next");
614 
615  // Tell the EH cleanup that we finished with the last element.
616  if (endOfInit.isValid()) Builder.CreateStore(nextElement, endOfInit);
617 
618  // Leave the loop if we're done.
619  llvm::Value *done = Builder.CreateICmpEQ(nextElement, end,
620  "arrayinit.done");
621  llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end");
622  Builder.CreateCondBr(done, endBB, bodyBB);
623  currentElement->addIncoming(nextElement, Builder.GetInsertBlock());
624 
625  CGF.EmitBlock(endBB);
626  }
627 
628  // Leave the partial-array cleanup if we entered one.
629  if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, cleanupDominator);
630 }
631 
632 //===----------------------------------------------------------------------===//
633 // Visitor Methods
634 //===----------------------------------------------------------------------===//
635 
636 void AggExprEmitter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E){
637  Visit(E->GetTemporaryExpr());
638 }
639 
640 void AggExprEmitter::VisitOpaqueValueExpr(OpaqueValueExpr *e) {
641  // If this is a unique OVE, just visit its source expression.
642  if (e->isUnique())
643  Visit(e->getSourceExpr());
644  else
645  EmitFinalDestCopy(e->getType(), CGF.getOrCreateOpaqueLValueMapping(e));
646 }
647 
648 void
649 AggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
650  if (Dest.isPotentiallyAliased() &&
651  E->getType().isPODType(CGF.getContext())) {
652  // For a POD type, just emit a load of the lvalue + a copy, because our
653  // compound literal might alias the destination.
654  EmitAggLoadOfLValue(E);
655  return;
656  }
657 
658  AggValueSlot Slot = EnsureSlot(E->getType());
659  CGF.EmitAggExpr(E->getInitializer(), Slot);
660 }
661 
662 /// Attempt to look through various unimportant expressions to find a
663 /// cast of the given kind.
665  while (true) {
666  op = op->IgnoreParens();
667  if (CastExpr *castE = dyn_cast<CastExpr>(op)) {
668  if (castE->getCastKind() == kind)
669  return castE->getSubExpr();
670  if (castE->getCastKind() == CK_NoOp)
671  continue;
672  }
673  return nullptr;
674  }
675 }
676 
677 void AggExprEmitter::VisitCastExpr(CastExpr *E) {
678  if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
679  CGF.CGM.EmitExplicitCastExprType(ECE, &CGF);
680  switch (E->getCastKind()) {
681  case CK_Dynamic: {
682  // FIXME: Can this actually happen? We have no test coverage for it.
683  assert(isa<CXXDynamicCastExpr>(E) && "CK_Dynamic without a dynamic_cast?");
684  LValue LV = CGF.EmitCheckedLValue(E->getSubExpr(),
686  // FIXME: Do we also need to handle property references here?
687  if (LV.isSimple())
688  CGF.EmitDynamicCast(LV.getAddress(), cast<CXXDynamicCastExpr>(E));
689  else
690  CGF.CGM.ErrorUnsupported(E, "non-simple lvalue dynamic_cast");
691 
692  if (!Dest.isIgnored())
693  CGF.CGM.ErrorUnsupported(E, "lvalue dynamic_cast with a destination");
694  break;
695  }
696 
697  case CK_ToUnion: {
698  // Evaluate even if the destination is ignored.
699  if (Dest.isIgnored()) {
701  /*ignoreResult=*/true);
702  break;
703  }
704 
705  // GCC union extension
706  QualType Ty = E->getSubExpr()->getType();
707  Address CastPtr =
708  Builder.CreateElementBitCast(Dest.getAddress(), CGF.ConvertType(Ty));
709  EmitInitializationToLValue(E->getSubExpr(),
710  CGF.MakeAddrLValue(CastPtr, Ty));
711  break;
712  }
713 
714  case CK_DerivedToBase:
715  case CK_BaseToDerived:
716  case CK_UncheckedDerivedToBase: {
717  llvm_unreachable("cannot perform hierarchy conversion in EmitAggExpr: "
718  "should have been unpacked before we got here");
719  }
720 
721  case CK_NonAtomicToAtomic:
722  case CK_AtomicToNonAtomic: {
723  bool isToAtomic = (E->getCastKind() == CK_NonAtomicToAtomic);
724 
725  // Determine the atomic and value types.
727  QualType valueType = E->getType();
728  if (isToAtomic) std::swap(atomicType, valueType);
729 
730  assert(atomicType->isAtomicType());
731  assert(CGF.getContext().hasSameUnqualifiedType(valueType,
732  atomicType->castAs<AtomicType>()->getValueType()));
733 
734  // Just recurse normally if we're ignoring the result or the
735  // atomic type doesn't change representation.
736  if (Dest.isIgnored() || !CGF.CGM.isPaddedAtomicType(atomicType)) {
737  return Visit(E->getSubExpr());
738  }
739 
740  CastKind peepholeTarget =
741  (isToAtomic ? CK_AtomicToNonAtomic : CK_NonAtomicToAtomic);
742 
743  // These two cases are reverses of each other; try to peephole them.
744  if (Expr *op = findPeephole(E->getSubExpr(), peepholeTarget)) {
745  assert(CGF.getContext().hasSameUnqualifiedType(op->getType(),
746  E->getType()) &&
747  "peephole significantly changed types?");
748  return Visit(op);
749  }
750 
751  // If we're converting an r-value of non-atomic type to an r-value
752  // of atomic type, just emit directly into the relevant sub-object.
753  if (isToAtomic) {
754  AggValueSlot valueDest = Dest;
755  if (!valueDest.isIgnored() && CGF.CGM.isPaddedAtomicType(atomicType)) {
756  // Zero-initialize. (Strictly speaking, we only need to initialize
757  // the padding at the end, but this is simpler.)
758  if (!Dest.isZeroed())
760 
761  // Build a GEP to refer to the subobject.
762  Address valueAddr =
763  CGF.Builder.CreateStructGEP(valueDest.getAddress(), 0,
764  CharUnits());
765  valueDest = AggValueSlot::forAddr(valueAddr,
766  valueDest.getQualifiers(),
767  valueDest.isExternallyDestructed(),
768  valueDest.requiresGCollection(),
769  valueDest.isPotentiallyAliased(),
772  }
773 
774  CGF.EmitAggExpr(E->getSubExpr(), valueDest);
775  return;
776  }
777 
778  // Otherwise, we're converting an atomic type to a non-atomic type.
779  // Make an atomic temporary, emit into that, and then copy the value out.
780  AggValueSlot atomicSlot =
781  CGF.CreateAggTemp(atomicType, "atomic-to-nonatomic.temp");
782  CGF.EmitAggExpr(E->getSubExpr(), atomicSlot);
783 
784  Address valueAddr =
785  Builder.CreateStructGEP(atomicSlot.getAddress(), 0, CharUnits());
786  RValue rvalue = RValue::getAggregate(valueAddr, atomicSlot.isVolatile());
787  return EmitFinalDestCopy(valueType, rvalue);
788  }
789 
790  case CK_LValueToRValue:
791  // If we're loading from a volatile type, force the destination
792  // into existence.
793  if (E->getSubExpr()->getType().isVolatileQualified()) {
794  EnsureDest(E->getType());
795  return Visit(E->getSubExpr());
796  }
797 
798  LLVM_FALLTHROUGH;
799 
800  case CK_NoOp:
801  case CK_UserDefinedConversion:
802  case CK_ConstructorConversion:
804  E->getType()) &&
805  "Implicit cast types must be compatible");
806  Visit(E->getSubExpr());
807  break;
808 
809  case CK_LValueBitCast:
810  llvm_unreachable("should not be emitting lvalue bitcast as rvalue");
811 
812  case CK_Dependent:
813  case CK_BitCast:
814  case CK_ArrayToPointerDecay:
815  case CK_FunctionToPointerDecay:
816  case CK_NullToPointer:
817  case CK_NullToMemberPointer:
818  case CK_BaseToDerivedMemberPointer:
819  case CK_DerivedToBaseMemberPointer:
820  case CK_MemberPointerToBoolean:
821  case CK_ReinterpretMemberPointer:
822  case CK_IntegralToPointer:
823  case CK_PointerToIntegral:
824  case CK_PointerToBoolean:
825  case CK_ToVoid:
826  case CK_VectorSplat:
827  case CK_IntegralCast:
828  case CK_BooleanToSignedIntegral:
829  case CK_IntegralToBoolean:
830  case CK_IntegralToFloating:
831  case CK_FloatingToIntegral:
832  case CK_FloatingToBoolean:
833  case CK_FloatingCast:
834  case CK_CPointerToObjCPointerCast:
835  case CK_BlockPointerToObjCPointerCast:
836  case CK_AnyPointerToBlockPointerCast:
837  case CK_ObjCObjectLValueCast:
838  case CK_FloatingRealToComplex:
839  case CK_FloatingComplexToReal:
840  case CK_FloatingComplexToBoolean:
841  case CK_FloatingComplexCast:
842  case CK_FloatingComplexToIntegralComplex:
843  case CK_IntegralRealToComplex:
844  case CK_IntegralComplexToReal:
845  case CK_IntegralComplexToBoolean:
846  case CK_IntegralComplexCast:
847  case CK_IntegralComplexToFloatingComplex:
848  case CK_ARCProduceObject:
849  case CK_ARCConsumeObject:
850  case CK_ARCReclaimReturnedObject:
851  case CK_ARCExtendBlockObject:
852  case CK_CopyAndAutoreleaseBlockObject:
853  case CK_BuiltinFnToFnPtr:
854  case CK_ZeroToOCLOpaqueType:
855  case CK_AddressSpaceConversion:
856  case CK_IntToOCLSampler:
857  case CK_FixedPointCast:
858  case CK_FixedPointToBoolean:
859  llvm_unreachable("cast kind invalid for aggregate types");
860  }
861 }
862 
863 void AggExprEmitter::VisitCallExpr(const CallExpr *E) {
864  if (E->getCallReturnType(CGF.getContext())->isReferenceType()) {
865  EmitAggLoadOfLValue(E);
866  return;
867  }
868 
869  withReturnValueSlot(E, [&](ReturnValueSlot Slot) {
870  return CGF.EmitCallExpr(E, Slot);
871  });
872 }
873 
874 void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) {
875  withReturnValueSlot(E, [&](ReturnValueSlot Slot) {
876  return CGF.EmitObjCMessageExpr(E, Slot);
877  });
878 }
879 
880 void AggExprEmitter::VisitBinComma(const BinaryOperator *E) {
881  CGF.EmitIgnoredExpr(E->getLHS());
882  Visit(E->getRHS());
883 }
884 
885 void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) {
887  CGF.EmitCompoundStmt(*E->getSubStmt(), true, Dest);
888 }
889 
894 };
895 
897  const BinaryOperator *E, llvm::Value *LHS,
899  const char *NameSuffix = "") {
900  QualType ArgTy = E->getLHS()->getType();
901  if (const ComplexType *CT = ArgTy->getAs<ComplexType>())
902  ArgTy = CT->getElementType();
903 
904  if (const auto *MPT = ArgTy->getAs<MemberPointerType>()) {
905  assert(Kind == CK_Equal &&
906  "member pointers may only be compared for equality");
908  CGF, LHS, RHS, MPT, /*IsInequality*/ false);
909  }
910 
911  // Compute the comparison instructions for the specified comparison kind.
912  struct CmpInstInfo {
913  const char *Name;
914  llvm::CmpInst::Predicate FCmp;
915  llvm::CmpInst::Predicate SCmp;
916  llvm::CmpInst::Predicate UCmp;
917  };
918  CmpInstInfo InstInfo = [&]() -> CmpInstInfo {
919  using FI = llvm::FCmpInst;
920  using II = llvm::ICmpInst;
921  switch (Kind) {
922  case CK_Less:
923  return {"cmp.lt", FI::FCMP_OLT, II::ICMP_SLT, II::ICMP_ULT};
924  case CK_Greater:
925  return {"cmp.gt", FI::FCMP_OGT, II::ICMP_SGT, II::ICMP_UGT};
926  case CK_Equal:
927  return {"cmp.eq", FI::FCMP_OEQ, II::ICMP_EQ, II::ICMP_EQ};
928  }
929  llvm_unreachable("Unrecognised CompareKind enum");
930  }();
931 
932  if (ArgTy->hasFloatingRepresentation())
933  return Builder.CreateFCmp(InstInfo.FCmp, LHS, RHS,
934  llvm::Twine(InstInfo.Name) + NameSuffix);
935  if (ArgTy->isIntegralOrEnumerationType() || ArgTy->isPointerType()) {
936  auto Inst =
937  ArgTy->hasSignedIntegerRepresentation() ? InstInfo.SCmp : InstInfo.UCmp;
938  return Builder.CreateICmp(Inst, LHS, RHS,
939  llvm::Twine(InstInfo.Name) + NameSuffix);
940  }
941 
942  llvm_unreachable("unsupported aggregate binary expression should have "
943  "already been handled");
944 }
945 
946 void AggExprEmitter::VisitBinCmp(const BinaryOperator *E) {
947  using llvm::BasicBlock;
948  using llvm::PHINode;
949  using llvm::Value;
950  assert(CGF.getContext().hasSameType(E->getLHS()->getType(),
951  E->getRHS()->getType()));
952  const ComparisonCategoryInfo &CmpInfo =
954  assert(CmpInfo.Record->isTriviallyCopyable() &&
955  "cannot copy non-trivially copyable aggregate");
956 
957  QualType ArgTy = E->getLHS()->getType();
958 
959  // TODO: Handle comparing these types.
960  if (ArgTy->isVectorType())
961  return CGF.ErrorUnsupported(
962  E, "aggregate three-way comparison with vector arguments");
963  if (!ArgTy->isIntegralOrEnumerationType() && !ArgTy->isRealFloatingType() &&
964  !ArgTy->isNullPtrType() && !ArgTy->isPointerType() &&
965  !ArgTy->isMemberPointerType() && !ArgTy->isAnyComplexType()) {
966  return CGF.ErrorUnsupported(E, "aggregate three-way comparison");
967  }
968  bool IsComplex = ArgTy->isAnyComplexType();
969 
970  // Evaluate the operands to the expression and extract their values.
971  auto EmitOperand = [&](Expr *E) -> std::pair<Value *, Value *> {
972  RValue RV = CGF.EmitAnyExpr(E);
973  if (RV.isScalar())
974  return {RV.getScalarVal(), nullptr};
975  if (RV.isAggregate())
976  return {RV.getAggregatePointer(), nullptr};
977  assert(RV.isComplex());
978  return RV.getComplexVal();
979  };
980  auto LHSValues = EmitOperand(E->getLHS()),
981  RHSValues = EmitOperand(E->getRHS());
982 
983  auto EmitCmp = [&](CompareKind K) {
984  Value *Cmp = EmitCompare(Builder, CGF, E, LHSValues.first, RHSValues.first,
985  K, IsComplex ? ".r" : "");
986  if (!IsComplex)
987  return Cmp;
988  assert(K == CompareKind::CK_Equal);
989  Value *CmpImag = EmitCompare(Builder, CGF, E, LHSValues.second,
990  RHSValues.second, K, ".i");
991  return Builder.CreateAnd(Cmp, CmpImag, "and.eq");
992  };
993  auto EmitCmpRes = [&](const ComparisonCategoryInfo::ValueInfo *VInfo) {
994  return Builder.getInt(VInfo->getIntValue());
995  };
996 
997  Value *Select;
998  if (ArgTy->isNullPtrType()) {
999  Select = EmitCmpRes(CmpInfo.getEqualOrEquiv());
1000  } else if (CmpInfo.isEquality()) {
1001  Select = Builder.CreateSelect(
1002  EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()),
1003  EmitCmpRes(CmpInfo.getNonequalOrNonequiv()), "sel.eq");
1004  } else if (!CmpInfo.isPartial()) {
1005  Value *SelectOne =
1006  Builder.CreateSelect(EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()),
1007  EmitCmpRes(CmpInfo.getGreater()), "sel.lt");
1008  Select = Builder.CreateSelect(EmitCmp(CK_Equal),
1009  EmitCmpRes(CmpInfo.getEqualOrEquiv()),
1010  SelectOne, "sel.eq");
1011  } else {
1012  Value *SelectEq = Builder.CreateSelect(
1013  EmitCmp(CK_Equal), EmitCmpRes(CmpInfo.getEqualOrEquiv()),
1014  EmitCmpRes(CmpInfo.getUnordered()), "sel.eq");
1015  Value *SelectGT = Builder.CreateSelect(EmitCmp(CK_Greater),
1016  EmitCmpRes(CmpInfo.getGreater()),
1017  SelectEq, "sel.gt");
1018  Select = Builder.CreateSelect(
1019  EmitCmp(CK_Less), EmitCmpRes(CmpInfo.getLess()), SelectGT, "sel.lt");
1020  }
1021  // Create the return value in the destination slot.
1022  EnsureDest(E->getType());
1023  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
1024 
1025  // Emit the address of the first (and only) field in the comparison category
1026  // type, and initialize it from the constant integer value selected above.
1028  DestLV, *CmpInfo.Record->field_begin());
1029  CGF.EmitStoreThroughLValue(RValue::get(Select), FieldLV, /*IsInit*/ true);
1030 
1031  // All done! The result is in the Dest slot.
1032 }
1033 
1034 void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) {
1035  if (E->getOpcode() == BO_PtrMemD || E->getOpcode() == BO_PtrMemI)
1036  VisitPointerToDataMemberBinaryOperator(E);
1037  else
1038  CGF.ErrorUnsupported(E, "aggregate binary expression");
1039 }
1040 
1041 void AggExprEmitter::VisitPointerToDataMemberBinaryOperator(
1042  const BinaryOperator *E) {
1044  EmitFinalDestCopy(E->getType(), LV);
1045 }
1046 
1047 /// Is the value of the given expression possibly a reference to or
1048 /// into a __block variable?
1049 static bool isBlockVarRef(const Expr *E) {
1050  // Make sure we look through parens.
1051  E = E->IgnoreParens();
1052 
1053  // Check for a direct reference to a __block variable.
1054  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
1055  const VarDecl *var = dyn_cast<VarDecl>(DRE->getDecl());
1056  return (var && var->hasAttr<BlocksAttr>());
1057  }
1058 
1059  // More complicated stuff.
1060 
1061  // Binary operators.
1062  if (const BinaryOperator *op = dyn_cast<BinaryOperator>(E)) {
1063  // For an assignment or pointer-to-member operation, just care
1064  // about the LHS.
1065  if (op->isAssignmentOp() || op->isPtrMemOp())
1066  return isBlockVarRef(op->getLHS());
1067 
1068  // For a comma, just care about the RHS.
1069  if (op->getOpcode() == BO_Comma)
1070  return isBlockVarRef(op->getRHS());
1071 
1072  // FIXME: pointer arithmetic?
1073  return false;
1074 
1075  // Check both sides of a conditional operator.
1076  } else if (const AbstractConditionalOperator *op
1077  = dyn_cast<AbstractConditionalOperator>(E)) {
1078  return isBlockVarRef(op->getTrueExpr())
1079  || isBlockVarRef(op->getFalseExpr());
1080 
1081  // OVEs are required to support BinaryConditionalOperators.
1082  } else if (const OpaqueValueExpr *op
1083  = dyn_cast<OpaqueValueExpr>(E)) {
1084  if (const Expr *src = op->getSourceExpr())
1085  return isBlockVarRef(src);
1086 
1087  // Casts are necessary to get things like (*(int*)&var) = foo().
1088  // We don't really care about the kind of cast here, except
1089  // we don't want to look through l2r casts, because it's okay
1090  // to get the *value* in a __block variable.
1091  } else if (const CastExpr *cast = dyn_cast<CastExpr>(E)) {
1092  if (cast->getCastKind() == CK_LValueToRValue)
1093  return false;
1094  return isBlockVarRef(cast->getSubExpr());
1095 
1096  // Handle unary operators. Again, just aggressively look through
1097  // it, ignoring the operation.
1098  } else if (const UnaryOperator *uop = dyn_cast<UnaryOperator>(E)) {
1099  return isBlockVarRef(uop->getSubExpr());
1100 
1101  // Look into the base of a field access.
1102  } else if (const MemberExpr *mem = dyn_cast<MemberExpr>(E)) {
1103  return isBlockVarRef(mem->getBase());
1104 
1105  // Look into the base of a subscript.
1106  } else if (const ArraySubscriptExpr *sub = dyn_cast<ArraySubscriptExpr>(E)) {
1107  return isBlockVarRef(sub->getBase());
1108  }
1109 
1110  return false;
1111 }
1112 
1113 void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
1114  // For an assignment to work, the value on the right has
1115  // to be compatible with the value on the left.
1116  assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
1117  E->getRHS()->getType())
1118  && "Invalid assignment");
1119 
1120  // If the LHS might be a __block variable, and the RHS can
1121  // potentially cause a block copy, we need to evaluate the RHS first
1122  // so that the assignment goes the right place.
1123  // This is pretty semantically fragile.
1124  if (isBlockVarRef(E->getLHS()) &&
1125  E->getRHS()->HasSideEffects(CGF.getContext())) {
1126  // Ensure that we have a destination, and evaluate the RHS into that.
1127  EnsureDest(E->getRHS()->getType());
1128  Visit(E->getRHS());
1129 
1130  // Now emit the LHS and copy into it.
1132 
1133  // That copy is an atomic copy if the LHS is atomic.
1134  if (LHS.getType()->isAtomicType() ||
1136  CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false);
1137  return;
1138  }
1139 
1140  EmitCopy(E->getLHS()->getType(),
1142  needsGC(E->getLHS()->getType()),
1145  Dest);
1146  return;
1147  }
1148 
1149  LValue LHS = CGF.EmitLValue(E->getLHS());
1150 
1151  // If we have an atomic type, evaluate into the destination and then
1152  // do an atomic copy.
1153  if (LHS.getType()->isAtomicType() ||
1155  EnsureDest(E->getRHS()->getType());
1156  Visit(E->getRHS());
1157  CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false);
1158  return;
1159  }
1160 
1161  // Codegen the RHS so that it stores directly into the LHS.
1162  AggValueSlot LHSSlot =
1164  needsGC(E->getLHS()->getType()),
1167  // A non-volatile aggregate destination might have volatile member.
1168  if (!LHSSlot.isVolatile() &&
1169  CGF.hasVolatileMember(E->getLHS()->getType()))
1170  LHSSlot.setVolatile(true);
1171 
1172  CGF.EmitAggExpr(E->getRHS(), LHSSlot);
1173 
1174  // Copy into the destination if the assignment isn't ignored.
1175  EmitFinalDestCopy(E->getType(), LHS);
1176 }
1177 
1178 void AggExprEmitter::
1179 VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
1180  llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
1181  llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
1182  llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
1183 
1184  // Bind the common expression if necessary.
1185  CodeGenFunction::OpaqueValueMapping binding(CGF, E);
1186 
1188  CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock,
1189  CGF.getProfileCount(E));
1190 
1191  // Save whether the destination's lifetime is externally managed.
1192  bool isExternallyDestructed = Dest.isExternallyDestructed();
1193 
1194  eval.begin(CGF);
1195  CGF.EmitBlock(LHSBlock);
1196  CGF.incrementProfileCounter(E);
1197  Visit(E->getTrueExpr());
1198  eval.end(CGF);
1199 
1200  assert(CGF.HaveInsertPoint() && "expression evaluation ended with no IP!");
1201  CGF.Builder.CreateBr(ContBlock);
1202 
1203  // If the result of an agg expression is unused, then the emission
1204  // of the LHS might need to create a destination slot. That's fine
1205  // with us, and we can safely emit the RHS into the same slot, but
1206  // we shouldn't claim that it's already being destructed.
1207  Dest.setExternallyDestructed(isExternallyDestructed);
1208 
1209  eval.begin(CGF);
1210  CGF.EmitBlock(RHSBlock);
1211  Visit(E->getFalseExpr());
1212  eval.end(CGF);
1213 
1214  CGF.EmitBlock(ContBlock);
1215 }
1216 
1217 void AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) {
1218  Visit(CE->getChosenSubExpr());
1219 }
1220 
1221 void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
1222  Address ArgValue = Address::invalid();
1223  Address ArgPtr = CGF.EmitVAArg(VE, ArgValue);
1224 
1225  // If EmitVAArg fails, emit an error.
1226  if (!ArgPtr.isValid()) {
1227  CGF.ErrorUnsupported(VE, "aggregate va_arg expression");
1228  return;
1229  }
1230 
1231  EmitFinalDestCopy(VE->getType(), CGF.MakeAddrLValue(ArgPtr, VE->getType()));
1232 }
1233 
1234 void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
1235  // Ensure that we have a slot, but if we already do, remember
1236  // whether it was externally destructed.
1237  bool wasExternallyDestructed = Dest.isExternallyDestructed();
1238  EnsureDest(E->getType());
1239 
1240  // We're going to push a destructor if there isn't already one.
1241  Dest.setExternallyDestructed();
1242 
1243  Visit(E->getSubExpr());
1244 
1245  // Push that destructor we promised.
1246  if (!wasExternallyDestructed)
1247  CGF.EmitCXXTemporary(E->getTemporary(), E->getType(), Dest.getAddress());
1248 }
1249 
1250 void
1251 AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) {
1252  AggValueSlot Slot = EnsureSlot(E->getType());
1253  CGF.EmitCXXConstructExpr(E, Slot);
1254 }
1255 
1256 void AggExprEmitter::VisitCXXInheritedCtorInitExpr(
1257  const CXXInheritedCtorInitExpr *E) {
1258  AggValueSlot Slot = EnsureSlot(E->getType());
1260  E->getConstructor(), E->constructsVBase(), Slot.getAddress(),
1261  E->inheritedFromVBase(), E);
1262 }
1263 
1264 void
1265 AggExprEmitter::VisitLambdaExpr(LambdaExpr *E) {
1266  AggValueSlot Slot = EnsureSlot(E->getType());
1267  CGF.EmitLambdaExpr(E, Slot);
1268 }
1269 
1270 void AggExprEmitter::VisitExprWithCleanups(ExprWithCleanups *E) {
1271  CGF.enterFullExpression(E);
1272  CodeGenFunction::RunCleanupsScope cleanups(CGF);
1273  Visit(E->getSubExpr());
1274 }
1275 
1276 void AggExprEmitter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
1277  QualType T = E->getType();
1278  AggValueSlot Slot = EnsureSlot(T);
1279  EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T));
1280 }
1281 
1282 void AggExprEmitter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
1283  QualType T = E->getType();
1284  AggValueSlot Slot = EnsureSlot(T);
1285  EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T));
1286 }
1287 
1288 /// isSimpleZero - If emitting this value will obviously just cause a store of
1289 /// zero to memory, return true. This can return false if uncertain, so it just
1290 /// handles simple cases.
1291 static bool isSimpleZero(const Expr *E, CodeGenFunction &CGF) {
1292  E = E->IgnoreParens();
1293 
1294  // 0
1295  if (const IntegerLiteral *IL = dyn_cast<IntegerLiteral>(E))
1296  return IL->getValue() == 0;
1297  // +0.0
1298  if (const FloatingLiteral *FL = dyn_cast<FloatingLiteral>(E))
1299  return FL->getValue().isPosZero();
1300  // int()
1301  if ((isa<ImplicitValueInitExpr>(E) || isa<CXXScalarValueInitExpr>(E)) &&
1302  CGF.getTypes().isZeroInitializable(E->getType()))
1303  return true;
1304  // (int*)0 - Null pointer expressions.
1305  if (const CastExpr *ICE = dyn_cast<CastExpr>(E))
1306  return ICE->getCastKind() == CK_NullToPointer &&
1308  // '\0'
1309  if (const CharacterLiteral *CL = dyn_cast<CharacterLiteral>(E))
1310  return CL->getValue() == 0;
1311 
1312  // Otherwise, hard case: conservatively return false.
1313  return false;
1314 }
1315 
1316 
1317 void
1318 AggExprEmitter::EmitInitializationToLValue(Expr *E, LValue LV) {
1319  QualType type = LV.getType();
1320  // FIXME: Ignore result?
1321  // FIXME: Are initializers affected by volatile?
1322  if (Dest.isZeroed() && isSimpleZero(E, CGF)) {
1323  // Storing "i32 0" to a zero'd memory location is a noop.
1324  return;
1325  } else if (isa<ImplicitValueInitExpr>(E) || isa<CXXScalarValueInitExpr>(E)) {
1326  return EmitNullInitializationToLValue(LV);
1327  } else if (isa<NoInitExpr>(E)) {
1328  // Do nothing.
1329  return;
1330  } else if (type->isReferenceType()) {
1331  RValue RV = CGF.EmitReferenceBindingToExpr(E);
1332  return CGF.EmitStoreThroughLValue(RV, LV);
1333  }
1334 
1335  switch (CGF.getEvaluationKind(type)) {
1336  case TEK_Complex:
1337  CGF.EmitComplexExprIntoLValue(E, LV, /*isInit*/ true);
1338  return;
1339  case TEK_Aggregate:
1345  Dest.isZeroed()));
1346  return;
1347  case TEK_Scalar:
1348  if (LV.isSimple()) {
1349  CGF.EmitScalarInit(E, /*D=*/nullptr, LV, /*Captured=*/false);
1350  } else {
1352  }
1353  return;
1354  }
1355  llvm_unreachable("bad evaluation kind");
1356 }
1357 
1358 void AggExprEmitter::EmitNullInitializationToLValue(LValue lv) {
1359  QualType type = lv.getType();
1360 
1361  // If the destination slot is already zeroed out before the aggregate is
1362  // copied into it, we don't have to emit any zeros here.
1363  if (Dest.isZeroed() && CGF.getTypes().isZeroInitializable(type))
1364  return;
1365 
1366  if (CGF.hasScalarEvaluationKind(type)) {
1367  // For non-aggregates, we can store the appropriate null constant.
1368  llvm::Value *null = CGF.CGM.EmitNullConstant(type);
1369  // Note that the following is not equivalent to
1370  // EmitStoreThroughBitfieldLValue for ARC types.
1371  if (lv.isBitField()) {
1373  } else {
1374  assert(lv.isSimple());
1375  CGF.EmitStoreOfScalar(null, lv, /* isInitialization */ true);
1376  }
1377  } else {
1378  // There's a potential optimization opportunity in combining
1379  // memsets; that would be easy for arrays, but relatively
1380  // difficult for structures with the current code.
1381  CGF.EmitNullInitialization(lv.getAddress(), lv.getType());
1382  }
1383 }
1384 
1385 void AggExprEmitter::VisitInitListExpr(InitListExpr *E) {
1386 #if 0
1387  // FIXME: Assess perf here? Figure out what cases are worth optimizing here
1388  // (Length of globals? Chunks of zeroed-out space?).
1389  //
1390  // If we can, prefer a copy from a global; this is a lot less code for long
1391  // globals, and it's easier for the current optimizers to analyze.
1392  if (llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, E->getType(), &CGF)) {
1393  llvm::GlobalVariable* GV =
1394  new llvm::GlobalVariable(CGF.CGM.getModule(), C->getType(), true,
1396  EmitFinalDestCopy(E->getType(), CGF.MakeAddrLValue(GV, E->getType()));
1397  return;
1398  }
1399 #endif
1400  if (E->hadArrayRangeDesignator())
1401  CGF.ErrorUnsupported(E, "GNU array range designator extension");
1402 
1403  if (E->isTransparent())
1404  return Visit(E->getInit(0));
1405 
1406  AggValueSlot Dest = EnsureSlot(E->getType());
1407 
1408  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
1409 
1410  // Handle initialization of an array.
1411  if (E->getType()->isArrayType()) {
1412  auto AType = cast<llvm::ArrayType>(Dest.getAddress().getElementType());
1413  EmitArrayInit(Dest.getAddress(), AType, E->getType(), E);
1414  return;
1415  }
1416 
1417  assert(E->getType()->isRecordType() && "Only support structs/unions here!");
1418 
1419  // Do struct initialization; this code just sets each individual member
1420  // to the approprate value. This makes bitfield support automatic;
1421  // the disadvantage is that the generated code is more difficult for
1422  // the optimizer, especially with bitfields.
1423  unsigned NumInitElements = E->getNumInits();
1424  RecordDecl *record = E->getType()->castAs<RecordType>()->getDecl();
1425 
1426  // We'll need to enter cleanup scopes in case any of the element
1427  // initializers throws an exception.
1429  llvm::Instruction *cleanupDominator = nullptr;
1430 
1431  unsigned curInitIndex = 0;
1432 
1433  // Emit initialization of base classes.
1434  if (auto *CXXRD = dyn_cast<CXXRecordDecl>(record)) {
1435  assert(E->getNumInits() >= CXXRD->getNumBases() &&
1436  "missing initializer for base class");
1437  for (auto &Base : CXXRD->bases()) {
1438  assert(!Base.isVirtual() && "should not see vbases here");
1439  auto *BaseRD = Base.getType()->getAsCXXRecordDecl();
1441  Dest.getAddress(), CXXRD, BaseRD,
1442  /*isBaseVirtual*/ false);
1444  V, Qualifiers(),
1448  CGF.overlapForBaseInit(CXXRD, BaseRD, Base.isVirtual()));
1449  CGF.EmitAggExpr(E->getInit(curInitIndex++), AggSlot);
1450 
1451  if (QualType::DestructionKind dtorKind =
1452  Base.getType().isDestructedType()) {
1453  CGF.pushDestroy(dtorKind, V, Base.getType());
1454  cleanups.push_back(CGF.EHStack.stable_begin());
1455  }
1456  }
1457  }
1458 
1459  // Prepare a 'this' for CXXDefaultInitExprs.
1461 
1462  if (record->isUnion()) {
1463  // Only initialize one field of a union. The field itself is
1464  // specified by the initializer list.
1465  if (!E->getInitializedFieldInUnion()) {
1466  // Empty union; we have nothing to do.
1467 
1468 #ifndef NDEBUG
1469  // Make sure that it's really an empty and not a failure of
1470  // semantic analysis.
1471  for (const auto *Field : record->fields())
1472  assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed");
1473 #endif
1474  return;
1475  }
1476 
1477  // FIXME: volatility
1478  FieldDecl *Field = E->getInitializedFieldInUnion();
1479 
1480  LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestLV, Field);
1481  if (NumInitElements) {
1482  // Store the initializer into the field
1483  EmitInitializationToLValue(E->getInit(0), FieldLoc);
1484  } else {
1485  // Default-initialize to null.
1486  EmitNullInitializationToLValue(FieldLoc);
1487  }
1488 
1489  return;
1490  }
1491 
1492  // Here we iterate over the fields; this makes it simpler to both
1493  // default-initialize fields and skip over unnamed fields.
1494  for (const auto *field : record->fields()) {
1495  // We're done once we hit the flexible array member.
1496  if (field->getType()->isIncompleteArrayType())
1497  break;
1498 
1499  // Always skip anonymous bitfields.
1500  if (field->isUnnamedBitfield())
1501  continue;
1502 
1503  // We're done if we reach the end of the explicit initializers, we
1504  // have a zeroed object, and the rest of the fields are
1505  // zero-initializable.
1506  if (curInitIndex == NumInitElements && Dest.isZeroed() &&
1507  CGF.getTypes().isZeroInitializable(E->getType()))
1508  break;
1509 
1510 
1511  LValue LV = CGF.EmitLValueForFieldInitialization(DestLV, field);
1512  // We never generate write-barries for initialized fields.
1513  LV.setNonGC(true);
1514 
1515  if (curInitIndex < NumInitElements) {
1516  // Store the initializer into the field.
1517  EmitInitializationToLValue(E->getInit(curInitIndex++), LV);
1518  } else {
1519  // We're out of initializers; default-initialize to null
1520  EmitNullInitializationToLValue(LV);
1521  }
1522 
1523  // Push a destructor if necessary.
1524  // FIXME: if we have an array of structures, all explicitly
1525  // initialized, we can end up pushing a linear number of cleanups.
1526  bool pushedCleanup = false;
1527  if (QualType::DestructionKind dtorKind
1528  = field->getType().isDestructedType()) {
1529  assert(LV.isSimple());
1530  if (CGF.needsEHCleanup(dtorKind)) {
1531  if (!cleanupDominator)
1532  cleanupDominator = CGF.Builder.CreateAlignedLoad(
1533  CGF.Int8Ty,
1534  llvm::Constant::getNullValue(CGF.Int8PtrTy),
1535  CharUnits::One()); // placeholder
1536 
1537  CGF.pushDestroy(EHCleanup, LV.getAddress(), field->getType(),
1538  CGF.getDestroyer(dtorKind), false);
1539  cleanups.push_back(CGF.EHStack.stable_begin());
1540  pushedCleanup = true;
1541  }
1542  }
1543 
1544  // If the GEP didn't get used because of a dead zero init or something
1545  // else, clean it up for -O0 builds and general tidiness.
1546  if (!pushedCleanup && LV.isSimple())
1547  if (llvm::GetElementPtrInst *GEP =
1548  dyn_cast<llvm::GetElementPtrInst>(LV.getPointer()))
1549  if (GEP->use_empty())
1550  GEP->eraseFromParent();
1551  }
1552 
1553  // Deactivate all the partial cleanups in reverse order, which
1554  // generally means popping them.
1555  for (unsigned i = cleanups.size(); i != 0; --i)
1556  CGF.DeactivateCleanupBlock(cleanups[i-1], cleanupDominator);
1557 
1558  // Destroy the placeholder if we made one.
1559  if (cleanupDominator)
1560  cleanupDominator->eraseFromParent();
1561 }
1562 
1563 void AggExprEmitter::VisitArrayInitLoopExpr(const ArrayInitLoopExpr *E,
1564  llvm::Value *outerBegin) {
1565  // Emit the common subexpression.
1567 
1568  Address destPtr = EnsureSlot(E->getType()).getAddress();
1569  uint64_t numElements = E->getArraySize().getZExtValue();
1570 
1571  if (!numElements)
1572  return;
1573 
1574  // destPtr is an array*. Construct an elementType* by drilling down a level.
1575  llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
1576  llvm::Value *indices[] = {zero, zero};
1577  llvm::Value *begin = Builder.CreateInBoundsGEP(destPtr.getPointer(), indices,
1578  "arrayinit.begin");
1579 
1580  // Prepare to special-case multidimensional array initialization: we avoid
1581  // emitting multiple destructor loops in that case.
1582  if (!outerBegin)
1583  outerBegin = begin;
1584  ArrayInitLoopExpr *InnerLoop = dyn_cast<ArrayInitLoopExpr>(E->getSubExpr());
1585 
1586  QualType elementType =
1587  CGF.getContext().getAsArrayType(E->getType())->getElementType();
1588  CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
1589  CharUnits elementAlign =
1590  destPtr.getAlignment().alignmentOfArrayElement(elementSize);
1591 
1592  llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
1593  llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body");
1594 
1595  // Jump into the body.
1596  CGF.EmitBlock(bodyBB);
1597  llvm::PHINode *index =
1598  Builder.CreatePHI(zero->getType(), 2, "arrayinit.index");
1599  index->addIncoming(zero, entryBB);
1600  llvm::Value *element = Builder.CreateInBoundsGEP(begin, index);
1601 
1602  // Prepare for a cleanup.
1603  QualType::DestructionKind dtorKind = elementType.isDestructedType();
1605  if (CGF.needsEHCleanup(dtorKind) && !InnerLoop) {
1606  if (outerBegin->getType() != element->getType())
1607  outerBegin = Builder.CreateBitCast(outerBegin, element->getType());
1608  CGF.pushRegularPartialArrayCleanup(outerBegin, element, elementType,
1609  elementAlign,
1610  CGF.getDestroyer(dtorKind));
1611  cleanup = CGF.EHStack.stable_begin();
1612  } else {
1613  dtorKind = QualType::DK_none;
1614  }
1615 
1616  // Emit the actual filler expression.
1617  {
1618  // Temporaries created in an array initialization loop are destroyed
1619  // at the end of each iteration.
1620  CodeGenFunction::RunCleanupsScope CleanupsScope(CGF);
1622  LValue elementLV =
1623  CGF.MakeAddrLValue(Address(element, elementAlign), elementType);
1624 
1625  if (InnerLoop) {
1626  // If the subexpression is an ArrayInitLoopExpr, share its cleanup.
1627  auto elementSlot = AggValueSlot::forLValue(
1628  elementLV, AggValueSlot::IsDestructed,
1632  AggExprEmitter(CGF, elementSlot, false)
1633  .VisitArrayInitLoopExpr(InnerLoop, outerBegin);
1634  } else
1635  EmitInitializationToLValue(E->getSubExpr(), elementLV);
1636  }
1637 
1638  // Move on to the next element.
1639  llvm::Value *nextIndex = Builder.CreateNUWAdd(
1640  index, llvm::ConstantInt::get(CGF.SizeTy, 1), "arrayinit.next");
1641  index->addIncoming(nextIndex, Builder.GetInsertBlock());
1642 
1643  // Leave the loop if we're done.
1644  llvm::Value *done = Builder.CreateICmpEQ(
1645  nextIndex, llvm::ConstantInt::get(CGF.SizeTy, numElements),
1646  "arrayinit.done");
1647  llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end");
1648  Builder.CreateCondBr(done, endBB, bodyBB);
1649 
1650  CGF.EmitBlock(endBB);
1651 
1652  // Leave the partial-array cleanup if we entered one.
1653  if (dtorKind)
1654  CGF.DeactivateCleanupBlock(cleanup, index);
1655 }
1656 
1657 void AggExprEmitter::VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E) {
1658  AggValueSlot Dest = EnsureSlot(E->getType());
1659 
1660  LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
1661  EmitInitializationToLValue(E->getBase(), DestLV);
1662  VisitInitListExpr(E->getUpdater());
1663 }
1664 
1665 //===----------------------------------------------------------------------===//
1666 // Entry Points into this File
1667 //===----------------------------------------------------------------------===//
1668 
1669 /// GetNumNonZeroBytesInInit - Get an approximate count of the number of
1670 /// non-zero bytes that will be stored when outputting the initializer for the
1671 /// specified initializer expression.
1673  E = E->IgnoreParens();
1674 
1675  // 0 and 0.0 won't require any non-zero stores!
1676  if (isSimpleZero(E, CGF)) return CharUnits::Zero();
1677 
1678  // If this is an initlist expr, sum up the size of sizes of the (present)
1679  // elements. If this is something weird, assume the whole thing is non-zero.
1680  const InitListExpr *ILE = dyn_cast<InitListExpr>(E);
1681  while (ILE && ILE->isTransparent())
1682  ILE = dyn_cast<InitListExpr>(ILE->getInit(0));
1683  if (!ILE || !CGF.getTypes().isZeroInitializable(ILE->getType()))
1684  return CGF.getContext().getTypeSizeInChars(E->getType());
1685 
1686  // InitListExprs for structs have to be handled carefully. If there are
1687  // reference members, we need to consider the size of the reference, not the
1688  // referencee. InitListExprs for unions and arrays can't have references.
1689  if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
1690  if (!RT->isUnionType()) {
1691  RecordDecl *SD = E->getType()->getAs<RecordType>()->getDecl();
1692  CharUnits NumNonZeroBytes = CharUnits::Zero();
1693 
1694  unsigned ILEElement = 0;
1695  if (auto *CXXRD = dyn_cast<CXXRecordDecl>(SD))
1696  while (ILEElement != CXXRD->getNumBases())
1697  NumNonZeroBytes +=
1698  GetNumNonZeroBytesInInit(ILE->getInit(ILEElement++), CGF);
1699  for (const auto *Field : SD->fields()) {
1700  // We're done once we hit the flexible array member or run out of
1701  // InitListExpr elements.
1702  if (Field->getType()->isIncompleteArrayType() ||
1703  ILEElement == ILE->getNumInits())
1704  break;
1705  if (Field->isUnnamedBitfield())
1706  continue;
1707 
1708  const Expr *E = ILE->getInit(ILEElement++);
1709 
1710  // Reference values are always non-null and have the width of a pointer.
1711  if (Field->getType()->isReferenceType())
1712  NumNonZeroBytes += CGF.getContext().toCharUnitsFromBits(
1713  CGF.getTarget().getPointerWidth(0));
1714  else
1715  NumNonZeroBytes += GetNumNonZeroBytesInInit(E, CGF);
1716  }
1717 
1718  return NumNonZeroBytes;
1719  }
1720  }
1721 
1722 
1723  CharUnits NumNonZeroBytes = CharUnits::Zero();
1724  for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i)
1725  NumNonZeroBytes += GetNumNonZeroBytesInInit(ILE->getInit(i), CGF);
1726  return NumNonZeroBytes;
1727 }
1728 
1729 /// CheckAggExprForMemSetUse - If the initializer is large and has a lot of
1730 /// zeros in it, emit a memset and avoid storing the individual zeros.
1731 ///
1732 static void CheckAggExprForMemSetUse(AggValueSlot &Slot, const Expr *E,
1733  CodeGenFunction &CGF) {
1734  // If the slot is already known to be zeroed, nothing to do. Don't mess with
1735  // volatile stores.
1736  if (Slot.isZeroed() || Slot.isVolatile() || !Slot.getAddress().isValid())
1737  return;
1738 
1739  // C++ objects with a user-declared constructor don't need zero'ing.
1740  if (CGF.getLangOpts().CPlusPlus)
1741  if (const RecordType *RT = CGF.getContext()
1742  .getBaseElementType(E->getType())->getAs<RecordType>()) {
1743  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1744  if (RD->hasUserDeclaredConstructor())
1745  return;
1746  }
1747 
1748  // If the type is 16-bytes or smaller, prefer individual stores over memset.
1749  CharUnits Size = Slot.getPreferredSize(CGF.getContext(), E->getType());
1750  if (Size <= CharUnits::fromQuantity(16))
1751  return;
1752 
1753  // Check to see if over 3/4 of the initializer are known to be zero. If so,
1754  // we prefer to emit memset + individual stores for the rest.
1755  CharUnits NumNonZeroBytes = GetNumNonZeroBytesInInit(E, CGF);
1756  if (NumNonZeroBytes*4 > Size)
1757  return;
1758 
1759  // Okay, it seems like a good idea to use an initial memset, emit the call.
1760  llvm::Constant *SizeVal = CGF.Builder.getInt64(Size.getQuantity());
1761 
1762  Address Loc = Slot.getAddress();
1763  Loc = CGF.Builder.CreateElementBitCast(Loc, CGF.Int8Ty);
1764  CGF.Builder.CreateMemSet(Loc, CGF.Builder.getInt8(0), SizeVal, false);
1765 
1766  // Tell the AggExprEmitter that the slot is known zero.
1767  Slot.setZeroed();
1768 }
1769 
1770 
1771 
1772 
1773 /// EmitAggExpr - Emit the computation of the specified expression of aggregate
1774 /// type. The result is computed into DestPtr. Note that if DestPtr is null,
1775 /// the value of the aggregate expression is not needed. If VolatileDest is
1776 /// true, DestPtr cannot be 0.
1778  assert(E && hasAggregateEvaluationKind(E->getType()) &&
1779  "Invalid aggregate expression to emit");
1780  assert((Slot.getAddress().isValid() || Slot.isIgnored()) &&
1781  "slot has bits but no address");
1782 
1783  // Optimize the slot if possible.
1784  CheckAggExprForMemSetUse(Slot, E, *this);
1785 
1786  AggExprEmitter(*this, Slot, Slot.isIgnored()).Visit(const_cast<Expr*>(E));
1787 }
1788 
1790  assert(hasAggregateEvaluationKind(E->getType()) && "Invalid argument!");
1791  Address Temp = CreateMemTemp(E->getType());
1792  LValue LV = MakeAddrLValue(Temp, E->getType());
1797  return LV;
1798 }
1799 
1801  const CXXRecordDecl *RD, const CXXRecordDecl *BaseRD, bool IsVirtual) {
1802  // Virtual bases are initialized first, in address order, so there's never
1803  // any overlap during their initialization.
1804  //
1805  // FIXME: Under P0840, this is no longer true: the tail padding of a vbase
1806  // of a field could be reused by a vbase of a containing class.
1807  if (IsVirtual)
1809 
1810  // If the base class is laid out entirely within the nvsize of the derived
1811  // class, its tail padding cannot yet be initialized, so we can issue
1812  // stores at the full width of the base class.
1813  const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1814  if (Layout.getBaseClassOffset(BaseRD) +
1815  getContext().getASTRecordLayout(BaseRD).getSize() <=
1816  Layout.getNonVirtualSize())
1818 
1819  // The tail padding may contain values we need to preserve.
1820  return AggValueSlot::MayOverlap;
1821 }
1822 
1824  AggValueSlot::Overlap_t MayOverlap,
1825  bool isVolatile) {
1826  assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
1827 
1828  Address DestPtr = Dest.getAddress();
1829  Address SrcPtr = Src.getAddress();
1830 
1831  if (getLangOpts().CPlusPlus) {
1832  if (const RecordType *RT = Ty->getAs<RecordType>()) {
1833  CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl());
1834  assert((Record->hasTrivialCopyConstructor() ||
1835  Record->hasTrivialCopyAssignment() ||
1836  Record->hasTrivialMoveConstructor() ||
1837  Record->hasTrivialMoveAssignment() ||
1838  Record->isUnion()) &&
1839  "Trying to aggregate-copy a type without a trivial copy/move "
1840  "constructor or assignment operator");
1841  // Ignore empty classes in C++.
1842  if (Record->isEmpty())
1843  return;
1844  }
1845  }
1846 
1847  // Aggregate assignment turns into llvm.memcpy. This is almost valid per
1848  // C99 6.5.16.1p3, which states "If the value being stored in an object is
1849  // read from another object that overlaps in anyway the storage of the first
1850  // object, then the overlap shall be exact and the two objects shall have
1851  // qualified or unqualified versions of a compatible type."
1852  //
1853  // memcpy is not defined if the source and destination pointers are exactly
1854  // equal, but other compilers do this optimization, and almost every memcpy
1855  // implementation handles this case safely. If there is a libc that does not
1856  // safely handle this, we can add a target hook.
1857 
1858  // Get data size info for this aggregate. Don't copy the tail padding if this
1859  // might be a potentially-overlapping subobject, since the tail padding might
1860  // be occupied by a different object. Otherwise, copying it is fine.
1861  std::pair<CharUnits, CharUnits> TypeInfo;
1862  if (MayOverlap)
1863  TypeInfo = getContext().getTypeInfoDataSizeInChars(Ty);
1864  else
1865  TypeInfo = getContext().getTypeInfoInChars(Ty);
1866 
1867  llvm::Value *SizeVal = nullptr;
1868  if (TypeInfo.first.isZero()) {
1869  // But note that getTypeInfo returns 0 for a VLA.
1870  if (auto *VAT = dyn_cast_or_null<VariableArrayType>(
1871  getContext().getAsArrayType(Ty))) {
1872  QualType BaseEltTy;
1873  SizeVal = emitArrayLength(VAT, BaseEltTy, DestPtr);
1874  TypeInfo = getContext().getTypeInfoInChars(BaseEltTy);
1875  assert(!TypeInfo.first.isZero());
1876  SizeVal = Builder.CreateNUWMul(
1877  SizeVal,
1878  llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity()));
1879  }
1880  }
1881  if (!SizeVal) {
1882  SizeVal = llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity());
1883  }
1884 
1885  // FIXME: If we have a volatile struct, the optimizer can remove what might
1886  // appear to be `extra' memory ops:
1887  //
1888  // volatile struct { int i; } a, b;
1889  //
1890  // int main() {
1891  // a = b;
1892  // a = b;
1893  // }
1894  //
1895  // we need to use a different call here. We use isVolatile to indicate when
1896  // either the source or the destination is volatile.
1897 
1898  DestPtr = Builder.CreateElementBitCast(DestPtr, Int8Ty);
1899  SrcPtr = Builder.CreateElementBitCast(SrcPtr, Int8Ty);
1900 
1901  // Don't do any of the memmove_collectable tests if GC isn't set.
1902  if (CGM.getLangOpts().getGC() == LangOptions::NonGC) {
1903  // fall through
1904  } else if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
1905  RecordDecl *Record = RecordTy->getDecl();
1906  if (Record->hasObjectMember()) {
1907  CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
1908  SizeVal);
1909  return;
1910  }
1911  } else if (Ty->isArrayType()) {
1912  QualType BaseType = getContext().getBaseElementType(Ty);
1913  if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
1914  if (RecordTy->getDecl()->hasObjectMember()) {
1915  CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
1916  SizeVal);
1917  return;
1918  }
1919  }
1920  }
1921 
1922  auto Inst = Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, isVolatile);
1923 
1924  // Determine the metadata to describe the position of any padding in this
1925  // memcpy, as well as the TBAA tags for the members of the struct, in case
1926  // the optimizer wishes to expand it in to scalar memory operations.
1927  if (llvm::MDNode *TBAAStructTag = CGM.getTBAAStructInfo(Ty))
1928  Inst->setMetadata(llvm::LLVMContext::MD_tbaa_struct, TBAAStructTag);
1929 
1930  if (CGM.getCodeGenOpts().NewStructPathTBAA) {
1931  TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForMemoryTransfer(
1932  Dest.getTBAAInfo(), Src.getTBAAInfo());
1933  CGM.DecorateInstructionWithTBAA(Inst, TBAAInfo);
1934  }
1935 }
bool isAggregate() const
Definition: CGValue.h:54
const llvm::DataLayout & getDataLayout() const
const Expr * getSubExpr() const
Definition: Expr.h:890
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:3979
Address getAddress() const
Definition: CGValue.h:583
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:1684
A (possibly-)qualified type.
Definition: Type.h:638
bool isPODType(const ASTContext &Context) const
Determine whether this is a Plain Old Data (POD) type (C++ 3.9p10).
Definition: Type.cpp:2101
bool isArrayType() const
Definition: Type.h:6349
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
void enterFullExpression(const FullExpr *E)
bool HaveInsertPoint() const
HaveInsertPoint - True if an insertion point is defined.
CompoundStmt * getSubStmt()
Definition: Expr.h:3778
const Expr * getInit(unsigned Init) const
Definition: Expr.h:4194
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:200
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:233
NeedsGCBarriers_t requiresGCollection() const
Definition: CGValue.h:575
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:2228
llvm::Value * getPointer() const
Definition: CGValue.h:579
bool isRecordType() const
Definition: Type.h:6373
Address EmitVAArg(VAArgExpr *VE, Address &VAListAddr)
Generate code to get an argument from the passed in pointer and update it accordingly.
Definition: CGCall.cpp:4558
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:4931
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:2020
Defines the C++ template declaration subclasses.
Opcode getOpcode() const
Definition: Expr.h:3283
ParenExpr - This represents a parethesized expression, e.g.
Definition: Expr.h:1855
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:1910
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:2816
Represents a call to a C++ constructor.
Definition: ExprCXX.h:1261
bool hasTrivialMoveConstructor() const
Determine whether this class has a trivial move constructor (C++11 [class.copy]p12) ...
Definition: DeclCXX.h:1423
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:615
QualType getValueType() const
Gets the type contained by this atomic type, i.e.
Definition: Type.h:5987
LValue EmitLValueForFieldInitialization(LValue Base, const FieldDecl *Field)
EmitLValueForFieldInitialization - Like EmitLValueForField, except that if the Field is a reference...
Definition: CGExpr.cpp:3981
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:4051
IsAliased_t isPotentiallyAliased() const
Definition: CGValue.h:595
const Expr * getResultExpr() const
The generic selection&#39;s result expression.
Definition: Expr.h:5047
void EmitAtomicStore(RValue rvalue, LValue lvalue, bool isInit)
Definition: CGAtomic.cpp:1895
QualType getElementType() const
Definition: Type.h:2851
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:1049
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:664
Represents a variable declaration or definition.
Definition: Decl.h:812
CompoundLiteralExpr - [C99 6.5.2.5].
Definition: Expr.h:2859
OpaqueValueExpr * getCommonExpr() const
Get the common subexpression shared by all initializations (the source array).
Definition: Expr.h:4781
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6734
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:1291
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:616
Implicit construction of a std::initializer_list<T> object from an array temporary within list-initia...
Definition: ExprCXX.h:623
llvm::Value * getPointer() const
Definition: Address.h:38
CXXConstructorDecl * getConstructor() const
Get the constructor that this expression will call.
Definition: ExprCXX.h:1457
A C++ throw-expression (C++ [except.throw]).
Definition: ExprCXX.h:1014
Represents an expression – generally a full-expression – that introduces cleanups to be run at the ...
Definition: ExprCXX.h:3016
void EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst, llvm::Value **Result=nullptr)
EmitStoreThroughBitfieldLValue - Store Src into Dst with same constraints as EmitStoreThroughLValue.
Definition: CGExpr.cpp:2007
The collection of all-type qualifiers we support.
Definition: Type.h:141
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:1930
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:1672
Represents a struct/union/class.
Definition: Decl.h:3602
bool isEmpty() const
Determine whether this is an empty class in the sense of (C++11 [meta.unary.prop]).
Definition: DeclCXX.h:1327
uint64_t getPointerWidth(unsigned AddrSpace) const
Return the width of pointers on this target, for the specified address space.
Definition: TargetInfo.h:348
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:1800
IsDestructed_t isExternallyDestructed() const
Definition: CGValue.h:551
Expr * GetTemporaryExpr() const
Retrieve the temporary-generating subexpression whose value will be materialized into a glvalue...
Definition: ExprCXX.h:4092
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:154
llvm::Value * EmitDynamicCast(Address V, const CXXDynamicCastExpr *DCE)
Definition: CGExprCXX.cpp:2165
RValue EmitReferenceBindingToExpr(const Expr *E)
Emits a reference binding to the passed in expression.
Definition: CGExpr.cpp:589
field_range fields() const
Definition: Decl.h:3793
Represents a member of a struct/union/class.
Definition: Decl.h:2588
Represents a place-holder for an object not to be initialized by anything.
Definition: Expr.h:4674
An RAII object to set (and then clear) a mapping for an OpaqueValueExpr.
bool isReferenceType() const
Definition: Type.h:6312
bool hasTrivialMoveAssignment() const
Determine whether this class has a trivial move assignment operator (C++11 [class.copy]p25)
Definition: DeclCXX.h:1463
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:1004
static AggValueSlot forAddr(Address addr, Qualifiers quals, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, Overlap_t mayOverlap, IsZeroed_t isZeroed=IsNotZeroed, IsSanitizerChecked_t isChecked=IsNotSanitizerChecked)
forAddr - Make a slot for an aggregate value.
Definition: CGValue.h:514
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:623
Expr * getSubExpr()
Definition: Expr.h:2997
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:444
bool isIntegralOrEnumerationType() const
Determine whether this type is an integral or enumeration type.
Definition: Type.h:6648
bool hadArrayRangeDesignator() const
Definition: Expr.h:4314
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:2158
Describes an C or C++ initializer list.
Definition: Expr.h:4146
A C++ typeid expression (C++ [expr.typeid]), which gets the type_info that corresponds to the supplie...
Definition: ExprCXX.h:668
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:1953
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:2205
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:3248
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6146
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:1461
llvm::CallInst * CreateMemCpy(Address Dest, Address Src, llvm::Value *Size, bool IsVolatile=false)
Definition: CGBuilder.h:274
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:4159
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:2932
Represents binding an expression to a temporary.
Definition: ExprCXX.h:1216
bool isSimple() const
Definition: CGValue.h:252
RValue EmitAtomicExpr(AtomicExpr *E)
Definition: CGAtomic.cpp:745
CXXTemporary * getTemporary()
Definition: ExprCXX.h:1235
A C++ lambda expression, which produces a function object (of unspecified type) that can be invoked l...
Definition: ExprCXX.h:1610
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:1072
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:1161
RValue EmitObjCMessageExpr(const ObjCMessageExpr *E, ReturnValueSlot Return=ReturnValueSlot())
Definition: CGObjC.cpp:405
bool hasAttr() const
Definition: DeclBase.h:531
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:571
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:4732
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
ConstantExpr - An expression that occurs in a constant context.
Definition: Expr.h:904
Represents a call to the builtin function __builtin_va_arg.
Definition: Expr.h:4052
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:3066
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:2283
An expression "T()" which creates a value-initialized rvalue of type T, which is a non-class type...
Definition: ExprCXX.h:1832
void callCStructMoveAssignmentOperator(LValue Dst, LValue Src)
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:558
Enters a new scope for capturing cleanups, all of which will be executed once the scope is exited...
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:6797
Address EmitCompoundStmt(const CompoundStmt &S, bool GetLast=false, AggValueSlot AVS=AggValueSlot::ignored())
EmitCompoundStmt - Emit a compound statement {..} node.
Definition: CGStmt.cpp:370
unsigned getNumInits() const
Definition: Expr.h:4176
Expr * getSubExpr() const
Get the initializer to use for each array element.
Definition: Expr.h:4786
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:3796
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:6381
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:2256
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:904
llvm::CallInst * CreateMemSet(Address Dest, llvm::Value *Value, llvm::Value *Size, bool IsVolatile=false)
Definition: CGBuilder.h:296
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:1907
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:3853
bool hasTrivialCopyConstructor() const
Determine whether this class has a trivial copy constructor (C++ [class.copy]p6, C++11 [class...
Definition: DeclCXX.h:1400
const Expr * getSubExpr() const
Definition: Expr.h:1871
const Expr * getSubExpr() const
Definition: ExprCXX.h:1239
ASTContext & getContext() const
RValue EmitAtomicLoad(LValue LV, SourceLocation SL, AggValueSlot Slot=AggValueSlot::ignored())
Definition: CGAtomic.cpp:1471
void callCStructCopyAssignmentOperator(LValue Dst, LValue Src)
RecordDecl * getDecl() const
Definition: Type.h:4384
const ValueInfo * getGreater() const
OpaqueValueExpr - An expression referring to an opaque object of a fixed type and value class...
Definition: Expr.h:945
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:142
Expr * getBase() const
Definition: Expr.h:4729
Kind
Represents a call to an inherited base class constructor from an inheriting constructor.
Definition: ExprCXX.h:1422
PseudoObjectExpr - An expression which accesses a pseudo-object l-value.
Definition: Expr.h:5260
bool inheritedFromVBase() const
Determine whether the inherited constructor is inherited from a virtual base of the object we constru...
Definition: ExprCXX.h:1471
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:1711
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:1450
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:1458
LangAS getAddressSpace() const
Return the address space of this type.
Definition: Type.h:6192
A saved depth on the scope stack.
Definition: EHScopeStack.h:107
Expr * getSubExpr() const
Definition: Expr.h:1937
LValue EmitCheckedLValue(const Expr *E, TypeCheckKind TCK)
Same as EmitLValue but additionally we generate checking code to guard against undefined behavior...
Definition: CGExpr.cpp:1196
CastKind getCastKind() const
Definition: Expr.h:2991
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:1789
void DeactivateCleanupBlock(EHScopeStack::stable_iterator Cleanup, llvm::Instruction *DominatingIP)
DeactivateCleanupBlock - Deactivates the given cleanup block.
Definition: CGCleanup.cpp:1246
The type is a struct containing a field whose type is neither PCK_Trivial nor PCK_VolatileTrivial.
Definition: Type.h:1128
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:1066
A scoped helper to set the current debug location to the specified location or preferred location of ...
Definition: CGDebugInfo.h:684
QualType getBaseElementType(const ArrayType *VAT) const
Return the innermost element type of an array type.
const ConstantArrayType * getAsConstantArrayType(QualType T) const
Definition: ASTContext.h:2412
StmtVisitor - This class implements a simple visitor for Stmt subclasses.
Definition: StmtVisitor.h:183
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:5394
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:1278
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:1732
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:1156
LValue EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E)
Definition: CGExpr.cpp:4802
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:2265
StmtExpr - This is the GNU Statement Expression extension: ({int X=4; X;}).
Definition: Expr.h:3762
QualType getType() const
Definition: CGValue.h:264
RValue EmitCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue=ReturnValueSlot())
Definition: CGExpr.cpp:4347
Expr * getArrayFiller()
If this initializer list initializes an array with more elements than there are initializers in the l...
Definition: Expr.h:4240
bool hasSameUnqualifiedType(QualType T1, QualType T2) const
Determine whether the given types are equivalent after cvr-qualifiers have been removed.
Definition: ASTContext.h:2292
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:215
const Expr * getInitializer() const
Definition: Expr.h:2885
Expr * getLHS() const
Definition: Expr.h:3288
void setExternallyDestructed(bool destructed=true)
Definition: CGValue.h:554
Represents a C11 generic selection.
Definition: Expr.h:4971
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:818
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:564
Dataflow Directional Tag Classes.
[C99 6.4.2.2] - A predefined identifier such as func.
Definition: Expr.h:1769
static AggValueSlot ignored()
ignored - Returns an aggregate value slot indicating that the aggregate value is being ignored...
Definition: CGValue.h:499
Address CreateStructGEP(Address Addr, unsigned Index, CharUnits Offset, const llvm::Twine &Name="")
Definition: CGBuilder.h:172
CompareKind
Definition: CGExprAgg.cpp:890
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:4296
llvm::LoadInst * CreateAlignedLoad(llvm::Value *Addr, CharUnits Align, const llvm::Twine &Name="")
Definition: CGBuilder.h:91
LValue EmitPseudoObjectLValue(const PseudoObjectExpr *e)
Definition: CGExpr.cpp:4936
bool hasUserDeclaredConstructor() const
Determine whether this class has any user-declared constructors.
Definition: DeclCXX.h:983
Represents a &#39;co_yield&#39; expression.
Definition: ExprCXX.h:4397
const Expr * getExpr() const
Definition: ExprCXX.h:1105
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:2760
bool isBitField() const
Definition: CGValue.h:254
llvm::StoreInst * CreateStore(llvm::Value *Val, Address Addr, bool IsVolatile=false)
Definition: CGBuilder.h:108
static AggValueSlot forLValue(const LValue &LV, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, Overlap_t mayOverlap, IsZeroed_t isZeroed=IsNotZeroed, IsSanitizerChecked_t isChecked=IsNotSanitizerChecked)
Definition: CGValue.h:540
llvm::Module & getModule() const
QualType getCallReturnType(const ASTContext &Ctx) const
getCallReturnType - Get the return type of the call expr.
Definition: Expr.cpp:1347
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:2017
void EmitAggExpr(const Expr *E, AggValueSlot AS)
EmitAggExpr - Emit the computation of the specified expression of aggregate type. ...
Definition: CGExprAgg.cpp:1777
void EmitExplicitCastExprType(const ExplicitCastExpr *E, CodeGenFunction *CGF=nullptr)
Emit type info if type of an expression is a variably modified type.
Definition: CGExpr.cpp:1009
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:4374
Complex values, per C99 6.2.5p11.
Definition: Type.h:2481
ArraySubscriptExpr - [C99 6.5.2.1] Array Subscripting.
Definition: Expr.h:2323
CodeGenTypes & getTypes() const
AbstractConditionalOperator - An abstract base class for ConditionalOperator and BinaryConditionalOpe...
Definition: Expr.h:3501
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:2894
bool isAtomicType() const
Definition: Type.h:6410
Represents a &#39;co_await&#39; expression.
Definition: ExprCXX.h:4314
bool isUnique() const
Definition: Expr.h:1012
llvm::Value * getAggregatePointer() const
Definition: CGValue.h:76
void EmitScalarInit(const Expr *init, const ValueDecl *D, LValue lvalue, bool capturedByInit)
Definition: CGDecl.cpp:740
bool hasSameType(QualType T1, QualType T2) const
Determine whether the given types T1 and T2 are equivalent.
Definition: ASTContext.h:2268
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:443
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:1136
CharUnits toCharUnitsFromBits(int64_t BitSize) const
Convert a size in bits to a size in characters.
Overlap_t mayOverlap() const
Definition: CGValue.h:599
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:896
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:2616
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:1874
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
Represents a loop initializing the elements of an array.
Definition: Expr.h:4764
ChooseExpr - GNU builtin-in function __builtin_choose_expr.
Definition: Expr.h:3938
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:1232
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:203
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:1577
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2407
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:1823
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1042
static RValue get(llvm::Value *V)
Definition: CGValue.h:86
bool isUnion() const
Definition: Decl.h:3261
Expr * getRHS() const
Definition: Expr.h:3290
bool isPointerType() const
Definition: Type.h:6300
bool hasObjectMember() const
Definition: Decl.h:3683
void EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr)
Definition: CGDecl.cpp:1082
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:4258
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:607
const LangOptions & getLangOpts() const
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2498
const ValueInfo * getUnordered() const
llvm::APInt getArraySize() const
Definition: Expr.h:4788
llvm::Value * getPointer() const
Definition: CGValue.h:323
Represents the canonical version of C arrays with a specified constant size.
Definition: Type.h:2876
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:4854
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:1936
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:2525
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:2025