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Expr.h
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1 //===--- Expr.h - Classes for representing expressions ----------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the Expr interface and subclasses.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_AST_EXPR_H
14 #define LLVM_CLANG_AST_EXPR_H
15 
16 #include "clang/AST/APValue.h"
17 #include "clang/AST/ASTVector.h"
18 #include "clang/AST/Decl.h"
21 #include "clang/AST/Stmt.h"
22 #include "clang/AST/TemplateBase.h"
23 #include "clang/AST/Type.h"
24 #include "clang/Basic/CharInfo.h"
25 #include "clang/Basic/FixedPoint.h"
27 #include "clang/Basic/SyncScope.h"
28 #include "clang/Basic/TypeTraits.h"
29 #include "llvm/ADT/APFloat.h"
30 #include "llvm/ADT/APSInt.h"
31 #include "llvm/ADT/iterator.h"
32 #include "llvm/ADT/iterator_range.h"
33 #include "llvm/ADT/SmallVector.h"
34 #include "llvm/ADT/StringRef.h"
35 #include "llvm/Support/AtomicOrdering.h"
36 #include "llvm/Support/Compiler.h"
37 #include "llvm/Support/TrailingObjects.h"
38 
39 namespace clang {
40  class APValue;
41  class ASTContext;
42  class BlockDecl;
43  class CXXBaseSpecifier;
44  class CXXMemberCallExpr;
45  class CXXOperatorCallExpr;
46  class CastExpr;
47  class Decl;
48  class IdentifierInfo;
49  class MaterializeTemporaryExpr;
50  class NamedDecl;
51  class ObjCPropertyRefExpr;
52  class OpaqueValueExpr;
53  class ParmVarDecl;
54  class StringLiteral;
55  class TargetInfo;
56  class ValueDecl;
57 
58 /// A simple array of base specifiers.
60 
61 /// An adjustment to be made to the temporary created when emitting a
62 /// reference binding, which accesses a particular subobject of that temporary.
64  enum {
68  } Kind;
69 
70  struct DTB {
73  };
74 
75  struct P {
78  };
79 
80  union {
83  struct P Ptr;
84  };
85 
88  : Kind(DerivedToBaseAdjustment) {
91  }
92 
94  : Kind(FieldAdjustment) {
95  this->Field = Field;
96  }
97 
99  : Kind(MemberPointerAdjustment) {
100  this->Ptr.MPT = MPT;
101  this->Ptr.RHS = RHS;
102  }
103 };
104 
105 /// This represents one expression. Note that Expr's are subclasses of Stmt.
106 /// This allows an expression to be transparently used any place a Stmt is
107 /// required.
108 class Expr : public ValueStmt {
109  QualType TR;
110 
111 protected:
113  bool TD, bool VD, bool ID, bool ContainsUnexpandedParameterPack)
114  : ValueStmt(SC)
115  {
116  ExprBits.TypeDependent = TD;
117  ExprBits.ValueDependent = VD;
118  ExprBits.InstantiationDependent = ID;
119  ExprBits.ValueKind = VK;
120  ExprBits.ObjectKind = OK;
121  assert(ExprBits.ObjectKind == OK && "truncated kind");
122  ExprBits.ContainsUnexpandedParameterPack = ContainsUnexpandedParameterPack;
123  setType(T);
124  }
125 
126  /// Construct an empty expression.
127  explicit Expr(StmtClass SC, EmptyShell) : ValueStmt(SC) { }
128 
129 public:
130  QualType getType() const { return TR; }
131  void setType(QualType t) {
132  // In C++, the type of an expression is always adjusted so that it
133  // will not have reference type (C++ [expr]p6). Use
134  // QualType::getNonReferenceType() to retrieve the non-reference
135  // type. Additionally, inspect Expr::isLvalue to determine whether
136  // an expression that is adjusted in this manner should be
137  // considered an lvalue.
138  assert((t.isNull() || !t->isReferenceType()) &&
139  "Expressions can't have reference type");
140 
141  TR = t;
142  }
143 
144  /// isValueDependent - Determines whether this expression is
145  /// value-dependent (C++ [temp.dep.constexpr]). For example, the
146  /// array bound of "Chars" in the following example is
147  /// value-dependent.
148  /// @code
149  /// template<int Size, char (&Chars)[Size]> struct meta_string;
150  /// @endcode
151  bool isValueDependent() const { return ExprBits.ValueDependent; }
152 
153  /// Set whether this expression is value-dependent or not.
154  void setValueDependent(bool VD) {
155  ExprBits.ValueDependent = VD;
156  }
157 
158  /// isTypeDependent - Determines whether this expression is
159  /// type-dependent (C++ [temp.dep.expr]), which means that its type
160  /// could change from one template instantiation to the next. For
161  /// example, the expressions "x" and "x + y" are type-dependent in
162  /// the following code, but "y" is not type-dependent:
163  /// @code
164  /// template<typename T>
165  /// void add(T x, int y) {
166  /// x + y;
167  /// }
168  /// @endcode
169  bool isTypeDependent() const { return ExprBits.TypeDependent; }
170 
171  /// Set whether this expression is type-dependent or not.
172  void setTypeDependent(bool TD) {
173  ExprBits.TypeDependent = TD;
174  }
175 
176  /// Whether this expression is instantiation-dependent, meaning that
177  /// it depends in some way on a template parameter, even if neither its type
178  /// nor (constant) value can change due to the template instantiation.
179  ///
180  /// In the following example, the expression \c sizeof(sizeof(T() + T())) is
181  /// instantiation-dependent (since it involves a template parameter \c T), but
182  /// is neither type- nor value-dependent, since the type of the inner
183  /// \c sizeof is known (\c std::size_t) and therefore the size of the outer
184  /// \c sizeof is known.
185  ///
186  /// \code
187  /// template<typename T>
188  /// void f(T x, T y) {
189  /// sizeof(sizeof(T() + T());
190  /// }
191  /// \endcode
192  ///
194  return ExprBits.InstantiationDependent;
195  }
196 
197  /// Set whether this expression is instantiation-dependent or not.
199  ExprBits.InstantiationDependent = ID;
200  }
201 
202  /// Whether this expression contains an unexpanded parameter
203  /// pack (for C++11 variadic templates).
204  ///
205  /// Given the following function template:
206  ///
207  /// \code
208  /// template<typename F, typename ...Types>
209  /// void forward(const F &f, Types &&...args) {
210  /// f(static_cast<Types&&>(args)...);
211  /// }
212  /// \endcode
213  ///
214  /// The expressions \c args and \c static_cast<Types&&>(args) both
215  /// contain parameter packs.
217  return ExprBits.ContainsUnexpandedParameterPack;
218  }
219 
220  /// Set the bit that describes whether this expression
221  /// contains an unexpanded parameter pack.
222  void setContainsUnexpandedParameterPack(bool PP = true) {
223  ExprBits.ContainsUnexpandedParameterPack = PP;
224  }
225 
226  /// getExprLoc - Return the preferred location for the arrow when diagnosing
227  /// a problem with a generic expression.
228  SourceLocation getExprLoc() const LLVM_READONLY;
229 
230  /// isUnusedResultAWarning - Return true if this immediate expression should
231  /// be warned about if the result is unused. If so, fill in expr, location,
232  /// and ranges with expr to warn on and source locations/ranges appropriate
233  /// for a warning.
234  bool isUnusedResultAWarning(const Expr *&WarnExpr, SourceLocation &Loc,
235  SourceRange &R1, SourceRange &R2,
236  ASTContext &Ctx) const;
237 
238  /// isLValue - True if this expression is an "l-value" according to
239  /// the rules of the current language. C and C++ give somewhat
240  /// different rules for this concept, but in general, the result of
241  /// an l-value expression identifies a specific object whereas the
242  /// result of an r-value expression is a value detached from any
243  /// specific storage.
244  ///
245  /// C++11 divides the concept of "r-value" into pure r-values
246  /// ("pr-values") and so-called expiring values ("x-values"), which
247  /// identify specific objects that can be safely cannibalized for
248  /// their resources. This is an unfortunate abuse of terminology on
249  /// the part of the C++ committee. In Clang, when we say "r-value",
250  /// we generally mean a pr-value.
251  bool isLValue() const { return getValueKind() == VK_LValue; }
252  bool isRValue() const { return getValueKind() == VK_RValue; }
253  bool isXValue() const { return getValueKind() == VK_XValue; }
254  bool isGLValue() const { return getValueKind() != VK_RValue; }
255 
266  LV_ArrayTemporary
267  };
268  /// Reasons why an expression might not be an l-value.
269  LValueClassification ClassifyLValue(ASTContext &Ctx) const;
270 
277  MLV_LValueCast, // Specialized form of MLV_InvalidExpression.
288  MLV_ArrayTemporary
289  };
290  /// isModifiableLvalue - C99 6.3.2.1: an lvalue that does not have array type,
291  /// does not have an incomplete type, does not have a const-qualified type,
292  /// and if it is a structure or union, does not have any member (including,
293  /// recursively, any member or element of all contained aggregates or unions)
294  /// with a const-qualified type.
295  ///
296  /// \param Loc [in,out] - A source location which *may* be filled
297  /// in with the location of the expression making this a
298  /// non-modifiable lvalue, if specified.
300  isModifiableLvalue(ASTContext &Ctx, SourceLocation *Loc = nullptr) const;
301 
302  /// The return type of classify(). Represents the C++11 expression
303  /// taxonomy.
305  public:
306  /// The various classification results. Most of these mean prvalue.
307  enum Kinds {
310  CL_Function, // Functions cannot be lvalues in C.
311  CL_Void, // Void cannot be an lvalue in C.
312  CL_AddressableVoid, // Void expression whose address can be taken in C.
313  CL_DuplicateVectorComponents, // A vector shuffle with dupes.
314  CL_MemberFunction, // An expression referring to a member function
316  CL_ClassTemporary, // A temporary of class type, or subobject thereof.
317  CL_ArrayTemporary, // A temporary of array type.
318  CL_ObjCMessageRValue, // ObjC message is an rvalue
319  CL_PRValue // A prvalue for any other reason, of any other type
320  };
321  /// The results of modification testing.
323  CM_Untested, // testModifiable was false.
325  CM_RValue, // Not modifiable because it's an rvalue
326  CM_Function, // Not modifiable because it's a function; C++ only
327  CM_LValueCast, // Same as CM_RValue, but indicates GCC cast-as-lvalue ext
328  CM_NoSetterProperty,// Implicit assignment to ObjC property without setter
333  CM_IncompleteType
334  };
335 
336  private:
337  friend class Expr;
338 
339  unsigned short Kind;
340  unsigned short Modifiable;
341 
342  explicit Classification(Kinds k, ModifiableType m)
343  : Kind(k), Modifiable(m)
344  {}
345 
346  public:
348 
349  Kinds getKind() const { return static_cast<Kinds>(Kind); }
351  assert(Modifiable != CM_Untested && "Did not test for modifiability.");
352  return static_cast<ModifiableType>(Modifiable);
353  }
354  bool isLValue() const { return Kind == CL_LValue; }
355  bool isXValue() const { return Kind == CL_XValue; }
356  bool isGLValue() const { return Kind <= CL_XValue; }
357  bool isPRValue() const { return Kind >= CL_Function; }
358  bool isRValue() const { return Kind >= CL_XValue; }
359  bool isModifiable() const { return getModifiable() == CM_Modifiable; }
360 
361  /// Create a simple, modifiably lvalue
363  return Classification(CL_LValue, CM_Modifiable);
364  }
365 
366  };
367  /// Classify - Classify this expression according to the C++11
368  /// expression taxonomy.
369  ///
370  /// C++11 defines ([basic.lval]) a new taxonomy of expressions to replace the
371  /// old lvalue vs rvalue. This function determines the type of expression this
372  /// is. There are three expression types:
373  /// - lvalues are classical lvalues as in C++03.
374  /// - prvalues are equivalent to rvalues in C++03.
375  /// - xvalues are expressions yielding unnamed rvalue references, e.g. a
376  /// function returning an rvalue reference.
377  /// lvalues and xvalues are collectively referred to as glvalues, while
378  /// prvalues and xvalues together form rvalues.
380  return ClassifyImpl(Ctx, nullptr);
381  }
382 
383  /// ClassifyModifiable - Classify this expression according to the
384  /// C++11 expression taxonomy, and see if it is valid on the left side
385  /// of an assignment.
386  ///
387  /// This function extends classify in that it also tests whether the
388  /// expression is modifiable (C99 6.3.2.1p1).
389  /// \param Loc A source location that might be filled with a relevant location
390  /// if the expression is not modifiable.
392  return ClassifyImpl(Ctx, &Loc);
393  }
394 
395  /// getValueKindForType - Given a formal return or parameter type,
396  /// give its value kind.
398  if (const ReferenceType *RT = T->getAs<ReferenceType>())
399  return (isa<LValueReferenceType>(RT)
400  ? VK_LValue
401  : (RT->getPointeeType()->isFunctionType()
402  ? VK_LValue : VK_XValue));
403  return VK_RValue;
404  }
405 
406  /// getValueKind - The value kind that this expression produces.
408  return static_cast<ExprValueKind>(ExprBits.ValueKind);
409  }
410 
411  /// getObjectKind - The object kind that this expression produces.
412  /// Object kinds are meaningful only for expressions that yield an
413  /// l-value or x-value.
415  return static_cast<ExprObjectKind>(ExprBits.ObjectKind);
416  }
417 
419  ExprObjectKind OK = getObjectKind();
420  return (OK == OK_Ordinary || OK == OK_BitField);
421  }
422 
423  /// setValueKind - Set the value kind produced by this expression.
424  void setValueKind(ExprValueKind Cat) { ExprBits.ValueKind = Cat; }
425 
426  /// setObjectKind - Set the object kind produced by this expression.
427  void setObjectKind(ExprObjectKind Cat) { ExprBits.ObjectKind = Cat; }
428 
429 private:
430  Classification ClassifyImpl(ASTContext &Ctx, SourceLocation *Loc) const;
431 
432 public:
433 
434  /// Returns true if this expression is a gl-value that
435  /// potentially refers to a bit-field.
436  ///
437  /// In C++, whether a gl-value refers to a bitfield is essentially
438  /// an aspect of the value-kind type system.
439  bool refersToBitField() const { return getObjectKind() == OK_BitField; }
440 
441  /// If this expression refers to a bit-field, retrieve the
442  /// declaration of that bit-field.
443  ///
444  /// Note that this returns a non-null pointer in subtly different
445  /// places than refersToBitField returns true. In particular, this can
446  /// return a non-null pointer even for r-values loaded from
447  /// bit-fields, but it will return null for a conditional bit-field.
448  FieldDecl *getSourceBitField();
449 
450  const FieldDecl *getSourceBitField() const {
451  return const_cast<Expr*>(this)->getSourceBitField();
452  }
453 
454  Decl *getReferencedDeclOfCallee();
456  return const_cast<Expr*>(this)->getReferencedDeclOfCallee();
457  }
458 
459  /// If this expression is an l-value for an Objective C
460  /// property, find the underlying property reference expression.
461  const ObjCPropertyRefExpr *getObjCProperty() const;
462 
463  /// Check if this expression is the ObjC 'self' implicit parameter.
464  bool isObjCSelfExpr() const;
465 
466  /// Returns whether this expression refers to a vector element.
467  bool refersToVectorElement() const;
468 
469  /// Returns whether this expression refers to a global register
470  /// variable.
471  bool refersToGlobalRegisterVar() const;
472 
473  /// Returns whether this expression has a placeholder type.
474  bool hasPlaceholderType() const {
475  return getType()->isPlaceholderType();
476  }
477 
478  /// Returns whether this expression has a specific placeholder type.
481  if (const BuiltinType *BT = dyn_cast<BuiltinType>(getType()))
482  return BT->getKind() == K;
483  return false;
484  }
485 
486  /// isKnownToHaveBooleanValue - Return true if this is an integer expression
487  /// that is known to return 0 or 1. This happens for _Bool/bool expressions
488  /// but also int expressions which are produced by things like comparisons in
489  /// C.
490  bool isKnownToHaveBooleanValue() const;
491 
492  /// isIntegerConstantExpr - Return true if this expression is a valid integer
493  /// constant expression, and, if so, return its value in Result. If not a
494  /// valid i-c-e, return false and fill in Loc (if specified) with the location
495  /// of the invalid expression.
496  ///
497  /// Note: This does not perform the implicit conversions required by C++11
498  /// [expr.const]p5.
499  bool isIntegerConstantExpr(llvm::APSInt &Result, const ASTContext &Ctx,
500  SourceLocation *Loc = nullptr,
501  bool isEvaluated = true) const;
502  bool isIntegerConstantExpr(const ASTContext &Ctx,
503  SourceLocation *Loc = nullptr) const;
504 
505  /// isCXX98IntegralConstantExpr - Return true if this expression is an
506  /// integral constant expression in C++98. Can only be used in C++.
507  bool isCXX98IntegralConstantExpr(const ASTContext &Ctx) const;
508 
509  /// isCXX11ConstantExpr - Return true if this expression is a constant
510  /// expression in C++11. Can only be used in C++.
511  ///
512  /// Note: This does not perform the implicit conversions required by C++11
513  /// [expr.const]p5.
514  bool isCXX11ConstantExpr(const ASTContext &Ctx, APValue *Result = nullptr,
515  SourceLocation *Loc = nullptr) const;
516 
517  /// isPotentialConstantExpr - Return true if this function's definition
518  /// might be usable in a constant expression in C++11, if it were marked
519  /// constexpr. Return false if the function can never produce a constant
520  /// expression, along with diagnostics describing why not.
521  static bool isPotentialConstantExpr(const FunctionDecl *FD,
523  PartialDiagnosticAt> &Diags);
524 
525  /// isPotentialConstantExprUnevaluted - Return true if this expression might
526  /// be usable in a constant expression in C++11 in an unevaluated context, if
527  /// it were in function FD marked constexpr. Return false if the function can
528  /// never produce a constant expression, along with diagnostics describing
529  /// why not.
530  static bool isPotentialConstantExprUnevaluated(Expr *E,
531  const FunctionDecl *FD,
533  PartialDiagnosticAt> &Diags);
534 
535  /// isConstantInitializer - Returns true if this expression can be emitted to
536  /// IR as a constant, and thus can be used as a constant initializer in C.
537  /// If this expression is not constant and Culprit is non-null,
538  /// it is used to store the address of first non constant expr.
539  bool isConstantInitializer(ASTContext &Ctx, bool ForRef,
540  const Expr **Culprit = nullptr) const;
541 
542  /// EvalStatus is a struct with detailed info about an evaluation in progress.
543  struct EvalStatus {
544  /// Whether the evaluated expression has side effects.
545  /// For example, (f() && 0) can be folded, but it still has side effects.
547 
548  /// Whether the evaluation hit undefined behavior.
549  /// For example, 1.0 / 0.0 can be folded to Inf, but has undefined behavior.
550  /// Likewise, INT_MAX + 1 can be folded to INT_MIN, but has UB.
552 
553  /// Diag - If this is non-null, it will be filled in with a stack of notes
554  /// indicating why evaluation failed (or why it failed to produce a constant
555  /// expression).
556  /// If the expression is unfoldable, the notes will indicate why it's not
557  /// foldable. If the expression is foldable, but not a constant expression,
558  /// the notes will describes why it isn't a constant expression. If the
559  /// expression *is* a constant expression, no notes will be produced.
561 
563  : HasSideEffects(false), HasUndefinedBehavior(false), Diag(nullptr) {}
564 
565  // hasSideEffects - Return true if the evaluated expression has
566  // side effects.
567  bool hasSideEffects() const {
568  return HasSideEffects;
569  }
570  };
571 
572  /// EvalResult is a struct with detailed info about an evaluated expression.
574  /// Val - This is the value the expression can be folded to.
576 
577  // isGlobalLValue - Return true if the evaluated lvalue expression
578  // is global.
579  bool isGlobalLValue() const;
580  };
581 
582  /// EvaluateAsRValue - Return true if this is a constant which we can fold to
583  /// an rvalue using any crazy technique (that has nothing to do with language
584  /// standards) that we want to, even if the expression has side-effects. If
585  /// this function returns true, it returns the folded constant in Result. If
586  /// the expression is a glvalue, an lvalue-to-rvalue conversion will be
587  /// applied.
588  bool EvaluateAsRValue(EvalResult &Result, const ASTContext &Ctx,
589  bool InConstantContext = false) const;
590 
591  /// EvaluateAsBooleanCondition - Return true if this is a constant
592  /// which we can fold and convert to a boolean condition using
593  /// any crazy technique that we want to, even if the expression has
594  /// side-effects.
595  bool EvaluateAsBooleanCondition(bool &Result, const ASTContext &Ctx) const;
596 
598  SE_NoSideEffects, ///< Strictly evaluate the expression.
599  SE_AllowUndefinedBehavior, ///< Allow UB that we can give a value, but not
600  ///< arbitrary unmodeled side effects.
601  SE_AllowSideEffects ///< Allow any unmodeled side effect.
602  };
603 
604  /// EvaluateAsInt - Return true if this is a constant which we can fold and
605  /// convert to an integer, using any crazy technique that we want to.
606  bool EvaluateAsInt(EvalResult &Result, const ASTContext &Ctx,
607  SideEffectsKind AllowSideEffects = SE_NoSideEffects) const;
608 
609  /// EvaluateAsFloat - Return true if this is a constant which we can fold and
610  /// convert to a floating point value, using any crazy technique that we
611  /// want to.
612  bool
613  EvaluateAsFloat(llvm::APFloat &Result, const ASTContext &Ctx,
614  SideEffectsKind AllowSideEffects = SE_NoSideEffects) const;
615 
616  /// EvaluateAsFloat - Return true if this is a constant which we can fold and
617  /// convert to a fixed point value.
619  EvalResult &Result, const ASTContext &Ctx,
620  SideEffectsKind AllowSideEffects = SE_NoSideEffects) const;
621 
622  /// isEvaluatable - Call EvaluateAsRValue to see if this expression can be
623  /// constant folded without side-effects, but discard the result.
624  bool isEvaluatable(const ASTContext &Ctx,
625  SideEffectsKind AllowSideEffects = SE_NoSideEffects) const;
626 
627  /// HasSideEffects - This routine returns true for all those expressions
628  /// which have any effect other than producing a value. Example is a function
629  /// call, volatile variable read, or throwing an exception. If
630  /// IncludePossibleEffects is false, this call treats certain expressions with
631  /// potential side effects (such as function call-like expressions,
632  /// instantiation-dependent expressions, or invocations from a macro) as not
633  /// having side effects.
634  bool HasSideEffects(const ASTContext &Ctx,
635  bool IncludePossibleEffects = true) const;
636 
637  /// Determine whether this expression involves a call to any function
638  /// that is not trivial.
639  bool hasNonTrivialCall(const ASTContext &Ctx) const;
640 
641  /// EvaluateKnownConstInt - Call EvaluateAsRValue and return the folded
642  /// integer. This must be called on an expression that constant folds to an
643  /// integer.
644  llvm::APSInt EvaluateKnownConstInt(
645  const ASTContext &Ctx,
646  SmallVectorImpl<PartialDiagnosticAt> *Diag = nullptr) const;
647 
648  llvm::APSInt EvaluateKnownConstIntCheckOverflow(
649  const ASTContext &Ctx,
650  SmallVectorImpl<PartialDiagnosticAt> *Diag = nullptr) const;
651 
652  void EvaluateForOverflow(const ASTContext &Ctx) const;
653 
654  /// EvaluateAsLValue - Evaluate an expression to see if we can fold it to an
655  /// lvalue with link time known address, with no side-effects.
656  bool EvaluateAsLValue(EvalResult &Result, const ASTContext &Ctx) const;
657 
658  /// EvaluateAsInitializer - Evaluate an expression as if it were the
659  /// initializer of the given declaration. Returns true if the initializer
660  /// can be folded to a constant, and produces any relevant notes. In C++11,
661  /// notes will be produced if the expression is not a constant expression.
662  bool EvaluateAsInitializer(APValue &Result, const ASTContext &Ctx,
663  const VarDecl *VD,
665 
666  /// EvaluateWithSubstitution - Evaluate an expression as if from the context
667  /// of a call to the given function with the given arguments, inside an
668  /// unevaluated context. Returns true if the expression could be folded to a
669  /// constant.
670  bool EvaluateWithSubstitution(APValue &Value, ASTContext &Ctx,
671  const FunctionDecl *Callee,
673  const Expr *This = nullptr) const;
674 
675  /// Indicates how the constant expression will be used.
676  enum ConstExprUsage { EvaluateForCodeGen, EvaluateForMangling };
677 
678  /// Evaluate an expression that is required to be a constant expression.
679  bool EvaluateAsConstantExpr(EvalResult &Result, ConstExprUsage Usage,
680  const ASTContext &Ctx) const;
681 
682  /// If the current Expr is a pointer, this will try to statically
683  /// determine the number of bytes available where the pointer is pointing.
684  /// Returns true if all of the above holds and we were able to figure out the
685  /// size, false otherwise.
686  ///
687  /// \param Type - How to evaluate the size of the Expr, as defined by the
688  /// "type" parameter of __builtin_object_size
689  bool tryEvaluateObjectSize(uint64_t &Result, ASTContext &Ctx,
690  unsigned Type) const;
691 
692  /// Enumeration used to describe the kind of Null pointer constant
693  /// returned from \c isNullPointerConstant().
695  /// Expression is not a Null pointer constant.
696  NPCK_NotNull = 0,
697 
698  /// Expression is a Null pointer constant built from a zero integer
699  /// expression that is not a simple, possibly parenthesized, zero literal.
700  /// C++ Core Issue 903 will classify these expressions as "not pointers"
701  /// once it is adopted.
702  /// http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
704 
705  /// Expression is a Null pointer constant built from a literal zero.
707 
708  /// Expression is a C++11 nullptr.
710 
711  /// Expression is a GNU-style __null constant.
712  NPCK_GNUNull
713  };
714 
715  /// Enumeration used to describe how \c isNullPointerConstant()
716  /// should cope with value-dependent expressions.
718  /// Specifies that the expression should never be value-dependent.
719  NPC_NeverValueDependent = 0,
720 
721  /// Specifies that a value-dependent expression of integral or
722  /// dependent type should be considered a null pointer constant.
724 
725  /// Specifies that a value-dependent expression should be considered
726  /// to never be a null pointer constant.
727  NPC_ValueDependentIsNotNull
728  };
729 
730  /// isNullPointerConstant - C99 6.3.2.3p3 - Test if this reduces down to
731  /// a Null pointer constant. The return value can further distinguish the
732  /// kind of NULL pointer constant that was detected.
733  NullPointerConstantKind isNullPointerConstant(
734  ASTContext &Ctx,
736 
737  /// isOBJCGCCandidate - Return true if this expression may be used in a read/
738  /// write barrier.
739  bool isOBJCGCCandidate(ASTContext &Ctx) const;
740 
741  /// Returns true if this expression is a bound member function.
742  bool isBoundMemberFunction(ASTContext &Ctx) const;
743 
744  /// Given an expression of bound-member type, find the type
745  /// of the member. Returns null if this is an *overloaded* bound
746  /// member expression.
747  static QualType findBoundMemberType(const Expr *expr);
748 
749  /// Skip past any implicit casts which might surround this expression until
750  /// reaching a fixed point. Skips:
751  /// * ImplicitCastExpr
752  /// * FullExpr
753  Expr *IgnoreImpCasts() LLVM_READONLY;
754  const Expr *IgnoreImpCasts() const {
755  return const_cast<Expr *>(this)->IgnoreImpCasts();
756  }
757 
758  /// Skip past any casts which might surround this expression until reaching
759  /// a fixed point. Skips:
760  /// * CastExpr
761  /// * FullExpr
762  /// * MaterializeTemporaryExpr
763  /// * SubstNonTypeTemplateParmExpr
764  Expr *IgnoreCasts() LLVM_READONLY;
765  const Expr *IgnoreCasts() const {
766  return const_cast<Expr *>(this)->IgnoreCasts();
767  }
768 
769  /// Skip past any implicit AST nodes which might surround this expression
770  /// until reaching a fixed point. Skips:
771  /// * What IgnoreImpCasts() skips
772  /// * MaterializeTemporaryExpr
773  /// * CXXBindTemporaryExpr
774  Expr *IgnoreImplicit() LLVM_READONLY;
775  const Expr *IgnoreImplicit() const {
776  return const_cast<Expr *>(this)->IgnoreImplicit();
777  }
778 
779  /// Skip past any parentheses which might surround this expression until
780  /// reaching a fixed point. Skips:
781  /// * ParenExpr
782  /// * UnaryOperator if `UO_Extension`
783  /// * GenericSelectionExpr if `!isResultDependent()`
784  /// * ChooseExpr if `!isConditionDependent()`
785  /// * ConstantExpr
786  Expr *IgnoreParens() LLVM_READONLY;
787  const Expr *IgnoreParens() const {
788  return const_cast<Expr *>(this)->IgnoreParens();
789  }
790 
791  /// Skip past any parentheses and implicit casts which might surround this
792  /// expression until reaching a fixed point.
793  /// FIXME: IgnoreParenImpCasts really ought to be equivalent to
794  /// IgnoreParens() + IgnoreImpCasts() until reaching a fixed point. However
795  /// this is currently not the case. Instead IgnoreParenImpCasts() skips:
796  /// * What IgnoreParens() skips
797  /// * ImplicitCastExpr
798  /// * MaterializeTemporaryExpr
799  /// * SubstNonTypeTemplateParmExpr
800  Expr *IgnoreParenImpCasts() LLVM_READONLY;
801  const Expr *IgnoreParenImpCasts() const {
802  return const_cast<Expr *>(this)->IgnoreParenImpCasts();
803  }
804 
805  /// Skip past any parentheses and casts which might surround this expression
806  /// until reaching a fixed point. Skips:
807  /// * What IgnoreParens() skips
808  /// * What IgnoreCasts() skips
809  Expr *IgnoreParenCasts() LLVM_READONLY;
810  const Expr *IgnoreParenCasts() const {
811  return const_cast<Expr *>(this)->IgnoreParenCasts();
812  }
813 
814  /// Skip conversion operators. If this Expr is a call to a conversion
815  /// operator, return the argument.
816  Expr *IgnoreConversionOperator() LLVM_READONLY;
818  return const_cast<Expr *>(this)->IgnoreConversionOperator();
819  }
820 
821  /// Skip past any parentheses and lvalue casts which might surround this
822  /// expression until reaching a fixed point. Skips:
823  /// * What IgnoreParens() skips
824  /// * What IgnoreCasts() skips, except that only lvalue-to-rvalue
825  /// casts are skipped
826  /// FIXME: This is intended purely as a temporary workaround for code
827  /// that hasn't yet been rewritten to do the right thing about those
828  /// casts, and may disappear along with the last internal use.
829  Expr *IgnoreParenLValueCasts() LLVM_READONLY;
830  const Expr *IgnoreParenLValueCasts() const {
831  return const_cast<Expr *>(this)->IgnoreParenLValueCasts();
832  }
833 
834  /// Skip past any parenthese and casts which do not change the value
835  /// (including ptr->int casts of the same size) until reaching a fixed point.
836  /// Skips:
837  /// * What IgnoreParens() skips
838  /// * CastExpr which do not change the value
839  /// * SubstNonTypeTemplateParmExpr
840  Expr *IgnoreParenNoopCasts(const ASTContext &Ctx) LLVM_READONLY;
841  const Expr *IgnoreParenNoopCasts(const ASTContext &Ctx) const {
842  return const_cast<Expr *>(this)->IgnoreParenNoopCasts(Ctx);
843  }
844 
845  /// Skip past any parentheses and derived-to-base casts until reaching a
846  /// fixed point. Skips:
847  /// * What IgnoreParens() skips
848  /// * CastExpr which represent a derived-to-base cast (CK_DerivedToBase,
849  /// CK_UncheckedDerivedToBase and CK_NoOp)
850  Expr *ignoreParenBaseCasts() LLVM_READONLY;
851  const Expr *ignoreParenBaseCasts() const {
852  return const_cast<Expr *>(this)->ignoreParenBaseCasts();
853  }
854 
855  /// Determine whether this expression is a default function argument.
856  ///
857  /// Default arguments are implicitly generated in the abstract syntax tree
858  /// by semantic analysis for function calls, object constructions, etc. in
859  /// C++. Default arguments are represented by \c CXXDefaultArgExpr nodes;
860  /// this routine also looks through any implicit casts to determine whether
861  /// the expression is a default argument.
862  bool isDefaultArgument() const;
863 
864  /// Determine whether the result of this expression is a
865  /// temporary object of the given class type.
866  bool isTemporaryObject(ASTContext &Ctx, const CXXRecordDecl *TempTy) const;
867 
868  /// Whether this expression is an implicit reference to 'this' in C++.
869  bool isImplicitCXXThis() const;
870 
871  static bool hasAnyTypeDependentArguments(ArrayRef<Expr *> Exprs);
872 
873  /// For an expression of class type or pointer to class type,
874  /// return the most derived class decl the expression is known to refer to.
875  ///
876  /// If this expression is a cast, this method looks through it to find the
877  /// most derived decl that can be inferred from the expression.
878  /// This is valid because derived-to-base conversions have undefined
879  /// behavior if the object isn't dynamically of the derived type.
880  const CXXRecordDecl *getBestDynamicClassType() const;
881 
882  /// Get the inner expression that determines the best dynamic class.
883  /// If this is a prvalue, we guarantee that it is of the most-derived type
884  /// for the object itself.
885  const Expr *getBestDynamicClassTypeExpr() const;
886 
887  /// Walk outwards from an expression we want to bind a reference to and
888  /// find the expression whose lifetime needs to be extended. Record
889  /// the LHSs of comma expressions and adjustments needed along the path.
890  const Expr *skipRValueSubobjectAdjustments(
892  SmallVectorImpl<SubobjectAdjustment> &Adjustments) const;
896  return skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
897  }
898 
899  static bool classof(const Stmt *T) {
900  return T->getStmtClass() >= firstExprConstant &&
901  T->getStmtClass() <= lastExprConstant;
902  }
903 };
904 
905 //===----------------------------------------------------------------------===//
906 // Wrapper Expressions.
907 //===----------------------------------------------------------------------===//
908 
909 /// FullExpr - Represents a "full-expression" node.
910 class FullExpr : public Expr {
911 protected:
913 
914  FullExpr(StmtClass SC, Expr *subexpr)
915  : Expr(SC, subexpr->getType(),
916  subexpr->getValueKind(), subexpr->getObjectKind(),
917  subexpr->isTypeDependent(), subexpr->isValueDependent(),
918  subexpr->isInstantiationDependent(),
919  subexpr->containsUnexpandedParameterPack()), SubExpr(subexpr) {}
921  : Expr(SC, Empty) {}
922 public:
923  const Expr *getSubExpr() const { return cast<Expr>(SubExpr); }
924  Expr *getSubExpr() { return cast<Expr>(SubExpr); }
925 
926  /// As with any mutator of the AST, be very careful when modifying an
927  /// existing AST to preserve its invariants.
928  void setSubExpr(Expr *E) { SubExpr = E; }
929 
930  static bool classof(const Stmt *T) {
931  return T->getStmtClass() >= firstFullExprConstant &&
932  T->getStmtClass() <= lastFullExprConstant;
933  }
934 };
935 
936 /// ConstantExpr - An expression that occurs in a constant context.
937 class ConstantExpr : public FullExpr {
938  ConstantExpr(Expr *subexpr)
939  : FullExpr(ConstantExprClass, subexpr) {}
940 
941 public:
942  static ConstantExpr *Create(const ASTContext &Context, Expr *E) {
943  assert(!isa<ConstantExpr>(E));
944  return new (Context) ConstantExpr(E);
945  }
946 
947  /// Build an empty constant expression wrapper.
948  explicit ConstantExpr(EmptyShell Empty)
949  : FullExpr(ConstantExprClass, Empty) {}
950 
951  SourceLocation getBeginLoc() const LLVM_READONLY {
952  return SubExpr->getBeginLoc();
953  }
954  SourceLocation getEndLoc() const LLVM_READONLY {
955  return SubExpr->getEndLoc();
956  }
957 
958  static bool classof(const Stmt *T) {
959  return T->getStmtClass() == ConstantExprClass;
960  }
961 
962  // Iterators
963  child_range children() { return child_range(&SubExpr, &SubExpr+1); }
965  return const_child_range(&SubExpr, &SubExpr + 1);
966  }
967 };
968 
969 //===----------------------------------------------------------------------===//
970 // Primary Expressions.
971 //===----------------------------------------------------------------------===//
972 
973 /// OpaqueValueExpr - An expression referring to an opaque object of a
974 /// fixed type and value class. These don't correspond to concrete
975 /// syntax; instead they're used to express operations (usually copy
976 /// operations) on values whose source is generally obvious from
977 /// context.
978 class OpaqueValueExpr : public Expr {
979  friend class ASTStmtReader;
980  Expr *SourceExpr;
981 
982 public:
985  Expr *SourceExpr = nullptr)
986  : Expr(OpaqueValueExprClass, T, VK, OK,
987  T->isDependentType() ||
988  (SourceExpr && SourceExpr->isTypeDependent()),
989  T->isDependentType() ||
990  (SourceExpr && SourceExpr->isValueDependent()),
991  T->isInstantiationDependentType() ||
992  (SourceExpr && SourceExpr->isInstantiationDependent()),
993  false),
994  SourceExpr(SourceExpr) {
995  setIsUnique(false);
996  OpaqueValueExprBits.Loc = Loc;
997  }
998 
999  /// Given an expression which invokes a copy constructor --- i.e. a
1000  /// CXXConstructExpr, possibly wrapped in an ExprWithCleanups ---
1001  /// find the OpaqueValueExpr that's the source of the construction.
1002  static const OpaqueValueExpr *findInCopyConstruct(const Expr *expr);
1003 
1004  explicit OpaqueValueExpr(EmptyShell Empty)
1005  : Expr(OpaqueValueExprClass, Empty) {}
1006 
1007  /// Retrieve the location of this expression.
1008  SourceLocation getLocation() const { return OpaqueValueExprBits.Loc; }
1009 
1010  SourceLocation getBeginLoc() const LLVM_READONLY {
1011  return SourceExpr ? SourceExpr->getBeginLoc() : getLocation();
1012  }
1013  SourceLocation getEndLoc() const LLVM_READONLY {
1014  return SourceExpr ? SourceExpr->getEndLoc() : getLocation();
1015  }
1016  SourceLocation getExprLoc() const LLVM_READONLY {
1017  return SourceExpr ? SourceExpr->getExprLoc() : getLocation();
1018  }
1019 
1022  }
1023 
1026  }
1027 
1028  /// The source expression of an opaque value expression is the
1029  /// expression which originally generated the value. This is
1030  /// provided as a convenience for analyses that don't wish to
1031  /// precisely model the execution behavior of the program.
1032  ///
1033  /// The source expression is typically set when building the
1034  /// expression which binds the opaque value expression in the first
1035  /// place.
1036  Expr *getSourceExpr() const { return SourceExpr; }
1037 
1038  void setIsUnique(bool V) {
1039  assert((!V || SourceExpr) &&
1040  "unique OVEs are expected to have source expressions");
1041  OpaqueValueExprBits.IsUnique = V;
1042  }
1043 
1044  bool isUnique() const { return OpaqueValueExprBits.IsUnique; }
1045 
1046  static bool classof(const Stmt *T) {
1047  return T->getStmtClass() == OpaqueValueExprClass;
1048  }
1049 };
1050 
1051 /// A reference to a declared variable, function, enum, etc.
1052 /// [C99 6.5.1p2]
1053 ///
1054 /// This encodes all the information about how a declaration is referenced
1055 /// within an expression.
1056 ///
1057 /// There are several optional constructs attached to DeclRefExprs only when
1058 /// they apply in order to conserve memory. These are laid out past the end of
1059 /// the object, and flags in the DeclRefExprBitfield track whether they exist:
1060 ///
1061 /// DeclRefExprBits.HasQualifier:
1062 /// Specifies when this declaration reference expression has a C++
1063 /// nested-name-specifier.
1064 /// DeclRefExprBits.HasFoundDecl:
1065 /// Specifies when this declaration reference expression has a record of
1066 /// a NamedDecl (different from the referenced ValueDecl) which was found
1067 /// during name lookup and/or overload resolution.
1068 /// DeclRefExprBits.HasTemplateKWAndArgsInfo:
1069 /// Specifies when this declaration reference expression has an explicit
1070 /// C++ template keyword and/or template argument list.
1071 /// DeclRefExprBits.RefersToEnclosingVariableOrCapture
1072 /// Specifies when this declaration reference expression (validly)
1073 /// refers to an enclosed local or a captured variable.
1074 class DeclRefExpr final
1075  : public Expr,
1076  private llvm::TrailingObjects<DeclRefExpr, NestedNameSpecifierLoc,
1077  NamedDecl *, ASTTemplateKWAndArgsInfo,
1078  TemplateArgumentLoc> {
1079  friend class ASTStmtReader;
1080  friend class ASTStmtWriter;
1081  friend TrailingObjects;
1082 
1083  /// The declaration that we are referencing.
1084  ValueDecl *D;
1085 
1086  /// Provides source/type location info for the declaration name
1087  /// embedded in D.
1088  DeclarationNameLoc DNLoc;
1089 
1090  size_t numTrailingObjects(OverloadToken<NestedNameSpecifierLoc>) const {
1091  return hasQualifier();
1092  }
1093 
1094  size_t numTrailingObjects(OverloadToken<NamedDecl *>) const {
1095  return hasFoundDecl();
1096  }
1097 
1098  size_t numTrailingObjects(OverloadToken<ASTTemplateKWAndArgsInfo>) const {
1099  return hasTemplateKWAndArgsInfo();
1100  }
1101 
1102  /// Test whether there is a distinct FoundDecl attached to the end of
1103  /// this DRE.
1104  bool hasFoundDecl() const { return DeclRefExprBits.HasFoundDecl; }
1105 
1106  DeclRefExpr(const ASTContext &Ctx, NestedNameSpecifierLoc QualifierLoc,
1107  SourceLocation TemplateKWLoc, ValueDecl *D,
1108  bool RefersToEnlosingVariableOrCapture,
1109  const DeclarationNameInfo &NameInfo, NamedDecl *FoundD,
1110  const TemplateArgumentListInfo *TemplateArgs, QualType T,
1111  ExprValueKind VK);
1112 
1113  /// Construct an empty declaration reference expression.
1114  explicit DeclRefExpr(EmptyShell Empty) : Expr(DeclRefExprClass, Empty) {}
1115 
1116  /// Computes the type- and value-dependence flags for this
1117  /// declaration reference expression.
1118  void computeDependence(const ASTContext &Ctx);
1119 
1120 public:
1121  DeclRefExpr(const ASTContext &Ctx, ValueDecl *D,
1122  bool RefersToEnclosingVariableOrCapture, QualType T,
1124  const DeclarationNameLoc &LocInfo = DeclarationNameLoc());
1125 
1126  static DeclRefExpr *
1127  Create(const ASTContext &Context, NestedNameSpecifierLoc QualifierLoc,
1128  SourceLocation TemplateKWLoc, ValueDecl *D,
1129  bool RefersToEnclosingVariableOrCapture, SourceLocation NameLoc,
1130  QualType T, ExprValueKind VK, NamedDecl *FoundD = nullptr,
1131  const TemplateArgumentListInfo *TemplateArgs = nullptr);
1132 
1133  static DeclRefExpr *
1134  Create(const ASTContext &Context, NestedNameSpecifierLoc QualifierLoc,
1135  SourceLocation TemplateKWLoc, ValueDecl *D,
1136  bool RefersToEnclosingVariableOrCapture,
1137  const DeclarationNameInfo &NameInfo, QualType T, ExprValueKind VK,
1138  NamedDecl *FoundD = nullptr,
1139  const TemplateArgumentListInfo *TemplateArgs = nullptr);
1140 
1141  /// Construct an empty declaration reference expression.
1142  static DeclRefExpr *CreateEmpty(const ASTContext &Context, bool HasQualifier,
1143  bool HasFoundDecl,
1144  bool HasTemplateKWAndArgsInfo,
1145  unsigned NumTemplateArgs);
1146 
1147  ValueDecl *getDecl() { return D; }
1148  const ValueDecl *getDecl() const { return D; }
1149  void setDecl(ValueDecl *NewD) { D = NewD; }
1150 
1152  return DeclarationNameInfo(getDecl()->getDeclName(), getLocation(), DNLoc);
1153  }
1154 
1155  SourceLocation getLocation() const { return DeclRefExprBits.Loc; }
1156  void setLocation(SourceLocation L) { DeclRefExprBits.Loc = L; }
1157  SourceLocation getBeginLoc() const LLVM_READONLY;
1158  SourceLocation getEndLoc() const LLVM_READONLY;
1159 
1160  /// Determine whether this declaration reference was preceded by a
1161  /// C++ nested-name-specifier, e.g., \c N::foo.
1162  bool hasQualifier() const { return DeclRefExprBits.HasQualifier; }
1163 
1164  /// If the name was qualified, retrieves the nested-name-specifier
1165  /// that precedes the name, with source-location information.
1167  if (!hasQualifier())
1168  return NestedNameSpecifierLoc();
1169  return *getTrailingObjects<NestedNameSpecifierLoc>();
1170  }
1171 
1172  /// If the name was qualified, retrieves the nested-name-specifier
1173  /// that precedes the name. Otherwise, returns NULL.
1175  return getQualifierLoc().getNestedNameSpecifier();
1176  }
1177 
1178  /// Get the NamedDecl through which this reference occurred.
1179  ///
1180  /// This Decl may be different from the ValueDecl actually referred to in the
1181  /// presence of using declarations, etc. It always returns non-NULL, and may
1182  /// simple return the ValueDecl when appropriate.
1183 
1185  return hasFoundDecl() ? *getTrailingObjects<NamedDecl *>() : D;
1186  }
1187 
1188  /// Get the NamedDecl through which this reference occurred.
1189  /// See non-const variant.
1190  const NamedDecl *getFoundDecl() const {
1191  return hasFoundDecl() ? *getTrailingObjects<NamedDecl *>() : D;
1192  }
1193 
1195  return DeclRefExprBits.HasTemplateKWAndArgsInfo;
1196  }
1197 
1198  /// Retrieve the location of the template keyword preceding
1199  /// this name, if any.
1201  if (!hasTemplateKWAndArgsInfo())
1202  return SourceLocation();
1203  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->TemplateKWLoc;
1204  }
1205 
1206  /// Retrieve the location of the left angle bracket starting the
1207  /// explicit template argument list following the name, if any.
1209  if (!hasTemplateKWAndArgsInfo())
1210  return SourceLocation();
1211  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->LAngleLoc;
1212  }
1213 
1214  /// Retrieve the location of the right angle bracket ending the
1215  /// explicit template argument list following the name, if any.
1217  if (!hasTemplateKWAndArgsInfo())
1218  return SourceLocation();
1219  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->RAngleLoc;
1220  }
1221 
1222  /// Determines whether the name in this declaration reference
1223  /// was preceded by the template keyword.
1224  bool hasTemplateKeyword() const { return getTemplateKeywordLoc().isValid(); }
1225 
1226  /// Determines whether this declaration reference was followed by an
1227  /// explicit template argument list.
1228  bool hasExplicitTemplateArgs() const { return getLAngleLoc().isValid(); }
1229 
1230  /// Copies the template arguments (if present) into the given
1231  /// structure.
1233  if (hasExplicitTemplateArgs())
1234  getTrailingObjects<ASTTemplateKWAndArgsInfo>()->copyInto(
1235  getTrailingObjects<TemplateArgumentLoc>(), List);
1236  }
1237 
1238  /// Retrieve the template arguments provided as part of this
1239  /// template-id.
1241  if (!hasExplicitTemplateArgs())
1242  return nullptr;
1243  return getTrailingObjects<TemplateArgumentLoc>();
1244  }
1245 
1246  /// Retrieve the number of template arguments provided as part of this
1247  /// template-id.
1248  unsigned getNumTemplateArgs() const {
1249  if (!hasExplicitTemplateArgs())
1250  return 0;
1251  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->NumTemplateArgs;
1252  }
1253 
1255  return {getTemplateArgs(), getNumTemplateArgs()};
1256  }
1257 
1258  /// Returns true if this expression refers to a function that
1259  /// was resolved from an overloaded set having size greater than 1.
1260  bool hadMultipleCandidates() const {
1261  return DeclRefExprBits.HadMultipleCandidates;
1262  }
1263  /// Sets the flag telling whether this expression refers to
1264  /// a function that was resolved from an overloaded set having size
1265  /// greater than 1.
1266  void setHadMultipleCandidates(bool V = true) {
1267  DeclRefExprBits.HadMultipleCandidates = V;
1268  }
1269 
1270  /// Does this DeclRefExpr refer to an enclosing local or a captured
1271  /// variable?
1273  return DeclRefExprBits.RefersToEnclosingVariableOrCapture;
1274  }
1275 
1276  static bool classof(const Stmt *T) {
1277  return T->getStmtClass() == DeclRefExprClass;
1278  }
1279 
1280  // Iterators
1283  }
1284 
1287  }
1288 };
1289 
1290 /// Used by IntegerLiteral/FloatingLiteral to store the numeric without
1291 /// leaking memory.
1292 ///
1293 /// For large floats/integers, APFloat/APInt will allocate memory from the heap
1294 /// to represent these numbers. Unfortunately, when we use a BumpPtrAllocator
1295 /// to allocate IntegerLiteral/FloatingLiteral nodes the memory associated with
1296 /// the APFloat/APInt values will never get freed. APNumericStorage uses
1297 /// ASTContext's allocator for memory allocation.
1299  union {
1300  uint64_t VAL; ///< Used to store the <= 64 bits integer value.
1301  uint64_t *pVal; ///< Used to store the >64 bits integer value.
1302  };
1303  unsigned BitWidth;
1304 
1305  bool hasAllocation() const { return llvm::APInt::getNumWords(BitWidth) > 1; }
1306 
1307  APNumericStorage(const APNumericStorage &) = delete;
1308  void operator=(const APNumericStorage &) = delete;
1309 
1310 protected:
1311  APNumericStorage() : VAL(0), BitWidth(0) { }
1312 
1313  llvm::APInt getIntValue() const {
1314  unsigned NumWords = llvm::APInt::getNumWords(BitWidth);
1315  if (NumWords > 1)
1316  return llvm::APInt(BitWidth, NumWords, pVal);
1317  else
1318  return llvm::APInt(BitWidth, VAL);
1319  }
1320  void setIntValue(const ASTContext &C, const llvm::APInt &Val);
1321 };
1322 
1324 public:
1325  llvm::APInt getValue() const { return getIntValue(); }
1326  void setValue(const ASTContext &C, const llvm::APInt &Val) {
1327  setIntValue(C, Val);
1328  }
1329 };
1330 
1332 public:
1333  llvm::APFloat getValue(const llvm::fltSemantics &Semantics) const {
1334  return llvm::APFloat(Semantics, getIntValue());
1335  }
1336  void setValue(const ASTContext &C, const llvm::APFloat &Val) {
1337  setIntValue(C, Val.bitcastToAPInt());
1338  }
1339 };
1340 
1341 class IntegerLiteral : public Expr, public APIntStorage {
1342  SourceLocation Loc;
1343 
1344  /// Construct an empty integer literal.
1345  explicit IntegerLiteral(EmptyShell Empty)
1346  : Expr(IntegerLiteralClass, Empty) { }
1347 
1348 public:
1349  // type should be IntTy, LongTy, LongLongTy, UnsignedIntTy, UnsignedLongTy,
1350  // or UnsignedLongLongTy
1351  IntegerLiteral(const ASTContext &C, const llvm::APInt &V, QualType type,
1352  SourceLocation l);
1353 
1354  /// Returns a new integer literal with value 'V' and type 'type'.
1355  /// \param type - either IntTy, LongTy, LongLongTy, UnsignedIntTy,
1356  /// UnsignedLongTy, or UnsignedLongLongTy which should match the size of V
1357  /// \param V - the value that the returned integer literal contains.
1358  static IntegerLiteral *Create(const ASTContext &C, const llvm::APInt &V,
1359  QualType type, SourceLocation l);
1360  /// Returns a new empty integer literal.
1361  static IntegerLiteral *Create(const ASTContext &C, EmptyShell Empty);
1362 
1363  SourceLocation getBeginLoc() const LLVM_READONLY { return Loc; }
1364  SourceLocation getEndLoc() const LLVM_READONLY { return Loc; }
1365 
1366  /// Retrieve the location of the literal.
1367  SourceLocation getLocation() const { return Loc; }
1368 
1369  void setLocation(SourceLocation Location) { Loc = Location; }
1370 
1371  static bool classof(const Stmt *T) {
1372  return T->getStmtClass() == IntegerLiteralClass;
1373  }
1374 
1375  // Iterators
1378  }
1381  }
1382 };
1383 
1384 class FixedPointLiteral : public Expr, public APIntStorage {
1385  SourceLocation Loc;
1386  unsigned Scale;
1387 
1388  /// \brief Construct an empty integer literal.
1389  explicit FixedPointLiteral(EmptyShell Empty)
1390  : Expr(FixedPointLiteralClass, Empty) {}
1391 
1392  public:
1393  FixedPointLiteral(const ASTContext &C, const llvm::APInt &V, QualType type,
1394  SourceLocation l, unsigned Scale);
1395 
1396  // Store the int as is without any bit shifting.
1397  static FixedPointLiteral *CreateFromRawInt(const ASTContext &C,
1398  const llvm::APInt &V,
1399  QualType type, SourceLocation l,
1400  unsigned Scale);
1401 
1402  SourceLocation getBeginLoc() const LLVM_READONLY { return Loc; }
1403  SourceLocation getEndLoc() const LLVM_READONLY { return Loc; }
1404 
1405  /// \brief Retrieve the location of the literal.
1406  SourceLocation getLocation() const { return Loc; }
1407 
1408  void setLocation(SourceLocation Location) { Loc = Location; }
1409 
1410  static bool classof(const Stmt *T) {
1411  return T->getStmtClass() == FixedPointLiteralClass;
1412  }
1413 
1414  std::string getValueAsString(unsigned Radix) const;
1415 
1416  // Iterators
1419  }
1422  }
1423 };
1424 
1425 class CharacterLiteral : public Expr {
1426 public:
1432  UTF32
1433  };
1434 
1435 private:
1436  unsigned Value;
1437  SourceLocation Loc;
1438 public:
1439  // type should be IntTy
1441  SourceLocation l)
1442  : Expr(CharacterLiteralClass, type, VK_RValue, OK_Ordinary, false, false,
1443  false, false),
1444  Value(value), Loc(l) {
1445  CharacterLiteralBits.Kind = kind;
1446  }
1447 
1448  /// Construct an empty character literal.
1449  CharacterLiteral(EmptyShell Empty) : Expr(CharacterLiteralClass, Empty) { }
1450 
1451  SourceLocation getLocation() const { return Loc; }
1453  return static_cast<CharacterKind>(CharacterLiteralBits.Kind);
1454  }
1455 
1456  SourceLocation getBeginLoc() const LLVM_READONLY { return Loc; }
1457  SourceLocation getEndLoc() const LLVM_READONLY { return Loc; }
1458 
1459  unsigned getValue() const { return Value; }
1460 
1461  void setLocation(SourceLocation Location) { Loc = Location; }
1462  void setKind(CharacterKind kind) { CharacterLiteralBits.Kind = kind; }
1463  void setValue(unsigned Val) { Value = Val; }
1464 
1465  static bool classof(const Stmt *T) {
1466  return T->getStmtClass() == CharacterLiteralClass;
1467  }
1468 
1469  // Iterators
1472  }
1475  }
1476 };
1477 
1478 class FloatingLiteral : public Expr, private APFloatStorage {
1479  SourceLocation Loc;
1480 
1481  FloatingLiteral(const ASTContext &C, const llvm::APFloat &V, bool isexact,
1483 
1484  /// Construct an empty floating-point literal.
1485  explicit FloatingLiteral(const ASTContext &C, EmptyShell Empty);
1486 
1487 public:
1488  static FloatingLiteral *Create(const ASTContext &C, const llvm::APFloat &V,
1489  bool isexact, QualType Type, SourceLocation L);
1490  static FloatingLiteral *Create(const ASTContext &C, EmptyShell Empty);
1491 
1492  llvm::APFloat getValue() const {
1493  return APFloatStorage::getValue(getSemantics());
1494  }
1495  void setValue(const ASTContext &C, const llvm::APFloat &Val) {
1496  assert(&getSemantics() == &Val.getSemantics() && "Inconsistent semantics");
1497  APFloatStorage::setValue(C, Val);
1498  }
1499 
1500  /// Get a raw enumeration value representing the floating-point semantics of
1501  /// this literal (32-bit IEEE, x87, ...), suitable for serialisation.
1503  return static_cast<APFloatSemantics>(FloatingLiteralBits.Semantics);
1504  }
1505 
1506  /// Set the raw enumeration value representing the floating-point semantics of
1507  /// this literal (32-bit IEEE, x87, ...), suitable for serialisation.
1509  FloatingLiteralBits.Semantics = Sem;
1510  }
1511 
1512  /// Return the APFloat semantics this literal uses.
1513  const llvm::fltSemantics &getSemantics() const;
1514 
1515  /// Set the APFloat semantics this literal uses.
1516  void setSemantics(const llvm::fltSemantics &Sem);
1517 
1518  bool isExact() const { return FloatingLiteralBits.IsExact; }
1519  void setExact(bool E) { FloatingLiteralBits.IsExact = E; }
1520 
1521  /// getValueAsApproximateDouble - This returns the value as an inaccurate
1522  /// double. Note that this may cause loss of precision, but is useful for
1523  /// debugging dumps, etc.
1524  double getValueAsApproximateDouble() const;
1525 
1526  SourceLocation getLocation() const { return Loc; }
1527  void setLocation(SourceLocation L) { Loc = L; }
1528 
1529  SourceLocation getBeginLoc() const LLVM_READONLY { return Loc; }
1530  SourceLocation getEndLoc() const LLVM_READONLY { return Loc; }
1531 
1532  static bool classof(const Stmt *T) {
1533  return T->getStmtClass() == FloatingLiteralClass;
1534  }
1535 
1536  // Iterators
1539  }
1542  }
1543 };
1544 
1545 /// ImaginaryLiteral - We support imaginary integer and floating point literals,
1546 /// like "1.0i". We represent these as a wrapper around FloatingLiteral and
1547 /// IntegerLiteral classes. Instances of this class always have a Complex type
1548 /// whose element type matches the subexpression.
1549 ///
1550 class ImaginaryLiteral : public Expr {
1551  Stmt *Val;
1552 public:
1554  : Expr(ImaginaryLiteralClass, Ty, VK_RValue, OK_Ordinary, false, false,
1555  false, false),
1556  Val(val) {}
1557 
1558  /// Build an empty imaginary literal.
1560  : Expr(ImaginaryLiteralClass, Empty) { }
1561 
1562  const Expr *getSubExpr() const { return cast<Expr>(Val); }
1563  Expr *getSubExpr() { return cast<Expr>(Val); }
1564  void setSubExpr(Expr *E) { Val = E; }
1565 
1566  SourceLocation getBeginLoc() const LLVM_READONLY {
1567  return Val->getBeginLoc();
1568  }
1569  SourceLocation getEndLoc() const LLVM_READONLY { return Val->getEndLoc(); }
1570 
1571  static bool classof(const Stmt *T) {
1572  return T->getStmtClass() == ImaginaryLiteralClass;
1573  }
1574 
1575  // Iterators
1576  child_range children() { return child_range(&Val, &Val+1); }
1578  return const_child_range(&Val, &Val + 1);
1579  }
1580 };
1581 
1582 /// StringLiteral - This represents a string literal expression, e.g. "foo"
1583 /// or L"bar" (wide strings). The actual string data can be obtained with
1584 /// getBytes() and is NOT null-terminated. The length of the string data is
1585 /// determined by calling getByteLength().
1586 ///
1587 /// The C type for a string is always a ConstantArrayType. In C++, the char
1588 /// type is const qualified, in C it is not.
1589 ///
1590 /// Note that strings in C can be formed by concatenation of multiple string
1591 /// literal pptokens in translation phase #6. This keeps track of the locations
1592 /// of each of these pieces.
1593 ///
1594 /// Strings in C can also be truncated and extended by assigning into arrays,
1595 /// e.g. with constructs like:
1596 /// char X[2] = "foobar";
1597 /// In this case, getByteLength() will return 6, but the string literal will
1598 /// have type "char[2]".
1599 class StringLiteral final
1600  : public Expr,
1601  private llvm::TrailingObjects<StringLiteral, unsigned, SourceLocation,
1602  char> {
1603  friend class ASTStmtReader;
1604  friend TrailingObjects;
1605 
1606  /// StringLiteral is followed by several trailing objects. They are in order:
1607  ///
1608  /// * A single unsigned storing the length in characters of this string. The
1609  /// length in bytes is this length times the width of a single character.
1610  /// Always present and stored as a trailing objects because storing it in
1611  /// StringLiteral would increase the size of StringLiteral by sizeof(void *)
1612  /// due to alignment requirements. If you add some data to StringLiteral,
1613  /// consider moving it inside StringLiteral.
1614  ///
1615  /// * An array of getNumConcatenated() SourceLocation, one for each of the
1616  /// token this string is made of.
1617  ///
1618  /// * An array of getByteLength() char used to store the string data.
1619 
1620 public:
1621  enum StringKind { Ascii, Wide, UTF8, UTF16, UTF32 };
1622 
1623 private:
1624  unsigned numTrailingObjects(OverloadToken<unsigned>) const { return 1; }
1625  unsigned numTrailingObjects(OverloadToken<SourceLocation>) const {
1626  return getNumConcatenated();
1627  }
1628 
1629  unsigned numTrailingObjects(OverloadToken<char>) const {
1630  return getByteLength();
1631  }
1632 
1633  char *getStrDataAsChar() { return getTrailingObjects<char>(); }
1634  const char *getStrDataAsChar() const { return getTrailingObjects<char>(); }
1635 
1636  const uint16_t *getStrDataAsUInt16() const {
1637  return reinterpret_cast<const uint16_t *>(getTrailingObjects<char>());
1638  }
1639 
1640  const uint32_t *getStrDataAsUInt32() const {
1641  return reinterpret_cast<const uint32_t *>(getTrailingObjects<char>());
1642  }
1643 
1644  /// Build a string literal.
1645  StringLiteral(const ASTContext &Ctx, StringRef Str, StringKind Kind,
1646  bool Pascal, QualType Ty, const SourceLocation *Loc,
1647  unsigned NumConcatenated);
1648 
1649  /// Build an empty string literal.
1650  StringLiteral(EmptyShell Empty, unsigned NumConcatenated, unsigned Length,
1651  unsigned CharByteWidth);
1652 
1653  /// Map a target and string kind to the appropriate character width.
1654  static unsigned mapCharByteWidth(TargetInfo const &Target, StringKind SK);
1655 
1656  /// Set one of the string literal token.
1657  void setStrTokenLoc(unsigned TokNum, SourceLocation L) {
1658  assert(TokNum < getNumConcatenated() && "Invalid tok number");
1659  getTrailingObjects<SourceLocation>()[TokNum] = L;
1660  }
1661 
1662 public:
1663  /// This is the "fully general" constructor that allows representation of
1664  /// strings formed from multiple concatenated tokens.
1665  static StringLiteral *Create(const ASTContext &Ctx, StringRef Str,
1666  StringKind Kind, bool Pascal, QualType Ty,
1667  const SourceLocation *Loc,
1668  unsigned NumConcatenated);
1669 
1670  /// Simple constructor for string literals made from one token.
1671  static StringLiteral *Create(const ASTContext &Ctx, StringRef Str,
1672  StringKind Kind, bool Pascal, QualType Ty,
1673  SourceLocation Loc) {
1674  return Create(Ctx, Str, Kind, Pascal, Ty, &Loc, 1);
1675  }
1676 
1677  /// Construct an empty string literal.
1678  static StringLiteral *CreateEmpty(const ASTContext &Ctx,
1679  unsigned NumConcatenated, unsigned Length,
1680  unsigned CharByteWidth);
1681 
1682  StringRef getString() const {
1683  assert(getCharByteWidth() == 1 &&
1684  "This function is used in places that assume strings use char");
1685  return StringRef(getStrDataAsChar(), getByteLength());
1686  }
1687 
1688  /// Allow access to clients that need the byte representation, such as
1689  /// ASTWriterStmt::VisitStringLiteral().
1690  StringRef getBytes() const {
1691  // FIXME: StringRef may not be the right type to use as a result for this.
1692  return StringRef(getStrDataAsChar(), getByteLength());
1693  }
1694 
1695  void outputString(raw_ostream &OS) const;
1696 
1697  uint32_t getCodeUnit(size_t i) const {
1698  assert(i < getLength() && "out of bounds access");
1699  switch (getCharByteWidth()) {
1700  case 1:
1701  return static_cast<unsigned char>(getStrDataAsChar()[i]);
1702  case 2:
1703  return getStrDataAsUInt16()[i];
1704  case 4:
1705  return getStrDataAsUInt32()[i];
1706  }
1707  llvm_unreachable("Unsupported character width!");
1708  }
1709 
1710  unsigned getByteLength() const { return getCharByteWidth() * getLength(); }
1711  unsigned getLength() const { return *getTrailingObjects<unsigned>(); }
1712  unsigned getCharByteWidth() const { return StringLiteralBits.CharByteWidth; }
1713 
1715  return static_cast<StringKind>(StringLiteralBits.Kind);
1716  }
1717 
1718  bool isAscii() const { return getKind() == Ascii; }
1719  bool isWide() const { return getKind() == Wide; }
1720  bool isUTF8() const { return getKind() == UTF8; }
1721  bool isUTF16() const { return getKind() == UTF16; }
1722  bool isUTF32() const { return getKind() == UTF32; }
1723  bool isPascal() const { return StringLiteralBits.IsPascal; }
1724 
1725  bool containsNonAscii() const {
1726  for (auto c : getString())
1727  if (!isASCII(c))
1728  return true;
1729  return false;
1730  }
1731 
1732  bool containsNonAsciiOrNull() const {
1733  for (auto c : getString())
1734  if (!isASCII(c) || !c)
1735  return true;
1736  return false;
1737  }
1738 
1739  /// getNumConcatenated - Get the number of string literal tokens that were
1740  /// concatenated in translation phase #6 to form this string literal.
1741  unsigned getNumConcatenated() const {
1742  return StringLiteralBits.NumConcatenated;
1743  }
1744 
1745  /// Get one of the string literal token.
1746  SourceLocation getStrTokenLoc(unsigned TokNum) const {
1747  assert(TokNum < getNumConcatenated() && "Invalid tok number");
1748  return getTrailingObjects<SourceLocation>()[TokNum];
1749  }
1750 
1751  /// getLocationOfByte - Return a source location that points to the specified
1752  /// byte of this string literal.
1753  ///
1754  /// Strings are amazingly complex. They can be formed from multiple tokens
1755  /// and can have escape sequences in them in addition to the usual trigraph
1756  /// and escaped newline business. This routine handles this complexity.
1757  ///
1759  getLocationOfByte(unsigned ByteNo, const SourceManager &SM,
1760  const LangOptions &Features, const TargetInfo &Target,
1761  unsigned *StartToken = nullptr,
1762  unsigned *StartTokenByteOffset = nullptr) const;
1763 
1765 
1766  tokloc_iterator tokloc_begin() const {
1767  return getTrailingObjects<SourceLocation>();
1768  }
1769 
1770  tokloc_iterator tokloc_end() const {
1771  return getTrailingObjects<SourceLocation>() + getNumConcatenated();
1772  }
1773 
1774  SourceLocation getBeginLoc() const LLVM_READONLY { return *tokloc_begin(); }
1775  SourceLocation getEndLoc() const LLVM_READONLY { return *(tokloc_end() - 1); }
1776 
1777  static bool classof(const Stmt *T) {
1778  return T->getStmtClass() == StringLiteralClass;
1779  }
1780 
1781  // Iterators
1784  }
1787  }
1788 };
1789 
1790 /// [C99 6.4.2.2] - A predefined identifier such as __func__.
1791 class PredefinedExpr final
1792  : public Expr,
1793  private llvm::TrailingObjects<PredefinedExpr, Stmt *> {
1794  friend class ASTStmtReader;
1795  friend TrailingObjects;
1796 
1797  // PredefinedExpr is optionally followed by a single trailing
1798  // "Stmt *" for the predefined identifier. It is present if and only if
1799  // hasFunctionName() is true and is always a "StringLiteral *".
1800 
1801 public:
1802  enum IdentKind {
1805  LFunction, // Same as Function, but as wide string.
1808  LFuncSig, // Same as FuncSig, but as as wide string
1810  /// The same as PrettyFunction, except that the
1811  /// 'virtual' keyword is omitted for virtual member functions.
1812  PrettyFunctionNoVirtual
1813  };
1814 
1815 private:
1817  StringLiteral *SL);
1818 
1819  explicit PredefinedExpr(EmptyShell Empty, bool HasFunctionName);
1820 
1821  /// True if this PredefinedExpr has storage for a function name.
1822  bool hasFunctionName() const { return PredefinedExprBits.HasFunctionName; }
1823 
1824  void setFunctionName(StringLiteral *SL) {
1825  assert(hasFunctionName() &&
1826  "This PredefinedExpr has no storage for a function name!");
1827  *getTrailingObjects<Stmt *>() = SL;
1828  }
1829 
1830 public:
1831  /// Create a PredefinedExpr.
1832  static PredefinedExpr *Create(const ASTContext &Ctx, SourceLocation L,
1833  QualType FNTy, IdentKind IK, StringLiteral *SL);
1834 
1835  /// Create an empty PredefinedExpr.
1836  static PredefinedExpr *CreateEmpty(const ASTContext &Ctx,
1837  bool HasFunctionName);
1838 
1840  return static_cast<IdentKind>(PredefinedExprBits.Kind);
1841  }
1842 
1843  SourceLocation getLocation() const { return PredefinedExprBits.Loc; }
1844  void setLocation(SourceLocation L) { PredefinedExprBits.Loc = L; }
1845 
1847  return hasFunctionName()
1848  ? static_cast<StringLiteral *>(*getTrailingObjects<Stmt *>())
1849  : nullptr;
1850  }
1851 
1853  return hasFunctionName()
1854  ? static_cast<StringLiteral *>(*getTrailingObjects<Stmt *>())
1855  : nullptr;
1856  }
1857 
1858  static StringRef getIdentKindName(IdentKind IK);
1859  static std::string ComputeName(IdentKind IK, const Decl *CurrentDecl);
1860 
1861  SourceLocation getBeginLoc() const { return getLocation(); }
1862  SourceLocation getEndLoc() const { return getLocation(); }
1863 
1864  static bool classof(const Stmt *T) {
1865  return T->getStmtClass() == PredefinedExprClass;
1866  }
1867 
1868  // Iterators
1870  return child_range(getTrailingObjects<Stmt *>(),
1871  getTrailingObjects<Stmt *>() + hasFunctionName());
1872  }
1873 };
1874 
1875 /// ParenExpr - This represents a parethesized expression, e.g. "(1)". This
1876 /// AST node is only formed if full location information is requested.
1877 class ParenExpr : public Expr {
1878  SourceLocation L, R;
1879  Stmt *Val;
1880 public:
1882  : Expr(ParenExprClass, val->getType(),
1883  val->getValueKind(), val->getObjectKind(),
1884  val->isTypeDependent(), val->isValueDependent(),
1885  val->isInstantiationDependent(),
1886  val->containsUnexpandedParameterPack()),
1887  L(l), R(r), Val(val) {}
1888 
1889  /// Construct an empty parenthesized expression.
1890  explicit ParenExpr(EmptyShell Empty)
1891  : Expr(ParenExprClass, Empty) { }
1892 
1893  const Expr *getSubExpr() const { return cast<Expr>(Val); }
1894  Expr *getSubExpr() { return cast<Expr>(Val); }
1895  void setSubExpr(Expr *E) { Val = E; }
1896 
1897  SourceLocation getBeginLoc() const LLVM_READONLY { return L; }
1898  SourceLocation getEndLoc() const LLVM_READONLY { return R; }
1899 
1900  /// Get the location of the left parentheses '('.
1901  SourceLocation getLParen() const { return L; }
1902  void setLParen(SourceLocation Loc) { L = Loc; }
1903 
1904  /// Get the location of the right parentheses ')'.
1905  SourceLocation getRParen() const { return R; }
1906  void setRParen(SourceLocation Loc) { R = Loc; }
1907 
1908  static bool classof(const Stmt *T) {
1909  return T->getStmtClass() == ParenExprClass;
1910  }
1911 
1912  // Iterators
1913  child_range children() { return child_range(&Val, &Val+1); }
1915  return const_child_range(&Val, &Val + 1);
1916  }
1917 };
1918 
1919 /// UnaryOperator - This represents the unary-expression's (except sizeof and
1920 /// alignof), the postinc/postdec operators from postfix-expression, and various
1921 /// extensions.
1922 ///
1923 /// Notes on various nodes:
1924 ///
1925 /// Real/Imag - These return the real/imag part of a complex operand. If
1926 /// applied to a non-complex value, the former returns its operand and the
1927 /// later returns zero in the type of the operand.
1928 ///
1929 class UnaryOperator : public Expr {
1930  Stmt *Val;
1931 
1932 public:
1934 
1935  UnaryOperator(Expr *input, Opcode opc, QualType type, ExprValueKind VK,
1936  ExprObjectKind OK, SourceLocation l, bool CanOverflow)
1937  : Expr(UnaryOperatorClass, type, VK, OK,
1938  input->isTypeDependent() || type->isDependentType(),
1939  input->isValueDependent(),
1940  (input->isInstantiationDependent() ||
1941  type->isInstantiationDependentType()),
1942  input->containsUnexpandedParameterPack()),
1943  Val(input) {
1944  UnaryOperatorBits.Opc = opc;
1945  UnaryOperatorBits.CanOverflow = CanOverflow;
1946  UnaryOperatorBits.Loc = l;
1947  }
1948 
1949  /// Build an empty unary operator.
1950  explicit UnaryOperator(EmptyShell Empty) : Expr(UnaryOperatorClass, Empty) {
1951  UnaryOperatorBits.Opc = UO_AddrOf;
1952  }
1953 
1954  Opcode getOpcode() const {
1955  return static_cast<Opcode>(UnaryOperatorBits.Opc);
1956  }
1957  void setOpcode(Opcode Opc) { UnaryOperatorBits.Opc = Opc; }
1958 
1959  Expr *getSubExpr() const { return cast<Expr>(Val); }
1960  void setSubExpr(Expr *E) { Val = E; }
1961 
1962  /// getOperatorLoc - Return the location of the operator.
1963  SourceLocation getOperatorLoc() const { return UnaryOperatorBits.Loc; }
1964  void setOperatorLoc(SourceLocation L) { UnaryOperatorBits.Loc = L; }
1965 
1966  /// Returns true if the unary operator can cause an overflow. For instance,
1967  /// signed int i = INT_MAX; i++;
1968  /// signed char c = CHAR_MAX; c++;
1969  /// Due to integer promotions, c++ is promoted to an int before the postfix
1970  /// increment, and the result is an int that cannot overflow. However, i++
1971  /// can overflow.
1972  bool canOverflow() const { return UnaryOperatorBits.CanOverflow; }
1973  void setCanOverflow(bool C) { UnaryOperatorBits.CanOverflow = C; }
1974 
1975  /// isPostfix - Return true if this is a postfix operation, like x++.
1976  static bool isPostfix(Opcode Op) {
1977  return Op == UO_PostInc || Op == UO_PostDec;
1978  }
1979 
1980  /// isPrefix - Return true if this is a prefix operation, like --x.
1981  static bool isPrefix(Opcode Op) {
1982  return Op == UO_PreInc || Op == UO_PreDec;
1983  }
1984 
1985  bool isPrefix() const { return isPrefix(getOpcode()); }
1986  bool isPostfix() const { return isPostfix(getOpcode()); }
1987 
1988  static bool isIncrementOp(Opcode Op) {
1989  return Op == UO_PreInc || Op == UO_PostInc;
1990  }
1991  bool isIncrementOp() const {
1992  return isIncrementOp(getOpcode());
1993  }
1994 
1995  static bool isDecrementOp(Opcode Op) {
1996  return Op == UO_PreDec || Op == UO_PostDec;
1997  }
1998  bool isDecrementOp() const {
1999  return isDecrementOp(getOpcode());
2000  }
2001 
2002  static bool isIncrementDecrementOp(Opcode Op) { return Op <= UO_PreDec; }
2003  bool isIncrementDecrementOp() const {
2004  return isIncrementDecrementOp(getOpcode());
2005  }
2006 
2007  static bool isArithmeticOp(Opcode Op) {
2008  return Op >= UO_Plus && Op <= UO_LNot;
2009  }
2010  bool isArithmeticOp() const { return isArithmeticOp(getOpcode()); }
2011 
2012  /// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
2013  /// corresponds to, e.g. "sizeof" or "[pre]++"
2014  static StringRef getOpcodeStr(Opcode Op);
2015 
2016  /// Retrieve the unary opcode that corresponds to the given
2017  /// overloaded operator.
2018  static Opcode getOverloadedOpcode(OverloadedOperatorKind OO, bool Postfix);
2019 
2020  /// Retrieve the overloaded operator kind that corresponds to
2021  /// the given unary opcode.
2022  static OverloadedOperatorKind getOverloadedOperator(Opcode Opc);
2023 
2024  SourceLocation getBeginLoc() const LLVM_READONLY {
2025  return isPostfix() ? Val->getBeginLoc() : getOperatorLoc();
2026  }
2027  SourceLocation getEndLoc() const LLVM_READONLY {
2028  return isPostfix() ? getOperatorLoc() : Val->getEndLoc();
2029  }
2030  SourceLocation getExprLoc() const { return getOperatorLoc(); }
2031 
2032  static bool classof(const Stmt *T) {
2033  return T->getStmtClass() == UnaryOperatorClass;
2034  }
2035 
2036  // Iterators
2037  child_range children() { return child_range(&Val, &Val+1); }
2039  return const_child_range(&Val, &Val + 1);
2040  }
2041 };
2042 
2043 /// Helper class for OffsetOfExpr.
2044 
2045 // __builtin_offsetof(type, identifier(.identifier|[expr])*)
2047 public:
2048  /// The kind of offsetof node we have.
2049  enum Kind {
2050  /// An index into an array.
2051  Array = 0x00,
2052  /// A field.
2053  Field = 0x01,
2054  /// A field in a dependent type, known only by its name.
2055  Identifier = 0x02,
2056  /// An implicit indirection through a C++ base class, when the
2057  /// field found is in a base class.
2058  Base = 0x03
2059  };
2060 
2061 private:
2062  enum { MaskBits = 2, Mask = 0x03 };
2063 
2064  /// The source range that covers this part of the designator.
2065  SourceRange Range;
2066 
2067  /// The data describing the designator, which comes in three
2068  /// different forms, depending on the lower two bits.
2069  /// - An unsigned index into the array of Expr*'s stored after this node
2070  /// in memory, for [constant-expression] designators.
2071  /// - A FieldDecl*, for references to a known field.
2072  /// - An IdentifierInfo*, for references to a field with a given name
2073  /// when the class type is dependent.
2074  /// - A CXXBaseSpecifier*, for references that look at a field in a
2075  /// base class.
2076  uintptr_t Data;
2077 
2078 public:
2079  /// Create an offsetof node that refers to an array element.
2080  OffsetOfNode(SourceLocation LBracketLoc, unsigned Index,
2081  SourceLocation RBracketLoc)
2082  : Range(LBracketLoc, RBracketLoc), Data((Index << 2) | Array) {}
2083 
2084  /// Create an offsetof node that refers to a field.
2086  : Range(DotLoc.isValid() ? DotLoc : NameLoc, NameLoc),
2087  Data(reinterpret_cast<uintptr_t>(Field) | OffsetOfNode::Field) {}
2088 
2089  /// Create an offsetof node that refers to an identifier.
2091  SourceLocation NameLoc)
2092  : Range(DotLoc.isValid() ? DotLoc : NameLoc, NameLoc),
2093  Data(reinterpret_cast<uintptr_t>(Name) | Identifier) {}
2094 
2095  /// Create an offsetof node that refers into a C++ base class.
2097  : Range(), Data(reinterpret_cast<uintptr_t>(Base) | OffsetOfNode::Base) {}
2098 
2099  /// Determine what kind of offsetof node this is.
2100  Kind getKind() const { return static_cast<Kind>(Data & Mask); }
2101 
2102  /// For an array element node, returns the index into the array
2103  /// of expressions.
2104  unsigned getArrayExprIndex() const {
2105  assert(getKind() == Array);
2106  return Data >> 2;
2107  }
2108 
2109  /// For a field offsetof node, returns the field.
2110  FieldDecl *getField() const {
2111  assert(getKind() == Field);
2112  return reinterpret_cast<FieldDecl *>(Data & ~(uintptr_t)Mask);
2113  }
2114 
2115  /// For a field or identifier offsetof node, returns the name of
2116  /// the field.
2117  IdentifierInfo *getFieldName() const;
2118 
2119  /// For a base class node, returns the base specifier.
2121  assert(getKind() == Base);
2122  return reinterpret_cast<CXXBaseSpecifier *>(Data & ~(uintptr_t)Mask);
2123  }
2124 
2125  /// Retrieve the source range that covers this offsetof node.
2126  ///
2127  /// For an array element node, the source range contains the locations of
2128  /// the square brackets. For a field or identifier node, the source range
2129  /// contains the location of the period (if there is one) and the
2130  /// identifier.
2131  SourceRange getSourceRange() const LLVM_READONLY { return Range; }
2132  SourceLocation getBeginLoc() const LLVM_READONLY { return Range.getBegin(); }
2133  SourceLocation getEndLoc() const LLVM_READONLY { return Range.getEnd(); }
2134 };
2135 
2136 /// OffsetOfExpr - [C99 7.17] - This represents an expression of the form
2137 /// offsetof(record-type, member-designator). For example, given:
2138 /// @code
2139 /// struct S {
2140 /// float f;
2141 /// double d;
2142 /// };
2143 /// struct T {
2144 /// int i;
2145 /// struct S s[10];
2146 /// };
2147 /// @endcode
2148 /// we can represent and evaluate the expression @c offsetof(struct T, s[2].d).
2149 
2150 class OffsetOfExpr final
2151  : public Expr,
2152  private llvm::TrailingObjects<OffsetOfExpr, OffsetOfNode, Expr *> {
2153  SourceLocation OperatorLoc, RParenLoc;
2154  // Base type;
2155  TypeSourceInfo *TSInfo;
2156  // Number of sub-components (i.e. instances of OffsetOfNode).
2157  unsigned NumComps;
2158  // Number of sub-expressions (i.e. array subscript expressions).
2159  unsigned NumExprs;
2160 
2161  size_t numTrailingObjects(OverloadToken<OffsetOfNode>) const {
2162  return NumComps;
2163  }
2164 
2166  SourceLocation OperatorLoc, TypeSourceInfo *tsi,
2168  SourceLocation RParenLoc);
2169 
2170  explicit OffsetOfExpr(unsigned numComps, unsigned numExprs)
2171  : Expr(OffsetOfExprClass, EmptyShell()),
2172  TSInfo(nullptr), NumComps(numComps), NumExprs(numExprs) {}
2173 
2174 public:
2175 
2176  static OffsetOfExpr *Create(const ASTContext &C, QualType type,
2177  SourceLocation OperatorLoc, TypeSourceInfo *tsi,
2178  ArrayRef<OffsetOfNode> comps,
2179  ArrayRef<Expr*> exprs, SourceLocation RParenLoc);
2180 
2181  static OffsetOfExpr *CreateEmpty(const ASTContext &C,
2182  unsigned NumComps, unsigned NumExprs);
2183 
2184  /// getOperatorLoc - Return the location of the operator.
2185  SourceLocation getOperatorLoc() const { return OperatorLoc; }
2186  void setOperatorLoc(SourceLocation L) { OperatorLoc = L; }
2187 
2188  /// Return the location of the right parentheses.
2189  SourceLocation getRParenLoc() const { return RParenLoc; }
2190  void setRParenLoc(SourceLocation R) { RParenLoc = R; }
2191 
2193  return TSInfo;
2194  }
2196  TSInfo = tsi;
2197  }
2198 
2199  const OffsetOfNode &getComponent(unsigned Idx) const {
2200  assert(Idx < NumComps && "Subscript out of range");
2201  return getTrailingObjects<OffsetOfNode>()[Idx];
2202  }
2203 
2204  void setComponent(unsigned Idx, OffsetOfNode ON) {
2205  assert(Idx < NumComps && "Subscript out of range");
2206  getTrailingObjects<OffsetOfNode>()[Idx] = ON;
2207  }
2208 
2209  unsigned getNumComponents() const {
2210  return NumComps;
2211  }
2212 
2213  Expr* getIndexExpr(unsigned Idx) {
2214  assert(Idx < NumExprs && "Subscript out of range");
2215  return getTrailingObjects<Expr *>()[Idx];
2216  }
2217 
2218  const Expr *getIndexExpr(unsigned Idx) const {
2219  assert(Idx < NumExprs && "Subscript out of range");
2220  return getTrailingObjects<Expr *>()[Idx];
2221  }
2222 
2223  void setIndexExpr(unsigned Idx, Expr* E) {
2224  assert(Idx < NumComps && "Subscript out of range");
2225  getTrailingObjects<Expr *>()[Idx] = E;
2226  }
2227 
2228  unsigned getNumExpressions() const {
2229  return NumExprs;
2230  }
2231 
2232  SourceLocation getBeginLoc() const LLVM_READONLY { return OperatorLoc; }
2233  SourceLocation getEndLoc() const LLVM_READONLY { return RParenLoc; }
2234 
2235  static bool classof(const Stmt *T) {
2236  return T->getStmtClass() == OffsetOfExprClass;
2237  }
2238 
2239  // Iterators
2241  Stmt **begin = reinterpret_cast<Stmt **>(getTrailingObjects<Expr *>());
2242  return child_range(begin, begin + NumExprs);
2243  }
2245  Stmt *const *begin =
2246  reinterpret_cast<Stmt *const *>(getTrailingObjects<Expr *>());
2247  return const_child_range(begin, begin + NumExprs);
2248  }
2250 };
2251 
2252 /// UnaryExprOrTypeTraitExpr - expression with either a type or (unevaluated)
2253 /// expression operand. Used for sizeof/alignof (C99 6.5.3.4) and
2254 /// vec_step (OpenCL 1.1 6.11.12).
2256  union {
2259  } Argument;
2260  SourceLocation OpLoc, RParenLoc;
2261 
2262 public:
2264  QualType resultType, SourceLocation op,
2265  SourceLocation rp) :
2266  Expr(UnaryExprOrTypeTraitExprClass, resultType, VK_RValue, OK_Ordinary,
2267  false, // Never type-dependent (C++ [temp.dep.expr]p3).
2268  // Value-dependent if the argument is type-dependent.
2269  TInfo->getType()->isDependentType(),
2270  TInfo->getType()->isInstantiationDependentType(),
2271  TInfo->getType()->containsUnexpandedParameterPack()),
2272  OpLoc(op), RParenLoc(rp) {
2273  UnaryExprOrTypeTraitExprBits.Kind = ExprKind;
2274  UnaryExprOrTypeTraitExprBits.IsType = true;
2275  Argument.Ty = TInfo;
2276  }
2277 
2279  QualType resultType, SourceLocation op,
2280  SourceLocation rp);
2281 
2282  /// Construct an empty sizeof/alignof expression.
2284  : Expr(UnaryExprOrTypeTraitExprClass, Empty) { }
2285 
2287  return static_cast<UnaryExprOrTypeTrait>(UnaryExprOrTypeTraitExprBits.Kind);
2288  }
2289  void setKind(UnaryExprOrTypeTrait K) { UnaryExprOrTypeTraitExprBits.Kind = K;}
2290 
2291  bool isArgumentType() const { return UnaryExprOrTypeTraitExprBits.IsType; }
2293  return getArgumentTypeInfo()->getType();
2294  }
2296  assert(isArgumentType() && "calling getArgumentType() when arg is expr");
2297  return Argument.Ty;
2298  }
2300  assert(!isArgumentType() && "calling getArgumentExpr() when arg is type");
2301  return static_cast<Expr*>(Argument.Ex);
2302  }
2303  const Expr *getArgumentExpr() const {
2304  return const_cast<UnaryExprOrTypeTraitExpr*>(this)->getArgumentExpr();
2305  }
2306 
2307  void setArgument(Expr *E) {
2308  Argument.Ex = E;
2309  UnaryExprOrTypeTraitExprBits.IsType = false;
2310  }
2312  Argument.Ty = TInfo;
2313  UnaryExprOrTypeTraitExprBits.IsType = true;
2314  }
2315 
2316  /// Gets the argument type, or the type of the argument expression, whichever
2317  /// is appropriate.
2319  return isArgumentType() ? getArgumentType() : getArgumentExpr()->getType();
2320  }
2321 
2322  SourceLocation getOperatorLoc() const { return OpLoc; }
2323  void setOperatorLoc(SourceLocation L) { OpLoc = L; }
2324 
2325  SourceLocation getRParenLoc() const { return RParenLoc; }
2326  void setRParenLoc(SourceLocation L) { RParenLoc = L; }
2327 
2328  SourceLocation getBeginLoc() const LLVM_READONLY { return OpLoc; }
2329  SourceLocation getEndLoc() const LLVM_READONLY { return RParenLoc; }
2330 
2331  static bool classof(const Stmt *T) {
2332  return T->getStmtClass() == UnaryExprOrTypeTraitExprClass;
2333  }
2334 
2335  // Iterators
2337  const_child_range children() const;
2338 };
2339 
2340 //===----------------------------------------------------------------------===//
2341 // Postfix Operators.
2342 //===----------------------------------------------------------------------===//
2343 
2344 /// ArraySubscriptExpr - [C99 6.5.2.1] Array Subscripting.
2345 class ArraySubscriptExpr : public Expr {
2346  enum { LHS, RHS, END_EXPR };
2347  Stmt *SubExprs[END_EXPR];
2348 
2349  bool lhsIsBase() const { return getRHS()->getType()->isIntegerType(); }
2350 
2351 public:
2354  SourceLocation rbracketloc)
2355  : Expr(ArraySubscriptExprClass, t, VK, OK,
2356  lhs->isTypeDependent() || rhs->isTypeDependent(),
2357  lhs->isValueDependent() || rhs->isValueDependent(),
2358  (lhs->isInstantiationDependent() ||
2359  rhs->isInstantiationDependent()),
2360  (lhs->containsUnexpandedParameterPack() ||
2361  rhs->containsUnexpandedParameterPack())) {
2362  SubExprs[LHS] = lhs;
2363  SubExprs[RHS] = rhs;
2364  ArraySubscriptExprBits.RBracketLoc = rbracketloc;
2365  }
2366 
2367  /// Create an empty array subscript expression.
2369  : Expr(ArraySubscriptExprClass, Shell) { }
2370 
2371  /// An array access can be written A[4] or 4[A] (both are equivalent).
2372  /// - getBase() and getIdx() always present the normalized view: A[4].
2373  /// In this case getBase() returns "A" and getIdx() returns "4".
2374  /// - getLHS() and getRHS() present the syntactic view. e.g. for
2375  /// 4[A] getLHS() returns "4".
2376  /// Note: Because vector element access is also written A[4] we must
2377  /// predicate the format conversion in getBase and getIdx only on the
2378  /// the type of the RHS, as it is possible for the LHS to be a vector of
2379  /// integer type
2380  Expr *getLHS() { return cast<Expr>(SubExprs[LHS]); }
2381  const Expr *getLHS() const { return cast<Expr>(SubExprs[LHS]); }
2382  void setLHS(Expr *E) { SubExprs[LHS] = E; }
2383 
2384  Expr *getRHS() { return cast<Expr>(SubExprs[RHS]); }
2385  const Expr *getRHS() const { return cast<Expr>(SubExprs[RHS]); }
2386  void setRHS(Expr *E) { SubExprs[RHS] = E; }
2387 
2388  Expr *getBase() { return lhsIsBase() ? getLHS() : getRHS(); }
2389  const Expr *getBase() const { return lhsIsBase() ? getLHS() : getRHS(); }
2390 
2391  Expr *getIdx() { return lhsIsBase() ? getRHS() : getLHS(); }
2392  const Expr *getIdx() const { return lhsIsBase() ? getRHS() : getLHS(); }
2393 
2394  SourceLocation getBeginLoc() const LLVM_READONLY {
2395  return getLHS()->getBeginLoc();
2396  }
2397  SourceLocation getEndLoc() const { return getRBracketLoc(); }
2398 
2400  return ArraySubscriptExprBits.RBracketLoc;
2401  }
2403  ArraySubscriptExprBits.RBracketLoc = L;
2404  }
2405 
2406  SourceLocation getExprLoc() const LLVM_READONLY {
2407  return getBase()->getExprLoc();
2408  }
2409 
2410  static bool classof(const Stmt *T) {
2411  return T->getStmtClass() == ArraySubscriptExprClass;
2412  }
2413 
2414  // Iterators
2416  return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
2417  }
2419  return const_child_range(&SubExprs[0], &SubExprs[0] + END_EXPR);
2420  }
2421 };
2422 
2423 /// CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
2424 /// CallExpr itself represents a normal function call, e.g., "f(x, 2)",
2425 /// while its subclasses may represent alternative syntax that (semantically)
2426 /// results in a function call. For example, CXXOperatorCallExpr is
2427 /// a subclass for overloaded operator calls that use operator syntax, e.g.,
2428 /// "str1 + str2" to resolve to a function call.
2429 class CallExpr : public Expr {
2430  enum { FN = 0, PREARGS_START = 1 };
2431 
2432  /// The number of arguments in the call expression.
2433  unsigned NumArgs;
2434 
2435  /// The location of the right parenthese. This has a different meaning for
2436  /// the derived classes of CallExpr.
2437  SourceLocation RParenLoc;
2438 
2439  void updateDependenciesFromArg(Expr *Arg);
2440 
2441  // CallExpr store some data in trailing objects. However since CallExpr
2442  // is used a base of other expression classes we cannot use
2443  // llvm::TrailingObjects. Instead we manually perform the pointer arithmetic
2444  // and casts.
2445  //
2446  // The trailing objects are in order:
2447  //
2448  // * A single "Stmt *" for the callee expression.
2449  //
2450  // * An array of getNumPreArgs() "Stmt *" for the pre-argument expressions.
2451  //
2452  // * An array of getNumArgs() "Stmt *" for the argument expressions.
2453  //
2454  // Note that we store the offset in bytes from the this pointer to the start
2455  // of the trailing objects. It would be perfectly possible to compute it
2456  // based on the dynamic kind of the CallExpr. However 1.) we have plenty of
2457  // space in the bit-fields of Stmt. 2.) It was benchmarked to be faster to
2458  // compute this once and then load the offset from the bit-fields of Stmt,
2459  // instead of re-computing the offset each time the trailing objects are
2460  // accessed.
2461 
2462  /// Return a pointer to the start of the trailing array of "Stmt *".
2463  Stmt **getTrailingStmts() {
2464  return reinterpret_cast<Stmt **>(reinterpret_cast<char *>(this) +
2465  CallExprBits.OffsetToTrailingObjects);
2466  }
2467  Stmt *const *getTrailingStmts() const {
2468  return const_cast<CallExpr *>(this)->getTrailingStmts();
2469  }
2470 
2471  /// Map a statement class to the appropriate offset in bytes from the
2472  /// this pointer to the trailing objects.
2473  static unsigned offsetToTrailingObjects(StmtClass SC);
2474 
2475 public:
2476  enum class ADLCallKind : bool { NotADL, UsesADL };
2477  static constexpr ADLCallKind NotADL = ADLCallKind::NotADL;
2478  static constexpr ADLCallKind UsesADL = ADLCallKind::UsesADL;
2479 
2480 protected:
2481  /// Build a call expression, assuming that appropriate storage has been
2482  /// allocated for the trailing objects.
2483  CallExpr(StmtClass SC, Expr *Fn, ArrayRef<Expr *> PreArgs,
2485  SourceLocation RParenLoc, unsigned MinNumArgs, ADLCallKind UsesADL);
2486 
2487  /// Build an empty call expression, for deserialization.
2488  CallExpr(StmtClass SC, unsigned NumPreArgs, unsigned NumArgs,
2489  EmptyShell Empty);
2490 
2491  /// Return the size in bytes needed for the trailing objects.
2492  /// Used by the derived classes to allocate the right amount of storage.
2493  static unsigned sizeOfTrailingObjects(unsigned NumPreArgs, unsigned NumArgs) {
2494  return (1 + NumPreArgs + NumArgs) * sizeof(Stmt *);
2495  }
2496 
2497  Stmt *getPreArg(unsigned I) {
2498  assert(I < getNumPreArgs() && "Prearg access out of range!");
2499  return getTrailingStmts()[PREARGS_START + I];
2500  }
2501  const Stmt *getPreArg(unsigned I) const {
2502  assert(I < getNumPreArgs() && "Prearg access out of range!");
2503  return getTrailingStmts()[PREARGS_START + I];
2504  }
2505  void setPreArg(unsigned I, Stmt *PreArg) {
2506  assert(I < getNumPreArgs() && "Prearg access out of range!");
2507  getTrailingStmts()[PREARGS_START + I] = PreArg;
2508  }
2509 
2510  unsigned getNumPreArgs() const { return CallExprBits.NumPreArgs; }
2511 
2512 public:
2513  /// Create a call expression. Fn is the callee expression, Args is the
2514  /// argument array, Ty is the type of the call expression (which is *not*
2515  /// the return type in general), VK is the value kind of the call expression
2516  /// (lvalue, rvalue, ...), and RParenLoc is the location of the right
2517  /// parenthese in the call expression. MinNumArgs specifies the minimum
2518  /// number of arguments. The actual number of arguments will be the greater
2519  /// of Args.size() and MinNumArgs. This is used in a few places to allocate
2520  /// enough storage for the default arguments. UsesADL specifies whether the
2521  /// callee was found through argument-dependent lookup.
2522  ///
2523  /// Note that you can use CreateTemporary if you need a temporary call
2524  /// expression on the stack.
2525  static CallExpr *Create(const ASTContext &Ctx, Expr *Fn,
2527  SourceLocation RParenLoc, unsigned MinNumArgs = 0,
2528  ADLCallKind UsesADL = NotADL);
2529 
2530  /// Create a temporary call expression with no arguments in the memory
2531  /// pointed to by Mem. Mem must points to at least sizeof(CallExpr)
2532  /// + sizeof(Stmt *) bytes of storage, aligned to alignof(CallExpr):
2533  ///
2534  /// \code{.cpp}
2535  /// llvm::AlignedCharArray<alignof(CallExpr),
2536  /// sizeof(CallExpr) + sizeof(Stmt *)> Buffer;
2537  /// CallExpr *TheCall = CallExpr::CreateTemporary(Buffer.buffer, etc);
2538  /// \endcode
2539  static CallExpr *CreateTemporary(void *Mem, Expr *Fn, QualType Ty,
2540  ExprValueKind VK, SourceLocation RParenLoc,
2541  ADLCallKind UsesADL = NotADL);
2542 
2543  /// Create an empty call expression, for deserialization.
2544  static CallExpr *CreateEmpty(const ASTContext &Ctx, unsigned NumArgs,
2545  EmptyShell Empty);
2546 
2547  Expr *getCallee() { return cast<Expr>(getTrailingStmts()[FN]); }
2548  const Expr *getCallee() const { return cast<Expr>(getTrailingStmts()[FN]); }
2549  void setCallee(Expr *F) { getTrailingStmts()[FN] = F; }
2550 
2552  return static_cast<ADLCallKind>(CallExprBits.UsesADL);
2553  }
2554  void setADLCallKind(ADLCallKind V = UsesADL) {
2555  CallExprBits.UsesADL = static_cast<bool>(V);
2556  }
2557  bool usesADL() const { return getADLCallKind() == UsesADL; }
2558 
2559  Decl *getCalleeDecl() { return getCallee()->getReferencedDeclOfCallee(); }
2560  const Decl *getCalleeDecl() const {
2561  return getCallee()->getReferencedDeclOfCallee();
2562  }
2563 
2564  /// If the callee is a FunctionDecl, return it. Otherwise return null.
2566  return dyn_cast_or_null<FunctionDecl>(getCalleeDecl());
2567  }
2569  return dyn_cast_or_null<FunctionDecl>(getCalleeDecl());
2570  }
2571 
2572  /// getNumArgs - Return the number of actual arguments to this call.
2573  unsigned getNumArgs() const { return NumArgs; }
2574 
2575  /// Retrieve the call arguments.
2577  return reinterpret_cast<Expr **>(getTrailingStmts() + PREARGS_START +
2578  getNumPreArgs());
2579  }
2580  const Expr *const *getArgs() const {
2581  return reinterpret_cast<const Expr *const *>(
2582  getTrailingStmts() + PREARGS_START + getNumPreArgs());
2583  }
2584 
2585  /// getArg - Return the specified argument.
2586  Expr *getArg(unsigned Arg) {
2587  assert(Arg < getNumArgs() && "Arg access out of range!");
2588  return getArgs()[Arg];
2589  }
2590  const Expr *getArg(unsigned Arg) const {
2591  assert(Arg < getNumArgs() && "Arg access out of range!");
2592  return getArgs()[Arg];
2593  }
2594 
2595  /// setArg - Set the specified argument.
2596  void setArg(unsigned Arg, Expr *ArgExpr) {
2597  assert(Arg < getNumArgs() && "Arg access out of range!");
2598  getArgs()[Arg] = ArgExpr;
2599  }
2600 
2601  /// Reduce the number of arguments in this call expression. This is used for
2602  /// example during error recovery to drop extra arguments. There is no way
2603  /// to perform the opposite because: 1.) We don't track how much storage
2604  /// we have for the argument array 2.) This would potentially require growing
2605  /// the argument array, something we cannot support since the arguments are
2606  /// stored in a trailing array.
2607  void shrinkNumArgs(unsigned NewNumArgs) {
2608  assert((NewNumArgs <= getNumArgs()) &&
2609  "shrinkNumArgs cannot increase the number of arguments!");
2610  NumArgs = NewNumArgs;
2611  }
2612 
2613  /// Bluntly set a new number of arguments without doing any checks whatsoever.
2614  /// Only used during construction of a CallExpr in a few places in Sema.
2615  /// FIXME: Find a way to remove it.
2616  void setNumArgsUnsafe(unsigned NewNumArgs) { NumArgs = NewNumArgs; }
2617 
2620  typedef llvm::iterator_range<arg_iterator> arg_range;
2621  typedef llvm::iterator_range<const_arg_iterator> const_arg_range;
2622 
2623  arg_range arguments() { return arg_range(arg_begin(), arg_end()); }
2624  const_arg_range arguments() const {
2625  return const_arg_range(arg_begin(), arg_end());
2626  }
2627 
2628  arg_iterator arg_begin() {
2629  return getTrailingStmts() + PREARGS_START + getNumPreArgs();
2630  }
2631  arg_iterator arg_end() { return arg_begin() + getNumArgs(); }
2632 
2633  const_arg_iterator arg_begin() const {
2634  return getTrailingStmts() + PREARGS_START + getNumPreArgs();
2635  }
2636  const_arg_iterator arg_end() const { return arg_begin() + getNumArgs(); }
2637 
2638  /// This method provides fast access to all the subexpressions of
2639  /// a CallExpr without going through the slower virtual child_iterator
2640  /// interface. This provides efficient reverse iteration of the
2641  /// subexpressions. This is currently used for CFG construction.
2643  return llvm::makeArrayRef(getTrailingStmts(),
2644  PREARGS_START + getNumPreArgs() + getNumArgs());
2645  }
2646 
2647  /// getNumCommas - Return the number of commas that must have been present in
2648  /// this function call.
2649  unsigned getNumCommas() const { return getNumArgs() ? getNumArgs() - 1 : 0; }
2650 
2651  /// getBuiltinCallee - If this is a call to a builtin, return the builtin ID
2652  /// of the callee. If not, return 0.
2653  unsigned getBuiltinCallee() const;
2654 
2655  /// Returns \c true if this is a call to a builtin which does not
2656  /// evaluate side-effects within its arguments.
2657  bool isUnevaluatedBuiltinCall(const ASTContext &Ctx) const;
2658 
2659  /// getCallReturnType - Get the return type of the call expr. This is not
2660  /// always the type of the expr itself, if the return type is a reference
2661  /// type.
2662  QualType getCallReturnType(const ASTContext &Ctx) const;
2663 
2664  /// Returns the WarnUnusedResultAttr that is either declared on the called
2665  /// function, or its return type declaration.
2666  const Attr *getUnusedResultAttr(const ASTContext &Ctx) const;
2667 
2668  /// Returns true if this call expression should warn on unused results.
2669  bool hasUnusedResultAttr(const ASTContext &Ctx) const {
2670  return getUnusedResultAttr(Ctx) != nullptr;
2671  }
2672 
2673  SourceLocation getRParenLoc() const { return RParenLoc; }
2674  void setRParenLoc(SourceLocation L) { RParenLoc = L; }
2675 
2676  SourceLocation getBeginLoc() const LLVM_READONLY;
2677  SourceLocation getEndLoc() const LLVM_READONLY;
2678 
2679  /// Return true if this is a call to __assume() or __builtin_assume() with
2680  /// a non-value-dependent constant parameter evaluating as false.
2681  bool isBuiltinAssumeFalse(const ASTContext &Ctx) const;
2682 
2683  bool isCallToStdMove() const {
2684  const FunctionDecl *FD = getDirectCallee();
2685  return getNumArgs() == 1 && FD && FD->isInStdNamespace() &&
2686  FD->getIdentifier() && FD->getIdentifier()->isStr("move");
2687  }
2688 
2689  static bool classof(const Stmt *T) {
2690  return T->getStmtClass() >= firstCallExprConstant &&
2691  T->getStmtClass() <= lastCallExprConstant;
2692  }
2693 
2694  // Iterators
2696  return child_range(getTrailingStmts(), getTrailingStmts() + PREARGS_START +
2697  getNumPreArgs() + getNumArgs());
2698  }
2699 
2701  return const_child_range(getTrailingStmts(),
2702  getTrailingStmts() + PREARGS_START +
2703  getNumPreArgs() + getNumArgs());
2704  }
2705 };
2706 
2707 /// Extra data stored in some MemberExpr objects.
2709  /// The nested-name-specifier that qualifies the name, including
2710  /// source-location information.
2712 
2713  /// The DeclAccessPair through which the MemberDecl was found due to
2714  /// name qualifiers.
2716 };
2717 
2718 /// MemberExpr - [C99 6.5.2.3] Structure and Union Members. X->F and X.F.
2719 ///
2720 class MemberExpr final
2721  : public Expr,
2722  private llvm::TrailingObjects<MemberExpr, MemberExprNameQualifier,
2723  ASTTemplateKWAndArgsInfo,
2724  TemplateArgumentLoc> {
2725  friend class ASTReader;
2726  friend class ASTStmtWriter;
2727  friend TrailingObjects;
2728 
2729  /// Base - the expression for the base pointer or structure references. In
2730  /// X.F, this is "X".
2731  Stmt *Base;
2732 
2733  /// MemberDecl - This is the decl being referenced by the field/member name.
2734  /// In X.F, this is the decl referenced by F.
2735  ValueDecl *MemberDecl;
2736 
2737  /// MemberDNLoc - Provides source/type location info for the
2738  /// declaration name embedded in MemberDecl.
2739  DeclarationNameLoc MemberDNLoc;
2740 
2741  /// MemberLoc - This is the location of the member name.
2742  SourceLocation MemberLoc;
2743 
2744  size_t numTrailingObjects(OverloadToken<MemberExprNameQualifier>) const {
2745  return hasQualifierOrFoundDecl();
2746  }
2747 
2748  size_t numTrailingObjects(OverloadToken<ASTTemplateKWAndArgsInfo>) const {
2749  return hasTemplateKWAndArgsInfo();
2750  }
2751 
2752  bool hasQualifierOrFoundDecl() const {
2753  return MemberExprBits.HasQualifierOrFoundDecl;
2754  }
2755 
2756  bool hasTemplateKWAndArgsInfo() const {
2757  return MemberExprBits.HasTemplateKWAndArgsInfo;
2758  }
2759 
2760 public:
2761  MemberExpr(Expr *base, bool isarrow, SourceLocation operatorloc,
2762  ValueDecl *memberdecl, const DeclarationNameInfo &NameInfo,
2764  : Expr(MemberExprClass, ty, VK, OK, base->isTypeDependent(),
2765  base->isValueDependent(), base->isInstantiationDependent(),
2766  base->containsUnexpandedParameterPack()),
2767  Base(base), MemberDecl(memberdecl), MemberDNLoc(NameInfo.getInfo()),
2768  MemberLoc(NameInfo.getLoc()) {
2769  assert(memberdecl->getDeclName() == NameInfo.getName());
2770  MemberExprBits.IsArrow = isarrow;
2771  MemberExprBits.HasQualifierOrFoundDecl = false;
2772  MemberExprBits.HasTemplateKWAndArgsInfo = false;
2773  MemberExprBits.HadMultipleCandidates = false;
2774  MemberExprBits.OperatorLoc = operatorloc;
2775  }
2776 
2777  // NOTE: this constructor should be used only when it is known that
2778  // the member name can not provide additional syntactic info
2779  // (i.e., source locations for C++ operator names or type source info
2780  // for constructors, destructors and conversion operators).
2781  MemberExpr(Expr *base, bool isarrow, SourceLocation operatorloc,
2782  ValueDecl *memberdecl, SourceLocation l, QualType ty,
2784  : Expr(MemberExprClass, ty, VK, OK, base->isTypeDependent(),
2785  base->isValueDependent(), base->isInstantiationDependent(),
2786  base->containsUnexpandedParameterPack()),
2787  Base(base), MemberDecl(memberdecl), MemberDNLoc(), MemberLoc(l) {
2788  MemberExprBits.IsArrow = isarrow;
2789  MemberExprBits.HasQualifierOrFoundDecl = false;
2790  MemberExprBits.HasTemplateKWAndArgsInfo = false;
2791  MemberExprBits.HadMultipleCandidates = false;
2792  MemberExprBits.OperatorLoc = operatorloc;
2793  }
2794 
2795  static MemberExpr *Create(const ASTContext &C, Expr *base, bool isarrow,
2796  SourceLocation OperatorLoc,
2797  NestedNameSpecifierLoc QualifierLoc,
2798  SourceLocation TemplateKWLoc, ValueDecl *memberdecl,
2799  DeclAccessPair founddecl,
2800  DeclarationNameInfo MemberNameInfo,
2801  const TemplateArgumentListInfo *targs, QualType ty,
2802  ExprValueKind VK, ExprObjectKind OK);
2803 
2804  void setBase(Expr *E) { Base = E; }
2805  Expr *getBase() const { return cast<Expr>(Base); }
2806 
2807  /// Retrieve the member declaration to which this expression refers.
2808  ///
2809  /// The returned declaration will be a FieldDecl or (in C++) a VarDecl (for
2810  /// static data members), a CXXMethodDecl, or an EnumConstantDecl.
2811  ValueDecl *getMemberDecl() const { return MemberDecl; }
2812  void setMemberDecl(ValueDecl *D) { MemberDecl = D; }
2813 
2814  /// Retrieves the declaration found by lookup.
2816  if (!hasQualifierOrFoundDecl())
2817  return DeclAccessPair::make(getMemberDecl(),
2818  getMemberDecl()->getAccess());
2819  return getTrailingObjects<MemberExprNameQualifier>()->FoundDecl;
2820  }
2821 
2822  /// Determines whether this member expression actually had
2823  /// a C++ nested-name-specifier prior to the name of the member, e.g.,
2824  /// x->Base::foo.
2825  bool hasQualifier() const { return getQualifier() != nullptr; }
2826 
2827  /// If the member name was qualified, retrieves the
2828  /// nested-name-specifier that precedes the member name, with source-location
2829  /// information.
2831  if (!hasQualifierOrFoundDecl())
2832  return NestedNameSpecifierLoc();
2833  return getTrailingObjects<MemberExprNameQualifier>()->QualifierLoc;
2834  }
2835 
2836  /// If the member name was qualified, retrieves the
2837  /// nested-name-specifier that precedes the member name. Otherwise, returns
2838  /// NULL.
2840  return getQualifierLoc().getNestedNameSpecifier();
2841  }
2842 
2843  /// Retrieve the location of the template keyword preceding
2844  /// the member name, if any.
2846  if (!hasTemplateKWAndArgsInfo())
2847  return SourceLocation();
2848  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->TemplateKWLoc;
2849  }
2850 
2851  /// Retrieve the location of the left angle bracket starting the
2852  /// explicit template argument list following the member name, if any.
2854  if (!hasTemplateKWAndArgsInfo())
2855  return SourceLocation();
2856  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->LAngleLoc;
2857  }
2858 
2859  /// Retrieve the location of the right angle bracket ending the
2860  /// explicit template argument list following the member name, if any.
2862  if (!hasTemplateKWAndArgsInfo())
2863  return SourceLocation();
2864  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->RAngleLoc;
2865  }
2866 
2867  /// Determines whether the member name was preceded by the template keyword.
2868  bool hasTemplateKeyword() const { return getTemplateKeywordLoc().isValid(); }
2869 
2870  /// Determines whether the member name was followed by an
2871  /// explicit template argument list.
2872  bool hasExplicitTemplateArgs() const { return getLAngleLoc().isValid(); }
2873 
2874  /// Copies the template arguments (if present) into the given
2875  /// structure.
2877  if (hasExplicitTemplateArgs())
2878  getTrailingObjects<ASTTemplateKWAndArgsInfo>()->copyInto(
2879  getTrailingObjects<TemplateArgumentLoc>(), List);
2880  }
2881 
2882  /// Retrieve the template arguments provided as part of this
2883  /// template-id.
2885  if (!hasExplicitTemplateArgs())
2886  return nullptr;
2887 
2888  return getTrailingObjects<TemplateArgumentLoc>();
2889  }
2890 
2891  /// Retrieve the number of template arguments provided as part of this
2892  /// template-id.
2893  unsigned getNumTemplateArgs() const {
2894  if (!hasExplicitTemplateArgs())
2895  return 0;
2896 
2897  return getTrailingObjects<ASTTemplateKWAndArgsInfo>()->NumTemplateArgs;
2898  }
2899 
2901  return {getTemplateArgs(), getNumTemplateArgs()};
2902  }
2903 
2904  /// Retrieve the member declaration name info.
2906  return DeclarationNameInfo(MemberDecl->getDeclName(),
2907  MemberLoc, MemberDNLoc);
2908  }
2909 
2910  SourceLocation getOperatorLoc() const { return MemberExprBits.OperatorLoc; }
2911 
2912  bool isArrow() const { return MemberExprBits.IsArrow; }
2913  void setArrow(bool A) { MemberExprBits.IsArrow = A; }
2914 
2915  /// getMemberLoc - Return the location of the "member", in X->F, it is the
2916  /// location of 'F'.
2917  SourceLocation getMemberLoc() const { return MemberLoc; }
2918  void setMemberLoc(SourceLocation L) { MemberLoc = L; }
2919 
2920  SourceLocation getBeginLoc() const LLVM_READONLY;
2921  SourceLocation getEndLoc() const LLVM_READONLY;
2922 
2923  SourceLocation getExprLoc() const LLVM_READONLY { return MemberLoc; }
2924 
2925  /// Determine whether the base of this explicit is implicit.
2926  bool isImplicitAccess() const {
2927  return getBase() && getBase()->isImplicitCXXThis();
2928  }
2929 
2930  /// Returns true if this member expression refers to a method that
2931  /// was resolved from an overloaded set having size greater than 1.
2932  bool hadMultipleCandidates() const {
2933  return MemberExprBits.HadMultipleCandidates;
2934  }
2935  /// Sets the flag telling whether this expression refers to
2936  /// a method that was resolved from an overloaded set having size
2937  /// greater than 1.
2938  void setHadMultipleCandidates(bool V = true) {
2939  MemberExprBits.HadMultipleCandidates = V;
2940  }
2941 
2942  /// Returns true if virtual dispatch is performed.
2943  /// If the member access is fully qualified, (i.e. X::f()), virtual
2944  /// dispatching is not performed. In -fapple-kext mode qualified
2945  /// calls to virtual method will still go through the vtable.
2946  bool performsVirtualDispatch(const LangOptions &LO) const {
2947  return LO.AppleKext || !hasQualifier();
2948  }
2949 
2950  static bool classof(const Stmt *T) {
2951  return T->getStmtClass() == MemberExprClass;
2952  }
2953 
2954  // Iterators
2955  child_range children() { return child_range(&Base, &Base+1); }
2957  return const_child_range(&Base, &Base + 1);
2958  }
2959 };
2960 
2961 /// CompoundLiteralExpr - [C99 6.5.2.5]
2962 ///
2963 class CompoundLiteralExpr : public Expr {
2964  /// LParenLoc - If non-null, this is the location of the left paren in a
2965  /// compound literal like "(int){4}". This can be null if this is a
2966  /// synthesized compound expression.
2967  SourceLocation LParenLoc;
2968 
2969  /// The type as written. This can be an incomplete array type, in
2970  /// which case the actual expression type will be different.
2971  /// The int part of the pair stores whether this expr is file scope.
2972  llvm::PointerIntPair<TypeSourceInfo *, 1, bool> TInfoAndScope;
2973  Stmt *Init;
2974 public:
2976  QualType T, ExprValueKind VK, Expr *init, bool fileScope)
2977  : Expr(CompoundLiteralExprClass, T, VK, OK_Ordinary,
2978  tinfo->getType()->isDependentType(),
2979  init->isValueDependent(),
2980  (init->isInstantiationDependent() ||
2981  tinfo->getType()->isInstantiationDependentType()),
2982  init->containsUnexpandedParameterPack()),
2983  LParenLoc(lparenloc), TInfoAndScope(tinfo, fileScope), Init(init) {}
2984 
2985  /// Construct an empty compound literal.
2987  : Expr(CompoundLiteralExprClass, Empty) { }
2988 
2989  const Expr *getInitializer() const { return cast<Expr>(Init); }
2990  Expr *getInitializer() { return cast<Expr>(Init); }
2991  void setInitializer(Expr *E) { Init = E; }
2992 
2993  bool isFileScope() const { return TInfoAndScope.getInt(); }
2994  void setFileScope(bool FS) { TInfoAndScope.setInt(FS); }
2995 
2996  SourceLocation getLParenLoc() const { return LParenLoc; }
2997  void setLParenLoc(SourceLocation L) { LParenLoc = L; }
2998 
3000  return TInfoAndScope.getPointer();
3001  }
3003  TInfoAndScope.setPointer(tinfo);
3004  }
3005 
3006  SourceLocation getBeginLoc() const LLVM_READONLY {
3007  // FIXME: Init should never be null.
3008  if (!Init)
3009  return SourceLocation();
3010  if (LParenLoc.isInvalid())
3011  return Init->getBeginLoc();
3012  return LParenLoc;
3013  }
3014  SourceLocation getEndLoc() const LLVM_READONLY {
3015  // FIXME: Init should never be null.
3016  if (!Init)
3017  return SourceLocation();
3018  return Init->getEndLoc();
3019  }
3020 
3021  static bool classof(const Stmt *T) {
3022  return T->getStmtClass() == CompoundLiteralExprClass;
3023  }
3024 
3025  // Iterators
3026  child_range children() { return child_range(&Init, &Init+1); }
3028  return const_child_range(&Init, &Init + 1);
3029  }
3030 };
3031 
3032 /// CastExpr - Base class for type casts, including both implicit
3033 /// casts (ImplicitCastExpr) and explicit casts that have some
3034 /// representation in the source code (ExplicitCastExpr's derived
3035 /// classes).
3036 class CastExpr : public Expr {
3037  Stmt *Op;
3038 
3039  bool CastConsistency() const;
3040 
3041  const CXXBaseSpecifier * const *path_buffer() const {
3042  return const_cast<CastExpr*>(this)->path_buffer();
3043  }
3044  CXXBaseSpecifier **path_buffer();
3045 
3046 protected:
3048  Expr *op, unsigned BasePathSize)
3049  : Expr(SC, ty, VK, OK_Ordinary,
3050  // Cast expressions are type-dependent if the type is
3051  // dependent (C++ [temp.dep.expr]p3).
3052  ty->isDependentType(),
3053  // Cast expressions are value-dependent if the type is
3054  // dependent or if the subexpression is value-dependent.
3055  ty->isDependentType() || (op && op->isValueDependent()),
3056  (ty->isInstantiationDependentType() ||
3057  (op && op->isInstantiationDependent())),
3058  // An implicit cast expression doesn't (lexically) contain an
3059  // unexpanded pack, even if its target type does.
3060  ((SC != ImplicitCastExprClass &&
3061  ty->containsUnexpandedParameterPack()) ||
3062  (op && op->containsUnexpandedParameterPack()))),
3063  Op(op) {
3064  CastExprBits.Kind = kind;
3065  CastExprBits.PartOfExplicitCast = false;
3066  CastExprBits.BasePathSize = BasePathSize;
3067  assert((CastExprBits.BasePathSize == BasePathSize) &&
3068  "BasePathSize overflow!");
3069  assert(CastConsistency());
3070  }
3071 
3072  /// Construct an empty cast.
3073  CastExpr(StmtClass SC, EmptyShell Empty, unsigned BasePathSize)
3074  : Expr(SC, Empty) {
3075  CastExprBits.PartOfExplicitCast = false;
3076  CastExprBits.BasePathSize = BasePathSize;
3077  assert((CastExprBits.BasePathSize == BasePathSize) &&
3078  "BasePathSize overflow!");
3079  }
3080 
3081 public:
3082  CastKind getCastKind() const { return (CastKind) CastExprBits.Kind; }
3083  void setCastKind(CastKind K) { CastExprBits.Kind = K; }
3084 
3085  static const char *getCastKindName(CastKind CK);
3086  const char *getCastKindName() const { return getCastKindName(getCastKind()); }
3087 
3088  Expr *getSubExpr() { return cast<Expr>(Op); }
3089  const Expr *getSubExpr() const { return cast<Expr>(Op); }
3090  void setSubExpr(Expr *E) { Op = E; }
3091 
3092  /// Retrieve the cast subexpression as it was written in the source
3093  /// code, looking through any implicit casts or other intermediate nodes
3094  /// introduced by semantic analysis.
3095  Expr *getSubExprAsWritten();
3096  const Expr *getSubExprAsWritten() const {
3097  return const_cast<CastExpr *>(this)->getSubExprAsWritten();
3098  }
3099 
3100  /// If this cast applies a user-defined conversion, retrieve the conversion
3101  /// function that it invokes.
3102  NamedDecl *getConversionFunction() const;
3103 
3105  typedef const CXXBaseSpecifier *const *path_const_iterator;
3106  bool path_empty() const { return path_size() == 0; }
3107  unsigned path_size() const { return CastExprBits.BasePathSize; }
3108  path_iterator path_begin() { return path_buffer(); }
3109  path_iterator path_end() { return path_buffer() + path_size(); }
3110  path_const_iterator path_begin() const { return path_buffer(); }
3111  path_const_iterator path_end() const { return path_buffer() + path_size(); }
3112 
3114  assert(getCastKind() == CK_ToUnion);
3115  return getTargetFieldForToUnionCast(getType(), getSubExpr()->getType());
3116  }
3117 
3118  static const FieldDecl *getTargetFieldForToUnionCast(QualType unionType,
3119  QualType opType);
3120  static const FieldDecl *getTargetFieldForToUnionCast(const RecordDecl *RD,
3121  QualType opType);
3122 
3123  static bool classof(const Stmt *T) {
3124  return T->getStmtClass() >= firstCastExprConstant &&
3125  T->getStmtClass() <= lastCastExprConstant;
3126  }
3127 
3128  // Iterators
3129  child_range children() { return child_range(&Op, &Op+1); }
3130  const_child_range children() const { return const_child_range(&Op, &Op + 1); }
3131 };
3132 
3133 /// ImplicitCastExpr - Allows us to explicitly represent implicit type
3134 /// conversions, which have no direct representation in the original
3135 /// source code. For example: converting T[]->T*, void f()->void
3136 /// (*f)(), float->double, short->int, etc.
3137 ///
3138 /// In C, implicit casts always produce rvalues. However, in C++, an
3139 /// implicit cast whose result is being bound to a reference will be
3140 /// an lvalue or xvalue. For example:
3141 ///
3142 /// @code
3143 /// class Base { };
3144 /// class Derived : public Base { };
3145 /// Derived &&ref();
3146 /// void f(Derived d) {
3147 /// Base& b = d; // initializer is an ImplicitCastExpr
3148 /// // to an lvalue of type Base
3149 /// Base&& r = ref(); // initializer is an ImplicitCastExpr
3150 /// // to an xvalue of type Base
3151 /// }
3152 /// @endcode
3153 class ImplicitCastExpr final
3154  : public CastExpr,
3155  private llvm::TrailingObjects<ImplicitCastExpr, CXXBaseSpecifier *> {
3156 
3158  unsigned BasePathLength, ExprValueKind VK)
3159  : CastExpr(ImplicitCastExprClass, ty, VK, kind, op, BasePathLength) { }
3160 
3161  /// Construct an empty implicit cast.
3162  explicit ImplicitCastExpr(EmptyShell Shell, unsigned PathSize)
3163  : CastExpr(ImplicitCastExprClass, Shell, PathSize) { }
3164 
3165 public:
3166  enum OnStack_t { OnStack };
3168  ExprValueKind VK)
3169  : CastExpr(ImplicitCastExprClass, ty, VK, kind, op, 0) {
3170  }
3171 
3172  bool isPartOfExplicitCast() const { return CastExprBits.PartOfExplicitCast; }
3173  void setIsPartOfExplicitCast(bool PartOfExplicitCast) {
3174  CastExprBits.PartOfExplicitCast = PartOfExplicitCast;
3175  }
3176 
3177  static ImplicitCastExpr *Create(const ASTContext &Context, QualType T,
3178  CastKind Kind, Expr *Operand,
3179  const CXXCastPath *BasePath,
3180  ExprValueKind Cat);
3181 
3182  static ImplicitCastExpr *CreateEmpty(const ASTContext &Context,
3183  unsigned PathSize);
3184 
3185  SourceLocation getBeginLoc() const LLVM_READONLY {
3186  return getSubExpr()->getBeginLoc();
3187  }
3188  SourceLocation getEndLoc() const LLVM_READONLY {
3189  return getSubExpr()->getEndLoc();
3190  }
3191 
3192  static bool classof(const Stmt *T) {
3193  return T->getStmtClass() == ImplicitCastExprClass;
3194  }
3195 
3197  friend class CastExpr;
3198 };
3199 
3200 /// ExplicitCastExpr - An explicit cast written in the source
3201 /// code.
3202 ///
3203 /// This class is effectively an abstract class, because it provides
3204 /// the basic representation of an explicitly-written cast without
3205 /// specifying which kind of cast (C cast, functional cast, static
3206 /// cast, etc.) was written; specific derived classes represent the
3207 /// particular style of cast and its location information.
3208 ///
3209 /// Unlike implicit casts, explicit cast nodes have two different
3210 /// types: the type that was written into the source code, and the
3211 /// actual type of the expression as determined by semantic
3212 /// analysis. These types may differ slightly. For example, in C++ one
3213 /// can cast to a reference type, which indicates that the resulting
3214 /// expression will be an lvalue or xvalue. The reference type, however,
3215 /// will not be used as the type of the expression.
3216 class ExplicitCastExpr : public CastExpr {
3217  /// TInfo - Source type info for the (written) type
3218  /// this expression is casting to.
3219  TypeSourceInfo *TInfo;
3220 
3221 protected:
3223  CastKind kind, Expr *op, unsigned PathSize,
3224  TypeSourceInfo *writtenTy)
3225  : CastExpr(SC, exprTy, VK, kind, op, PathSize), TInfo(writtenTy) {}
3226 
3227  /// Construct an empty explicit cast.
3228  ExplicitCastExpr(StmtClass SC, EmptyShell Shell, unsigned PathSize)
3229  : CastExpr(SC, Shell, PathSize) { }
3230 
3231 public:
3232  /// getTypeInfoAsWritten - Returns the type source info for the type
3233  /// that this expression is casting to.
3234  TypeSourceInfo *getTypeInfoAsWritten() const { return TInfo; }
3235  void setTypeInfoAsWritten(TypeSourceInfo *writtenTy) { TInfo = writtenTy; }
3236 
3237  /// getTypeAsWritten - Returns the type that this expression is
3238  /// casting to, as written in the source code.
3239  QualType getTypeAsWritten() const { return TInfo->getType(); }
3240 
3241  static bool classof(const Stmt *T) {
3242  return T->getStmtClass() >= firstExplicitCastExprConstant &&
3243  T->getStmtClass() <= lastExplicitCastExprConstant;
3244  }
3245 };
3246 
3247 /// CStyleCastExpr - An explicit cast in C (C99 6.5.4) or a C-style
3248 /// cast in C++ (C++ [expr.cast]), which uses the syntax
3249 /// (Type)expr. For example: @c (int)f.
3250 class CStyleCastExpr final
3251  : public ExplicitCastExpr,
3252  private llvm::TrailingObjects<CStyleCastExpr, CXXBaseSpecifier *> {
3253  SourceLocation LPLoc; // the location of the left paren
3254  SourceLocation RPLoc; // the location of the right paren
3255 
3257  unsigned PathSize, TypeSourceInfo *writtenTy,
3259  : ExplicitCastExpr(CStyleCastExprClass, exprTy, vk, kind, op, PathSize,
3260  writtenTy), LPLoc(l), RPLoc(r) {}
3261 
3262  /// Construct an empty C-style explicit cast.
3263  explicit CStyleCastExpr(EmptyShell Shell, unsigned PathSize)
3264  : ExplicitCastExpr(CStyleCastExprClass, Shell, PathSize) { }
3265 
3266 public:
3267  static CStyleCastExpr *Create(const ASTContext &Context, QualType T,
3268  ExprValueKind VK, CastKind K,
3269  Expr *Op, const CXXCastPath *BasePath,
3270  TypeSourceInfo *WrittenTy, SourceLocation L,
3271  SourceLocation R);
3272 
3273  static CStyleCastExpr *CreateEmpty(const ASTContext &Context,
3274  unsigned PathSize);
3275 
3276  SourceLocation getLParenLoc() const { return LPLoc; }
3277  void setLParenLoc(SourceLocation L) { LPLoc = L; }
3278 
3279  SourceLocation getRParenLoc() const { return RPLoc; }
3280  void setRParenLoc(SourceLocation L) { RPLoc = L; }
3281 
3282  SourceLocation getBeginLoc() const LLVM_READONLY { return LPLoc; }
3283  SourceLocation getEndLoc() const LLVM_READONLY {
3284  return getSubExpr()->getEndLoc();
3285  }
3286 
3287  static bool classof(const Stmt *T) {
3288  return T->getStmtClass() == CStyleCastExprClass;
3289  }
3290 
3292  friend class CastExpr;
3293 };
3294 
3295 /// A builtin binary operation expression such as "x + y" or "x <= y".
3296 ///
3297 /// This expression node kind describes a builtin binary operation,
3298 /// such as "x + y" for integer values "x" and "y". The operands will
3299 /// already have been converted to appropriate types (e.g., by
3300 /// performing promotions or conversions).
3301 ///
3302 /// In C++, where operators may be overloaded, a different kind of
3303 /// expression node (CXXOperatorCallExpr) is used to express the
3304 /// invocation of an overloaded operator with operator syntax. Within
3305 /// a C++ template, whether BinaryOperator or CXXOperatorCallExpr is
3306 /// used to store an expression "x + y" depends on the subexpressions
3307 /// for x and y. If neither x or y is type-dependent, and the "+"
3308 /// operator resolves to a built-in operation, BinaryOperator will be
3309 /// used to express the computation (x and y may still be
3310 /// value-dependent). If either x or y is type-dependent, or if the
3311 /// "+" resolves to an overloaded operator, CXXOperatorCallExpr will
3312 /// be used to express the computation.
3313 class BinaryOperator : public Expr {
3314  enum { LHS, RHS, END_EXPR };
3315  Stmt *SubExprs[END_EXPR];
3316 
3317 public:
3319 
3320  BinaryOperator(Expr *lhs, Expr *rhs, Opcode opc, QualType ResTy,
3322  SourceLocation opLoc, FPOptions FPFeatures)
3323  : Expr(BinaryOperatorClass, ResTy, VK, OK,
3324  lhs->isTypeDependent() || rhs->isTypeDependent(),
3325  lhs->isValueDependent() || rhs->isValueDependent(),
3326  (lhs->isInstantiationDependent() ||
3327  rhs->isInstantiationDependent()),
3328  (lhs->containsUnexpandedParameterPack() ||
3329  rhs->containsUnexpandedParameterPack())) {
3330  BinaryOperatorBits.Opc = opc;
3331  BinaryOperatorBits.FPFeatures = FPFeatures.getInt();
3332  BinaryOperatorBits.OpLoc = opLoc;
3333  SubExprs[LHS] = lhs;
3334  SubExprs[RHS] = rhs;
3335  assert(!isCompoundAssignmentOp() &&
3336  "Use CompoundAssignOperator for compound assignments");
3337  }
3338 
3339  /// Construct an empty binary operator.
3340  explicit BinaryOperator(EmptyShell Empty) : Expr(BinaryOperatorClass, Empty) {
3341  BinaryOperatorBits.Opc = BO_Comma;
3342  }
3343 
3344  SourceLocation getExprLoc() const { return getOperatorLoc(); }
3345  SourceLocation getOperatorLoc() const { return BinaryOperatorBits.OpLoc; }
3346  void setOperatorLoc(SourceLocation L) { BinaryOperatorBits.OpLoc = L; }
3347 
3348  Opcode getOpcode() const {
3349  return static_cast<Opcode>(BinaryOperatorBits.Opc);
3350  }
3351  void setOpcode(Opcode Opc) { BinaryOperatorBits.Opc = Opc; }
3352 
3353  Expr *getLHS() const { return cast<Expr>(SubExprs[LHS]); }
3354  void setLHS(Expr *E) { SubExprs[LHS] = E; }
3355  Expr *getRHS() const { return cast<Expr>(SubExprs[RHS]); }
3356  void setRHS(Expr *E) { SubExprs[RHS] = E; }
3357 
3358  SourceLocation getBeginLoc() const LLVM_READONLY {
3359  return getLHS()->getBeginLoc();
3360  }
3361  SourceLocation getEndLoc() const LLVM_READONLY {
3362  return getRHS()->getEndLoc();
3363  }
3364 
3365  /// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
3366  /// corresponds to, e.g. "<<=".
3367  static StringRef getOpcodeStr(Opcode Op);
3368 
3369  StringRef getOpcodeStr() const { return getOpcodeStr(getOpcode()); }
3370 
3371  /// Retrieve the binary opcode that corresponds to the given
3372  /// overloaded operator.
3373  static Opcode getOverloadedOpcode(OverloadedOperatorKind OO);
3374 
3375  /// Retrieve the overloaded operator kind that corresponds to
3376  /// the given binary opcode.
3377  static OverloadedOperatorKind getOverloadedOperator(Opcode Opc);
3378 
3379  /// predicates to categorize the respective opcodes.
3380  static bool isPtrMemOp(Opcode Opc) {
3381  return Opc == BO_PtrMemD || Opc == BO_PtrMemI;
3382  }
3383  bool isPtrMemOp() const { return isPtrMemOp(getOpcode()); }
3384 
3385  static bool isMultiplicativeOp(Opcode Opc) {
3386  return Opc >= BO_Mul && Opc <= BO_Rem;
3387  }
3389  static bool isAdditiveOp(Opcode Opc) { return Opc == BO_Add || Opc==BO_Sub; }
3390  bool isAdditiveOp() const { return isAdditiveOp(getOpcode()); }
3391  static bool isShiftOp(Opcode Opc) { return Opc == BO_Shl || Opc == BO_Shr; }
3392  bool isShiftOp() const { return isShiftOp(getOpcode()); }
3393 
3394  static bool isBitwiseOp(Opcode Opc) { return Opc >= BO_And && Opc <= BO_Or; }
3395  bool isBitwiseOp() const { return isBitwiseOp(getOpcode()); }
3396 
3397  static bool isRelationalOp(Opcode Opc) { return Opc >= BO_LT && Opc<=BO_GE; }
3398  bool isRelationalOp() const { return isRelationalOp(getOpcode()); }
3399 
3400  static bool isEqualityOp(Opcode Opc) { return Opc == BO_EQ || Opc == BO_NE; }
3401  bool isEqualityOp() const { return isEqualityOp(getOpcode()); }
3402 
3403  static bool isComparisonOp(Opcode Opc) { return Opc >= BO_Cmp && Opc<=BO_NE; }
3404  bool isComparisonOp() const { return isComparisonOp(getOpcode()); }
3405 
3406  static Opcode negateComparisonOp(Opcode Opc) {
3407  switch (Opc) {
3408  default:
3409  llvm_unreachable("Not a comparison operator.");
3410  case BO_LT: return BO_GE;
3411  case BO_GT: return BO_LE;
3412  case BO_LE: return BO_GT;
3413  case BO_GE: return BO_LT;
3414  case BO_EQ: return BO_NE;
3415  case BO_NE: return BO_EQ;
3416  }
3417  }
3418 
3419  static Opcode reverseComparisonOp(Opcode Opc) {
3420  switch (Opc) {
3421  default:
3422  llvm_unreachable("Not a comparison operator.");
3423  case BO_LT: return BO_GT;
3424  case BO_GT: return BO_LT;
3425  case BO_LE: return BO_GE;
3426  case BO_GE: return BO_LE;
3427  case BO_EQ:
3428  case BO_NE:
3429  return Opc;
3430  }
3431  }
3432 
3433  static bool isLogicalOp(Opcode Opc) { return Opc == BO_LAnd || Opc==BO_LOr; }
3434  bool isLogicalOp() const { return isLogicalOp(getOpcode()); }
3435 
3436  static bool isAssignmentOp(Opcode Opc) {
3437  return Opc >= BO_Assign && Opc <= BO_OrAssign;
3438  }
3439  bool isAssignmentOp() const { return isAssignmentOp(getOpcode()); }
3440 
3441  static bool isCompoundAssignmentOp(Opcode Opc) {
3442  return Opc > BO_Assign && Opc <= BO_OrAssign;
3443  }
3444  bool isCompoundAssignmentOp() const {
3445  return isCompoundAssignmentOp(getOpcode());
3446  }
3447  static Opcode getOpForCompoundAssignment(Opcode Opc) {
3448  assert(isCompoundAssignmentOp(Opc));
3449  if (Opc >= BO_AndAssign)
3450  return Opcode(unsigned(Opc) - BO_AndAssign + BO_And);
3451  else
3452  return Opcode(unsigned(Opc) - BO_MulAssign + BO_Mul);
3453  }
3454 
3455  static bool isShiftAssignOp(Opcode Opc) {
3456  return Opc == BO_ShlAssign || Opc == BO_ShrAssign;
3457  }
3458  bool isShiftAssignOp() const {
3459  return isShiftAssignOp(getOpcode());
3460  }
3461 
3462  // Return true if a binary operator using the specified opcode and operands
3463  // would match the 'p = (i8*)nullptr + n' idiom for casting a pointer-sized
3464  // integer to a pointer.
3465  static bool isNullPointerArithmeticExtension(ASTContext &Ctx, Opcode Opc,
3466  Expr *LHS, Expr *RHS);
3467 
3468  static bool classof(const Stmt *S) {
3469  return S->getStmtClass() >= firstBinaryOperatorConstant &&
3470  S->getStmtClass() <= lastBinaryOperatorConstant;
3471  }
3472 
3473  // Iterators
3475  return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
3476  }
3478  return const_child_range(&SubExprs[0], &SubExprs[0] + END_EXPR);
3479  }
3480 
3481  // Set the FP contractability status of this operator. Only meaningful for
3482  // operations on floating point types.
3484  BinaryOperatorBits.FPFeatures = F.getInt();
3485  }
3486 
3488  return FPOptions(BinaryOperatorBits.FPFeatures);
3489  }
3490 
3491  // Get the FP contractability status of this operator. Only meaningful for
3492  // operations on floating point types.
3494  return getFPFeatures().allowFPContractWithinStatement();
3495  }
3496 
3497  // Get the FENV_ACCESS status of this operator. Only meaningful for
3498  // operations on floating point types.
3499  bool isFEnvAccessOn() const { return getFPFeatures().allowFEnvAccess(); }
3500 
3501 protected:
3502  BinaryOperator(Expr *lhs, Expr *rhs, Opcode opc, QualType ResTy,
3504  SourceLocation opLoc, FPOptions FPFeatures, bool dead2)
3505  : Expr(CompoundAssignOperatorClass, ResTy, VK, OK,
3506  lhs->isTypeDependent() || rhs->isTypeDependent(),
3507  lhs->isValueDependent() || rhs->isValueDependent(),
3508  (lhs->isInstantiationDependent() ||
3509  rhs->isInstantiationDependent()),
3510  (lhs->containsUnexpandedParameterPack() ||
3511  rhs->containsUnexpandedParameterPack())) {
3512  BinaryOperatorBits.Opc = opc;
3513  BinaryOperatorBits.FPFeatures = FPFeatures.getInt();
3514  BinaryOperatorBits.OpLoc = opLoc;
3515  SubExprs[LHS] = lhs;
3516  SubExprs[RHS] = rhs;
3517  }
3518 
3519  BinaryOperator(StmtClass SC, EmptyShell Empty) : Expr(SC, Empty) {
3520  BinaryOperatorBits.Opc = BO_MulAssign;
3521  }
3522 };
3523 
3524 /// CompoundAssignOperator - For compound assignments (e.g. +=), we keep
3525 /// track of the type the operation is performed in. Due to the semantics of
3526 /// these operators, the operands are promoted, the arithmetic performed, an
3527 /// implicit conversion back to the result type done, then the assignment takes
3528 /// place. This captures the intermediate type which the computation is done
3529 /// in.
3531  QualType ComputationLHSType;
3532  QualType ComputationResultType;
3533 public:
3534  CompoundAssignOperator(Expr *lhs, Expr *rhs, Opcode opc, QualType ResType,
3536  QualType CompLHSType, QualType CompResultType,
3537  SourceLocation OpLoc, FPOptions FPFeatures)
3538  : BinaryOperator(lhs, rhs, opc, ResType, VK, OK, OpLoc, FPFeatures,
3539  true),
3540  ComputationLHSType(CompLHSType),
3541  ComputationResultType(CompResultType) {
3542  assert(isCompoundAssignmentOp() &&
3543  "Only should be used for compound assignments");
3544  }
3545 
3546  /// Build an empty compound assignment operator expression.
3548  : BinaryOperator(CompoundAssignOperatorClass, Empty) { }
3549 
3550  // The two computation types are the type the LHS is converted
3551  // to for the computation and the type of the result; the two are
3552  // distinct in a few cases (specifically, int+=ptr and ptr-=ptr).
3553  QualType getComputationLHSType() const { return ComputationLHSType; }
3554  void setComputationLHSType(QualType T) { ComputationLHSType = T; }
3555 
3556  QualType getComputationResultType() const { return ComputationResultType; }
3557  void setComputationResultType(QualType T) { ComputationResultType = T; }
3558 
3559  static bool classof(const Stmt *S) {
3560  return S->getStmtClass() == CompoundAssignOperatorClass;
3561  }
3562 };
3563 
3564 /// AbstractConditionalOperator - An abstract base class for
3565 /// ConditionalOperator and BinaryConditionalOperator.
3567  SourceLocation QuestionLoc, ColonLoc;
3568  friend class ASTStmtReader;
3569 
3570 protected:
3573  bool TD, bool VD, bool ID,
3574  bool ContainsUnexpandedParameterPack,
3575  SourceLocation qloc,
3576  SourceLocation cloc)
3577  : Expr(SC, T, VK, OK, TD, VD, ID, ContainsUnexpandedParameterPack),
3578  QuestionLoc(qloc), ColonLoc(cloc) {}
3579 
3581  : Expr(SC, Empty) { }
3582 
3583 public:
3584  // getCond - Return the expression representing the condition for
3585  // the ?: operator.
3586  Expr *getCond() const;
3587 
3588  // getTrueExpr - Return the subexpression representing the value of
3589  // the expression if the condition evaluates to true.
3590  Expr *getTrueExpr() const;
3591 
3592  // getFalseExpr - Return the subexpression representing the value of
3593  // the expression if the condition evaluates to false. This is
3594  // the same as getRHS.
3595  Expr *getFalseExpr() const;
3596 
3597  SourceLocation getQuestionLoc() const { return QuestionLoc; }
3599 
3600  static bool classof(const Stmt *T) {
3601  return T->getStmtClass() == ConditionalOperatorClass ||
3602  T->getStmtClass() == BinaryConditionalOperatorClass;
3603  }
3604 };
3605 
3606 /// ConditionalOperator - The ?: ternary operator. The GNU "missing
3607 /// middle" extension is a BinaryConditionalOperator.
3609  enum { COND, LHS, RHS, END_EXPR };
3610  Stmt* SubExprs[END_EXPR]; // Left/Middle/Right hand sides.
3611 
3612  friend class ASTStmtReader;
3613 public:
3615  SourceLocation CLoc, Expr *rhs,
3617  : AbstractConditionalOperator(ConditionalOperatorClass, t, VK, OK,
3618  // FIXME: the type of the conditional operator doesn't
3619  // depend on the type of the conditional, but the standard
3620  // seems to imply that it could. File a bug!
3621  (lhs->isTypeDependent() || rhs->isTypeDependent()),
3622  (cond->isValueDependent() || lhs->isValueDependent() ||
3623  rhs->isValueDependent()),
3624  (cond->isInstantiationDependent() ||
3625  lhs->isInstantiationDependent() ||
3626  rhs->isInstantiationDependent()),
3627  (cond->containsUnexpandedParameterPack() ||
3628  lhs->containsUnexpandedParameterPack() ||
3629  rhs->containsUnexpandedParameterPack()),
3630  QLoc, CLoc) {
3631  SubExprs[COND] = cond;
3632  SubExprs[LHS] = lhs;
3633  SubExprs[RHS] = rhs;
3634  }
3635 
3636  /// Build an empty conditional operator.
3638  : AbstractConditionalOperator(ConditionalOperatorClass, Empty) { }
3639 
3640  // getCond - Return the expression representing the condition for
3641  // the ?: operator.
3642  Expr *getCond() const { return cast<Expr>(SubExprs[COND]); }
3643 
3644  // getTrueExpr - Return the subexpression representing the value of
3645  // the expression if the condition evaluates to true.
3646  Expr *getTrueExpr() const { return cast<Expr>(SubExprs[LHS]); }
3647 
3648  // getFalseExpr - Return the subexpression representing the value of
3649  // the expression if the condition evaluates to false. This is
3650  // the same as getRHS.
3651  Expr *getFalseExpr() const { return cast<Expr>(SubExprs[RHS]); }
3652 
3653  Expr *getLHS() const { return cast<Expr>(SubExprs[LHS]); }
3654  Expr *getRHS() const { return cast<Expr>(SubExprs[RHS]); }
3655 
3656  SourceLocation getBeginLoc() const LLVM_READONLY {
3657  return getCond()->getBeginLoc();
3658  }
3659  SourceLocation getEndLoc() const LLVM_READONLY {
3660  return getRHS()->getEndLoc();
3661  }
3662 
3663  static bool classof(const Stmt *T) {
3664  return T->getStmtClass() == ConditionalOperatorClass;
3665  }
3666 
3667  // Iterators
3669  return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
3670  }
3672  return const_child_range(&SubExprs[0], &SubExprs[0] + END_EXPR);
3673  }
3674 };
3675 
3676 /// BinaryConditionalOperator - The GNU extension to the conditional
3677 /// operator which allows the middle operand to be omitted.
3678 ///
3679 /// This is a different expression kind on the assumption that almost
3680 /// every client ends up needing to know that these are different.
3682  enum { COMMON, COND, LHS, RHS, NUM_SUBEXPRS };
3683 
3684  /// - the common condition/left-hand-side expression, which will be
3685  /// evaluated as the opaque value
3686  /// - the condition, expressed in terms of the opaque value
3687  /// - the left-hand-side, expressed in terms of the opaque value
3688  /// - the right-hand-side
3689  Stmt *SubExprs[NUM_SUBEXPRS];
3690  OpaqueValueExpr *OpaqueValue;
3691 
3692  friend class ASTStmtReader;
3693 public:
3695  Expr *cond, Expr *lhs, Expr *rhs,
3696  SourceLocation qloc, SourceLocation cloc,
3698  : AbstractConditionalOperator(BinaryConditionalOperatorClass, t, VK, OK,
3699  (common->isTypeDependent() || rhs->isTypeDependent()),
3700  (common->isValueDependent() || rhs->isValueDependent()),
3701  (common->isInstantiationDependent() ||
3702  rhs->isInstantiationDependent()),
3703  (common->containsUnexpandedParameterPack() ||
3704  rhs->containsUnexpandedParameterPack()),
3705  qloc, cloc),
3706  OpaqueValue(opaqueValue) {
3707  SubExprs[COMMON] = common;
3708  SubExprs[COND] = cond;
3709  SubExprs[LHS] = lhs;
3710  SubExprs[RHS] = rhs;
3711  assert(OpaqueValue->getSourceExpr() == common && "Wrong opaque value");
3712  }
3713 
3714  /// Build an empty conditional operator.
3716  : AbstractConditionalOperator(BinaryConditionalOperatorClass, Empty) { }
3717 
3718  /// getCommon - Return the common expression, written to the
3719  /// left of the condition. The opaque value will be bound to the
3720  /// result of this expression.
3721  Expr *getCommon() const { return cast<Expr>(SubExprs[COMMON]); }
3722 
3723  /// getOpaqueValue - Return the opaque value placeholder.
3724  OpaqueValueExpr *getOpaqueValue() const { return OpaqueValue; }
3725 
3726  /// getCond - Return the condition expression; this is defined
3727  /// in terms of the opaque value.
3728  Expr *getCond() const { return cast<Expr>(SubExprs[COND]); }
3729 
3730  /// getTrueExpr - Return the subexpression which will be
3731  /// evaluated if the condition evaluates to true; this is defined
3732  /// in terms of the opaque value.
3733  Expr *getTrueExpr() const {
3734  return cast<Expr>(SubExprs[LHS]);
3735  }
3736 
3737  /// getFalseExpr - Return the subexpression which will be
3738  /// evaluated if the condnition evaluates to false; this is
3739  /// defined in terms of the opaque value.
3740  Expr *getFalseExpr() const {
3741  return cast<Expr>(SubExprs[RHS]);
3742  }
3743 
3744  SourceLocation getBeginLoc() const LLVM_READONLY {
3745  return getCommon()->getBeginLoc();
3746  }
3747  SourceLocation getEndLoc() const LLVM_READONLY {
3748  return getFalseExpr()->getEndLoc();
3749  }
3750 
3751  static bool classof(const Stmt *T) {
3752  return T->getStmtClass() == BinaryConditionalOperatorClass;
3753  }
3754 
3755  // Iterators
3757  return child_range(SubExprs, SubExprs + NUM_SUBEXPRS);
3758  }
3760  return const_child_range(SubExprs, SubExprs + NUM_SUBEXPRS);
3761  }
3762 };
3763 
3765  if (const ConditionalOperator *co = dyn_cast<ConditionalOperator>(this))
3766  return co->getCond();
3767  return cast<BinaryConditionalOperator>(this)->getCond();
3768 }
3769 
3771  if (const ConditionalOperator *co = dyn_cast<ConditionalOperator>(this))
3772  return co->getTrueExpr();
3773  return cast<BinaryConditionalOperator>(this)->getTrueExpr();
3774 }
3775 
3777  if (const ConditionalOperator *co = dyn_cast<ConditionalOperator>(this))
3778  return co->getFalseExpr();
3779  return cast<BinaryConditionalOperator>(this)->getFalseExpr();
3780 }
3781 
3782 /// AddrLabelExpr - The GNU address of label extension, representing &&label.
3783 class AddrLabelExpr : public Expr {
3784  SourceLocation AmpAmpLoc, LabelLoc;
3785  LabelDecl *Label;
3786 public:
3788  QualType t)
3789  : Expr(AddrLabelExprClass, t, VK_RValue, OK_Ordinary, false, false, false,
3790  false),
3791  AmpAmpLoc(AALoc), LabelLoc(LLoc), Label(L) {}
3792 
3793  /// Build an empty address of a label expression.
3794  explicit AddrLabelExpr(EmptyShell Empty)
3795  : Expr(AddrLabelExprClass, Empty) { }
3796 
3797  SourceLocation getAmpAmpLoc() const { return AmpAmpLoc; }
3798  void setAmpAmpLoc(SourceLocation L) { AmpAmpLoc = L; }
3799  SourceLocation getLabelLoc() const { return LabelLoc; }
3800  void setLabelLoc(SourceLocation L) { LabelLoc = L; }
3801 
3802  SourceLocation getBeginLoc() const LLVM_READONLY { return AmpAmpLoc; }
3803  SourceLocation getEndLoc() const LLVM_READONLY { return LabelLoc; }
3804 
3805  LabelDecl *getLabel() const { return Label; }
3806  void setLabel(LabelDecl *L) { Label = L; }
3807 
3808  static bool classof(const Stmt *T) {
3809  return T->getStmtClass() == AddrLabelExprClass;
3810  }
3811 
3812  // Iterators
3815  }
3818  }
3819 };
3820 
3821 /// StmtExpr - This is the GNU Statement Expression extension: ({int X=4; X;}).
3822 /// The StmtExpr contains a single CompoundStmt node, which it evaluates and
3823 /// takes the value of the last subexpression.
3824 ///
3825 /// A StmtExpr is always an r-value; values "returned" out of a
3826 /// StmtExpr will be copied.
3827 class StmtExpr : public Expr {
3828  Stmt *SubStmt;
3829  SourceLocation LParenLoc, RParenLoc;
3830 public:
3831  // FIXME: Does type-dependence need to be computed differently?
3832  // FIXME: Do we need to compute instantiation instantiation-dependence for
3833  // statements? (ugh!)
3835  SourceLocation lp, SourceLocation rp) :
3836  Expr(StmtExprClass, T, VK_RValue, OK_Ordinary,
3837  T->isDependentType(), false, false, false),
3838  SubStmt(substmt), LParenLoc(lp), RParenLoc(rp) { }
3839 
3840  /// Build an empty statement expression.
3841  explicit StmtExpr(EmptyShell Empty) : Expr(StmtExprClass, Empty) { }
3842 
3843  CompoundStmt *getSubStmt() { return cast<CompoundStmt>(SubStmt); }
3844  const CompoundStmt *getSubStmt() const { return cast<CompoundStmt>(SubStmt); }
3845  void setSubStmt(CompoundStmt *S) { SubStmt = S; }
3846 
3847  SourceLocation getBeginLoc() const LLVM_READONLY { return LParenLoc; }
3848  SourceLocation getEndLoc() const LLVM_READONLY { return RParenLoc; }
3849 
3850  SourceLocation getLParenLoc() const { return LParenLoc; }
3851  void setLParenLoc(SourceLocation L) { LParenLoc = L; }
3852  SourceLocation getRParenLoc() const { return RParenLoc; }
3853  void setRParenLoc(SourceLocation L) { RParenLoc = L; }
3854 
3855  static bool classof(const Stmt *T) {
3856  return T->getStmtClass() == StmtExprClass;
3857  }
3858 
3859  // Iterators
3860  child_range children() { return child_range(&SubStmt, &SubStmt+1); }
3862  return const_child_range(&SubStmt, &SubStmt + 1);
3863  }
3864 };
3865 
3866 /// ShuffleVectorExpr - clang-specific builtin-in function
3867 /// __builtin_shufflevector.
3868 /// This AST node represents a operator that does a constant
3869 /// shuffle, similar to LLVM's shufflevector instruction. It takes
3870 /// two vectors and a variable number of constant indices,
3871 /// and returns the appropriately shuffled vector.
3872 class ShuffleVectorExpr : public Expr {
3873  SourceLocation BuiltinLoc, RParenLoc;
3874 
3875  // SubExprs - the list of values passed to the __builtin_shufflevector
3876  // function. The first two are vectors, and the rest are constant
3877  // indices. The number of values in this list is always
3878  // 2+the number of indices in the vector type.
3879  Stmt **SubExprs;
3880  unsigned NumExprs;
3881 
3882 public:
3884  SourceLocation BLoc, SourceLocation RP);
3885 
3886  /// Build an empty vector-shuffle expression.
3888  : Expr(ShuffleVectorExprClass, Empty), SubExprs(nullptr) { }
3889 
3890  SourceLocation getBuiltinLoc() const { return BuiltinLoc; }
3891  void setBuiltinLoc(SourceLocation L) { BuiltinLoc = L; }
3892 
3893  SourceLocation getRParenLoc() const { return RParenLoc; }
3894  void setRParenLoc(SourceLocation L) { RParenLoc = L; }
3895 
3896  SourceLocation getBeginLoc() const LLVM_READONLY { return BuiltinLoc; }
3897  SourceLocation getEndLoc() const LLVM_READONLY { return RParenLoc; }
3898 
3899  static bool classof(const Stmt *T) {
3900  return T->getStmtClass() == ShuffleVectorExprClass;
3901  }
3902 
3903  /// getNumSubExprs - Return the size of the SubExprs array. This includes the
3904  /// constant expression, the actual arguments passed in, and the function
3905  /// pointers.
3906  unsigned getNumSubExprs() const { return NumExprs; }
3907 
3908  /// Retrieve the array of expressions.
3909  Expr **getSubExprs() { return reinterpret_cast<Expr **>(SubExprs); }
3910 
3911  /// getExpr - Return the Expr at the specified index.
3912  Expr *getExpr(unsigned Index) {
3913  assert((Index < NumExprs) && "Arg access out of range!");
3914  return cast<Expr>(SubExprs[Index]);
3915  }
3916  const Expr *getExpr(unsigned Index) const {
3917  assert((Index < NumExprs) && "Arg access out of range!");
3918  return cast<Expr>(SubExprs[Index]);
3919  }
3920 
3921  void setExprs(const ASTContext &C, ArrayRef<Expr *> Exprs);
3922 
3923  llvm::APSInt getShuffleMaskIdx(const ASTContext &Ctx, unsigned N) const {
3924  assert((N < NumExprs - 2) && "Shuffle idx out of range!");
3925  return getExpr(N+2)->EvaluateKnownConstInt(Ctx);
3926  }
3927 
3928  // Iterators
3930  return child_range(&SubExprs[0], &SubExprs[0]+NumExprs);
3931  }
3933  return const_child_range(&SubExprs[0], &SubExprs[0] + NumExprs);
3934  }
3935 };
3936 
3937 /// ConvertVectorExpr - Clang builtin function __builtin_convertvector
3938 /// This AST node provides support for converting a vector type to another
3939 /// vector type of the same arity.
3940 class ConvertVectorExpr : public Expr {
3941 private:
3942  Stmt *SrcExpr;
3943  TypeSourceInfo *TInfo;
3944  SourceLocation BuiltinLoc, RParenLoc;
3945 
3946  friend class ASTReader;
3947  friend class ASTStmtReader;
3948  explicit ConvertVectorExpr(EmptyShell Empty) : Expr(ConvertVectorExprClass, Empty) {}
3949 
3950 public:
3953  SourceLocation BuiltinLoc, SourceLocation RParenLoc)
3954  : Expr(ConvertVectorExprClass, DstType, VK, OK,
3955  DstType->isDependentType(),
3956  DstType->isDependentType() || SrcExpr->isValueDependent(),
3957  (DstType->isInstantiationDependentType() ||
3958  SrcExpr->isInstantiationDependent()),
3959  (DstType->containsUnexpandedParameterPack() ||
3960  SrcExpr->containsUnexpandedParameterPack())),
3961  SrcExpr(SrcExpr), TInfo(TI), BuiltinLoc(BuiltinLoc), RParenLoc(RParenLoc) {}
3962 
3963  /// getSrcExpr - Return the Expr to be converted.
3964  Expr *getSrcExpr() const { return cast<Expr>(SrcExpr); }
3965 
3966  /// getTypeSourceInfo - Return the destination type.
3968  return TInfo;
3969  }
3971  TInfo = ti;
3972  }
3973 
3974  /// getBuiltinLoc - Return the location of the __builtin_convertvector token.
3975  SourceLocation getBuiltinLoc() const { return BuiltinLoc; }
3976 
3977  /// getRParenLoc - Return the location of final right parenthesis.
3978  SourceLocation getRParenLoc() const { return RParenLoc; }
3979 
3980  SourceLocation getBeginLoc() const LLVM_READONLY { return BuiltinLoc; }
3981  SourceLocation getEndLoc() const LLVM_READONLY { return RParenLoc; }
3982 
3983  static bool classof(const Stmt *T) {
3984  return T->getStmtClass() == ConvertVectorExprClass;
3985  }
3986 
3987  // Iterators
3988  child_range children() { return child_range(&SrcExpr, &SrcExpr+1); }
3990  return const_child_range(&SrcExpr, &SrcExpr + 1);
3991  }
3992 };
3993 
3994 /// ChooseExpr - GNU builtin-in function __builtin_choose_expr.
3995 /// This AST node is similar to the conditional operator (?:) in C, with
3996 /// the following exceptions:
3997 /// - the test expression must be a integer constant expression.
3998 /// - the expression returned acts like the chosen subexpression in every
3999 /// visible way: the type is the same as that of the chosen subexpression,
4000 /// and all predicates (whether it's an l-value, whether it's an integer
4001 /// constant expression, etc.) return the same result as for the chosen
4002 /// sub-expression.
4003 class ChooseExpr : public Expr {
4004  enum { COND, LHS, RHS, END_EXPR };
4005  Stmt* SubExprs[END_EXPR]; // Left/Middle/Right hand sides.
4006  SourceLocation BuiltinLoc, RParenLoc;
4007  bool CondIsTrue;
4008 public:
4009  ChooseExpr(SourceLocation BLoc, Expr *cond, Expr *lhs, Expr *rhs,
4011  SourceLocation RP, bool condIsTrue,
4012  bool TypeDependent, bool ValueDependent)
4013  : Expr(ChooseExprClass, t, VK, OK, TypeDependent, ValueDependent,
4014  (cond->isInstantiationDependent() ||
4015  lhs->isInstantiationDependent() ||
4016  rhs->isInstantiationDependent()),
4017  (cond->containsUnexpandedParameterPack() ||
4018  lhs->containsUnexpandedParameterPack() ||
4019  rhs->containsUnexpandedParameterPack())),
4020  BuiltinLoc(BLoc), RParenLoc(RP), CondIsTrue(condIsTrue) {
4021  SubExprs[COND] = cond;
4022  SubExprs[LHS] = lhs;
4023  SubExprs[RHS] = rhs;
4024  }
4025 
4026  /// Build an empty __builtin_choose_expr.
4027  explicit ChooseExpr(EmptyShell Empty) : Expr(ChooseExprClass, Empty) { }
4028 
4029  /// isConditionTrue - Return whether the condition is true (i.e. not
4030  /// equal to zero).
4031  bool isConditionTrue() const {
4032  assert(!isConditionDependent() &&
4033  "Dependent condition isn't true or false");
4034  return CondIsTrue;
4035  }
4036  void setIsConditionTrue(bool isTrue) { CondIsTrue = isTrue; }
4037 
4038  bool isConditionDependent() const {
4039  return getCond()->isTypeDependent() || getCond()->isValueDependent();
4040  }
4041 
4042  /// getChosenSubExpr - Return the subexpression chosen according to the
4043  /// condition.
4045  return isConditionTrue() ? getLHS() : getRHS();
4046  }
4047 
4048  Expr *getCond() const { return cast<Expr>(SubExprs[COND]); }
4049  void setCond(Expr *E) { SubExprs[COND] = E; }
4050  Expr *getLHS() const { return cast<Expr>(SubExprs[LHS]); }
4051  void setLHS(Expr *E) { SubExprs[LHS] = E; }
4052  Expr *getRHS() const { return cast<Expr>(SubExprs[RHS]); }
4053  void setRHS(Expr *E) { SubExprs[RHS] = E; }
4054 
4055  SourceLocation getBuiltinLoc() const { return BuiltinLoc; }
4056  void setBuiltinLoc(SourceLocation L) { BuiltinLoc = L; }
4057 
4058  SourceLocation getRParenLoc() const { return RParenLoc; }
4059  void setRParenLoc(SourceLocation L) { RParenLoc = L; }
4060 
4061  SourceLocation getBeginLoc() const LLVM_READONLY { return BuiltinLoc; }
4062  SourceLocation getEndLoc() const LLVM_READONLY { return RParenLoc; }
4063 
4064  static bool classof(const Stmt *T) {
4065  return T->getStmtClass() == ChooseExprClass;
4066  }
4067 
4068  // Iterators
4070  return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
4071  }
4073  return const_child_range(&SubExprs[0], &SubExprs[0] + END_EXPR);
4074  }
4075 };
4076 
4077 /// GNUNullExpr - Implements the GNU __null extension, which is a name
4078 /// for a null pointer constant that has integral type (e.g., int or
4079 /// long) and is the same size and alignment as a pointer. The __null
4080 /// extension is typically only used by system headers, which define
4081 /// NULL as __null in C++ rather than using 0 (which is an integer
4082 /// that may not match the size of a pointer).
4083 class GNUNullExpr : public Expr {
4084  /// TokenLoc - The location of the __null keyword.
4085  SourceLocation TokenLoc;
4086 
4087 public:
4089  : Expr(GNUNullExprClass, Ty, VK_RValue, OK_Ordinary, false, false, false,
4090  false),
4091  TokenLoc(Loc) { }
4092 
4093  /// Build an empty GNU __null expression.
4094  explicit GNUNullExpr(EmptyShell Empty) : Expr(GNUNullExprClass, Empty) { }
4095 
4096  /// getTokenLocation - The location of the __null token.
4097  SourceLocation getTokenLocation() const { return TokenLoc; }
4098  void setTokenLocation(SourceLocation L) { TokenLoc = L; }
4099 
4100  SourceLocation getBeginLoc() const LLVM_READONLY { return TokenLoc; }
4101  SourceLocation getEndLoc() const LLVM_READONLY { return TokenLoc; }
4102 
4103  static bool classof(const Stmt *T) {
4104  return T->getStmtClass() == GNUNullExprClass;
4105  }
4106 
4107  // Iterators
4110  }
4113  }
4114 };
4115 
4116 /// Represents a call to the builtin function \c __builtin_va_arg.
4117 class VAArgExpr : public Expr {
4118  Stmt *Val;
4119  llvm::PointerIntPair<TypeSourceInfo *, 1, bool> TInfo;
4120  SourceLocation BuiltinLoc, RParenLoc;
4121 public:
4123  SourceLocation RPLoc, QualType t, bool IsMS)
4124  : Expr(VAArgExprClass, t, VK_RValue, OK_Ordinary, t->isDependentType(),
4125  false, (TInfo->getType()->isInstantiationDependentType() ||
4126  e->isInstantiationDependent()),
4127  (TInfo->getType()->containsUnexpandedParameterPack() ||
4128  e->containsUnexpandedParameterPack())),
4129  Val(e), TInfo(TInfo, IsMS), BuiltinLoc(BLoc), RParenLoc(RPLoc) {}
4130 
4131  /// Create an empty __builtin_va_arg expression.
4132  explicit VAArgExpr(EmptyShell Empty)
4133  : Expr(VAArgExprClass, Empty), Val(nullptr), TInfo(nullptr, false) {}
4134 
4135  const Expr *getSubExpr() const { return cast<Expr>(Val); }
4136  Expr *getSubExpr() { return cast<Expr>(Val); }
4137  void setSubExpr(Expr *E) { Val = E; }
4138 
4139  /// Returns whether this is really a Win64 ABI va_arg expression.
4140  bool isMicrosoftABI() const { return TInfo.getInt(); }
4141  void setIsMicrosoftABI(bool IsMS) { TInfo.setInt(IsMS); }
4142 
4143  TypeSourceInfo *getWrittenTypeInfo() const { return TInfo.getPointer(); }
4144  void setWrittenTypeInfo(TypeSourceInfo *TI) { TInfo.setPointer(TI); }
4145 
4146  SourceLocation getBuiltinLoc() const { return BuiltinLoc; }
4147  void setBuiltinLoc(SourceLocation L) { BuiltinLoc = L; }
4148 
4149  SourceLocation getRParenLoc() const { return RParenLoc; }
4150  void setRParenLoc(SourceLocation L) { RParenLoc = L; }
4151 
4152  SourceLocation getBeginLoc() const LLVM_READONLY { return BuiltinLoc; }
4153  SourceLocation getEndLoc() const LLVM_READONLY { return RParenLoc; }
4154 
4155  static bool classof(const Stmt *T) {
4156  return T->getStmtClass() == VAArgExprClass;
4157  }
4158 
4159  // Iterators
4160  child_range children() { return child_range(&Val, &Val+1); }
4162  return const_child_range(&Val, &Val + 1);
4163  }
4164 };
4165 
4166 /// Describes an C or C++ initializer list.
4167 ///
4168 /// InitListExpr describes an initializer list, which can be used to
4169 /// initialize objects of different types, including
4170 /// struct/class/union types, arrays, and vectors. For example:
4171 ///
4172 /// @code
4173 /// struct foo x = { 1, { 2, 3 } };
4174 /// @endcode
4175 ///
4176 /// Prior to semantic analysis, an initializer list will represent the
4177 /// initializer list as written by the user, but will have the
4178 /// placeholder type "void". This initializer list is called the
4179 /// syntactic form of the initializer, and may contain C99 designated
4180 /// initializers (represented as DesignatedInitExprs), initializations
4181 /// of subobject members without explicit braces, and so on. Clients
4182 /// interested in the original syntax of the initializer list should
4183 /// use the syntactic form of the initializer list.
4184 ///
4185 /// After semantic analysis, the initializer list will represent the
4186 /// semantic form of the initializer, where the initializations of all
4187 /// subobjects are made explicit with nested InitListExpr nodes and
4188 /// C99 designators have been eliminated by placing the designated
4189 /// initializations into the subobject they initialize. Additionally,
4190 /// any "holes" in the initialization, where no initializer has been
4191 /// specified for a particular subobject, will be replaced with
4192 /// implicitly-generated ImplicitValueInitExpr expressions that
4193 /// value-initialize the subobjects. Note, however, that the
4194 /// initializer lists may still have fewer initializers than there are
4195 /// elements to initialize within the object.
4196 ///
4197 /// After semantic analysis has completed, given an initializer list,
4198 /// method isSemanticForm() returns true if and only if this is the
4199 /// semantic form of the initializer list (note: the same AST node
4200 /// may at the same time be the syntactic form).
4201 /// Given the semantic form of the initializer list, one can retrieve
4202 /// the syntactic form of that initializer list (when different)
4203 /// using method getSyntacticForm(); the method returns null if applied
4204 /// to a initializer list which is already in syntactic form.
4205 /// Similarly, given the syntactic form (i.e., an initializer list such
4206 /// that isSemanticForm() returns false), one can retrieve the semantic
4207 /// form using method getSemanticForm().
4208 /// Since many initializer lists have the same syntactic and semantic forms,
4209 /// getSyntacticForm() may return NULL, indicating that the current
4210 /// semantic initializer list also serves as its syntactic form.
4211 class InitListExpr : public Expr {
4212  // FIXME: Eliminate this vector in favor of ASTContext allocation
4214  InitExprsTy InitExprs;
4215  SourceLocation LBraceLoc, RBraceLoc;
4216 
4217  /// The alternative form of the initializer list (if it exists).
4218  /// The int part of the pair stores whether this initializer list is
4219  /// in semantic form. If not null, the pointer points to:
4220  /// - the syntactic form, if this is in semantic form;
4221  /// - the semantic form, if this is in syntactic form.
4222  llvm::PointerIntPair<InitListExpr *, 1, bool> AltForm;
4223 
4224  /// Either:
4225  /// If this initializer list initializes an array with more elements than
4226  /// there are initializers in the list, specifies an expression to be used
4227  /// for value initialization of the rest of the elements.
4228  /// Or
4229  /// If this initializer list initializes a union, specifies which
4230  /// field within the union will be initialized.
4231  llvm::PointerUnion<Expr *, FieldDecl *> ArrayFillerOrUnionFieldInit;
4232 
4233 public:
4234  InitListExpr(const ASTContext &C, SourceLocation lbraceloc,
4235  ArrayRef<Expr*> initExprs, SourceLocation rbraceloc);
4236 
4237  /// Build an empty initializer list.
4238  explicit InitListExpr(EmptyShell Empty)
4239  : Expr(InitListExprClass, Empty), AltForm(nullptr, true) { }
4240 
4241  unsigned getNumInits() const { return InitExprs.size(); }
4242 
4243  /// Retrieve the set of initializers.
4244  Expr **getInits() { return reinterpret_cast<Expr **>(InitExprs.data()); }
4245 
4246  /// Retrieve the set of initializers.
4247  Expr * const *getInits() const {
4248  return reinterpret_cast<Expr * const *>(InitExprs.data());
4249  }
4250 
4252  return llvm::makeArrayRef(getInits(), getNumInits());
4253  }
4254 
4256  return llvm::makeArrayRef(getInits(), getNumInits());
4257  }
4258 
4259  const Expr *getInit(unsigned Init) const {
4260  assert(Init < getNumInits() && "Initializer access out of range!");
4261  return cast_or_null<Expr>(InitExprs[Init]);
4262  }
4263 
4264  Expr *getInit(unsigned Init) {
4265  assert(Init < getNumInits() && "Initializer access out of range!");
4266  return cast_or_null<Expr>(InitExprs[Init]);
4267  }
4268 
4269  void setInit(unsigned Init, Expr *expr) {
4270  assert(Init < getNumInits() && "Initializer access out of range!");
4271  InitExprs[Init] = expr;
4272 
4273  if (expr) {
4274  ExprBits.TypeDependent |= expr->isTypeDependent();
4275  ExprBits.ValueDependent |= expr->isValueDependent();
4276  ExprBits.InstantiationDependent |= expr->isInstantiationDependent();
4277  ExprBits.ContainsUnexpandedParameterPack |=
4279  }
4280  }
4281 
4282  /// Reserve space for some number of initializers.
4283  void reserveInits(const ASTContext &C, unsigned NumInits);
4284 
4285  /// Specify the number of initializers
4286  ///
4287  /// If there are more than @p NumInits initializers, the remaining
4288  /// initializers will be destroyed. If there are fewer than @p
4289  /// NumInits initializers, NULL expressions will be added for the
4290  /// unknown initializers.
4291  void resizeInits(const ASTContext &Context, unsigned NumInits);
4292 
4293  /// Updates the initializer at index @p Init with the new
4294  /// expression @p expr, and returns the old expression at that
4295  /// location.
4296  ///
4297  /// When @p Init is out of range for this initializer list, the
4298  /// initializer list will be extended with NULL expressions to
4299  /// accommodate the new entry.
4300  Expr *updateInit(const ASTContext &C, unsigned Init, Expr *expr);
4301 
4302  /// If this initializer list initializes an array with more elements
4303  /// than there are initializers in the list, specifies an expression to be
4304  /// used for value initialization of the rest of the elements.
4306  return ArrayFillerOrUnionFieldInit.dyn_cast<Expr *>();
4307  }
4308  const Expr *getArrayFiller() const {
4309  return const_cast<InitListExpr *>(this)->getArrayFiller();
4310  }
4311  void setArrayFiller(Expr *filler);
4312 
4313  /// Return true if this is an array initializer and its array "filler"
4314  /// has been set.
4315  bool hasArrayFiller() const { return getArrayFiller(); }
4316 
4317  /// If this initializes a union, specifies which field in the
4318  /// union to initialize.
4319  ///
4320  /// Typically, this field is the first named field within the
4321  /// union. However, a designated initializer can specify the
4322  /// initialization of a different field within the union.
4324  return ArrayFillerOrUnionFieldInit.dyn_cast<FieldDecl *>();
4325  }
4327  return const_cast<InitListExpr *>(this)->getInitializedFieldInUnion();
4328  }
4330  assert((FD == nullptr
4331  || getInitializedFieldInUnion() == nullptr
4332  || getInitializedFieldInUnion() == FD)
4333  && "Only one field of a union may be initialized at a time!");
4334  ArrayFillerOrUnionFieldInit = FD;
4335  }
4336 
4337  // Explicit InitListExpr's originate from source code (and have valid source
4338  // locations). Implicit InitListExpr's are created by the semantic analyzer.
4339  bool isExplicit() const {
4340  return LBraceLoc.isValid() && RBraceLoc.isValid();
4341  }
4342 
4343  // Is this an initializer for an array of characters, initialized by a string
4344  // literal or an @encode?
4345  bool isStringLiteralInit() const;
4346 
4347  /// Is this a transparent initializer list (that is, an InitListExpr that is
4348  /// purely syntactic, and whose semantics are that of the sole contained
4349  /// initializer)?
4350  bool isTransparent() const;
4351 
4352  /// Is this the zero initializer {0} in a language which considers it
4353  /// idiomatic?
4354  bool isIdiomaticZeroInitializer(const LangOptions &LangOpts) const;
4355 
4356  SourceLocation getLBraceLoc() const { return LBraceLoc; }
4357  void setLBraceLoc(SourceLocation Loc) { LBraceLoc = Loc; }
4358  SourceLocation getRBraceLoc() const { return RBraceLoc; }
4359  void setRBraceLoc(SourceLocation Loc) { RBraceLoc = Loc; }
4360 
4361  bool isSemanticForm() const { return AltForm.getInt(); }
4363  return isSemanticForm() ? nullptr : AltForm.getPointer();
4364  }
4365  bool isSyntacticForm() const {
4366  return !AltForm.getInt() || !AltForm.getPointer();
4367  }
4369  return isSemanticForm() ? AltForm.getPointer() : nullptr;
4370  }
4371 
4373  AltForm.setPointer(Init);
4374  AltForm.setInt(true);
4375  Init->AltForm.setPointer(this);
4376  Init->AltForm.setInt(false);
4377  }
4378 
4380  return InitListExprBits.HadArrayRangeDesignator != 0;
4381  }
4382  void sawArrayRangeDesignator(bool ARD = true) {
4383  InitListExprBits.HadArrayRangeDesignator = ARD;
4384  }
4385 
4386  SourceLocation getBeginLoc() const LLVM_READONLY;
4387  SourceLocation getEndLoc() const LLVM_READONLY;
4388 
4389  static bool classof(const Stmt *T) {
4390  return T->getStmtClass() == InitListExprClass;
4391  }
4392 
4393  // Iterators
4395  const_child_range CCR = const_cast<const InitListExpr *>(this)->children();
4396  return child_range(cast_away_const(CCR.begin()),
4397  cast_away_const(CCR.end()));
4398  }
4399 
4401  // FIXME: This does not include the array filler expression.
4402  if (InitExprs.empty())
4404  return const_child_range(&InitExprs[0], &InitExprs[0] + InitExprs.size());
4405  }
4406 
4411 
4412  iterator begin() { return InitExprs.begin(); }
4413  const_iterator begin() const { return InitExprs.begin(); }
4414  iterator end() { return InitExprs.end(); }
4415  const_iterator end() const { return InitExprs.end(); }
4416  reverse_iterator rbegin() { return InitExprs.rbegin(); }
4417  const_reverse_iterator rbegin() const { return InitExprs.rbegin(); }
4418  reverse_iterator rend() { return InitExprs.rend(); }
4419  const_reverse_iterator rend() const { return InitExprs.rend(); }
4420 
4421  friend class ASTStmtReader;
4422  friend class ASTStmtWriter;
4423 };
4424 
4425 /// Represents a C99 designated initializer expression.
4426 ///
4427 /// A designated initializer expression (C99 6.7.8) contains one or
4428 /// more designators (which can be field designators, array
4429 /// designators, or GNU array-range designators) followed by an
4430 /// expression that initializes the field or element(s) that the
4431 /// designators refer to. For example, given:
4432 ///
4433 /// @code
4434 /// struct point {
4435 /// double x;
4436 /// double y;
4437 /// };
4438 /// struct point ptarray[10] = { [2].y = 1.0, [2].x = 2.0, [0].x = 1.0 };
4439 /// @endcode
4440 ///
4441 /// The InitListExpr contains three DesignatedInitExprs, the first of
4442 /// which covers @c [2].y=1.0. This DesignatedInitExpr will have two
4443 /// designators, one array designator for @c [2] followed by one field
4444 /// designator for @c .y. The initialization expression will be 1.0.
4446  : public Expr,
4447  private llvm::TrailingObjects<DesignatedInitExpr, Stmt *> {
4448 public:
4449  /// Forward declaration of the Designator class.
4450  class Designator;
4451 
4452 private:
4453  /// The location of the '=' or ':' prior to the actual initializer
4454  /// expression.
4455  SourceLocation EqualOrColonLoc;
4456 
4457  /// Whether this designated initializer used the GNU deprecated
4458  /// syntax rather than the C99 '=' syntax.
4459  unsigned GNUSyntax : 1;
4460 
4461  /// The number of designators in this initializer expression.
4462  unsigned NumDesignators : 15;
4463 
4464  /// The number of subexpressions of this initializer expression,
4465  /// which contains both the initializer and any additional
4466  /// expressions used by array and array-range designators.
4467  unsigned NumSubExprs : 16;
4468 
4469  /// The designators in this designated initialization
4470  /// expression.
4471  Designator *Designators;
4472 
4474  llvm::ArrayRef<Designator> Designators,
4475  SourceLocation EqualOrColonLoc, bool GNUSyntax,
4476  ArrayRef<Expr *> IndexExprs, Expr *Init);
4477 
4478  explicit DesignatedInitExpr(unsigned NumSubExprs)
4479  : Expr(DesignatedInitExprClass, EmptyShell()),
4480  NumDesignators(0), NumSubExprs(NumSubExprs), Designators(nullptr) { }
4481 
4482 public:
4483  /// A field designator, e.g., ".x".
4485  /// Refers to the field that is being initialized. The low bit
4486  /// of this field determines whether this is actually a pointer
4487  /// to an IdentifierInfo (if 1) or a FieldDecl (if 0). When
4488  /// initially constructed, a field designator will store an
4489  /// IdentifierInfo*. After semantic analysis has resolved that
4490  /// name, the field designator will instead store a FieldDecl*.
4492 
4493  /// The location of the '.' in the designated initializer.
4494  unsigned DotLoc;
4495 
4496  /// The location of the field name in the designated initializer.
4497  unsigned FieldLoc;
4498  };
4499 
4500  /// An array or GNU array-range designator, e.g., "[9]" or "[10..15]".
4502  /// Location of the first index expression within the designated
4503  /// initializer expression's list of subexpressions.
4504  unsigned Index;
4505  /// The location of the '[' starting the array range designator.
4506  unsigned LBracketLoc;
4507  /// The location of the ellipsis separating the start and end
4508  /// indices. Only valid for GNU array-range designators.
4509  unsigned EllipsisLoc;
4510  /// The location of the ']' terminating the array range designator.
4511  unsigned RBracketLoc;
4512  };
4513 
4514  /// Represents a single C99 designator.
4515  ///
4516  /// @todo This class is infuriatingly similar to clang::Designator,
4517  /// but minor differences (storing indices vs. storing pointers)
4518  /// keep us from reusing it. Try harder, later, to rectify these
4519  /// differences.
4520  class Designator {
4521  /// The kind of designator this describes.
4522  enum {
4524  ArrayDesignator,
4525  ArrayRangeDesignator
4526  } Kind;
4527 
4528  union {
4529  /// A field designator, e.g., ".x".
4531  /// An array or GNU array-range designator, e.g., "[9]" or "[10..15]".
4532  struct ArrayOrRangeDesignator ArrayOrRange;
4533  };
4534  friend class DesignatedInitExpr;
4535 
4536  public:
4538 
4539  /// Initializes a field designator.
4540  Designator(const IdentifierInfo *FieldName, SourceLocation DotLoc,
4541  SourceLocation FieldLoc)
4542  : Kind(FieldDesignator) {
4543  Field.NameOrField = reinterpret_cast<uintptr_t>(FieldName) | 0x01;
4544  Field.DotLoc = DotLoc.getRawEncoding();
4545  Field.FieldLoc = FieldLoc.getRawEncoding();
4546  }
4547 
4548  /// Initializes an array designator.
4549  Designator(unsigned Index, SourceLocation LBracketLoc,
4550  SourceLocation RBracketLoc)
4551  : Kind(ArrayDesignator) {
4552  ArrayOrRange.Index = Index;
4553  ArrayOrRange.LBracketLoc = LBracketLoc.getRawEncoding();
4554  ArrayOrRange.EllipsisLoc = SourceLocation().getRawEncoding();
4555  ArrayOrRange.RBracketLoc = RBracketLoc.getRawEncoding();
4556  }
4557 
4558  /// Initializes a GNU array-range designator.
4559  Designator(unsigned Index, SourceLocation LBracketLoc,
4560  SourceLocation EllipsisLoc, SourceLocation RBracketLoc)
4561  : Kind(ArrayRangeDesignator) {
4562  ArrayOrRange.Index = Index;
4563  ArrayOrRange.LBracketLoc = LBracketLoc.getRawEncoding();
4564  ArrayOrRange.EllipsisLoc = EllipsisLoc.getRawEncoding();
4565  ArrayOrRange.RBracketLoc = RBracketLoc.getRawEncoding();
4566  }
4567 
4568  bool isFieldDesignator() const { return Kind == FieldDesignator; }
4569  bool isArrayDesignator() const { return Kind == ArrayDesignator; }
4570  bool isArrayRangeDesignator() const { return Kind == ArrayRangeDesignator; }
4571 
4572  IdentifierInfo *getFieldName() const;
4573 
4574  FieldDecl *getField() const {
4575  assert(Kind == FieldDesignator && "Only valid on a field designator");
4576  if (Field.NameOrField & 0x01)
4577  return nullptr;
4578  else
4579  return reinterpret_cast<FieldDecl *>(Field.NameOrField);
4580  }
4581 
4582  void setField(FieldDecl *FD) {
4583  assert(Kind == FieldDesignator && "Only valid on a field designator");
4584  Field.NameOrField = reinterpret_cast<uintptr_t>(FD);
4585  }
4586 
4588  assert(Kind == FieldDesignator && "Only valid on a field designator");
4590  }
4591 
4593  assert(Kind == FieldDesignator && "Only valid on a field designator");
4594  return SourceLocation::getFromRawEncoding(Field.FieldLoc);
4595  }
4596 
4598  assert((Kind == ArrayDesignator || Kind == ArrayRangeDesignator) &&
4599  "Only valid on an array or array-range designator");
4600  return SourceLocation::getFromRawEncoding(ArrayOrRange.LBracketLoc);
4601  }
4602 
4604  assert((Kind == ArrayDesignator || Kind == ArrayRangeDesignator) &&
4605  "Only valid on an array or array-range designator");
4606  return SourceLocation::getFromRawEncoding(ArrayOrRange.RBracketLoc);
4607  }
4608 
4610  assert(Kind == ArrayRangeDesignator &&
4611  "Only valid on an array-range designator");
4612  return SourceLocation::getFromRawEncoding(ArrayOrRange.EllipsisLoc);
4613  }
4614 
4615  unsigned getFirstExprIndex() const {
4616  assert((Kind == ArrayDesignator || Kind == ArrayRangeDesignator) &&
4617  "Only valid on an array or array-range designator");
4618  return ArrayOrRange.Index;
4619  }
4620 
4621  SourceLocation getBeginLoc() const LLVM_READONLY {
4622  if (Kind == FieldDesignator)
4623  return getDotLoc().isInvalid()? getFieldLoc() : getDotLoc();
4624  else
4625  return getLBracketLoc();
4626  }
4627  SourceLocation getEndLoc() const LLVM_READONLY {
4628  return Kind == FieldDesignator ? getFieldLoc() : getRBracketLoc();
4629  }
4630  SourceRange getSourceRange() const LLVM_READONLY {
4631  return SourceRange(getBeginLoc(), getEndLoc());
4632  }
4633  };
4634 
4635  static DesignatedInitExpr *Create(const ASTContext &C,
4636  llvm::ArrayRef<Designator> Designators,
4637  ArrayRef<Expr*> IndexExprs,
4638  SourceLocation EqualOrColonLoc,
4639  bool GNUSyntax, Expr *Init);
4640 
4641  static DesignatedInitExpr *CreateEmpty(const ASTContext &C,
4642  unsigned NumIndexExprs);
4643 
4644  /// Returns the number of designators in this initializer.
4645  unsigned size() const { return NumDesignators; }
4646 
4647  // Iterator access to the designators.
4649  return {Designators, NumDesignators};
4650  }
4651 
4653  return {Designators, NumDesignators};
4654  }
4655 
4656  Designator *getDesignator(unsigned Idx) { return &designators()[Idx]; }
4657  const Designator *getDesignator(unsigned Idx) const {
4658  return &designators()[Idx];
4659  }
4660 
4661  void setDesignators(const ASTContext &C, const Designator *Desigs,
4662  unsigned NumDesigs);
4663 
4664  Expr *getArrayIndex(const Designator &D) const;
4665  Expr *getArrayRangeStart(const Designator &D) const;
4666  Expr *getArrayRangeEnd(const Designator &D) const;
4667 
4668  /// Retrieve the location of the '=' that precedes the
4669  /// initializer value itself, if present.
4670  SourceLocation getEqualOrColonLoc() const { return EqualOrColonLoc; }
4671  void setEqualOrColonLoc(SourceLocation L) { EqualOrColonLoc = L; }
4672 
4673  /// Determines whether this designated initializer used the
4674  /// deprecated GNU syntax for designated initializers.
4675  bool usesGNUSyntax() const { return GNUSyntax; }
4676  void setGNUSyntax(bool GNU) { GNUSyntax = GNU; }
4677 
4678  /// Retrieve the initializer value.
4679  Expr *getInit() const {
4680  return cast<Expr>(*const_cast<DesignatedInitExpr*>(this)->child_begin());
4681  }
4682 
4683  void setInit(Expr *init) {
4684  *child_begin() = init;
4685  }
4686 
4687  /// Retrieve the total number of subexpressions in this
4688  /// designated initializer expression, including the actual
4689  /// initialized value and any expressions that occur within array
4690  /// and array-range designators.
4691  unsigned getNumSubExprs() const { return NumSubExprs; }
4692 
4693  Expr *getSubExpr(unsigned Idx) const {
4694  assert(Idx < NumSubExprs && "Subscript out of range");
4695  return cast<Expr>(getTrailingObjects<Stmt *>()[Idx]);
4696  }
4697 
4698  void setSubExpr(unsigned Idx, Expr *E) {
4699  assert(Idx < NumSubExprs && "Subscript out of range");
4700  getTrailingObjects<Stmt *>()[Idx] = E;
4701  }
4702 
4703  /// Replaces the designator at index @p Idx with the series
4704  /// of designators in [First, Last).
4705  void ExpandDesignator(const ASTContext &C, unsigned Idx,
4706  const Designator *First, const Designator *Last);
4707 
4708  SourceRange getDesignatorsSourceRange() const;
4709 
4710  SourceLocation getBeginLoc() const LLVM_READONLY;
4711  SourceLocation getEndLoc() const LLVM_READONLY;
4712 
4713  static bool classof(const Stmt *T) {
4714  return T->getStmtClass() == DesignatedInitExprClass;
4715  }
4716 
4717  // Iterators
4719  Stmt **begin = getTrailingObjects<Stmt *>();
4720  return child_range(begin, begin + NumSubExprs);
4721  }
4723  Stmt * const *begin = getTrailingObjects<Stmt *>();
4724  return const_child_range(begin, begin + NumSubExprs);
4725  }
4726 
4728 };
4729 
4730 /// Represents a place-holder for an object not to be initialized by
4731 /// anything.
4732 ///
4733 /// This only makes sense when it appears as part of an updater of a
4734 /// DesignatedInitUpdateExpr (see below). The base expression of a DIUE
4735 /// initializes a big object, and the NoInitExpr's mark the spots within the
4736 /// big object not to be overwritten by the updater.
4737 ///
4738 /// \see DesignatedInitUpdateExpr
4739 class NoInitExpr : public Expr {
4740 public:
4741  explicit NoInitExpr(QualType ty)
4742  : Expr(NoInitExprClass, ty, VK_RValue, OK_Ordinary,
4743  false, false, ty->isInstantiationDependentType(), false) { }
4744 
4745  explicit NoInitExpr(EmptyShell Empty)
4746  : Expr(NoInitExprClass, Empty) { }
4747 
4748  static bool classof(const Stmt *T) {
4749  return T->getStmtClass() == NoInitExprClass;
4750  }
4751 
4752  SourceLocation getBeginLoc() const LLVM_READONLY { return SourceLocation(); }
4753  SourceLocation getEndLoc() const LLVM_READONLY { return SourceLocation(); }
4754 
4755  // Iterators
4758  }
4761  }
4762 };
4763 
4764 // In cases like:
4765 // struct Q { int a, b, c; };
4766 // Q *getQ();
4767 // void foo() {
4768 // struct A { Q q; } a = { *getQ(), .q.b = 3 };
4769 // }
4770 //
4771 // We will have an InitListExpr for a, with type A, and then a
4772 // DesignatedInitUpdateExpr for "a.q" with type Q. The "base" for this DIUE
4773 // is the call expression *getQ(); the "updater" for the DIUE is ".q.b = 3"
4774 //
4776  // BaseAndUpdaterExprs[0] is the base expression;
4777  // BaseAndUpdaterExprs[1] is an InitListExpr overwriting part of the base.
4778  Stmt *BaseAndUpdaterExprs[2];
4779 
4780 public:
4782  Expr *baseExprs, SourceLocation rBraceLoc);
4783 
4785  : Expr(DesignatedInitUpdateExprClass, Empty) { }
4786 
4787  SourceLocation getBeginLoc() const LLVM_READONLY;
4788  SourceLocation getEndLoc() const LLVM_READONLY;
4789 
4790  static bool classof(const Stmt *T) {
4791  return T->getStmtClass() == DesignatedInitUpdateExprClass;
4792  }
4793 
4794  Expr *getBase() const { return cast<Expr>(BaseAndUpdaterExprs[0]); }
4795  void setBase(Expr *Base) { BaseAndUpdaterExprs[0] = Base; }
4796 
4798  return cast<InitListExpr>(BaseAndUpdaterExprs[1]);
4799  }
4800  void setUpdater(Expr *Updater) { BaseAndUpdaterExprs[1] = Updater; }
4801 
4802  // Iterators
4803  // children = the base and the updater
4805  return child_range(&BaseAndUpdaterExprs[0], &BaseAndUpdaterExprs[0] + 2);
4806  }
4808  return const_child_range(&BaseAndUpdaterExprs[0],
4809  &BaseAndUpdaterExprs[0] + 2);
4810  }
4811 };
4812 
4813 /// Represents a loop initializing the elements of an array.
4814 ///
4815 /// The need to initialize the elements of an array occurs in a number of
4816 /// contexts:
4817 ///
4818 /// * in the implicit copy/move constructor for a class with an array member
4819 /// * when a lambda-expression captures an array by value
4820 /// * when a decomposition declaration decomposes an array
4821 ///
4822 /// There are two subexpressions: a common expression (the source array)
4823 /// that is evaluated once up-front, and a per-element initializer that
4824 /// runs once for each array element.
4825 ///
4826 /// Within the per-element initializer, the common expression may be referenced
4827 /// via an OpaqueValueExpr, and the current index may be obtained via an
4828 /// ArrayInitIndexExpr.
4829 class ArrayInitLoopExpr : public Expr {
4830  Stmt *SubExprs[2];
4831 
4832  explicit ArrayInitLoopExpr(EmptyShell Empty)
4833  : Expr(ArrayInitLoopExprClass, Empty), SubExprs{} {}
4834 
4835 public:
4836  explicit ArrayInitLoopExpr(QualType T, Expr *CommonInit, Expr *ElementInit)
4837  : Expr(ArrayInitLoopExprClass, T, VK_RValue, OK_Ordinary, false,
4838  CommonInit->isValueDependent() || ElementInit->isValueDependent(),
4839  T->isInstantiationDependentType(),
4840  CommonInit->containsUnexpandedParameterPack() ||
4841  ElementInit->containsUnexpandedParameterPack()),
4842  SubExprs{CommonInit, ElementInit} {}
4843 
4844  /// Get the common subexpression shared by all initializations (the source
4845  /// array).
4847  return cast<OpaqueValueExpr>(SubExprs[0]);
4848  }
4849 
4850  /// Get the initializer to use for each array element.
4851  Expr *getSubExpr() const { return cast<Expr>(SubExprs[1]); }
4852 
4853  llvm::APInt getArraySize() const {
4854  return cast<ConstantArrayType>(getType()->castAsArrayTypeUnsafe())
4855  ->getSize();
4856  }
4857 
4858  static bool classof(const Stmt *S) {
4859  return S->getStmtClass() == ArrayInitLoopExprClass;
4860  }
4861 
4862  SourceLocation getBeginLoc() const LLVM_READONLY {
4863  return getCommonExpr()->getBeginLoc();
4864  }
4865  SourceLocation getEndLoc() const LLVM_READONLY {
4866  return getCommonExpr()->getEndLoc();
4867  }
4868 
4870  return child_range(SubExprs, SubExprs + 2);
4871  }
4873  return const_child_range(SubExprs, SubExprs + 2);
4874  }
4875 
4876  friend class ASTReader;
4877  friend class ASTStmtReader;
4878  friend class ASTStmtWriter;
4879 };
4880 
4881 /// Represents the index of the current element of an array being
4882 /// initialized by an ArrayInitLoopExpr. This can only appear within the
4883 /// subexpression of an ArrayInitLoopExpr.