1//===--- Expr.cpp - Expression AST Node Implementation --------------------===//
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 implements the Expr class and subclasses.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/AST/Expr.h"
14#include "clang/AST/APValue.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/Attr.h"
17#include "clang/AST/DeclCXX.h"
18#include "clang/AST/DeclObjC.h"
19#include "clang/AST/DeclTemplate.h"
20#include "clang/AST/EvaluatedExprVisitor.h"
21#include "clang/AST/ExprCXX.h"
22#include "clang/AST/Mangle.h"
23#include "clang/AST/RecordLayout.h"
24#include "clang/AST/StmtVisitor.h"
25#include "clang/Basic/Builtins.h"
26#include "clang/Basic/CharInfo.h"
27#include "clang/Basic/SourceManager.h"
28#include "clang/Basic/TargetInfo.h"
29#include "clang/Lex/Lexer.h"
30#include "clang/Lex/LiteralSupport.h"
31#include "llvm/Support/ErrorHandling.h"
32#include "llvm/Support/raw_ostream.h"
33#include <algorithm>
34#include <cstring>
35using namespace clang;
36
37const Expr *Expr::getBestDynamicClassTypeExpr() const {
38  const Expr *E = this;
39  while (true) {
40    E = E->ignoreParenBaseCasts();
41
42    // Follow the RHS of a comma operator.
43    if (auto *BO = dyn_cast<BinaryOperator>(E)) {
44      if (BO->getOpcode() == BO_Comma) {
45        E = BO->getRHS();
46        continue;
47      }
48    }
49
50    // Step into initializer for materialized temporaries.
51    if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E)) {
52      E = MTE->getSubExpr();
53      continue;
54    }
55
56    break;
57  }
58
59  return E;
60}
61
62const CXXRecordDecl *Expr::getBestDynamicClassType() const {
63  const Expr *E = getBestDynamicClassTypeExpr();
64  QualType DerivedType = E->getType();
65  if (const PointerType *PTy = DerivedType->getAs<PointerType>())
66    DerivedType = PTy->getPointeeType();
67
68  if (DerivedType->isDependentType())
69    return nullptr;
70
71  const RecordType *Ty = DerivedType->castAs<RecordType>();
72  Decl *D = Ty->getDecl();
73  return cast<CXXRecordDecl>(D);
74}
75
76const Expr *Expr::skipRValueSubobjectAdjustments(
77    SmallVectorImpl<const Expr *> &CommaLHSs,
78    SmallVectorImpl<SubobjectAdjustment> &Adjustments) const {
79  const Expr *E = this;
80  while (true) {
81    E = E->IgnoreParens();
82
83    if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
84      if ((CE->getCastKind() == CK_DerivedToBase ||
85           CE->getCastKind() == CK_UncheckedDerivedToBase) &&
86          E->getType()->isRecordType()) {
87        E = CE->getSubExpr();
88        auto *Derived =
89            cast<CXXRecordDecl>(E->getType()->castAs<RecordType>()->getDecl());
90        Adjustments.push_back(SubobjectAdjustment(CE, Derived));
91        continue;
92      }
93
94      if (CE->getCastKind() == CK_NoOp) {
95        E = CE->getSubExpr();
96        continue;
97      }
98    } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
99      if (!ME->isArrow()) {
100        assert(ME->getBase()->getType()->isRecordType());
101        if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
102          if (!Field->isBitField() && !Field->getType()->isReferenceType()) {
103            E = ME->getBase();
104            Adjustments.push_back(SubobjectAdjustment(Field));
105            continue;
106          }
107        }
108      }
109    } else if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
110      if (BO->getOpcode() == BO_PtrMemD) {
111        assert(BO->getRHS()->isRValue());
112        E = BO->getLHS();
113        const MemberPointerType *MPT =
114          BO->getRHS()->getType()->getAs<MemberPointerType>();
115        Adjustments.push_back(SubobjectAdjustment(MPT, BO->getRHS()));
116        continue;
117      } else if (BO->getOpcode() == BO_Comma) {
118        CommaLHSs.push_back(BO->getLHS());
119        E = BO->getRHS();
120        continue;
121      }
122    }
123
124    // Nothing changed.
125    break;
126  }
127  return E;
128}
129
130bool Expr::isKnownToHaveBooleanValue(bool Semantic) const {
131  const Expr *E = IgnoreParens();
132
133  // If this value has _Bool type, it is obvious 0/1.
134  if (E->getType()->isBooleanType()) return true;
135  // If this is a non-scalar-integer type, we don't care enough to try.
136  if (!E->getType()->isIntegralOrEnumerationType()) return false;
137
138  if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
139    switch (UO->getOpcode()) {
140    case UO_Plus:
141      return UO->getSubExpr()->isKnownToHaveBooleanValue(Semantic);
142    case UO_LNot:
143      return true;
144    default:
145      return false;
146    }
147  }
148
149  // Only look through implicit casts.  If the user writes
150  // '(int) (a && b)' treat it as an arbitrary int.
151  // FIXME: Should we look through any cast expression in !Semantic mode?
152  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E))
153    return CE->getSubExpr()->isKnownToHaveBooleanValue(Semantic);
154
155  if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
156    switch (BO->getOpcode()) {
157    default: return false;
158    case BO_LT:   // Relational operators.
159    case BO_GT:
160    case BO_LE:
161    case BO_GE:
162    case BO_EQ:   // Equality operators.
163    case BO_NE:
164    case BO_LAnd: // AND operator.
165    case BO_LOr:  // Logical OR operator.
166      return true;
167
168    case BO_And:  // Bitwise AND operator.
169    case BO_Xor:  // Bitwise XOR operator.
170    case BO_Or:   // Bitwise OR operator.
171      // Handle things like (x==2)|(y==12).
172      return BO->getLHS()->isKnownToHaveBooleanValue(Semantic) &&
173             BO->getRHS()->isKnownToHaveBooleanValue(Semantic);
174
175    case BO_Comma:
176    case BO_Assign:
177      return BO->getRHS()->isKnownToHaveBooleanValue(Semantic);
178    }
179  }
180
181  if (const ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E))
182    return CO->getTrueExpr()->isKnownToHaveBooleanValue(Semantic) &&
183           CO->getFalseExpr()->isKnownToHaveBooleanValue(Semantic);
184
185  if (isa<ObjCBoolLiteralExpr>(E))
186    return true;
187
188  if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E))
189    return OVE->getSourceExpr()->isKnownToHaveBooleanValue(Semantic);
190
191  if (const FieldDecl *FD = E->getSourceBitField())
192    if (!Semantic && FD->getType()->isUnsignedIntegerType() &&
193        !FD->getBitWidth()->isValueDependent() &&
194        FD->getBitWidthValue(FD->getASTContext()) == 1)
195      return true;
196
197  return false;
198}
199
200// Amusing macro metaprogramming hack: check whether a class provides
201// a more specific implementation of getExprLoc().
202//
203// See also Stmt.cpp:{getBeginLoc(),getEndLoc()}.
204namespace {
205  /// This implementation is used when a class provides a custom
206  /// implementation of getExprLoc.
207  template <class E, class T>
208  SourceLocation getExprLocImpl(const Expr *expr,
209                                SourceLocation (T::*v)() const) {
210    return static_cast<const E*>(expr)->getExprLoc();
211  }
212
213  /// This implementation is used when a class doesn't provide
214  /// a custom implementation of getExprLoc.  Overload resolution
215  /// should pick it over the implementation above because it's
216  /// more specialized according to function template partial ordering.
217  template <class E>
218  SourceLocation getExprLocImpl(const Expr *expr,
219                                SourceLocation (Expr::*v)() const) {
220    return static_cast<const E *>(expr)->getBeginLoc();
221  }
222}
223
224SourceLocation Expr::getExprLoc() const {
225  switch (getStmtClass()) {
226  case Stmt::NoStmtClass: llvm_unreachable("statement without class");
227#define ABSTRACT_STMT(type)
228#define STMT(type, base) \
229  case Stmt::type##Class: break;
230#define EXPR(type, base) \
231  case Stmt::type##Class: return getExprLocImpl<type>(this, &type::getExprLoc);
232#include "clang/AST/StmtNodes.inc"
233  }
234  llvm_unreachable("unknown expression kind");
235}
236
237//===----------------------------------------------------------------------===//
238// Primary Expressions.
239//===----------------------------------------------------------------------===//
240
241static void AssertResultStorageKind(ConstantExpr::ResultStorageKind Kind) {
242  assert((Kind == ConstantExpr::RSK_APValue ||
243          Kind == ConstantExpr::RSK_Int64 || Kind == ConstantExpr::RSK_None) &&
244         "Invalid StorageKind Value");
245}
246
247ConstantExpr::ResultStorageKind
248ConstantExpr::getStorageKind(const APValue &Value) {
249  switch (Value.getKind()) {
250  case APValue::None:
251  case APValue::Indeterminate:
252    return ConstantExpr::RSK_None;
253  case APValue::Int:
254    if (!Value.getInt().needsCleanup())
255      return ConstantExpr::RSK_Int64;
256    LLVM_FALLTHROUGH;
257  default:
258    return ConstantExpr::RSK_APValue;
259  }
260}
261
262ConstantExpr::ResultStorageKind
263ConstantExpr::getStorageKind(const Type *T, const ASTContext &Context) {
264  if (T->isIntegralOrEnumerationType() && Context.getTypeInfo(T).Width <= 64)
265    return ConstantExpr::RSK_Int64;
266  return ConstantExpr::RSK_APValue;
267}
268
269void ConstantExpr::DefaultInit(ResultStorageKind StorageKind) {
270  ConstantExprBits.ResultKind = StorageKind;
271  ConstantExprBits.APValueKind = APValue::None;
272  ConstantExprBits.HasCleanup = false;
273  if (StorageKind == ConstantExpr::RSK_APValue)
274    ::new (getTrailingObjects<APValue>()) APValue();
275}
276
277ConstantExpr::ConstantExpr(Expr *subexpr, ResultStorageKind StorageKind)
278    : FullExpr(ConstantExprClass, subexpr) {
279  DefaultInit(StorageKind);
280}
281
282ConstantExpr *ConstantExpr::Create(const ASTContext &Context, Expr *E,
283                                   ResultStorageKind StorageKind) {
284  assert(!isa<ConstantExpr>(E));
285  AssertResultStorageKind(StorageKind);
286  unsigned Size = totalSizeToAlloc<APValue, uint64_t>(
287      StorageKind == ConstantExpr::RSK_APValue,
288      StorageKind == ConstantExpr::RSK_Int64);
289  void *Mem = Context.Allocate(Size, alignof(ConstantExpr));
290  ConstantExpr *Self = new (Mem) ConstantExpr(E, StorageKind);
291  return Self;
292}
293
294ConstantExpr *ConstantExpr::Create(const ASTContext &Context, Expr *E,
295                                   const APValue &Result) {
296  ResultStorageKind StorageKind = getStorageKind(Result);
297  ConstantExpr *Self = Create(Context, E, StorageKind);
298  Self->SetResult(Result, Context);
299  return Self;
300}
301
302ConstantExpr::ConstantExpr(ResultStorageKind StorageKind, EmptyShell Empty)
303    : FullExpr(ConstantExprClass, Empty) {
304  DefaultInit(StorageKind);
305}
306
307ConstantExpr *ConstantExpr::CreateEmpty(const ASTContext &Context,
308                                        ResultStorageKind StorageKind,
309                                        EmptyShell Empty) {
310  AssertResultStorageKind(StorageKind);
311  unsigned Size = totalSizeToAlloc<APValue, uint64_t>(
312      StorageKind == ConstantExpr::RSK_APValue,
313      StorageKind == ConstantExpr::RSK_Int64);
314  void *Mem = Context.Allocate(Size, alignof(ConstantExpr));
315  ConstantExpr *Self = new (Mem) ConstantExpr(StorageKind, Empty);
316  return Self;
317}
318
319void ConstantExpr::MoveIntoResult(APValue &Value, const ASTContext &Context) {
320  assert(getStorageKind(Value) == ConstantExprBits.ResultKind &&
321         "Invalid storage for this value kind");
322  ConstantExprBits.APValueKind = Value.getKind();
323  switch (ConstantExprBits.ResultKind) {
324  case RSK_None:
325    return;
326  case RSK_Int64:
327    Int64Result() = *Value.getInt().getRawData();
328    ConstantExprBits.BitWidth = Value.getInt().getBitWidth();
329    ConstantExprBits.IsUnsigned = Value.getInt().isUnsigned();
330    return;
331  case RSK_APValue:
332    if (!ConstantExprBits.HasCleanup && Value.needsCleanup()) {
333      ConstantExprBits.HasCleanup = true;
334      Context.addDestruction(&APValueResult());
335    }
336    APValueResult() = std::move(Value);
337    return;
338  }
339  llvm_unreachable("Invalid ResultKind Bits");
340}
341
342llvm::APSInt ConstantExpr::getResultAsAPSInt() const {
343  switch (ConstantExprBits.ResultKind) {
344  case ConstantExpr::RSK_APValue:
345    return APValueResult().getInt();
346  case ConstantExpr::RSK_Int64:
347    return llvm::APSInt(llvm::APInt(ConstantExprBits.BitWidth, Int64Result()),
348                        ConstantExprBits.IsUnsigned);
349  default:
350    llvm_unreachable("invalid Accessor");
351  }
352}
353
354APValue ConstantExpr::getAPValueResult() const {
355  switch (ConstantExprBits.ResultKind) {
356  case ConstantExpr::RSK_APValue:
357    return APValueResult();
358  case ConstantExpr::RSK_Int64:
359    return APValue(
360        llvm::APSInt(llvm::APInt(ConstantExprBits.BitWidth, Int64Result()),
361                     ConstantExprBits.IsUnsigned));
362  case ConstantExpr::RSK_None:
363    return APValue();
364  }
365  llvm_unreachable("invalid ResultKind");
366}
367
368/// Compute the type-, value-, and instantiation-dependence of a
369/// declaration reference
370/// based on the declaration being referenced.
371static void computeDeclRefDependence(const ASTContext &Ctx, NamedDecl *D,
372                                     QualType T, bool &TypeDependent,
373                                     bool &ValueDependent,
374                                     bool &InstantiationDependent) {
375  TypeDependent = false;
376  ValueDependent = false;
377  InstantiationDependent = false;
378
379  // (TD) C++ [temp.dep.expr]p3:
380  //   An id-expression is type-dependent if it contains:
381  //
382  // and
383  //
384  // (VD) C++ [temp.dep.constexpr]p2:
385  //  An identifier is value-dependent if it is:
386
387  //  (TD)  - an identifier that was declared with dependent type
388  //  (VD)  - a name declared with a dependent type,
389  if (T->isDependentType()) {
390    TypeDependent = true;
391    ValueDependent = true;
392    InstantiationDependent = true;
393    return;
394  } else if (T->isInstantiationDependentType()) {
395    InstantiationDependent = true;
396  }
397
398  //  (TD)  - a conversion-function-id that specifies a dependent type
399  if (D->getDeclName().getNameKind()
400                                == DeclarationName::CXXConversionFunctionName) {
401    QualType T = D->getDeclName().getCXXNameType();
402    if (T->isDependentType()) {
403      TypeDependent = true;
404      ValueDependent = true;
405      InstantiationDependent = true;
406      return;
407    }
408
409    if (T->isInstantiationDependentType())
410      InstantiationDependent = true;
411  }
412
413  //  (VD)  - the name of a non-type template parameter,
414  if (isa<NonTypeTemplateParmDecl>(D)) {
415    ValueDependent = true;
416    InstantiationDependent = true;
417    return;
418  }
419
420  //  (VD) - a constant with integral or enumeration type and is
421  //         initialized with an expression that is value-dependent.
422  //  (VD) - a constant with literal type and is initialized with an
423  //         expression that is value-dependent [C++11].
424  //  (VD) - FIXME: Missing from the standard:
425  //       -  an entity with reference type and is initialized with an
426  //          expression that is value-dependent [C++11]
427  if (VarDecl *Var = dyn_cast<VarDecl>(D)) {
428    if ((Ctx.getLangOpts().CPlusPlus11 ?
429           Var->getType()->isLiteralType(Ctx) :
430           Var->getType()->isIntegralOrEnumerationType()) &&
431        (Var->getType().isConstQualified() ||
432         Var->getType()->isReferenceType())) {
433      if (const Expr *Init = Var->getAnyInitializer())
434        if (Init->isValueDependent()) {
435          ValueDependent = true;
436          InstantiationDependent = true;
437        }
438    }
439
440    // (VD) - FIXME: Missing from the standard:
441    //      -  a member function or a static data member of the current
442    //         instantiation
443    if (Var->isStaticDataMember() &&
444        Var->getDeclContext()->isDependentContext()) {
445      ValueDependent = true;
446      InstantiationDependent = true;
447      TypeSourceInfo *TInfo = Var->getFirstDecl()->getTypeSourceInfo();
448      if (TInfo->getType()->isIncompleteArrayType())
449        TypeDependent = true;
450    }
451
452    return;
453  }
454
455  // (VD) - FIXME: Missing from the standard:
456  //      -  a member function or a static data member of the current
457  //         instantiation
458  if (isa<CXXMethodDecl>(D) && D->getDeclContext()->isDependentContext()) {
459    ValueDependent = true;
460    InstantiationDependent = true;
461  }
462}
463
464void DeclRefExpr::computeDependence(const ASTContext &Ctx) {
465  bool TypeDependent = false;
466  bool ValueDependent = false;
467  bool InstantiationDependent = false;
468  computeDeclRefDependence(Ctx, getDecl(), getType(), TypeDependent,
469                           ValueDependent, InstantiationDependent);
470
471  ExprBits.TypeDependent |= TypeDependent;
472  ExprBits.ValueDependent |= ValueDependent;
473  ExprBits.InstantiationDependent |= InstantiationDependent;
474
475  // Is the declaration a parameter pack?
476  if (getDecl()->isParameterPack())
477    ExprBits.ContainsUnexpandedParameterPack = true;
478}
479
480DeclRefExpr::DeclRefExpr(const ASTContext &Ctx, ValueDecl *D,
481                         bool RefersToEnclosingVariableOrCapture, QualType T,
482                         ExprValueKind VK, SourceLocation L,
483                         const DeclarationNameLoc &LocInfo,
484                         NonOdrUseReason NOUR)
485    : Expr(DeclRefExprClass, T, VK, OK_Ordinary, false, false, false, false),
486      D(D), DNLoc(LocInfo) {
487  DeclRefExprBits.HasQualifier = false;
488  DeclRefExprBits.HasTemplateKWAndArgsInfo = false;
489  DeclRefExprBits.HasFoundDecl = false;
490  DeclRefExprBits.HadMultipleCandidates = false;
491  DeclRefExprBits.RefersToEnclosingVariableOrCapture =
492      RefersToEnclosingVariableOrCapture;
493  DeclRefExprBits.NonOdrUseReason = NOUR;
494  DeclRefExprBits.Loc = L;
495  computeDependence(Ctx);
496}
497
498DeclRefExpr::DeclRefExpr(const ASTContext &Ctx,
499                         NestedNameSpecifierLoc QualifierLoc,
500                         SourceLocation TemplateKWLoc, ValueDecl *D,
501                         bool RefersToEnclosingVariableOrCapture,
502                         const DeclarationNameInfo &NameInfo, NamedDecl *FoundD,
503                         const TemplateArgumentListInfo *TemplateArgs,
504                         QualType T, ExprValueKind VK, NonOdrUseReason NOUR)
505    : Expr(DeclRefExprClass, T, VK, OK_Ordinary, false, false, false, false),
506      D(D), DNLoc(NameInfo.getInfo()) {
507  DeclRefExprBits.Loc = NameInfo.getLoc();
508  DeclRefExprBits.HasQualifier = QualifierLoc ? 1 : 0;
509  if (QualifierLoc) {
510    new (getTrailingObjects<NestedNameSpecifierLoc>())
511        NestedNameSpecifierLoc(QualifierLoc);
512    auto *NNS = QualifierLoc.getNestedNameSpecifier();
513    if (NNS->isInstantiationDependent())
514      ExprBits.InstantiationDependent = true;
515    if (NNS->containsUnexpandedParameterPack())
516      ExprBits.ContainsUnexpandedParameterPack = true;
517  }
518  DeclRefExprBits.HasFoundDecl = FoundD ? 1 : 0;
519  if (FoundD)
520    *getTrailingObjects<NamedDecl *>() = FoundD;
521  DeclRefExprBits.HasTemplateKWAndArgsInfo
522    = (TemplateArgs || TemplateKWLoc.isValid()) ? 1 : 0;
523  DeclRefExprBits.RefersToEnclosingVariableOrCapture =
524      RefersToEnclosingVariableOrCapture;
525  DeclRefExprBits.NonOdrUseReason = NOUR;
526  if (TemplateArgs) {
527    bool Dependent = false;
528    bool InstantiationDependent = false;
529    bool ContainsUnexpandedParameterPack = false;
530    getTrailingObjects<ASTTemplateKWAndArgsInfo>()->initializeFrom(
531        TemplateKWLoc, *TemplateArgs, getTrailingObjects<TemplateArgumentLoc>(),
532        Dependent, InstantiationDependent, ContainsUnexpandedParameterPack);
533    assert(!Dependent && "built a DeclRefExpr with dependent template args");
534    ExprBits.InstantiationDependent |= InstantiationDependent;
535    ExprBits.ContainsUnexpandedParameterPack |= ContainsUnexpandedParameterPack;
536  } else if (TemplateKWLoc.isValid()) {
537    getTrailingObjects<ASTTemplateKWAndArgsInfo>()->initializeFrom(
538        TemplateKWLoc);
539  }
540  DeclRefExprBits.HadMultipleCandidates = 0;
541
542  computeDependence(Ctx);
543}
544
545DeclRefExpr *DeclRefExpr::Create(const ASTContext &Context,
546                                 NestedNameSpecifierLoc QualifierLoc,
547                                 SourceLocation TemplateKWLoc, ValueDecl *D,
548                                 bool RefersToEnclosingVariableOrCapture,
549                                 SourceLocation NameLoc, QualType T,
550                                 ExprValueKind VK, NamedDecl *FoundD,
551                                 const TemplateArgumentListInfo *TemplateArgs,
552                                 NonOdrUseReason NOUR) {
553  return Create(Context, QualifierLoc, TemplateKWLoc, D,
554                RefersToEnclosingVariableOrCapture,
555                DeclarationNameInfo(D->getDeclName(), NameLoc),
556                T, VK, FoundD, TemplateArgs, NOUR);
557}
558
559DeclRefExpr *DeclRefExpr::Create(const ASTContext &Context,
560                                 NestedNameSpecifierLoc QualifierLoc,
561                                 SourceLocation TemplateKWLoc, ValueDecl *D,
562                                 bool RefersToEnclosingVariableOrCapture,
563                                 const DeclarationNameInfo &NameInfo,
564                                 QualType T, ExprValueKind VK,
565                                 NamedDecl *FoundD,
566                                 const TemplateArgumentListInfo *TemplateArgs,
567                                 NonOdrUseReason NOUR) {
568  // Filter out cases where the found Decl is the same as the value refenenced.
569  if (D == FoundD)
570    FoundD = nullptr;
571
572  bool HasTemplateKWAndArgsInfo = TemplateArgs || TemplateKWLoc.isValid();
573  std::size_t Size =
574      totalSizeToAlloc<NestedNameSpecifierLoc, NamedDecl *,
575                       ASTTemplateKWAndArgsInfo, TemplateArgumentLoc>(
576          QualifierLoc ? 1 : 0, FoundD ? 1 : 0,
577          HasTemplateKWAndArgsInfo ? 1 : 0,
578          TemplateArgs ? TemplateArgs->size() : 0);
579
580  void *Mem = Context.Allocate(Size, alignof(DeclRefExpr));
581  return new (Mem) DeclRefExpr(Context, QualifierLoc, TemplateKWLoc, D,
582                               RefersToEnclosingVariableOrCapture, NameInfo,
583                               FoundD, TemplateArgs, T, VK, NOUR);
584}
585
586DeclRefExpr *DeclRefExpr::CreateEmpty(const ASTContext &Context,
587                                      bool HasQualifier,
588                                      bool HasFoundDecl,
589                                      bool HasTemplateKWAndArgsInfo,
590                                      unsigned NumTemplateArgs) {
591  assert(NumTemplateArgs == 0 || HasTemplateKWAndArgsInfo);
592  std::size_t Size =
593      totalSizeToAlloc<NestedNameSpecifierLoc, NamedDecl *,
594                       ASTTemplateKWAndArgsInfo, TemplateArgumentLoc>(
595          HasQualifier ? 1 : 0, HasFoundDecl ? 1 : 0, HasTemplateKWAndArgsInfo,
596          NumTemplateArgs);
597  void *Mem = Context.Allocate(Size, alignof(DeclRefExpr));
598  return new (Mem) DeclRefExpr(EmptyShell());
599}
600
601SourceLocation DeclRefExpr::getBeginLoc() const {
602  if (hasQualifier())
603    return getQualifierLoc().getBeginLoc();
604  return getNameInfo().getBeginLoc();
605}
606SourceLocation DeclRefExpr::getEndLoc() const {
607  if (hasExplicitTemplateArgs())
608    return getRAngleLoc();
609  return getNameInfo().getEndLoc();
610}
611
612PredefinedExpr::PredefinedExpr(SourceLocation L, QualType FNTy, IdentKind IK,
613                               StringLiteral *SL)
614    : Expr(PredefinedExprClass, FNTy, VK_LValue, OK_Ordinary,
615           FNTy->isDependentType(), FNTy->isDependentType(),
616           FNTy->isInstantiationDependentType(),
617           /*ContainsUnexpandedParameterPack=*/false) {
618  PredefinedExprBits.Kind = IK;
619  assert((getIdentKind() == IK) &&
620         "IdentKind do not fit in PredefinedExprBitfields!");
621  bool HasFunctionName = SL != nullptr;
622  PredefinedExprBits.HasFunctionName = HasFunctionName;
623  PredefinedExprBits.Loc = L;
624  if (HasFunctionName)
625    setFunctionName(SL);
626}
627
628PredefinedExpr::PredefinedExpr(EmptyShell Empty, bool HasFunctionName)
629    : Expr(PredefinedExprClass, Empty) {
630  PredefinedExprBits.HasFunctionName = HasFunctionName;
631}
632
633PredefinedExpr *PredefinedExpr::Create(const ASTContext &Ctx, SourceLocation L,
634                                       QualType FNTy, IdentKind IK,
635                                       StringLiteral *SL) {
636  bool HasFunctionName = SL != nullptr;
637  void *Mem = Ctx.Allocate(totalSizeToAlloc<Stmt *>(HasFunctionName),
638                           alignof(PredefinedExpr));
639  return new (Mem) PredefinedExpr(L, FNTy, IK, SL);
640}
641
642PredefinedExpr *PredefinedExpr::CreateEmpty(const ASTContext &Ctx,
643                                            bool HasFunctionName) {
644  void *Mem = Ctx.Allocate(totalSizeToAlloc<Stmt *>(HasFunctionName),
645                           alignof(PredefinedExpr));
646  return new (Mem) PredefinedExpr(EmptyShell(), HasFunctionName);
647}
648
649StringRef PredefinedExpr::getIdentKindName(PredefinedExpr::IdentKind IK) {
650  switch (IK) {
651  case Func:
652    return "__func__";
653  case Function:
654    return "__FUNCTION__";
655  case FuncDName:
656    return "__FUNCDNAME__";
657  case LFunction:
658    return "L__FUNCTION__";
659  case PrettyFunction:
660    return "__PRETTY_FUNCTION__";
661  case FuncSig:
662    return "__FUNCSIG__";
663  case LFuncSig:
664    return "L__FUNCSIG__";
665  case PrettyFunctionNoVirtual:
666    break;
667  }
668  llvm_unreachable("Unknown ident kind for PredefinedExpr");
669}
670
671// FIXME: Maybe this should use DeclPrinter with a special "print predefined
672// expr" policy instead.
673std::string PredefinedExpr::ComputeName(IdentKind IK, const Decl *CurrentDecl) {
674  ASTContext &Context = CurrentDecl->getASTContext();
675
676  if (IK == PredefinedExpr::FuncDName) {
677    if (const NamedDecl *ND = dyn_cast<NamedDecl>(CurrentDecl)) {
678      std::unique_ptr<MangleContext> MC;
679      MC.reset(Context.createMangleContext());
680
681      if (MC->shouldMangleDeclName(ND)) {
682        SmallString<256> Buffer;
683        llvm::raw_svector_ostream Out(Buffer);
684        if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(ND))
685          MC->mangleCXXCtor(CD, Ctor_Base, Out);
686        else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(ND))
687          MC->mangleCXXDtor(DD, Dtor_Base, Out);
688        else
689          MC->mangleName(ND, Out);
690
691        if (!Buffer.empty() && Buffer.front() == '\01')
692          return Buffer.substr(1);
693        return Buffer.str();
694      } else
695        return ND->getIdentifier()->getName();
696    }
697    return "";
698  }
699  if (isa<BlockDecl>(CurrentDecl)) {
700    // For blocks we only emit something if it is enclosed in a function
701    // For top-level block we'd like to include the name of variable, but we
702    // don't have it at this point.
703    auto DC = CurrentDecl->getDeclContext();
704    if (DC->isFileContext())
705      return "";
706
707    SmallString<256> Buffer;
708    llvm::raw_svector_ostream Out(Buffer);
709    if (auto *DCBlock = dyn_cast<BlockDecl>(DC))
710      // For nested blocks, propagate up to the parent.
711      Out << ComputeName(IK, DCBlock);
712    else if (auto *DCDecl = dyn_cast<Decl>(DC))
713      Out << ComputeName(IK, DCDecl) << "_block_invoke";
714    return Out.str();
715  }
716  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurrentDecl)) {
717    if (IK != PrettyFunction && IK != PrettyFunctionNoVirtual &&
718        IK != FuncSig && IK != LFuncSig)
719      return FD->getNameAsString();
720
721    SmallString<256> Name;
722    llvm::raw_svector_ostream Out(Name);
723
724    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
725      if (MD->isVirtual() && IK != PrettyFunctionNoVirtual)
726        Out << "virtual ";
727      if (MD->isStatic())
728        Out << "static ";
729    }
730
731    PrintingPolicy Policy(Context.getLangOpts());
732    std::string Proto;
733    llvm::raw_string_ostream POut(Proto);
734
735    const FunctionDecl *Decl = FD;
736    if (const FunctionDecl* Pattern = FD->getTemplateInstantiationPattern())
737      Decl = Pattern;
738    const FunctionType *AFT = Decl->getType()->getAs<FunctionType>();
739    const FunctionProtoType *FT = nullptr;
740    if (FD->hasWrittenPrototype())
741      FT = dyn_cast<FunctionProtoType>(AFT);
742
743    if (IK == FuncSig || IK == LFuncSig) {
744      switch (AFT->getCallConv()) {
745      case CC_C: POut << "__cdecl "; break;
746      case CC_X86StdCall: POut << "__stdcall "; break;
747      case CC_X86FastCall: POut << "__fastcall "; break;
748      case CC_X86ThisCall: POut << "__thiscall "; break;
749      case CC_X86VectorCall: POut << "__vectorcall "; break;
750      case CC_X86RegCall: POut << "__regcall "; break;
751      // Only bother printing the conventions that MSVC knows about.
752      default: break;
753      }
754    }
755
756    FD->printQualifiedName(POut, Policy);
757
758    POut << "(";
759    if (FT) {
760      for (unsigned i = 0, e = Decl->getNumParams(); i != e; ++i) {
761        if (i) POut << ", ";
762        POut << Decl->getParamDecl(i)->getType().stream(Policy);
763      }
764
765      if (FT->isVariadic()) {
766        if (FD->getNumParams()) POut << ", ";
767        POut << "...";
768      } else if ((IK == FuncSig || IK == LFuncSig ||
769                  !Context.getLangOpts().CPlusPlus) &&
770                 !Decl->getNumParams()) {
771        POut << "void";
772      }
773    }
774    POut << ")";
775
776    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
777      assert(FT && "We must have a written prototype in this case.");
778      if (FT->isConst())
779        POut << " const";
780      if (FT->isVolatile())
781        POut << " volatile";
782      RefQualifierKind Ref = MD->getRefQualifier();
783      if (Ref == RQ_LValue)
784        POut << " &";
785      else if (Ref == RQ_RValue)
786        POut << " &&";
787    }
788
789    typedef SmallVector<const ClassTemplateSpecializationDecl *, 8> SpecsTy;
790    SpecsTy Specs;
791    const DeclContext *Ctx = FD->getDeclContext();
792    while (Ctx && isa<NamedDecl>(Ctx)) {
793      const ClassTemplateSpecializationDecl *Spec
794                               = dyn_cast<ClassTemplateSpecializationDecl>(Ctx);
795      if (Spec && !Spec->isExplicitSpecialization())
796        Specs.push_back(Spec);
797      Ctx = Ctx->getParent();
798    }
799
800    std::string TemplateParams;
801    llvm::raw_string_ostream TOut(TemplateParams);
802    for (SpecsTy::reverse_iterator I = Specs.rbegin(), E = Specs.rend();
803         I != E; ++I) {
804      const TemplateParameterList *Params
805                  = (*I)->getSpecializedTemplate()->getTemplateParameters();
806      const TemplateArgumentList &Args = (*I)->getTemplateArgs();
807      assert(Params->size() == Args.size());
808      for (unsigned i = 0, numParams = Params->size(); i != numParams; ++i) {
809        StringRef Param = Params->getParam(i)->getName();
810        if (Param.empty()) continue;
811        TOut << Param << " = ";
812        Args.get(i).print(Policy, TOut);
813        TOut << ", ";
814      }
815    }
816
817    FunctionTemplateSpecializationInfo *FSI
818                                          = FD->getTemplateSpecializationInfo();
819    if (FSI && !FSI->isExplicitSpecialization()) {
820      const TemplateParameterList* Params
821                                  = FSI->getTemplate()->getTemplateParameters();
822      const TemplateArgumentList* Args = FSI->TemplateArguments;
823      assert(Params->size() == Args->size());
824      for (unsigned i = 0, e = Params->size(); i != e; ++i) {
825        StringRef Param = Params->getParam(i)->getName();
826        if (Param.empty()) continue;
827        TOut << Param << " = ";
828        Args->get(i).print(Policy, TOut);
829        TOut << ", ";
830      }
831    }
832
833    TOut.flush();
834    if (!TemplateParams.empty()) {
835      // remove the trailing comma and space
836      TemplateParams.resize(TemplateParams.size() - 2);
837      POut << " [" << TemplateParams << "]";
838    }
839
840    POut.flush();
841
842    // Print "auto" for all deduced return types. This includes C++1y return
843    // type deduction and lambdas. For trailing return types resolve the
844    // decltype expression. Otherwise print the real type when this is
845    // not a constructor or destructor.
846    if (isa<CXXMethodDecl>(FD) &&
847         cast<CXXMethodDecl>(FD)->getParent()->isLambda())
848      Proto = "auto " + Proto;
849    else if (FT && FT->getReturnType()->getAs<DecltypeType>())
850      FT->getReturnType()
851          ->getAs<DecltypeType>()
852          ->getUnderlyingType()
853          .getAsStringInternal(Proto, Policy);
854    else if (!isa<CXXConstructorDecl>(FD) && !isa<CXXDestructorDecl>(FD))
855      AFT->getReturnType().getAsStringInternal(Proto, Policy);
856
857    Out << Proto;
858
859    return Name.str().str();
860  }
861  if (const CapturedDecl *CD = dyn_cast<CapturedDecl>(CurrentDecl)) {
862    for (const DeclContext *DC = CD->getParent(); DC; DC = DC->getParent())
863      // Skip to its enclosing function or method, but not its enclosing
864      // CapturedDecl.
865      if (DC->isFunctionOrMethod() && (DC->getDeclKind() != Decl::Captured)) {
866        const Decl *D = Decl::castFromDeclContext(DC);
867        return ComputeName(IK, D);
868      }
869    llvm_unreachable("CapturedDecl not inside a function or method");
870  }
871  if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CurrentDecl)) {
872    SmallString<256> Name;
873    llvm::raw_svector_ostream Out(Name);
874    Out << (MD->isInstanceMethod() ? '-' : '+');
875    Out << '[';
876
877    // For incorrect code, there might not be an ObjCInterfaceDecl.  Do
878    // a null check to avoid a crash.
879    if (const ObjCInterfaceDecl *ID = MD->getClassInterface())
880      Out << *ID;
881
882    if (const ObjCCategoryImplDecl *CID =
883        dyn_cast<ObjCCategoryImplDecl>(MD->getDeclContext()))
884      Out << '(' << *CID << ')';
885
886    Out <<  ' ';
887    MD->getSelector().print(Out);
888    Out <<  ']';
889
890    return Name.str().str();
891  }
892  if (isa<TranslationUnitDecl>(CurrentDecl) && IK == PrettyFunction) {
893    // __PRETTY_FUNCTION__ -> "top level", the others produce an empty string.
894    return "top level";
895  }
896  return "";
897}
898
899void APNumericStorage::setIntValue(const ASTContext &C,
900                                   const llvm::APInt &Val) {
901  if (hasAllocation())
902    C.Deallocate(pVal);
903
904  BitWidth = Val.getBitWidth();
905  unsigned NumWords = Val.getNumWords();
906  const uint64_t* Words = Val.getRawData();
907  if (NumWords > 1) {
908    pVal = new (C) uint64_t[NumWords];
909    std::copy(Words, Words + NumWords, pVal);
910  } else if (NumWords == 1)
911    VAL = Words[0];
912  else
913    VAL = 0;
914}
915
916IntegerLiteral::IntegerLiteral(const ASTContext &C, const llvm::APInt &V,
917                               QualType type, SourceLocation l)
918  : Expr(IntegerLiteralClass, type, VK_RValue, OK_Ordinary, false, false,
919         false, false),
920    Loc(l) {
921  assert(type->isIntegerType() && "Illegal type in IntegerLiteral");
922  assert(V.getBitWidth() == C.getIntWidth(type) &&
923         "Integer type is not the correct size for constant.");
924  setValue(C, V);
925}
926
927IntegerLiteral *
928IntegerLiteral::Create(const ASTContext &C, const llvm::APInt &V,
929                       QualType type, SourceLocation l) {
930  return new (C) IntegerLiteral(C, V, type, l);
931}
932
933IntegerLiteral *
934IntegerLiteral::Create(const ASTContext &C, EmptyShell Empty) {
935  return new (C) IntegerLiteral(Empty);
936}
937
938FixedPointLiteral::FixedPointLiteral(const ASTContext &C, const llvm::APInt &V,
939                                     QualType type, SourceLocation l,
940                                     unsigned Scale)
941    : Expr(FixedPointLiteralClass, type, VK_RValue, OK_Ordinary, false, false,
942           false, false),
943      Loc(l), Scale(Scale) {
944  assert(type->isFixedPointType() && "Illegal type in FixedPointLiteral");
945  assert(V.getBitWidth() == C.getTypeInfo(type).Width &&
946         "Fixed point type is not the correct size for constant.");
947  setValue(C, V);
948}
949
950FixedPointLiteral *FixedPointLiteral::CreateFromRawInt(const ASTContext &C,
951                                                       const llvm::APInt &V,
952                                                       QualType type,
953                                                       SourceLocation l,
954                                                       unsigned Scale) {
955  return new (C) FixedPointLiteral(C, V, type, l, Scale);
956}
957
958std::string FixedPointLiteral::getValueAsString(unsigned Radix) const {
959  // Currently the longest decimal number that can be printed is the max for an
960  // unsigned long _Accum: 4294967295.99999999976716935634613037109375
961  // which is 43 characters.
962  SmallString<64> S;
963  FixedPointValueToString(
964      S, llvm::APSInt::getUnsigned(getValue().getZExtValue()), Scale);
965  return S.str();
966}
967
968FloatingLiteral::FloatingLiteral(const ASTContext &C, const llvm::APFloat &V,
969                                 bool isexact, QualType Type, SourceLocation L)
970  : Expr(FloatingLiteralClass, Type, VK_RValue, OK_Ordinary, false, false,
971         false, false), Loc(L) {
972  setSemantics(V.getSemantics());
973  FloatingLiteralBits.IsExact = isexact;
974  setValue(C, V);
975}
976
977FloatingLiteral::FloatingLiteral(const ASTContext &C, EmptyShell Empty)
978  : Expr(FloatingLiteralClass, Empty) {
979  setRawSemantics(llvm::APFloatBase::S_IEEEhalf);
980  FloatingLiteralBits.IsExact = false;
981}
982
983FloatingLiteral *
984FloatingLiteral::Create(const ASTContext &C, const llvm::APFloat &V,
985                        bool isexact, QualType Type, SourceLocation L) {
986  return new (C) FloatingLiteral(C, V, isexact, Type, L);
987}
988
989FloatingLiteral *
990FloatingLiteral::Create(const ASTContext &C, EmptyShell Empty) {
991  return new (C) FloatingLiteral(C, Empty);
992}
993
994/// getValueAsApproximateDouble - This returns the value as an inaccurate
995/// double.  Note that this may cause loss of precision, but is useful for
996/// debugging dumps, etc.
997double FloatingLiteral::getValueAsApproximateDouble() const {
998  llvm::APFloat V = getValue();
999  bool ignored;
1000  V.convert(llvm::APFloat::IEEEdouble(), llvm::APFloat::rmNearestTiesToEven,
1001            &ignored);
1002  return V.convertToDouble();
1003}
1004
1005unsigned StringLiteral::mapCharByteWidth(TargetInfo const &Target,
1006                                         StringKind SK) {
1007  unsigned CharByteWidth = 0;
1008  switch (SK) {
1009  case Ascii:
1010  case UTF8:
1011    CharByteWidth = Target.getCharWidth();
1012    break;
1013  case Wide:
1014    CharByteWidth = Target.getWCharWidth();
1015    break;
1016  case UTF16:
1017    CharByteWidth = Target.getChar16Width();
1018    break;
1019  case UTF32:
1020    CharByteWidth = Target.getChar32Width();
1021    break;
1022  }
1023  assert((CharByteWidth & 7) == 0 && "Assumes character size is byte multiple");
1024  CharByteWidth /= 8;
1025  assert((CharByteWidth == 1 || CharByteWidth == 2 || CharByteWidth == 4) &&
1026         "The only supported character byte widths are 1,2 and 4!");
1027  return CharByteWidth;
1028}
1029
1030StringLiteral::StringLiteral(const ASTContext &Ctx, StringRef Str,
1031                             StringKind Kind, bool Pascal, QualType Ty,
1032                             const SourceLocation *Loc,
1033                             unsigned NumConcatenated)
1034    : Expr(StringLiteralClass, Ty, VK_LValue, OK_Ordinary, false, false, false,
1035           false) {
1036  assert(Ctx.getAsConstantArrayType(Ty) &&
1037         "StringLiteral must be of constant array type!");
1038  unsigned CharByteWidth = mapCharByteWidth(Ctx.getTargetInfo(), Kind);
1039  unsigned ByteLength = Str.size();
1040  assert((ByteLength % CharByteWidth == 0) &&
1041         "The size of the data must be a multiple of CharByteWidth!");
1042
1043  // Avoid the expensive division. The compiler should be able to figure it
1044  // out by itself. However as of clang 7, even with the appropriate
1045  // llvm_unreachable added just here, it is not able to do so.
1046  unsigned Length;
1047  switch (CharByteWidth) {
1048  case 1:
1049    Length = ByteLength;
1050    break;
1051  case 2:
1052    Length = ByteLength / 2;
1053    break;
1054  case 4:
1055    Length = ByteLength / 4;
1056    break;
1057  default:
1058    llvm_unreachable("Unsupported character width!");
1059  }
1060
1061  StringLiteralBits.Kind = Kind;
1062  StringLiteralBits.CharByteWidth = CharByteWidth;
1063  StringLiteralBits.IsPascal = Pascal;
1064  StringLiteralBits.NumConcatenated = NumConcatenated;
1065  *getTrailingObjects<unsigned>() = Length;
1066
1067  // Initialize the trailing array of SourceLocation.
1068  // This is safe since SourceLocation is POD-like.
1069  std::memcpy(getTrailingObjects<SourceLocation>(), Loc,
1070              NumConcatenated * sizeof(SourceLocation));
1071
1072  // Initialize the trailing array of char holding the string data.
1073  std::memcpy(getTrailingObjects<char>(), Str.data(), ByteLength);
1074}
1075
1076StringLiteral::StringLiteral(EmptyShell Empty, unsigned NumConcatenated,
1077                             unsigned Length, unsigned CharByteWidth)
1078    : Expr(StringLiteralClass, Empty) {
1079  StringLiteralBits.CharByteWidth = CharByteWidth;
1080  StringLiteralBits.NumConcatenated = NumConcatenated;
1081  *getTrailingObjects<unsigned>() = Length;
1082}
1083
1084StringLiteral *StringLiteral::Create(const ASTContext &Ctx, StringRef Str,
1085                                     StringKind Kind, bool Pascal, QualType Ty,
1086                                     const SourceLocation *Loc,
1087                                     unsigned NumConcatenated) {
1088  void *Mem = Ctx.Allocate(totalSizeToAlloc<unsigned, SourceLocation, char>(
1089                               1, NumConcatenated, Str.size()),
1090                           alignof(StringLiteral));
1091  return new (Mem)
1092      StringLiteral(Ctx, Str, Kind, Pascal, Ty, Loc, NumConcatenated);
1093}
1094
1095StringLiteral *StringLiteral::CreateEmpty(const ASTContext &Ctx,
1096                                          unsigned NumConcatenated,
1097                                          unsigned Length,
1098                                          unsigned CharByteWidth) {
1099  void *Mem = Ctx.Allocate(totalSizeToAlloc<unsigned, SourceLocation, char>(
1100                               1, NumConcatenated, Length * CharByteWidth),
1101                           alignof(StringLiteral));
1102  return new (Mem)
1103      StringLiteral(EmptyShell(), NumConcatenated, Length, CharByteWidth);
1104}
1105
1106void StringLiteral::outputString(raw_ostream &OS) const {
1107  switch (getKind()) {
1108  case Ascii: break; // no prefix.
1109  case Wide:  OS << 'L'; break;
1110  case UTF8:  OS << "u8"; break;
1111  case UTF16: OS << 'u'; break;
1112  case UTF32: OS << 'U'; break;
1113  }
1114  OS << '"';
1115  static const char Hex[] = "0123456789ABCDEF";
1116
1117  unsigned LastSlashX = getLength();
1118  for (unsigned I = 0, N = getLength(); I != N; ++I) {
1119    switch (uint32_t Char = getCodeUnit(I)) {
1120    default:
1121      // FIXME: Convert UTF-8 back to codepoints before rendering.
1122
1123      // Convert UTF-16 surrogate pairs back to codepoints before rendering.
1124      // Leave invalid surrogates alone; we'll use \x for those.
1125      if (getKind() == UTF16 && I != N - 1 && Char >= 0xd800 &&
1126          Char <= 0xdbff) {
1127        uint32_t Trail = getCodeUnit(I + 1);
1128        if (Trail >= 0xdc00 && Trail <= 0xdfff) {
1129          Char = 0x10000 + ((Char - 0xd800) << 10) + (Trail - 0xdc00);
1130          ++I;
1131        }
1132      }
1133
1134      if (Char > 0xff) {
1135        // If this is a wide string, output characters over 0xff using \x
1136        // escapes. Otherwise, this is a UTF-16 or UTF-32 string, and Char is a
1137        // codepoint: use \x escapes for invalid codepoints.
1138        if (getKind() == Wide ||
1139            (Char >= 0xd800 && Char <= 0xdfff) || Char >= 0x110000) {
1140          // FIXME: Is this the best way to print wchar_t?
1141          OS << "\\x";
1142          int Shift = 28;
1143          while ((Char >> Shift) == 0)
1144            Shift -= 4;
1145          for (/**/; Shift >= 0; Shift -= 4)
1146            OS << Hex[(Char >> Shift) & 15];
1147          LastSlashX = I;
1148          break;
1149        }
1150
1151        if (Char > 0xffff)
1152          OS << "\\U00"
1153             << Hex[(Char >> 20) & 15]
1154             << Hex[(Char >> 16) & 15];
1155        else
1156          OS << "\\u";
1157        OS << Hex[(Char >> 12) & 15]
1158           << Hex[(Char >>  8) & 15]
1159           << Hex[(Char >>  4) & 15]
1160           << Hex[(Char >>  0) & 15];
1161        break;
1162      }
1163
1164      // If we used \x... for the previous character, and this character is a
1165      // hexadecimal digit, prevent it being slurped as part of the \x.
1166      if (LastSlashX + 1 == I) {
1167        switch (Char) {
1168          case '0': case '1': case '2': case '3': case '4':
1169          case '5': case '6': case '7': case '8': case '9':
1170          case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
1171          case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
1172            OS << "\"\"";
1173        }
1174      }
1175
1176      assert(Char <= 0xff &&
1177             "Characters above 0xff should already have been handled.");
1178
1179      if (isPrintable(Char))
1180        OS << (char)Char;
1181      else  // Output anything hard as an octal escape.
1182        OS << '\\'
1183           << (char)('0' + ((Char >> 6) & 7))
1184           << (char)('0' + ((Char >> 3) & 7))
1185           << (char)('0' + ((Char >> 0) & 7));
1186      break;
1187    // Handle some common non-printable cases to make dumps prettier.
1188    case '\\': OS << "\\\\"; break;
1189    case '"': OS << "\\\""; break;
1190    case '\a': OS << "\\a"; break;
1191    case '\b': OS << "\\b"; break;
1192    case '\f': OS << "\\f"; break;
1193    case '\n': OS << "\\n"; break;
1194    case '\r': OS << "\\r"; break;
1195    case '\t': OS << "\\t"; break;
1196    case '\v': OS << "\\v"; break;
1197    }
1198  }
1199  OS << '"';
1200}
1201
1202/// getLocationOfByte - Return a source location that points to the specified
1203/// byte of this string literal.
1204///
1205/// Strings are amazingly complex.  They can be formed from multiple tokens and
1206/// can have escape sequences in them in addition to the usual trigraph and
1207/// escaped newline business.  This routine handles this complexity.
1208///
1209/// The *StartToken sets the first token to be searched in this function and
1210/// the *StartTokenByteOffset is the byte offset of the first token. Before
1211/// returning, it updates the *StartToken to the TokNo of the token being found
1212/// and sets *StartTokenByteOffset to the byte offset of the token in the
1213/// string.
1214/// Using these two parameters can reduce the time complexity from O(n^2) to
1215/// O(n) if one wants to get the location of byte for all the tokens in a
1216/// string.
1217///
1218SourceLocation
1219StringLiteral::getLocationOfByte(unsigned ByteNo, const SourceManager &SM,
1220                                 const LangOptions &Features,
1221                                 const TargetInfo &Target, unsigned *StartToken,
1222                                 unsigned *StartTokenByteOffset) const {
1223  assert((getKind() == StringLiteral::Ascii ||
1224          getKind() == StringLiteral::UTF8) &&
1225         "Only narrow string literals are currently supported");
1226
1227  // Loop over all of the tokens in this string until we find the one that
1228  // contains the byte we're looking for.
1229  unsigned TokNo = 0;
1230  unsigned StringOffset = 0;
1231  if (StartToken)
1232    TokNo = *StartToken;
1233  if (StartTokenByteOffset) {
1234    StringOffset = *StartTokenByteOffset;
1235    ByteNo -= StringOffset;
1236  }
1237  while (1) {
1238    assert(TokNo < getNumConcatenated() && "Invalid byte number!");
1239    SourceLocation StrTokLoc = getStrTokenLoc(TokNo);
1240
1241    // Get the spelling of the string so that we can get the data that makes up
1242    // the string literal, not the identifier for the macro it is potentially
1243    // expanded through.
1244    SourceLocation StrTokSpellingLoc = SM.getSpellingLoc(StrTokLoc);
1245
1246    // Re-lex the token to get its length and original spelling.
1247    std::pair<FileID, unsigned> LocInfo =
1248        SM.getDecomposedLoc(StrTokSpellingLoc);
1249    bool Invalid = false;
1250    StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
1251    if (Invalid) {
1252      if (StartTokenByteOffset != nullptr)
1253        *StartTokenByteOffset = StringOffset;
1254      if (StartToken != nullptr)
1255        *StartToken = TokNo;
1256      return StrTokSpellingLoc;
1257    }
1258
1259    const char *StrData = Buffer.data()+LocInfo.second;
1260
1261    // Create a lexer starting at the beginning of this token.
1262    Lexer TheLexer(SM.getLocForStartOfFile(LocInfo.first), Features,
1263                   Buffer.begin(), StrData, Buffer.end());
1264    Token TheTok;
1265    TheLexer.LexFromRawLexer(TheTok);
1266
1267    // Use the StringLiteralParser to compute the length of the string in bytes.
1268    StringLiteralParser SLP(TheTok, SM, Features, Target);
1269    unsigned TokNumBytes = SLP.GetStringLength();
1270
1271    // If the byte is in this token, return the location of the byte.
1272    if (ByteNo < TokNumBytes ||
1273        (ByteNo == TokNumBytes && TokNo == getNumConcatenated() - 1)) {
1274      unsigned Offset = SLP.getOffsetOfStringByte(TheTok, ByteNo);
1275
1276      // Now that we know the offset of the token in the spelling, use the
1277      // preprocessor to get the offset in the original source.
1278      if (StartTokenByteOffset != nullptr)
1279        *StartTokenByteOffset = StringOffset;
1280      if (StartToken != nullptr)
1281        *StartToken = TokNo;
1282      return Lexer::AdvanceToTokenCharacter(StrTokLoc, Offset, SM, Features);
1283    }
1284
1285    // Move to the next string token.
1286    StringOffset += TokNumBytes;
1287    ++TokNo;
1288    ByteNo -= TokNumBytes;
1289  }
1290}
1291
1292/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
1293/// corresponds to, e.g. "sizeof" or "[pre]++".
1294StringRef UnaryOperator::getOpcodeStr(Opcode Op) {
1295  switch (Op) {
1296#define UNARY_OPERATION(Name, Spelling) case UO_##Name: return Spelling;
1297#include "clang/AST/OperationKinds.def"
1298  }
1299  llvm_unreachable("Unknown unary operator");
1300}
1301
1302UnaryOperatorKind
1303UnaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO, bool Postfix) {
1304  switch (OO) {
1305  default: llvm_unreachable("No unary operator for overloaded function");
1306  case OO_PlusPlus:   return Postfix ? UO_PostInc : UO_PreInc;
1307  case OO_MinusMinus: return Postfix ? UO_PostDec : UO_PreDec;
1308  case OO_Amp:        return UO_AddrOf;
1309  case OO_Star:       return UO_Deref;
1310  case OO_Plus:       return UO_Plus;
1311  case OO_Minus:      return UO_Minus;
1312  case OO_Tilde:      return UO_Not;
1313  case OO_Exclaim:    return UO_LNot;
1314  case OO_Coawait:    return UO_Coawait;
1315  }
1316}
1317
1318OverloadedOperatorKind UnaryOperator::getOverloadedOperator(Opcode Opc) {
1319  switch (Opc) {
1320  case UO_PostInc: case UO_PreInc: return OO_PlusPlus;
1321  case UO_PostDec: case UO_PreDec: return OO_MinusMinus;
1322  case UO_AddrOf: return OO_Amp;
1323  case UO_Deref: return OO_Star;
1324  case UO_Plus: return OO_Plus;
1325  case UO_Minus: return OO_Minus;
1326  case UO_Not: return OO_Tilde;
1327  case UO_LNot: return OO_Exclaim;
1328  case UO_Coawait: return OO_Coawait;
1329  default: return OO_None;
1330  }
1331}
1332
1333
1334//===----------------------------------------------------------------------===//
1335// Postfix Operators.
1336//===----------------------------------------------------------------------===//
1337
1338CallExpr::CallExpr(StmtClass SC, Expr *Fn, ArrayRef<Expr *> PreArgs,
1339                   ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
1340                   SourceLocation RParenLoc, unsigned MinNumArgs,
1341                   ADLCallKind UsesADL)
1342    : Expr(SC, Ty, VK, OK_Ordinary, Fn->isTypeDependent(),
1343           Fn->isValueDependent(), Fn->isInstantiationDependent(),
1344           Fn->containsUnexpandedParameterPack()),
1345      RParenLoc(RParenLoc) {
1346  NumArgs = std::max<unsigned>(Args.size(), MinNumArgs);
1347  unsigned NumPreArgs = PreArgs.size();
1348  CallExprBits.NumPreArgs = NumPreArgs;
1349  assert((NumPreArgs == getNumPreArgs()) && "NumPreArgs overflow!");
1350
1351  unsigned OffsetToTrailingObjects = offsetToTrailingObjects(SC);
1352  CallExprBits.OffsetToTrailingObjects = OffsetToTrailingObjects;
1353  assert((CallExprBits.OffsetToTrailingObjects == OffsetToTrailingObjects) &&
1354         "OffsetToTrailingObjects overflow!");
1355
1356  CallExprBits.UsesADL = static_cast<bool>(UsesADL);
1357
1358  setCallee(Fn);
1359  for (unsigned I = 0; I != NumPreArgs; ++I) {
1360    updateDependenciesFromArg(PreArgs[I]);
1361    setPreArg(I, PreArgs[I]);
1362  }
1363  for (unsigned I = 0; I != Args.size(); ++I) {
1364    updateDependenciesFromArg(Args[I]);
1365    setArg(I, Args[I]);
1366  }
1367  for (unsigned I = Args.size(); I != NumArgs; ++I) {
1368    setArg(I, nullptr);
1369  }
1370}
1371
1372CallExpr::CallExpr(StmtClass SC, unsigned NumPreArgs, unsigned NumArgs,
1373                   EmptyShell Empty)
1374    : Expr(SC, Empty), NumArgs(NumArgs) {
1375  CallExprBits.NumPreArgs = NumPreArgs;
1376  assert((NumPreArgs == getNumPreArgs()) && "NumPreArgs overflow!");
1377
1378  unsigned OffsetToTrailingObjects = offsetToTrailingObjects(SC);
1379  CallExprBits.OffsetToTrailingObjects = OffsetToTrailingObjects;
1380  assert((CallExprBits.OffsetToTrailingObjects == OffsetToTrailingObjects) &&
1381         "OffsetToTrailingObjects overflow!");
1382}
1383
1384CallExpr *CallExpr::Create(const ASTContext &Ctx, Expr *Fn,
1385                           ArrayRef<Expr *> Args, QualType Ty, ExprValueKind VK,
1386                           SourceLocation RParenLoc, unsigned MinNumArgs,
1387                           ADLCallKind UsesADL) {
1388  unsigned NumArgs = std::max<unsigned>(Args.size(), MinNumArgs);
1389  unsigned SizeOfTrailingObjects =
1390      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/0, NumArgs);
1391  void *Mem =
1392      Ctx.Allocate(sizeof(CallExpr) + SizeOfTrailingObjects, alignof(CallExpr));
1393  return new (Mem) CallExpr(CallExprClass, Fn, /*PreArgs=*/{}, Args, Ty, VK,
1394                            RParenLoc, MinNumArgs, UsesADL);
1395}
1396
1397CallExpr *CallExpr::CreateTemporary(void *Mem, Expr *Fn, QualType Ty,
1398                                    ExprValueKind VK, SourceLocation RParenLoc,
1399                                    ADLCallKind UsesADL) {
1400  assert(!(reinterpret_cast<uintptr_t>(Mem) % alignof(CallExpr)) &&
1401         "Misaligned memory in CallExpr::CreateTemporary!");
1402  return new (Mem) CallExpr(CallExprClass, Fn, /*PreArgs=*/{}, /*Args=*/{}, Ty,
1403                            VK, RParenLoc, /*MinNumArgs=*/0, UsesADL);
1404}
1405
1406CallExpr *CallExpr::CreateEmpty(const ASTContext &Ctx, unsigned NumArgs,
1407                                EmptyShell Empty) {
1408  unsigned SizeOfTrailingObjects =
1409      CallExpr::sizeOfTrailingObjects(/*NumPreArgs=*/0, NumArgs);
1410  void *Mem =
1411      Ctx.Allocate(sizeof(CallExpr) + SizeOfTrailingObjects, alignof(CallExpr));
1412  return new (Mem) CallExpr(CallExprClass, /*NumPreArgs=*/0, NumArgs, Empty);
1413}
1414
1415unsigned CallExpr::offsetToTrailingObjects(StmtClass SC) {
1416  switch (SC) {
1417  case CallExprClass:
1418    return sizeof(CallExpr);
1419  case CXXOperatorCallExprClass:
1420    return sizeof(CXXOperatorCallExpr);
1421  case CXXMemberCallExprClass:
1422    return sizeof(CXXMemberCallExpr);
1423  case UserDefinedLiteralClass:
1424    return sizeof(UserDefinedLiteral);
1425  case CUDAKernelCallExprClass:
1426    return sizeof(CUDAKernelCallExpr);
1427  default:
1428    llvm_unreachable("unexpected class deriving from CallExpr!");
1429  }
1430}
1431
1432void CallExpr::updateDependenciesFromArg(Expr *Arg) {
1433  if (Arg->isTypeDependent())
1434    ExprBits.TypeDependent = true;
1435  if (Arg->isValueDependent())
1436    ExprBits.ValueDependent = true;
1437  if (Arg->isInstantiationDependent())
1438    ExprBits.InstantiationDependent = true;
1439  if (Arg->containsUnexpandedParameterPack())
1440    ExprBits.ContainsUnexpandedParameterPack = true;
1441}
1442
1443Decl *Expr::getReferencedDeclOfCallee() {
1444  Expr *CEE = IgnoreParenImpCasts();
1445
1446  while (SubstNonTypeTemplateParmExpr *NTTP
1447                                = dyn_cast<SubstNonTypeTemplateParmExpr>(CEE)) {
1448    CEE = NTTP->getReplacement()->IgnoreParenCasts();
1449  }
1450
1451  // If we're calling a dereference, look at the pointer instead.
1452  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CEE)) {
1453    if (BO->isPtrMemOp())
1454      CEE = BO->getRHS()->IgnoreParenCasts();
1455  } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(CEE)) {
1456    if (UO->getOpcode() == UO_Deref)
1457      CEE = UO->getSubExpr()->IgnoreParenCasts();
1458  }
1459  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE))
1460    return DRE->getDecl();
1461  if (MemberExpr *ME = dyn_cast<MemberExpr>(CEE))
1462    return ME->getMemberDecl();
1463  if (auto *BE = dyn_cast<BlockExpr>(CEE))
1464    return BE->getBlockDecl();
1465
1466  return nullptr;
1467}
1468
1469/// getBuiltinCallee - If this is a call to a builtin, return the builtin ID. If
1470/// not, return 0.
1471unsigned CallExpr::getBuiltinCallee() const {
1472  // All simple function calls (e.g. func()) are implicitly cast to pointer to
1473  // function. As a result, we try and obtain the DeclRefExpr from the
1474  // ImplicitCastExpr.
1475  const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
1476  if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
1477    return 0;
1478
1479  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
1480  if (!DRE)
1481    return 0;
1482
1483  const FunctionDecl *FDecl = dyn_cast<FunctionDecl>(DRE->getDecl());
1484  if (!FDecl)
1485    return 0;
1486
1487  if (!FDecl->getIdentifier())
1488    return 0;
1489
1490  return FDecl->getBuiltinID();
1491}
1492
1493bool CallExpr::isUnevaluatedBuiltinCall(const ASTContext &Ctx) const {
1494  if (unsigned BI = getBuiltinCallee())
1495    return Ctx.BuiltinInfo.isUnevaluated(BI);
1496  return false;
1497}
1498
1499QualType CallExpr::getCallReturnType(const ASTContext &Ctx) const {
1500  const Expr *Callee = getCallee();
1501  QualType CalleeType = Callee->getType();
1502  if (const auto *FnTypePtr = CalleeType->getAs<PointerType>()) {
1503    CalleeType = FnTypePtr->getPointeeType();
1504  } else if (const auto *BPT = CalleeType->getAs<BlockPointerType>()) {
1505    CalleeType = BPT->getPointeeType();
1506  } else if (CalleeType->isSpecificPlaceholderType(BuiltinType::BoundMember)) {
1507    if (isa<CXXPseudoDestructorExpr>(Callee->IgnoreParens()))
1508      return Ctx.VoidTy;
1509
1510    // This should never be overloaded and so should never return null.
1511    CalleeType = Expr::findBoundMemberType(Callee);
1512  }
1513
1514  const FunctionType *FnType = CalleeType->castAs<FunctionType>();
1515  return FnType->getReturnType();
1516}
1517
1518const Attr *CallExpr::getUnusedResultAttr(const ASTContext &Ctx) const {
1519  // If the return type is a struct, union, or enum that is marked nodiscard,
1520  // then return the return type attribute.
1521  if (const TagDecl *TD = getCallReturnType(Ctx)->getAsTagDecl())
1522    if (const auto *A = TD->getAttr<WarnUnusedResultAttr>())
1523      return A;
1524
1525  // Otherwise, see if the callee is marked nodiscard and return that attribute
1526  // instead.
1527  const Decl *D = getCalleeDecl();
1528  return D ? D->getAttr<WarnUnusedResultAttr>() : nullptr;
1529}
1530
1531SourceLocation CallExpr::getBeginLoc() const {
1532  if (isa<CXXOperatorCallExpr>(this))
1533    return cast<CXXOperatorCallExpr>(this)->getBeginLoc();
1534
1535  SourceLocation begin = getCallee()->getBeginLoc();
1536  if (begin.isInvalid() && getNumArgs() > 0 && getArg(0))
1537    begin = getArg(0)->getBeginLoc();
1538  return begin;
1539}
1540SourceLocation CallExpr::getEndLoc() const {
1541  if (isa<CXXOperatorCallExpr>(this))
1542    return cast<CXXOperatorCallExpr>(this)->getEndLoc();
1543
1544  SourceLocation end = getRParenLoc();
1545  if (end.isInvalid() && getNumArgs() > 0 && getArg(getNumArgs() - 1))
1546    end = getArg(getNumArgs() - 1)->getEndLoc();
1547  return end;
1548}
1549
1550OffsetOfExpr *OffsetOfExpr::Create(const ASTContext &C, QualType type,
1551                                   SourceLocation OperatorLoc,
1552                                   TypeSourceInfo *tsi,
1553                                   ArrayRef<OffsetOfNode> comps,
1554                                   ArrayRef<Expr*> exprs,
1555                                   SourceLocation RParenLoc) {
1556  void *Mem = C.Allocate(
1557      totalSizeToAlloc<OffsetOfNode, Expr *>(comps.size(), exprs.size()));
1558
1559  return new (Mem) OffsetOfExpr(C, type, OperatorLoc, tsi, comps, exprs,
1560                                RParenLoc);
1561}
1562
1563OffsetOfExpr *OffsetOfExpr::CreateEmpty(const ASTContext &C,
1564                                        unsigned numComps, unsigned numExprs) {
1565  void *Mem =
1566      C.Allocate(totalSizeToAlloc<OffsetOfNode, Expr *>(numComps, numExprs));
1567  return new (Mem) OffsetOfExpr(numComps, numExprs);
1568}
1569
1570OffsetOfExpr::OffsetOfExpr(const ASTContext &C, QualType type,
1571                           SourceLocation OperatorLoc, TypeSourceInfo *tsi,
1572                           ArrayRef<OffsetOfNode> comps, ArrayRef<Expr*> exprs,
1573                           SourceLocation RParenLoc)
1574  : Expr(OffsetOfExprClass, type, VK_RValue, OK_Ordinary,
1575         /*TypeDependent=*/false,
1576         /*ValueDependent=*/tsi->getType()->isDependentType(),
1577         tsi->getType()->isInstantiationDependentType(),
1578         tsi->getType()->containsUnexpandedParameterPack()),
1579    OperatorLoc(OperatorLoc), RParenLoc(RParenLoc), TSInfo(tsi),
1580    NumComps(comps.size()), NumExprs(exprs.size())
1581{
1582  for (unsigned i = 0; i != comps.size(); ++i) {
1583    setComponent(i, comps[i]);
1584  }
1585
1586  for (unsigned i = 0; i != exprs.size(); ++i) {
1587    if (exprs[i]->isTypeDependent() || exprs[i]->isValueDependent())
1588      ExprBits.ValueDependent = true;
1589    if (exprs[i]->containsUnexpandedParameterPack())
1590      ExprBits.ContainsUnexpandedParameterPack = true;
1591
1592    setIndexExpr(i, exprs[i]);
1593  }
1594}
1595
1596IdentifierInfo *OffsetOfNode::getFieldName() const {
1597  assert(getKind() == Field || getKind() == Identifier);
1598  if (getKind() == Field)
1599    return getField()->getIdentifier();
1600
1601  return reinterpret_cast<IdentifierInfo *> (Data & ~(uintptr_t)Mask);
1602}
1603
1604UnaryExprOrTypeTraitExpr::UnaryExprOrTypeTraitExpr(
1605    UnaryExprOrTypeTrait ExprKind, Expr *E, QualType resultType,
1606    SourceLocation op, SourceLocation rp)
1607    : Expr(UnaryExprOrTypeTraitExprClass, resultType, VK_RValue, OK_Ordinary,
1608           false, // Never type-dependent (C++ [temp.dep.expr]p3).
1609           // Value-dependent if the argument is type-dependent.
1610           E->isTypeDependent(), E->isInstantiationDependent(),
1611           E->containsUnexpandedParameterPack()),
1612      OpLoc(op), RParenLoc(rp) {
1613  UnaryExprOrTypeTraitExprBits.Kind = ExprKind;
1614  UnaryExprOrTypeTraitExprBits.IsType = false;
1615  Argument.Ex = E;
1616
1617  // Check to see if we are in the situation where alignof(decl) should be
1618  // dependent because decl's alignment is dependent.
1619  if (ExprKind == UETT_AlignOf || ExprKind == UETT_PreferredAlignOf) {
1620    if (!isValueDependent() || !isInstantiationDependent()) {
1621      E = E->IgnoreParens();
1622
1623      const ValueDecl *D = nullptr;
1624      if (const auto *DRE = dyn_cast<DeclRefExpr>(E))
1625        D = DRE->getDecl();
1626      else if (const auto *ME = dyn_cast<MemberExpr>(E))
1627        D = ME->getMemberDecl();
1628
1629      if (D) {
1630        for (const auto *I : D->specific_attrs<AlignedAttr>()) {
1631          if (I->isAlignmentDependent()) {
1632            setValueDependent(true);
1633            setInstantiationDependent(true);
1634            break;
1635          }
1636        }
1637      }
1638    }
1639  }
1640}
1641
1642MemberExpr::MemberExpr(Expr *Base, bool IsArrow, SourceLocation OperatorLoc,
1643                       ValueDecl *MemberDecl,
1644                       const DeclarationNameInfo &NameInfo, QualType T,
1645                       ExprValueKind VK, ExprObjectKind OK,
1646                       NonOdrUseReason NOUR)
1647    : Expr(MemberExprClass, T, VK, OK, Base->isTypeDependent(),
1648           Base->isValueDependent(), Base->isInstantiationDependent(),
1649           Base->containsUnexpandedParameterPack()),
1650      Base(Base), MemberDecl(MemberDecl), MemberDNLoc(NameInfo.getInfo()),
1651      MemberLoc(NameInfo.getLoc()) {
1652  assert(!NameInfo.getName() ||
1653         MemberDecl->getDeclName() == NameInfo.getName());
1654  MemberExprBits.IsArrow = IsArrow;
1655  MemberExprBits.HasQualifierOrFoundDecl = false;
1656  MemberExprBits.HasTemplateKWAndArgsInfo = false;
1657  MemberExprBits.HadMultipleCandidates = false;
1658  MemberExprBits.NonOdrUseReason = NOUR;
1659  MemberExprBits.OperatorLoc = OperatorLoc;
1660}
1661
1662MemberExpr *MemberExpr::Create(
1663    const ASTContext &C, Expr *Base, bool IsArrow, SourceLocation OperatorLoc,
1664    NestedNameSpecifierLoc QualifierLoc, SourceLocation TemplateKWLoc,
1665    ValueDecl *MemberDecl, DeclAccessPair FoundDecl,
1666    DeclarationNameInfo NameInfo, const TemplateArgumentListInfo *TemplateArgs,
1667    QualType T, ExprValueKind VK, ExprObjectKind OK, NonOdrUseReason NOUR) {
1668  bool HasQualOrFound = QualifierLoc || FoundDecl.getDecl() != MemberDecl ||
1669                        FoundDecl.getAccess() != MemberDecl->getAccess();
1670  bool HasTemplateKWAndArgsInfo = TemplateArgs || TemplateKWLoc.isValid();
1671  std::size_t Size =
1672      totalSizeToAlloc<MemberExprNameQualifier, ASTTemplateKWAndArgsInfo,
1673                       TemplateArgumentLoc>(
1674          HasQualOrFound ? 1 : 0, HasTemplateKWAndArgsInfo ? 1 : 0,
1675          TemplateArgs ? TemplateArgs->size() : 0);
1676
1677  void *Mem = C.Allocate(Size, alignof(MemberExpr));
1678  MemberExpr *E = new (Mem) MemberExpr(Base, IsArrow, OperatorLoc, MemberDecl,
1679                                       NameInfo, T, VK, OK, NOUR);
1680
1681  if (isa<FieldDecl>(MemberDecl)) {
1682    DeclContext *DC = MemberDecl->getDeclContext();
1683    // dyn_cast_or_null is used to handle objC variables which do not
1684    // have a declaration context.
1685    CXXRecordDecl *RD = dyn_cast_or_null<CXXRecordDecl>(DC);
1686    if (RD && RD->isDependentContext() && RD->isCurrentInstantiation(DC))
1687      E->setTypeDependent(T->isDependentType());
1688
1689    // Bitfield with value-dependent width is type-dependent.
1690    FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl);
1691    if (FD && FD->isBitField() && FD->getBitWidth()->isValueDependent())
1692      E->setTypeDependent(true);
1693  }
1694
1695  if (HasQualOrFound) {
1696    // FIXME: Wrong. We should be looking at the member declaration we found.
1697    if (QualifierLoc && QualifierLoc.getNestedNameSpecifier()->isDependent()) {
1698      E->setValueDependent(true);
1699      E->setTypeDependent(true);
1700      E->setInstantiationDependent(true);
1701    }
1702    else if (QualifierLoc &&
1703             QualifierLoc.getNestedNameSpecifier()->isInstantiationDependent())
1704      E->setInstantiationDependent(true);
1705
1706    E->MemberExprBits.HasQualifierOrFoundDecl = true;
1707
1708    MemberExprNameQualifier *NQ =
1709        E->getTrailingObjects<MemberExprNameQualifier>();
1710    NQ->QualifierLoc = QualifierLoc;
1711    NQ->FoundDecl = FoundDecl;
1712  }
1713
1714  E->MemberExprBits.HasTemplateKWAndArgsInfo =
1715      TemplateArgs || TemplateKWLoc.isValid();
1716
1717  if (TemplateArgs) {
1718    bool Dependent = false;
1719    bool InstantiationDependent = false;
1720    bool ContainsUnexpandedParameterPack = false;
1721    E->getTrailingObjects<ASTTemplateKWAndArgsInfo>()->initializeFrom(
1722        TemplateKWLoc, *TemplateArgs,
1723        E->getTrailingObjects<TemplateArgumentLoc>(), Dependent,
1724        InstantiationDependent, ContainsUnexpandedParameterPack);
1725    if (InstantiationDependent)
1726      E->setInstantiationDependent(true);
1727  } else if (TemplateKWLoc.isValid()) {
1728    E->getTrailingObjects<ASTTemplateKWAndArgsInfo>()->initializeFrom(
1729        TemplateKWLoc);
1730  }
1731
1732  return E;
1733}
1734
1735MemberExpr *MemberExpr::CreateEmpty(const ASTContext &Context,
1736                                    bool HasQualifier, bool HasFoundDecl,
1737                                    bool HasTemplateKWAndArgsInfo,
1738                                    unsigned NumTemplateArgs) {
1739  assert((!NumTemplateArgs || HasTemplateKWAndArgsInfo) &&
1740         "template args but no template arg info?");
1741  bool HasQualOrFound = HasQualifier || HasFoundDecl;
1742  std::size_t Size =
1743      totalSizeToAlloc<MemberExprNameQualifier, ASTTemplateKWAndArgsInfo,
1744                       TemplateArgumentLoc>(HasQualOrFound ? 1 : 0,
1745                                            HasTemplateKWAndArgsInfo ? 1 : 0,
1746                                            NumTemplateArgs);
1747  void *Mem = Context.Allocate(Size, alignof(MemberExpr));
1748  return new (Mem) MemberExpr(EmptyShell());
1749}
1750
1751SourceLocation MemberExpr::getBeginLoc() const {
1752  if (isImplicitAccess()) {
1753    if (hasQualifier())
1754      return getQualifierLoc().getBeginLoc();
1755    return MemberLoc;
1756  }
1757
1758  // FIXME: We don't want this to happen. Rather, we should be able to
1759  // detect all kinds of implicit accesses more cleanly.
1760  SourceLocation BaseStartLoc = getBase()->getBeginLoc();
1761  if (BaseStartLoc.isValid())
1762    return BaseStartLoc;
1763  return MemberLoc;
1764}
1765SourceLocation MemberExpr::getEndLoc() const {
1766  SourceLocation EndLoc = getMemberNameInfo().getEndLoc();
1767  if (hasExplicitTemplateArgs())
1768    EndLoc = getRAngleLoc();
1769  else if (EndLoc.isInvalid())
1770    EndLoc = getBase()->getEndLoc();
1771  return EndLoc;
1772}
1773
1774bool CastExpr::CastConsistency() const {
1775  switch (getCastKind()) {
1776  case CK_DerivedToBase:
1777  case CK_UncheckedDerivedToBase:
1778  case CK_DerivedToBaseMemberPointer:
1779  case CK_BaseToDerived:
1780  case CK_BaseToDerivedMemberPointer:
1781    assert(!path_empty() && "Cast kind should have a base path!");
1782    break;
1783
1784  case CK_CPointerToObjCPointerCast:
1785    assert(getType()->isObjCObjectPointerType());
1786    assert(getSubExpr()->getType()->isPointerType());
1787    goto CheckNoBasePath;
1788
1789  case CK_BlockPointerToObjCPointerCast:
1790    assert(getType()->isObjCObjectPointerType());
1791    assert(getSubExpr()->getType()->isBlockPointerType());
1792    goto CheckNoBasePath;
1793
1794  case CK_ReinterpretMemberPointer:
1795    assert(getType()->isMemberPointerType());
1796    assert(getSubExpr()->getType()->isMemberPointerType());
1797    goto CheckNoBasePath;
1798
1799  case CK_BitCast:
1800    // Arbitrary casts to C pointer types count as bitcasts.
1801    // Otherwise, we should only have block and ObjC pointer casts
1802    // here if they stay within the type kind.
1803    if (!getType()->isPointerType()) {
1804      assert(getType()->isObjCObjectPointerType() ==
1805             getSubExpr()->getType()->isObjCObjectPointerType());
1806      assert(getType()->isBlockPointerType() ==
1807             getSubExpr()->getType()->isBlockPointerType());
1808    }
1809    goto CheckNoBasePath;
1810
1811  case CK_AnyPointerToBlockPointerCast:
1812    assert(getType()->isBlockPointerType());
1813    assert(getSubExpr()->getType()->isAnyPointerType() &&
1814           !getSubExpr()->getType()->isBlockPointerType());
1815    goto CheckNoBasePath;
1816
1817  case CK_CopyAndAutoreleaseBlockObject:
1818    assert(getType()->isBlockPointerType());
1819    assert(getSubExpr()->getType()->isBlockPointerType());
1820    goto CheckNoBasePath;
1821
1822  case CK_FunctionToPointerDecay:
1823    assert(getType()->isPointerType());
1824    assert(getSubExpr()->getType()->isFunctionType());
1825    goto CheckNoBasePath;
1826
1827  case CK_AddressSpaceConversion: {
1828    auto Ty = getType();
1829    auto SETy = getSubExpr()->getType();
1830    assert(getValueKindForType(Ty) == Expr::getValueKindForType(SETy));
1831    if (isRValue()) {
1832      Ty = Ty->getPointeeType();
1833      SETy = SETy->getPointeeType();
1834    }
1835    assert(!Ty.isNull() && !SETy.isNull() &&
1836           Ty.getAddressSpace() != SETy.getAddressSpace());
1837    goto CheckNoBasePath;
1838  }
1839  // These should not have an inheritance path.
1840  case CK_Dynamic:
1841  case CK_ToUnion:
1842  case CK_ArrayToPointerDecay:
1843  case CK_NullToMemberPointer:
1844  case CK_NullToPointer:
1845  case CK_ConstructorConversion:
1846  case CK_IntegralToPointer:
1847  case CK_PointerToIntegral:
1848  case CK_ToVoid:
1849  case CK_VectorSplat:
1850  case CK_IntegralCast:
1851  case CK_BooleanToSignedIntegral:
1852  case CK_IntegralToFloating:
1853  case CK_FloatingToIntegral:
1854  case CK_FloatingCast:
1855  case CK_ObjCObjectLValueCast:
1856  case CK_FloatingRealToComplex:
1857  case CK_FloatingComplexToReal:
1858  case CK_FloatingComplexCast:
1859  case CK_FloatingComplexToIntegralComplex:
1860  case CK_IntegralRealToComplex:
1861  case CK_IntegralComplexToReal:
1862  case CK_IntegralComplexCast:
1863  case CK_IntegralComplexToFloatingComplex:
1864  case CK_ARCProduceObject:
1865  case CK_ARCConsumeObject:
1866  case CK_ARCReclaimReturnedObject:
1867  case CK_ARCExtendBlockObject:
1868  case CK_ZeroToOCLOpaqueType:
1869  case CK_IntToOCLSampler:
1870  case CK_FixedPointCast:
1871  case CK_FixedPointToIntegral:
1872  case CK_IntegralToFixedPoint:
1873    assert(!getType()->isBooleanType() && "unheralded conversion to bool");
1874    goto CheckNoBasePath;
1875
1876  case CK_Dependent:
1877  case CK_LValueToRValue:
1878  case CK_NoOp:
1879  case CK_AtomicToNonAtomic:
1880  case CK_NonAtomicToAtomic:
1881  case CK_PointerToBoolean:
1882  case CK_IntegralToBoolean:
1883  case CK_FloatingToBoolean:
1884  case CK_MemberPointerToBoolean:
1885  case CK_FloatingComplexToBoolean:
1886  case CK_IntegralComplexToBoolean:
1887  case CK_LValueBitCast:            // -> bool&
1888  case CK_LValueToRValueBitCast:
1889  case CK_UserDefinedConversion:    // operator bool()
1890  case CK_BuiltinFnToFnPtr:
1891  case CK_FixedPointToBoolean:
1892  CheckNoBasePath:
1893    assert(path_empty() && "Cast kind should not have a base path!");
1894    break;
1895  }
1896  return true;
1897}
1898
1899const char *CastExpr::getCastKindName(CastKind CK) {
1900  switch (CK) {
1901#define CAST_OPERATION(Name) case CK_##Name: return #Name;
1902#include "clang/AST/OperationKinds.def"
1903  }
1904  llvm_unreachable("Unhandled cast kind!");
1905}
1906
1907namespace {
1908  const Expr *skipImplicitTemporary(const Expr *E) {
1909    // Skip through reference binding to temporary.
1910    if (auto *Materialize = dyn_cast<MaterializeTemporaryExpr>(E))
1911      E = Materialize->getSubExpr();
1912
1913    // Skip any temporary bindings; they're implicit.
1914    if (auto *Binder = dyn_cast<CXXBindTemporaryExpr>(E))
1915      E = Binder->getSubExpr();
1916
1917    return E;
1918  }
1919}
1920
1921Expr *CastExpr::getSubExprAsWritten() {
1922  const Expr *SubExpr = nullptr;
1923  const CastExpr *E = this;
1924  do {
1925    SubExpr = skipImplicitTemporary(E->getSubExpr());
1926
1927    // Conversions by constructor and conversion functions have a
1928    // subexpression describing the call; strip it off.
1929    if (E->getCastKind() == CK_ConstructorConversion)
1930      SubExpr =
1931        skipImplicitTemporary(cast<CXXConstructExpr>(SubExpr)->getArg(0));
1932    else if (E->getCastKind() == CK_UserDefinedConversion) {
1933      assert((isa<CXXMemberCallExpr>(SubExpr) ||
1934              isa<BlockExpr>(SubExpr)) &&
1935             "Unexpected SubExpr for CK_UserDefinedConversion.");
1936      if (auto *MCE = dyn_cast<CXXMemberCallExpr>(SubExpr))
1937        SubExpr = MCE->getImplicitObjectArgument();
1938    }
1939
1940    // If the subexpression we're left with is an implicit cast, look
1941    // through that, too.
1942  } while ((E = dyn_cast<ImplicitCastExpr>(SubExpr)));
1943
1944  return const_cast<Expr*>(SubExpr);
1945}
1946
1947NamedDecl *CastExpr::getConversionFunction() const {
1948  const Expr *SubExpr = nullptr;
1949
1950  for (const CastExpr *E = this; E; E = dyn_cast<ImplicitCastExpr>(SubExpr)) {
1951    SubExpr = skipImplicitTemporary(E->getSubExpr());
1952
1953    if (E->getCastKind() == CK_ConstructorConversion)
1954      return cast<CXXConstructExpr>(SubExpr)->getConstructor();
1955
1956    if (E->getCastKind() == CK_UserDefinedConversion) {
1957      if (auto *MCE = dyn_cast<CXXMemberCallExpr>(SubExpr))
1958        return MCE->getMethodDecl();
1959    }
1960  }
1961
1962  return nullptr;
1963}
1964
1965CXXBaseSpecifier **CastExpr::path_buffer() {
1966  switch (getStmtClass()) {
1967#define ABSTRACT_STMT(x)
1968#define CASTEXPR(Type, Base)                                                   \
1969  case Stmt::Type##Class:                                                      \
1970    return static_cast<Type *>(this)->getTrailingObjects<CXXBaseSpecifier *>();
1971#define STMT(Type, Base)
1972#include "clang/AST/StmtNodes.inc"
1973  default:
1974    llvm_unreachable("non-cast expressions not possible here");
1975  }
1976}
1977
1978const FieldDecl *CastExpr::getTargetFieldForToUnionCast(QualType unionType,
1979                                                        QualType opType) {
1980  auto RD = unionType->castAs<RecordType>()->getDecl();
1981  return getTargetFieldForToUnionCast(RD, opType);
1982}
1983
1984const FieldDecl *CastExpr::getTargetFieldForToUnionCast(const RecordDecl *RD,
1985                                                        QualType OpType) {
1986  auto &Ctx = RD->getASTContext();
1987  RecordDecl::field_iterator Field, FieldEnd;
1988  for (Field = RD->field_begin(), FieldEnd = RD->field_end();
1989       Field != FieldEnd; ++Field) {
1990    if (Ctx.hasSameUnqualifiedType(Field->getType(), OpType) &&
1991        !Field->isUnnamedBitfield()) {
1992      return *Field;
1993    }
1994  }
1995  return nullptr;
1996}
1997
1998ImplicitCastExpr *ImplicitCastExpr::Create(const ASTContext &C, QualType T,
1999                                           CastKind Kind, Expr *Operand,
2000                                           const CXXCastPath *BasePath,
2001                                           ExprValueKind VK) {
2002  unsigned PathSize = (BasePath ? BasePath->size() : 0);
2003  void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
2004  // Per C++ [conv.lval]p3, lvalue-to-rvalue conversions on class and
2005  // std::nullptr_t have special semantics not captured by CK_LValueToRValue.
2006  assert((Kind != CK_LValueToRValue ||
2007          !(T->isNullPtrType() || T->getAsCXXRecordDecl())) &&
2008         "invalid type for lvalue-to-rvalue conversion");
2009  ImplicitCastExpr *E =
2010    new (Buffer) ImplicitCastExpr(T, Kind, Operand, PathSize, VK);
2011  if (PathSize)
2012    std::uninitialized_copy_n(BasePath->data(), BasePath->size(),
2013                              E->getTrailingObjects<CXXBaseSpecifier *>());
2014  return E;
2015}
2016
2017ImplicitCastExpr *ImplicitCastExpr::CreateEmpty(const ASTContext &C,
2018                                                unsigned PathSize) {
2019  void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
2020  return new (Buffer) ImplicitCastExpr(EmptyShell(), PathSize);
2021}
2022
2023
2024CStyleCastExpr *CStyleCastExpr::Create(const ASTContext &C, QualType T,
2025                                       ExprValueKind VK, CastKind K, Expr *Op,
2026                                       const CXXCastPath *BasePath,
2027                                       TypeSourceInfo *WrittenTy,
2028                                       SourceLocation L, SourceLocation R) {
2029  unsigned PathSize = (BasePath ? BasePath->size() : 0);
2030  void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
2031  CStyleCastExpr *E =
2032    new (Buffer) CStyleCastExpr(T, VK, K, Op, PathSize, WrittenTy, L, R);
2033  if (PathSize)
2034    std::uninitialized_copy_n(BasePath->data(), BasePath->size(),
2035                              E->getTrailingObjects<CXXBaseSpecifier *>());
2036  return E;
2037}
2038
2039CStyleCastExpr *CStyleCastExpr::CreateEmpty(const ASTContext &C,
2040                                            unsigned PathSize) {
2041  void *Buffer = C.Allocate(totalSizeToAlloc<CXXBaseSpecifier *>(PathSize));
2042  return new (Buffer) CStyleCastExpr(EmptyShell(), PathSize);
2043}
2044
2045/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
2046/// corresponds to, e.g. "<<=".
2047StringRef BinaryOperator::getOpcodeStr(Opcode Op) {
2048  switch (Op) {
2049#define BINARY_OPERATION(Name, Spelling) case BO_##Name: return Spelling;
2050#include "clang/AST/OperationKinds.def"
2051  }
2052  llvm_unreachable("Invalid OpCode!");
2053}
2054
2055BinaryOperatorKind
2056BinaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO) {
2057  switch (OO) {
2058  default: llvm_unreachable("Not an overloadable binary operator");
2059  case OO_Plus: return BO_Add;
2060  case OO_Minus: return BO_Sub;
2061  case OO_Star: return BO_Mul;
2062  case OO_Slash: return BO_Div;
2063  case OO_Percent: return BO_Rem;
2064  case OO_Caret: return BO_Xor;
2065  case OO_Amp: return BO_And;
2066  case OO_Pipe: return BO_Or;
2067  case OO_Equal: return BO_Assign;
2068  case OO_Spaceship: return BO_Cmp;
2069  case OO_Less: return BO_LT;
2070  case OO_Greater: return BO_GT;
2071  case OO_PlusEqual: return BO_AddAssign;
2072  case OO_MinusEqual: return BO_SubAssign;
2073  case OO_StarEqual: return BO_MulAssign;
2074  case OO_SlashEqual: return BO_DivAssign;
2075  case OO_PercentEqual: return BO_RemAssign;
2076  case OO_CaretEqual: return BO_XorAssign;
2077  case OO_AmpEqual: return BO_AndAssign;
2078  case OO_PipeEqual: return BO_OrAssign;
2079  case OO_LessLess: return BO_Shl;
2080  case OO_GreaterGreater: return BO_Shr;
2081  case OO_LessLessEqual: return BO_ShlAssign;
2082  case OO_GreaterGreaterEqual: return BO_ShrAssign;
2083  case OO_EqualEqual: return BO_EQ;
2084  case OO_ExclaimEqual: return BO_NE;
2085  case OO_LessEqual: return BO_LE;
2086  case OO_GreaterEqual: return BO_GE;
2087  case OO_AmpAmp: return BO_LAnd;
2088  case OO_PipePipe: return BO_LOr;
2089  case OO_Comma: return BO_Comma;
2090  case OO_ArrowStar: return BO_PtrMemI;
2091  }
2092}
2093
2094OverloadedOperatorKind BinaryOperator::getOverloadedOperator(Opcode Opc) {
2095  static const OverloadedOperatorKind OverOps[] = {
2096    /* .* Cannot be overloaded */OO_None, OO_ArrowStar,
2097    OO_Star, OO_Slash, OO_Percent,
2098    OO_Plus, OO_Minus,
2099    OO_LessLess, OO_GreaterGreater,
2100    OO_Spaceship,
2101    OO_Less, OO_Greater, OO_LessEqual, OO_GreaterEqual,
2102    OO_EqualEqual, OO_ExclaimEqual,
2103    OO_Amp,
2104    OO_Caret,
2105    OO_Pipe,
2106    OO_AmpAmp,
2107    OO_PipePipe,
2108    OO_Equal, OO_StarEqual,
2109    OO_SlashEqual, OO_PercentEqual,
2110    OO_PlusEqual, OO_MinusEqual,
2111    OO_LessLessEqual, OO_GreaterGreaterEqual,
2112    OO_AmpEqual, OO_CaretEqual,
2113    OO_PipeEqual,
2114    OO_Comma
2115  };
2116  return OverOps[Opc];
2117}
2118
2119bool BinaryOperator::isNullPointerArithmeticExtension(ASTContext &Ctx,
2120                                                      Opcode Opc,
2121                                                      Expr *LHS, Expr *RHS) {
2122  if (Opc != BO_Add)
2123    return false;
2124
2125  // Check that we have one pointer and one integer operand.
2126  Expr *PExp;
2127  if (LHS->getType()->isPointerType()) {
2128    if (!RHS->getType()->isIntegerType())
2129      return false;
2130    PExp = LHS;
2131  } else if (RHS->getType()->isPointerType()) {
2132    if (!LHS->getType()->isIntegerType())
2133      return false;
2134    PExp = RHS;
2135  } else {
2136    return false;
2137  }
2138
2139  // Check that the pointer is a nullptr.
2140  if (!PExp->IgnoreParenCasts()
2141          ->isNullPointerConstant(Ctx, Expr::NPC_ValueDependentIsNotNull))
2142    return false;
2143
2144  // Check that the pointee type is char-sized.
2145  const PointerType *PTy = PExp->getType()->getAs<PointerType>();
2146  if (!PTy || !PTy->getPointeeType()->isCharType())
2147    return false;
2148
2149  return true;
2150}
2151
2152static QualType getDecayedSourceLocExprType(const ASTContext &Ctx,
2153                                            SourceLocExpr::IdentKind Kind) {
2154  switch (Kind) {
2155  case SourceLocExpr::File:
2156  case SourceLocExpr::Function: {
2157    QualType ArrTy = Ctx.getStringLiteralArrayType(Ctx.CharTy, 0);
2158    return Ctx.getPointerType(ArrTy->getAsArrayTypeUnsafe()->getElementType());
2159  }
2160  case SourceLocExpr::Line:
2161  case SourceLocExpr::Column:
2162    return Ctx.UnsignedIntTy;
2163  }
2164  llvm_unreachable("unhandled case");
2165}
2166
2167SourceLocExpr::SourceLocExpr(const ASTContext &Ctx, IdentKind Kind,
2168                             SourceLocation BLoc, SourceLocation RParenLoc,
2169                             DeclContext *ParentContext)
2170    : Expr(SourceLocExprClass, getDecayedSourceLocExprType(Ctx, Kind),
2171           VK_RValue, OK_Ordinary, false, false, false, false),
2172      BuiltinLoc(BLoc), RParenLoc(RParenLoc), ParentContext(ParentContext) {
2173  SourceLocExprBits.Kind = Kind;
2174}
2175
2176StringRef SourceLocExpr::getBuiltinStr() const {
2177  switch (getIdentKind()) {
2178  case File:
2179    return "__builtin_FILE";
2180  case Function:
2181    return "__builtin_FUNCTION";
2182  case Line:
2183    return "__builtin_LINE";
2184  case Column:
2185    return "__builtin_COLUMN";
2186  }
2187  llvm_unreachable("unexpected IdentKind!");
2188}
2189
2190APValue SourceLocExpr::EvaluateInContext(const ASTContext &Ctx,
2191                                         const Expr *DefaultExpr) const {
2192  SourceLocation Loc;
2193  const DeclContext *Context;
2194
2195  std::tie(Loc,
2196           Context) = [&]() -> std::pair<SourceLocation, const DeclContext *> {
2197    if (auto *DIE = dyn_cast_or_null<CXXDefaultInitExpr>(DefaultExpr))
2198      return {DIE->getUsedLocation(), DIE->getUsedContext()};
2199    if (auto *DAE = dyn_cast_or_null<CXXDefaultArgExpr>(DefaultExpr))
2200      return {DAE->getUsedLocation(), DAE->getUsedContext()};
2201    return {this->getLocation(), this->getParentContext()};
2202  }();
2203
2204  PresumedLoc PLoc = Ctx.getSourceManager().getPresumedLoc(
2205      Ctx.getSourceManager().getExpansionRange(Loc).getEnd());
2206
2207  auto MakeStringLiteral = [&](StringRef Tmp) {
2208    using LValuePathEntry = APValue::LValuePathEntry;
2209    StringLiteral *Res = Ctx.getPredefinedStringLiteralFromCache(Tmp);
2210    // Decay the string to a pointer to the first character.
2211    LValuePathEntry Path[1] = {LValuePathEntry::ArrayIndex(0)};
2212    return APValue(Res, CharUnits::Zero(), Path, /*OnePastTheEnd=*/false);
2213  };
2214
2215  switch (getIdentKind()) {
2216  case SourceLocExpr::File:
2217    return MakeStringLiteral(PLoc.getFilename());
2218  case SourceLocExpr::Function: {
2219    const Decl *CurDecl = dyn_cast_or_null<Decl>(Context);
2220    return MakeStringLiteral(
2221        CurDecl ? PredefinedExpr::ComputeName(PredefinedExpr::Function, CurDecl)
2222                : std::string(""));
2223  }
2224  case SourceLocExpr::Line:
2225  case SourceLocExpr::Column: {
2226    llvm::APSInt IntVal(Ctx.getIntWidth(Ctx.UnsignedIntTy),
2227                        /*isUnsigned=*/true);
2228    IntVal = getIdentKind() == SourceLocExpr::Line ? PLoc.getLine()
2229                                                   : PLoc.getColumn();
2230    return APValue(IntVal);
2231  }
2232  }
2233  llvm_unreachable("unhandled case");
2234}
2235
2236InitListExpr::InitListExpr(const ASTContext &C, SourceLocation lbraceloc,
2237                           ArrayRef<Expr*> initExprs, SourceLocation rbraceloc)
2238  : Expr(InitListExprClass, QualType(), VK_RValue, OK_Ordinary, false, false,
2239         false, false),
2240    InitExprs(C, initExprs.size()),
2241    LBraceLoc(lbraceloc), RBraceLoc(rbraceloc), AltForm(nullptr, true)
2242{
2243  sawArrayRangeDesignator(false);
2244  for (unsigned I = 0; I != initExprs.size(); ++I) {
2245    if (initExprs[I]->isTypeDependent())
2246      ExprBits.TypeDependent = true;
2247    if (initExprs[I]->isValueDependent())
2248      ExprBits.ValueDependent = true;
2249    if (initExprs[I]->isInstantiationDependent())
2250      ExprBits.InstantiationDependent = true;
2251    if (initExprs[I]->containsUnexpandedParameterPack())
2252      ExprBits.ContainsUnexpandedParameterPack = true;
2253  }
2254
2255  InitExprs.insert(C, InitExprs.end(), initExprs.begin(), initExprs.end());
2256}
2257
2258void InitListExpr::reserveInits(const ASTContext &C, unsigned NumInits) {
2259  if (NumInits > InitExprs.size())
2260    InitExprs.reserve(C, NumInits);
2261}
2262
2263void InitListExpr::resizeInits(const ASTContext &C, unsigned NumInits) {
2264  InitExprs.resize(C, NumInits, nullptr);
2265}
2266
2267Expr *InitListExpr::updateInit(const ASTContext &C, unsigned Init, Expr *expr) {
2268  if (Init >= InitExprs.size()) {
2269    InitExprs.insert(C, InitExprs.end(), Init - InitExprs.size() + 1, nullptr);
2270    setInit(Init, expr);
2271    return nullptr;
2272  }
2273
2274  Expr *Result = cast_or_null<Expr>(InitExprs[Init]);
2275  setInit(Init, expr);
2276  return Result;
2277}
2278
2279void InitListExpr::setArrayFiller(Expr *filler) {
2280  assert(!hasArrayFiller() && "Filler already set!");
2281  ArrayFillerOrUnionFieldInit = filler;
2282  // Fill out any "holes" in the array due to designated initializers.
2283  Expr **inits = getInits();
2284  for (unsigned i = 0, e = getNumInits(); i != e; ++i)
2285    if (inits[i] == nullptr)
2286      inits[i] = filler;
2287}
2288
2289bool InitListExpr::isStringLiteralInit() const {
2290  if (getNumInits() != 1)
2291    return false;
2292  const ArrayType *AT = getType()->getAsArrayTypeUnsafe();
2293  if (!AT || !AT->getElementType()->isIntegerType())
2294    return false;
2295  // It is possible for getInit() to return null.
2296  const Expr *Init = getInit(0);
2297  if (!Init)
2298    return false;
2299  Init = Init->IgnoreParens();
2300  return isa<StringLiteral>(Init) || isa<ObjCEncodeExpr>(Init);
2301}
2302
2303bool InitListExpr::isTransparent() const {
2304  assert(isSemanticForm() && "syntactic form never semantically transparent");
2305
2306  // A glvalue InitListExpr is always just sugar.
2307  if (isGLValue()) {
2308    assert(getNumInits() == 1 && "multiple inits in glvalue init list");
2309    return true;
2310  }
2311
2312  // Otherwise, we're sugar if and only if we have exactly one initializer that
2313  // is of the same type.
2314  if (getNumInits() != 1 || !getInit(0))
2315    return false;
2316
2317  // Don't confuse aggregate initialization of a struct X { X &x; }; with a
2318  // transparent struct copy.
2319  if (!getInit(0)->isRValue() && getType()->isRecordType())
2320    return false;
2321
2322  return getType().getCanonicalType() ==
2323         getInit(0)->getType().getCanonicalType();
2324}
2325
2326bool InitListExpr::isIdiomaticZeroInitializer(const LangOptions &LangOpts) const {
2327  assert(isSyntacticForm() && "only test syntactic form as zero initializer");
2328
2329  if (LangOpts.CPlusPlus || getNumInits() != 1 || !getInit(0)) {
2330    return false;
2331  }
2332
2333  const IntegerLiteral *Lit = dyn_cast<IntegerLiteral>(getInit(0)->IgnoreImplicit());
2334  return Lit && Lit->getValue() == 0;
2335}
2336
2337SourceLocation InitListExpr::getBeginLoc() const {
2338  if (InitListExpr *SyntacticForm = getSyntacticForm())
2339    return SyntacticForm->getBeginLoc();
2340  SourceLocation Beg = LBraceLoc;
2341  if (Beg.isInvalid()) {
2342    // Find the first non-null initializer.
2343    for (InitExprsTy::const_iterator I = InitExprs.begin(),
2344                                     E = InitExprs.end();
2345      I != E; ++I) {
2346      if (Stmt *S = *I) {
2347        Beg = S->getBeginLoc();
2348        break;
2349      }
2350    }
2351  }
2352  return Beg;
2353}
2354
2355SourceLocation InitListExpr::getEndLoc() const {
2356  if (InitListExpr *SyntacticForm = getSyntacticForm())
2357    return SyntacticForm->getEndLoc();
2358  SourceLocation End = RBraceLoc;
2359  if (End.isInvalid()) {
2360    // Find the first non-null initializer from the end.
2361    for (InitExprsTy::const_reverse_iterator I = InitExprs.rbegin(),
2362         E = InitExprs.rend();
2363         I != E; ++I) {
2364      if (Stmt *S = *I) {
2365        End = S->getEndLoc();
2366        break;
2367      }
2368    }
2369  }
2370  return End;
2371}
2372
2373/// getFunctionType - Return the underlying function type for this block.
2374///
2375const FunctionProtoType *BlockExpr::getFunctionType() const {
2376  // The block pointer is never sugared, but the function type might be.
2377  return cast<BlockPointerType>(getType())
2378           ->getPointeeType()->castAs<FunctionProtoType>();
2379}
2380
2381SourceLocation BlockExpr::getCaretLocation() const {
2382  return TheBlock->getCaretLocation();
2383}
2384const Stmt *BlockExpr::getBody() const {
2385  return TheBlock->getBody();
2386}
2387Stmt *BlockExpr::getBody() {
2388  return TheBlock->getBody();
2389}
2390
2391
2392//===----------------------------------------------------------------------===//
2393// Generic Expression Routines
2394//===----------------------------------------------------------------------===//
2395
2396/// isUnusedResultAWarning - Return true if this immediate expression should
2397/// be warned about if the result is unused.  If so, fill in Loc and Ranges
2398/// with location to warn on and the source range[s] to report with the
2399/// warning.
2400bool Expr::isUnusedResultAWarning(const Expr *&WarnE, SourceLocation &Loc,
2401                                  SourceRange &R1, SourceRange &R2,
2402                                  ASTContext &Ctx) const {
2403  // Don't warn if the expr is type dependent. The type could end up
2404  // instantiating to void.
2405  if (isTypeDependent())
2406    return false;
2407
2408  switch (getStmtClass()) {
2409  default:
2410    if (getType()->isVoidType())
2411      return false;
2412    WarnE = this;
2413    Loc = getExprLoc();
2414    R1 = getSourceRange();
2415    return true;
2416  case ParenExprClass:
2417    return cast<ParenExpr>(this)->getSubExpr()->
2418      isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2419  case GenericSelectionExprClass:
2420    return cast<GenericSelectionExpr>(this)->getResultExpr()->
2421      isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2422  case CoawaitExprClass:
2423  case CoyieldExprClass:
2424    return cast<CoroutineSuspendExpr>(this)->getResumeExpr()->
2425      isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2426  case ChooseExprClass:
2427    return cast<ChooseExpr>(this)->getChosenSubExpr()->
2428      isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2429  case UnaryOperatorClass: {
2430    const UnaryOperator *UO = cast<UnaryOperator>(this);
2431
2432    switch (UO->getOpcode()) {
2433    case UO_Plus:
2434    case UO_Minus:
2435    case UO_AddrOf:
2436    case UO_Not:
2437    case UO_LNot:
2438    case UO_Deref:
2439      break;
2440    case UO_Coawait:
2441      // This is just the 'operator co_await' call inside the guts of a
2442      // dependent co_await call.
2443    case UO_PostInc:
2444    case UO_PostDec:
2445    case UO_PreInc:
2446    case UO_PreDec:                 // ++/--
2447      return false;  // Not a warning.
2448    case UO_Real:
2449    case UO_Imag:
2450      // accessing a piece of a volatile complex is a side-effect.
2451      if (Ctx.getCanonicalType(UO->getSubExpr()->getType())
2452          .isVolatileQualified())
2453        return false;
2454      break;
2455    case UO_Extension:
2456      return UO->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2457    }
2458    WarnE = this;
2459    Loc = UO->getOperatorLoc();
2460    R1 = UO->getSubExpr()->getSourceRange();
2461    return true;
2462  }
2463  case BinaryOperatorClass: {
2464    const BinaryOperator *BO = cast<BinaryOperator>(this);
2465    switch (BO->getOpcode()) {
2466      default:
2467        break;
2468      // Consider the RHS of comma for side effects. LHS was checked by
2469      // Sema::CheckCommaOperands.
2470      case BO_Comma:
2471        // ((foo = <blah>), 0) is an idiom for hiding the result (and
2472        // lvalue-ness) of an assignment written in a macro.
2473        if (IntegerLiteral *IE =
2474              dyn_cast<IntegerLiteral>(BO->getRHS()->IgnoreParens()))
2475          if (IE->getValue() == 0)
2476            return false;
2477        return BO->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2478      // Consider '||', '&&' to have side effects if the LHS or RHS does.
2479      case BO_LAnd:
2480      case BO_LOr:
2481        if (!BO->getLHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx) ||
2482            !BO->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx))
2483          return false;
2484        break;
2485    }
2486    if (BO->isAssignmentOp())
2487      return false;
2488    WarnE = this;
2489    Loc = BO->getOperatorLoc();
2490    R1 = BO->getLHS()->getSourceRange();
2491    R2 = BO->getRHS()->getSourceRange();
2492    return true;
2493  }
2494  case CompoundAssignOperatorClass:
2495  case VAArgExprClass:
2496  case AtomicExprClass:
2497    return false;
2498
2499  case ConditionalOperatorClass: {
2500    // If only one of the LHS or RHS is a warning, the operator might
2501    // be being used for control flow. Only warn if both the LHS and
2502    // RHS are warnings.
2503    const auto *Exp = cast<ConditionalOperator>(this);
2504    return Exp->getLHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx) &&
2505           Exp->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2506  }
2507  case BinaryConditionalOperatorClass: {
2508    const auto *Exp = cast<BinaryConditionalOperator>(this);
2509    return Exp->getFalseExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2510  }
2511
2512  case MemberExprClass:
2513    WarnE = this;
2514    Loc = cast<MemberExpr>(this)->getMemberLoc();
2515    R1 = SourceRange(Loc, Loc);
2516    R2 = cast<MemberExpr>(this)->getBase()->getSourceRange();
2517    return true;
2518
2519  case ArraySubscriptExprClass:
2520    WarnE = this;
2521    Loc = cast<ArraySubscriptExpr>(this)->getRBracketLoc();
2522    R1 = cast<ArraySubscriptExpr>(this)->getLHS()->getSourceRange();
2523    R2 = cast<ArraySubscriptExpr>(this)->getRHS()->getSourceRange();
2524    return true;
2525
2526  case CXXOperatorCallExprClass: {
2527    // Warn about operator ==,!=,<,>,<=, and >= even when user-defined operator
2528    // overloads as there is no reasonable way to define these such that they
2529    // have non-trivial, desirable side-effects. See the -Wunused-comparison
2530    // warning: operators == and != are commonly typo'ed, and so warning on them
2531    // provides additional value as well. If this list is updated,
2532    // DiagnoseUnusedComparison should be as well.
2533    const CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(this);
2534    switch (Op->getOperator()) {
2535    default:
2536      break;
2537    case OO_EqualEqual:
2538    case OO_ExclaimEqual:
2539    case OO_Less:
2540    case OO_Greater:
2541    case OO_GreaterEqual:
2542    case OO_LessEqual:
2543      if (Op->getCallReturnType(Ctx)->isReferenceType() ||
2544          Op->getCallReturnType(Ctx)->isVoidType())
2545        break;
2546      WarnE = this;
2547      Loc = Op->getOperatorLoc();
2548      R1 = Op->getSourceRange();
2549      return true;
2550    }
2551
2552    // Fallthrough for generic call handling.
2553    LLVM_FALLTHROUGH;
2554  }
2555  case CallExprClass:
2556  case CXXMemberCallExprClass:
2557  case UserDefinedLiteralClass: {
2558    // If this is a direct call, get the callee.
2559    const CallExpr *CE = cast<CallExpr>(this);
2560    if (const Decl *FD = CE->getCalleeDecl()) {
2561      // If the callee has attribute pure, const, or warn_unused_result, warn
2562      // about it. void foo() { strlen("bar"); } should warn.
2563      //
2564      // Note: If new cases are added here, DiagnoseUnusedExprResult should be
2565      // updated to match for QoI.
2566      if (CE->hasUnusedResultAttr(Ctx) ||
2567          FD->hasAttr<PureAttr>() || FD->hasAttr<ConstAttr>()) {
2568        WarnE = this;
2569        Loc = CE->getCallee()->getBeginLoc();
2570        R1 = CE->getCallee()->getSourceRange();
2571
2572        if (unsigned NumArgs = CE->getNumArgs())
2573          R2 = SourceRange(CE->getArg(0)->getBeginLoc(),
2574                           CE->getArg(NumArgs - 1)->getEndLoc());
2575        return true;
2576      }
2577    }
2578    return false;
2579  }
2580
2581  // If we don't know precisely what we're looking at, let's not warn.
2582  case UnresolvedLookupExprClass:
2583  case CXXUnresolvedConstructExprClass:
2584    return false;
2585
2586  case CXXTemporaryObjectExprClass:
2587  case CXXConstructExprClass: {
2588    if (const CXXRecordDecl *Type = getType()->getAsCXXRecordDecl()) {
2589      const auto *WarnURAttr = Type->getAttr<WarnUnusedResultAttr>();
2590      if (Type->hasAttr<WarnUnusedAttr>() ||
2591          (WarnURAttr && WarnURAttr->IsCXX11NoDiscard())) {
2592        WarnE = this;
2593        Loc = getBeginLoc();
2594        R1 = getSourceRange();
2595        return true;
2596      }
2597    }
2598
2599    const auto *CE = cast<CXXConstructExpr>(this);
2600    if (const CXXConstructorDecl *Ctor = CE->getConstructor()) {
2601      const auto *WarnURAttr = Ctor->getAttr<WarnUnusedResultAttr>();
2602      if (WarnURAttr && WarnURAttr->IsCXX11NoDiscard()) {
2603        WarnE = this;
2604        Loc = getBeginLoc();
2605        R1 = getSourceRange();
2606
2607        if (unsigned NumArgs = CE->getNumArgs())
2608          R2 = SourceRange(CE->getArg(0)->getBeginLoc(),
2609                           CE->getArg(NumArgs - 1)->getEndLoc());
2610        return true;
2611      }
2612    }
2613
2614    return false;
2615  }
2616
2617  case ObjCMessageExprClass: {
2618    const ObjCMessageExpr *ME = cast<ObjCMessageExpr>(this);
2619    if (Ctx.getLangOpts().ObjCAutoRefCount &&
2620        ME->isInstanceMessage() &&
2621        !ME->getType()->isVoidType() &&
2622        ME->getMethodFamily() == OMF_init) {
2623      WarnE = this;
2624      Loc = getExprLoc();
2625      R1 = ME->getSourceRange();
2626      return true;
2627    }
2628
2629    if (const ObjCMethodDecl *MD = ME->getMethodDecl())
2630      if (MD->hasAttr<WarnUnusedResultAttr>()) {
2631        WarnE = this;
2632        Loc = getExprLoc();
2633        return true;
2634      }
2635
2636    return false;
2637  }
2638
2639  case ObjCPropertyRefExprClass:
2640    WarnE = this;
2641    Loc = getExprLoc();
2642    R1 = getSourceRange();
2643    return true;
2644
2645  case PseudoObjectExprClass: {
2646    const PseudoObjectExpr *PO = cast<PseudoObjectExpr>(this);
2647
2648    // Only complain about things that have the form of a getter.
2649    if (isa<UnaryOperator>(PO->getSyntacticForm()) ||
2650        isa<BinaryOperator>(PO->getSyntacticForm()))
2651      return false;
2652
2653    WarnE = this;
2654    Loc = getExprLoc();
2655    R1 = getSourceRange();
2656    return true;
2657  }
2658
2659  case StmtExprClass: {
2660    // Statement exprs don't logically have side effects themselves, but are
2661    // sometimes used in macros in ways that give them a type that is unused.
2662    // For example ({ blah; foo(); }) will end up with a type if foo has a type.
2663    // however, if the result of the stmt expr is dead, we don't want to emit a
2664    // warning.
2665    const CompoundStmt *CS = cast<StmtExpr>(this)->getSubStmt();
2666    if (!CS->body_empty()) {
2667      if (const Expr *E = dyn_cast<Expr>(CS->body_back()))
2668        return E->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2669      if (const LabelStmt *Label = dyn_cast<LabelStmt>(CS->body_back()))
2670        if (const Expr *E = dyn_cast<Expr>(Label->getSubStmt()))
2671          return E->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2672    }
2673
2674    if (getType()->isVoidType())
2675      return false;
2676    WarnE = this;
2677    Loc = cast<StmtExpr>(this)->getLParenLoc();
2678    R1 = getSourceRange();
2679    return true;
2680  }
2681  case CXXFunctionalCastExprClass:
2682  case CStyleCastExprClass: {
2683    // Ignore an explicit cast to void unless the operand is a non-trivial
2684    // volatile lvalue.
2685    const CastExpr *CE = cast<CastExpr>(this);
2686    if (CE->getCastKind() == CK_ToVoid) {
2687      if (CE->getSubExpr()->isGLValue() &&
2688          CE->getSubExpr()->getType().isVolatileQualified()) {
2689        const DeclRefExpr *DRE =
2690            dyn_cast<DeclRefExpr>(CE->getSubExpr()->IgnoreParens());
2691        if (!(DRE && isa<VarDecl>(DRE->getDecl()) &&
2692              cast<VarDecl>(DRE->getDecl())->hasLocalStorage()) &&
2693            !isa<CallExpr>(CE->getSubExpr()->IgnoreParens())) {
2694          return CE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc,
2695                                                          R1, R2, Ctx);
2696        }
2697      }
2698      return false;
2699    }
2700
2701    // If this is a cast to a constructor conversion, check the operand.
2702    // Otherwise, the result of the cast is unused.
2703    if (CE->getCastKind() == CK_ConstructorConversion)
2704      return CE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2705
2706    WarnE = this;
2707    if (const CXXFunctionalCastExpr *CXXCE =
2708            dyn_cast<CXXFunctionalCastExpr>(this)) {
2709      Loc = CXXCE->getBeginLoc();
2710      R1 = CXXCE->getSubExpr()->getSourceRange();
2711    } else {
2712      const CStyleCastExpr *CStyleCE = cast<CStyleCastExpr>(this);
2713      Loc = CStyleCE->getLParenLoc();
2714      R1 = CStyleCE->getSubExpr()->getSourceRange();
2715    }
2716    return true;
2717  }
2718  case ImplicitCastExprClass: {
2719    const CastExpr *ICE = cast<ImplicitCastExpr>(this);
2720
2721    // lvalue-to-rvalue conversion on a volatile lvalue is a side-effect.
2722    if (ICE->getCastKind() == CK_LValueToRValue &&
2723        ICE->getSubExpr()->getType().isVolatileQualified())
2724      return false;
2725
2726    return ICE->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2727  }
2728  case CXXDefaultArgExprClass:
2729    return (cast<CXXDefaultArgExpr>(this)
2730            ->getExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx));
2731  case CXXDefaultInitExprClass:
2732    return (cast<CXXDefaultInitExpr>(this)
2733            ->getExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx));
2734
2735  case CXXNewExprClass:
2736    // FIXME: In theory, there might be new expressions that don't have side
2737    // effects (e.g. a placement new with an uninitialized POD).
2738  case CXXDeleteExprClass:
2739    return false;
2740  case MaterializeTemporaryExprClass:
2741    return cast<MaterializeTemporaryExpr>(this)
2742        ->getSubExpr()
2743        ->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2744  case CXXBindTemporaryExprClass:
2745    return cast<CXXBindTemporaryExpr>(this)->getSubExpr()
2746               ->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2747  case ExprWithCleanupsClass:
2748    return cast<ExprWithCleanups>(this)->getSubExpr()
2749               ->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
2750  }
2751}
2752
2753/// isOBJCGCCandidate - Check if an expression is objc gc'able.
2754/// returns true, if it is; false otherwise.
2755bool Expr::isOBJCGCCandidate(ASTContext &Ctx) const {
2756  const Expr *E = IgnoreParens();
2757  switch (E->getStmtClass()) {
2758  default:
2759    return false;
2760  case ObjCIvarRefExprClass:
2761    return true;
2762  case Expr::UnaryOperatorClass:
2763    return cast<UnaryOperator>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
2764  case ImplicitCastExprClass:
2765    return cast<ImplicitCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
2766  case MaterializeTemporaryExprClass:
2767    return cast<MaterializeTemporaryExpr>(E)->getSubExpr()->isOBJCGCCandidate(
2768        Ctx);
2769  case CStyleCastExprClass:
2770    return cast<CStyleCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
2771  case DeclRefExprClass: {
2772    const Decl *D = cast<DeclRefExpr>(E)->getDecl();
2773
2774    if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
2775      if (VD->hasGlobalStorage())
2776        return true;
2777      QualType T = VD->getType();
2778      // dereferencing to a  pointer is always a gc'able candidate,
2779      // unless it is __weak.
2780      return T->isPointerType() &&
2781             (Ctx.getObjCGCAttrKind(T) != Qualifiers::Weak);
2782    }
2783    return false;
2784  }
2785  case MemberExprClass: {
2786    const MemberExpr *M = cast<MemberExpr>(E);
2787    return M->getBase()->isOBJCGCCandidate(Ctx);
2788  }
2789  case ArraySubscriptExprClass:
2790    return cast<ArraySubscriptExpr>(E)->getBase()->isOBJCGCCandidate(Ctx);
2791  }
2792}
2793
2794bool Expr::isBoundMemberFunction(ASTContext &Ctx) const {
2795  if (isTypeDependent())
2796    return false;
2797  return ClassifyLValue(Ctx) == Expr::LV_MemberFunction;
2798}
2799
2800QualType Expr::findBoundMemberType(const Expr *expr) {
2801  assert(expr->hasPlaceholderType(BuiltinType::BoundMember));
2802
2803  // Bound member expressions are always one of these possibilities:
2804  //   x->m      x.m      x->*y      x.*y
2805  // (possibly parenthesized)
2806
2807  expr = expr->IgnoreParens();
2808  if (const MemberExpr *mem = dyn_cast<MemberExpr>(expr)) {
2809    assert(isa<CXXMethodDecl>(mem->getMemberDecl()));
2810    return mem->getMemberDecl()->getType();
2811  }
2812
2813  if (const BinaryOperator *op = dyn_cast<BinaryOperator>(expr)) {
2814    QualType type = op->getRHS()->getType()->castAs<MemberPointerType>()
2815                      ->getPointeeType();
2816    assert(type->isFunctionType());
2817    return type;
2818  }
2819
2820  assert(isa<UnresolvedMemberExpr>(expr) || isa<CXXPseudoDestructorExpr>(expr));
2821  return QualType();
2822}
2823
2824static Expr *IgnoreImpCastsSingleStep(Expr *E) {
2825  if (auto *ICE = dyn_cast<ImplicitCastExpr>(E))
2826    return ICE->getSubExpr();
2827
2828  if (auto *FE = dyn_cast<FullExpr>(E))
2829    return FE->getSubExpr();
2830
2831  return E;
2832}
2833
2834static Expr *IgnoreImpCastsExtraSingleStep(Expr *E) {
2835  // FIXME: Skip MaterializeTemporaryExpr and SubstNonTypeTemplateParmExpr in
2836  // addition to what IgnoreImpCasts() skips to account for the current
2837  // behaviour of IgnoreParenImpCasts().
2838  Expr *SubE = IgnoreImpCastsSingleStep(E);
2839  if (SubE != E)
2840    return SubE;
2841
2842  if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E))
2843    return MTE->getSubExpr();
2844
2845  if (auto *NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E))
2846    return NTTP->getReplacement();
2847
2848  return E;
2849}
2850
2851static Expr *IgnoreCastsSingleStep(Expr *E) {
2852  if (auto *CE = dyn_cast<CastExpr>(E))
2853    return CE->getSubExpr();
2854
2855  if (auto *FE = dyn_cast<FullExpr>(E))
2856    return FE->getSubExpr();
2857
2858  if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E))
2859    return MTE->getSubExpr();
2860
2861  if (auto *NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E))
2862    return NTTP->getReplacement();
2863
2864  return E;
2865}
2866
2867static Expr *IgnoreLValueCastsSingleStep(Expr *E) {
2868  // Skip what IgnoreCastsSingleStep skips, except that only
2869  // lvalue-to-rvalue casts are skipped.
2870  if (auto *CE = dyn_cast<CastExpr>(E))
2871    if (CE->getCastKind() != CK_LValueToRValue)
2872      return E;
2873
2874  return IgnoreCastsSingleStep(E);
2875}
2876
2877static Expr *IgnoreBaseCastsSingleStep(Expr *E) {
2878  if (auto *CE = dyn_cast<CastExpr>(E))
2879    if (CE->getCastKind() == CK_DerivedToBase ||
2880        CE->getCastKind() == CK_UncheckedDerivedToBase ||
2881        CE->getCastKind() == CK_NoOp)
2882      return CE->getSubExpr();
2883
2884  return E;
2885}
2886
2887static Expr *IgnoreImplicitSingleStep(Expr *E) {
2888  Expr *SubE = IgnoreImpCastsSingleStep(E);
2889  if (SubE != E)
2890    return SubE;
2891
2892  if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(E))
2893    return MTE->getSubExpr();
2894
2895  if (auto *BTE = dyn_cast<CXXBindTemporaryExpr>(E))
2896    return BTE->getSubExpr();
2897
2898  return E;
2899}
2900
2901static Expr *IgnoreImplicitAsWrittenSingleStep(Expr *E) {
2902  if (auto *ICE = dyn_cast<ImplicitCastExpr>(E))
2903    return ICE->getSubExprAsWritten();
2904
2905  return IgnoreImplicitSingleStep(E);
2906}
2907
2908static Expr *IgnoreParensSingleStep(Expr *E) {
2909  if (auto *PE = dyn_cast<ParenExpr>(E))
2910    return PE->getSubExpr();
2911
2912  if (auto *UO = dyn_cast<UnaryOperator>(E)) {
2913    if (UO->getOpcode() == UO_Extension)
2914      return UO->getSubExpr();
2915  }
2916
2917  else if (auto *GSE = dyn_cast<GenericSelectionExpr>(E)) {
2918    if (!GSE->isResultDependent())
2919      return GSE->getResultExpr();
2920  }
2921
2922  else if (auto *CE = dyn_cast<ChooseExpr>(E)) {
2923    if (!CE->isConditionDependent())
2924      return CE->getChosenSubExpr();
2925  }
2926
2927  else if (auto *CE = dyn_cast<ConstantExpr>(E))
2928    return CE->getSubExpr();
2929
2930  return E;
2931}
2932
2933static Expr *IgnoreNoopCastsSingleStep(const ASTContext &Ctx, Expr *E) {
2934  if (auto *CE = dyn_cast<CastExpr>(E)) {
2935    // We ignore integer <-> casts that are of the same width, ptr<->ptr and
2936    // ptr<->int casts of the same width. We also ignore all identity casts.
2937    Expr *SubExpr = CE->getSubExpr();
2938    bool IsIdentityCast =
2939        Ctx.hasSameUnqualifiedType(E->getType(), SubExpr->getType());
2940    bool IsSameWidthCast =
2941        (E->getType()->isPointerType() || E->getType()->isIntegralType(Ctx)) &&
2942        (SubExpr->getType()->isPointerType() ||
2943         SubExpr->getType()->isIntegralType(Ctx)) &&
2944        (Ctx.getTypeSize(E->getType()) == Ctx.getTypeSize(SubExpr->getType()));
2945
2946    if (IsIdentityCast || IsSameWidthCast)
2947      return SubExpr;
2948  }
2949
2950  else if (auto *NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E))
2951    return NTTP->getReplacement();
2952
2953  return E;
2954}
2955
2956static Expr *IgnoreExprNodesImpl(Expr *E) { return E; }
2957template <typename FnTy, typename... FnTys>
2958static Expr *IgnoreExprNodesImpl(Expr *E, FnTy &&Fn, FnTys &&... Fns) {
2959  return IgnoreExprNodesImpl(Fn(E), std::forward<FnTys>(Fns)...);
2960}
2961
2962/// Given an expression E and functions Fn_1,...,Fn_n : Expr * -> Expr *,
2963/// Recursively apply each of the functions to E until reaching a fixed point.
2964/// Note that a null E is valid; in this case nothing is done.
2965template <typename... FnTys>
2966static Expr *IgnoreExprNodes(Expr *E, FnTys &&... Fns) {
2967  Expr *LastE = nullptr;
2968  while (E != LastE) {
2969    LastE = E;
2970    E = IgnoreExprNodesImpl(E, std::forward<FnTys>(Fns)...);
2971  }
2972  return E;
2973}
2974
2975Expr *Expr::IgnoreImpCasts() {
2976  return IgnoreExprNodes(this, IgnoreImpCastsSingleStep);
2977}
2978
2979Expr *Expr::IgnoreCasts() {
2980  return IgnoreExprNodes(this, IgnoreCastsSingleStep);
2981}
2982
2983Expr *Expr::IgnoreImplicit() {
2984  return IgnoreExprNodes(this, IgnoreImplicitSingleStep);
2985}
2986
2987Expr *Expr::IgnoreImplicitAsWritten() {
2988  return IgnoreExprNodes(this, IgnoreImplicitAsWrittenSingleStep);
2989}
2990
2991Expr *Expr::IgnoreParens() {
2992  return IgnoreExprNodes(this, IgnoreParensSingleStep);
2993}
2994
2995Expr *Expr::IgnoreParenImpCasts() {
2996  return IgnoreExprNodes(this, IgnoreParensSingleStep,
2997                         IgnoreImpCastsExtraSingleStep);
2998}
2999
3000Expr *Expr::IgnoreParenCasts() {
3001  return IgnoreExprNodes(this, IgnoreParensSingleStep, IgnoreCastsSingleStep);
3002}
3003
3004Expr *Expr::IgnoreConversionOperator() {
3005  if (auto *MCE = dyn_cast<CXXMemberCallExpr>(this)) {
3006    if (MCE->getMethodDecl() && isa<CXXConversionDecl>(MCE->getMethodDecl()))
3007      return MCE->getImplicitObjectArgument();
3008  }
3009  return this;
3010}
3011
3012Expr *Expr::IgnoreParenLValueCasts() {
3013  return IgnoreExprNodes(this, IgnoreParensSingleStep,
3014                         IgnoreLValueCastsSingleStep);
3015}
3016
3017Expr *Expr::ignoreParenBaseCasts() {
3018  return IgnoreExprNodes(this, IgnoreParensSingleStep,
3019                         IgnoreBaseCastsSingleStep);
3020}
3021
3022Expr *Expr::IgnoreParenNoopCasts(const ASTContext &Ctx) {
3023  return IgnoreExprNodes(this, IgnoreParensSingleStep, [&Ctx](Expr *E) {
3024    return IgnoreNoopCastsSingleStep(Ctx, E);
3025  });
3026}
3027
3028Expr *Expr::IgnoreUnlessSpelledInSource() {
3029  Expr *E = this;
3030
3031  Expr *LastE = nullptr;
3032  while (E != LastE) {
3033    LastE = E;
3034    E = E->IgnoreParenImpCasts();
3035
3036    auto SR = E->getSourceRange();
3037
3038    if (auto *C = dyn_cast<CXXConstructExpr>(E)) {
3039      if (C->getNumArgs() == 1) {
3040        Expr *A = C->getArg(0);
3041        if (A->getSourceRange() == SR || !isa<CXXTemporaryObjectExpr>(C))
3042          E = A;
3043      }
3044    }
3045
3046    if (auto *C = dyn_cast<CXXMemberCallExpr>(E)) {
3047      Expr *ExprNode = C->getImplicitObjectArgument()->IgnoreParenImpCasts();
3048      if (ExprNode->getSourceRange() == SR)
3049        E = ExprNode;
3050    }
3051  }
3052
3053  return E;
3054}
3055
3056bool Expr::isDefaultArgument() const {
3057  const Expr *E = this;
3058  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
3059    E = M->getSubExpr();
3060
3061  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
3062    E = ICE->getSubExprAsWritten();
3063
3064  return isa<CXXDefaultArgExpr>(E);
3065}
3066
3067/// Skip over any no-op casts and any temporary-binding
3068/// expressions.
3069static const Expr *skipTemporaryBindingsNoOpCastsAndParens(const Expr *E) {
3070  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
3071    E = M->getSubExpr();
3072
3073  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
3074    if (ICE->getCastKind() == CK_NoOp)
3075      E = ICE->getSubExpr();
3076    else
3077      break;
3078  }
3079
3080  while (const CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(E))
3081    E = BE->getSubExpr();
3082
3083  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
3084    if (ICE->getCastKind() == CK_NoOp)
3085      E = ICE->getSubExpr();
3086    else
3087      break;
3088  }
3089
3090  return E->IgnoreParens();
3091}
3092
3093/// isTemporaryObject - Determines if this expression produces a
3094/// temporary of the given class type.
3095bool Expr::isTemporaryObject(ASTContext &C, const CXXRecordDecl *TempTy) const {
3096  if (!C.hasSameUnqualifiedType(getType(), C.getTypeDeclType(TempTy)))
3097    return false;
3098
3099  const Expr *E = skipTemporaryBindingsNoOpCastsAndParens(this);
3100
3101  // Temporaries are by definition pr-values of class type.
3102  if (!E->Classify(C).isPRValue()) {
3103    // In this context, property reference is a message call and is pr-value.
3104    if (!isa<ObjCPropertyRefExpr>(E))
3105      return false;
3106  }
3107
3108  // Black-list a few cases which yield pr-values of class type that don't
3109  // refer to temporaries of that type:
3110
3111  // - implicit derived-to-base conversions
3112  if (isa<ImplicitCastExpr>(E)) {
3113    switch (cast<ImplicitCastExpr>(E)->getCastKind()) {
3114    case CK_DerivedToBase:
3115    case CK_UncheckedDerivedToBase:
3116      return false;
3117    default:
3118      break;
3119    }
3120  }
3121
3122  // - member expressions (all)
3123  if (isa<MemberExpr>(E))
3124    return false;
3125
3126  if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E))
3127    if (BO->isPtrMemOp())
3128      return false;
3129
3130  // - opaque values (all)
3131  if (isa<OpaqueValueExpr>(E))
3132    return false;
3133
3134  return true;
3135}
3136
3137bool Expr::isImplicitCXXThis() const {
3138  const Expr *E = this;
3139
3140  // Strip away parentheses and casts we don't care about.
3141  while (true) {
3142    if (const ParenExpr *Paren = dyn_cast<ParenExpr>(E)) {
3143      E = Paren->getSubExpr();
3144      continue;
3145    }
3146
3147    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
3148      if (ICE->getCastKind() == CK_NoOp ||
3149          ICE->getCastKind() == CK_LValueToRValue ||
3150          ICE->getCastKind() == CK_DerivedToBase ||
3151          ICE->getCastKind() == CK_UncheckedDerivedToBase) {
3152        E = ICE->getSubExpr();
3153        continue;
3154      }
3155    }
3156
3157    if (const UnaryOperator* UnOp = dyn_cast<UnaryOperator>(E)) {
3158      if (UnOp->getOpcode() == UO_Extension) {
3159        E = UnOp->getSubExpr();
3160        continue;
3161      }
3162    }
3163
3164    if (const MaterializeTemporaryExpr *M
3165                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
3166      E = M->getSubExpr();
3167      continue;
3168    }
3169
3170    break;
3171  }
3172
3173  if (const CXXThisExpr *This = dyn_cast<CXXThisExpr>(E))
3174    return This->isImplicit();
3175
3176  return false;
3177}
3178
3179/// hasAnyTypeDependentArguments - Determines if any of the expressions
3180/// in Exprs is type-dependent.
3181bool Expr::hasAnyTypeDependentArguments(ArrayRef<Expr *> Exprs) {
3182  for (unsigned I = 0; I < Exprs.size(); ++I)
3183    if (Exprs[I]->isTypeDependent())
3184      return true;
3185
3186  return false;
3187}
3188
3189bool Expr::isConstantInitializer(ASTContext &Ctx, bool IsForRef,
3190                                 const Expr **Culprit) const {
3191  assert(!isValueDependent() &&
3192         "Expression evaluator can't be called on a dependent expression.");
3193
3194  // This function is attempting whether an expression is an initializer
3195  // which can be evaluated at compile-time. It very closely parallels
3196  // ConstExprEmitter in CGExprConstant.cpp; if they don't match, it
3197  // will lead to unexpected results.  Like ConstExprEmitter, it falls back
3198  // to isEvaluatable most of the time.
3199  //
3200  // If we ever capture reference-binding directly in the AST, we can
3201  // kill the second parameter.
3202
3203  if (IsForRef) {
3204    EvalResult Result;
3205    if (EvaluateAsLValue(Result, Ctx) && !Result.HasSideEffects)
3206      return true;
3207    if (Culprit)
3208      *Culprit = this;
3209    return false;
3210  }
3211
3212  switch (getStmtClass()) {
3213  default: break;
3214  case StringLiteralClass:
3215  case ObjCEncodeExprClass:
3216    return true;
3217  case CXXTemporaryObjectExprClass:
3218  case CXXConstructExprClass: {
3219    const CXXConstructExpr *CE = cast<CXXConstructExpr>(this);
3220
3221    if (CE->getConstructor()->isTrivial() &&
3222        CE->getConstructor()->getParent()->hasTrivialDestructor()) {
3223      // Trivial default constructor
3224      if (!CE->getNumArgs()) return true;
3225
3226      // Trivial copy constructor
3227      assert(CE->getNumArgs() == 1 && "trivial ctor with > 1 argument");
3228      return CE->getArg(0)->isConstantInitializer(Ctx, false, Culprit);
3229    }
3230
3231    break;
3232  }
3233  case ConstantExprClass: {
3234    // FIXME: We should be able to return "true" here, but it can lead to extra
3235    // error messages. E.g. in Sema/array-init.c.
3236    const Expr *Exp = cast<ConstantExpr>(this)->getSubExpr();
3237    return Exp->isConstantInitializer(Ctx, false, Culprit);
3238  }
3239  case CompoundLiteralExprClass: {
3240    // This handles gcc's extension that allows global initializers like
3241    // "struct x {int x;} x = (struct x) {};".
3242    // FIXME: This accepts other cases it shouldn't!
3243    const Expr *Exp = cast<CompoundLiteralExpr>(this)->getInitializer();
3244    return Exp->isConstantInitializer(Ctx, false, Culprit);
3245  }
3246  case DesignatedInitUpdateExprClass: {
3247    const DesignatedInitUpdateExpr *DIUE = cast<DesignatedInitUpdateExpr>(this);
3248    return DIUE->getBase()->isConstantInitializer(Ctx, false, Culprit) &&
3249           DIUE->getUpdater()->isConstantInitializer(Ctx, false, Culprit);
3250  }
3251  case InitListExprClass: {
3252    const InitListExpr *ILE = cast<InitListExpr>(this);
3253    assert(ILE->isSemanticForm() && "InitListExpr must be in semantic form");
3254    if (ILE->getType()->isArrayType()) {
3255      unsigned numInits = ILE->getNumInits();
3256      for (unsigned i = 0; i < numInits; i++) {
3257        if (!ILE->getInit(i)->isConstantInitializer(Ctx, false, Culprit))
3258          return false;
3259      }
3260      return true;
3261    }
3262
3263    if (ILE->getType()->isRecordType()) {
3264      unsigned ElementNo = 0;
3265      RecordDecl *RD = ILE->getType()->castAs<RecordType>()->getDecl();
3266      for (const auto *Field : RD->fields()) {
3267        // If this is a union, skip all the fields that aren't being initialized.
3268        if (RD->isUnion() && ILE->getInitializedFieldInUnion() != Field)
3269          continue;
3270
3271        // Don't emit anonymous bitfields, they just affect layout.
3272        if (Field->isUnnamedBitfield())
3273          continue;
3274
3275        if (ElementNo < ILE->getNumInits()) {
3276          const Expr *Elt = ILE->getInit(ElementNo++);
3277          if (Field->isBitField()) {
3278            // Bitfields have to evaluate to an integer.
3279            EvalResult Result;
3280            if (!Elt->EvaluateAsInt(Result, Ctx)) {
3281              if (Culprit)
3282                *Culprit = Elt;
3283              return false;
3284            }
3285          } else {
3286            bool RefType = Field->getType()->isReferenceType();
3287            if (!Elt->isConstantInitializer(Ctx, RefType, Culprit))
3288              return false;
3289          }
3290        }
3291      }
3292      return true;
3293    }
3294
3295    break;
3296  }
3297  case ImplicitValueInitExprClass:
3298  case NoInitExprClass:
3299    return true;
3300  case ParenExprClass:
3301    return cast<ParenExpr>(this)->getSubExpr()
3302      ->isConstantInitializer(Ctx, IsForRef, Culprit);
3303  case GenericSelectionExprClass:
3304    return cast<GenericSelectionExpr>(this)->getResultExpr()
3305      ->isConstantInitializer(Ctx, IsForRef, Culprit);
3306  case ChooseExprClass:
3307    if (cast<ChooseExpr>(this)->isConditionDependent()) {
3308      if (Culprit)
3309        *Culprit = this;
3310      return false;
3311    }
3312    return cast<ChooseExpr>(this)->getChosenSubExpr()
3313      ->isConstantInitializer(Ctx, IsForRef, Culprit);
3314  case UnaryOperatorClass: {
3315    const UnaryOperator* Exp = cast<UnaryOperator>(this);
3316    if (Exp->getOpcode() == UO_Extension)
3317      return Exp->getSubExpr()->isConstantInitializer(Ctx, false, Culprit);
3318    break;
3319  }
3320  case CXXFunctionalCastExprClass:
3321  case CXXStaticCastExprClass:
3322  case ImplicitCastExprClass:
3323  case CStyleCastExprClass:
3324  case ObjCBridgedCastExprClass:
3325  case CXXDynamicCastExprClass:
3326  case CXXReinterpretCastExprClass:
3327  case CXXConstCastExprClass: {
3328    const CastExpr *CE = cast<CastExpr>(this);
3329
3330    // Handle misc casts we want to ignore.
3331    if (CE->getCastKind() == CK_NoOp ||
3332        CE->getCastKind() == CK_LValueToRValue ||
3333        CE->getCastKind() == CK_ToUnion ||
3334        CE->getCastKind() == CK_ConstructorConversion ||
3335        CE->getCastKind() == CK_NonAtomicToAtomic ||
3336        CE->getCastKind() == CK_AtomicToNonAtomic ||
3337        CE->getCastKind() == CK_IntToOCLSampler)
3338      return CE->getSubExpr()->isConstantInitializer(Ctx, false, Culprit);
3339
3340    break;
3341  }
3342  case MaterializeTemporaryExprClass:
3343    return cast<MaterializeTemporaryExpr>(this)
3344        ->getSubExpr()
3345        ->isConstantInitializer(Ctx, false, Culprit);
3346
3347  case SubstNonTypeTemplateParmExprClass:
3348    return cast<SubstNonTypeTemplateParmExpr>(this)->getReplacement()
3349      ->isConstantInitializer(Ctx, false, Culprit);
3350  case CXXDefaultArgExprClass:
3351    return cast<CXXDefaultArgExpr>(this)->getExpr()
3352      ->isConstantInitializer(Ctx, false, Culprit);
3353  case CXXDefaultInitExprClass:
3354    return cast<CXXDefaultInitExpr>(this)->getExpr()
3355      ->isConstantInitializer(Ctx, false, Culprit);
3356  }
3357  // Allow certain forms of UB in constant initializers: signed integer
3358  // overflow and floating-point division by zero. We'll give a warning on
3359  // these, but they're common enough that we have to accept them.
3360  if (isEvaluatable(Ctx, SE_AllowUndefinedBehavior))
3361    return true;
3362  if (Culprit)
3363    *Culprit = this;
3364  return false;
3365}
3366
3367bool CallExpr::isBuiltinAssumeFalse(const ASTContext &Ctx) const {
3368  const FunctionDecl* FD = getDirectCallee();
3369  if (!FD || (FD->getBuiltinID() != Builtin::BI__assume &&
3370              FD->getBuiltinID() != Builtin::BI__builtin_assume))
3371    return false;
3372
3373  const Expr* Arg = getArg(0);
3374  bool ArgVal;
3375  return !Arg->isValueDependent() &&
3376         Arg->EvaluateAsBooleanCondition(ArgVal, Ctx) && !ArgVal;
3377}
3378
3379namespace {
3380  /// Look for any side effects within a Stmt.
3381  class SideEffectFinder : public ConstEvaluatedExprVisitor<SideEffectFinder> {
3382    typedef ConstEvaluatedExprVisitor<SideEffectFinder> Inherited;
3383    const bool IncludePossibleEffects;
3384    bool HasSideEffects;
3385
3386  public:
3387    explicit SideEffectFinder(const ASTContext &Context, bool IncludePossible)
3388      : Inherited(Context),
3389        IncludePossibleEffects(IncludePossible), HasSideEffects(false) { }
3390
3391    bool hasSideEffects() const { return HasSideEffects; }
3392
3393    void VisitExpr(const Expr *E) {
3394      if (!HasSideEffects &&
3395          E->HasSideEffects(Context, IncludePossibleEffects))
3396        HasSideEffects = true;
3397    }
3398  };
3399}
3400
3401bool Expr::HasSideEffects(const ASTContext &Ctx,
3402                          bool IncludePossibleEffects) const {
3403  // In circumstances where we care about definite side effects instead of
3404  // potential side effects, we want to ignore expressions that are part of a
3405  // macro expansion as a potential side effect.
3406  if (!IncludePossibleEffects && getExprLoc().isMacroID())
3407    return false;
3408
3409  if (isInstantiationDependent())
3410    return IncludePossibleEffects;
3411
3412  switch (getStmtClass()) {
3413  case NoStmtClass:
3414  #define ABSTRACT_STMT(Type)
3415  #define STMT(Type, Base) case Type##Class:
3416  #define EXPR(Type, Base)
3417  #include "clang/AST/StmtNodes.inc"
3418    llvm_unreachable("unexpected Expr kind");
3419
3420  case DependentScopeDeclRefExprClass:
3421  case CXXUnresolvedConstructExprClass:
3422  case CXXDependentScopeMemberExprClass:
3423  case UnresolvedLookupExprClass:
3424  case UnresolvedMemberExprClass:
3425  case PackExpansionExprClass:
3426  case SubstNonTypeTemplateParmPackExprClass:
3427  case FunctionParmPackExprClass:
3428  case TypoExprClass:
3429  case CXXFoldExprClass:
3430    llvm_unreachable("shouldn't see dependent / unresolved nodes here");
3431
3432  case DeclRefExprClass:
3433  case ObjCIvarRefExprClass:
3434  case PredefinedExprClass:
3435  case IntegerLiteralClass:
3436  case FixedPointLiteralClass:
3437  case FloatingLiteralClass:
3438  case ImaginaryLiteralClass:
3439  case StringLiteralClass:
3440  case CharacterLiteralClass:
3441  case OffsetOfExprClass:
3442  case ImplicitValueInitExprClass:
3443  case UnaryExprOrTypeTraitExprClass:
3444  case AddrLabelExprClass:
3445  case GNUNullExprClass:
3446  case ArrayInitIndexExprClass:
3447  case NoInitExprClass:
3448  case CXXBoolLiteralExprClass:
3449  case CXXNullPtrLiteralExprClass:
3450  case CXXThisExprClass:
3451  case CXXScalarValueInitExprClass:
3452  case TypeTraitExprClass:
3453  case ArrayTypeTraitExprClass:
3454  case ExpressionTraitExprClass:
3455  case CXXNoexceptExprClass:
3456  case SizeOfPackExprClass:
3457  case ObjCStringLiteralClass:
3458  case ObjCEncodeExprClass:
3459  case ObjCBoolLiteralExprClass:
3460  case ObjCAvailabilityCheckExprClass:
3461  case CXXUuidofExprClass:
3462  case OpaqueValueExprClass:
3463  case SourceLocExprClass:
3464  case ConceptSpecializationExprClass:
3465  case RequiresExprClass:
3466    // These never have a side-effect.
3467    return false;
3468
3469  case ConstantExprClass:
3470    // FIXME: Move this into the "return false;" block above.
3471    return cast<ConstantExpr>(this)->getSubExpr()->HasSideEffects(
3472        Ctx, IncludePossibleEffects);
3473
3474  case CallExprClass:
3475  case CXXOperatorCallExprClass:
3476  case CXXMemberCallExprClass:
3477  case CUDAKernelCallExprClass:
3478  case UserDefinedLiteralClass: {
3479    // We don't know a call definitely has side effects, except for calls
3480    // to pure/const functions that definitely don't.
3481    // If the call itself is considered side-effect free, check the operands.
3482    const Decl *FD = cast<CallExpr>(this)->getCalleeDecl();
3483    bool IsPure = FD && (FD->hasAttr<ConstAttr>() || FD->hasAttr<PureAttr>());
3484    if (IsPure || !IncludePossibleEffects)
3485      break;
3486    return true;
3487  }
3488
3489  case BlockExprClass:
3490  case CXXBindTemporaryExprClass:
3491    if (!IncludePossibleEffects)
3492      break;
3493    return true;
3494
3495  case MSPropertyRefExprClass:
3496  case MSPropertySubscriptExprClass:
3497  case CompoundAssignOperatorClass:
3498  case VAArgExprClass:
3499  case AtomicExprClass:
3500  case CXXThrowExprClass:
3501  case CXXNewExprClass:
3502  case CXXDeleteExprClass:
3503  case CoawaitExprClass:
3504  case DependentCoawaitExprClass:
3505  case CoyieldExprClass:
3506    // These always have a side-effect.
3507    return true;
3508
3509  case StmtExprClass: {
3510    // StmtExprs have a side-effect if any substatement does.
3511    SideEffectFinder Finder(Ctx, IncludePossibleEffects);
3512    Finder.Visit(cast<StmtExpr>(this)->getSubStmt());
3513    return Finder.hasSideEffects();
3514  }
3515
3516  case ExprWithCleanupsClass:
3517    if (IncludePossibleEffects)
3518      if (cast<ExprWithCleanups>(this)->cleanupsHaveSideEffects())
3519        return true;
3520    break;
3521
3522  case ParenExprClass:
3523  case ArraySubscriptExprClass:
3524  case OMPArraySectionExprClass:
3525  case MemberExprClass:
3526  case ConditionalOperatorClass:
3527  case BinaryConditionalOperatorClass:
3528  case CompoundLiteralExprClass:
3529  case ExtVectorElementExprClass:
3530  case DesignatedInitExprClass:
3531  case DesignatedInitUpdateExprClass:
3532  case ArrayInitLoopExprClass:
3533  case ParenListExprClass:
3534  case CXXPseudoDestructorExprClass:
3535  case CXXRewrittenBinaryOperatorClass:
3536  case CXXStdInitializerListExprClass:
3537  case SubstNonTypeTemplateParmExprClass:
3538  case MaterializeTemporaryExprClass:
3539  case ShuffleVectorExprClass:
3540  case ConvertVectorExprClass:
3541  case AsTypeExprClass:
3542    // These have a side-effect if any subexpression does.
3543    break;
3544
3545  case UnaryOperatorClass:
3546    if (cast<UnaryOperator>(this)->isIncrementDecrementOp())
3547      return true;
3548    break;
3549
3550  case BinaryOperatorClass:
3551    if (cast<BinaryOperator>(this)->isAssignmentOp())
3552      return true;
3553    break;
3554
3555  case InitListExprClass:
3556    // FIXME: The children for an InitListExpr doesn't include the array filler.
3557    if (const Expr *E = cast<InitListExpr>(this)->getArrayFiller())
3558      if (E->HasSideEffects(Ctx, IncludePossibleEffects))
3559        return true;
3560    break;
3561
3562  case GenericSelectionExprClass:
3563    return cast<GenericSelectionExpr>(this)->getResultExpr()->
3564        HasSideEffects(Ctx, IncludePossibleEffects);
3565
3566  case ChooseExprClass:
3567    return cast<ChooseExpr>(this)->getChosenSubExpr()->HasSideEffects(
3568        Ctx, IncludePossibleEffects);
3569
3570  case CXXDefaultArgExprClass:
3571    return cast<CXXDefaultArgExpr>(this)->getExpr()->HasSideEffects(
3572        Ctx, IncludePossibleEffects);
3573
3574  case CXXDefaultInitExprClass: {
3575    const FieldDecl *FD = cast<CXXDefaultInitExpr>(this)->getField();
3576    if (const Expr *E = FD->getInClassInitializer())
3577      return E->HasSideEffects(Ctx, IncludePossibleEffects);
3578    // If we've not yet parsed the initializer, assume it has side-effects.
3579    return true;
3580  }
3581
3582  case CXXDynamicCastExprClass: {
3583    // A dynamic_cast expression has side-effects if it can throw.
3584    const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(this);
3585    if (DCE->getTypeAsWritten()->isReferenceType() &&
3586        DCE->getCastKind() == CK_Dynamic)
3587      return true;
3588    }
3589    LLVM_FALLTHROUGH;
3590  case ImplicitCastExprClass:
3591  case CStyleCastExprClass:
3592  case CXXStaticCastExprClass:
3593  case CXXReinterpretCastExprClass:
3594  case CXXConstCastExprClass:
3595  case CXXFunctionalCastExprClass:
3596  case BuiltinBitCastExprClass: {
3597    // While volatile reads are side-effecting in both C and C++, we treat them
3598    // as having possible (not definite) side-effects. This allows idiomatic
3599    // code to behave without warning, such as sizeof(*v) for a volatile-
3600    // qualified pointer.
3601    if (!IncludePossibleEffects)
3602      break;
3603
3604    const CastExpr *CE = cast<CastExpr>(this);
3605    if (CE->getCastKind() == CK_LValueToRValue &&
3606        CE->getSubExpr()->getType().isVolatileQualified())
3607      return true;
3608    break;
3609  }
3610
3611  case CXXTypeidExprClass:
3612    // typeid might throw if its subexpression is potentially-evaluated, so has
3613    // side-effects in that case whether or not its subexpression does.
3614    return cast<CXXTypeidExpr>(this)->isPotentiallyEvaluated();
3615
3616  case CXXConstructExprClass:
3617  case CXXTemporaryObjectExprClass: {
3618    const CXXConstructExpr *CE = cast<CXXConstructExpr>(this);
3619    if (!CE->getConstructor()->isTrivial() && IncludePossibleEffects)
3620      return true;
3621    // A trivial constructor does not add any side-effects of its own. Just look
3622    // at its arguments.
3623    break;
3624  }
3625
3626  case CXXInheritedCtorInitExprClass: {
3627    const auto *ICIE = cast<CXXInheritedCtorInitExpr>(this);
3628    if (!ICIE->getConstructor()->isTrivial() && IncludePossibleEffects)
3629      return true;
3630    break;
3631  }
3632
3633  case LambdaExprClass: {
3634    const LambdaExpr *LE = cast<LambdaExpr>(this);
3635    for (Expr *E : LE->capture_inits())
3636      if (E->HasSideEffects(Ctx, IncludePossibleEffects))
3637        return true;
3638    return false;
3639  }
3640
3641  case PseudoObjectExprClass: {
3642    // Only look for side-effects in the semantic form, and look past
3643    // OpaqueValueExpr bindings in that form.
3644    const PseudoObjectExpr *PO = cast<PseudoObjectExpr>(this);
3645    for (PseudoObjectExpr::const_semantics_iterator I = PO->semantics_begin(),
3646                                                    E = PO->semantics_end();
3647         I != E; ++I) {
3648      const Expr *Subexpr = *I;
3649      if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Subexpr))
3650        Subexpr = OVE->getSourceExpr();
3651      if (Subexpr->HasSideEffects(Ctx, IncludePossibleEffects))
3652        return true;
3653    }
3654    return false;
3655  }
3656
3657  case ObjCBoxedExprClass:
3658  case ObjCArrayLiteralClass:
3659  case ObjCDictionaryLiteralClass:
3660  case ObjCSelectorExprClass:
3661  case ObjCProtocolExprClass:
3662  case ObjCIsaExprClass:
3663  case ObjCIndirectCopyRestoreExprClass:
3664  case ObjCSubscriptRefExprClass:
3665  case ObjCBridgedCastExprClass:
3666  case ObjCMessageExprClass:
3667  case ObjCPropertyRefExprClass:
3668  // FIXME: Classify these cases better.
3669    if (IncludePossibleEffects)
3670      return true;
3671    break;
3672  }
3673
3674  // Recurse to children.
3675  for (const Stmt *SubStmt : children())
3676    if (SubStmt &&
3677        cast<Expr>(SubStmt)->HasSideEffects(Ctx, IncludePossibleEffects))
3678      return true;
3679
3680  return false;
3681}
3682
3683namespace {
3684  /// Look for a call to a non-trivial function within an expression.
3685  class NonTrivialCallFinder : public ConstEvaluatedExprVisitor<NonTrivialCallFinder>
3686  {
3687    typedef ConstEvaluatedExprVisitor<NonTrivialCallFinder> Inherited;
3688
3689    bool NonTrivial;
3690
3691  public:
3692    explicit NonTrivialCallFinder(const ASTContext &Context)
3693      : Inherited(Context), NonTrivial(false) { }
3694
3695    bool hasNonTrivialCall() const { return NonTrivial; }
3696
3697    void VisitCallExpr(const CallExpr *E) {
3698      if (const CXXMethodDecl *Method
3699          = dyn_cast_or_null<const CXXMethodDecl>(E->getCalleeDecl())) {
3700        if (Method->isTrivial()) {
3701          // Recurse to children of the call.
3702          Inherited::VisitStmt(E);
3703          return;
3704        }
3705      }
3706
3707      NonTrivial = true;
3708    }
3709
3710    void VisitCXXConstructExpr(const CXXConstructExpr *E) {
3711      if (E->getConstructor()->isTrivial()) {
3712        // Recurse to children of the call.
3713        Inherited::VisitStmt(E);
3714        return;
3715      }
3716
3717      NonTrivial = true;
3718    }
3719
3720    void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *E) {
3721      if (E->getTemporary()->getDestructor()->isTrivial()) {
3722        Inherited::VisitStmt(E);
3723        return;
3724      }
3725
3726      NonTrivial = true;
3727    }
3728  };
3729}
3730
3731bool Expr::hasNonTrivialCall(const ASTContext &Ctx) const {
3732  NonTrivialCallFinder Finder(Ctx);
3733  Finder.Visit(this);
3734  return Finder.hasNonTrivialCall();
3735}
3736
3737/// isNullPointerConstant - C99 6.3.2.3p3 - Return whether this is a null
3738/// pointer constant or not, as well as the specific kind of constant detected.
3739/// Null pointer constants can be integer constant expressions with the
3740/// value zero, casts of zero to void*, nullptr (C++0X), or __null
3741/// (a GNU extension).
3742Expr::NullPointerConstantKind
3743Expr::isNullPointerConstant(ASTContext &Ctx,
3744                            NullPointerConstantValueDependence NPC) const {
3745  if (isValueDependent() &&
3746      (!Ctx.getLangOpts().CPlusPlus11 || Ctx.getLangOpts().MSVCCompat)) {
3747    switch (NPC) {
3748    case NPC_NeverValueDependent:
3749      llvm_unreachable("Unexpected value dependent expression!");
3750    case NPC_ValueDependentIsNull:
3751      if (isTypeDependent() || getType()->isIntegralType(Ctx))
3752        return NPCK_ZeroExpression;
3753      else
3754        return NPCK_NotNull;
3755
3756    case NPC_ValueDependentIsNotNull:
3757      return NPCK_NotNull;
3758    }
3759  }
3760
3761  // Strip off a cast to void*, if it exists. Except in C++.
3762  if (const ExplicitCastExpr *CE = dyn_cast<ExplicitCastExpr>(this)) {
3763    if (!Ctx.getLangOpts().CPlusPlus) {
3764      // Check that it is a cast to void*.
3765      if (const PointerType *PT = CE->getType()->getAs<PointerType>()) {
3766        QualType Pointee = PT->getPointeeType();
3767        Qualifiers Qs = Pointee.getQualifiers();
3768        // Only (void*)0 or equivalent are treated as nullptr. If pointee type
3769        // has non-default address space it is not treated as nullptr.
3770        // (__generic void*)0 in OpenCL 2.0 should not be treated as nullptr
3771        // since it cannot be assigned to a pointer to constant address space.
3772        if ((Ctx.getLangOpts().OpenCLVersion >= 200 &&
3773             Pointee.getAddressSpace() == LangAS::opencl_generic) ||
3774            (Ctx.getLangOpts().OpenCL &&
3775             Ctx.getLangOpts().OpenCLVersion < 200 &&
3776             Pointee.getAddressSpace() == LangAS::opencl_private))
3777          Qs.removeAddressSpace();
3778
3779        if (Pointee->isVoidType() && Qs.empty() && // to void*
3780            CE->getSubExpr()->getType()->isIntegerType()) // from int
3781          return CE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
3782      }
3783    }
3784  } else if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(this)) {
3785    // Ignore the ImplicitCastExpr type entirely.
3786    return ICE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
3787  } else if (const ParenExpr *PE = dyn_cast<ParenExpr>(this)) {
3788    // Accept ((void*)0) as a null pointer constant, as many other
3789    // implementations do.
3790    return PE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
3791  } else if (const GenericSelectionExpr *GE =
3792               dyn_cast<GenericSelectionExpr>(this)) {
3793    if (GE->isResultDependent())
3794      return NPCK_NotNull;
3795    return GE->getResultExpr()->isNullPointerConstant(Ctx, NPC);
3796  } else if (const ChooseExpr *CE = dyn_cast<ChooseExpr>(this)) {
3797    if (CE->isConditionDependent())
3798      return NPCK_NotNull;
3799    return CE->getChosenSubExpr()->isNullPointerConstant(Ctx, NPC);
3800  } else if (const CXXDefaultArgExpr *DefaultArg
3801               = dyn_cast<CXXDefaultArgExpr>(this)) {
3802    // See through default argument expressions.
3803    return DefaultArg->getExpr()->isNullPointerConstant(Ctx, NPC);
3804  } else if (const CXXDefaultInitExpr *DefaultInit
3805               = dyn_cast<CXXDefaultInitExpr>(this)) {
3806    // See through default initializer expressions.
3807    return DefaultInit->getExpr()->isNullPointerConstant(Ctx, NPC);
3808  } else if (isa<GNUNullExpr>(this)) {
3809    // The GNU __null extension is always a null pointer constant.
3810    return NPCK_GNUNull;
3811  } else if (const MaterializeTemporaryExpr *M
3812                                   = dyn_cast<MaterializeTemporaryExpr>(this)) {
3813    return M->getSubExpr()->isNullPointerConstant(Ctx, NPC);
3814  } else if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(this)) {
3815    if (const Expr *Source = OVE->getSourceExpr())
3816      return Source->isNullPointerConstant(Ctx, NPC);
3817  }
3818
3819  // C++11 nullptr_t is always a null pointer constant.
3820  if (getType()->isNullPtrType())
3821    return NPCK_CXX11_nullptr;
3822
3823  if (const RecordType *UT = getType()->getAsUnionType())
3824    if (!Ctx.getLangOpts().CPlusPlus11 &&
3825        UT && UT->getDecl()->hasAttr<TransparentUnionAttr>())
3826      if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(this)){
3827        const Expr *InitExpr = CLE->getInitializer();
3828        if (const InitListExpr *ILE = dyn_cast<InitListExpr>(InitExpr))
3829          return ILE->getInit(0)->isNullPointerConstant(Ctx, NPC);
3830      }
3831  // This expression must be an integer type.
3832  if (!getType()->isIntegerType() ||
3833      (Ctx.getLangOpts().CPlusPlus && getType()->isEnumeralType()))
3834    return NPCK_NotNull;
3835
3836  if (Ctx.getLangOpts().CPlusPlus11) {
3837    // C++11 [conv.ptr]p1: A null pointer constant is an integer literal with
3838    // value zero or a prvalue of type std::nullptr_t.
3839    // Microsoft mode permits C++98 rules reflecting MSVC behavior.
3840    const IntegerLiteral *Lit = dyn_cast<IntegerLiteral>(this);
3841    if (Lit && !Lit->getValue())
3842      return NPCK_ZeroLiteral;
3843    else if (!Ctx.getLangOpts().MSVCCompat || !isCXX98IntegralConstantExpr(Ctx))
3844      return NPCK_NotNull;
3845  } else {
3846    // If we have an integer constant expression, we need to *evaluate* it and
3847    // test for the value 0.
3848    if (!isIntegerConstantExpr(Ctx))
3849      return NPCK_NotNull;
3850  }
3851
3852  if (EvaluateKnownConstInt(Ctx) != 0)
3853    return NPCK_NotNull;
3854
3855  if (isa<IntegerLiteral>(this))
3856    return NPCK_ZeroLiteral;
3857  return NPCK_ZeroExpression;
3858}
3859
3860/// If this expression is an l-value for an Objective C
3861/// property, find the underlying property reference expression.
3862const ObjCPropertyRefExpr *Expr::getObjCProperty() const {
3863  const Expr *E = this;
3864  while (true) {
3865    assert((E->getValueKind() == VK_LValue &&
3866            E->getObjectKind() == OK_ObjCProperty) &&
3867           "expression is not a property reference");
3868    E = E->IgnoreParenCasts();
3869    if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
3870      if (BO->getOpcode() == BO_Comma) {
3871        E = BO->getRHS();
3872        continue;
3873      }
3874    }
3875
3876    break;
3877  }
3878
3879  return cast<ObjCPropertyRefExpr>(E);
3880}
3881
3882bool Expr::isObjCSelfExpr() const {
3883  const Expr *E = IgnoreParenImpCasts();
3884
3885  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E);
3886  if (!DRE)
3887    return false;
3888
3889  const ImplicitParamDecl *Param = dyn_cast<ImplicitParamDecl>(DRE->getDecl());
3890  if (!Param)
3891    return false;
3892
3893  const ObjCMethodDecl *M = dyn_cast<ObjCMethodDecl>(Param->getDeclContext());
3894  if (!M)
3895    return false;
3896
3897  return M->getSelfDecl() == Param;
3898}
3899
3900FieldDecl *Expr::getSourceBitField() {
3901  Expr *E = this->IgnoreParens();
3902
3903  while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
3904    if (ICE->getCastKind() == CK_LValueToRValue ||
3905        (ICE->getValueKind() != VK_RValue && ICE->getCastKind() == CK_NoOp))
3906      E = ICE->getSubExpr()->IgnoreParens();
3907    else
3908      break;
3909  }
3910
3911  if (MemberExpr *MemRef = dyn_cast<MemberExpr>(E))
3912    if (FieldDecl *Field = dyn_cast<FieldDecl>(MemRef->getMemberDecl()))
3913      if (Field->isBitField())
3914        return Field;
3915
3916  if (ObjCIvarRefExpr *IvarRef = dyn_cast<ObjCIvarRefExpr>(E)) {
3917    FieldDecl *Ivar = IvarRef->getDecl();
3918    if (Ivar->isBitField())
3919      return Ivar;
3920  }
3921
3922  if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E)) {
3923    if (FieldDecl *Field = dyn_cast<FieldDecl>(DeclRef->getDecl()))
3924      if (Field->isBitField())
3925        return Field;
3926
3927    if (BindingDecl *BD = dyn_cast<BindingDecl>(DeclRef->getDecl()))
3928      if (Expr *E = BD->getBinding())
3929        return E->getSourceBitField();
3930  }
3931
3932  if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E)) {
3933    if (BinOp->isAssignmentOp() && BinOp->getLHS())
3934      return BinOp->getLHS()->getSourceBitField();
3935
3936    if (BinOp->getOpcode() == BO_Comma && BinOp->getRHS())
3937      return BinOp->getRHS()->getSourceBitField();
3938  }
3939
3940  if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E))
3941    if (UnOp->isPrefix() && UnOp->isIncrementDecrementOp())
3942      return UnOp->getSubExpr()->getSourceBitField();
3943
3944  return nullptr;
3945}
3946
3947bool Expr::refersToVectorElement() const {
3948  // FIXME: Why do we not just look at the ObjectKind here?
3949  const Expr *E = this->IgnoreParens();
3950
3951  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
3952    if (ICE->getValueKind() != VK_RValue &&
3953        ICE->getCastKind() == CK_NoOp)
3954      E = ICE->getSubExpr()->IgnoreParens();
3955    else
3956      break;
3957  }
3958
3959  if (const ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(E))
3960    return ASE->getBase()->getType()->isVectorType();
3961
3962  if (isa<ExtVectorElementExpr>(E))
3963    return true;
3964
3965  if (auto *DRE = dyn_cast<DeclRefExpr>(E))
3966    if (auto *BD = dyn_cast<BindingDecl>(DRE->getDecl()))
3967      if (auto *E = BD->getBinding())
3968        return E->refersToVectorElement();
3969
3970  return false;
3971}
3972
3973bool Expr::refersToGlobalRegisterVar() const {
3974  const Expr *E = this->IgnoreParenImpCasts();
3975
3976  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
3977    if (const auto *VD = dyn_cast<VarDecl>(DRE->getDecl()))
3978      if (VD->getStorageClass() == SC_Register &&
3979          VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
3980        return true;
3981
3982  return false;
3983}
3984
3985bool Expr::isSameComparisonOperand(const Expr* E1, const Expr* E2) {
3986  E1 = E1->IgnoreParens();
3987  E2 = E2->IgnoreParens();
3988
3989  if (E1->getStmtClass() != E2->getStmtClass())
3990    return false;
3991
3992  switch (E1->getStmtClass()) {
3993    default:
3994      return false;
3995    case CXXThisExprClass:
3996      return true;
3997    case DeclRefExprClass: {
3998      // DeclRefExpr without an ImplicitCastExpr can happen for integral
3999      // template parameters.
4000      const auto *DRE1 = cast<DeclRefExpr>(E1);
4001      const auto *DRE2 = cast<DeclRefExpr>(E2);
4002      return DRE1->isRValue() && DRE2->isRValue() &&
4003             DRE1->getDecl() == DRE2->getDecl();
4004    }
4005    case ImplicitCastExprClass: {
4006      // Peel off implicit casts.
4007      while (true) {
4008        const auto *ICE1 = dyn_cast<ImplicitCastExpr>(E1);
4009        const auto *ICE2 = dyn_cast<ImplicitCastExpr>(E2);
4010        if (!ICE1 || !ICE2)
4011          return false;
4012        if (ICE1->getCastKind() != ICE2->getCastKind())
4013          return false;
4014        E1 = ICE1->getSubExpr()->IgnoreParens();
4015        E2 = ICE2->getSubExpr()->IgnoreParens();
4016        // The final cast must be one of these types.
4017        if (ICE1->getCastKind() == CK_LValueToRValue ||
4018            ICE1->getCastKind() == CK_ArrayToPointerDecay ||
4019            ICE1->getCastKind() == CK_FunctionToPointerDecay) {
4020          break;
4021        }
4022      }
4023
4024      const auto *DRE1 = dyn_cast<DeclRefExpr>(E1);
4025      const auto *DRE2 = dyn_cast<DeclRefExpr>(E2);
4026      if (DRE1 && DRE2)
4027        return declaresSameEntity(DRE1->getDecl(), DRE2->getDecl());
4028
4029      const auto *Ivar1 = dyn_cast<ObjCIvarRefExpr>(E1);
4030      const auto *Ivar2 = dyn_cast<ObjCIvarRefExpr>(E2);
4031      if (Ivar1 && Ivar2) {
4032        return Ivar1->isFreeIvar() && Ivar2->isFreeIvar() &&
4033               declaresSameEntity(Ivar1->getDecl(), Ivar2->getDecl());
4034      }
4035
4036      const auto *Array1 = dyn_cast<ArraySubscriptExpr>(E1);
4037      const auto *Array2 = dyn_cast<ArraySubscriptExpr>(E2);
4038      if (Array1 && Array2) {
4039        if (!isSameComparisonOperand(Array1->getBase(), Array2->getBase()))
4040          return false;
4041
4042        auto Idx1 = Array1->getIdx();
4043        auto Idx2 = Array2->getIdx();
4044        const auto Integer1 = dyn_cast<IntegerLiteral>(Idx1);
4045        const auto Integer2 = dyn_cast<IntegerLiteral>(Idx2);
4046        if (Integer1 && Integer2) {
4047          if (!llvm::APInt::isSameValue(Integer1->getValue(),
4048                                        Integer2->getValue()))
4049            return false;
4050        } else {
4051          if (!isSameComparisonOperand(Idx1, Idx2))
4052            return false;
4053        }
4054
4055        return true;
4056      }
4057
4058      // Walk the MemberExpr chain.
4059      while (isa<MemberExpr>(E1) && isa<MemberExpr>(E2)) {
4060        const auto *ME1 = cast<MemberExpr>(E1);
4061        const auto *ME2 = cast<MemberExpr>(E2);
4062        if (!declaresSameEntity(ME1->getMemberDecl(), ME2->getMemberDecl()))
4063          return false;
4064        if (const auto *D = dyn_cast<VarDecl>(ME1->getMemberDecl()))
4065          if (D->isStaticDataMember())
4066            return true;
4067        E1 = ME1->getBase()->IgnoreParenImpCasts();
4068        E2 = ME2->getBase()->IgnoreParenImpCasts();
4069      }
4070
4071      if (isa<CXXThisExpr>(E1) && isa<CXXThisExpr>(E2))
4072        return true;
4073
4074      // A static member variable can end the MemberExpr chain with either
4075      // a MemberExpr or a DeclRefExpr.
4076      auto getAnyDecl = [](const Expr *E) -> const ValueDecl * {
4077        if (const auto *DRE = dyn_cast<DeclRefExpr>(E))
4078          return DRE->getDecl();
4079        if (const auto *ME = dyn_cast<MemberExpr>(E))
4080          return ME->getMemberDecl();
4081        return nullptr;
4082      };
4083
4084      const ValueDecl *VD1 = getAnyDecl(E1);
4085      const ValueDecl *VD2 = getAnyDecl(E2);
4086      return declaresSameEntity(VD1, VD2);
4087    }
4088  }
4089}
4090
4091/// isArrow - Return true if the base expression is a pointer to vector,
4092/// return false if the base expression is a vector.
4093bool ExtVectorElementExpr::isArrow() const {
4094  return getBase()->getType()->isPointerType();
4095}
4096
4097unsigned ExtVectorElementExpr::getNumElements() const {
4098  if (const VectorType *VT = getType()->getAs<VectorType>())
4099    return VT->getNumElements();
4100  return 1;
4101}
4102
4103/// containsDuplicateElements - Return true if any element access is repeated.
4104bool ExtVectorElementExpr::containsDuplicateElements() const {
4105  // FIXME: Refactor this code to an accessor on the AST node which returns the
4106  // "type" of component access, and share with code below and in Sema.
4107  StringRef Comp = Accessor->getName();
4108
4109  // Halving swizzles do not contain duplicate elements.
4110  if (Comp == "hi" || Comp == "lo" || Comp == "even" || Comp == "odd")
4111    return false;
4112
4113  // Advance past s-char prefix on hex swizzles.
4114  if (Comp[0] == 's' || Comp[0] == 'S')
4115    Comp = Comp.substr(1);
4116
4117  for (unsigned i = 0, e = Comp.size(); i != e; ++i)
4118    if (Comp.substr(i + 1).find(Comp[i]) != StringRef::npos)
4119        return true;
4120
4121  return false;
4122}
4123
4124/// getEncodedElementAccess - We encode the fields as a llvm ConstantArray.
4125void ExtVectorElementExpr::getEncodedElementAccess(
4126    SmallVectorImpl<uint32_t> &Elts) const {
4127  StringRef Comp = Accessor->getName();
4128  bool isNumericAccessor = false;
4129  if (Comp[0] == 's' || Comp[0] == 'S') {
4130    Comp = Comp.substr(1);
4131    isNumericAccessor = true;
4132  }
4133
4134  bool isHi =   Comp == "hi";
4135  bool isLo =   Comp == "lo";
4136  bool isEven = Comp == "even";
4137  bool isOdd  = Comp == "odd";
4138
4139  for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
4140    uint64_t Index;
4141
4142    if (isHi)
4143      Index = e + i;
4144    else if (isLo)
4145      Index = i;
4146    else if (isEven)
4147      Index = 2 * i;
4148    else if (isOdd)
4149      Index = 2 * i + 1;
4150    else
4151      Index = ExtVectorType::getAccessorIdx(Comp[i], isNumericAccessor);
4152
4153    Elts.push_back(Index);
4154  }
4155}
4156
4157ShuffleVectorExpr::ShuffleVectorExpr(const ASTContext &C, ArrayRef<Expr*> args,
4158                                     QualType Type, SourceLocation BLoc,
4159                                     SourceLocation RP)
4160   : Expr(ShuffleVectorExprClass, Type, VK_RValue, OK_Ordinary,
4161          Type->isDependentType(), Type->isDependentType(),
4162          Type->isInstantiationDependentType(),
4163          Type->containsUnexpandedParameterPack()),
4164     BuiltinLoc(BLoc), RParenLoc(RP), NumExprs(args.size())
4165{
4166  SubExprs = new (C) Stmt*[args.size()];
4167  for (unsigned i = 0; i != args.size(); i++) {
4168    if (args[i]->isTypeDependent())
4169      ExprBits.TypeDependent = true;
4170    if (args[i]->isValueDependent())
4171      ExprBits.ValueDependent = true;
4172    if (args[i]->isInstantiationDependent())
4173      ExprBits.InstantiationDependent = true;
4174    if (args[i]->containsUnexpandedParameterPack())
4175      ExprBits.ContainsUnexpandedParameterPack = true;
4176
4177    SubExprs[i] = args[i];
4178  }
4179}
4180
4181void ShuffleVectorExpr::setExprs(const ASTContext &C, ArrayRef<Expr *> Exprs) {
4182  if (SubExprs) C.Deallocate(SubExprs);
4183
4184  this->NumExprs = Exprs.size();
4185  SubExprs = new (C) Stmt*[NumExprs];
4186  memcpy(SubExprs, Exprs.data(), sizeof(Expr *) * Exprs.size());
4187}
4188
4189GenericSelectionExpr::GenericSelectionExpr(
4190    const ASTContext &, SourceLocation GenericLoc, Expr *ControllingExpr,
4191    ArrayRef<TypeSourceInfo *> AssocTypes, ArrayRef<Expr *> AssocExprs,
4192    SourceLocation DefaultLoc, SourceLocation RParenLoc,
4193    bool ContainsUnexpandedParameterPack, unsigned ResultIndex)
4194    : Expr(GenericSelectionExprClass, AssocExprs[ResultIndex]->getType(),
4195           AssocExprs[ResultIndex]->getValueKind(),
4196           AssocExprs[ResultIndex]->getObjectKind(),
4197           AssocExprs[ResultIndex]->isTypeDependent(),
4198           AssocExprs[ResultIndex]->isValueDependent(),
4199           AssocExprs[ResultIndex]->isInstantiationDependent(),
4200           ContainsUnexpandedParameterPack),
4201      NumAssocs(AssocExprs.size()), ResultIndex(ResultIndex),
4202      DefaultLoc(DefaultLoc), RParenLoc(RParenLoc) {
4203  assert(AssocTypes.size() == AssocExprs.size() &&
4204         "Must have the same number of association expressions"
4205         " and TypeSourceInfo!");
4206  assert(ResultIndex < NumAssocs && "ResultIndex is out-of-bounds!");
4207
4208  GenericSelectionExprBits.GenericLoc = GenericLoc;
4209  getTrailingObjects<Stmt *>()[ControllingIndex] = ControllingExpr;
4210  std::copy(AssocExprs.begin(), AssocExprs.end(),
4211            getTrailingObjects<Stmt *>() + AssocExprStartIndex);
4212  std::copy(AssocTypes.begin(), AssocTypes.end(),
4213            getTrailingObjects<TypeSourceInfo *>());
4214}
4215
4216GenericSelectionExpr::GenericSelectionExpr(
4217    const ASTContext &Context, SourceLocation GenericLoc, Expr *ControllingExpr,
4218    ArrayRef<TypeSourceInfo *> AssocTypes, ArrayRef<Expr *> AssocExprs,
4219    SourceLocation DefaultLoc, SourceLocation RParenLoc,
4220    bool ContainsUnexpandedParameterPack)
4221    : Expr(GenericSelectionExprClass, Context.DependentTy, VK_RValue,
4222           OK_Ordinary,
4223           /*isTypeDependent=*/true,
4224           /*isValueDependent=*/true,
4225           /*isInstantiationDependent=*/true, ContainsUnexpandedParameterPack),
4226      NumAssocs(AssocExprs.size()), ResultIndex(ResultDependentIndex),
4227      DefaultLoc(DefaultLoc), RParenLoc(RParenLoc) {
4228  assert(AssocTypes.size() == AssocExprs.size() &&
4229         "Must have the same number of association expressions"
4230         " and TypeSourceInfo!");
4231
4232  GenericSelectionExprBits.GenericLoc = GenericLoc;
4233  getTrailingObjects<Stmt *>()[ControllingIndex] = ControllingExpr;
4234  std::copy(AssocExprs.begin(), AssocExprs.end(),
4235            getTrailingObjects<Stmt *>() + AssocExprStartIndex);
4236  std::copy(AssocTypes.begin(), AssocTypes.end(),
4237            getTrailingObjects<TypeSourceInfo *>());
4238}
4239
4240GenericSelectionExpr::GenericSelectionExpr(EmptyShell Empty, unsigned NumAssocs)
4241    : Expr(GenericSelectionExprClass, Empty), NumAssocs(NumAssocs) {}
4242
4243GenericSelectionExpr *GenericSelectionExpr::Create(
4244    const ASTContext &Context, SourceLocation GenericLoc, Expr *ControllingExpr,
4245    ArrayRef<TypeSourceInfo *> AssocTypes, ArrayRef<Expr *> AssocExprs,
4246    SourceLocation DefaultLoc, SourceLocation RParenLoc,
4247    bool ContainsUnexpandedParameterPack, unsigned ResultIndex) {
4248  unsigned NumAssocs = AssocExprs.size();
4249  void *Mem = Context.Allocate(
4250      totalSizeToAlloc<Stmt *, TypeSourceInfo *>(1 + NumAssocs, NumAssocs),
4251      alignof(GenericSelectionExpr));
4252  return new (Mem) GenericSelectionExpr(
4253      Context, GenericLoc, ControllingExpr, AssocTypes, AssocExprs, DefaultLoc,
4254      RParenLoc, ContainsUnexpandedParameterPack, ResultIndex);
4255}
4256
4257GenericSelectionExpr *GenericSelectionExpr::Create(
4258    const ASTContext &Context, SourceLocation GenericLoc, Expr *ControllingExpr,
4259    ArrayRef<TypeSourceInfo *> AssocTypes, ArrayRef<Expr *> AssocExprs,
4260    SourceLocation DefaultLoc, SourceLocation RParenLoc,
4261    bool ContainsUnexpandedParameterPack) {
4262  unsigned NumAssocs = AssocExprs.size();
4263  void *Mem = Context.Allocate(
4264      totalSizeToAlloc<Stmt *, TypeSourceInfo *>(1 + NumAssocs, NumAssocs),
4265      alignof(GenericSelectionExpr));
4266  return new (Mem) GenericSelectionExpr(
4267      Context, GenericLoc, ControllingExpr, AssocTypes, AssocExprs, DefaultLoc,
4268      RParenLoc, ContainsUnexpandedParameterPack);
4269}
4270
4271GenericSelectionExpr *
4272GenericSelectionExpr::CreateEmpty(const ASTContext &Context,
4273                                  unsigned NumAssocs) {
4274  void *Mem = Context.Allocate(
4275      totalSizeToAlloc<Stmt *, TypeSourceInfo *>(1 + NumAssocs, NumAssocs),
4276      alignof(GenericSelectionExpr));
4277  return new (Mem) GenericSelectionExpr(EmptyShell(), NumAssocs);
4278}
4279
4280//===----------------------------------------------------------------------===//
4281//  DesignatedInitExpr
4282//===----------------------------------------------------------------------===//
4283
4284IdentifierInfo *DesignatedInitExpr::Designator::getFieldName() const {
4285  assert(Kind == FieldDesignator && "Only valid on a field designator");
4286  if (Field.NameOrField & 0x01)
4287    return reinterpret_cast<IdentifierInfo *>(Field.NameOrField&~0x01);
4288  else
4289    return getField()->getIdentifier();
4290}
4291
4292DesignatedInitExpr::DesignatedInitExpr(const ASTContext &C, QualType Ty,
4293                                       llvm::ArrayRef<Designator> Designators,
4294                                       SourceLocation EqualOrColonLoc,
4295                                       bool GNUSyntax,
4296                                       ArrayRef<Expr*> IndexExprs,
4297                                       Expr *Init)
4298  : Expr(DesignatedInitExprClass, Ty,
4299         Init->getValueKind(), Init->getObjectKind(),
4300         Init->isTypeDependent(), Init->isValueDependent(),
4301         Init->isInstantiationDependent(),
4302         Init->containsUnexpandedParameterPack()),
4303    EqualOrColonLoc(EqualOrColonLoc), GNUSyntax(GNUSyntax),
4304    NumDesignators(Designators.size()), NumSubExprs(IndexExprs.size() + 1) {
4305  this->Designators = new (C) Designator[NumDesignators];
4306
4307  // Record the initializer itself.
4308  child_iterator Child = child_begin();
4309  *Child++ = Init;
4310
4311  // Copy the designators and their subexpressions, computing
4312  // value-dependence along the way.
4313  unsigned IndexIdx = 0;
4314  for (unsigned I = 0; I != NumDesignators; ++I) {
4315    this->Designators[I] = Designators[I];
4316
4317    if (this->Designators[I].isArrayDesignator()) {
4318      // Compute type- and value-dependence.
4319      Expr *Index = IndexExprs[IndexIdx];
4320      if (Index->isTypeDependent() || Index->isValueDependent())
4321        ExprBits.TypeDependent = ExprBits.ValueDependent = true;
4322      if (Index->isInstantiationDependent())
4323        ExprBits.InstantiationDependent = true;
4324      // Propagate unexpanded parameter packs.
4325      if (Index->containsUnexpandedParameterPack())
4326        ExprBits.ContainsUnexpandedParameterPack = true;
4327
4328      // Copy the index expressions into permanent storage.
4329      *Child++ = IndexExprs[IndexIdx++];
4330    } else if (this->Designators[I].isArrayRangeDesignator()) {
4331      // Compute type- and value-dependence.
4332      Expr *Start = IndexExprs[IndexIdx];
4333      Expr *End = IndexExprs[IndexIdx + 1];
4334      if (Start->isTypeDependent() || Start->isValueDependent() ||
4335          End->isTypeDependent() || End->isValueDependent()) {
4336        ExprBits.TypeDependent = ExprBits.ValueDependent = true;
4337        ExprBits.InstantiationDependent = true;
4338      } else if (Start->isInstantiationDependent() ||
4339                 End->isInstantiationDependent()) {
4340        ExprBits.InstantiationDependent = true;
4341      }
4342
4343      // Propagate unexpanded parameter packs.
4344      if (Start->containsUnexpandedParameterPack() ||
4345          End->containsUnexpandedParameterPack())
4346        ExprBits.ContainsUnexpandedParameterPack = true;
4347
4348      // Copy the start/end expressions into permanent storage.
4349      *Child++ = IndexExprs[IndexIdx++];
4350      *Child++ = IndexExprs[IndexIdx++];
4351    }
4352  }
4353
4354  assert(IndexIdx == IndexExprs.size() && "Wrong number of index expressions");
4355}
4356
4357DesignatedInitExpr *
4358DesignatedInitExpr::Create(const ASTContext &C,
4359                           llvm::ArrayRef<Designator> Designators,
4360                           ArrayRef<Expr*> IndexExprs,
4361                           SourceLocation ColonOrEqualLoc,
4362                           bool UsesColonSyntax, Expr *Init) {
4363  void *Mem = C.Allocate(totalSizeToAlloc<Stmt *>(IndexExprs.size() + 1),
4364                         alignof(DesignatedInitExpr));
4365  return new (Mem) DesignatedInitExpr(C, C.VoidTy, Designators,
4366                                      ColonOrEqualLoc, UsesColonSyntax,
4367                                      IndexExprs, Init);
4368}
4369
4370DesignatedInitExpr *DesignatedInitExpr::CreateEmpty(const ASTContext &C,
4371                                                    unsigned NumIndexExprs) {
4372  void *Mem = C.Allocate(totalSizeToAlloc<Stmt *>(NumIndexExprs + 1),
4373                         alignof(DesignatedInitExpr));
4374  return new (Mem) DesignatedInitExpr(NumIndexExprs + 1);
4375}
4376
4377void DesignatedInitExpr::setDesignators(const ASTContext &C,
4378                                        const Designator *Desigs,
4379                                        unsigned NumDesigs) {
4380  Designators = new (C) Designator[NumDesigs];
4381  NumDesignators = NumDesigs;
4382  for (unsigned I = 0; I != NumDesigs; ++I)
4383    Designators[I] = Desigs[I];
4384}
4385
4386SourceRange DesignatedInitExpr::getDesignatorsSourceRange() const {
4387  DesignatedInitExpr *DIE = const_cast<DesignatedInitExpr*>(this);
4388  if (size() == 1)
4389    return DIE->getDesignator(0)->getSourceRange();
4390  return SourceRange(DIE->getDesignator(0)->getBeginLoc(),
4391                     DIE->getDesignator(size() - 1)->getEndLoc());
4392}
4393
4394SourceLocation DesignatedInitExpr::getBeginLoc() const {
4395  SourceLocation StartLoc;
4396  auto *DIE = const_cast<DesignatedInitExpr *>(this);
4397  Designator &First = *DIE->getDesignator(0);
4398  if (First.isFieldDesignator()) {
4399    if (GNUSyntax)
4400      StartLoc = SourceLocation::getFromRawEncoding(First.Field.FieldLoc);
4401    else
4402      StartLoc = SourceLocation::getFromRawEncoding(First.Field.DotLoc);
4403  } else
4404    StartLoc =
4405      SourceLocation::getFromRawEncoding(First.ArrayOrRange.LBracketLoc);
4406  return StartLoc;
4407}
4408
4409SourceLocation DesignatedInitExpr::getEndLoc() const {
4410  return getInit()->getEndLoc();
4411}
4412
4413Expr *DesignatedInitExpr::getArrayIndex(const Designator& D) const {
4414  assert(D.Kind == Designator::ArrayDesignator && "Requires array designator");
4415  return getSubExpr(D.ArrayOrRange.Index + 1);
4416}
4417
4418Expr *DesignatedInitExpr::getArrayRangeStart(const Designator &D) const {
4419  assert(D.Kind == Designator::ArrayRangeDesignator &&
4420         "Requires array range designator");
4421  return getSubExpr(D.ArrayOrRange.Index + 1);
4422}
4423
4424Expr *DesignatedInitExpr::getArrayRangeEnd(const Designator &D) const {
4425  assert(D.Kind == Designator::ArrayRangeDesignator &&
4426         "Requires array range designator");
4427  return getSubExpr(D.ArrayOrRange.Index + 2);
4428}
4429
4430/// Replaces the designator at index @p Idx with the series
4431/// of designators in [First, Last).
4432void DesignatedInitExpr::ExpandDesignator(const ASTContext &C, unsigned Idx,
4433                                          const Designator *First,
4434                                          const Designator *Last) {
4435  unsigned NumNewDesignators = Last - First;
4436  if (NumNewDesignators == 0) {
4437    std::copy_backward(Designators + Idx + 1,
4438                       Designators + NumDesignators,
4439                       Designators + Idx);
4440    --NumNewDesignators;
4441    return;
4442  } else if (NumNewDesignators == 1) {
4443    Designators[Idx] = *First;
4444    return;
4445  }
4446
4447  Designator *NewDesignators
4448    = new (C) Designator[NumDesignators - 1 + NumNewDesignators];
4449  std::copy(Designators, Designators + Idx, NewDesignators);
4450  std::copy(First, Last, NewDesignators + Idx);
4451  std::copy(Designators + Idx + 1, Designators + NumDesignators,
4452            NewDesignators + Idx + NumNewDesignators);
4453  Designators = NewDesignators;
4454  NumDesignators = NumDesignators - 1 + NumNewDesignators;
4455}
4456
4457DesignatedInitUpdateExpr::DesignatedInitUpdateExpr(const ASTContext &C,
4458    SourceLocation lBraceLoc, Expr *baseExpr, SourceLocation rBraceLoc)
4459  : Expr(DesignatedInitUpdateExprClass, baseExpr->getType(), VK_RValue,
4460         OK_Ordinary, false, false, false, false) {
4461  BaseAndUpdaterExprs[0] = baseExpr;
4462
4463  InitListExpr *ILE = new (C) InitListExpr(C, lBraceLoc, None, rBraceLoc);
4464  ILE->setType(baseExpr->getType());
4465  BaseAndUpdaterExprs[1] = ILE;
4466}
4467
4468SourceLocation DesignatedInitUpdateExpr::getBeginLoc() const {
4469  return getBase()->getBeginLoc();
4470}
4471
4472SourceLocation DesignatedInitUpdateExpr::getEndLoc() const {
4473  return getBase()->getEndLoc();
4474}
4475
4476ParenListExpr::ParenListExpr(SourceLocation LParenLoc, ArrayRef<Expr *> Exprs,
4477                             SourceLocation RParenLoc)
4478    : Expr(ParenListExprClass, QualType(), VK_RValue, OK_Ordinary, false, false,
4479           false, false),
4480      LParenLoc(LParenLoc), RParenLoc(RParenLoc) {
4481  ParenListExprBits.NumExprs = Exprs.size();
4482
4483  for (unsigned I = 0, N = Exprs.size(); I != N; ++I) {
4484    if (Exprs[I]->isTypeDependent())
4485      ExprBits.TypeDependent = true;
4486    if (Exprs[I]->isValueDependent())
4487      ExprBits.ValueDependent = true;
4488    if (Exprs[I]->isInstantiationDependent())
4489      ExprBits.InstantiationDependent = true;
4490    if (Exprs[I]->containsUnexpandedParameterPack())
4491      ExprBits.ContainsUnexpandedParameterPack = true;
4492
4493    getTrailingObjects<Stmt *>()[I] = Exprs[I];
4494  }
4495}
4496
4497ParenListExpr::ParenListExpr(EmptyShell Empty, unsigned NumExprs)
4498    : Expr(ParenListExprClass, Empty) {
4499  ParenListExprBits.NumExprs = NumExprs;
4500}
4501
4502ParenListExpr *ParenListExpr::Create(const ASTContext &Ctx,
4503                                     SourceLocation LParenLoc,
4504                                     ArrayRef<Expr *> Exprs,
4505                                     SourceLocation RParenLoc) {
4506  void *Mem = Ctx.Allocate(totalSizeToAlloc<Stmt *>(Exprs.size()),
4507                           alignof(ParenListExpr));
4508  return new (Mem) ParenListExpr(LParenLoc, Exprs, RParenLoc);
4509}
4510
4511ParenListExpr *ParenListExpr::CreateEmpty(const ASTContext &Ctx,
4512                                          unsigned NumExprs) {
4513  void *Mem =
4514      Ctx.Allocate(totalSizeToAlloc<Stmt *>(NumExprs), alignof(ParenListExpr));
4515  return new (Mem) ParenListExpr(EmptyShell(), NumExprs);
4516}
4517
4518const OpaqueValueExpr *OpaqueValueExpr::findInCopyConstruct(const Expr *e) {
4519  if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(e))
4520    e = ewc->getSubExpr();
4521  if (const MaterializeTemporaryExpr *m = dyn_cast<MaterializeTemporaryExpr>(e))
4522    e = m->getSubExpr();
4523  e = cast<CXXConstructExpr>(e)->getArg(0);
4524  while (const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
4525    e = ice->getSubExpr();
4526  return cast<OpaqueValueExpr>(e);
4527}
4528
4529PseudoObjectExpr *PseudoObjectExpr::Create(const ASTContext &Context,
4530                                           EmptyShell sh,
4531                                           unsigned numSemanticExprs) {
4532  void *buffer =
4533      Context.Allocate(totalSizeToAlloc<Expr *>(1 + numSemanticExprs),
4534                       alignof(PseudoObjectExpr));
4535  return new(buffer) PseudoObjectExpr(sh, numSemanticExprs);
4536}
4537
4538PseudoObjectExpr::PseudoObjectExpr(EmptyShell shell, unsigned numSemanticExprs)
4539  : Expr(PseudoObjectExprClass, shell) {
4540  PseudoObjectExprBits.NumSubExprs = numSemanticExprs + 1;
4541}
4542
4543PseudoObjectExpr *PseudoObjectExpr::Create(const ASTContext &C, Expr *syntax,
4544                                           ArrayRef<Expr*> semantics,
4545                                           unsigned resultIndex) {
4546  assert(syntax && "no syntactic expression!");
4547  assert(semantics.size() && "no semantic expressions!");
4548
4549  QualType type;
4550  ExprValueKind VK;
4551  if (resultIndex == NoResult) {
4552    type = C.VoidTy;
4553    VK = VK_RValue;
4554  } else {
4555    assert(resultIndex < semantics.size());
4556    type = semantics[resultIndex]->getType();
4557    VK = semantics[resultIndex]->getValueKind();
4558    assert(semantics[resultIndex]->getObjectKind() == OK_Ordinary);
4559  }
4560
4561  void *buffer = C.Allocate(totalSizeToAlloc<Expr *>(semantics.size() + 1),
4562                            alignof(PseudoObjectExpr));
4563  return new(buffer) PseudoObjectExpr(type, VK, syntax, semantics,
4564                                      resultIndex);
4565}
4566
4567PseudoObjectExpr::PseudoObjectExpr(QualType type, ExprValueKind VK,
4568                                   Expr *syntax, ArrayRef<Expr*> semantics,
4569                                   unsigned resultIndex)
4570  : Expr(PseudoObjectExprClass, type, VK, OK_Ordinary,
4571         /*filled in at end of ctor*/ false, false, false, false) {
4572  PseudoObjectExprBits.NumSubExprs = semantics.size() + 1;
4573  PseudoObjectExprBits.ResultIndex = resultIndex + 1;
4574
4575  for (unsigned i = 0, e = semantics.size() + 1; i != e; ++i) {
4576    Expr *E = (i == 0 ? syntax : semantics[i-1]);
4577    getSubExprsBuffer()[i] = E;
4578
4579    if (E->isTypeDependent())
4580      ExprBits.TypeDependent = true;
4581    if (E->isValueDependent())
4582      ExprBits.ValueDependent = true;
4583    if (E->isInstantiationDependent())
4584      ExprBits.InstantiationDependent = true;
4585    if (E->containsUnexpandedParameterPack())
4586      ExprBits.ContainsUnexpandedParameterPack = true;
4587
4588    if (isa<OpaqueValueExpr>(E))
4589      assert(cast<OpaqueValueExpr>(E)->getSourceExpr() != nullptr &&
4590             "opaque-value semantic expressions for pseudo-object "
4591             "operations must have sources");
4592  }
4593}
4594
4595//===----------------------------------------------------------------------===//
4596//  Child Iterators for iterating over subexpressions/substatements
4597//===----------------------------------------------------------------------===//
4598
4599// UnaryExprOrTypeTraitExpr
4600Stmt::child_range UnaryExprOrTypeTraitExpr::children() {
4601  const_child_range CCR =
4602      const_cast<const UnaryExprOrTypeTraitExpr *>(this)->children();
4603  return child_range(cast_away_const(CCR.begin()), cast_away_const(CCR.end()));
4604}
4605
4606Stmt::const_child_range UnaryExprOrTypeTraitExpr::children() const {
4607  // If this is of a type and the type is a VLA type (and not a typedef), the
4608  // size expression of the VLA needs to be treated as an executable expression.
4609  // Why isn't this weirdness documented better in StmtIterator?
4610  if (isArgumentType()) {
4611    if (const VariableArrayType *T =
4612            dyn_cast<VariableArrayType>(getArgumentType().getTypePtr()))
4613      return const_child_range(const_child_iterator(T), const_child_iterator());
4614    return const_child_range(const_child_iterator(), const_child_iterator());
4615  }
4616  return const_child_range(&Argument.Ex, &Argument.Ex + 1);
4617}
4618
4619AtomicExpr::AtomicExpr(SourceLocation BLoc, ArrayRef<Expr*> args,
4620                       QualType t, AtomicOp op, SourceLocation RP)
4621  : Expr(AtomicExprClass, t, VK_RValue, OK_Ordinary,
4622         false, false, false, false),
4623    NumSubExprs(args.size()), BuiltinLoc(BLoc), RParenLoc(RP), Op(op)
4624{
4625  assert(args.size() == getNumSubExprs(op) && "wrong number of subexpressions");
4626  for (unsigned i = 0; i != args.size(); i++) {
4627    if (args[i]->isTypeDependent())
4628      ExprBits.TypeDependent = true;
4629    if (args[i]->isValueDependent())
4630      ExprBits.ValueDependent = true;
4631    if (args[i]->isInstantiationDependent())
4632      ExprBits.InstantiationDependent = true;
4633    if (args[i]->containsUnexpandedParameterPack())
4634      ExprBits.ContainsUnexpandedParameterPack = true;
4635
4636    SubExprs[i] = args[i];
4637  }
4638}
4639
4640unsigned AtomicExpr::getNumSubExprs(AtomicOp Op) {
4641  switch (Op) {
4642  case AO__c11_atomic_init:
4643  case AO__opencl_atomic_init:
4644  case AO__c11_atomic_load:
4645  case AO__atomic_load_n:
4646    return 2;
4647
4648  case AO__opencl_atomic_load:
4649  case AO__c11_atomic_store:
4650  case AO__c11_atomic_exchange:
4651  case AO__atomic_load:
4652  case AO__atomic_store:
4653  case AO__atomic_store_n:
4654  case AO__atomic_exchange_n:
4655  case AO__c11_atomic_fetch_add:
4656  case AO__c11_atomic_fetch_sub:
4657  case AO__c11_atomic_fetch_and:
4658  case AO__c11_atomic_fetch_or:
4659  case AO__c11_atomic_fetch_xor:
4660  case AO__c11_atomic_fetch_max:
4661  case AO__c11_atomic_fetch_min:
4662  case AO__atomic_fetch_add:
4663  case AO__atomic_fetch_sub:
4664  case AO__atomic_fetch_and:
4665  case AO__atomic_fetch_or:
4666  case AO__atomic_fetch_xor:
4667  case AO__atomic_fetch_nand:
4668  case AO__atomic_add_fetch:
4669  case AO__atomic_sub_fetch:
4670  case AO__atomic_and_fetch:
4671  case AO__atomic_or_fetch:
4672  case AO__atomic_xor_fetch:
4673  case AO__atomic_nand_fetch:
4674  case AO__atomic_min_fetch:
4675  case AO__atomic_max_fetch:
4676  case AO__atomic_fetch_min:
4677  case AO__atomic_fetch_max:
4678    return 3;
4679
4680  case AO__opencl_atomic_store:
4681  case AO__opencl_atomic_exchange:
4682  case AO__opencl_atomic_fetch_add:
4683  case AO__opencl_atomic_fetch_sub:
4684  case AO__opencl_atomic_fetch_and:
4685  case AO__opencl_atomic_fetch_or:
4686  case AO__opencl_atomic_fetch_xor:
4687  case AO__opencl_atomic_fetch_min:
4688  case AO__opencl_atomic_fetch_max:
4689  case AO__atomic_exchange:
4690    return 4;
4691
4692  case AO__c11_atomic_compare_exchange_strong:
4693  case AO__c11_atomic_compare_exchange_weak:
4694    return 5;
4695
4696  case AO__opencl_atomic_compare_exchange_strong:
4697  case AO__opencl_atomic_compare_exchange_weak:
4698  case AO__atomic_compare_exchange:
4699  case AO__atomic_compare_exchange_n:
4700    return 6;
4701  }
4702  llvm_unreachable("unknown atomic op");
4703}
4704
4705QualType AtomicExpr::getValueType() const {
4706  auto T = getPtr()->getType()->castAs<PointerType>()->getPointeeType();
4707  if (auto AT = T->getAs<AtomicType>())
4708    return AT->getValueType();
4709  return T;
4710}
4711
4712QualType OMPArraySectionExpr::getBaseOriginalType(const Expr *Base) {
4713  unsigned ArraySectionCount = 0;
4714  while (auto *OASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParens())) {
4715    Base = OASE->getBase();
4716    ++ArraySectionCount;
4717  }
4718  while (auto *ASE =
4719             dyn_cast<ArraySubscriptExpr>(Base->IgnoreParenImpCasts())) {
4720    Base = ASE->getBase();
4721    ++ArraySectionCount;
4722  }
4723  Base = Base->IgnoreParenImpCasts();
4724  auto OriginalTy = Base->getType();
4725  if (auto *DRE = dyn_cast<DeclRefExpr>(Base))
4726    if (auto *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl()))
4727      OriginalTy = PVD->getOriginalType().getNonReferenceType();
4728
4729  for (unsigned Cnt = 0; Cnt < ArraySectionCount; ++Cnt) {
4730    if (OriginalTy->isAnyPointerType())
4731      OriginalTy = OriginalTy->getPointeeType();
4732    else {
4733      assert (OriginalTy->isArrayType());
4734      OriginalTy = OriginalTy->castAsArrayTypeUnsafe()->getElementType();
4735    }
4736  }
4737  return OriginalTy;
4738}
4739