Expr.cpp revision 226633 
1//===--- Expr.cpp - Expression AST Node Implementation --------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the Expr class and subclasses.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/AST/Expr.h"
15#include "clang/AST/ExprCXX.h"
16#include "clang/AST/APValue.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/DeclObjC.h"
19#include "clang/AST/DeclCXX.h"
20#include "clang/AST/DeclTemplate.h"
21#include "clang/AST/RecordLayout.h"
22#include "clang/AST/StmtVisitor.h"
23#include "clang/Lex/LiteralSupport.h"
24#include "clang/Lex/Lexer.h"
25#include "clang/Sema/SemaDiagnostic.h"
26#include "clang/Basic/Builtins.h"
27#include "clang/Basic/SourceManager.h"
28#include "clang/Basic/TargetInfo.h"
29#include "llvm/Support/ErrorHandling.h"
30#include "llvm/Support/raw_ostream.h"
31#include <algorithm>
32using namespace clang;
33
34/// isKnownToHaveBooleanValue - Return true if this is an integer expression
35/// that is known to return 0 or 1.  This happens for _Bool/bool expressions
36/// but also int expressions which are produced by things like comparisons in
37/// C.
38bool Expr::isKnownToHaveBooleanValue() const {
39  const Expr *E = IgnoreParens();
40
41  // If this value has _Bool type, it is obvious 0/1.
42  if (E->getType()->isBooleanType()) return true;
43  // If this is a non-scalar-integer type, we don't care enough to try.
44  if (!E->getType()->isIntegralOrEnumerationType()) return false;
45
46  if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
47    switch (UO->getOpcode()) {
48    case UO_Plus:
49      return UO->getSubExpr()->isKnownToHaveBooleanValue();
50    default:
51      return false;
52    }
53  }
54
55  // Only look through implicit casts.  If the user writes
56  // '(int) (a && b)' treat it as an arbitrary int.
57  if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E))
58    return CE->getSubExpr()->isKnownToHaveBooleanValue();
59
60  if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
61    switch (BO->getOpcode()) {
62    default: return false;
63    case BO_LT:   // Relational operators.
64    case BO_GT:
65    case BO_LE:
66    case BO_GE:
67    case BO_EQ:   // Equality operators.
68    case BO_NE:
69    case BO_LAnd: // AND operator.
70    case BO_LOr:  // Logical OR operator.
71      return true;
72
73    case BO_And:  // Bitwise AND operator.
74    case BO_Xor:  // Bitwise XOR operator.
75    case BO_Or:   // Bitwise OR operator.
76      // Handle things like (x==2)|(y==12).
77      return BO->getLHS()->isKnownToHaveBooleanValue() &&
78             BO->getRHS()->isKnownToHaveBooleanValue();
79
80    case BO_Comma:
81    case BO_Assign:
82      return BO->getRHS()->isKnownToHaveBooleanValue();
83    }
84  }
85
86  if (const ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E))
87    return CO->getTrueExpr()->isKnownToHaveBooleanValue() &&
88           CO->getFalseExpr()->isKnownToHaveBooleanValue();
89
90  return false;
91}
92
93// Amusing macro metaprogramming hack: check whether a class provides
94// a more specific implementation of getExprLoc().
95namespace {
96  /// This implementation is used when a class provides a custom
97  /// implementation of getExprLoc.
98  template <class E, class T>
99  SourceLocation getExprLocImpl(const Expr *expr,
100                                SourceLocation (T::*v)() const) {
101    return static_cast<const E*>(expr)->getExprLoc();
102  }
103
104  /// This implementation is used when a class doesn't provide
105  /// a custom implementation of getExprLoc.  Overload resolution
106  /// should pick it over the implementation above because it's
107  /// more specialized according to function template partial ordering.
108  template <class E>
109  SourceLocation getExprLocImpl(const Expr *expr,
110                                SourceLocation (Expr::*v)() const) {
111    return static_cast<const E*>(expr)->getSourceRange().getBegin();
112  }
113}
114
115SourceLocation Expr::getExprLoc() const {
116  switch (getStmtClass()) {
117  case Stmt::NoStmtClass: llvm_unreachable("statement without class");
118#define ABSTRACT_STMT(type)
119#define STMT(type, base) \
120  case Stmt::type##Class: llvm_unreachable(#type " is not an Expr"); break;
121#define EXPR(type, base) \
122  case Stmt::type##Class: return getExprLocImpl<type>(this, &type::getExprLoc);
123#include "clang/AST/StmtNodes.inc"
124  }
125  llvm_unreachable("unknown statement kind");
126  return SourceLocation();
127}
128
129//===----------------------------------------------------------------------===//
130// Primary Expressions.
131//===----------------------------------------------------------------------===//
132
133/// \brief Compute the type-, value-, and instantiation-dependence of a
134/// declaration reference
135/// based on the declaration being referenced.
136static void computeDeclRefDependence(NamedDecl *D, QualType T,
137                                     bool &TypeDependent,
138                                     bool &ValueDependent,
139                                     bool &InstantiationDependent) {
140  TypeDependent = false;
141  ValueDependent = false;
142  InstantiationDependent = false;
143
144  // (TD) C++ [temp.dep.expr]p3:
145  //   An id-expression is type-dependent if it contains:
146  //
147  // and
148  //
149  // (VD) C++ [temp.dep.constexpr]p2:
150  //  An identifier is value-dependent if it is:
151
152  //  (TD)  - an identifier that was declared with dependent type
153  //  (VD)  - a name declared with a dependent type,
154  if (T->isDependentType()) {
155    TypeDependent = true;
156    ValueDependent = true;
157    InstantiationDependent = true;
158    return;
159  } else if (T->isInstantiationDependentType()) {
160    InstantiationDependent = true;
161  }
162
163  //  (TD)  - a conversion-function-id that specifies a dependent type
164  if (D->getDeclName().getNameKind()
165                                == DeclarationName::CXXConversionFunctionName) {
166    QualType T = D->getDeclName().getCXXNameType();
167    if (T->isDependentType()) {
168      TypeDependent = true;
169      ValueDependent = true;
170      InstantiationDependent = true;
171      return;
172    }
173
174    if (T->isInstantiationDependentType())
175      InstantiationDependent = true;
176  }
177
178  //  (VD)  - the name of a non-type template parameter,
179  if (isa<NonTypeTemplateParmDecl>(D)) {
180    ValueDependent = true;
181    InstantiationDependent = true;
182    return;
183  }
184
185  //  (VD) - a constant with integral or enumeration type and is
186  //         initialized with an expression that is value-dependent.
187  if (VarDecl *Var = dyn_cast<VarDecl>(D)) {
188    if (Var->getType()->isIntegralOrEnumerationType() &&
189        Var->getType().getCVRQualifiers() == Qualifiers::Const) {
190      if (const Expr *Init = Var->getAnyInitializer())
191        if (Init->isValueDependent()) {
192          ValueDependent = true;
193          InstantiationDependent = true;
194        }
195    }
196
197    // (VD) - FIXME: Missing from the standard:
198    //      -  a member function or a static data member of the current
199    //         instantiation
200    else if (Var->isStaticDataMember() &&
201             Var->getDeclContext()->isDependentContext()) {
202      ValueDependent = true;
203      InstantiationDependent = true;
204    }
205
206    return;
207  }
208
209  // (VD) - FIXME: Missing from the standard:
210  //      -  a member function or a static data member of the current
211  //         instantiation
212  if (isa<CXXMethodDecl>(D) && D->getDeclContext()->isDependentContext()) {
213    ValueDependent = true;
214    InstantiationDependent = true;
215    return;
216  }
217}
218
219void DeclRefExpr::computeDependence() {
220  bool TypeDependent = false;
221  bool ValueDependent = false;
222  bool InstantiationDependent = false;
223  computeDeclRefDependence(getDecl(), getType(), TypeDependent, ValueDependent,
224                           InstantiationDependent);
225
226  // (TD) C++ [temp.dep.expr]p3:
227  //   An id-expression is type-dependent if it contains:
228  //
229  // and
230  //
231  // (VD) C++ [temp.dep.constexpr]p2:
232  //  An identifier is value-dependent if it is:
233  if (!TypeDependent && !ValueDependent &&
234      hasExplicitTemplateArgs() &&
235      TemplateSpecializationType::anyDependentTemplateArguments(
236                                                            getTemplateArgs(),
237                                                       getNumTemplateArgs(),
238                                                      InstantiationDependent)) {
239    TypeDependent = true;
240    ValueDependent = true;
241    InstantiationDependent = true;
242  }
243
244  ExprBits.TypeDependent = TypeDependent;
245  ExprBits.ValueDependent = ValueDependent;
246  ExprBits.InstantiationDependent = InstantiationDependent;
247
248  // Is the declaration a parameter pack?
249  if (getDecl()->isParameterPack())
250    ExprBits.ContainsUnexpandedParameterPack = true;
251}
252
253DeclRefExpr::DeclRefExpr(NestedNameSpecifierLoc QualifierLoc,
254                         ValueDecl *D, const DeclarationNameInfo &NameInfo,
255                         NamedDecl *FoundD,
256                         const TemplateArgumentListInfo *TemplateArgs,
257                         QualType T, ExprValueKind VK)
258  : Expr(DeclRefExprClass, T, VK, OK_Ordinary, false, false, false, false),
259    D(D), Loc(NameInfo.getLoc()), DNLoc(NameInfo.getInfo()) {
260  DeclRefExprBits.HasQualifier = QualifierLoc ? 1 : 0;
261  if (QualifierLoc)
262    getInternalQualifierLoc() = QualifierLoc;
263  DeclRefExprBits.HasFoundDecl = FoundD ? 1 : 0;
264  if (FoundD)
265    getInternalFoundDecl() = FoundD;
266  DeclRefExprBits.HasExplicitTemplateArgs = TemplateArgs ? 1 : 0;
267  if (TemplateArgs) {
268    bool Dependent = false;
269    bool InstantiationDependent = false;
270    bool ContainsUnexpandedParameterPack = false;
271    getExplicitTemplateArgs().initializeFrom(*TemplateArgs, Dependent,
272                                             InstantiationDependent,
273                                             ContainsUnexpandedParameterPack);
274    if (InstantiationDependent)
275      setInstantiationDependent(true);
276  }
277  DeclRefExprBits.HadMultipleCandidates = 0;
278
279  computeDependence();
280}
281
282DeclRefExpr *DeclRefExpr::Create(ASTContext &Context,
283                                 NestedNameSpecifierLoc QualifierLoc,
284                                 ValueDecl *D,
285                                 SourceLocation NameLoc,
286                                 QualType T,
287                                 ExprValueKind VK,
288                                 NamedDecl *FoundD,
289                                 const TemplateArgumentListInfo *TemplateArgs) {
290  return Create(Context, QualifierLoc, D,
291                DeclarationNameInfo(D->getDeclName(), NameLoc),
292                T, VK, FoundD, TemplateArgs);
293}
294
295DeclRefExpr *DeclRefExpr::Create(ASTContext &Context,
296                                 NestedNameSpecifierLoc QualifierLoc,
297                                 ValueDecl *D,
298                                 const DeclarationNameInfo &NameInfo,
299                                 QualType T,
300                                 ExprValueKind VK,
301                                 NamedDecl *FoundD,
302                                 const TemplateArgumentListInfo *TemplateArgs) {
303  // Filter out cases where the found Decl is the same as the value refenenced.
304  if (D == FoundD)
305    FoundD = 0;
306
307  std::size_t Size = sizeof(DeclRefExpr);
308  if (QualifierLoc != 0)
309    Size += sizeof(NestedNameSpecifierLoc);
310  if (FoundD)
311    Size += sizeof(NamedDecl *);
312  if (TemplateArgs)
313    Size += ASTTemplateArgumentListInfo::sizeFor(*TemplateArgs);
314
315  void *Mem = Context.Allocate(Size, llvm::alignOf<DeclRefExpr>());
316  return new (Mem) DeclRefExpr(QualifierLoc, D, NameInfo, FoundD, TemplateArgs,
317                               T, VK);
318}
319
320DeclRefExpr *DeclRefExpr::CreateEmpty(ASTContext &Context,
321                                      bool HasQualifier,
322                                      bool HasFoundDecl,
323                                      bool HasExplicitTemplateArgs,
324                                      unsigned NumTemplateArgs) {
325  std::size_t Size = sizeof(DeclRefExpr);
326  if (HasQualifier)
327    Size += sizeof(NestedNameSpecifierLoc);
328  if (HasFoundDecl)
329    Size += sizeof(NamedDecl *);
330  if (HasExplicitTemplateArgs)
331    Size += ASTTemplateArgumentListInfo::sizeFor(NumTemplateArgs);
332
333  void *Mem = Context.Allocate(Size, llvm::alignOf<DeclRefExpr>());
334  return new (Mem) DeclRefExpr(EmptyShell());
335}
336
337SourceRange DeclRefExpr::getSourceRange() const {
338  SourceRange R = getNameInfo().getSourceRange();
339  if (hasQualifier())
340    R.setBegin(getQualifierLoc().getBeginLoc());
341  if (hasExplicitTemplateArgs())
342    R.setEnd(getRAngleLoc());
343  return R;
344}
345
346// FIXME: Maybe this should use DeclPrinter with a special "print predefined
347// expr" policy instead.
348std::string PredefinedExpr::ComputeName(IdentType IT, const Decl *CurrentDecl) {
349  ASTContext &Context = CurrentDecl->getASTContext();
350
351  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurrentDecl)) {
352    if (IT != PrettyFunction && IT != PrettyFunctionNoVirtual)
353      return FD->getNameAsString();
354
355    llvm::SmallString<256> Name;
356    llvm::raw_svector_ostream Out(Name);
357
358    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
359      if (MD->isVirtual() && IT != PrettyFunctionNoVirtual)
360        Out << "virtual ";
361      if (MD->isStatic())
362        Out << "static ";
363    }
364
365    PrintingPolicy Policy(Context.getLangOptions());
366
367    std::string Proto = FD->getQualifiedNameAsString(Policy);
368
369    const FunctionType *AFT = FD->getType()->getAs<FunctionType>();
370    const FunctionProtoType *FT = 0;
371    if (FD->hasWrittenPrototype())
372      FT = dyn_cast<FunctionProtoType>(AFT);
373
374    Proto += "(";
375    if (FT) {
376      llvm::raw_string_ostream POut(Proto);
377      for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
378        if (i) POut << ", ";
379        std::string Param;
380        FD->getParamDecl(i)->getType().getAsStringInternal(Param, Policy);
381        POut << Param;
382      }
383
384      if (FT->isVariadic()) {
385        if (FD->getNumParams()) POut << ", ";
386        POut << "...";
387      }
388    }
389    Proto += ")";
390
391    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
392      Qualifiers ThisQuals = Qualifiers::fromCVRMask(MD->getTypeQualifiers());
393      if (ThisQuals.hasConst())
394        Proto += " const";
395      if (ThisQuals.hasVolatile())
396        Proto += " volatile";
397    }
398
399    if (!isa<CXXConstructorDecl>(FD) && !isa<CXXDestructorDecl>(FD))
400      AFT->getResultType().getAsStringInternal(Proto, Policy);
401
402    Out << Proto;
403
404    Out.flush();
405    return Name.str().str();
406  }
407  if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CurrentDecl)) {
408    llvm::SmallString<256> Name;
409    llvm::raw_svector_ostream Out(Name);
410    Out << (MD->isInstanceMethod() ? '-' : '+');
411    Out << '[';
412
413    // For incorrect code, there might not be an ObjCInterfaceDecl.  Do
414    // a null check to avoid a crash.
415    if (const ObjCInterfaceDecl *ID = MD->getClassInterface())
416      Out << *ID;
417
418    if (const ObjCCategoryImplDecl *CID =
419        dyn_cast<ObjCCategoryImplDecl>(MD->getDeclContext()))
420      Out << '(' << CID << ')';
421
422    Out <<  ' ';
423    Out << MD->getSelector().getAsString();
424    Out <<  ']';
425
426    Out.flush();
427    return Name.str().str();
428  }
429  if (isa<TranslationUnitDecl>(CurrentDecl) && IT == PrettyFunction) {
430    // __PRETTY_FUNCTION__ -> "top level", the others produce an empty string.
431    return "top level";
432  }
433  return "";
434}
435
436void APNumericStorage::setIntValue(ASTContext &C, const llvm::APInt &Val) {
437  if (hasAllocation())
438    C.Deallocate(pVal);
439
440  BitWidth = Val.getBitWidth();
441  unsigned NumWords = Val.getNumWords();
442  const uint64_t* Words = Val.getRawData();
443  if (NumWords > 1) {
444    pVal = new (C) uint64_t[NumWords];
445    std::copy(Words, Words + NumWords, pVal);
446  } else if (NumWords == 1)
447    VAL = Words[0];
448  else
449    VAL = 0;
450}
451
452IntegerLiteral *
453IntegerLiteral::Create(ASTContext &C, const llvm::APInt &V,
454                       QualType type, SourceLocation l) {
455  return new (C) IntegerLiteral(C, V, type, l);
456}
457
458IntegerLiteral *
459IntegerLiteral::Create(ASTContext &C, EmptyShell Empty) {
460  return new (C) IntegerLiteral(Empty);
461}
462
463FloatingLiteral *
464FloatingLiteral::Create(ASTContext &C, const llvm::APFloat &V,
465                        bool isexact, QualType Type, SourceLocation L) {
466  return new (C) FloatingLiteral(C, V, isexact, Type, L);
467}
468
469FloatingLiteral *
470FloatingLiteral::Create(ASTContext &C, EmptyShell Empty) {
471  return new (C) FloatingLiteral(Empty);
472}
473
474/// getValueAsApproximateDouble - This returns the value as an inaccurate
475/// double.  Note that this may cause loss of precision, but is useful for
476/// debugging dumps, etc.
477double FloatingLiteral::getValueAsApproximateDouble() const {
478  llvm::APFloat V = getValue();
479  bool ignored;
480  V.convert(llvm::APFloat::IEEEdouble, llvm::APFloat::rmNearestTiesToEven,
481            &ignored);
482  return V.convertToDouble();
483}
484
485StringLiteral *StringLiteral::Create(ASTContext &C, StringRef Str,
486                                     StringKind Kind, bool Pascal, QualType Ty,
487                                     const SourceLocation *Loc,
488                                     unsigned NumStrs) {
489  // Allocate enough space for the StringLiteral plus an array of locations for
490  // any concatenated string tokens.
491  void *Mem = C.Allocate(sizeof(StringLiteral)+
492                         sizeof(SourceLocation)*(NumStrs-1),
493                         llvm::alignOf<StringLiteral>());
494  StringLiteral *SL = new (Mem) StringLiteral(Ty);
495
496  // OPTIMIZE: could allocate this appended to the StringLiteral.
497  char *AStrData = new (C, 1) char[Str.size()];
498  memcpy(AStrData, Str.data(), Str.size());
499  SL->StrData = AStrData;
500  SL->ByteLength = Str.size();
501  SL->Kind = Kind;
502  SL->IsPascal = Pascal;
503  SL->TokLocs[0] = Loc[0];
504  SL->NumConcatenated = NumStrs;
505
506  if (NumStrs != 1)
507    memcpy(&SL->TokLocs[1], Loc+1, sizeof(SourceLocation)*(NumStrs-1));
508  return SL;
509}
510
511StringLiteral *StringLiteral::CreateEmpty(ASTContext &C, unsigned NumStrs) {
512  void *Mem = C.Allocate(sizeof(StringLiteral)+
513                         sizeof(SourceLocation)*(NumStrs-1),
514                         llvm::alignOf<StringLiteral>());
515  StringLiteral *SL = new (Mem) StringLiteral(QualType());
516  SL->StrData = 0;
517  SL->ByteLength = 0;
518  SL->NumConcatenated = NumStrs;
519  return SL;
520}
521
522void StringLiteral::setString(ASTContext &C, StringRef Str) {
523  char *AStrData = new (C, 1) char[Str.size()];
524  memcpy(AStrData, Str.data(), Str.size());
525  StrData = AStrData;
526  ByteLength = Str.size();
527}
528
529/// getLocationOfByte - Return a source location that points to the specified
530/// byte of this string literal.
531///
532/// Strings are amazingly complex.  They can be formed from multiple tokens and
533/// can have escape sequences in them in addition to the usual trigraph and
534/// escaped newline business.  This routine handles this complexity.
535///
536SourceLocation StringLiteral::
537getLocationOfByte(unsigned ByteNo, const SourceManager &SM,
538                  const LangOptions &Features, const TargetInfo &Target) const {
539  assert(Kind == StringLiteral::Ascii && "This only works for ASCII strings");
540
541  // Loop over all of the tokens in this string until we find the one that
542  // contains the byte we're looking for.
543  unsigned TokNo = 0;
544  while (1) {
545    assert(TokNo < getNumConcatenated() && "Invalid byte number!");
546    SourceLocation StrTokLoc = getStrTokenLoc(TokNo);
547
548    // Get the spelling of the string so that we can get the data that makes up
549    // the string literal, not the identifier for the macro it is potentially
550    // expanded through.
551    SourceLocation StrTokSpellingLoc = SM.getSpellingLoc(StrTokLoc);
552
553    // Re-lex the token to get its length and original spelling.
554    std::pair<FileID, unsigned> LocInfo =SM.getDecomposedLoc(StrTokSpellingLoc);
555    bool Invalid = false;
556    StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
557    if (Invalid)
558      return StrTokSpellingLoc;
559
560    const char *StrData = Buffer.data()+LocInfo.second;
561
562    // Create a langops struct and enable trigraphs.  This is sufficient for
563    // relexing tokens.
564    LangOptions LangOpts;
565    LangOpts.Trigraphs = true;
566
567    // Create a lexer starting at the beginning of this token.
568    Lexer TheLexer(StrTokSpellingLoc, Features, Buffer.begin(), StrData,
569                   Buffer.end());
570    Token TheTok;
571    TheLexer.LexFromRawLexer(TheTok);
572
573    // Use the StringLiteralParser to compute the length of the string in bytes.
574    StringLiteralParser SLP(&TheTok, 1, SM, Features, Target);
575    unsigned TokNumBytes = SLP.GetStringLength();
576
577    // If the byte is in this token, return the location of the byte.
578    if (ByteNo < TokNumBytes ||
579        (ByteNo == TokNumBytes && TokNo == getNumConcatenated() - 1)) {
580      unsigned Offset = SLP.getOffsetOfStringByte(TheTok, ByteNo);
581
582      // Now that we know the offset of the token in the spelling, use the
583      // preprocessor to get the offset in the original source.
584      return Lexer::AdvanceToTokenCharacter(StrTokLoc, Offset, SM, Features);
585    }
586
587    // Move to the next string token.
588    ++TokNo;
589    ByteNo -= TokNumBytes;
590  }
591}
592
593
594
595/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
596/// corresponds to, e.g. "sizeof" or "[pre]++".
597const char *UnaryOperator::getOpcodeStr(Opcode Op) {
598  switch (Op) {
599  default: llvm_unreachable("Unknown unary operator");
600  case UO_PostInc: return "++";
601  case UO_PostDec: return "--";
602  case UO_PreInc:  return "++";
603  case UO_PreDec:  return "--";
604  case UO_AddrOf:  return "&";
605  case UO_Deref:   return "*";
606  case UO_Plus:    return "+";
607  case UO_Minus:   return "-";
608  case UO_Not:     return "~";
609  case UO_LNot:    return "!";
610  case UO_Real:    return "__real";
611  case UO_Imag:    return "__imag";
612  case UO_Extension: return "__extension__";
613  }
614}
615
616UnaryOperatorKind
617UnaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO, bool Postfix) {
618  switch (OO) {
619  default: llvm_unreachable("No unary operator for overloaded function");
620  case OO_PlusPlus:   return Postfix ? UO_PostInc : UO_PreInc;
621  case OO_MinusMinus: return Postfix ? UO_PostDec : UO_PreDec;
622  case OO_Amp:        return UO_AddrOf;
623  case OO_Star:       return UO_Deref;
624  case OO_Plus:       return UO_Plus;
625  case OO_Minus:      return UO_Minus;
626  case OO_Tilde:      return UO_Not;
627  case OO_Exclaim:    return UO_LNot;
628  }
629}
630
631OverloadedOperatorKind UnaryOperator::getOverloadedOperator(Opcode Opc) {
632  switch (Opc) {
633  case UO_PostInc: case UO_PreInc: return OO_PlusPlus;
634  case UO_PostDec: case UO_PreDec: return OO_MinusMinus;
635  case UO_AddrOf: return OO_Amp;
636  case UO_Deref: return OO_Star;
637  case UO_Plus: return OO_Plus;
638  case UO_Minus: return OO_Minus;
639  case UO_Not: return OO_Tilde;
640  case UO_LNot: return OO_Exclaim;
641  default: return OO_None;
642  }
643}
644
645
646//===----------------------------------------------------------------------===//
647// Postfix Operators.
648//===----------------------------------------------------------------------===//
649
650CallExpr::CallExpr(ASTContext& C, StmtClass SC, Expr *fn, unsigned NumPreArgs,
651                   Expr **args, unsigned numargs, QualType t, ExprValueKind VK,
652                   SourceLocation rparenloc)
653  : Expr(SC, t, VK, OK_Ordinary,
654         fn->isTypeDependent(),
655         fn->isValueDependent(),
656         fn->isInstantiationDependent(),
657         fn->containsUnexpandedParameterPack()),
658    NumArgs(numargs) {
659
660  SubExprs = new (C) Stmt*[numargs+PREARGS_START+NumPreArgs];
661  SubExprs[FN] = fn;
662  for (unsigned i = 0; i != numargs; ++i) {
663    if (args[i]->isTypeDependent())
664      ExprBits.TypeDependent = true;
665    if (args[i]->isValueDependent())
666      ExprBits.ValueDependent = true;
667    if (args[i]->isInstantiationDependent())
668      ExprBits.InstantiationDependent = true;
669    if (args[i]->containsUnexpandedParameterPack())
670      ExprBits.ContainsUnexpandedParameterPack = true;
671
672    SubExprs[i+PREARGS_START+NumPreArgs] = args[i];
673  }
674
675  CallExprBits.NumPreArgs = NumPreArgs;
676  RParenLoc = rparenloc;
677}
678
679CallExpr::CallExpr(ASTContext& C, Expr *fn, Expr **args, unsigned numargs,
680                   QualType t, ExprValueKind VK, SourceLocation rparenloc)
681  : Expr(CallExprClass, t, VK, OK_Ordinary,
682         fn->isTypeDependent(),
683         fn->isValueDependent(),
684         fn->isInstantiationDependent(),
685         fn->containsUnexpandedParameterPack()),
686    NumArgs(numargs) {
687
688  SubExprs = new (C) Stmt*[numargs+PREARGS_START];
689  SubExprs[FN] = fn;
690  for (unsigned i = 0; i != numargs; ++i) {
691    if (args[i]->isTypeDependent())
692      ExprBits.TypeDependent = true;
693    if (args[i]->isValueDependent())
694      ExprBits.ValueDependent = true;
695    if (args[i]->isInstantiationDependent())
696      ExprBits.InstantiationDependent = true;
697    if (args[i]->containsUnexpandedParameterPack())
698      ExprBits.ContainsUnexpandedParameterPack = true;
699
700    SubExprs[i+PREARGS_START] = args[i];
701  }
702
703  CallExprBits.NumPreArgs = 0;
704  RParenLoc = rparenloc;
705}
706
707CallExpr::CallExpr(ASTContext &C, StmtClass SC, EmptyShell Empty)
708  : Expr(SC, Empty), SubExprs(0), NumArgs(0) {
709  // FIXME: Why do we allocate this?
710  SubExprs = new (C) Stmt*[PREARGS_START];
711  CallExprBits.NumPreArgs = 0;
712}
713
714CallExpr::CallExpr(ASTContext &C, StmtClass SC, unsigned NumPreArgs,
715                   EmptyShell Empty)
716  : Expr(SC, Empty), SubExprs(0), NumArgs(0) {
717  // FIXME: Why do we allocate this?
718  SubExprs = new (C) Stmt*[PREARGS_START+NumPreArgs];
719  CallExprBits.NumPreArgs = NumPreArgs;
720}
721
722Decl *CallExpr::getCalleeDecl() {
723  Expr *CEE = getCallee()->IgnoreParenImpCasts();
724
725  while (SubstNonTypeTemplateParmExpr *NTTP
726                                = dyn_cast<SubstNonTypeTemplateParmExpr>(CEE)) {
727    CEE = NTTP->getReplacement()->IgnoreParenCasts();
728  }
729
730  // If we're calling a dereference, look at the pointer instead.
731  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CEE)) {
732    if (BO->isPtrMemOp())
733      CEE = BO->getRHS()->IgnoreParenCasts();
734  } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(CEE)) {
735    if (UO->getOpcode() == UO_Deref)
736      CEE = UO->getSubExpr()->IgnoreParenCasts();
737  }
738  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE))
739    return DRE->getDecl();
740  if (MemberExpr *ME = dyn_cast<MemberExpr>(CEE))
741    return ME->getMemberDecl();
742
743  return 0;
744}
745
746FunctionDecl *CallExpr::getDirectCallee() {
747  return dyn_cast_or_null<FunctionDecl>(getCalleeDecl());
748}
749
750/// setNumArgs - This changes the number of arguments present in this call.
751/// Any orphaned expressions are deleted by this, and any new operands are set
752/// to null.
753void CallExpr::setNumArgs(ASTContext& C, unsigned NumArgs) {
754  // No change, just return.
755  if (NumArgs == getNumArgs()) return;
756
757  // If shrinking # arguments, just delete the extras and forgot them.
758  if (NumArgs < getNumArgs()) {
759    this->NumArgs = NumArgs;
760    return;
761  }
762
763  // Otherwise, we are growing the # arguments.  New an bigger argument array.
764  unsigned NumPreArgs = getNumPreArgs();
765  Stmt **NewSubExprs = new (C) Stmt*[NumArgs+PREARGS_START+NumPreArgs];
766  // Copy over args.
767  for (unsigned i = 0; i != getNumArgs()+PREARGS_START+NumPreArgs; ++i)
768    NewSubExprs[i] = SubExprs[i];
769  // Null out new args.
770  for (unsigned i = getNumArgs()+PREARGS_START+NumPreArgs;
771       i != NumArgs+PREARGS_START+NumPreArgs; ++i)
772    NewSubExprs[i] = 0;
773
774  if (SubExprs) C.Deallocate(SubExprs);
775  SubExprs = NewSubExprs;
776  this->NumArgs = NumArgs;
777}
778
779/// isBuiltinCall - If this is a call to a builtin, return the builtin ID.  If
780/// not, return 0.
781unsigned CallExpr::isBuiltinCall(const ASTContext &Context) const {
782  // All simple function calls (e.g. func()) are implicitly cast to pointer to
783  // function. As a result, we try and obtain the DeclRefExpr from the
784  // ImplicitCastExpr.
785  const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
786  if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
787    return 0;
788
789  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
790  if (!DRE)
791    return 0;
792
793  const FunctionDecl *FDecl = dyn_cast<FunctionDecl>(DRE->getDecl());
794  if (!FDecl)
795    return 0;
796
797  if (!FDecl->getIdentifier())
798    return 0;
799
800  return FDecl->getBuiltinID();
801}
802
803QualType CallExpr::getCallReturnType() const {
804  QualType CalleeType = getCallee()->getType();
805  if (const PointerType *FnTypePtr = CalleeType->getAs<PointerType>())
806    CalleeType = FnTypePtr->getPointeeType();
807  else if (const BlockPointerType *BPT = CalleeType->getAs<BlockPointerType>())
808    CalleeType = BPT->getPointeeType();
809  else if (CalleeType->isSpecificPlaceholderType(BuiltinType::BoundMember))
810    // This should never be overloaded and so should never return null.
811    CalleeType = Expr::findBoundMemberType(getCallee());
812
813  const FunctionType *FnType = CalleeType->castAs<FunctionType>();
814  return FnType->getResultType();
815}
816
817SourceRange CallExpr::getSourceRange() const {
818  if (isa<CXXOperatorCallExpr>(this))
819    return cast<CXXOperatorCallExpr>(this)->getSourceRange();
820
821  SourceLocation begin = getCallee()->getLocStart();
822  if (begin.isInvalid() && getNumArgs() > 0)
823    begin = getArg(0)->getLocStart();
824  SourceLocation end = getRParenLoc();
825  if (end.isInvalid() && getNumArgs() > 0)
826    end = getArg(getNumArgs() - 1)->getLocEnd();
827  return SourceRange(begin, end);
828}
829
830OffsetOfExpr *OffsetOfExpr::Create(ASTContext &C, QualType type,
831                                   SourceLocation OperatorLoc,
832                                   TypeSourceInfo *tsi,
833                                   OffsetOfNode* compsPtr, unsigned numComps,
834                                   Expr** exprsPtr, unsigned numExprs,
835                                   SourceLocation RParenLoc) {
836  void *Mem = C.Allocate(sizeof(OffsetOfExpr) +
837                         sizeof(OffsetOfNode) * numComps +
838                         sizeof(Expr*) * numExprs);
839
840  return new (Mem) OffsetOfExpr(C, type, OperatorLoc, tsi, compsPtr, numComps,
841                                exprsPtr, numExprs, RParenLoc);
842}
843
844OffsetOfExpr *OffsetOfExpr::CreateEmpty(ASTContext &C,
845                                        unsigned numComps, unsigned numExprs) {
846  void *Mem = C.Allocate(sizeof(OffsetOfExpr) +
847                         sizeof(OffsetOfNode) * numComps +
848                         sizeof(Expr*) * numExprs);
849  return new (Mem) OffsetOfExpr(numComps, numExprs);
850}
851
852OffsetOfExpr::OffsetOfExpr(ASTContext &C, QualType type,
853                           SourceLocation OperatorLoc, TypeSourceInfo *tsi,
854                           OffsetOfNode* compsPtr, unsigned numComps,
855                           Expr** exprsPtr, unsigned numExprs,
856                           SourceLocation RParenLoc)
857  : Expr(OffsetOfExprClass, type, VK_RValue, OK_Ordinary,
858         /*TypeDependent=*/false,
859         /*ValueDependent=*/tsi->getType()->isDependentType(),
860         tsi->getType()->isInstantiationDependentType(),
861         tsi->getType()->containsUnexpandedParameterPack()),
862    OperatorLoc(OperatorLoc), RParenLoc(RParenLoc), TSInfo(tsi),
863    NumComps(numComps), NumExprs(numExprs)
864{
865  for(unsigned i = 0; i < numComps; ++i) {
866    setComponent(i, compsPtr[i]);
867  }
868
869  for(unsigned i = 0; i < numExprs; ++i) {
870    if (exprsPtr[i]->isTypeDependent() || exprsPtr[i]->isValueDependent())
871      ExprBits.ValueDependent = true;
872    if (exprsPtr[i]->containsUnexpandedParameterPack())
873      ExprBits.ContainsUnexpandedParameterPack = true;
874
875    setIndexExpr(i, exprsPtr[i]);
876  }
877}
878
879IdentifierInfo *OffsetOfExpr::OffsetOfNode::getFieldName() const {
880  assert(getKind() == Field || getKind() == Identifier);
881  if (getKind() == Field)
882    return getField()->getIdentifier();
883
884  return reinterpret_cast<IdentifierInfo *> (Data & ~(uintptr_t)Mask);
885}
886
887MemberExpr *MemberExpr::Create(ASTContext &C, Expr *base, bool isarrow,
888                               NestedNameSpecifierLoc QualifierLoc,
889                               ValueDecl *memberdecl,
890                               DeclAccessPair founddecl,
891                               DeclarationNameInfo nameinfo,
892                               const TemplateArgumentListInfo *targs,
893                               QualType ty,
894                               ExprValueKind vk,
895                               ExprObjectKind ok) {
896  std::size_t Size = sizeof(MemberExpr);
897
898  bool hasQualOrFound = (QualifierLoc ||
899                         founddecl.getDecl() != memberdecl ||
900                         founddecl.getAccess() != memberdecl->getAccess());
901  if (hasQualOrFound)
902    Size += sizeof(MemberNameQualifier);
903
904  if (targs)
905    Size += ASTTemplateArgumentListInfo::sizeFor(*targs);
906
907  void *Mem = C.Allocate(Size, llvm::alignOf<MemberExpr>());
908  MemberExpr *E = new (Mem) MemberExpr(base, isarrow, memberdecl, nameinfo,
909                                       ty, vk, ok);
910
911  if (hasQualOrFound) {
912    // FIXME: Wrong. We should be looking at the member declaration we found.
913    if (QualifierLoc && QualifierLoc.getNestedNameSpecifier()->isDependent()) {
914      E->setValueDependent(true);
915      E->setTypeDependent(true);
916      E->setInstantiationDependent(true);
917    }
918    else if (QualifierLoc &&
919             QualifierLoc.getNestedNameSpecifier()->isInstantiationDependent())
920      E->setInstantiationDependent(true);
921
922    E->HasQualifierOrFoundDecl = true;
923
924    MemberNameQualifier *NQ = E->getMemberQualifier();
925    NQ->QualifierLoc = QualifierLoc;
926    NQ->FoundDecl = founddecl;
927  }
928
929  if (targs) {
930    bool Dependent = false;
931    bool InstantiationDependent = false;
932    bool ContainsUnexpandedParameterPack = false;
933    E->HasExplicitTemplateArgumentList = true;
934    E->getExplicitTemplateArgs().initializeFrom(*targs, Dependent,
935                                                InstantiationDependent,
936                                              ContainsUnexpandedParameterPack);
937    if (InstantiationDependent)
938      E->setInstantiationDependent(true);
939  }
940
941  return E;
942}
943
944SourceRange MemberExpr::getSourceRange() const {
945  SourceLocation StartLoc;
946  if (isImplicitAccess()) {
947    if (hasQualifier())
948      StartLoc = getQualifierLoc().getBeginLoc();
949    else
950      StartLoc = MemberLoc;
951  } else {
952    // FIXME: We don't want this to happen. Rather, we should be able to
953    // detect all kinds of implicit accesses more cleanly.
954    StartLoc = getBase()->getLocStart();
955    if (StartLoc.isInvalid())
956      StartLoc = MemberLoc;
957  }
958
959  SourceLocation EndLoc =
960    HasExplicitTemplateArgumentList? getRAngleLoc()
961                                   : getMemberNameInfo().getEndLoc();
962
963  return SourceRange(StartLoc, EndLoc);
964}
965
966void CastExpr::CheckCastConsistency() const {
967  switch (getCastKind()) {
968  case CK_DerivedToBase:
969  case CK_UncheckedDerivedToBase:
970  case CK_DerivedToBaseMemberPointer:
971  case CK_BaseToDerived:
972  case CK_BaseToDerivedMemberPointer:
973    assert(!path_empty() && "Cast kind should have a base path!");
974    break;
975
976  case CK_CPointerToObjCPointerCast:
977    assert(getType()->isObjCObjectPointerType());
978    assert(getSubExpr()->getType()->isPointerType());
979    goto CheckNoBasePath;
980
981  case CK_BlockPointerToObjCPointerCast:
982    assert(getType()->isObjCObjectPointerType());
983    assert(getSubExpr()->getType()->isBlockPointerType());
984    goto CheckNoBasePath;
985
986  case CK_BitCast:
987    // Arbitrary casts to C pointer types count as bitcasts.
988    // Otherwise, we should only have block and ObjC pointer casts
989    // here if they stay within the type kind.
990    if (!getType()->isPointerType()) {
991      assert(getType()->isObjCObjectPointerType() ==
992             getSubExpr()->getType()->isObjCObjectPointerType());
993      assert(getType()->isBlockPointerType() ==
994             getSubExpr()->getType()->isBlockPointerType());
995    }
996    goto CheckNoBasePath;
997
998  case CK_AnyPointerToBlockPointerCast:
999    assert(getType()->isBlockPointerType());
1000    assert(getSubExpr()->getType()->isAnyPointerType() &&
1001           !getSubExpr()->getType()->isBlockPointerType());
1002    goto CheckNoBasePath;
1003
1004  // These should not have an inheritance path.
1005  case CK_Dynamic:
1006  case CK_ToUnion:
1007  case CK_ArrayToPointerDecay:
1008  case CK_FunctionToPointerDecay:
1009  case CK_NullToMemberPointer:
1010  case CK_NullToPointer:
1011  case CK_ConstructorConversion:
1012  case CK_IntegralToPointer:
1013  case CK_PointerToIntegral:
1014  case CK_ToVoid:
1015  case CK_VectorSplat:
1016  case CK_IntegralCast:
1017  case CK_IntegralToFloating:
1018  case CK_FloatingToIntegral:
1019  case CK_FloatingCast:
1020  case CK_ObjCObjectLValueCast:
1021  case CK_FloatingRealToComplex:
1022  case CK_FloatingComplexToReal:
1023  case CK_FloatingComplexCast:
1024  case CK_FloatingComplexToIntegralComplex:
1025  case CK_IntegralRealToComplex:
1026  case CK_IntegralComplexToReal:
1027  case CK_IntegralComplexCast:
1028  case CK_IntegralComplexToFloatingComplex:
1029  case CK_ARCProduceObject:
1030  case CK_ARCConsumeObject:
1031  case CK_ARCReclaimReturnedObject:
1032  case CK_ARCExtendBlockObject:
1033    assert(!getType()->isBooleanType() && "unheralded conversion to bool");
1034    goto CheckNoBasePath;
1035
1036  case CK_Dependent:
1037  case CK_LValueToRValue:
1038  case CK_GetObjCProperty:
1039  case CK_NoOp:
1040  case CK_PointerToBoolean:
1041  case CK_IntegralToBoolean:
1042  case CK_FloatingToBoolean:
1043  case CK_MemberPointerToBoolean:
1044  case CK_FloatingComplexToBoolean:
1045  case CK_IntegralComplexToBoolean:
1046  case CK_LValueBitCast:            // -> bool&
1047  case CK_UserDefinedConversion:    // operator bool()
1048  CheckNoBasePath:
1049    assert(path_empty() && "Cast kind should not have a base path!");
1050    break;
1051  }
1052}
1053
1054const char *CastExpr::getCastKindName() const {
1055  switch (getCastKind()) {
1056  case CK_Dependent:
1057    return "Dependent";
1058  case CK_BitCast:
1059    return "BitCast";
1060  case CK_LValueBitCast:
1061    return "LValueBitCast";
1062  case CK_LValueToRValue:
1063    return "LValueToRValue";
1064  case CK_GetObjCProperty:
1065    return "GetObjCProperty";
1066  case CK_NoOp:
1067    return "NoOp";
1068  case CK_BaseToDerived:
1069    return "BaseToDerived";
1070  case CK_DerivedToBase:
1071    return "DerivedToBase";
1072  case CK_UncheckedDerivedToBase:
1073    return "UncheckedDerivedToBase";
1074  case CK_Dynamic:
1075    return "Dynamic";
1076  case CK_ToUnion:
1077    return "ToUnion";
1078  case CK_ArrayToPointerDecay:
1079    return "ArrayToPointerDecay";
1080  case CK_FunctionToPointerDecay:
1081    return "FunctionToPointerDecay";
1082  case CK_NullToMemberPointer:
1083    return "NullToMemberPointer";
1084  case CK_NullToPointer:
1085    return "NullToPointer";
1086  case CK_BaseToDerivedMemberPointer:
1087    return "BaseToDerivedMemberPointer";
1088  case CK_DerivedToBaseMemberPointer:
1089    return "DerivedToBaseMemberPointer";
1090  case CK_UserDefinedConversion:
1091    return "UserDefinedConversion";
1092  case CK_ConstructorConversion:
1093    return "ConstructorConversion";
1094  case CK_IntegralToPointer:
1095    return "IntegralToPointer";
1096  case CK_PointerToIntegral:
1097    return "PointerToIntegral";
1098  case CK_PointerToBoolean:
1099    return "PointerToBoolean";
1100  case CK_ToVoid:
1101    return "ToVoid";
1102  case CK_VectorSplat:
1103    return "VectorSplat";
1104  case CK_IntegralCast:
1105    return "IntegralCast";
1106  case CK_IntegralToBoolean:
1107    return "IntegralToBoolean";
1108  case CK_IntegralToFloating:
1109    return "IntegralToFloating";
1110  case CK_FloatingToIntegral:
1111    return "FloatingToIntegral";
1112  case CK_FloatingCast:
1113    return "FloatingCast";
1114  case CK_FloatingToBoolean:
1115    return "FloatingToBoolean";
1116  case CK_MemberPointerToBoolean:
1117    return "MemberPointerToBoolean";
1118  case CK_CPointerToObjCPointerCast:
1119    return "CPointerToObjCPointerCast";
1120  case CK_BlockPointerToObjCPointerCast:
1121    return "BlockPointerToObjCPointerCast";
1122  case CK_AnyPointerToBlockPointerCast:
1123    return "AnyPointerToBlockPointerCast";
1124  case CK_ObjCObjectLValueCast:
1125    return "ObjCObjectLValueCast";
1126  case CK_FloatingRealToComplex:
1127    return "FloatingRealToComplex";
1128  case CK_FloatingComplexToReal:
1129    return "FloatingComplexToReal";
1130  case CK_FloatingComplexToBoolean:
1131    return "FloatingComplexToBoolean";
1132  case CK_FloatingComplexCast:
1133    return "FloatingComplexCast";
1134  case CK_FloatingComplexToIntegralComplex:
1135    return "FloatingComplexToIntegralComplex";
1136  case CK_IntegralRealToComplex:
1137    return "IntegralRealToComplex";
1138  case CK_IntegralComplexToReal:
1139    return "IntegralComplexToReal";
1140  case CK_IntegralComplexToBoolean:
1141    return "IntegralComplexToBoolean";
1142  case CK_IntegralComplexCast:
1143    return "IntegralComplexCast";
1144  case CK_IntegralComplexToFloatingComplex:
1145    return "IntegralComplexToFloatingComplex";
1146  case CK_ARCConsumeObject:
1147    return "ARCConsumeObject";
1148  case CK_ARCProduceObject:
1149    return "ARCProduceObject";
1150  case CK_ARCReclaimReturnedObject:
1151    return "ARCReclaimReturnedObject";
1152  case CK_ARCExtendBlockObject:
1153    return "ARCCExtendBlockObject";
1154  }
1155
1156  llvm_unreachable("Unhandled cast kind!");
1157  return 0;
1158}
1159
1160Expr *CastExpr::getSubExprAsWritten() {
1161  Expr *SubExpr = 0;
1162  CastExpr *E = this;
1163  do {
1164    SubExpr = E->getSubExpr();
1165
1166    // Skip through reference binding to temporary.
1167    if (MaterializeTemporaryExpr *Materialize
1168                                  = dyn_cast<MaterializeTemporaryExpr>(SubExpr))
1169      SubExpr = Materialize->GetTemporaryExpr();
1170
1171    // Skip any temporary bindings; they're implicit.
1172    if (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(SubExpr))
1173      SubExpr = Binder->getSubExpr();
1174
1175    // Conversions by constructor and conversion functions have a
1176    // subexpression describing the call; strip it off.
1177    if (E->getCastKind() == CK_ConstructorConversion)
1178      SubExpr = cast<CXXConstructExpr>(SubExpr)->getArg(0);
1179    else if (E->getCastKind() == CK_UserDefinedConversion)
1180      SubExpr = cast<CXXMemberCallExpr>(SubExpr)->getImplicitObjectArgument();
1181
1182    // If the subexpression we're left with is an implicit cast, look
1183    // through that, too.
1184  } while ((E = dyn_cast<ImplicitCastExpr>(SubExpr)));
1185
1186  return SubExpr;
1187}
1188
1189CXXBaseSpecifier **CastExpr::path_buffer() {
1190  switch (getStmtClass()) {
1191#define ABSTRACT_STMT(x)
1192#define CASTEXPR(Type, Base) \
1193  case Stmt::Type##Class: \
1194    return reinterpret_cast<CXXBaseSpecifier**>(static_cast<Type*>(this)+1);
1195#define STMT(Type, Base)
1196#include "clang/AST/StmtNodes.inc"
1197  default:
1198    llvm_unreachable("non-cast expressions not possible here");
1199    return 0;
1200  }
1201}
1202
1203void CastExpr::setCastPath(const CXXCastPath &Path) {
1204  assert(Path.size() == path_size());
1205  memcpy(path_buffer(), Path.data(), Path.size() * sizeof(CXXBaseSpecifier*));
1206}
1207
1208ImplicitCastExpr *ImplicitCastExpr::Create(ASTContext &C, QualType T,
1209                                           CastKind Kind, Expr *Operand,
1210                                           const CXXCastPath *BasePath,
1211                                           ExprValueKind VK) {
1212  unsigned PathSize = (BasePath ? BasePath->size() : 0);
1213  void *Buffer =
1214    C.Allocate(sizeof(ImplicitCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1215  ImplicitCastExpr *E =
1216    new (Buffer) ImplicitCastExpr(T, Kind, Operand, PathSize, VK);
1217  if (PathSize) E->setCastPath(*BasePath);
1218  return E;
1219}
1220
1221ImplicitCastExpr *ImplicitCastExpr::CreateEmpty(ASTContext &C,
1222                                                unsigned PathSize) {
1223  void *Buffer =
1224    C.Allocate(sizeof(ImplicitCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1225  return new (Buffer) ImplicitCastExpr(EmptyShell(), PathSize);
1226}
1227
1228
1229CStyleCastExpr *CStyleCastExpr::Create(ASTContext &C, QualType T,
1230                                       ExprValueKind VK, CastKind K, Expr *Op,
1231                                       const CXXCastPath *BasePath,
1232                                       TypeSourceInfo *WrittenTy,
1233                                       SourceLocation L, SourceLocation R) {
1234  unsigned PathSize = (BasePath ? BasePath->size() : 0);
1235  void *Buffer =
1236    C.Allocate(sizeof(CStyleCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1237  CStyleCastExpr *E =
1238    new (Buffer) CStyleCastExpr(T, VK, K, Op, PathSize, WrittenTy, L, R);
1239  if (PathSize) E->setCastPath(*BasePath);
1240  return E;
1241}
1242
1243CStyleCastExpr *CStyleCastExpr::CreateEmpty(ASTContext &C, unsigned PathSize) {
1244  void *Buffer =
1245    C.Allocate(sizeof(CStyleCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1246  return new (Buffer) CStyleCastExpr(EmptyShell(), PathSize);
1247}
1248
1249/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
1250/// corresponds to, e.g. "<<=".
1251const char *BinaryOperator::getOpcodeStr(Opcode Op) {
1252  switch (Op) {
1253  case BO_PtrMemD:   return ".*";
1254  case BO_PtrMemI:   return "->*";
1255  case BO_Mul:       return "*";
1256  case BO_Div:       return "/";
1257  case BO_Rem:       return "%";
1258  case BO_Add:       return "+";
1259  case BO_Sub:       return "-";
1260  case BO_Shl:       return "<<";
1261  case BO_Shr:       return ">>";
1262  case BO_LT:        return "<";
1263  case BO_GT:        return ">";
1264  case BO_LE:        return "<=";
1265  case BO_GE:        return ">=";
1266  case BO_EQ:        return "==";
1267  case BO_NE:        return "!=";
1268  case BO_And:       return "&";
1269  case BO_Xor:       return "^";
1270  case BO_Or:        return "|";
1271  case BO_LAnd:      return "&&";
1272  case BO_LOr:       return "||";
1273  case BO_Assign:    return "=";
1274  case BO_MulAssign: return "*=";
1275  case BO_DivAssign: return "/=";
1276  case BO_RemAssign: return "%=";
1277  case BO_AddAssign: return "+=";
1278  case BO_SubAssign: return "-=";
1279  case BO_ShlAssign: return "<<=";
1280  case BO_ShrAssign: return ">>=";
1281  case BO_AndAssign: return "&=";
1282  case BO_XorAssign: return "^=";
1283  case BO_OrAssign:  return "|=";
1284  case BO_Comma:     return ",";
1285  }
1286
1287  return "";
1288}
1289
1290BinaryOperatorKind
1291BinaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO) {
1292  switch (OO) {
1293  default: llvm_unreachable("Not an overloadable binary operator");
1294  case OO_Plus: return BO_Add;
1295  case OO_Minus: return BO_Sub;
1296  case OO_Star: return BO_Mul;
1297  case OO_Slash: return BO_Div;
1298  case OO_Percent: return BO_Rem;
1299  case OO_Caret: return BO_Xor;
1300  case OO_Amp: return BO_And;
1301  case OO_Pipe: return BO_Or;
1302  case OO_Equal: return BO_Assign;
1303  case OO_Less: return BO_LT;
1304  case OO_Greater: return BO_GT;
1305  case OO_PlusEqual: return BO_AddAssign;
1306  case OO_MinusEqual: return BO_SubAssign;
1307  case OO_StarEqual: return BO_MulAssign;
1308  case OO_SlashEqual: return BO_DivAssign;
1309  case OO_PercentEqual: return BO_RemAssign;
1310  case OO_CaretEqual: return BO_XorAssign;
1311  case OO_AmpEqual: return BO_AndAssign;
1312  case OO_PipeEqual: return BO_OrAssign;
1313  case OO_LessLess: return BO_Shl;
1314  case OO_GreaterGreater: return BO_Shr;
1315  case OO_LessLessEqual: return BO_ShlAssign;
1316  case OO_GreaterGreaterEqual: return BO_ShrAssign;
1317  case OO_EqualEqual: return BO_EQ;
1318  case OO_ExclaimEqual: return BO_NE;
1319  case OO_LessEqual: return BO_LE;
1320  case OO_GreaterEqual: return BO_GE;
1321  case OO_AmpAmp: return BO_LAnd;
1322  case OO_PipePipe: return BO_LOr;
1323  case OO_Comma: return BO_Comma;
1324  case OO_ArrowStar: return BO_PtrMemI;
1325  }
1326}
1327
1328OverloadedOperatorKind BinaryOperator::getOverloadedOperator(Opcode Opc) {
1329  static const OverloadedOperatorKind OverOps[] = {
1330    /* .* Cannot be overloaded */OO_None, OO_ArrowStar,
1331    OO_Star, OO_Slash, OO_Percent,
1332    OO_Plus, OO_Minus,
1333    OO_LessLess, OO_GreaterGreater,
1334    OO_Less, OO_Greater, OO_LessEqual, OO_GreaterEqual,
1335    OO_EqualEqual, OO_ExclaimEqual,
1336    OO_Amp,
1337    OO_Caret,
1338    OO_Pipe,
1339    OO_AmpAmp,
1340    OO_PipePipe,
1341    OO_Equal, OO_StarEqual,
1342    OO_SlashEqual, OO_PercentEqual,
1343    OO_PlusEqual, OO_MinusEqual,
1344    OO_LessLessEqual, OO_GreaterGreaterEqual,
1345    OO_AmpEqual, OO_CaretEqual,
1346    OO_PipeEqual,
1347    OO_Comma
1348  };
1349  return OverOps[Opc];
1350}
1351
1352InitListExpr::InitListExpr(ASTContext &C, SourceLocation lbraceloc,
1353                           Expr **initExprs, unsigned numInits,
1354                           SourceLocation rbraceloc)
1355  : Expr(InitListExprClass, QualType(), VK_RValue, OK_Ordinary, false, false,
1356         false, false),
1357    InitExprs(C, numInits),
1358    LBraceLoc(lbraceloc), RBraceLoc(rbraceloc), SyntacticForm(0),
1359    HadArrayRangeDesignator(false)
1360{
1361  for (unsigned I = 0; I != numInits; ++I) {
1362    if (initExprs[I]->isTypeDependent())
1363      ExprBits.TypeDependent = true;
1364    if (initExprs[I]->isValueDependent())
1365      ExprBits.ValueDependent = true;
1366    if (initExprs[I]->isInstantiationDependent())
1367      ExprBits.InstantiationDependent = true;
1368    if (initExprs[I]->containsUnexpandedParameterPack())
1369      ExprBits.ContainsUnexpandedParameterPack = true;
1370  }
1371
1372  InitExprs.insert(C, InitExprs.end(), initExprs, initExprs+numInits);
1373}
1374
1375void InitListExpr::reserveInits(ASTContext &C, unsigned NumInits) {
1376  if (NumInits > InitExprs.size())
1377    InitExprs.reserve(C, NumInits);
1378}
1379
1380void InitListExpr::resizeInits(ASTContext &C, unsigned NumInits) {
1381  InitExprs.resize(C, NumInits, 0);
1382}
1383
1384Expr *InitListExpr::updateInit(ASTContext &C, unsigned Init, Expr *expr) {
1385  if (Init >= InitExprs.size()) {
1386    InitExprs.insert(C, InitExprs.end(), Init - InitExprs.size() + 1, 0);
1387    InitExprs.back() = expr;
1388    return 0;
1389  }
1390
1391  Expr *Result = cast_or_null<Expr>(InitExprs[Init]);
1392  InitExprs[Init] = expr;
1393  return Result;
1394}
1395
1396void InitListExpr::setArrayFiller(Expr *filler) {
1397  ArrayFillerOrUnionFieldInit = filler;
1398  // Fill out any "holes" in the array due to designated initializers.
1399  Expr **inits = getInits();
1400  for (unsigned i = 0, e = getNumInits(); i != e; ++i)
1401    if (inits[i] == 0)
1402      inits[i] = filler;
1403}
1404
1405SourceRange InitListExpr::getSourceRange() const {
1406  if (SyntacticForm)
1407    return SyntacticForm->getSourceRange();
1408  SourceLocation Beg = LBraceLoc, End = RBraceLoc;
1409  if (Beg.isInvalid()) {
1410    // Find the first non-null initializer.
1411    for (InitExprsTy::const_iterator I = InitExprs.begin(),
1412                                     E = InitExprs.end();
1413      I != E; ++I) {
1414      if (Stmt *S = *I) {
1415        Beg = S->getLocStart();
1416        break;
1417      }
1418    }
1419  }
1420  if (End.isInvalid()) {
1421    // Find the first non-null initializer from the end.
1422    for (InitExprsTy::const_reverse_iterator I = InitExprs.rbegin(),
1423                                             E = InitExprs.rend();
1424      I != E; ++I) {
1425      if (Stmt *S = *I) {
1426        End = S->getSourceRange().getEnd();
1427        break;
1428      }
1429    }
1430  }
1431  return SourceRange(Beg, End);
1432}
1433
1434/// getFunctionType - Return the underlying function type for this block.
1435///
1436const FunctionType *BlockExpr::getFunctionType() const {
1437  return getType()->getAs<BlockPointerType>()->
1438                    getPointeeType()->getAs<FunctionType>();
1439}
1440
1441SourceLocation BlockExpr::getCaretLocation() const {
1442  return TheBlock->getCaretLocation();
1443}
1444const Stmt *BlockExpr::getBody() const {
1445  return TheBlock->getBody();
1446}
1447Stmt *BlockExpr::getBody() {
1448  return TheBlock->getBody();
1449}
1450
1451
1452//===----------------------------------------------------------------------===//
1453// Generic Expression Routines
1454//===----------------------------------------------------------------------===//
1455
1456/// isUnusedResultAWarning - Return true if this immediate expression should
1457/// be warned about if the result is unused.  If so, fill in Loc and Ranges
1458/// with location to warn on and the source range[s] to report with the
1459/// warning.
1460bool Expr::isUnusedResultAWarning(SourceLocation &Loc, SourceRange &R1,
1461                                  SourceRange &R2, ASTContext &Ctx) const {
1462  // Don't warn if the expr is type dependent. The type could end up
1463  // instantiating to void.
1464  if (isTypeDependent())
1465    return false;
1466
1467  switch (getStmtClass()) {
1468  default:
1469    if (getType()->isVoidType())
1470      return false;
1471    Loc = getExprLoc();
1472    R1 = getSourceRange();
1473    return true;
1474  case ParenExprClass:
1475    return cast<ParenExpr>(this)->getSubExpr()->
1476      isUnusedResultAWarning(Loc, R1, R2, Ctx);
1477  case GenericSelectionExprClass:
1478    return cast<GenericSelectionExpr>(this)->getResultExpr()->
1479      isUnusedResultAWarning(Loc, R1, R2, Ctx);
1480  case UnaryOperatorClass: {
1481    const UnaryOperator *UO = cast<UnaryOperator>(this);
1482
1483    switch (UO->getOpcode()) {
1484    default: break;
1485    case UO_PostInc:
1486    case UO_PostDec:
1487    case UO_PreInc:
1488    case UO_PreDec:                 // ++/--
1489      return false;  // Not a warning.
1490    case UO_Deref:
1491      // Dereferencing a volatile pointer is a side-effect.
1492      if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1493        return false;
1494      break;
1495    case UO_Real:
1496    case UO_Imag:
1497      // accessing a piece of a volatile complex is a side-effect.
1498      if (Ctx.getCanonicalType(UO->getSubExpr()->getType())
1499          .isVolatileQualified())
1500        return false;
1501      break;
1502    case UO_Extension:
1503      return UO->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1504    }
1505    Loc = UO->getOperatorLoc();
1506    R1 = UO->getSubExpr()->getSourceRange();
1507    return true;
1508  }
1509  case BinaryOperatorClass: {
1510    const BinaryOperator *BO = cast<BinaryOperator>(this);
1511    switch (BO->getOpcode()) {
1512      default:
1513        break;
1514      // Consider the RHS of comma for side effects. LHS was checked by
1515      // Sema::CheckCommaOperands.
1516      case BO_Comma:
1517        // ((foo = <blah>), 0) is an idiom for hiding the result (and
1518        // lvalue-ness) of an assignment written in a macro.
1519        if (IntegerLiteral *IE =
1520              dyn_cast<IntegerLiteral>(BO->getRHS()->IgnoreParens()))
1521          if (IE->getValue() == 0)
1522            return false;
1523        return BO->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1524      // Consider '||', '&&' to have side effects if the LHS or RHS does.
1525      case BO_LAnd:
1526      case BO_LOr:
1527        if (!BO->getLHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx) ||
1528            !BO->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx))
1529          return false;
1530        break;
1531    }
1532    if (BO->isAssignmentOp())
1533      return false;
1534    Loc = BO->getOperatorLoc();
1535    R1 = BO->getLHS()->getSourceRange();
1536    R2 = BO->getRHS()->getSourceRange();
1537    return true;
1538  }
1539  case CompoundAssignOperatorClass:
1540  case VAArgExprClass:
1541  case AtomicExprClass:
1542    return false;
1543
1544  case ConditionalOperatorClass: {
1545    // If only one of the LHS or RHS is a warning, the operator might
1546    // be being used for control flow. Only warn if both the LHS and
1547    // RHS are warnings.
1548    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
1549    if (!Exp->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx))
1550      return false;
1551    if (!Exp->getLHS())
1552      return true;
1553    return Exp->getLHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1554  }
1555
1556  case MemberExprClass:
1557    // If the base pointer or element is to a volatile pointer/field, accessing
1558    // it is a side effect.
1559    if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1560      return false;
1561    Loc = cast<MemberExpr>(this)->getMemberLoc();
1562    R1 = SourceRange(Loc, Loc);
1563    R2 = cast<MemberExpr>(this)->getBase()->getSourceRange();
1564    return true;
1565
1566  case ArraySubscriptExprClass:
1567    // If the base pointer or element is to a volatile pointer/field, accessing
1568    // it is a side effect.
1569    if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1570      return false;
1571    Loc = cast<ArraySubscriptExpr>(this)->getRBracketLoc();
1572    R1 = cast<ArraySubscriptExpr>(this)->getLHS()->getSourceRange();
1573    R2 = cast<ArraySubscriptExpr>(this)->getRHS()->getSourceRange();
1574    return true;
1575
1576  case CXXOperatorCallExprClass: {
1577    // We warn about operator== and operator!= even when user-defined operator
1578    // overloads as there is no reasonable way to define these such that they
1579    // have non-trivial, desirable side-effects. See the -Wunused-comparison
1580    // warning: these operators are commonly typo'ed, and so warning on them
1581    // provides additional value as well. If this list is updated,
1582    // DiagnoseUnusedComparison should be as well.
1583    const CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(this);
1584    if (Op->getOperator() == OO_EqualEqual ||
1585        Op->getOperator() == OO_ExclaimEqual) {
1586      Loc = Op->getOperatorLoc();
1587      R1 = Op->getSourceRange();
1588      return true;
1589    }
1590
1591    // Fallthrough for generic call handling.
1592  }
1593  case CallExprClass:
1594  case CXXMemberCallExprClass: {
1595    // If this is a direct call, get the callee.
1596    const CallExpr *CE = cast<CallExpr>(this);
1597    if (const Decl *FD = CE->getCalleeDecl()) {
1598      // If the callee has attribute pure, const, or warn_unused_result, warn
1599      // about it. void foo() { strlen("bar"); } should warn.
1600      //
1601      // Note: If new cases are added here, DiagnoseUnusedExprResult should be
1602      // updated to match for QoI.
1603      if (FD->getAttr<WarnUnusedResultAttr>() ||
1604          FD->getAttr<PureAttr>() || FD->getAttr<ConstAttr>()) {
1605        Loc = CE->getCallee()->getLocStart();
1606        R1 = CE->getCallee()->getSourceRange();
1607
1608        if (unsigned NumArgs = CE->getNumArgs())
1609          R2 = SourceRange(CE->getArg(0)->getLocStart(),
1610                           CE->getArg(NumArgs-1)->getLocEnd());
1611        return true;
1612      }
1613    }
1614    return false;
1615  }
1616
1617  case CXXTemporaryObjectExprClass:
1618  case CXXConstructExprClass:
1619    return false;
1620
1621  case ObjCMessageExprClass: {
1622    const ObjCMessageExpr *ME = cast<ObjCMessageExpr>(this);
1623    if (Ctx.getLangOptions().ObjCAutoRefCount &&
1624        ME->isInstanceMessage() &&
1625        !ME->getType()->isVoidType() &&
1626        ME->getSelector().getIdentifierInfoForSlot(0) &&
1627        ME->getSelector().getIdentifierInfoForSlot(0)
1628                                               ->getName().startswith("init")) {
1629      Loc = getExprLoc();
1630      R1 = ME->getSourceRange();
1631      return true;
1632    }
1633
1634    const ObjCMethodDecl *MD = ME->getMethodDecl();
1635    if (MD && MD->getAttr<WarnUnusedResultAttr>()) {
1636      Loc = getExprLoc();
1637      return true;
1638    }
1639    return false;
1640  }
1641
1642  case ObjCPropertyRefExprClass:
1643    Loc = getExprLoc();
1644    R1 = getSourceRange();
1645    return true;
1646
1647  case StmtExprClass: {
1648    // Statement exprs don't logically have side effects themselves, but are
1649    // sometimes used in macros in ways that give them a type that is unused.
1650    // For example ({ blah; foo(); }) will end up with a type if foo has a type.
1651    // however, if the result of the stmt expr is dead, we don't want to emit a
1652    // warning.
1653    const CompoundStmt *CS = cast<StmtExpr>(this)->getSubStmt();
1654    if (!CS->body_empty()) {
1655      if (const Expr *E = dyn_cast<Expr>(CS->body_back()))
1656        return E->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1657      if (const LabelStmt *Label = dyn_cast<LabelStmt>(CS->body_back()))
1658        if (const Expr *E = dyn_cast<Expr>(Label->getSubStmt()))
1659          return E->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1660    }
1661
1662    if (getType()->isVoidType())
1663      return false;
1664    Loc = cast<StmtExpr>(this)->getLParenLoc();
1665    R1 = getSourceRange();
1666    return true;
1667  }
1668  case CStyleCastExprClass:
1669    // If this is an explicit cast to void, allow it.  People do this when they
1670    // think they know what they're doing :).
1671    if (getType()->isVoidType())
1672      return false;
1673    Loc = cast<CStyleCastExpr>(this)->getLParenLoc();
1674    R1 = cast<CStyleCastExpr>(this)->getSubExpr()->getSourceRange();
1675    return true;
1676  case CXXFunctionalCastExprClass: {
1677    if (getType()->isVoidType())
1678      return false;
1679    const CastExpr *CE = cast<CastExpr>(this);
1680
1681    // If this is a cast to void or a constructor conversion, check the operand.
1682    // Otherwise, the result of the cast is unused.
1683    if (CE->getCastKind() == CK_ToVoid ||
1684        CE->getCastKind() == CK_ConstructorConversion)
1685      return (cast<CastExpr>(this)->getSubExpr()
1686              ->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1687    Loc = cast<CXXFunctionalCastExpr>(this)->getTypeBeginLoc();
1688    R1 = cast<CXXFunctionalCastExpr>(this)->getSubExpr()->getSourceRange();
1689    return true;
1690  }
1691
1692  case ImplicitCastExprClass:
1693    // Check the operand, since implicit casts are inserted by Sema
1694    return (cast<ImplicitCastExpr>(this)
1695            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1696
1697  case CXXDefaultArgExprClass:
1698    return (cast<CXXDefaultArgExpr>(this)
1699            ->getExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1700
1701  case CXXNewExprClass:
1702    // FIXME: In theory, there might be new expressions that don't have side
1703    // effects (e.g. a placement new with an uninitialized POD).
1704  case CXXDeleteExprClass:
1705    return false;
1706  case CXXBindTemporaryExprClass:
1707    return (cast<CXXBindTemporaryExpr>(this)
1708            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1709  case ExprWithCleanupsClass:
1710    return (cast<ExprWithCleanups>(this)
1711            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1712  }
1713}
1714
1715/// isOBJCGCCandidate - Check if an expression is objc gc'able.
1716/// returns true, if it is; false otherwise.
1717bool Expr::isOBJCGCCandidate(ASTContext &Ctx) const {
1718  const Expr *E = IgnoreParens();
1719  switch (E->getStmtClass()) {
1720  default:
1721    return false;
1722  case ObjCIvarRefExprClass:
1723    return true;
1724  case Expr::UnaryOperatorClass:
1725    return cast<UnaryOperator>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1726  case ImplicitCastExprClass:
1727    return cast<ImplicitCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1728  case MaterializeTemporaryExprClass:
1729    return cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr()
1730                                                      ->isOBJCGCCandidate(Ctx);
1731  case CStyleCastExprClass:
1732    return cast<CStyleCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1733  case BlockDeclRefExprClass:
1734  case DeclRefExprClass: {
1735
1736    const Decl *D;
1737    if (const BlockDeclRefExpr *BDRE = dyn_cast<BlockDeclRefExpr>(E))
1738        D = BDRE->getDecl();
1739    else
1740        D = cast<DeclRefExpr>(E)->getDecl();
1741
1742    if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1743      if (VD->hasGlobalStorage())
1744        return true;
1745      QualType T = VD->getType();
1746      // dereferencing to a  pointer is always a gc'able candidate,
1747      // unless it is __weak.
1748      return T->isPointerType() &&
1749             (Ctx.getObjCGCAttrKind(T) != Qualifiers::Weak);
1750    }
1751    return false;
1752  }
1753  case MemberExprClass: {
1754    const MemberExpr *M = cast<MemberExpr>(E);
1755    return M->getBase()->isOBJCGCCandidate(Ctx);
1756  }
1757  case ArraySubscriptExprClass:
1758    return cast<ArraySubscriptExpr>(E)->getBase()->isOBJCGCCandidate(Ctx);
1759  }
1760}
1761
1762bool Expr::isBoundMemberFunction(ASTContext &Ctx) const {
1763  if (isTypeDependent())
1764    return false;
1765  return ClassifyLValue(Ctx) == Expr::LV_MemberFunction;
1766}
1767
1768QualType Expr::findBoundMemberType(const Expr *expr) {
1769  assert(expr->getType()->isSpecificPlaceholderType(BuiltinType::BoundMember));
1770
1771  // Bound member expressions are always one of these possibilities:
1772  //   x->m      x.m      x->*y      x.*y
1773  // (possibly parenthesized)
1774
1775  expr = expr->IgnoreParens();
1776  if (const MemberExpr *mem = dyn_cast<MemberExpr>(expr)) {
1777    assert(isa<CXXMethodDecl>(mem->getMemberDecl()));
1778    return mem->getMemberDecl()->getType();
1779  }
1780
1781  if (const BinaryOperator *op = dyn_cast<BinaryOperator>(expr)) {
1782    QualType type = op->getRHS()->getType()->castAs<MemberPointerType>()
1783                      ->getPointeeType();
1784    assert(type->isFunctionType());
1785    return type;
1786  }
1787
1788  assert(isa<UnresolvedMemberExpr>(expr));
1789  return QualType();
1790}
1791
1792static Expr::CanThrowResult MergeCanThrow(Expr::CanThrowResult CT1,
1793                                          Expr::CanThrowResult CT2) {
1794  // CanThrowResult constants are ordered so that the maximum is the correct
1795  // merge result.
1796  return CT1 > CT2 ? CT1 : CT2;
1797}
1798
1799static Expr::CanThrowResult CanSubExprsThrow(ASTContext &C, const Expr *CE) {
1800  Expr *E = const_cast<Expr*>(CE);
1801  Expr::CanThrowResult R = Expr::CT_Cannot;
1802  for (Expr::child_range I = E->children(); I && R != Expr::CT_Can; ++I) {
1803    R = MergeCanThrow(R, cast<Expr>(*I)->CanThrow(C));
1804  }
1805  return R;
1806}
1807
1808static Expr::CanThrowResult CanCalleeThrow(ASTContext &Ctx, const Expr *E,
1809                                           const Decl *D,
1810                                           bool NullThrows = true) {
1811  if (!D)
1812    return NullThrows ? Expr::CT_Can : Expr::CT_Cannot;
1813
1814  // See if we can get a function type from the decl somehow.
1815  const ValueDecl *VD = dyn_cast<ValueDecl>(D);
1816  if (!VD) // If we have no clue what we're calling, assume the worst.
1817    return Expr::CT_Can;
1818
1819  // As an extension, we assume that __attribute__((nothrow)) functions don't
1820  // throw.
1821  if (isa<FunctionDecl>(D) && D->hasAttr<NoThrowAttr>())
1822    return Expr::CT_Cannot;
1823
1824  QualType T = VD->getType();
1825  const FunctionProtoType *FT;
1826  if ((FT = T->getAs<FunctionProtoType>())) {
1827  } else if (const PointerType *PT = T->getAs<PointerType>())
1828    FT = PT->getPointeeType()->getAs<FunctionProtoType>();
1829  else if (const ReferenceType *RT = T->getAs<ReferenceType>())
1830    FT = RT->getPointeeType()->getAs<FunctionProtoType>();
1831  else if (const MemberPointerType *MT = T->getAs<MemberPointerType>())
1832    FT = MT->getPointeeType()->getAs<FunctionProtoType>();
1833  else if (const BlockPointerType *BT = T->getAs<BlockPointerType>())
1834    FT = BT->getPointeeType()->getAs<FunctionProtoType>();
1835
1836  if (!FT)
1837    return Expr::CT_Can;
1838
1839  if (FT->getExceptionSpecType() == EST_Delayed) {
1840    assert(isa<CXXConstructorDecl>(D) &&
1841           "only constructor exception specs can be unknown");
1842    Ctx.getDiagnostics().Report(E->getLocStart(),
1843                                diag::err_exception_spec_unknown)
1844      << E->getSourceRange();
1845    return Expr::CT_Can;
1846  }
1847
1848  return FT->isNothrow(Ctx) ? Expr::CT_Cannot : Expr::CT_Can;
1849}
1850
1851static Expr::CanThrowResult CanDynamicCastThrow(const CXXDynamicCastExpr *DC) {
1852  if (DC->isTypeDependent())
1853    return Expr::CT_Dependent;
1854
1855  if (!DC->getTypeAsWritten()->isReferenceType())
1856    return Expr::CT_Cannot;
1857
1858  if (DC->getSubExpr()->isTypeDependent())
1859    return Expr::CT_Dependent;
1860
1861  return DC->getCastKind() == clang::CK_Dynamic? Expr::CT_Can : Expr::CT_Cannot;
1862}
1863
1864static Expr::CanThrowResult CanTypeidThrow(ASTContext &C,
1865                                           const CXXTypeidExpr *DC) {
1866  if (DC->isTypeOperand())
1867    return Expr::CT_Cannot;
1868
1869  Expr *Op = DC->getExprOperand();
1870  if (Op->isTypeDependent())
1871    return Expr::CT_Dependent;
1872
1873  const RecordType *RT = Op->getType()->getAs<RecordType>();
1874  if (!RT)
1875    return Expr::CT_Cannot;
1876
1877  if (!cast<CXXRecordDecl>(RT->getDecl())->isPolymorphic())
1878    return Expr::CT_Cannot;
1879
1880  if (Op->Classify(C).isPRValue())
1881    return Expr::CT_Cannot;
1882
1883  return Expr::CT_Can;
1884}
1885
1886Expr::CanThrowResult Expr::CanThrow(ASTContext &C) const {
1887  // C++ [expr.unary.noexcept]p3:
1888  //   [Can throw] if in a potentially-evaluated context the expression would
1889  //   contain:
1890  switch (getStmtClass()) {
1891  case CXXThrowExprClass:
1892    //   - a potentially evaluated throw-expression
1893    return CT_Can;
1894
1895  case CXXDynamicCastExprClass: {
1896    //   - a potentially evaluated dynamic_cast expression dynamic_cast<T>(v),
1897    //     where T is a reference type, that requires a run-time check
1898    CanThrowResult CT = CanDynamicCastThrow(cast<CXXDynamicCastExpr>(this));
1899    if (CT == CT_Can)
1900      return CT;
1901    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1902  }
1903
1904  case CXXTypeidExprClass:
1905    //   - a potentially evaluated typeid expression applied to a glvalue
1906    //     expression whose type is a polymorphic class type
1907    return CanTypeidThrow(C, cast<CXXTypeidExpr>(this));
1908
1909    //   - a potentially evaluated call to a function, member function, function
1910    //     pointer, or member function pointer that does not have a non-throwing
1911    //     exception-specification
1912  case CallExprClass:
1913  case CXXOperatorCallExprClass:
1914  case CXXMemberCallExprClass: {
1915    const CallExpr *CE = cast<CallExpr>(this);
1916    CanThrowResult CT;
1917    if (isTypeDependent())
1918      CT = CT_Dependent;
1919    else if (isa<CXXPseudoDestructorExpr>(CE->getCallee()->IgnoreParens()))
1920      CT = CT_Cannot;
1921    else
1922      CT = CanCalleeThrow(C, this, CE->getCalleeDecl());
1923    if (CT == CT_Can)
1924      return CT;
1925    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1926  }
1927
1928  case CXXConstructExprClass:
1929  case CXXTemporaryObjectExprClass: {
1930    CanThrowResult CT = CanCalleeThrow(C, this,
1931        cast<CXXConstructExpr>(this)->getConstructor());
1932    if (CT == CT_Can)
1933      return CT;
1934    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1935  }
1936
1937  case CXXNewExprClass: {
1938    CanThrowResult CT;
1939    if (isTypeDependent())
1940      CT = CT_Dependent;
1941    else
1942      CT = MergeCanThrow(
1943        CanCalleeThrow(C, this, cast<CXXNewExpr>(this)->getOperatorNew()),
1944        CanCalleeThrow(C, this, cast<CXXNewExpr>(this)->getConstructor(),
1945                       /*NullThrows*/false));
1946    if (CT == CT_Can)
1947      return CT;
1948    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1949  }
1950
1951  case CXXDeleteExprClass: {
1952    CanThrowResult CT;
1953    QualType DTy = cast<CXXDeleteExpr>(this)->getDestroyedType();
1954    if (DTy.isNull() || DTy->isDependentType()) {
1955      CT = CT_Dependent;
1956    } else {
1957      CT = CanCalleeThrow(C, this,
1958                          cast<CXXDeleteExpr>(this)->getOperatorDelete());
1959      if (const RecordType *RT = DTy->getAs<RecordType>()) {
1960        const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1961        CT = MergeCanThrow(CT, CanCalleeThrow(C, this, RD->getDestructor()));
1962      }
1963      if (CT == CT_Can)
1964        return CT;
1965    }
1966    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1967  }
1968
1969  case CXXBindTemporaryExprClass: {
1970    // The bound temporary has to be destroyed again, which might throw.
1971    CanThrowResult CT = CanCalleeThrow(C, this,
1972      cast<CXXBindTemporaryExpr>(this)->getTemporary()->getDestructor());
1973    if (CT == CT_Can)
1974      return CT;
1975    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1976  }
1977
1978    // ObjC message sends are like function calls, but never have exception
1979    // specs.
1980  case ObjCMessageExprClass:
1981  case ObjCPropertyRefExprClass:
1982    return CT_Can;
1983
1984    // Many other things have subexpressions, so we have to test those.
1985    // Some are simple:
1986  case ParenExprClass:
1987  case MemberExprClass:
1988  case CXXReinterpretCastExprClass:
1989  case CXXConstCastExprClass:
1990  case ConditionalOperatorClass:
1991  case CompoundLiteralExprClass:
1992  case ExtVectorElementExprClass:
1993  case InitListExprClass:
1994  case DesignatedInitExprClass:
1995  case ParenListExprClass:
1996  case VAArgExprClass:
1997  case CXXDefaultArgExprClass:
1998  case ExprWithCleanupsClass:
1999  case ObjCIvarRefExprClass:
2000  case ObjCIsaExprClass:
2001  case ShuffleVectorExprClass:
2002    return CanSubExprsThrow(C, this);
2003
2004    // Some might be dependent for other reasons.
2005  case UnaryOperatorClass:
2006  case ArraySubscriptExprClass:
2007  case ImplicitCastExprClass:
2008  case CStyleCastExprClass:
2009  case CXXStaticCastExprClass:
2010  case CXXFunctionalCastExprClass:
2011  case BinaryOperatorClass:
2012  case CompoundAssignOperatorClass:
2013  case MaterializeTemporaryExprClass: {
2014    CanThrowResult CT = isTypeDependent() ? CT_Dependent : CT_Cannot;
2015    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
2016  }
2017
2018    // FIXME: We should handle StmtExpr, but that opens a MASSIVE can of worms.
2019  case StmtExprClass:
2020    return CT_Can;
2021
2022  case ChooseExprClass:
2023    if (isTypeDependent() || isValueDependent())
2024      return CT_Dependent;
2025    return cast<ChooseExpr>(this)->getChosenSubExpr(C)->CanThrow(C);
2026
2027  case GenericSelectionExprClass:
2028    if (cast<GenericSelectionExpr>(this)->isResultDependent())
2029      return CT_Dependent;
2030    return cast<GenericSelectionExpr>(this)->getResultExpr()->CanThrow(C);
2031
2032    // Some expressions are always dependent.
2033  case DependentScopeDeclRefExprClass:
2034  case CXXUnresolvedConstructExprClass:
2035  case CXXDependentScopeMemberExprClass:
2036    return CT_Dependent;
2037
2038  default:
2039    // All other expressions don't have subexpressions, or else they are
2040    // unevaluated.
2041    return CT_Cannot;
2042  }
2043}
2044
2045Expr* Expr::IgnoreParens() {
2046  Expr* E = this;
2047  while (true) {
2048    if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
2049      E = P->getSubExpr();
2050      continue;
2051    }
2052    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2053      if (P->getOpcode() == UO_Extension) {
2054        E = P->getSubExpr();
2055        continue;
2056      }
2057    }
2058    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2059      if (!P->isResultDependent()) {
2060        E = P->getResultExpr();
2061        continue;
2062      }
2063    }
2064    return E;
2065  }
2066}
2067
2068/// IgnoreParenCasts - Ignore parentheses and casts.  Strip off any ParenExpr
2069/// or CastExprs or ImplicitCastExprs, returning their operand.
2070Expr *Expr::IgnoreParenCasts() {
2071  Expr *E = this;
2072  while (true) {
2073    if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
2074      E = P->getSubExpr();
2075      continue;
2076    }
2077    if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2078      E = P->getSubExpr();
2079      continue;
2080    }
2081    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2082      if (P->getOpcode() == UO_Extension) {
2083        E = P->getSubExpr();
2084        continue;
2085      }
2086    }
2087    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2088      if (!P->isResultDependent()) {
2089        E = P->getResultExpr();
2090        continue;
2091      }
2092    }
2093    if (MaterializeTemporaryExpr *Materialize
2094                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2095      E = Materialize->GetTemporaryExpr();
2096      continue;
2097    }
2098    if (SubstNonTypeTemplateParmExpr *NTTP
2099                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2100      E = NTTP->getReplacement();
2101      continue;
2102    }
2103    return E;
2104  }
2105}
2106
2107/// IgnoreParenLValueCasts - Ignore parentheses and lvalue-to-rvalue
2108/// casts.  This is intended purely as a temporary workaround for code
2109/// that hasn't yet been rewritten to do the right thing about those
2110/// casts, and may disappear along with the last internal use.
2111Expr *Expr::IgnoreParenLValueCasts() {
2112  Expr *E = this;
2113  while (true) {
2114    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2115      E = P->getSubExpr();
2116      continue;
2117    } else if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2118      if (P->getCastKind() == CK_LValueToRValue) {
2119        E = P->getSubExpr();
2120        continue;
2121      }
2122    } else if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2123      if (P->getOpcode() == UO_Extension) {
2124        E = P->getSubExpr();
2125        continue;
2126      }
2127    } else if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2128      if (!P->isResultDependent()) {
2129        E = P->getResultExpr();
2130        continue;
2131      }
2132    } else if (MaterializeTemporaryExpr *Materialize
2133                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2134      E = Materialize->GetTemporaryExpr();
2135      continue;
2136    } else if (SubstNonTypeTemplateParmExpr *NTTP
2137                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2138      E = NTTP->getReplacement();
2139      continue;
2140    }
2141    break;
2142  }
2143  return E;
2144}
2145
2146Expr *Expr::IgnoreParenImpCasts() {
2147  Expr *E = this;
2148  while (true) {
2149    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2150      E = P->getSubExpr();
2151      continue;
2152    }
2153    if (ImplicitCastExpr *P = dyn_cast<ImplicitCastExpr>(E)) {
2154      E = P->getSubExpr();
2155      continue;
2156    }
2157    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2158      if (P->getOpcode() == UO_Extension) {
2159        E = P->getSubExpr();
2160        continue;
2161      }
2162    }
2163    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2164      if (!P->isResultDependent()) {
2165        E = P->getResultExpr();
2166        continue;
2167      }
2168    }
2169    if (MaterializeTemporaryExpr *Materialize
2170                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2171      E = Materialize->GetTemporaryExpr();
2172      continue;
2173    }
2174    if (SubstNonTypeTemplateParmExpr *NTTP
2175                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2176      E = NTTP->getReplacement();
2177      continue;
2178    }
2179    return E;
2180  }
2181}
2182
2183Expr *Expr::IgnoreConversionOperator() {
2184  if (CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(this)) {
2185    if (MCE->getMethodDecl() && isa<CXXConversionDecl>(MCE->getMethodDecl()))
2186      return MCE->getImplicitObjectArgument();
2187  }
2188  return this;
2189}
2190
2191/// IgnoreParenNoopCasts - Ignore parentheses and casts that do not change the
2192/// value (including ptr->int casts of the same size).  Strip off any
2193/// ParenExpr or CastExprs, returning their operand.
2194Expr *Expr::IgnoreParenNoopCasts(ASTContext &Ctx) {
2195  Expr *E = this;
2196  while (true) {
2197    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2198      E = P->getSubExpr();
2199      continue;
2200    }
2201
2202    if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2203      // We ignore integer <-> casts that are of the same width, ptr<->ptr and
2204      // ptr<->int casts of the same width.  We also ignore all identity casts.
2205      Expr *SE = P->getSubExpr();
2206
2207      if (Ctx.hasSameUnqualifiedType(E->getType(), SE->getType())) {
2208        E = SE;
2209        continue;
2210      }
2211
2212      if ((E->getType()->isPointerType() ||
2213           E->getType()->isIntegralType(Ctx)) &&
2214          (SE->getType()->isPointerType() ||
2215           SE->getType()->isIntegralType(Ctx)) &&
2216          Ctx.getTypeSize(E->getType()) == Ctx.getTypeSize(SE->getType())) {
2217        E = SE;
2218        continue;
2219      }
2220    }
2221
2222    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2223      if (P->getOpcode() == UO_Extension) {
2224        E = P->getSubExpr();
2225        continue;
2226      }
2227    }
2228
2229    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2230      if (!P->isResultDependent()) {
2231        E = P->getResultExpr();
2232        continue;
2233      }
2234    }
2235
2236    if (SubstNonTypeTemplateParmExpr *NTTP
2237                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2238      E = NTTP->getReplacement();
2239      continue;
2240    }
2241
2242    return E;
2243  }
2244}
2245
2246bool Expr::isDefaultArgument() const {
2247  const Expr *E = this;
2248  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
2249    E = M->GetTemporaryExpr();
2250
2251  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
2252    E = ICE->getSubExprAsWritten();
2253
2254  return isa<CXXDefaultArgExpr>(E);
2255}
2256
2257/// \brief Skip over any no-op casts and any temporary-binding
2258/// expressions.
2259static const Expr *skipTemporaryBindingsNoOpCastsAndParens(const Expr *E) {
2260  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
2261    E = M->GetTemporaryExpr();
2262
2263  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2264    if (ICE->getCastKind() == CK_NoOp)
2265      E = ICE->getSubExpr();
2266    else
2267      break;
2268  }
2269
2270  while (const CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(E))
2271    E = BE->getSubExpr();
2272
2273  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2274    if (ICE->getCastKind() == CK_NoOp)
2275      E = ICE->getSubExpr();
2276    else
2277      break;
2278  }
2279
2280  return E->IgnoreParens();
2281}
2282
2283/// isTemporaryObject - Determines if this expression produces a
2284/// temporary of the given class type.
2285bool Expr::isTemporaryObject(ASTContext &C, const CXXRecordDecl *TempTy) const {
2286  if (!C.hasSameUnqualifiedType(getType(), C.getTypeDeclType(TempTy)))
2287    return false;
2288
2289  const Expr *E = skipTemporaryBindingsNoOpCastsAndParens(this);
2290
2291  // Temporaries are by definition pr-values of class type.
2292  if (!E->Classify(C).isPRValue()) {
2293    // In this context, property reference is a message call and is pr-value.
2294    if (!isa<ObjCPropertyRefExpr>(E))
2295      return false;
2296  }
2297
2298  // Black-list a few cases which yield pr-values of class type that don't
2299  // refer to temporaries of that type:
2300
2301  // - implicit derived-to-base conversions
2302  if (isa<ImplicitCastExpr>(E)) {
2303    switch (cast<ImplicitCastExpr>(E)->getCastKind()) {
2304    case CK_DerivedToBase:
2305    case CK_UncheckedDerivedToBase:
2306      return false;
2307    default:
2308      break;
2309    }
2310  }
2311
2312  // - member expressions (all)
2313  if (isa<MemberExpr>(E))
2314    return false;
2315
2316  // - opaque values (all)
2317  if (isa<OpaqueValueExpr>(E))
2318    return false;
2319
2320  return true;
2321}
2322
2323bool Expr::isImplicitCXXThis() const {
2324  const Expr *E = this;
2325
2326  // Strip away parentheses and casts we don't care about.
2327  while (true) {
2328    if (const ParenExpr *Paren = dyn_cast<ParenExpr>(E)) {
2329      E = Paren->getSubExpr();
2330      continue;
2331    }
2332
2333    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2334      if (ICE->getCastKind() == CK_NoOp ||
2335          ICE->getCastKind() == CK_LValueToRValue ||
2336          ICE->getCastKind() == CK_DerivedToBase ||
2337          ICE->getCastKind() == CK_UncheckedDerivedToBase) {
2338        E = ICE->getSubExpr();
2339        continue;
2340      }
2341    }
2342
2343    if (const UnaryOperator* UnOp = dyn_cast<UnaryOperator>(E)) {
2344      if (UnOp->getOpcode() == UO_Extension) {
2345        E = UnOp->getSubExpr();
2346        continue;
2347      }
2348    }
2349
2350    if (const MaterializeTemporaryExpr *M
2351                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2352      E = M->GetTemporaryExpr();
2353      continue;
2354    }
2355
2356    break;
2357  }
2358
2359  if (const CXXThisExpr *This = dyn_cast<CXXThisExpr>(E))
2360    return This->isImplicit();
2361
2362  return false;
2363}
2364
2365/// hasAnyTypeDependentArguments - Determines if any of the expressions
2366/// in Exprs is type-dependent.
2367bool Expr::hasAnyTypeDependentArguments(Expr** Exprs, unsigned NumExprs) {
2368  for (unsigned I = 0; I < NumExprs; ++I)
2369    if (Exprs[I]->isTypeDependent())
2370      return true;
2371
2372  return false;
2373}
2374
2375/// hasAnyValueDependentArguments - Determines if any of the expressions
2376/// in Exprs is value-dependent.
2377bool Expr::hasAnyValueDependentArguments(Expr** Exprs, unsigned NumExprs) {
2378  for (unsigned I = 0; I < NumExprs; ++I)
2379    if (Exprs[I]->isValueDependent())
2380      return true;
2381
2382  return false;
2383}
2384
2385bool Expr::isConstantInitializer(ASTContext &Ctx, bool IsForRef) const {
2386  // This function is attempting whether an expression is an initializer
2387  // which can be evaluated at compile-time.  isEvaluatable handles most
2388  // of the cases, but it can't deal with some initializer-specific
2389  // expressions, and it can't deal with aggregates; we deal with those here,
2390  // and fall back to isEvaluatable for the other cases.
2391
2392  // If we ever capture reference-binding directly in the AST, we can
2393  // kill the second parameter.
2394
2395  if (IsForRef) {
2396    EvalResult Result;
2397    return EvaluateAsLValue(Result, Ctx) && !Result.HasSideEffects;
2398  }
2399
2400  switch (getStmtClass()) {
2401  default: break;
2402  case StringLiteralClass:
2403  case ObjCStringLiteralClass:
2404  case ObjCEncodeExprClass:
2405    return true;
2406  case CXXTemporaryObjectExprClass:
2407  case CXXConstructExprClass: {
2408    const CXXConstructExpr *CE = cast<CXXConstructExpr>(this);
2409
2410    // Only if it's
2411    // 1) an application of the trivial default constructor or
2412    if (!CE->getConstructor()->isTrivial()) return false;
2413    if (!CE->getNumArgs()) return true;
2414
2415    // 2) an elidable trivial copy construction of an operand which is
2416    //    itself a constant initializer.  Note that we consider the
2417    //    operand on its own, *not* as a reference binding.
2418    return CE->isElidable() &&
2419           CE->getArg(0)->isConstantInitializer(Ctx, false);
2420  }
2421  case CompoundLiteralExprClass: {
2422    // This handles gcc's extension that allows global initializers like
2423    // "struct x {int x;} x = (struct x) {};".
2424    // FIXME: This accepts other cases it shouldn't!
2425    const Expr *Exp = cast<CompoundLiteralExpr>(this)->getInitializer();
2426    return Exp->isConstantInitializer(Ctx, false);
2427  }
2428  case InitListExprClass: {
2429    // FIXME: This doesn't deal with fields with reference types correctly.
2430    // FIXME: This incorrectly allows pointers cast to integers to be assigned
2431    // to bitfields.
2432    const InitListExpr *Exp = cast<InitListExpr>(this);
2433    unsigned numInits = Exp->getNumInits();
2434    for (unsigned i = 0; i < numInits; i++) {
2435      if (!Exp->getInit(i)->isConstantInitializer(Ctx, false))
2436        return false;
2437    }
2438    return true;
2439  }
2440  case ImplicitValueInitExprClass:
2441    return true;
2442  case ParenExprClass:
2443    return cast<ParenExpr>(this)->getSubExpr()
2444      ->isConstantInitializer(Ctx, IsForRef);
2445  case GenericSelectionExprClass:
2446    if (cast<GenericSelectionExpr>(this)->isResultDependent())
2447      return false;
2448    return cast<GenericSelectionExpr>(this)->getResultExpr()
2449      ->isConstantInitializer(Ctx, IsForRef);
2450  case ChooseExprClass:
2451    return cast<ChooseExpr>(this)->getChosenSubExpr(Ctx)
2452      ->isConstantInitializer(Ctx, IsForRef);
2453  case UnaryOperatorClass: {
2454    const UnaryOperator* Exp = cast<UnaryOperator>(this);
2455    if (Exp->getOpcode() == UO_Extension)
2456      return Exp->getSubExpr()->isConstantInitializer(Ctx, false);
2457    break;
2458  }
2459  case BinaryOperatorClass: {
2460    // Special case &&foo - &&bar.  It would be nice to generalize this somehow
2461    // but this handles the common case.
2462    const BinaryOperator *Exp = cast<BinaryOperator>(this);
2463    if (Exp->getOpcode() == BO_Sub &&
2464        isa<AddrLabelExpr>(Exp->getLHS()->IgnoreParenNoopCasts(Ctx)) &&
2465        isa<AddrLabelExpr>(Exp->getRHS()->IgnoreParenNoopCasts(Ctx)))
2466      return true;
2467    break;
2468  }
2469  case CXXFunctionalCastExprClass:
2470  case CXXStaticCastExprClass:
2471  case ImplicitCastExprClass:
2472  case CStyleCastExprClass:
2473    // Handle casts with a destination that's a struct or union; this
2474    // deals with both the gcc no-op struct cast extension and the
2475    // cast-to-union extension.
2476    if (getType()->isRecordType())
2477      return cast<CastExpr>(this)->getSubExpr()
2478        ->isConstantInitializer(Ctx, false);
2479
2480    // Integer->integer casts can be handled here, which is important for
2481    // things like (int)(&&x-&&y).  Scary but true.
2482    if (getType()->isIntegerType() &&
2483        cast<CastExpr>(this)->getSubExpr()->getType()->isIntegerType())
2484      return cast<CastExpr>(this)->getSubExpr()
2485        ->isConstantInitializer(Ctx, false);
2486
2487    break;
2488
2489  case MaterializeTemporaryExprClass:
2490    return cast<MaterializeTemporaryExpr>(this)->GetTemporaryExpr()
2491                                            ->isConstantInitializer(Ctx, false);
2492  }
2493  return isEvaluatable(Ctx);
2494}
2495
2496/// isNullPointerConstant - C99 6.3.2.3p3 - Return whether this is a null
2497/// pointer constant or not, as well as the specific kind of constant detected.
2498/// Null pointer constants can be integer constant expressions with the
2499/// value zero, casts of zero to void*, nullptr (C++0X), or __null
2500/// (a GNU extension).
2501Expr::NullPointerConstantKind
2502Expr::isNullPointerConstant(ASTContext &Ctx,
2503                            NullPointerConstantValueDependence NPC) const {
2504  if (isValueDependent()) {
2505    switch (NPC) {
2506    case NPC_NeverValueDependent:
2507      llvm_unreachable("Unexpected value dependent expression!");
2508    case NPC_ValueDependentIsNull:
2509      if (isTypeDependent() || getType()->isIntegralType(Ctx))
2510        return NPCK_ZeroInteger;
2511      else
2512        return NPCK_NotNull;
2513
2514    case NPC_ValueDependentIsNotNull:
2515      return NPCK_NotNull;
2516    }
2517  }
2518
2519  // Strip off a cast to void*, if it exists. Except in C++.
2520  if (const ExplicitCastExpr *CE = dyn_cast<ExplicitCastExpr>(this)) {
2521    if (!Ctx.getLangOptions().CPlusPlus) {
2522      // Check that it is a cast to void*.
2523      if (const PointerType *PT = CE->getType()->getAs<PointerType>()) {
2524        QualType Pointee = PT->getPointeeType();
2525        if (!Pointee.hasQualifiers() &&
2526            Pointee->isVoidType() &&                              // to void*
2527            CE->getSubExpr()->getType()->isIntegerType())         // from int.
2528          return CE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2529      }
2530    }
2531  } else if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(this)) {
2532    // Ignore the ImplicitCastExpr type entirely.
2533    return ICE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2534  } else if (const ParenExpr *PE = dyn_cast<ParenExpr>(this)) {
2535    // Accept ((void*)0) as a null pointer constant, as many other
2536    // implementations do.
2537    return PE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2538  } else if (const GenericSelectionExpr *GE =
2539               dyn_cast<GenericSelectionExpr>(this)) {
2540    return GE->getResultExpr()->isNullPointerConstant(Ctx, NPC);
2541  } else if (const CXXDefaultArgExpr *DefaultArg
2542               = dyn_cast<CXXDefaultArgExpr>(this)) {
2543    // See through default argument expressions
2544    return DefaultArg->getExpr()->isNullPointerConstant(Ctx, NPC);
2545  } else if (isa<GNUNullExpr>(this)) {
2546    // The GNU __null extension is always a null pointer constant.
2547    return NPCK_GNUNull;
2548  } else if (const MaterializeTemporaryExpr *M
2549                                   = dyn_cast<MaterializeTemporaryExpr>(this)) {
2550    return M->GetTemporaryExpr()->isNullPointerConstant(Ctx, NPC);
2551  }
2552
2553  // C++0x nullptr_t is always a null pointer constant.
2554  if (getType()->isNullPtrType())
2555    return NPCK_CXX0X_nullptr;
2556
2557  if (const RecordType *UT = getType()->getAsUnionType())
2558    if (UT && UT->getDecl()->hasAttr<TransparentUnionAttr>())
2559      if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(this)){
2560        const Expr *InitExpr = CLE->getInitializer();
2561        if (const InitListExpr *ILE = dyn_cast<InitListExpr>(InitExpr))
2562          return ILE->getInit(0)->isNullPointerConstant(Ctx, NPC);
2563      }
2564  // This expression must be an integer type.
2565  if (!getType()->isIntegerType() ||
2566      (Ctx.getLangOptions().CPlusPlus && getType()->isEnumeralType()))
2567    return NPCK_NotNull;
2568
2569  // If we have an integer constant expression, we need to *evaluate* it and
2570  // test for the value 0.
2571  llvm::APSInt Result;
2572  bool IsNull = isIntegerConstantExpr(Result, Ctx) && Result == 0;
2573
2574  return (IsNull ? NPCK_ZeroInteger : NPCK_NotNull);
2575}
2576
2577/// \brief If this expression is an l-value for an Objective C
2578/// property, find the underlying property reference expression.
2579const ObjCPropertyRefExpr *Expr::getObjCProperty() const {
2580  const Expr *E = this;
2581  while (true) {
2582    assert((E->getValueKind() == VK_LValue &&
2583            E->getObjectKind() == OK_ObjCProperty) &&
2584           "expression is not a property reference");
2585    E = E->IgnoreParenCasts();
2586    if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
2587      if (BO->getOpcode() == BO_Comma) {
2588        E = BO->getRHS();
2589        continue;
2590      }
2591    }
2592
2593    break;
2594  }
2595
2596  return cast<ObjCPropertyRefExpr>(E);
2597}
2598
2599FieldDecl *Expr::getBitField() {
2600  Expr *E = this->IgnoreParens();
2601
2602  while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2603    if (ICE->getCastKind() == CK_LValueToRValue ||
2604        (ICE->getValueKind() != VK_RValue && ICE->getCastKind() == CK_NoOp))
2605      E = ICE->getSubExpr()->IgnoreParens();
2606    else
2607      break;
2608  }
2609
2610  if (MemberExpr *MemRef = dyn_cast<MemberExpr>(E))
2611    if (FieldDecl *Field = dyn_cast<FieldDecl>(MemRef->getMemberDecl()))
2612      if (Field->isBitField())
2613        return Field;
2614
2615  if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E))
2616    if (FieldDecl *Field = dyn_cast<FieldDecl>(DeclRef->getDecl()))
2617      if (Field->isBitField())
2618        return Field;
2619
2620  if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E)) {
2621    if (BinOp->isAssignmentOp() && BinOp->getLHS())
2622      return BinOp->getLHS()->getBitField();
2623
2624    if (BinOp->getOpcode() == BO_Comma && BinOp->getRHS())
2625      return BinOp->getRHS()->getBitField();
2626  }
2627
2628  return 0;
2629}
2630
2631bool Expr::refersToVectorElement() const {
2632  const Expr *E = this->IgnoreParens();
2633
2634  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2635    if (ICE->getValueKind() != VK_RValue &&
2636        ICE->getCastKind() == CK_NoOp)
2637      E = ICE->getSubExpr()->IgnoreParens();
2638    else
2639      break;
2640  }
2641
2642  if (const ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(E))
2643    return ASE->getBase()->getType()->isVectorType();
2644
2645  if (isa<ExtVectorElementExpr>(E))
2646    return true;
2647
2648  return false;
2649}
2650
2651/// isArrow - Return true if the base expression is a pointer to vector,
2652/// return false if the base expression is a vector.
2653bool ExtVectorElementExpr::isArrow() const {
2654  return getBase()->getType()->isPointerType();
2655}
2656
2657unsigned ExtVectorElementExpr::getNumElements() const {
2658  if (const VectorType *VT = getType()->getAs<VectorType>())
2659    return VT->getNumElements();
2660  return 1;
2661}
2662
2663/// containsDuplicateElements - Return true if any element access is repeated.
2664bool ExtVectorElementExpr::containsDuplicateElements() const {
2665  // FIXME: Refactor this code to an accessor on the AST node which returns the
2666  // "type" of component access, and share with code below and in Sema.
2667  StringRef Comp = Accessor->getName();
2668
2669  // Halving swizzles do not contain duplicate elements.
2670  if (Comp == "hi" || Comp == "lo" || Comp == "even" || Comp == "odd")
2671    return false;
2672
2673  // Advance past s-char prefix on hex swizzles.
2674  if (Comp[0] == 's' || Comp[0] == 'S')
2675    Comp = Comp.substr(1);
2676
2677  for (unsigned i = 0, e = Comp.size(); i != e; ++i)
2678    if (Comp.substr(i + 1).find(Comp[i]) != StringRef::npos)
2679        return true;
2680
2681  return false;
2682}
2683
2684/// getEncodedElementAccess - We encode the fields as a llvm ConstantArray.
2685void ExtVectorElementExpr::getEncodedElementAccess(
2686                                  SmallVectorImpl<unsigned> &Elts) const {
2687  StringRef Comp = Accessor->getName();
2688  if (Comp[0] == 's' || Comp[0] == 'S')
2689    Comp = Comp.substr(1);
2690
2691  bool isHi =   Comp == "hi";
2692  bool isLo =   Comp == "lo";
2693  bool isEven = Comp == "even";
2694  bool isOdd  = Comp == "odd";
2695
2696  for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
2697    uint64_t Index;
2698
2699    if (isHi)
2700      Index = e + i;
2701    else if (isLo)
2702      Index = i;
2703    else if (isEven)
2704      Index = 2 * i;
2705    else if (isOdd)
2706      Index = 2 * i + 1;
2707    else
2708      Index = ExtVectorType::getAccessorIdx(Comp[i]);
2709
2710    Elts.push_back(Index);
2711  }
2712}
2713
2714ObjCMessageExpr::ObjCMessageExpr(QualType T,
2715                                 ExprValueKind VK,
2716                                 SourceLocation LBracLoc,
2717                                 SourceLocation SuperLoc,
2718                                 bool IsInstanceSuper,
2719                                 QualType SuperType,
2720                                 Selector Sel,
2721                                 ArrayRef<SourceLocation> SelLocs,
2722                                 SelectorLocationsKind SelLocsK,
2723                                 ObjCMethodDecl *Method,
2724                                 ArrayRef<Expr *> Args,
2725                                 SourceLocation RBracLoc)
2726  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary,
2727         /*TypeDependent=*/false, /*ValueDependent=*/false,
2728         /*InstantiationDependent=*/false,
2729         /*ContainsUnexpandedParameterPack=*/false),
2730    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2731                                                       : Sel.getAsOpaquePtr())),
2732    Kind(IsInstanceSuper? SuperInstance : SuperClass),
2733    HasMethod(Method != 0), IsDelegateInitCall(false), SuperLoc(SuperLoc),
2734    LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2735{
2736  initArgsAndSelLocs(Args, SelLocs, SelLocsK);
2737  setReceiverPointer(SuperType.getAsOpaquePtr());
2738}
2739
2740ObjCMessageExpr::ObjCMessageExpr(QualType T,
2741                                 ExprValueKind VK,
2742                                 SourceLocation LBracLoc,
2743                                 TypeSourceInfo *Receiver,
2744                                 Selector Sel,
2745                                 ArrayRef<SourceLocation> SelLocs,
2746                                 SelectorLocationsKind SelLocsK,
2747                                 ObjCMethodDecl *Method,
2748                                 ArrayRef<Expr *> Args,
2749                                 SourceLocation RBracLoc)
2750  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, T->isDependentType(),
2751         T->isDependentType(), T->isInstantiationDependentType(),
2752         T->containsUnexpandedParameterPack()),
2753    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2754                                                       : Sel.getAsOpaquePtr())),
2755    Kind(Class),
2756    HasMethod(Method != 0), IsDelegateInitCall(false),
2757    LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2758{
2759  initArgsAndSelLocs(Args, SelLocs, SelLocsK);
2760  setReceiverPointer(Receiver);
2761}
2762
2763ObjCMessageExpr::ObjCMessageExpr(QualType T,
2764                                 ExprValueKind VK,
2765                                 SourceLocation LBracLoc,
2766                                 Expr *Receiver,
2767                                 Selector Sel,
2768                                 ArrayRef<SourceLocation> SelLocs,
2769                                 SelectorLocationsKind SelLocsK,
2770                                 ObjCMethodDecl *Method,
2771                                 ArrayRef<Expr *> Args,
2772                                 SourceLocation RBracLoc)
2773  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, Receiver->isTypeDependent(),
2774         Receiver->isTypeDependent(),
2775         Receiver->isInstantiationDependent(),
2776         Receiver->containsUnexpandedParameterPack()),
2777    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2778                                                       : Sel.getAsOpaquePtr())),
2779    Kind(Instance),
2780    HasMethod(Method != 0), IsDelegateInitCall(false),
2781    LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2782{
2783  initArgsAndSelLocs(Args, SelLocs, SelLocsK);
2784  setReceiverPointer(Receiver);
2785}
2786
2787void ObjCMessageExpr::initArgsAndSelLocs(ArrayRef<Expr *> Args,
2788                                         ArrayRef<SourceLocation> SelLocs,
2789                                         SelectorLocationsKind SelLocsK) {
2790  setNumArgs(Args.size());
2791  Expr **MyArgs = getArgs();
2792  for (unsigned I = 0; I != Args.size(); ++I) {
2793    if (Args[I]->isTypeDependent())
2794      ExprBits.TypeDependent = true;
2795    if (Args[I]->isValueDependent())
2796      ExprBits.ValueDependent = true;
2797    if (Args[I]->isInstantiationDependent())
2798      ExprBits.InstantiationDependent = true;
2799    if (Args[I]->containsUnexpandedParameterPack())
2800      ExprBits.ContainsUnexpandedParameterPack = true;
2801
2802    MyArgs[I] = Args[I];
2803  }
2804
2805  SelLocsKind = SelLocsK;
2806  if (SelLocsK == SelLoc_NonStandard)
2807    std::copy(SelLocs.begin(), SelLocs.end(), getStoredSelLocs());
2808}
2809
2810ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2811                                         ExprValueKind VK,
2812                                         SourceLocation LBracLoc,
2813                                         SourceLocation SuperLoc,
2814                                         bool IsInstanceSuper,
2815                                         QualType SuperType,
2816                                         Selector Sel,
2817                                         ArrayRef<SourceLocation> SelLocs,
2818                                         ObjCMethodDecl *Method,
2819                                         ArrayRef<Expr *> Args,
2820                                         SourceLocation RBracLoc) {
2821  SelectorLocationsKind SelLocsK;
2822  ObjCMessageExpr *Mem = alloc(Context, Args, RBracLoc, SelLocs, Sel, SelLocsK);
2823  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, SuperLoc, IsInstanceSuper,
2824                                   SuperType, Sel, SelLocs, SelLocsK,
2825                                   Method, Args, RBracLoc);
2826}
2827
2828ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2829                                         ExprValueKind VK,
2830                                         SourceLocation LBracLoc,
2831                                         TypeSourceInfo *Receiver,
2832                                         Selector Sel,
2833                                         ArrayRef<SourceLocation> SelLocs,
2834                                         ObjCMethodDecl *Method,
2835                                         ArrayRef<Expr *> Args,
2836                                         SourceLocation RBracLoc) {
2837  SelectorLocationsKind SelLocsK;
2838  ObjCMessageExpr *Mem = alloc(Context, Args, RBracLoc, SelLocs, Sel, SelLocsK);
2839  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel,
2840                                   SelLocs, SelLocsK, Method, Args, RBracLoc);
2841}
2842
2843ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2844                                         ExprValueKind VK,
2845                                         SourceLocation LBracLoc,
2846                                         Expr *Receiver,
2847                                         Selector Sel,
2848                                         ArrayRef<SourceLocation> SelLocs,
2849                                         ObjCMethodDecl *Method,
2850                                         ArrayRef<Expr *> Args,
2851                                         SourceLocation RBracLoc) {
2852  SelectorLocationsKind SelLocsK;
2853  ObjCMessageExpr *Mem = alloc(Context, Args, RBracLoc, SelLocs, Sel, SelLocsK);
2854  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel,
2855                                   SelLocs, SelLocsK, Method, Args, RBracLoc);
2856}
2857
2858ObjCMessageExpr *ObjCMessageExpr::CreateEmpty(ASTContext &Context,
2859                                              unsigned NumArgs,
2860                                              unsigned NumStoredSelLocs) {
2861  ObjCMessageExpr *Mem = alloc(Context, NumArgs, NumStoredSelLocs);
2862  return new (Mem) ObjCMessageExpr(EmptyShell(), NumArgs);
2863}
2864
2865ObjCMessageExpr *ObjCMessageExpr::alloc(ASTContext &C,
2866                                        ArrayRef<Expr *> Args,
2867                                        SourceLocation RBraceLoc,
2868                                        ArrayRef<SourceLocation> SelLocs,
2869                                        Selector Sel,
2870                                        SelectorLocationsKind &SelLocsK) {
2871  SelLocsK = hasStandardSelectorLocs(Sel, SelLocs, Args, RBraceLoc);
2872  unsigned NumStoredSelLocs = (SelLocsK == SelLoc_NonStandard) ? SelLocs.size()
2873                                                               : 0;
2874  return alloc(C, Args.size(), NumStoredSelLocs);
2875}
2876
2877ObjCMessageExpr *ObjCMessageExpr::alloc(ASTContext &C,
2878                                        unsigned NumArgs,
2879                                        unsigned NumStoredSelLocs) {
2880  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2881    NumArgs * sizeof(Expr *) + NumStoredSelLocs * sizeof(SourceLocation);
2882  return (ObjCMessageExpr *)C.Allocate(Size,
2883                                     llvm::AlignOf<ObjCMessageExpr>::Alignment);
2884}
2885
2886void ObjCMessageExpr::getSelectorLocs(
2887                               SmallVectorImpl<SourceLocation> &SelLocs) const {
2888  for (unsigned i = 0, e = getNumSelectorLocs(); i != e; ++i)
2889    SelLocs.push_back(getSelectorLoc(i));
2890}
2891
2892SourceRange ObjCMessageExpr::getReceiverRange() const {
2893  switch (getReceiverKind()) {
2894  case Instance:
2895    return getInstanceReceiver()->getSourceRange();
2896
2897  case Class:
2898    return getClassReceiverTypeInfo()->getTypeLoc().getSourceRange();
2899
2900  case SuperInstance:
2901  case SuperClass:
2902    return getSuperLoc();
2903  }
2904
2905  return SourceLocation();
2906}
2907
2908Selector ObjCMessageExpr::getSelector() const {
2909  if (HasMethod)
2910    return reinterpret_cast<const ObjCMethodDecl *>(SelectorOrMethod)
2911                                                               ->getSelector();
2912  return Selector(SelectorOrMethod);
2913}
2914
2915ObjCInterfaceDecl *ObjCMessageExpr::getReceiverInterface() const {
2916  switch (getReceiverKind()) {
2917  case Instance:
2918    if (const ObjCObjectPointerType *Ptr
2919          = getInstanceReceiver()->getType()->getAs<ObjCObjectPointerType>())
2920      return Ptr->getInterfaceDecl();
2921    break;
2922
2923  case Class:
2924    if (const ObjCObjectType *Ty
2925          = getClassReceiver()->getAs<ObjCObjectType>())
2926      return Ty->getInterface();
2927    break;
2928
2929  case SuperInstance:
2930    if (const ObjCObjectPointerType *Ptr
2931          = getSuperType()->getAs<ObjCObjectPointerType>())
2932      return Ptr->getInterfaceDecl();
2933    break;
2934
2935  case SuperClass:
2936    if (const ObjCObjectType *Iface
2937          = getSuperType()->getAs<ObjCObjectType>())
2938      return Iface->getInterface();
2939    break;
2940  }
2941
2942  return 0;
2943}
2944
2945StringRef ObjCBridgedCastExpr::getBridgeKindName() const {
2946  switch (getBridgeKind()) {
2947  case OBC_Bridge:
2948    return "__bridge";
2949  case OBC_BridgeTransfer:
2950    return "__bridge_transfer";
2951  case OBC_BridgeRetained:
2952    return "__bridge_retained";
2953  }
2954
2955  return "__bridge";
2956}
2957
2958bool ChooseExpr::isConditionTrue(const ASTContext &C) const {
2959  return getCond()->EvaluateKnownConstInt(C) != 0;
2960}
2961
2962ShuffleVectorExpr::ShuffleVectorExpr(ASTContext &C, Expr **args, unsigned nexpr,
2963                                     QualType Type, SourceLocation BLoc,
2964                                     SourceLocation RP)
2965   : Expr(ShuffleVectorExprClass, Type, VK_RValue, OK_Ordinary,
2966          Type->isDependentType(), Type->isDependentType(),
2967          Type->isInstantiationDependentType(),
2968          Type->containsUnexpandedParameterPack()),
2969     BuiltinLoc(BLoc), RParenLoc(RP), NumExprs(nexpr)
2970{
2971  SubExprs = new (C) Stmt*[nexpr];
2972  for (unsigned i = 0; i < nexpr; i++) {
2973    if (args[i]->isTypeDependent())
2974      ExprBits.TypeDependent = true;
2975    if (args[i]->isValueDependent())
2976      ExprBits.ValueDependent = true;
2977    if (args[i]->isInstantiationDependent())
2978      ExprBits.InstantiationDependent = true;
2979    if (args[i]->containsUnexpandedParameterPack())
2980      ExprBits.ContainsUnexpandedParameterPack = true;
2981
2982    SubExprs[i] = args[i];
2983  }
2984}
2985
2986void ShuffleVectorExpr::setExprs(ASTContext &C, Expr ** Exprs,
2987                                 unsigned NumExprs) {
2988  if (SubExprs) C.Deallocate(SubExprs);
2989
2990  SubExprs = new (C) Stmt* [NumExprs];
2991  this->NumExprs = NumExprs;
2992  memcpy(SubExprs, Exprs, sizeof(Expr *) * NumExprs);
2993}
2994
2995GenericSelectionExpr::GenericSelectionExpr(ASTContext &Context,
2996                               SourceLocation GenericLoc, Expr *ControllingExpr,
2997                               TypeSourceInfo **AssocTypes, Expr **AssocExprs,
2998                               unsigned NumAssocs, SourceLocation DefaultLoc,
2999                               SourceLocation RParenLoc,
3000                               bool ContainsUnexpandedParameterPack,
3001                               unsigned ResultIndex)
3002  : Expr(GenericSelectionExprClass,
3003         AssocExprs[ResultIndex]->getType(),
3004         AssocExprs[ResultIndex]->getValueKind(),
3005         AssocExprs[ResultIndex]->getObjectKind(),
3006         AssocExprs[ResultIndex]->isTypeDependent(),
3007         AssocExprs[ResultIndex]->isValueDependent(),
3008         AssocExprs[ResultIndex]->isInstantiationDependent(),
3009         ContainsUnexpandedParameterPack),
3010    AssocTypes(new (Context) TypeSourceInfo*[NumAssocs]),
3011    SubExprs(new (Context) Stmt*[END_EXPR+NumAssocs]), NumAssocs(NumAssocs),
3012    ResultIndex(ResultIndex), GenericLoc(GenericLoc), DefaultLoc(DefaultLoc),
3013    RParenLoc(RParenLoc) {
3014  SubExprs[CONTROLLING] = ControllingExpr;
3015  std::copy(AssocTypes, AssocTypes+NumAssocs, this->AssocTypes);
3016  std::copy(AssocExprs, AssocExprs+NumAssocs, SubExprs+END_EXPR);
3017}
3018
3019GenericSelectionExpr::GenericSelectionExpr(ASTContext &Context,
3020                               SourceLocation GenericLoc, Expr *ControllingExpr,
3021                               TypeSourceInfo **AssocTypes, Expr **AssocExprs,
3022                               unsigned NumAssocs, SourceLocation DefaultLoc,
3023                               SourceLocation RParenLoc,
3024                               bool ContainsUnexpandedParameterPack)
3025  : Expr(GenericSelectionExprClass,
3026         Context.DependentTy,
3027         VK_RValue,
3028         OK_Ordinary,
3029         /*isTypeDependent=*/true,
3030         /*isValueDependent=*/true,
3031         /*isInstantiationDependent=*/true,
3032         ContainsUnexpandedParameterPack),
3033    AssocTypes(new (Context) TypeSourceInfo*[NumAssocs]),
3034    SubExprs(new (Context) Stmt*[END_EXPR+NumAssocs]), NumAssocs(NumAssocs),
3035    ResultIndex(-1U), GenericLoc(GenericLoc), DefaultLoc(DefaultLoc),
3036    RParenLoc(RParenLoc) {
3037  SubExprs[CONTROLLING] = ControllingExpr;
3038  std::copy(AssocTypes, AssocTypes+NumAssocs, this->AssocTypes);
3039  std::copy(AssocExprs, AssocExprs+NumAssocs, SubExprs+END_EXPR);
3040}
3041
3042//===----------------------------------------------------------------------===//
3043//  DesignatedInitExpr
3044//===----------------------------------------------------------------------===//
3045
3046IdentifierInfo *DesignatedInitExpr::Designator::getFieldName() const {
3047  assert(Kind == FieldDesignator && "Only valid on a field designator");
3048  if (Field.NameOrField & 0x01)
3049    return reinterpret_cast<IdentifierInfo *>(Field.NameOrField&~0x01);
3050  else
3051    return getField()->getIdentifier();
3052}
3053
3054DesignatedInitExpr::DesignatedInitExpr(ASTContext &C, QualType Ty,
3055                                       unsigned NumDesignators,
3056                                       const Designator *Designators,
3057                                       SourceLocation EqualOrColonLoc,
3058                                       bool GNUSyntax,
3059                                       Expr **IndexExprs,
3060                                       unsigned NumIndexExprs,
3061                                       Expr *Init)
3062  : Expr(DesignatedInitExprClass, Ty,
3063         Init->getValueKind(), Init->getObjectKind(),
3064         Init->isTypeDependent(), Init->isValueDependent(),
3065         Init->isInstantiationDependent(),
3066         Init->containsUnexpandedParameterPack()),
3067    EqualOrColonLoc(EqualOrColonLoc), GNUSyntax(GNUSyntax),
3068    NumDesignators(NumDesignators), NumSubExprs(NumIndexExprs + 1) {
3069  this->Designators = new (C) Designator[NumDesignators];
3070
3071  // Record the initializer itself.
3072  child_range Child = children();
3073  *Child++ = Init;
3074
3075  // Copy the designators and their subexpressions, computing
3076  // value-dependence along the way.
3077  unsigned IndexIdx = 0;
3078  for (unsigned I = 0; I != NumDesignators; ++I) {
3079    this->Designators[I] = Designators[I];
3080
3081    if (this->Designators[I].isArrayDesignator()) {
3082      // Compute type- and value-dependence.
3083      Expr *Index = IndexExprs[IndexIdx];
3084      if (Index->isTypeDependent() || Index->isValueDependent())
3085        ExprBits.ValueDependent = true;
3086      if (Index->isInstantiationDependent())
3087        ExprBits.InstantiationDependent = true;
3088      // Propagate unexpanded parameter packs.
3089      if (Index->containsUnexpandedParameterPack())
3090        ExprBits.ContainsUnexpandedParameterPack = true;
3091
3092      // Copy the index expressions into permanent storage.
3093      *Child++ = IndexExprs[IndexIdx++];
3094    } else if (this->Designators[I].isArrayRangeDesignator()) {
3095      // Compute type- and value-dependence.
3096      Expr *Start = IndexExprs[IndexIdx];
3097      Expr *End = IndexExprs[IndexIdx + 1];
3098      if (Start->isTypeDependent() || Start->isValueDependent() ||
3099          End->isTypeDependent() || End->isValueDependent()) {
3100        ExprBits.ValueDependent = true;
3101        ExprBits.InstantiationDependent = true;
3102      } else if (Start->isInstantiationDependent() ||
3103                 End->isInstantiationDependent()) {
3104        ExprBits.InstantiationDependent = true;
3105      }
3106
3107      // Propagate unexpanded parameter packs.
3108      if (Start->containsUnexpandedParameterPack() ||
3109          End->containsUnexpandedParameterPack())
3110        ExprBits.ContainsUnexpandedParameterPack = true;
3111
3112      // Copy the start/end expressions into permanent storage.
3113      *Child++ = IndexExprs[IndexIdx++];
3114      *Child++ = IndexExprs[IndexIdx++];
3115    }
3116  }
3117
3118  assert(IndexIdx == NumIndexExprs && "Wrong number of index expressions");
3119}
3120
3121DesignatedInitExpr *
3122DesignatedInitExpr::Create(ASTContext &C, Designator *Designators,
3123                           unsigned NumDesignators,
3124                           Expr **IndexExprs, unsigned NumIndexExprs,
3125                           SourceLocation ColonOrEqualLoc,
3126                           bool UsesColonSyntax, Expr *Init) {
3127  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
3128                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
3129  return new (Mem) DesignatedInitExpr(C, C.VoidTy, NumDesignators, Designators,
3130                                      ColonOrEqualLoc, UsesColonSyntax,
3131                                      IndexExprs, NumIndexExprs, Init);
3132}
3133
3134DesignatedInitExpr *DesignatedInitExpr::CreateEmpty(ASTContext &C,
3135                                                    unsigned NumIndexExprs) {
3136  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
3137                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
3138  return new (Mem) DesignatedInitExpr(NumIndexExprs + 1);
3139}
3140
3141void DesignatedInitExpr::setDesignators(ASTContext &C,
3142                                        const Designator *Desigs,
3143                                        unsigned NumDesigs) {
3144  Designators = new (C) Designator[NumDesigs];
3145  NumDesignators = NumDesigs;
3146  for (unsigned I = 0; I != NumDesigs; ++I)
3147    Designators[I] = Desigs[I];
3148}
3149
3150SourceRange DesignatedInitExpr::getDesignatorsSourceRange() const {
3151  DesignatedInitExpr *DIE = const_cast<DesignatedInitExpr*>(this);
3152  if (size() == 1)
3153    return DIE->getDesignator(0)->getSourceRange();
3154  return SourceRange(DIE->getDesignator(0)->getStartLocation(),
3155                     DIE->getDesignator(size()-1)->getEndLocation());
3156}
3157
3158SourceRange DesignatedInitExpr::getSourceRange() const {
3159  SourceLocation StartLoc;
3160  Designator &First =
3161    *const_cast<DesignatedInitExpr*>(this)->designators_begin();
3162  if (First.isFieldDesignator()) {
3163    if (GNUSyntax)
3164      StartLoc = SourceLocation::getFromRawEncoding(First.Field.FieldLoc);
3165    else
3166      StartLoc = SourceLocation::getFromRawEncoding(First.Field.DotLoc);
3167  } else
3168    StartLoc =
3169      SourceLocation::getFromRawEncoding(First.ArrayOrRange.LBracketLoc);
3170  return SourceRange(StartLoc, getInit()->getSourceRange().getEnd());
3171}
3172
3173Expr *DesignatedInitExpr::getArrayIndex(const Designator& D) {
3174  assert(D.Kind == Designator::ArrayDesignator && "Requires array designator");
3175  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3176  Ptr += sizeof(DesignatedInitExpr);
3177  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3178  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
3179}
3180
3181Expr *DesignatedInitExpr::getArrayRangeStart(const Designator& D) {
3182  assert(D.Kind == Designator::ArrayRangeDesignator &&
3183         "Requires array range designator");
3184  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3185  Ptr += sizeof(DesignatedInitExpr);
3186  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3187  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
3188}
3189
3190Expr *DesignatedInitExpr::getArrayRangeEnd(const Designator& D) {
3191  assert(D.Kind == Designator::ArrayRangeDesignator &&
3192         "Requires array range designator");
3193  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3194  Ptr += sizeof(DesignatedInitExpr);
3195  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3196  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 2));
3197}
3198
3199/// \brief Replaces the designator at index @p Idx with the series
3200/// of designators in [First, Last).
3201void DesignatedInitExpr::ExpandDesignator(ASTContext &C, unsigned Idx,
3202                                          const Designator *First,
3203                                          const Designator *Last) {
3204  unsigned NumNewDesignators = Last - First;
3205  if (NumNewDesignators == 0) {
3206    std::copy_backward(Designators + Idx + 1,
3207                       Designators + NumDesignators,
3208                       Designators + Idx);
3209    --NumNewDesignators;
3210    return;
3211  } else if (NumNewDesignators == 1) {
3212    Designators[Idx] = *First;
3213    return;
3214  }
3215
3216  Designator *NewDesignators
3217    = new (C) Designator[NumDesignators - 1 + NumNewDesignators];
3218  std::copy(Designators, Designators + Idx, NewDesignators);
3219  std::copy(First, Last, NewDesignators + Idx);
3220  std::copy(Designators + Idx + 1, Designators + NumDesignators,
3221            NewDesignators + Idx + NumNewDesignators);
3222  Designators = NewDesignators;
3223  NumDesignators = NumDesignators - 1 + NumNewDesignators;
3224}
3225
3226ParenListExpr::ParenListExpr(ASTContext& C, SourceLocation lparenloc,
3227                             Expr **exprs, unsigned nexprs,
3228                             SourceLocation rparenloc, QualType T)
3229  : Expr(ParenListExprClass, T, VK_RValue, OK_Ordinary,
3230         false, false, false, false),
3231    NumExprs(nexprs), LParenLoc(lparenloc), RParenLoc(rparenloc) {
3232  assert(!T.isNull() && "ParenListExpr must have a valid type");
3233  Exprs = new (C) Stmt*[nexprs];
3234  for (unsigned i = 0; i != nexprs; ++i) {
3235    if (exprs[i]->isTypeDependent())
3236      ExprBits.TypeDependent = true;
3237    if (exprs[i]->isValueDependent())
3238      ExprBits.ValueDependent = true;
3239    if (exprs[i]->isInstantiationDependent())
3240      ExprBits.InstantiationDependent = true;
3241    if (exprs[i]->containsUnexpandedParameterPack())
3242      ExprBits.ContainsUnexpandedParameterPack = true;
3243
3244    Exprs[i] = exprs[i];
3245  }
3246}
3247
3248const OpaqueValueExpr *OpaqueValueExpr::findInCopyConstruct(const Expr *e) {
3249  if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(e))
3250    e = ewc->getSubExpr();
3251  if (const MaterializeTemporaryExpr *m = dyn_cast<MaterializeTemporaryExpr>(e))
3252    e = m->GetTemporaryExpr();
3253  e = cast<CXXConstructExpr>(e)->getArg(0);
3254  while (const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
3255    e = ice->getSubExpr();
3256  return cast<OpaqueValueExpr>(e);
3257}
3258
3259//===----------------------------------------------------------------------===//
3260//  ExprIterator.
3261//===----------------------------------------------------------------------===//
3262
3263Expr* ExprIterator::operator[](size_t idx) { return cast<Expr>(I[idx]); }
3264Expr* ExprIterator::operator*() const { return cast<Expr>(*I); }
3265Expr* ExprIterator::operator->() const { return cast<Expr>(*I); }
3266const Expr* ConstExprIterator::operator[](size_t idx) const {
3267  return cast<Expr>(I[idx]);
3268}
3269const Expr* ConstExprIterator::operator*() const { return cast<Expr>(*I); }
3270const Expr* ConstExprIterator::operator->() const { return cast<Expr>(*I); }
3271
3272//===----------------------------------------------------------------------===//
3273//  Child Iterators for iterating over subexpressions/substatements
3274//===----------------------------------------------------------------------===//
3275
3276// UnaryExprOrTypeTraitExpr
3277Stmt::child_range UnaryExprOrTypeTraitExpr::children() {
3278  // If this is of a type and the type is a VLA type (and not a typedef), the
3279  // size expression of the VLA needs to be treated as an executable expression.
3280  // Why isn't this weirdness documented better in StmtIterator?
3281  if (isArgumentType()) {
3282    if (const VariableArrayType* T = dyn_cast<VariableArrayType>(
3283                                   getArgumentType().getTypePtr()))
3284      return child_range(child_iterator(T), child_iterator());
3285    return child_range();
3286  }
3287  return child_range(&Argument.Ex, &Argument.Ex + 1);
3288}
3289
3290// ObjCMessageExpr
3291Stmt::child_range ObjCMessageExpr::children() {
3292  Stmt **begin;
3293  if (getReceiverKind() == Instance)
3294    begin = reinterpret_cast<Stmt **>(this + 1);
3295  else
3296    begin = reinterpret_cast<Stmt **>(getArgs());
3297  return child_range(begin,
3298                     reinterpret_cast<Stmt **>(getArgs() + getNumArgs()));
3299}
3300
3301// Blocks
3302BlockDeclRefExpr::BlockDeclRefExpr(VarDecl *d, QualType t, ExprValueKind VK,
3303                                   SourceLocation l, bool ByRef,
3304                                   bool constAdded)
3305  : Expr(BlockDeclRefExprClass, t, VK, OK_Ordinary, false, false, false,
3306         d->isParameterPack()),
3307    D(d), Loc(l), IsByRef(ByRef), ConstQualAdded(constAdded)
3308{
3309  bool TypeDependent = false;
3310  bool ValueDependent = false;
3311  bool InstantiationDependent = false;
3312  computeDeclRefDependence(D, getType(), TypeDependent, ValueDependent,
3313                           InstantiationDependent);
3314  ExprBits.TypeDependent = TypeDependent;
3315  ExprBits.ValueDependent = ValueDependent;
3316  ExprBits.InstantiationDependent = InstantiationDependent;
3317}
3318
3319
3320AtomicExpr::AtomicExpr(SourceLocation BLoc, Expr **args, unsigned nexpr,
3321                       QualType t, AtomicOp op, SourceLocation RP)
3322  : Expr(AtomicExprClass, t, VK_RValue, OK_Ordinary,
3323         false, false, false, false),
3324    NumSubExprs(nexpr), BuiltinLoc(BLoc), RParenLoc(RP), Op(op)
3325{
3326  for (unsigned i = 0; i < nexpr; i++) {
3327    if (args[i]->isTypeDependent())
3328      ExprBits.TypeDependent = true;
3329    if (args[i]->isValueDependent())
3330      ExprBits.ValueDependent = true;
3331    if (args[i]->isInstantiationDependent())
3332      ExprBits.InstantiationDependent = true;
3333    if (args[i]->containsUnexpandedParameterPack())
3334      ExprBits.ContainsUnexpandedParameterPack = true;
3335
3336    SubExprs[i] = args[i];
3337  }
3338}
3339