Expr.cpp revision b219cfc4d75f0a03630b7c4509ef791b7e97b2c8 
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
278  computeDependence();
279}
280
281DeclRefExpr *DeclRefExpr::Create(ASTContext &Context,
282                                 NestedNameSpecifierLoc QualifierLoc,
283                                 ValueDecl *D,
284                                 SourceLocation NameLoc,
285                                 QualType T,
286                                 ExprValueKind VK,
287                                 NamedDecl *FoundD,
288                                 const TemplateArgumentListInfo *TemplateArgs) {
289  return Create(Context, QualifierLoc, D,
290                DeclarationNameInfo(D->getDeclName(), NameLoc),
291                T, VK, FoundD, TemplateArgs);
292}
293
294DeclRefExpr *DeclRefExpr::Create(ASTContext &Context,
295                                 NestedNameSpecifierLoc QualifierLoc,
296                                 ValueDecl *D,
297                                 const DeclarationNameInfo &NameInfo,
298                                 QualType T,
299                                 ExprValueKind VK,
300                                 NamedDecl *FoundD,
301                                 const TemplateArgumentListInfo *TemplateArgs) {
302  // Filter out cases where the found Decl is the same as the value refenenced.
303  if (D == FoundD)
304    FoundD = 0;
305
306  std::size_t Size = sizeof(DeclRefExpr);
307  if (QualifierLoc != 0)
308    Size += sizeof(NestedNameSpecifierLoc);
309  if (FoundD)
310    Size += sizeof(NamedDecl *);
311  if (TemplateArgs)
312    Size += ASTTemplateArgumentListInfo::sizeFor(*TemplateArgs);
313
314  void *Mem = Context.Allocate(Size, llvm::alignOf<DeclRefExpr>());
315  return new (Mem) DeclRefExpr(QualifierLoc, D, NameInfo, FoundD, TemplateArgs,
316                               T, VK);
317}
318
319DeclRefExpr *DeclRefExpr::CreateEmpty(ASTContext &Context,
320                                      bool HasQualifier,
321                                      bool HasFoundDecl,
322                                      bool HasExplicitTemplateArgs,
323                                      unsigned NumTemplateArgs) {
324  std::size_t Size = sizeof(DeclRefExpr);
325  if (HasQualifier)
326    Size += sizeof(NestedNameSpecifierLoc);
327  if (HasFoundDecl)
328    Size += sizeof(NamedDecl *);
329  if (HasExplicitTemplateArgs)
330    Size += ASTTemplateArgumentListInfo::sizeFor(NumTemplateArgs);
331
332  void *Mem = Context.Allocate(Size, llvm::alignOf<DeclRefExpr>());
333  return new (Mem) DeclRefExpr(EmptyShell());
334}
335
336SourceRange DeclRefExpr::getSourceRange() const {
337  SourceRange R = getNameInfo().getSourceRange();
338  if (hasQualifier())
339    R.setBegin(getQualifierLoc().getBeginLoc());
340  if (hasExplicitTemplateArgs())
341    R.setEnd(getRAngleLoc());
342  return R;
343}
344
345// FIXME: Maybe this should use DeclPrinter with a special "print predefined
346// expr" policy instead.
347std::string PredefinedExpr::ComputeName(IdentType IT, const Decl *CurrentDecl) {
348  ASTContext &Context = CurrentDecl->getASTContext();
349
350  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurrentDecl)) {
351    if (IT != PrettyFunction && IT != PrettyFunctionNoVirtual)
352      return FD->getNameAsString();
353
354    llvm::SmallString<256> Name;
355    llvm::raw_svector_ostream Out(Name);
356
357    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
358      if (MD->isVirtual() && IT != PrettyFunctionNoVirtual)
359        Out << "virtual ";
360      if (MD->isStatic())
361        Out << "static ";
362    }
363
364    PrintingPolicy Policy(Context.getLangOptions());
365
366    std::string Proto = FD->getQualifiedNameAsString(Policy);
367
368    const FunctionType *AFT = FD->getType()->getAs<FunctionType>();
369    const FunctionProtoType *FT = 0;
370    if (FD->hasWrittenPrototype())
371      FT = dyn_cast<FunctionProtoType>(AFT);
372
373    Proto += "(";
374    if (FT) {
375      llvm::raw_string_ostream POut(Proto);
376      for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
377        if (i) POut << ", ";
378        std::string Param;
379        FD->getParamDecl(i)->getType().getAsStringInternal(Param, Policy);
380        POut << Param;
381      }
382
383      if (FT->isVariadic()) {
384        if (FD->getNumParams()) POut << ", ";
385        POut << "...";
386      }
387    }
388    Proto += ")";
389
390    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
391      Qualifiers ThisQuals = Qualifiers::fromCVRMask(MD->getTypeQualifiers());
392      if (ThisQuals.hasConst())
393        Proto += " const";
394      if (ThisQuals.hasVolatile())
395        Proto += " volatile";
396    }
397
398    if (!isa<CXXConstructorDecl>(FD) && !isa<CXXDestructorDecl>(FD))
399      AFT->getResultType().getAsStringInternal(Proto, Policy);
400
401    Out << Proto;
402
403    Out.flush();
404    return Name.str().str();
405  }
406  if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CurrentDecl)) {
407    llvm::SmallString<256> Name;
408    llvm::raw_svector_ostream Out(Name);
409    Out << (MD->isInstanceMethod() ? '-' : '+');
410    Out << '[';
411
412    // For incorrect code, there might not be an ObjCInterfaceDecl.  Do
413    // a null check to avoid a crash.
414    if (const ObjCInterfaceDecl *ID = MD->getClassInterface())
415      Out << ID;
416
417    if (const ObjCCategoryImplDecl *CID =
418        dyn_cast<ObjCCategoryImplDecl>(MD->getDeclContext()))
419      Out << '(' << CID << ')';
420
421    Out <<  ' ';
422    Out << MD->getSelector().getAsString();
423    Out <<  ']';
424
425    Out.flush();
426    return Name.str().str();
427  }
428  if (isa<TranslationUnitDecl>(CurrentDecl) && IT == PrettyFunction) {
429    // __PRETTY_FUNCTION__ -> "top level", the others produce an empty string.
430    return "top level";
431  }
432  return "";
433}
434
435void APNumericStorage::setIntValue(ASTContext &C, const llvm::APInt &Val) {
436  if (hasAllocation())
437    C.Deallocate(pVal);
438
439  BitWidth = Val.getBitWidth();
440  unsigned NumWords = Val.getNumWords();
441  const uint64_t* Words = Val.getRawData();
442  if (NumWords > 1) {
443    pVal = new (C) uint64_t[NumWords];
444    std::copy(Words, Words + NumWords, pVal);
445  } else if (NumWords == 1)
446    VAL = Words[0];
447  else
448    VAL = 0;
449}
450
451IntegerLiteral *
452IntegerLiteral::Create(ASTContext &C, const llvm::APInt &V,
453                       QualType type, SourceLocation l) {
454  return new (C) IntegerLiteral(C, V, type, l);
455}
456
457IntegerLiteral *
458IntegerLiteral::Create(ASTContext &C, EmptyShell Empty) {
459  return new (C) IntegerLiteral(Empty);
460}
461
462FloatingLiteral *
463FloatingLiteral::Create(ASTContext &C, const llvm::APFloat &V,
464                        bool isexact, QualType Type, SourceLocation L) {
465  return new (C) FloatingLiteral(C, V, isexact, Type, L);
466}
467
468FloatingLiteral *
469FloatingLiteral::Create(ASTContext &C, EmptyShell Empty) {
470  return new (C) FloatingLiteral(Empty);
471}
472
473/// getValueAsApproximateDouble - This returns the value as an inaccurate
474/// double.  Note that this may cause loss of precision, but is useful for
475/// debugging dumps, etc.
476double FloatingLiteral::getValueAsApproximateDouble() const {
477  llvm::APFloat V = getValue();
478  bool ignored;
479  V.convert(llvm::APFloat::IEEEdouble, llvm::APFloat::rmNearestTiesToEven,
480            &ignored);
481  return V.convertToDouble();
482}
483
484StringLiteral *StringLiteral::Create(ASTContext &C, StringRef Str,
485                                     StringKind Kind, bool Pascal, QualType Ty,
486                                     const SourceLocation *Loc,
487                                     unsigned NumStrs) {
488  // Allocate enough space for the StringLiteral plus an array of locations for
489  // any concatenated string tokens.
490  void *Mem = C.Allocate(sizeof(StringLiteral)+
491                         sizeof(SourceLocation)*(NumStrs-1),
492                         llvm::alignOf<StringLiteral>());
493  StringLiteral *SL = new (Mem) StringLiteral(Ty);
494
495  // OPTIMIZE: could allocate this appended to the StringLiteral.
496  char *AStrData = new (C, 1) char[Str.size()];
497  memcpy(AStrData, Str.data(), Str.size());
498  SL->StrData = AStrData;
499  SL->ByteLength = Str.size();
500  SL->Kind = Kind;
501  SL->IsPascal = Pascal;
502  SL->TokLocs[0] = Loc[0];
503  SL->NumConcatenated = NumStrs;
504
505  if (NumStrs != 1)
506    memcpy(&SL->TokLocs[1], Loc+1, sizeof(SourceLocation)*(NumStrs-1));
507  return SL;
508}
509
510StringLiteral *StringLiteral::CreateEmpty(ASTContext &C, unsigned NumStrs) {
511  void *Mem = C.Allocate(sizeof(StringLiteral)+
512                         sizeof(SourceLocation)*(NumStrs-1),
513                         llvm::alignOf<StringLiteral>());
514  StringLiteral *SL = new (Mem) StringLiteral(QualType());
515  SL->StrData = 0;
516  SL->ByteLength = 0;
517  SL->NumConcatenated = NumStrs;
518  return SL;
519}
520
521void StringLiteral::setString(ASTContext &C, StringRef Str) {
522  char *AStrData = new (C, 1) char[Str.size()];
523  memcpy(AStrData, Str.data(), Str.size());
524  StrData = AStrData;
525  ByteLength = Str.size();
526}
527
528/// getLocationOfByte - Return a source location that points to the specified
529/// byte of this string literal.
530///
531/// Strings are amazingly complex.  They can be formed from multiple tokens and
532/// can have escape sequences in them in addition to the usual trigraph and
533/// escaped newline business.  This routine handles this complexity.
534///
535SourceLocation StringLiteral::
536getLocationOfByte(unsigned ByteNo, const SourceManager &SM,
537                  const LangOptions &Features, const TargetInfo &Target) const {
538  assert(Kind == StringLiteral::Ascii && "This only works for ASCII strings");
539
540  // Loop over all of the tokens in this string until we find the one that
541  // contains the byte we're looking for.
542  unsigned TokNo = 0;
543  while (1) {
544    assert(TokNo < getNumConcatenated() && "Invalid byte number!");
545    SourceLocation StrTokLoc = getStrTokenLoc(TokNo);
546
547    // Get the spelling of the string so that we can get the data that makes up
548    // the string literal, not the identifier for the macro it is potentially
549    // expanded through.
550    SourceLocation StrTokSpellingLoc = SM.getSpellingLoc(StrTokLoc);
551
552    // Re-lex the token to get its length and original spelling.
553    std::pair<FileID, unsigned> LocInfo =SM.getDecomposedLoc(StrTokSpellingLoc);
554    bool Invalid = false;
555    StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
556    if (Invalid)
557      return StrTokSpellingLoc;
558
559    const char *StrData = Buffer.data()+LocInfo.second;
560
561    // Create a langops struct and enable trigraphs.  This is sufficient for
562    // relexing tokens.
563    LangOptions LangOpts;
564    LangOpts.Trigraphs = true;
565
566    // Create a lexer starting at the beginning of this token.
567    Lexer TheLexer(StrTokSpellingLoc, Features, Buffer.begin(), StrData,
568                   Buffer.end());
569    Token TheTok;
570    TheLexer.LexFromRawLexer(TheTok);
571
572    // Use the StringLiteralParser to compute the length of the string in bytes.
573    StringLiteralParser SLP(&TheTok, 1, SM, Features, Target);
574    unsigned TokNumBytes = SLP.GetStringLength();
575
576    // If the byte is in this token, return the location of the byte.
577    if (ByteNo < TokNumBytes ||
578        (ByteNo == TokNumBytes && TokNo == getNumConcatenated() - 1)) {
579      unsigned Offset = SLP.getOffsetOfStringByte(TheTok, ByteNo);
580
581      // Now that we know the offset of the token in the spelling, use the
582      // preprocessor to get the offset in the original source.
583      return Lexer::AdvanceToTokenCharacter(StrTokLoc, Offset, SM, Features);
584    }
585
586    // Move to the next string token.
587    ++TokNo;
588    ByteNo -= TokNumBytes;
589  }
590}
591
592
593
594/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
595/// corresponds to, e.g. "sizeof" or "[pre]++".
596const char *UnaryOperator::getOpcodeStr(Opcode Op) {
597  switch (Op) {
598  default: llvm_unreachable("Unknown unary operator");
599  case UO_PostInc: return "++";
600  case UO_PostDec: return "--";
601  case UO_PreInc:  return "++";
602  case UO_PreDec:  return "--";
603  case UO_AddrOf:  return "&";
604  case UO_Deref:   return "*";
605  case UO_Plus:    return "+";
606  case UO_Minus:   return "-";
607  case UO_Not:     return "~";
608  case UO_LNot:    return "!";
609  case UO_Real:    return "__real";
610  case UO_Imag:    return "__imag";
611  case UO_Extension: return "__extension__";
612  }
613}
614
615UnaryOperatorKind
616UnaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO, bool Postfix) {
617  switch (OO) {
618  default: llvm_unreachable("No unary operator for overloaded function");
619  case OO_PlusPlus:   return Postfix ? UO_PostInc : UO_PreInc;
620  case OO_MinusMinus: return Postfix ? UO_PostDec : UO_PreDec;
621  case OO_Amp:        return UO_AddrOf;
622  case OO_Star:       return UO_Deref;
623  case OO_Plus:       return UO_Plus;
624  case OO_Minus:      return UO_Minus;
625  case OO_Tilde:      return UO_Not;
626  case OO_Exclaim:    return UO_LNot;
627  }
628}
629
630OverloadedOperatorKind UnaryOperator::getOverloadedOperator(Opcode Opc) {
631  switch (Opc) {
632  case UO_PostInc: case UO_PreInc: return OO_PlusPlus;
633  case UO_PostDec: case UO_PreDec: return OO_MinusMinus;
634  case UO_AddrOf: return OO_Amp;
635  case UO_Deref: return OO_Star;
636  case UO_Plus: return OO_Plus;
637  case UO_Minus: return OO_Minus;
638  case UO_Not: return OO_Tilde;
639  case UO_LNot: return OO_Exclaim;
640  default: return OO_None;
641  }
642}
643
644
645//===----------------------------------------------------------------------===//
646// Postfix Operators.
647//===----------------------------------------------------------------------===//
648
649CallExpr::CallExpr(ASTContext& C, StmtClass SC, Expr *fn, unsigned NumPreArgs,
650                   Expr **args, unsigned numargs, QualType t, ExprValueKind VK,
651                   SourceLocation rparenloc)
652  : Expr(SC, t, VK, OK_Ordinary,
653         fn->isTypeDependent(),
654         fn->isValueDependent(),
655         fn->isInstantiationDependent(),
656         fn->containsUnexpandedParameterPack()),
657    NumArgs(numargs) {
658
659  SubExprs = new (C) Stmt*[numargs+PREARGS_START+NumPreArgs];
660  SubExprs[FN] = fn;
661  for (unsigned i = 0; i != numargs; ++i) {
662    if (args[i]->isTypeDependent())
663      ExprBits.TypeDependent = true;
664    if (args[i]->isValueDependent())
665      ExprBits.ValueDependent = true;
666    if (args[i]->isInstantiationDependent())
667      ExprBits.InstantiationDependent = true;
668    if (args[i]->containsUnexpandedParameterPack())
669      ExprBits.ContainsUnexpandedParameterPack = true;
670
671    SubExprs[i+PREARGS_START+NumPreArgs] = args[i];
672  }
673
674  CallExprBits.NumPreArgs = NumPreArgs;
675  RParenLoc = rparenloc;
676}
677
678CallExpr::CallExpr(ASTContext& C, Expr *fn, Expr **args, unsigned numargs,
679                   QualType t, ExprValueKind VK, SourceLocation rparenloc)
680  : Expr(CallExprClass, t, VK, OK_Ordinary,
681         fn->isTypeDependent(),
682         fn->isValueDependent(),
683         fn->isInstantiationDependent(),
684         fn->containsUnexpandedParameterPack()),
685    NumArgs(numargs) {
686
687  SubExprs = new (C) Stmt*[numargs+PREARGS_START];
688  SubExprs[FN] = fn;
689  for (unsigned i = 0; i != numargs; ++i) {
690    if (args[i]->isTypeDependent())
691      ExprBits.TypeDependent = true;
692    if (args[i]->isValueDependent())
693      ExprBits.ValueDependent = true;
694    if (args[i]->isInstantiationDependent())
695      ExprBits.InstantiationDependent = true;
696    if (args[i]->containsUnexpandedParameterPack())
697      ExprBits.ContainsUnexpandedParameterPack = true;
698
699    SubExprs[i+PREARGS_START] = args[i];
700  }
701
702  CallExprBits.NumPreArgs = 0;
703  RParenLoc = rparenloc;
704}
705
706CallExpr::CallExpr(ASTContext &C, StmtClass SC, EmptyShell Empty)
707  : Expr(SC, Empty), SubExprs(0), NumArgs(0) {
708  // FIXME: Why do we allocate this?
709  SubExprs = new (C) Stmt*[PREARGS_START];
710  CallExprBits.NumPreArgs = 0;
711}
712
713CallExpr::CallExpr(ASTContext &C, StmtClass SC, unsigned NumPreArgs,
714                   EmptyShell Empty)
715  : Expr(SC, Empty), SubExprs(0), NumArgs(0) {
716  // FIXME: Why do we allocate this?
717  SubExprs = new (C) Stmt*[PREARGS_START+NumPreArgs];
718  CallExprBits.NumPreArgs = NumPreArgs;
719}
720
721Decl *CallExpr::getCalleeDecl() {
722  Expr *CEE = getCallee()->IgnoreParenImpCasts();
723
724  while (SubstNonTypeTemplateParmExpr *NTTP
725                                = dyn_cast<SubstNonTypeTemplateParmExpr>(CEE)) {
726    CEE = NTTP->getReplacement()->IgnoreParenCasts();
727  }
728
729  // If we're calling a dereference, look at the pointer instead.
730  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CEE)) {
731    if (BO->isPtrMemOp())
732      CEE = BO->getRHS()->IgnoreParenCasts();
733  } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(CEE)) {
734    if (UO->getOpcode() == UO_Deref)
735      CEE = UO->getSubExpr()->IgnoreParenCasts();
736  }
737  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE))
738    return DRE->getDecl();
739  if (MemberExpr *ME = dyn_cast<MemberExpr>(CEE))
740    return ME->getMemberDecl();
741
742  return 0;
743}
744
745FunctionDecl *CallExpr::getDirectCallee() {
746  return dyn_cast_or_null<FunctionDecl>(getCalleeDecl());
747}
748
749/// setNumArgs - This changes the number of arguments present in this call.
750/// Any orphaned expressions are deleted by this, and any new operands are set
751/// to null.
752void CallExpr::setNumArgs(ASTContext& C, unsigned NumArgs) {
753  // No change, just return.
754  if (NumArgs == getNumArgs()) return;
755
756  // If shrinking # arguments, just delete the extras and forgot them.
757  if (NumArgs < getNumArgs()) {
758    this->NumArgs = NumArgs;
759    return;
760  }
761
762  // Otherwise, we are growing the # arguments.  New an bigger argument array.
763  unsigned NumPreArgs = getNumPreArgs();
764  Stmt **NewSubExprs = new (C) Stmt*[NumArgs+PREARGS_START+NumPreArgs];
765  // Copy over args.
766  for (unsigned i = 0; i != getNumArgs()+PREARGS_START+NumPreArgs; ++i)
767    NewSubExprs[i] = SubExprs[i];
768  // Null out new args.
769  for (unsigned i = getNumArgs()+PREARGS_START+NumPreArgs;
770       i != NumArgs+PREARGS_START+NumPreArgs; ++i)
771    NewSubExprs[i] = 0;
772
773  if (SubExprs) C.Deallocate(SubExprs);
774  SubExprs = NewSubExprs;
775  this->NumArgs = NumArgs;
776}
777
778/// isBuiltinCall - If this is a call to a builtin, return the builtin ID.  If
779/// not, return 0.
780unsigned CallExpr::isBuiltinCall(const ASTContext &Context) const {
781  // All simple function calls (e.g. func()) are implicitly cast to pointer to
782  // function. As a result, we try and obtain the DeclRefExpr from the
783  // ImplicitCastExpr.
784  const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
785  if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
786    return 0;
787
788  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
789  if (!DRE)
790    return 0;
791
792  const FunctionDecl *FDecl = dyn_cast<FunctionDecl>(DRE->getDecl());
793  if (!FDecl)
794    return 0;
795
796  if (!FDecl->getIdentifier())
797    return 0;
798
799  return FDecl->getBuiltinID();
800}
801
802QualType CallExpr::getCallReturnType() const {
803  QualType CalleeType = getCallee()->getType();
804  if (const PointerType *FnTypePtr = CalleeType->getAs<PointerType>())
805    CalleeType = FnTypePtr->getPointeeType();
806  else if (const BlockPointerType *BPT = CalleeType->getAs<BlockPointerType>())
807    CalleeType = BPT->getPointeeType();
808  else if (CalleeType->isSpecificPlaceholderType(BuiltinType::BoundMember))
809    // This should never be overloaded and so should never return null.
810    CalleeType = Expr::findBoundMemberType(getCallee());
811
812  const FunctionType *FnType = CalleeType->castAs<FunctionType>();
813  return FnType->getResultType();
814}
815
816SourceRange CallExpr::getSourceRange() const {
817  if (isa<CXXOperatorCallExpr>(this))
818    return cast<CXXOperatorCallExpr>(this)->getSourceRange();
819
820  SourceLocation begin = getCallee()->getLocStart();
821  if (begin.isInvalid() && getNumArgs() > 0)
822    begin = getArg(0)->getLocStart();
823  SourceLocation end = getRParenLoc();
824  if (end.isInvalid() && getNumArgs() > 0)
825    end = getArg(getNumArgs() - 1)->getLocEnd();
826  return SourceRange(begin, end);
827}
828
829OffsetOfExpr *OffsetOfExpr::Create(ASTContext &C, QualType type,
830                                   SourceLocation OperatorLoc,
831                                   TypeSourceInfo *tsi,
832                                   OffsetOfNode* compsPtr, unsigned numComps,
833                                   Expr** exprsPtr, unsigned numExprs,
834                                   SourceLocation RParenLoc) {
835  void *Mem = C.Allocate(sizeof(OffsetOfExpr) +
836                         sizeof(OffsetOfNode) * numComps +
837                         sizeof(Expr*) * numExprs);
838
839  return new (Mem) OffsetOfExpr(C, type, OperatorLoc, tsi, compsPtr, numComps,
840                                exprsPtr, numExprs, RParenLoc);
841}
842
843OffsetOfExpr *OffsetOfExpr::CreateEmpty(ASTContext &C,
844                                        unsigned numComps, unsigned numExprs) {
845  void *Mem = C.Allocate(sizeof(OffsetOfExpr) +
846                         sizeof(OffsetOfNode) * numComps +
847                         sizeof(Expr*) * numExprs);
848  return new (Mem) OffsetOfExpr(numComps, numExprs);
849}
850
851OffsetOfExpr::OffsetOfExpr(ASTContext &C, QualType type,
852                           SourceLocation OperatorLoc, TypeSourceInfo *tsi,
853                           OffsetOfNode* compsPtr, unsigned numComps,
854                           Expr** exprsPtr, unsigned numExprs,
855                           SourceLocation RParenLoc)
856  : Expr(OffsetOfExprClass, type, VK_RValue, OK_Ordinary,
857         /*TypeDependent=*/false,
858         /*ValueDependent=*/tsi->getType()->isDependentType(),
859         tsi->getType()->isInstantiationDependentType(),
860         tsi->getType()->containsUnexpandedParameterPack()),
861    OperatorLoc(OperatorLoc), RParenLoc(RParenLoc), TSInfo(tsi),
862    NumComps(numComps), NumExprs(numExprs)
863{
864  for(unsigned i = 0; i < numComps; ++i) {
865    setComponent(i, compsPtr[i]);
866  }
867
868  for(unsigned i = 0; i < numExprs; ++i) {
869    if (exprsPtr[i]->isTypeDependent() || exprsPtr[i]->isValueDependent())
870      ExprBits.ValueDependent = true;
871    if (exprsPtr[i]->containsUnexpandedParameterPack())
872      ExprBits.ContainsUnexpandedParameterPack = true;
873
874    setIndexExpr(i, exprsPtr[i]);
875  }
876}
877
878IdentifierInfo *OffsetOfExpr::OffsetOfNode::getFieldName() const {
879  assert(getKind() == Field || getKind() == Identifier);
880  if (getKind() == Field)
881    return getField()->getIdentifier();
882
883  return reinterpret_cast<IdentifierInfo *> (Data & ~(uintptr_t)Mask);
884}
885
886MemberExpr *MemberExpr::Create(ASTContext &C, Expr *base, bool isarrow,
887                               NestedNameSpecifierLoc QualifierLoc,
888                               ValueDecl *memberdecl,
889                               DeclAccessPair founddecl,
890                               DeclarationNameInfo nameinfo,
891                               const TemplateArgumentListInfo *targs,
892                               QualType ty,
893                               ExprValueKind vk,
894                               ExprObjectKind ok) {
895  std::size_t Size = sizeof(MemberExpr);
896
897  bool hasQualOrFound = (QualifierLoc ||
898                         founddecl.getDecl() != memberdecl ||
899                         founddecl.getAccess() != memberdecl->getAccess());
900  if (hasQualOrFound)
901    Size += sizeof(MemberNameQualifier);
902
903  if (targs)
904    Size += ASTTemplateArgumentListInfo::sizeFor(*targs);
905
906  void *Mem = C.Allocate(Size, llvm::alignOf<MemberExpr>());
907  MemberExpr *E = new (Mem) MemberExpr(base, isarrow, memberdecl, nameinfo,
908                                       ty, vk, ok);
909
910  if (hasQualOrFound) {
911    // FIXME: Wrong. We should be looking at the member declaration we found.
912    if (QualifierLoc && QualifierLoc.getNestedNameSpecifier()->isDependent()) {
913      E->setValueDependent(true);
914      E->setTypeDependent(true);
915      E->setInstantiationDependent(true);
916    }
917    else if (QualifierLoc &&
918             QualifierLoc.getNestedNameSpecifier()->isInstantiationDependent())
919      E->setInstantiationDependent(true);
920
921    E->HasQualifierOrFoundDecl = true;
922
923    MemberNameQualifier *NQ = E->getMemberQualifier();
924    NQ->QualifierLoc = QualifierLoc;
925    NQ->FoundDecl = founddecl;
926  }
927
928  if (targs) {
929    bool Dependent = false;
930    bool InstantiationDependent = false;
931    bool ContainsUnexpandedParameterPack = false;
932    E->HasExplicitTemplateArgumentList = true;
933    E->getExplicitTemplateArgs().initializeFrom(*targs, Dependent,
934                                                InstantiationDependent,
935                                              ContainsUnexpandedParameterPack);
936    if (InstantiationDependent)
937      E->setInstantiationDependent(true);
938  }
939
940  return E;
941}
942
943SourceRange MemberExpr::getSourceRange() const {
944  SourceLocation StartLoc;
945  if (isImplicitAccess()) {
946    if (hasQualifier())
947      StartLoc = getQualifierLoc().getBeginLoc();
948    else
949      StartLoc = MemberLoc;
950  } else {
951    // FIXME: We don't want this to happen. Rather, we should be able to
952    // detect all kinds of implicit accesses more cleanly.
953    StartLoc = getBase()->getLocStart();
954    if (StartLoc.isInvalid())
955      StartLoc = MemberLoc;
956  }
957
958  SourceLocation EndLoc =
959    HasExplicitTemplateArgumentList? getRAngleLoc()
960                                   : getMemberNameInfo().getEndLoc();
961
962  return SourceRange(StartLoc, EndLoc);
963}
964
965void CastExpr::CheckCastConsistency() const {
966  switch (getCastKind()) {
967  case CK_DerivedToBase:
968  case CK_UncheckedDerivedToBase:
969  case CK_DerivedToBaseMemberPointer:
970  case CK_BaseToDerived:
971  case CK_BaseToDerivedMemberPointer:
972    assert(!path_empty() && "Cast kind should have a base path!");
973    break;
974
975  case CK_CPointerToObjCPointerCast:
976    assert(getType()->isObjCObjectPointerType());
977    assert(getSubExpr()->getType()->isPointerType());
978    goto CheckNoBasePath;
979
980  case CK_BlockPointerToObjCPointerCast:
981    assert(getType()->isObjCObjectPointerType());
982    assert(getSubExpr()->getType()->isBlockPointerType());
983    goto CheckNoBasePath;
984
985  case CK_BitCast:
986    // Arbitrary casts to C pointer types count as bitcasts.
987    // Otherwise, we should only have block and ObjC pointer casts
988    // here if they stay within the type kind.
989    if (!getType()->isPointerType()) {
990      assert(getType()->isObjCObjectPointerType() ==
991             getSubExpr()->getType()->isObjCObjectPointerType());
992      assert(getType()->isBlockPointerType() ==
993             getSubExpr()->getType()->isBlockPointerType());
994    }
995    goto CheckNoBasePath;
996
997  case CK_AnyPointerToBlockPointerCast:
998    assert(getType()->isBlockPointerType());
999    assert(getSubExpr()->getType()->isAnyPointerType() &&
1000           !getSubExpr()->getType()->isBlockPointerType());
1001    goto CheckNoBasePath;
1002
1003  // These should not have an inheritance path.
1004  case CK_Dynamic:
1005  case CK_ToUnion:
1006  case CK_ArrayToPointerDecay:
1007  case CK_FunctionToPointerDecay:
1008  case CK_NullToMemberPointer:
1009  case CK_NullToPointer:
1010  case CK_ConstructorConversion:
1011  case CK_IntegralToPointer:
1012  case CK_PointerToIntegral:
1013  case CK_ToVoid:
1014  case CK_VectorSplat:
1015  case CK_IntegralCast:
1016  case CK_IntegralToFloating:
1017  case CK_FloatingToIntegral:
1018  case CK_FloatingCast:
1019  case CK_ObjCObjectLValueCast:
1020  case CK_FloatingRealToComplex:
1021  case CK_FloatingComplexToReal:
1022  case CK_FloatingComplexCast:
1023  case CK_FloatingComplexToIntegralComplex:
1024  case CK_IntegralRealToComplex:
1025  case CK_IntegralComplexToReal:
1026  case CK_IntegralComplexCast:
1027  case CK_IntegralComplexToFloatingComplex:
1028  case CK_ARCProduceObject:
1029  case CK_ARCConsumeObject:
1030  case CK_ARCReclaimReturnedObject:
1031  case CK_ARCExtendBlockObject:
1032    assert(!getType()->isBooleanType() && "unheralded conversion to bool");
1033    goto CheckNoBasePath;
1034
1035  case CK_Dependent:
1036  case CK_LValueToRValue:
1037  case CK_GetObjCProperty:
1038  case CK_NoOp:
1039  case CK_PointerToBoolean:
1040  case CK_IntegralToBoolean:
1041  case CK_FloatingToBoolean:
1042  case CK_MemberPointerToBoolean:
1043  case CK_FloatingComplexToBoolean:
1044  case CK_IntegralComplexToBoolean:
1045  case CK_LValueBitCast:            // -> bool&
1046  case CK_UserDefinedConversion:    // operator bool()
1047  CheckNoBasePath:
1048    assert(path_empty() && "Cast kind should not have a base path!");
1049    break;
1050  }
1051}
1052
1053const char *CastExpr::getCastKindName() const {
1054  switch (getCastKind()) {
1055  case CK_Dependent:
1056    return "Dependent";
1057  case CK_BitCast:
1058    return "BitCast";
1059  case CK_LValueBitCast:
1060    return "LValueBitCast";
1061  case CK_LValueToRValue:
1062    return "LValueToRValue";
1063  case CK_GetObjCProperty:
1064    return "GetObjCProperty";
1065  case CK_NoOp:
1066    return "NoOp";
1067  case CK_BaseToDerived:
1068    return "BaseToDerived";
1069  case CK_DerivedToBase:
1070    return "DerivedToBase";
1071  case CK_UncheckedDerivedToBase:
1072    return "UncheckedDerivedToBase";
1073  case CK_Dynamic:
1074    return "Dynamic";
1075  case CK_ToUnion:
1076    return "ToUnion";
1077  case CK_ArrayToPointerDecay:
1078    return "ArrayToPointerDecay";
1079  case CK_FunctionToPointerDecay:
1080    return "FunctionToPointerDecay";
1081  case CK_NullToMemberPointer:
1082    return "NullToMemberPointer";
1083  case CK_NullToPointer:
1084    return "NullToPointer";
1085  case CK_BaseToDerivedMemberPointer:
1086    return "BaseToDerivedMemberPointer";
1087  case CK_DerivedToBaseMemberPointer:
1088    return "DerivedToBaseMemberPointer";
1089  case CK_UserDefinedConversion:
1090    return "UserDefinedConversion";
1091  case CK_ConstructorConversion:
1092    return "ConstructorConversion";
1093  case CK_IntegralToPointer:
1094    return "IntegralToPointer";
1095  case CK_PointerToIntegral:
1096    return "PointerToIntegral";
1097  case CK_PointerToBoolean:
1098    return "PointerToBoolean";
1099  case CK_ToVoid:
1100    return "ToVoid";
1101  case CK_VectorSplat:
1102    return "VectorSplat";
1103  case CK_IntegralCast:
1104    return "IntegralCast";
1105  case CK_IntegralToBoolean:
1106    return "IntegralToBoolean";
1107  case CK_IntegralToFloating:
1108    return "IntegralToFloating";
1109  case CK_FloatingToIntegral:
1110    return "FloatingToIntegral";
1111  case CK_FloatingCast:
1112    return "FloatingCast";
1113  case CK_FloatingToBoolean:
1114    return "FloatingToBoolean";
1115  case CK_MemberPointerToBoolean:
1116    return "MemberPointerToBoolean";
1117  case CK_CPointerToObjCPointerCast:
1118    return "CPointerToObjCPointerCast";
1119  case CK_BlockPointerToObjCPointerCast:
1120    return "BlockPointerToObjCPointerCast";
1121  case CK_AnyPointerToBlockPointerCast:
1122    return "AnyPointerToBlockPointerCast";
1123  case CK_ObjCObjectLValueCast:
1124    return "ObjCObjectLValueCast";
1125  case CK_FloatingRealToComplex:
1126    return "FloatingRealToComplex";
1127  case CK_FloatingComplexToReal:
1128    return "FloatingComplexToReal";
1129  case CK_FloatingComplexToBoolean:
1130    return "FloatingComplexToBoolean";
1131  case CK_FloatingComplexCast:
1132    return "FloatingComplexCast";
1133  case CK_FloatingComplexToIntegralComplex:
1134    return "FloatingComplexToIntegralComplex";
1135  case CK_IntegralRealToComplex:
1136    return "IntegralRealToComplex";
1137  case CK_IntegralComplexToReal:
1138    return "IntegralComplexToReal";
1139  case CK_IntegralComplexToBoolean:
1140    return "IntegralComplexToBoolean";
1141  case CK_IntegralComplexCast:
1142    return "IntegralComplexCast";
1143  case CK_IntegralComplexToFloatingComplex:
1144    return "IntegralComplexToFloatingComplex";
1145  case CK_ARCConsumeObject:
1146    return "ARCConsumeObject";
1147  case CK_ARCProduceObject:
1148    return "ARCProduceObject";
1149  case CK_ARCReclaimReturnedObject:
1150    return "ARCReclaimReturnedObject";
1151  case CK_ARCExtendBlockObject:
1152    return "ARCCExtendBlockObject";
1153  }
1154
1155  llvm_unreachable("Unhandled cast kind!");
1156  return 0;
1157}
1158
1159Expr *CastExpr::getSubExprAsWritten() {
1160  Expr *SubExpr = 0;
1161  CastExpr *E = this;
1162  do {
1163    SubExpr = E->getSubExpr();
1164
1165    // Skip through reference binding to temporary.
1166    if (MaterializeTemporaryExpr *Materialize
1167                                  = dyn_cast<MaterializeTemporaryExpr>(SubExpr))
1168      SubExpr = Materialize->GetTemporaryExpr();
1169
1170    // Skip any temporary bindings; they're implicit.
1171    if (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(SubExpr))
1172      SubExpr = Binder->getSubExpr();
1173
1174    // Conversions by constructor and conversion functions have a
1175    // subexpression describing the call; strip it off.
1176    if (E->getCastKind() == CK_ConstructorConversion)
1177      SubExpr = cast<CXXConstructExpr>(SubExpr)->getArg(0);
1178    else if (E->getCastKind() == CK_UserDefinedConversion)
1179      SubExpr = cast<CXXMemberCallExpr>(SubExpr)->getImplicitObjectArgument();
1180
1181    // If the subexpression we're left with is an implicit cast, look
1182    // through that, too.
1183  } while ((E = dyn_cast<ImplicitCastExpr>(SubExpr)));
1184
1185  return SubExpr;
1186}
1187
1188CXXBaseSpecifier **CastExpr::path_buffer() {
1189  switch (getStmtClass()) {
1190#define ABSTRACT_STMT(x)
1191#define CASTEXPR(Type, Base) \
1192  case Stmt::Type##Class: \
1193    return reinterpret_cast<CXXBaseSpecifier**>(static_cast<Type*>(this)+1);
1194#define STMT(Type, Base)
1195#include "clang/AST/StmtNodes.inc"
1196  default:
1197    llvm_unreachable("non-cast expressions not possible here");
1198    return 0;
1199  }
1200}
1201
1202void CastExpr::setCastPath(const CXXCastPath &Path) {
1203  assert(Path.size() == path_size());
1204  memcpy(path_buffer(), Path.data(), Path.size() * sizeof(CXXBaseSpecifier*));
1205}
1206
1207ImplicitCastExpr *ImplicitCastExpr::Create(ASTContext &C, QualType T,
1208                                           CastKind Kind, Expr *Operand,
1209                                           const CXXCastPath *BasePath,
1210                                           ExprValueKind VK) {
1211  unsigned PathSize = (BasePath ? BasePath->size() : 0);
1212  void *Buffer =
1213    C.Allocate(sizeof(ImplicitCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1214  ImplicitCastExpr *E =
1215    new (Buffer) ImplicitCastExpr(T, Kind, Operand, PathSize, VK);
1216  if (PathSize) E->setCastPath(*BasePath);
1217  return E;
1218}
1219
1220ImplicitCastExpr *ImplicitCastExpr::CreateEmpty(ASTContext &C,
1221                                                unsigned PathSize) {
1222  void *Buffer =
1223    C.Allocate(sizeof(ImplicitCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1224  return new (Buffer) ImplicitCastExpr(EmptyShell(), PathSize);
1225}
1226
1227
1228CStyleCastExpr *CStyleCastExpr::Create(ASTContext &C, QualType T,
1229                                       ExprValueKind VK, CastKind K, Expr *Op,
1230                                       const CXXCastPath *BasePath,
1231                                       TypeSourceInfo *WrittenTy,
1232                                       SourceLocation L, SourceLocation R) {
1233  unsigned PathSize = (BasePath ? BasePath->size() : 0);
1234  void *Buffer =
1235    C.Allocate(sizeof(CStyleCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1236  CStyleCastExpr *E =
1237    new (Buffer) CStyleCastExpr(T, VK, K, Op, PathSize, WrittenTy, L, R);
1238  if (PathSize) E->setCastPath(*BasePath);
1239  return E;
1240}
1241
1242CStyleCastExpr *CStyleCastExpr::CreateEmpty(ASTContext &C, unsigned PathSize) {
1243  void *Buffer =
1244    C.Allocate(sizeof(CStyleCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1245  return new (Buffer) CStyleCastExpr(EmptyShell(), PathSize);
1246}
1247
1248/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
1249/// corresponds to, e.g. "<<=".
1250const char *BinaryOperator::getOpcodeStr(Opcode Op) {
1251  switch (Op) {
1252  case BO_PtrMemD:   return ".*";
1253  case BO_PtrMemI:   return "->*";
1254  case BO_Mul:       return "*";
1255  case BO_Div:       return "/";
1256  case BO_Rem:       return "%";
1257  case BO_Add:       return "+";
1258  case BO_Sub:       return "-";
1259  case BO_Shl:       return "<<";
1260  case BO_Shr:       return ">>";
1261  case BO_LT:        return "<";
1262  case BO_GT:        return ">";
1263  case BO_LE:        return "<=";
1264  case BO_GE:        return ">=";
1265  case BO_EQ:        return "==";
1266  case BO_NE:        return "!=";
1267  case BO_And:       return "&";
1268  case BO_Xor:       return "^";
1269  case BO_Or:        return "|";
1270  case BO_LAnd:      return "&&";
1271  case BO_LOr:       return "||";
1272  case BO_Assign:    return "=";
1273  case BO_MulAssign: return "*=";
1274  case BO_DivAssign: return "/=";
1275  case BO_RemAssign: return "%=";
1276  case BO_AddAssign: return "+=";
1277  case BO_SubAssign: return "-=";
1278  case BO_ShlAssign: return "<<=";
1279  case BO_ShrAssign: return ">>=";
1280  case BO_AndAssign: return "&=";
1281  case BO_XorAssign: return "^=";
1282  case BO_OrAssign:  return "|=";
1283  case BO_Comma:     return ",";
1284  }
1285
1286  return "";
1287}
1288
1289BinaryOperatorKind
1290BinaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO) {
1291  switch (OO) {
1292  default: llvm_unreachable("Not an overloadable binary operator");
1293  case OO_Plus: return BO_Add;
1294  case OO_Minus: return BO_Sub;
1295  case OO_Star: return BO_Mul;
1296  case OO_Slash: return BO_Div;
1297  case OO_Percent: return BO_Rem;
1298  case OO_Caret: return BO_Xor;
1299  case OO_Amp: return BO_And;
1300  case OO_Pipe: return BO_Or;
1301  case OO_Equal: return BO_Assign;
1302  case OO_Less: return BO_LT;
1303  case OO_Greater: return BO_GT;
1304  case OO_PlusEqual: return BO_AddAssign;
1305  case OO_MinusEqual: return BO_SubAssign;
1306  case OO_StarEqual: return BO_MulAssign;
1307  case OO_SlashEqual: return BO_DivAssign;
1308  case OO_PercentEqual: return BO_RemAssign;
1309  case OO_CaretEqual: return BO_XorAssign;
1310  case OO_AmpEqual: return BO_AndAssign;
1311  case OO_PipeEqual: return BO_OrAssign;
1312  case OO_LessLess: return BO_Shl;
1313  case OO_GreaterGreater: return BO_Shr;
1314  case OO_LessLessEqual: return BO_ShlAssign;
1315  case OO_GreaterGreaterEqual: return BO_ShrAssign;
1316  case OO_EqualEqual: return BO_EQ;
1317  case OO_ExclaimEqual: return BO_NE;
1318  case OO_LessEqual: return BO_LE;
1319  case OO_GreaterEqual: return BO_GE;
1320  case OO_AmpAmp: return BO_LAnd;
1321  case OO_PipePipe: return BO_LOr;
1322  case OO_Comma: return BO_Comma;
1323  case OO_ArrowStar: return BO_PtrMemI;
1324  }
1325}
1326
1327OverloadedOperatorKind BinaryOperator::getOverloadedOperator(Opcode Opc) {
1328  static const OverloadedOperatorKind OverOps[] = {
1329    /* .* Cannot be overloaded */OO_None, OO_ArrowStar,
1330    OO_Star, OO_Slash, OO_Percent,
1331    OO_Plus, OO_Minus,
1332    OO_LessLess, OO_GreaterGreater,
1333    OO_Less, OO_Greater, OO_LessEqual, OO_GreaterEqual,
1334    OO_EqualEqual, OO_ExclaimEqual,
1335    OO_Amp,
1336    OO_Caret,
1337    OO_Pipe,
1338    OO_AmpAmp,
1339    OO_PipePipe,
1340    OO_Equal, OO_StarEqual,
1341    OO_SlashEqual, OO_PercentEqual,
1342    OO_PlusEqual, OO_MinusEqual,
1343    OO_LessLessEqual, OO_GreaterGreaterEqual,
1344    OO_AmpEqual, OO_CaretEqual,
1345    OO_PipeEqual,
1346    OO_Comma
1347  };
1348  return OverOps[Opc];
1349}
1350
1351InitListExpr::InitListExpr(ASTContext &C, SourceLocation lbraceloc,
1352                           Expr **initExprs, unsigned numInits,
1353                           SourceLocation rbraceloc)
1354  : Expr(InitListExprClass, QualType(), VK_RValue, OK_Ordinary, false, false,
1355         false, false),
1356    InitExprs(C, numInits),
1357    LBraceLoc(lbraceloc), RBraceLoc(rbraceloc), SyntacticForm(0),
1358    HadArrayRangeDesignator(false)
1359{
1360  for (unsigned I = 0; I != numInits; ++I) {
1361    if (initExprs[I]->isTypeDependent())
1362      ExprBits.TypeDependent = true;
1363    if (initExprs[I]->isValueDependent())
1364      ExprBits.ValueDependent = true;
1365    if (initExprs[I]->isInstantiationDependent())
1366      ExprBits.InstantiationDependent = true;
1367    if (initExprs[I]->containsUnexpandedParameterPack())
1368      ExprBits.ContainsUnexpandedParameterPack = true;
1369  }
1370
1371  InitExprs.insert(C, InitExprs.end(), initExprs, initExprs+numInits);
1372}
1373
1374void InitListExpr::reserveInits(ASTContext &C, unsigned NumInits) {
1375  if (NumInits > InitExprs.size())
1376    InitExprs.reserve(C, NumInits);
1377}
1378
1379void InitListExpr::resizeInits(ASTContext &C, unsigned NumInits) {
1380  InitExprs.resize(C, NumInits, 0);
1381}
1382
1383Expr *InitListExpr::updateInit(ASTContext &C, unsigned Init, Expr *expr) {
1384  if (Init >= InitExprs.size()) {
1385    InitExprs.insert(C, InitExprs.end(), Init - InitExprs.size() + 1, 0);
1386    InitExprs.back() = expr;
1387    return 0;
1388  }
1389
1390  Expr *Result = cast_or_null<Expr>(InitExprs[Init]);
1391  InitExprs[Init] = expr;
1392  return Result;
1393}
1394
1395void InitListExpr::setArrayFiller(Expr *filler) {
1396  ArrayFillerOrUnionFieldInit = filler;
1397  // Fill out any "holes" in the array due to designated initializers.
1398  Expr **inits = getInits();
1399  for (unsigned i = 0, e = getNumInits(); i != e; ++i)
1400    if (inits[i] == 0)
1401      inits[i] = filler;
1402}
1403
1404SourceRange InitListExpr::getSourceRange() const {
1405  if (SyntacticForm)
1406    return SyntacticForm->getSourceRange();
1407  SourceLocation Beg = LBraceLoc, End = RBraceLoc;
1408  if (Beg.isInvalid()) {
1409    // Find the first non-null initializer.
1410    for (InitExprsTy::const_iterator I = InitExprs.begin(),
1411                                     E = InitExprs.end();
1412      I != E; ++I) {
1413      if (Stmt *S = *I) {
1414        Beg = S->getLocStart();
1415        break;
1416      }
1417    }
1418  }
1419  if (End.isInvalid()) {
1420    // Find the first non-null initializer from the end.
1421    for (InitExprsTy::const_reverse_iterator I = InitExprs.rbegin(),
1422                                             E = InitExprs.rend();
1423      I != E; ++I) {
1424      if (Stmt *S = *I) {
1425        End = S->getSourceRange().getEnd();
1426        break;
1427      }
1428    }
1429  }
1430  return SourceRange(Beg, End);
1431}
1432
1433/// getFunctionType - Return the underlying function type for this block.
1434///
1435const FunctionType *BlockExpr::getFunctionType() const {
1436  return getType()->getAs<BlockPointerType>()->
1437                    getPointeeType()->getAs<FunctionType>();
1438}
1439
1440SourceLocation BlockExpr::getCaretLocation() const {
1441  return TheBlock->getCaretLocation();
1442}
1443const Stmt *BlockExpr::getBody() const {
1444  return TheBlock->getBody();
1445}
1446Stmt *BlockExpr::getBody() {
1447  return TheBlock->getBody();
1448}
1449
1450
1451//===----------------------------------------------------------------------===//
1452// Generic Expression Routines
1453//===----------------------------------------------------------------------===//
1454
1455/// isUnusedResultAWarning - Return true if this immediate expression should
1456/// be warned about if the result is unused.  If so, fill in Loc and Ranges
1457/// with location to warn on and the source range[s] to report with the
1458/// warning.
1459bool Expr::isUnusedResultAWarning(SourceLocation &Loc, SourceRange &R1,
1460                                  SourceRange &R2, ASTContext &Ctx) const {
1461  // Don't warn if the expr is type dependent. The type could end up
1462  // instantiating to void.
1463  if (isTypeDependent())
1464    return false;
1465
1466  switch (getStmtClass()) {
1467  default:
1468    if (getType()->isVoidType())
1469      return false;
1470    Loc = getExprLoc();
1471    R1 = getSourceRange();
1472    return true;
1473  case ParenExprClass:
1474    return cast<ParenExpr>(this)->getSubExpr()->
1475      isUnusedResultAWarning(Loc, R1, R2, Ctx);
1476  case GenericSelectionExprClass:
1477    return cast<GenericSelectionExpr>(this)->getResultExpr()->
1478      isUnusedResultAWarning(Loc, R1, R2, Ctx);
1479  case UnaryOperatorClass: {
1480    const UnaryOperator *UO = cast<UnaryOperator>(this);
1481
1482    switch (UO->getOpcode()) {
1483    default: break;
1484    case UO_PostInc:
1485    case UO_PostDec:
1486    case UO_PreInc:
1487    case UO_PreDec:                 // ++/--
1488      return false;  // Not a warning.
1489    case UO_Deref:
1490      // Dereferencing a volatile pointer is a side-effect.
1491      if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1492        return false;
1493      break;
1494    case UO_Real:
1495    case UO_Imag:
1496      // accessing a piece of a volatile complex is a side-effect.
1497      if (Ctx.getCanonicalType(UO->getSubExpr()->getType())
1498          .isVolatileQualified())
1499        return false;
1500      break;
1501    case UO_Extension:
1502      return UO->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1503    }
1504    Loc = UO->getOperatorLoc();
1505    R1 = UO->getSubExpr()->getSourceRange();
1506    return true;
1507  }
1508  case BinaryOperatorClass: {
1509    const BinaryOperator *BO = cast<BinaryOperator>(this);
1510    switch (BO->getOpcode()) {
1511      default:
1512        break;
1513      // Consider the RHS of comma for side effects. LHS was checked by
1514      // Sema::CheckCommaOperands.
1515      case BO_Comma:
1516        // ((foo = <blah>), 0) is an idiom for hiding the result (and
1517        // lvalue-ness) of an assignment written in a macro.
1518        if (IntegerLiteral *IE =
1519              dyn_cast<IntegerLiteral>(BO->getRHS()->IgnoreParens()))
1520          if (IE->getValue() == 0)
1521            return false;
1522        return BO->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1523      // Consider '||', '&&' to have side effects if the LHS or RHS does.
1524      case BO_LAnd:
1525      case BO_LOr:
1526        if (!BO->getLHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx) ||
1527            !BO->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx))
1528          return false;
1529        break;
1530    }
1531    if (BO->isAssignmentOp())
1532      return false;
1533    Loc = BO->getOperatorLoc();
1534    R1 = BO->getLHS()->getSourceRange();
1535    R2 = BO->getRHS()->getSourceRange();
1536    return true;
1537  }
1538  case CompoundAssignOperatorClass:
1539  case VAArgExprClass:
1540    return false;
1541
1542  case ConditionalOperatorClass: {
1543    // If only one of the LHS or RHS is a warning, the operator might
1544    // be being used for control flow. Only warn if both the LHS and
1545    // RHS are warnings.
1546    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
1547    if (!Exp->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx))
1548      return false;
1549    if (!Exp->getLHS())
1550      return true;
1551    return Exp->getLHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1552  }
1553
1554  case MemberExprClass:
1555    // If the base pointer or element is to a volatile pointer/field, accessing
1556    // it is a side effect.
1557    if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1558      return false;
1559    Loc = cast<MemberExpr>(this)->getMemberLoc();
1560    R1 = SourceRange(Loc, Loc);
1561    R2 = cast<MemberExpr>(this)->getBase()->getSourceRange();
1562    return true;
1563
1564  case ArraySubscriptExprClass:
1565    // If the base pointer or element is to a volatile pointer/field, accessing
1566    // it is a side effect.
1567    if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1568      return false;
1569    Loc = cast<ArraySubscriptExpr>(this)->getRBracketLoc();
1570    R1 = cast<ArraySubscriptExpr>(this)->getLHS()->getSourceRange();
1571    R2 = cast<ArraySubscriptExpr>(this)->getRHS()->getSourceRange();
1572    return true;
1573
1574  case CXXOperatorCallExprClass: {
1575    // We warn about operator== and operator!= even when user-defined operator
1576    // overloads as there is no reasonable way to define these such that they
1577    // have non-trivial, desirable side-effects. See the -Wunused-comparison
1578    // warning: these operators are commonly typo'ed, and so warning on them
1579    // provides additional value as well. If this list is updated,
1580    // DiagnoseUnusedComparison should be as well.
1581    const CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(this);
1582    if (Op->getOperator() == OO_EqualEqual ||
1583        Op->getOperator() == OO_ExclaimEqual) {
1584      Loc = Op->getOperatorLoc();
1585      R1 = Op->getSourceRange();
1586      return true;
1587    }
1588
1589    // Fallthrough for generic call handling.
1590  }
1591  case CallExprClass:
1592  case CXXMemberCallExprClass: {
1593    // If this is a direct call, get the callee.
1594    const CallExpr *CE = cast<CallExpr>(this);
1595    if (const Decl *FD = CE->getCalleeDecl()) {
1596      // If the callee has attribute pure, const, or warn_unused_result, warn
1597      // about it. void foo() { strlen("bar"); } should warn.
1598      //
1599      // Note: If new cases are added here, DiagnoseUnusedExprResult should be
1600      // updated to match for QoI.
1601      if (FD->getAttr<WarnUnusedResultAttr>() ||
1602          FD->getAttr<PureAttr>() || FD->getAttr<ConstAttr>()) {
1603        Loc = CE->getCallee()->getLocStart();
1604        R1 = CE->getCallee()->getSourceRange();
1605
1606        if (unsigned NumArgs = CE->getNumArgs())
1607          R2 = SourceRange(CE->getArg(0)->getLocStart(),
1608                           CE->getArg(NumArgs-1)->getLocEnd());
1609        return true;
1610      }
1611    }
1612    return false;
1613  }
1614
1615  case CXXTemporaryObjectExprClass:
1616  case CXXConstructExprClass:
1617    return false;
1618
1619  case ObjCMessageExprClass: {
1620    const ObjCMessageExpr *ME = cast<ObjCMessageExpr>(this);
1621    if (Ctx.getLangOptions().ObjCAutoRefCount &&
1622        ME->isInstanceMessage() &&
1623        !ME->getType()->isVoidType() &&
1624        ME->getSelector().getIdentifierInfoForSlot(0) &&
1625        ME->getSelector().getIdentifierInfoForSlot(0)
1626                                               ->getName().startswith("init")) {
1627      Loc = getExprLoc();
1628      R1 = ME->getSourceRange();
1629      return true;
1630    }
1631
1632    const ObjCMethodDecl *MD = ME->getMethodDecl();
1633    if (MD && MD->getAttr<WarnUnusedResultAttr>()) {
1634      Loc = getExprLoc();
1635      return true;
1636    }
1637    return false;
1638  }
1639
1640  case ObjCPropertyRefExprClass:
1641    Loc = getExprLoc();
1642    R1 = getSourceRange();
1643    return true;
1644
1645  case StmtExprClass: {
1646    // Statement exprs don't logically have side effects themselves, but are
1647    // sometimes used in macros in ways that give them a type that is unused.
1648    // For example ({ blah; foo(); }) will end up with a type if foo has a type.
1649    // however, if the result of the stmt expr is dead, we don't want to emit a
1650    // warning.
1651    const CompoundStmt *CS = cast<StmtExpr>(this)->getSubStmt();
1652    if (!CS->body_empty()) {
1653      if (const Expr *E = dyn_cast<Expr>(CS->body_back()))
1654        return E->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1655      if (const LabelStmt *Label = dyn_cast<LabelStmt>(CS->body_back()))
1656        if (const Expr *E = dyn_cast<Expr>(Label->getSubStmt()))
1657          return E->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1658    }
1659
1660    if (getType()->isVoidType())
1661      return false;
1662    Loc = cast<StmtExpr>(this)->getLParenLoc();
1663    R1 = getSourceRange();
1664    return true;
1665  }
1666  case CStyleCastExprClass:
1667    // If this is an explicit cast to void, allow it.  People do this when they
1668    // think they know what they're doing :).
1669    if (getType()->isVoidType())
1670      return false;
1671    Loc = cast<CStyleCastExpr>(this)->getLParenLoc();
1672    R1 = cast<CStyleCastExpr>(this)->getSubExpr()->getSourceRange();
1673    return true;
1674  case CXXFunctionalCastExprClass: {
1675    if (getType()->isVoidType())
1676      return false;
1677    const CastExpr *CE = cast<CastExpr>(this);
1678
1679    // If this is a cast to void or a constructor conversion, check the operand.
1680    // Otherwise, the result of the cast is unused.
1681    if (CE->getCastKind() == CK_ToVoid ||
1682        CE->getCastKind() == CK_ConstructorConversion)
1683      return (cast<CastExpr>(this)->getSubExpr()
1684              ->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1685    Loc = cast<CXXFunctionalCastExpr>(this)->getTypeBeginLoc();
1686    R1 = cast<CXXFunctionalCastExpr>(this)->getSubExpr()->getSourceRange();
1687    return true;
1688  }
1689
1690  case ImplicitCastExprClass:
1691    // Check the operand, since implicit casts are inserted by Sema
1692    return (cast<ImplicitCastExpr>(this)
1693            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1694
1695  case CXXDefaultArgExprClass:
1696    return (cast<CXXDefaultArgExpr>(this)
1697            ->getExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1698
1699  case CXXNewExprClass:
1700    // FIXME: In theory, there might be new expressions that don't have side
1701    // effects (e.g. a placement new with an uninitialized POD).
1702  case CXXDeleteExprClass:
1703    return false;
1704  case CXXBindTemporaryExprClass:
1705    return (cast<CXXBindTemporaryExpr>(this)
1706            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1707  case ExprWithCleanupsClass:
1708    return (cast<ExprWithCleanups>(this)
1709            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1710  }
1711}
1712
1713/// isOBJCGCCandidate - Check if an expression is objc gc'able.
1714/// returns true, if it is; false otherwise.
1715bool Expr::isOBJCGCCandidate(ASTContext &Ctx) const {
1716  const Expr *E = IgnoreParens();
1717  switch (E->getStmtClass()) {
1718  default:
1719    return false;
1720  case ObjCIvarRefExprClass:
1721    return true;
1722  case Expr::UnaryOperatorClass:
1723    return cast<UnaryOperator>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1724  case ImplicitCastExprClass:
1725    return cast<ImplicitCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1726  case MaterializeTemporaryExprClass:
1727    return cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr()
1728                                                      ->isOBJCGCCandidate(Ctx);
1729  case CStyleCastExprClass:
1730    return cast<CStyleCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1731  case DeclRefExprClass: {
1732    const Decl *D = cast<DeclRefExpr>(E)->getDecl();
1733    if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1734      if (VD->hasGlobalStorage())
1735        return true;
1736      QualType T = VD->getType();
1737      // dereferencing to a  pointer is always a gc'able candidate,
1738      // unless it is __weak.
1739      return T->isPointerType() &&
1740             (Ctx.getObjCGCAttrKind(T) != Qualifiers::Weak);
1741    }
1742    return false;
1743  }
1744  case MemberExprClass: {
1745    const MemberExpr *M = cast<MemberExpr>(E);
1746    return M->getBase()->isOBJCGCCandidate(Ctx);
1747  }
1748  case ArraySubscriptExprClass:
1749    return cast<ArraySubscriptExpr>(E)->getBase()->isOBJCGCCandidate(Ctx);
1750  }
1751}
1752
1753bool Expr::isBoundMemberFunction(ASTContext &Ctx) const {
1754  if (isTypeDependent())
1755    return false;
1756  return ClassifyLValue(Ctx) == Expr::LV_MemberFunction;
1757}
1758
1759QualType Expr::findBoundMemberType(const Expr *expr) {
1760  assert(expr->getType()->isSpecificPlaceholderType(BuiltinType::BoundMember));
1761
1762  // Bound member expressions are always one of these possibilities:
1763  //   x->m      x.m      x->*y      x.*y
1764  // (possibly parenthesized)
1765
1766  expr = expr->IgnoreParens();
1767  if (const MemberExpr *mem = dyn_cast<MemberExpr>(expr)) {
1768    assert(isa<CXXMethodDecl>(mem->getMemberDecl()));
1769    return mem->getMemberDecl()->getType();
1770  }
1771
1772  if (const BinaryOperator *op = dyn_cast<BinaryOperator>(expr)) {
1773    QualType type = op->getRHS()->getType()->castAs<MemberPointerType>()
1774                      ->getPointeeType();
1775    assert(type->isFunctionType());
1776    return type;
1777  }
1778
1779  assert(isa<UnresolvedMemberExpr>(expr));
1780  return QualType();
1781}
1782
1783static Expr::CanThrowResult MergeCanThrow(Expr::CanThrowResult CT1,
1784                                          Expr::CanThrowResult CT2) {
1785  // CanThrowResult constants are ordered so that the maximum is the correct
1786  // merge result.
1787  return CT1 > CT2 ? CT1 : CT2;
1788}
1789
1790static Expr::CanThrowResult CanSubExprsThrow(ASTContext &C, const Expr *CE) {
1791  Expr *E = const_cast<Expr*>(CE);
1792  Expr::CanThrowResult R = Expr::CT_Cannot;
1793  for (Expr::child_range I = E->children(); I && R != Expr::CT_Can; ++I) {
1794    R = MergeCanThrow(R, cast<Expr>(*I)->CanThrow(C));
1795  }
1796  return R;
1797}
1798
1799static Expr::CanThrowResult CanCalleeThrow(ASTContext &Ctx, const Expr *E,
1800                                           const Decl *D,
1801                                           bool NullThrows = true) {
1802  if (!D)
1803    return NullThrows ? Expr::CT_Can : Expr::CT_Cannot;
1804
1805  // See if we can get a function type from the decl somehow.
1806  const ValueDecl *VD = dyn_cast<ValueDecl>(D);
1807  if (!VD) // If we have no clue what we're calling, assume the worst.
1808    return Expr::CT_Can;
1809
1810  // As an extension, we assume that __attribute__((nothrow)) functions don't
1811  // throw.
1812  if (isa<FunctionDecl>(D) && D->hasAttr<NoThrowAttr>())
1813    return Expr::CT_Cannot;
1814
1815  QualType T = VD->getType();
1816  const FunctionProtoType *FT;
1817  if ((FT = T->getAs<FunctionProtoType>())) {
1818  } else if (const PointerType *PT = T->getAs<PointerType>())
1819    FT = PT->getPointeeType()->getAs<FunctionProtoType>();
1820  else if (const ReferenceType *RT = T->getAs<ReferenceType>())
1821    FT = RT->getPointeeType()->getAs<FunctionProtoType>();
1822  else if (const MemberPointerType *MT = T->getAs<MemberPointerType>())
1823    FT = MT->getPointeeType()->getAs<FunctionProtoType>();
1824  else if (const BlockPointerType *BT = T->getAs<BlockPointerType>())
1825    FT = BT->getPointeeType()->getAs<FunctionProtoType>();
1826
1827  if (!FT)
1828    return Expr::CT_Can;
1829
1830  if (FT->getExceptionSpecType() == EST_Delayed) {
1831    assert(isa<CXXConstructorDecl>(D) &&
1832           "only constructor exception specs can be unknown");
1833    Ctx.getDiagnostics().Report(E->getLocStart(),
1834                                diag::err_exception_spec_unknown)
1835      << E->getSourceRange();
1836    return Expr::CT_Can;
1837  }
1838
1839  return FT->isNothrow(Ctx) ? Expr::CT_Cannot : Expr::CT_Can;
1840}
1841
1842static Expr::CanThrowResult CanDynamicCastThrow(const CXXDynamicCastExpr *DC) {
1843  if (DC->isTypeDependent())
1844    return Expr::CT_Dependent;
1845
1846  if (!DC->getTypeAsWritten()->isReferenceType())
1847    return Expr::CT_Cannot;
1848
1849  if (DC->getSubExpr()->isTypeDependent())
1850    return Expr::CT_Dependent;
1851
1852  return DC->getCastKind() == clang::CK_Dynamic? Expr::CT_Can : Expr::CT_Cannot;
1853}
1854
1855static Expr::CanThrowResult CanTypeidThrow(ASTContext &C,
1856                                           const CXXTypeidExpr *DC) {
1857  if (DC->isTypeOperand())
1858    return Expr::CT_Cannot;
1859
1860  Expr *Op = DC->getExprOperand();
1861  if (Op->isTypeDependent())
1862    return Expr::CT_Dependent;
1863
1864  const RecordType *RT = Op->getType()->getAs<RecordType>();
1865  if (!RT)
1866    return Expr::CT_Cannot;
1867
1868  if (!cast<CXXRecordDecl>(RT->getDecl())->isPolymorphic())
1869    return Expr::CT_Cannot;
1870
1871  if (Op->Classify(C).isPRValue())
1872    return Expr::CT_Cannot;
1873
1874  return Expr::CT_Can;
1875}
1876
1877Expr::CanThrowResult Expr::CanThrow(ASTContext &C) const {
1878  // C++ [expr.unary.noexcept]p3:
1879  //   [Can throw] if in a potentially-evaluated context the expression would
1880  //   contain:
1881  switch (getStmtClass()) {
1882  case CXXThrowExprClass:
1883    //   - a potentially evaluated throw-expression
1884    return CT_Can;
1885
1886  case CXXDynamicCastExprClass: {
1887    //   - a potentially evaluated dynamic_cast expression dynamic_cast<T>(v),
1888    //     where T is a reference type, that requires a run-time check
1889    CanThrowResult CT = CanDynamicCastThrow(cast<CXXDynamicCastExpr>(this));
1890    if (CT == CT_Can)
1891      return CT;
1892    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1893  }
1894
1895  case CXXTypeidExprClass:
1896    //   - a potentially evaluated typeid expression applied to a glvalue
1897    //     expression whose type is a polymorphic class type
1898    return CanTypeidThrow(C, cast<CXXTypeidExpr>(this));
1899
1900    //   - a potentially evaluated call to a function, member function, function
1901    //     pointer, or member function pointer that does not have a non-throwing
1902    //     exception-specification
1903  case CallExprClass:
1904  case CXXOperatorCallExprClass:
1905  case CXXMemberCallExprClass: {
1906    const CallExpr *CE = cast<CallExpr>(this);
1907    CanThrowResult CT;
1908    if (isTypeDependent())
1909      CT = CT_Dependent;
1910    else if (isa<CXXPseudoDestructorExpr>(CE->getCallee()->IgnoreParens()))
1911      CT = CT_Cannot;
1912    else
1913      CT = CanCalleeThrow(C, this, CE->getCalleeDecl());
1914    if (CT == CT_Can)
1915      return CT;
1916    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1917  }
1918
1919  case CXXConstructExprClass:
1920  case CXXTemporaryObjectExprClass: {
1921    CanThrowResult CT = CanCalleeThrow(C, this,
1922        cast<CXXConstructExpr>(this)->getConstructor());
1923    if (CT == CT_Can)
1924      return CT;
1925    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1926  }
1927
1928  case CXXNewExprClass: {
1929    CanThrowResult CT;
1930    if (isTypeDependent())
1931      CT = CT_Dependent;
1932    else
1933      CT = MergeCanThrow(
1934        CanCalleeThrow(C, this, cast<CXXNewExpr>(this)->getOperatorNew()),
1935        CanCalleeThrow(C, this, cast<CXXNewExpr>(this)->getConstructor(),
1936                       /*NullThrows*/false));
1937    if (CT == CT_Can)
1938      return CT;
1939    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1940  }
1941
1942  case CXXDeleteExprClass: {
1943    CanThrowResult CT;
1944    QualType DTy = cast<CXXDeleteExpr>(this)->getDestroyedType();
1945    if (DTy.isNull() || DTy->isDependentType()) {
1946      CT = CT_Dependent;
1947    } else {
1948      CT = CanCalleeThrow(C, this,
1949                          cast<CXXDeleteExpr>(this)->getOperatorDelete());
1950      if (const RecordType *RT = DTy->getAs<RecordType>()) {
1951        const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1952        CT = MergeCanThrow(CT, CanCalleeThrow(C, this, RD->getDestructor()));
1953      }
1954      if (CT == CT_Can)
1955        return CT;
1956    }
1957    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1958  }
1959
1960  case CXXBindTemporaryExprClass: {
1961    // The bound temporary has to be destroyed again, which might throw.
1962    CanThrowResult CT = CanCalleeThrow(C, this,
1963      cast<CXXBindTemporaryExpr>(this)->getTemporary()->getDestructor());
1964    if (CT == CT_Can)
1965      return CT;
1966    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1967  }
1968
1969    // ObjC message sends are like function calls, but never have exception
1970    // specs.
1971  case ObjCMessageExprClass:
1972  case ObjCPropertyRefExprClass:
1973    return CT_Can;
1974
1975    // Many other things have subexpressions, so we have to test those.
1976    // Some are simple:
1977  case ParenExprClass:
1978  case MemberExprClass:
1979  case CXXReinterpretCastExprClass:
1980  case CXXConstCastExprClass:
1981  case ConditionalOperatorClass:
1982  case CompoundLiteralExprClass:
1983  case ExtVectorElementExprClass:
1984  case InitListExprClass:
1985  case DesignatedInitExprClass:
1986  case ParenListExprClass:
1987  case VAArgExprClass:
1988  case CXXDefaultArgExprClass:
1989  case ExprWithCleanupsClass:
1990  case ObjCIvarRefExprClass:
1991  case ObjCIsaExprClass:
1992  case ShuffleVectorExprClass:
1993    return CanSubExprsThrow(C, this);
1994
1995    // Some might be dependent for other reasons.
1996  case UnaryOperatorClass:
1997  case ArraySubscriptExprClass:
1998  case ImplicitCastExprClass:
1999  case CStyleCastExprClass:
2000  case CXXStaticCastExprClass:
2001  case CXXFunctionalCastExprClass:
2002  case BinaryOperatorClass:
2003  case CompoundAssignOperatorClass:
2004  case MaterializeTemporaryExprClass: {
2005    CanThrowResult CT = isTypeDependent() ? CT_Dependent : CT_Cannot;
2006    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
2007  }
2008
2009    // FIXME: We should handle StmtExpr, but that opens a MASSIVE can of worms.
2010  case StmtExprClass:
2011    return CT_Can;
2012
2013  case ChooseExprClass:
2014    if (isTypeDependent() || isValueDependent())
2015      return CT_Dependent;
2016    return cast<ChooseExpr>(this)->getChosenSubExpr(C)->CanThrow(C);
2017
2018  case GenericSelectionExprClass:
2019    if (cast<GenericSelectionExpr>(this)->isResultDependent())
2020      return CT_Dependent;
2021    return cast<GenericSelectionExpr>(this)->getResultExpr()->CanThrow(C);
2022
2023    // Some expressions are always dependent.
2024  case DependentScopeDeclRefExprClass:
2025  case CXXUnresolvedConstructExprClass:
2026  case CXXDependentScopeMemberExprClass:
2027    return CT_Dependent;
2028
2029  default:
2030    // All other expressions don't have subexpressions, or else they are
2031    // unevaluated.
2032    return CT_Cannot;
2033  }
2034}
2035
2036Expr* Expr::IgnoreParens() {
2037  Expr* E = this;
2038  while (true) {
2039    if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
2040      E = P->getSubExpr();
2041      continue;
2042    }
2043    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2044      if (P->getOpcode() == UO_Extension) {
2045        E = P->getSubExpr();
2046        continue;
2047      }
2048    }
2049    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2050      if (!P->isResultDependent()) {
2051        E = P->getResultExpr();
2052        continue;
2053      }
2054    }
2055    return E;
2056  }
2057}
2058
2059/// IgnoreParenCasts - Ignore parentheses and casts.  Strip off any ParenExpr
2060/// or CastExprs or ImplicitCastExprs, returning their operand.
2061Expr *Expr::IgnoreParenCasts() {
2062  Expr *E = this;
2063  while (true) {
2064    if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
2065      E = P->getSubExpr();
2066      continue;
2067    }
2068    if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2069      E = P->getSubExpr();
2070      continue;
2071    }
2072    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2073      if (P->getOpcode() == UO_Extension) {
2074        E = P->getSubExpr();
2075        continue;
2076      }
2077    }
2078    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2079      if (!P->isResultDependent()) {
2080        E = P->getResultExpr();
2081        continue;
2082      }
2083    }
2084    if (MaterializeTemporaryExpr *Materialize
2085                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2086      E = Materialize->GetTemporaryExpr();
2087      continue;
2088    }
2089    if (SubstNonTypeTemplateParmExpr *NTTP
2090                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2091      E = NTTP->getReplacement();
2092      continue;
2093    }
2094    return E;
2095  }
2096}
2097
2098/// IgnoreParenLValueCasts - Ignore parentheses and lvalue-to-rvalue
2099/// casts.  This is intended purely as a temporary workaround for code
2100/// that hasn't yet been rewritten to do the right thing about those
2101/// casts, and may disappear along with the last internal use.
2102Expr *Expr::IgnoreParenLValueCasts() {
2103  Expr *E = this;
2104  while (true) {
2105    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2106      E = P->getSubExpr();
2107      continue;
2108    } else if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2109      if (P->getCastKind() == CK_LValueToRValue) {
2110        E = P->getSubExpr();
2111        continue;
2112      }
2113    } else if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2114      if (P->getOpcode() == UO_Extension) {
2115        E = P->getSubExpr();
2116        continue;
2117      }
2118    } else if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2119      if (!P->isResultDependent()) {
2120        E = P->getResultExpr();
2121        continue;
2122      }
2123    } else if (MaterializeTemporaryExpr *Materialize
2124                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2125      E = Materialize->GetTemporaryExpr();
2126      continue;
2127    } else if (SubstNonTypeTemplateParmExpr *NTTP
2128                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2129      E = NTTP->getReplacement();
2130      continue;
2131    }
2132    break;
2133  }
2134  return E;
2135}
2136
2137Expr *Expr::IgnoreParenImpCasts() {
2138  Expr *E = this;
2139  while (true) {
2140    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2141      E = P->getSubExpr();
2142      continue;
2143    }
2144    if (ImplicitCastExpr *P = dyn_cast<ImplicitCastExpr>(E)) {
2145      E = P->getSubExpr();
2146      continue;
2147    }
2148    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2149      if (P->getOpcode() == UO_Extension) {
2150        E = P->getSubExpr();
2151        continue;
2152      }
2153    }
2154    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2155      if (!P->isResultDependent()) {
2156        E = P->getResultExpr();
2157        continue;
2158      }
2159    }
2160    if (MaterializeTemporaryExpr *Materialize
2161                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2162      E = Materialize->GetTemporaryExpr();
2163      continue;
2164    }
2165    if (SubstNonTypeTemplateParmExpr *NTTP
2166                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2167      E = NTTP->getReplacement();
2168      continue;
2169    }
2170    return E;
2171  }
2172}
2173
2174Expr *Expr::IgnoreConversionOperator() {
2175  if (CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(this)) {
2176    if (MCE->getMethodDecl() && isa<CXXConversionDecl>(MCE->getMethodDecl()))
2177      return MCE->getImplicitObjectArgument();
2178  }
2179  return this;
2180}
2181
2182/// IgnoreParenNoopCasts - Ignore parentheses and casts that do not change the
2183/// value (including ptr->int casts of the same size).  Strip off any
2184/// ParenExpr or CastExprs, returning their operand.
2185Expr *Expr::IgnoreParenNoopCasts(ASTContext &Ctx) {
2186  Expr *E = this;
2187  while (true) {
2188    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2189      E = P->getSubExpr();
2190      continue;
2191    }
2192
2193    if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2194      // We ignore integer <-> casts that are of the same width, ptr<->ptr and
2195      // ptr<->int casts of the same width.  We also ignore all identity casts.
2196      Expr *SE = P->getSubExpr();
2197
2198      if (Ctx.hasSameUnqualifiedType(E->getType(), SE->getType())) {
2199        E = SE;
2200        continue;
2201      }
2202
2203      if ((E->getType()->isPointerType() ||
2204           E->getType()->isIntegralType(Ctx)) &&
2205          (SE->getType()->isPointerType() ||
2206           SE->getType()->isIntegralType(Ctx)) &&
2207          Ctx.getTypeSize(E->getType()) == Ctx.getTypeSize(SE->getType())) {
2208        E = SE;
2209        continue;
2210      }
2211    }
2212
2213    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2214      if (P->getOpcode() == UO_Extension) {
2215        E = P->getSubExpr();
2216        continue;
2217      }
2218    }
2219
2220    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2221      if (!P->isResultDependent()) {
2222        E = P->getResultExpr();
2223        continue;
2224      }
2225    }
2226
2227    if (SubstNonTypeTemplateParmExpr *NTTP
2228                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2229      E = NTTP->getReplacement();
2230      continue;
2231    }
2232
2233    return E;
2234  }
2235}
2236
2237bool Expr::isDefaultArgument() const {
2238  const Expr *E = this;
2239  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
2240    E = M->GetTemporaryExpr();
2241
2242  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
2243    E = ICE->getSubExprAsWritten();
2244
2245  return isa<CXXDefaultArgExpr>(E);
2246}
2247
2248/// \brief Skip over any no-op casts and any temporary-binding
2249/// expressions.
2250static const Expr *skipTemporaryBindingsNoOpCastsAndParens(const Expr *E) {
2251  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
2252    E = M->GetTemporaryExpr();
2253
2254  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2255    if (ICE->getCastKind() == CK_NoOp)
2256      E = ICE->getSubExpr();
2257    else
2258      break;
2259  }
2260
2261  while (const CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(E))
2262    E = BE->getSubExpr();
2263
2264  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2265    if (ICE->getCastKind() == CK_NoOp)
2266      E = ICE->getSubExpr();
2267    else
2268      break;
2269  }
2270
2271  return E->IgnoreParens();
2272}
2273
2274/// isTemporaryObject - Determines if this expression produces a
2275/// temporary of the given class type.
2276bool Expr::isTemporaryObject(ASTContext &C, const CXXRecordDecl *TempTy) const {
2277  if (!C.hasSameUnqualifiedType(getType(), C.getTypeDeclType(TempTy)))
2278    return false;
2279
2280  const Expr *E = skipTemporaryBindingsNoOpCastsAndParens(this);
2281
2282  // Temporaries are by definition pr-values of class type.
2283  if (!E->Classify(C).isPRValue()) {
2284    // In this context, property reference is a message call and is pr-value.
2285    if (!isa<ObjCPropertyRefExpr>(E))
2286      return false;
2287  }
2288
2289  // Black-list a few cases which yield pr-values of class type that don't
2290  // refer to temporaries of that type:
2291
2292  // - implicit derived-to-base conversions
2293  if (isa<ImplicitCastExpr>(E)) {
2294    switch (cast<ImplicitCastExpr>(E)->getCastKind()) {
2295    case CK_DerivedToBase:
2296    case CK_UncheckedDerivedToBase:
2297      return false;
2298    default:
2299      break;
2300    }
2301  }
2302
2303  // - member expressions (all)
2304  if (isa<MemberExpr>(E))
2305    return false;
2306
2307  // - opaque values (all)
2308  if (isa<OpaqueValueExpr>(E))
2309    return false;
2310
2311  return true;
2312}
2313
2314bool Expr::isImplicitCXXThis() const {
2315  const Expr *E = this;
2316
2317  // Strip away parentheses and casts we don't care about.
2318  while (true) {
2319    if (const ParenExpr *Paren = dyn_cast<ParenExpr>(E)) {
2320      E = Paren->getSubExpr();
2321      continue;
2322    }
2323
2324    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2325      if (ICE->getCastKind() == CK_NoOp ||
2326          ICE->getCastKind() == CK_LValueToRValue ||
2327          ICE->getCastKind() == CK_DerivedToBase ||
2328          ICE->getCastKind() == CK_UncheckedDerivedToBase) {
2329        E = ICE->getSubExpr();
2330        continue;
2331      }
2332    }
2333
2334    if (const UnaryOperator* UnOp = dyn_cast<UnaryOperator>(E)) {
2335      if (UnOp->getOpcode() == UO_Extension) {
2336        E = UnOp->getSubExpr();
2337        continue;
2338      }
2339    }
2340
2341    if (const MaterializeTemporaryExpr *M
2342                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2343      E = M->GetTemporaryExpr();
2344      continue;
2345    }
2346
2347    break;
2348  }
2349
2350  if (const CXXThisExpr *This = dyn_cast<CXXThisExpr>(E))
2351    return This->isImplicit();
2352
2353  return false;
2354}
2355
2356/// hasAnyTypeDependentArguments - Determines if any of the expressions
2357/// in Exprs is type-dependent.
2358bool Expr::hasAnyTypeDependentArguments(Expr** Exprs, unsigned NumExprs) {
2359  for (unsigned I = 0; I < NumExprs; ++I)
2360    if (Exprs[I]->isTypeDependent())
2361      return true;
2362
2363  return false;
2364}
2365
2366/// hasAnyValueDependentArguments - Determines if any of the expressions
2367/// in Exprs is value-dependent.
2368bool Expr::hasAnyValueDependentArguments(Expr** Exprs, unsigned NumExprs) {
2369  for (unsigned I = 0; I < NumExprs; ++I)
2370    if (Exprs[I]->isValueDependent())
2371      return true;
2372
2373  return false;
2374}
2375
2376bool Expr::isConstantInitializer(ASTContext &Ctx, bool IsForRef) const {
2377  // This function is attempting whether an expression is an initializer
2378  // which can be evaluated at compile-time.  isEvaluatable handles most
2379  // of the cases, but it can't deal with some initializer-specific
2380  // expressions, and it can't deal with aggregates; we deal with those here,
2381  // and fall back to isEvaluatable for the other cases.
2382
2383  // If we ever capture reference-binding directly in the AST, we can
2384  // kill the second parameter.
2385
2386  if (IsForRef) {
2387    EvalResult Result;
2388    return EvaluateAsLValue(Result, Ctx) && !Result.HasSideEffects;
2389  }
2390
2391  switch (getStmtClass()) {
2392  default: break;
2393  case StringLiteralClass:
2394  case ObjCStringLiteralClass:
2395  case ObjCEncodeExprClass:
2396    return true;
2397  case CXXTemporaryObjectExprClass:
2398  case CXXConstructExprClass: {
2399    const CXXConstructExpr *CE = cast<CXXConstructExpr>(this);
2400
2401    // Only if it's
2402    // 1) an application of the trivial default constructor or
2403    if (!CE->getConstructor()->isTrivial()) return false;
2404    if (!CE->getNumArgs()) return true;
2405
2406    // 2) an elidable trivial copy construction of an operand which is
2407    //    itself a constant initializer.  Note that we consider the
2408    //    operand on its own, *not* as a reference binding.
2409    return CE->isElidable() &&
2410           CE->getArg(0)->isConstantInitializer(Ctx, false);
2411  }
2412  case CompoundLiteralExprClass: {
2413    // This handles gcc's extension that allows global initializers like
2414    // "struct x {int x;} x = (struct x) {};".
2415    // FIXME: This accepts other cases it shouldn't!
2416    const Expr *Exp = cast<CompoundLiteralExpr>(this)->getInitializer();
2417    return Exp->isConstantInitializer(Ctx, false);
2418  }
2419  case InitListExprClass: {
2420    // FIXME: This doesn't deal with fields with reference types correctly.
2421    // FIXME: This incorrectly allows pointers cast to integers to be assigned
2422    // to bitfields.
2423    const InitListExpr *Exp = cast<InitListExpr>(this);
2424    unsigned numInits = Exp->getNumInits();
2425    for (unsigned i = 0; i < numInits; i++) {
2426      if (!Exp->getInit(i)->isConstantInitializer(Ctx, false))
2427        return false;
2428    }
2429    return true;
2430  }
2431  case ImplicitValueInitExprClass:
2432    return true;
2433  case ParenExprClass:
2434    return cast<ParenExpr>(this)->getSubExpr()
2435      ->isConstantInitializer(Ctx, IsForRef);
2436  case GenericSelectionExprClass:
2437    if (cast<GenericSelectionExpr>(this)->isResultDependent())
2438      return false;
2439    return cast<GenericSelectionExpr>(this)->getResultExpr()
2440      ->isConstantInitializer(Ctx, IsForRef);
2441  case ChooseExprClass:
2442    return cast<ChooseExpr>(this)->getChosenSubExpr(Ctx)
2443      ->isConstantInitializer(Ctx, IsForRef);
2444  case UnaryOperatorClass: {
2445    const UnaryOperator* Exp = cast<UnaryOperator>(this);
2446    if (Exp->getOpcode() == UO_Extension)
2447      return Exp->getSubExpr()->isConstantInitializer(Ctx, false);
2448    break;
2449  }
2450  case BinaryOperatorClass: {
2451    // Special case &&foo - &&bar.  It would be nice to generalize this somehow
2452    // but this handles the common case.
2453    const BinaryOperator *Exp = cast<BinaryOperator>(this);
2454    if (Exp->getOpcode() == BO_Sub &&
2455        isa<AddrLabelExpr>(Exp->getLHS()->IgnoreParenNoopCasts(Ctx)) &&
2456        isa<AddrLabelExpr>(Exp->getRHS()->IgnoreParenNoopCasts(Ctx)))
2457      return true;
2458    break;
2459  }
2460  case CXXFunctionalCastExprClass:
2461  case CXXStaticCastExprClass:
2462  case ImplicitCastExprClass:
2463  case CStyleCastExprClass:
2464    // Handle casts with a destination that's a struct or union; this
2465    // deals with both the gcc no-op struct cast extension and the
2466    // cast-to-union extension.
2467    if (getType()->isRecordType())
2468      return cast<CastExpr>(this)->getSubExpr()
2469        ->isConstantInitializer(Ctx, false);
2470
2471    // Integer->integer casts can be handled here, which is important for
2472    // things like (int)(&&x-&&y).  Scary but true.
2473    if (getType()->isIntegerType() &&
2474        cast<CastExpr>(this)->getSubExpr()->getType()->isIntegerType())
2475      return cast<CastExpr>(this)->getSubExpr()
2476        ->isConstantInitializer(Ctx, false);
2477
2478    break;
2479
2480  case MaterializeTemporaryExprClass:
2481    return cast<MaterializeTemporaryExpr>(this)->GetTemporaryExpr()
2482                                            ->isConstantInitializer(Ctx, false);
2483  }
2484  return isEvaluatable(Ctx);
2485}
2486
2487/// isNullPointerConstant - C99 6.3.2.3p3 - Return whether this is a null
2488/// pointer constant or not, as well as the specific kind of constant detected.
2489/// Null pointer constants can be integer constant expressions with the
2490/// value zero, casts of zero to void*, nullptr (C++0X), or __null
2491/// (a GNU extension).
2492Expr::NullPointerConstantKind
2493Expr::isNullPointerConstant(ASTContext &Ctx,
2494                            NullPointerConstantValueDependence NPC) const {
2495  if (isValueDependent()) {
2496    switch (NPC) {
2497    case NPC_NeverValueDependent:
2498      llvm_unreachable("Unexpected value dependent expression!");
2499      // If the unthinkable happens, fall through to the safest alternative.
2500
2501    case NPC_ValueDependentIsNull:
2502      if (isTypeDependent() || getType()->isIntegralType(Ctx))
2503        return NPCK_ZeroInteger;
2504      else
2505        return NPCK_NotNull;
2506
2507    case NPC_ValueDependentIsNotNull:
2508      return NPCK_NotNull;
2509    }
2510  }
2511
2512  // Strip off a cast to void*, if it exists. Except in C++.
2513  if (const ExplicitCastExpr *CE = dyn_cast<ExplicitCastExpr>(this)) {
2514    if (!Ctx.getLangOptions().CPlusPlus) {
2515      // Check that it is a cast to void*.
2516      if (const PointerType *PT = CE->getType()->getAs<PointerType>()) {
2517        QualType Pointee = PT->getPointeeType();
2518        if (!Pointee.hasQualifiers() &&
2519            Pointee->isVoidType() &&                              // to void*
2520            CE->getSubExpr()->getType()->isIntegerType())         // from int.
2521          return CE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2522      }
2523    }
2524  } else if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(this)) {
2525    // Ignore the ImplicitCastExpr type entirely.
2526    return ICE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2527  } else if (const ParenExpr *PE = dyn_cast<ParenExpr>(this)) {
2528    // Accept ((void*)0) as a null pointer constant, as many other
2529    // implementations do.
2530    return PE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2531  } else if (const GenericSelectionExpr *GE =
2532               dyn_cast<GenericSelectionExpr>(this)) {
2533    return GE->getResultExpr()->isNullPointerConstant(Ctx, NPC);
2534  } else if (const CXXDefaultArgExpr *DefaultArg
2535               = dyn_cast<CXXDefaultArgExpr>(this)) {
2536    // See through default argument expressions
2537    return DefaultArg->getExpr()->isNullPointerConstant(Ctx, NPC);
2538  } else if (isa<GNUNullExpr>(this)) {
2539    // The GNU __null extension is always a null pointer constant.
2540    return NPCK_GNUNull;
2541  } else if (const MaterializeTemporaryExpr *M
2542                                   = dyn_cast<MaterializeTemporaryExpr>(this)) {
2543    return M->GetTemporaryExpr()->isNullPointerConstant(Ctx, NPC);
2544  }
2545
2546  // C++0x nullptr_t is always a null pointer constant.
2547  if (getType()->isNullPtrType())
2548    return NPCK_CXX0X_nullptr;
2549
2550  if (const RecordType *UT = getType()->getAsUnionType())
2551    if (UT && UT->getDecl()->hasAttr<TransparentUnionAttr>())
2552      if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(this)){
2553        const Expr *InitExpr = CLE->getInitializer();
2554        if (const InitListExpr *ILE = dyn_cast<InitListExpr>(InitExpr))
2555          return ILE->getInit(0)->isNullPointerConstant(Ctx, NPC);
2556      }
2557  // This expression must be an integer type.
2558  if (!getType()->isIntegerType() ||
2559      (Ctx.getLangOptions().CPlusPlus && getType()->isEnumeralType()))
2560    return NPCK_NotNull;
2561
2562  // If we have an integer constant expression, we need to *evaluate* it and
2563  // test for the value 0.
2564  llvm::APSInt Result;
2565  bool IsNull = isIntegerConstantExpr(Result, Ctx) && Result == 0;
2566
2567  return (IsNull ? NPCK_ZeroInteger : NPCK_NotNull);
2568}
2569
2570/// \brief If this expression is an l-value for an Objective C
2571/// property, find the underlying property reference expression.
2572const ObjCPropertyRefExpr *Expr::getObjCProperty() const {
2573  const Expr *E = this;
2574  while (true) {
2575    assert((E->getValueKind() == VK_LValue &&
2576            E->getObjectKind() == OK_ObjCProperty) &&
2577           "expression is not a property reference");
2578    E = E->IgnoreParenCasts();
2579    if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
2580      if (BO->getOpcode() == BO_Comma) {
2581        E = BO->getRHS();
2582        continue;
2583      }
2584    }
2585
2586    break;
2587  }
2588
2589  return cast<ObjCPropertyRefExpr>(E);
2590}
2591
2592FieldDecl *Expr::getBitField() {
2593  Expr *E = this->IgnoreParens();
2594
2595  while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2596    if (ICE->getCastKind() == CK_LValueToRValue ||
2597        (ICE->getValueKind() != VK_RValue && ICE->getCastKind() == CK_NoOp))
2598      E = ICE->getSubExpr()->IgnoreParens();
2599    else
2600      break;
2601  }
2602
2603  if (MemberExpr *MemRef = dyn_cast<MemberExpr>(E))
2604    if (FieldDecl *Field = dyn_cast<FieldDecl>(MemRef->getMemberDecl()))
2605      if (Field->isBitField())
2606        return Field;
2607
2608  if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E))
2609    if (FieldDecl *Field = dyn_cast<FieldDecl>(DeclRef->getDecl()))
2610      if (Field->isBitField())
2611        return Field;
2612
2613  if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E)) {
2614    if (BinOp->isAssignmentOp() && BinOp->getLHS())
2615      return BinOp->getLHS()->getBitField();
2616
2617    if (BinOp->getOpcode() == BO_Comma && BinOp->getRHS())
2618      return BinOp->getRHS()->getBitField();
2619  }
2620
2621  return 0;
2622}
2623
2624bool Expr::refersToVectorElement() const {
2625  const Expr *E = this->IgnoreParens();
2626
2627  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2628    if (ICE->getValueKind() != VK_RValue &&
2629        ICE->getCastKind() == CK_NoOp)
2630      E = ICE->getSubExpr()->IgnoreParens();
2631    else
2632      break;
2633  }
2634
2635  if (const ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(E))
2636    return ASE->getBase()->getType()->isVectorType();
2637
2638  if (isa<ExtVectorElementExpr>(E))
2639    return true;
2640
2641  return false;
2642}
2643
2644/// isArrow - Return true if the base expression is a pointer to vector,
2645/// return false if the base expression is a vector.
2646bool ExtVectorElementExpr::isArrow() const {
2647  return getBase()->getType()->isPointerType();
2648}
2649
2650unsigned ExtVectorElementExpr::getNumElements() const {
2651  if (const VectorType *VT = getType()->getAs<VectorType>())
2652    return VT->getNumElements();
2653  return 1;
2654}
2655
2656/// containsDuplicateElements - Return true if any element access is repeated.
2657bool ExtVectorElementExpr::containsDuplicateElements() const {
2658  // FIXME: Refactor this code to an accessor on the AST node which returns the
2659  // "type" of component access, and share with code below and in Sema.
2660  StringRef Comp = Accessor->getName();
2661
2662  // Halving swizzles do not contain duplicate elements.
2663  if (Comp == "hi" || Comp == "lo" || Comp == "even" || Comp == "odd")
2664    return false;
2665
2666  // Advance past s-char prefix on hex swizzles.
2667  if (Comp[0] == 's' || Comp[0] == 'S')
2668    Comp = Comp.substr(1);
2669
2670  for (unsigned i = 0, e = Comp.size(); i != e; ++i)
2671    if (Comp.substr(i + 1).find(Comp[i]) != StringRef::npos)
2672        return true;
2673
2674  return false;
2675}
2676
2677/// getEncodedElementAccess - We encode the fields as a llvm ConstantArray.
2678void ExtVectorElementExpr::getEncodedElementAccess(
2679                                  SmallVectorImpl<unsigned> &Elts) const {
2680  StringRef Comp = Accessor->getName();
2681  if (Comp[0] == 's' || Comp[0] == 'S')
2682    Comp = Comp.substr(1);
2683
2684  bool isHi =   Comp == "hi";
2685  bool isLo =   Comp == "lo";
2686  bool isEven = Comp == "even";
2687  bool isOdd  = Comp == "odd";
2688
2689  for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
2690    uint64_t Index;
2691
2692    if (isHi)
2693      Index = e + i;
2694    else if (isLo)
2695      Index = i;
2696    else if (isEven)
2697      Index = 2 * i;
2698    else if (isOdd)
2699      Index = 2 * i + 1;
2700    else
2701      Index = ExtVectorType::getAccessorIdx(Comp[i]);
2702
2703    Elts.push_back(Index);
2704  }
2705}
2706
2707ObjCMessageExpr::ObjCMessageExpr(QualType T,
2708                                 ExprValueKind VK,
2709                                 SourceLocation LBracLoc,
2710                                 SourceLocation SuperLoc,
2711                                 bool IsInstanceSuper,
2712                                 QualType SuperType,
2713                                 Selector Sel,
2714                                 SourceLocation SelLoc,
2715                                 ObjCMethodDecl *Method,
2716                                 Expr **Args, unsigned NumArgs,
2717                                 SourceLocation RBracLoc)
2718  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary,
2719         /*TypeDependent=*/false, /*ValueDependent=*/false,
2720         /*InstantiationDependent=*/false,
2721         /*ContainsUnexpandedParameterPack=*/false),
2722    NumArgs(NumArgs), Kind(IsInstanceSuper? SuperInstance : SuperClass),
2723    HasMethod(Method != 0), IsDelegateInitCall(false), SuperLoc(SuperLoc),
2724    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2725                                                       : Sel.getAsOpaquePtr())),
2726    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2727{
2728  setReceiverPointer(SuperType.getAsOpaquePtr());
2729  if (NumArgs)
2730    memcpy(getArgs(), Args, NumArgs * sizeof(Expr *));
2731}
2732
2733ObjCMessageExpr::ObjCMessageExpr(QualType T,
2734                                 ExprValueKind VK,
2735                                 SourceLocation LBracLoc,
2736                                 TypeSourceInfo *Receiver,
2737                                 Selector Sel,
2738                                 SourceLocation SelLoc,
2739                                 ObjCMethodDecl *Method,
2740                                 Expr **Args, unsigned NumArgs,
2741                                 SourceLocation RBracLoc)
2742  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, T->isDependentType(),
2743         T->isDependentType(), T->isInstantiationDependentType(),
2744         T->containsUnexpandedParameterPack()),
2745    NumArgs(NumArgs), Kind(Class),
2746    HasMethod(Method != 0), IsDelegateInitCall(false),
2747    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2748                                                       : Sel.getAsOpaquePtr())),
2749    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2750{
2751  setReceiverPointer(Receiver);
2752  Expr **MyArgs = getArgs();
2753  for (unsigned I = 0; I != NumArgs; ++I) {
2754    if (Args[I]->isTypeDependent())
2755      ExprBits.TypeDependent = true;
2756    if (Args[I]->isValueDependent())
2757      ExprBits.ValueDependent = true;
2758    if (Args[I]->isInstantiationDependent())
2759      ExprBits.InstantiationDependent = true;
2760    if (Args[I]->containsUnexpandedParameterPack())
2761      ExprBits.ContainsUnexpandedParameterPack = true;
2762
2763    MyArgs[I] = Args[I];
2764  }
2765}
2766
2767ObjCMessageExpr::ObjCMessageExpr(QualType T,
2768                                 ExprValueKind VK,
2769                                 SourceLocation LBracLoc,
2770                                 Expr *Receiver,
2771                                 Selector Sel,
2772                                 SourceLocation SelLoc,
2773                                 ObjCMethodDecl *Method,
2774                                 Expr **Args, unsigned NumArgs,
2775                                 SourceLocation RBracLoc)
2776  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, Receiver->isTypeDependent(),
2777         Receiver->isTypeDependent(),
2778         Receiver->isInstantiationDependent(),
2779         Receiver->containsUnexpandedParameterPack()),
2780    NumArgs(NumArgs), Kind(Instance),
2781    HasMethod(Method != 0), IsDelegateInitCall(false),
2782    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2783                                                       : Sel.getAsOpaquePtr())),
2784    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2785{
2786  setReceiverPointer(Receiver);
2787  Expr **MyArgs = getArgs();
2788  for (unsigned I = 0; I != NumArgs; ++I) {
2789    if (Args[I]->isTypeDependent())
2790      ExprBits.TypeDependent = true;
2791    if (Args[I]->isValueDependent())
2792      ExprBits.ValueDependent = true;
2793    if (Args[I]->isInstantiationDependent())
2794      ExprBits.InstantiationDependent = true;
2795    if (Args[I]->containsUnexpandedParameterPack())
2796      ExprBits.ContainsUnexpandedParameterPack = true;
2797
2798    MyArgs[I] = Args[I];
2799  }
2800}
2801
2802ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2803                                         ExprValueKind VK,
2804                                         SourceLocation LBracLoc,
2805                                         SourceLocation SuperLoc,
2806                                         bool IsInstanceSuper,
2807                                         QualType SuperType,
2808                                         Selector Sel,
2809                                         SourceLocation SelLoc,
2810                                         ObjCMethodDecl *Method,
2811                                         Expr **Args, unsigned NumArgs,
2812                                         SourceLocation RBracLoc) {
2813  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2814    NumArgs * sizeof(Expr *);
2815  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2816  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, SuperLoc, IsInstanceSuper,
2817                                   SuperType, Sel, SelLoc, Method, Args,NumArgs,
2818                                   RBracLoc);
2819}
2820
2821ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2822                                         ExprValueKind VK,
2823                                         SourceLocation LBracLoc,
2824                                         TypeSourceInfo *Receiver,
2825                                         Selector Sel,
2826                                         SourceLocation SelLoc,
2827                                         ObjCMethodDecl *Method,
2828                                         Expr **Args, unsigned NumArgs,
2829                                         SourceLocation RBracLoc) {
2830  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2831    NumArgs * sizeof(Expr *);
2832  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2833  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel, SelLoc,
2834                                   Method, Args, NumArgs, RBracLoc);
2835}
2836
2837ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2838                                         ExprValueKind VK,
2839                                         SourceLocation LBracLoc,
2840                                         Expr *Receiver,
2841                                         Selector Sel,
2842                                         SourceLocation SelLoc,
2843                                         ObjCMethodDecl *Method,
2844                                         Expr **Args, unsigned NumArgs,
2845                                         SourceLocation RBracLoc) {
2846  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2847    NumArgs * sizeof(Expr *);
2848  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2849  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel, SelLoc,
2850                                   Method, Args, NumArgs, RBracLoc);
2851}
2852
2853ObjCMessageExpr *ObjCMessageExpr::CreateEmpty(ASTContext &Context,
2854                                              unsigned NumArgs) {
2855  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2856    NumArgs * sizeof(Expr *);
2857  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2858  return new (Mem) ObjCMessageExpr(EmptyShell(), NumArgs);
2859}
2860
2861SourceRange ObjCMessageExpr::getReceiverRange() const {
2862  switch (getReceiverKind()) {
2863  case Instance:
2864    return getInstanceReceiver()->getSourceRange();
2865
2866  case Class:
2867    return getClassReceiverTypeInfo()->getTypeLoc().getSourceRange();
2868
2869  case SuperInstance:
2870  case SuperClass:
2871    return getSuperLoc();
2872  }
2873
2874  return SourceLocation();
2875}
2876
2877Selector ObjCMessageExpr::getSelector() const {
2878  if (HasMethod)
2879    return reinterpret_cast<const ObjCMethodDecl *>(SelectorOrMethod)
2880                                                               ->getSelector();
2881  return Selector(SelectorOrMethod);
2882}
2883
2884ObjCInterfaceDecl *ObjCMessageExpr::getReceiverInterface() const {
2885  switch (getReceiverKind()) {
2886  case Instance:
2887    if (const ObjCObjectPointerType *Ptr
2888          = getInstanceReceiver()->getType()->getAs<ObjCObjectPointerType>())
2889      return Ptr->getInterfaceDecl();
2890    break;
2891
2892  case Class:
2893    if (const ObjCObjectType *Ty
2894          = getClassReceiver()->getAs<ObjCObjectType>())
2895      return Ty->getInterface();
2896    break;
2897
2898  case SuperInstance:
2899    if (const ObjCObjectPointerType *Ptr
2900          = getSuperType()->getAs<ObjCObjectPointerType>())
2901      return Ptr->getInterfaceDecl();
2902    break;
2903
2904  case SuperClass:
2905    if (const ObjCObjectType *Iface
2906          = getSuperType()->getAs<ObjCObjectType>())
2907      return Iface->getInterface();
2908    break;
2909  }
2910
2911  return 0;
2912}
2913
2914StringRef ObjCBridgedCastExpr::getBridgeKindName() const {
2915  switch (getBridgeKind()) {
2916  case OBC_Bridge:
2917    return "__bridge";
2918  case OBC_BridgeTransfer:
2919    return "__bridge_transfer";
2920  case OBC_BridgeRetained:
2921    return "__bridge_retained";
2922  }
2923
2924  return "__bridge";
2925}
2926
2927bool ChooseExpr::isConditionTrue(const ASTContext &C) const {
2928  return getCond()->EvaluateAsInt(C) != 0;
2929}
2930
2931ShuffleVectorExpr::ShuffleVectorExpr(ASTContext &C, Expr **args, unsigned nexpr,
2932                                     QualType Type, SourceLocation BLoc,
2933                                     SourceLocation RP)
2934   : Expr(ShuffleVectorExprClass, Type, VK_RValue, OK_Ordinary,
2935          Type->isDependentType(), Type->isDependentType(),
2936          Type->isInstantiationDependentType(),
2937          Type->containsUnexpandedParameterPack()),
2938     BuiltinLoc(BLoc), RParenLoc(RP), NumExprs(nexpr)
2939{
2940  SubExprs = new (C) Stmt*[nexpr];
2941  for (unsigned i = 0; i < nexpr; i++) {
2942    if (args[i]->isTypeDependent())
2943      ExprBits.TypeDependent = true;
2944    if (args[i]->isValueDependent())
2945      ExprBits.ValueDependent = true;
2946    if (args[i]->isInstantiationDependent())
2947      ExprBits.InstantiationDependent = true;
2948    if (args[i]->containsUnexpandedParameterPack())
2949      ExprBits.ContainsUnexpandedParameterPack = true;
2950
2951    SubExprs[i] = args[i];
2952  }
2953}
2954
2955void ShuffleVectorExpr::setExprs(ASTContext &C, Expr ** Exprs,
2956                                 unsigned NumExprs) {
2957  if (SubExprs) C.Deallocate(SubExprs);
2958
2959  SubExprs = new (C) Stmt* [NumExprs];
2960  this->NumExprs = NumExprs;
2961  memcpy(SubExprs, Exprs, sizeof(Expr *) * NumExprs);
2962}
2963
2964GenericSelectionExpr::GenericSelectionExpr(ASTContext &Context,
2965                               SourceLocation GenericLoc, Expr *ControllingExpr,
2966                               TypeSourceInfo **AssocTypes, Expr **AssocExprs,
2967                               unsigned NumAssocs, SourceLocation DefaultLoc,
2968                               SourceLocation RParenLoc,
2969                               bool ContainsUnexpandedParameterPack,
2970                               unsigned ResultIndex)
2971  : Expr(GenericSelectionExprClass,
2972         AssocExprs[ResultIndex]->getType(),
2973         AssocExprs[ResultIndex]->getValueKind(),
2974         AssocExprs[ResultIndex]->getObjectKind(),
2975         AssocExprs[ResultIndex]->isTypeDependent(),
2976         AssocExprs[ResultIndex]->isValueDependent(),
2977         AssocExprs[ResultIndex]->isInstantiationDependent(),
2978         ContainsUnexpandedParameterPack),
2979    AssocTypes(new (Context) TypeSourceInfo*[NumAssocs]),
2980    SubExprs(new (Context) Stmt*[END_EXPR+NumAssocs]), NumAssocs(NumAssocs),
2981    ResultIndex(ResultIndex), GenericLoc(GenericLoc), DefaultLoc(DefaultLoc),
2982    RParenLoc(RParenLoc) {
2983  SubExprs[CONTROLLING] = ControllingExpr;
2984  std::copy(AssocTypes, AssocTypes+NumAssocs, this->AssocTypes);
2985  std::copy(AssocExprs, AssocExprs+NumAssocs, SubExprs+END_EXPR);
2986}
2987
2988GenericSelectionExpr::GenericSelectionExpr(ASTContext &Context,
2989                               SourceLocation GenericLoc, Expr *ControllingExpr,
2990                               TypeSourceInfo **AssocTypes, Expr **AssocExprs,
2991                               unsigned NumAssocs, SourceLocation DefaultLoc,
2992                               SourceLocation RParenLoc,
2993                               bool ContainsUnexpandedParameterPack)
2994  : Expr(GenericSelectionExprClass,
2995         Context.DependentTy,
2996         VK_RValue,
2997         OK_Ordinary,
2998         /*isTypeDependent=*/true,
2999         /*isValueDependent=*/true,
3000         /*isInstantiationDependent=*/true,
3001         ContainsUnexpandedParameterPack),
3002    AssocTypes(new (Context) TypeSourceInfo*[NumAssocs]),
3003    SubExprs(new (Context) Stmt*[END_EXPR+NumAssocs]), NumAssocs(NumAssocs),
3004    ResultIndex(-1U), GenericLoc(GenericLoc), DefaultLoc(DefaultLoc),
3005    RParenLoc(RParenLoc) {
3006  SubExprs[CONTROLLING] = ControllingExpr;
3007  std::copy(AssocTypes, AssocTypes+NumAssocs, this->AssocTypes);
3008  std::copy(AssocExprs, AssocExprs+NumAssocs, SubExprs+END_EXPR);
3009}
3010
3011//===----------------------------------------------------------------------===//
3012//  DesignatedInitExpr
3013//===----------------------------------------------------------------------===//
3014
3015IdentifierInfo *DesignatedInitExpr::Designator::getFieldName() const {
3016  assert(Kind == FieldDesignator && "Only valid on a field designator");
3017  if (Field.NameOrField & 0x01)
3018    return reinterpret_cast<IdentifierInfo *>(Field.NameOrField&~0x01);
3019  else
3020    return getField()->getIdentifier();
3021}
3022
3023DesignatedInitExpr::DesignatedInitExpr(ASTContext &C, QualType Ty,
3024                                       unsigned NumDesignators,
3025                                       const Designator *Designators,
3026                                       SourceLocation EqualOrColonLoc,
3027                                       bool GNUSyntax,
3028                                       Expr **IndexExprs,
3029                                       unsigned NumIndexExprs,
3030                                       Expr *Init)
3031  : Expr(DesignatedInitExprClass, Ty,
3032         Init->getValueKind(), Init->getObjectKind(),
3033         Init->isTypeDependent(), Init->isValueDependent(),
3034         Init->isInstantiationDependent(),
3035         Init->containsUnexpandedParameterPack()),
3036    EqualOrColonLoc(EqualOrColonLoc), GNUSyntax(GNUSyntax),
3037    NumDesignators(NumDesignators), NumSubExprs(NumIndexExprs + 1) {
3038  this->Designators = new (C) Designator[NumDesignators];
3039
3040  // Record the initializer itself.
3041  child_range Child = children();
3042  *Child++ = Init;
3043
3044  // Copy the designators and their subexpressions, computing
3045  // value-dependence along the way.
3046  unsigned IndexIdx = 0;
3047  for (unsigned I = 0; I != NumDesignators; ++I) {
3048    this->Designators[I] = Designators[I];
3049
3050    if (this->Designators[I].isArrayDesignator()) {
3051      // Compute type- and value-dependence.
3052      Expr *Index = IndexExprs[IndexIdx];
3053      if (Index->isTypeDependent() || Index->isValueDependent())
3054        ExprBits.ValueDependent = true;
3055      if (Index->isInstantiationDependent())
3056        ExprBits.InstantiationDependent = true;
3057      // Propagate unexpanded parameter packs.
3058      if (Index->containsUnexpandedParameterPack())
3059        ExprBits.ContainsUnexpandedParameterPack = true;
3060
3061      // Copy the index expressions into permanent storage.
3062      *Child++ = IndexExprs[IndexIdx++];
3063    } else if (this->Designators[I].isArrayRangeDesignator()) {
3064      // Compute type- and value-dependence.
3065      Expr *Start = IndexExprs[IndexIdx];
3066      Expr *End = IndexExprs[IndexIdx + 1];
3067      if (Start->isTypeDependent() || Start->isValueDependent() ||
3068          End->isTypeDependent() || End->isValueDependent()) {
3069        ExprBits.ValueDependent = true;
3070        ExprBits.InstantiationDependent = true;
3071      } else if (Start->isInstantiationDependent() ||
3072                 End->isInstantiationDependent()) {
3073        ExprBits.InstantiationDependent = true;
3074      }
3075
3076      // Propagate unexpanded parameter packs.
3077      if (Start->containsUnexpandedParameterPack() ||
3078          End->containsUnexpandedParameterPack())
3079        ExprBits.ContainsUnexpandedParameterPack = true;
3080
3081      // Copy the start/end expressions into permanent storage.
3082      *Child++ = IndexExprs[IndexIdx++];
3083      *Child++ = IndexExprs[IndexIdx++];
3084    }
3085  }
3086
3087  assert(IndexIdx == NumIndexExprs && "Wrong number of index expressions");
3088}
3089
3090DesignatedInitExpr *
3091DesignatedInitExpr::Create(ASTContext &C, Designator *Designators,
3092                           unsigned NumDesignators,
3093                           Expr **IndexExprs, unsigned NumIndexExprs,
3094                           SourceLocation ColonOrEqualLoc,
3095                           bool UsesColonSyntax, Expr *Init) {
3096  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
3097                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
3098  return new (Mem) DesignatedInitExpr(C, C.VoidTy, NumDesignators, Designators,
3099                                      ColonOrEqualLoc, UsesColonSyntax,
3100                                      IndexExprs, NumIndexExprs, Init);
3101}
3102
3103DesignatedInitExpr *DesignatedInitExpr::CreateEmpty(ASTContext &C,
3104                                                    unsigned NumIndexExprs) {
3105  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
3106                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
3107  return new (Mem) DesignatedInitExpr(NumIndexExprs + 1);
3108}
3109
3110void DesignatedInitExpr::setDesignators(ASTContext &C,
3111                                        const Designator *Desigs,
3112                                        unsigned NumDesigs) {
3113  Designators = new (C) Designator[NumDesigs];
3114  NumDesignators = NumDesigs;
3115  for (unsigned I = 0; I != NumDesigs; ++I)
3116    Designators[I] = Desigs[I];
3117}
3118
3119SourceRange DesignatedInitExpr::getDesignatorsSourceRange() const {
3120  DesignatedInitExpr *DIE = const_cast<DesignatedInitExpr*>(this);
3121  if (size() == 1)
3122    return DIE->getDesignator(0)->getSourceRange();
3123  return SourceRange(DIE->getDesignator(0)->getStartLocation(),
3124                     DIE->getDesignator(size()-1)->getEndLocation());
3125}
3126
3127SourceRange DesignatedInitExpr::getSourceRange() const {
3128  SourceLocation StartLoc;
3129  Designator &First =
3130    *const_cast<DesignatedInitExpr*>(this)->designators_begin();
3131  if (First.isFieldDesignator()) {
3132    if (GNUSyntax)
3133      StartLoc = SourceLocation::getFromRawEncoding(First.Field.FieldLoc);
3134    else
3135      StartLoc = SourceLocation::getFromRawEncoding(First.Field.DotLoc);
3136  } else
3137    StartLoc =
3138      SourceLocation::getFromRawEncoding(First.ArrayOrRange.LBracketLoc);
3139  return SourceRange(StartLoc, getInit()->getSourceRange().getEnd());
3140}
3141
3142Expr *DesignatedInitExpr::getArrayIndex(const Designator& D) {
3143  assert(D.Kind == Designator::ArrayDesignator && "Requires array designator");
3144  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3145  Ptr += sizeof(DesignatedInitExpr);
3146  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3147  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
3148}
3149
3150Expr *DesignatedInitExpr::getArrayRangeStart(const Designator& D) {
3151  assert(D.Kind == Designator::ArrayRangeDesignator &&
3152         "Requires array range designator");
3153  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3154  Ptr += sizeof(DesignatedInitExpr);
3155  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3156  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
3157}
3158
3159Expr *DesignatedInitExpr::getArrayRangeEnd(const Designator& D) {
3160  assert(D.Kind == Designator::ArrayRangeDesignator &&
3161         "Requires array range designator");
3162  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3163  Ptr += sizeof(DesignatedInitExpr);
3164  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3165  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 2));
3166}
3167
3168/// \brief Replaces the designator at index @p Idx with the series
3169/// of designators in [First, Last).
3170void DesignatedInitExpr::ExpandDesignator(ASTContext &C, unsigned Idx,
3171                                          const Designator *First,
3172                                          const Designator *Last) {
3173  unsigned NumNewDesignators = Last - First;
3174  if (NumNewDesignators == 0) {
3175    std::copy_backward(Designators + Idx + 1,
3176                       Designators + NumDesignators,
3177                       Designators + Idx);
3178    --NumNewDesignators;
3179    return;
3180  } else if (NumNewDesignators == 1) {
3181    Designators[Idx] = *First;
3182    return;
3183  }
3184
3185  Designator *NewDesignators
3186    = new (C) Designator[NumDesignators - 1 + NumNewDesignators];
3187  std::copy(Designators, Designators + Idx, NewDesignators);
3188  std::copy(First, Last, NewDesignators + Idx);
3189  std::copy(Designators + Idx + 1, Designators + NumDesignators,
3190            NewDesignators + Idx + NumNewDesignators);
3191  Designators = NewDesignators;
3192  NumDesignators = NumDesignators - 1 + NumNewDesignators;
3193}
3194
3195ParenListExpr::ParenListExpr(ASTContext& C, SourceLocation lparenloc,
3196                             Expr **exprs, unsigned nexprs,
3197                             SourceLocation rparenloc, QualType T)
3198  : Expr(ParenListExprClass, T, VK_RValue, OK_Ordinary,
3199         false, false, false, false),
3200    NumExprs(nexprs), LParenLoc(lparenloc), RParenLoc(rparenloc) {
3201  assert(!T.isNull() && "ParenListExpr must have a valid type");
3202  Exprs = new (C) Stmt*[nexprs];
3203  for (unsigned i = 0; i != nexprs; ++i) {
3204    if (exprs[i]->isTypeDependent())
3205      ExprBits.TypeDependent = true;
3206    if (exprs[i]->isValueDependent())
3207      ExprBits.ValueDependent = true;
3208    if (exprs[i]->isInstantiationDependent())
3209      ExprBits.InstantiationDependent = true;
3210    if (exprs[i]->containsUnexpandedParameterPack())
3211      ExprBits.ContainsUnexpandedParameterPack = true;
3212
3213    Exprs[i] = exprs[i];
3214  }
3215}
3216
3217const OpaqueValueExpr *OpaqueValueExpr::findInCopyConstruct(const Expr *e) {
3218  if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(e))
3219    e = ewc->getSubExpr();
3220  if (const MaterializeTemporaryExpr *m = dyn_cast<MaterializeTemporaryExpr>(e))
3221    e = m->GetTemporaryExpr();
3222  e = cast<CXXConstructExpr>(e)->getArg(0);
3223  while (const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
3224    e = ice->getSubExpr();
3225  return cast<OpaqueValueExpr>(e);
3226}
3227
3228//===----------------------------------------------------------------------===//
3229//  ExprIterator.
3230//===----------------------------------------------------------------------===//
3231
3232Expr* ExprIterator::operator[](size_t idx) { return cast<Expr>(I[idx]); }
3233Expr* ExprIterator::operator*() const { return cast<Expr>(*I); }
3234Expr* ExprIterator::operator->() const { return cast<Expr>(*I); }
3235const Expr* ConstExprIterator::operator[](size_t idx) const {
3236  return cast<Expr>(I[idx]);
3237}
3238const Expr* ConstExprIterator::operator*() const { return cast<Expr>(*I); }
3239const Expr* ConstExprIterator::operator->() const { return cast<Expr>(*I); }
3240
3241//===----------------------------------------------------------------------===//
3242//  Child Iterators for iterating over subexpressions/substatements
3243//===----------------------------------------------------------------------===//
3244
3245// UnaryExprOrTypeTraitExpr
3246Stmt::child_range UnaryExprOrTypeTraitExpr::children() {
3247  // If this is of a type and the type is a VLA type (and not a typedef), the
3248  // size expression of the VLA needs to be treated as an executable expression.
3249  // Why isn't this weirdness documented better in StmtIterator?
3250  if (isArgumentType()) {
3251    if (const VariableArrayType* T = dyn_cast<VariableArrayType>(
3252                                   getArgumentType().getTypePtr()))
3253      return child_range(child_iterator(T), child_iterator());
3254    return child_range();
3255  }
3256  return child_range(&Argument.Ex, &Argument.Ex + 1);
3257}
3258
3259// ObjCMessageExpr
3260Stmt::child_range ObjCMessageExpr::children() {
3261  Stmt **begin;
3262  if (getReceiverKind() == Instance)
3263    begin = reinterpret_cast<Stmt **>(this + 1);
3264  else
3265    begin = reinterpret_cast<Stmt **>(getArgs());
3266  return child_range(begin,
3267                     reinterpret_cast<Stmt **>(getArgs() + getNumArgs()));
3268}
3269
3270// Blocks
3271BlockDeclRefExpr::BlockDeclRefExpr(VarDecl *d, QualType t, ExprValueKind VK,
3272                                   SourceLocation l, bool ByRef,
3273                                   bool constAdded)
3274  : Expr(BlockDeclRefExprClass, t, VK, OK_Ordinary, false, false, false,
3275         d->isParameterPack()),
3276    D(d), Loc(l), IsByRef(ByRef), ConstQualAdded(constAdded)
3277{
3278  bool TypeDependent = false;
3279  bool ValueDependent = false;
3280  bool InstantiationDependent = false;
3281  computeDeclRefDependence(D, getType(), TypeDependent, ValueDependent,
3282                           InstantiationDependent);
3283  ExprBits.TypeDependent = TypeDependent;
3284  ExprBits.ValueDependent = ValueDependent;
3285  ExprBits.InstantiationDependent = InstantiationDependent;
3286}
3287