Expr.cpp revision e3f834950801f1334f1b3f3f7e9a34062905fe1d 
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 BlockDeclRefExprClass:
1732  case DeclRefExprClass: {
1733
1734    const Decl *D;
1735    if (const BlockDeclRefExpr *BDRE = dyn_cast<BlockDeclRefExpr>(E))
1736        D = BDRE->getDecl();
1737    else
1738        D = cast<DeclRefExpr>(E)->getDecl();
1739
1740    if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1741      if (VD->hasGlobalStorage())
1742        return true;
1743      QualType T = VD->getType();
1744      // dereferencing to a  pointer is always a gc'able candidate,
1745      // unless it is __weak.
1746      return T->isPointerType() &&
1747             (Ctx.getObjCGCAttrKind(T) != Qualifiers::Weak);
1748    }
1749    return false;
1750  }
1751  case MemberExprClass: {
1752    const MemberExpr *M = cast<MemberExpr>(E);
1753    return M->getBase()->isOBJCGCCandidate(Ctx);
1754  }
1755  case ArraySubscriptExprClass:
1756    return cast<ArraySubscriptExpr>(E)->getBase()->isOBJCGCCandidate(Ctx);
1757  }
1758}
1759
1760bool Expr::isBoundMemberFunction(ASTContext &Ctx) const {
1761  if (isTypeDependent())
1762    return false;
1763  return ClassifyLValue(Ctx) == Expr::LV_MemberFunction;
1764}
1765
1766QualType Expr::findBoundMemberType(const Expr *expr) {
1767  assert(expr->getType()->isSpecificPlaceholderType(BuiltinType::BoundMember));
1768
1769  // Bound member expressions are always one of these possibilities:
1770  //   x->m      x.m      x->*y      x.*y
1771  // (possibly parenthesized)
1772
1773  expr = expr->IgnoreParens();
1774  if (const MemberExpr *mem = dyn_cast<MemberExpr>(expr)) {
1775    assert(isa<CXXMethodDecl>(mem->getMemberDecl()));
1776    return mem->getMemberDecl()->getType();
1777  }
1778
1779  if (const BinaryOperator *op = dyn_cast<BinaryOperator>(expr)) {
1780    QualType type = op->getRHS()->getType()->castAs<MemberPointerType>()
1781                      ->getPointeeType();
1782    assert(type->isFunctionType());
1783    return type;
1784  }
1785
1786  assert(isa<UnresolvedMemberExpr>(expr));
1787  return QualType();
1788}
1789
1790static Expr::CanThrowResult MergeCanThrow(Expr::CanThrowResult CT1,
1791                                          Expr::CanThrowResult CT2) {
1792  // CanThrowResult constants are ordered so that the maximum is the correct
1793  // merge result.
1794  return CT1 > CT2 ? CT1 : CT2;
1795}
1796
1797static Expr::CanThrowResult CanSubExprsThrow(ASTContext &C, const Expr *CE) {
1798  Expr *E = const_cast<Expr*>(CE);
1799  Expr::CanThrowResult R = Expr::CT_Cannot;
1800  for (Expr::child_range I = E->children(); I && R != Expr::CT_Can; ++I) {
1801    R = MergeCanThrow(R, cast<Expr>(*I)->CanThrow(C));
1802  }
1803  return R;
1804}
1805
1806static Expr::CanThrowResult CanCalleeThrow(ASTContext &Ctx, const Expr *E,
1807                                           const Decl *D,
1808                                           bool NullThrows = true) {
1809  if (!D)
1810    return NullThrows ? Expr::CT_Can : Expr::CT_Cannot;
1811
1812  // See if we can get a function type from the decl somehow.
1813  const ValueDecl *VD = dyn_cast<ValueDecl>(D);
1814  if (!VD) // If we have no clue what we're calling, assume the worst.
1815    return Expr::CT_Can;
1816
1817  // As an extension, we assume that __attribute__((nothrow)) functions don't
1818  // throw.
1819  if (isa<FunctionDecl>(D) && D->hasAttr<NoThrowAttr>())
1820    return Expr::CT_Cannot;
1821
1822  QualType T = VD->getType();
1823  const FunctionProtoType *FT;
1824  if ((FT = T->getAs<FunctionProtoType>())) {
1825  } else if (const PointerType *PT = T->getAs<PointerType>())
1826    FT = PT->getPointeeType()->getAs<FunctionProtoType>();
1827  else if (const ReferenceType *RT = T->getAs<ReferenceType>())
1828    FT = RT->getPointeeType()->getAs<FunctionProtoType>();
1829  else if (const MemberPointerType *MT = T->getAs<MemberPointerType>())
1830    FT = MT->getPointeeType()->getAs<FunctionProtoType>();
1831  else if (const BlockPointerType *BT = T->getAs<BlockPointerType>())
1832    FT = BT->getPointeeType()->getAs<FunctionProtoType>();
1833
1834  if (!FT)
1835    return Expr::CT_Can;
1836
1837  if (FT->getExceptionSpecType() == EST_Delayed) {
1838    assert(isa<CXXConstructorDecl>(D) &&
1839           "only constructor exception specs can be unknown");
1840    Ctx.getDiagnostics().Report(E->getLocStart(),
1841                                diag::err_exception_spec_unknown)
1842      << E->getSourceRange();
1843    return Expr::CT_Can;
1844  }
1845
1846  return FT->isNothrow(Ctx) ? Expr::CT_Cannot : Expr::CT_Can;
1847}
1848
1849static Expr::CanThrowResult CanDynamicCastThrow(const CXXDynamicCastExpr *DC) {
1850  if (DC->isTypeDependent())
1851    return Expr::CT_Dependent;
1852
1853  if (!DC->getTypeAsWritten()->isReferenceType())
1854    return Expr::CT_Cannot;
1855
1856  if (DC->getSubExpr()->isTypeDependent())
1857    return Expr::CT_Dependent;
1858
1859  return DC->getCastKind() == clang::CK_Dynamic? Expr::CT_Can : Expr::CT_Cannot;
1860}
1861
1862static Expr::CanThrowResult CanTypeidThrow(ASTContext &C,
1863                                           const CXXTypeidExpr *DC) {
1864  if (DC->isTypeOperand())
1865    return Expr::CT_Cannot;
1866
1867  Expr *Op = DC->getExprOperand();
1868  if (Op->isTypeDependent())
1869    return Expr::CT_Dependent;
1870
1871  const RecordType *RT = Op->getType()->getAs<RecordType>();
1872  if (!RT)
1873    return Expr::CT_Cannot;
1874
1875  if (!cast<CXXRecordDecl>(RT->getDecl())->isPolymorphic())
1876    return Expr::CT_Cannot;
1877
1878  if (Op->Classify(C).isPRValue())
1879    return Expr::CT_Cannot;
1880
1881  return Expr::CT_Can;
1882}
1883
1884Expr::CanThrowResult Expr::CanThrow(ASTContext &C) const {
1885  // C++ [expr.unary.noexcept]p3:
1886  //   [Can throw] if in a potentially-evaluated context the expression would
1887  //   contain:
1888  switch (getStmtClass()) {
1889  case CXXThrowExprClass:
1890    //   - a potentially evaluated throw-expression
1891    return CT_Can;
1892
1893  case CXXDynamicCastExprClass: {
1894    //   - a potentially evaluated dynamic_cast expression dynamic_cast<T>(v),
1895    //     where T is a reference type, that requires a run-time check
1896    CanThrowResult CT = CanDynamicCastThrow(cast<CXXDynamicCastExpr>(this));
1897    if (CT == CT_Can)
1898      return CT;
1899    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1900  }
1901
1902  case CXXTypeidExprClass:
1903    //   - a potentially evaluated typeid expression applied to a glvalue
1904    //     expression whose type is a polymorphic class type
1905    return CanTypeidThrow(C, cast<CXXTypeidExpr>(this));
1906
1907    //   - a potentially evaluated call to a function, member function, function
1908    //     pointer, or member function pointer that does not have a non-throwing
1909    //     exception-specification
1910  case CallExprClass:
1911  case CXXOperatorCallExprClass:
1912  case CXXMemberCallExprClass: {
1913    const CallExpr *CE = cast<CallExpr>(this);
1914    CanThrowResult CT;
1915    if (isTypeDependent())
1916      CT = CT_Dependent;
1917    else if (isa<CXXPseudoDestructorExpr>(CE->getCallee()->IgnoreParens()))
1918      CT = CT_Cannot;
1919    else
1920      CT = CanCalleeThrow(C, this, CE->getCalleeDecl());
1921    if (CT == CT_Can)
1922      return CT;
1923    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1924  }
1925
1926  case CXXConstructExprClass:
1927  case CXXTemporaryObjectExprClass: {
1928    CanThrowResult CT = CanCalleeThrow(C, this,
1929        cast<CXXConstructExpr>(this)->getConstructor());
1930    if (CT == CT_Can)
1931      return CT;
1932    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1933  }
1934
1935  case CXXNewExprClass: {
1936    CanThrowResult CT;
1937    if (isTypeDependent())
1938      CT = CT_Dependent;
1939    else
1940      CT = MergeCanThrow(
1941        CanCalleeThrow(C, this, cast<CXXNewExpr>(this)->getOperatorNew()),
1942        CanCalleeThrow(C, this, cast<CXXNewExpr>(this)->getConstructor(),
1943                       /*NullThrows*/false));
1944    if (CT == CT_Can)
1945      return CT;
1946    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1947  }
1948
1949  case CXXDeleteExprClass: {
1950    CanThrowResult CT;
1951    QualType DTy = cast<CXXDeleteExpr>(this)->getDestroyedType();
1952    if (DTy.isNull() || DTy->isDependentType()) {
1953      CT = CT_Dependent;
1954    } else {
1955      CT = CanCalleeThrow(C, this,
1956                          cast<CXXDeleteExpr>(this)->getOperatorDelete());
1957      if (const RecordType *RT = DTy->getAs<RecordType>()) {
1958        const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1959        CT = MergeCanThrow(CT, CanCalleeThrow(C, this, RD->getDestructor()));
1960      }
1961      if (CT == CT_Can)
1962        return CT;
1963    }
1964    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1965  }
1966
1967  case CXXBindTemporaryExprClass: {
1968    // The bound temporary has to be destroyed again, which might throw.
1969    CanThrowResult CT = CanCalleeThrow(C, this,
1970      cast<CXXBindTemporaryExpr>(this)->getTemporary()->getDestructor());
1971    if (CT == CT_Can)
1972      return CT;
1973    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1974  }
1975
1976    // ObjC message sends are like function calls, but never have exception
1977    // specs.
1978  case ObjCMessageExprClass:
1979  case ObjCPropertyRefExprClass:
1980    return CT_Can;
1981
1982    // Many other things have subexpressions, so we have to test those.
1983    // Some are simple:
1984  case ParenExprClass:
1985  case MemberExprClass:
1986  case CXXReinterpretCastExprClass:
1987  case CXXConstCastExprClass:
1988  case ConditionalOperatorClass:
1989  case CompoundLiteralExprClass:
1990  case ExtVectorElementExprClass:
1991  case InitListExprClass:
1992  case DesignatedInitExprClass:
1993  case ParenListExprClass:
1994  case VAArgExprClass:
1995  case CXXDefaultArgExprClass:
1996  case ExprWithCleanupsClass:
1997  case ObjCIvarRefExprClass:
1998  case ObjCIsaExprClass:
1999  case ShuffleVectorExprClass:
2000    return CanSubExprsThrow(C, this);
2001
2002    // Some might be dependent for other reasons.
2003  case UnaryOperatorClass:
2004  case ArraySubscriptExprClass:
2005  case ImplicitCastExprClass:
2006  case CStyleCastExprClass:
2007  case CXXStaticCastExprClass:
2008  case CXXFunctionalCastExprClass:
2009  case BinaryOperatorClass:
2010  case CompoundAssignOperatorClass:
2011  case MaterializeTemporaryExprClass: {
2012    CanThrowResult CT = isTypeDependent() ? CT_Dependent : CT_Cannot;
2013    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
2014  }
2015
2016    // FIXME: We should handle StmtExpr, but that opens a MASSIVE can of worms.
2017  case StmtExprClass:
2018    return CT_Can;
2019
2020  case ChooseExprClass:
2021    if (isTypeDependent() || isValueDependent())
2022      return CT_Dependent;
2023    return cast<ChooseExpr>(this)->getChosenSubExpr(C)->CanThrow(C);
2024
2025  case GenericSelectionExprClass:
2026    if (cast<GenericSelectionExpr>(this)->isResultDependent())
2027      return CT_Dependent;
2028    return cast<GenericSelectionExpr>(this)->getResultExpr()->CanThrow(C);
2029
2030    // Some expressions are always dependent.
2031  case DependentScopeDeclRefExprClass:
2032  case CXXUnresolvedConstructExprClass:
2033  case CXXDependentScopeMemberExprClass:
2034    return CT_Dependent;
2035
2036  default:
2037    // All other expressions don't have subexpressions, or else they are
2038    // unevaluated.
2039    return CT_Cannot;
2040  }
2041}
2042
2043Expr* Expr::IgnoreParens() {
2044  Expr* E = this;
2045  while (true) {
2046    if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
2047      E = P->getSubExpr();
2048      continue;
2049    }
2050    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2051      if (P->getOpcode() == UO_Extension) {
2052        E = P->getSubExpr();
2053        continue;
2054      }
2055    }
2056    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2057      if (!P->isResultDependent()) {
2058        E = P->getResultExpr();
2059        continue;
2060      }
2061    }
2062    return E;
2063  }
2064}
2065
2066/// IgnoreParenCasts - Ignore parentheses and casts.  Strip off any ParenExpr
2067/// or CastExprs or ImplicitCastExprs, returning their operand.
2068Expr *Expr::IgnoreParenCasts() {
2069  Expr *E = this;
2070  while (true) {
2071    if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
2072      E = P->getSubExpr();
2073      continue;
2074    }
2075    if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2076      E = P->getSubExpr();
2077      continue;
2078    }
2079    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2080      if (P->getOpcode() == UO_Extension) {
2081        E = P->getSubExpr();
2082        continue;
2083      }
2084    }
2085    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2086      if (!P->isResultDependent()) {
2087        E = P->getResultExpr();
2088        continue;
2089      }
2090    }
2091    if (MaterializeTemporaryExpr *Materialize
2092                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2093      E = Materialize->GetTemporaryExpr();
2094      continue;
2095    }
2096    if (SubstNonTypeTemplateParmExpr *NTTP
2097                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2098      E = NTTP->getReplacement();
2099      continue;
2100    }
2101    return E;
2102  }
2103}
2104
2105/// IgnoreParenLValueCasts - Ignore parentheses and lvalue-to-rvalue
2106/// casts.  This is intended purely as a temporary workaround for code
2107/// that hasn't yet been rewritten to do the right thing about those
2108/// casts, and may disappear along with the last internal use.
2109Expr *Expr::IgnoreParenLValueCasts() {
2110  Expr *E = this;
2111  while (true) {
2112    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2113      E = P->getSubExpr();
2114      continue;
2115    } else if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2116      if (P->getCastKind() == CK_LValueToRValue) {
2117        E = P->getSubExpr();
2118        continue;
2119      }
2120    } else if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2121      if (P->getOpcode() == UO_Extension) {
2122        E = P->getSubExpr();
2123        continue;
2124      }
2125    } else if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2126      if (!P->isResultDependent()) {
2127        E = P->getResultExpr();
2128        continue;
2129      }
2130    } else if (MaterializeTemporaryExpr *Materialize
2131                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2132      E = Materialize->GetTemporaryExpr();
2133      continue;
2134    } else if (SubstNonTypeTemplateParmExpr *NTTP
2135                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2136      E = NTTP->getReplacement();
2137      continue;
2138    }
2139    break;
2140  }
2141  return E;
2142}
2143
2144Expr *Expr::IgnoreParenImpCasts() {
2145  Expr *E = this;
2146  while (true) {
2147    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2148      E = P->getSubExpr();
2149      continue;
2150    }
2151    if (ImplicitCastExpr *P = dyn_cast<ImplicitCastExpr>(E)) {
2152      E = P->getSubExpr();
2153      continue;
2154    }
2155    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2156      if (P->getOpcode() == UO_Extension) {
2157        E = P->getSubExpr();
2158        continue;
2159      }
2160    }
2161    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2162      if (!P->isResultDependent()) {
2163        E = P->getResultExpr();
2164        continue;
2165      }
2166    }
2167    if (MaterializeTemporaryExpr *Materialize
2168                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2169      E = Materialize->GetTemporaryExpr();
2170      continue;
2171    }
2172    if (SubstNonTypeTemplateParmExpr *NTTP
2173                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2174      E = NTTP->getReplacement();
2175      continue;
2176    }
2177    return E;
2178  }
2179}
2180
2181Expr *Expr::IgnoreConversionOperator() {
2182  if (CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(this)) {
2183    if (MCE->getMethodDecl() && isa<CXXConversionDecl>(MCE->getMethodDecl()))
2184      return MCE->getImplicitObjectArgument();
2185  }
2186  return this;
2187}
2188
2189/// IgnoreParenNoopCasts - Ignore parentheses and casts that do not change the
2190/// value (including ptr->int casts of the same size).  Strip off any
2191/// ParenExpr or CastExprs, returning their operand.
2192Expr *Expr::IgnoreParenNoopCasts(ASTContext &Ctx) {
2193  Expr *E = this;
2194  while (true) {
2195    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2196      E = P->getSubExpr();
2197      continue;
2198    }
2199
2200    if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2201      // We ignore integer <-> casts that are of the same width, ptr<->ptr and
2202      // ptr<->int casts of the same width.  We also ignore all identity casts.
2203      Expr *SE = P->getSubExpr();
2204
2205      if (Ctx.hasSameUnqualifiedType(E->getType(), SE->getType())) {
2206        E = SE;
2207        continue;
2208      }
2209
2210      if ((E->getType()->isPointerType() ||
2211           E->getType()->isIntegralType(Ctx)) &&
2212          (SE->getType()->isPointerType() ||
2213           SE->getType()->isIntegralType(Ctx)) &&
2214          Ctx.getTypeSize(E->getType()) == Ctx.getTypeSize(SE->getType())) {
2215        E = SE;
2216        continue;
2217      }
2218    }
2219
2220    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2221      if (P->getOpcode() == UO_Extension) {
2222        E = P->getSubExpr();
2223        continue;
2224      }
2225    }
2226
2227    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2228      if (!P->isResultDependent()) {
2229        E = P->getResultExpr();
2230        continue;
2231      }
2232    }
2233
2234    if (SubstNonTypeTemplateParmExpr *NTTP
2235                                  = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
2236      E = NTTP->getReplacement();
2237      continue;
2238    }
2239
2240    return E;
2241  }
2242}
2243
2244bool Expr::isDefaultArgument() const {
2245  const Expr *E = this;
2246  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
2247    E = M->GetTemporaryExpr();
2248
2249  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
2250    E = ICE->getSubExprAsWritten();
2251
2252  return isa<CXXDefaultArgExpr>(E);
2253}
2254
2255/// \brief Skip over any no-op casts and any temporary-binding
2256/// expressions.
2257static const Expr *skipTemporaryBindingsNoOpCastsAndParens(const Expr *E) {
2258  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
2259    E = M->GetTemporaryExpr();
2260
2261  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2262    if (ICE->getCastKind() == CK_NoOp)
2263      E = ICE->getSubExpr();
2264    else
2265      break;
2266  }
2267
2268  while (const CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(E))
2269    E = BE->getSubExpr();
2270
2271  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2272    if (ICE->getCastKind() == CK_NoOp)
2273      E = ICE->getSubExpr();
2274    else
2275      break;
2276  }
2277
2278  return E->IgnoreParens();
2279}
2280
2281/// isTemporaryObject - Determines if this expression produces a
2282/// temporary of the given class type.
2283bool Expr::isTemporaryObject(ASTContext &C, const CXXRecordDecl *TempTy) const {
2284  if (!C.hasSameUnqualifiedType(getType(), C.getTypeDeclType(TempTy)))
2285    return false;
2286
2287  const Expr *E = skipTemporaryBindingsNoOpCastsAndParens(this);
2288
2289  // Temporaries are by definition pr-values of class type.
2290  if (!E->Classify(C).isPRValue()) {
2291    // In this context, property reference is a message call and is pr-value.
2292    if (!isa<ObjCPropertyRefExpr>(E))
2293      return false;
2294  }
2295
2296  // Black-list a few cases which yield pr-values of class type that don't
2297  // refer to temporaries of that type:
2298
2299  // - implicit derived-to-base conversions
2300  if (isa<ImplicitCastExpr>(E)) {
2301    switch (cast<ImplicitCastExpr>(E)->getCastKind()) {
2302    case CK_DerivedToBase:
2303    case CK_UncheckedDerivedToBase:
2304      return false;
2305    default:
2306      break;
2307    }
2308  }
2309
2310  // - member expressions (all)
2311  if (isa<MemberExpr>(E))
2312    return false;
2313
2314  // - opaque values (all)
2315  if (isa<OpaqueValueExpr>(E))
2316    return false;
2317
2318  return true;
2319}
2320
2321bool Expr::isImplicitCXXThis() const {
2322  const Expr *E = this;
2323
2324  // Strip away parentheses and casts we don't care about.
2325  while (true) {
2326    if (const ParenExpr *Paren = dyn_cast<ParenExpr>(E)) {
2327      E = Paren->getSubExpr();
2328      continue;
2329    }
2330
2331    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2332      if (ICE->getCastKind() == CK_NoOp ||
2333          ICE->getCastKind() == CK_LValueToRValue ||
2334          ICE->getCastKind() == CK_DerivedToBase ||
2335          ICE->getCastKind() == CK_UncheckedDerivedToBase) {
2336        E = ICE->getSubExpr();
2337        continue;
2338      }
2339    }
2340
2341    if (const UnaryOperator* UnOp = dyn_cast<UnaryOperator>(E)) {
2342      if (UnOp->getOpcode() == UO_Extension) {
2343        E = UnOp->getSubExpr();
2344        continue;
2345      }
2346    }
2347
2348    if (const MaterializeTemporaryExpr *M
2349                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2350      E = M->GetTemporaryExpr();
2351      continue;
2352    }
2353
2354    break;
2355  }
2356
2357  if (const CXXThisExpr *This = dyn_cast<CXXThisExpr>(E))
2358    return This->isImplicit();
2359
2360  return false;
2361}
2362
2363/// hasAnyTypeDependentArguments - Determines if any of the expressions
2364/// in Exprs is type-dependent.
2365bool Expr::hasAnyTypeDependentArguments(Expr** Exprs, unsigned NumExprs) {
2366  for (unsigned I = 0; I < NumExprs; ++I)
2367    if (Exprs[I]->isTypeDependent())
2368      return true;
2369
2370  return false;
2371}
2372
2373/// hasAnyValueDependentArguments - Determines if any of the expressions
2374/// in Exprs is value-dependent.
2375bool Expr::hasAnyValueDependentArguments(Expr** Exprs, unsigned NumExprs) {
2376  for (unsigned I = 0; I < NumExprs; ++I)
2377    if (Exprs[I]->isValueDependent())
2378      return true;
2379
2380  return false;
2381}
2382
2383bool Expr::isConstantInitializer(ASTContext &Ctx, bool IsForRef) const {
2384  // This function is attempting whether an expression is an initializer
2385  // which can be evaluated at compile-time.  isEvaluatable handles most
2386  // of the cases, but it can't deal with some initializer-specific
2387  // expressions, and it can't deal with aggregates; we deal with those here,
2388  // and fall back to isEvaluatable for the other cases.
2389
2390  // If we ever capture reference-binding directly in the AST, we can
2391  // kill the second parameter.
2392
2393  if (IsForRef) {
2394    EvalResult Result;
2395    return EvaluateAsLValue(Result, Ctx) && !Result.HasSideEffects;
2396  }
2397
2398  switch (getStmtClass()) {
2399  default: break;
2400  case StringLiteralClass:
2401  case ObjCStringLiteralClass:
2402  case ObjCEncodeExprClass:
2403    return true;
2404  case CXXTemporaryObjectExprClass:
2405  case CXXConstructExprClass: {
2406    const CXXConstructExpr *CE = cast<CXXConstructExpr>(this);
2407
2408    // Only if it's
2409    // 1) an application of the trivial default constructor or
2410    if (!CE->getConstructor()->isTrivial()) return false;
2411    if (!CE->getNumArgs()) return true;
2412
2413    // 2) an elidable trivial copy construction of an operand which is
2414    //    itself a constant initializer.  Note that we consider the
2415    //    operand on its own, *not* as a reference binding.
2416    return CE->isElidable() &&
2417           CE->getArg(0)->isConstantInitializer(Ctx, false);
2418  }
2419  case CompoundLiteralExprClass: {
2420    // This handles gcc's extension that allows global initializers like
2421    // "struct x {int x;} x = (struct x) {};".
2422    // FIXME: This accepts other cases it shouldn't!
2423    const Expr *Exp = cast<CompoundLiteralExpr>(this)->getInitializer();
2424    return Exp->isConstantInitializer(Ctx, false);
2425  }
2426  case InitListExprClass: {
2427    // FIXME: This doesn't deal with fields with reference types correctly.
2428    // FIXME: This incorrectly allows pointers cast to integers to be assigned
2429    // to bitfields.
2430    const InitListExpr *Exp = cast<InitListExpr>(this);
2431    unsigned numInits = Exp->getNumInits();
2432    for (unsigned i = 0; i < numInits; i++) {
2433      if (!Exp->getInit(i)->isConstantInitializer(Ctx, false))
2434        return false;
2435    }
2436    return true;
2437  }
2438  case ImplicitValueInitExprClass:
2439    return true;
2440  case ParenExprClass:
2441    return cast<ParenExpr>(this)->getSubExpr()
2442      ->isConstantInitializer(Ctx, IsForRef);
2443  case GenericSelectionExprClass:
2444    if (cast<GenericSelectionExpr>(this)->isResultDependent())
2445      return false;
2446    return cast<GenericSelectionExpr>(this)->getResultExpr()
2447      ->isConstantInitializer(Ctx, IsForRef);
2448  case ChooseExprClass:
2449    return cast<ChooseExpr>(this)->getChosenSubExpr(Ctx)
2450      ->isConstantInitializer(Ctx, IsForRef);
2451  case UnaryOperatorClass: {
2452    const UnaryOperator* Exp = cast<UnaryOperator>(this);
2453    if (Exp->getOpcode() == UO_Extension)
2454      return Exp->getSubExpr()->isConstantInitializer(Ctx, false);
2455    break;
2456  }
2457  case BinaryOperatorClass: {
2458    // Special case &&foo - &&bar.  It would be nice to generalize this somehow
2459    // but this handles the common case.
2460    const BinaryOperator *Exp = cast<BinaryOperator>(this);
2461    if (Exp->getOpcode() == BO_Sub &&
2462        isa<AddrLabelExpr>(Exp->getLHS()->IgnoreParenNoopCasts(Ctx)) &&
2463        isa<AddrLabelExpr>(Exp->getRHS()->IgnoreParenNoopCasts(Ctx)))
2464      return true;
2465    break;
2466  }
2467  case CXXFunctionalCastExprClass:
2468  case CXXStaticCastExprClass:
2469  case ImplicitCastExprClass:
2470  case CStyleCastExprClass:
2471    // Handle casts with a destination that's a struct or union; this
2472    // deals with both the gcc no-op struct cast extension and the
2473    // cast-to-union extension.
2474    if (getType()->isRecordType())
2475      return cast<CastExpr>(this)->getSubExpr()
2476        ->isConstantInitializer(Ctx, false);
2477
2478    // Integer->integer casts can be handled here, which is important for
2479    // things like (int)(&&x-&&y).  Scary but true.
2480    if (getType()->isIntegerType() &&
2481        cast<CastExpr>(this)->getSubExpr()->getType()->isIntegerType())
2482      return cast<CastExpr>(this)->getSubExpr()
2483        ->isConstantInitializer(Ctx, false);
2484
2485    break;
2486
2487  case MaterializeTemporaryExprClass:
2488    return cast<MaterializeTemporaryExpr>(this)->GetTemporaryExpr()
2489                                            ->isConstantInitializer(Ctx, false);
2490  }
2491  return isEvaluatable(Ctx);
2492}
2493
2494/// isNullPointerConstant - C99 6.3.2.3p3 - Return whether this is a null
2495/// pointer constant or not, as well as the specific kind of constant detected.
2496/// Null pointer constants can be integer constant expressions with the
2497/// value zero, casts of zero to void*, nullptr (C++0X), or __null
2498/// (a GNU extension).
2499Expr::NullPointerConstantKind
2500Expr::isNullPointerConstant(ASTContext &Ctx,
2501                            NullPointerConstantValueDependence NPC) const {
2502  if (isValueDependent()) {
2503    switch (NPC) {
2504    case NPC_NeverValueDependent:
2505      llvm_unreachable("Unexpected value dependent expression!");
2506      // If the unthinkable happens, fall through to the safest alternative.
2507
2508    case NPC_ValueDependentIsNull:
2509      if (isTypeDependent() || getType()->isIntegralType(Ctx))
2510        return NPCK_ZeroInteger;
2511      else
2512        return NPCK_NotNull;
2513
2514    case NPC_ValueDependentIsNotNull:
2515      return NPCK_NotNull;
2516    }
2517  }
2518
2519  // Strip off a cast to void*, if it exists. Except in C++.
2520  if (const ExplicitCastExpr *CE = dyn_cast<ExplicitCastExpr>(this)) {
2521    if (!Ctx.getLangOptions().CPlusPlus) {
2522      // Check that it is a cast to void*.
2523      if (const PointerType *PT = CE->getType()->getAs<PointerType>()) {
2524        QualType Pointee = PT->getPointeeType();
2525        if (!Pointee.hasQualifiers() &&
2526            Pointee->isVoidType() &&                              // to void*
2527            CE->getSubExpr()->getType()->isIntegerType())         // from int.
2528          return CE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2529      }
2530    }
2531  } else if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(this)) {
2532    // Ignore the ImplicitCastExpr type entirely.
2533    return ICE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2534  } else if (const ParenExpr *PE = dyn_cast<ParenExpr>(this)) {
2535    // Accept ((void*)0) as a null pointer constant, as many other
2536    // implementations do.
2537    return PE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2538  } else if (const GenericSelectionExpr *GE =
2539               dyn_cast<GenericSelectionExpr>(this)) {
2540    return GE->getResultExpr()->isNullPointerConstant(Ctx, NPC);
2541  } else if (const CXXDefaultArgExpr *DefaultArg
2542               = dyn_cast<CXXDefaultArgExpr>(this)) {
2543    // See through default argument expressions
2544    return DefaultArg->getExpr()->isNullPointerConstant(Ctx, NPC);
2545  } else if (isa<GNUNullExpr>(this)) {
2546    // The GNU __null extension is always a null pointer constant.
2547    return NPCK_GNUNull;
2548  } else if (const MaterializeTemporaryExpr *M
2549                                   = dyn_cast<MaterializeTemporaryExpr>(this)) {
2550    return M->GetTemporaryExpr()->isNullPointerConstant(Ctx, NPC);
2551  }
2552
2553  // C++0x nullptr_t is always a null pointer constant.
2554  if (getType()->isNullPtrType())
2555    return NPCK_CXX0X_nullptr;
2556
2557  if (const RecordType *UT = getType()->getAsUnionType())
2558    if (UT && UT->getDecl()->hasAttr<TransparentUnionAttr>())
2559      if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(this)){
2560        const Expr *InitExpr = CLE->getInitializer();
2561        if (const InitListExpr *ILE = dyn_cast<InitListExpr>(InitExpr))
2562          return ILE->getInit(0)->isNullPointerConstant(Ctx, NPC);
2563      }
2564  // This expression must be an integer type.
2565  if (!getType()->isIntegerType() ||
2566      (Ctx.getLangOptions().CPlusPlus && getType()->isEnumeralType()))
2567    return NPCK_NotNull;
2568
2569  // If we have an integer constant expression, we need to *evaluate* it and
2570  // test for the value 0.
2571  llvm::APSInt Result;
2572  bool IsNull = isIntegerConstantExpr(Result, Ctx) && Result == 0;
2573
2574  return (IsNull ? NPCK_ZeroInteger : NPCK_NotNull);
2575}
2576
2577/// \brief If this expression is an l-value for an Objective C
2578/// property, find the underlying property reference expression.
2579const ObjCPropertyRefExpr *Expr::getObjCProperty() const {
2580  const Expr *E = this;
2581  while (true) {
2582    assert((E->getValueKind() == VK_LValue &&
2583            E->getObjectKind() == OK_ObjCProperty) &&
2584           "expression is not a property reference");
2585    E = E->IgnoreParenCasts();
2586    if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
2587      if (BO->getOpcode() == BO_Comma) {
2588        E = BO->getRHS();
2589        continue;
2590      }
2591    }
2592
2593    break;
2594  }
2595
2596  return cast<ObjCPropertyRefExpr>(E);
2597}
2598
2599FieldDecl *Expr::getBitField() {
2600  Expr *E = this->IgnoreParens();
2601
2602  while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2603    if (ICE->getCastKind() == CK_LValueToRValue ||
2604        (ICE->getValueKind() != VK_RValue && ICE->getCastKind() == CK_NoOp))
2605      E = ICE->getSubExpr()->IgnoreParens();
2606    else
2607      break;
2608  }
2609
2610  if (MemberExpr *MemRef = dyn_cast<MemberExpr>(E))
2611    if (FieldDecl *Field = dyn_cast<FieldDecl>(MemRef->getMemberDecl()))
2612      if (Field->isBitField())
2613        return Field;
2614
2615  if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E))
2616    if (FieldDecl *Field = dyn_cast<FieldDecl>(DeclRef->getDecl()))
2617      if (Field->isBitField())
2618        return Field;
2619
2620  if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E)) {
2621    if (BinOp->isAssignmentOp() && BinOp->getLHS())
2622      return BinOp->getLHS()->getBitField();
2623
2624    if (BinOp->getOpcode() == BO_Comma && BinOp->getRHS())
2625      return BinOp->getRHS()->getBitField();
2626  }
2627
2628  return 0;
2629}
2630
2631bool Expr::refersToVectorElement() const {
2632  const Expr *E = this->IgnoreParens();
2633
2634  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2635    if (ICE->getValueKind() != VK_RValue &&
2636        ICE->getCastKind() == CK_NoOp)
2637      E = ICE->getSubExpr()->IgnoreParens();
2638    else
2639      break;
2640  }
2641
2642  if (const ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(E))
2643    return ASE->getBase()->getType()->isVectorType();
2644
2645  if (isa<ExtVectorElementExpr>(E))
2646    return true;
2647
2648  return false;
2649}
2650
2651/// isArrow - Return true if the base expression is a pointer to vector,
2652/// return false if the base expression is a vector.
2653bool ExtVectorElementExpr::isArrow() const {
2654  return getBase()->getType()->isPointerType();
2655}
2656
2657unsigned ExtVectorElementExpr::getNumElements() const {
2658  if (const VectorType *VT = getType()->getAs<VectorType>())
2659    return VT->getNumElements();
2660  return 1;
2661}
2662
2663/// containsDuplicateElements - Return true if any element access is repeated.
2664bool ExtVectorElementExpr::containsDuplicateElements() const {
2665  // FIXME: Refactor this code to an accessor on the AST node which returns the
2666  // "type" of component access, and share with code below and in Sema.
2667  StringRef Comp = Accessor->getName();
2668
2669  // Halving swizzles do not contain duplicate elements.
2670  if (Comp == "hi" || Comp == "lo" || Comp == "even" || Comp == "odd")
2671    return false;
2672
2673  // Advance past s-char prefix on hex swizzles.
2674  if (Comp[0] == 's' || Comp[0] == 'S')
2675    Comp = Comp.substr(1);
2676
2677  for (unsigned i = 0, e = Comp.size(); i != e; ++i)
2678    if (Comp.substr(i + 1).find(Comp[i]) != StringRef::npos)
2679        return true;
2680
2681  return false;
2682}
2683
2684/// getEncodedElementAccess - We encode the fields as a llvm ConstantArray.
2685void ExtVectorElementExpr::getEncodedElementAccess(
2686                                  SmallVectorImpl<unsigned> &Elts) const {
2687  StringRef Comp = Accessor->getName();
2688  if (Comp[0] == 's' || Comp[0] == 'S')
2689    Comp = Comp.substr(1);
2690
2691  bool isHi =   Comp == "hi";
2692  bool isLo =   Comp == "lo";
2693  bool isEven = Comp == "even";
2694  bool isOdd  = Comp == "odd";
2695
2696  for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
2697    uint64_t Index;
2698
2699    if (isHi)
2700      Index = e + i;
2701    else if (isLo)
2702      Index = i;
2703    else if (isEven)
2704      Index = 2 * i;
2705    else if (isOdd)
2706      Index = 2 * i + 1;
2707    else
2708      Index = ExtVectorType::getAccessorIdx(Comp[i]);
2709
2710    Elts.push_back(Index);
2711  }
2712}
2713
2714ObjCMessageExpr::ObjCMessageExpr(QualType T,
2715                                 ExprValueKind VK,
2716                                 SourceLocation LBracLoc,
2717                                 SourceLocation SuperLoc,
2718                                 bool IsInstanceSuper,
2719                                 QualType SuperType,
2720                                 Selector Sel,
2721                                 SourceLocation SelLoc,
2722                                 ObjCMethodDecl *Method,
2723                                 Expr **Args, unsigned NumArgs,
2724                                 SourceLocation RBracLoc)
2725  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary,
2726         /*TypeDependent=*/false, /*ValueDependent=*/false,
2727         /*InstantiationDependent=*/false,
2728         /*ContainsUnexpandedParameterPack=*/false),
2729    NumArgs(NumArgs), Kind(IsInstanceSuper? SuperInstance : SuperClass),
2730    HasMethod(Method != 0), IsDelegateInitCall(false), SuperLoc(SuperLoc),
2731    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2732                                                       : Sel.getAsOpaquePtr())),
2733    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2734{
2735  setReceiverPointer(SuperType.getAsOpaquePtr());
2736  if (NumArgs)
2737    memcpy(getArgs(), Args, NumArgs * sizeof(Expr *));
2738}
2739
2740ObjCMessageExpr::ObjCMessageExpr(QualType T,
2741                                 ExprValueKind VK,
2742                                 SourceLocation LBracLoc,
2743                                 TypeSourceInfo *Receiver,
2744                                 Selector Sel,
2745                                 SourceLocation SelLoc,
2746                                 ObjCMethodDecl *Method,
2747                                 Expr **Args, unsigned NumArgs,
2748                                 SourceLocation RBracLoc)
2749  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, T->isDependentType(),
2750         T->isDependentType(), T->isInstantiationDependentType(),
2751         T->containsUnexpandedParameterPack()),
2752    NumArgs(NumArgs), Kind(Class),
2753    HasMethod(Method != 0), IsDelegateInitCall(false),
2754    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2755                                                       : Sel.getAsOpaquePtr())),
2756    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2757{
2758  setReceiverPointer(Receiver);
2759  Expr **MyArgs = getArgs();
2760  for (unsigned I = 0; I != NumArgs; ++I) {
2761    if (Args[I]->isTypeDependent())
2762      ExprBits.TypeDependent = true;
2763    if (Args[I]->isValueDependent())
2764      ExprBits.ValueDependent = true;
2765    if (Args[I]->isInstantiationDependent())
2766      ExprBits.InstantiationDependent = true;
2767    if (Args[I]->containsUnexpandedParameterPack())
2768      ExprBits.ContainsUnexpandedParameterPack = true;
2769
2770    MyArgs[I] = Args[I];
2771  }
2772}
2773
2774ObjCMessageExpr::ObjCMessageExpr(QualType T,
2775                                 ExprValueKind VK,
2776                                 SourceLocation LBracLoc,
2777                                 Expr *Receiver,
2778                                 Selector Sel,
2779                                 SourceLocation SelLoc,
2780                                 ObjCMethodDecl *Method,
2781                                 Expr **Args, unsigned NumArgs,
2782                                 SourceLocation RBracLoc)
2783  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, Receiver->isTypeDependent(),
2784         Receiver->isTypeDependent(),
2785         Receiver->isInstantiationDependent(),
2786         Receiver->containsUnexpandedParameterPack()),
2787    NumArgs(NumArgs), Kind(Instance),
2788    HasMethod(Method != 0), IsDelegateInitCall(false),
2789    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2790                                                       : Sel.getAsOpaquePtr())),
2791    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2792{
2793  setReceiverPointer(Receiver);
2794  Expr **MyArgs = getArgs();
2795  for (unsigned I = 0; I != NumArgs; ++I) {
2796    if (Args[I]->isTypeDependent())
2797      ExprBits.TypeDependent = true;
2798    if (Args[I]->isValueDependent())
2799      ExprBits.ValueDependent = true;
2800    if (Args[I]->isInstantiationDependent())
2801      ExprBits.InstantiationDependent = true;
2802    if (Args[I]->containsUnexpandedParameterPack())
2803      ExprBits.ContainsUnexpandedParameterPack = true;
2804
2805    MyArgs[I] = Args[I];
2806  }
2807}
2808
2809ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2810                                         ExprValueKind VK,
2811                                         SourceLocation LBracLoc,
2812                                         SourceLocation SuperLoc,
2813                                         bool IsInstanceSuper,
2814                                         QualType SuperType,
2815                                         Selector Sel,
2816                                         SourceLocation SelLoc,
2817                                         ObjCMethodDecl *Method,
2818                                         Expr **Args, unsigned NumArgs,
2819                                         SourceLocation RBracLoc) {
2820  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2821    NumArgs * sizeof(Expr *);
2822  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2823  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, SuperLoc, IsInstanceSuper,
2824                                   SuperType, Sel, SelLoc, Method, Args,NumArgs,
2825                                   RBracLoc);
2826}
2827
2828ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2829                                         ExprValueKind VK,
2830                                         SourceLocation LBracLoc,
2831                                         TypeSourceInfo *Receiver,
2832                                         Selector Sel,
2833                                         SourceLocation SelLoc,
2834                                         ObjCMethodDecl *Method,
2835                                         Expr **Args, unsigned NumArgs,
2836                                         SourceLocation RBracLoc) {
2837  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2838    NumArgs * sizeof(Expr *);
2839  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2840  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel, SelLoc,
2841                                   Method, Args, NumArgs, RBracLoc);
2842}
2843
2844ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2845                                         ExprValueKind VK,
2846                                         SourceLocation LBracLoc,
2847                                         Expr *Receiver,
2848                                         Selector Sel,
2849                                         SourceLocation SelLoc,
2850                                         ObjCMethodDecl *Method,
2851                                         Expr **Args, unsigned NumArgs,
2852                                         SourceLocation RBracLoc) {
2853  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2854    NumArgs * sizeof(Expr *);
2855  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2856  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel, SelLoc,
2857                                   Method, Args, NumArgs, RBracLoc);
2858}
2859
2860ObjCMessageExpr *ObjCMessageExpr::CreateEmpty(ASTContext &Context,
2861                                              unsigned NumArgs) {
2862  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2863    NumArgs * sizeof(Expr *);
2864  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2865  return new (Mem) ObjCMessageExpr(EmptyShell(), NumArgs);
2866}
2867
2868SourceRange ObjCMessageExpr::getReceiverRange() const {
2869  switch (getReceiverKind()) {
2870  case Instance:
2871    return getInstanceReceiver()->getSourceRange();
2872
2873  case Class:
2874    return getClassReceiverTypeInfo()->getTypeLoc().getSourceRange();
2875
2876  case SuperInstance:
2877  case SuperClass:
2878    return getSuperLoc();
2879  }
2880
2881  return SourceLocation();
2882}
2883
2884Selector ObjCMessageExpr::getSelector() const {
2885  if (HasMethod)
2886    return reinterpret_cast<const ObjCMethodDecl *>(SelectorOrMethod)
2887                                                               ->getSelector();
2888  return Selector(SelectorOrMethod);
2889}
2890
2891ObjCInterfaceDecl *ObjCMessageExpr::getReceiverInterface() const {
2892  switch (getReceiverKind()) {
2893  case Instance:
2894    if (const ObjCObjectPointerType *Ptr
2895          = getInstanceReceiver()->getType()->getAs<ObjCObjectPointerType>())
2896      return Ptr->getInterfaceDecl();
2897    break;
2898
2899  case Class:
2900    if (const ObjCObjectType *Ty
2901          = getClassReceiver()->getAs<ObjCObjectType>())
2902      return Ty->getInterface();
2903    break;
2904
2905  case SuperInstance:
2906    if (const ObjCObjectPointerType *Ptr
2907          = getSuperType()->getAs<ObjCObjectPointerType>())
2908      return Ptr->getInterfaceDecl();
2909    break;
2910
2911  case SuperClass:
2912    if (const ObjCObjectType *Iface
2913          = getSuperType()->getAs<ObjCObjectType>())
2914      return Iface->getInterface();
2915    break;
2916  }
2917
2918  return 0;
2919}
2920
2921StringRef ObjCBridgedCastExpr::getBridgeKindName() const {
2922  switch (getBridgeKind()) {
2923  case OBC_Bridge:
2924    return "__bridge";
2925  case OBC_BridgeTransfer:
2926    return "__bridge_transfer";
2927  case OBC_BridgeRetained:
2928    return "__bridge_retained";
2929  }
2930
2931  return "__bridge";
2932}
2933
2934bool ChooseExpr::isConditionTrue(const ASTContext &C) const {
2935  return getCond()->EvaluateAsInt(C) != 0;
2936}
2937
2938ShuffleVectorExpr::ShuffleVectorExpr(ASTContext &C, Expr **args, unsigned nexpr,
2939                                     QualType Type, SourceLocation BLoc,
2940                                     SourceLocation RP)
2941   : Expr(ShuffleVectorExprClass, Type, VK_RValue, OK_Ordinary,
2942          Type->isDependentType(), Type->isDependentType(),
2943          Type->isInstantiationDependentType(),
2944          Type->containsUnexpandedParameterPack()),
2945     BuiltinLoc(BLoc), RParenLoc(RP), NumExprs(nexpr)
2946{
2947  SubExprs = new (C) Stmt*[nexpr];
2948  for (unsigned i = 0; i < nexpr; i++) {
2949    if (args[i]->isTypeDependent())
2950      ExprBits.TypeDependent = true;
2951    if (args[i]->isValueDependent())
2952      ExprBits.ValueDependent = true;
2953    if (args[i]->isInstantiationDependent())
2954      ExprBits.InstantiationDependent = true;
2955    if (args[i]->containsUnexpandedParameterPack())
2956      ExprBits.ContainsUnexpandedParameterPack = true;
2957
2958    SubExprs[i] = args[i];
2959  }
2960}
2961
2962void ShuffleVectorExpr::setExprs(ASTContext &C, Expr ** Exprs,
2963                                 unsigned NumExprs) {
2964  if (SubExprs) C.Deallocate(SubExprs);
2965
2966  SubExprs = new (C) Stmt* [NumExprs];
2967  this->NumExprs = NumExprs;
2968  memcpy(SubExprs, Exprs, sizeof(Expr *) * NumExprs);
2969}
2970
2971GenericSelectionExpr::GenericSelectionExpr(ASTContext &Context,
2972                               SourceLocation GenericLoc, Expr *ControllingExpr,
2973                               TypeSourceInfo **AssocTypes, Expr **AssocExprs,
2974                               unsigned NumAssocs, SourceLocation DefaultLoc,
2975                               SourceLocation RParenLoc,
2976                               bool ContainsUnexpandedParameterPack,
2977                               unsigned ResultIndex)
2978  : Expr(GenericSelectionExprClass,
2979         AssocExprs[ResultIndex]->getType(),
2980         AssocExprs[ResultIndex]->getValueKind(),
2981         AssocExprs[ResultIndex]->getObjectKind(),
2982         AssocExprs[ResultIndex]->isTypeDependent(),
2983         AssocExprs[ResultIndex]->isValueDependent(),
2984         AssocExprs[ResultIndex]->isInstantiationDependent(),
2985         ContainsUnexpandedParameterPack),
2986    AssocTypes(new (Context) TypeSourceInfo*[NumAssocs]),
2987    SubExprs(new (Context) Stmt*[END_EXPR+NumAssocs]), NumAssocs(NumAssocs),
2988    ResultIndex(ResultIndex), GenericLoc(GenericLoc), DefaultLoc(DefaultLoc),
2989    RParenLoc(RParenLoc) {
2990  SubExprs[CONTROLLING] = ControllingExpr;
2991  std::copy(AssocTypes, AssocTypes+NumAssocs, this->AssocTypes);
2992  std::copy(AssocExprs, AssocExprs+NumAssocs, SubExprs+END_EXPR);
2993}
2994
2995GenericSelectionExpr::GenericSelectionExpr(ASTContext &Context,
2996                               SourceLocation GenericLoc, Expr *ControllingExpr,
2997                               TypeSourceInfo **AssocTypes, Expr **AssocExprs,
2998                               unsigned NumAssocs, SourceLocation DefaultLoc,
2999                               SourceLocation RParenLoc,
3000                               bool ContainsUnexpandedParameterPack)
3001  : Expr(GenericSelectionExprClass,
3002         Context.DependentTy,
3003         VK_RValue,
3004         OK_Ordinary,
3005         /*isTypeDependent=*/true,
3006         /*isValueDependent=*/true,
3007         /*isInstantiationDependent=*/true,
3008         ContainsUnexpandedParameterPack),
3009    AssocTypes(new (Context) TypeSourceInfo*[NumAssocs]),
3010    SubExprs(new (Context) Stmt*[END_EXPR+NumAssocs]), NumAssocs(NumAssocs),
3011    ResultIndex(-1U), GenericLoc(GenericLoc), DefaultLoc(DefaultLoc),
3012    RParenLoc(RParenLoc) {
3013  SubExprs[CONTROLLING] = ControllingExpr;
3014  std::copy(AssocTypes, AssocTypes+NumAssocs, this->AssocTypes);
3015  std::copy(AssocExprs, AssocExprs+NumAssocs, SubExprs+END_EXPR);
3016}
3017
3018//===----------------------------------------------------------------------===//
3019//  DesignatedInitExpr
3020//===----------------------------------------------------------------------===//
3021
3022IdentifierInfo *DesignatedInitExpr::Designator::getFieldName() const {
3023  assert(Kind == FieldDesignator && "Only valid on a field designator");
3024  if (Field.NameOrField & 0x01)
3025    return reinterpret_cast<IdentifierInfo *>(Field.NameOrField&~0x01);
3026  else
3027    return getField()->getIdentifier();
3028}
3029
3030DesignatedInitExpr::DesignatedInitExpr(ASTContext &C, QualType Ty,
3031                                       unsigned NumDesignators,
3032                                       const Designator *Designators,
3033                                       SourceLocation EqualOrColonLoc,
3034                                       bool GNUSyntax,
3035                                       Expr **IndexExprs,
3036                                       unsigned NumIndexExprs,
3037                                       Expr *Init)
3038  : Expr(DesignatedInitExprClass, Ty,
3039         Init->getValueKind(), Init->getObjectKind(),
3040         Init->isTypeDependent(), Init->isValueDependent(),
3041         Init->isInstantiationDependent(),
3042         Init->containsUnexpandedParameterPack()),
3043    EqualOrColonLoc(EqualOrColonLoc), GNUSyntax(GNUSyntax),
3044    NumDesignators(NumDesignators), NumSubExprs(NumIndexExprs + 1) {
3045  this->Designators = new (C) Designator[NumDesignators];
3046
3047  // Record the initializer itself.
3048  child_range Child = children();
3049  *Child++ = Init;
3050
3051  // Copy the designators and their subexpressions, computing
3052  // value-dependence along the way.
3053  unsigned IndexIdx = 0;
3054  for (unsigned I = 0; I != NumDesignators; ++I) {
3055    this->Designators[I] = Designators[I];
3056
3057    if (this->Designators[I].isArrayDesignator()) {
3058      // Compute type- and value-dependence.
3059      Expr *Index = IndexExprs[IndexIdx];
3060      if (Index->isTypeDependent() || Index->isValueDependent())
3061        ExprBits.ValueDependent = true;
3062      if (Index->isInstantiationDependent())
3063        ExprBits.InstantiationDependent = true;
3064      // Propagate unexpanded parameter packs.
3065      if (Index->containsUnexpandedParameterPack())
3066        ExprBits.ContainsUnexpandedParameterPack = true;
3067
3068      // Copy the index expressions into permanent storage.
3069      *Child++ = IndexExprs[IndexIdx++];
3070    } else if (this->Designators[I].isArrayRangeDesignator()) {
3071      // Compute type- and value-dependence.
3072      Expr *Start = IndexExprs[IndexIdx];
3073      Expr *End = IndexExprs[IndexIdx + 1];
3074      if (Start->isTypeDependent() || Start->isValueDependent() ||
3075          End->isTypeDependent() || End->isValueDependent()) {
3076        ExprBits.ValueDependent = true;
3077        ExprBits.InstantiationDependent = true;
3078      } else if (Start->isInstantiationDependent() ||
3079                 End->isInstantiationDependent()) {
3080        ExprBits.InstantiationDependent = true;
3081      }
3082
3083      // Propagate unexpanded parameter packs.
3084      if (Start->containsUnexpandedParameterPack() ||
3085          End->containsUnexpandedParameterPack())
3086        ExprBits.ContainsUnexpandedParameterPack = true;
3087
3088      // Copy the start/end expressions into permanent storage.
3089      *Child++ = IndexExprs[IndexIdx++];
3090      *Child++ = IndexExprs[IndexIdx++];
3091    }
3092  }
3093
3094  assert(IndexIdx == NumIndexExprs && "Wrong number of index expressions");
3095}
3096
3097DesignatedInitExpr *
3098DesignatedInitExpr::Create(ASTContext &C, Designator *Designators,
3099                           unsigned NumDesignators,
3100                           Expr **IndexExprs, unsigned NumIndexExprs,
3101                           SourceLocation ColonOrEqualLoc,
3102                           bool UsesColonSyntax, Expr *Init) {
3103  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
3104                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
3105  return new (Mem) DesignatedInitExpr(C, C.VoidTy, NumDesignators, Designators,
3106                                      ColonOrEqualLoc, UsesColonSyntax,
3107                                      IndexExprs, NumIndexExprs, Init);
3108}
3109
3110DesignatedInitExpr *DesignatedInitExpr::CreateEmpty(ASTContext &C,
3111                                                    unsigned NumIndexExprs) {
3112  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
3113                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
3114  return new (Mem) DesignatedInitExpr(NumIndexExprs + 1);
3115}
3116
3117void DesignatedInitExpr::setDesignators(ASTContext &C,
3118                                        const Designator *Desigs,
3119                                        unsigned NumDesigs) {
3120  Designators = new (C) Designator[NumDesigs];
3121  NumDesignators = NumDesigs;
3122  for (unsigned I = 0; I != NumDesigs; ++I)
3123    Designators[I] = Desigs[I];
3124}
3125
3126SourceRange DesignatedInitExpr::getDesignatorsSourceRange() const {
3127  DesignatedInitExpr *DIE = const_cast<DesignatedInitExpr*>(this);
3128  if (size() == 1)
3129    return DIE->getDesignator(0)->getSourceRange();
3130  return SourceRange(DIE->getDesignator(0)->getStartLocation(),
3131                     DIE->getDesignator(size()-1)->getEndLocation());
3132}
3133
3134SourceRange DesignatedInitExpr::getSourceRange() const {
3135  SourceLocation StartLoc;
3136  Designator &First =
3137    *const_cast<DesignatedInitExpr*>(this)->designators_begin();
3138  if (First.isFieldDesignator()) {
3139    if (GNUSyntax)
3140      StartLoc = SourceLocation::getFromRawEncoding(First.Field.FieldLoc);
3141    else
3142      StartLoc = SourceLocation::getFromRawEncoding(First.Field.DotLoc);
3143  } else
3144    StartLoc =
3145      SourceLocation::getFromRawEncoding(First.ArrayOrRange.LBracketLoc);
3146  return SourceRange(StartLoc, getInit()->getSourceRange().getEnd());
3147}
3148
3149Expr *DesignatedInitExpr::getArrayIndex(const Designator& D) {
3150  assert(D.Kind == Designator::ArrayDesignator && "Requires array designator");
3151  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3152  Ptr += sizeof(DesignatedInitExpr);
3153  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3154  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
3155}
3156
3157Expr *DesignatedInitExpr::getArrayRangeStart(const Designator& D) {
3158  assert(D.Kind == Designator::ArrayRangeDesignator &&
3159         "Requires array range designator");
3160  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3161  Ptr += sizeof(DesignatedInitExpr);
3162  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3163  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
3164}
3165
3166Expr *DesignatedInitExpr::getArrayRangeEnd(const Designator& D) {
3167  assert(D.Kind == Designator::ArrayRangeDesignator &&
3168         "Requires array range designator");
3169  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3170  Ptr += sizeof(DesignatedInitExpr);
3171  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3172  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 2));
3173}
3174
3175/// \brief Replaces the designator at index @p Idx with the series
3176/// of designators in [First, Last).
3177void DesignatedInitExpr::ExpandDesignator(ASTContext &C, unsigned Idx,
3178                                          const Designator *First,
3179                                          const Designator *Last) {
3180  unsigned NumNewDesignators = Last - First;
3181  if (NumNewDesignators == 0) {
3182    std::copy_backward(Designators + Idx + 1,
3183                       Designators + NumDesignators,
3184                       Designators + Idx);
3185    --NumNewDesignators;
3186    return;
3187  } else if (NumNewDesignators == 1) {
3188    Designators[Idx] = *First;
3189    return;
3190  }
3191
3192  Designator *NewDesignators
3193    = new (C) Designator[NumDesignators - 1 + NumNewDesignators];
3194  std::copy(Designators, Designators + Idx, NewDesignators);
3195  std::copy(First, Last, NewDesignators + Idx);
3196  std::copy(Designators + Idx + 1, Designators + NumDesignators,
3197            NewDesignators + Idx + NumNewDesignators);
3198  Designators = NewDesignators;
3199  NumDesignators = NumDesignators - 1 + NumNewDesignators;
3200}
3201
3202ParenListExpr::ParenListExpr(ASTContext& C, SourceLocation lparenloc,
3203                             Expr **exprs, unsigned nexprs,
3204                             SourceLocation rparenloc, QualType T)
3205  : Expr(ParenListExprClass, T, VK_RValue, OK_Ordinary,
3206         false, false, false, false),
3207    NumExprs(nexprs), LParenLoc(lparenloc), RParenLoc(rparenloc) {
3208  assert(!T.isNull() && "ParenListExpr must have a valid type");
3209  Exprs = new (C) Stmt*[nexprs];
3210  for (unsigned i = 0; i != nexprs; ++i) {
3211    if (exprs[i]->isTypeDependent())
3212      ExprBits.TypeDependent = true;
3213    if (exprs[i]->isValueDependent())
3214      ExprBits.ValueDependent = true;
3215    if (exprs[i]->isInstantiationDependent())
3216      ExprBits.InstantiationDependent = true;
3217    if (exprs[i]->containsUnexpandedParameterPack())
3218      ExprBits.ContainsUnexpandedParameterPack = true;
3219
3220    Exprs[i] = exprs[i];
3221  }
3222}
3223
3224const OpaqueValueExpr *OpaqueValueExpr::findInCopyConstruct(const Expr *e) {
3225  if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(e))
3226    e = ewc->getSubExpr();
3227  if (const MaterializeTemporaryExpr *m = dyn_cast<MaterializeTemporaryExpr>(e))
3228    e = m->GetTemporaryExpr();
3229  e = cast<CXXConstructExpr>(e)->getArg(0);
3230  while (const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
3231    e = ice->getSubExpr();
3232  return cast<OpaqueValueExpr>(e);
3233}
3234
3235//===----------------------------------------------------------------------===//
3236//  ExprIterator.
3237//===----------------------------------------------------------------------===//
3238
3239Expr* ExprIterator::operator[](size_t idx) { return cast<Expr>(I[idx]); }
3240Expr* ExprIterator::operator*() const { return cast<Expr>(*I); }
3241Expr* ExprIterator::operator->() const { return cast<Expr>(*I); }
3242const Expr* ConstExprIterator::operator[](size_t idx) const {
3243  return cast<Expr>(I[idx]);
3244}
3245const Expr* ConstExprIterator::operator*() const { return cast<Expr>(*I); }
3246const Expr* ConstExprIterator::operator->() const { return cast<Expr>(*I); }
3247
3248//===----------------------------------------------------------------------===//
3249//  Child Iterators for iterating over subexpressions/substatements
3250//===----------------------------------------------------------------------===//
3251
3252// UnaryExprOrTypeTraitExpr
3253Stmt::child_range UnaryExprOrTypeTraitExpr::children() {
3254  // If this is of a type and the type is a VLA type (and not a typedef), the
3255  // size expression of the VLA needs to be treated as an executable expression.
3256  // Why isn't this weirdness documented better in StmtIterator?
3257  if (isArgumentType()) {
3258    if (const VariableArrayType* T = dyn_cast<VariableArrayType>(
3259                                   getArgumentType().getTypePtr()))
3260      return child_range(child_iterator(T), child_iterator());
3261    return child_range();
3262  }
3263  return child_range(&Argument.Ex, &Argument.Ex + 1);
3264}
3265
3266// ObjCMessageExpr
3267Stmt::child_range ObjCMessageExpr::children() {
3268  Stmt **begin;
3269  if (getReceiverKind() == Instance)
3270    begin = reinterpret_cast<Stmt **>(this + 1);
3271  else
3272    begin = reinterpret_cast<Stmt **>(getArgs());
3273  return child_range(begin,
3274                     reinterpret_cast<Stmt **>(getArgs() + getNumArgs()));
3275}
3276
3277// Blocks
3278BlockDeclRefExpr::BlockDeclRefExpr(VarDecl *d, QualType t, ExprValueKind VK,
3279                                   SourceLocation l, bool ByRef,
3280                                   bool constAdded)
3281  : Expr(BlockDeclRefExprClass, t, VK, OK_Ordinary, false, false, false,
3282         d->isParameterPack()),
3283    D(d), Loc(l), IsByRef(ByRef), ConstQualAdded(constAdded)
3284{
3285  bool TypeDependent = false;
3286  bool ValueDependent = false;
3287  bool InstantiationDependent = false;
3288  computeDeclRefDependence(D, getType(), TypeDependent, ValueDependent,
3289                           InstantiationDependent);
3290  ExprBits.TypeDependent = TypeDependent;
3291  ExprBits.ValueDependent = ValueDependent;
3292  ExprBits.InstantiationDependent = InstantiationDependent;
3293}
3294