Expr.cpp revision 14d251cd62942bf7d56bb87a267ba2ca2f7fae3e 
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
133void ExplicitTemplateArgumentList::initializeFrom(
134                                      const TemplateArgumentListInfo &Info) {
135  LAngleLoc = Info.getLAngleLoc();
136  RAngleLoc = Info.getRAngleLoc();
137  NumTemplateArgs = Info.size();
138
139  TemplateArgumentLoc *ArgBuffer = getTemplateArgs();
140  for (unsigned i = 0; i != NumTemplateArgs; ++i)
141    new (&ArgBuffer[i]) TemplateArgumentLoc(Info[i]);
142}
143
144void ExplicitTemplateArgumentList::initializeFrom(
145                                   const TemplateArgumentListInfo &Info,
146                                   bool &Dependent,
147                                   bool &ContainsUnexpandedParameterPack) {
148  LAngleLoc = Info.getLAngleLoc();
149  RAngleLoc = Info.getRAngleLoc();
150  NumTemplateArgs = Info.size();
151
152  TemplateArgumentLoc *ArgBuffer = getTemplateArgs();
153  for (unsigned i = 0; i != NumTemplateArgs; ++i) {
154    Dependent = Dependent || Info[i].getArgument().isDependent();
155    ContainsUnexpandedParameterPack
156      = ContainsUnexpandedParameterPack ||
157        Info[i].getArgument().containsUnexpandedParameterPack();
158
159    new (&ArgBuffer[i]) TemplateArgumentLoc(Info[i]);
160  }
161}
162
163void ExplicitTemplateArgumentList::copyInto(
164                                      TemplateArgumentListInfo &Info) const {
165  Info.setLAngleLoc(LAngleLoc);
166  Info.setRAngleLoc(RAngleLoc);
167  for (unsigned I = 0; I != NumTemplateArgs; ++I)
168    Info.addArgument(getTemplateArgs()[I]);
169}
170
171std::size_t ExplicitTemplateArgumentList::sizeFor(unsigned NumTemplateArgs) {
172  return sizeof(ExplicitTemplateArgumentList) +
173         sizeof(TemplateArgumentLoc) * NumTemplateArgs;
174}
175
176std::size_t ExplicitTemplateArgumentList::sizeFor(
177                                      const TemplateArgumentListInfo &Info) {
178  return sizeFor(Info.size());
179}
180
181/// \brief Compute the type- and value-dependence of a declaration reference
182/// based on the declaration being referenced.
183static void computeDeclRefDependence(NamedDecl *D, QualType T,
184                                     bool &TypeDependent,
185                                     bool &ValueDependent) {
186  TypeDependent = false;
187  ValueDependent = false;
188
189
190  // (TD) C++ [temp.dep.expr]p3:
191  //   An id-expression is type-dependent if it contains:
192  //
193  // and
194  //
195  // (VD) C++ [temp.dep.constexpr]p2:
196  //  An identifier is value-dependent if it is:
197
198  //  (TD)  - an identifier that was declared with dependent type
199  //  (VD)  - a name declared with a dependent type,
200  if (T->isDependentType()) {
201    TypeDependent = true;
202    ValueDependent = true;
203    return;
204  }
205
206  //  (TD)  - a conversion-function-id that specifies a dependent type
207  if (D->getDeclName().getNameKind()
208           == DeclarationName::CXXConversionFunctionName &&
209           D->getDeclName().getCXXNameType()->isDependentType()) {
210    TypeDependent = true;
211    ValueDependent = true;
212    return;
213  }
214  //  (VD)  - the name of a non-type template parameter,
215  if (isa<NonTypeTemplateParmDecl>(D)) {
216    ValueDependent = true;
217    return;
218  }
219
220  //  (VD) - a constant with integral or enumeration type and is
221  //         initialized with an expression that is value-dependent.
222  if (VarDecl *Var = dyn_cast<VarDecl>(D)) {
223    if (Var->getType()->isIntegralOrEnumerationType() &&
224        Var->getType().getCVRQualifiers() == Qualifiers::Const) {
225      if (const Expr *Init = Var->getAnyInitializer())
226        if (Init->isValueDependent())
227          ValueDependent = true;
228    }
229
230    // (VD) - FIXME: Missing from the standard:
231    //      -  a member function or a static data member of the current
232    //         instantiation
233    else if (Var->isStaticDataMember() &&
234             Var->getDeclContext()->isDependentContext())
235      ValueDependent = true;
236
237    return;
238  }
239
240  // (VD) - FIXME: Missing from the standard:
241  //      -  a member function or a static data member of the current
242  //         instantiation
243  if (isa<CXXMethodDecl>(D) && D->getDeclContext()->isDependentContext()) {
244    ValueDependent = true;
245    return;
246  }
247}
248
249void DeclRefExpr::computeDependence() {
250  bool TypeDependent = false;
251  bool ValueDependent = false;
252  computeDeclRefDependence(getDecl(), getType(), TypeDependent, ValueDependent);
253
254  // (TD) C++ [temp.dep.expr]p3:
255  //   An id-expression is type-dependent if it contains:
256  //
257  // and
258  //
259  // (VD) C++ [temp.dep.constexpr]p2:
260  //  An identifier is value-dependent if it is:
261  if (!TypeDependent && !ValueDependent &&
262      hasExplicitTemplateArgs() &&
263      TemplateSpecializationType::anyDependentTemplateArguments(
264                                                            getTemplateArgs(),
265                                                       getNumTemplateArgs())) {
266    TypeDependent = true;
267    ValueDependent = true;
268  }
269
270  ExprBits.TypeDependent = TypeDependent;
271  ExprBits.ValueDependent = ValueDependent;
272
273  // Is the declaration a parameter pack?
274  if (getDecl()->isParameterPack())
275    ExprBits.ContainsUnexpandedParameterPack = true;
276}
277
278DeclRefExpr::DeclRefExpr(NestedNameSpecifierLoc QualifierLoc,
279                         ValueDecl *D, const DeclarationNameInfo &NameInfo,
280                         NamedDecl *FoundD,
281                         const TemplateArgumentListInfo *TemplateArgs,
282                         QualType T, ExprValueKind VK)
283  : Expr(DeclRefExprClass, T, VK, OK_Ordinary, false, false, false),
284    D(D), Loc(NameInfo.getLoc()), DNLoc(NameInfo.getInfo()) {
285  DeclRefExprBits.HasQualifier = QualifierLoc ? 1 : 0;
286  if (QualifierLoc)
287    getInternalQualifierLoc() = QualifierLoc;
288  DeclRefExprBits.HasFoundDecl = FoundD ? 1 : 0;
289  if (FoundD)
290    getInternalFoundDecl() = FoundD;
291  DeclRefExprBits.HasExplicitTemplateArgs = TemplateArgs ? 1 : 0;
292  if (TemplateArgs)
293    getExplicitTemplateArgs().initializeFrom(*TemplateArgs);
294
295  computeDependence();
296}
297
298DeclRefExpr *DeclRefExpr::Create(ASTContext &Context,
299                                 NestedNameSpecifierLoc QualifierLoc,
300                                 ValueDecl *D,
301                                 SourceLocation NameLoc,
302                                 QualType T,
303                                 ExprValueKind VK,
304                                 NamedDecl *FoundD,
305                                 const TemplateArgumentListInfo *TemplateArgs) {
306  return Create(Context, QualifierLoc, D,
307                DeclarationNameInfo(D->getDeclName(), NameLoc),
308                T, VK, FoundD, TemplateArgs);
309}
310
311DeclRefExpr *DeclRefExpr::Create(ASTContext &Context,
312                                 NestedNameSpecifierLoc QualifierLoc,
313                                 ValueDecl *D,
314                                 const DeclarationNameInfo &NameInfo,
315                                 QualType T,
316                                 ExprValueKind VK,
317                                 NamedDecl *FoundD,
318                                 const TemplateArgumentListInfo *TemplateArgs) {
319  // Filter out cases where the found Decl is the same as the value refenenced.
320  if (D == FoundD)
321    FoundD = 0;
322
323  std::size_t Size = sizeof(DeclRefExpr);
324  if (QualifierLoc != 0)
325    Size += sizeof(NestedNameSpecifierLoc);
326  if (FoundD)
327    Size += sizeof(NamedDecl *);
328  if (TemplateArgs)
329    Size += ExplicitTemplateArgumentList::sizeFor(*TemplateArgs);
330
331  void *Mem = Context.Allocate(Size, llvm::alignOf<DeclRefExpr>());
332  return new (Mem) DeclRefExpr(QualifierLoc, D, NameInfo, FoundD, TemplateArgs,
333                               T, VK);
334}
335
336DeclRefExpr *DeclRefExpr::CreateEmpty(ASTContext &Context,
337                                      bool HasQualifier,
338                                      bool HasFoundDecl,
339                                      bool HasExplicitTemplateArgs,
340                                      unsigned NumTemplateArgs) {
341  std::size_t Size = sizeof(DeclRefExpr);
342  if (HasQualifier)
343    Size += sizeof(NestedNameSpecifierLoc);
344  if (HasFoundDecl)
345    Size += sizeof(NamedDecl *);
346  if (HasExplicitTemplateArgs)
347    Size += ExplicitTemplateArgumentList::sizeFor(NumTemplateArgs);
348
349  void *Mem = Context.Allocate(Size, llvm::alignOf<DeclRefExpr>());
350  return new (Mem) DeclRefExpr(EmptyShell());
351}
352
353SourceRange DeclRefExpr::getSourceRange() const {
354  SourceRange R = getNameInfo().getSourceRange();
355  if (hasQualifier())
356    R.setBegin(getQualifierLoc().getBeginLoc());
357  if (hasExplicitTemplateArgs())
358    R.setEnd(getRAngleLoc());
359  return R;
360}
361
362// FIXME: Maybe this should use DeclPrinter with a special "print predefined
363// expr" policy instead.
364std::string PredefinedExpr::ComputeName(IdentType IT, const Decl *CurrentDecl) {
365  ASTContext &Context = CurrentDecl->getASTContext();
366
367  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurrentDecl)) {
368    if (IT != PrettyFunction && IT != PrettyFunctionNoVirtual)
369      return FD->getNameAsString();
370
371    llvm::SmallString<256> Name;
372    llvm::raw_svector_ostream Out(Name);
373
374    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
375      if (MD->isVirtual() && IT != PrettyFunctionNoVirtual)
376        Out << "virtual ";
377      if (MD->isStatic())
378        Out << "static ";
379    }
380
381    PrintingPolicy Policy(Context.getLangOptions());
382
383    std::string Proto = FD->getQualifiedNameAsString(Policy);
384
385    const FunctionType *AFT = FD->getType()->getAs<FunctionType>();
386    const FunctionProtoType *FT = 0;
387    if (FD->hasWrittenPrototype())
388      FT = dyn_cast<FunctionProtoType>(AFT);
389
390    Proto += "(";
391    if (FT) {
392      llvm::raw_string_ostream POut(Proto);
393      for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
394        if (i) POut << ", ";
395        std::string Param;
396        FD->getParamDecl(i)->getType().getAsStringInternal(Param, Policy);
397        POut << Param;
398      }
399
400      if (FT->isVariadic()) {
401        if (FD->getNumParams()) POut << ", ";
402        POut << "...";
403      }
404    }
405    Proto += ")";
406
407    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
408      Qualifiers ThisQuals = Qualifiers::fromCVRMask(MD->getTypeQualifiers());
409      if (ThisQuals.hasConst())
410        Proto += " const";
411      if (ThisQuals.hasVolatile())
412        Proto += " volatile";
413    }
414
415    if (!isa<CXXConstructorDecl>(FD) && !isa<CXXDestructorDecl>(FD))
416      AFT->getResultType().getAsStringInternal(Proto, Policy);
417
418    Out << Proto;
419
420    Out.flush();
421    return Name.str().str();
422  }
423  if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CurrentDecl)) {
424    llvm::SmallString<256> Name;
425    llvm::raw_svector_ostream Out(Name);
426    Out << (MD->isInstanceMethod() ? '-' : '+');
427    Out << '[';
428
429    // For incorrect code, there might not be an ObjCInterfaceDecl.  Do
430    // a null check to avoid a crash.
431    if (const ObjCInterfaceDecl *ID = MD->getClassInterface())
432      Out << ID;
433
434    if (const ObjCCategoryImplDecl *CID =
435        dyn_cast<ObjCCategoryImplDecl>(MD->getDeclContext()))
436      Out << '(' << CID << ')';
437
438    Out <<  ' ';
439    Out << MD->getSelector().getAsString();
440    Out <<  ']';
441
442    Out.flush();
443    return Name.str().str();
444  }
445  if (isa<TranslationUnitDecl>(CurrentDecl) && IT == PrettyFunction) {
446    // __PRETTY_FUNCTION__ -> "top level", the others produce an empty string.
447    return "top level";
448  }
449  return "";
450}
451
452void APNumericStorage::setIntValue(ASTContext &C, const llvm::APInt &Val) {
453  if (hasAllocation())
454    C.Deallocate(pVal);
455
456  BitWidth = Val.getBitWidth();
457  unsigned NumWords = Val.getNumWords();
458  const uint64_t* Words = Val.getRawData();
459  if (NumWords > 1) {
460    pVal = new (C) uint64_t[NumWords];
461    std::copy(Words, Words + NumWords, pVal);
462  } else if (NumWords == 1)
463    VAL = Words[0];
464  else
465    VAL = 0;
466}
467
468IntegerLiteral *
469IntegerLiteral::Create(ASTContext &C, const llvm::APInt &V,
470                       QualType type, SourceLocation l) {
471  return new (C) IntegerLiteral(C, V, type, l);
472}
473
474IntegerLiteral *
475IntegerLiteral::Create(ASTContext &C, EmptyShell Empty) {
476  return new (C) IntegerLiteral(Empty);
477}
478
479FloatingLiteral *
480FloatingLiteral::Create(ASTContext &C, const llvm::APFloat &V,
481                        bool isexact, QualType Type, SourceLocation L) {
482  return new (C) FloatingLiteral(C, V, isexact, Type, L);
483}
484
485FloatingLiteral *
486FloatingLiteral::Create(ASTContext &C, EmptyShell Empty) {
487  return new (C) FloatingLiteral(Empty);
488}
489
490/// getValueAsApproximateDouble - This returns the value as an inaccurate
491/// double.  Note that this may cause loss of precision, but is useful for
492/// debugging dumps, etc.
493double FloatingLiteral::getValueAsApproximateDouble() const {
494  llvm::APFloat V = getValue();
495  bool ignored;
496  V.convert(llvm::APFloat::IEEEdouble, llvm::APFloat::rmNearestTiesToEven,
497            &ignored);
498  return V.convertToDouble();
499}
500
501StringLiteral *StringLiteral::Create(ASTContext &C, llvm::StringRef Str,
502                                     bool Wide,
503                                     bool Pascal, QualType Ty,
504                                     const SourceLocation *Loc,
505                                     unsigned NumStrs) {
506  // Allocate enough space for the StringLiteral plus an array of locations for
507  // any concatenated string tokens.
508  void *Mem = C.Allocate(sizeof(StringLiteral)+
509                         sizeof(SourceLocation)*(NumStrs-1),
510                         llvm::alignOf<StringLiteral>());
511  StringLiteral *SL = new (Mem) StringLiteral(Ty);
512
513  // OPTIMIZE: could allocate this appended to the StringLiteral.
514  char *AStrData = new (C, 1) char[Str.size()];
515  memcpy(AStrData, Str.data(), Str.size());
516  SL->StrData = AStrData;
517  SL->ByteLength = Str.size();
518  SL->IsWide = Wide;
519  SL->IsPascal = Pascal;
520  SL->TokLocs[0] = Loc[0];
521  SL->NumConcatenated = NumStrs;
522
523  if (NumStrs != 1)
524    memcpy(&SL->TokLocs[1], Loc+1, sizeof(SourceLocation)*(NumStrs-1));
525  return SL;
526}
527
528StringLiteral *StringLiteral::CreateEmpty(ASTContext &C, unsigned NumStrs) {
529  void *Mem = C.Allocate(sizeof(StringLiteral)+
530                         sizeof(SourceLocation)*(NumStrs-1),
531                         llvm::alignOf<StringLiteral>());
532  StringLiteral *SL = new (Mem) StringLiteral(QualType());
533  SL->StrData = 0;
534  SL->ByteLength = 0;
535  SL->NumConcatenated = NumStrs;
536  return SL;
537}
538
539void StringLiteral::setString(ASTContext &C, llvm::StringRef Str) {
540  char *AStrData = new (C, 1) char[Str.size()];
541  memcpy(AStrData, Str.data(), Str.size());
542  StrData = AStrData;
543  ByteLength = Str.size();
544}
545
546/// getLocationOfByte - Return a source location that points to the specified
547/// byte of this string literal.
548///
549/// Strings are amazingly complex.  They can be formed from multiple tokens and
550/// can have escape sequences in them in addition to the usual trigraph and
551/// escaped newline business.  This routine handles this complexity.
552///
553SourceLocation StringLiteral::
554getLocationOfByte(unsigned ByteNo, const SourceManager &SM,
555                  const LangOptions &Features, const TargetInfo &Target) const {
556  assert(!isWide() && "This doesn't work for wide strings yet");
557
558  // Loop over all of the tokens in this string until we find the one that
559  // contains the byte we're looking for.
560  unsigned TokNo = 0;
561  while (1) {
562    assert(TokNo < getNumConcatenated() && "Invalid byte number!");
563    SourceLocation StrTokLoc = getStrTokenLoc(TokNo);
564
565    // Get the spelling of the string so that we can get the data that makes up
566    // the string literal, not the identifier for the macro it is potentially
567    // expanded through.
568    SourceLocation StrTokSpellingLoc = SM.getSpellingLoc(StrTokLoc);
569
570    // Re-lex the token to get its length and original spelling.
571    std::pair<FileID, unsigned> LocInfo =SM.getDecomposedLoc(StrTokSpellingLoc);
572    bool Invalid = false;
573    llvm::StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
574    if (Invalid)
575      return StrTokSpellingLoc;
576
577    const char *StrData = Buffer.data()+LocInfo.second;
578
579    // Create a langops struct and enable trigraphs.  This is sufficient for
580    // relexing tokens.
581    LangOptions LangOpts;
582    LangOpts.Trigraphs = true;
583
584    // Create a lexer starting at the beginning of this token.
585    Lexer TheLexer(StrTokSpellingLoc, Features, Buffer.begin(), StrData,
586                   Buffer.end());
587    Token TheTok;
588    TheLexer.LexFromRawLexer(TheTok);
589
590    // Use the StringLiteralParser to compute the length of the string in bytes.
591    StringLiteralParser SLP(&TheTok, 1, SM, Features, Target);
592    unsigned TokNumBytes = SLP.GetStringLength();
593
594    // If the byte is in this token, return the location of the byte.
595    if (ByteNo < TokNumBytes ||
596        (ByteNo == TokNumBytes && TokNo == getNumConcatenated())) {
597      unsigned Offset = SLP.getOffsetOfStringByte(TheTok, ByteNo);
598
599      // Now that we know the offset of the token in the spelling, use the
600      // preprocessor to get the offset in the original source.
601      return Lexer::AdvanceToTokenCharacter(StrTokLoc, Offset, SM, Features);
602    }
603
604    // Move to the next string token.
605    ++TokNo;
606    ByteNo -= TokNumBytes;
607  }
608}
609
610
611
612/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
613/// corresponds to, e.g. "sizeof" or "[pre]++".
614const char *UnaryOperator::getOpcodeStr(Opcode Op) {
615  switch (Op) {
616  default: assert(0 && "Unknown unary operator");
617  case UO_PostInc: return "++";
618  case UO_PostDec: return "--";
619  case UO_PreInc:  return "++";
620  case UO_PreDec:  return "--";
621  case UO_AddrOf:  return "&";
622  case UO_Deref:   return "*";
623  case UO_Plus:    return "+";
624  case UO_Minus:   return "-";
625  case UO_Not:     return "~";
626  case UO_LNot:    return "!";
627  case UO_Real:    return "__real";
628  case UO_Imag:    return "__imag";
629  case UO_Extension: return "__extension__";
630  }
631}
632
633UnaryOperatorKind
634UnaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO, bool Postfix) {
635  switch (OO) {
636  default: assert(false && "No unary operator for overloaded function");
637  case OO_PlusPlus:   return Postfix ? UO_PostInc : UO_PreInc;
638  case OO_MinusMinus: return Postfix ? UO_PostDec : UO_PreDec;
639  case OO_Amp:        return UO_AddrOf;
640  case OO_Star:       return UO_Deref;
641  case OO_Plus:       return UO_Plus;
642  case OO_Minus:      return UO_Minus;
643  case OO_Tilde:      return UO_Not;
644  case OO_Exclaim:    return UO_LNot;
645  }
646}
647
648OverloadedOperatorKind UnaryOperator::getOverloadedOperator(Opcode Opc) {
649  switch (Opc) {
650  case UO_PostInc: case UO_PreInc: return OO_PlusPlus;
651  case UO_PostDec: case UO_PreDec: return OO_MinusMinus;
652  case UO_AddrOf: return OO_Amp;
653  case UO_Deref: return OO_Star;
654  case UO_Plus: return OO_Plus;
655  case UO_Minus: return OO_Minus;
656  case UO_Not: return OO_Tilde;
657  case UO_LNot: return OO_Exclaim;
658  default: return OO_None;
659  }
660}
661
662
663//===----------------------------------------------------------------------===//
664// Postfix Operators.
665//===----------------------------------------------------------------------===//
666
667CallExpr::CallExpr(ASTContext& C, StmtClass SC, Expr *fn, unsigned NumPreArgs,
668                   Expr **args, unsigned numargs, QualType t, ExprValueKind VK,
669                   SourceLocation rparenloc)
670  : Expr(SC, t, VK, OK_Ordinary,
671         fn->isTypeDependent(),
672         fn->isValueDependent(),
673         fn->containsUnexpandedParameterPack()),
674    NumArgs(numargs) {
675
676  SubExprs = new (C) Stmt*[numargs+PREARGS_START+NumPreArgs];
677  SubExprs[FN] = fn;
678  for (unsigned i = 0; i != numargs; ++i) {
679    if (args[i]->isTypeDependent())
680      ExprBits.TypeDependent = true;
681    if (args[i]->isValueDependent())
682      ExprBits.ValueDependent = true;
683    if (args[i]->containsUnexpandedParameterPack())
684      ExprBits.ContainsUnexpandedParameterPack = true;
685
686    SubExprs[i+PREARGS_START+NumPreArgs] = args[i];
687  }
688
689  CallExprBits.NumPreArgs = NumPreArgs;
690  RParenLoc = rparenloc;
691}
692
693CallExpr::CallExpr(ASTContext& C, Expr *fn, Expr **args, unsigned numargs,
694                   QualType t, ExprValueKind VK, SourceLocation rparenloc)
695  : Expr(CallExprClass, t, VK, OK_Ordinary,
696         fn->isTypeDependent(),
697         fn->isValueDependent(),
698         fn->containsUnexpandedParameterPack()),
699    NumArgs(numargs) {
700
701  SubExprs = new (C) Stmt*[numargs+PREARGS_START];
702  SubExprs[FN] = fn;
703  for (unsigned i = 0; i != numargs; ++i) {
704    if (args[i]->isTypeDependent())
705      ExprBits.TypeDependent = true;
706    if (args[i]->isValueDependent())
707      ExprBits.ValueDependent = true;
708    if (args[i]->containsUnexpandedParameterPack())
709      ExprBits.ContainsUnexpandedParameterPack = true;
710
711    SubExprs[i+PREARGS_START] = args[i];
712  }
713
714  CallExprBits.NumPreArgs = 0;
715  RParenLoc = rparenloc;
716}
717
718CallExpr::CallExpr(ASTContext &C, StmtClass SC, EmptyShell Empty)
719  : Expr(SC, Empty), SubExprs(0), NumArgs(0) {
720  // FIXME: Why do we allocate this?
721  SubExprs = new (C) Stmt*[PREARGS_START];
722  CallExprBits.NumPreArgs = 0;
723}
724
725CallExpr::CallExpr(ASTContext &C, StmtClass SC, unsigned NumPreArgs,
726                   EmptyShell Empty)
727  : Expr(SC, Empty), SubExprs(0), NumArgs(0) {
728  // FIXME: Why do we allocate this?
729  SubExprs = new (C) Stmt*[PREARGS_START+NumPreArgs];
730  CallExprBits.NumPreArgs = NumPreArgs;
731}
732
733Decl *CallExpr::getCalleeDecl() {
734  Expr *CEE = getCallee()->IgnoreParenCasts();
735  // If we're calling a dereference, look at the pointer instead.
736  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CEE)) {
737    if (BO->isPtrMemOp())
738      CEE = BO->getRHS()->IgnoreParenCasts();
739  } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(CEE)) {
740    if (UO->getOpcode() == UO_Deref)
741      CEE = UO->getSubExpr()->IgnoreParenCasts();
742  }
743  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE))
744    return DRE->getDecl();
745  if (MemberExpr *ME = dyn_cast<MemberExpr>(CEE))
746    return ME->getMemberDecl();
747
748  return 0;
749}
750
751FunctionDecl *CallExpr::getDirectCallee() {
752  return dyn_cast_or_null<FunctionDecl>(getCalleeDecl());
753}
754
755/// setNumArgs - This changes the number of arguments present in this call.
756/// Any orphaned expressions are deleted by this, and any new operands are set
757/// to null.
758void CallExpr::setNumArgs(ASTContext& C, unsigned NumArgs) {
759  // No change, just return.
760  if (NumArgs == getNumArgs()) return;
761
762  // If shrinking # arguments, just delete the extras and forgot them.
763  if (NumArgs < getNumArgs()) {
764    this->NumArgs = NumArgs;
765    return;
766  }
767
768  // Otherwise, we are growing the # arguments.  New an bigger argument array.
769  unsigned NumPreArgs = getNumPreArgs();
770  Stmt **NewSubExprs = new (C) Stmt*[NumArgs+PREARGS_START+NumPreArgs];
771  // Copy over args.
772  for (unsigned i = 0; i != getNumArgs()+PREARGS_START+NumPreArgs; ++i)
773    NewSubExprs[i] = SubExprs[i];
774  // Null out new args.
775  for (unsigned i = getNumArgs()+PREARGS_START+NumPreArgs;
776       i != NumArgs+PREARGS_START+NumPreArgs; ++i)
777    NewSubExprs[i] = 0;
778
779  if (SubExprs) C.Deallocate(SubExprs);
780  SubExprs = NewSubExprs;
781  this->NumArgs = NumArgs;
782}
783
784/// isBuiltinCall - If this is a call to a builtin, return the builtin ID.  If
785/// not, return 0.
786unsigned CallExpr::isBuiltinCall(const ASTContext &Context) const {
787  // All simple function calls (e.g. func()) are implicitly cast to pointer to
788  // function. As a result, we try and obtain the DeclRefExpr from the
789  // ImplicitCastExpr.
790  const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
791  if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
792    return 0;
793
794  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
795  if (!DRE)
796    return 0;
797
798  const FunctionDecl *FDecl = dyn_cast<FunctionDecl>(DRE->getDecl());
799  if (!FDecl)
800    return 0;
801
802  if (!FDecl->getIdentifier())
803    return 0;
804
805  return FDecl->getBuiltinID();
806}
807
808QualType CallExpr::getCallReturnType() const {
809  QualType CalleeType = getCallee()->getType();
810  if (const PointerType *FnTypePtr = CalleeType->getAs<PointerType>())
811    CalleeType = FnTypePtr->getPointeeType();
812  else if (const BlockPointerType *BPT = CalleeType->getAs<BlockPointerType>())
813    CalleeType = BPT->getPointeeType();
814  else if (CalleeType->isSpecificPlaceholderType(BuiltinType::BoundMember))
815    // This should never be overloaded and so should never return null.
816    CalleeType = Expr::findBoundMemberType(getCallee());
817
818  const FunctionType *FnType = CalleeType->castAs<FunctionType>();
819  return FnType->getResultType();
820}
821
822SourceRange CallExpr::getSourceRange() const {
823  if (isa<CXXOperatorCallExpr>(this))
824    return cast<CXXOperatorCallExpr>(this)->getSourceRange();
825
826  SourceLocation begin = getCallee()->getLocStart();
827  if (begin.isInvalid() && getNumArgs() > 0)
828    begin = getArg(0)->getLocStart();
829  SourceLocation end = getRParenLoc();
830  if (end.isInvalid() && getNumArgs() > 0)
831    end = getArg(getNumArgs() - 1)->getLocEnd();
832  return SourceRange(begin, end);
833}
834
835OffsetOfExpr *OffsetOfExpr::Create(ASTContext &C, QualType type,
836                                   SourceLocation OperatorLoc,
837                                   TypeSourceInfo *tsi,
838                                   OffsetOfNode* compsPtr, unsigned numComps,
839                                   Expr** exprsPtr, unsigned numExprs,
840                                   SourceLocation RParenLoc) {
841  void *Mem = C.Allocate(sizeof(OffsetOfExpr) +
842                         sizeof(OffsetOfNode) * numComps +
843                         sizeof(Expr*) * numExprs);
844
845  return new (Mem) OffsetOfExpr(C, type, OperatorLoc, tsi, compsPtr, numComps,
846                                exprsPtr, numExprs, RParenLoc);
847}
848
849OffsetOfExpr *OffsetOfExpr::CreateEmpty(ASTContext &C,
850                                        unsigned numComps, unsigned numExprs) {
851  void *Mem = C.Allocate(sizeof(OffsetOfExpr) +
852                         sizeof(OffsetOfNode) * numComps +
853                         sizeof(Expr*) * numExprs);
854  return new (Mem) OffsetOfExpr(numComps, numExprs);
855}
856
857OffsetOfExpr::OffsetOfExpr(ASTContext &C, QualType type,
858                           SourceLocation OperatorLoc, TypeSourceInfo *tsi,
859                           OffsetOfNode* compsPtr, unsigned numComps,
860                           Expr** exprsPtr, unsigned numExprs,
861                           SourceLocation RParenLoc)
862  : Expr(OffsetOfExprClass, type, VK_RValue, OK_Ordinary,
863         /*TypeDependent=*/false,
864         /*ValueDependent=*/tsi->getType()->isDependentType(),
865         tsi->getType()->containsUnexpandedParameterPack()),
866    OperatorLoc(OperatorLoc), RParenLoc(RParenLoc), TSInfo(tsi),
867    NumComps(numComps), NumExprs(numExprs)
868{
869  for(unsigned i = 0; i < numComps; ++i) {
870    setComponent(i, compsPtr[i]);
871  }
872
873  for(unsigned i = 0; i < numExprs; ++i) {
874    if (exprsPtr[i]->isTypeDependent() || exprsPtr[i]->isValueDependent())
875      ExprBits.ValueDependent = true;
876    if (exprsPtr[i]->containsUnexpandedParameterPack())
877      ExprBits.ContainsUnexpandedParameterPack = true;
878
879    setIndexExpr(i, exprsPtr[i]);
880  }
881}
882
883IdentifierInfo *OffsetOfExpr::OffsetOfNode::getFieldName() const {
884  assert(getKind() == Field || getKind() == Identifier);
885  if (getKind() == Field)
886    return getField()->getIdentifier();
887
888  return reinterpret_cast<IdentifierInfo *> (Data & ~(uintptr_t)Mask);
889}
890
891MemberExpr *MemberExpr::Create(ASTContext &C, Expr *base, bool isarrow,
892                               NestedNameSpecifierLoc QualifierLoc,
893                               ValueDecl *memberdecl,
894                               DeclAccessPair founddecl,
895                               DeclarationNameInfo nameinfo,
896                               const TemplateArgumentListInfo *targs,
897                               QualType ty,
898                               ExprValueKind vk,
899                               ExprObjectKind ok) {
900  std::size_t Size = sizeof(MemberExpr);
901
902  bool hasQualOrFound = (QualifierLoc ||
903                         founddecl.getDecl() != memberdecl ||
904                         founddecl.getAccess() != memberdecl->getAccess());
905  if (hasQualOrFound)
906    Size += sizeof(MemberNameQualifier);
907
908  if (targs)
909    Size += ExplicitTemplateArgumentList::sizeFor(*targs);
910
911  void *Mem = C.Allocate(Size, llvm::alignOf<MemberExpr>());
912  MemberExpr *E = new (Mem) MemberExpr(base, isarrow, memberdecl, nameinfo,
913                                       ty, vk, ok);
914
915  if (hasQualOrFound) {
916    // FIXME: Wrong. We should be looking at the member declaration we found.
917    if (QualifierLoc && QualifierLoc.getNestedNameSpecifier()->isDependent()) {
918      E->setValueDependent(true);
919      E->setTypeDependent(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    E->HasExplicitTemplateArgumentList = true;
930    E->getExplicitTemplateArgs().initializeFrom(*targs);
931  }
932
933  return E;
934}
935
936SourceRange MemberExpr::getSourceRange() const {
937  SourceLocation StartLoc;
938  if (isImplicitAccess()) {
939    if (hasQualifier())
940      StartLoc = getQualifierLoc().getBeginLoc();
941    else
942      StartLoc = MemberLoc;
943  } else {
944    // FIXME: We don't want this to happen. Rather, we should be able to
945    // detect all kinds of implicit accesses more cleanly.
946    StartLoc = getBase()->getLocStart();
947    if (StartLoc.isInvalid())
948      StartLoc = MemberLoc;
949  }
950
951  SourceLocation EndLoc =
952    HasExplicitTemplateArgumentList? getRAngleLoc()
953                                   : getMemberNameInfo().getEndLoc();
954
955  return SourceRange(StartLoc, EndLoc);
956}
957
958const char *CastExpr::getCastKindName() const {
959  switch (getCastKind()) {
960  case CK_Dependent:
961    return "Dependent";
962  case CK_BitCast:
963    return "BitCast";
964  case CK_LValueBitCast:
965    return "LValueBitCast";
966  case CK_LValueToRValue:
967    return "LValueToRValue";
968  case CK_GetObjCProperty:
969    return "GetObjCProperty";
970  case CK_NoOp:
971    return "NoOp";
972  case CK_BaseToDerived:
973    return "BaseToDerived";
974  case CK_DerivedToBase:
975    return "DerivedToBase";
976  case CK_UncheckedDerivedToBase:
977    return "UncheckedDerivedToBase";
978  case CK_Dynamic:
979    return "Dynamic";
980  case CK_ToUnion:
981    return "ToUnion";
982  case CK_ArrayToPointerDecay:
983    return "ArrayToPointerDecay";
984  case CK_FunctionToPointerDecay:
985    return "FunctionToPointerDecay";
986  case CK_NullToMemberPointer:
987    return "NullToMemberPointer";
988  case CK_NullToPointer:
989    return "NullToPointer";
990  case CK_BaseToDerivedMemberPointer:
991    return "BaseToDerivedMemberPointer";
992  case CK_DerivedToBaseMemberPointer:
993    return "DerivedToBaseMemberPointer";
994  case CK_UserDefinedConversion:
995    return "UserDefinedConversion";
996  case CK_ConstructorConversion:
997    return "ConstructorConversion";
998  case CK_IntegralToPointer:
999    return "IntegralToPointer";
1000  case CK_PointerToIntegral:
1001    return "PointerToIntegral";
1002  case CK_PointerToBoolean:
1003    return "PointerToBoolean";
1004  case CK_ToVoid:
1005    return "ToVoid";
1006  case CK_VectorSplat:
1007    return "VectorSplat";
1008  case CK_IntegralCast:
1009    return "IntegralCast";
1010  case CK_IntegralToBoolean:
1011    return "IntegralToBoolean";
1012  case CK_IntegralToFloating:
1013    return "IntegralToFloating";
1014  case CK_FloatingToIntegral:
1015    return "FloatingToIntegral";
1016  case CK_FloatingCast:
1017    return "FloatingCast";
1018  case CK_FloatingToBoolean:
1019    return "FloatingToBoolean";
1020  case CK_MemberPointerToBoolean:
1021    return "MemberPointerToBoolean";
1022  case CK_AnyPointerToObjCPointerCast:
1023    return "AnyPointerToObjCPointerCast";
1024  case CK_AnyPointerToBlockPointerCast:
1025    return "AnyPointerToBlockPointerCast";
1026  case CK_ObjCObjectLValueCast:
1027    return "ObjCObjectLValueCast";
1028  case CK_FloatingRealToComplex:
1029    return "FloatingRealToComplex";
1030  case CK_FloatingComplexToReal:
1031    return "FloatingComplexToReal";
1032  case CK_FloatingComplexToBoolean:
1033    return "FloatingComplexToBoolean";
1034  case CK_FloatingComplexCast:
1035    return "FloatingComplexCast";
1036  case CK_FloatingComplexToIntegralComplex:
1037    return "FloatingComplexToIntegralComplex";
1038  case CK_IntegralRealToComplex:
1039    return "IntegralRealToComplex";
1040  case CK_IntegralComplexToReal:
1041    return "IntegralComplexToReal";
1042  case CK_IntegralComplexToBoolean:
1043    return "IntegralComplexToBoolean";
1044  case CK_IntegralComplexCast:
1045    return "IntegralComplexCast";
1046  case CK_IntegralComplexToFloatingComplex:
1047    return "IntegralComplexToFloatingComplex";
1048  case CK_ObjCConsumeObject:
1049    return "ObjCConsumeObject";
1050  case CK_ObjCProduceObject:
1051    return "ObjCProduceObject";
1052  }
1053
1054  llvm_unreachable("Unhandled cast kind!");
1055  return 0;
1056}
1057
1058Expr *CastExpr::getSubExprAsWritten() {
1059  Expr *SubExpr = 0;
1060  CastExpr *E = this;
1061  do {
1062    SubExpr = E->getSubExpr();
1063
1064    // Skip through reference binding to temporary.
1065    if (MaterializeTemporaryExpr *Materialize
1066                                  = dyn_cast<MaterializeTemporaryExpr>(SubExpr))
1067      SubExpr = Materialize->GetTemporaryExpr();
1068
1069    // Skip any temporary bindings; they're implicit.
1070    if (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(SubExpr))
1071      SubExpr = Binder->getSubExpr();
1072
1073    // Conversions by constructor and conversion functions have a
1074    // subexpression describing the call; strip it off.
1075    if (E->getCastKind() == CK_ConstructorConversion)
1076      SubExpr = cast<CXXConstructExpr>(SubExpr)->getArg(0);
1077    else if (E->getCastKind() == CK_UserDefinedConversion)
1078      SubExpr = cast<CXXMemberCallExpr>(SubExpr)->getImplicitObjectArgument();
1079
1080    // If the subexpression we're left with is an implicit cast, look
1081    // through that, too.
1082  } while ((E = dyn_cast<ImplicitCastExpr>(SubExpr)));
1083
1084  return SubExpr;
1085}
1086
1087CXXBaseSpecifier **CastExpr::path_buffer() {
1088  switch (getStmtClass()) {
1089#define ABSTRACT_STMT(x)
1090#define CASTEXPR(Type, Base) \
1091  case Stmt::Type##Class: \
1092    return reinterpret_cast<CXXBaseSpecifier**>(static_cast<Type*>(this)+1);
1093#define STMT(Type, Base)
1094#include "clang/AST/StmtNodes.inc"
1095  default:
1096    llvm_unreachable("non-cast expressions not possible here");
1097    return 0;
1098  }
1099}
1100
1101void CastExpr::setCastPath(const CXXCastPath &Path) {
1102  assert(Path.size() == path_size());
1103  memcpy(path_buffer(), Path.data(), Path.size() * sizeof(CXXBaseSpecifier*));
1104}
1105
1106ImplicitCastExpr *ImplicitCastExpr::Create(ASTContext &C, QualType T,
1107                                           CastKind Kind, Expr *Operand,
1108                                           const CXXCastPath *BasePath,
1109                                           ExprValueKind VK) {
1110  unsigned PathSize = (BasePath ? BasePath->size() : 0);
1111  void *Buffer =
1112    C.Allocate(sizeof(ImplicitCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1113  ImplicitCastExpr *E =
1114    new (Buffer) ImplicitCastExpr(T, Kind, Operand, PathSize, VK);
1115  if (PathSize) E->setCastPath(*BasePath);
1116  return E;
1117}
1118
1119ImplicitCastExpr *ImplicitCastExpr::CreateEmpty(ASTContext &C,
1120                                                unsigned PathSize) {
1121  void *Buffer =
1122    C.Allocate(sizeof(ImplicitCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1123  return new (Buffer) ImplicitCastExpr(EmptyShell(), PathSize);
1124}
1125
1126
1127CStyleCastExpr *CStyleCastExpr::Create(ASTContext &C, QualType T,
1128                                       ExprValueKind VK, CastKind K, Expr *Op,
1129                                       const CXXCastPath *BasePath,
1130                                       TypeSourceInfo *WrittenTy,
1131                                       SourceLocation L, SourceLocation R) {
1132  unsigned PathSize = (BasePath ? BasePath->size() : 0);
1133  void *Buffer =
1134    C.Allocate(sizeof(CStyleCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1135  CStyleCastExpr *E =
1136    new (Buffer) CStyleCastExpr(T, VK, K, Op, PathSize, WrittenTy, L, R);
1137  if (PathSize) E->setCastPath(*BasePath);
1138  return E;
1139}
1140
1141CStyleCastExpr *CStyleCastExpr::CreateEmpty(ASTContext &C, unsigned PathSize) {
1142  void *Buffer =
1143    C.Allocate(sizeof(CStyleCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1144  return new (Buffer) CStyleCastExpr(EmptyShell(), PathSize);
1145}
1146
1147/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
1148/// corresponds to, e.g. "<<=".
1149const char *BinaryOperator::getOpcodeStr(Opcode Op) {
1150  switch (Op) {
1151  case BO_PtrMemD:   return ".*";
1152  case BO_PtrMemI:   return "->*";
1153  case BO_Mul:       return "*";
1154  case BO_Div:       return "/";
1155  case BO_Rem:       return "%";
1156  case BO_Add:       return "+";
1157  case BO_Sub:       return "-";
1158  case BO_Shl:       return "<<";
1159  case BO_Shr:       return ">>";
1160  case BO_LT:        return "<";
1161  case BO_GT:        return ">";
1162  case BO_LE:        return "<=";
1163  case BO_GE:        return ">=";
1164  case BO_EQ:        return "==";
1165  case BO_NE:        return "!=";
1166  case BO_And:       return "&";
1167  case BO_Xor:       return "^";
1168  case BO_Or:        return "|";
1169  case BO_LAnd:      return "&&";
1170  case BO_LOr:       return "||";
1171  case BO_Assign:    return "=";
1172  case BO_MulAssign: return "*=";
1173  case BO_DivAssign: return "/=";
1174  case BO_RemAssign: return "%=";
1175  case BO_AddAssign: return "+=";
1176  case BO_SubAssign: return "-=";
1177  case BO_ShlAssign: return "<<=";
1178  case BO_ShrAssign: return ">>=";
1179  case BO_AndAssign: return "&=";
1180  case BO_XorAssign: return "^=";
1181  case BO_OrAssign:  return "|=";
1182  case BO_Comma:     return ",";
1183  }
1184
1185  return "";
1186}
1187
1188BinaryOperatorKind
1189BinaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO) {
1190  switch (OO) {
1191  default: assert(false && "Not an overloadable binary operator");
1192  case OO_Plus: return BO_Add;
1193  case OO_Minus: return BO_Sub;
1194  case OO_Star: return BO_Mul;
1195  case OO_Slash: return BO_Div;
1196  case OO_Percent: return BO_Rem;
1197  case OO_Caret: return BO_Xor;
1198  case OO_Amp: return BO_And;
1199  case OO_Pipe: return BO_Or;
1200  case OO_Equal: return BO_Assign;
1201  case OO_Less: return BO_LT;
1202  case OO_Greater: return BO_GT;
1203  case OO_PlusEqual: return BO_AddAssign;
1204  case OO_MinusEqual: return BO_SubAssign;
1205  case OO_StarEqual: return BO_MulAssign;
1206  case OO_SlashEqual: return BO_DivAssign;
1207  case OO_PercentEqual: return BO_RemAssign;
1208  case OO_CaretEqual: return BO_XorAssign;
1209  case OO_AmpEqual: return BO_AndAssign;
1210  case OO_PipeEqual: return BO_OrAssign;
1211  case OO_LessLess: return BO_Shl;
1212  case OO_GreaterGreater: return BO_Shr;
1213  case OO_LessLessEqual: return BO_ShlAssign;
1214  case OO_GreaterGreaterEqual: return BO_ShrAssign;
1215  case OO_EqualEqual: return BO_EQ;
1216  case OO_ExclaimEqual: return BO_NE;
1217  case OO_LessEqual: return BO_LE;
1218  case OO_GreaterEqual: return BO_GE;
1219  case OO_AmpAmp: return BO_LAnd;
1220  case OO_PipePipe: return BO_LOr;
1221  case OO_Comma: return BO_Comma;
1222  case OO_ArrowStar: return BO_PtrMemI;
1223  }
1224}
1225
1226OverloadedOperatorKind BinaryOperator::getOverloadedOperator(Opcode Opc) {
1227  static const OverloadedOperatorKind OverOps[] = {
1228    /* .* Cannot be overloaded */OO_None, OO_ArrowStar,
1229    OO_Star, OO_Slash, OO_Percent,
1230    OO_Plus, OO_Minus,
1231    OO_LessLess, OO_GreaterGreater,
1232    OO_Less, OO_Greater, OO_LessEqual, OO_GreaterEqual,
1233    OO_EqualEqual, OO_ExclaimEqual,
1234    OO_Amp,
1235    OO_Caret,
1236    OO_Pipe,
1237    OO_AmpAmp,
1238    OO_PipePipe,
1239    OO_Equal, OO_StarEqual,
1240    OO_SlashEqual, OO_PercentEqual,
1241    OO_PlusEqual, OO_MinusEqual,
1242    OO_LessLessEqual, OO_GreaterGreaterEqual,
1243    OO_AmpEqual, OO_CaretEqual,
1244    OO_PipeEqual,
1245    OO_Comma
1246  };
1247  return OverOps[Opc];
1248}
1249
1250InitListExpr::InitListExpr(ASTContext &C, SourceLocation lbraceloc,
1251                           Expr **initExprs, unsigned numInits,
1252                           SourceLocation rbraceloc)
1253  : Expr(InitListExprClass, QualType(), VK_RValue, OK_Ordinary, false, false,
1254         false),
1255    InitExprs(C, numInits),
1256    LBraceLoc(lbraceloc), RBraceLoc(rbraceloc), SyntacticForm(0),
1257    HadArrayRangeDesignator(false)
1258{
1259  for (unsigned I = 0; I != numInits; ++I) {
1260    if (initExprs[I]->isTypeDependent())
1261      ExprBits.TypeDependent = true;
1262    if (initExprs[I]->isValueDependent())
1263      ExprBits.ValueDependent = true;
1264    if (initExprs[I]->containsUnexpandedParameterPack())
1265      ExprBits.ContainsUnexpandedParameterPack = true;
1266  }
1267
1268  InitExprs.insert(C, InitExprs.end(), initExprs, initExprs+numInits);
1269}
1270
1271void InitListExpr::reserveInits(ASTContext &C, unsigned NumInits) {
1272  if (NumInits > InitExprs.size())
1273    InitExprs.reserve(C, NumInits);
1274}
1275
1276void InitListExpr::resizeInits(ASTContext &C, unsigned NumInits) {
1277  InitExprs.resize(C, NumInits, 0);
1278}
1279
1280Expr *InitListExpr::updateInit(ASTContext &C, unsigned Init, Expr *expr) {
1281  if (Init >= InitExprs.size()) {
1282    InitExprs.insert(C, InitExprs.end(), Init - InitExprs.size() + 1, 0);
1283    InitExprs.back() = expr;
1284    return 0;
1285  }
1286
1287  Expr *Result = cast_or_null<Expr>(InitExprs[Init]);
1288  InitExprs[Init] = expr;
1289  return Result;
1290}
1291
1292void InitListExpr::setArrayFiller(Expr *filler) {
1293  ArrayFillerOrUnionFieldInit = filler;
1294  // Fill out any "holes" in the array due to designated initializers.
1295  Expr **inits = getInits();
1296  for (unsigned i = 0, e = getNumInits(); i != e; ++i)
1297    if (inits[i] == 0)
1298      inits[i] = filler;
1299}
1300
1301SourceRange InitListExpr::getSourceRange() const {
1302  if (SyntacticForm)
1303    return SyntacticForm->getSourceRange();
1304  SourceLocation Beg = LBraceLoc, End = RBraceLoc;
1305  if (Beg.isInvalid()) {
1306    // Find the first non-null initializer.
1307    for (InitExprsTy::const_iterator I = InitExprs.begin(),
1308                                     E = InitExprs.end();
1309      I != E; ++I) {
1310      if (Stmt *S = *I) {
1311        Beg = S->getLocStart();
1312        break;
1313      }
1314    }
1315  }
1316  if (End.isInvalid()) {
1317    // Find the first non-null initializer from the end.
1318    for (InitExprsTy::const_reverse_iterator I = InitExprs.rbegin(),
1319                                             E = InitExprs.rend();
1320      I != E; ++I) {
1321      if (Stmt *S = *I) {
1322        End = S->getSourceRange().getEnd();
1323        break;
1324      }
1325    }
1326  }
1327  return SourceRange(Beg, End);
1328}
1329
1330/// getFunctionType - Return the underlying function type for this block.
1331///
1332const FunctionType *BlockExpr::getFunctionType() const {
1333  return getType()->getAs<BlockPointerType>()->
1334                    getPointeeType()->getAs<FunctionType>();
1335}
1336
1337SourceLocation BlockExpr::getCaretLocation() const {
1338  return TheBlock->getCaretLocation();
1339}
1340const Stmt *BlockExpr::getBody() const {
1341  return TheBlock->getBody();
1342}
1343Stmt *BlockExpr::getBody() {
1344  return TheBlock->getBody();
1345}
1346
1347
1348//===----------------------------------------------------------------------===//
1349// Generic Expression Routines
1350//===----------------------------------------------------------------------===//
1351
1352/// isUnusedResultAWarning - Return true if this immediate expression should
1353/// be warned about if the result is unused.  If so, fill in Loc and Ranges
1354/// with location to warn on and the source range[s] to report with the
1355/// warning.
1356bool Expr::isUnusedResultAWarning(SourceLocation &Loc, SourceRange &R1,
1357                                  SourceRange &R2, ASTContext &Ctx) const {
1358  // Don't warn if the expr is type dependent. The type could end up
1359  // instantiating to void.
1360  if (isTypeDependent())
1361    return false;
1362
1363  switch (getStmtClass()) {
1364  default:
1365    if (getType()->isVoidType())
1366      return false;
1367    Loc = getExprLoc();
1368    R1 = getSourceRange();
1369    return true;
1370  case ParenExprClass:
1371    return cast<ParenExpr>(this)->getSubExpr()->
1372      isUnusedResultAWarning(Loc, R1, R2, Ctx);
1373  case GenericSelectionExprClass:
1374    return cast<GenericSelectionExpr>(this)->getResultExpr()->
1375      isUnusedResultAWarning(Loc, R1, R2, Ctx);
1376  case UnaryOperatorClass: {
1377    const UnaryOperator *UO = cast<UnaryOperator>(this);
1378
1379    switch (UO->getOpcode()) {
1380    default: break;
1381    case UO_PostInc:
1382    case UO_PostDec:
1383    case UO_PreInc:
1384    case UO_PreDec:                 // ++/--
1385      return false;  // Not a warning.
1386    case UO_Deref:
1387      // Dereferencing a volatile pointer is a side-effect.
1388      if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1389        return false;
1390      break;
1391    case UO_Real:
1392    case UO_Imag:
1393      // accessing a piece of a volatile complex is a side-effect.
1394      if (Ctx.getCanonicalType(UO->getSubExpr()->getType())
1395          .isVolatileQualified())
1396        return false;
1397      break;
1398    case UO_Extension:
1399      return UO->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1400    }
1401    Loc = UO->getOperatorLoc();
1402    R1 = UO->getSubExpr()->getSourceRange();
1403    return true;
1404  }
1405  case BinaryOperatorClass: {
1406    const BinaryOperator *BO = cast<BinaryOperator>(this);
1407    switch (BO->getOpcode()) {
1408      default:
1409        break;
1410      // Consider the RHS of comma for side effects. LHS was checked by
1411      // Sema::CheckCommaOperands.
1412      case BO_Comma:
1413        // ((foo = <blah>), 0) is an idiom for hiding the result (and
1414        // lvalue-ness) of an assignment written in a macro.
1415        if (IntegerLiteral *IE =
1416              dyn_cast<IntegerLiteral>(BO->getRHS()->IgnoreParens()))
1417          if (IE->getValue() == 0)
1418            return false;
1419        return BO->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1420      // Consider '||', '&&' to have side effects if the LHS or RHS does.
1421      case BO_LAnd:
1422      case BO_LOr:
1423        if (!BO->getLHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx) ||
1424            !BO->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx))
1425          return false;
1426        break;
1427    }
1428    if (BO->isAssignmentOp())
1429      return false;
1430    Loc = BO->getOperatorLoc();
1431    R1 = BO->getLHS()->getSourceRange();
1432    R2 = BO->getRHS()->getSourceRange();
1433    return true;
1434  }
1435  case CompoundAssignOperatorClass:
1436  case VAArgExprClass:
1437    return false;
1438
1439  case ConditionalOperatorClass: {
1440    // If only one of the LHS or RHS is a warning, the operator might
1441    // be being used for control flow. Only warn if both the LHS and
1442    // RHS are warnings.
1443    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
1444    if (!Exp->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx))
1445      return false;
1446    if (!Exp->getLHS())
1447      return true;
1448    return Exp->getLHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1449  }
1450
1451  case MemberExprClass:
1452    // If the base pointer or element is to a volatile pointer/field, accessing
1453    // it is a side effect.
1454    if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1455      return false;
1456    Loc = cast<MemberExpr>(this)->getMemberLoc();
1457    R1 = SourceRange(Loc, Loc);
1458    R2 = cast<MemberExpr>(this)->getBase()->getSourceRange();
1459    return true;
1460
1461  case ArraySubscriptExprClass:
1462    // If the base pointer or element is to a volatile pointer/field, accessing
1463    // it is a side effect.
1464    if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1465      return false;
1466    Loc = cast<ArraySubscriptExpr>(this)->getRBracketLoc();
1467    R1 = cast<ArraySubscriptExpr>(this)->getLHS()->getSourceRange();
1468    R2 = cast<ArraySubscriptExpr>(this)->getRHS()->getSourceRange();
1469    return true;
1470
1471  case CallExprClass:
1472  case CXXOperatorCallExprClass:
1473  case CXXMemberCallExprClass: {
1474    // If this is a direct call, get the callee.
1475    const CallExpr *CE = cast<CallExpr>(this);
1476    if (const Decl *FD = CE->getCalleeDecl()) {
1477      // If the callee has attribute pure, const, or warn_unused_result, warn
1478      // about it. void foo() { strlen("bar"); } should warn.
1479      //
1480      // Note: If new cases are added here, DiagnoseUnusedExprResult should be
1481      // updated to match for QoI.
1482      if (FD->getAttr<WarnUnusedResultAttr>() ||
1483          FD->getAttr<PureAttr>() || FD->getAttr<ConstAttr>()) {
1484        Loc = CE->getCallee()->getLocStart();
1485        R1 = CE->getCallee()->getSourceRange();
1486
1487        if (unsigned NumArgs = CE->getNumArgs())
1488          R2 = SourceRange(CE->getArg(0)->getLocStart(),
1489                           CE->getArg(NumArgs-1)->getLocEnd());
1490        return true;
1491      }
1492    }
1493    return false;
1494  }
1495
1496  case CXXTemporaryObjectExprClass:
1497  case CXXConstructExprClass:
1498    return false;
1499
1500  case ObjCMessageExprClass: {
1501    const ObjCMessageExpr *ME = cast<ObjCMessageExpr>(this);
1502    if (Ctx.getLangOptions().ObjCAutoRefCount &&
1503        ME->isInstanceMessage() &&
1504        !ME->getType()->isVoidType() &&
1505        ME->getSelector().getIdentifierInfoForSlot(0) &&
1506        ME->getSelector().getIdentifierInfoForSlot(0)
1507                                               ->getName().startswith("init")) {
1508      Loc = getExprLoc();
1509      R1 = ME->getSourceRange();
1510      return true;
1511    }
1512
1513    const ObjCMethodDecl *MD = ME->getMethodDecl();
1514    if (MD && MD->getAttr<WarnUnusedResultAttr>()) {
1515      Loc = getExprLoc();
1516      return true;
1517    }
1518    return false;
1519  }
1520
1521  case ObjCPropertyRefExprClass:
1522    Loc = getExprLoc();
1523    R1 = getSourceRange();
1524    return true;
1525
1526  case StmtExprClass: {
1527    // Statement exprs don't logically have side effects themselves, but are
1528    // sometimes used in macros in ways that give them a type that is unused.
1529    // For example ({ blah; foo(); }) will end up with a type if foo has a type.
1530    // however, if the result of the stmt expr is dead, we don't want to emit a
1531    // warning.
1532    const CompoundStmt *CS = cast<StmtExpr>(this)->getSubStmt();
1533    if (!CS->body_empty()) {
1534      if (const Expr *E = dyn_cast<Expr>(CS->body_back()))
1535        return E->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1536      if (const LabelStmt *Label = dyn_cast<LabelStmt>(CS->body_back()))
1537        if (const Expr *E = dyn_cast<Expr>(Label->getSubStmt()))
1538          return E->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1539    }
1540
1541    if (getType()->isVoidType())
1542      return false;
1543    Loc = cast<StmtExpr>(this)->getLParenLoc();
1544    R1 = getSourceRange();
1545    return true;
1546  }
1547  case CStyleCastExprClass:
1548    // If this is an explicit cast to void, allow it.  People do this when they
1549    // think they know what they're doing :).
1550    if (getType()->isVoidType())
1551      return false;
1552    Loc = cast<CStyleCastExpr>(this)->getLParenLoc();
1553    R1 = cast<CStyleCastExpr>(this)->getSubExpr()->getSourceRange();
1554    return true;
1555  case CXXFunctionalCastExprClass: {
1556    if (getType()->isVoidType())
1557      return false;
1558    const CastExpr *CE = cast<CastExpr>(this);
1559
1560    // If this is a cast to void or a constructor conversion, check the operand.
1561    // Otherwise, the result of the cast is unused.
1562    if (CE->getCastKind() == CK_ToVoid ||
1563        CE->getCastKind() == CK_ConstructorConversion)
1564      return (cast<CastExpr>(this)->getSubExpr()
1565              ->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1566    Loc = cast<CXXFunctionalCastExpr>(this)->getTypeBeginLoc();
1567    R1 = cast<CXXFunctionalCastExpr>(this)->getSubExpr()->getSourceRange();
1568    return true;
1569  }
1570
1571  case ImplicitCastExprClass:
1572    // Check the operand, since implicit casts are inserted by Sema
1573    return (cast<ImplicitCastExpr>(this)
1574            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1575
1576  case MaterializeTemporaryExprClass:
1577    return cast<MaterializeTemporaryExpr>(this)->GetTemporaryExpr()
1578                                    ->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1579
1580  case CXXDefaultArgExprClass:
1581    return (cast<CXXDefaultArgExpr>(this)
1582            ->getExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1583
1584  case CXXNewExprClass:
1585    // FIXME: In theory, there might be new expressions that don't have side
1586    // effects (e.g. a placement new with an uninitialized POD).
1587  case CXXDeleteExprClass:
1588    return false;
1589  case CXXBindTemporaryExprClass:
1590    return (cast<CXXBindTemporaryExpr>(this)
1591            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1592  case ExprWithCleanupsClass:
1593    return (cast<ExprWithCleanups>(this)
1594            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1595  }
1596}
1597
1598/// isOBJCGCCandidate - Check if an expression is objc gc'able.
1599/// returns true, if it is; false otherwise.
1600bool Expr::isOBJCGCCandidate(ASTContext &Ctx) const {
1601  const Expr *E = IgnoreParens();
1602  switch (E->getStmtClass()) {
1603  default:
1604    return false;
1605  case ObjCIvarRefExprClass:
1606    return true;
1607  case Expr::UnaryOperatorClass:
1608    return cast<UnaryOperator>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1609  case ImplicitCastExprClass:
1610    return cast<ImplicitCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1611  case MaterializeTemporaryExprClass:
1612    return cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr()
1613                                                      ->isOBJCGCCandidate(Ctx);
1614  case CStyleCastExprClass:
1615    return cast<CStyleCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1616  case DeclRefExprClass: {
1617    const Decl *D = cast<DeclRefExpr>(E)->getDecl();
1618    if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1619      if (VD->hasGlobalStorage())
1620        return true;
1621      QualType T = VD->getType();
1622      // dereferencing to a  pointer is always a gc'able candidate,
1623      // unless it is __weak.
1624      return T->isPointerType() &&
1625             (Ctx.getObjCGCAttrKind(T) != Qualifiers::Weak);
1626    }
1627    return false;
1628  }
1629  case MemberExprClass: {
1630    const MemberExpr *M = cast<MemberExpr>(E);
1631    return M->getBase()->isOBJCGCCandidate(Ctx);
1632  }
1633  case ArraySubscriptExprClass:
1634    return cast<ArraySubscriptExpr>(E)->getBase()->isOBJCGCCandidate(Ctx);
1635  }
1636}
1637
1638bool Expr::isBoundMemberFunction(ASTContext &Ctx) const {
1639  if (isTypeDependent())
1640    return false;
1641  return ClassifyLValue(Ctx) == Expr::LV_MemberFunction;
1642}
1643
1644QualType Expr::findBoundMemberType(const Expr *expr) {
1645  assert(expr->getType()->isSpecificPlaceholderType(BuiltinType::BoundMember));
1646
1647  // Bound member expressions are always one of these possibilities:
1648  //   x->m      x.m      x->*y      x.*y
1649  // (possibly parenthesized)
1650
1651  expr = expr->IgnoreParens();
1652  if (const MemberExpr *mem = dyn_cast<MemberExpr>(expr)) {
1653    assert(isa<CXXMethodDecl>(mem->getMemberDecl()));
1654    return mem->getMemberDecl()->getType();
1655  }
1656
1657  if (const BinaryOperator *op = dyn_cast<BinaryOperator>(expr)) {
1658    QualType type = op->getRHS()->getType()->castAs<MemberPointerType>()
1659                      ->getPointeeType();
1660    assert(type->isFunctionType());
1661    return type;
1662  }
1663
1664  assert(isa<UnresolvedMemberExpr>(expr));
1665  return QualType();
1666}
1667
1668static Expr::CanThrowResult MergeCanThrow(Expr::CanThrowResult CT1,
1669                                          Expr::CanThrowResult CT2) {
1670  // CanThrowResult constants are ordered so that the maximum is the correct
1671  // merge result.
1672  return CT1 > CT2 ? CT1 : CT2;
1673}
1674
1675static Expr::CanThrowResult CanSubExprsThrow(ASTContext &C, const Expr *CE) {
1676  Expr *E = const_cast<Expr*>(CE);
1677  Expr::CanThrowResult R = Expr::CT_Cannot;
1678  for (Expr::child_range I = E->children(); I && R != Expr::CT_Can; ++I) {
1679    R = MergeCanThrow(R, cast<Expr>(*I)->CanThrow(C));
1680  }
1681  return R;
1682}
1683
1684static Expr::CanThrowResult CanCalleeThrow(ASTContext &Ctx, const Expr *E,
1685                                           const Decl *D,
1686                                           bool NullThrows = true) {
1687  if (!D)
1688    return NullThrows ? Expr::CT_Can : Expr::CT_Cannot;
1689
1690  // See if we can get a function type from the decl somehow.
1691  const ValueDecl *VD = dyn_cast<ValueDecl>(D);
1692  if (!VD) // If we have no clue what we're calling, assume the worst.
1693    return Expr::CT_Can;
1694
1695  // As an extension, we assume that __attribute__((nothrow)) functions don't
1696  // throw.
1697  if (isa<FunctionDecl>(D) && D->hasAttr<NoThrowAttr>())
1698    return Expr::CT_Cannot;
1699
1700  QualType T = VD->getType();
1701  const FunctionProtoType *FT;
1702  if ((FT = T->getAs<FunctionProtoType>())) {
1703  } else if (const PointerType *PT = T->getAs<PointerType>())
1704    FT = PT->getPointeeType()->getAs<FunctionProtoType>();
1705  else if (const ReferenceType *RT = T->getAs<ReferenceType>())
1706    FT = RT->getPointeeType()->getAs<FunctionProtoType>();
1707  else if (const MemberPointerType *MT = T->getAs<MemberPointerType>())
1708    FT = MT->getPointeeType()->getAs<FunctionProtoType>();
1709  else if (const BlockPointerType *BT = T->getAs<BlockPointerType>())
1710    FT = BT->getPointeeType()->getAs<FunctionProtoType>();
1711
1712  if (!FT)
1713    return Expr::CT_Can;
1714
1715  if (FT->getExceptionSpecType() == EST_Delayed) {
1716    assert(isa<CXXConstructorDecl>(D) &&
1717           "only constructor exception specs can be unknown");
1718    Ctx.getDiagnostics().Report(E->getLocStart(),
1719                                diag::err_exception_spec_unknown)
1720      << E->getSourceRange();
1721    return Expr::CT_Can;
1722  }
1723
1724  return FT->isNothrow(Ctx) ? Expr::CT_Cannot : Expr::CT_Can;
1725}
1726
1727static Expr::CanThrowResult CanDynamicCastThrow(const CXXDynamicCastExpr *DC) {
1728  if (DC->isTypeDependent())
1729    return Expr::CT_Dependent;
1730
1731  if (!DC->getTypeAsWritten()->isReferenceType())
1732    return Expr::CT_Cannot;
1733
1734  if (DC->getSubExpr()->isTypeDependent())
1735    return Expr::CT_Dependent;
1736
1737  return DC->getCastKind() == clang::CK_Dynamic? Expr::CT_Can : Expr::CT_Cannot;
1738}
1739
1740static Expr::CanThrowResult CanTypeidThrow(ASTContext &C,
1741                                           const CXXTypeidExpr *DC) {
1742  if (DC->isTypeOperand())
1743    return Expr::CT_Cannot;
1744
1745  Expr *Op = DC->getExprOperand();
1746  if (Op->isTypeDependent())
1747    return Expr::CT_Dependent;
1748
1749  const RecordType *RT = Op->getType()->getAs<RecordType>();
1750  if (!RT)
1751    return Expr::CT_Cannot;
1752
1753  if (!cast<CXXRecordDecl>(RT->getDecl())->isPolymorphic())
1754    return Expr::CT_Cannot;
1755
1756  if (Op->Classify(C).isPRValue())
1757    return Expr::CT_Cannot;
1758
1759  return Expr::CT_Can;
1760}
1761
1762Expr::CanThrowResult Expr::CanThrow(ASTContext &C) const {
1763  // C++ [expr.unary.noexcept]p3:
1764  //   [Can throw] if in a potentially-evaluated context the expression would
1765  //   contain:
1766  switch (getStmtClass()) {
1767  case CXXThrowExprClass:
1768    //   - a potentially evaluated throw-expression
1769    return CT_Can;
1770
1771  case CXXDynamicCastExprClass: {
1772    //   - a potentially evaluated dynamic_cast expression dynamic_cast<T>(v),
1773    //     where T is a reference type, that requires a run-time check
1774    CanThrowResult CT = CanDynamicCastThrow(cast<CXXDynamicCastExpr>(this));
1775    if (CT == CT_Can)
1776      return CT;
1777    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1778  }
1779
1780  case CXXTypeidExprClass:
1781    //   - a potentially evaluated typeid expression applied to a glvalue
1782    //     expression whose type is a polymorphic class type
1783    return CanTypeidThrow(C, cast<CXXTypeidExpr>(this));
1784
1785    //   - a potentially evaluated call to a function, member function, function
1786    //     pointer, or member function pointer that does not have a non-throwing
1787    //     exception-specification
1788  case CallExprClass:
1789  case CXXOperatorCallExprClass:
1790  case CXXMemberCallExprClass: {
1791    const CallExpr *CE = cast<CallExpr>(this);
1792    CanThrowResult CT;
1793    if (isTypeDependent())
1794      CT = CT_Dependent;
1795    else if (isa<CXXPseudoDestructorExpr>(CE->getCallee()->IgnoreParens()))
1796      CT = CT_Cannot;
1797    else
1798      CT = CanCalleeThrow(C, this, CE->getCalleeDecl());
1799    if (CT == CT_Can)
1800      return CT;
1801    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1802  }
1803
1804  case CXXConstructExprClass:
1805  case CXXTemporaryObjectExprClass: {
1806    CanThrowResult CT = CanCalleeThrow(C, this,
1807        cast<CXXConstructExpr>(this)->getConstructor());
1808    if (CT == CT_Can)
1809      return CT;
1810    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1811  }
1812
1813  case CXXNewExprClass: {
1814    CanThrowResult CT;
1815    if (isTypeDependent())
1816      CT = CT_Dependent;
1817    else
1818      CT = MergeCanThrow(
1819        CanCalleeThrow(C, this, cast<CXXNewExpr>(this)->getOperatorNew()),
1820        CanCalleeThrow(C, this, cast<CXXNewExpr>(this)->getConstructor(),
1821                       /*NullThrows*/false));
1822    if (CT == CT_Can)
1823      return CT;
1824    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1825  }
1826
1827  case CXXDeleteExprClass: {
1828    CanThrowResult CT;
1829    QualType DTy = cast<CXXDeleteExpr>(this)->getDestroyedType();
1830    if (DTy.isNull() || DTy->isDependentType()) {
1831      CT = CT_Dependent;
1832    } else {
1833      CT = CanCalleeThrow(C, this,
1834                          cast<CXXDeleteExpr>(this)->getOperatorDelete());
1835      if (const RecordType *RT = DTy->getAs<RecordType>()) {
1836        const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1837        CT = MergeCanThrow(CT, CanCalleeThrow(C, this, RD->getDestructor()));
1838      }
1839      if (CT == CT_Can)
1840        return CT;
1841    }
1842    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1843  }
1844
1845  case CXXBindTemporaryExprClass: {
1846    // The bound temporary has to be destroyed again, which might throw.
1847    CanThrowResult CT = CanCalleeThrow(C, this,
1848      cast<CXXBindTemporaryExpr>(this)->getTemporary()->getDestructor());
1849    if (CT == CT_Can)
1850      return CT;
1851    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1852  }
1853
1854    // ObjC message sends are like function calls, but never have exception
1855    // specs.
1856  case ObjCMessageExprClass:
1857  case ObjCPropertyRefExprClass:
1858    return CT_Can;
1859
1860    // Many other things have subexpressions, so we have to test those.
1861    // Some are simple:
1862  case ParenExprClass:
1863  case MemberExprClass:
1864  case CXXReinterpretCastExprClass:
1865  case CXXConstCastExprClass:
1866  case ConditionalOperatorClass:
1867  case CompoundLiteralExprClass:
1868  case ExtVectorElementExprClass:
1869  case InitListExprClass:
1870  case DesignatedInitExprClass:
1871  case ParenListExprClass:
1872  case VAArgExprClass:
1873  case CXXDefaultArgExprClass:
1874  case ExprWithCleanupsClass:
1875  case ObjCIvarRefExprClass:
1876  case ObjCIsaExprClass:
1877  case ShuffleVectorExprClass:
1878    return CanSubExprsThrow(C, this);
1879
1880    // Some might be dependent for other reasons.
1881  case UnaryOperatorClass:
1882  case ArraySubscriptExprClass:
1883  case ImplicitCastExprClass:
1884  case CStyleCastExprClass:
1885  case CXXStaticCastExprClass:
1886  case CXXFunctionalCastExprClass:
1887  case BinaryOperatorClass:
1888  case CompoundAssignOperatorClass:
1889  case MaterializeTemporaryExprClass: {
1890    CanThrowResult CT = isTypeDependent() ? CT_Dependent : CT_Cannot;
1891    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1892  }
1893
1894    // FIXME: We should handle StmtExpr, but that opens a MASSIVE can of worms.
1895  case StmtExprClass:
1896    return CT_Can;
1897
1898  case ChooseExprClass:
1899    if (isTypeDependent() || isValueDependent())
1900      return CT_Dependent;
1901    return cast<ChooseExpr>(this)->getChosenSubExpr(C)->CanThrow(C);
1902
1903  case GenericSelectionExprClass:
1904    if (cast<GenericSelectionExpr>(this)->isResultDependent())
1905      return CT_Dependent;
1906    return cast<GenericSelectionExpr>(this)->getResultExpr()->CanThrow(C);
1907
1908    // Some expressions are always dependent.
1909  case DependentScopeDeclRefExprClass:
1910  case CXXUnresolvedConstructExprClass:
1911  case CXXDependentScopeMemberExprClass:
1912    return CT_Dependent;
1913
1914  default:
1915    // All other expressions don't have subexpressions, or else they are
1916    // unevaluated.
1917    return CT_Cannot;
1918  }
1919}
1920
1921Expr* Expr::IgnoreParens() {
1922  Expr* E = this;
1923  while (true) {
1924    if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
1925      E = P->getSubExpr();
1926      continue;
1927    }
1928    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
1929      if (P->getOpcode() == UO_Extension) {
1930        E = P->getSubExpr();
1931        continue;
1932      }
1933    }
1934    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
1935      if (!P->isResultDependent()) {
1936        E = P->getResultExpr();
1937        continue;
1938      }
1939    }
1940    return E;
1941  }
1942}
1943
1944/// IgnoreParenCasts - Ignore parentheses and casts.  Strip off any ParenExpr
1945/// or CastExprs or ImplicitCastExprs, returning their operand.
1946Expr *Expr::IgnoreParenCasts() {
1947  Expr *E = this;
1948  while (true) {
1949    if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
1950      E = P->getSubExpr();
1951      continue;
1952    }
1953    if (CastExpr *P = dyn_cast<CastExpr>(E)) {
1954      E = P->getSubExpr();
1955      continue;
1956    }
1957    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
1958      if (P->getOpcode() == UO_Extension) {
1959        E = P->getSubExpr();
1960        continue;
1961      }
1962    }
1963    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
1964      if (!P->isResultDependent()) {
1965        E = P->getResultExpr();
1966        continue;
1967      }
1968    }
1969    if (MaterializeTemporaryExpr *Materialize
1970                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
1971      E = Materialize->GetTemporaryExpr();
1972      continue;
1973    }
1974
1975    return E;
1976  }
1977}
1978
1979/// IgnoreParenLValueCasts - Ignore parentheses and lvalue-to-rvalue
1980/// casts.  This is intended purely as a temporary workaround for code
1981/// that hasn't yet been rewritten to do the right thing about those
1982/// casts, and may disappear along with the last internal use.
1983Expr *Expr::IgnoreParenLValueCasts() {
1984  Expr *E = this;
1985  while (true) {
1986    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
1987      E = P->getSubExpr();
1988      continue;
1989    } else if (CastExpr *P = dyn_cast<CastExpr>(E)) {
1990      if (P->getCastKind() == CK_LValueToRValue) {
1991        E = P->getSubExpr();
1992        continue;
1993      }
1994    } else if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
1995      if (P->getOpcode() == UO_Extension) {
1996        E = P->getSubExpr();
1997        continue;
1998      }
1999    } else if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2000      if (!P->isResultDependent()) {
2001        E = P->getResultExpr();
2002        continue;
2003      }
2004    } else if (MaterializeTemporaryExpr *Materialize
2005                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2006      E = Materialize->GetTemporaryExpr();
2007      continue;
2008    }
2009    break;
2010  }
2011  return E;
2012}
2013
2014Expr *Expr::IgnoreParenImpCasts() {
2015  Expr *E = this;
2016  while (true) {
2017    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2018      E = P->getSubExpr();
2019      continue;
2020    }
2021    if (ImplicitCastExpr *P = dyn_cast<ImplicitCastExpr>(E)) {
2022      E = P->getSubExpr();
2023      continue;
2024    }
2025    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2026      if (P->getOpcode() == UO_Extension) {
2027        E = P->getSubExpr();
2028        continue;
2029      }
2030    }
2031    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2032      if (!P->isResultDependent()) {
2033        E = P->getResultExpr();
2034        continue;
2035      }
2036    }
2037    if (MaterializeTemporaryExpr *Materialize
2038                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2039      E = Materialize->GetTemporaryExpr();
2040      continue;
2041    }
2042    return E;
2043  }
2044}
2045
2046Expr *Expr::IgnoreConversionOperator() {
2047  if (CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(this)) {
2048    if (MCE->getMethodDecl() && isa<CXXConversionDecl>(MCE->getMethodDecl()))
2049      return MCE->getImplicitObjectArgument();
2050  }
2051  return this;
2052}
2053
2054/// IgnoreParenNoopCasts - Ignore parentheses and casts that do not change the
2055/// value (including ptr->int casts of the same size).  Strip off any
2056/// ParenExpr or CastExprs, returning their operand.
2057Expr *Expr::IgnoreParenNoopCasts(ASTContext &Ctx) {
2058  Expr *E = this;
2059  while (true) {
2060    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2061      E = P->getSubExpr();
2062      continue;
2063    }
2064
2065    if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2066      // We ignore integer <-> casts that are of the same width, ptr<->ptr and
2067      // ptr<->int casts of the same width.  We also ignore all identity casts.
2068      Expr *SE = P->getSubExpr();
2069
2070      if (Ctx.hasSameUnqualifiedType(E->getType(), SE->getType())) {
2071        E = SE;
2072        continue;
2073      }
2074
2075      if ((E->getType()->isPointerType() ||
2076           E->getType()->isIntegralType(Ctx)) &&
2077          (SE->getType()->isPointerType() ||
2078           SE->getType()->isIntegralType(Ctx)) &&
2079          Ctx.getTypeSize(E->getType()) == Ctx.getTypeSize(SE->getType())) {
2080        E = SE;
2081        continue;
2082      }
2083    }
2084
2085    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2086      if (P->getOpcode() == UO_Extension) {
2087        E = P->getSubExpr();
2088        continue;
2089      }
2090    }
2091
2092    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2093      if (!P->isResultDependent()) {
2094        E = P->getResultExpr();
2095        continue;
2096      }
2097    }
2098
2099    return E;
2100  }
2101}
2102
2103bool Expr::isDefaultArgument() const {
2104  const Expr *E = this;
2105  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
2106    E = M->GetTemporaryExpr();
2107
2108  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
2109    E = ICE->getSubExprAsWritten();
2110
2111  return isa<CXXDefaultArgExpr>(E);
2112}
2113
2114/// \brief Skip over any no-op casts and any temporary-binding
2115/// expressions.
2116static const Expr *skipTemporaryBindingsNoOpCastsAndParens(const Expr *E) {
2117  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
2118    E = M->GetTemporaryExpr();
2119
2120  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2121    if (ICE->getCastKind() == CK_NoOp)
2122      E = ICE->getSubExpr();
2123    else
2124      break;
2125  }
2126
2127  while (const CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(E))
2128    E = BE->getSubExpr();
2129
2130  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2131    if (ICE->getCastKind() == CK_NoOp)
2132      E = ICE->getSubExpr();
2133    else
2134      break;
2135  }
2136
2137  return E->IgnoreParens();
2138}
2139
2140/// isTemporaryObject - Determines if this expression produces a
2141/// temporary of the given class type.
2142bool Expr::isTemporaryObject(ASTContext &C, const CXXRecordDecl *TempTy) const {
2143  if (!C.hasSameUnqualifiedType(getType(), C.getTypeDeclType(TempTy)))
2144    return false;
2145
2146  const Expr *E = skipTemporaryBindingsNoOpCastsAndParens(this);
2147
2148  // Temporaries are by definition pr-values of class type.
2149  if (!E->Classify(C).isPRValue()) {
2150    // In this context, property reference is a message call and is pr-value.
2151    if (!isa<ObjCPropertyRefExpr>(E))
2152      return false;
2153  }
2154
2155  // Black-list a few cases which yield pr-values of class type that don't
2156  // refer to temporaries of that type:
2157
2158  // - implicit derived-to-base conversions
2159  if (isa<ImplicitCastExpr>(E)) {
2160    switch (cast<ImplicitCastExpr>(E)->getCastKind()) {
2161    case CK_DerivedToBase:
2162    case CK_UncheckedDerivedToBase:
2163      return false;
2164    default:
2165      break;
2166    }
2167  }
2168
2169  // - member expressions (all)
2170  if (isa<MemberExpr>(E))
2171    return false;
2172
2173  // - opaque values (all)
2174  if (isa<OpaqueValueExpr>(E))
2175    return false;
2176
2177  return true;
2178}
2179
2180bool Expr::isImplicitCXXThis() const {
2181  const Expr *E = this;
2182
2183  // Strip away parentheses and casts we don't care about.
2184  while (true) {
2185    if (const ParenExpr *Paren = dyn_cast<ParenExpr>(E)) {
2186      E = Paren->getSubExpr();
2187      continue;
2188    }
2189
2190    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2191      if (ICE->getCastKind() == CK_NoOp ||
2192          ICE->getCastKind() == CK_LValueToRValue ||
2193          ICE->getCastKind() == CK_DerivedToBase ||
2194          ICE->getCastKind() == CK_UncheckedDerivedToBase) {
2195        E = ICE->getSubExpr();
2196        continue;
2197      }
2198    }
2199
2200    if (const UnaryOperator* UnOp = dyn_cast<UnaryOperator>(E)) {
2201      if (UnOp->getOpcode() == UO_Extension) {
2202        E = UnOp->getSubExpr();
2203        continue;
2204      }
2205    }
2206
2207    if (const MaterializeTemporaryExpr *M
2208                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2209      E = M->GetTemporaryExpr();
2210      continue;
2211    }
2212
2213    break;
2214  }
2215
2216  if (const CXXThisExpr *This = dyn_cast<CXXThisExpr>(E))
2217    return This->isImplicit();
2218
2219  return false;
2220}
2221
2222/// hasAnyTypeDependentArguments - Determines if any of the expressions
2223/// in Exprs is type-dependent.
2224bool Expr::hasAnyTypeDependentArguments(Expr** Exprs, unsigned NumExprs) {
2225  for (unsigned I = 0; I < NumExprs; ++I)
2226    if (Exprs[I]->isTypeDependent())
2227      return true;
2228
2229  return false;
2230}
2231
2232/// hasAnyValueDependentArguments - Determines if any of the expressions
2233/// in Exprs is value-dependent.
2234bool Expr::hasAnyValueDependentArguments(Expr** Exprs, unsigned NumExprs) {
2235  for (unsigned I = 0; I < NumExprs; ++I)
2236    if (Exprs[I]->isValueDependent())
2237      return true;
2238
2239  return false;
2240}
2241
2242bool Expr::isConstantInitializer(ASTContext &Ctx, bool IsForRef) const {
2243  // This function is attempting whether an expression is an initializer
2244  // which can be evaluated at compile-time.  isEvaluatable handles most
2245  // of the cases, but it can't deal with some initializer-specific
2246  // expressions, and it can't deal with aggregates; we deal with those here,
2247  // and fall back to isEvaluatable for the other cases.
2248
2249  // If we ever capture reference-binding directly in the AST, we can
2250  // kill the second parameter.
2251
2252  if (IsForRef) {
2253    EvalResult Result;
2254    return EvaluateAsLValue(Result, Ctx) && !Result.HasSideEffects;
2255  }
2256
2257  switch (getStmtClass()) {
2258  default: break;
2259  case StringLiteralClass:
2260  case ObjCStringLiteralClass:
2261  case ObjCEncodeExprClass:
2262    return true;
2263  case CXXTemporaryObjectExprClass:
2264  case CXXConstructExprClass: {
2265    const CXXConstructExpr *CE = cast<CXXConstructExpr>(this);
2266
2267    // Only if it's
2268    // 1) an application of the trivial default constructor or
2269    if (!CE->getConstructor()->isTrivial()) return false;
2270    if (!CE->getNumArgs()) return true;
2271
2272    // 2) an elidable trivial copy construction of an operand which is
2273    //    itself a constant initializer.  Note that we consider the
2274    //    operand on its own, *not* as a reference binding.
2275    return CE->isElidable() &&
2276           CE->getArg(0)->isConstantInitializer(Ctx, false);
2277  }
2278  case CompoundLiteralExprClass: {
2279    // This handles gcc's extension that allows global initializers like
2280    // "struct x {int x;} x = (struct x) {};".
2281    // FIXME: This accepts other cases it shouldn't!
2282    const Expr *Exp = cast<CompoundLiteralExpr>(this)->getInitializer();
2283    return Exp->isConstantInitializer(Ctx, false);
2284  }
2285  case InitListExprClass: {
2286    // FIXME: This doesn't deal with fields with reference types correctly.
2287    // FIXME: This incorrectly allows pointers cast to integers to be assigned
2288    // to bitfields.
2289    const InitListExpr *Exp = cast<InitListExpr>(this);
2290    unsigned numInits = Exp->getNumInits();
2291    for (unsigned i = 0; i < numInits; i++) {
2292      if (!Exp->getInit(i)->isConstantInitializer(Ctx, false))
2293        return false;
2294    }
2295    return true;
2296  }
2297  case ImplicitValueInitExprClass:
2298    return true;
2299  case ParenExprClass:
2300    return cast<ParenExpr>(this)->getSubExpr()
2301      ->isConstantInitializer(Ctx, IsForRef);
2302  case GenericSelectionExprClass:
2303    if (cast<GenericSelectionExpr>(this)->isResultDependent())
2304      return false;
2305    return cast<GenericSelectionExpr>(this)->getResultExpr()
2306      ->isConstantInitializer(Ctx, IsForRef);
2307  case ChooseExprClass:
2308    return cast<ChooseExpr>(this)->getChosenSubExpr(Ctx)
2309      ->isConstantInitializer(Ctx, IsForRef);
2310  case UnaryOperatorClass: {
2311    const UnaryOperator* Exp = cast<UnaryOperator>(this);
2312    if (Exp->getOpcode() == UO_Extension)
2313      return Exp->getSubExpr()->isConstantInitializer(Ctx, false);
2314    break;
2315  }
2316  case BinaryOperatorClass: {
2317    // Special case &&foo - &&bar.  It would be nice to generalize this somehow
2318    // but this handles the common case.
2319    const BinaryOperator *Exp = cast<BinaryOperator>(this);
2320    if (Exp->getOpcode() == BO_Sub &&
2321        isa<AddrLabelExpr>(Exp->getLHS()->IgnoreParenNoopCasts(Ctx)) &&
2322        isa<AddrLabelExpr>(Exp->getRHS()->IgnoreParenNoopCasts(Ctx)))
2323      return true;
2324    break;
2325  }
2326  case CXXFunctionalCastExprClass:
2327  case CXXStaticCastExprClass:
2328  case ImplicitCastExprClass:
2329  case CStyleCastExprClass:
2330    // Handle casts with a destination that's a struct or union; this
2331    // deals with both the gcc no-op struct cast extension and the
2332    // cast-to-union extension.
2333    if (getType()->isRecordType())
2334      return cast<CastExpr>(this)->getSubExpr()
2335        ->isConstantInitializer(Ctx, false);
2336
2337    // Integer->integer casts can be handled here, which is important for
2338    // things like (int)(&&x-&&y).  Scary but true.
2339    if (getType()->isIntegerType() &&
2340        cast<CastExpr>(this)->getSubExpr()->getType()->isIntegerType())
2341      return cast<CastExpr>(this)->getSubExpr()
2342        ->isConstantInitializer(Ctx, false);
2343
2344    break;
2345
2346  case MaterializeTemporaryExprClass:
2347    return llvm::cast<MaterializeTemporaryExpr>(this)->GetTemporaryExpr()
2348                                            ->isConstantInitializer(Ctx, false);
2349  }
2350  return isEvaluatable(Ctx);
2351}
2352
2353/// isNullPointerConstant - C99 6.3.2.3p3 - Return whether this is a null
2354/// pointer constant or not, as well as the specific kind of constant detected.
2355/// Null pointer constants can be integer constant expressions with the
2356/// value zero, casts of zero to void*, nullptr (C++0X), or __null
2357/// (a GNU extension).
2358Expr::NullPointerConstantKind
2359Expr::isNullPointerConstant(ASTContext &Ctx,
2360                            NullPointerConstantValueDependence NPC) const {
2361  if (isValueDependent()) {
2362    switch (NPC) {
2363    case NPC_NeverValueDependent:
2364      assert(false && "Unexpected value dependent expression!");
2365      // If the unthinkable happens, fall through to the safest alternative.
2366
2367    case NPC_ValueDependentIsNull:
2368      if (isTypeDependent() || getType()->isIntegralType(Ctx))
2369        return NPCK_ZeroInteger;
2370      else
2371        return NPCK_NotNull;
2372
2373    case NPC_ValueDependentIsNotNull:
2374      return NPCK_NotNull;
2375    }
2376  }
2377
2378  // Strip off a cast to void*, if it exists. Except in C++.
2379  if (const ExplicitCastExpr *CE = dyn_cast<ExplicitCastExpr>(this)) {
2380    if (!Ctx.getLangOptions().CPlusPlus) {
2381      // Check that it is a cast to void*.
2382      if (const PointerType *PT = CE->getType()->getAs<PointerType>()) {
2383        QualType Pointee = PT->getPointeeType();
2384        if (!Pointee.hasQualifiers() &&
2385            Pointee->isVoidType() &&                              // to void*
2386            CE->getSubExpr()->getType()->isIntegerType())         // from int.
2387          return CE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2388      }
2389    }
2390  } else if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(this)) {
2391    // Ignore the ImplicitCastExpr type entirely.
2392    return ICE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2393  } else if (const ParenExpr *PE = dyn_cast<ParenExpr>(this)) {
2394    // Accept ((void*)0) as a null pointer constant, as many other
2395    // implementations do.
2396    return PE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2397  } else if (const GenericSelectionExpr *GE =
2398               dyn_cast<GenericSelectionExpr>(this)) {
2399    return GE->getResultExpr()->isNullPointerConstant(Ctx, NPC);
2400  } else if (const CXXDefaultArgExpr *DefaultArg
2401               = dyn_cast<CXXDefaultArgExpr>(this)) {
2402    // See through default argument expressions
2403    return DefaultArg->getExpr()->isNullPointerConstant(Ctx, NPC);
2404  } else if (isa<GNUNullExpr>(this)) {
2405    // The GNU __null extension is always a null pointer constant.
2406    return NPCK_GNUNull;
2407  } else if (const MaterializeTemporaryExpr *M
2408                                   = dyn_cast<MaterializeTemporaryExpr>(this)) {
2409    return M->GetTemporaryExpr()->isNullPointerConstant(Ctx, NPC);
2410  }
2411
2412  // C++0x nullptr_t is always a null pointer constant.
2413  if (getType()->isNullPtrType())
2414    return NPCK_CXX0X_nullptr;
2415
2416  if (const RecordType *UT = getType()->getAsUnionType())
2417    if (UT && UT->getDecl()->hasAttr<TransparentUnionAttr>())
2418      if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(this)){
2419        const Expr *InitExpr = CLE->getInitializer();
2420        if (const InitListExpr *ILE = dyn_cast<InitListExpr>(InitExpr))
2421          return ILE->getInit(0)->isNullPointerConstant(Ctx, NPC);
2422      }
2423  // This expression must be an integer type.
2424  if (!getType()->isIntegerType() ||
2425      (Ctx.getLangOptions().CPlusPlus && getType()->isEnumeralType()))
2426    return NPCK_NotNull;
2427
2428  // If we have an integer constant expression, we need to *evaluate* it and
2429  // test for the value 0.
2430  llvm::APSInt Result;
2431  bool IsNull = isIntegerConstantExpr(Result, Ctx) && Result == 0;
2432
2433  return (IsNull ? NPCK_ZeroInteger : NPCK_NotNull);
2434}
2435
2436/// \brief If this expression is an l-value for an Objective C
2437/// property, find the underlying property reference expression.
2438const ObjCPropertyRefExpr *Expr::getObjCProperty() const {
2439  const Expr *E = this;
2440  while (true) {
2441    assert((E->getValueKind() == VK_LValue &&
2442            E->getObjectKind() == OK_ObjCProperty) &&
2443           "expression is not a property reference");
2444    E = E->IgnoreParenCasts();
2445    if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
2446      if (BO->getOpcode() == BO_Comma) {
2447        E = BO->getRHS();
2448        continue;
2449      }
2450    }
2451
2452    break;
2453  }
2454
2455  return cast<ObjCPropertyRefExpr>(E);
2456}
2457
2458FieldDecl *Expr::getBitField() {
2459  Expr *E = this->IgnoreParens();
2460
2461  while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2462    if (ICE->getCastKind() == CK_LValueToRValue ||
2463        (ICE->getValueKind() != VK_RValue && ICE->getCastKind() == CK_NoOp))
2464      E = ICE->getSubExpr()->IgnoreParens();
2465    else
2466      break;
2467  }
2468
2469  if (MemberExpr *MemRef = dyn_cast<MemberExpr>(E))
2470    if (FieldDecl *Field = dyn_cast<FieldDecl>(MemRef->getMemberDecl()))
2471      if (Field->isBitField())
2472        return Field;
2473
2474  if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E))
2475    if (FieldDecl *Field = dyn_cast<FieldDecl>(DeclRef->getDecl()))
2476      if (Field->isBitField())
2477        return Field;
2478
2479  if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E))
2480    if (BinOp->isAssignmentOp() && BinOp->getLHS())
2481      return BinOp->getLHS()->getBitField();
2482
2483  return 0;
2484}
2485
2486bool Expr::refersToVectorElement() const {
2487  const Expr *E = this->IgnoreParens();
2488
2489  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2490    if (ICE->getValueKind() != VK_RValue &&
2491        ICE->getCastKind() == CK_NoOp)
2492      E = ICE->getSubExpr()->IgnoreParens();
2493    else
2494      break;
2495  }
2496
2497  if (const ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(E))
2498    return ASE->getBase()->getType()->isVectorType();
2499
2500  if (isa<ExtVectorElementExpr>(E))
2501    return true;
2502
2503  return false;
2504}
2505
2506/// isArrow - Return true if the base expression is a pointer to vector,
2507/// return false if the base expression is a vector.
2508bool ExtVectorElementExpr::isArrow() const {
2509  return getBase()->getType()->isPointerType();
2510}
2511
2512unsigned ExtVectorElementExpr::getNumElements() const {
2513  if (const VectorType *VT = getType()->getAs<VectorType>())
2514    return VT->getNumElements();
2515  return 1;
2516}
2517
2518/// containsDuplicateElements - Return true if any element access is repeated.
2519bool ExtVectorElementExpr::containsDuplicateElements() const {
2520  // FIXME: Refactor this code to an accessor on the AST node which returns the
2521  // "type" of component access, and share with code below and in Sema.
2522  llvm::StringRef Comp = Accessor->getName();
2523
2524  // Halving swizzles do not contain duplicate elements.
2525  if (Comp == "hi" || Comp == "lo" || Comp == "even" || Comp == "odd")
2526    return false;
2527
2528  // Advance past s-char prefix on hex swizzles.
2529  if (Comp[0] == 's' || Comp[0] == 'S')
2530    Comp = Comp.substr(1);
2531
2532  for (unsigned i = 0, e = Comp.size(); i != e; ++i)
2533    if (Comp.substr(i + 1).find(Comp[i]) != llvm::StringRef::npos)
2534        return true;
2535
2536  return false;
2537}
2538
2539/// getEncodedElementAccess - We encode the fields as a llvm ConstantArray.
2540void ExtVectorElementExpr::getEncodedElementAccess(
2541                                  llvm::SmallVectorImpl<unsigned> &Elts) const {
2542  llvm::StringRef Comp = Accessor->getName();
2543  if (Comp[0] == 's' || Comp[0] == 'S')
2544    Comp = Comp.substr(1);
2545
2546  bool isHi =   Comp == "hi";
2547  bool isLo =   Comp == "lo";
2548  bool isEven = Comp == "even";
2549  bool isOdd  = Comp == "odd";
2550
2551  for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
2552    uint64_t Index;
2553
2554    if (isHi)
2555      Index = e + i;
2556    else if (isLo)
2557      Index = i;
2558    else if (isEven)
2559      Index = 2 * i;
2560    else if (isOdd)
2561      Index = 2 * i + 1;
2562    else
2563      Index = ExtVectorType::getAccessorIdx(Comp[i]);
2564
2565    Elts.push_back(Index);
2566  }
2567}
2568
2569ObjCMessageExpr::ObjCMessageExpr(QualType T,
2570                                 ExprValueKind VK,
2571                                 SourceLocation LBracLoc,
2572                                 SourceLocation SuperLoc,
2573                                 bool IsInstanceSuper,
2574                                 QualType SuperType,
2575                                 Selector Sel,
2576                                 SourceLocation SelLoc,
2577                                 ObjCMethodDecl *Method,
2578                                 Expr **Args, unsigned NumArgs,
2579                                 SourceLocation RBracLoc)
2580  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary,
2581         /*TypeDependent=*/false, /*ValueDependent=*/false,
2582         /*ContainsUnexpandedParameterPack=*/false),
2583    NumArgs(NumArgs), Kind(IsInstanceSuper? SuperInstance : SuperClass),
2584    HasMethod(Method != 0), IsDelegateInitCall(false), SuperLoc(SuperLoc),
2585    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2586                                                       : Sel.getAsOpaquePtr())),
2587    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2588{
2589  setReceiverPointer(SuperType.getAsOpaquePtr());
2590  if (NumArgs)
2591    memcpy(getArgs(), Args, NumArgs * sizeof(Expr *));
2592}
2593
2594ObjCMessageExpr::ObjCMessageExpr(QualType T,
2595                                 ExprValueKind VK,
2596                                 SourceLocation LBracLoc,
2597                                 TypeSourceInfo *Receiver,
2598                                 Selector Sel,
2599                                 SourceLocation SelLoc,
2600                                 ObjCMethodDecl *Method,
2601                                 Expr **Args, unsigned NumArgs,
2602                                 SourceLocation RBracLoc)
2603  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, T->isDependentType(),
2604         T->isDependentType(), T->containsUnexpandedParameterPack()),
2605    NumArgs(NumArgs), Kind(Class),
2606    HasMethod(Method != 0), IsDelegateInitCall(false),
2607    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2608                                                       : Sel.getAsOpaquePtr())),
2609    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2610{
2611  setReceiverPointer(Receiver);
2612  Expr **MyArgs = getArgs();
2613  for (unsigned I = 0; I != NumArgs; ++I) {
2614    if (Args[I]->isTypeDependent())
2615      ExprBits.TypeDependent = true;
2616    if (Args[I]->isValueDependent())
2617      ExprBits.ValueDependent = true;
2618    if (Args[I]->containsUnexpandedParameterPack())
2619      ExprBits.ContainsUnexpandedParameterPack = true;
2620
2621    MyArgs[I] = Args[I];
2622  }
2623}
2624
2625ObjCMessageExpr::ObjCMessageExpr(QualType T,
2626                                 ExprValueKind VK,
2627                                 SourceLocation LBracLoc,
2628                                 Expr *Receiver,
2629                                 Selector Sel,
2630                                 SourceLocation SelLoc,
2631                                 ObjCMethodDecl *Method,
2632                                 Expr **Args, unsigned NumArgs,
2633                                 SourceLocation RBracLoc)
2634  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, Receiver->isTypeDependent(),
2635         Receiver->isTypeDependent(),
2636         Receiver->containsUnexpandedParameterPack()),
2637    NumArgs(NumArgs), Kind(Instance),
2638    HasMethod(Method != 0), IsDelegateInitCall(false),
2639    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2640                                                       : Sel.getAsOpaquePtr())),
2641    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2642{
2643  setReceiverPointer(Receiver);
2644  Expr **MyArgs = getArgs();
2645  for (unsigned I = 0; I != NumArgs; ++I) {
2646    if (Args[I]->isTypeDependent())
2647      ExprBits.TypeDependent = true;
2648    if (Args[I]->isValueDependent())
2649      ExprBits.ValueDependent = true;
2650    if (Args[I]->containsUnexpandedParameterPack())
2651      ExprBits.ContainsUnexpandedParameterPack = true;
2652
2653    MyArgs[I] = Args[I];
2654  }
2655}
2656
2657ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2658                                         ExprValueKind VK,
2659                                         SourceLocation LBracLoc,
2660                                         SourceLocation SuperLoc,
2661                                         bool IsInstanceSuper,
2662                                         QualType SuperType,
2663                                         Selector Sel,
2664                                         SourceLocation SelLoc,
2665                                         ObjCMethodDecl *Method,
2666                                         Expr **Args, unsigned NumArgs,
2667                                         SourceLocation RBracLoc) {
2668  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2669    NumArgs * sizeof(Expr *);
2670  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2671  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, SuperLoc, IsInstanceSuper,
2672                                   SuperType, Sel, SelLoc, Method, Args,NumArgs,
2673                                   RBracLoc);
2674}
2675
2676ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2677                                         ExprValueKind VK,
2678                                         SourceLocation LBracLoc,
2679                                         TypeSourceInfo *Receiver,
2680                                         Selector Sel,
2681                                         SourceLocation SelLoc,
2682                                         ObjCMethodDecl *Method,
2683                                         Expr **Args, unsigned NumArgs,
2684                                         SourceLocation RBracLoc) {
2685  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2686    NumArgs * sizeof(Expr *);
2687  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2688  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel, SelLoc,
2689                                   Method, Args, NumArgs, RBracLoc);
2690}
2691
2692ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2693                                         ExprValueKind VK,
2694                                         SourceLocation LBracLoc,
2695                                         Expr *Receiver,
2696                                         Selector Sel,
2697                                         SourceLocation SelLoc,
2698                                         ObjCMethodDecl *Method,
2699                                         Expr **Args, unsigned NumArgs,
2700                                         SourceLocation RBracLoc) {
2701  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2702    NumArgs * sizeof(Expr *);
2703  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2704  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel, SelLoc,
2705                                   Method, Args, NumArgs, RBracLoc);
2706}
2707
2708ObjCMessageExpr *ObjCMessageExpr::CreateEmpty(ASTContext &Context,
2709                                              unsigned NumArgs) {
2710  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2711    NumArgs * sizeof(Expr *);
2712  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2713  return new (Mem) ObjCMessageExpr(EmptyShell(), NumArgs);
2714}
2715
2716SourceRange ObjCMessageExpr::getReceiverRange() const {
2717  switch (getReceiverKind()) {
2718  case Instance:
2719    return getInstanceReceiver()->getSourceRange();
2720
2721  case Class:
2722    return getClassReceiverTypeInfo()->getTypeLoc().getSourceRange();
2723
2724  case SuperInstance:
2725  case SuperClass:
2726    return getSuperLoc();
2727  }
2728
2729  return SourceLocation();
2730}
2731
2732Selector ObjCMessageExpr::getSelector() const {
2733  if (HasMethod)
2734    return reinterpret_cast<const ObjCMethodDecl *>(SelectorOrMethod)
2735                                                               ->getSelector();
2736  return Selector(SelectorOrMethod);
2737}
2738
2739ObjCInterfaceDecl *ObjCMessageExpr::getReceiverInterface() const {
2740  switch (getReceiverKind()) {
2741  case Instance:
2742    if (const ObjCObjectPointerType *Ptr
2743          = getInstanceReceiver()->getType()->getAs<ObjCObjectPointerType>())
2744      return Ptr->getInterfaceDecl();
2745    break;
2746
2747  case Class:
2748    if (const ObjCObjectType *Ty
2749          = getClassReceiver()->getAs<ObjCObjectType>())
2750      return Ty->getInterface();
2751    break;
2752
2753  case SuperInstance:
2754    if (const ObjCObjectPointerType *Ptr
2755          = getSuperType()->getAs<ObjCObjectPointerType>())
2756      return Ptr->getInterfaceDecl();
2757    break;
2758
2759  case SuperClass:
2760    if (const ObjCObjectType *Iface
2761          = getSuperType()->getAs<ObjCObjectType>())
2762      return Iface->getInterface();
2763    break;
2764  }
2765
2766  return 0;
2767}
2768
2769llvm::StringRef ObjCBridgedCastExpr::getBridgeKindName() const {
2770  switch (getBridgeKind()) {
2771  case OBC_Bridge:
2772    return "__bridge";
2773  case OBC_BridgeTransfer:
2774    return "__bridge_transfer";
2775  case OBC_BridgeRetained:
2776    return "__bridge_retained";
2777  }
2778
2779  return "__bridge";
2780}
2781
2782bool ChooseExpr::isConditionTrue(const ASTContext &C) const {
2783  return getCond()->EvaluateAsInt(C) != 0;
2784}
2785
2786ShuffleVectorExpr::ShuffleVectorExpr(ASTContext &C, Expr **args, unsigned nexpr,
2787                                     QualType Type, SourceLocation BLoc,
2788                                     SourceLocation RP)
2789   : Expr(ShuffleVectorExprClass, Type, VK_RValue, OK_Ordinary,
2790          Type->isDependentType(), Type->isDependentType(),
2791          Type->containsUnexpandedParameterPack()),
2792     BuiltinLoc(BLoc), RParenLoc(RP), NumExprs(nexpr)
2793{
2794  SubExprs = new (C) Stmt*[nexpr];
2795  for (unsigned i = 0; i < nexpr; i++) {
2796    if (args[i]->isTypeDependent())
2797      ExprBits.TypeDependent = true;
2798    if (args[i]->isValueDependent())
2799      ExprBits.ValueDependent = true;
2800    if (args[i]->containsUnexpandedParameterPack())
2801      ExprBits.ContainsUnexpandedParameterPack = true;
2802
2803    SubExprs[i] = args[i];
2804  }
2805}
2806
2807void ShuffleVectorExpr::setExprs(ASTContext &C, Expr ** Exprs,
2808                                 unsigned NumExprs) {
2809  if (SubExprs) C.Deallocate(SubExprs);
2810
2811  SubExprs = new (C) Stmt* [NumExprs];
2812  this->NumExprs = NumExprs;
2813  memcpy(SubExprs, Exprs, sizeof(Expr *) * NumExprs);
2814}
2815
2816GenericSelectionExpr::GenericSelectionExpr(ASTContext &Context,
2817                               SourceLocation GenericLoc, Expr *ControllingExpr,
2818                               TypeSourceInfo **AssocTypes, Expr **AssocExprs,
2819                               unsigned NumAssocs, SourceLocation DefaultLoc,
2820                               SourceLocation RParenLoc,
2821                               bool ContainsUnexpandedParameterPack,
2822                               unsigned ResultIndex)
2823  : Expr(GenericSelectionExprClass,
2824         AssocExprs[ResultIndex]->getType(),
2825         AssocExprs[ResultIndex]->getValueKind(),
2826         AssocExprs[ResultIndex]->getObjectKind(),
2827         AssocExprs[ResultIndex]->isTypeDependent(),
2828         AssocExprs[ResultIndex]->isValueDependent(),
2829         ContainsUnexpandedParameterPack),
2830    AssocTypes(new (Context) TypeSourceInfo*[NumAssocs]),
2831    SubExprs(new (Context) Stmt*[END_EXPR+NumAssocs]), NumAssocs(NumAssocs),
2832    ResultIndex(ResultIndex), GenericLoc(GenericLoc), DefaultLoc(DefaultLoc),
2833    RParenLoc(RParenLoc) {
2834  SubExprs[CONTROLLING] = ControllingExpr;
2835  std::copy(AssocTypes, AssocTypes+NumAssocs, this->AssocTypes);
2836  std::copy(AssocExprs, AssocExprs+NumAssocs, SubExprs+END_EXPR);
2837}
2838
2839GenericSelectionExpr::GenericSelectionExpr(ASTContext &Context,
2840                               SourceLocation GenericLoc, Expr *ControllingExpr,
2841                               TypeSourceInfo **AssocTypes, Expr **AssocExprs,
2842                               unsigned NumAssocs, SourceLocation DefaultLoc,
2843                               SourceLocation RParenLoc,
2844                               bool ContainsUnexpandedParameterPack)
2845  : Expr(GenericSelectionExprClass,
2846         Context.DependentTy,
2847         VK_RValue,
2848         OK_Ordinary,
2849         /*isTypeDependent=*/  true,
2850         /*isValueDependent=*/ true,
2851         ContainsUnexpandedParameterPack),
2852    AssocTypes(new (Context) TypeSourceInfo*[NumAssocs]),
2853    SubExprs(new (Context) Stmt*[END_EXPR+NumAssocs]), NumAssocs(NumAssocs),
2854    ResultIndex(-1U), GenericLoc(GenericLoc), DefaultLoc(DefaultLoc),
2855    RParenLoc(RParenLoc) {
2856  SubExprs[CONTROLLING] = ControllingExpr;
2857  std::copy(AssocTypes, AssocTypes+NumAssocs, this->AssocTypes);
2858  std::copy(AssocExprs, AssocExprs+NumAssocs, SubExprs+END_EXPR);
2859}
2860
2861//===----------------------------------------------------------------------===//
2862//  DesignatedInitExpr
2863//===----------------------------------------------------------------------===//
2864
2865IdentifierInfo *DesignatedInitExpr::Designator::getFieldName() const {
2866  assert(Kind == FieldDesignator && "Only valid on a field designator");
2867  if (Field.NameOrField & 0x01)
2868    return reinterpret_cast<IdentifierInfo *>(Field.NameOrField&~0x01);
2869  else
2870    return getField()->getIdentifier();
2871}
2872
2873DesignatedInitExpr::DesignatedInitExpr(ASTContext &C, QualType Ty,
2874                                       unsigned NumDesignators,
2875                                       const Designator *Designators,
2876                                       SourceLocation EqualOrColonLoc,
2877                                       bool GNUSyntax,
2878                                       Expr **IndexExprs,
2879                                       unsigned NumIndexExprs,
2880                                       Expr *Init)
2881  : Expr(DesignatedInitExprClass, Ty,
2882         Init->getValueKind(), Init->getObjectKind(),
2883         Init->isTypeDependent(), Init->isValueDependent(),
2884         Init->containsUnexpandedParameterPack()),
2885    EqualOrColonLoc(EqualOrColonLoc), GNUSyntax(GNUSyntax),
2886    NumDesignators(NumDesignators), NumSubExprs(NumIndexExprs + 1) {
2887  this->Designators = new (C) Designator[NumDesignators];
2888
2889  // Record the initializer itself.
2890  child_range Child = children();
2891  *Child++ = Init;
2892
2893  // Copy the designators and their subexpressions, computing
2894  // value-dependence along the way.
2895  unsigned IndexIdx = 0;
2896  for (unsigned I = 0; I != NumDesignators; ++I) {
2897    this->Designators[I] = Designators[I];
2898
2899    if (this->Designators[I].isArrayDesignator()) {
2900      // Compute type- and value-dependence.
2901      Expr *Index = IndexExprs[IndexIdx];
2902      if (Index->isTypeDependent() || Index->isValueDependent())
2903        ExprBits.ValueDependent = true;
2904
2905      // Propagate unexpanded parameter packs.
2906      if (Index->containsUnexpandedParameterPack())
2907        ExprBits.ContainsUnexpandedParameterPack = true;
2908
2909      // Copy the index expressions into permanent storage.
2910      *Child++ = IndexExprs[IndexIdx++];
2911    } else if (this->Designators[I].isArrayRangeDesignator()) {
2912      // Compute type- and value-dependence.
2913      Expr *Start = IndexExprs[IndexIdx];
2914      Expr *End = IndexExprs[IndexIdx + 1];
2915      if (Start->isTypeDependent() || Start->isValueDependent() ||
2916          End->isTypeDependent() || End->isValueDependent())
2917        ExprBits.ValueDependent = true;
2918
2919      // Propagate unexpanded parameter packs.
2920      if (Start->containsUnexpandedParameterPack() ||
2921          End->containsUnexpandedParameterPack())
2922        ExprBits.ContainsUnexpandedParameterPack = true;
2923
2924      // Copy the start/end expressions into permanent storage.
2925      *Child++ = IndexExprs[IndexIdx++];
2926      *Child++ = IndexExprs[IndexIdx++];
2927    }
2928  }
2929
2930  assert(IndexIdx == NumIndexExprs && "Wrong number of index expressions");
2931}
2932
2933DesignatedInitExpr *
2934DesignatedInitExpr::Create(ASTContext &C, Designator *Designators,
2935                           unsigned NumDesignators,
2936                           Expr **IndexExprs, unsigned NumIndexExprs,
2937                           SourceLocation ColonOrEqualLoc,
2938                           bool UsesColonSyntax, Expr *Init) {
2939  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
2940                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
2941  return new (Mem) DesignatedInitExpr(C, C.VoidTy, NumDesignators, Designators,
2942                                      ColonOrEqualLoc, UsesColonSyntax,
2943                                      IndexExprs, NumIndexExprs, Init);
2944}
2945
2946DesignatedInitExpr *DesignatedInitExpr::CreateEmpty(ASTContext &C,
2947                                                    unsigned NumIndexExprs) {
2948  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
2949                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
2950  return new (Mem) DesignatedInitExpr(NumIndexExprs + 1);
2951}
2952
2953void DesignatedInitExpr::setDesignators(ASTContext &C,
2954                                        const Designator *Desigs,
2955                                        unsigned NumDesigs) {
2956  Designators = new (C) Designator[NumDesigs];
2957  NumDesignators = NumDesigs;
2958  for (unsigned I = 0; I != NumDesigs; ++I)
2959    Designators[I] = Desigs[I];
2960}
2961
2962SourceRange DesignatedInitExpr::getDesignatorsSourceRange() const {
2963  DesignatedInitExpr *DIE = const_cast<DesignatedInitExpr*>(this);
2964  if (size() == 1)
2965    return DIE->getDesignator(0)->getSourceRange();
2966  return SourceRange(DIE->getDesignator(0)->getStartLocation(),
2967                     DIE->getDesignator(size()-1)->getEndLocation());
2968}
2969
2970SourceRange DesignatedInitExpr::getSourceRange() const {
2971  SourceLocation StartLoc;
2972  Designator &First =
2973    *const_cast<DesignatedInitExpr*>(this)->designators_begin();
2974  if (First.isFieldDesignator()) {
2975    if (GNUSyntax)
2976      StartLoc = SourceLocation::getFromRawEncoding(First.Field.FieldLoc);
2977    else
2978      StartLoc = SourceLocation::getFromRawEncoding(First.Field.DotLoc);
2979  } else
2980    StartLoc =
2981      SourceLocation::getFromRawEncoding(First.ArrayOrRange.LBracketLoc);
2982  return SourceRange(StartLoc, getInit()->getSourceRange().getEnd());
2983}
2984
2985Expr *DesignatedInitExpr::getArrayIndex(const Designator& D) {
2986  assert(D.Kind == Designator::ArrayDesignator && "Requires array designator");
2987  char* Ptr = static_cast<char*>(static_cast<void *>(this));
2988  Ptr += sizeof(DesignatedInitExpr);
2989  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
2990  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
2991}
2992
2993Expr *DesignatedInitExpr::getArrayRangeStart(const Designator& D) {
2994  assert(D.Kind == Designator::ArrayRangeDesignator &&
2995         "Requires array range designator");
2996  char* Ptr = static_cast<char*>(static_cast<void *>(this));
2997  Ptr += sizeof(DesignatedInitExpr);
2998  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
2999  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
3000}
3001
3002Expr *DesignatedInitExpr::getArrayRangeEnd(const Designator& D) {
3003  assert(D.Kind == Designator::ArrayRangeDesignator &&
3004         "Requires array range designator");
3005  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3006  Ptr += sizeof(DesignatedInitExpr);
3007  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3008  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 2));
3009}
3010
3011/// \brief Replaces the designator at index @p Idx with the series
3012/// of designators in [First, Last).
3013void DesignatedInitExpr::ExpandDesignator(ASTContext &C, unsigned Idx,
3014                                          const Designator *First,
3015                                          const Designator *Last) {
3016  unsigned NumNewDesignators = Last - First;
3017  if (NumNewDesignators == 0) {
3018    std::copy_backward(Designators + Idx + 1,
3019                       Designators + NumDesignators,
3020                       Designators + Idx);
3021    --NumNewDesignators;
3022    return;
3023  } else if (NumNewDesignators == 1) {
3024    Designators[Idx] = *First;
3025    return;
3026  }
3027
3028  Designator *NewDesignators
3029    = new (C) Designator[NumDesignators - 1 + NumNewDesignators];
3030  std::copy(Designators, Designators + Idx, NewDesignators);
3031  std::copy(First, Last, NewDesignators + Idx);
3032  std::copy(Designators + Idx + 1, Designators + NumDesignators,
3033            NewDesignators + Idx + NumNewDesignators);
3034  Designators = NewDesignators;
3035  NumDesignators = NumDesignators - 1 + NumNewDesignators;
3036}
3037
3038ParenListExpr::ParenListExpr(ASTContext& C, SourceLocation lparenloc,
3039                             Expr **exprs, unsigned nexprs,
3040                             SourceLocation rparenloc)
3041  : Expr(ParenListExprClass, QualType(), VK_RValue, OK_Ordinary,
3042         false, false, false),
3043    NumExprs(nexprs), LParenLoc(lparenloc), RParenLoc(rparenloc) {
3044
3045  Exprs = new (C) Stmt*[nexprs];
3046  for (unsigned i = 0; i != nexprs; ++i) {
3047    if (exprs[i]->isTypeDependent())
3048      ExprBits.TypeDependent = true;
3049    if (exprs[i]->isValueDependent())
3050      ExprBits.ValueDependent = true;
3051    if (exprs[i]->containsUnexpandedParameterPack())
3052      ExprBits.ContainsUnexpandedParameterPack = true;
3053
3054    Exprs[i] = exprs[i];
3055  }
3056}
3057
3058const OpaqueValueExpr *OpaqueValueExpr::findInCopyConstruct(const Expr *e) {
3059  if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(e))
3060    e = ewc->getSubExpr();
3061  if (const MaterializeTemporaryExpr *m = dyn_cast<MaterializeTemporaryExpr>(e))
3062    e = m->GetTemporaryExpr();
3063  e = cast<CXXConstructExpr>(e)->getArg(0);
3064  while (const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
3065    e = ice->getSubExpr();
3066  return cast<OpaqueValueExpr>(e);
3067}
3068
3069//===----------------------------------------------------------------------===//
3070//  ExprIterator.
3071//===----------------------------------------------------------------------===//
3072
3073Expr* ExprIterator::operator[](size_t idx) { return cast<Expr>(I[idx]); }
3074Expr* ExprIterator::operator*() const { return cast<Expr>(*I); }
3075Expr* ExprIterator::operator->() const { return cast<Expr>(*I); }
3076const Expr* ConstExprIterator::operator[](size_t idx) const {
3077  return cast<Expr>(I[idx]);
3078}
3079const Expr* ConstExprIterator::operator*() const { return cast<Expr>(*I); }
3080const Expr* ConstExprIterator::operator->() const { return cast<Expr>(*I); }
3081
3082//===----------------------------------------------------------------------===//
3083//  Child Iterators for iterating over subexpressions/substatements
3084//===----------------------------------------------------------------------===//
3085
3086// UnaryExprOrTypeTraitExpr
3087Stmt::child_range UnaryExprOrTypeTraitExpr::children() {
3088  // If this is of a type and the type is a VLA type (and not a typedef), the
3089  // size expression of the VLA needs to be treated as an executable expression.
3090  // Why isn't this weirdness documented better in StmtIterator?
3091  if (isArgumentType()) {
3092    if (const VariableArrayType* T = dyn_cast<VariableArrayType>(
3093                                   getArgumentType().getTypePtr()))
3094      return child_range(child_iterator(T), child_iterator());
3095    return child_range();
3096  }
3097  return child_range(&Argument.Ex, &Argument.Ex + 1);
3098}
3099
3100// ObjCMessageExpr
3101Stmt::child_range ObjCMessageExpr::children() {
3102  Stmt **begin;
3103  if (getReceiverKind() == Instance)
3104    begin = reinterpret_cast<Stmt **>(this + 1);
3105  else
3106    begin = reinterpret_cast<Stmt **>(getArgs());
3107  return child_range(begin,
3108                     reinterpret_cast<Stmt **>(getArgs() + getNumArgs()));
3109}
3110
3111// Blocks
3112BlockDeclRefExpr::BlockDeclRefExpr(VarDecl *d, QualType t, ExprValueKind VK,
3113                                   SourceLocation l, bool ByRef,
3114                                   bool constAdded)
3115  : Expr(BlockDeclRefExprClass, t, VK, OK_Ordinary, false, false,
3116         d->isParameterPack()),
3117    D(d), Loc(l), IsByRef(ByRef), ConstQualAdded(constAdded)
3118{
3119  bool TypeDependent = false;
3120  bool ValueDependent = false;
3121  computeDeclRefDependence(D, getType(), TypeDependent, ValueDependent);
3122  ExprBits.TypeDependent = TypeDependent;
3123  ExprBits.ValueDependent = ValueDependent;
3124}
3125