Expr.cpp revision 224145 
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 &InstantiationDependent,
148                                       bool &ContainsUnexpandedParameterPack) {
149  LAngleLoc = Info.getLAngleLoc();
150  RAngleLoc = Info.getRAngleLoc();
151  NumTemplateArgs = Info.size();
152
153  TemplateArgumentLoc *ArgBuffer = getTemplateArgs();
154  for (unsigned i = 0; i != NumTemplateArgs; ++i) {
155    Dependent = Dependent || Info[i].getArgument().isDependent();
156    InstantiationDependent = InstantiationDependent ||
157                             Info[i].getArgument().isInstantiationDependent();
158    ContainsUnexpandedParameterPack
159      = ContainsUnexpandedParameterPack ||
160        Info[i].getArgument().containsUnexpandedParameterPack();
161
162    new (&ArgBuffer[i]) TemplateArgumentLoc(Info[i]);
163  }
164}
165
166void ExplicitTemplateArgumentList::copyInto(
167                                      TemplateArgumentListInfo &Info) const {
168  Info.setLAngleLoc(LAngleLoc);
169  Info.setRAngleLoc(RAngleLoc);
170  for (unsigned I = 0; I != NumTemplateArgs; ++I)
171    Info.addArgument(getTemplateArgs()[I]);
172}
173
174std::size_t ExplicitTemplateArgumentList::sizeFor(unsigned NumTemplateArgs) {
175  return sizeof(ExplicitTemplateArgumentList) +
176         sizeof(TemplateArgumentLoc) * NumTemplateArgs;
177}
178
179std::size_t ExplicitTemplateArgumentList::sizeFor(
180                                      const TemplateArgumentListInfo &Info) {
181  return sizeFor(Info.size());
182}
183
184/// \brief Compute the type-, value-, and instantiation-dependence of a
185/// declaration reference
186/// based on the declaration being referenced.
187static void computeDeclRefDependence(NamedDecl *D, QualType T,
188                                     bool &TypeDependent,
189                                     bool &ValueDependent,
190                                     bool &InstantiationDependent) {
191  TypeDependent = false;
192  ValueDependent = false;
193  InstantiationDependent = false;
194
195  // (TD) C++ [temp.dep.expr]p3:
196  //   An id-expression is type-dependent if it contains:
197  //
198  // and
199  //
200  // (VD) C++ [temp.dep.constexpr]p2:
201  //  An identifier is value-dependent if it is:
202
203  //  (TD)  - an identifier that was declared with dependent type
204  //  (VD)  - a name declared with a dependent type,
205  if (T->isDependentType()) {
206    TypeDependent = true;
207    ValueDependent = true;
208    InstantiationDependent = true;
209    return;
210  } else if (T->isInstantiationDependentType()) {
211    InstantiationDependent = true;
212  }
213
214  //  (TD)  - a conversion-function-id that specifies a dependent type
215  if (D->getDeclName().getNameKind()
216                                == DeclarationName::CXXConversionFunctionName) {
217    QualType T = D->getDeclName().getCXXNameType();
218    if (T->isDependentType()) {
219      TypeDependent = true;
220      ValueDependent = true;
221      InstantiationDependent = true;
222      return;
223    }
224
225    if (T->isInstantiationDependentType())
226      InstantiationDependent = true;
227  }
228
229  //  (VD)  - the name of a non-type template parameter,
230  if (isa<NonTypeTemplateParmDecl>(D)) {
231    ValueDependent = true;
232    InstantiationDependent = true;
233    return;
234  }
235
236  //  (VD) - a constant with integral or enumeration type and is
237  //         initialized with an expression that is value-dependent.
238  if (VarDecl *Var = dyn_cast<VarDecl>(D)) {
239    if (Var->getType()->isIntegralOrEnumerationType() &&
240        Var->getType().getCVRQualifiers() == Qualifiers::Const) {
241      if (const Expr *Init = Var->getAnyInitializer())
242        if (Init->isValueDependent()) {
243          ValueDependent = true;
244          InstantiationDependent = true;
245        }
246    }
247
248    // (VD) - FIXME: Missing from the standard:
249    //      -  a member function or a static data member of the current
250    //         instantiation
251    else if (Var->isStaticDataMember() &&
252             Var->getDeclContext()->isDependentContext()) {
253      ValueDependent = true;
254      InstantiationDependent = true;
255    }
256
257    return;
258  }
259
260  // (VD) - FIXME: Missing from the standard:
261  //      -  a member function or a static data member of the current
262  //         instantiation
263  if (isa<CXXMethodDecl>(D) && D->getDeclContext()->isDependentContext()) {
264    ValueDependent = true;
265    InstantiationDependent = true;
266    return;
267  }
268}
269
270void DeclRefExpr::computeDependence() {
271  bool TypeDependent = false;
272  bool ValueDependent = false;
273  bool InstantiationDependent = false;
274  computeDeclRefDependence(getDecl(), getType(), TypeDependent, ValueDependent,
275                           InstantiationDependent);
276
277  // (TD) C++ [temp.dep.expr]p3:
278  //   An id-expression is type-dependent if it contains:
279  //
280  // and
281  //
282  // (VD) C++ [temp.dep.constexpr]p2:
283  //  An identifier is value-dependent if it is:
284  if (!TypeDependent && !ValueDependent &&
285      hasExplicitTemplateArgs() &&
286      TemplateSpecializationType::anyDependentTemplateArguments(
287                                                            getTemplateArgs(),
288                                                       getNumTemplateArgs(),
289                                                      InstantiationDependent)) {
290    TypeDependent = true;
291    ValueDependent = true;
292    InstantiationDependent = true;
293  }
294
295  ExprBits.TypeDependent = TypeDependent;
296  ExprBits.ValueDependent = ValueDependent;
297  ExprBits.InstantiationDependent = InstantiationDependent;
298
299  // Is the declaration a parameter pack?
300  if (getDecl()->isParameterPack())
301    ExprBits.ContainsUnexpandedParameterPack = true;
302}
303
304DeclRefExpr::DeclRefExpr(NestedNameSpecifierLoc QualifierLoc,
305                         ValueDecl *D, const DeclarationNameInfo &NameInfo,
306                         NamedDecl *FoundD,
307                         const TemplateArgumentListInfo *TemplateArgs,
308                         QualType T, ExprValueKind VK)
309  : Expr(DeclRefExprClass, T, VK, OK_Ordinary, false, false, false, false),
310    D(D), Loc(NameInfo.getLoc()), DNLoc(NameInfo.getInfo()) {
311  DeclRefExprBits.HasQualifier = QualifierLoc ? 1 : 0;
312  if (QualifierLoc)
313    getInternalQualifierLoc() = QualifierLoc;
314  DeclRefExprBits.HasFoundDecl = FoundD ? 1 : 0;
315  if (FoundD)
316    getInternalFoundDecl() = FoundD;
317  DeclRefExprBits.HasExplicitTemplateArgs = TemplateArgs ? 1 : 0;
318  if (TemplateArgs) {
319    bool Dependent = false;
320    bool InstantiationDependent = false;
321    bool ContainsUnexpandedParameterPack = false;
322    getExplicitTemplateArgs().initializeFrom(*TemplateArgs, Dependent,
323                                             InstantiationDependent,
324                                             ContainsUnexpandedParameterPack);
325    if (InstantiationDependent)
326      setInstantiationDependent(true);
327  }
328
329  computeDependence();
330}
331
332DeclRefExpr *DeclRefExpr::Create(ASTContext &Context,
333                                 NestedNameSpecifierLoc QualifierLoc,
334                                 ValueDecl *D,
335                                 SourceLocation NameLoc,
336                                 QualType T,
337                                 ExprValueKind VK,
338                                 NamedDecl *FoundD,
339                                 const TemplateArgumentListInfo *TemplateArgs) {
340  return Create(Context, QualifierLoc, D,
341                DeclarationNameInfo(D->getDeclName(), NameLoc),
342                T, VK, FoundD, TemplateArgs);
343}
344
345DeclRefExpr *DeclRefExpr::Create(ASTContext &Context,
346                                 NestedNameSpecifierLoc QualifierLoc,
347                                 ValueDecl *D,
348                                 const DeclarationNameInfo &NameInfo,
349                                 QualType T,
350                                 ExprValueKind VK,
351                                 NamedDecl *FoundD,
352                                 const TemplateArgumentListInfo *TemplateArgs) {
353  // Filter out cases where the found Decl is the same as the value refenenced.
354  if (D == FoundD)
355    FoundD = 0;
356
357  std::size_t Size = sizeof(DeclRefExpr);
358  if (QualifierLoc != 0)
359    Size += sizeof(NestedNameSpecifierLoc);
360  if (FoundD)
361    Size += sizeof(NamedDecl *);
362  if (TemplateArgs)
363    Size += ExplicitTemplateArgumentList::sizeFor(*TemplateArgs);
364
365  void *Mem = Context.Allocate(Size, llvm::alignOf<DeclRefExpr>());
366  return new (Mem) DeclRefExpr(QualifierLoc, D, NameInfo, FoundD, TemplateArgs,
367                               T, VK);
368}
369
370DeclRefExpr *DeclRefExpr::CreateEmpty(ASTContext &Context,
371                                      bool HasQualifier,
372                                      bool HasFoundDecl,
373                                      bool HasExplicitTemplateArgs,
374                                      unsigned NumTemplateArgs) {
375  std::size_t Size = sizeof(DeclRefExpr);
376  if (HasQualifier)
377    Size += sizeof(NestedNameSpecifierLoc);
378  if (HasFoundDecl)
379    Size += sizeof(NamedDecl *);
380  if (HasExplicitTemplateArgs)
381    Size += ExplicitTemplateArgumentList::sizeFor(NumTemplateArgs);
382
383  void *Mem = Context.Allocate(Size, llvm::alignOf<DeclRefExpr>());
384  return new (Mem) DeclRefExpr(EmptyShell());
385}
386
387SourceRange DeclRefExpr::getSourceRange() const {
388  SourceRange R = getNameInfo().getSourceRange();
389  if (hasQualifier())
390    R.setBegin(getQualifierLoc().getBeginLoc());
391  if (hasExplicitTemplateArgs())
392    R.setEnd(getRAngleLoc());
393  return R;
394}
395
396// FIXME: Maybe this should use DeclPrinter with a special "print predefined
397// expr" policy instead.
398std::string PredefinedExpr::ComputeName(IdentType IT, const Decl *CurrentDecl) {
399  ASTContext &Context = CurrentDecl->getASTContext();
400
401  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurrentDecl)) {
402    if (IT != PrettyFunction && IT != PrettyFunctionNoVirtual)
403      return FD->getNameAsString();
404
405    llvm::SmallString<256> Name;
406    llvm::raw_svector_ostream Out(Name);
407
408    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
409      if (MD->isVirtual() && IT != PrettyFunctionNoVirtual)
410        Out << "virtual ";
411      if (MD->isStatic())
412        Out << "static ";
413    }
414
415    PrintingPolicy Policy(Context.getLangOptions());
416
417    std::string Proto = FD->getQualifiedNameAsString(Policy);
418
419    const FunctionType *AFT = FD->getType()->getAs<FunctionType>();
420    const FunctionProtoType *FT = 0;
421    if (FD->hasWrittenPrototype())
422      FT = dyn_cast<FunctionProtoType>(AFT);
423
424    Proto += "(";
425    if (FT) {
426      llvm::raw_string_ostream POut(Proto);
427      for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
428        if (i) POut << ", ";
429        std::string Param;
430        FD->getParamDecl(i)->getType().getAsStringInternal(Param, Policy);
431        POut << Param;
432      }
433
434      if (FT->isVariadic()) {
435        if (FD->getNumParams()) POut << ", ";
436        POut << "...";
437      }
438    }
439    Proto += ")";
440
441    if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
442      Qualifiers ThisQuals = Qualifiers::fromCVRMask(MD->getTypeQualifiers());
443      if (ThisQuals.hasConst())
444        Proto += " const";
445      if (ThisQuals.hasVolatile())
446        Proto += " volatile";
447    }
448
449    if (!isa<CXXConstructorDecl>(FD) && !isa<CXXDestructorDecl>(FD))
450      AFT->getResultType().getAsStringInternal(Proto, Policy);
451
452    Out << Proto;
453
454    Out.flush();
455    return Name.str().str();
456  }
457  if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(CurrentDecl)) {
458    llvm::SmallString<256> Name;
459    llvm::raw_svector_ostream Out(Name);
460    Out << (MD->isInstanceMethod() ? '-' : '+');
461    Out << '[';
462
463    // For incorrect code, there might not be an ObjCInterfaceDecl.  Do
464    // a null check to avoid a crash.
465    if (const ObjCInterfaceDecl *ID = MD->getClassInterface())
466      Out << ID;
467
468    if (const ObjCCategoryImplDecl *CID =
469        dyn_cast<ObjCCategoryImplDecl>(MD->getDeclContext()))
470      Out << '(' << CID << ')';
471
472    Out <<  ' ';
473    Out << MD->getSelector().getAsString();
474    Out <<  ']';
475
476    Out.flush();
477    return Name.str().str();
478  }
479  if (isa<TranslationUnitDecl>(CurrentDecl) && IT == PrettyFunction) {
480    // __PRETTY_FUNCTION__ -> "top level", the others produce an empty string.
481    return "top level";
482  }
483  return "";
484}
485
486void APNumericStorage::setIntValue(ASTContext &C, const llvm::APInt &Val) {
487  if (hasAllocation())
488    C.Deallocate(pVal);
489
490  BitWidth = Val.getBitWidth();
491  unsigned NumWords = Val.getNumWords();
492  const uint64_t* Words = Val.getRawData();
493  if (NumWords > 1) {
494    pVal = new (C) uint64_t[NumWords];
495    std::copy(Words, Words + NumWords, pVal);
496  } else if (NumWords == 1)
497    VAL = Words[0];
498  else
499    VAL = 0;
500}
501
502IntegerLiteral *
503IntegerLiteral::Create(ASTContext &C, const llvm::APInt &V,
504                       QualType type, SourceLocation l) {
505  return new (C) IntegerLiteral(C, V, type, l);
506}
507
508IntegerLiteral *
509IntegerLiteral::Create(ASTContext &C, EmptyShell Empty) {
510  return new (C) IntegerLiteral(Empty);
511}
512
513FloatingLiteral *
514FloatingLiteral::Create(ASTContext &C, const llvm::APFloat &V,
515                        bool isexact, QualType Type, SourceLocation L) {
516  return new (C) FloatingLiteral(C, V, isexact, Type, L);
517}
518
519FloatingLiteral *
520FloatingLiteral::Create(ASTContext &C, EmptyShell Empty) {
521  return new (C) FloatingLiteral(Empty);
522}
523
524/// getValueAsApproximateDouble - This returns the value as an inaccurate
525/// double.  Note that this may cause loss of precision, but is useful for
526/// debugging dumps, etc.
527double FloatingLiteral::getValueAsApproximateDouble() const {
528  llvm::APFloat V = getValue();
529  bool ignored;
530  V.convert(llvm::APFloat::IEEEdouble, llvm::APFloat::rmNearestTiesToEven,
531            &ignored);
532  return V.convertToDouble();
533}
534
535StringLiteral *StringLiteral::Create(ASTContext &C, llvm::StringRef Str,
536                                     bool Wide,
537                                     bool Pascal, QualType Ty,
538                                     const SourceLocation *Loc,
539                                     unsigned NumStrs) {
540  // Allocate enough space for the StringLiteral plus an array of locations for
541  // any concatenated string tokens.
542  void *Mem = C.Allocate(sizeof(StringLiteral)+
543                         sizeof(SourceLocation)*(NumStrs-1),
544                         llvm::alignOf<StringLiteral>());
545  StringLiteral *SL = new (Mem) StringLiteral(Ty);
546
547  // OPTIMIZE: could allocate this appended to the StringLiteral.
548  char *AStrData = new (C, 1) char[Str.size()];
549  memcpy(AStrData, Str.data(), Str.size());
550  SL->StrData = AStrData;
551  SL->ByteLength = Str.size();
552  SL->IsWide = Wide;
553  SL->IsPascal = Pascal;
554  SL->TokLocs[0] = Loc[0];
555  SL->NumConcatenated = NumStrs;
556
557  if (NumStrs != 1)
558    memcpy(&SL->TokLocs[1], Loc+1, sizeof(SourceLocation)*(NumStrs-1));
559  return SL;
560}
561
562StringLiteral *StringLiteral::CreateEmpty(ASTContext &C, unsigned NumStrs) {
563  void *Mem = C.Allocate(sizeof(StringLiteral)+
564                         sizeof(SourceLocation)*(NumStrs-1),
565                         llvm::alignOf<StringLiteral>());
566  StringLiteral *SL = new (Mem) StringLiteral(QualType());
567  SL->StrData = 0;
568  SL->ByteLength = 0;
569  SL->NumConcatenated = NumStrs;
570  return SL;
571}
572
573void StringLiteral::setString(ASTContext &C, llvm::StringRef Str) {
574  char *AStrData = new (C, 1) char[Str.size()];
575  memcpy(AStrData, Str.data(), Str.size());
576  StrData = AStrData;
577  ByteLength = Str.size();
578}
579
580/// getLocationOfByte - Return a source location that points to the specified
581/// byte of this string literal.
582///
583/// Strings are amazingly complex.  They can be formed from multiple tokens and
584/// can have escape sequences in them in addition to the usual trigraph and
585/// escaped newline business.  This routine handles this complexity.
586///
587SourceLocation StringLiteral::
588getLocationOfByte(unsigned ByteNo, const SourceManager &SM,
589                  const LangOptions &Features, const TargetInfo &Target) const {
590  assert(!isWide() && "This doesn't work for wide strings yet");
591
592  // Loop over all of the tokens in this string until we find the one that
593  // contains the byte we're looking for.
594  unsigned TokNo = 0;
595  while (1) {
596    assert(TokNo < getNumConcatenated() && "Invalid byte number!");
597    SourceLocation StrTokLoc = getStrTokenLoc(TokNo);
598
599    // Get the spelling of the string so that we can get the data that makes up
600    // the string literal, not the identifier for the macro it is potentially
601    // expanded through.
602    SourceLocation StrTokSpellingLoc = SM.getSpellingLoc(StrTokLoc);
603
604    // Re-lex the token to get its length and original spelling.
605    std::pair<FileID, unsigned> LocInfo =SM.getDecomposedLoc(StrTokSpellingLoc);
606    bool Invalid = false;
607    llvm::StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
608    if (Invalid)
609      return StrTokSpellingLoc;
610
611    const char *StrData = Buffer.data()+LocInfo.second;
612
613    // Create a langops struct and enable trigraphs.  This is sufficient for
614    // relexing tokens.
615    LangOptions LangOpts;
616    LangOpts.Trigraphs = true;
617
618    // Create a lexer starting at the beginning of this token.
619    Lexer TheLexer(StrTokSpellingLoc, Features, Buffer.begin(), StrData,
620                   Buffer.end());
621    Token TheTok;
622    TheLexer.LexFromRawLexer(TheTok);
623
624    // Use the StringLiteralParser to compute the length of the string in bytes.
625    StringLiteralParser SLP(&TheTok, 1, SM, Features, Target);
626    unsigned TokNumBytes = SLP.GetStringLength();
627
628    // If the byte is in this token, return the location of the byte.
629    if (ByteNo < TokNumBytes ||
630        (ByteNo == TokNumBytes && TokNo == getNumConcatenated() - 1)) {
631      unsigned Offset = SLP.getOffsetOfStringByte(TheTok, ByteNo);
632
633      // Now that we know the offset of the token in the spelling, use the
634      // preprocessor to get the offset in the original source.
635      return Lexer::AdvanceToTokenCharacter(StrTokLoc, Offset, SM, Features);
636    }
637
638    // Move to the next string token.
639    ++TokNo;
640    ByteNo -= TokNumBytes;
641  }
642}
643
644
645
646/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
647/// corresponds to, e.g. "sizeof" or "[pre]++".
648const char *UnaryOperator::getOpcodeStr(Opcode Op) {
649  switch (Op) {
650  default: assert(0 && "Unknown unary operator");
651  case UO_PostInc: return "++";
652  case UO_PostDec: return "--";
653  case UO_PreInc:  return "++";
654  case UO_PreDec:  return "--";
655  case UO_AddrOf:  return "&";
656  case UO_Deref:   return "*";
657  case UO_Plus:    return "+";
658  case UO_Minus:   return "-";
659  case UO_Not:     return "~";
660  case UO_LNot:    return "!";
661  case UO_Real:    return "__real";
662  case UO_Imag:    return "__imag";
663  case UO_Extension: return "__extension__";
664  }
665}
666
667UnaryOperatorKind
668UnaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO, bool Postfix) {
669  switch (OO) {
670  default: assert(false && "No unary operator for overloaded function");
671  case OO_PlusPlus:   return Postfix ? UO_PostInc : UO_PreInc;
672  case OO_MinusMinus: return Postfix ? UO_PostDec : UO_PreDec;
673  case OO_Amp:        return UO_AddrOf;
674  case OO_Star:       return UO_Deref;
675  case OO_Plus:       return UO_Plus;
676  case OO_Minus:      return UO_Minus;
677  case OO_Tilde:      return UO_Not;
678  case OO_Exclaim:    return UO_LNot;
679  }
680}
681
682OverloadedOperatorKind UnaryOperator::getOverloadedOperator(Opcode Opc) {
683  switch (Opc) {
684  case UO_PostInc: case UO_PreInc: return OO_PlusPlus;
685  case UO_PostDec: case UO_PreDec: return OO_MinusMinus;
686  case UO_AddrOf: return OO_Amp;
687  case UO_Deref: return OO_Star;
688  case UO_Plus: return OO_Plus;
689  case UO_Minus: return OO_Minus;
690  case UO_Not: return OO_Tilde;
691  case UO_LNot: return OO_Exclaim;
692  default: return OO_None;
693  }
694}
695
696
697//===----------------------------------------------------------------------===//
698// Postfix Operators.
699//===----------------------------------------------------------------------===//
700
701CallExpr::CallExpr(ASTContext& C, StmtClass SC, Expr *fn, unsigned NumPreArgs,
702                   Expr **args, unsigned numargs, QualType t, ExprValueKind VK,
703                   SourceLocation rparenloc)
704  : Expr(SC, t, VK, OK_Ordinary,
705         fn->isTypeDependent(),
706         fn->isValueDependent(),
707         fn->isInstantiationDependent(),
708         fn->containsUnexpandedParameterPack()),
709    NumArgs(numargs) {
710
711  SubExprs = new (C) Stmt*[numargs+PREARGS_START+NumPreArgs];
712  SubExprs[FN] = fn;
713  for (unsigned i = 0; i != numargs; ++i) {
714    if (args[i]->isTypeDependent())
715      ExprBits.TypeDependent = true;
716    if (args[i]->isValueDependent())
717      ExprBits.ValueDependent = true;
718    if (args[i]->isInstantiationDependent())
719      ExprBits.InstantiationDependent = true;
720    if (args[i]->containsUnexpandedParameterPack())
721      ExprBits.ContainsUnexpandedParameterPack = true;
722
723    SubExprs[i+PREARGS_START+NumPreArgs] = args[i];
724  }
725
726  CallExprBits.NumPreArgs = NumPreArgs;
727  RParenLoc = rparenloc;
728}
729
730CallExpr::CallExpr(ASTContext& C, Expr *fn, Expr **args, unsigned numargs,
731                   QualType t, ExprValueKind VK, SourceLocation rparenloc)
732  : Expr(CallExprClass, t, VK, OK_Ordinary,
733         fn->isTypeDependent(),
734         fn->isValueDependent(),
735         fn->isInstantiationDependent(),
736         fn->containsUnexpandedParameterPack()),
737    NumArgs(numargs) {
738
739  SubExprs = new (C) Stmt*[numargs+PREARGS_START];
740  SubExprs[FN] = fn;
741  for (unsigned i = 0; i != numargs; ++i) {
742    if (args[i]->isTypeDependent())
743      ExprBits.TypeDependent = true;
744    if (args[i]->isValueDependent())
745      ExprBits.ValueDependent = true;
746    if (args[i]->isInstantiationDependent())
747      ExprBits.InstantiationDependent = true;
748    if (args[i]->containsUnexpandedParameterPack())
749      ExprBits.ContainsUnexpandedParameterPack = true;
750
751    SubExprs[i+PREARGS_START] = args[i];
752  }
753
754  CallExprBits.NumPreArgs = 0;
755  RParenLoc = rparenloc;
756}
757
758CallExpr::CallExpr(ASTContext &C, StmtClass SC, EmptyShell Empty)
759  : Expr(SC, Empty), SubExprs(0), NumArgs(0) {
760  // FIXME: Why do we allocate this?
761  SubExprs = new (C) Stmt*[PREARGS_START];
762  CallExprBits.NumPreArgs = 0;
763}
764
765CallExpr::CallExpr(ASTContext &C, StmtClass SC, unsigned NumPreArgs,
766                   EmptyShell Empty)
767  : Expr(SC, Empty), SubExprs(0), NumArgs(0) {
768  // FIXME: Why do we allocate this?
769  SubExprs = new (C) Stmt*[PREARGS_START+NumPreArgs];
770  CallExprBits.NumPreArgs = NumPreArgs;
771}
772
773Decl *CallExpr::getCalleeDecl() {
774  Expr *CEE = getCallee()->IgnoreParenCasts();
775  // If we're calling a dereference, look at the pointer instead.
776  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CEE)) {
777    if (BO->isPtrMemOp())
778      CEE = BO->getRHS()->IgnoreParenCasts();
779  } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(CEE)) {
780    if (UO->getOpcode() == UO_Deref)
781      CEE = UO->getSubExpr()->IgnoreParenCasts();
782  }
783  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE))
784    return DRE->getDecl();
785  if (MemberExpr *ME = dyn_cast<MemberExpr>(CEE))
786    return ME->getMemberDecl();
787
788  return 0;
789}
790
791FunctionDecl *CallExpr::getDirectCallee() {
792  return dyn_cast_or_null<FunctionDecl>(getCalleeDecl());
793}
794
795/// setNumArgs - This changes the number of arguments present in this call.
796/// Any orphaned expressions are deleted by this, and any new operands are set
797/// to null.
798void CallExpr::setNumArgs(ASTContext& C, unsigned NumArgs) {
799  // No change, just return.
800  if (NumArgs == getNumArgs()) return;
801
802  // If shrinking # arguments, just delete the extras and forgot them.
803  if (NumArgs < getNumArgs()) {
804    this->NumArgs = NumArgs;
805    return;
806  }
807
808  // Otherwise, we are growing the # arguments.  New an bigger argument array.
809  unsigned NumPreArgs = getNumPreArgs();
810  Stmt **NewSubExprs = new (C) Stmt*[NumArgs+PREARGS_START+NumPreArgs];
811  // Copy over args.
812  for (unsigned i = 0; i != getNumArgs()+PREARGS_START+NumPreArgs; ++i)
813    NewSubExprs[i] = SubExprs[i];
814  // Null out new args.
815  for (unsigned i = getNumArgs()+PREARGS_START+NumPreArgs;
816       i != NumArgs+PREARGS_START+NumPreArgs; ++i)
817    NewSubExprs[i] = 0;
818
819  if (SubExprs) C.Deallocate(SubExprs);
820  SubExprs = NewSubExprs;
821  this->NumArgs = NumArgs;
822}
823
824/// isBuiltinCall - If this is a call to a builtin, return the builtin ID.  If
825/// not, return 0.
826unsigned CallExpr::isBuiltinCall(const ASTContext &Context) const {
827  // All simple function calls (e.g. func()) are implicitly cast to pointer to
828  // function. As a result, we try and obtain the DeclRefExpr from the
829  // ImplicitCastExpr.
830  const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
831  if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
832    return 0;
833
834  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
835  if (!DRE)
836    return 0;
837
838  const FunctionDecl *FDecl = dyn_cast<FunctionDecl>(DRE->getDecl());
839  if (!FDecl)
840    return 0;
841
842  if (!FDecl->getIdentifier())
843    return 0;
844
845  return FDecl->getBuiltinID();
846}
847
848QualType CallExpr::getCallReturnType() const {
849  QualType CalleeType = getCallee()->getType();
850  if (const PointerType *FnTypePtr = CalleeType->getAs<PointerType>())
851    CalleeType = FnTypePtr->getPointeeType();
852  else if (const BlockPointerType *BPT = CalleeType->getAs<BlockPointerType>())
853    CalleeType = BPT->getPointeeType();
854  else if (CalleeType->isSpecificPlaceholderType(BuiltinType::BoundMember))
855    // This should never be overloaded and so should never return null.
856    CalleeType = Expr::findBoundMemberType(getCallee());
857
858  const FunctionType *FnType = CalleeType->castAs<FunctionType>();
859  return FnType->getResultType();
860}
861
862SourceRange CallExpr::getSourceRange() const {
863  if (isa<CXXOperatorCallExpr>(this))
864    return cast<CXXOperatorCallExpr>(this)->getSourceRange();
865
866  SourceLocation begin = getCallee()->getLocStart();
867  if (begin.isInvalid() && getNumArgs() > 0)
868    begin = getArg(0)->getLocStart();
869  SourceLocation end = getRParenLoc();
870  if (end.isInvalid() && getNumArgs() > 0)
871    end = getArg(getNumArgs() - 1)->getLocEnd();
872  return SourceRange(begin, end);
873}
874
875OffsetOfExpr *OffsetOfExpr::Create(ASTContext &C, QualType type,
876                                   SourceLocation OperatorLoc,
877                                   TypeSourceInfo *tsi,
878                                   OffsetOfNode* compsPtr, unsigned numComps,
879                                   Expr** exprsPtr, unsigned numExprs,
880                                   SourceLocation RParenLoc) {
881  void *Mem = C.Allocate(sizeof(OffsetOfExpr) +
882                         sizeof(OffsetOfNode) * numComps +
883                         sizeof(Expr*) * numExprs);
884
885  return new (Mem) OffsetOfExpr(C, type, OperatorLoc, tsi, compsPtr, numComps,
886                                exprsPtr, numExprs, RParenLoc);
887}
888
889OffsetOfExpr *OffsetOfExpr::CreateEmpty(ASTContext &C,
890                                        unsigned numComps, unsigned numExprs) {
891  void *Mem = C.Allocate(sizeof(OffsetOfExpr) +
892                         sizeof(OffsetOfNode) * numComps +
893                         sizeof(Expr*) * numExprs);
894  return new (Mem) OffsetOfExpr(numComps, numExprs);
895}
896
897OffsetOfExpr::OffsetOfExpr(ASTContext &C, QualType type,
898                           SourceLocation OperatorLoc, TypeSourceInfo *tsi,
899                           OffsetOfNode* compsPtr, unsigned numComps,
900                           Expr** exprsPtr, unsigned numExprs,
901                           SourceLocation RParenLoc)
902  : Expr(OffsetOfExprClass, type, VK_RValue, OK_Ordinary,
903         /*TypeDependent=*/false,
904         /*ValueDependent=*/tsi->getType()->isDependentType(),
905         tsi->getType()->isInstantiationDependentType(),
906         tsi->getType()->containsUnexpandedParameterPack()),
907    OperatorLoc(OperatorLoc), RParenLoc(RParenLoc), TSInfo(tsi),
908    NumComps(numComps), NumExprs(numExprs)
909{
910  for(unsigned i = 0; i < numComps; ++i) {
911    setComponent(i, compsPtr[i]);
912  }
913
914  for(unsigned i = 0; i < numExprs; ++i) {
915    if (exprsPtr[i]->isTypeDependent() || exprsPtr[i]->isValueDependent())
916      ExprBits.ValueDependent = true;
917    if (exprsPtr[i]->containsUnexpandedParameterPack())
918      ExprBits.ContainsUnexpandedParameterPack = true;
919
920    setIndexExpr(i, exprsPtr[i]);
921  }
922}
923
924IdentifierInfo *OffsetOfExpr::OffsetOfNode::getFieldName() const {
925  assert(getKind() == Field || getKind() == Identifier);
926  if (getKind() == Field)
927    return getField()->getIdentifier();
928
929  return reinterpret_cast<IdentifierInfo *> (Data & ~(uintptr_t)Mask);
930}
931
932MemberExpr *MemberExpr::Create(ASTContext &C, Expr *base, bool isarrow,
933                               NestedNameSpecifierLoc QualifierLoc,
934                               ValueDecl *memberdecl,
935                               DeclAccessPair founddecl,
936                               DeclarationNameInfo nameinfo,
937                               const TemplateArgumentListInfo *targs,
938                               QualType ty,
939                               ExprValueKind vk,
940                               ExprObjectKind ok) {
941  std::size_t Size = sizeof(MemberExpr);
942
943  bool hasQualOrFound = (QualifierLoc ||
944                         founddecl.getDecl() != memberdecl ||
945                         founddecl.getAccess() != memberdecl->getAccess());
946  if (hasQualOrFound)
947    Size += sizeof(MemberNameQualifier);
948
949  if (targs)
950    Size += ExplicitTemplateArgumentList::sizeFor(*targs);
951
952  void *Mem = C.Allocate(Size, llvm::alignOf<MemberExpr>());
953  MemberExpr *E = new (Mem) MemberExpr(base, isarrow, memberdecl, nameinfo,
954                                       ty, vk, ok);
955
956  if (hasQualOrFound) {
957    // FIXME: Wrong. We should be looking at the member declaration we found.
958    if (QualifierLoc && QualifierLoc.getNestedNameSpecifier()->isDependent()) {
959      E->setValueDependent(true);
960      E->setTypeDependent(true);
961      E->setInstantiationDependent(true);
962    }
963    else if (QualifierLoc &&
964             QualifierLoc.getNestedNameSpecifier()->isInstantiationDependent())
965      E->setInstantiationDependent(true);
966
967    E->HasQualifierOrFoundDecl = true;
968
969    MemberNameQualifier *NQ = E->getMemberQualifier();
970    NQ->QualifierLoc = QualifierLoc;
971    NQ->FoundDecl = founddecl;
972  }
973
974  if (targs) {
975    bool Dependent = false;
976    bool InstantiationDependent = false;
977    bool ContainsUnexpandedParameterPack = false;
978    E->HasExplicitTemplateArgumentList = true;
979    E->getExplicitTemplateArgs().initializeFrom(*targs, Dependent,
980                                                InstantiationDependent,
981                                              ContainsUnexpandedParameterPack);
982    if (InstantiationDependent)
983      E->setInstantiationDependent(true);
984  }
985
986  return E;
987}
988
989SourceRange MemberExpr::getSourceRange() const {
990  SourceLocation StartLoc;
991  if (isImplicitAccess()) {
992    if (hasQualifier())
993      StartLoc = getQualifierLoc().getBeginLoc();
994    else
995      StartLoc = MemberLoc;
996  } else {
997    // FIXME: We don't want this to happen. Rather, we should be able to
998    // detect all kinds of implicit accesses more cleanly.
999    StartLoc = getBase()->getLocStart();
1000    if (StartLoc.isInvalid())
1001      StartLoc = MemberLoc;
1002  }
1003
1004  SourceLocation EndLoc =
1005    HasExplicitTemplateArgumentList? getRAngleLoc()
1006                                   : getMemberNameInfo().getEndLoc();
1007
1008  return SourceRange(StartLoc, EndLoc);
1009}
1010
1011const char *CastExpr::getCastKindName() const {
1012  switch (getCastKind()) {
1013  case CK_Dependent:
1014    return "Dependent";
1015  case CK_BitCast:
1016    return "BitCast";
1017  case CK_LValueBitCast:
1018    return "LValueBitCast";
1019  case CK_LValueToRValue:
1020    return "LValueToRValue";
1021  case CK_GetObjCProperty:
1022    return "GetObjCProperty";
1023  case CK_NoOp:
1024    return "NoOp";
1025  case CK_BaseToDerived:
1026    return "BaseToDerived";
1027  case CK_DerivedToBase:
1028    return "DerivedToBase";
1029  case CK_UncheckedDerivedToBase:
1030    return "UncheckedDerivedToBase";
1031  case CK_Dynamic:
1032    return "Dynamic";
1033  case CK_ToUnion:
1034    return "ToUnion";
1035  case CK_ArrayToPointerDecay:
1036    return "ArrayToPointerDecay";
1037  case CK_FunctionToPointerDecay:
1038    return "FunctionToPointerDecay";
1039  case CK_NullToMemberPointer:
1040    return "NullToMemberPointer";
1041  case CK_NullToPointer:
1042    return "NullToPointer";
1043  case CK_BaseToDerivedMemberPointer:
1044    return "BaseToDerivedMemberPointer";
1045  case CK_DerivedToBaseMemberPointer:
1046    return "DerivedToBaseMemberPointer";
1047  case CK_UserDefinedConversion:
1048    return "UserDefinedConversion";
1049  case CK_ConstructorConversion:
1050    return "ConstructorConversion";
1051  case CK_IntegralToPointer:
1052    return "IntegralToPointer";
1053  case CK_PointerToIntegral:
1054    return "PointerToIntegral";
1055  case CK_PointerToBoolean:
1056    return "PointerToBoolean";
1057  case CK_ToVoid:
1058    return "ToVoid";
1059  case CK_VectorSplat:
1060    return "VectorSplat";
1061  case CK_IntegralCast:
1062    return "IntegralCast";
1063  case CK_IntegralToBoolean:
1064    return "IntegralToBoolean";
1065  case CK_IntegralToFloating:
1066    return "IntegralToFloating";
1067  case CK_FloatingToIntegral:
1068    return "FloatingToIntegral";
1069  case CK_FloatingCast:
1070    return "FloatingCast";
1071  case CK_FloatingToBoolean:
1072    return "FloatingToBoolean";
1073  case CK_MemberPointerToBoolean:
1074    return "MemberPointerToBoolean";
1075  case CK_AnyPointerToObjCPointerCast:
1076    return "AnyPointerToObjCPointerCast";
1077  case CK_AnyPointerToBlockPointerCast:
1078    return "AnyPointerToBlockPointerCast";
1079  case CK_ObjCObjectLValueCast:
1080    return "ObjCObjectLValueCast";
1081  case CK_FloatingRealToComplex:
1082    return "FloatingRealToComplex";
1083  case CK_FloatingComplexToReal:
1084    return "FloatingComplexToReal";
1085  case CK_FloatingComplexToBoolean:
1086    return "FloatingComplexToBoolean";
1087  case CK_FloatingComplexCast:
1088    return "FloatingComplexCast";
1089  case CK_FloatingComplexToIntegralComplex:
1090    return "FloatingComplexToIntegralComplex";
1091  case CK_IntegralRealToComplex:
1092    return "IntegralRealToComplex";
1093  case CK_IntegralComplexToReal:
1094    return "IntegralComplexToReal";
1095  case CK_IntegralComplexToBoolean:
1096    return "IntegralComplexToBoolean";
1097  case CK_IntegralComplexCast:
1098    return "IntegralComplexCast";
1099  case CK_IntegralComplexToFloatingComplex:
1100    return "IntegralComplexToFloatingComplex";
1101  case CK_ObjCConsumeObject:
1102    return "ObjCConsumeObject";
1103  case CK_ObjCProduceObject:
1104    return "ObjCProduceObject";
1105  case CK_ObjCReclaimReturnedObject:
1106    return "ObjCReclaimReturnedObject";
1107  }
1108
1109  llvm_unreachable("Unhandled cast kind!");
1110  return 0;
1111}
1112
1113Expr *CastExpr::getSubExprAsWritten() {
1114  Expr *SubExpr = 0;
1115  CastExpr *E = this;
1116  do {
1117    SubExpr = E->getSubExpr();
1118
1119    // Skip through reference binding to temporary.
1120    if (MaterializeTemporaryExpr *Materialize
1121                                  = dyn_cast<MaterializeTemporaryExpr>(SubExpr))
1122      SubExpr = Materialize->GetTemporaryExpr();
1123
1124    // Skip any temporary bindings; they're implicit.
1125    if (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(SubExpr))
1126      SubExpr = Binder->getSubExpr();
1127
1128    // Conversions by constructor and conversion functions have a
1129    // subexpression describing the call; strip it off.
1130    if (E->getCastKind() == CK_ConstructorConversion)
1131      SubExpr = cast<CXXConstructExpr>(SubExpr)->getArg(0);
1132    else if (E->getCastKind() == CK_UserDefinedConversion)
1133      SubExpr = cast<CXXMemberCallExpr>(SubExpr)->getImplicitObjectArgument();
1134
1135    // If the subexpression we're left with is an implicit cast, look
1136    // through that, too.
1137  } while ((E = dyn_cast<ImplicitCastExpr>(SubExpr)));
1138
1139  return SubExpr;
1140}
1141
1142CXXBaseSpecifier **CastExpr::path_buffer() {
1143  switch (getStmtClass()) {
1144#define ABSTRACT_STMT(x)
1145#define CASTEXPR(Type, Base) \
1146  case Stmt::Type##Class: \
1147    return reinterpret_cast<CXXBaseSpecifier**>(static_cast<Type*>(this)+1);
1148#define STMT(Type, Base)
1149#include "clang/AST/StmtNodes.inc"
1150  default:
1151    llvm_unreachable("non-cast expressions not possible here");
1152    return 0;
1153  }
1154}
1155
1156void CastExpr::setCastPath(const CXXCastPath &Path) {
1157  assert(Path.size() == path_size());
1158  memcpy(path_buffer(), Path.data(), Path.size() * sizeof(CXXBaseSpecifier*));
1159}
1160
1161ImplicitCastExpr *ImplicitCastExpr::Create(ASTContext &C, QualType T,
1162                                           CastKind Kind, Expr *Operand,
1163                                           const CXXCastPath *BasePath,
1164                                           ExprValueKind VK) {
1165  unsigned PathSize = (BasePath ? BasePath->size() : 0);
1166  void *Buffer =
1167    C.Allocate(sizeof(ImplicitCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1168  ImplicitCastExpr *E =
1169    new (Buffer) ImplicitCastExpr(T, Kind, Operand, PathSize, VK);
1170  if (PathSize) E->setCastPath(*BasePath);
1171  return E;
1172}
1173
1174ImplicitCastExpr *ImplicitCastExpr::CreateEmpty(ASTContext &C,
1175                                                unsigned PathSize) {
1176  void *Buffer =
1177    C.Allocate(sizeof(ImplicitCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1178  return new (Buffer) ImplicitCastExpr(EmptyShell(), PathSize);
1179}
1180
1181
1182CStyleCastExpr *CStyleCastExpr::Create(ASTContext &C, QualType T,
1183                                       ExprValueKind VK, CastKind K, Expr *Op,
1184                                       const CXXCastPath *BasePath,
1185                                       TypeSourceInfo *WrittenTy,
1186                                       SourceLocation L, SourceLocation R) {
1187  unsigned PathSize = (BasePath ? BasePath->size() : 0);
1188  void *Buffer =
1189    C.Allocate(sizeof(CStyleCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1190  CStyleCastExpr *E =
1191    new (Buffer) CStyleCastExpr(T, VK, K, Op, PathSize, WrittenTy, L, R);
1192  if (PathSize) E->setCastPath(*BasePath);
1193  return E;
1194}
1195
1196CStyleCastExpr *CStyleCastExpr::CreateEmpty(ASTContext &C, unsigned PathSize) {
1197  void *Buffer =
1198    C.Allocate(sizeof(CStyleCastExpr) + PathSize * sizeof(CXXBaseSpecifier*));
1199  return new (Buffer) CStyleCastExpr(EmptyShell(), PathSize);
1200}
1201
1202/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
1203/// corresponds to, e.g. "<<=".
1204const char *BinaryOperator::getOpcodeStr(Opcode Op) {
1205  switch (Op) {
1206  case BO_PtrMemD:   return ".*";
1207  case BO_PtrMemI:   return "->*";
1208  case BO_Mul:       return "*";
1209  case BO_Div:       return "/";
1210  case BO_Rem:       return "%";
1211  case BO_Add:       return "+";
1212  case BO_Sub:       return "-";
1213  case BO_Shl:       return "<<";
1214  case BO_Shr:       return ">>";
1215  case BO_LT:        return "<";
1216  case BO_GT:        return ">";
1217  case BO_LE:        return "<=";
1218  case BO_GE:        return ">=";
1219  case BO_EQ:        return "==";
1220  case BO_NE:        return "!=";
1221  case BO_And:       return "&";
1222  case BO_Xor:       return "^";
1223  case BO_Or:        return "|";
1224  case BO_LAnd:      return "&&";
1225  case BO_LOr:       return "||";
1226  case BO_Assign:    return "=";
1227  case BO_MulAssign: return "*=";
1228  case BO_DivAssign: return "/=";
1229  case BO_RemAssign: return "%=";
1230  case BO_AddAssign: return "+=";
1231  case BO_SubAssign: return "-=";
1232  case BO_ShlAssign: return "<<=";
1233  case BO_ShrAssign: return ">>=";
1234  case BO_AndAssign: return "&=";
1235  case BO_XorAssign: return "^=";
1236  case BO_OrAssign:  return "|=";
1237  case BO_Comma:     return ",";
1238  }
1239
1240  return "";
1241}
1242
1243BinaryOperatorKind
1244BinaryOperator::getOverloadedOpcode(OverloadedOperatorKind OO) {
1245  switch (OO) {
1246  default: assert(false && "Not an overloadable binary operator");
1247  case OO_Plus: return BO_Add;
1248  case OO_Minus: return BO_Sub;
1249  case OO_Star: return BO_Mul;
1250  case OO_Slash: return BO_Div;
1251  case OO_Percent: return BO_Rem;
1252  case OO_Caret: return BO_Xor;
1253  case OO_Amp: return BO_And;
1254  case OO_Pipe: return BO_Or;
1255  case OO_Equal: return BO_Assign;
1256  case OO_Less: return BO_LT;
1257  case OO_Greater: return BO_GT;
1258  case OO_PlusEqual: return BO_AddAssign;
1259  case OO_MinusEqual: return BO_SubAssign;
1260  case OO_StarEqual: return BO_MulAssign;
1261  case OO_SlashEqual: return BO_DivAssign;
1262  case OO_PercentEqual: return BO_RemAssign;
1263  case OO_CaretEqual: return BO_XorAssign;
1264  case OO_AmpEqual: return BO_AndAssign;
1265  case OO_PipeEqual: return BO_OrAssign;
1266  case OO_LessLess: return BO_Shl;
1267  case OO_GreaterGreater: return BO_Shr;
1268  case OO_LessLessEqual: return BO_ShlAssign;
1269  case OO_GreaterGreaterEqual: return BO_ShrAssign;
1270  case OO_EqualEqual: return BO_EQ;
1271  case OO_ExclaimEqual: return BO_NE;
1272  case OO_LessEqual: return BO_LE;
1273  case OO_GreaterEqual: return BO_GE;
1274  case OO_AmpAmp: return BO_LAnd;
1275  case OO_PipePipe: return BO_LOr;
1276  case OO_Comma: return BO_Comma;
1277  case OO_ArrowStar: return BO_PtrMemI;
1278  }
1279}
1280
1281OverloadedOperatorKind BinaryOperator::getOverloadedOperator(Opcode Opc) {
1282  static const OverloadedOperatorKind OverOps[] = {
1283    /* .* Cannot be overloaded */OO_None, OO_ArrowStar,
1284    OO_Star, OO_Slash, OO_Percent,
1285    OO_Plus, OO_Minus,
1286    OO_LessLess, OO_GreaterGreater,
1287    OO_Less, OO_Greater, OO_LessEqual, OO_GreaterEqual,
1288    OO_EqualEqual, OO_ExclaimEqual,
1289    OO_Amp,
1290    OO_Caret,
1291    OO_Pipe,
1292    OO_AmpAmp,
1293    OO_PipePipe,
1294    OO_Equal, OO_StarEqual,
1295    OO_SlashEqual, OO_PercentEqual,
1296    OO_PlusEqual, OO_MinusEqual,
1297    OO_LessLessEqual, OO_GreaterGreaterEqual,
1298    OO_AmpEqual, OO_CaretEqual,
1299    OO_PipeEqual,
1300    OO_Comma
1301  };
1302  return OverOps[Opc];
1303}
1304
1305InitListExpr::InitListExpr(ASTContext &C, SourceLocation lbraceloc,
1306                           Expr **initExprs, unsigned numInits,
1307                           SourceLocation rbraceloc)
1308  : Expr(InitListExprClass, QualType(), VK_RValue, OK_Ordinary, false, false,
1309         false, false),
1310    InitExprs(C, numInits),
1311    LBraceLoc(lbraceloc), RBraceLoc(rbraceloc), SyntacticForm(0),
1312    HadArrayRangeDesignator(false)
1313{
1314  for (unsigned I = 0; I != numInits; ++I) {
1315    if (initExprs[I]->isTypeDependent())
1316      ExprBits.TypeDependent = true;
1317    if (initExprs[I]->isValueDependent())
1318      ExprBits.ValueDependent = true;
1319    if (initExprs[I]->isInstantiationDependent())
1320      ExprBits.InstantiationDependent = true;
1321    if (initExprs[I]->containsUnexpandedParameterPack())
1322      ExprBits.ContainsUnexpandedParameterPack = true;
1323  }
1324
1325  InitExprs.insert(C, InitExprs.end(), initExprs, initExprs+numInits);
1326}
1327
1328void InitListExpr::reserveInits(ASTContext &C, unsigned NumInits) {
1329  if (NumInits > InitExprs.size())
1330    InitExprs.reserve(C, NumInits);
1331}
1332
1333void InitListExpr::resizeInits(ASTContext &C, unsigned NumInits) {
1334  InitExprs.resize(C, NumInits, 0);
1335}
1336
1337Expr *InitListExpr::updateInit(ASTContext &C, unsigned Init, Expr *expr) {
1338  if (Init >= InitExprs.size()) {
1339    InitExprs.insert(C, InitExprs.end(), Init - InitExprs.size() + 1, 0);
1340    InitExprs.back() = expr;
1341    return 0;
1342  }
1343
1344  Expr *Result = cast_or_null<Expr>(InitExprs[Init]);
1345  InitExprs[Init] = expr;
1346  return Result;
1347}
1348
1349void InitListExpr::setArrayFiller(Expr *filler) {
1350  ArrayFillerOrUnionFieldInit = filler;
1351  // Fill out any "holes" in the array due to designated initializers.
1352  Expr **inits = getInits();
1353  for (unsigned i = 0, e = getNumInits(); i != e; ++i)
1354    if (inits[i] == 0)
1355      inits[i] = filler;
1356}
1357
1358SourceRange InitListExpr::getSourceRange() const {
1359  if (SyntacticForm)
1360    return SyntacticForm->getSourceRange();
1361  SourceLocation Beg = LBraceLoc, End = RBraceLoc;
1362  if (Beg.isInvalid()) {
1363    // Find the first non-null initializer.
1364    for (InitExprsTy::const_iterator I = InitExprs.begin(),
1365                                     E = InitExprs.end();
1366      I != E; ++I) {
1367      if (Stmt *S = *I) {
1368        Beg = S->getLocStart();
1369        break;
1370      }
1371    }
1372  }
1373  if (End.isInvalid()) {
1374    // Find the first non-null initializer from the end.
1375    for (InitExprsTy::const_reverse_iterator I = InitExprs.rbegin(),
1376                                             E = InitExprs.rend();
1377      I != E; ++I) {
1378      if (Stmt *S = *I) {
1379        End = S->getSourceRange().getEnd();
1380        break;
1381      }
1382    }
1383  }
1384  return SourceRange(Beg, End);
1385}
1386
1387/// getFunctionType - Return the underlying function type for this block.
1388///
1389const FunctionType *BlockExpr::getFunctionType() const {
1390  return getType()->getAs<BlockPointerType>()->
1391                    getPointeeType()->getAs<FunctionType>();
1392}
1393
1394SourceLocation BlockExpr::getCaretLocation() const {
1395  return TheBlock->getCaretLocation();
1396}
1397const Stmt *BlockExpr::getBody() const {
1398  return TheBlock->getBody();
1399}
1400Stmt *BlockExpr::getBody() {
1401  return TheBlock->getBody();
1402}
1403
1404
1405//===----------------------------------------------------------------------===//
1406// Generic Expression Routines
1407//===----------------------------------------------------------------------===//
1408
1409/// isUnusedResultAWarning - Return true if this immediate expression should
1410/// be warned about if the result is unused.  If so, fill in Loc and Ranges
1411/// with location to warn on and the source range[s] to report with the
1412/// warning.
1413bool Expr::isUnusedResultAWarning(SourceLocation &Loc, SourceRange &R1,
1414                                  SourceRange &R2, ASTContext &Ctx) const {
1415  // Don't warn if the expr is type dependent. The type could end up
1416  // instantiating to void.
1417  if (isTypeDependent())
1418    return false;
1419
1420  switch (getStmtClass()) {
1421  default:
1422    if (getType()->isVoidType())
1423      return false;
1424    Loc = getExprLoc();
1425    R1 = getSourceRange();
1426    return true;
1427  case ParenExprClass:
1428    return cast<ParenExpr>(this)->getSubExpr()->
1429      isUnusedResultAWarning(Loc, R1, R2, Ctx);
1430  case GenericSelectionExprClass:
1431    return cast<GenericSelectionExpr>(this)->getResultExpr()->
1432      isUnusedResultAWarning(Loc, R1, R2, Ctx);
1433  case UnaryOperatorClass: {
1434    const UnaryOperator *UO = cast<UnaryOperator>(this);
1435
1436    switch (UO->getOpcode()) {
1437    default: break;
1438    case UO_PostInc:
1439    case UO_PostDec:
1440    case UO_PreInc:
1441    case UO_PreDec:                 // ++/--
1442      return false;  // Not a warning.
1443    case UO_Deref:
1444      // Dereferencing a volatile pointer is a side-effect.
1445      if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1446        return false;
1447      break;
1448    case UO_Real:
1449    case UO_Imag:
1450      // accessing a piece of a volatile complex is a side-effect.
1451      if (Ctx.getCanonicalType(UO->getSubExpr()->getType())
1452          .isVolatileQualified())
1453        return false;
1454      break;
1455    case UO_Extension:
1456      return UO->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1457    }
1458    Loc = UO->getOperatorLoc();
1459    R1 = UO->getSubExpr()->getSourceRange();
1460    return true;
1461  }
1462  case BinaryOperatorClass: {
1463    const BinaryOperator *BO = cast<BinaryOperator>(this);
1464    switch (BO->getOpcode()) {
1465      default:
1466        break;
1467      // Consider the RHS of comma for side effects. LHS was checked by
1468      // Sema::CheckCommaOperands.
1469      case BO_Comma:
1470        // ((foo = <blah>), 0) is an idiom for hiding the result (and
1471        // lvalue-ness) of an assignment written in a macro.
1472        if (IntegerLiteral *IE =
1473              dyn_cast<IntegerLiteral>(BO->getRHS()->IgnoreParens()))
1474          if (IE->getValue() == 0)
1475            return false;
1476        return BO->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1477      // Consider '||', '&&' to have side effects if the LHS or RHS does.
1478      case BO_LAnd:
1479      case BO_LOr:
1480        if (!BO->getLHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx) ||
1481            !BO->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx))
1482          return false;
1483        break;
1484    }
1485    if (BO->isAssignmentOp())
1486      return false;
1487    Loc = BO->getOperatorLoc();
1488    R1 = BO->getLHS()->getSourceRange();
1489    R2 = BO->getRHS()->getSourceRange();
1490    return true;
1491  }
1492  case CompoundAssignOperatorClass:
1493  case VAArgExprClass:
1494    return false;
1495
1496  case ConditionalOperatorClass: {
1497    // If only one of the LHS or RHS is a warning, the operator might
1498    // be being used for control flow. Only warn if both the LHS and
1499    // RHS are warnings.
1500    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
1501    if (!Exp->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx))
1502      return false;
1503    if (!Exp->getLHS())
1504      return true;
1505    return Exp->getLHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1506  }
1507
1508  case MemberExprClass:
1509    // If the base pointer or element is to a volatile pointer/field, accessing
1510    // it is a side effect.
1511    if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1512      return false;
1513    Loc = cast<MemberExpr>(this)->getMemberLoc();
1514    R1 = SourceRange(Loc, Loc);
1515    R2 = cast<MemberExpr>(this)->getBase()->getSourceRange();
1516    return true;
1517
1518  case ArraySubscriptExprClass:
1519    // If the base pointer or element is to a volatile pointer/field, accessing
1520    // it is a side effect.
1521    if (Ctx.getCanonicalType(getType()).isVolatileQualified())
1522      return false;
1523    Loc = cast<ArraySubscriptExpr>(this)->getRBracketLoc();
1524    R1 = cast<ArraySubscriptExpr>(this)->getLHS()->getSourceRange();
1525    R2 = cast<ArraySubscriptExpr>(this)->getRHS()->getSourceRange();
1526    return true;
1527
1528  case CallExprClass:
1529  case CXXOperatorCallExprClass:
1530  case CXXMemberCallExprClass: {
1531    // If this is a direct call, get the callee.
1532    const CallExpr *CE = cast<CallExpr>(this);
1533    if (const Decl *FD = CE->getCalleeDecl()) {
1534      // If the callee has attribute pure, const, or warn_unused_result, warn
1535      // about it. void foo() { strlen("bar"); } should warn.
1536      //
1537      // Note: If new cases are added here, DiagnoseUnusedExprResult should be
1538      // updated to match for QoI.
1539      if (FD->getAttr<WarnUnusedResultAttr>() ||
1540          FD->getAttr<PureAttr>() || FD->getAttr<ConstAttr>()) {
1541        Loc = CE->getCallee()->getLocStart();
1542        R1 = CE->getCallee()->getSourceRange();
1543
1544        if (unsigned NumArgs = CE->getNumArgs())
1545          R2 = SourceRange(CE->getArg(0)->getLocStart(),
1546                           CE->getArg(NumArgs-1)->getLocEnd());
1547        return true;
1548      }
1549    }
1550    return false;
1551  }
1552
1553  case CXXTemporaryObjectExprClass:
1554  case CXXConstructExprClass:
1555    return false;
1556
1557  case ObjCMessageExprClass: {
1558    const ObjCMessageExpr *ME = cast<ObjCMessageExpr>(this);
1559    if (Ctx.getLangOptions().ObjCAutoRefCount &&
1560        ME->isInstanceMessage() &&
1561        !ME->getType()->isVoidType() &&
1562        ME->getSelector().getIdentifierInfoForSlot(0) &&
1563        ME->getSelector().getIdentifierInfoForSlot(0)
1564                                               ->getName().startswith("init")) {
1565      Loc = getExprLoc();
1566      R1 = ME->getSourceRange();
1567      return true;
1568    }
1569
1570    const ObjCMethodDecl *MD = ME->getMethodDecl();
1571    if (MD && MD->getAttr<WarnUnusedResultAttr>()) {
1572      Loc = getExprLoc();
1573      return true;
1574    }
1575    return false;
1576  }
1577
1578  case ObjCPropertyRefExprClass:
1579    Loc = getExprLoc();
1580    R1 = getSourceRange();
1581    return true;
1582
1583  case StmtExprClass: {
1584    // Statement exprs don't logically have side effects themselves, but are
1585    // sometimes used in macros in ways that give them a type that is unused.
1586    // For example ({ blah; foo(); }) will end up with a type if foo has a type.
1587    // however, if the result of the stmt expr is dead, we don't want to emit a
1588    // warning.
1589    const CompoundStmt *CS = cast<StmtExpr>(this)->getSubStmt();
1590    if (!CS->body_empty()) {
1591      if (const Expr *E = dyn_cast<Expr>(CS->body_back()))
1592        return E->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1593      if (const LabelStmt *Label = dyn_cast<LabelStmt>(CS->body_back()))
1594        if (const Expr *E = dyn_cast<Expr>(Label->getSubStmt()))
1595          return E->isUnusedResultAWarning(Loc, R1, R2, Ctx);
1596    }
1597
1598    if (getType()->isVoidType())
1599      return false;
1600    Loc = cast<StmtExpr>(this)->getLParenLoc();
1601    R1 = getSourceRange();
1602    return true;
1603  }
1604  case CStyleCastExprClass:
1605    // If this is an explicit cast to void, allow it.  People do this when they
1606    // think they know what they're doing :).
1607    if (getType()->isVoidType())
1608      return false;
1609    Loc = cast<CStyleCastExpr>(this)->getLParenLoc();
1610    R1 = cast<CStyleCastExpr>(this)->getSubExpr()->getSourceRange();
1611    return true;
1612  case CXXFunctionalCastExprClass: {
1613    if (getType()->isVoidType())
1614      return false;
1615    const CastExpr *CE = cast<CastExpr>(this);
1616
1617    // If this is a cast to void or a constructor conversion, check the operand.
1618    // Otherwise, the result of the cast is unused.
1619    if (CE->getCastKind() == CK_ToVoid ||
1620        CE->getCastKind() == CK_ConstructorConversion)
1621      return (cast<CastExpr>(this)->getSubExpr()
1622              ->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1623    Loc = cast<CXXFunctionalCastExpr>(this)->getTypeBeginLoc();
1624    R1 = cast<CXXFunctionalCastExpr>(this)->getSubExpr()->getSourceRange();
1625    return true;
1626  }
1627
1628  case ImplicitCastExprClass:
1629    // Check the operand, since implicit casts are inserted by Sema
1630    return (cast<ImplicitCastExpr>(this)
1631            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1632
1633  case CXXDefaultArgExprClass:
1634    return (cast<CXXDefaultArgExpr>(this)
1635            ->getExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1636
1637  case CXXNewExprClass:
1638    // FIXME: In theory, there might be new expressions that don't have side
1639    // effects (e.g. a placement new with an uninitialized POD).
1640  case CXXDeleteExprClass:
1641    return false;
1642  case CXXBindTemporaryExprClass:
1643    return (cast<CXXBindTemporaryExpr>(this)
1644            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1645  case ExprWithCleanupsClass:
1646    return (cast<ExprWithCleanups>(this)
1647            ->getSubExpr()->isUnusedResultAWarning(Loc, R1, R2, Ctx));
1648  }
1649}
1650
1651/// isOBJCGCCandidate - Check if an expression is objc gc'able.
1652/// returns true, if it is; false otherwise.
1653bool Expr::isOBJCGCCandidate(ASTContext &Ctx) const {
1654  const Expr *E = IgnoreParens();
1655  switch (E->getStmtClass()) {
1656  default:
1657    return false;
1658  case ObjCIvarRefExprClass:
1659    return true;
1660  case Expr::UnaryOperatorClass:
1661    return cast<UnaryOperator>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1662  case ImplicitCastExprClass:
1663    return cast<ImplicitCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1664  case MaterializeTemporaryExprClass:
1665    return cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr()
1666                                                      ->isOBJCGCCandidate(Ctx);
1667  case CStyleCastExprClass:
1668    return cast<CStyleCastExpr>(E)->getSubExpr()->isOBJCGCCandidate(Ctx);
1669  case DeclRefExprClass: {
1670    const Decl *D = cast<DeclRefExpr>(E)->getDecl();
1671    if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1672      if (VD->hasGlobalStorage())
1673        return true;
1674      QualType T = VD->getType();
1675      // dereferencing to a  pointer is always a gc'able candidate,
1676      // unless it is __weak.
1677      return T->isPointerType() &&
1678             (Ctx.getObjCGCAttrKind(T) != Qualifiers::Weak);
1679    }
1680    return false;
1681  }
1682  case MemberExprClass: {
1683    const MemberExpr *M = cast<MemberExpr>(E);
1684    return M->getBase()->isOBJCGCCandidate(Ctx);
1685  }
1686  case ArraySubscriptExprClass:
1687    return cast<ArraySubscriptExpr>(E)->getBase()->isOBJCGCCandidate(Ctx);
1688  }
1689}
1690
1691bool Expr::isBoundMemberFunction(ASTContext &Ctx) const {
1692  if (isTypeDependent())
1693    return false;
1694  return ClassifyLValue(Ctx) == Expr::LV_MemberFunction;
1695}
1696
1697QualType Expr::findBoundMemberType(const Expr *expr) {
1698  assert(expr->getType()->isSpecificPlaceholderType(BuiltinType::BoundMember));
1699
1700  // Bound member expressions are always one of these possibilities:
1701  //   x->m      x.m      x->*y      x.*y
1702  // (possibly parenthesized)
1703
1704  expr = expr->IgnoreParens();
1705  if (const MemberExpr *mem = dyn_cast<MemberExpr>(expr)) {
1706    assert(isa<CXXMethodDecl>(mem->getMemberDecl()));
1707    return mem->getMemberDecl()->getType();
1708  }
1709
1710  if (const BinaryOperator *op = dyn_cast<BinaryOperator>(expr)) {
1711    QualType type = op->getRHS()->getType()->castAs<MemberPointerType>()
1712                      ->getPointeeType();
1713    assert(type->isFunctionType());
1714    return type;
1715  }
1716
1717  assert(isa<UnresolvedMemberExpr>(expr));
1718  return QualType();
1719}
1720
1721static Expr::CanThrowResult MergeCanThrow(Expr::CanThrowResult CT1,
1722                                          Expr::CanThrowResult CT2) {
1723  // CanThrowResult constants are ordered so that the maximum is the correct
1724  // merge result.
1725  return CT1 > CT2 ? CT1 : CT2;
1726}
1727
1728static Expr::CanThrowResult CanSubExprsThrow(ASTContext &C, const Expr *CE) {
1729  Expr *E = const_cast<Expr*>(CE);
1730  Expr::CanThrowResult R = Expr::CT_Cannot;
1731  for (Expr::child_range I = E->children(); I && R != Expr::CT_Can; ++I) {
1732    R = MergeCanThrow(R, cast<Expr>(*I)->CanThrow(C));
1733  }
1734  return R;
1735}
1736
1737static Expr::CanThrowResult CanCalleeThrow(ASTContext &Ctx, const Expr *E,
1738                                           const Decl *D,
1739                                           bool NullThrows = true) {
1740  if (!D)
1741    return NullThrows ? Expr::CT_Can : Expr::CT_Cannot;
1742
1743  // See if we can get a function type from the decl somehow.
1744  const ValueDecl *VD = dyn_cast<ValueDecl>(D);
1745  if (!VD) // If we have no clue what we're calling, assume the worst.
1746    return Expr::CT_Can;
1747
1748  // As an extension, we assume that __attribute__((nothrow)) functions don't
1749  // throw.
1750  if (isa<FunctionDecl>(D) && D->hasAttr<NoThrowAttr>())
1751    return Expr::CT_Cannot;
1752
1753  QualType T = VD->getType();
1754  const FunctionProtoType *FT;
1755  if ((FT = T->getAs<FunctionProtoType>())) {
1756  } else if (const PointerType *PT = T->getAs<PointerType>())
1757    FT = PT->getPointeeType()->getAs<FunctionProtoType>();
1758  else if (const ReferenceType *RT = T->getAs<ReferenceType>())
1759    FT = RT->getPointeeType()->getAs<FunctionProtoType>();
1760  else if (const MemberPointerType *MT = T->getAs<MemberPointerType>())
1761    FT = MT->getPointeeType()->getAs<FunctionProtoType>();
1762  else if (const BlockPointerType *BT = T->getAs<BlockPointerType>())
1763    FT = BT->getPointeeType()->getAs<FunctionProtoType>();
1764
1765  if (!FT)
1766    return Expr::CT_Can;
1767
1768  if (FT->getExceptionSpecType() == EST_Delayed) {
1769    assert(isa<CXXConstructorDecl>(D) &&
1770           "only constructor exception specs can be unknown");
1771    Ctx.getDiagnostics().Report(E->getLocStart(),
1772                                diag::err_exception_spec_unknown)
1773      << E->getSourceRange();
1774    return Expr::CT_Can;
1775  }
1776
1777  return FT->isNothrow(Ctx) ? Expr::CT_Cannot : Expr::CT_Can;
1778}
1779
1780static Expr::CanThrowResult CanDynamicCastThrow(const CXXDynamicCastExpr *DC) {
1781  if (DC->isTypeDependent())
1782    return Expr::CT_Dependent;
1783
1784  if (!DC->getTypeAsWritten()->isReferenceType())
1785    return Expr::CT_Cannot;
1786
1787  if (DC->getSubExpr()->isTypeDependent())
1788    return Expr::CT_Dependent;
1789
1790  return DC->getCastKind() == clang::CK_Dynamic? Expr::CT_Can : Expr::CT_Cannot;
1791}
1792
1793static Expr::CanThrowResult CanTypeidThrow(ASTContext &C,
1794                                           const CXXTypeidExpr *DC) {
1795  if (DC->isTypeOperand())
1796    return Expr::CT_Cannot;
1797
1798  Expr *Op = DC->getExprOperand();
1799  if (Op->isTypeDependent())
1800    return Expr::CT_Dependent;
1801
1802  const RecordType *RT = Op->getType()->getAs<RecordType>();
1803  if (!RT)
1804    return Expr::CT_Cannot;
1805
1806  if (!cast<CXXRecordDecl>(RT->getDecl())->isPolymorphic())
1807    return Expr::CT_Cannot;
1808
1809  if (Op->Classify(C).isPRValue())
1810    return Expr::CT_Cannot;
1811
1812  return Expr::CT_Can;
1813}
1814
1815Expr::CanThrowResult Expr::CanThrow(ASTContext &C) const {
1816  // C++ [expr.unary.noexcept]p3:
1817  //   [Can throw] if in a potentially-evaluated context the expression would
1818  //   contain:
1819  switch (getStmtClass()) {
1820  case CXXThrowExprClass:
1821    //   - a potentially evaluated throw-expression
1822    return CT_Can;
1823
1824  case CXXDynamicCastExprClass: {
1825    //   - a potentially evaluated dynamic_cast expression dynamic_cast<T>(v),
1826    //     where T is a reference type, that requires a run-time check
1827    CanThrowResult CT = CanDynamicCastThrow(cast<CXXDynamicCastExpr>(this));
1828    if (CT == CT_Can)
1829      return CT;
1830    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1831  }
1832
1833  case CXXTypeidExprClass:
1834    //   - a potentially evaluated typeid expression applied to a glvalue
1835    //     expression whose type is a polymorphic class type
1836    return CanTypeidThrow(C, cast<CXXTypeidExpr>(this));
1837
1838    //   - a potentially evaluated call to a function, member function, function
1839    //     pointer, or member function pointer that does not have a non-throwing
1840    //     exception-specification
1841  case CallExprClass:
1842  case CXXOperatorCallExprClass:
1843  case CXXMemberCallExprClass: {
1844    const CallExpr *CE = cast<CallExpr>(this);
1845    CanThrowResult CT;
1846    if (isTypeDependent())
1847      CT = CT_Dependent;
1848    else if (isa<CXXPseudoDestructorExpr>(CE->getCallee()->IgnoreParens()))
1849      CT = CT_Cannot;
1850    else
1851      CT = CanCalleeThrow(C, this, CE->getCalleeDecl());
1852    if (CT == CT_Can)
1853      return CT;
1854    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1855  }
1856
1857  case CXXConstructExprClass:
1858  case CXXTemporaryObjectExprClass: {
1859    CanThrowResult CT = CanCalleeThrow(C, this,
1860        cast<CXXConstructExpr>(this)->getConstructor());
1861    if (CT == CT_Can)
1862      return CT;
1863    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1864  }
1865
1866  case CXXNewExprClass: {
1867    CanThrowResult CT;
1868    if (isTypeDependent())
1869      CT = CT_Dependent;
1870    else
1871      CT = MergeCanThrow(
1872        CanCalleeThrow(C, this, cast<CXXNewExpr>(this)->getOperatorNew()),
1873        CanCalleeThrow(C, this, cast<CXXNewExpr>(this)->getConstructor(),
1874                       /*NullThrows*/false));
1875    if (CT == CT_Can)
1876      return CT;
1877    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1878  }
1879
1880  case CXXDeleteExprClass: {
1881    CanThrowResult CT;
1882    QualType DTy = cast<CXXDeleteExpr>(this)->getDestroyedType();
1883    if (DTy.isNull() || DTy->isDependentType()) {
1884      CT = CT_Dependent;
1885    } else {
1886      CT = CanCalleeThrow(C, this,
1887                          cast<CXXDeleteExpr>(this)->getOperatorDelete());
1888      if (const RecordType *RT = DTy->getAs<RecordType>()) {
1889        const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1890        CT = MergeCanThrow(CT, CanCalleeThrow(C, this, RD->getDestructor()));
1891      }
1892      if (CT == CT_Can)
1893        return CT;
1894    }
1895    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1896  }
1897
1898  case CXXBindTemporaryExprClass: {
1899    // The bound temporary has to be destroyed again, which might throw.
1900    CanThrowResult CT = CanCalleeThrow(C, this,
1901      cast<CXXBindTemporaryExpr>(this)->getTemporary()->getDestructor());
1902    if (CT == CT_Can)
1903      return CT;
1904    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1905  }
1906
1907    // ObjC message sends are like function calls, but never have exception
1908    // specs.
1909  case ObjCMessageExprClass:
1910  case ObjCPropertyRefExprClass:
1911    return CT_Can;
1912
1913    // Many other things have subexpressions, so we have to test those.
1914    // Some are simple:
1915  case ParenExprClass:
1916  case MemberExprClass:
1917  case CXXReinterpretCastExprClass:
1918  case CXXConstCastExprClass:
1919  case ConditionalOperatorClass:
1920  case CompoundLiteralExprClass:
1921  case ExtVectorElementExprClass:
1922  case InitListExprClass:
1923  case DesignatedInitExprClass:
1924  case ParenListExprClass:
1925  case VAArgExprClass:
1926  case CXXDefaultArgExprClass:
1927  case ExprWithCleanupsClass:
1928  case ObjCIvarRefExprClass:
1929  case ObjCIsaExprClass:
1930  case ShuffleVectorExprClass:
1931    return CanSubExprsThrow(C, this);
1932
1933    // Some might be dependent for other reasons.
1934  case UnaryOperatorClass:
1935  case ArraySubscriptExprClass:
1936  case ImplicitCastExprClass:
1937  case CStyleCastExprClass:
1938  case CXXStaticCastExprClass:
1939  case CXXFunctionalCastExprClass:
1940  case BinaryOperatorClass:
1941  case CompoundAssignOperatorClass:
1942  case MaterializeTemporaryExprClass: {
1943    CanThrowResult CT = isTypeDependent() ? CT_Dependent : CT_Cannot;
1944    return MergeCanThrow(CT, CanSubExprsThrow(C, this));
1945  }
1946
1947    // FIXME: We should handle StmtExpr, but that opens a MASSIVE can of worms.
1948  case StmtExprClass:
1949    return CT_Can;
1950
1951  case ChooseExprClass:
1952    if (isTypeDependent() || isValueDependent())
1953      return CT_Dependent;
1954    return cast<ChooseExpr>(this)->getChosenSubExpr(C)->CanThrow(C);
1955
1956  case GenericSelectionExprClass:
1957    if (cast<GenericSelectionExpr>(this)->isResultDependent())
1958      return CT_Dependent;
1959    return cast<GenericSelectionExpr>(this)->getResultExpr()->CanThrow(C);
1960
1961    // Some expressions are always dependent.
1962  case DependentScopeDeclRefExprClass:
1963  case CXXUnresolvedConstructExprClass:
1964  case CXXDependentScopeMemberExprClass:
1965    return CT_Dependent;
1966
1967  default:
1968    // All other expressions don't have subexpressions, or else they are
1969    // unevaluated.
1970    return CT_Cannot;
1971  }
1972}
1973
1974Expr* Expr::IgnoreParens() {
1975  Expr* E = this;
1976  while (true) {
1977    if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
1978      E = P->getSubExpr();
1979      continue;
1980    }
1981    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
1982      if (P->getOpcode() == UO_Extension) {
1983        E = P->getSubExpr();
1984        continue;
1985      }
1986    }
1987    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
1988      if (!P->isResultDependent()) {
1989        E = P->getResultExpr();
1990        continue;
1991      }
1992    }
1993    return E;
1994  }
1995}
1996
1997/// IgnoreParenCasts - Ignore parentheses and casts.  Strip off any ParenExpr
1998/// or CastExprs or ImplicitCastExprs, returning their operand.
1999Expr *Expr::IgnoreParenCasts() {
2000  Expr *E = this;
2001  while (true) {
2002    if (ParenExpr* P = dyn_cast<ParenExpr>(E)) {
2003      E = P->getSubExpr();
2004      continue;
2005    }
2006    if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2007      E = P->getSubExpr();
2008      continue;
2009    }
2010    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2011      if (P->getOpcode() == UO_Extension) {
2012        E = P->getSubExpr();
2013        continue;
2014      }
2015    }
2016    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2017      if (!P->isResultDependent()) {
2018        E = P->getResultExpr();
2019        continue;
2020      }
2021    }
2022    if (MaterializeTemporaryExpr *Materialize
2023                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2024      E = Materialize->GetTemporaryExpr();
2025      continue;
2026    }
2027
2028    return E;
2029  }
2030}
2031
2032/// IgnoreParenLValueCasts - Ignore parentheses and lvalue-to-rvalue
2033/// casts.  This is intended purely as a temporary workaround for code
2034/// that hasn't yet been rewritten to do the right thing about those
2035/// casts, and may disappear along with the last internal use.
2036Expr *Expr::IgnoreParenLValueCasts() {
2037  Expr *E = this;
2038  while (true) {
2039    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2040      E = P->getSubExpr();
2041      continue;
2042    } else if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2043      if (P->getCastKind() == CK_LValueToRValue) {
2044        E = P->getSubExpr();
2045        continue;
2046      }
2047    } else if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2048      if (P->getOpcode() == UO_Extension) {
2049        E = P->getSubExpr();
2050        continue;
2051      }
2052    } else if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2053      if (!P->isResultDependent()) {
2054        E = P->getResultExpr();
2055        continue;
2056      }
2057    } else if (MaterializeTemporaryExpr *Materialize
2058                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2059      E = Materialize->GetTemporaryExpr();
2060      continue;
2061    }
2062    break;
2063  }
2064  return E;
2065}
2066
2067Expr *Expr::IgnoreParenImpCasts() {
2068  Expr *E = this;
2069  while (true) {
2070    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2071      E = P->getSubExpr();
2072      continue;
2073    }
2074    if (ImplicitCastExpr *P = dyn_cast<ImplicitCastExpr>(E)) {
2075      E = P->getSubExpr();
2076      continue;
2077    }
2078    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2079      if (P->getOpcode() == UO_Extension) {
2080        E = P->getSubExpr();
2081        continue;
2082      }
2083    }
2084    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2085      if (!P->isResultDependent()) {
2086        E = P->getResultExpr();
2087        continue;
2088      }
2089    }
2090    if (MaterializeTemporaryExpr *Materialize
2091                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2092      E = Materialize->GetTemporaryExpr();
2093      continue;
2094    }
2095    return E;
2096  }
2097}
2098
2099Expr *Expr::IgnoreConversionOperator() {
2100  if (CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(this)) {
2101    if (MCE->getMethodDecl() && isa<CXXConversionDecl>(MCE->getMethodDecl()))
2102      return MCE->getImplicitObjectArgument();
2103  }
2104  return this;
2105}
2106
2107/// IgnoreParenNoopCasts - Ignore parentheses and casts that do not change the
2108/// value (including ptr->int casts of the same size).  Strip off any
2109/// ParenExpr or CastExprs, returning their operand.
2110Expr *Expr::IgnoreParenNoopCasts(ASTContext &Ctx) {
2111  Expr *E = this;
2112  while (true) {
2113    if (ParenExpr *P = dyn_cast<ParenExpr>(E)) {
2114      E = P->getSubExpr();
2115      continue;
2116    }
2117
2118    if (CastExpr *P = dyn_cast<CastExpr>(E)) {
2119      // We ignore integer <-> casts that are of the same width, ptr<->ptr and
2120      // ptr<->int casts of the same width.  We also ignore all identity casts.
2121      Expr *SE = P->getSubExpr();
2122
2123      if (Ctx.hasSameUnqualifiedType(E->getType(), SE->getType())) {
2124        E = SE;
2125        continue;
2126      }
2127
2128      if ((E->getType()->isPointerType() ||
2129           E->getType()->isIntegralType(Ctx)) &&
2130          (SE->getType()->isPointerType() ||
2131           SE->getType()->isIntegralType(Ctx)) &&
2132          Ctx.getTypeSize(E->getType()) == Ctx.getTypeSize(SE->getType())) {
2133        E = SE;
2134        continue;
2135      }
2136    }
2137
2138    if (UnaryOperator* P = dyn_cast<UnaryOperator>(E)) {
2139      if (P->getOpcode() == UO_Extension) {
2140        E = P->getSubExpr();
2141        continue;
2142      }
2143    }
2144
2145    if (GenericSelectionExpr* P = dyn_cast<GenericSelectionExpr>(E)) {
2146      if (!P->isResultDependent()) {
2147        E = P->getResultExpr();
2148        continue;
2149      }
2150    }
2151
2152    return E;
2153  }
2154}
2155
2156bool Expr::isDefaultArgument() const {
2157  const Expr *E = this;
2158  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
2159    E = M->GetTemporaryExpr();
2160
2161  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
2162    E = ICE->getSubExprAsWritten();
2163
2164  return isa<CXXDefaultArgExpr>(E);
2165}
2166
2167/// \brief Skip over any no-op casts and any temporary-binding
2168/// expressions.
2169static const Expr *skipTemporaryBindingsNoOpCastsAndParens(const Expr *E) {
2170  if (const MaterializeTemporaryExpr *M = dyn_cast<MaterializeTemporaryExpr>(E))
2171    E = M->GetTemporaryExpr();
2172
2173  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2174    if (ICE->getCastKind() == CK_NoOp)
2175      E = ICE->getSubExpr();
2176    else
2177      break;
2178  }
2179
2180  while (const CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(E))
2181    E = BE->getSubExpr();
2182
2183  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2184    if (ICE->getCastKind() == CK_NoOp)
2185      E = ICE->getSubExpr();
2186    else
2187      break;
2188  }
2189
2190  return E->IgnoreParens();
2191}
2192
2193/// isTemporaryObject - Determines if this expression produces a
2194/// temporary of the given class type.
2195bool Expr::isTemporaryObject(ASTContext &C, const CXXRecordDecl *TempTy) const {
2196  if (!C.hasSameUnqualifiedType(getType(), C.getTypeDeclType(TempTy)))
2197    return false;
2198
2199  const Expr *E = skipTemporaryBindingsNoOpCastsAndParens(this);
2200
2201  // Temporaries are by definition pr-values of class type.
2202  if (!E->Classify(C).isPRValue()) {
2203    // In this context, property reference is a message call and is pr-value.
2204    if (!isa<ObjCPropertyRefExpr>(E))
2205      return false;
2206  }
2207
2208  // Black-list a few cases which yield pr-values of class type that don't
2209  // refer to temporaries of that type:
2210
2211  // - implicit derived-to-base conversions
2212  if (isa<ImplicitCastExpr>(E)) {
2213    switch (cast<ImplicitCastExpr>(E)->getCastKind()) {
2214    case CK_DerivedToBase:
2215    case CK_UncheckedDerivedToBase:
2216      return false;
2217    default:
2218      break;
2219    }
2220  }
2221
2222  // - member expressions (all)
2223  if (isa<MemberExpr>(E))
2224    return false;
2225
2226  // - opaque values (all)
2227  if (isa<OpaqueValueExpr>(E))
2228    return false;
2229
2230  return true;
2231}
2232
2233bool Expr::isImplicitCXXThis() const {
2234  const Expr *E = this;
2235
2236  // Strip away parentheses and casts we don't care about.
2237  while (true) {
2238    if (const ParenExpr *Paren = dyn_cast<ParenExpr>(E)) {
2239      E = Paren->getSubExpr();
2240      continue;
2241    }
2242
2243    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2244      if (ICE->getCastKind() == CK_NoOp ||
2245          ICE->getCastKind() == CK_LValueToRValue ||
2246          ICE->getCastKind() == CK_DerivedToBase ||
2247          ICE->getCastKind() == CK_UncheckedDerivedToBase) {
2248        E = ICE->getSubExpr();
2249        continue;
2250      }
2251    }
2252
2253    if (const UnaryOperator* UnOp = dyn_cast<UnaryOperator>(E)) {
2254      if (UnOp->getOpcode() == UO_Extension) {
2255        E = UnOp->getSubExpr();
2256        continue;
2257      }
2258    }
2259
2260    if (const MaterializeTemporaryExpr *M
2261                                      = dyn_cast<MaterializeTemporaryExpr>(E)) {
2262      E = M->GetTemporaryExpr();
2263      continue;
2264    }
2265
2266    break;
2267  }
2268
2269  if (const CXXThisExpr *This = dyn_cast<CXXThisExpr>(E))
2270    return This->isImplicit();
2271
2272  return false;
2273}
2274
2275/// hasAnyTypeDependentArguments - Determines if any of the expressions
2276/// in Exprs is type-dependent.
2277bool Expr::hasAnyTypeDependentArguments(Expr** Exprs, unsigned NumExprs) {
2278  for (unsigned I = 0; I < NumExprs; ++I)
2279    if (Exprs[I]->isTypeDependent())
2280      return true;
2281
2282  return false;
2283}
2284
2285/// hasAnyValueDependentArguments - Determines if any of the expressions
2286/// in Exprs is value-dependent.
2287bool Expr::hasAnyValueDependentArguments(Expr** Exprs, unsigned NumExprs) {
2288  for (unsigned I = 0; I < NumExprs; ++I)
2289    if (Exprs[I]->isValueDependent())
2290      return true;
2291
2292  return false;
2293}
2294
2295bool Expr::isConstantInitializer(ASTContext &Ctx, bool IsForRef) const {
2296  // This function is attempting whether an expression is an initializer
2297  // which can be evaluated at compile-time.  isEvaluatable handles most
2298  // of the cases, but it can't deal with some initializer-specific
2299  // expressions, and it can't deal with aggregates; we deal with those here,
2300  // and fall back to isEvaluatable for the other cases.
2301
2302  // If we ever capture reference-binding directly in the AST, we can
2303  // kill the second parameter.
2304
2305  if (IsForRef) {
2306    EvalResult Result;
2307    return EvaluateAsLValue(Result, Ctx) && !Result.HasSideEffects;
2308  }
2309
2310  switch (getStmtClass()) {
2311  default: break;
2312  case StringLiteralClass:
2313  case ObjCStringLiteralClass:
2314  case ObjCEncodeExprClass:
2315    return true;
2316  case CXXTemporaryObjectExprClass:
2317  case CXXConstructExprClass: {
2318    const CXXConstructExpr *CE = cast<CXXConstructExpr>(this);
2319
2320    // Only if it's
2321    // 1) an application of the trivial default constructor or
2322    if (!CE->getConstructor()->isTrivial()) return false;
2323    if (!CE->getNumArgs()) return true;
2324
2325    // 2) an elidable trivial copy construction of an operand which is
2326    //    itself a constant initializer.  Note that we consider the
2327    //    operand on its own, *not* as a reference binding.
2328    return CE->isElidable() &&
2329           CE->getArg(0)->isConstantInitializer(Ctx, false);
2330  }
2331  case CompoundLiteralExprClass: {
2332    // This handles gcc's extension that allows global initializers like
2333    // "struct x {int x;} x = (struct x) {};".
2334    // FIXME: This accepts other cases it shouldn't!
2335    const Expr *Exp = cast<CompoundLiteralExpr>(this)->getInitializer();
2336    return Exp->isConstantInitializer(Ctx, false);
2337  }
2338  case InitListExprClass: {
2339    // FIXME: This doesn't deal with fields with reference types correctly.
2340    // FIXME: This incorrectly allows pointers cast to integers to be assigned
2341    // to bitfields.
2342    const InitListExpr *Exp = cast<InitListExpr>(this);
2343    unsigned numInits = Exp->getNumInits();
2344    for (unsigned i = 0; i < numInits; i++) {
2345      if (!Exp->getInit(i)->isConstantInitializer(Ctx, false))
2346        return false;
2347    }
2348    return true;
2349  }
2350  case ImplicitValueInitExprClass:
2351    return true;
2352  case ParenExprClass:
2353    return cast<ParenExpr>(this)->getSubExpr()
2354      ->isConstantInitializer(Ctx, IsForRef);
2355  case GenericSelectionExprClass:
2356    if (cast<GenericSelectionExpr>(this)->isResultDependent())
2357      return false;
2358    return cast<GenericSelectionExpr>(this)->getResultExpr()
2359      ->isConstantInitializer(Ctx, IsForRef);
2360  case ChooseExprClass:
2361    return cast<ChooseExpr>(this)->getChosenSubExpr(Ctx)
2362      ->isConstantInitializer(Ctx, IsForRef);
2363  case UnaryOperatorClass: {
2364    const UnaryOperator* Exp = cast<UnaryOperator>(this);
2365    if (Exp->getOpcode() == UO_Extension)
2366      return Exp->getSubExpr()->isConstantInitializer(Ctx, false);
2367    break;
2368  }
2369  case BinaryOperatorClass: {
2370    // Special case &&foo - &&bar.  It would be nice to generalize this somehow
2371    // but this handles the common case.
2372    const BinaryOperator *Exp = cast<BinaryOperator>(this);
2373    if (Exp->getOpcode() == BO_Sub &&
2374        isa<AddrLabelExpr>(Exp->getLHS()->IgnoreParenNoopCasts(Ctx)) &&
2375        isa<AddrLabelExpr>(Exp->getRHS()->IgnoreParenNoopCasts(Ctx)))
2376      return true;
2377    break;
2378  }
2379  case CXXFunctionalCastExprClass:
2380  case CXXStaticCastExprClass:
2381  case ImplicitCastExprClass:
2382  case CStyleCastExprClass:
2383    // Handle casts with a destination that's a struct or union; this
2384    // deals with both the gcc no-op struct cast extension and the
2385    // cast-to-union extension.
2386    if (getType()->isRecordType())
2387      return cast<CastExpr>(this)->getSubExpr()
2388        ->isConstantInitializer(Ctx, false);
2389
2390    // Integer->integer casts can be handled here, which is important for
2391    // things like (int)(&&x-&&y).  Scary but true.
2392    if (getType()->isIntegerType() &&
2393        cast<CastExpr>(this)->getSubExpr()->getType()->isIntegerType())
2394      return cast<CastExpr>(this)->getSubExpr()
2395        ->isConstantInitializer(Ctx, false);
2396
2397    break;
2398
2399  case MaterializeTemporaryExprClass:
2400    return llvm::cast<MaterializeTemporaryExpr>(this)->GetTemporaryExpr()
2401                                            ->isConstantInitializer(Ctx, false);
2402  }
2403  return isEvaluatable(Ctx);
2404}
2405
2406/// isNullPointerConstant - C99 6.3.2.3p3 - Return whether this is a null
2407/// pointer constant or not, as well as the specific kind of constant detected.
2408/// Null pointer constants can be integer constant expressions with the
2409/// value zero, casts of zero to void*, nullptr (C++0X), or __null
2410/// (a GNU extension).
2411Expr::NullPointerConstantKind
2412Expr::isNullPointerConstant(ASTContext &Ctx,
2413                            NullPointerConstantValueDependence NPC) const {
2414  if (isValueDependent()) {
2415    switch (NPC) {
2416    case NPC_NeverValueDependent:
2417      assert(false && "Unexpected value dependent expression!");
2418      // If the unthinkable happens, fall through to the safest alternative.
2419
2420    case NPC_ValueDependentIsNull:
2421      if (isTypeDependent() || getType()->isIntegralType(Ctx))
2422        return NPCK_ZeroInteger;
2423      else
2424        return NPCK_NotNull;
2425
2426    case NPC_ValueDependentIsNotNull:
2427      return NPCK_NotNull;
2428    }
2429  }
2430
2431  // Strip off a cast to void*, if it exists. Except in C++.
2432  if (const ExplicitCastExpr *CE = dyn_cast<ExplicitCastExpr>(this)) {
2433    if (!Ctx.getLangOptions().CPlusPlus) {
2434      // Check that it is a cast to void*.
2435      if (const PointerType *PT = CE->getType()->getAs<PointerType>()) {
2436        QualType Pointee = PT->getPointeeType();
2437        if (!Pointee.hasQualifiers() &&
2438            Pointee->isVoidType() &&                              // to void*
2439            CE->getSubExpr()->getType()->isIntegerType())         // from int.
2440          return CE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2441      }
2442    }
2443  } else if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(this)) {
2444    // Ignore the ImplicitCastExpr type entirely.
2445    return ICE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2446  } else if (const ParenExpr *PE = dyn_cast<ParenExpr>(this)) {
2447    // Accept ((void*)0) as a null pointer constant, as many other
2448    // implementations do.
2449    return PE->getSubExpr()->isNullPointerConstant(Ctx, NPC);
2450  } else if (const GenericSelectionExpr *GE =
2451               dyn_cast<GenericSelectionExpr>(this)) {
2452    return GE->getResultExpr()->isNullPointerConstant(Ctx, NPC);
2453  } else if (const CXXDefaultArgExpr *DefaultArg
2454               = dyn_cast<CXXDefaultArgExpr>(this)) {
2455    // See through default argument expressions
2456    return DefaultArg->getExpr()->isNullPointerConstant(Ctx, NPC);
2457  } else if (isa<GNUNullExpr>(this)) {
2458    // The GNU __null extension is always a null pointer constant.
2459    return NPCK_GNUNull;
2460  } else if (const MaterializeTemporaryExpr *M
2461                                   = dyn_cast<MaterializeTemporaryExpr>(this)) {
2462    return M->GetTemporaryExpr()->isNullPointerConstant(Ctx, NPC);
2463  }
2464
2465  // C++0x nullptr_t is always a null pointer constant.
2466  if (getType()->isNullPtrType())
2467    return NPCK_CXX0X_nullptr;
2468
2469  if (const RecordType *UT = getType()->getAsUnionType())
2470    if (UT && UT->getDecl()->hasAttr<TransparentUnionAttr>())
2471      if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(this)){
2472        const Expr *InitExpr = CLE->getInitializer();
2473        if (const InitListExpr *ILE = dyn_cast<InitListExpr>(InitExpr))
2474          return ILE->getInit(0)->isNullPointerConstant(Ctx, NPC);
2475      }
2476  // This expression must be an integer type.
2477  if (!getType()->isIntegerType() ||
2478      (Ctx.getLangOptions().CPlusPlus && getType()->isEnumeralType()))
2479    return NPCK_NotNull;
2480
2481  // If we have an integer constant expression, we need to *evaluate* it and
2482  // test for the value 0.
2483  llvm::APSInt Result;
2484  bool IsNull = isIntegerConstantExpr(Result, Ctx) && Result == 0;
2485
2486  return (IsNull ? NPCK_ZeroInteger : NPCK_NotNull);
2487}
2488
2489/// \brief If this expression is an l-value for an Objective C
2490/// property, find the underlying property reference expression.
2491const ObjCPropertyRefExpr *Expr::getObjCProperty() const {
2492  const Expr *E = this;
2493  while (true) {
2494    assert((E->getValueKind() == VK_LValue &&
2495            E->getObjectKind() == OK_ObjCProperty) &&
2496           "expression is not a property reference");
2497    E = E->IgnoreParenCasts();
2498    if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
2499      if (BO->getOpcode() == BO_Comma) {
2500        E = BO->getRHS();
2501        continue;
2502      }
2503    }
2504
2505    break;
2506  }
2507
2508  return cast<ObjCPropertyRefExpr>(E);
2509}
2510
2511FieldDecl *Expr::getBitField() {
2512  Expr *E = this->IgnoreParens();
2513
2514  while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2515    if (ICE->getCastKind() == CK_LValueToRValue ||
2516        (ICE->getValueKind() != VK_RValue && ICE->getCastKind() == CK_NoOp))
2517      E = ICE->getSubExpr()->IgnoreParens();
2518    else
2519      break;
2520  }
2521
2522  if (MemberExpr *MemRef = dyn_cast<MemberExpr>(E))
2523    if (FieldDecl *Field = dyn_cast<FieldDecl>(MemRef->getMemberDecl()))
2524      if (Field->isBitField())
2525        return Field;
2526
2527  if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E))
2528    if (FieldDecl *Field = dyn_cast<FieldDecl>(DeclRef->getDecl()))
2529      if (Field->isBitField())
2530        return Field;
2531
2532  if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E)) {
2533    if (BinOp->isAssignmentOp() && BinOp->getLHS())
2534      return BinOp->getLHS()->getBitField();
2535
2536    if (BinOp->getOpcode() == BO_Comma && BinOp->getRHS())
2537      return BinOp->getRHS()->getBitField();
2538  }
2539
2540  return 0;
2541}
2542
2543bool Expr::refersToVectorElement() const {
2544  const Expr *E = this->IgnoreParens();
2545
2546  while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
2547    if (ICE->getValueKind() != VK_RValue &&
2548        ICE->getCastKind() == CK_NoOp)
2549      E = ICE->getSubExpr()->IgnoreParens();
2550    else
2551      break;
2552  }
2553
2554  if (const ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(E))
2555    return ASE->getBase()->getType()->isVectorType();
2556
2557  if (isa<ExtVectorElementExpr>(E))
2558    return true;
2559
2560  return false;
2561}
2562
2563/// isArrow - Return true if the base expression is a pointer to vector,
2564/// return false if the base expression is a vector.
2565bool ExtVectorElementExpr::isArrow() const {
2566  return getBase()->getType()->isPointerType();
2567}
2568
2569unsigned ExtVectorElementExpr::getNumElements() const {
2570  if (const VectorType *VT = getType()->getAs<VectorType>())
2571    return VT->getNumElements();
2572  return 1;
2573}
2574
2575/// containsDuplicateElements - Return true if any element access is repeated.
2576bool ExtVectorElementExpr::containsDuplicateElements() const {
2577  // FIXME: Refactor this code to an accessor on the AST node which returns the
2578  // "type" of component access, and share with code below and in Sema.
2579  llvm::StringRef Comp = Accessor->getName();
2580
2581  // Halving swizzles do not contain duplicate elements.
2582  if (Comp == "hi" || Comp == "lo" || Comp == "even" || Comp == "odd")
2583    return false;
2584
2585  // Advance past s-char prefix on hex swizzles.
2586  if (Comp[0] == 's' || Comp[0] == 'S')
2587    Comp = Comp.substr(1);
2588
2589  for (unsigned i = 0, e = Comp.size(); i != e; ++i)
2590    if (Comp.substr(i + 1).find(Comp[i]) != llvm::StringRef::npos)
2591        return true;
2592
2593  return false;
2594}
2595
2596/// getEncodedElementAccess - We encode the fields as a llvm ConstantArray.
2597void ExtVectorElementExpr::getEncodedElementAccess(
2598                                  llvm::SmallVectorImpl<unsigned> &Elts) const {
2599  llvm::StringRef Comp = Accessor->getName();
2600  if (Comp[0] == 's' || Comp[0] == 'S')
2601    Comp = Comp.substr(1);
2602
2603  bool isHi =   Comp == "hi";
2604  bool isLo =   Comp == "lo";
2605  bool isEven = Comp == "even";
2606  bool isOdd  = Comp == "odd";
2607
2608  for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
2609    uint64_t Index;
2610
2611    if (isHi)
2612      Index = e + i;
2613    else if (isLo)
2614      Index = i;
2615    else if (isEven)
2616      Index = 2 * i;
2617    else if (isOdd)
2618      Index = 2 * i + 1;
2619    else
2620      Index = ExtVectorType::getAccessorIdx(Comp[i]);
2621
2622    Elts.push_back(Index);
2623  }
2624}
2625
2626ObjCMessageExpr::ObjCMessageExpr(QualType T,
2627                                 ExprValueKind VK,
2628                                 SourceLocation LBracLoc,
2629                                 SourceLocation SuperLoc,
2630                                 bool IsInstanceSuper,
2631                                 QualType SuperType,
2632                                 Selector Sel,
2633                                 SourceLocation SelLoc,
2634                                 ObjCMethodDecl *Method,
2635                                 Expr **Args, unsigned NumArgs,
2636                                 SourceLocation RBracLoc)
2637  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary,
2638         /*TypeDependent=*/false, /*ValueDependent=*/false,
2639         /*InstantiationDependent=*/false,
2640         /*ContainsUnexpandedParameterPack=*/false),
2641    NumArgs(NumArgs), Kind(IsInstanceSuper? SuperInstance : SuperClass),
2642    HasMethod(Method != 0), IsDelegateInitCall(false), SuperLoc(SuperLoc),
2643    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2644                                                       : Sel.getAsOpaquePtr())),
2645    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2646{
2647  setReceiverPointer(SuperType.getAsOpaquePtr());
2648  if (NumArgs)
2649    memcpy(getArgs(), Args, NumArgs * sizeof(Expr *));
2650}
2651
2652ObjCMessageExpr::ObjCMessageExpr(QualType T,
2653                                 ExprValueKind VK,
2654                                 SourceLocation LBracLoc,
2655                                 TypeSourceInfo *Receiver,
2656                                 Selector Sel,
2657                                 SourceLocation SelLoc,
2658                                 ObjCMethodDecl *Method,
2659                                 Expr **Args, unsigned NumArgs,
2660                                 SourceLocation RBracLoc)
2661  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, T->isDependentType(),
2662         T->isDependentType(), T->isInstantiationDependentType(),
2663         T->containsUnexpandedParameterPack()),
2664    NumArgs(NumArgs), Kind(Class),
2665    HasMethod(Method != 0), IsDelegateInitCall(false),
2666    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2667                                                       : Sel.getAsOpaquePtr())),
2668    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2669{
2670  setReceiverPointer(Receiver);
2671  Expr **MyArgs = getArgs();
2672  for (unsigned I = 0; I != NumArgs; ++I) {
2673    if (Args[I]->isTypeDependent())
2674      ExprBits.TypeDependent = true;
2675    if (Args[I]->isValueDependent())
2676      ExprBits.ValueDependent = true;
2677    if (Args[I]->isInstantiationDependent())
2678      ExprBits.InstantiationDependent = true;
2679    if (Args[I]->containsUnexpandedParameterPack())
2680      ExprBits.ContainsUnexpandedParameterPack = true;
2681
2682    MyArgs[I] = Args[I];
2683  }
2684}
2685
2686ObjCMessageExpr::ObjCMessageExpr(QualType T,
2687                                 ExprValueKind VK,
2688                                 SourceLocation LBracLoc,
2689                                 Expr *Receiver,
2690                                 Selector Sel,
2691                                 SourceLocation SelLoc,
2692                                 ObjCMethodDecl *Method,
2693                                 Expr **Args, unsigned NumArgs,
2694                                 SourceLocation RBracLoc)
2695  : Expr(ObjCMessageExprClass, T, VK, OK_Ordinary, Receiver->isTypeDependent(),
2696         Receiver->isTypeDependent(),
2697         Receiver->isInstantiationDependent(),
2698         Receiver->containsUnexpandedParameterPack()),
2699    NumArgs(NumArgs), Kind(Instance),
2700    HasMethod(Method != 0), IsDelegateInitCall(false),
2701    SelectorOrMethod(reinterpret_cast<uintptr_t>(Method? Method
2702                                                       : Sel.getAsOpaquePtr())),
2703    SelectorLoc(SelLoc), LBracLoc(LBracLoc), RBracLoc(RBracLoc)
2704{
2705  setReceiverPointer(Receiver);
2706  Expr **MyArgs = getArgs();
2707  for (unsigned I = 0; I != NumArgs; ++I) {
2708    if (Args[I]->isTypeDependent())
2709      ExprBits.TypeDependent = true;
2710    if (Args[I]->isValueDependent())
2711      ExprBits.ValueDependent = true;
2712    if (Args[I]->isInstantiationDependent())
2713      ExprBits.InstantiationDependent = true;
2714    if (Args[I]->containsUnexpandedParameterPack())
2715      ExprBits.ContainsUnexpandedParameterPack = true;
2716
2717    MyArgs[I] = Args[I];
2718  }
2719}
2720
2721ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2722                                         ExprValueKind VK,
2723                                         SourceLocation LBracLoc,
2724                                         SourceLocation SuperLoc,
2725                                         bool IsInstanceSuper,
2726                                         QualType SuperType,
2727                                         Selector Sel,
2728                                         SourceLocation SelLoc,
2729                                         ObjCMethodDecl *Method,
2730                                         Expr **Args, unsigned NumArgs,
2731                                         SourceLocation RBracLoc) {
2732  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2733    NumArgs * sizeof(Expr *);
2734  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2735  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, SuperLoc, IsInstanceSuper,
2736                                   SuperType, Sel, SelLoc, Method, Args,NumArgs,
2737                                   RBracLoc);
2738}
2739
2740ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2741                                         ExprValueKind VK,
2742                                         SourceLocation LBracLoc,
2743                                         TypeSourceInfo *Receiver,
2744                                         Selector Sel,
2745                                         SourceLocation SelLoc,
2746                                         ObjCMethodDecl *Method,
2747                                         Expr **Args, unsigned NumArgs,
2748                                         SourceLocation RBracLoc) {
2749  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2750    NumArgs * sizeof(Expr *);
2751  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2752  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel, SelLoc,
2753                                   Method, Args, NumArgs, RBracLoc);
2754}
2755
2756ObjCMessageExpr *ObjCMessageExpr::Create(ASTContext &Context, QualType T,
2757                                         ExprValueKind VK,
2758                                         SourceLocation LBracLoc,
2759                                         Expr *Receiver,
2760                                         Selector Sel,
2761                                         SourceLocation SelLoc,
2762                                         ObjCMethodDecl *Method,
2763                                         Expr **Args, unsigned NumArgs,
2764                                         SourceLocation RBracLoc) {
2765  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2766    NumArgs * sizeof(Expr *);
2767  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2768  return new (Mem) ObjCMessageExpr(T, VK, LBracLoc, Receiver, Sel, SelLoc,
2769                                   Method, Args, NumArgs, RBracLoc);
2770}
2771
2772ObjCMessageExpr *ObjCMessageExpr::CreateEmpty(ASTContext &Context,
2773                                              unsigned NumArgs) {
2774  unsigned Size = sizeof(ObjCMessageExpr) + sizeof(void *) +
2775    NumArgs * sizeof(Expr *);
2776  void *Mem = Context.Allocate(Size, llvm::AlignOf<ObjCMessageExpr>::Alignment);
2777  return new (Mem) ObjCMessageExpr(EmptyShell(), NumArgs);
2778}
2779
2780SourceRange ObjCMessageExpr::getReceiverRange() const {
2781  switch (getReceiverKind()) {
2782  case Instance:
2783    return getInstanceReceiver()->getSourceRange();
2784
2785  case Class:
2786    return getClassReceiverTypeInfo()->getTypeLoc().getSourceRange();
2787
2788  case SuperInstance:
2789  case SuperClass:
2790    return getSuperLoc();
2791  }
2792
2793  return SourceLocation();
2794}
2795
2796Selector ObjCMessageExpr::getSelector() const {
2797  if (HasMethod)
2798    return reinterpret_cast<const ObjCMethodDecl *>(SelectorOrMethod)
2799                                                               ->getSelector();
2800  return Selector(SelectorOrMethod);
2801}
2802
2803ObjCInterfaceDecl *ObjCMessageExpr::getReceiverInterface() const {
2804  switch (getReceiverKind()) {
2805  case Instance:
2806    if (const ObjCObjectPointerType *Ptr
2807          = getInstanceReceiver()->getType()->getAs<ObjCObjectPointerType>())
2808      return Ptr->getInterfaceDecl();
2809    break;
2810
2811  case Class:
2812    if (const ObjCObjectType *Ty
2813          = getClassReceiver()->getAs<ObjCObjectType>())
2814      return Ty->getInterface();
2815    break;
2816
2817  case SuperInstance:
2818    if (const ObjCObjectPointerType *Ptr
2819          = getSuperType()->getAs<ObjCObjectPointerType>())
2820      return Ptr->getInterfaceDecl();
2821    break;
2822
2823  case SuperClass:
2824    if (const ObjCObjectType *Iface
2825          = getSuperType()->getAs<ObjCObjectType>())
2826      return Iface->getInterface();
2827    break;
2828  }
2829
2830  return 0;
2831}
2832
2833llvm::StringRef ObjCBridgedCastExpr::getBridgeKindName() const {
2834  switch (getBridgeKind()) {
2835  case OBC_Bridge:
2836    return "__bridge";
2837  case OBC_BridgeTransfer:
2838    return "__bridge_transfer";
2839  case OBC_BridgeRetained:
2840    return "__bridge_retained";
2841  }
2842
2843  return "__bridge";
2844}
2845
2846bool ChooseExpr::isConditionTrue(const ASTContext &C) const {
2847  return getCond()->EvaluateAsInt(C) != 0;
2848}
2849
2850ShuffleVectorExpr::ShuffleVectorExpr(ASTContext &C, Expr **args, unsigned nexpr,
2851                                     QualType Type, SourceLocation BLoc,
2852                                     SourceLocation RP)
2853   : Expr(ShuffleVectorExprClass, Type, VK_RValue, OK_Ordinary,
2854          Type->isDependentType(), Type->isDependentType(),
2855          Type->isInstantiationDependentType(),
2856          Type->containsUnexpandedParameterPack()),
2857     BuiltinLoc(BLoc), RParenLoc(RP), NumExprs(nexpr)
2858{
2859  SubExprs = new (C) Stmt*[nexpr];
2860  for (unsigned i = 0; i < nexpr; i++) {
2861    if (args[i]->isTypeDependent())
2862      ExprBits.TypeDependent = true;
2863    if (args[i]->isValueDependent())
2864      ExprBits.ValueDependent = true;
2865    if (args[i]->isInstantiationDependent())
2866      ExprBits.InstantiationDependent = true;
2867    if (args[i]->containsUnexpandedParameterPack())
2868      ExprBits.ContainsUnexpandedParameterPack = true;
2869
2870    SubExprs[i] = args[i];
2871  }
2872}
2873
2874void ShuffleVectorExpr::setExprs(ASTContext &C, Expr ** Exprs,
2875                                 unsigned NumExprs) {
2876  if (SubExprs) C.Deallocate(SubExprs);
2877
2878  SubExprs = new (C) Stmt* [NumExprs];
2879  this->NumExprs = NumExprs;
2880  memcpy(SubExprs, Exprs, sizeof(Expr *) * NumExprs);
2881}
2882
2883GenericSelectionExpr::GenericSelectionExpr(ASTContext &Context,
2884                               SourceLocation GenericLoc, Expr *ControllingExpr,
2885                               TypeSourceInfo **AssocTypes, Expr **AssocExprs,
2886                               unsigned NumAssocs, SourceLocation DefaultLoc,
2887                               SourceLocation RParenLoc,
2888                               bool ContainsUnexpandedParameterPack,
2889                               unsigned ResultIndex)
2890  : Expr(GenericSelectionExprClass,
2891         AssocExprs[ResultIndex]->getType(),
2892         AssocExprs[ResultIndex]->getValueKind(),
2893         AssocExprs[ResultIndex]->getObjectKind(),
2894         AssocExprs[ResultIndex]->isTypeDependent(),
2895         AssocExprs[ResultIndex]->isValueDependent(),
2896         AssocExprs[ResultIndex]->isInstantiationDependent(),
2897         ContainsUnexpandedParameterPack),
2898    AssocTypes(new (Context) TypeSourceInfo*[NumAssocs]),
2899    SubExprs(new (Context) Stmt*[END_EXPR+NumAssocs]), NumAssocs(NumAssocs),
2900    ResultIndex(ResultIndex), GenericLoc(GenericLoc), DefaultLoc(DefaultLoc),
2901    RParenLoc(RParenLoc) {
2902  SubExprs[CONTROLLING] = ControllingExpr;
2903  std::copy(AssocTypes, AssocTypes+NumAssocs, this->AssocTypes);
2904  std::copy(AssocExprs, AssocExprs+NumAssocs, SubExprs+END_EXPR);
2905}
2906
2907GenericSelectionExpr::GenericSelectionExpr(ASTContext &Context,
2908                               SourceLocation GenericLoc, Expr *ControllingExpr,
2909                               TypeSourceInfo **AssocTypes, Expr **AssocExprs,
2910                               unsigned NumAssocs, SourceLocation DefaultLoc,
2911                               SourceLocation RParenLoc,
2912                               bool ContainsUnexpandedParameterPack)
2913  : Expr(GenericSelectionExprClass,
2914         Context.DependentTy,
2915         VK_RValue,
2916         OK_Ordinary,
2917         /*isTypeDependent=*/true,
2918         /*isValueDependent=*/true,
2919         /*isInstantiationDependent=*/true,
2920         ContainsUnexpandedParameterPack),
2921    AssocTypes(new (Context) TypeSourceInfo*[NumAssocs]),
2922    SubExprs(new (Context) Stmt*[END_EXPR+NumAssocs]), NumAssocs(NumAssocs),
2923    ResultIndex(-1U), GenericLoc(GenericLoc), DefaultLoc(DefaultLoc),
2924    RParenLoc(RParenLoc) {
2925  SubExprs[CONTROLLING] = ControllingExpr;
2926  std::copy(AssocTypes, AssocTypes+NumAssocs, this->AssocTypes);
2927  std::copy(AssocExprs, AssocExprs+NumAssocs, SubExprs+END_EXPR);
2928}
2929
2930//===----------------------------------------------------------------------===//
2931//  DesignatedInitExpr
2932//===----------------------------------------------------------------------===//
2933
2934IdentifierInfo *DesignatedInitExpr::Designator::getFieldName() const {
2935  assert(Kind == FieldDesignator && "Only valid on a field designator");
2936  if (Field.NameOrField & 0x01)
2937    return reinterpret_cast<IdentifierInfo *>(Field.NameOrField&~0x01);
2938  else
2939    return getField()->getIdentifier();
2940}
2941
2942DesignatedInitExpr::DesignatedInitExpr(ASTContext &C, QualType Ty,
2943                                       unsigned NumDesignators,
2944                                       const Designator *Designators,
2945                                       SourceLocation EqualOrColonLoc,
2946                                       bool GNUSyntax,
2947                                       Expr **IndexExprs,
2948                                       unsigned NumIndexExprs,
2949                                       Expr *Init)
2950  : Expr(DesignatedInitExprClass, Ty,
2951         Init->getValueKind(), Init->getObjectKind(),
2952         Init->isTypeDependent(), Init->isValueDependent(),
2953         Init->isInstantiationDependent(),
2954         Init->containsUnexpandedParameterPack()),
2955    EqualOrColonLoc(EqualOrColonLoc), GNUSyntax(GNUSyntax),
2956    NumDesignators(NumDesignators), NumSubExprs(NumIndexExprs + 1) {
2957  this->Designators = new (C) Designator[NumDesignators];
2958
2959  // Record the initializer itself.
2960  child_range Child = children();
2961  *Child++ = Init;
2962
2963  // Copy the designators and their subexpressions, computing
2964  // value-dependence along the way.
2965  unsigned IndexIdx = 0;
2966  for (unsigned I = 0; I != NumDesignators; ++I) {
2967    this->Designators[I] = Designators[I];
2968
2969    if (this->Designators[I].isArrayDesignator()) {
2970      // Compute type- and value-dependence.
2971      Expr *Index = IndexExprs[IndexIdx];
2972      if (Index->isTypeDependent() || Index->isValueDependent())
2973        ExprBits.ValueDependent = true;
2974      if (Index->isInstantiationDependent())
2975        ExprBits.InstantiationDependent = true;
2976      // Propagate unexpanded parameter packs.
2977      if (Index->containsUnexpandedParameterPack())
2978        ExprBits.ContainsUnexpandedParameterPack = true;
2979
2980      // Copy the index expressions into permanent storage.
2981      *Child++ = IndexExprs[IndexIdx++];
2982    } else if (this->Designators[I].isArrayRangeDesignator()) {
2983      // Compute type- and value-dependence.
2984      Expr *Start = IndexExprs[IndexIdx];
2985      Expr *End = IndexExprs[IndexIdx + 1];
2986      if (Start->isTypeDependent() || Start->isValueDependent() ||
2987          End->isTypeDependent() || End->isValueDependent()) {
2988        ExprBits.ValueDependent = true;
2989        ExprBits.InstantiationDependent = true;
2990      } else if (Start->isInstantiationDependent() ||
2991                 End->isInstantiationDependent()) {
2992        ExprBits.InstantiationDependent = true;
2993      }
2994
2995      // Propagate unexpanded parameter packs.
2996      if (Start->containsUnexpandedParameterPack() ||
2997          End->containsUnexpandedParameterPack())
2998        ExprBits.ContainsUnexpandedParameterPack = true;
2999
3000      // Copy the start/end expressions into permanent storage.
3001      *Child++ = IndexExprs[IndexIdx++];
3002      *Child++ = IndexExprs[IndexIdx++];
3003    }
3004  }
3005
3006  assert(IndexIdx == NumIndexExprs && "Wrong number of index expressions");
3007}
3008
3009DesignatedInitExpr *
3010DesignatedInitExpr::Create(ASTContext &C, Designator *Designators,
3011                           unsigned NumDesignators,
3012                           Expr **IndexExprs, unsigned NumIndexExprs,
3013                           SourceLocation ColonOrEqualLoc,
3014                           bool UsesColonSyntax, Expr *Init) {
3015  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
3016                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
3017  return new (Mem) DesignatedInitExpr(C, C.VoidTy, NumDesignators, Designators,
3018                                      ColonOrEqualLoc, UsesColonSyntax,
3019                                      IndexExprs, NumIndexExprs, Init);
3020}
3021
3022DesignatedInitExpr *DesignatedInitExpr::CreateEmpty(ASTContext &C,
3023                                                    unsigned NumIndexExprs) {
3024  void *Mem = C.Allocate(sizeof(DesignatedInitExpr) +
3025                         sizeof(Stmt *) * (NumIndexExprs + 1), 8);
3026  return new (Mem) DesignatedInitExpr(NumIndexExprs + 1);
3027}
3028
3029void DesignatedInitExpr::setDesignators(ASTContext &C,
3030                                        const Designator *Desigs,
3031                                        unsigned NumDesigs) {
3032  Designators = new (C) Designator[NumDesigs];
3033  NumDesignators = NumDesigs;
3034  for (unsigned I = 0; I != NumDesigs; ++I)
3035    Designators[I] = Desigs[I];
3036}
3037
3038SourceRange DesignatedInitExpr::getDesignatorsSourceRange() const {
3039  DesignatedInitExpr *DIE = const_cast<DesignatedInitExpr*>(this);
3040  if (size() == 1)
3041    return DIE->getDesignator(0)->getSourceRange();
3042  return SourceRange(DIE->getDesignator(0)->getStartLocation(),
3043                     DIE->getDesignator(size()-1)->getEndLocation());
3044}
3045
3046SourceRange DesignatedInitExpr::getSourceRange() const {
3047  SourceLocation StartLoc;
3048  Designator &First =
3049    *const_cast<DesignatedInitExpr*>(this)->designators_begin();
3050  if (First.isFieldDesignator()) {
3051    if (GNUSyntax)
3052      StartLoc = SourceLocation::getFromRawEncoding(First.Field.FieldLoc);
3053    else
3054      StartLoc = SourceLocation::getFromRawEncoding(First.Field.DotLoc);
3055  } else
3056    StartLoc =
3057      SourceLocation::getFromRawEncoding(First.ArrayOrRange.LBracketLoc);
3058  return SourceRange(StartLoc, getInit()->getSourceRange().getEnd());
3059}
3060
3061Expr *DesignatedInitExpr::getArrayIndex(const Designator& D) {
3062  assert(D.Kind == Designator::ArrayDesignator && "Requires array designator");
3063  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3064  Ptr += sizeof(DesignatedInitExpr);
3065  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3066  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
3067}
3068
3069Expr *DesignatedInitExpr::getArrayRangeStart(const Designator& D) {
3070  assert(D.Kind == Designator::ArrayRangeDesignator &&
3071         "Requires array range designator");
3072  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3073  Ptr += sizeof(DesignatedInitExpr);
3074  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3075  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 1));
3076}
3077
3078Expr *DesignatedInitExpr::getArrayRangeEnd(const Designator& D) {
3079  assert(D.Kind == Designator::ArrayRangeDesignator &&
3080         "Requires array range designator");
3081  char* Ptr = static_cast<char*>(static_cast<void *>(this));
3082  Ptr += sizeof(DesignatedInitExpr);
3083  Stmt **SubExprs = reinterpret_cast<Stmt**>(reinterpret_cast<void**>(Ptr));
3084  return cast<Expr>(*(SubExprs + D.ArrayOrRange.Index + 2));
3085}
3086
3087/// \brief Replaces the designator at index @p Idx with the series
3088/// of designators in [First, Last).
3089void DesignatedInitExpr::ExpandDesignator(ASTContext &C, unsigned Idx,
3090                                          const Designator *First,
3091                                          const Designator *Last) {
3092  unsigned NumNewDesignators = Last - First;
3093  if (NumNewDesignators == 0) {
3094    std::copy_backward(Designators + Idx + 1,
3095                       Designators + NumDesignators,
3096                       Designators + Idx);
3097    --NumNewDesignators;
3098    return;
3099  } else if (NumNewDesignators == 1) {
3100    Designators[Idx] = *First;
3101    return;
3102  }
3103
3104  Designator *NewDesignators
3105    = new (C) Designator[NumDesignators - 1 + NumNewDesignators];
3106  std::copy(Designators, Designators + Idx, NewDesignators);
3107  std::copy(First, Last, NewDesignators + Idx);
3108  std::copy(Designators + Idx + 1, Designators + NumDesignators,
3109            NewDesignators + Idx + NumNewDesignators);
3110  Designators = NewDesignators;
3111  NumDesignators = NumDesignators - 1 + NumNewDesignators;
3112}
3113
3114ParenListExpr::ParenListExpr(ASTContext& C, SourceLocation lparenloc,
3115                             Expr **exprs, unsigned nexprs,
3116                             SourceLocation rparenloc, QualType T)
3117  : Expr(ParenListExprClass, T, VK_RValue, OK_Ordinary,
3118         false, false, false, false),
3119    NumExprs(nexprs), LParenLoc(lparenloc), RParenLoc(rparenloc) {
3120  assert(!T.isNull() && "ParenListExpr must have a valid type");
3121  Exprs = new (C) Stmt*[nexprs];
3122  for (unsigned i = 0; i != nexprs; ++i) {
3123    if (exprs[i]->isTypeDependent())
3124      ExprBits.TypeDependent = true;
3125    if (exprs[i]->isValueDependent())
3126      ExprBits.ValueDependent = true;
3127    if (exprs[i]->isInstantiationDependent())
3128      ExprBits.InstantiationDependent = true;
3129    if (exprs[i]->containsUnexpandedParameterPack())
3130      ExprBits.ContainsUnexpandedParameterPack = true;
3131
3132    Exprs[i] = exprs[i];
3133  }
3134}
3135
3136const OpaqueValueExpr *OpaqueValueExpr::findInCopyConstruct(const Expr *e) {
3137  if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(e))
3138    e = ewc->getSubExpr();
3139  if (const MaterializeTemporaryExpr *m = dyn_cast<MaterializeTemporaryExpr>(e))
3140    e = m->GetTemporaryExpr();
3141  e = cast<CXXConstructExpr>(e)->getArg(0);
3142  while (const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
3143    e = ice->getSubExpr();
3144  return cast<OpaqueValueExpr>(e);
3145}
3146
3147//===----------------------------------------------------------------------===//
3148//  ExprIterator.
3149//===----------------------------------------------------------------------===//
3150
3151Expr* ExprIterator::operator[](size_t idx) { return cast<Expr>(I[idx]); }
3152Expr* ExprIterator::operator*() const { return cast<Expr>(*I); }
3153Expr* ExprIterator::operator->() const { return cast<Expr>(*I); }
3154const Expr* ConstExprIterator::operator[](size_t idx) const {
3155  return cast<Expr>(I[idx]);
3156}
3157const Expr* ConstExprIterator::operator*() const { return cast<Expr>(*I); }
3158const Expr* ConstExprIterator::operator->() const { return cast<Expr>(*I); }
3159
3160//===----------------------------------------------------------------------===//
3161//  Child Iterators for iterating over subexpressions/substatements
3162//===----------------------------------------------------------------------===//
3163
3164// UnaryExprOrTypeTraitExpr
3165Stmt::child_range UnaryExprOrTypeTraitExpr::children() {
3166  // If this is of a type and the type is a VLA type (and not a typedef), the
3167  // size expression of the VLA needs to be treated as an executable expression.
3168  // Why isn't this weirdness documented better in StmtIterator?
3169  if (isArgumentType()) {
3170    if (const VariableArrayType* T = dyn_cast<VariableArrayType>(
3171                                   getArgumentType().getTypePtr()))
3172      return child_range(child_iterator(T), child_iterator());
3173    return child_range();
3174  }
3175  return child_range(&Argument.Ex, &Argument.Ex + 1);
3176}
3177
3178// ObjCMessageExpr
3179Stmt::child_range ObjCMessageExpr::children() {
3180  Stmt **begin;
3181  if (getReceiverKind() == Instance)
3182    begin = reinterpret_cast<Stmt **>(this + 1);
3183  else
3184    begin = reinterpret_cast<Stmt **>(getArgs());
3185  return child_range(begin,
3186                     reinterpret_cast<Stmt **>(getArgs() + getNumArgs()));
3187}
3188
3189// Blocks
3190BlockDeclRefExpr::BlockDeclRefExpr(VarDecl *d, QualType t, ExprValueKind VK,
3191                                   SourceLocation l, bool ByRef,
3192                                   bool constAdded)
3193  : Expr(BlockDeclRefExprClass, t, VK, OK_Ordinary, false, false, false,
3194         d->isParameterPack()),
3195    D(d), Loc(l), IsByRef(ByRef), ConstQualAdded(constAdded)
3196{
3197  bool TypeDependent = false;
3198  bool ValueDependent = false;
3199  bool InstantiationDependent = false;
3200  computeDeclRefDependence(D, getType(), TypeDependent, ValueDependent,
3201                           InstantiationDependent);
3202  ExprBits.TypeDependent = TypeDependent;
3203  ExprBits.ValueDependent = ValueDependent;
3204  ExprBits.InstantiationDependent = InstantiationDependent;
3205}
3206