Expr.cpp revision e3e9add4fd788927df6f545570e7838db59c01d7 
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/ExprObjC.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/StmtVisitor.h"
17#include "clang/Basic/IdentifierTable.h"
18#include "clang/Basic/TargetInfo.h"
19using namespace clang;
20
21//===----------------------------------------------------------------------===//
22// Primary Expressions.
23//===----------------------------------------------------------------------===//
24
25StringLiteral::StringLiteral(const char *strData, unsigned byteLength,
26                             bool Wide, QualType t, SourceLocation firstLoc,
27                             SourceLocation lastLoc) :
28  Expr(StringLiteralClass, t) {
29  // OPTIMIZE: could allocate this appended to the StringLiteral.
30  char *AStrData = new char[byteLength];
31  memcpy(AStrData, strData, byteLength);
32  StrData = AStrData;
33  ByteLength = byteLength;
34  IsWide = Wide;
35  firstTokLoc = firstLoc;
36  lastTokLoc = lastLoc;
37}
38
39StringLiteral::~StringLiteral() {
40  delete[] StrData;
41}
42
43bool UnaryOperator::isPostfix(Opcode Op) {
44  switch (Op) {
45  case PostInc:
46  case PostDec:
47    return true;
48  default:
49    return false;
50  }
51}
52
53/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
54/// corresponds to, e.g. "sizeof" or "[pre]++".
55const char *UnaryOperator::getOpcodeStr(Opcode Op) {
56  switch (Op) {
57  default: assert(0 && "Unknown unary operator");
58  case PostInc: return "++";
59  case PostDec: return "--";
60  case PreInc:  return "++";
61  case PreDec:  return "--";
62  case AddrOf:  return "&";
63  case Deref:   return "*";
64  case Plus:    return "+";
65  case Minus:   return "-";
66  case Not:     return "~";
67  case LNot:    return "!";
68  case Real:    return "__real";
69  case Imag:    return "__imag";
70  case SizeOf:  return "sizeof";
71  case AlignOf: return "alignof";
72  case Extension: return "__extension__";
73  case OffsetOf: return "__builtin_offsetof";
74  }
75}
76
77//===----------------------------------------------------------------------===//
78// Postfix Operators.
79//===----------------------------------------------------------------------===//
80
81
82CallExpr::CallExpr(Expr *fn, Expr **args, unsigned numargs, QualType t,
83                   SourceLocation rparenloc)
84  : Expr(CallExprClass, t), NumArgs(numargs) {
85  SubExprs = new Expr*[numargs+1];
86  SubExprs[FN] = fn;
87  for (unsigned i = 0; i != numargs; ++i)
88    SubExprs[i+ARGS_START] = args[i];
89  RParenLoc = rparenloc;
90}
91
92/// setNumArgs - This changes the number of arguments present in this call.
93/// Any orphaned expressions are deleted by this, and any new operands are set
94/// to null.
95void CallExpr::setNumArgs(unsigned NumArgs) {
96  // No change, just return.
97  if (NumArgs == getNumArgs()) return;
98
99  // If shrinking # arguments, just delete the extras and forgot them.
100  if (NumArgs < getNumArgs()) {
101    for (unsigned i = NumArgs, e = getNumArgs(); i != e; ++i)
102      delete getArg(i);
103    this->NumArgs = NumArgs;
104    return;
105  }
106
107  // Otherwise, we are growing the # arguments.  New an bigger argument array.
108  Expr **NewSubExprs = new Expr*[NumArgs+1];
109  // Copy over args.
110  for (unsigned i = 0; i != getNumArgs()+ARGS_START; ++i)
111    NewSubExprs[i] = SubExprs[i];
112  // Null out new args.
113  for (unsigned i = getNumArgs()+ARGS_START; i != NumArgs+ARGS_START; ++i)
114    NewSubExprs[i] = 0;
115
116  delete[] SubExprs;
117  SubExprs = NewSubExprs;
118  this->NumArgs = NumArgs;
119}
120
121bool CallExpr::isBuiltinConstantExpr() const {
122  // All simple function calls (e.g. func()) are implicitly cast to pointer to
123  // function. As a result, we try and obtain the DeclRefExpr from the
124  // ImplicitCastExpr.
125  const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
126  if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
127    return false;
128
129  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
130  if (!DRE)
131    return false;
132
133  const FunctionDecl *FDecl = dyn_cast<FunctionDecl>(DRE->getDecl());
134  if (!FDecl)
135    return false;
136
137  unsigned builtinID = FDecl->getIdentifier()->getBuiltinID();
138  if (!builtinID)
139    return false;
140
141  // We have a builtin that is a constant expression
142  return builtinID == Builtin::BI__builtin___CFStringMakeConstantString ||
143         builtinID == Builtin::BI__builtin_classify_type;
144}
145
146bool CallExpr::isBuiltinClassifyType(llvm::APSInt &Result) const {
147  // The following enum mimics gcc's internal "typeclass.h" file.
148  enum gcc_type_class {
149    no_type_class = -1,
150    void_type_class, integer_type_class, char_type_class,
151    enumeral_type_class, boolean_type_class,
152    pointer_type_class, reference_type_class, offset_type_class,
153    real_type_class, complex_type_class,
154    function_type_class, method_type_class,
155    record_type_class, union_type_class,
156    array_type_class, string_type_class,
157    lang_type_class
158  };
159  Result.setIsSigned(true);
160
161  // All simple function calls (e.g. func()) are implicitly cast to pointer to
162  // function. As a result, we try and obtain the DeclRefExpr from the
163  // ImplicitCastExpr.
164  const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
165  if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
166    return false;
167  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
168  if (!DRE)
169    return false;
170
171  // We have a DeclRefExpr.
172  if (strcmp(DRE->getDecl()->getName(), "__builtin_classify_type") == 0) {
173    // If no argument was supplied, default to "no_type_class". This isn't
174    // ideal, however it's what gcc does.
175    Result = static_cast<uint64_t>(no_type_class);
176    if (NumArgs >= 1) {
177      QualType argType = getArg(0)->getType();
178
179      if (argType->isVoidType())
180        Result = void_type_class;
181      else if (argType->isEnumeralType())
182        Result = enumeral_type_class;
183      else if (argType->isBooleanType())
184        Result = boolean_type_class;
185      else if (argType->isCharType())
186        Result = string_type_class; // gcc doesn't appear to use char_type_class
187      else if (argType->isIntegerType())
188        Result = integer_type_class;
189      else if (argType->isPointerType())
190        Result = pointer_type_class;
191      else if (argType->isReferenceType())
192        Result = reference_type_class;
193      else if (argType->isRealType())
194        Result = real_type_class;
195      else if (argType->isComplexType())
196        Result = complex_type_class;
197      else if (argType->isFunctionType())
198        Result = function_type_class;
199      else if (argType->isStructureType())
200        Result = record_type_class;
201      else if (argType->isUnionType())
202        Result = union_type_class;
203      else if (argType->isArrayType())
204        Result = array_type_class;
205      else if (argType->isUnionType())
206        Result = union_type_class;
207      else  // FIXME: offset_type_class, method_type_class, & lang_type_class?
208        assert(0 && "CallExpr::isBuiltinClassifyType(): unimplemented type");
209    }
210    return true;
211  }
212  return false;
213}
214
215/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
216/// corresponds to, e.g. "<<=".
217const char *BinaryOperator::getOpcodeStr(Opcode Op) {
218  switch (Op) {
219  default: assert(0 && "Unknown binary operator");
220  case Mul:       return "*";
221  case Div:       return "/";
222  case Rem:       return "%";
223  case Add:       return "+";
224  case Sub:       return "-";
225  case Shl:       return "<<";
226  case Shr:       return ">>";
227  case LT:        return "<";
228  case GT:        return ">";
229  case LE:        return "<=";
230  case GE:        return ">=";
231  case EQ:        return "==";
232  case NE:        return "!=";
233  case And:       return "&";
234  case Xor:       return "^";
235  case Or:        return "|";
236  case LAnd:      return "&&";
237  case LOr:       return "||";
238  case Assign:    return "=";
239  case MulAssign: return "*=";
240  case DivAssign: return "/=";
241  case RemAssign: return "%=";
242  case AddAssign: return "+=";
243  case SubAssign: return "-=";
244  case ShlAssign: return "<<=";
245  case ShrAssign: return ">>=";
246  case AndAssign: return "&=";
247  case XorAssign: return "^=";
248  case OrAssign:  return "|=";
249  case Comma:     return ",";
250  }
251}
252
253InitListExpr::InitListExpr(SourceLocation lbraceloc,
254                           Expr **initexprs, unsigned numinits,
255                           SourceLocation rbraceloc)
256  : Expr(InitListExprClass, QualType()),
257    LBraceLoc(lbraceloc), RBraceLoc(rbraceloc)
258{
259  for (unsigned i = 0; i != numinits; i++)
260    InitExprs.push_back(initexprs[i]);
261}
262
263//===----------------------------------------------------------------------===//
264// Generic Expression Routines
265//===----------------------------------------------------------------------===//
266
267/// hasLocalSideEffect - Return true if this immediate expression has side
268/// effects, not counting any sub-expressions.
269bool Expr::hasLocalSideEffect() const {
270  switch (getStmtClass()) {
271  default:
272    return false;
273  case ParenExprClass:
274    return cast<ParenExpr>(this)->getSubExpr()->hasLocalSideEffect();
275  case UnaryOperatorClass: {
276    const UnaryOperator *UO = cast<UnaryOperator>(this);
277
278    switch (UO->getOpcode()) {
279    default: return false;
280    case UnaryOperator::PostInc:
281    case UnaryOperator::PostDec:
282    case UnaryOperator::PreInc:
283    case UnaryOperator::PreDec:
284      return true;                     // ++/--
285
286    case UnaryOperator::Deref:
287      // Dereferencing a volatile pointer is a side-effect.
288      return getType().isVolatileQualified();
289    case UnaryOperator::Real:
290    case UnaryOperator::Imag:
291      // accessing a piece of a volatile complex is a side-effect.
292      return UO->getSubExpr()->getType().isVolatileQualified();
293
294    case UnaryOperator::Extension:
295      return UO->getSubExpr()->hasLocalSideEffect();
296    }
297  }
298  case BinaryOperatorClass: {
299    const BinaryOperator *BinOp = cast<BinaryOperator>(this);
300    // Consider comma to have side effects if the LHS and RHS both do.
301    if (BinOp->getOpcode() == BinaryOperator::Comma)
302      return BinOp->getLHS()->hasLocalSideEffect() &&
303             BinOp->getRHS()->hasLocalSideEffect();
304
305    return BinOp->isAssignmentOp();
306  }
307  case CompoundAssignOperatorClass:
308    return true;
309
310  case ConditionalOperatorClass: {
311    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
312    return Exp->getCond()->hasLocalSideEffect()
313           || (Exp->getLHS() && Exp->getLHS()->hasLocalSideEffect())
314           || (Exp->getRHS() && Exp->getRHS()->hasLocalSideEffect());
315  }
316
317  case MemberExprClass:
318  case ArraySubscriptExprClass:
319    // If the base pointer or element is to a volatile pointer/field, accessing
320    // if is a side effect.
321    return getType().isVolatileQualified();
322
323  case CallExprClass:
324    // TODO: check attributes for pure/const.   "void foo() { strlen("bar"); }"
325    // should warn.
326    return true;
327  case ObjCMessageExprClass:
328    return true;
329  case StmtExprClass:
330    // TODO: check the inside of the statement expression
331    return true;
332
333  case CastExprClass:
334    // If this is a cast to void, check the operand.  Otherwise, the result of
335    // the cast is unused.
336    if (getType()->isVoidType())
337      return cast<CastExpr>(this)->getSubExpr()->hasLocalSideEffect();
338    return false;
339
340  case ImplicitCastExprClass:
341    // Check the operand, since implicit casts are inserted by Sema
342    return cast<ImplicitCastExpr>(this)->getSubExpr()->hasLocalSideEffect();
343
344  case CXXDefaultArgExprClass:
345    return cast<CXXDefaultArgExpr>(this)->getExpr()->hasLocalSideEffect();
346  }
347}
348
349/// isLvalue - C99 6.3.2.1: an lvalue is an expression with an object type or an
350/// incomplete type other than void. Nonarray expressions that can be lvalues:
351///  - name, where name must be a variable
352///  - e[i]
353///  - (e), where e must be an lvalue
354///  - e.name, where e must be an lvalue
355///  - e->name
356///  - *e, the type of e cannot be a function type
357///  - string-constant
358///  - (__real__ e) and (__imag__ e) where e is an lvalue  [GNU extension]
359///  - reference type [C++ [expr]]
360///
361Expr::isLvalueResult Expr::isLvalue() const {
362  // first, check the type (C99 6.3.2.1)
363  if (TR->isFunctionType()) // from isObjectType()
364    return LV_NotObjectType;
365
366  // Allow qualified void which is an incomplete type other than void (yuck).
367  if (TR->isVoidType() && !TR.getCanonicalType().getCVRQualifiers())
368    return LV_IncompleteVoidType;
369
370  if (TR->isReferenceType()) // C++ [expr]
371    return LV_Valid;
372
373  // the type looks fine, now check the expression
374  switch (getStmtClass()) {
375  case StringLiteralClass: // C99 6.5.1p4
376    return LV_Valid;
377  case ArraySubscriptExprClass: // C99 6.5.3p4 (e1[e2] == (*((e1)+(e2))))
378    // For vectors, make sure base is an lvalue (i.e. not a function call).
379    if (cast<ArraySubscriptExpr>(this)->getBase()->getType()->isVectorType())
380      return cast<ArraySubscriptExpr>(this)->getBase()->isLvalue();
381    return LV_Valid;
382  case DeclRefExprClass: // C99 6.5.1p2
383    if (isa<VarDecl>(cast<DeclRefExpr>(this)->getDecl()))
384      return LV_Valid;
385    break;
386  case MemberExprClass: { // C99 6.5.2.3p4
387    const MemberExpr *m = cast<MemberExpr>(this);
388    return m->isArrow() ? LV_Valid : m->getBase()->isLvalue();
389  }
390  case UnaryOperatorClass:
391    if (cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Deref)
392      return LV_Valid; // C99 6.5.3p4
393
394    if (cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Real ||
395        cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Imag)
396      return cast<UnaryOperator>(this)->getSubExpr()->isLvalue();  // GNU.
397    break;
398  case ParenExprClass: // C99 6.5.1p5
399    return cast<ParenExpr>(this)->getSubExpr()->isLvalue();
400  case CompoundLiteralExprClass: // C99 6.5.2.5p5
401    return LV_Valid;
402  case ExtVectorElementExprClass:
403    if (cast<ExtVectorElementExpr>(this)->containsDuplicateElements())
404      return LV_DuplicateVectorComponents;
405    return LV_Valid;
406  case ObjCIvarRefExprClass: // ObjC instance variables are lvalues.
407    return LV_Valid;
408  case ObjCPropertyRefExprClass: // FIXME: check if read-only property.
409    return LV_Valid;
410  case PreDefinedExprClass:
411    return LV_Valid;
412  case CXXDefaultArgExprClass:
413    return cast<CXXDefaultArgExpr>(this)->getExpr()->isLvalue();
414  default:
415    break;
416  }
417  return LV_InvalidExpression;
418}
419
420/// isModifiableLvalue - C99 6.3.2.1: an lvalue that does not have array type,
421/// does not have an incomplete type, does not have a const-qualified type, and
422/// if it is a structure or union, does not have any member (including,
423/// recursively, any member or element of all contained aggregates or unions)
424/// with a const-qualified type.
425Expr::isModifiableLvalueResult Expr::isModifiableLvalue() const {
426  isLvalueResult lvalResult = isLvalue();
427
428  switch (lvalResult) {
429  case LV_Valid: break;
430  case LV_NotObjectType: return MLV_NotObjectType;
431  case LV_IncompleteVoidType: return MLV_IncompleteVoidType;
432  case LV_DuplicateVectorComponents: return MLV_DuplicateVectorComponents;
433  case LV_InvalidExpression: return MLV_InvalidExpression;
434  }
435  if (TR.isConstQualified())
436    return MLV_ConstQualified;
437  if (TR->isArrayType())
438    return MLV_ArrayType;
439  if (TR->isIncompleteType())
440    return MLV_IncompleteType;
441
442  if (const RecordType *r = dyn_cast<RecordType>(TR.getCanonicalType())) {
443    if (r->hasConstFields())
444      return MLV_ConstQualified;
445  }
446  return MLV_Valid;
447}
448
449/// hasGlobalStorage - Return true if this expression has static storage
450/// duration.  This means that the address of this expression is a link-time
451/// constant.
452bool Expr::hasGlobalStorage() const {
453  switch (getStmtClass()) {
454  default:
455    return false;
456  case ParenExprClass:
457    return cast<ParenExpr>(this)->getSubExpr()->hasGlobalStorage();
458  case ImplicitCastExprClass:
459    return cast<ImplicitCastExpr>(this)->getSubExpr()->hasGlobalStorage();
460  case CompoundLiteralExprClass:
461    return cast<CompoundLiteralExpr>(this)->isFileScope();
462  case DeclRefExprClass: {
463    const Decl *D = cast<DeclRefExpr>(this)->getDecl();
464    if (const VarDecl *VD = dyn_cast<VarDecl>(D))
465      return VD->hasGlobalStorage();
466    if (isa<FunctionDecl>(D))
467      return true;
468    return false;
469  }
470  case MemberExprClass: {
471    const MemberExpr *M = cast<MemberExpr>(this);
472    return !M->isArrow() && M->getBase()->hasGlobalStorage();
473  }
474  case ArraySubscriptExprClass:
475    return cast<ArraySubscriptExpr>(this)->getBase()->hasGlobalStorage();
476  case PreDefinedExprClass:
477    return true;
478  case CXXDefaultArgExprClass:
479    return cast<CXXDefaultArgExpr>(this)->getExpr()->hasGlobalStorage();
480  }
481}
482
483Expr* Expr::IgnoreParens() {
484  Expr* E = this;
485  while (ParenExpr* P = dyn_cast<ParenExpr>(E))
486    E = P->getSubExpr();
487
488  return E;
489}
490
491/// IgnoreParenCasts - Ignore parentheses and casts.  Strip off any ParenExpr
492/// or CastExprs or ImplicitCastExprs, returning their operand.
493Expr *Expr::IgnoreParenCasts() {
494  Expr *E = this;
495  while (true) {
496    if (ParenExpr *P = dyn_cast<ParenExpr>(E))
497      E = P->getSubExpr();
498    else if (CastExpr *P = dyn_cast<CastExpr>(E))
499      E = P->getSubExpr();
500    else if (ImplicitCastExpr *P = dyn_cast<ImplicitCastExpr>(E))
501      E = P->getSubExpr();
502    else
503      return E;
504  }
505}
506
507
508bool Expr::isConstantExpr(ASTContext &Ctx, SourceLocation *Loc) const {
509  switch (getStmtClass()) {
510  default:
511    if (Loc) *Loc = getLocStart();
512    return false;
513  case ParenExprClass:
514    return cast<ParenExpr>(this)->getSubExpr()->isConstantExpr(Ctx, Loc);
515  case StringLiteralClass:
516  case ObjCStringLiteralClass:
517  case FloatingLiteralClass:
518  case IntegerLiteralClass:
519  case CharacterLiteralClass:
520  case ImaginaryLiteralClass:
521  case TypesCompatibleExprClass:
522  case CXXBoolLiteralExprClass:
523    return true;
524  case CallExprClass: {
525    const CallExpr *CE = cast<CallExpr>(this);
526    if (CE->isBuiltinConstantExpr())
527      return true;
528    if (Loc) *Loc = getLocStart();
529    return false;
530  }
531  case DeclRefExprClass: {
532    const Decl *D = cast<DeclRefExpr>(this)->getDecl();
533    // Accept address of function.
534    if (isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D))
535      return true;
536    if (Loc) *Loc = getLocStart();
537    if (isa<VarDecl>(D))
538      return TR->isArrayType();
539    return false;
540  }
541  case CompoundLiteralExprClass:
542    if (Loc) *Loc = getLocStart();
543    // Allow "(int []){2,4}", since the array will be converted to a pointer.
544    // Allow "(vector type){2,4}" since the elements are all constant.
545    return TR->isArrayType() || TR->isVectorType();
546  case UnaryOperatorClass: {
547    const UnaryOperator *Exp = cast<UnaryOperator>(this);
548
549    // C99 6.6p9
550    if (Exp->getOpcode() == UnaryOperator::AddrOf) {
551      if (!Exp->getSubExpr()->hasGlobalStorage()) {
552        if (Loc) *Loc = getLocStart();
553        return false;
554      }
555      return true;
556    }
557
558    // Get the operand value.  If this is sizeof/alignof, do not evalute the
559    // operand.  This affects C99 6.6p3.
560    if (!Exp->isSizeOfAlignOfOp() &&
561        Exp->getOpcode() != UnaryOperator::OffsetOf &&
562        !Exp->getSubExpr()->isConstantExpr(Ctx, Loc))
563      return false;
564
565    switch (Exp->getOpcode()) {
566    // Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
567    // See C99 6.6p3.
568    default:
569      if (Loc) *Loc = Exp->getOperatorLoc();
570      return false;
571    case UnaryOperator::Extension:
572      return true;  // FIXME: this is wrong.
573    case UnaryOperator::SizeOf:
574    case UnaryOperator::AlignOf:
575    case UnaryOperator::OffsetOf:
576      // sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
577      if (!Exp->getSubExpr()->getType()->isConstantSizeType()) {
578        if (Loc) *Loc = Exp->getOperatorLoc();
579        return false;
580      }
581      return true;
582    case UnaryOperator::LNot:
583    case UnaryOperator::Plus:
584    case UnaryOperator::Minus:
585    case UnaryOperator::Not:
586      return true;
587    }
588  }
589  case SizeOfAlignOfTypeExprClass: {
590    const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(this);
591    // alignof always evaluates to a constant.
592    if (Exp->isSizeOf() && !Exp->getArgumentType()->isVoidType() &&
593        !Exp->getArgumentType()->isConstantSizeType()) {
594      if (Loc) *Loc = Exp->getOperatorLoc();
595      return false;
596    }
597    return true;
598  }
599  case BinaryOperatorClass: {
600    const BinaryOperator *Exp = cast<BinaryOperator>(this);
601
602    // The LHS of a constant expr is always evaluated and needed.
603    if (!Exp->getLHS()->isConstantExpr(Ctx, Loc))
604      return false;
605
606    if (!Exp->getRHS()->isConstantExpr(Ctx, Loc))
607      return false;
608    return true;
609  }
610  case ImplicitCastExprClass:
611  case CastExprClass: {
612    const Expr *SubExpr;
613    SourceLocation CastLoc;
614    if (const CastExpr *C = dyn_cast<CastExpr>(this)) {
615      SubExpr = C->getSubExpr();
616      CastLoc = C->getLParenLoc();
617    } else {
618      SubExpr = cast<ImplicitCastExpr>(this)->getSubExpr();
619      CastLoc = getLocStart();
620    }
621    if (!SubExpr->isConstantExpr(Ctx, Loc)) {
622      if (Loc) *Loc = SubExpr->getLocStart();
623      return false;
624    }
625    return true;
626  }
627  case ConditionalOperatorClass: {
628    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
629    if (!Exp->getCond()->isConstantExpr(Ctx, Loc) ||
630        // Handle the GNU extension for missing LHS.
631        !(Exp->getLHS() && Exp->getLHS()->isConstantExpr(Ctx, Loc)) ||
632        !Exp->getRHS()->isConstantExpr(Ctx, Loc))
633      return false;
634    return true;
635  }
636  case InitListExprClass: {
637    const InitListExpr *Exp = cast<InitListExpr>(this);
638    unsigned numInits = Exp->getNumInits();
639    for (unsigned i = 0; i < numInits; i++) {
640      if (!Exp->getInit(i)->isConstantExpr(Ctx, Loc)) {
641        if (Loc) *Loc = Exp->getInit(i)->getLocStart();
642        return false;
643      }
644    }
645    return true;
646  }
647  case CXXDefaultArgExprClass:
648    return cast<CXXDefaultArgExpr>(this)->getExpr()->isConstantExpr(Ctx, Loc);
649  }
650}
651
652/// isIntegerConstantExpr - this recursive routine will test if an expression is
653/// an integer constant expression. Note: With the introduction of VLA's in
654/// C99 the result of the sizeof operator is no longer always a constant
655/// expression. The generalization of the wording to include any subexpression
656/// that is not evaluated (C99 6.6p3) means that nonconstant subexpressions
657/// can appear as operands to other operators (e.g. &&, ||, ?:). For instance,
658/// "0 || f()" can be treated as a constant expression. In C90 this expression,
659/// occurring in a context requiring a constant, would have been a constraint
660/// violation. FIXME: This routine currently implements C90 semantics.
661/// To properly implement C99 semantics this routine will need to evaluate
662/// expressions involving operators previously mentioned.
663
664/// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero,
665/// comma, etc
666///
667/// FIXME: This should ext-warn on overflow during evaluation!  ISO C does not
668/// permit this.  This includes things like (int)1e1000
669///
670/// FIXME: Handle offsetof.  Two things to do:  Handle GCC's __builtin_offsetof
671/// to support gcc 4.0+  and handle the idiom GCC recognizes with a null pointer
672/// cast+dereference.
673bool Expr::isIntegerConstantExpr(llvm::APSInt &Result, ASTContext &Ctx,
674                                 SourceLocation *Loc, bool isEvaluated) const {
675  switch (getStmtClass()) {
676  default:
677    if (Loc) *Loc = getLocStart();
678    return false;
679  case ParenExprClass:
680    return cast<ParenExpr>(this)->getSubExpr()->
681                     isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated);
682  case IntegerLiteralClass:
683    Result = cast<IntegerLiteral>(this)->getValue();
684    break;
685  case CharacterLiteralClass: {
686    const CharacterLiteral *CL = cast<CharacterLiteral>(this);
687    Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
688    Result = CL->getValue();
689    Result.setIsUnsigned(!getType()->isSignedIntegerType());
690    break;
691  }
692  case TypesCompatibleExprClass: {
693    const TypesCompatibleExpr *TCE = cast<TypesCompatibleExpr>(this);
694    Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
695    Result = Ctx.typesAreCompatible(TCE->getArgType1(), TCE->getArgType2());
696    break;
697  }
698  case CallExprClass: {
699    const CallExpr *CE = cast<CallExpr>(this);
700    Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
701    if (CE->isBuiltinClassifyType(Result))
702      break;
703    if (Loc) *Loc = getLocStart();
704    return false;
705  }
706  case DeclRefExprClass:
707    if (const EnumConstantDecl *D =
708          dyn_cast<EnumConstantDecl>(cast<DeclRefExpr>(this)->getDecl())) {
709      Result = D->getInitVal();
710      break;
711    }
712    if (Loc) *Loc = getLocStart();
713    return false;
714  case UnaryOperatorClass: {
715    const UnaryOperator *Exp = cast<UnaryOperator>(this);
716
717    // Get the operand value.  If this is sizeof/alignof, do not evalute the
718    // operand.  This affects C99 6.6p3.
719    if (!Exp->isSizeOfAlignOfOp() && !Exp->isOffsetOfOp() &&
720        !Exp->getSubExpr()->isIntegerConstantExpr(Result, Ctx, Loc,isEvaluated))
721      return false;
722
723    switch (Exp->getOpcode()) {
724    // Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
725    // See C99 6.6p3.
726    default:
727      if (Loc) *Loc = Exp->getOperatorLoc();
728      return false;
729    case UnaryOperator::Extension:
730      return true;  // FIXME: this is wrong.
731    case UnaryOperator::SizeOf:
732    case UnaryOperator::AlignOf:
733      // Return the result in the right width.
734      Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
735
736      // sizeof(void) and __alignof__(void) = 1 as a gcc extension.
737      if (Exp->getSubExpr()->getType()->isVoidType()) {
738        Result = 1;
739        break;
740      }
741
742      // sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
743      if (!Exp->getSubExpr()->getType()->isConstantSizeType()) {
744        if (Loc) *Loc = Exp->getOperatorLoc();
745        return false;
746      }
747
748      // Get information about the size or align.
749      if (Exp->getSubExpr()->getType()->isFunctionType()) {
750        // GCC extension: sizeof(function) = 1.
751        Result = Exp->getOpcode() == UnaryOperator::AlignOf ? 4 : 1;
752      } else {
753        unsigned CharSize = Ctx.Target.getCharWidth();
754        if (Exp->getOpcode() == UnaryOperator::AlignOf)
755          Result = Ctx.getTypeAlign(Exp->getSubExpr()->getType()) / CharSize;
756        else
757          Result = Ctx.getTypeSize(Exp->getSubExpr()->getType()) / CharSize;
758      }
759      break;
760    case UnaryOperator::LNot: {
761      bool Val = Result == 0;
762      Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
763      Result = Val;
764      break;
765    }
766    case UnaryOperator::Plus:
767      break;
768    case UnaryOperator::Minus:
769      Result = -Result;
770      break;
771    case UnaryOperator::Not:
772      Result = ~Result;
773      break;
774    case UnaryOperator::OffsetOf:
775      Result = Exp->evaluateOffsetOf(Ctx);
776    }
777    break;
778  }
779  case SizeOfAlignOfTypeExprClass: {
780    const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(this);
781
782    // Return the result in the right width.
783    Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
784
785    // sizeof(void) and __alignof__(void) = 1 as a gcc extension.
786    if (Exp->getArgumentType()->isVoidType()) {
787      Result = 1;
788      break;
789    }
790
791    // alignof always evaluates to a constant, sizeof does if arg is not VLA.
792    if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) {
793      if (Loc) *Loc = Exp->getOperatorLoc();
794      return false;
795    }
796
797    // Get information about the size or align.
798    if (Exp->getArgumentType()->isFunctionType()) {
799      // GCC extension: sizeof(function) = 1.
800      Result = Exp->isSizeOf() ? 1 : 4;
801    } else {
802      unsigned CharSize = Ctx.Target.getCharWidth();
803      if (Exp->isSizeOf())
804        Result = Ctx.getTypeSize(Exp->getArgumentType()) / CharSize;
805      else
806        Result = Ctx.getTypeAlign(Exp->getArgumentType()) / CharSize;
807    }
808    break;
809  }
810  case BinaryOperatorClass: {
811    const BinaryOperator *Exp = cast<BinaryOperator>(this);
812
813    // The LHS of a constant expr is always evaluated and needed.
814    if (!Exp->getLHS()->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
815      return false;
816
817    llvm::APSInt RHS(Result);
818
819    // The short-circuiting &&/|| operators don't necessarily evaluate their
820    // RHS.  Make sure to pass isEvaluated down correctly.
821    if (Exp->isLogicalOp()) {
822      bool RHSEval;
823      if (Exp->getOpcode() == BinaryOperator::LAnd)
824        RHSEval = Result != 0;
825      else {
826        assert(Exp->getOpcode() == BinaryOperator::LOr &&"Unexpected logical");
827        RHSEval = Result == 0;
828      }
829
830      if (!Exp->getRHS()->isIntegerConstantExpr(RHS, Ctx, Loc,
831                                                isEvaluated & RHSEval))
832        return false;
833    } else {
834      if (!Exp->getRHS()->isIntegerConstantExpr(RHS, Ctx, Loc, isEvaluated))
835        return false;
836    }
837
838    switch (Exp->getOpcode()) {
839    default:
840      if (Loc) *Loc = getLocStart();
841      return false;
842    case BinaryOperator::Mul:
843      Result *= RHS;
844      break;
845    case BinaryOperator::Div:
846      if (RHS == 0) {
847        if (!isEvaluated) break;
848        if (Loc) *Loc = getLocStart();
849        return false;
850      }
851      Result /= RHS;
852      break;
853    case BinaryOperator::Rem:
854      if (RHS == 0) {
855        if (!isEvaluated) break;
856        if (Loc) *Loc = getLocStart();
857        return false;
858      }
859      Result %= RHS;
860      break;
861    case BinaryOperator::Add: Result += RHS; break;
862    case BinaryOperator::Sub: Result -= RHS; break;
863    case BinaryOperator::Shl:
864      Result <<=
865        static_cast<uint32_t>(RHS.getLimitedValue(Result.getBitWidth()-1));
866      break;
867    case BinaryOperator::Shr:
868      Result >>=
869        static_cast<uint32_t>(RHS.getLimitedValue(Result.getBitWidth()-1));
870      break;
871    case BinaryOperator::LT:  Result = Result < RHS; break;
872    case BinaryOperator::GT:  Result = Result > RHS; break;
873    case BinaryOperator::LE:  Result = Result <= RHS; break;
874    case BinaryOperator::GE:  Result = Result >= RHS; break;
875    case BinaryOperator::EQ:  Result = Result == RHS; break;
876    case BinaryOperator::NE:  Result = Result != RHS; break;
877    case BinaryOperator::And: Result &= RHS; break;
878    case BinaryOperator::Xor: Result ^= RHS; break;
879    case BinaryOperator::Or:  Result |= RHS; break;
880    case BinaryOperator::LAnd:
881      Result = Result != 0 && RHS != 0;
882      break;
883    case BinaryOperator::LOr:
884      Result = Result != 0 || RHS != 0;
885      break;
886
887    case BinaryOperator::Comma:
888      // C99 6.6p3: "shall not contain assignment, ..., or comma operators,
889      // *except* when they are contained within a subexpression that is not
890      // evaluated".  Note that Assignment can never happen due to constraints
891      // on the LHS subexpr, so we don't need to check it here.
892      if (isEvaluated) {
893        if (Loc) *Loc = getLocStart();
894        return false;
895      }
896
897      // The result of the constant expr is the RHS.
898      Result = RHS;
899      return true;
900    }
901
902    assert(!Exp->isAssignmentOp() && "LHS can't be a constant expr!");
903    break;
904  }
905  case ImplicitCastExprClass:
906  case CastExprClass: {
907    const Expr *SubExpr;
908    SourceLocation CastLoc;
909    if (const CastExpr *C = dyn_cast<CastExpr>(this)) {
910      SubExpr = C->getSubExpr();
911      CastLoc = C->getLParenLoc();
912    } else {
913      SubExpr = cast<ImplicitCastExpr>(this)->getSubExpr();
914      CastLoc = getLocStart();
915    }
916
917    // C99 6.6p6: shall only convert arithmetic types to integer types.
918    if (!SubExpr->getType()->isArithmeticType() ||
919        !getType()->isIntegerType()) {
920      if (Loc) *Loc = SubExpr->getLocStart();
921      return false;
922    }
923
924    uint32_t DestWidth = static_cast<uint32_t>(Ctx.getTypeSize(getType()));
925
926    // Handle simple integer->integer casts.
927    if (SubExpr->getType()->isIntegerType()) {
928      if (!SubExpr->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
929        return false;
930
931      // Figure out if this is a truncate, extend or noop cast.
932      // If the input is signed, do a sign extend, noop, or truncate.
933      if (getType()->isBooleanType()) {
934        // Conversion to bool compares against zero.
935        Result = Result != 0;
936        Result.zextOrTrunc(DestWidth);
937      } else if (SubExpr->getType()->isSignedIntegerType())
938        Result.sextOrTrunc(DestWidth);
939      else  // If the input is unsigned, do a zero extend, noop, or truncate.
940        Result.zextOrTrunc(DestWidth);
941      break;
942    }
943
944    // Allow floating constants that are the immediate operands of casts or that
945    // are parenthesized.
946    const Expr *Operand = SubExpr;
947    while (const ParenExpr *PE = dyn_cast<ParenExpr>(Operand))
948      Operand = PE->getSubExpr();
949
950    // If this isn't a floating literal, we can't handle it.
951    const FloatingLiteral *FL = dyn_cast<FloatingLiteral>(Operand);
952    if (!FL) {
953      if (Loc) *Loc = Operand->getLocStart();
954      return false;
955    }
956
957    // If the destination is boolean, compare against zero.
958    if (getType()->isBooleanType()) {
959      Result = !FL->getValue().isZero();
960      Result.zextOrTrunc(DestWidth);
961      break;
962    }
963
964    // Determine whether we are converting to unsigned or signed.
965    bool DestSigned = getType()->isSignedIntegerType();
966
967    // TODO: Warn on overflow, but probably not here: isIntegerConstantExpr can
968    // be called multiple times per AST.
969    uint64_t Space[4];
970    (void)FL->getValue().convertToInteger(Space, DestWidth, DestSigned,
971                                          llvm::APFloat::rmTowardZero);
972    Result = llvm::APInt(DestWidth, 4, Space);
973    break;
974  }
975  case ConditionalOperatorClass: {
976    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
977
978    if (!Exp->getCond()->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
979      return false;
980
981    const Expr *TrueExp  = Exp->getLHS();
982    const Expr *FalseExp = Exp->getRHS();
983    if (Result == 0) std::swap(TrueExp, FalseExp);
984
985    // Evaluate the false one first, discard the result.
986    if (FalseExp && !FalseExp->isIntegerConstantExpr(Result, Ctx, Loc, false))
987      return false;
988    // Evalute the true one, capture the result.
989    if (TrueExp &&
990        !TrueExp->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
991      return false;
992    break;
993  }
994  case CXXDefaultArgExprClass:
995    return cast<CXXDefaultArgExpr>(this)
996             ->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated);
997  }
998
999  // Cases that are valid constant exprs fall through to here.
1000  Result.setIsUnsigned(getType()->isUnsignedIntegerType());
1001  return true;
1002}
1003
1004/// isNullPointerConstant - C99 6.3.2.3p3 -  Return true if this is either an
1005/// integer constant expression with the value zero, or if this is one that is
1006/// cast to void*.
1007bool Expr::isNullPointerConstant(ASTContext &Ctx) const {
1008  // Strip off a cast to void*, if it exists.
1009  if (const CastExpr *CE = dyn_cast<CastExpr>(this)) {
1010    // Check that it is a cast to void*.
1011    if (const PointerType *PT = CE->getType()->getAsPointerType()) {
1012      QualType Pointee = PT->getPointeeType();
1013      if (Pointee.getCVRQualifiers() == 0 &&
1014          Pointee->isVoidType() &&                                 // to void*
1015          CE->getSubExpr()->getType()->isIntegerType())            // from int.
1016        return CE->getSubExpr()->isNullPointerConstant(Ctx);
1017    }
1018  } else if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(this)) {
1019    // Ignore the ImplicitCastExpr type entirely.
1020    return ICE->getSubExpr()->isNullPointerConstant(Ctx);
1021  } else if (const ParenExpr *PE = dyn_cast<ParenExpr>(this)) {
1022    // Accept ((void*)0) as a null pointer constant, as many other
1023    // implementations do.
1024    return PE->getSubExpr()->isNullPointerConstant(Ctx);
1025  } else if (const CXXDefaultArgExpr *DefaultArg
1026               = dyn_cast<CXXDefaultArgExpr>(this)) {
1027    // See through default argument expressions
1028    return DefaultArg->getExpr()->isNullPointerConstant(Ctx);
1029  }
1030
1031  // This expression must be an integer type.
1032  if (!getType()->isIntegerType())
1033    return false;
1034
1035  // If we have an integer constant expression, we need to *evaluate* it and
1036  // test for the value 0.
1037  llvm::APSInt Val(32);
1038  return isIntegerConstantExpr(Val, Ctx, 0, true) && Val == 0;
1039}
1040
1041unsigned ExtVectorElementExpr::getNumElements() const {
1042  if (const VectorType *VT = getType()->getAsVectorType())
1043    return VT->getNumElements();
1044  return 1;
1045}
1046
1047/// containsDuplicateElements - Return true if any element access is repeated.
1048bool ExtVectorElementExpr::containsDuplicateElements() const {
1049  const char *compStr = Accessor.getName();
1050  unsigned length = strlen(compStr);
1051
1052  for (unsigned i = 0; i < length-1; i++) {
1053    const char *s = compStr+i;
1054    for (const char c = *s++; *s; s++)
1055      if (c == *s)
1056        return true;
1057  }
1058  return false;
1059}
1060
1061/// getEncodedElementAccess - We encode the fields as a llvm ConstantArray.
1062void ExtVectorElementExpr::getEncodedElementAccess(
1063                                  llvm::SmallVectorImpl<unsigned> &Elts) const {
1064  const char *compStr = Accessor.getName();
1065
1066  bool isHi =   !strcmp(compStr, "hi");
1067  bool isLo =   !strcmp(compStr, "lo");
1068  bool isEven = !strcmp(compStr, "e");
1069  bool isOdd  = !strcmp(compStr, "o");
1070
1071  for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
1072    uint64_t Index;
1073
1074    if (isHi)
1075      Index = e + i;
1076    else if (isLo)
1077      Index = i;
1078    else if (isEven)
1079      Index = 2 * i;
1080    else if (isOdd)
1081      Index = 2 * i + 1;
1082    else
1083      Index = ExtVectorType::getAccessorIdx(compStr[i]);
1084
1085    Elts.push_back(Index);
1086  }
1087}
1088
1089// constructor for instance messages.
1090ObjCMessageExpr::ObjCMessageExpr(Expr *receiver, Selector selInfo,
1091                QualType retType, ObjCMethodDecl *mproto,
1092                SourceLocation LBrac, SourceLocation RBrac,
1093                Expr **ArgExprs, unsigned nargs)
1094  : Expr(ObjCMessageExprClass, retType), SelName(selInfo),
1095    MethodProto(mproto) {
1096  NumArgs = nargs;
1097  SubExprs = new Expr*[NumArgs+1];
1098  SubExprs[RECEIVER] = receiver;
1099  if (NumArgs) {
1100    for (unsigned i = 0; i != NumArgs; ++i)
1101      SubExprs[i+ARGS_START] = static_cast<Expr *>(ArgExprs[i]);
1102  }
1103  LBracloc = LBrac;
1104  RBracloc = RBrac;
1105}
1106
1107// constructor for class messages.
1108// FIXME: clsName should be typed to ObjCInterfaceType
1109ObjCMessageExpr::ObjCMessageExpr(IdentifierInfo *clsName, Selector selInfo,
1110                QualType retType, ObjCMethodDecl *mproto,
1111                SourceLocation LBrac, SourceLocation RBrac,
1112                Expr **ArgExprs, unsigned nargs)
1113  : Expr(ObjCMessageExprClass, retType), SelName(selInfo),
1114    MethodProto(mproto) {
1115  NumArgs = nargs;
1116  SubExprs = new Expr*[NumArgs+1];
1117  SubExprs[RECEIVER] = (Expr*) ((uintptr_t) clsName | 0x1);
1118  if (NumArgs) {
1119    for (unsigned i = 0; i != NumArgs; ++i)
1120      SubExprs[i+ARGS_START] = static_cast<Expr *>(ArgExprs[i]);
1121  }
1122  LBracloc = LBrac;
1123  RBracloc = RBrac;
1124}
1125
1126bool ChooseExpr::isConditionTrue(ASTContext &C) const {
1127  llvm::APSInt CondVal(32);
1128  bool IsConst = getCond()->isIntegerConstantExpr(CondVal, C);
1129  assert(IsConst && "Condition of choose expr must be i-c-e"); IsConst=IsConst;
1130  return CondVal != 0;
1131}
1132
1133static int64_t evaluateOffsetOf(ASTContext& C, const Expr *E)
1134{
1135  if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
1136    QualType Ty = ME->getBase()->getType();
1137
1138    RecordDecl *RD = Ty->getAsRecordType()->getDecl();
1139    const ASTRecordLayout &RL = C.getASTRecordLayout(RD);
1140    FieldDecl *FD = ME->getMemberDecl();
1141
1142    // FIXME: This is linear time.
1143    unsigned i = 0, e = 0;
1144    for (i = 0, e = RD->getNumMembers(); i != e; i++) {
1145      if (RD->getMember(i) == FD)
1146        break;
1147    }
1148
1149    return RL.getFieldOffset(i) + evaluateOffsetOf(C, ME->getBase());
1150  } else if (const ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(E)) {
1151    const Expr *Base = ASE->getBase();
1152    llvm::APSInt Idx(32);
1153    bool ICE = ASE->getIdx()->isIntegerConstantExpr(Idx, C);
1154    assert(ICE && "Array index is not a constant integer!");
1155
1156    int64_t size = C.getTypeSize(ASE->getType());
1157    size *= Idx.getSExtValue();
1158
1159    return size + evaluateOffsetOf(C, Base);
1160  } else if (isa<CompoundLiteralExpr>(E))
1161    return 0;
1162
1163  assert(0 && "Unknown offsetof subexpression!");
1164  return 0;
1165}
1166
1167int64_t UnaryOperator::evaluateOffsetOf(ASTContext& C) const
1168{
1169  assert(Opc == OffsetOf && "Unary operator not offsetof!");
1170
1171  unsigned CharSize = C.Target.getCharWidth();
1172  return ::evaluateOffsetOf(C, Val) / CharSize;
1173}
1174
1175//===----------------------------------------------------------------------===//
1176//  Child Iterators for iterating over subexpressions/substatements
1177//===----------------------------------------------------------------------===//
1178
1179// DeclRefExpr
1180Stmt::child_iterator DeclRefExpr::child_begin() { return child_iterator(); }
1181Stmt::child_iterator DeclRefExpr::child_end() { return child_iterator(); }
1182
1183// ObjCIvarRefExpr
1184Stmt::child_iterator ObjCIvarRefExpr::child_begin() {
1185  return reinterpret_cast<Stmt**>(&Base);
1186}
1187
1188Stmt::child_iterator ObjCIvarRefExpr::child_end() {
1189  return reinterpret_cast<Stmt**>(&Base)+1;
1190}
1191
1192// ObjCPropertyRefExpr
1193Stmt::child_iterator ObjCPropertyRefExpr::child_begin() {
1194  return reinterpret_cast<Stmt**>(&Base);
1195}
1196
1197Stmt::child_iterator ObjCPropertyRefExpr::child_end() {
1198  return reinterpret_cast<Stmt**>(&Base)+1;
1199}
1200
1201// ObjCSuperRefExpr
1202Stmt::child_iterator ObjCSuperRefExpr::child_begin() { return child_iterator();}
1203Stmt::child_iterator ObjCSuperRefExpr::child_end() { return child_iterator(); }
1204
1205// PreDefinedExpr
1206Stmt::child_iterator PreDefinedExpr::child_begin() { return child_iterator(); }
1207Stmt::child_iterator PreDefinedExpr::child_end() { return child_iterator(); }
1208
1209// IntegerLiteral
1210Stmt::child_iterator IntegerLiteral::child_begin() { return child_iterator(); }
1211Stmt::child_iterator IntegerLiteral::child_end() { return child_iterator(); }
1212
1213// CharacterLiteral
1214Stmt::child_iterator CharacterLiteral::child_begin() { return child_iterator(); }
1215Stmt::child_iterator CharacterLiteral::child_end() { return child_iterator(); }
1216
1217// FloatingLiteral
1218Stmt::child_iterator FloatingLiteral::child_begin() { return child_iterator(); }
1219Stmt::child_iterator FloatingLiteral::child_end() { return child_iterator(); }
1220
1221// ImaginaryLiteral
1222Stmt::child_iterator ImaginaryLiteral::child_begin() {
1223  return reinterpret_cast<Stmt**>(&Val);
1224}
1225Stmt::child_iterator ImaginaryLiteral::child_end() {
1226  return reinterpret_cast<Stmt**>(&Val)+1;
1227}
1228
1229// StringLiteral
1230Stmt::child_iterator StringLiteral::child_begin() { return child_iterator(); }
1231Stmt::child_iterator StringLiteral::child_end() { return child_iterator(); }
1232
1233// ParenExpr
1234Stmt::child_iterator ParenExpr::child_begin() {
1235  return reinterpret_cast<Stmt**>(&Val);
1236}
1237Stmt::child_iterator ParenExpr::child_end() {
1238  return reinterpret_cast<Stmt**>(&Val)+1;
1239}
1240
1241// UnaryOperator
1242Stmt::child_iterator UnaryOperator::child_begin() {
1243  return reinterpret_cast<Stmt**>(&Val);
1244}
1245Stmt::child_iterator UnaryOperator::child_end() {
1246  return reinterpret_cast<Stmt**>(&Val+1);
1247}
1248
1249// SizeOfAlignOfTypeExpr
1250Stmt::child_iterator SizeOfAlignOfTypeExpr::child_begin() {
1251  // If the type is a VLA type (and not a typedef), the size expression of the
1252  // VLA needs to be treated as an executable expression.
1253  if (VariableArrayType* T = dyn_cast<VariableArrayType>(Ty.getTypePtr()))
1254    return child_iterator(T);
1255  else
1256    return child_iterator();
1257}
1258Stmt::child_iterator SizeOfAlignOfTypeExpr::child_end() {
1259  return child_iterator();
1260}
1261
1262// ArraySubscriptExpr
1263Stmt::child_iterator ArraySubscriptExpr::child_begin() {
1264  return reinterpret_cast<Stmt**>(&SubExprs);
1265}
1266Stmt::child_iterator ArraySubscriptExpr::child_end() {
1267  return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
1268}
1269
1270// CallExpr
1271Stmt::child_iterator CallExpr::child_begin() {
1272  return reinterpret_cast<Stmt**>(&SubExprs[0]);
1273}
1274Stmt::child_iterator CallExpr::child_end() {
1275  return reinterpret_cast<Stmt**>(&SubExprs[NumArgs+ARGS_START]);
1276}
1277
1278// MemberExpr
1279Stmt::child_iterator MemberExpr::child_begin() {
1280  return reinterpret_cast<Stmt**>(&Base);
1281}
1282Stmt::child_iterator MemberExpr::child_end() {
1283  return reinterpret_cast<Stmt**>(&Base)+1;
1284}
1285
1286// ExtVectorElementExpr
1287Stmt::child_iterator ExtVectorElementExpr::child_begin() {
1288  return reinterpret_cast<Stmt**>(&Base);
1289}
1290Stmt::child_iterator ExtVectorElementExpr::child_end() {
1291  return reinterpret_cast<Stmt**>(&Base)+1;
1292}
1293
1294// CompoundLiteralExpr
1295Stmt::child_iterator CompoundLiteralExpr::child_begin() {
1296  return reinterpret_cast<Stmt**>(&Init);
1297}
1298Stmt::child_iterator CompoundLiteralExpr::child_end() {
1299  return reinterpret_cast<Stmt**>(&Init)+1;
1300}
1301
1302// ImplicitCastExpr
1303Stmt::child_iterator ImplicitCastExpr::child_begin() {
1304  return reinterpret_cast<Stmt**>(&Op);
1305}
1306Stmt::child_iterator ImplicitCastExpr::child_end() {
1307  return reinterpret_cast<Stmt**>(&Op)+1;
1308}
1309
1310// CastExpr
1311Stmt::child_iterator CastExpr::child_begin() {
1312  return reinterpret_cast<Stmt**>(&Op);
1313}
1314Stmt::child_iterator CastExpr::child_end() {
1315  return reinterpret_cast<Stmt**>(&Op)+1;
1316}
1317
1318// BinaryOperator
1319Stmt::child_iterator BinaryOperator::child_begin() {
1320  return reinterpret_cast<Stmt**>(&SubExprs);
1321}
1322Stmt::child_iterator BinaryOperator::child_end() {
1323  return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
1324}
1325
1326// ConditionalOperator
1327Stmt::child_iterator ConditionalOperator::child_begin() {
1328  return reinterpret_cast<Stmt**>(&SubExprs);
1329}
1330Stmt::child_iterator ConditionalOperator::child_end() {
1331  return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
1332}
1333
1334// AddrLabelExpr
1335Stmt::child_iterator AddrLabelExpr::child_begin() { return child_iterator(); }
1336Stmt::child_iterator AddrLabelExpr::child_end() { return child_iterator(); }
1337
1338// StmtExpr
1339Stmt::child_iterator StmtExpr::child_begin() {
1340  return reinterpret_cast<Stmt**>(&SubStmt);
1341}
1342Stmt::child_iterator StmtExpr::child_end() {
1343  return reinterpret_cast<Stmt**>(&SubStmt)+1;
1344}
1345
1346// TypesCompatibleExpr
1347Stmt::child_iterator TypesCompatibleExpr::child_begin() {
1348  return child_iterator();
1349}
1350
1351Stmt::child_iterator TypesCompatibleExpr::child_end() {
1352  return child_iterator();
1353}
1354
1355// ChooseExpr
1356Stmt::child_iterator ChooseExpr::child_begin() {
1357  return reinterpret_cast<Stmt**>(&SubExprs);
1358}
1359
1360Stmt::child_iterator ChooseExpr::child_end() {
1361  return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
1362}
1363
1364// OverloadExpr
1365Stmt::child_iterator OverloadExpr::child_begin() {
1366  return reinterpret_cast<Stmt**>(&SubExprs[0]);
1367}
1368Stmt::child_iterator OverloadExpr::child_end() {
1369  return reinterpret_cast<Stmt**>(&SubExprs[NumExprs]);
1370}
1371
1372// ShuffleVectorExpr
1373Stmt::child_iterator ShuffleVectorExpr::child_begin() {
1374  return reinterpret_cast<Stmt**>(&SubExprs[0]);
1375}
1376Stmt::child_iterator ShuffleVectorExpr::child_end() {
1377  return reinterpret_cast<Stmt**>(&SubExprs[NumExprs]);
1378}
1379
1380// VAArgExpr
1381Stmt::child_iterator VAArgExpr::child_begin() {
1382  return reinterpret_cast<Stmt**>(&Val);
1383}
1384
1385Stmt::child_iterator VAArgExpr::child_end() {
1386  return reinterpret_cast<Stmt**>(&Val)+1;
1387}
1388
1389// InitListExpr
1390Stmt::child_iterator InitListExpr::child_begin() {
1391  return reinterpret_cast<Stmt**>(InitExprs.size() ?
1392                                  &InitExprs[0] : 0);
1393}
1394Stmt::child_iterator InitListExpr::child_end() {
1395  return reinterpret_cast<Stmt**>(InitExprs.size() ?
1396                                  &InitExprs[0] + InitExprs.size() : 0);
1397}
1398
1399// ObjCStringLiteral
1400Stmt::child_iterator ObjCStringLiteral::child_begin() {
1401  return child_iterator();
1402}
1403Stmt::child_iterator ObjCStringLiteral::child_end() {
1404  return child_iterator();
1405}
1406
1407// ObjCEncodeExpr
1408Stmt::child_iterator ObjCEncodeExpr::child_begin() { return child_iterator(); }
1409Stmt::child_iterator ObjCEncodeExpr::child_end() { return child_iterator(); }
1410
1411// ObjCSelectorExpr
1412Stmt::child_iterator ObjCSelectorExpr::child_begin() {
1413  return child_iterator();
1414}
1415Stmt::child_iterator ObjCSelectorExpr::child_end() {
1416  return child_iterator();
1417}
1418
1419// ObjCProtocolExpr
1420Stmt::child_iterator ObjCProtocolExpr::child_begin() {
1421  return child_iterator();
1422}
1423Stmt::child_iterator ObjCProtocolExpr::child_end() {
1424  return child_iterator();
1425}
1426
1427// ObjCMessageExpr
1428Stmt::child_iterator ObjCMessageExpr::child_begin() {
1429  return reinterpret_cast<Stmt**>(&SubExprs[ getReceiver() ? 0 : ARGS_START ]);
1430}
1431Stmt::child_iterator ObjCMessageExpr::child_end() {
1432  return reinterpret_cast<Stmt**>(&SubExprs[getNumArgs()+ARGS_START]);
1433}
1434
1435