Expr.cpp revision d38617c8a50f9729c254ab76cd359af797c6739b 
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/ASTContext.h"
16#include "clang/AST/StmtVisitor.h"
17#include "clang/Basic/IdentifierTable.h"
18#include "clang/Basic/TargetInfo.h"
19#include "llvm/Constants.h"
20#include "llvm/DerivedTypes.h"
21using namespace clang;
22
23//===----------------------------------------------------------------------===//
24// Primary Expressions.
25//===----------------------------------------------------------------------===//
26
27StringLiteral::StringLiteral(const char *strData, unsigned byteLength,
28                             bool Wide, QualType t, SourceLocation firstLoc,
29                             SourceLocation lastLoc) :
30  Expr(StringLiteralClass, t) {
31  // OPTIMIZE: could allocate this appended to the StringLiteral.
32  char *AStrData = new char[byteLength];
33  memcpy(AStrData, strData, byteLength);
34  StrData = AStrData;
35  ByteLength = byteLength;
36  IsWide = Wide;
37  firstTokLoc = firstLoc;
38  lastTokLoc = lastLoc;
39}
40
41StringLiteral::~StringLiteral() {
42  delete[] StrData;
43}
44
45bool UnaryOperator::isPostfix(Opcode Op) {
46  switch (Op) {
47  case PostInc:
48  case PostDec:
49    return true;
50  default:
51    return false;
52  }
53}
54
55/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
56/// corresponds to, e.g. "sizeof" or "[pre]++".
57const char *UnaryOperator::getOpcodeStr(Opcode Op) {
58  switch (Op) {
59  default: assert(0 && "Unknown unary operator");
60  case PostInc: return "++";
61  case PostDec: return "--";
62  case PreInc:  return "++";
63  case PreDec:  return "--";
64  case AddrOf:  return "&";
65  case Deref:   return "*";
66  case Plus:    return "+";
67  case Minus:   return "-";
68  case Not:     return "~";
69  case LNot:    return "!";
70  case Real:    return "__real";
71  case Imag:    return "__imag";
72  case SizeOf:  return "sizeof";
73  case AlignOf: return "alignof";
74  case Extension: return "__extension__";
75  case OffsetOf: return "__builtin_offsetof";
76  }
77}
78
79//===----------------------------------------------------------------------===//
80// Postfix Operators.
81//===----------------------------------------------------------------------===//
82
83
84CallExpr::CallExpr(Expr *fn, Expr **args, unsigned numargs, QualType t,
85                   SourceLocation rparenloc)
86  : Expr(CallExprClass, t), NumArgs(numargs) {
87  SubExprs = new Expr*[numargs+1];
88  SubExprs[FN] = fn;
89  for (unsigned i = 0; i != numargs; ++i)
90    SubExprs[i+ARGS_START] = args[i];
91  RParenLoc = rparenloc;
92}
93
94/// setNumArgs - This changes the number of arguments present in this call.
95/// Any orphaned expressions are deleted by this, and any new operands are set
96/// to null.
97void CallExpr::setNumArgs(unsigned NumArgs) {
98  // No change, just return.
99  if (NumArgs == getNumArgs()) return;
100
101  // If shrinking # arguments, just delete the extras and forgot them.
102  if (NumArgs < getNumArgs()) {
103    for (unsigned i = NumArgs, e = getNumArgs(); i != e; ++i)
104      delete getArg(i);
105    this->NumArgs = NumArgs;
106    return;
107  }
108
109  // Otherwise, we are growing the # arguments.  New an bigger argument array.
110  Expr **NewSubExprs = new Expr*[NumArgs+1];
111  // Copy over args.
112  for (unsigned i = 0; i != getNumArgs()+ARGS_START; ++i)
113    NewSubExprs[i] = SubExprs[i];
114  // Null out new args.
115  for (unsigned i = getNumArgs()+ARGS_START; i != NumArgs+ARGS_START; ++i)
116    NewSubExprs[i] = 0;
117
118  delete[] SubExprs;
119  SubExprs = NewSubExprs;
120  this->NumArgs = NumArgs;
121}
122
123bool CallExpr::isBuiltinConstantExpr() const {
124  // All simple function calls (e.g. func()) are implicitly cast to pointer to
125  // function. As a result, we try and obtain the DeclRefExpr from the
126  // ImplicitCastExpr.
127  const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
128  if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
129    return false;
130
131  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
132  if (!DRE)
133    return false;
134
135  const FunctionDecl *FDecl = dyn_cast<FunctionDecl>(DRE->getDecl());
136  if (!FDecl)
137    return false;
138
139  unsigned builtinID = FDecl->getIdentifier()->getBuiltinID();
140  if (!builtinID)
141    return false;
142
143  // We have a builtin that is a constant expression
144  if (builtinID == Builtin::BI__builtin___CFStringMakeConstantString)
145    return true;
146  return false;
147}
148
149bool CallExpr::isBuiltinClassifyType(llvm::APSInt &Result) const {
150  // The following enum mimics gcc's internal "typeclass.h" file.
151  enum gcc_type_class {
152    no_type_class = -1,
153    void_type_class, integer_type_class, char_type_class,
154    enumeral_type_class, boolean_type_class,
155    pointer_type_class, reference_type_class, offset_type_class,
156    real_type_class, complex_type_class,
157    function_type_class, method_type_class,
158    record_type_class, union_type_class,
159    array_type_class, string_type_class,
160    lang_type_class
161  };
162  Result.setIsSigned(true);
163
164  // All simple function calls (e.g. func()) are implicitly cast to pointer to
165  // function. As a result, we try and obtain the DeclRefExpr from the
166  // ImplicitCastExpr.
167  const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(getCallee());
168  if (!ICE) // FIXME: deal with more complex calls (e.g. (func)(), (*func)()).
169    return false;
170  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr());
171  if (!DRE)
172    return false;
173
174  // We have a DeclRefExpr.
175  if (strcmp(DRE->getDecl()->getName(), "__builtin_classify_type") == 0) {
176    // If no argument was supplied, default to "no_type_class". This isn't
177    // ideal, however it's what gcc does.
178    Result = static_cast<uint64_t>(no_type_class);
179    if (NumArgs >= 1) {
180      QualType argType = getArg(0)->getType();
181
182      if (argType->isVoidType())
183        Result = void_type_class;
184      else if (argType->isEnumeralType())
185        Result = enumeral_type_class;
186      else if (argType->isBooleanType())
187        Result = boolean_type_class;
188      else if (argType->isCharType())
189        Result = string_type_class; // gcc doesn't appear to use char_type_class
190      else if (argType->isIntegerType())
191        Result = integer_type_class;
192      else if (argType->isPointerType())
193        Result = pointer_type_class;
194      else if (argType->isReferenceType())
195        Result = reference_type_class;
196      else if (argType->isRealType())
197        Result = real_type_class;
198      else if (argType->isComplexType())
199        Result = complex_type_class;
200      else if (argType->isFunctionType())
201        Result = function_type_class;
202      else if (argType->isStructureType())
203        Result = record_type_class;
204      else if (argType->isUnionType())
205        Result = union_type_class;
206      else if (argType->isArrayType())
207        Result = array_type_class;
208      else if (argType->isUnionType())
209        Result = union_type_class;
210      else  // FIXME: offset_type_class, method_type_class, & lang_type_class?
211        assert(0 && "CallExpr::isBuiltinClassifyType(): unimplemented type");
212    }
213    return true;
214  }
215  return false;
216}
217
218/// getOpcodeStr - Turn an Opcode enum value into the punctuation char it
219/// corresponds to, e.g. "<<=".
220const char *BinaryOperator::getOpcodeStr(Opcode Op) {
221  switch (Op) {
222  default: assert(0 && "Unknown binary operator");
223  case Mul:       return "*";
224  case Div:       return "/";
225  case Rem:       return "%";
226  case Add:       return "+";
227  case Sub:       return "-";
228  case Shl:       return "<<";
229  case Shr:       return ">>";
230  case LT:        return "<";
231  case GT:        return ">";
232  case LE:        return "<=";
233  case GE:        return ">=";
234  case EQ:        return "==";
235  case NE:        return "!=";
236  case And:       return "&";
237  case Xor:       return "^";
238  case Or:        return "|";
239  case LAnd:      return "&&";
240  case LOr:       return "||";
241  case Assign:    return "=";
242  case MulAssign: return "*=";
243  case DivAssign: return "/=";
244  case RemAssign: return "%=";
245  case AddAssign: return "+=";
246  case SubAssign: return "-=";
247  case ShlAssign: return "<<=";
248  case ShrAssign: return ">>=";
249  case AndAssign: return "&=";
250  case XorAssign: return "^=";
251  case OrAssign:  return "|=";
252  case Comma:     return ",";
253  }
254}
255
256InitListExpr::InitListExpr(SourceLocation lbraceloc,
257                           Expr **initexprs, unsigned numinits,
258                           SourceLocation rbraceloc)
259  : Expr(InitListExprClass, QualType()),
260    LBraceLoc(lbraceloc), RBraceLoc(rbraceloc)
261{
262  for (unsigned i = 0; i != numinits; i++)
263    InitExprs.push_back(initexprs[i]);
264}
265
266//===----------------------------------------------------------------------===//
267// Generic Expression Routines
268//===----------------------------------------------------------------------===//
269
270/// hasLocalSideEffect - Return true if this immediate expression has side
271/// effects, not counting any sub-expressions.
272bool Expr::hasLocalSideEffect() const {
273  switch (getStmtClass()) {
274  default:
275    return false;
276  case ParenExprClass:
277    return cast<ParenExpr>(this)->getSubExpr()->hasLocalSideEffect();
278  case UnaryOperatorClass: {
279    const UnaryOperator *UO = cast<UnaryOperator>(this);
280
281    switch (UO->getOpcode()) {
282    default: return false;
283    case UnaryOperator::PostInc:
284    case UnaryOperator::PostDec:
285    case UnaryOperator::PreInc:
286    case UnaryOperator::PreDec:
287      return true;                     // ++/--
288
289    case UnaryOperator::Deref:
290      // Dereferencing a volatile pointer is a side-effect.
291      return getType().isVolatileQualified();
292    case UnaryOperator::Real:
293    case UnaryOperator::Imag:
294      // accessing a piece of a volatile complex is a side-effect.
295      return UO->getSubExpr()->getType().isVolatileQualified();
296
297    case UnaryOperator::Extension:
298      return UO->getSubExpr()->hasLocalSideEffect();
299    }
300  }
301  case BinaryOperatorClass: {
302    const BinaryOperator *BinOp = cast<BinaryOperator>(this);
303    // Consider comma to have side effects if the LHS and RHS both do.
304    if (BinOp->getOpcode() == BinaryOperator::Comma)
305      return BinOp->getLHS()->hasLocalSideEffect() &&
306             BinOp->getRHS()->hasLocalSideEffect();
307
308    return BinOp->isAssignmentOp();
309  }
310  case CompoundAssignOperatorClass:
311    return true;
312
313  case ConditionalOperatorClass: {
314    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
315    return Exp->getCond()->hasLocalSideEffect()
316           || (Exp->getLHS() && Exp->getLHS()->hasLocalSideEffect())
317           || (Exp->getRHS() && Exp->getRHS()->hasLocalSideEffect());
318  }
319
320  case MemberExprClass:
321  case ArraySubscriptExprClass:
322    // If the base pointer or element is to a volatile pointer/field, accessing
323    // if is a side effect.
324    return getType().isVolatileQualified();
325
326  case CallExprClass:
327    // TODO: check attributes for pure/const.   "void foo() { strlen("bar"); }"
328    // should warn.
329    return true;
330  case ObjCMessageExprClass:
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 CXXDefaultArgExprClass:
341    return cast<CXXDefaultArgExpr>(this)->getExpr()->hasLocalSideEffect();
342  }
343}
344
345/// isLvalue - C99 6.3.2.1: an lvalue is an expression with an object type or an
346/// incomplete type other than void. Nonarray expressions that can be lvalues:
347///  - name, where name must be a variable
348///  - e[i]
349///  - (e), where e must be an lvalue
350///  - e.name, where e must be an lvalue
351///  - e->name
352///  - *e, the type of e cannot be a function type
353///  - string-constant
354///  - (__real__ e) and (__imag__ e) where e is an lvalue  [GNU extension]
355///  - reference type [C++ [expr]]
356///
357Expr::isLvalueResult Expr::isLvalue() const {
358  // first, check the type (C99 6.3.2.1)
359  if (TR->isFunctionType()) // from isObjectType()
360    return LV_NotObjectType;
361
362  // Allow qualified void which is an incomplete type other than void (yuck).
363  if (TR->isVoidType() && !TR.getCanonicalType().getCVRQualifiers())
364    return LV_IncompleteVoidType;
365
366  if (TR->isReferenceType()) // C++ [expr]
367    return LV_Valid;
368
369  // the type looks fine, now check the expression
370  switch (getStmtClass()) {
371  case StringLiteralClass: // C99 6.5.1p4
372    return LV_Valid;
373  case ArraySubscriptExprClass: // C99 6.5.3p4 (e1[e2] == (*((e1)+(e2))))
374    // For vectors, make sure base is an lvalue (i.e. not a function call).
375    if (cast<ArraySubscriptExpr>(this)->getBase()->getType()->isVectorType())
376      return cast<ArraySubscriptExpr>(this)->getBase()->isLvalue();
377    return LV_Valid;
378  case DeclRefExprClass: // C99 6.5.1p2
379    if (isa<VarDecl>(cast<DeclRefExpr>(this)->getDecl()))
380      return LV_Valid;
381    break;
382  case MemberExprClass: { // C99 6.5.2.3p4
383    const MemberExpr *m = cast<MemberExpr>(this);
384    return m->isArrow() ? LV_Valid : m->getBase()->isLvalue();
385  }
386  case UnaryOperatorClass:
387    if (cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Deref)
388      return LV_Valid; // C99 6.5.3p4
389
390    if (cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Real ||
391        cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Imag)
392      return cast<UnaryOperator>(this)->getSubExpr()->isLvalue();  // GNU.
393    break;
394  case ParenExprClass: // C99 6.5.1p5
395    return cast<ParenExpr>(this)->getSubExpr()->isLvalue();
396  case CompoundLiteralExprClass: // C99 6.5.2.5p5
397    return LV_Valid;
398  case ExtVectorElementExprClass:
399    if (cast<ExtVectorElementExpr>(this)->containsDuplicateElements())
400      return LV_DuplicateVectorComponents;
401    return LV_Valid;
402  case ObjCIvarRefExprClass: // ObjC instance variables are lvalues.
403    return LV_Valid;
404  case PreDefinedExprClass:
405    return LV_Valid;
406  case CXXDefaultArgExprClass:
407    return cast<CXXDefaultArgExpr>(this)->getExpr()->isLvalue();
408  default:
409    break;
410  }
411  return LV_InvalidExpression;
412}
413
414/// isModifiableLvalue - C99 6.3.2.1: an lvalue that does not have array type,
415/// does not have an incomplete type, does not have a const-qualified type, and
416/// if it is a structure or union, does not have any member (including,
417/// recursively, any member or element of all contained aggregates or unions)
418/// with a const-qualified type.
419Expr::isModifiableLvalueResult Expr::isModifiableLvalue() const {
420  isLvalueResult lvalResult = isLvalue();
421
422  switch (lvalResult) {
423  case LV_Valid: break;
424  case LV_NotObjectType: return MLV_NotObjectType;
425  case LV_IncompleteVoidType: return MLV_IncompleteVoidType;
426  case LV_DuplicateVectorComponents: return MLV_DuplicateVectorComponents;
427  case LV_InvalidExpression: return MLV_InvalidExpression;
428  }
429  if (TR.isConstQualified())
430    return MLV_ConstQualified;
431  if (TR->isArrayType())
432    return MLV_ArrayType;
433  if (TR->isIncompleteType())
434    return MLV_IncompleteType;
435
436  if (const RecordType *r = dyn_cast<RecordType>(TR.getCanonicalType())) {
437    if (r->hasConstFields())
438      return MLV_ConstQualified;
439  }
440  return MLV_Valid;
441}
442
443/// hasGlobalStorage - Return true if this expression has static storage
444/// duration.  This means that the address of this expression is a link-time
445/// constant.
446bool Expr::hasGlobalStorage() const {
447  switch (getStmtClass()) {
448  default:
449    return false;
450  case ParenExprClass:
451    return cast<ParenExpr>(this)->getSubExpr()->hasGlobalStorage();
452  case ImplicitCastExprClass:
453    return cast<ImplicitCastExpr>(this)->getSubExpr()->hasGlobalStorage();
454  case CompoundLiteralExprClass:
455    return cast<CompoundLiteralExpr>(this)->isFileScope();
456  case DeclRefExprClass: {
457    const Decl *D = cast<DeclRefExpr>(this)->getDecl();
458    if (const VarDecl *VD = dyn_cast<VarDecl>(D))
459      return VD->hasGlobalStorage();
460    if (isa<FunctionDecl>(D))
461      return true;
462    return false;
463  }
464  case MemberExprClass: {
465    const MemberExpr *M = cast<MemberExpr>(this);
466    return !M->isArrow() && M->getBase()->hasGlobalStorage();
467  }
468  case ArraySubscriptExprClass:
469    return cast<ArraySubscriptExpr>(this)->getBase()->hasGlobalStorage();
470  case PreDefinedExprClass:
471    return true;
472  case CXXDefaultArgExprClass:
473    return cast<CXXDefaultArgExpr>(this)->getExpr()->hasGlobalStorage();
474  }
475}
476
477Expr* Expr::IgnoreParens() {
478  Expr* E = this;
479  while (ParenExpr* P = dyn_cast<ParenExpr>(E))
480    E = P->getSubExpr();
481
482  return E;
483}
484
485/// IgnoreParenCasts - Ignore parentheses and casts.  Strip off any ParenExpr
486/// or CastExprs or ImplicitCastExprs, returning their operand.
487Expr *Expr::IgnoreParenCasts() {
488  Expr *E = this;
489  while (true) {
490    if (ParenExpr *P = dyn_cast<ParenExpr>(E))
491      E = P->getSubExpr();
492    else if (CastExpr *P = dyn_cast<CastExpr>(E))
493      E = P->getSubExpr();
494    else if (ImplicitCastExpr *P = dyn_cast<ImplicitCastExpr>(E))
495      E = P->getSubExpr();
496    else
497      return E;
498  }
499}
500
501
502bool Expr::isConstantExpr(ASTContext &Ctx, SourceLocation *Loc) const {
503  return true;
504  switch (getStmtClass()) {
505  default:
506    if (Loc) *Loc = getLocStart();
507    return false;
508  case ParenExprClass:
509    return cast<ParenExpr>(this)->getSubExpr()->isConstantExpr(Ctx, Loc);
510  case StringLiteralClass:
511  case ObjCStringLiteralClass:
512  case FloatingLiteralClass:
513  case IntegerLiteralClass:
514  case CharacterLiteralClass:
515  case ImaginaryLiteralClass:
516  case TypesCompatibleExprClass:
517  case CXXBoolLiteralExprClass:
518    return true;
519  case CallExprClass: {
520    const CallExpr *CE = cast<CallExpr>(this);
521    llvm::APSInt Result(32);
522    Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
523    if (CE->isBuiltinClassifyType(Result))
524      return true;
525    if (CE->isBuiltinConstantExpr())
526      return true;
527    if (Loc) *Loc = getLocStart();
528    return false;
529  }
530  case DeclRefExprClass: {
531    const Decl *D = cast<DeclRefExpr>(this)->getDecl();
532    // Accept address of function.
533    if (isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D))
534      return true;
535    if (Loc) *Loc = getLocStart();
536    if (isa<VarDecl>(D))
537      return TR->isArrayType();
538    return false;
539  }
540  case CompoundLiteralExprClass:
541    if (Loc) *Loc = getLocStart();
542    // Allow "(int []){2,4}", since the array will be converted to a pointer.
543    // Allow "(vector type){2,4}" since the elements are all constant.
544    return TR->isArrayType() || TR->isVectorType();
545  case UnaryOperatorClass: {
546    const UnaryOperator *Exp = cast<UnaryOperator>(this);
547
548    // C99 6.6p9
549    if (Exp->getOpcode() == UnaryOperator::AddrOf) {
550      if (!Exp->getSubExpr()->hasGlobalStorage()) {
551        if (Loc) *Loc = getLocStart();
552        return false;
553      }
554      return true;
555    }
556
557    // Get the operand value.  If this is sizeof/alignof, do not evalute the
558    // operand.  This affects C99 6.6p3.
559    if (!Exp->isSizeOfAlignOfOp() &&
560        Exp->getOpcode() != UnaryOperator::OffsetOf &&
561        !Exp->getSubExpr()->isConstantExpr(Ctx, Loc))
562      return false;
563
564    switch (Exp->getOpcode()) {
565    // Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
566    // See C99 6.6p3.
567    default:
568      if (Loc) *Loc = Exp->getOperatorLoc();
569      return false;
570    case UnaryOperator::Extension:
571      return true;  // FIXME: this is wrong.
572    case UnaryOperator::SizeOf:
573    case UnaryOperator::AlignOf:
574    case UnaryOperator::OffsetOf:
575      // sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
576      if (!Exp->getSubExpr()->getType()->isConstantSizeType()) {
577        if (Loc) *Loc = Exp->getOperatorLoc();
578        return false;
579      }
580      return true;
581    case UnaryOperator::LNot:
582    case UnaryOperator::Plus:
583    case UnaryOperator::Minus:
584    case UnaryOperator::Not:
585      return true;
586    }
587  }
588  case SizeOfAlignOfTypeExprClass: {
589    const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(this);
590    // alignof always evaluates to a constant.
591    if (Exp->isSizeOf() && !Exp->getArgumentType()->isVoidType() &&
592        !Exp->getArgumentType()->isConstantSizeType()) {
593      if (Loc) *Loc = Exp->getOperatorLoc();
594      return false;
595    }
596    return true;
597  }
598  case BinaryOperatorClass: {
599    const BinaryOperator *Exp = cast<BinaryOperator>(this);
600
601    // The LHS of a constant expr is always evaluated and needed.
602    if (!Exp->getLHS()->isConstantExpr(Ctx, Loc))
603      return false;
604
605    if (!Exp->getRHS()->isConstantExpr(Ctx, Loc))
606      return false;
607    return true;
608  }
609  case ImplicitCastExprClass:
610  case CastExprClass: {
611    const Expr *SubExpr;
612    SourceLocation CastLoc;
613    if (const CastExpr *C = dyn_cast<CastExpr>(this)) {
614      SubExpr = C->getSubExpr();
615      CastLoc = C->getLParenLoc();
616    } else {
617      SubExpr = cast<ImplicitCastExpr>(this)->getSubExpr();
618      CastLoc = getLocStart();
619    }
620    if (!SubExpr->isConstantExpr(Ctx, Loc)) {
621      if (Loc) *Loc = SubExpr->getLocStart();
622      return false;
623    }
624    return true;
625  }
626  case ConditionalOperatorClass: {
627    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
628    if (!Exp->getCond()->isConstantExpr(Ctx, Loc) ||
629        // Handle the GNU extension for missing LHS.
630        !(Exp->getLHS() && Exp->getLHS()->isConstantExpr(Ctx, Loc)) ||
631        !Exp->getRHS()->isConstantExpr(Ctx, Loc))
632      return false;
633    return true;
634  }
635  case InitListExprClass: {
636    const InitListExpr *Exp = cast<InitListExpr>(this);
637    unsigned numInits = Exp->getNumInits();
638    for (unsigned i = 0; i < numInits; i++) {
639      if (!Exp->getInit(i)->isConstantExpr(Ctx, Loc)) {
640        if (Loc) *Loc = Exp->getInit(i)->getLocStart();
641        return false;
642      }
643    }
644    return true;
645  }
646  case CXXDefaultArgExprClass:
647    return cast<CXXDefaultArgExpr>(this)->getExpr()->isConstantExpr(Ctx, Loc);
648  }
649}
650
651/// isIntegerConstantExpr - this recursive routine will test if an expression is
652/// an integer constant expression. Note: With the introduction of VLA's in
653/// C99 the result of the sizeof operator is no longer always a constant
654/// expression. The generalization of the wording to include any subexpression
655/// that is not evaluated (C99 6.6p3) means that nonconstant subexpressions
656/// can appear as operands to other operators (e.g. &&, ||, ?:). For instance,
657/// "0 || f()" can be treated as a constant expression. In C90 this expression,
658/// occurring in a context requiring a constant, would have been a constraint
659/// violation. FIXME: This routine currently implements C90 semantics.
660/// To properly implement C99 semantics this routine will need to evaluate
661/// expressions involving operators previously mentioned.
662
663/// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero,
664/// comma, etc
665///
666/// FIXME: This should ext-warn on overflow during evaluation!  ISO C does not
667/// permit this.  This includes things like (int)1e1000
668///
669/// FIXME: Handle offsetof.  Two things to do:  Handle GCC's __builtin_offsetof
670/// to support gcc 4.0+  and handle the idiom GCC recognizes with a null pointer
671/// cast+dereference.
672bool Expr::isIntegerConstantExpr(llvm::APSInt &Result, ASTContext &Ctx,
673                                 SourceLocation *Loc, bool isEvaluated) const {
674  switch (getStmtClass()) {
675  default:
676    if (Loc) *Loc = getLocStart();
677    return false;
678  case ParenExprClass:
679    return cast<ParenExpr>(this)->getSubExpr()->
680                     isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated);
681  case IntegerLiteralClass:
682    Result = cast<IntegerLiteral>(this)->getValue();
683    break;
684  case CharacterLiteralClass: {
685    const CharacterLiteral *CL = cast<CharacterLiteral>(this);
686    Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
687    Result = CL->getValue();
688    Result.setIsUnsigned(!getType()->isSignedIntegerType());
689    break;
690  }
691  case TypesCompatibleExprClass: {
692    const TypesCompatibleExpr *TCE = cast<TypesCompatibleExpr>(this);
693    Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
694    Result = Ctx.typesAreCompatible(TCE->getArgType1(), TCE->getArgType2());
695    break;
696  }
697  case CallExprClass: {
698    const CallExpr *CE = cast<CallExpr>(this);
699    Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
700    if (CE->isBuiltinClassifyType(Result))
701      break;
702    if (Loc) *Loc = getLocStart();
703    return false;
704  }
705  case DeclRefExprClass:
706    if (const EnumConstantDecl *D =
707          dyn_cast<EnumConstantDecl>(cast<DeclRefExpr>(this)->getDecl())) {
708      Result = D->getInitVal();
709      break;
710    }
711    if (Loc) *Loc = getLocStart();
712    return false;
713  case UnaryOperatorClass: {
714    const UnaryOperator *Exp = cast<UnaryOperator>(this);
715
716    // Get the operand value.  If this is sizeof/alignof, do not evalute the
717    // operand.  This affects C99 6.6p3.
718    if (!Exp->isSizeOfAlignOfOp() && !Exp->isOffsetOfOp() &&
719        !Exp->getSubExpr()->isIntegerConstantExpr(Result, Ctx, Loc,isEvaluated))
720      return false;
721
722    switch (Exp->getOpcode()) {
723    // Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
724    // See C99 6.6p3.
725    default:
726      if (Loc) *Loc = Exp->getOperatorLoc();
727      return false;
728    case UnaryOperator::Extension:
729      return true;  // FIXME: this is wrong.
730    case UnaryOperator::SizeOf:
731    case UnaryOperator::AlignOf:
732      // Return the result in the right width.
733      Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
734
735      // sizeof(void) and __alignof__(void) = 1 as a gcc extension.
736      if (Exp->getSubExpr()->getType()->isVoidType()) {
737        Result = 1;
738        break;
739      }
740
741      // sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
742      if (!Exp->getSubExpr()->getType()->isConstantSizeType()) {
743        if (Loc) *Loc = Exp->getOperatorLoc();
744        return false;
745      }
746
747      // Get information about the size or align.
748      if (Exp->getSubExpr()->getType()->isFunctionType()) {
749        // GCC extension: sizeof(function) = 1.
750        Result = Exp->getOpcode() == UnaryOperator::AlignOf ? 4 : 1;
751      } else {
752        unsigned CharSize = Ctx.Target.getCharWidth();
753        if (Exp->getOpcode() == UnaryOperator::AlignOf)
754          Result = Ctx.getTypeAlign(Exp->getSubExpr()->getType()) / CharSize;
755        else
756          Result = Ctx.getTypeSize(Exp->getSubExpr()->getType()) / CharSize;
757      }
758      break;
759    case UnaryOperator::LNot: {
760      bool Val = Result == 0;
761      Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
762      Result = Val;
763      break;
764    }
765    case UnaryOperator::Plus:
766      break;
767    case UnaryOperator::Minus:
768      Result = -Result;
769      break;
770    case UnaryOperator::Not:
771      Result = ~Result;
772      break;
773    case UnaryOperator::OffsetOf:
774      Result = Exp->evaluateOffsetOf(Ctx);
775    }
776    break;
777  }
778  case SizeOfAlignOfTypeExprClass: {
779    const SizeOfAlignOfTypeExpr *Exp = cast<SizeOfAlignOfTypeExpr>(this);
780
781    // Return the result in the right width.
782    Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
783
784    // sizeof(void) and __alignof__(void) = 1 as a gcc extension.
785    if (Exp->getArgumentType()->isVoidType()) {
786      Result = 1;
787      break;
788    }
789
790    // alignof always evaluates to a constant, sizeof does if arg is not VLA.
791    if (Exp->isSizeOf() && !Exp->getArgumentType()->isConstantSizeType()) {
792      if (Loc) *Loc = Exp->getOperatorLoc();
793      return false;
794    }
795
796    // Get information about the size or align.
797    if (Exp->getArgumentType()->isFunctionType()) {
798      // GCC extension: sizeof(function) = 1.
799      Result = Exp->isSizeOf() ? 1 : 4;
800    } else {
801      unsigned CharSize = Ctx.Target.getCharWidth();
802      if (Exp->isSizeOf())
803        Result = Ctx.getTypeSize(Exp->getArgumentType()) / CharSize;
804      else
805        Result = Ctx.getTypeAlign(Exp->getArgumentType()) / CharSize;
806    }
807    break;
808  }
809  case BinaryOperatorClass: {
810    const BinaryOperator *Exp = cast<BinaryOperator>(this);
811
812    // The LHS of a constant expr is always evaluated and needed.
813    if (!Exp->getLHS()->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
814      return false;
815
816    llvm::APSInt RHS(Result);
817
818    // The short-circuiting &&/|| operators don't necessarily evaluate their
819    // RHS.  Make sure to pass isEvaluated down correctly.
820    if (Exp->isLogicalOp()) {
821      bool RHSEval;
822      if (Exp->getOpcode() == BinaryOperator::LAnd)
823        RHSEval = Result != 0;
824      else {
825        assert(Exp->getOpcode() == BinaryOperator::LOr &&"Unexpected logical");
826        RHSEval = Result == 0;
827      }
828
829      if (!Exp->getRHS()->isIntegerConstantExpr(RHS, Ctx, Loc,
830                                                isEvaluated & RHSEval))
831        return false;
832    } else {
833      if (!Exp->getRHS()->isIntegerConstantExpr(RHS, Ctx, Loc, isEvaluated))
834        return false;
835    }
836
837    switch (Exp->getOpcode()) {
838    default:
839      if (Loc) *Loc = getLocStart();
840      return false;
841    case BinaryOperator::Mul:
842      Result *= RHS;
843      break;
844    case BinaryOperator::Div:
845      if (RHS == 0) {
846        if (!isEvaluated) break;
847        if (Loc) *Loc = getLocStart();
848        return false;
849      }
850      Result /= RHS;
851      break;
852    case BinaryOperator::Rem:
853      if (RHS == 0) {
854        if (!isEvaluated) break;
855        if (Loc) *Loc = getLocStart();
856        return false;
857      }
858      Result %= RHS;
859      break;
860    case BinaryOperator::Add: Result += RHS; break;
861    case BinaryOperator::Sub: Result -= RHS; break;
862    case BinaryOperator::Shl:
863      Result <<=
864        static_cast<uint32_t>(RHS.getLimitedValue(Result.getBitWidth()-1));
865      break;
866    case BinaryOperator::Shr:
867      Result >>=
868        static_cast<uint32_t>(RHS.getLimitedValue(Result.getBitWidth()-1));
869      break;
870    case BinaryOperator::LT:  Result = Result < RHS; break;
871    case BinaryOperator::GT:  Result = Result > RHS; break;
872    case BinaryOperator::LE:  Result = Result <= RHS; break;
873    case BinaryOperator::GE:  Result = Result >= RHS; break;
874    case BinaryOperator::EQ:  Result = Result == RHS; break;
875    case BinaryOperator::NE:  Result = Result != RHS; break;
876    case BinaryOperator::And: Result &= RHS; break;
877    case BinaryOperator::Xor: Result ^= RHS; break;
878    case BinaryOperator::Or:  Result |= RHS; break;
879    case BinaryOperator::LAnd:
880      Result = Result != 0 && RHS != 0;
881      break;
882    case BinaryOperator::LOr:
883      Result = Result != 0 || RHS != 0;
884      break;
885
886    case BinaryOperator::Comma:
887      // C99 6.6p3: "shall not contain assignment, ..., or comma operators,
888      // *except* when they are contained within a subexpression that is not
889      // evaluated".  Note that Assignment can never happen due to constraints
890      // on the LHS subexpr, so we don't need to check it here.
891      if (isEvaluated) {
892        if (Loc) *Loc = getLocStart();
893        return false;
894      }
895
896      // The result of the constant expr is the RHS.
897      Result = RHS;
898      return true;
899    }
900
901    assert(!Exp->isAssignmentOp() && "LHS can't be a constant expr!");
902    break;
903  }
904  case ImplicitCastExprClass:
905  case CastExprClass: {
906    const Expr *SubExpr;
907    SourceLocation CastLoc;
908    if (const CastExpr *C = dyn_cast<CastExpr>(this)) {
909      SubExpr = C->getSubExpr();
910      CastLoc = C->getLParenLoc();
911    } else {
912      SubExpr = cast<ImplicitCastExpr>(this)->getSubExpr();
913      CastLoc = getLocStart();
914    }
915
916    // C99 6.6p6: shall only convert arithmetic types to integer types.
917    if (!SubExpr->getType()->isArithmeticType() ||
918        !getType()->isIntegerType()) {
919      if (Loc) *Loc = SubExpr->getLocStart();
920      return false;
921    }
922
923    uint32_t DestWidth = static_cast<uint32_t>(Ctx.getTypeSize(getType()));
924
925    // Handle simple integer->integer casts.
926    if (SubExpr->getType()->isIntegerType()) {
927      if (!SubExpr->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
928        return false;
929
930      // Figure out if this is a truncate, extend or noop cast.
931      // If the input is signed, do a sign extend, noop, or truncate.
932      if (getType()->isBooleanType()) {
933        // Conversion to bool compares against zero.
934        Result = Result != 0;
935        Result.zextOrTrunc(DestWidth);
936      } else if (SubExpr->getType()->isSignedIntegerType())
937        Result.sextOrTrunc(DestWidth);
938      else  // If the input is unsigned, do a zero extend, noop, or truncate.
939        Result.zextOrTrunc(DestWidth);
940      break;
941    }
942
943    // Allow floating constants that are the immediate operands of casts or that
944    // are parenthesized.
945    const Expr *Operand = SubExpr;
946    while (const ParenExpr *PE = dyn_cast<ParenExpr>(Operand))
947      Operand = PE->getSubExpr();
948
949    // If this isn't a floating literal, we can't handle it.
950    const FloatingLiteral *FL = dyn_cast<FloatingLiteral>(Operand);
951    if (!FL) {
952      if (Loc) *Loc = Operand->getLocStart();
953      return false;
954    }
955
956    // If the destination is boolean, compare against zero.
957    if (getType()->isBooleanType()) {
958      Result = !FL->getValue().isZero();
959      Result.zextOrTrunc(DestWidth);
960      break;
961    }
962
963    // Determine whether we are converting to unsigned or signed.
964    bool DestSigned = getType()->isSignedIntegerType();
965
966    // TODO: Warn on overflow, but probably not here: isIntegerConstantExpr can
967    // be called multiple times per AST.
968    uint64_t Space[4];
969    (void)FL->getValue().convertToInteger(Space, DestWidth, DestSigned,
970                                          llvm::APFloat::rmTowardZero);
971    Result = llvm::APInt(DestWidth, 4, Space);
972    break;
973  }
974  case ConditionalOperatorClass: {
975    const ConditionalOperator *Exp = cast<ConditionalOperator>(this);
976
977    if (!Exp->getCond()->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
978      return false;
979
980    const Expr *TrueExp  = Exp->getLHS();
981    const Expr *FalseExp = Exp->getRHS();
982    if (Result == 0) std::swap(TrueExp, FalseExp);
983
984    // Evaluate the false one first, discard the result.
985    if (FalseExp && !FalseExp->isIntegerConstantExpr(Result, Ctx, Loc, false))
986      return false;
987    // Evalute the true one, capture the result.
988    if (TrueExp &&
989        !TrueExp->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated))
990      return false;
991    break;
992  }
993  case CXXDefaultArgExprClass:
994    return cast<CXXDefaultArgExpr>(this)
995             ->isIntegerConstantExpr(Result, Ctx, Loc, isEvaluated);
996  }
997
998  // Cases that are valid constant exprs fall through to here.
999  Result.setIsUnsigned(getType()->isUnsignedIntegerType());
1000  return true;
1001}
1002
1003/// isNullPointerConstant - C99 6.3.2.3p3 -  Return true if this is either an
1004/// integer constant expression with the value zero, or if this is one that is
1005/// cast to void*.
1006bool Expr::isNullPointerConstant(ASTContext &Ctx) const {
1007  // Strip off a cast to void*, if it exists.
1008  if (const CastExpr *CE = dyn_cast<CastExpr>(this)) {
1009    // Check that it is a cast to void*.
1010    if (const PointerType *PT = CE->getType()->getAsPointerType()) {
1011      QualType Pointee = PT->getPointeeType();
1012      if (Pointee.getCVRQualifiers() == 0 &&
1013          Pointee->isVoidType() &&                                 // to void*
1014          CE->getSubExpr()->getType()->isIntegerType())            // from int.
1015        return CE->getSubExpr()->isNullPointerConstant(Ctx);
1016    }
1017  } else if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(this)) {
1018    // Ignore the ImplicitCastExpr type entirely.
1019    return ICE->getSubExpr()->isNullPointerConstant(Ctx);
1020  } else if (const ParenExpr *PE = dyn_cast<ParenExpr>(this)) {
1021    // Accept ((void*)0) as a null pointer constant, as many other
1022    // implementations do.
1023    return PE->getSubExpr()->isNullPointerConstant(Ctx);
1024  } else if (const CXXDefaultArgExpr *DefaultArg
1025               = dyn_cast<CXXDefaultArgExpr>(this)) {
1026    // See through default argument expressions
1027    return DefaultArg->getExpr()->isNullPointerConstant(Ctx);
1028  }
1029
1030  // This expression must be an integer type.
1031  if (!getType()->isIntegerType())
1032    return false;
1033
1034  // If we have an integer constant expression, we need to *evaluate* it and
1035  // test for the value 0.
1036  llvm::APSInt Val(32);
1037  return isIntegerConstantExpr(Val, Ctx, 0, true) && Val == 0;
1038}
1039
1040unsigned ExtVectorElementExpr::getNumElements() const {
1041  if (const VectorType *VT = getType()->getAsVectorType())
1042    return VT->getNumElements();
1043  return 1;
1044}
1045
1046/// containsDuplicateElements - Return true if any element access is repeated.
1047bool ExtVectorElementExpr::containsDuplicateElements() const {
1048  const char *compStr = Accessor.getName();
1049  unsigned length = strlen(compStr);
1050
1051  for (unsigned i = 0; i < length-1; i++) {
1052    const char *s = compStr+i;
1053    for (const char c = *s++; *s; s++)
1054      if (c == *s)
1055        return true;
1056  }
1057  return false;
1058}
1059
1060/// getEncodedElementAccess - We encode the fields as a llvm ConstantArray.
1061void ExtVectorElementExpr::getEncodedElementAccess(
1062                                  llvm::SmallVectorImpl<unsigned> &Elts) const {
1063  const char *compStr = Accessor.getName();
1064
1065  bool isHi =   !strcmp(compStr, "hi");
1066  bool isLo =   !strcmp(compStr, "lo");
1067  bool isEven = !strcmp(compStr, "e");
1068  bool isOdd  = !strcmp(compStr, "o");
1069
1070  for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
1071    uint64_t Index;
1072
1073    if (isHi)
1074      Index = e + i;
1075    else if (isLo)
1076      Index = i;
1077    else if (isEven)
1078      Index = 2 * i;
1079    else if (isOdd)
1080      Index = 2 * i + 1;
1081    else
1082      Index = ExtVectorType::getAccessorIdx(compStr[i]);
1083
1084    Elts.push_back(Index);
1085  }
1086}
1087
1088unsigned
1089ExtVectorElementExpr::getAccessedFieldNo(unsigned Idx,
1090                                         const llvm::Constant *Elts) {
1091  if (isa<llvm::ConstantAggregateZero>(Elts))
1092    return 0;
1093
1094  return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
1095}
1096
1097// constructor for instance messages.
1098ObjCMessageExpr::ObjCMessageExpr(Expr *receiver, Selector selInfo,
1099                QualType retType, ObjCMethodDecl *mproto,
1100                SourceLocation LBrac, SourceLocation RBrac,
1101                Expr **ArgExprs, unsigned nargs)
1102  : Expr(ObjCMessageExprClass, retType), SelName(selInfo),
1103    MethodProto(mproto) {
1104  NumArgs = nargs;
1105  SubExprs = new Expr*[NumArgs+1];
1106  SubExprs[RECEIVER] = receiver;
1107  if (NumArgs) {
1108    for (unsigned i = 0; i != NumArgs; ++i)
1109      SubExprs[i+ARGS_START] = static_cast<Expr *>(ArgExprs[i]);
1110  }
1111  LBracloc = LBrac;
1112  RBracloc = RBrac;
1113}
1114
1115// constructor for class messages.
1116// FIXME: clsName should be typed to ObjCInterfaceType
1117ObjCMessageExpr::ObjCMessageExpr(IdentifierInfo *clsName, Selector selInfo,
1118                QualType retType, ObjCMethodDecl *mproto,
1119                SourceLocation LBrac, SourceLocation RBrac,
1120                Expr **ArgExprs, unsigned nargs)
1121  : Expr(ObjCMessageExprClass, retType), SelName(selInfo),
1122    MethodProto(mproto) {
1123  NumArgs = nargs;
1124  SubExprs = new Expr*[NumArgs+1];
1125  SubExprs[RECEIVER] = (Expr*) ((uintptr_t) clsName | 0x1);
1126  if (NumArgs) {
1127    for (unsigned i = 0; i != NumArgs; ++i)
1128      SubExprs[i+ARGS_START] = static_cast<Expr *>(ArgExprs[i]);
1129  }
1130  LBracloc = LBrac;
1131  RBracloc = RBrac;
1132}
1133
1134bool ChooseExpr::isConditionTrue(ASTContext &C) const {
1135  llvm::APSInt CondVal(32);
1136  bool IsConst = getCond()->isIntegerConstantExpr(CondVal, C);
1137  assert(IsConst && "Condition of choose expr must be i-c-e"); IsConst=IsConst;
1138  return CondVal != 0;
1139}
1140
1141static int64_t evaluateOffsetOf(ASTContext& C, const Expr *E)
1142{
1143  if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
1144    QualType Ty = ME->getBase()->getType();
1145
1146    RecordDecl *RD = Ty->getAsRecordType()->getDecl();
1147    const ASTRecordLayout &RL = C.getASTRecordLayout(RD);
1148    FieldDecl *FD = ME->getMemberDecl();
1149
1150    // FIXME: This is linear time.
1151    unsigned i = 0, e = 0;
1152    for (i = 0, e = RD->getNumMembers(); i != e; i++) {
1153      if (RD->getMember(i) == FD)
1154        break;
1155    }
1156
1157    return RL.getFieldOffset(i) + evaluateOffsetOf(C, ME->getBase());
1158  } else if (const ArraySubscriptExpr *ASE = dyn_cast<ArraySubscriptExpr>(E)) {
1159    const Expr *Base = ASE->getBase();
1160    llvm::APSInt Idx(32);
1161    bool ICE = ASE->getIdx()->isIntegerConstantExpr(Idx, C);
1162    assert(ICE && "Array index is not a constant integer!");
1163
1164    int64_t size = C.getTypeSize(ASE->getType());
1165    size *= Idx.getSExtValue();
1166
1167    return size + evaluateOffsetOf(C, Base);
1168  } else if (isa<CompoundLiteralExpr>(E))
1169    return 0;
1170
1171  assert(0 && "Unknown offsetof subexpression!");
1172  return 0;
1173}
1174
1175int64_t UnaryOperator::evaluateOffsetOf(ASTContext& C) const
1176{
1177  assert(Opc == OffsetOf && "Unary operator not offsetof!");
1178
1179  unsigned CharSize = C.Target.getCharWidth();
1180  return ::evaluateOffsetOf(C, Val) / CharSize;
1181}
1182
1183//===----------------------------------------------------------------------===//
1184//  Child Iterators for iterating over subexpressions/substatements
1185//===----------------------------------------------------------------------===//
1186
1187// DeclRefExpr
1188Stmt::child_iterator DeclRefExpr::child_begin() { return child_iterator(); }
1189Stmt::child_iterator DeclRefExpr::child_end() { return child_iterator(); }
1190
1191// ObjCIvarRefExpr
1192Stmt::child_iterator ObjCIvarRefExpr::child_begin() {
1193  return reinterpret_cast<Stmt**>(&Base);
1194}
1195
1196Stmt::child_iterator ObjCIvarRefExpr::child_end() {
1197  return reinterpret_cast<Stmt**>(&Base)+1;
1198}
1199
1200// PreDefinedExpr
1201Stmt::child_iterator PreDefinedExpr::child_begin() { return child_iterator(); }
1202Stmt::child_iterator PreDefinedExpr::child_end() { return child_iterator(); }
1203
1204// IntegerLiteral
1205Stmt::child_iterator IntegerLiteral::child_begin() { return child_iterator(); }
1206Stmt::child_iterator IntegerLiteral::child_end() { return child_iterator(); }
1207
1208// CharacterLiteral
1209Stmt::child_iterator CharacterLiteral::child_begin() { return child_iterator(); }
1210Stmt::child_iterator CharacterLiteral::child_end() { return child_iterator(); }
1211
1212// FloatingLiteral
1213Stmt::child_iterator FloatingLiteral::child_begin() { return child_iterator(); }
1214Stmt::child_iterator FloatingLiteral::child_end() { return child_iterator(); }
1215
1216// ImaginaryLiteral
1217Stmt::child_iterator ImaginaryLiteral::child_begin() {
1218  return reinterpret_cast<Stmt**>(&Val);
1219}
1220Stmt::child_iterator ImaginaryLiteral::child_end() {
1221  return reinterpret_cast<Stmt**>(&Val)+1;
1222}
1223
1224// StringLiteral
1225Stmt::child_iterator StringLiteral::child_begin() { return child_iterator(); }
1226Stmt::child_iterator StringLiteral::child_end() { return child_iterator(); }
1227
1228// ParenExpr
1229Stmt::child_iterator ParenExpr::child_begin() {
1230  return reinterpret_cast<Stmt**>(&Val);
1231}
1232Stmt::child_iterator ParenExpr::child_end() {
1233  return reinterpret_cast<Stmt**>(&Val)+1;
1234}
1235
1236// UnaryOperator
1237Stmt::child_iterator UnaryOperator::child_begin() {
1238  return reinterpret_cast<Stmt**>(&Val);
1239}
1240Stmt::child_iterator UnaryOperator::child_end() {
1241  return reinterpret_cast<Stmt**>(&Val+1);
1242}
1243
1244// SizeOfAlignOfTypeExpr
1245Stmt::child_iterator SizeOfAlignOfTypeExpr::child_begin() {
1246  // If the type is a VLA type (and not a typedef), the size expression of the
1247  // VLA needs to be treated as an executable expression.
1248  if (VariableArrayType* T = dyn_cast<VariableArrayType>(Ty.getTypePtr()))
1249    return child_iterator(T);
1250  else
1251    return child_iterator();
1252}
1253Stmt::child_iterator SizeOfAlignOfTypeExpr::child_end() {
1254  return child_iterator();
1255}
1256
1257// ArraySubscriptExpr
1258Stmt::child_iterator ArraySubscriptExpr::child_begin() {
1259  return reinterpret_cast<Stmt**>(&SubExprs);
1260}
1261Stmt::child_iterator ArraySubscriptExpr::child_end() {
1262  return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
1263}
1264
1265// CallExpr
1266Stmt::child_iterator CallExpr::child_begin() {
1267  return reinterpret_cast<Stmt**>(&SubExprs[0]);
1268}
1269Stmt::child_iterator CallExpr::child_end() {
1270  return reinterpret_cast<Stmt**>(&SubExprs[NumArgs+ARGS_START]);
1271}
1272
1273// MemberExpr
1274Stmt::child_iterator MemberExpr::child_begin() {
1275  return reinterpret_cast<Stmt**>(&Base);
1276}
1277Stmt::child_iterator MemberExpr::child_end() {
1278  return reinterpret_cast<Stmt**>(&Base)+1;
1279}
1280
1281// ExtVectorElementExpr
1282Stmt::child_iterator ExtVectorElementExpr::child_begin() {
1283  return reinterpret_cast<Stmt**>(&Base);
1284}
1285Stmt::child_iterator ExtVectorElementExpr::child_end() {
1286  return reinterpret_cast<Stmt**>(&Base)+1;
1287}
1288
1289// CompoundLiteralExpr
1290Stmt::child_iterator CompoundLiteralExpr::child_begin() {
1291  return reinterpret_cast<Stmt**>(&Init);
1292}
1293Stmt::child_iterator CompoundLiteralExpr::child_end() {
1294  return reinterpret_cast<Stmt**>(&Init)+1;
1295}
1296
1297// ImplicitCastExpr
1298Stmt::child_iterator ImplicitCastExpr::child_begin() {
1299  return reinterpret_cast<Stmt**>(&Op);
1300}
1301Stmt::child_iterator ImplicitCastExpr::child_end() {
1302  return reinterpret_cast<Stmt**>(&Op)+1;
1303}
1304
1305// CastExpr
1306Stmt::child_iterator CastExpr::child_begin() {
1307  return reinterpret_cast<Stmt**>(&Op);
1308}
1309Stmt::child_iterator CastExpr::child_end() {
1310  return reinterpret_cast<Stmt**>(&Op)+1;
1311}
1312
1313// BinaryOperator
1314Stmt::child_iterator BinaryOperator::child_begin() {
1315  return reinterpret_cast<Stmt**>(&SubExprs);
1316}
1317Stmt::child_iterator BinaryOperator::child_end() {
1318  return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
1319}
1320
1321// ConditionalOperator
1322Stmt::child_iterator ConditionalOperator::child_begin() {
1323  return reinterpret_cast<Stmt**>(&SubExprs);
1324}
1325Stmt::child_iterator ConditionalOperator::child_end() {
1326  return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
1327}
1328
1329// AddrLabelExpr
1330Stmt::child_iterator AddrLabelExpr::child_begin() { return child_iterator(); }
1331Stmt::child_iterator AddrLabelExpr::child_end() { return child_iterator(); }
1332
1333// StmtExpr
1334Stmt::child_iterator StmtExpr::child_begin() {
1335  return reinterpret_cast<Stmt**>(&SubStmt);
1336}
1337Stmt::child_iterator StmtExpr::child_end() {
1338  return reinterpret_cast<Stmt**>(&SubStmt)+1;
1339}
1340
1341// TypesCompatibleExpr
1342Stmt::child_iterator TypesCompatibleExpr::child_begin() {
1343  return child_iterator();
1344}
1345
1346Stmt::child_iterator TypesCompatibleExpr::child_end() {
1347  return child_iterator();
1348}
1349
1350// ChooseExpr
1351Stmt::child_iterator ChooseExpr::child_begin() {
1352  return reinterpret_cast<Stmt**>(&SubExprs);
1353}
1354
1355Stmt::child_iterator ChooseExpr::child_end() {
1356  return reinterpret_cast<Stmt**>(&SubExprs)+END_EXPR;
1357}
1358
1359// OverloadExpr
1360Stmt::child_iterator OverloadExpr::child_begin() {
1361  return reinterpret_cast<Stmt**>(&SubExprs[0]);
1362}
1363Stmt::child_iterator OverloadExpr::child_end() {
1364  return reinterpret_cast<Stmt**>(&SubExprs[NumExprs]);
1365}
1366
1367// ShuffleVectorExpr
1368Stmt::child_iterator ShuffleVectorExpr::child_begin() {
1369  return reinterpret_cast<Stmt**>(&SubExprs[0]);
1370}
1371Stmt::child_iterator ShuffleVectorExpr::child_end() {
1372  return reinterpret_cast<Stmt**>(&SubExprs[NumExprs]);
1373}
1374
1375// VAArgExpr
1376Stmt::child_iterator VAArgExpr::child_begin() {
1377  return reinterpret_cast<Stmt**>(&Val);
1378}
1379
1380Stmt::child_iterator VAArgExpr::child_end() {
1381  return reinterpret_cast<Stmt**>(&Val)+1;
1382}
1383
1384// InitListExpr
1385Stmt::child_iterator InitListExpr::child_begin() {
1386  return reinterpret_cast<Stmt**>(InitExprs.size() ?
1387                                  &InitExprs[0] : 0);
1388}
1389Stmt::child_iterator InitListExpr::child_end() {
1390  return reinterpret_cast<Stmt**>(InitExprs.size() ?
1391                                  &InitExprs[0] + InitExprs.size() : 0);
1392}
1393
1394// ObjCStringLiteral
1395Stmt::child_iterator ObjCStringLiteral::child_begin() {
1396  return child_iterator();
1397}
1398Stmt::child_iterator ObjCStringLiteral::child_end() {
1399  return child_iterator();
1400}
1401
1402// ObjCEncodeExpr
1403Stmt::child_iterator ObjCEncodeExpr::child_begin() { return child_iterator(); }
1404Stmt::child_iterator ObjCEncodeExpr::child_end() { return child_iterator(); }
1405
1406// ObjCSelectorExpr
1407Stmt::child_iterator ObjCSelectorExpr::child_begin() {
1408  return child_iterator();
1409}
1410Stmt::child_iterator ObjCSelectorExpr::child_end() {
1411  return child_iterator();
1412}
1413
1414// ObjCProtocolExpr
1415Stmt::child_iterator ObjCProtocolExpr::child_begin() {
1416  return child_iterator();
1417}
1418Stmt::child_iterator ObjCProtocolExpr::child_end() {
1419  return child_iterator();
1420}
1421
1422// ObjCMessageExpr
1423Stmt::child_iterator ObjCMessageExpr::child_begin() {
1424  return reinterpret_cast<Stmt**>(&SubExprs[ getReceiver() ? 0 : ARGS_START ]);
1425}
1426Stmt::child_iterator ObjCMessageExpr::child_end() {
1427  return reinterpret_cast<Stmt**>(&SubExprs[getNumArgs()+ARGS_START]);
1428}
1429
1430