1 //===--- DeclCXX.cpp - C++ Declaration 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 C++ related Decl classes.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/AST/DeclCXX.h"
15 #include "clang/AST/DeclTemplate.h"
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/Expr.h"
18 #include "clang/Basic/IdentifierTable.h"
19 #include "llvm/ADT/STLExtras.h"
20 using namespace clang;
21 
22 //===----------------------------------------------------------------------===//
23 // Decl Allocation/Deallocation Method Implementations
24 //===----------------------------------------------------------------------===//
25 
26 CXXRecordDecl::CXXRecordDecl(Kind K, TagKind TK, DeclContext *DC,
27                              SourceLocation L, IdentifierInfo *Id)
28   : RecordDecl(K, TK, DC, L, Id),
29     UserDeclaredConstructor(false), UserDeclaredCopyConstructor(false),
30     UserDeclaredCopyAssignment(false), UserDeclaredDestructor(false),
31     Aggregate(true), PlainOldData(true), Polymorphic(false), Abstract(false),
32     HasTrivialConstructor(true), HasTrivialDestructor(true),
33     Bases(0), NumBases(0), Conversions(DC, DeclarationName()),
34     TemplateOrInstantiation() { }
35 
36 CXXRecordDecl *CXXRecordDecl::Create(ASTContext &C, TagKind TK, DeclContext *DC,
37                                      SourceLocation L, IdentifierInfo *Id,
38                                      CXXRecordDecl* PrevDecl,
39                                      bool DelayTypeCreation) {
40   CXXRecordDecl* R = new (C) CXXRecordDecl(CXXRecord, TK, DC, L, Id);
41   if (!DelayTypeCreation)
42     C.getTypeDeclType(R, PrevDecl);
43   return R;
44 }
45 
46 CXXRecordDecl::~CXXRecordDecl() {
47   delete [] Bases;
48 }
49 
50 void
51 CXXRecordDecl::setBases(CXXBaseSpecifier const * const *Bases,
52                         unsigned NumBases) {
53   // C++ [dcl.init.aggr]p1:
54   //   An aggregate is an array or a class (clause 9) with [...]
55   //   no base classes [...].
56   Aggregate = false;
57 
58   if (this->Bases)
59     delete [] this->Bases;
60 
61   // FIXME: allocate using the ASTContext
62   this->Bases = new CXXBaseSpecifier[NumBases];
63   this->NumBases = NumBases;
64   for (unsigned i = 0; i < NumBases; ++i)
65     this->Bases[i] = *Bases[i];
66 }
67 
68 bool CXXRecordDecl::hasConstCopyConstructor(ASTContext &Context) const {
69   QualType ClassType
70     = Context.getTypeDeclType(const_cast<CXXRecordDecl*>(this));
71   DeclarationName ConstructorName
72     = Context.DeclarationNames.getCXXConstructorName(
73                                            Context.getCanonicalType(ClassType));
74   unsigned TypeQuals;
75   DeclContext::lookup_const_iterator Con, ConEnd;
76   for (llvm::tie(Con, ConEnd) = this->lookup(Context, ConstructorName);
77        Con != ConEnd; ++Con) {
78     if (cast<CXXConstructorDecl>(*Con)->isCopyConstructor(Context, TypeQuals) &&
79         (TypeQuals & QualType::Const) != 0)
80       return true;
81   }
82 
83   return false;
84 }
85 
86 bool CXXRecordDecl::hasConstCopyAssignment(ASTContext &Context) const {
87   QualType ClassType = Context.getCanonicalType(Context.getTypeDeclType(
88     const_cast<CXXRecordDecl*>(this)));
89   DeclarationName OpName =Context.DeclarationNames.getCXXOperatorName(OO_Equal);
90 
91   DeclContext::lookup_const_iterator Op, OpEnd;
92   for (llvm::tie(Op, OpEnd) = this->lookup(Context, OpName);
93        Op != OpEnd; ++Op) {
94     // C++ [class.copy]p9:
95     //   A user-declared copy assignment operator is a non-static non-template
96     //   member function of class X with exactly one parameter of type X, X&,
97     //   const X&, volatile X& or const volatile X&.
98     const CXXMethodDecl* Method = cast<CXXMethodDecl>(*Op);
99     if (Method->isStatic())
100       continue;
101     // TODO: Skip templates? Or is this implicitly done due to parameter types?
102     const FunctionProtoType *FnType =
103       Method->getType()->getAsFunctionProtoType();
104     assert(FnType && "Overloaded operator has no prototype.");
105     // Don't assert on this; an invalid decl might have been left in the AST.
106     if (FnType->getNumArgs() != 1 || FnType->isVariadic())
107       continue;
108     bool AcceptsConst = true;
109     QualType ArgType = FnType->getArgType(0);
110     if (const LValueReferenceType *Ref = ArgType->getAsLValueReferenceType()) {
111       ArgType = Ref->getPointeeType();
112       // Is it a non-const lvalue reference?
113       if (!ArgType.isConstQualified())
114         AcceptsConst = false;
115     }
116     if (Context.getCanonicalType(ArgType).getUnqualifiedType() != ClassType)
117       continue;
118 
119     // We have a single argument of type cv X or cv X&, i.e. we've found the
120     // copy assignment operator. Return whether it accepts const arguments.
121     return AcceptsConst;
122   }
123   assert(isInvalidDecl() &&
124          "No copy assignment operator declared in valid code.");
125   return false;
126 }
127 
128 void
129 CXXRecordDecl::addedConstructor(ASTContext &Context,
130                                 CXXConstructorDecl *ConDecl) {
131   if (!ConDecl->isImplicit()) {
132     // Note that we have a user-declared constructor.
133     UserDeclaredConstructor = true;
134 
135     // C++ [dcl.init.aggr]p1:
136     //   An aggregate is an array or a class (clause 9) with no
137     //   user-declared constructors (12.1) [...].
138     Aggregate = false;
139 
140     // C++ [class]p4:
141     //   A POD-struct is an aggregate class [...]
142     PlainOldData = false;
143 
144     // C++ [class.ctor]p5:
145     //   A constructor is trivial if it is an implicitly-declared default
146     //   constructor.
147     HasTrivialConstructor = false;
148 
149     // Note when we have a user-declared copy constructor, which will
150     // suppress the implicit declaration of a copy constructor.
151     if (ConDecl->isCopyConstructor(Context))
152       UserDeclaredCopyConstructor = true;
153   }
154 }
155 
156 void CXXRecordDecl::addedAssignmentOperator(ASTContext &Context,
157                                             CXXMethodDecl *OpDecl) {
158   // We're interested specifically in copy assignment operators.
159   // Unlike addedConstructor, this method is not called for implicit
160   // declarations.
161   const FunctionProtoType *FnType = OpDecl->getType()->getAsFunctionProtoType();
162   assert(FnType && "Overloaded operator has no proto function type.");
163   assert(FnType->getNumArgs() == 1 && !FnType->isVariadic());
164   QualType ArgType = FnType->getArgType(0);
165   if (const LValueReferenceType *Ref = ArgType->getAsLValueReferenceType())
166     ArgType = Ref->getPointeeType();
167 
168   ArgType = ArgType.getUnqualifiedType();
169   QualType ClassType = Context.getCanonicalType(Context.getTypeDeclType(
170     const_cast<CXXRecordDecl*>(this)));
171 
172   if (ClassType != Context.getCanonicalType(ArgType))
173     return;
174 
175   // This is a copy assignment operator.
176   // Suppress the implicit declaration of a copy constructor.
177   UserDeclaredCopyAssignment = true;
178 
179   // C++ [class]p4:
180   //   A POD-struct is an aggregate class that [...] has no user-defined copy
181   //   assignment operator [...].
182   PlainOldData = false;
183 }
184 
185 void CXXRecordDecl::addConversionFunction(ASTContext &Context,
186                                           CXXConversionDecl *ConvDecl) {
187   Conversions.addOverload(ConvDecl);
188 }
189 
190 const CXXDestructorDecl *
191 CXXRecordDecl::getDestructor(ASTContext &Context) {
192   QualType ClassType = Context.getTypeDeclType(this);
193 
194   DeclarationName Name
195     = Context.DeclarationNames.getCXXDestructorName(ClassType);
196 
197   DeclContext::lookup_iterator I, E;
198   llvm::tie(I, E) = lookup(Context, Name);
199   assert(I != E && "Did not find a destructor!");
200 
201   const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(*I);
202   assert(++I == E && "Found more than one destructor!");
203 
204   return Dtor;
205 }
206 
207 CXXMethodDecl *
208 CXXMethodDecl::Create(ASTContext &C, CXXRecordDecl *RD,
209                       SourceLocation L, DeclarationName N,
210                       QualType T, bool isStatic, bool isInline) {
211   return new (C) CXXMethodDecl(CXXMethod, RD, L, N, T, isStatic, isInline);
212 }
213 
214 
215 typedef llvm::DenseMap<const CXXMethodDecl*,
216                        std::vector<const CXXMethodDecl *> *>
217                        OverriddenMethodsMapTy;
218 
219 static OverriddenMethodsMapTy *OverriddenMethods = 0;
220 
221 void CXXMethodDecl::addOverriddenMethod(const CXXMethodDecl *MD) {
222   // FIXME: The CXXMethodDecl dtor needs to remove and free the entry.
223 
224   if (!OverriddenMethods)
225     OverriddenMethods = new OverriddenMethodsMapTy();
226 
227   std::vector<const CXXMethodDecl *> *&Methods = (*OverriddenMethods)[this];
228   if (!Methods)
229     Methods = new std::vector<const CXXMethodDecl *>;
230 
231   Methods->push_back(MD);
232 }
233 
234 CXXMethodDecl::method_iterator CXXMethodDecl::begin_overridden_methods() const {
235   if (!OverriddenMethods)
236     return 0;
237 
238   OverriddenMethodsMapTy::iterator it = OverriddenMethods->find(this);
239   if (it == OverriddenMethods->end())
240     return 0;
241   return &(*it->second)[0];
242 }
243 
244 CXXMethodDecl::method_iterator CXXMethodDecl::end_overridden_methods() const {
245   if (!OverriddenMethods)
246     return 0;
247 
248   OverriddenMethodsMapTy::iterator it = OverriddenMethods->find(this);
249   if (it == OverriddenMethods->end())
250     return 0;
251 
252   return &(*it->second)[it->second->size()];
253 }
254 
255 QualType CXXMethodDecl::getThisType(ASTContext &C) const {
256   // C++ 9.3.2p1: The type of this in a member function of a class X is X*.
257   // If the member function is declared const, the type of this is const X*,
258   // if the member function is declared volatile, the type of this is
259   // volatile X*, and if the member function is declared const volatile,
260   // the type of this is const volatile X*.
261 
262   assert(isInstance() && "No 'this' for static methods!");
263   QualType ClassTy = C.getTagDeclType(const_cast<CXXRecordDecl*>(getParent()));
264   ClassTy = ClassTy.getWithAdditionalQualifiers(getTypeQualifiers());
265   return C.getPointerType(ClassTy).withConst();
266 }
267 
268 CXXBaseOrMemberInitializer::
269 CXXBaseOrMemberInitializer(QualType BaseType, Expr **Args, unsigned NumArgs)
270   : Args(0), NumArgs(0) {
271   BaseOrMember = reinterpret_cast<uintptr_t>(BaseType.getTypePtr());
272   assert((BaseOrMember & 0x01) == 0 && "Invalid base class type pointer");
273   BaseOrMember |= 0x01;
274 
275   if (NumArgs > 0) {
276     this->NumArgs = NumArgs;
277     this->Args = new Expr*[NumArgs];
278     for (unsigned Idx = 0; Idx < NumArgs; ++Idx)
279       this->Args[Idx] = Args[Idx];
280   }
281 }
282 
283 CXXBaseOrMemberInitializer::
284 CXXBaseOrMemberInitializer(FieldDecl *Member, Expr **Args, unsigned NumArgs)
285   : Args(0), NumArgs(0) {
286   BaseOrMember = reinterpret_cast<uintptr_t>(Member);
287   assert((BaseOrMember & 0x01) == 0 && "Invalid member pointer");
288 
289   if (NumArgs > 0) {
290     this->NumArgs = NumArgs;
291     this->Args = new Expr*[NumArgs];
292     for (unsigned Idx = 0; Idx < NumArgs; ++Idx)
293       this->Args[Idx] = Args[Idx];
294   }
295 }
296 
297 CXXBaseOrMemberInitializer::~CXXBaseOrMemberInitializer() {
298   delete [] Args;
299 }
300 
301 CXXConstructorDecl *
302 CXXConstructorDecl::Create(ASTContext &C, CXXRecordDecl *RD,
303                            SourceLocation L, DeclarationName N,
304                            QualType T, bool isExplicit,
305                            bool isInline, bool isImplicitlyDeclared) {
306   assert(N.getNameKind() == DeclarationName::CXXConstructorName &&
307          "Name must refer to a constructor");
308   return new (C) CXXConstructorDecl(RD, L, N, T, isExplicit, isInline,
309                                       isImplicitlyDeclared);
310 }
311 
312 bool CXXConstructorDecl::isDefaultConstructor() const {
313   // C++ [class.ctor]p5:
314   //   A default constructor for a class X is a constructor of class
315   //   X that can be called without an argument.
316   return (getNumParams() == 0) ||
317          (getNumParams() > 0 && getParamDecl(0)->getDefaultArg() != 0);
318 }
319 
320 bool
321 CXXConstructorDecl::isCopyConstructor(ASTContext &Context,
322                                       unsigned &TypeQuals) const {
323   // C++ [class.copy]p2:
324   //   A non-template constructor for class X is a copy constructor
325   //   if its first parameter is of type X&, const X&, volatile X& or
326   //   const volatile X&, and either there are no other parameters
327   //   or else all other parameters have default arguments (8.3.6).
328   if ((getNumParams() < 1) ||
329       (getNumParams() > 1 && !getParamDecl(1)->hasDefaultArg()))
330     return false;
331 
332   const ParmVarDecl *Param = getParamDecl(0);
333 
334   // Do we have a reference type? Rvalue references don't count.
335   const LValueReferenceType *ParamRefType =
336     Param->getType()->getAsLValueReferenceType();
337   if (!ParamRefType)
338     return false;
339 
340   // Is it a reference to our class type?
341   QualType PointeeType
342     = Context.getCanonicalType(ParamRefType->getPointeeType());
343   QualType ClassTy
344     = Context.getTagDeclType(const_cast<CXXRecordDecl*>(getParent()));
345   if (PointeeType.getUnqualifiedType() != ClassTy)
346     return false;
347 
348   // We have a copy constructor.
349   TypeQuals = PointeeType.getCVRQualifiers();
350   return true;
351 }
352 
353 bool CXXConstructorDecl::isConvertingConstructor() const {
354   // C++ [class.conv.ctor]p1:
355   //   A constructor declared without the function-specifier explicit
356   //   that can be called with a single parameter specifies a
357   //   conversion from the type of its first parameter to the type of
358   //   its class. Such a constructor is called a converting
359   //   constructor.
360   if (isExplicit())
361     return false;
362 
363   return (getNumParams() == 0 &&
364           getType()->getAsFunctionProtoType()->isVariadic()) ||
365          (getNumParams() == 1) ||
366          (getNumParams() > 1 && getParamDecl(1)->hasDefaultArg());
367 }
368 
369 CXXDestructorDecl *
370 CXXDestructorDecl::Create(ASTContext &C, CXXRecordDecl *RD,
371                           SourceLocation L, DeclarationName N,
372                           QualType T, bool isInline,
373                           bool isImplicitlyDeclared) {
374   assert(N.getNameKind() == DeclarationName::CXXDestructorName &&
375          "Name must refer to a destructor");
376   return new (C) CXXDestructorDecl(RD, L, N, T, isInline,
377                                    isImplicitlyDeclared);
378 }
379 
380 CXXConversionDecl *
381 CXXConversionDecl::Create(ASTContext &C, CXXRecordDecl *RD,
382                           SourceLocation L, DeclarationName N,
383                           QualType T, bool isInline, bool isExplicit) {
384   assert(N.getNameKind() == DeclarationName::CXXConversionFunctionName &&
385          "Name must refer to a conversion function");
386   return new (C) CXXConversionDecl(RD, L, N, T, isInline, isExplicit);
387 }
388 
389 OverloadedFunctionDecl *
390 OverloadedFunctionDecl::Create(ASTContext &C, DeclContext *DC,
391                                DeclarationName N) {
392   return new (C) OverloadedFunctionDecl(DC, N);
393 }
394 
395 LinkageSpecDecl *LinkageSpecDecl::Create(ASTContext &C,
396                                          DeclContext *DC,
397                                          SourceLocation L,
398                                          LanguageIDs Lang, bool Braces) {
399   return new (C) LinkageSpecDecl(DC, L, Lang, Braces);
400 }
401 
402 UsingDirectiveDecl *UsingDirectiveDecl::Create(ASTContext &C, DeclContext *DC,
403                                                SourceLocation L,
404                                                SourceLocation NamespaceLoc,
405                                                SourceRange QualifierRange,
406                                                NestedNameSpecifier *Qualifier,
407                                                SourceLocation IdentLoc,
408                                                NamespaceDecl *Used,
409                                                DeclContext *CommonAncestor) {
410   return new (C) UsingDirectiveDecl(DC, L, NamespaceLoc, QualifierRange,
411                                     Qualifier, IdentLoc, Used, CommonAncestor);
412 }
413 
414 NamespaceAliasDecl *NamespaceAliasDecl::Create(ASTContext &C, DeclContext *DC,
415                                                SourceLocation L,
416                                                SourceLocation AliasLoc,
417                                                IdentifierInfo *Alias,
418                                                SourceRange QualifierRange,
419                                                NestedNameSpecifier *Qualifier,
420                                                SourceLocation IdentLoc,
421                                                NamedDecl *Namespace) {
422   return new (C) NamespaceAliasDecl(DC, L, AliasLoc, Alias, QualifierRange,
423                                     Qualifier, IdentLoc, Namespace);
424 }
425 
426 StaticAssertDecl *StaticAssertDecl::Create(ASTContext &C, DeclContext *DC,
427                                            SourceLocation L, Expr *AssertExpr,
428                                            StringLiteral *Message) {
429   return new (C) StaticAssertDecl(DC, L, AssertExpr, Message);
430 }
431 
432 void StaticAssertDecl::Destroy(ASTContext& C) {
433   AssertExpr->Destroy(C);
434   Message->Destroy(C);
435   this->~StaticAssertDecl();
436   C.Deallocate((void *)this);
437 }
438 
439 StaticAssertDecl::~StaticAssertDecl() {
440 }
441 
442 static const char *getAccessName(AccessSpecifier AS) {
443   switch (AS) {
444     default:
445     case AS_none:
446       assert("Invalid access specifier!");
447       return 0;
448     case AS_public:
449       return "public";
450     case AS_private:
451       return "private";
452     case AS_protected:
453       return "protected";
454   }
455 }
456 
457 const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
458                                            AccessSpecifier AS) {
459   return DB << getAccessName(AS);
460 }
461 
462 
463