Introduce Decl::getPreviousDecl() and Decl::getMostRecentDecl(),

virtual functions that provide previous/most recent redeclaration
information for any declaration. Use this to eliminate the redundant,
less efficient getPreviousDecl() functions.

llvm-svn: 148184

clang/include/clang/AST/Decl.h

@@ -461,6 +461,14 @@ public:
     return AnonOrFirstNamespaceAndInline.getPointer();
   }
   
+  virtual NamespaceDecl *getPreviousDecl() {
+    return redeclarable_base::getPreviousDeclaration();
+  }
+
+  virtual NamespaceDecl *getMostRecentDecl() {
+    return redeclarable_base::getMostRecentDeclaration();
+  }
+
   virtual SourceRange getSourceRange() const {
     return SourceRange(LocStart, RBraceLoc);
   }
@@ -790,6 +798,14 @@ public:
     return redeclarable_base::redecls_end();
   }
 
+  virtual VarDecl *getPreviousDecl() {
+    return redeclarable_base::getPreviousDeclaration();
+  }
+  
+  virtual VarDecl *getMostRecentDecl() {
+    return redeclarable_base::getMostRecentDeclaration();
+  }
+
   static VarDecl *Create(ASTContext &C, DeclContext *DC,
                          SourceLocation StartLoc, SourceLocation IdLoc,
                          IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo,
@@ -1499,6 +1515,14 @@ public:
     return redeclarable_base::redecls_end();
   }
 
+  virtual FunctionDecl *getPreviousDecl() {
+    return redeclarable_base::getPreviousDeclaration();
+  }
+ 
+  virtual FunctionDecl *getMostRecentDecl() {
+    return redeclarable_base::getMostRecentDeclaration();
+  }
+
   static FunctionDecl *Create(ASTContext &C, DeclContext *DC,
                               SourceLocation StartLoc, SourceLocation NLoc,
                               DeclarationName N, QualType T,
@@ -2281,6 +2305,14 @@ public:
     return redeclarable_base::redecls_end();
   }
 
+  virtual TypedefNameDecl *getPreviousDecl() {
+    return redeclarable_base::getPreviousDeclaration();
+  }
+  
+  virtual TypedefNameDecl *getMostRecentDecl() {
+    return redeclarable_base::getMostRecentDeclaration();
+  }
+
   TypeSourceInfo *getTypeSourceInfo() const {
     return TInfo;
   }
@@ -2449,6 +2481,14 @@ public:
     return redeclarable_base::redecls_end();
   }
 
+  virtual TagDecl *getPreviousDecl() {
+    return redeclarable_base::getPreviousDeclaration();
+  }
+  
+  virtual TagDecl *getMostRecentDecl() {
+    return redeclarable_base::getMostRecentDeclaration();
+  }
+
   SourceLocation getRBraceLoc() const { return RBraceLoc; }
   void setRBraceLoc(SourceLocation L) { RBraceLoc = L; }
 

clang/include/clang/AST/DeclBase.h

@@ -716,6 +716,14 @@ public:
   }
   redecl_iterator redecls_end() const { return redecl_iterator(); }
 
+  /// \brief Retrieve the previous declaration that declares the same entity
+  /// as this declaration, or NULL if there is no previous declaration.
+  virtual Decl *getPreviousDecl() { return 0; }
+  
+  /// \brief Retrieve the most recent declaration that declares the same entity
+  /// as this declaration (which may be this declaration).
+  virtual Decl *getMostRecentDecl() { return this; }
+  
   /// getBody - If this Decl represents a declaration for a body of code,
   ///  such as a function or method definition, this method returns the
   ///  top-level Stmt* of that body.  Otherwise this method returns null.

clang/include/clang/AST/DeclObjC.h

@@ -938,6 +938,14 @@ public:
     return redeclarable_base::redecls_end();
   }
 
+  virtual ObjCInterfaceDecl *getPreviousDecl() {
+    return redeclarable_base::getPreviousDeclaration();
+  }
+  
+  virtual ObjCInterfaceDecl *getMostRecentDecl() {
+    return redeclarable_base::getMostRecentDeclaration();
+  }
+
   /// Retrieves the canonical declaration of this Objective-C class.
   ObjCInterfaceDecl *getCanonicalDecl() {
     return getFirstDeclaration();
@@ -1218,7 +1226,15 @@ public:
   redecl_iterator redecls_end() const {
     return redeclarable_base::redecls_end();
   }
-                           
+   
+  virtual ObjCProtocolDecl *getPreviousDecl() {
+    return redeclarable_base::getPreviousDeclaration();
+  }
+ 
+  virtual ObjCProtocolDecl *getMostRecentDecl() {
+    return redeclarable_base::getMostRecentDeclaration();
+  }
+
   /// Retrieves the canonical declaration of this Objective-C protocol.
   ObjCProtocolDecl *getCanonicalDecl() {
     return getFirstDeclaration();

clang/include/clang/AST/DeclTemplate.h

@@ -630,6 +630,14 @@ public:
     return redeclarable_base::redecls_end();
   }
 
+  virtual RedeclarableTemplateDecl *getPreviousDecl() {
+    return redeclarable_base::getPreviousDeclaration();
+  }
+  
+  virtual RedeclarableTemplateDecl *getMostRecentDecl() {
+    return redeclarable_base::getMostRecentDeclaration();
+  }
+
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classof(const RedeclarableTemplateDecl *D) { return true; }

clang/lib/Sema/SemaTemplate.cpp

@@ -4489,7 +4489,7 @@ Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) {
 
 /// \brief Determine what kind of template specialization the given declaration
 /// is.
-static TemplateSpecializationKind getTemplateSpecializationKind(NamedDecl *D) {
+static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D) {
   if (!D)
     return TSK_Undeclared;
 
@@ -4767,23 +4767,6 @@ static bool CheckClassTemplatePartialSpecializationArgs(Sema &S,
   return false;
 }
 
-/// \brief Retrieve the previous declaration of the given declaration.
-static NamedDecl *getPreviousDecl(NamedDecl *ND) {
-  if (VarDecl *VD = dyn_cast<VarDecl>(ND))
-    return VD->getPreviousDeclaration();
-  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
-    return FD->getPreviousDeclaration();
-  if (TagDecl *TD = dyn_cast<TagDecl>(ND))
-    return TD->getPreviousDeclaration();
-  if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(ND))
-    return TD->getPreviousDeclaration();
-  if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
-    return FTD->getPreviousDeclaration();
-  if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(ND))
-    return CTD->getPreviousDeclaration();
-  return 0;
-}
-
 DeclResult
 Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
                                        TagUseKind TUK,
@@ -5114,7 +5097,7 @@ Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
   //   use occurs; no diagnostic is required.
   if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
     bool Okay = false;
-    for (NamedDecl *Prev = PrevDecl; Prev; Prev = getPreviousDecl(Prev)) {
+    for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
       // Is there any previous explicit specialization declaration?
       if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
         Okay = true;
@@ -5248,13 +5231,13 @@ static void StripImplicitInstantiation(NamedDecl *D) {
 /// \brief Compute the diagnostic location for an explicit instantiation
 //  declaration or definition.
 static SourceLocation DiagLocForExplicitInstantiation(
-    NamedDecl* Decl, SourceLocation PointOfInstantiation) {
+    NamedDecl* D, SourceLocation PointOfInstantiation) {
   // Explicit instantiations following a specialization have no effect and
   // hence no PointOfInstantiation. In that case, walk decl backwards
   // until a valid name loc is found.
   SourceLocation PrevDiagLoc = PointOfInstantiation;
-  for (NamedDecl *Prev = Decl; Prev && !PrevDiagLoc.isValid();
-      Prev = getPreviousDecl(Prev)) {
+  for (Decl *Prev = D; Prev && !PrevDiagLoc.isValid();
+       Prev = Prev->getPreviousDecl()) {
     PrevDiagLoc = Prev->getLocation();
   }
   assert(PrevDiagLoc.isValid() &&
@@ -5328,7 +5311,7 @@ Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
       //   before the first use of that specialization that would cause an
       //   implicit instantiation to take place, in every translation unit in
       //   which such a use occurs; no diagnostic is required.
-      for (NamedDecl *Prev = PrevDecl; Prev; Prev = getPreviousDecl(Prev)) {
+      for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
         // Is there any previous explicit specialization declaration?
         if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization)
           return false;
@@ -5419,7 +5402,7 @@ Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
       //   of a template appears after a declaration of an explicit
       //   specialization for that template, the explicit instantiation has no
       //   effect.
-      for (NamedDecl *Prev = PrevDecl; Prev; Prev = getPreviousDecl(Prev)) {
+      for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
         // Is there any previous explicit specialization declaration?
         if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
           HasNoEffect = true;

clang/lib/Serialization/ASTReaderDecl.cpp

@@ -2211,46 +2211,6 @@ namespace {
   };
 }
 
-/// \brief Retrieve the previous declaration to D.
-static Decl *getPreviousDecl(Decl *D) {
-  if (TagDecl *TD = dyn_cast<TagDecl>(D))
-    return TD->getPreviousDeclaration();
-  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
-    return FD->getPreviousDeclaration();
-  if (VarDecl *VD = dyn_cast<VarDecl>(D))
-    return VD->getPreviousDeclaration();
-  if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(D))
-    return TD->getPreviousDeclaration();
-  if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
-    return ID->getPreviousDeclaration();
-  if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
-    return PD->getPreviousDeclaration();
-  if (NamespaceDecl *ND = dyn_cast<NamespaceDecl>(D))
-    return ND->getPreviousDeclaration();
-  
-  return cast<RedeclarableTemplateDecl>(D)->getPreviousDeclaration();
-}
-
-/// \brief Retrieve the most recent declaration of D.
-static Decl *getMostRecentDecl(Decl *D) {
-  if (TagDecl *TD = dyn_cast<TagDecl>(D))
-    return TD->getMostRecentDeclaration();
-  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
-    return FD->getMostRecentDeclaration();
-  if (VarDecl *VD = dyn_cast<VarDecl>(D))
-    return VD->getMostRecentDeclaration();
-  if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(D))
-    return TD->getMostRecentDeclaration();
-  if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
-    return ID->getMostRecentDeclaration();
-  if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
-    return PD->getMostRecentDeclaration();
-  if (NamespaceDecl *ND = dyn_cast<NamespaceDecl>(D))
-    return ND->getMostRecentDeclaration();
-
-  return cast<RedeclarableTemplateDecl>(D)->getMostRecentDeclaration();
-}
-
 void ASTReader::loadPendingDeclChain(serialization::GlobalDeclID ID) {
   Decl *D = GetDecl(ID);  
   Decl *CanonDecl = D->getCanonicalDecl();
@@ -2276,11 +2236,11 @@ void ASTReader::loadPendingDeclChain(serialization::GlobalDeclID ID) {
     return;
     
   // Capture all of the parsed declarations and put them at the end.
-  Decl *MostRecent = getMostRecentDecl(CanonDecl);
+  Decl *MostRecent = CanonDecl->getMostRecentDecl();
   Decl *FirstParsed = MostRecent;
   if (CanonDecl != MostRecent && !MostRecent->isFromASTFile()) {
     Decl *Current = MostRecent;
-    while (Decl *Prev = getPreviousDecl(Current)) {
+    while (Decl *Prev = Current->getPreviousDecl()) {
       if (Prev == CanonDecl)
         break;