Don't compute a patched/semantic storage class.

For variables and functions clang used to store two storage classes. The one
"as written" in the code and a patched one, which, for example, propagates
static to the following decls.

This apparently is from the days clang lacked linkage computation. It is now
redundant and this patch removes it.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178663 91177308-0d34-0410-b5e6-96231b3b80d8

38 files changed, 220 insertions, 339 deletions

diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index 504553c17a..d9a3364606 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -111,9 +111,14 @@ succeeded). Essentially all previous 'cast' usage should be replaced with
 'castAs' and 'dyn_cast' should be replaced with 'getAs'. See r175462 for the
 first example of such a change along with many examples of how code was
 migrated to the new API.
- 
-API change 1
-^^^^^^^^^^^^
+
+Storage Class
+^^^^^^^^^^^^^
+
+For each variable and function Clang used to keep the storage class as written
+in the source, the linkage and a semantic storage class. This was a bit
+redundant and the semantic storage class has been removed. The method
+getStorageClass now returns what is written it the source code for that decl.
 
 ...
 
diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index c89c73134c..0294b9fde8 100644
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -660,7 +660,6 @@ private:
     friend class ASTDeclReader;
 
     unsigned SClass : 3;
-    unsigned SClassAsWritten : 3;
     unsigned ThreadSpecified : 1;
     unsigned InitStyle : 2;
 
@@ -727,14 +726,12 @@ protected:
 
   VarDecl(Kind DK, DeclContext *DC, SourceLocation StartLoc,
           SourceLocation IdLoc, IdentifierInfo *Id,
-          QualType T, TypeSourceInfo *TInfo, StorageClass SC,
-          StorageClass SCAsWritten)
+          QualType T, TypeSourceInfo *TInfo, StorageClass SC)
     : DeclaratorDecl(DK, DC, IdLoc, Id, T, TInfo, StartLoc), Init() {
     assert(sizeof(VarDeclBitfields) <= sizeof(unsigned));
     assert(sizeof(ParmVarDeclBitfields) <= sizeof(unsigned));
     AllBits = 0;
     VarDeclBits.SClass = SC;
-    VarDeclBits.SClassAsWritten = SCAsWritten;
     // Everything else is implicitly initialized to false.
   }
 
@@ -757,23 +754,18 @@ public:
   static VarDecl *Create(ASTContext &C, DeclContext *DC,
                          SourceLocation StartLoc, SourceLocation IdLoc,
                          IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo,
-                         StorageClass S, StorageClass SCAsWritten);
+                         StorageClass S);
 
   static VarDecl *CreateDeserialized(ASTContext &C, unsigned ID);
   
   virtual SourceRange getSourceRange() const LLVM_READONLY;
 
+  /// \brief Returns the storage class as written in the source. For the
+  /// computed linkage of symbol, see getLinkage.
   StorageClass getStorageClass() const {
     return (StorageClass) VarDeclBits.SClass;
   }
-  StorageClass getStorageClassAsWritten() const {
-    return (StorageClass) VarDeclBits.SClassAsWritten;
-  }
   void setStorageClass(StorageClass SC);
-  void setStorageClassAsWritten(StorageClass SC) {
-    assert(isLegalForVariable(SC));
-    VarDeclBits.SClassAsWritten = SC;
-  }
 
   void setThreadSpecified(bool T) { VarDeclBits.ThreadSpecified = T; }
   bool isThreadSpecified() const {
@@ -805,13 +797,6 @@ public:
            getStorageClass() == SC_PrivateExtern;
   }
 
-  /// \brief Returns true if a variable was written with extern or
-  /// __private_extern__ storage.
-  bool hasExternalStorageAsWritten() const {
-    return getStorageClassAsWritten() == SC_Extern ||
-           getStorageClassAsWritten() == SC_PrivateExtern;
-  }
-
   /// hasGlobalStorage - Returns true for all variables that do not
   ///  have local storage.  This includs all global variables as well
   ///  as static variables declared within a function.
@@ -1145,7 +1130,7 @@ public:
   ImplicitParamDecl(DeclContext *DC, SourceLocation IdLoc,
                     IdentifierInfo *Id, QualType Type)
     : VarDecl(ImplicitParam, DC, IdLoc, IdLoc, Id, Type,
-              /*tinfo*/ 0, SC_None, SC_None) {
+              /*tinfo*/ 0, SC_None) {
     setImplicit();
   }
 
@@ -1164,8 +1149,8 @@ protected:
   ParmVarDecl(Kind DK, DeclContext *DC, SourceLocation StartLoc,
               SourceLocation IdLoc, IdentifierInfo *Id,
               QualType T, TypeSourceInfo *TInfo,
-              StorageClass S, StorageClass SCAsWritten, Expr *DefArg)
-    : VarDecl(DK, DC, StartLoc, IdLoc, Id, T, TInfo, S, SCAsWritten) {
+              StorageClass S, Expr *DefArg)
+    : VarDecl(DK, DC, StartLoc, IdLoc, Id, T, TInfo, S) {
     assert(ParmVarDeclBits.HasInheritedDefaultArg == false);
     assert(ParmVarDeclBits.IsKNRPromoted == false);
     assert(ParmVarDeclBits.IsObjCMethodParam == false);
@@ -1177,8 +1162,7 @@ public:
                              SourceLocation StartLoc,
                              SourceLocation IdLoc, IdentifierInfo *Id,
                              QualType T, TypeSourceInfo *TInfo,
-                             StorageClass S, StorageClass SCAsWritten,
-                             Expr *DefArg);
+                             StorageClass S, Expr *DefArg);
 
   static ParmVarDecl *CreateDeserialized(ASTContext &C, unsigned ID);
   
@@ -1383,7 +1367,6 @@ private:
   // FIXME: This can be packed into the bitfields in Decl.
   // NOTE: VC++ treats enums as signed, avoid using the StorageClass enum
   unsigned SClass : 2;
-  unsigned SClassAsWritten : 2;
   bool IsInline : 1;
   bool IsInlineSpecified : 1;
   bool IsVirtualAsWritten : 1;
@@ -1473,13 +1456,13 @@ protected:
   FunctionDecl(Kind DK, DeclContext *DC, SourceLocation StartLoc,
                const DeclarationNameInfo &NameInfo,
                QualType T, TypeSourceInfo *TInfo,
-               StorageClass S, StorageClass SCAsWritten, bool isInlineSpecified,
+               StorageClass S, bool isInlineSpecified,
                bool isConstexprSpecified)
     : DeclaratorDecl(DK, DC, NameInfo.getLoc(), NameInfo.getName(), T, TInfo,
                      StartLoc),
       DeclContext(DK),
       ParamInfo(0), Body(),
-      SClass(S), SClassAsWritten(SCAsWritten),
+      SClass(S),
       IsInline(isInlineSpecified), IsInlineSpecified(isInlineSpecified),
       IsVirtualAsWritten(false), IsPure(false), HasInheritedPrototype(false),
       HasWrittenPrototype(true), IsDeleted(false), IsTrivial(false),
@@ -1511,13 +1494,12 @@ public:
                               DeclarationName N, QualType T,
                               TypeSourceInfo *TInfo,
                               StorageClass SC,
-                              StorageClass SCAsWritten,
                               bool isInlineSpecified = false,
                               bool hasWrittenPrototype = true,
                               bool isConstexprSpecified = false) {
     DeclarationNameInfo NameInfo(N, NLoc);
     return FunctionDecl::Create(C, DC, StartLoc, NameInfo, T, TInfo,
-                                SC, SCAsWritten,
+                                SC,
                                 isInlineSpecified, hasWrittenPrototype,
                                 isConstexprSpecified);
   }
@@ -1527,7 +1509,6 @@ public:
                               const DeclarationNameInfo &NameInfo,
                               QualType T, TypeSourceInfo *TInfo,
                               StorageClass SC,
-                              StorageClass SCAsWritten,
                               bool isInlineSpecified,
                               bool hasWrittenPrototype,
                               bool isConstexprSpecified = false);
@@ -1779,12 +1760,9 @@ public:
     return getType()->getAs<FunctionType>()->getCallResultType(getASTContext());
   }
 
+  /// \brief Returns the storage class as written in the source. For the
+  /// computed linkage of symbol, see getLinkage.
   StorageClass getStorageClass() const { return StorageClass(SClass); }
-  void setStorageClass(StorageClass SC);
-
-  StorageClass getStorageClassAsWritten() const {
-    return StorageClass(SClassAsWritten);
-  }
 
   /// \brief Determine whether the "inline" keyword was specified for this
   /// function.
diff --git a/include/clang/AST/DeclCXX.h b/include/clang/AST/DeclCXX.h
index 430e6d8cc5..05ff49c64c 100644
--- a/include/clang/AST/DeclCXX.h
+++ b/include/clang/AST/DeclCXX.h
@@ -1573,11 +1573,10 @@ protected:
   CXXMethodDecl(Kind DK, CXXRecordDecl *RD, SourceLocation StartLoc,
                 const DeclarationNameInfo &NameInfo,
                 QualType T, TypeSourceInfo *TInfo,
-                bool isStatic, StorageClass SCAsWritten, bool isInline,
+                StorageClass SC, bool isInline,
                 bool isConstexpr, SourceLocation EndLocation)
     : FunctionDecl(DK, RD, StartLoc, NameInfo, T, TInfo,
-                   (isStatic ? SC_Static : SC_None),
-                   SCAsWritten, isInline, isConstexpr) {
+                   SC, isInline, isConstexpr) {
     if (EndLocation.isValid())
       setRangeEnd(EndLocation);
   }
@@ -1587,15 +1586,14 @@ public:
                                SourceLocation StartLoc,
                                const DeclarationNameInfo &NameInfo,
                                QualType T, TypeSourceInfo *TInfo,
-                               bool isStatic,
-                               StorageClass SCAsWritten,
+                               StorageClass SC,
                                bool isInline,
                                bool isConstexpr,
                                SourceLocation EndLocation);
 
   static CXXMethodDecl *CreateDeserialized(ASTContext &C, unsigned ID);
-  
-  bool isStatic() const { return getStorageClass() == SC_Static; }
+
+  bool isStatic() const;
   bool isInstance() const { return !isStatic(); }
 
   bool isConst() const { return getType()->castAs<FunctionType>()->isConst(); }
@@ -2003,7 +2001,7 @@ class CXXConstructorDecl : public CXXMethodDecl {
                      QualType T, TypeSourceInfo *TInfo,
                      bool isExplicitSpecified, bool isInline,
                      bool isImplicitlyDeclared, bool isConstexpr)
-    : CXXMethodDecl(CXXConstructor, RD, StartLoc, NameInfo, T, TInfo, false,
+    : CXXMethodDecl(CXXConstructor, RD, StartLoc, NameInfo, T, TInfo,
                     SC_None, isInline, isConstexpr, SourceLocation()),
       IsExplicitSpecified(isExplicitSpecified), ImplicitlyDefined(false),
       CtorInitializers(0), NumCtorInitializers(0) {
@@ -2222,7 +2220,7 @@ class CXXDestructorDecl : public CXXMethodDecl {
                     const DeclarationNameInfo &NameInfo,
                     QualType T, TypeSourceInfo *TInfo,
                     bool isInline, bool isImplicitlyDeclared)
-    : CXXMethodDecl(CXXDestructor, RD, StartLoc, NameInfo, T, TInfo, false,
+    : CXXMethodDecl(CXXDestructor, RD, StartLoc, NameInfo, T, TInfo,
                     SC_None, isInline, /*isConstexpr=*/false, SourceLocation()),
       ImplicitlyDefined(false), OperatorDelete(0) {
     setImplicit(isImplicitlyDeclared);
@@ -2289,7 +2287,7 @@ class CXXConversionDecl : public CXXMethodDecl {
                     QualType T, TypeSourceInfo *TInfo,
                     bool isInline, bool isExplicitSpecified,
                     bool isConstexpr, SourceLocation EndLocation)
-    : CXXMethodDecl(CXXConversion, RD, StartLoc, NameInfo, T, TInfo, false,
+    : CXXMethodDecl(CXXConversion, RD, StartLoc, NameInfo, T, TInfo,
                     SC_None, isInline, isConstexpr, EndLocation),
       IsExplicitSpecified(isExplicitSpecified) { }
 
diff --git a/include/clang/Sema/DeclSpec.h b/include/clang/Sema/DeclSpec.h
index 48cd4d14f8..5b90784dcf 100644
--- a/include/clang/Sema/DeclSpec.h
+++ b/include/clang/Sema/DeclSpec.h
@@ -338,8 +338,6 @@ private:
   // constexpr-specifier
   unsigned Constexpr_specified : 1;
 
-  /*SCS*/unsigned StorageClassSpecAsWritten : 3;
-
   union {
     UnionParsedType TypeRep;
     Decl *DeclRep;
@@ -378,7 +376,6 @@ private:
 
   WrittenBuiltinSpecs writtenBS;
   void SaveWrittenBuiltinSpecs();
-  void SaveStorageSpecifierAsWritten();
 
   ObjCDeclSpec *ObjCQualifiers;
 
@@ -418,7 +415,6 @@ public:
       FS_noreturn_specified(false),
       Friend_specified(false),
       Constexpr_specified(false),
-      StorageClassSpecAsWritten(SCS_unspecified),
       Attrs(attrFactory),
       ProtocolQualifiers(0),
       NumProtocolQualifiers(0),
@@ -553,10 +549,6 @@ public:
   /// DeclSpec includes.
   unsigned getParsedSpecifiers() const;
 
-  SCS getStorageClassSpecAsWritten() const {
-    return (SCS)StorageClassSpecAsWritten;
-  }
-
   /// isEmpty - Return true if this declaration specifier is completely empty:
   /// no tokens were parsed in the production of it.
   bool isEmpty() const {
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 7b07352d3c..d17557260e 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -1402,7 +1402,7 @@ public:
   ParmVarDecl *CheckParameter(DeclContext *DC, SourceLocation StartLoc,
                               SourceLocation NameLoc, IdentifierInfo *Name,
                               QualType T, TypeSourceInfo *TSInfo,
-                              StorageClass SC, StorageClass SCAsWritten);
+                              StorageClass SC);
   void ActOnParamDefaultArgument(Decl *param,
                                  SourceLocation EqualLoc,
                                  Expr *defarg);
diff --git a/lib/AST/ASTDumper.cpp b/lib/AST/ASTDumper.cpp
index 740153029b..b1d174b855 100644
--- a/lib/AST/ASTDumper.cpp
+++ b/lib/AST/ASTDumper.cpp
@@ -749,7 +749,7 @@ void ASTDumper::VisitFunctionDecl(const FunctionDecl *D) {
   dumpName(D);
   dumpType(D->getType());
 
-  StorageClass SC = D->getStorageClassAsWritten();
+  StorageClass SC = D->getStorageClass();
   if (SC != SC_None)
     OS << ' ' << VarDecl::getStorageClassSpecifierString(SC);
   if (D->isInlineSpecified())
@@ -850,7 +850,7 @@ void ASTDumper::VisitFieldDecl(const FieldDecl *D) {
 void ASTDumper::VisitVarDecl(const VarDecl *D) {
   dumpName(D);
   dumpType(D->getType());
-  StorageClass SC = D->getStorageClassAsWritten();
+  StorageClass SC = D->getStorageClass();
   if (SC != SC_None)
     OS << ' ' << VarDecl::getStorageClassSpecifierString(SC);
   if (D->isThreadSpecified())
diff --git a/lib/AST/ASTImporter.cpp b/lib/AST/ASTImporter.cpp
index 01d1a1e917..d2e6d29705 100644
--- a/lib/AST/ASTImporter.cpp
+++ b/lib/AST/ASTImporter.cpp
@@ -2716,8 +2716,7 @@ Decl *ASTNodeImporter::VisitFunctionDecl(FunctionDecl *D) {
                                        cast<CXXRecordDecl>(DC),
                                        D->getInnerLocStart(),
                                        NameInfo, T, TInfo,
-                                       Method->isStatic(),
-                                       Method->getStorageClassAsWritten(),
+                                       Method->getStorageClass(),
                                        Method->isInlineSpecified(),
                                        D->isConstexpr(),
                                        Importer.Import(D->getLocEnd()));
@@ -2725,7 +2724,6 @@ Decl *ASTNodeImporter::VisitFunctionDecl(FunctionDecl *D) {
     ToFunction = FunctionDecl::Create(Importer.getToContext(), DC,
                                       D->getInnerLocStart(),
                                       NameInfo, T, TInfo, D->getStorageClass(),
-                                      D->getStorageClassAsWritten(),
                                       D->isInlineSpecified(),
                                       D->hasWrittenPrototype(),
                                       D->isConstexpr());
@@ -3076,8 +3074,7 @@ Decl *ASTNodeImporter::VisitVarDecl(VarDecl *D) {
                                    Importer.Import(D->getInnerLocStart()),
                                    Loc, Name.getAsIdentifierInfo(),
                                    T, TInfo,
-                                   D->getStorageClass(),
-                                   D->getStorageClassAsWritten());
+                                   D->getStorageClass());
   ToVar->setQualifierInfo(Importer.Import(D->getQualifierLoc()));
   ToVar->setAccess(D->getAccess());
   ToVar->setLexicalDeclContext(LexicalDC);
@@ -3145,7 +3142,6 @@ Decl *ASTNodeImporter::VisitParmVarDecl(ParmVarDecl *D) {
                                      Importer.Import(D->getInnerLocStart()),
                                             Loc, Name.getAsIdentifierInfo(),
                                             T, TInfo, D->getStorageClass(),
-                                             D->getStorageClassAsWritten(),
                                             /*FIXME: Default argument*/ 0);
   ToParm->setHasInheritedDefaultArg(D->hasInheritedDefaultArg());
   return Importer.Imported(D, ToParm);
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 4b92069762..9505d299ab 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -498,26 +498,24 @@ static LinkageInfo getLVForNamespaceScopeDecl(const NamedDecl *D,
     //   declared to have external linkage; or (there is no equivalent in C99)
     if (Context.getLangOpts().CPlusPlus &&
         Var->getType().isConstQualified() && 
-        !Var->getType().isVolatileQualified() &&
-        Var->getStorageClass() != SC_Extern &&
-        Var->getStorageClass() != SC_PrivateExtern) {
-      bool FoundExtern = false;
-      for (const VarDecl *PrevVar = Var->getPreviousDecl();
-           PrevVar && !FoundExtern; 
-           PrevVar = PrevVar->getPreviousDecl())
-        if (isExternalLinkage(PrevVar->getLinkage()))
-          FoundExtern = true;
-      
-      if (!FoundExtern)
-        return LinkageInfo::internal();
-    }
-    if (Var->getStorageClass() == SC_None) {
+        !Var->getType().isVolatileQualified()) {
       const VarDecl *PrevVar = Var->getPreviousDecl();
-      for (; PrevVar; PrevVar = PrevVar->getPreviousDecl())
-        if (PrevVar->getStorageClass() == SC_PrivateExtern)
-          break;
       if (PrevVar)
         return PrevVar->getLinkageAndVisibility();
+
+      if (Var->getStorageClass() != SC_Extern &&
+          Var->getStorageClass() != SC_PrivateExtern)
+        return LinkageInfo::internal();
+    }
+
+    for (const VarDecl *PrevVar = Var->getPreviousDecl(); PrevVar;
+         PrevVar = PrevVar->getPreviousDecl()) {
+      if (PrevVar->getStorageClass() == SC_PrivateExtern &&
+          Var->getStorageClass() == SC_None)
+        return PrevVar->getLinkageAndVisibility();
+      // Explicitly declared static.
+      if (PrevVar->getStorageClass() == SC_Static)
+        return LinkageInfo::internal();
     }
   } else if (isa<FunctionDecl>(D) || isa<FunctionTemplateDecl>(D)) {
     // C++ [temp]p4:
@@ -531,7 +529,7 @@ static LinkageInfo getLVForNamespaceScopeDecl(const NamedDecl *D,
       Function = cast<FunctionDecl>(D);
 
     // Explicitly declared static.
-    if (Function->getStorageClass() == SC_Static)
+    if (Function->getCanonicalDecl()->getStorageClass() == SC_Static)
       return LinkageInfo(InternalLinkage, DefaultVisibility, false);
   } else if (const FieldDecl *Field = dyn_cast<FieldDecl>(D)) {
     //   - a data member of an anonymous union.
@@ -995,7 +993,7 @@ static LinkageInfo getLVForLocalDecl(const NamedDecl *D,
       return LinkageInfo::uniqueExternal();
 
     // This is a "void f();" which got merged with a file static.
-    if (Function->getStorageClass() == SC_Static)
+    if (Function->getCanonicalDecl()->getStorageClass() == SC_Static)
       return LinkageInfo::internal();
 
     LinkageInfo LV;
@@ -1013,15 +1011,11 @@ static LinkageInfo getLVForLocalDecl(const NamedDecl *D,
   }
 
   if (const VarDecl *Var = dyn_cast<VarDecl>(D)) {
-    if (Var->hasExternalStorageAsWritten()) {
+    if (Var->hasExternalStorage()) {
       if (Var->isInAnonymousNamespace() &&
           !Var->getDeclContext()->isExternCContext())
         return LinkageInfo::uniqueExternal();
 
-      // This is an "extern int foo;" which got merged with a file static.
-      if (Var->getStorageClass() == SC_Static)
-        return LinkageInfo::internal();
-
       LinkageInfo LV;
       if (Var->getStorageClass() == SC_PrivateExtern)
         LV.mergeVisibility(HiddenVisibility, true);
@@ -1030,9 +1024,13 @@ static LinkageInfo getLVForLocalDecl(const NamedDecl *D,
           LV.mergeVisibility(*Vis, true);
       }
 
-      // Note that Sema::MergeVarDecl already takes care of implementing
-      // C99 6.2.2p4 and propagating the visibility attribute, so we don't
-      // have to do it here.
+      if (const VarDecl *Prev = Var->getPreviousDecl()) {
+        LinkageInfo PrevLV = getLVForDecl(Prev, computation);
+        if (PrevLV.getLinkage())
+          LV.setLinkage(PrevLV.getLinkage());
+        LV.mergeVisibility(PrevLV);
+      }
+
       return LV;
     }
   }
@@ -1467,21 +1465,18 @@ const char *VarDecl::getStorageClassSpecifierString(StorageClass SC) {
 VarDecl *VarDecl::Create(ASTContext &C, DeclContext *DC,
                          SourceLocation StartL, SourceLocation IdL,
                          IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo,
-                         StorageClass S, StorageClass SCAsWritten) {
-  return new (C) VarDecl(Var, DC, StartL, IdL, Id, T, TInfo, S, SCAsWritten);
+                         StorageClass S) {
+  return new (C) VarDecl(Var, DC, StartL, IdL, Id, T, TInfo, S);
 }
 
 VarDecl *VarDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
   void *Mem = AllocateDeserializedDecl(C, ID, sizeof(VarDecl));
   return new (Mem) VarDecl(Var, 0, SourceLocation(), SourceLocation(), 0, 
-                           QualType(), 0, SC_None, SC_None);
+                           QualType(), 0, SC_None);
 }
 
 void VarDecl::setStorageClass(StorageClass SC) {
   assert(isLegalForVariable(SC));
-  if (getStorageClass() != SC)
-    assert(isLinkageValid());
-
   VarDeclBits.SClass = SC;
 }
 
@@ -1581,7 +1576,7 @@ VarDecl::DefinitionKind VarDecl::isThisDeclarationADefinition(
   if (hasExternalStorage())
     return DeclarationOnly;
 
-  if (hasExternalStorageAsWritten()) {
+  if (hasExternalStorage()) {
     for (const VarDecl *PrevVar = getPreviousDecl();
          PrevVar; PrevVar = PrevVar->getPreviousDecl()) {
       if (PrevVar->getLinkage() == InternalLinkage)
@@ -1879,16 +1874,15 @@ ParmVarDecl *ParmVarDecl::Create(ASTContext &C, DeclContext *DC,
                                  SourceLocation StartLoc,
                                  SourceLocation IdLoc, IdentifierInfo *Id,
                                  QualType T, TypeSourceInfo *TInfo,
-                                 StorageClass S, StorageClass SCAsWritten,
-                                 Expr *DefArg) {
+                                 StorageClass S, Expr *DefArg) {
   return new (C) ParmVarDecl(ParmVar, DC, StartLoc, IdLoc, Id, T, TInfo,
-                             S, SCAsWritten, DefArg);
+                             S, DefArg);
 }
 
 ParmVarDecl *ParmVarDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
   void *Mem = AllocateDeserializedDecl(C, ID, sizeof(ParmVarDecl));
   return new (Mem) ParmVarDecl(ParmVar, 0, SourceLocation(), SourceLocation(),
-                               0, QualType(), 0, SC_None, SC_None, 0);
+                               0, QualType(), 0, SC_None, 0);
 }
 
 SourceRange ParmVarDecl::getSourceRange() const {
@@ -2067,7 +2061,7 @@ bool FunctionDecl::isGlobal() const {
   if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(this))
     return Method->isStatic();
 
-  if (getStorageClass() == SC_Static)
+  if (getCanonicalDecl()->getStorageClass() == SC_Static)
     return false;
 
   for (const DeclContext *DC = getDeclContext();
@@ -2112,14 +2106,6 @@ FunctionDecl *FunctionDecl::getCanonicalDecl() {
   return getFirstDeclaration();
 }
 
-void FunctionDecl::setStorageClass(StorageClass SC) {
-  assert(isLegalForFunction(SC));
-  if (getStorageClass() != SC)
-    assert(isLinkageValid());
-
-  SClass = SC;
-}
-
 /// \brief Returns a value indicating whether this function
 /// corresponds to a builtin function.
 ///
@@ -2270,7 +2256,7 @@ bool FunctionDecl::doesDeclarationForceExternallyVisibleDefinition() const {
     //
     // FIXME: What happens if gnu_inline gets added on after the first
     // declaration?
-    if (!isInlineSpecified() || getStorageClassAsWritten() == SC_Extern)
+    if (!isInlineSpecified() || getStorageClass() == SC_Extern)
       return false;
 
     const FunctionDecl *Prev = this;
@@ -2282,10 +2268,10 @@ bool FunctionDecl::doesDeclarationForceExternallyVisibleDefinition() const {
         // If it's not the case that both 'inline' and 'extern' are
         // specified on the definition, then it is always externally visible.
         if (!Prev->isInlineSpecified() ||
-            Prev->getStorageClassAsWritten() != SC_Extern)
+            Prev->getStorageClass() != SC_Extern)
           return false;
       } else if (Prev->isInlineSpecified() && 
-                 Prev->getStorageClassAsWritten() != SC_Extern) {
+                 Prev->getStorageClass() != SC_Extern) {
         return false;
       }
     }
@@ -2340,7 +2326,7 @@ bool FunctionDecl::isInlineDefinitionExternallyVisible() const {
     // If it's not the case that both 'inline' and 'extern' are
     // specified on the definition, then this inline definition is
     // externally visible.
-    if (!(isInlineSpecified() && getStorageClassAsWritten() == SC_Extern))
+    if (!(isInlineSpecified() && getStorageClass() == SC_Extern))
       return true;
     
     // If any declaration is 'inline' but not 'extern', then this definition
@@ -2349,7 +2335,7 @@ bool FunctionDecl::isInlineDefinitionExternallyVisible() const {
          Redecl != RedeclEnd;
          ++Redecl) {
       if (Redecl->isInlineSpecified() && 
-          Redecl->getStorageClassAsWritten() != SC_Extern)
+          Redecl->getStorageClass() != SC_Extern)
         return true;
     }    
     
@@ -3212,12 +3198,12 @@ FunctionDecl *FunctionDecl::Create(ASTContext &C, DeclContext *DC,
                                    SourceLocation StartLoc,
                                    const DeclarationNameInfo &NameInfo,
                                    QualType T, TypeSourceInfo *TInfo,
-                                   StorageClass SC, StorageClass SCAsWritten,
+                                   StorageClass SC,
                                    bool isInlineSpecified, 
                                    bool hasWrittenPrototype,
                                    bool isConstexprSpecified) {
   FunctionDecl *New = new (C) FunctionDecl(Function, DC, StartLoc, NameInfo,
-                                           T, TInfo, SC, SCAsWritten,
+                                           T, TInfo, SC,
                                            isInlineSpecified,
                                            isConstexprSpecified);
   New->HasWrittenPrototype = hasWrittenPrototype;
@@ -3228,7 +3214,7 @@ FunctionDecl *FunctionDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
   void *Mem = AllocateDeserializedDecl(C, ID, sizeof(FunctionDecl));
   return new (Mem) FunctionDecl(Function, 0, SourceLocation(), 
                                 DeclarationNameInfo(), QualType(), 0,
-                                SC_None, SC_None, false, false);
+                                SC_None, false, false);
 }
 
 BlockDecl *BlockDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L) {
diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp
index 1e60560485..bd6d99cd59 100644
--- a/lib/AST/DeclBase.cpp
+++ b/lib/AST/DeclBase.cpp
@@ -435,7 +435,7 @@ bool Decl::canBeWeakImported(bool &IsDefinition) const {
 
   // Variables, if they aren't definitions.
   if (const VarDecl *Var = dyn_cast<VarDecl>(this)) {
-    if (!Var->hasExternalStorage() || Var->getInit()) {
+    if (Var->isThisDeclarationADefinition()) {
       IsDefinition = true;
       return false;
     }
diff --git a/lib/AST/DeclCXX.cpp b/lib/AS