[-fms-extensions] Permit 'override' in C++98 and 'sealed' as a synonym for 'final'

Summary: Some MS headers use these features.

Reviewers: rnk, rsmith

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1948

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192936 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/StmtPrinter.cpp b/lib/AST/StmtPrinter.cpp
index 55cfd3f..29e8e9f 100644
--- a/lib/AST/StmtPrinter.cpp
+++ b/lib/AST/StmtPrinter.cpp
@@ -1712,6 +1712,7 @@
   case UTT_IsReference:             return "__is_reference";
   case UTT_IsRvalueReference:       return "__is_rvalue_reference";
   case UTT_IsScalar:                return "__is_scalar";
+  case UTT_IsSealed:                return "__is_sealed";
   case UTT_IsSigned:                return "__is_signed";
   case UTT_IsStandardLayout:        return "__is_standard_layout";
   case UTT_IsTrivial:               return "__is_trivial";
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index 9c998ea..f20633f 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -983,6 +983,7 @@
            .Case("is_standard_layout", LangOpts.CPlusPlus)
            .Case("is_pod", LangOpts.CPlusPlus)
            .Case("is_polymorphic", LangOpts.CPlusPlus)
+           .Case("is_sealed", LangOpts.MicrosoftExt)
            .Case("is_trivial", LangOpts.CPlusPlus)
            .Case("is_trivially_assignable", LangOpts.CPlusPlus)
            .Case("is_trivially_constructible", LangOpts.CPlusPlus)
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index 21b24bf..4625745 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -1837,12 +1837,17 @@
     // Initialize the contextual keywords.
     if (!Ident_final) {
       Ident_final = &PP.getIdentifierTable().get("final");
+      if (getLangOpts().MicrosoftExt)
+        Ident_sealed = &PP.getIdentifierTable().get("sealed");
       Ident_override = &PP.getIdentifierTable().get("override");
     }
 
     if (II == Ident_override)
       return VirtSpecifiers::VS_Override;
 
+    if (II == Ident_sealed)
+      return VirtSpecifiers::VS_Sealed;
+
     if (II == Ident_final)
       return VirtSpecifiers::VS_Final;
   }
@@ -1870,14 +1875,18 @@
         << PrevSpec
         << FixItHint::CreateRemoval(Tok.getLocation());
 
-    if (IsInterface && Specifier == VirtSpecifiers::VS_Final) {
+    if (IsInterface && (Specifier == VirtSpecifiers::VS_Final ||
+                        Specifier == VirtSpecifiers::VS_Sealed)) {
       Diag(Tok.getLocation(), diag::err_override_control_interface)
         << VirtSpecifiers::getSpecifierName(Specifier);
+    } else if (Specifier == VirtSpecifiers::VS_Sealed) {
+      Diag(Tok.getLocation(), diag::ext_ms_sealed_keyword);
     } else {
-      Diag(Tok.getLocation(), getLangOpts().CPlusPlus11 ?
-           diag::warn_cxx98_compat_override_control_keyword :
-           diag::ext_override_control_keyword)
-        << VirtSpecifiers::getSpecifierName(Specifier);
+      Diag(Tok.getLocation(),
+           getLangOpts().CPlusPlus11
+               ? diag::warn_cxx98_compat_override_control_keyword
+               : diag::ext_override_control_keyword)
+          << VirtSpecifiers::getSpecifierName(Specifier);
     }
     ConsumeToken();
   }
@@ -1895,10 +1904,13 @@
   // Initialize the contextual keywords.
   if (!Ident_final) {
     Ident_final = &PP.getIdentifierTable().get("final");
+    if (getLangOpts().MicrosoftExt)
+      Ident_sealed = &PP.getIdentifierTable().get("sealed");
     Ident_override = &PP.getIdentifierTable().get("override");
   }
-  
-  return Tok.getIdentifierInfo() == Ident_final;
+
+  return Tok.getIdentifierInfo() == Ident_final ||
+         Tok.getIdentifierInfo() == Ident_sealed;
 }
 
 /// ParseCXXClassMemberDeclaration - Parse a C++ class member declaration.
@@ -1929,6 +1941,7 @@
 ///       virt-specifier:
 ///         override
 ///         final
+/// [MS]    sealed
 /// 
 ///       pure-specifier:
 ///         '= 0'
@@ -2520,20 +2533,27 @@
     Actions.ActOnTagStartDefinition(getCurScope(), TagDecl);
 
   SourceLocation FinalLoc;
+  bool IsFinalSpelledSealed = false;
 
   // Parse the optional 'final' keyword.
   if (getLangOpts().CPlusPlus && Tok.is(tok::identifier)) {
-    assert(isCXX11FinalKeyword() && "not a class definition");
+    VirtSpecifiers::Specifier Specifier = isCXX11VirtSpecifier(Tok);
+    assert((Specifier == VirtSpecifiers::VS_Final ||
+            Specifier == VirtSpecifiers::VS_Sealed) &&
+           "not a class definition");
     FinalLoc = ConsumeToken();
+    IsFinalSpelledSealed = Specifier == VirtSpecifiers::VS_Sealed;
 
-    if (TagType == DeclSpec::TST_interface) {
+    if (TagType == DeclSpec::TST_interface)
       Diag(FinalLoc, diag::err_override_control_interface)
-        << "final";
-    } else {
-      Diag(FinalLoc, getLangOpts().CPlusPlus11 ?
-           diag::warn_cxx98_compat_override_control_keyword :
-           diag::ext_override_control_keyword) << "final";
-    }
+        << VirtSpecifiers::getSpecifierName(Specifier);
+    else if (Specifier == VirtSpecifiers::VS_Final)
+      Diag(FinalLoc, getLangOpts().CPlusPlus11
+                         ? diag::warn_cxx98_compat_override_control_keyword
+                         : diag::ext_override_control_keyword)
+        << VirtSpecifiers::getSpecifierName(Specifier);
+    else if (Specifier == VirtSpecifiers::VS_Sealed)
+      Diag(FinalLoc, diag::ext_ms_sealed_keyword);
 
     // Parse any C++11 attributes after 'final' keyword.
     // These attributes are not allowed to appear here,
@@ -2560,6 +2580,7 @@
 
   if (TagDecl)
     Actions.ActOnStartCXXMemberDeclarations(getCurScope(), TagDecl, FinalLoc,
+                                            IsFinalSpelledSealed,
                                             T.getOpenLocation());
 
   // C++ 11p3: Members of a class defined with the keyword class are private
diff --git a/lib/Parse/ParseExpr.cpp b/lib/Parse/ParseExpr.cpp
index a82d5ce..8867b08 100644
--- a/lib/Parse/ParseExpr.cpp
+++ b/lib/Parse/ParseExpr.cpp
@@ -591,6 +591,7 @@
 ///                   '__is_final'
 ///                   '__is_pod'
 ///                   '__is_polymorphic'
+///                   '__is_sealed'                           [MS]
 ///                   '__is_trivial'
 ///                   '__is_union'
 ///
@@ -1200,6 +1201,7 @@
   case tok::kw___is_trivially_copyable:
   case tok::kw___is_union:
   case tok::kw___is_final:
+  case tok::kw___is_sealed:
   case tok::kw___has_trivial_constructor:
   case tok::kw___has_trivial_move_constructor:
   case tok::kw___has_trivial_copy:
diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index e9a5a88..4dd63e3 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -2669,6 +2669,7 @@
   case tok::kw___is_reference:               return UTT_IsReference;
   case tok::kw___is_rvalue_reference:        return UTT_IsRvalueReference;
   case tok::kw___is_scalar:                  return UTT_IsScalar;
+  case tok::kw___is_sealed:                  return UTT_IsSealed;
   case tok::kw___is_signed:                  return UTT_IsSigned;
   case tok::kw___is_standard_layout:         return UTT_IsStandardLayout;
   case tok::kw___is_trivial:                 return UTT_IsTrivial;
diff --git a/lib/Parse/ParseTentative.cpp b/lib/Parse/ParseTentative.cpp
index 7d1475c..2dc16d3 100644
--- a/lib/Parse/ParseTentative.cpp
+++ b/lib/Parse/ParseTentative.cpp
@@ -962,6 +962,7 @@
   case tok::kw___is_literal_type:
   case tok::kw___is_pod:
   case tok::kw___is_polymorphic:
+  case tok::kw___is_sealed:
   case tok::kw___is_trivial:
   case tok::kw___is_trivially_assignable:
   case tok::kw___is_trivially_constructible:
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index f0a3d91..9b6c97a 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -486,6 +486,7 @@
 
   Ident_instancetype = 0;
   Ident_final = 0;
+  Ident_sealed = 0;
   Ident_override = 0;
 
   Ident_super = &PP.getIdentifierTable().get("super");
diff --git a/lib/Sema/DeclSpec.cpp b/lib/Sema/DeclSpec.cpp
index 5d4fce7..46914f6 100644
--- a/lib/Sema/DeclSpec.cpp
+++ b/lib/Sema/DeclSpec.cpp
@@ -1118,6 +1118,7 @@
   switch (VS) {
   default: llvm_unreachable("Unknown specifier!");
   case VS_Override: VS_overrideLoc = Loc; break;
+  case VS_Sealed:
   case VS_Final:    VS_finalLoc = Loc; break;
   }
 
@@ -1129,5 +1130,6 @@
   default: llvm_unreachable("Unknown specifier");
   case VS_Override: return "override";
   case VS_Final: return "final";
+  case VS_Sealed: return "sealed";
   }
 }
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index f56ef42..632cc19 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -10957,6 +10957,7 @@
 
 void Sema::ActOnStartCXXMemberDeclarations(Scope *S, Decl *TagD,
                                            SourceLocation FinalLoc,
+                                           bool IsFinalSpelledSealed,
                                            SourceLocation LBraceLoc) {
   AdjustDeclIfTemplate(TagD);
   CXXRecordDecl *Record = cast<CXXRecordDecl>(TagD);
@@ -10967,8 +10968,9 @@
     return;
 
   if (FinalLoc.isValid())
-    Record->addAttr(new (Context) FinalAttr(FinalLoc, Context));
-    
+    Record->addAttr(new (Context)
+                    FinalAttr(FinalLoc, Context, IsFinalSpelledSealed));
+
   // C++ [class]p2:
   //   [...] The class-name is also inserted into the scope of the
   //   class itself; this is known as the injected-class-name. For
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index bd864b3..81283e1 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -1373,9 +1373,10 @@
   // C++ [class]p3:
   //   If a class is marked final and it appears as a base-type-specifier in 
   //   base-clause, the program is ill-formed.
-  if (CXXBaseDecl->hasAttr<FinalAttr>()) {
+  if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
     Diag(BaseLoc, diag::err_class_marked_final_used_as_base) 
-      << CXXBaseDecl->getDeclName();
+      << CXXBaseDecl->getDeclName()
+      << FA->isSpelledAsSealed();
     Diag(CXXBaseDecl->getLocation(), diag::note_previous_decl)
       << CXXBaseDecl->getDeclName();
     return 0;
@@ -1762,7 +1763,8 @@
       } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
         Diag(FA->getLocation(),
              diag::override_keyword_hides_virtual_member_function)
-            << "final" << (OverloadedMethods.size() > 1);
+          << (FA->isSpelledAsSealed() ? "sealed" : "final")
+          << (OverloadedMethods.size() > 1);
       }
       NoteHiddenVirtualMethods(MD, OverloadedMethods);
       MD->setInvalidDecl();
@@ -1782,7 +1784,8 @@
     if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
       Diag(FA->getLocation(),
            diag::override_keyword_only_allowed_on_virtual_member_functions)
-        << "final" << FixItHint::CreateRemoval(FA->getLocation());
+        << (FA->isSpelledAsSealed() ? "sealed" : "final")
+        << FixItHint::CreateRemoval(FA->getLocation());
       D->dropAttr<FinalAttr>();
     }
     return;
@@ -1804,11 +1807,13 @@
 /// C++11 [class.virtual]p4.
 bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
                                                   const CXXMethodDecl *Old) {
-  if (!Old->hasAttr<FinalAttr>())
+  FinalAttr *FA = Old->getAttr<FinalAttr>();
+  if (!FA)
     return false;
 
   Diag(New->getLocation(), diag::err_final_function_overridden)
-    << New->getDeclName();
+    << New->getDeclName()
+    << FA->isSpelledAsSealed();
   Diag(Old->getLocation(), diag::note_overridden_virtual_function);
   return true;
 }
@@ -2067,7 +2072,8 @@
   if (VS.isOverrideSpecified())
     Member->addAttr(new (Context) OverrideAttr(VS.getOverrideLoc(), Context));
   if (VS.isFinalSpecified())
-    Member->addAttr(new (Context) FinalAttr(VS.getFinalLoc(), Context));
+    Member->addAttr(new (Context) FinalAttr(VS.getFinalLoc(), Context,
+                                            VS.isFinalSpelledSealed()));
 
   if (VS.getLastLocation().isValid()) {
     // Update the end location of a method that has a virt-specifiers.
@@ -4406,9 +4412,12 @@
            diag::warn_non_virtual_dtor) << Context.getRecordType(Record);
   }
 
-  if (Record->isAbstract() && Record->hasAttr<FinalAttr>()) {
-    Diag(Record->getLocation(), diag::warn_abstract_final_class);
-    DiagnoseAbstractType(Record);
+  if (Record->isAbstract()) {
+    if (FinalAttr *FA = Record->getAttr<FinalAttr>()) {
+      Diag(Record->getLocation(), diag::warn_abstract_final_class)
+        << FA->isSpelledAsSealed();
+      DiagnoseAbstractType(Record);
+    }
   }
 
   if (!Record->isDependentType()) {
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 837d383..323cd26 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -3131,6 +3131,7 @@
 
   // These traits require a complete type.
   case UTT_IsFinal:
+  case UTT_IsSealed:
 
     // These trait expressions are designed to help implement predicates in
     // [meta.unary.prop] despite not being named the same. They are specified
@@ -3304,6 +3305,11 @@
     if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
       return RD->hasAttr<FinalAttr>();
     return false;
+  case UTT_IsSealed:
+    if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
+      if (FinalAttr *FA = RD->getAttr<FinalAttr>())
+        return FA->isSpelledAsSealed();
+    return false;
   case UTT_IsSigned:
     return T->isSignedIntegerType();
   case UTT_IsUnsigned: