Support for definitions of member enumerations of class templates outside the
class template's definition, and for explicit specializations of such enum
members.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153304 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 34ec7a8..3b7113d 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -2674,6 +2674,24 @@
   TagDecl::completeDefinition();
 }
 
+TemplateSpecializationKind EnumDecl::getTemplateSpecializationKind() const {
+  if (MemberSpecializationInfo *MSI = getMemberSpecializationInfo())
+    return MSI->getTemplateSpecializationKind();
+
+  return TSK_Undeclared;
+}
+
+void EnumDecl::setTemplateSpecializationKind(TemplateSpecializationKind TSK,
+                                         SourceLocation PointOfInstantiation) {
+  MemberSpecializationInfo *MSI = getMemberSpecializationInfo();
+  assert(MSI && "Not an instantiated member enumeration?");
+  MSI->setTemplateSpecializationKind(TSK);
+  if (TSK != TSK_ExplicitSpecialization &&
+      PointOfInstantiation.isValid() &&
+      MSI->getPointOfInstantiation().isInvalid())
+    MSI->setPointOfInstantiation(PointOfInstantiation);
+}
+
 EnumDecl *EnumDecl::getInstantiatedFromMemberEnum() const {
   if (SpecializationInfo)
     return cast<EnumDecl>(SpecializationInfo->getInstantiatedFrom());
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 6f344f6..24386d0 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -2611,19 +2611,20 @@
 ///         'enum' identifier
 /// [GNU]   'enum' attributes[opt] identifier
 ///
-/// [C++0x] enum-head '{' enumerator-list[opt] '}'
-/// [C++0x] enum-head '{' enumerator-list ','  '}'
+/// [C++11] enum-head '{' enumerator-list[opt] '}'
+/// [C++11] enum-head '{' enumerator-list ','  '}'
 ///
-///       enum-head: [C++0x]
-///         enum-key attributes[opt] identifier[opt] enum-base[opt]
-///         enum-key attributes[opt] nested-name-specifier identifier enum-base[opt]
+///       enum-head: [C++11]
+///         enum-key attribute-specifier-seq[opt] identifier[opt] enum-base[opt]
+///         enum-key attribute-specifier-seq[opt] nested-name-specifier
+///             identifier enum-base[opt]
 ///
-///       enum-key: [C++0x]
+///       enum-key: [C++11]
 ///         'enum'
 ///         'enum' 'class'
 ///         'enum' 'struct'
 ///
-///       enum-base: [C++0x]
+///       enum-base: [C++11]
 ///         ':' type-specifier-seq
 ///
 /// [C++] elaborated-type-specifier:
@@ -2648,7 +2649,14 @@
     IsScopedUsingClassTag = Tok.is(tok::kw_class);
     ScopedEnumKWLoc = ConsumeToken();
   }
-  
+
+  // C++11 [temp.explicit]p12: The usual access controls do not apply to names
+  // used to specify explicit instantiations. We extend this to also cover
+  // explicit specializations.
+  Sema::SuppressAccessChecksRAII SuppressAccess(Actions,
+    TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation ||
+    TemplateInfo.Kind == ParsedTemplateInfo::ExplicitSpecialization);
+
   // If attributes exist after tag, parse them.
   ParsedAttributes attrs(AttrFactory);
   MaybeParseGNUAttributes(attrs);
@@ -2711,6 +2719,9 @@
     IsScopedUsingClassTag = false;
   }
 
+  // Stop suppressing access control now we've parsed the enum name.
+  SuppressAccess.done();
+
   TypeResult BaseType;
 
   // Parse the fixed underlying type.
@@ -2801,34 +2812,44 @@
     TUK = Sema::TUK_Declaration;
   else
     TUK = Sema::TUK_Reference;
-  
-  // enums cannot be templates, although they can be referenced from a 
-  // template.
+
+  MultiTemplateParamsArg TParams;
   if (TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate &&
       TUK != Sema::TUK_Reference) {
-    Diag(Tok, diag::err_enum_template);
-    
-    // Skip the rest of this declarator, up until the comma or semicolon.
-    SkipUntil(tok::comma, true);
-    return;      
+    if (!getLangOpts().CPlusPlus0x || !SS.isSet()) {
+      // Skip the rest of this declarator, up until the comma or semicolon.
+      Diag(Tok, diag::err_enum_template);
+      SkipUntil(tok::comma, true);
+      return;
+    }
+
+    if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation) {
+      // Enumerations can't be explicitly instantiated.
+      DS.SetTypeSpecError();
+      Diag(StartLoc, diag::err_explicit_instantiation_enum);
+      return;
+    }
+
+    assert(TemplateInfo.TemplateParams && "no template parameters");
+    TParams = MultiTemplateParamsArg(TemplateInfo.TemplateParams->data(),
+                                     TemplateInfo.TemplateParams->size());
   }
-  
+
   if (!Name && TUK != Sema::TUK_Definition) {
     Diag(Tok, diag::err_enumerator_unnamed_no_def);
-    
+
     // Skip the rest of this declarator, up until the comma or semicolon.
     SkipUntil(tok::comma, true);
     return;
   }
-      
+
   bool Owned = false;
   bool IsDependent = false;
   const char *PrevSpec = 0;
   unsigned DiagID;
   Decl *TagDecl = Actions.ActOnTag(getCurScope(), DeclSpec::TST_enum, TUK,
                                    StartLoc, SS, Name, NameLoc, attrs.getList(),
-                                   AS, DS.getModulePrivateSpecLoc(),
-                                   MultiTemplateParamsArg(Actions),
+                                   AS, DS.getModulePrivateSpecLoc(), TParams,
                                    Owned, IsDependent, ScopedEnumKWLoc,
                                    IsScopedUsingClassTag, BaseType);
 
@@ -2870,10 +2891,14 @@
   }
 
   if (Tok.is(tok::l_brace) && TUK != Sema::TUK_Reference) {
-    if (TUK == Sema::TUK_Friend)
+    if (TUK == Sema::TUK_Friend) {
       Diag(Tok, diag::err_friend_decl_defines_type)
         << SourceRange(DS.getFriendSpecLoc());
-    ParseEnumBody(StartLoc, TagDecl);
+      ConsumeBrace();
+      SkipUntil(tok::r_brace);
+    } else {
+      ParseEnumBody(StartLoc, TagDecl);
+    }
   }
 
   if (DS.SetTypeSpecType(DeclSpec::TST_enum, StartLoc,
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index cf18a5b..9321c13 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -968,12 +968,9 @@
   // As an extension we do not perform access checking on the names used to
   // specify explicit specializations either. This is important to allow
   // specializing traits classes for private types.
-  bool SuppressingAccessChecks = false;
-  if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation ||
-      TemplateInfo.Kind == ParsedTemplateInfo::ExplicitSpecialization) {
-    Actions.ActOnStartSuppressingAccessChecks();
-    SuppressingAccessChecks = true;
-  }
+  Sema::SuppressAccessChecksRAII SuppressAccess(Actions,
+    TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation ||
+    TemplateInfo.Kind == ParsedTemplateInfo::ExplicitSpecialization);
 
   ParsedAttributes attrs(AttrFactory);
   // If attributes exist after tag, parse them.
@@ -1102,17 +1099,13 @@
 
       DS.SetTypeSpecError();
       SkipUntil(tok::semi, false, true);
-      if (SuppressingAccessChecks)
-        Actions.ActOnStopSuppressingAccessChecks();
-
       return;
     }
   }
 
   // As soon as we're finished parsing the class's template-id, turn access
   // checking back on.
-  if (SuppressingAccessChecks)
-    Actions.ActOnStopSuppressingAccessChecks();
+  SuppressAccess.done();
 
   // There are four options here.
   //  - If we are in a trailing return type, this is always just a reference,
diff --git a/lib/Sema/SemaCXXScopeSpec.cpp b/lib/Sema/SemaCXXScopeSpec.cpp
index 5e6c27b..5a0fcec 100644
--- a/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/lib/Sema/SemaCXXScopeSpec.cpp
@@ -246,10 +246,14 @@
   EnumDecl *ED = enumType->getDecl();
   if (EnumDecl *Pattern = ED->getInstantiatedFromMemberEnum()) {
     MemberSpecializationInfo *MSI = ED->getMemberSpecializationInfo();
-    if (MSI->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
-      return InstantiateEnum(loc, ED, Pattern,
-                             getTemplateInstantiationArgs(ED),
-                             TSK_ImplicitInstantiation);
+    if (MSI->getTemplateSpecializationKind() != TSK_ExplicitSpecialization) {
+      if (InstantiateEnum(loc, ED, Pattern, getTemplateInstantiationArgs(ED),
+                          TSK_ImplicitInstantiation)) {
+        SS.SetInvalid(SS.getRange());
+        return true;
+      }
+      return false;
+    }
   }
 
   Diag(loc, diag::err_incomplete_nested_name_spec)
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 15cd745..71f567f 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -8283,10 +8283,19 @@
               // If we're defining a specialization and the previous definition
               // is from an implicit instantiation, don't emit an error
               // here; we'll catch this in the general case below.
-              if (!isExplicitSpecialization ||
-                  !isa<CXXRecordDecl>(Def) ||
-                  cast<CXXRecordDecl>(Def)->getTemplateSpecializationKind() 
-                                               == TSK_ExplicitSpecialization) {
+              bool IsExplicitSpecializationAfterInstantiation = false;
+              if (isExplicitSpecialization) {
+                if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Def))
+                  IsExplicitSpecializationAfterInstantiation =
+                    RD->getTemplateSpecializationKind() !=
+                    TSK_ExplicitSpecialization;
+                else if (EnumDecl *ED = dyn_cast<EnumDecl>(Def))
+                  IsExplicitSpecializationAfterInstantiation =
+                    ED->getTemplateSpecializationKind() !=
+                    TSK_ExplicitSpecialization;
+              }
+
+              if (!IsExplicitSpecializationAfterInstantiation) {
                 // A redeclaration in function prototype scope in C isn't
                 // visible elsewhere, so merely issue a warning.
                 if (!getLangOpts().CPlusPlus && S->containedInPrototypeScope())
diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index 0382a83..e47bc1c 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -1413,8 +1413,7 @@
   assert((!isa<TagDecl>(LookupCtx) ||
           LookupCtx->isDependentContext() ||
           cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
-          Context.getTypeDeclType(cast<TagDecl>(LookupCtx))->getAs<TagType>()
-            ->isBeingDefined()) &&
+          cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
          "Declaration context must already be complete!");
 
   // Perform qualified name lookup into the LookupCtx.
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 680e6ea..3a4a6f5 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -4699,8 +4699,11 @@
     EntityKind = 4;
   else if (isa<RecordDecl>(Specialized))
     EntityKind = 5;
+  else if (isa<EnumDecl>(Specialized) && S.getLangOpts().CPlusPlus0x)
+    EntityKind = 6;
   else {
-    S.Diag(Loc, diag::err_template_spec_unknown_kind);
+    S.Diag(Loc, diag::err_template_spec_unknown_kind)
+      << S.getLangOpts().CPlusPlus0x;
     S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
     return true;
   }
@@ -5816,6 +5819,14 @@
       InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass();
       MSInfo = PrevRecord->getMemberSpecializationInfo();
     }
+  } else if (isa<EnumDecl>(Member)) {
+    EnumDecl *PrevEnum;
+    if (Previous.isSingleResult() &&
+        (PrevEnum = dyn_cast<EnumDecl>(Previous.getFoundDecl()))) {
+      Instantiation = PrevEnum;
+      InstantiatedFrom = PrevEnum->getInstantiatedFromMemberEnum();
+      MSInfo = PrevEnum->getMemberSpecializationInfo();
+    }
   }
 
   if (!Instantiation) {
@@ -5906,8 +5917,7 @@
                                                 cast<VarDecl>(InstantiatedFrom),
                                                 TSK_ExplicitSpecialization);
     MarkUnusedFileScopedDecl(InstantiationVar);
-  } else {
-    assert(isa<CXXRecordDecl>(Member) && "Only member classes remain");
+  } else if (isa<CXXRecordDecl>(Member)) {
     CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation);
     if (InstantiationClass->getTemplateSpecializationKind() ==
           TSK_ImplicitInstantiation) {
@@ -5919,6 +5929,18 @@
     cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
                                         cast<CXXRecordDecl>(InstantiatedFrom),
                                                    TSK_ExplicitSpecialization);
+  } else {
+    assert(isa<EnumDecl>(Member) && "Only member enums remain");
+    EnumDecl *InstantiationEnum = cast<EnumDecl>(Instantiation);
+    if (InstantiationEnum->getTemplateSpecializationKind() ==
+          TSK_ImplicitInstantiation) {
+      InstantiationEnum->setTemplateSpecializationKind(
+                                                   TSK_ExplicitSpecialization);
+      InstantiationEnum->setLocation(Member->getLocation());
+    }
+
+    cast<EnumDecl>(Member)->setInstantiationOfMemberEnum(
+        cast<EnumDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
   }
 
   // Save the caller the trouble of having to figure out which declaration
@@ -6219,11 +6241,7 @@
     return true;
 
   TagDecl *Tag = cast<TagDecl>(TagD);
-  if (Tag->isEnum()) {
-    Diag(TemplateLoc, diag::err_explicit_instantiation_enum)
-      << Context.getTypeDeclType(Tag);
-    return true;
-  }
+  assert(!Tag->isEnum() && "shouldn't see enumerations here");
 
   if (Tag->isInvalidDecl())
     return true;
diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index c2ebbf4..afa65ea 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1843,7 +1843,20 @@
         if (OldField->getInClassInitializer())
           FieldsWithMemberInitializers.push_back(std::make_pair(OldField,
                                                                 Field));
-      } else if (NewMember->isInvalidDecl())
+      } else if (EnumDecl *Enum = dyn_cast<EnumDecl>(NewMember)) {
+        // C++11 [temp.inst]p1: The implicit instantiation of a class template
+        // specialization causes the implicit instantiation of the definitions
+        // of unscoped member enumerations.
+        // Record a point of instantiation for this implicit instantiation.
+        if (TSK == TSK_ImplicitInstantiation && !Enum->isScoped()) {
+          MemberSpecializationInfo *MSInfo =Enum->getMemberSpecializationInfo();
+          assert(MSInfo && "no spec info for member enum specialization");
+          MSInfo->setTemplateSpecializationKind(TSK_ImplicitInstantiation);
+          MSInfo->setPointOfInstantiation(PointOfInstantiation);
+        }
+      }
+
+      if (NewMember->isInvalidDecl())
         Invalid = true;
     } else {
       // FIXME: Eventually, a NULL return will mean that one of the
diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index d0ba4db..ebc43d4 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -600,7 +600,7 @@
   // not the definitions of scoped member enumerations.
   // FIXME: There appears to be no wording for what happens for an enum defined
   // within a block scope, but we treat that like a member of a class template.
-  if (!Enum->isScoped())
+  if (!Enum->isScoped() && D->getDefinition())
     InstantiateEnumDefinition(Enum, D);
 
   return Enum;
@@ -610,6 +610,9 @@
     EnumDecl *Enum, EnumDecl *Pattern) {
   Enum->startDefinition();
 
+  // Update the location to refer to the definition.
+  Enum->setLocation(Pattern->getLocation());
+
   SmallVector<Decl*, 4> Enumerators;
 
   EnumConstantDecl *LastEnumConst = 0;