Be more careful around dependent nested-name-specifiers, complaining

when they are not complete (since we could not match them up to
anything) and ensuring that enum parsing can cope with dependent
elaborated-type-specifiers. Fixes PR6915 and PR6649.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@102247 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 56 insertions, 5 deletions

diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index a034a325f4..6669d40cca 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -1934,21 +1934,55 @@ void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
     TUK = Action::TUK_Reference;
   bool Owned = false;
   bool IsDependent = false;
+  SourceLocation TSTLoc = NameLoc.isValid()? NameLoc : StartLoc;
+  const char *PrevSpec = 0;
+  unsigned DiagID;
   DeclPtrTy TagDecl = Actions.ActOnTag(CurScope, DeclSpec::TST_enum, TUK,
                                        StartLoc, SS, Name, NameLoc, Attr.get(),
                                        AS,
                                        Action::MultiTemplateParamsArg(Actions),
                                        Owned, IsDependent);
-  assert(!IsDependent && "didn't expect dependent enum");
+  if (IsDependent) {
+    // This enum has a dependent nested-name-specifier. Handle it as a 
+    // dependent tag.
+    if (!Name) {
+      DS.SetTypeSpecError();
+      Diag(Tok, diag::err_expected_type_name_after_typename);
+      return;
+    }
+    
+    TypeResult Type = Actions.ActOnDependentTag(CurScope, DeclSpec::TST_enum,
+                                                TUK, SS, Name, StartLoc, 
+                                                NameLoc);
+    if (Type.isInvalid()) {
+      DS.SetTypeSpecError();
+      return;
+    }
+    
+    if (DS.SetTypeSpecType(DeclSpec::TST_typename, TSTLoc, PrevSpec, DiagID,
+                           Type.get(), false))
+      Diag(StartLoc, DiagID) << PrevSpec;
+    
+    return;
+  }
 
+  if (!TagDecl.get()) {
+    // The action failed to produce an enumeration tag. If this is a 
+    // definition, consume the entire definition.
+    if (Tok.is(tok::l_brace)) {
+      ConsumeBrace();
+      SkipUntil(tok::r_brace);
+    }
+    
+    DS.SetTypeSpecError();
+    return;
+  }
+  
   if (Tok.is(tok::l_brace))
     ParseEnumBody(StartLoc, TagDecl);
 
   // FIXME: The DeclSpec should keep the locations of both the keyword and the
   // name (if there is one).
-  SourceLocation TSTLoc = NameLoc.isValid()? NameLoc : StartLoc;
-  const char *PrevSpec = 0;
-  unsigned DiagID;
   if (DS.SetTypeSpecType(DeclSpec::TST_enum, TSTLoc, PrevSpec, DiagID,
                          TagDecl.getAs<void>(), Owned))
     Diag(StartLoc, DiagID) << PrevSpec;
diff --git a/lib/Sema/SemaCXXScopeSpec.cpp b/lib/Sema/SemaCXXScopeSpec.cpp
index e9d206e53b..89f8aec6e0 100644
--- a/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/lib/Sema/SemaCXXScopeSpec.cpp
@@ -235,6 +235,16 @@ bool Sema::RequireCompleteDeclContext(CXXScopeSpec &SS) {
     return false;
 
   DeclContext *DC = computeDeclContext(SS, true);
+  if (!DC) {
+    // It's dependent.
+    assert(isDependentScopeSpecifier(SS) && 
+           "No context for non-dependent scope specifier?");
+    Diag(SS.getRange().getBegin(), diag::err_dependent_nested_name_spec)
+      << SS.getRange();
+    SS.setScopeRep(0);
+    return true;
+  }
+  
   if (TagDecl *Tag = dyn_cast<TagDecl>(DC)) {
     // If this is a dependent type, then we consider it complete.
     if (Tag->isDependentContext())
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index b8ff182be0..bf2cba10c7 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -5313,7 +5313,7 @@ CreateNewDecl:
 void Sema::ActOnTagStartDefinition(Scope *S, DeclPtrTy TagD) {
   AdjustDeclIfTemplate(TagD);
   TagDecl *Tag = cast<TagDecl>(TagD.getAs<Decl>());
-
+  
   // Enter the tag context.
   PushDeclContext(S, Tag);
 }
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 1075f41399..14d04563d6 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -5117,6 +5117,13 @@ Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
   }
   assert(Keyword != ETK_None && "Invalid tag kind!");
 
+  if (TUK == TUK_Declaration || TUK == TUK_Definition) {
+    Diag(NameLoc, diag::err_dependent_tag_decl)
+      << (TUK == TUK_Definition) << TagDecl::getTagKindForTypeSpec(TagSpec)
+      << SS.getRange();
+    return true;
+  }
+  
   return Context.getDependentNameType(Keyword, NNS, Name).getAsOpaquePtr();
 }