When we parse a tag specifier, keep track of whether that tag
specifier resulted in the creation of a new TagDecl node, which
happens either when the tag specifier was a definition or when the tag
specifier was the first declaration of that tag type. This information
has several uses, the first of which is implemented in this commit:

  1) In C++, one is not allowed to define tag types within a type
  specifier (e.g., static_cast<struct S { int x; } *>(0) is
  ill-formed) or within the result or parameter types of a
  function. We now diagnose this.

  2) We can extend DeclGroups to contain information about any tags
  that are declared/defined within the declaration specifiers of a
  variable, e.g.,

    struct Point { int x, y, z; } p;

  This will help improve AST printing and template instantiation,
  among other things.

  3) For C99, we can keep track of whether a tag type is defined
  within the type of a parameter, to properly cope with cases like,
  e.g.,

    int bar(struct T2 { int x; } y) {
      struct T2 z;
    }

  We can also do similar things wherever there is a type specifier,
  e.g., to keep track of where the definition of S occurs in this
  legal C99 code:

    (struct S { int x, y; } *)0

  



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@72555 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index a7d3b52..cfbd909 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -479,6 +479,7 @@
   // FIXME: When TK == TK_Reference and we have a template-id, we need
   // to turn that template-id into a type.
 
+  bool Owned = false;
   if (TemplateId && TK != Action::TK_Reference) {
     // Explicit specialization, class template partial specialization,
     // or explicit instantiation.
@@ -582,7 +583,7 @@
 
     // Declaration or definition of a class type
     TagOrTempResult = Actions.ActOnTag(CurScope, TagType, TK, StartLoc, SS, 
-                                       Name, NameLoc, Attr, AS);
+                                       Name, NameLoc, Attr, AS, Owned);
   }
 
   // Parse the optional base clause (C++ only).
@@ -608,7 +609,7 @@
   }
   
   if (DS.SetTypeSpecType(TagType, StartLoc, PrevSpec, 
-                         TagOrTempResult.get().getAs<void>()))
+                         TagOrTempResult.get().getAs<void>(), Owned))
     Diag(StartLoc, diag::err_invalid_decl_spec_combination) << PrevSpec;
   
   if (DS.isFriendSpecified())