implement support for "enum class"

This adds support for the C++11 "enum class" feature.  This is
PR c++/15246.

I chose to use the existing TYPE_DECLARED_CLASS rather than introduce
a new type code.  This seemed both simple and clear to me.

I made overloading support for the new enum types strict.  This is how
it works in C++; and it didn't seem like an undue burden to keep this,
particularly because enum constants are printed symbolically by gdb.

Built and regtested on x86-64 Fedora 20.

2014-04-14  Tom Tromey  <tromey@redhat.com>

	PR c++/15246:
	* c-exp.y (type_aggregate_p): New function.
	(qualified_name, classify_inner_name): Use it.
	* c-typeprint.c (c_type_print_base): Handle TYPE_DECLARED_CLASS
	and TYPE_TARGET_TYPE of an enum type.
	* dwarf2read.c (read_enumeration_type): Set TYPE_DECLARED_CLASS on
	an enum type.
	(determine_prefix) <case DW_TAG_enumeration_type>: New case;
	handle TYPE_DECLARED_CLASS.
	* gdbtypes.c (rank_one_type): Handle TYPE_DECLARED_CLASS on enum
	types.
	* gdbtypes.h (TYPE_DECLARED_CLASS): Update comment.
	* valops.c (enum_constant_from_type): New function.
	(value_aggregate_elt): Use it.
	* cp-namespace.c (cp_lookup_nested_symbol): Handle
	TYPE_CODE_ENUM.

2014-04-14  Tom Tromey  <tromey@redhat.com>

	* gdb.cp/classes.exp (test_enums): Handle underlying type.
	* gdb.dwarf2/enum-type.exp: Add test for enum with underlying
	type.
	* gdb.cp/enum-class.exp: New file.
	* gdb.cp/enum-class.cc: New file.

1 files changed, 40 insertions, 0 deletions

diff --git a/gdb/valops.c b/gdb/valops.c
index 8c252d6..7f2d5f0 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -3020,6 +3020,42 @@ destructor_name_p (const char *name, struct type *type)
   return 0;
 }
 
+/* Find an enum constant named NAME in TYPE.  TYPE must be an "enum
+   class".  If the name is found, return a value representing it;
+   otherwise throw an exception.  */
+
+static struct value *
+enum_constant_from_type (struct type *type, const char *name)
+{
+  int i;
+  int name_len = strlen (name);
+
+  gdb_assert (TYPE_CODE (type) == TYPE_CODE_ENUM
+	      && TYPE_DECLARED_CLASS (type));
+
+  for (i = TYPE_N_BASECLASSES (type); i < TYPE_NFIELDS (type); ++i)
+    {
+      const char *fname = TYPE_FIELD_NAME (type, i);
+      int len;
+
+      if (TYPE_FIELD_LOC_KIND (type, i) != FIELD_LOC_KIND_ENUMVAL
+	  || fname == NULL)
+	continue;
+
+      /* Look for the trailing "::NAME", since enum class constant
+	 names are qualified here.  */
+      len = strlen (fname);
+      if (len + 2 >= name_len
+	  && fname[len - name_len - 2] == ':'
+	  && fname[len - name_len - 1] == ':'
+	  && strcmp (&fname[len - name_len], name) == 0)
+	return value_from_longest (type, TYPE_FIELD_ENUMVAL (type, i));
+    }
+
+  error (_("no constant named \"%s\" in enum \"%s\""),
+	 name, TYPE_TAG_NAME (type));
+}
+
 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
    return the appropriate member (or the address of the member, if
    WANT_ADDRESS).  This function is used to resolve user expressions
@@ -3041,6 +3077,10 @@ value_aggregate_elt (struct type *curtype, const char *name,
     case TYPE_CODE_NAMESPACE:
       return value_namespace_elt (curtype, name, 
 				  want_address, noside);
+
+    case TYPE_CODE_ENUM:
+      return enum_constant_from_type (curtype, name);
+
     default:
       internal_error (__FILE__, __LINE__,
 		      _("non-aggregate type in value_aggregate_elt"));