Implement type aliasing

The separate types are in the file, but there are multiple issues

tools/qfcc/include/type.h

@@ -138,8 +138,9 @@ void chain_type (type_t *type);
 
 /**	Append a type to the end of a type chain.
 
-	The type chain must be made up of only field, pointer, function and array
+	The type chain must be made up of only field, pointer, function, array
-	types, as other types do not have auxiliary type fields.
+	and alias (typedef) types, as other types do not have auxiliary type
+	fields.
 
 	\param type		The type chain to which the type will be appended.
 	\param new		The type to be appended. May be any type.
@@ -153,6 +154,7 @@ type_t *field_type (type_t *aux);
 type_t *pointer_type (type_t *aux);
 type_t *array_type (type_t *aux, int size);
 type_t *based_array_type (type_t *aux, int base, int top);
+type_t *alias_type (type_t *aux, const char *name);
 void print_type_str (struct dstring_s *str, const type_t *type);
 void print_type (const type_t *type);
 const char *encode_params (const type_t *type);

tools/qfcc/source/dump_globals.c

@@ -423,6 +423,7 @@ static const char *ty_meta_names[] = {
 	"ty_enum",
 	"ty_array",
 	"ty_class",
+	"ty_alias",
 };
 #define NUM_META ((int)(sizeof (ty_meta_names) / sizeof (ty_meta_names[0])))
 

tools/qfcc/source/obj_type.c

@@ -253,6 +253,22 @@ qfo_encode_class (type_t *type)
 	return def;
 }
 
+static def_t *
+qfo_encode_alias (type_t *type)
+{
+	qfot_type_t *enc;
+	def_t      *def;
+	def_t      *alias_type_def;
+
+	alias_type_def = qfo_encode_type (type->t.alias.type);
+
+	def = qfo_new_encoding (type, sizeof (enc->t.alias));
+	enc = D_POINTER (qfot_type_t, def);
+	ENC_DEF (enc->t.alias.type, alias_type_def);
+	ENC_STR (enc->t.alias.name, type->name);
+	return def;
+}
+
 def_t *
 qfo_encode_type (type_t *type)
 {
@@ -265,6 +281,7 @@ qfo_encode_type (type_t *type)
 		qfo_encode_struct,	// ty_enum
 		qfo_encode_array,	// ty_array
 		qfo_encode_class,	// ty_class
+		qfo_encode_alias,	// ty_alias
 	};
 
 	if (type->type_def && type->type_def->external) {
@@ -274,7 +291,7 @@ qfo_encode_type (type_t *type)
 	}
 	if (type->type_def)
 		return type->type_def;
-	if (type->meta > ty_class)
+	if (type->meta > sizeof (funcs) / (sizeof (funcs[0])))
 		internal_error (0, "bad type meta type");
 	if (!type->encoding)
 		type->encoding = type_get_encoding (type);

tools/qfcc/source/qc-parse.y

@@ -406,6 +406,7 @@ external_decl
 			$1->type = find_type (append_type ($1->type, spec.type));
 			if (spec.is_typedef) {
 				$1->sy_type = sy_type;
+				$1->type = alias_type ($1->type, $1->name);
 				symtab_addsymbol (current_symtab, $1);
 			} else {
 				initialize_def ($1, 0, current_symtab->space, spec.storage);

tools/qfcc/source/type.c

@@ -445,6 +445,25 @@ based_array_type (type_t *aux, int base, int top)
 	return new;
 }
 
+type_t *
+alias_type (type_t *aux, const char *name)
+{
+	type_t      _new;
+	type_t     *new = &_new;
+
+	if (!aux || !name) {
+		internal_error (0, "alias to null type or with no name");
+	}
+	memset (&_new, 0, sizeof (_new));
+	new->name = save_string (name);
+	new->meta = ty_alias;
+	new->type = aux->type;
+	new->alignment = aux->alignment;
+	new->t.alias.type = aux;
+	new = find_type (new);
+	return new;
+}
+
 void
 print_type_str (dstring_t *str, const type_t *type)
 {