+ return ret;
+}
+
+/*
+ * We can represent type specifiers as a bitmap, which gives us a finite
+ * list of acceptable bitmap values according to the C standard. However,
+ * the "long" specifier is allowed to occur more than once, but only at most
+ * 2 times. Treat it as a special case, assigning an unused bit to represent
+ * the second long.
+ */
+#define MAP_LLONG_BIT 31
+#define MAP_LONG_BIT (CDECL_TYPE_LONG-CDECL_SPEC_TYPE)
+#define CDECL_TYPE_LLONG (CDECL_SPEC_TYPE+MAP_LLONG_BIT)
+
+#include "typemap.h"
+
+/*
+ * Convert the declaration specifiers to a bitmap with each bit
+ * corresponding to one specific type specifier.
+ */
+static int valid_typespec(struct cdecl_declspec *s)
+{
+ struct cdecl_declspec *c;
+ unsigned long map = 0;
+
+ for (c = s; c; c = c->next) {
+ unsigned long bit;
+
+ if (cdecl_spec_kind(c) != CDECL_SPEC_TYPE)
+ continue;
+
+ bit = c->type - CDECL_SPEC_TYPE;
+ assert(bit < MAP_LLONG_BIT);
+ bit = 1ul << bit;
+
+ /* "long" special case */
+ if ((map & bit) == 1ul << MAP_LONG_BIT)
+ bit = 1ul << MAP_LLONG_BIT;
+
+ if (map & bit) {
+ if (bit == 1ul << MAP_LLONG_BIT)
+ cdecl__errmsg(CDECL__ETOOLONG);
+ else
+ cdecl__errmsg(CDECL__EDUPTYPE);
+ return false;
+ }
+ map |= bit;
+ }
+
+ if (typemap_is_valid(map))
+ return true;
+
+ if (map == 0)
+ cdecl__errmsg(CDECL__ENOTYPE);
+ else
+ cdecl__errmsg(CDECL__EBADTYPE);
+
+ return false;