Fix type parsing

the check on incomplete struct/union/enum types was too early,
disallowing mixed specifiers and qualifiers.  Simply rely on
the size (->c) field for that.  See testcases.

tccgen.c

@@ -2200,7 +2200,7 @@ ST_FUNC int type_size(CType *type, int *a)
         *a = 8;
 #endif
         return 8;
-    } else if (bt == VT_INT || bt == VT_ENUM || bt == VT_FLOAT) {
+    } else if (bt == VT_INT || bt == VT_FLOAT) {
         *a = 4;
         return 4;
     } else if (bt == VT_SHORT) {
@@ -2209,6 +2209,10 @@ ST_FUNC int type_size(CType *type, int *a)
     } else if (bt == VT_QLONG || bt == VT_QFLOAT) {
         *a = 8;
         return 16;
+    } else if (bt == VT_ENUM) {
+	*a = 4;
+	/* Enums might be incomplete, so don't just return '4' here.  */
+	return type->ref->c;
     } else {
         /* char, void, function, _Bool */
         *a = 1;
@@ -2902,7 +2906,7 @@ static void parse_attribute(AttributeDef *ad)
 }
 
 /* enum/struct/union declaration. u is either VT_ENUM or VT_STRUCT */
-static void struct_decl(CType *type, int u, int tdef)
+static void struct_decl(CType *type, int u)
 {
     int a, v, size, align, maxalign, c, offset, flexible;
     int bit_size, bit_pos, bsize, bt, lbit_pos, prevbt;
@@ -2923,8 +2927,7 @@ static void struct_decl(CType *type, int u, int tdef)
             if (s->type.t != a)
                 tcc_error("invalid type");
             goto do_decl;
-        } else if (tok >= TOK_IDENT && !tdef)
-            tcc_error("unknown struct/union/enum");
+        }
     } else {
         v = anon_sym++;
     }
@@ -3229,14 +3232,14 @@ static int parse_btype(CType *type, AttributeDef *ad)
             }
             break;
         case TOK_ENUM:
-            struct_decl(&type1, VT_ENUM, t & (VT_TYPEDEF | VT_EXTERN));
+            struct_decl(&type1, VT_ENUM);
         basic_type2:
             u = type1.t;
             type->ref = type1.ref;
             goto basic_type1;
         case TOK_STRUCT:
         case TOK_UNION:
-            struct_decl(&type1, VT_STRUCT, t & (VT_TYPEDEF | VT_EXTERN));
+            struct_decl(&type1, VT_STRUCT);
             goto basic_type2;
 
             /* type modifiers */

tests/tests2/61_undefined_enum.expect

@@ -1 +1 @@
-61_undefined_enum.c:1: error: unknown struct/union/enum
+61_undefined_enum.c:1: error: unknown type size

tests/tests2/81_types.c

@@ -0,0 +1,9 @@
+/* The following are all valid decls, even though some subtypes
+   are incomplete.  */
+enum E *e;
+const enum E *e1;
+enum E const *e2;
+struct S *s;
+const struct S *s1;
+struct S const *s2;
+int main () { return 0; }