stage1 支持聚合类型方法

stage1/spl_layout.c

@@ -130,6 +130,39 @@ static usize round_up_bits(usize x, usize align_bits) {
 
 static bool layout_agg(spl_layout_t *layout, spl_type_node_t *tn, spl_layout_info_t *out) {
     usize n = vec_size(tn->agg_type.variants);
+
+    if (tn->kind == SPL_TYPE_ENUM) {
+        spl_type_id_t tag_tid = tn->agg_type.tag_type;
+        if (!tag_tid)
+            return false;
+        spl_layout_info_t *tag_info = infos_at(layout, tag_tid);
+        if (!tag_info || !tag_info->resolved)
+            return false;
+
+        usize tag_align_bits = tag_info->align_bits ? tag_info->align_bits : 8;
+        usize payload_align_bits = 8;
+        usize payload_size_bits = 0;
+
+        for (usize i = 0; i < n; ++i) {
+            spl_type_member_t *m = &vec_at(tn->agg_type.variants, i);
+            spl_layout_info_t *fi = infos_at(layout, m->type_id);
+            if (!fi || !fi->resolved)
+                return false;
+            usize fa = fi->align_bits ? fi->align_bits : 8;
+            if (fa > payload_align_bits)
+                payload_align_bits = fa;
+            if (fi->size_bits > payload_size_bits)
+                payload_size_bits = fi->size_bits;
+        }
+
+        usize payload_off = round_up_bits(tag_info->size_bits, payload_align_bits);
+        usize final_align_bits =
+            tag_align_bits > payload_align_bits ? tag_align_bits : payload_align_bits;
+        out->size_bits = round_up_bits(payload_off + payload_size_bits, final_align_bits);
+        out->align_bits = final_align_bits;
+        return true;
+    }
+
     if (n == 0) {
         out->size_bits = 0;
         out->align_bits = 8;
@@ -163,7 +196,6 @@ static bool layout_agg(spl_layout_t *layout, spl_type_node_t *tn, spl_layout_inf
             max_align_bits = field_align_bits;
     }
 
-    /* 聚合对齐策略 */
     usize final_align_bits = max_align_bits;
     if (layout->aggregate.align_rule == ALIGN_FIXED) {
         final_align_bits = layout->aggregate.fixed_align * 8;