stage1 支持函数指针

stage1/spl_sema.c

@@ -1775,6 +1775,16 @@ static spl_lang_type_id_t sema_infer(spl_sema_t *sema, spl_ast_node_ref_t ref) {
             return bt;
         }
         case SPL_UNARY_OP_ADDRESS: {
+            spl_ast_node_t *operand = spl_ast_node(sema->ast, n->unary.operand);
+            if (operand && operand->kind == SPL_AST_EXPR_IDENT) {
+                spl_def_node_t *def = spl_def_node(sema->type, operand->resolved_def_id);
+                if (def && def->kind == SPL_DEF_FN) {
+                    spl_diag_error(sema->diag, SPL_DIAG_KIND_TYPE_MISMATCH, &n->dbg,
+                                   "cannot take address of a function: the function name "
+                                   "itself is a function pointer");
+                    return 0;
+                }
+            }
             spl_lang_type_id_t p = spl_lang_make_ptr(sema->type, op);
             n->resolved_lang_tid = p;
             return p;