wip: working on loop infinity checker

src/compiler/fzl_walker.c

@@ -14,6 +14,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+extern bool is_infinite_loop(fzl_walker_t *walker, size_t ls, size_t le);
+
 char *null_name = "<null>";
 char wlast_err[256];
 
@@ -271,6 +273,16 @@ fzl_walk_res_t walk(fzl_walker_t *walker, fzl_node_t *node)
         push_word(walker, start_ip);
         push_op(walker, FZL_OPCODE_RM_ENVTABLE);
 
+        bool is_infinite =
+            is_infinite_loop(walker, start_ip, walker->op_count - 2);
+        if (is_infinite)
+        {
+          snprintf(wlast_err, sizeof(wlast_err),
+                   "'%s': infinite loop detected at %ld:%ld",
+                   node->token->filename, node->token->ln, node->token->cn);
+          return (fzl_walk_res_t){.error = true, .error_msg = wlast_err};
+        }
+
         for (size_t i = walker->sym_top - 1; i > newctx->initial_env_lvl; i--)
           fzl_freesymt(walker->syms[--walker->sym_top]);