crash vm trace

source/cell.c

@@ -28,6 +28,7 @@ static int run_test_suite(size_t heap_size);
 
 cell_rt *root_cell = NULL;
 static char *shop_path = NULL;
+volatile JSContext *g_crash_ctx = NULL;
 static char *core_path = NULL;
 static int native_mode = 0;
 static int warn_mode = 1;
@@ -408,6 +409,13 @@ static void signal_handler(int sig)
 #endif
   if (!str) return;
 
+  /* Reset handler to default so a double-fault terminates immediately */
+  signal(sig, SIG_DFL);
+
+  /* Try to print the JS stack (best-effort, signal-safe) */
+  if (g_crash_ctx)
+    JS_CrashPrintStack((JSContext *)g_crash_ctx);
+
   exit_handler();
 }
 
@@ -689,7 +697,9 @@ int cell_init(int argc, char **argv)
     JS_DeleteGCRef(ctx, &args_ref);
     JSValue hidden_env = JS_Stone(ctx, env_ref.val);
 
+    g_crash_ctx = ctx;
     JSValue result = JS_RunMachBin(ctx, (const uint8_t *)bin_data, bin_size, hidden_env);
+    g_crash_ctx = NULL;
     JS_DeleteGCRef(ctx, &env_ref);
     free(bin_data);