bugfix: sys:setq bindable check must be warning.

The problem is that during the expansion of something like (do
inc @1), the place expansion will generate a (sys:setq @1 ...)
form which undergoes expansion before the processing which
converts @1 to a gensym. But now that throws an error during
the expansion of the sys:setq form that @1 isn't a bindable
symbol. Since warnings are suppressed during this expansion
phase, we can make it a warning.

* eval.c (not_bindable_warning): New static function.
(do_expand): For the assignment special forms,
throw a warning if the target isn't a bindable symbol,
not an error.

1 files changed, 7 insertions, 1 deletions

diff --git a/eval.c b/eval.c
index 0ff18ba0..87224afd 100644
--- a/eval.c
+++ b/eval.c
@@ -755,6 +755,12 @@ noreturn static val not_bindable_error(val form, val sym)
              car(form), sym, nao);
 }
 
+static val not_bindable_warning(val form, val sym)
+{
+  return eval_warn(form, lit("~s: ~s is not a bindable symbol"),
+                   car(form), sym, nao);
+}
+
 static val expand_params_rec(val params, val menv,
                              val macro_style_p, val form,
                              val *pspecials);
@@ -3984,7 +3990,7 @@ static val do_expand(val form, val menv)
           eval_error(form, lit("~s: excess arguments"), sym, nao);
 
         if (!bindable(car(args)))
-          not_bindable_error(form, car(args));
+          not_bindable_warning(form, car(args));
       }
 
       if (form_ex == form && args_ex == args) {