Report chain of macro-expansions in errors.

* eval.c (origin_hash): New global variable.
(lookup_origin): New function.
(expand_macro): Enter original form into origin hash, keyed by
new form.
(eval_init): gc-protect and initialize origin_hash.

* eval.h (lookup_origin): Declared.

* parser.c (repl): Report chain of expansions from
last_form_evaled.

* unwind.c (uw_throw): Likewise.

1 files changed, 1 insertions, 0 deletions

diff --git a/eval.h b/eval.h
index 05f9061f..78a0f8b0 100644
--- a/eval.h
+++ b/eval.h
@@ -31,6 +31,7 @@ extern val eq_s, eql_s, equal_s;
 extern val last_form_evaled, last_form_expanded;
 
 noreturn val eval_error(val form, val fmt, ...);
+val lookup_origin(val form);
 val make_env(val fbindings, val vbindings, val up_env);
 val copy_env(val oenv);
 val env_fbind(val env, val sym, val fun);