Set macro ancestry info in place expansions.

* eval.c (set_origin): New static function.
(eval_init): Register set_origin as sys:set-macro-ancestor.

* share/txr/stdlib/place.tl (sys:pl-expand): Set macro
ancestry when expanding a place macro.
(sys:cp-origin): New function.
(call-update-expander, call-clobber-expander,
call-delete-expander): Use sys:cp-origin to walk through
expanded code and attach the place form as the macro
ancestor of all the getter, setter or deleter calls,
effectively to say that those calls are expansions of
the place, which is approximately the case.

2 files changed, 21 insertions, 4 deletions

diff --git a/eval.c b/eval.c
index 36228f1e..c00f6a80 100644
--- a/eval.c
+++ b/eval.c
@@ -220,6 +220,12 @@ val lookup_origin(val form)
   return gethash(origin_hash, form);
 }
 
+static val set_origin(val form, val origin)
+{
+  (void) sethash(origin_hash, form, origin);
+  return form;
+}
+
 void error_trace(val exsym, val exvals, val out_stream, val prefix)
 {
   val last = last_form_evaled;
@@ -5071,6 +5077,7 @@ void eval_init(void)
   reg_fun(intern(lit("source-loc"), user_package), func_n1(source_loc));
   reg_fun(intern(lit("source-loc-str"), user_package), func_n2o(source_loc_str, 1));
   reg_fun(intern(lit("macro-ancestor"), user_package), func_n1(lookup_origin));
+  reg_fun(intern(lit("set-macro-ancestor"), system_package), func_n2(set_origin));
   reg_fun(intern(lit("rlcp"), user_package), func_n2(rlcp));
 
   eval_error_s = intern(lit("eval-error"), user_package);
diff --git a/share/txr/stdlib/place.tl b/share/txr/stdlib/place.tl
index 02a5c653..b22e4a16 100644
--- a/share/txr/stdlib/place.tl
+++ b/share/txr/stdlib/place.tl
@@ -132,7 +132,9 @@
         (let ((pm-expander [*place-macro* (if (consp unex-place)
                                             (car unex-place))]))
           (when pm-expander
-            (sys:setq place [pm-expander unex-place])))
+            (sys:setq place (sys:set-macro-ancestor
+                              [pm-expander unex-place]
+                              unex-place))))
         (sys:setq place (macroexpand place env))
         (when (or (eq place unex-place)
                   (null place)
@@ -143,20 +145,28 @@
           (return place))
         (sys:setq unex-place place))))
 
+  (defun sys:cp-origin (to-tree from-form . syms)
+    (tree-case to-tree
+      ((a . d) (when (memq a syms)
+                 (sys:set-macro-ancestor to-tree from-form))
+               (sys:cp-origin a from-form . syms)
+               (sys:cp-origin d from-form . syms)))
+    to-tree)
+
   (defun call-update-expander (getter setter unex-place env body)
     (let* ((place (sys:pl-expand unex-place env))
            (expander (get-update-expander place)))
-      [expander getter setter place body]))
+      (sys:cp-origin [expander getter setter place body] place setter getter)))
 
   (defun call-clobber-expander (ssetter unex-place env body)
     (let* ((place (sys:pl-expand unex-place env))
            (expander (get-clobber-expander place)))
-      [expander ssetter place body]))
+      (sys:cp-origin [expander ssetter place body] place ssetter)))
 
   (defun call-delete-expander (deleter unex-place env body)
     (let* ((place (sys:pl-expand unex-place env))
            (expander (get-delete-expander place)))
-      [expander deleter place body])))
+      (sys:cp-origin [expander deleter place body] place deleter))))
 
 (defmacro with-update-expander ((getter setter) unex-place env body)
   ^(with-gensyms (,getter ,setter)