Silence macro expansion during completion at point

* lisp/emacs-lisp/macroexp.el (macroexp-inhibit-compiler-macros): Add
variable.
(macroexp--compiler-macro): Inspect that new variable and, if it is
non-nil, return the input form unchanged.
* lisp/progmodes/elisp-mode.el (elisp--local-variables): Silence
messages.  Avoid compiler macros.  (Bug#58148)

2 files changed, 19 insertions, 7 deletions

diff --git a/lisp/emacs-lisp/macroexp.el b/lisp/emacs-lisp/macroexp.el
index 3ef924a5c73..6eb670d6dc1 100644
--- a/lisp/emacs-lisp/macroexp.el
+++ b/lisp/emacs-lisp/macroexp.el
@@ -105,13 +105,21 @@ each clause."
         (macroexp--all-forms clause skip)
       clause)))
 
+(defvar macroexp-inhibit-compiler-macros nil
+  "Inhibit application of compiler macros if non-nil.")
+
 (defun macroexp--compiler-macro (handler form)
-  (condition-case-unless-debug err
-      (apply handler form (cdr form))
-    (error
-     (message "Warning: Optimization failure for %S: Handler: %S\n%S"
-              (car form) handler err)
-     form)))
+  "Apply compiler macro HANDLER to FORM and return the result.
+Unless `macroexp-inhibit-compiler-macros' is non-nil, in which
+case return FORM unchanged."
+  (if macroexp-inhibit-compiler-macros
+      form
+    (condition-case-unless-debug err
+        (apply handler form (cdr form))
+      (error
+       (message "Warning: Optimization failure for %S: Handler: %S\n%S"
+                (car form) handler err)
+       form))))
 
 (defun macroexp--funcall-if-compiled (_form)
   "Pseudo function used internally by macroexp to delay warnings.
diff --git a/lisp/progmodes/elisp-mode.el b/lisp/progmodes/elisp-mode.el
index 664299df288..ff90a744ea3 100644
--- a/lisp/progmodes/elisp-mode.el
+++ b/lisp/progmodes/elisp-mode.el
@@ -460,7 +460,11 @@ use of `macroexpand-all' as a way to find the \"underlying raw code\".")
                    (message "Ignoring macroexpansion error: %S" err) form))))
              (sexp
               (unwind-protect
-                  (let ((warning-minimum-log-level :emergency))
+                  ;; Silence any macro expansion errors when
+                  ;; attempting completion at point (bug#58148).
+                  (let ((inhibit-message t)
+                        (macroexp-inhibit-compiler-macros t)
+                        (warning-minimum-log-level :emergency))
                     (advice-add 'macroexpand-1 :around macroexpand-advice)
                     (macroexpand-all sexp elisp--local-macroenv))
                 (advice-remove 'macroexpand-1 macroexpand-advice)))