From 615be919f38cd3c94f8926baa82102985ff2b7dd Mon Sep 17 00:00:00 2001
From: Stas Boukarev <stassats@gmail.com>
Date: Wed, 4 Jun 2014 16:28:26 +0400
Subject: [PATCH] Optimize PROBE-FILE.

In QUERY-FILE-SYSTEM, avoid formatting an error message if no error is
requested. FORMAT is not expanded during the build, making it even
slower.
---
 src/code/filesys.lisp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/code/filesys.lisp b/src/code/filesys.lisp
index a8bf4ec5c..5df2f54ad 100644
--- a/src/code/filesys.lisp
+++ b/src/code/filesys.lisp
@@ -294,10 +294,12 @@
              :format-control "~@<can't find the ~A of wild pathname ~A~
                               (physicalized from ~A).~:>"
              :format-arguments (list query-for pathname pathspec)))
-    (flet ((fail (note-format pathname errno)
-             (if errorp
-                 (simple-file-perror note-format pathname errno)
-                 (return-from query-file-system nil))))
+    (macrolet ((fail (note-format pathname errno)
+                 ;; Do this as a macro to avoid evaluating format
+                 ;; calls when ERROP is NIL
+                 `(if errorp
+                      (simple-file-perror ,note-format ,pathname ,errno)
+                      (return-from query-file-system nil))))
       (let ((filename (native-namestring pathname :as-file t)))
         #!+win32
         (case query-for