Docs: more notes for local_scan/dlfunc

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 5e48221237fbe685ec3ecaaa594094c6d35fac56..8be9b7121424e62d151ac73780f8bc8ecf26aac8 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -33648,7 +33648,12 @@ directory, so you might set
 HAVE_LOCAL_SCAN=yes
 LOCAL_SCAN_SOURCE=Local/local_scan.c
 .endd
-for example. The function must be called &[local_scan()]&. It is called by
+for example. The function must be called &[local_scan()]&;
+.new
+the source file(s) for it should first #define LOCAL_SCAN
+and then #include "local_scan.h".
+.wen
+It is called by
 Exim after it has received a message, when the success return code is about to
 be sent. This is after all the ACLs have been run. The return code from your
 function controls whether the message is actually accepted or not. There is a

diff --git a/src/src/local_scan.h b/src/src/local_scan.h
index 548f70dbd60f9ce7648711130965e6d6a1f13fad..23da01b2b7c9e27322a35155e6ffa3edc209fa80 100644 (file)
--- a/src/src/local_scan.h
+++ b/src/src/local_scan.h
@@ -2,14 +2,16 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) University of Cambridge 1995 - 2019 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* This file is the header that is the only Exim header to be included in the
 source for the local_scan.c() function. It contains definitions that are made
-available for use in that function, and which are documented.
+available for use in that function, and which are documented.  That source
+should first #define LOCAL_SCAN
 
 This API is also used for functions called by the ${dlfunc expansion item.
+Source for those should first #define DLFUNC_IMPL and then include this file.
 Coders of dlfunc routines should read the notes on tainting at the start of
 store.c
 */