X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/0a49a7a4f1090b6f1ce1d0f9d969804c9226b53e..0f5014860e54132a13e4ecc2f7f1859a9f3a971b:/src/src/osfunctions.h

diff --git a/src/src/osfunctions.h b/src/src/osfunctions.h
index 67f7b0ebd..552712744 100644
--- a/src/src/osfunctions.h
+++ b/src/src/osfunctions.h
@@ -1,5 +1,3 @@
-/* $Cambridge: exim/src/src/osfunctions.h,v 1.5 2009/11/16 19:50:37 nm4 Exp $ */
-
 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
@@ -14,10 +12,25 @@ that uses a type that isn't defined for them. */
 extern ip_address_item *os_common_find_running_interfaces(void);
 #endif
 
-extern int     os_getloadavg(void);
-extern void    os_restarting_signal(int, void (*)(int));
-extern void    os_non_restarting_signal(int, void (*)(int));
-extern char   *os_strexit(int);     /* char to match os_strsignal */
-extern char   *os_strsignal(int);   /* char to match strsignal in some OS */
+/* If these exist as a macro, then they're overridden away from us and we
+rely upon the system headers to provide prototype declarations for us.
+Notably, strsignal() is not in the Single Unix Specification (v3) and
+predicting constness is awkward. */
+
+#ifndef os_getloadavg
+extern int           os_getloadavg(void);
+#endif
+#ifndef os_restarting_signal
+extern void          os_restarting_signal(int, void (*)(int));
+#endif
+#ifndef os_non_restarting_signal
+extern void          os_non_restarting_signal(int, void (*)(int));
+#endif
+#ifndef os_strexit
+extern const char   *os_strexit(int);     /* char to match os_strsignal */
+#endif
+#ifndef os_strsignal
+extern const char   *os_strsignal(int);   /* char to match strsignal in some OS */
+#endif
 
 /* End of osfunctions.h */