X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/29f20a41029cc5e36a8756ad8dfda64d0ed314ce..5fa5f96fcfb9aa3c73e4ce9289a30be1e616e576:/src/src/osfunctions.h

diff --git a/src/src/osfunctions.h b/src/src/osfunctions.h
index a6cec0dc2..1010ff556 100644
--- a/src/src/osfunctions.h
+++ b/src/src/osfunctions.h
@@ -14,13 +14,23 @@ that uses a type that isn't defined for them. */
 extern ip_address_item *os_common_find_running_interfaces(void);
 #endif
 
+/* 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 */
-
-/* When os_strsignal aliases to a system function, don't define an
-additional prototype */
+#endif
 #ifndef os_strsignal
 extern const char   *os_strsignal(int);   /* char to match strsignal in some OS */
 #endif