From 8ae413235d4b3f68f0858a3ce2cd65291f9cbe64 Mon Sep 17 00:00:00 2001
From: Vasil Dimov <vd@FreeBSD.org>
Date: Sun, 11 Mar 2018 20:19:26 +0100
Subject: [PATCH] Remove redundant checks for MSG_* from configure.ac

It is redundant to check for the presence of MSG_NOSIGNAL macro in
configure.ac, define HAVE_MSG_NOSIGNAL and then check whether the later
is defined in the source code. Instead we can check directly whether
MSG_NOSIGNAL is defined. Same for MSG_DONTWAIT.

In addition to that, the checks we had in configure.ac produce a
compiler warning about unused variable and thus could fail if
-Werror is present and erroneously proclaim that the macros are
not available.
---
 configure.ac    | 16 ----------------
 src/net.cpp     |  5 +++--
 src/netbase.cpp |  2 +-
 3 files changed, 4 insertions(+), 19 deletions(-)

diff --git a/configure.ac b/configure.ac
index 80116d597f..4f57750a1a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -643,22 +643,6 @@ AC_CHECK_DECLS([bswap_16, bswap_32, bswap_64],,,
 
 AC_CHECK_DECLS([__builtin_clz, __builtin_clzl, __builtin_clzll])
 
-dnl Check for MSG_NOSIGNAL
-AC_MSG_CHECKING(for MSG_NOSIGNAL)
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/socket.h>]],
- [[ int f = MSG_NOSIGNAL; ]])],
- [ AC_MSG_RESULT(yes); AC_DEFINE(HAVE_MSG_NOSIGNAL, 1,[Define this symbol if you have MSG_NOSIGNAL]) ],
- [ AC_MSG_RESULT(no)]
-)
-
-dnl Check for MSG_DONTWAIT
-AC_MSG_CHECKING(for MSG_DONTWAIT)
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/socket.h>]],
- [[ int f = MSG_DONTWAIT; ]])],
- [ AC_MSG_RESULT(yes); AC_DEFINE(HAVE_MSG_DONTWAIT, 1,[Define this symbol if you have MSG_DONTWAIT]) ],
- [ AC_MSG_RESULT(no)]
-)
-
 dnl Check for malloc_info (for memory statistics information in getmemoryinfo)
 AC_MSG_CHECKING(for getmemoryinfo)
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <malloc.h>]],
diff --git a/src/net.cpp b/src/net.cpp
index 53a0a9b180..4849e067aa 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -42,12 +42,13 @@
 // We add a random period time (0 to 1 seconds) to feeler connections to prevent synchronization.
 #define FEELER_SLEEP_WINDOW 1
 
-#if !defined(HAVE_MSG_NOSIGNAL)
+// MSG_NOSIGNAL is not available on some platforms, if it doesn't exist define it as 0
+#if !defined(MSG_NOSIGNAL)
 #define MSG_NOSIGNAL 0
 #endif
 
 // MSG_DONTWAIT is not available on some platforms, if it doesn't exist define it as 0
-#if !defined(HAVE_MSG_DONTWAIT)
+#if !defined(MSG_DONTWAIT)
 #define MSG_DONTWAIT 0
 #endif
 
diff --git a/src/netbase.cpp b/src/netbase.cpp
index 3ea3141d5e..92ac1c4c85 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -21,7 +21,7 @@
 #include <boost/algorithm/string/case_conv.hpp> // for to_lower()
 #include <boost/algorithm/string/predicate.hpp> // for startswith() and endswith()
 
-#if !defined(HAVE_MSG_NOSIGNAL)
+#if !defined(MSG_NOSIGNAL)
 #define MSG_NOSIGNAL 0
 #endif