Merge #12678: build: Fix a few compilation issues with Clang 7 and -Werror

8ae413235 Remove redundant checks for MSG_* from configure.ac (Vasil Dimov)
71129e026 Do not check for main() in libminiupnpc (Vasil Dimov)
8c632f73c ax_boost_{chrono,unit_test_framework}.m4: take changes from upstream (Vasil Dimov)

Pull request description:

Tree-SHA512: a99ef98c0b94f892eadeda24b3d55c25bedf225b98c6e4178cf6c2d886b44d43e9f75414d0b37db9ac261cec2350666e5e64fab9c104249dd34ff485c51663cb

5 files changed, 14 insertions, 29 deletions

diff --git a/build-aux/m4/ax_boost_chrono.m4 b/build-aux/m4/ax_boost_chrono.m4
index 318ecea17f..e9b0f2061c 100644
--- a/build-aux/m4/ax_boost_chrono.m4
+++ b/build-aux/m4/ax_boost_chrono.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_boost_chrono.html
+#     https://www.gnu.org/software/autoconf-archive/ax_boost_chrono.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -8,7 +8,7 @@
 #
 # DESCRIPTION
 #
-#   Test for System library from the Boost C++ libraries. The macro requires
+#   Test for Chrono library from the Boost C++ libraries. The macro requires
 #   a preceding call to AX_BOOST_BASE. Further documentation is available at
 #   <http://randspringer.de/boost/index.html>.
 #
@@ -29,7 +29,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 1
+#serial 4
 
 AC_DEFUN([AX_BOOST_CHRONO],
 [
@@ -68,7 +68,7 @@ AC_DEFUN([AX_BOOST_CHRONO],
 			 CXXFLAGS_SAVE=$CXXFLAGS
 
 			 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[@%:@include <boost/chrono.hpp>]],
-                                   [[boost::chrono::system_clock::time_point time;]])],
+                                   [[boost::chrono::system_clock::time_point* time = new boost::chrono::system_clock::time_point; delete time;]])],
                    ax_cv_boost_chrono=yes, ax_cv_boost_chrono=no)
 			 CXXFLAGS=$CXXFLAGS_SAVE
              AC_LANG_POP([C++])
diff --git a/build-aux/m4/ax_boost_unit_test_framework.m4 b/build-aux/m4/ax_boost_unit_test_framework.m4
index 4efd1e2f18..0cdbe752cf 100644
--- a/build-aux/m4/ax_boost_unit_test_framework.m4
+++ b/build-aux/m4/ax_boost_unit_test_framework.m4
@@ -1,6 +1,6 @@
-# ================================================================================
-#  http://www.gnu.org/software/autoconf-archive/ax_boost_unit_test_framework.html
-# ================================================================================
+# =================================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_boost_unit_test_framework.html
+# =================================================================================
 #
 # SYNOPSIS
 #
@@ -29,7 +29,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 19
+#serial 21
 
 AC_DEFUN([AX_BOOST_UNIT_TEST_FRAMEWORK],
 [
@@ -66,7 +66,7 @@ AC_DEFUN([AX_BOOST_UNIT_TEST_FRAMEWORK],
         [AC_LANG_PUSH([C++])
 			 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[@%:@include <boost/test/unit_test.hpp>]],
                                     [[using boost::unit_test::test_suite;
-							 test_suite* test= BOOST_TEST_SUITE( "Unit test example 1" ); return 0;]])],
+							 test_suite* test= BOOST_TEST_SUITE( "Unit test example 1" ); if (test == NULL) { return 1; } else { return 0; }]])],
                    ax_cv_boost_unit_test_framework=yes, ax_cv_boost_unit_test_framework=no)
          AC_LANG_POP([C++])
 		])
diff --git a/configure.ac b/configure.ac
index 18f707f0ba..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>]],
@@ -771,7 +755,7 @@ dnl Check for libminiupnpc (optional)
 if test x$use_upnp != xno; then
   AC_CHECK_HEADERS(
     [miniupnpc/miniwget.h miniupnpc/miniupnpc.h miniupnpc/upnpcommands.h miniupnpc/upnperrors.h],
-    [AC_CHECK_LIB([miniupnpc], [main],[MINIUPNPC_LIBS=-lminiupnpc], [have_miniupnpc=no])],
+    [AC_CHECK_LIB([miniupnpc], [upnpDiscover], [MINIUPNPC_LIBS=-lminiupnpc], [have_miniupnpc=no])],
     [have_miniupnpc=no]
   )
 fi
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