(gl_PREREQ_GETADDRINFO): Use AC_GNU_SOURCE,

GNU declares only getaddrinfo as an (POSIX) extension.
Check for sys/types.h, sys/socket.h, and netdb.h too,
needed by getaddrinfo.h.
Check if getaddrinfo, freeaddrinfo and gai_strerror are
declared by the POSIX headers.
Check if struct addrinfo is declared.

diff --git a/m4/getaddrinfo.m4 b/m4/getaddrinfo.m4
index 07f7896ee505bea500a5346e2c18b8749740d9ef..f95bb1a93f349b05e35819318c1621903e306403 100644 (file)
--- a/m4/getaddrinfo.m4
+++ b/m4/getaddrinfo.m4
@@ -18,5 +18,22 @@ AC_DEFUN([gl_PREREQ_GETADDRINFO], [
   AC_REQUIRE([gl_C_RESTRICT])
   AC_REQUIRE([gl_SOCKET_FAMILIES])
   AC_REQUIRE([AC_C_INLINE])
-  AC_CHECK_HEADERS_ONCE([netinet/in.h])
+  AC_REQUIRE([AC_GNU_SOURCE])
+  AC_CHECK_HEADERS_ONCE(sys/socket.h netdb.h sys/types.h netinet/in.h)
+  AC_CHECK_DECLS([getaddrinfo, freeaddrinfo, gai_strerror],,,[
+#ifdef HAVE_SYS_SOCKET_H
+# include <sys/socket.h>
+#endif
+#ifdef HAVE_NETDB_H
+# include <netdb.h>
+#endif
+])
+  AC_CHECK_TYPES([struct addrinfo],,,[
+#ifdef HAVE_SYS_SOCKET_H
+# include <sys/socket.h>
+#endif
+#ifdef HAVE_NETDB_H
+# include <netdb.h>
+#endif
+])
 ])