[gcc r12-2126] [Ada] Keepalive control on Windows

[Pierre-Marie de Rodat <pmderodat@gcc.gnu.org>]

https://gcc.gnu.org/g:125bb16bece454843ca420fd033351d1a80976a4

commit r12-2126-g125bb16bece454843ca420fd033351d1a80976a4
Author: Dmitriy Anisimkov <anisimko@adacore.com>
Date:   Thu May 20 19:55:02 2021 +0600

    [Ada] Keepalive control on Windows
    
    gcc/ada/
    
            * s-oscons-tmplt.c (TCP_KEEPCNT TCP_KEEPIDLE, TCP_KEEPINTVL):
            Hardcode on Windows if undefined.

Diff:
---
 gcc/ada/s-oscons-tmplt.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/gcc/ada/s-oscons-tmplt.c b/gcc/ada/s-oscons-tmplt.c
index d42e663fdde..044e203cdb6 100644
--- a/gcc/ada/s-oscons-tmplt.c
+++ b/gcc/ada/s-oscons-tmplt.c
@@ -1502,18 +1502,36 @@ CNS(MSG_Forced_Flags, "")
 CND(TCP_NODELAY, "Do not coalesce packets")
 
 #ifndef TCP_KEEPCNT
+#ifdef __MINGW32__
+/* Windows headers can be too old to have all available constants.
+ * We know this one. */
+# define TCP_KEEPCNT 16
+#else
 # define TCP_KEEPCNT -1
 #endif
+#endif
 CND(TCP_KEEPCNT, "Maximum number of keepalive probes")
 
 #ifndef TCP_KEEPIDLE
+#ifdef __MINGW32__
+/* Windows headers can be too old to have all available constants.
+ * We know this one. */
+# define TCP_KEEPIDLE 3
+#else
 # define TCP_KEEPIDLE -1
 #endif
+#endif
 CND(TCP_KEEPIDLE, "Idle time before TCP starts sending keepalive probes")
 
 #ifndef TCP_KEEPINTVL
+#ifdef __MINGW32__
+/* Windows headers can be too old to have all available constants.
+ * We know this one. */
+# define TCP_KEEPINTVL 17
+#else
 # define TCP_KEEPINTVL -1
 #endif
+#endif
 CND(TCP_KEEPINTVL, "Time between individual keepalive probes")
 
 #ifndef SO_REUSEADDR