Add probe for sa_len availability in sockaddr struct

diff --git a/U/modified/d_socket.U b/U/modified/d_socket.U
index 3ff6df2..c6756e5 100644 (file)
--- a/U/modified/d_socket.U
+++ b/U/modified/d_socket.U
@@ -20,7 +20,7 @@
 ?RCS:
 ?MAKE:d_socket d_oldsock d_sockpair socketlib sockethdr \
        d_msg_ctrunc d_msg_dontroute d_msg_oob d_msg_peek d_msg_proxy \
-       d_scm_rights: \
+       d_scm_rights d_sockaddr_sa_len: \
        contains echo n c ar nm nm_opt nm_extract Inlibc Csym _a \
        Compile cat rm_try Setvar Hasfield
 ?MAKE: -pick add $@ %<
@@ -66,6 +66,11 @@
 ?S:    which indicates that the SCM_RIGHTS is available.  #ifdef is
 ?S:    not enough because it may be an enum, glibc has been known to do this.
 ?S:.
+?S:d_sockaddr_sa_len:
+?S:    This variable conditionally defines the HAS_SOCKADDR_SA_LEN symbol,
+?S:    which indicates that a struct sockaddr structure has the sa_len
+?S:    member.
+?S:.
 ?S:socketlib:
 ?S:    This variable has the names of any libraries needed for socket support.
 ?S:.
@@ -115,8 +120,14 @@
 ?C:    Checking just with #ifdef might not be enough because this symbol
 ?C:    has been known to be an enum.
 ?C:.
+?C:HAS_SOCKADDR_SA_LEN:
+?C:    This symbol, if defined, indicates that the struct sockaddr
+?C:    structure has a member called sa_len, indicating the length of
+?C:    the structure.
+?C:.
 ?H:#$d_socket  HAS_SOCKET              /**/
 ?H:#$d_sockpair        HAS_SOCKETPAIR  /**/
+?H:#$d_sockaddr_sa_len HAS_SOCKADDR_SA_LEN     /**/
 ?H:#$d_oldsock USE_OLDSOCKET   /**/
 ?H:#$d_msg_ctrunc      HAS_MSG_CTRUNC  /**/
 ?H:#$d_msg_dontroute   HAS_MSG_DONTROUTE       /**/
@@ -127,7 +138,7 @@
 ?H:.
 ?T:val net ENUM enum
 ?F:try.c
-?LINT:set d_sockpair
+?LINT:set d_sockpair d_sockaddr_sa_len
 ?LINT:set d_msg_ctrunc d_msg_dontroute d_msg_oob d_msg_peek d_msg_proxy
 ?LINT:set d_scm_rights
 : see whether socket exists
@@ -204,6 +215,24 @@ eval $inlibc
 @end
 
 echo " "
+?X: ...
+echo "Checking the availability sa_len in the sock struct ..." >&4
+$cat >try.c <<EOF
+#include <sys/types.h>
+#include <sys/socket.h>
+int main() {
+struct sockaddr sa;
+return (sa.sa_len);
+}
+EOF
+val="$undef"
+set try; if eval $compile; then
+       val="$define"
+fi
+set d_sockaddr_sa_len; eval $setvar
+$rm_try
+
+echo " "
 ?X: these constants are known to be troublesomely defined as enums
 ?X: so that ifdef will not work for detecting their presence.
 echo "Checking the availability of certain socket constants..." >&4