libstdc++: Make Networking TS headers more portable [PR100285]

Add more preprocessor conditions to check for constants being defined
before using them, so that the Networking TS headers can be compiled on
a wider range of platforms.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/100285
	* configure.ac: Check for O_NONBLOCK.
	* configure: Regenerate.
	* include/experimental/internet: Include <ws2tcpip.h> for
	Windows.  Use preprocessor conditions around more constants.
	* include/experimental/socket: Use preprocessor conditions
	around more constants.
	* testsuite/experimental/net/internet/resolver/base.cc: Only use
	constants when the corresponding C macro is defined.
	* testsuite/experimental/net/socket/basic_socket.cc: Likewise.
	* testsuite/experimental/net/socket/socket_base.cc: Likewise.
	Make preprocessor checks more fine-grained.

2 files changed, 33 insertions, 5 deletions

diff --git a/libstdc++-v3/include/experimental/internet b/libstdc++-v3/include/experimental/internet
index f6d6ef34504..6ce070ae775 100644
--- a/libstdc++-v3/include/experimental/internet
+++ b/libstdc++-v3/include/experimental/internet
@@ -61,6 +61,10 @@
 # include <netdb.h>		// getaddrinfo etc.
 #endif
 
+#if defined _WIN32 && __has_include(<ws2tcpip.h>)
+# include <ws2tcpip.h>
+#endif
+
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -263,7 +267,11 @@ namespace ip
     _S_ntoh_32(uint32_t __n) { return __builtin_bswap32(__n); }
 #endif
 
+#ifdef _GLIBCXX_HAVE_ARPA_INET_H
     in_addr_t _M_addr; // network byte order
+#else
+    uint32_t _M_addr;
+#endif
   };
 
   /// An IPv6 address.
@@ -705,7 +713,7 @@ namespace ip
   inline address_v4
   make_address_v4(string_view __str, error_code& __ec) noexcept
   {
-    char __buf[INET_ADDRSTRLEN];
+    char __buf[16]; // INET_ADDRSTRLEN isn't defined on Windows
     auto __len = __str.copy(__buf, sizeof(__buf));
     if (__len == sizeof(__buf))
       {
@@ -1686,9 +1694,15 @@ namespace ip
 #ifdef AI_NUMERICSERV
     static constexpr flags numeric_service	= (flags)AI_NUMERICSERV;
 #endif
+#ifdef AI_V4MAPPED
     static constexpr flags v4_mapped		= (flags)AI_V4MAPPED;
+#endif
+#ifdef AI_ALL
     static constexpr flags all_matching		= (flags)AI_ALL;
+#endif
+#ifdef AI_ADDRCONFIG
     static constexpr flags address_configured	= (flags)AI_ADDRCONFIG;
+#endif
 
     friend constexpr flags
     operator&(flags __f1, flags __f2) noexcept
diff --git a/libstdc++-v3/include/experimental/socket b/libstdc++-v3/include/experimental/socket
index 6d1c114254a..94241649777 100644
--- a/libstdc++-v3/include/experimental/socket
+++ b/libstdc++-v3/include/experimental/socket
@@ -293,11 +293,14 @@ inline namespace v1
       static const int _S_level = SOL_SOCKET;
       static const int _S_name = SO_SNDLOWAT;
     };
+#endif // HAVE_SYS_SOCKET_H
 
     enum shutdown_type : int { };
+#if defined SHUT_RD && defined SHUT_WR && defined SHUT_RDWR
     static constexpr shutdown_type shutdown_receive = (shutdown_type)SHUT_RD;
     static constexpr shutdown_type shutdown_send    = (shutdown_type)SHUT_WR;
     static constexpr shutdown_type shutdown_both    = (shutdown_type)SHUT_RDWR;
+#endif
 
     enum wait_type : int { };
 #ifdef _GLIBCXX_HAVE_POLL_H
@@ -311,14 +314,20 @@ inline namespace v1
 #endif
 
     enum message_flags : int { };
+#if defined MSG_PEEK && defined MSG_OOB && defined MSG_DONTROUTE
     static constexpr message_flags message_peek
       = (message_flags)MSG_PEEK;
     static constexpr message_flags message_out_of_band
       = (message_flags)MSG_OOB;
     static constexpr message_flags message_do_not_route
       = (message_flags)MSG_DONTROUTE;
+#endif
 
-    static const int max_listen_connections = SOMAXCONN;
+#ifdef SOMAXCONN
+    static constexpr int max_listen_connections = SOMAXCONN;
+#else
+    static constexpr int max_listen_connections = 4;
+#endif
 
     // message_flags bitmask operations are defined as hidden friends.
 
@@ -350,6 +359,7 @@ inline namespace v1
     operator^=(message_flags& __f1, message_flags __f2) noexcept
     { return __f1 = (__f1 ^ __f2); }
 
+#ifdef _GLIBCXX_HAVE_SYS_SOCKET_H
   protected:
     struct __msg_hdr : ::msghdr
     {
@@ -483,7 +493,7 @@ inline namespace v1
     void
     native_non_blocking(bool __mode, error_code& __ec)
     {
-#ifdef _GLIBCXX_HAVE_FCNTL_H
+#if defined _GLIBCXX_HAVE_FCNTL_H && defined _GLIBCXX_HAVE_DECL_O_NONBLOCK
       int __flags = ::fcntl(_M_sockfd, F_GETFL, 0);
       if (__flags >= 0)
 	{
@@ -508,7 +518,7 @@ inline namespace v1
     bool
     native_non_blocking() const
     {
-#ifdef _GLIBCXX_HAVE_FCNTL_H
+#if defined _GLIBCXX_HAVE_FCNTL_H && defined _GLIBCXX_HAVE_DECL_O_NONBLOCK
       if (_M_bits.native_non_blocking == -1)
 	{
 	  const int __flags = ::fcntl(_M_sockfd, F_GETFL, 0);
@@ -714,7 +724,9 @@ inline namespace v1
 	  {
 	    error_code __ec;
 	    cancel(__ec);
+#ifdef _GLIBCXX_HAVE_SYS_SOCKET_H
 	    set_option(socket_base::linger{false, chrono::seconds{}}, __ec);
+#endif
 	    ::close(_M_sockfd);
 	  }
       }
@@ -1892,11 +1904,13 @@ inline namespace v1
       { open(__protocol); }
 
       basic_socket_acceptor(io_context& __ctx, const endpoint_type& __endpoint,
-			    bool __reuse_addr = true)
+			    [[__maybe_unused__]] bool __reuse_addr = true)
       : basic_socket_acceptor(__ctx, __endpoint.protocol())
       {
+#ifdef _GLIBCXX_HAVE_SYS_SOCKET_H
 	if (__reuse_addr)
 	  set_option(reuse_address(true));
+#endif
 	bind(__endpoint);
 	listen();
       }