Unix: Remove now unnecessary I/O defines, cleanup

- `LIBC_FILEIO_ENABLED` wasn't defined anywhere, even in _other platforms_.
- `NO_NETWORK` is also never defined. It probably isn't enough anyway to
  disable network APIs in the current codebase.
- `UNIX_SOCKET_UNAVAILABLE` is never defined in this code but used by some
  other platforms, clarify that.
- `NO_STATVFS` can be removed as Android supports it since API level 19,
  which is our current min SDK level. It's also only used for
  `DirAccessUnix::get_space_left()` which is anyway overridden by
  `DirAccessJAndroid::get_space_left()` so it shouldn't make a difference.
  * Fixed documentation for `DirAccess.get_space_left()`.
- `NO_FCNTL` is likely also a remnant of early Android days, in current NDK
  r23 it seems to be available. Also cleaned up unused `fcntl.h` includes.
- `NO_ALLOCA` is never defined, and we use alloca in many places now.

1 files changed, 11 insertions, 17 deletions

diff --git a/drivers/unix/net_socket_posix.cpp b/drivers/unix/net_socket_posix.cpp
index 86adf33d62..72ae609fb4 100644
--- a/drivers/unix/net_socket_posix.cpp
+++ b/drivers/unix/net_socket_posix.cpp
@@ -30,32 +30,30 @@
 
 #include "net_socket_posix.h"
 
+// Some proprietary Unix-derived platforms don't expose Unix sockets
+// so this allows skipping this file to reimplement this API differently.
 #ifndef UNIX_SOCKET_UNAVAILABLE
+
 #if defined(UNIX_ENABLED)
 
 #include <errno.h>
+#include <fcntl.h>
 #include <netdb.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
 #include <poll.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/ioctl.h>
+#include <sys/socket.h>
 #include <sys/types.h>
 #include <unistd.h>
-#ifndef NO_FCNTL
-#include <fcntl.h>
-#else
-#include <sys/ioctl.h>
-#endif
-#include <netinet/in.h>
 
-#include <sys/socket.h>
 #ifdef WEB_ENABLED
 #include <arpa/inet.h>
 #endif
 
-#include <netinet/tcp.h>
-
 // BSD calls this flag IPV6_JOIN_GROUP
 #if !defined(IPV6_ADD_MEMBERSHIP) && defined(IPV6_JOIN_GROUP)
 #define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
@@ -93,7 +91,7 @@
 #define SIO_UDP_NETRESET _WSAIOW(IOC_VENDOR, 15)
 #endif
 
-#endif
+#endif // UNIX_ENABLED
 
 size_t NetSocketPosix::_set_addr_storage(struct sockaddr_storage *p_addr, const IPAddress &p_ip, uint16_t p_port, IP::Type p_ip_type) {
 	memset(p_addr, 0, sizeof(struct sockaddr_storage));
@@ -309,14 +307,9 @@ void NetSocketPosix::_set_socket(SOCKET_TYPE p_sock, IP::Type p_ip_type, bool p_
 void NetSocketPosix::_set_close_exec_enabled(bool p_enabled) {
 #ifndef WINDOWS_ENABLED
 	// Enable close on exec to avoid sharing with subprocesses. Off by default on Windows.
-#if defined(NO_FCNTL)
-	unsigned long par = p_enabled ? 1 : 0;
-	SOCK_IOCTL(_sock, FIOCLEX, &par);
-#else
 	int opts = fcntl(_sock, F_GETFD);
 	fcntl(_sock, F_SETFD, opts | FD_CLOEXEC);
 #endif
-#endif
 }
 
 Error NetSocketPosix::open(Type p_sock_type, IP::Type &ip_type) {
@@ -658,7 +651,7 @@ void NetSocketPosix::set_blocking_enabled(bool p_enabled) {
 	ERR_FAIL_COND(!is_open());
 
 	int ret = 0;
-#if defined(WINDOWS_ENABLED) || defined(NO_FCNTL)
+#if defined(WINDOWS_ENABLED)
 	unsigned long par = p_enabled ? 0 : 1;
 	ret = SOCK_IOCTL(_sock, FIONBIO, &par);
 #else
@@ -781,4 +774,5 @@ Error NetSocketPosix::join_multicast_group(const IPAddress &p_multi_address, Str
 Error NetSocketPosix::leave_multicast_group(const IPAddress &p_multi_address, String p_if_name) {
 	return _change_multicast_group(p_multi_address, p_if_name, false);
 }
-#endif
+
+#endif // UNIX_SOCKET_UNAVAILABLE