[libc] Introduce sys/socket.h

[jeffbailey]

Summary

This adds sys/socket.h and some definitions on Linux.

[jeffbailey]

Add missing newline.

[sivachandra]

LGTM but added an inline comment asking to add some documentation.

libc/include/llvm-libc-macros/linux/sys-socket-macros.h

13

Add a comment (against each constant) explaining:

1. What they indicate
2. How you arrived at the value. It can be something simple like, "Value specified by POSIX", or "Value matches Linux definition from <linux header>".
3. Which standard or extension specifies/requires the definition.

[jeffbailey]

Update comments per Siva's feedback.

libc/config/linux/aarch64/headers.txt

 set(TARGET_PUBLIC_HEADERS
     libc.include.assert
     libc.include.ctype
     libc.include.errno
     libc.include.fenv
     libc.include.inttypes
     libc.include.math
     libc.include.pthread
     libc.include.signal
     libc.include.stdio
     libc.include.stdlib
     libc.include.string
     libc.include.sys_mman
+    libc.include.sys_socket
     libc.include.sys_syscall
     libc.include.threads
     libc.include.time
     libc.include.unistd
 )

libc/config/linux/x86_64/headers.txt

set(TARGET_PUBLIC_HEADERS
 
     libc.include.sys_auxv
     libc.include.sys_ioctl
     libc.include.sys_mman
     libc.include.sys_prctl
     libc.include.sys_random
     libc.include.sys_resource
     libc.include.sys_select
+    libc.include.sys_socket
     libc.include.sys_stat
     libc.include.sys_syscall
     libc.include.sys_time
     libc.include.sys_types
     libc.include.sys_utsname
     libc.include.sys_wait
 )

libc/include/CMakeLists.txt

add_gen_header(
   GEN_HDR sys/sendfile.h
   DEPENDS
     .llvm_libc_common_h
     .llvm-libc-types.off_t
     .llvm-libc-types.ssize_t
 )
 
 add_gen_header(
+  sys_socket
+  DEF_FILE sys/socket.h.def
+  GEN_HDR sys/socket.h
+  DEPENDS
+    .llvm_libc_common_h
+    .llvm-libc-macros.sys_socket_macros
+)
+
+add_gen_header(
   sys_syscall
   DEF_FILE sys/syscall.h.def
   GEN_HDR sys/syscall.h
   PARAMS
     syscall_numbers=../config/${LIBC_TARGET_OS}/syscall_numbers.h.inc
   DATA_FILES
     ../config/${LIBC_TARGET_OS}/syscall_numbers.h.inc
 )

libc/include/llvm-libc-macros/CMakeLists.txt

 
 add_header(
   sys_select_macros
   HDR
     sys-select-macros.h
 )
 
 add_header(
+  sys_socket_macros
+  HDR
+    sys-socket-macros.h
+  DEPENDS
+    .linux.sys_socket_macros
+)
+
+add_header(
   sys_time_macros
   HDR
     sys-time-macros.h
   DEPENDS
     .linux.sys_time_macros
 )
 
 add_header(

libc/include/llvm-libc-macros/linux/CMakeLists.txt

 
 add_header(
   sys_random_macros
   HDR
     sys-random-macros.h
 )
 
 add_header(
+  sys_socket_macros
+  HDR
+    sys-socket-macros.h
+)
+
+add_header(
   sys_wait_macros
   HDR
     sys-wait-macros.h
 )
 
 add_header(
   time_macros
   HDR

libc/include/llvm-libc-macros/linux/sys-socket-macros.h

+//===-- Definition of macros from sys/socket.h ----------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __LLVM_LIBC_MACROS_LINUX_SYS_SOCKET_MACROS_H
+#define __LLVM_LIBC_MACROS_LINUX_SYS_SOCKET_MACROS_H
+
+// IEEE Std 1003.1-2017 - basedefs/sys_socket.h.html
+// Macro values come from the Linux syscall interface.
+
+#define AF_UNSPEC 0 // Unspecified
+#define AF_UNIX 1   // Unix domain sockets
+#define AF_LOCAL 1  // POSIX name for AF_UNIX
+#define AF_INET 2   // Internet IPv4 Protocol
+#define AF_INET6 10 // IP version 6
+
+#endif // __LLVM_LIBC_MACROS_LINUX_SYS_SOCKET_MACROS_H

libc/include/llvm-libc-macros/sys-socket-macros.h

+//===-- Macros defined in sys/socket.h header file ------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __LLVM_LIBC_MACROS_SYS_SOCKET_MACROS_H
+#define __LLVM_LIBC_MACROS_SYS_SOCKET_MACROS_H
+
+#ifdef __unix__
+#include "linux/sys-socket-macros.h"
+#endif
+
+#endif // __LLVM_LIBC_MACROS_SYS_SOCKET_MACROS_H

libc/include/sys/socket.h.def

+//===-- POSIX header sys/socket.h -----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SYS_SOCKET_H
+#define LLVM_LIBC_SYS_SOCKET_H
+
+#include <__llvm-libc-common.h>
+
+#include <llvm-libc-macros/sys-socket-macros.h>
+
+%%public_api()
+
+#endif // LLVM_LIBC_SYS_SOCKET_H

libc/spec/linux.td

HeaderSpec SysRandom = HeaderSpec<
             ArgSpec<VoidPtr>,
             ArgSpec<SizeTType>,
             ArgSpec<UnsignedIntType>
           ]
         >,
       ]
   >;
 
+  HeaderSpec SysSocket = HeaderSpec<
+      "sys/socket.h",
+      [
+        Macro<"AF_UNSPEC">,
+        Macro<"AF_LOCAL">,
+        Macro<"AF_INET">,
+        Macro<"AF_INET6">,
+      ],
+      [], // Types
+      [], // Enumerations
+      []  // Functions
+  >;
+
   HeaderSpec SysTime = HeaderSpec<
       "sys/time.h",
       [
         Macro<"timeradd">,
         Macro<"timersub">,
         Macro<"timerclear">,
         Macro<"timerisset">,
         Macro<"timercmp">,
HeaderSpec Signal = HeaderSpec<
       ]
   >;
 
   let Headers = [
     Errno,
     SysMMan,
     SysPrctl,
     SysRandom,
+    SysSocket,
     SysTime,
     Signal,
   ];
 }