[libc] add socket function

This patch adds the function "socket" from the header "sys/socket". It's
a simple syscall wrapper, and I plan on adding the related functions in
a followup patch.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D149622

4 files changed, 42 insertions, 0 deletions

diff --git a/libc/test/src/sys/CMakeLists.txt b/libc/test/src/sys/CMakeLists.txt
index 94f62123d2c4..5ef97fe81770 100644
--- a/libc/test/src/sys/CMakeLists.txt
+++ b/libc/test/src/sys/CMakeLists.txt
@@ -3,6 +3,7 @@ add_subdirectory(random)
 add_subdirectory(resource)
 add_subdirectory(select)
 add_subdirectory(sendfile)
+add_subdirectory(socket)
 add_subdirectory(stat)
 add_subdirectory(utsname)
 add_subdirectory(wait)
diff --git a/libc/test/src/sys/socket/CMakeLists.txt b/libc/test/src/sys/socket/CMakeLists.txt
new file mode 100644
index 000000000000..b4bbe81c92ff
--- /dev/null
+++ b/libc/test/src/sys/socket/CMakeLists.txt
@@ -0,0 +1,3 @@
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+  add_subdirectory(${LIBC_TARGET_OS})
+endif()
diff --git a/libc/test/src/sys/socket/linux/CMakeLists.txt b/libc/test/src/sys/socket/linux/CMakeLists.txt
new file mode 100644
index 000000000000..4380597e5515
--- /dev/null
+++ b/libc/test/src/sys/socket/linux/CMakeLists.txt
@@ -0,0 +1,14 @@
+add_custom_target(libc_sys_socket_unittests)
+
+add_libc_unittest(
+  socket_test
+  SUITE
+    libc_sys_socket_unittests
+  SRCS
+    socket_test.cpp
+  DEPENDS
+    libc.include.sys_socket
+    libc.src.errno.errno
+    libc.src.sys.socket.socket
+    libc.src.unistd.close
+)
diff --git a/libc/test/src/sys/socket/linux/socket_test.cpp b/libc/test/src/sys/socket/linux/socket_test.cpp
new file mode 100644
index 000000000000..6826594e52d7
--- /dev/null
+++ b/libc/test/src/sys/socket/linux/socket_test.cpp
@@ -0,0 +1,24 @@
+//===-- Unittests for socket ----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/sys/socket/socket.h"
+
+#include "src/unistd/close.h"
+
+#include "src/errno/libc_errno.h"
+#include "test/UnitTest/Test.h"
+
+#include <sys/socket.h> // For AF_LOCAL and SOCK_DGRAM
+
+TEST(LlvmLibcSocketTest, LocalSocket) {
+  int sock = __llvm_libc::socket(AF_LOCAL, SOCK_DGRAM, 0);
+  ASSERT_GE(sock, 0);
+  ASSERT_EQ(libc_errno, 0);
+
+  __llvm_libc::close(sock);
+}