[libc-commits] [libc] Reland: [libc] implement ioctl ([libc] implement ioctl #85890) (PR #90317)

[Nick Desaulniers via libc-commits]

================
@@ -0,0 +1,27 @@
+//===-- Unittests for ioctl -----------------------------------------------===//
+//
+// 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/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/errno/libc_errno.h"
+#include "src/sys/ioctl/ioctl.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include "test/UnitTest/LibcTest.h"
+#include "test/UnitTest/Test.h"
+
+#include <sys/syscall.h>
+#include <unistd.h>
+
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
+
+TEST(LlvmLibcIoctlTest, InvalidFileDescriptor) {
+  int fd = 10;
+  unsigned long request = 10;
+  int res = LIBC_NAMESPACE::ioctl(fd, request, NULL);
----------------
nickdesaulniers wrote:

Perhaps `FS_IOC_GETFLAGS`.
https://man7.org/linux/man-pages/man2/ioctl_iflags.2.html

That is used as the example for ioctl in Michael Kerrisk's The Linux Programming Interface page 308.

https://github.com/llvm/llvm-project/pull/90317