[libc-commits] [libc] [libc] add ioctl (PR #141393)

[Michael Jones via libc-commits]

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@@ -0,0 +1,69 @@
+//===-- 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/errno/libc_errno.h"
+#include "src/fcntl/open.h"
+#include "src/sys/ioctl/ioctl.h"
+#include "src/unistd/close.h"
+#include "src/unistd/read.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+
+#include "hdr/sys_ioctl_macros.h"
+
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
+
+TEST(LlvmLibcSysIoctlTest, TestFileFIONREAD) {
+  LIBC_NAMESPACE::libc_errno = 0;
+
+  constexpr const char TEST_MSG[] = "ioctl test";
+  constexpr int TEST_MSG_SIZE = sizeof(TEST_MSG) - 1;
+  constexpr const char *TEST_FILE = "testdata/ioctl.test";
+  int fd = LIBC_NAMESPACE::open(TEST_FILE, O_RDONLY);
+  ASSERT_ERRNO_SUCCESS();
+  ASSERT_GT(fd, 0);
+
+  // FIONREAD reports the number of available bytes to read for the passed fd
+  // This will report the full size of the file, as we haven't read anything yet
+  int n = -1;
+  int ret = LIBC_NAMESPACE::ioctl(fd, FIONREAD, &n);
+  ASSERT_ERRNO_SUCCESS();
+  ASSERT_GT(ret, -1);
+  ASSERT_EQ(n, TEST_MSG_SIZE);
+
+  // But if we read some bytes...
+  constexpr int READ_COUNT = 5;
+  char read_buffer[READ_COUNT];
+  ASSERT_THAT((int)LIBC_NAMESPACE::read(fd, read_buffer, READ_COUNT),
+              Succeeds(READ_COUNT));
+
+  // ... n should have decreased by the number of bytes we've read
+  int n_after_reading = -1;
+  ret = LIBC_NAMESPACE::ioctl(fd, FIONREAD, &n_after_reading);
+  ASSERT_ERRNO_SUCCESS();
+  ASSERT_GT(ret, -1);
+  ASSERT_EQ(n - READ_COUNT, n_after_reading);
+
+  ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
+}
+
+TEST(LlvmLibcSysIoctlTest, InvalidIoctlCommand) {
+  LIBC_NAMESPACE::libc_errno = 0;
+
+  int fd = LIBC_NAMESPACE::open("/dev/zero", O_RDONLY);
----------------
michaelrj-google wrote:

I'd recommend using the same file as in the other test. It might be easier to merge them to avoid needing to create two files.

https://github.com/llvm/llvm-project/pull/141393