[libc-commits] [libc] [libc][fcntl] Implement posix_fadvise function. (PR #220790)

[Pavel Labath via libc-commits]

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@@ -0,0 +1,76 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Unittests for posix_fadvise.
+///
+//===----------------------------------------------------------------------===//
+
+#include "hdr/errno_macros.h"
+#include "hdr/fcntl_macros.h"
+#include "hdr/sys_stat_macros.h"
+#include "src/fcntl/creat.h"
+#include "src/fcntl/posix_fadvise.h"
+#include "src/unistd/close.h"
+#include "src/unistd/pipe.h"
+#include "test/UnitTest/ErrnoCheckingTest.h"
+#include "test/UnitTest/Test.h"
+
+using LlvmLibcPosixFadviseTest = LIBC_NAMESPACE::testing::ErrnoCheckingTest;
+
+TEST_F(LlvmLibcPosixFadviseTest, InvalidFileDescriptor) {
+  EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(-1, 0, 0, POSIX_FADV_NORMAL), EBADF);
+  // posix_fadvise must return the error directly and not set errno.
+  ASSERT_ERRNO_SUCCESS();
+}
+
+TEST_F(LlvmLibcPosixFadviseTest, ValidFile) {
+  constexpr const char *TEST_FILE = "testdata/posix_fadvise.test";
+  int fd = LIBC_NAMESPACE::creat(TEST_FILE, S_IRWXU);
+  ASSERT_ERRNO_SUCCESS();
+  ASSERT_GT(fd, 0);
+
+  EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_NORMAL), 0);
+  EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_RANDOM), 0);
+  EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_SEQUENTIAL), 0);
+  EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_WILLNEED), 0);
+  EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED), 0);
+  EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_NOREUSE), 0);
+
+  // Non-zero offset and length
+  EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 10, 20, POSIX_FADV_NORMAL), 0);
+
+  // Invalid advice
+  EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, -1), EINVAL);
+  ASSERT_ERRNO_SUCCESS();
+
+  // Negative len
+  EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, -1, POSIX_FADV_NORMAL),
+            EINVAL);
+  ASSERT_ERRNO_SUCCESS();
+
+  EXPECT_EQ(LIBC_NAMESPACE::close(fd), 0);
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labath wrote:

Also, I recommend using scope_exit to make sure it gets cleaned up in case of errors. Using memfd_create might also be an option.

https://github.com/llvm/llvm-project/pull/220790