[libc] Add implementation of functions stat, fstat and lstat.

All supporting type and macro definitions have also been added.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D134262

1 files changed, 51 insertions, 0 deletions

diff --git a/libc/test/src/sys/stat/fstat_test.cpp b/libc/test/src/sys/stat/fstat_test.cpp
new file mode 100644
index 000000000000..d05f31d35aa2
--- /dev/null
+++ b/libc/test/src/sys/stat/fstat_test.cpp
@@ -0,0 +1,51 @@
+//===-- Unittests for fstat -----------------------------------------------===//
+//
+// 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/fcntl/open.h"
+#include "src/sys/stat/fstat.h"
+#include "src/unistd/close.h"
+#include "src/unistd/unlink.h"
+#include "test/ErrnoSetterMatcher.h"
+#include "utils/UnitTest/Test.h"
+#include "utils/testutils/FDReader.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+
+TEST(LlvmLibcFStatTest, CreatAndReadMode) {
+  using __llvm_libc::testing::ErrnoSetterMatcher::Fails;
+  using __llvm_libc::testing::ErrnoSetterMatcher::Succeeds;
+
+  // The test file is initially writable. We open it for writing and ensure
+  // that it indeed can be opened for writing. Next, we close the file and
+  // make it readonly using chmod. We test that chmod actually succeeded by
+  // trying to open the file for writing and failing.
+  constexpr const char *TEST_FILE = "testdata/fstat.test";
+  errno = 0;
+
+  int fd = __llvm_libc::open(TEST_FILE, O_CREAT | O_WRONLY, S_IRWXU);
+  ASSERT_GT(fd, 0);
+  ASSERT_EQ(errno, 0);
+
+  struct stat statbuf;
+  ASSERT_THAT(__llvm_libc::fstat(fd, &statbuf), Succeeds(0));
+
+  ASSERT_EQ(int(statbuf.st_mode), int(S_IRWXU | S_IFREG));
+
+  ASSERT_THAT(__llvm_libc::close(fd), Succeeds(0));
+  ASSERT_THAT(__llvm_libc::unlink(TEST_FILE), Succeeds(0));
+}
+
+TEST(LlvmLibcFStatTest, NonExistentFile) {
+  errno = 0;
+  using __llvm_libc::testing::ErrnoSetterMatcher::Fails;
+  struct stat statbuf;
+  ASSERT_THAT(__llvm_libc::fstat(-1, &statbuf), Fails(EBADF));
+  errno = 0;
+}