1//===-- Unittests for dup3 ------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "src/fcntl/open.h"
10#include "src/unistd/close.h"
11#include "src/unistd/dup3.h"
12#include "src/unistd/read.h"
13#include "src/unistd/unlink.h"
14#include "src/unistd/write.h"
15#include "test/UnitTest/ErrnoCheckingTest.h"
16#include "test/UnitTest/ErrnoSetterMatcher.h"
17#include "test/UnitTest/Test.h"
18
19#include <sys/stat.h>
20
21using LlvmLibcdupTest = LIBC_NAMESPACE::testing::ErrnoCheckingTest;
22
23// The tests here are exactly the same as those of dup2. We only test the
24// plumbing of the dup3 syscall and not the dup3 functionality itself as it is
25// a simple syscall wrapper. Testing dup3 functionality is beyond the scope of
26// this test.
27
28TEST_F(LlvmLibcdupTest, ReadAndWriteViaDup) {
29 constexpr int DUPFD = 0xD0;
30 using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
31 using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
32 constexpr const char *FILENAME = "dup3.test";
33 auto TEST_FILE = libc_make_test_file_path(FILENAME);
34 int fd = LIBC_NAMESPACE::open(TEST_FILE, O_WRONLY | O_CREAT, S_IRWXU);
35 ASSERT_ERRNO_SUCCESS();
36 ASSERT_GT(fd, 0);
37 int dupfd = LIBC_NAMESPACE::dup3(fd, DUPFD, 0);
38 ASSERT_ERRNO_SUCCESS();
39 ASSERT_EQ(dupfd, DUPFD);
40
41 // Write something via the dup
42 constexpr char WRITE_DATA[] = "Hello, dup!";
43 constexpr size_t WRITE_SIZE = sizeof(WRITE_DATA);
44 ASSERT_EQ(ssize_t(WRITE_SIZE),
45 LIBC_NAMESPACE::write(dupfd, WRITE_DATA, WRITE_SIZE));
46 ASSERT_THAT(LIBC_NAMESPACE::close(dupfd), Succeeds(0));
47
48 // Reopen the file for reading and create a dup.
49 fd = LIBC_NAMESPACE::open(TEST_FILE, O_RDONLY);
50 ASSERT_ERRNO_SUCCESS();
51 ASSERT_GT(fd, 0);
52 dupfd = LIBC_NAMESPACE::dup3(fd, DUPFD, 0);
53 ASSERT_ERRNO_SUCCESS();
54 ASSERT_EQ(dupfd, DUPFD);
55
56 // Read the file content via the dup.
57 char buf[WRITE_SIZE];
58 ASSERT_THAT(LIBC_NAMESPACE::read(dupfd, buf, WRITE_SIZE),
59 Succeeds(WRITE_SIZE));
60 ASSERT_STREQ(buf, WRITE_DATA);
61
62 // Verify that, unlike dup2, duping to the same fd value with dup3 fails.
63 ASSERT_THAT(LIBC_NAMESPACE::dup3(dupfd, dupfd, 0), Fails(EINVAL));
64
65 ASSERT_THAT(LIBC_NAMESPACE::close(dupfd), Succeeds(0));
66 ASSERT_THAT(LIBC_NAMESPACE::unlink(TEST_FILE), Succeeds(0));
67}
68
69TEST_F(LlvmLibcdupTest, DupBadFD) {
70 using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
71 ASSERT_THAT(LIBC_NAMESPACE::dup3(-1, 123, 0), Fails(EBADF));
72}
73

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source code of libc/test/src/unistd/dup3_test.cpp