libc/test/src/unistd/dup2_test.cpp

   1 //===-- Unittests for dup -------------------------------------------------===//
   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/errno/libc_errno.h"
  10 #include "src/fcntl/open.h"
  11 #include "src/unistd/close.h"
  12 #include "src/unistd/dup2.h"
  13 #include "src/unistd/read.h"
  14 #include "src/unistd/unlink.h"
  15 #include "src/unistd/write.h"
  16 #include "test/UnitTest/ErrnoSetterMatcher.h"
  17 #include "test/UnitTest/Test.h"
  18
  19 #include <sys/stat.h>
  20
  21 TEST(LlvmLibcdupTest, ReadAndWriteViaDup) {
  22   constexpr int DUPFD = 0xD0;
  23   LIBC_NAMESPACE::libc_errno = 0;
  24   using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
  25   constexpr const char *FILENAME = "dup2.test";
  26   auto TEST_FILE = libc_make_test_file_path(FILENAME);
  27   int fd = LIBC_NAMESPACE::open(TEST_FILE, O_WRONLY | O_CREAT, S_IRWXU);
  28   ASSERT_ERRNO_SUCCESS();
  29   ASSERT_GT(fd, 0);
  30   int dupfd = LIBC_NAMESPACE::dup2(fd, DUPFD);
  31   ASSERT_ERRNO_SUCCESS();
  32   ASSERT_EQ(dupfd, DUPFD);
  33
  34   // Write something via the dup
  35   constexpr char WRITE_DATA[] = "Hello, dup!";
  36   constexpr size_t WRITE_SIZE = sizeof(WRITE_DATA);
  37   ASSERT_EQ(ssize_t(WRITE_SIZE),
  38             LIBC_NAMESPACE::write(dupfd, WRITE_DATA, WRITE_SIZE));
  39   ASSERT_THAT(LIBC_NAMESPACE::close(dupfd), Succeeds(0));
  40
  41   // Reopen the file for reading and create a dup.
  42   fd = LIBC_NAMESPACE::open(TEST_FILE, O_RDONLY);
  43   ASSERT_ERRNO_SUCCESS();
  44   ASSERT_GT(fd, 0);
  45   dupfd = LIBC_NAMESPACE::dup2(fd, DUPFD);
  46   ASSERT_ERRNO_SUCCESS();
  47   ASSERT_EQ(dupfd, DUPFD);
  48
  49   // Read the file content via the dup.
  50   char buf[WRITE_SIZE];
  51   ASSERT_THAT(LIBC_NAMESPACE::read(dupfd, buf, WRITE_SIZE),
  52               Succeeds(WRITE_SIZE));
  53   ASSERT_STREQ(buf, WRITE_DATA);
  54
  55   // Verify that duping to the same fd value succeeds.
  56   ASSERT_THAT(LIBC_NAMESPACE::dup2(dupfd, dupfd), Succeeds(dupfd));
  57
  58   ASSERT_THAT(LIBC_NAMESPACE::close(dupfd), Succeeds(0));
  59   ASSERT_THAT(LIBC_NAMESPACE::unlink(TEST_FILE), Succeeds(0));
  60 }
  61
  62 TEST(LlvmLibcdupTest, DupBadFD) {
  63   using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
  64   ASSERT_THAT(LIBC_NAMESPACE::dup2(-1, 123), Fails(EBADF));
  65 }