libc/test/src/unistd/pread_pwrite_test.cpp

   1 //===-- Unittests for pread and pwrite ------------------------------------===//
   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/fsync.h"
  13 #include "src/unistd/pread.h"
  14 #include "src/unistd/pwrite.h"
  15 #include "src/unistd/unlink.h"
  16 #include "src/unistd/write.h"
  17 #include "test/UnitTest/ErrnoSetterMatcher.h"
  18 #include "test/UnitTest/Test.h"
  19
  20 #include <sys/stat.h>
  21
  22 TEST(LlvmLibcUniStd, PWriteAndPReadBackTest) {
  23   // The strategy here is that we first create a file and write to it. Next,
  24   // we open that file again and write at an offset. Finally, we open the
  25   // file again and pread at an offset and make sure that only expected data
  26   // is being read back. This also confirms that pwrite happened successfully.
  27   constexpr const char HELLO[] = "hello";
  28   constexpr int HELLO_SIZE = sizeof(HELLO);
  29   constexpr off_t OFFSET = 3;
  30   constexpr const char OFFSET_TEXT[] = "helhello";
  31   constexpr int OFFSET_TEXT_SIZE = sizeof(OFFSET_TEXT);
  32
  33   using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
  34
  35   constexpr const char *FILENAME = "pread_pwrite.test";
  36   auto TEST_FILE = libc_make_test_file_path(FILENAME);
  37   int fd = LIBC_NAMESPACE::open(TEST_FILE, O_WRONLY | O_CREAT, S_IRWXU);
  38   ASSERT_ERRNO_SUCCESS();
  39   ASSERT_GT(fd, 0);
  40   ASSERT_THAT(LIBC_NAMESPACE::write(fd, HELLO, HELLO_SIZE),
  41               Succeeds(HELLO_SIZE));
  42   ASSERT_THAT(LIBC_NAMESPACE::fsync(fd), Succeeds(0));
  43   ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
  44
  45   fd = LIBC_NAMESPACE::open(TEST_FILE, O_WRONLY);
  46   ASSERT_ERRNO_SUCCESS();
  47   ASSERT_GT(fd, 0);
  48   ASSERT_THAT(LIBC_NAMESPACE::pwrite(fd, HELLO, HELLO_SIZE, OFFSET),
  49               Succeeds(HELLO_SIZE));
  50   ASSERT_THAT(LIBC_NAMESPACE::fsync(fd), Succeeds(0));
  51   ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
  52
  53   fd = LIBC_NAMESPACE::open(TEST_FILE, O_RDONLY);
  54   ASSERT_ERRNO_SUCCESS();
  55   ASSERT_GT(fd, 0);
  56   char read_buf[OFFSET_TEXT_SIZE];
  57   ASSERT_THAT(LIBC_NAMESPACE::pread(fd, read_buf, HELLO_SIZE, OFFSET),
  58               Succeeds(HELLO_SIZE));
  59   EXPECT_STREQ(read_buf, HELLO);
  60   ASSERT_THAT(LIBC_NAMESPACE::pread(fd, read_buf, OFFSET_TEXT_SIZE, 0),
  61               Succeeds(OFFSET_TEXT_SIZE));
  62   EXPECT_STREQ(read_buf, OFFSET_TEXT);
  63   ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
  64
  65   ASSERT_THAT(LIBC_NAMESPACE::unlink(TEST_FILE), Succeeds(0));
  66 }
  67
  68 TEST(LlvmLibcUniStd, PWriteFails) {
  69   using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
  70   EXPECT_THAT(LIBC_NAMESPACE::pwrite(-1, "", 1, 0), Fails(EBADF));
  71 }
  72
  73 TEST(LlvmLibcUniStd, PReadFails) {
  74   using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
  75   EXPECT_THAT(LIBC_NAMESPACE::pread(-1, nullptr, 1, 0), Fails(EBADF));
  76 }