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