libc/test/src/unistd/ftruncate_test.cpp

   1 //===-- Unittests for ftruncate -------------------------------------------===//
   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/__support/CPP/string_view.h"
  10 #include "src/errno/libc_errno.h"
  11 #include "src/fcntl/open.h"
  12 #include "src/unistd/close.h"
  13 #include "src/unistd/ftruncate.h"
  14 #include "src/unistd/read.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 namespace cpp = LIBC_NAMESPACE::cpp;
  23
  24 TEST(LlvmLibcFtruncateTest, CreateAndTruncate) {
  25   using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
  26   constexpr const char *FILENAME = "ftruncate.test";
  27   auto TEST_FILE = libc_make_test_file_path(FILENAME);
  28   constexpr const char WRITE_DATA[] = "hello, ftruncate";
  29   constexpr size_t WRITE_SIZE = sizeof(WRITE_DATA);
  30   char buf[WRITE_SIZE];
  31
  32   // The test strategy is as follows:
  33   //   1. Create a normal file with some data in it.
  34   //   2. Read it to make sure what was written is actually in the file.
  35   //   3. Truncate to 1 byte.
  36   //   4. Try to read more than 1 byte and fail.
  37   LIBC_NAMESPACE::libc_errno = 0;
  38   int fd = LIBC_NAMESPACE::open(TEST_FILE, O_WRONLY | O_CREAT, S_IRWXU);
  39   ASSERT_ERRNO_SUCCESS();
  40   ASSERT_GT(fd, 0);
  41   ASSERT_EQ(ssize_t(WRITE_SIZE),
  42             LIBC_NAMESPACE::write(fd, WRITE_DATA, WRITE_SIZE));
  43   ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
  44
  45   fd = LIBC_NAMESPACE::open(TEST_FILE, O_RDONLY);
  46   ASSERT_ERRNO_SUCCESS();
  47   ASSERT_GT(fd, 0);
  48   ASSERT_EQ(ssize_t(WRITE_SIZE), LIBC_NAMESPACE::read(fd, buf, WRITE_SIZE));
  49   ASSERT_EQ(cpp::string_view(buf), cpp::string_view(WRITE_DATA));
  50   ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
  51
  52   // For ftruncate operation to succeed, the file should be opened for
  53   // writing.
  54   fd = LIBC_NAMESPACE::open(TEST_FILE, O_WRONLY);
  55   ASSERT_GT(fd, 0);
  56   ASSERT_ERRNO_SUCCESS();
  57   ASSERT_THAT(LIBC_NAMESPACE::ftruncate(fd, off_t(1)), Succeeds(0));
  58   ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
  59
  60   fd = LIBC_NAMESPACE::open(TEST_FILE, O_RDONLY);
  61   ASSERT_ERRNO_SUCCESS();
  62   ASSERT_GT(fd, 0);
  63   ASSERT_EQ(ssize_t(1), LIBC_NAMESPACE::read(fd, buf, WRITE_SIZE));
  64   ASSERT_EQ(buf[0], WRITE_DATA[0]);
  65   ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
  66
  67   ASSERT_THAT(LIBC_NAMESPACE::unlink(TEST_FILE), Succeeds(0));
  68 }
  69
  70 TEST(LlvmLibcFtruncateTest, TruncateBadFD) {
  71   using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
  72   ASSERT_THAT(LIBC_NAMESPACE::ftruncate(0, off_t(1)), Fails(EINVAL));
  73 }