/* Verify that ftell returns the correct value at various points before and

   after the handler on which it is called becomes active.

   Copyright (C) 2014-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <errno.h>

#include <unistd.h>

#include <fcntl.h>

#include <locale.h>

#include <wchar.h>

static int do_test (void);

#define TEST_FUNCTION do_test ()

#include "../test-skeleton.c"

#define get_handles_fdopen(filename, fd, fp, fd_mode, mode) \

({									      \

  int ret = 0;								      \

  (fd) = open ((filename), (fd_mode), 0);				      \

  if ((fd) == -1)							      \

    {									      \

      printf ("open failed: %m\n");					      \

      ret = 1;								      \

    }									      \

  else									      \

    {									      \

      (fp) = fdopen ((fd), (mode));					      \

      if ((fp) == NULL)							      \

	{								      \

	  printf ("fdopen failed: %m\n");				      \

	  close (fd);							      \

	  ret = 1;							      \

	}								      \

    }									      \

  ret;									      \

})

#define get_handles_fopen(filename, fd, fp, mode) \

({									      \

  int ret = 0;								      \

  (fp) = fopen ((filename), (mode));					      \

  if ((fp) == NULL)							      \

    {									      \

      printf ("fopen failed: %m\n");					      \

      ret = 1;								      \

    }									      \

  else									      \

    {									      \

      (fd) = fileno (fp);						      \

      if ((fd) == -1)							      \

	{								      \

	  printf ("fileno failed: %m\n");				      \

	  ret = 1;							      \

	}								      \

    }									      \

  ret;									      \

})

/* data points to either char_data or wide_data, depending on whether we're

   testing regular file mode or wide mode respectively.  Similarly,

   fputs_func points to either fputs or fputws.  data_len keeps track of the

   length of the current data and file_len maintains the current file

   length.  */

static const void *data;

static const char *char_data = "abcdef";

static const wchar_t *wide_data = L"abcdef";

static size_t data_len;

static size_t file_len;

typedef int (*fputs_func_t) (const void *data, FILE *fp);

typedef void *(*fgets_func_t) (void *ws, int n, FILE *fp);

fputs_func_t fputs_func;

fgets_func_t fgets_func;

/* This test verifies that the offset reported by ftell is correct after the

   file is truncated using ftruncate.  ftruncate does not change the file

   offset on truncation and hence, SEEK_CUR should continue to point to the

   old offset and not be changed to the new offset.  */

static int

do_ftruncate_test (const char *filename)

{

  FILE *fp = NULL;

  int fd;

  int ret = 0;

  struct test

    {

      const char *mode;

      int fd_mode;

    } test_modes[] = {

	  {"r+", O_RDWR},

	  {"w", O_WRONLY | O_TRUNC},

	  {"w+", O_RDWR | O_TRUNC},

	  {"a", O_WRONLY},

	  {"a+", O_RDWR}

    };

  for (int j = 0; j < 2; j++)

    {

      for (int i = 0; i < sizeof (test_modes) / sizeof (struct test); i++)

	{

	  int fileret;

	  printf ("\tftruncate: %s (file, \"%s\"): ",

		  j == 0 ? "fopen" : "fdopen",

		  test_modes[i].mode);

	  if (j == 0)

	    fileret = get_handles_fopen (filename, fd, fp, test_modes[i].mode);

	  else

	    fileret = get_handles_fdopen (filename, fd, fp,

					  test_modes[i].fd_mode,

					  test_modes[i].mode);

	  if (fileret != 0)

	    return fileret;

	  /* Write some data.  */

	  size_t written = fputs_func (data, fp);

	  if (written == EOF)

	    {

	      printf ("fputs[1] failed to write data\n");

	      ret |= 1;

	    }

	  /* Record the offset.  */

	  long offset = ftell (fp);

	  /* Flush data to allow switching active handles.  */

	  if (fflush (fp))

	    {

	      printf ("Flush failed: %m\n");

	      ret |= 1;

	    }

	  /* Now truncate the file.  */

	  if (ftruncate (fd, 0) != 0)

	    {

	      printf ("Failed to truncate file: %m\n");

	      ret |= 1;

	    }

	  /* ftruncate does not change the offset, so there is no need to call

	     anything to be able to switch active handles.  */

	  long new_offset = ftell (fp);

	  /* The offset should remain unchanged since ftruncate does not update

	     it.  */

	  if (offset != new_offset)

	    {

	      printf ("Incorrect offset.  Expected %ld, but got %ld\n",

		      offset, new_offset);

	      ret |= 1;

	    }

	  else

	    printf ("offset = %ld\n", offset);

	  fclose (fp);

	}

    }

  return ret;

}

/* Test that ftell output after a rewind is correct.  */

static int

do_rewind_test (const char *filename)

{

  int ret = 0;

  struct test

    {

      const char *mode;

      int fd_mode;

      size_t old_off;

      size_t new_off;

    } test_modes[] = {

	  {"w", O_WRONLY | O_TRUNC, 0, data_len},

	  {"w+", O_RDWR | O_TRUNC, 0, data_len},

	  {"r+", O_RDWR, 0, data_len},

	  /* The new offsets for 'a' and 'a+' modes have to factor in the

	     previous writes since they always append to the end of the

	     file.  */

	  {"a", O_WRONLY, 0, 3 * data_len},

	  {"a+", O_RDWR, 0, 4 * data_len},

    };

  /* Empty the file before the test so that our offsets are simple to

     calculate.  */

  FILE *fp = fopen (filename, "w");

  if (fp == NULL)

    {

      printf ("Failed to open file for emptying\n");

      return 1;

    }

  fclose (fp);

  for (int j = 0; j < 2; j++)

    {

      for (int i = 0; i < sizeof (test_modes) / sizeof (struct test); i++)

	{

	  FILE *fp;

	  int fd;

	  int fileret;

	  printf ("\trewind: %s (file, \"%s\"): ", j == 0 ? "fdopen" : "fopen",

		  test_modes[i].mode);

	  if (j == 0)

	    fileret = get_handles_fdopen (filename, fd, fp,

					  test_modes[i].fd_mode,

					  test_modes[i].mode);

	  else

	    fileret = get_handles_fopen (filename, fd, fp, test_modes[i].mode);

	  if (fileret != 0)

	    return fileret;

	  /* Write some content to the file, rewind and ensure that the ftell

	     output after the rewind is 0.  POSIX does not specify what the

	     behavior is when a file is rewound in 'a' mode, so we retain

	     current behavior, which is to keep the 0 offset.  */

	  size_t written = fputs_func (data, fp);

	  if (written == EOF)

	    {

	      printf ("fputs[1] failed to write data\n");

	      ret |= 1;

	    }

	  rewind (fp);

	  long offset = ftell (fp);

	  if (offset != test_modes[i].old_off)

	    {

	      printf ("Incorrect old offset.  Expected %zu, but got %ld, ",

		      test_modes[i].old_off, offset);

	      ret |= 1;

	    }

	  else

	    printf ("old offset = %ld, ", offset);

	  written = fputs_func (data, fp);

	  if (written == EOF)

	    {

	      printf ("fputs[1] failed to write data\n");

	      ret |= 1;

	    }

	  /* After this write, the offset in append modes should factor in the

	     implicit lseek to the end of file.  */

	  offset = ftell (fp);

	  if (offset != test_modes[i].new_off)

	    {

	      printf ("Incorrect new offset.  Expected %zu, but got %ld\n",

		      test_modes[i].new_off, offset);

	      ret |= 1;

	    }

	  else

	    printf ("new offset = %ld\n", offset);

	}

    }

  return ret;

}

/* Test that the value of ftell is not cached when the stream handle is not

   active.  */

static int

do_ftell_test (const char *filename)

{

  int ret = 0;

  struct test

    {

      const char *mode;

      int fd_mode;

      size_t old_off;

      size_t new_off;

      size_t eof_off;

    } test_modes[] = {

	  /* In w, w+ and r+ modes, the file position should be at the

	     beginning of the file.  After the write, the offset should be

	     updated to data_len.  We don't use eof_off in w and a modes since

	     they don't allow reading.  */

	  {"w", O_WRONLY | O_TRUNC, 0, data_len, 0},

	  {"w+", O_RDWR | O_TRUNC, 0, data_len, 2 * data_len},

	  {"r+", O_RDWR, 0, data_len, 3 * data_len},

	  /* For the 'a' mode, the initial file position should be the

	     current end of file. After the write, the offset has data_len

	     added to the old value.  For a+ mode however, the initial file

	     position is the file position of the underlying file descriptor,

	     since it is initially assumed to be in read mode.  */

	  {"a", O_WRONLY, 3 * data_len, 4 * data_len, 5 * data_len},

	  {"a+", O_RDWR, 0, 5 * data_len, 6 * data_len},

    };

  for (int j = 0; j < 2; j++)

    {

      for (int i = 0; i < sizeof (test_modes) / sizeof (struct test); i++)

	{

	  FILE *fp;

	  int fd;

	  int fileret;

	  printf ("\tftell: %s (file, \"%s\"): ", j == 0 ? "fdopen" : "fopen",

		  test_modes[i].mode);

	  if (j == 0)

	    fileret = get_handles_fdopen (filename, fd, fp,

					  test_modes[i].fd_mode,

					  test_modes[i].mode);

	  else

	    fileret = get_handles_fopen (filename, fd, fp, test_modes[i].mode);

	  if (fileret != 0)

	    return fileret;

	  long off = ftell (fp);

	  if (off != test_modes[i].old_off)

	    {

	      printf ("Incorrect old offset.  Expected %zu but got %ld, ",

		      test_modes[i].old_off, off);

	      ret |= 1;

	    }

	  else

	    printf ("old offset = %ld, ", off);

	  /* The effect of this write on the offset should be seen in the ftell

	     call that follows it.  */

	  int write_ret = write (fd, data, data_len);

	  if (write_ret != data_len)

	    {

	      printf ("write failed (%m)\n");

	      ret |= 1;

	    }

	  off = ftell (fp);

	  if (off != test_modes[i].new_off)

	    {

	      printf ("Incorrect new offset.  Expected %zu but got %ld",

		      test_modes[i].new_off, off);

	      ret |= 1;

	    }

	  else

	    printf ("new offset = %ld", off);

	  /* Read to the end, write some data to the fd and check if ftell can

	     see the new ofset.  Do this test only for files that allow

	     reading.  */

	  if (test_modes[i].fd_mode != O_WRONLY)

	    {

	      wchar_t tmpbuf[data_len];

	      rewind (fp);

	      while (fgets_func (tmpbuf, data_len, fp) && !feof (fp));

	      write_ret = write (fd, data, data_len);

	      if (write_ret != data_len)

		{

		  printf ("write failed (%m)\n");

		  ret |= 1;

		}

	      off = ftell (fp);

	      if (off != test_modes[i].eof_off)

		{

		  printf (", Incorrect offset after read EOF.  "

			  "Expected %zu but got %ld\n",

			  test_modes[i].eof_off, off);

		  ret |= 1;

		}

	      else

		printf (", offset after EOF = %ld\n", off);

	    }

	  else

	    putc ('\n', stdout);

	  fclose (fp);

	}

    }

  return ret;

}

/* This test opens the file for writing, moves the file offset of the

   underlying file, writes out data and then checks if ftell trips on it.  */

static int

do_write_test (const char *filename)

{

  FILE *fp = NULL;

  int fd;

  int ret = 0;

  struct test

    {

      const char *mode;

      int fd_mode;

    } test_modes[] = {

	  {"w", O_WRONLY | O_TRUNC},

	  {"w+", O_RDWR | O_TRUNC},

	  {"r+", O_RDWR}

    };

  for (int j = 0; j < 2; j++)

    {

      for (int i = 0; i < sizeof (test_modes) / sizeof (struct test); i++)

	{

	  int fileret;

	  printf ("\twrite: %s (file, \"%s\"): ", j == 0 ? "fopen" : "fdopen",

		  test_modes[i].mode);

	  if (j == 0)

	    fileret = get_handles_fopen (filename, fd, fp, test_modes[i].mode);

	  else

	    fileret = get_handles_fdopen (filename, fd, fp,

					  test_modes[i].fd_mode,

					  test_modes[i].mode);

	  if (fileret != 0)

	    return fileret;

	  /* Move offset to just before the end of the file.  */

	  off_t seek_ret = lseek (fd, file_len - 1, SEEK_SET);

	  if (seek_ret == -1)

	    {

	      printf ("lseek failed: %m\n");

	      ret |= 1;

	    }

	  /* Write some data.  */

	  size_t written = fputs_func (data, fp);

	  if (written == EOF)

	    {

	      printf ("fputs[1] failed to write data\n");

	      ret |= 1;

	    }

	  /* Verify that the offset points to the end of the file.  The length

	     of the file would be the original length + the length of data

	     written to it - the amount by which we moved the offset using

	     lseek.  */

	  long offset = ftell (fp);

	  file_len = file_len - 1 + data_len;

	  if (offset != file_len)

	    {

	      printf ("Incorrect offset.  Expected %zu, but got %ld\n",

		      file_len, offset);

	      ret |= 1;

	    }

	  printf ("offset = %ld\n", offset);

	  fclose (fp);

	}

    }

  return ret;

}

/* This test opens a file in append mode, writes some data, and then verifies

   that ftell does not trip over it.  */

static int

do_append_test (const char *filename)

{

  FILE *fp = NULL;

  int ret = 0;

  int fd;

  struct test

    {

      const char *mode;

      int fd_mode;

    } test_modes[] = {

	  {"a", O_WRONLY},

	  {"a+", O_RDWR}

    };

  for (int j = 0; j < 2; j++)

    {

      for (int i = 0; i < sizeof (test_modes) / sizeof (struct test); i++)

	{

	  int fileret;

	  printf ("\tappend: %s (file, \"%s\"): ", j == 0 ? "fopen" : "fdopen",

		  test_modes[i].mode);

	  if (j == 0)

	    fileret = get_handles_fopen (filename, fd, fp, test_modes[i].mode);

	  else

	    fileret = get_handles_fdopen (filename, fd, fp,

					  test_modes[i].fd_mode,

					  test_modes[i].mode);

	  if (fileret != 0)

	    return fileret;

	  /* Write some data.  */

	  size_t written = fputs_func (data, fp);

	  if (written == EOF)

	    {

	      printf ("fputs[1] failed to write all data\n");

	      ret |= 1;

	    }

	  /* Verify that the offset points to the end of the file.  The file

	     len is maintained by adding data_len each time to reflect the data

	     written to it.  */

	  long offset = ftell (fp);

	  file_len += data_len;

	  if (offset != file_len)

	    {

	      printf ("Incorrect offset.  Expected %zu, but got %ld\n",

		      file_len, offset);

	      ret |= 1;

	    }

	  printf ("offset = %ld\n", offset);

	  fclose (fp);

	}

    }

  /* For fdopen in 'a' mode, the file descriptor should not change if the file

     is already open with the O_APPEND flag set.  */

  fd = open (filename, O_WRONLY | O_APPEND, 0);

  if (fd == -1)

    {

      printf ("open(O_APPEND) failed: %m\n");

      return 1;

    }

  off_t seek_ret = lseek (fd, file_len - 1, SEEK_SET);

  if (seek_ret == -1)

    {

      printf ("lseek[O_APPEND][0] failed: %m\n");

      ret |= 1;

    }

  fp = fdopen (fd, "a");

  if (fp == NULL)

    {

      printf ("fdopen(O_APPEND) failed: %m\n");

      close (fd);

      return 1;

    }

  off_t new_seek_ret = lseek (fd, 0, SEEK_CUR);

  if (seek_ret == -1)

    {

      printf ("lseek[O_APPEND][1] failed: %m\n");

      ret |= 1;

    }

  printf ("\tappend: fdopen (file, \"a\"): O_APPEND: ");

  if (seek_ret != new_seek_ret)

    {

      printf ("incorrectly modified file offset to %jd, should be %jd",

	      (intmax_t)  new_seek_ret, (intmax_t) seek_ret);

      ret |= 1;

    }

  else

    printf ("retained current file offset %jd", (intmax_t) seek_ret);

  new_seek_ret = ftello (fp);

  if (seek_ret != new_seek_ret)

    {

      printf (", ftello reported incorrect offset %jd, should be %jd\n",

	      (intmax_t) new_seek_ret, (intmax_t) seek_ret);

      ret |= 1;

    }

  else

    printf (", ftello reported correct offset %jd\n", (intmax_t) seek_ret);

  fclose (fp);

  return ret;

}

static int

do_one_test (const char *filename)

{

  int ret = 0;

  ret |= do_ftell_test (filename);

  ret |= do_write_test (filename);

  ret |= do_append_test (filename);

  ret |= do_rewind_test (filename);

  ret |= do_ftruncate_test (filename);

  return ret;

}

/* Run a set of tests for ftell for regular files and wide mode files.  */

static int

do_test (void)

{

  int ret = 0;

  FILE *fp = NULL;

  char *filename;

  size_t written;

  int fd = create_temp_file ("tst-active-handler-tmp.", &filename);

  if (fd == -1)

    {

      printf ("create_temp_file: %m\n");

      return 1;

    }

  fp = fdopen (fd, "w");

  if (fp == NULL)

    {

      printf ("fdopen[0]: %m\n");

      close (fd);

      return 1;

    }

  data = char_data;

  data_len = strlen (char_data);

  file_len = strlen (char_data);

  written = fputs (data, fp);

  if (written == EOF)

    {

      printf ("fputs[1] failed to write data\n");

      ret = 1;

    }

  fclose (fp);

  if (ret)

    return ret;

  /* Tests for regular files.  */

  puts ("Regular mode:");

  fputs_func = (fputs_func_t) fputs;

  fgets_func = (fgets_func_t) fgets;

  data = char_data;

  data_len = strlen (char_data);

  ret |= do_one_test (filename);

  /* Truncate the file before repeating the tests in wide mode.  */

  fp = fopen (filename, "w");

  if (fp == NULL)

    {

      printf ("fopen failed %m\n");

      return 1;

    }

  fclose (fp);

  /* Tests for wide files.  */

  puts ("Wide mode:");

  if (setlocale (LC_ALL, "en_US.UTF-8") == NULL)

    {

      printf ("Cannot set en_US.UTF-8 locale.\n");

      return 1;

    }

  fputs_func = (fputs_func_t) fputws;

  fgets_func = (fgets_func_t) fgetws;

  data = wide_data;

  data_len = wcslen (wide_data);

  ret |= do_one_test (filename);

  return ret;

}