/* Test for fgetsgent_r and buffer sizes.

   Copyright (C) 2020 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

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

#include <array_length.h>

#include <errno.h>

#include <gshadow.h>

#include <stdbool.h>

#include <stdlib.h>

#include <support/check.h>

#include <support/support.h>

#include <support/temp_file.h>

#include <support/xmemstream.h>

#include <support/xstdio.h>

/* Turn a parsed struct back into a line string.  The returned string

   should be freed.  */

static char *

format_ent (const struct sgrp *e)

{

  struct xmemstream stream;

  xopen_memstream (&stream);

  TEST_COMPARE (putsgent (e, stream.out), 0);

  xfclose_memstream (&stream);

  return stream.buffer;

}

/* An entry in the input file along with the expected output.  */

struct input

{

  const char *line;		/* Line in the file.  */

  const char *expected;		/* Expected output.  NULL if skipped.  */

};

const struct input inputs[] =

  {

   /* Regular entries.  */

   { "g1:x1::\n", "g1:x1::\n" },

   { "g2:x2:a1:\n", "g2:x2:a1:\n" },

   { "g3:x3:a2:u1\n", "g3:x3:a2:u1\n" },

   { "g4:x4:a3,a4:u2,u3,u4\n", "g4:x4:a3,a4:u2,u3,u4\n" },

   /* Comments and empty lines.  */

   { "\n", NULL },

   { " \n", NULL },

   { "\t\n", NULL },

   { "#g:x::\n", NULL },

   { " #g:x::\n", NULL },

   { "\t#g:x::\n", NULL },

   { " \t#g:x::\n", NULL },

   /* Marker for synchronization.  */

   { "g5:x5::\n", "g5:x5::\n" },

   /* Leading whitespace.  */

   { " g6:x6::\n", "g6:x6::\n" },

   { "\tg7:x7::\n", "g7:x7::\n" },

   /* This is expected to trigger buffer exhaustion during parsing

      (bug 20338).  */

   {

    "g8:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:u5,u6,u7,u8,u9:\n",

    "g8:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:u5,u6,u7,u8,u9:\n",

   },

   {

    "g9:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx::a5,a6,a7,a8,a9,a10\n",

    "g9:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx::a5,a6,a7,a8,a9,a10\n",

   },

  };

/* Writes the test data to a temporary file and returns its name.  The

   returned pointer should be freed.  */

static char *

create_test_file (void)

{

  char *path;

  int fd = create_temp_file ("tst-fgetsgent_r-", &path);

  FILE *fp = fdopen (fd, "w");

  TEST_VERIFY_EXIT (fp != NULL);

  for (size_t i = 0; i < array_length (inputs); ++i)

    fputs (inputs[i].line, fp);

  xfclose (fp);

  return path;

}

/* Read the test file with the indicated start buffer size.  Return

   true if the buffer size had to be increased during reading.  */

static bool

run_test (const char *path, size_t buffer_size)

{

  bool resized = false;

  FILE *fp = xfopen (path, "r");

  /* This avoids repeated lseek system calls (bug 26257).  */

  TEST_COMPARE (fseeko64 (fp, 0, SEEK_SET), 0);

  size_t i = 0;

  while (true)

    {

      /* Skip over unused expected entries.  */

      while (i < array_length (inputs) && inputs[i].expected == NULL)

	++i;

      /* Store the data on the heap, to help valgrind to detect

	 invalid accesses.  */

      struct sgrp *result_storage = xmalloc (sizeof (*result_storage));

      char *buffer = xmalloc (buffer_size);

      struct sgrp **result_pointer_storage

	= xmalloc (sizeof (*result_pointer_storage));

      int ret = fgetsgent_r (fp, result_storage, buffer, buffer_size,

			     result_pointer_storage);

      if (ret == 0)

	{

	  TEST_VERIFY (*result_pointer_storage != NULL);

	  TEST_VERIFY (i < array_length (inputs));

	  if (*result_pointer_storage != NULL

	      && i < array_length (inputs))

	    {

	      char * actual = format_ent (*result_pointer_storage);

	      TEST_COMPARE_STRING (inputs[i].expected, actual);

	      free (actual);

	      ++i;

	    }

	  else

	    break;

	}

      else

	{

	  TEST_VERIFY (*result_pointer_storage == NULL);

	  TEST_COMPARE (ret, errno);

	  if (ret == ENOENT)

	    {

	      TEST_COMPARE (i, array_length (inputs));

	      free (result_pointer_storage);

	      free (buffer);

	      free (result_storage);

	      break;

	    }

	  else if (ret == ERANGE)

	    {

	      resized = true;

	      ++buffer_size;

	    }

	  else

	    FAIL_EXIT1 ("read failure: %m");

	}

      free (result_pointer_storage);

      free (buffer);

      free (result_storage);

    }

  xfclose (fp);

  return resized;

}

static int

do_test (void)

{

  char *path = create_test_file ();

  for (size_t buffer_size = 3; ; ++buffer_size)

    {

      bool resized = run_test (path, buffer_size);

      if (!resized)

	break;

    }

  free (path);

  return 0;

}

#include <support/test-driver.c>