libio: Update tst-fmemopen2.c

This patch updates tst-fmemopen2 to check for fmemopen with NULL buffer
inputs and also refactor the code a bit.

The test relies on a POSIX compliant fmemopen implementation.

	* stdio-common/tst-fmemopen2.c (do_test): Add test for NULL and zero
	length buffers.
	* stdio-common/tst-fmemopen.c (do_test): Refactor to use
	test-skeleton.c.

1 files changed, 203 insertions, 17 deletions

diff --git a/stdio-common/tst-fmemopen2.c b/stdio-common/tst-fmemopen2.c
index e9d8b63..2f26f20 100644
--- a/stdio-common/tst-fmemopen2.c
+++ b/stdio-common/tst-fmemopen2.c
@@ -1,71 +1,257 @@
+/* fmemopen tests.
+   Copyright (C) 2015 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 <assert.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/types.h>
+#include <errno.h>
 
-
+/* Check fmemopen with user provided buffer open for write.  */
 static int
-do_test (void)
+do_test_with_buffer (void)
 {
   int result = 0;
   char buf[100];
-  FILE *fp = fmemopen (buf, sizeof (buf), "w");
+  const size_t nbuf = sizeof (buf);
+
+  FILE *fp = fmemopen (buf, nbuf, "w");
   if (fp == NULL)
     {
-      puts ("fmemopen failed");
-      return 0;
+      printf ("FAIL: fmemopen failedi (%s)\n", __FUNCTION__);
+      return 1;
     }
+
+  /* Default write operation, check if file position is correct after it.  */
   static const char str[] = "hello world";
-#define nstr (sizeof (str) - 1)
+  const size_t nstr = sizeof (str) - 1;
   fputs (str, fp);
   off_t o = ftello (fp);
   if (o != nstr)
     {
-      printf ("first ftello returned %jd, expected %zu\n",
-	      (intmax_t) o, nstr);
+      printf ("FAIL: first ftello returned %jd, expected %zu\n",
+	      (intmax_t)o, nstr);
       result = 1;
     }
+
+  /* Rewind stream and seek tests, the position size should be equal to
+     buffer size provided in open function.  */
   rewind (fp);
   o = ftello (fp);
   if (o != 0)
     {
-      printf ("second ftello returned %jd, expected 0\n", (intmax_t) o);
+      printf ("FAIL: second ftello returned %jd, expected 0\n",
+	      (intmax_t)o);
       result = 1;
     }
   if (fseeko (fp, 0, SEEK_END) != 0)
     {
-      puts ("fseeko failed");
-      return 1;
+      printf ("FAIL: fseeko failed\n");
+      result = 1;
     }
   o = ftello (fp);
   if (o != nstr)
     {
-      printf ("third ftello returned %jd, expected %zu\n",
-	      (intmax_t) o, nstr);
+      printf ("FAIL: third ftello returned %jd, expected %zu\n",
+	      (intmax_t)o, nbuf);
       result = 1;
     }
+
+  /* Rewind the stream and recheck by using a shorter string.  */
   rewind (fp);
   static const char str2[] = "just hello";
-#define nstr2 (sizeof (str2) - 1)
+  const size_t nstr2 = sizeof (str2) - 1;
   assert (nstr2 < nstr);
   fputs (str2, fp);
   o = ftello (fp);
   if (o != nstr2)
     {
-      printf ("fourth ftello returned %jd, expected %zu\n",
-	      (intmax_t) o, nstr2);
+      printf ("FAIL: fourth ftello returned %jd, expected %zu\n",
+	      (intmax_t)o, nstr2);
       result = 1;
     }
   fclose (fp);
+
+  /* Again, but now with a larger string.  */
   static const char str3[] = "just hellod";
   if (strcmp (buf, str3) != 0)
     {
-      printf ("final string is \"%s\", expected \"%s\"\n",
+      printf ("FAIL: final string is \"%s\", expected \"%s\"\n",
               buf, str3);
       result = 1;
     }
   return result;
 }
 
+/* Check fmemopen without user provided buffer open for write.  */
+static int
+do_test_without_buffer (void)
+{
+  int result = 0;
+  const size_t nbuf = 100;
+
+  FILE *fp = fmemopen (NULL, nbuf, "w");
+  if (fp == NULL)
+    {
+      printf ("FAIL: fmemopen failed (%s)\n", __FUNCTION__);
+      return 1;
+    }
+
+  static const char str[] = "hello world";
+  const size_t nstr = sizeof (str) - 1;
+
+  /* Default write operation, check if file position is correct after it.  */
+  fputs (str, fp);
+  off_t o = ftello (fp);
+  if (o != nstr)
+    {
+      printf ("FAIL: first ftello returned %ld, expected %zu\n", o, nstr);
+      result = 1;
+    }
+  if (fseeko (fp, 0, SEEK_END) != 0)
+    {
+      printf ("FAIL: fseeko failed\n");
+      result = 1;
+    }
+  o = ftello (fp);
+  if (o != nstr)
+    {
+      printf ("FAIL: second ftello returned %ld, expected %zu\n", o, nbuf);
+      result = 1;
+    }
+
+  /* Rewind the stream and recheck by using a shorter string.  */
+  rewind (fp);
+  static const char str2[] = "just hello";
+  const size_t nstr2 = sizeof (str2) - 1;
+  assert (nstr2 < nstr);
+  fputs (str2, fp);
+  o = ftello (fp);
+  if (o != nstr2)
+    {
+      printf ("FAIL: third ftello returned %ld, expected %zu\n", o, nstr2);
+      result = 1;
+    }
+  fclose (fp);
+
+  return result;
+}
+
+/* Check fmemopen with a buffer lenght of zero.  */
+static int
+do_test_length_zero (void)
+{
+  int result = 0;
+  FILE *fp;
+#define BUFCONTENTS "testing buffer"
+  char buf[100] = BUFCONTENTS;
+  const size_t nbuf = 0;
+  int r;
+
+  fp = fmemopen (buf, nbuf, "r");
+  if (fp == NULL)
+    {
+      printf ("FAIL: fmemopen failed (%s)\n", __FUNCTION__);
+      return 1;
+    }
+
+  /* Reading any data on a zero-length buffer should return EOF.  */
+  if ((r = fgetc (fp)) != EOF)
+    {
+      printf ("FAIL: fgetc on a zero-length returned: %d\n", r);
+      result = 1;
+    }
+  off_t o = ftello (fp);
+  if (o != 0)
+    {
+      printf ("FAIL: first ftello returned %ld, expected 0\n", o);
+      result = 1;
+    }
+  fclose (fp);
+
+  /* Writing any data shall start at current position and shall not pass
+     current buffer size beyond the size in fmemopen call.  */
+  fp = fmemopen (buf, nbuf, "w");
+  if (fp == NULL)
+    {
+      printf ("FAIL: second fmemopen failed (%s)\n", __FUNCTION__);
+      return 1;
+    }
+
+  static const char str[] = "hello world";
+  /* Because of buffering, the fputs call itself will not fail. However the
+     final buffer should be not changed because length 0 was passed to the
+     fmemopen call.  */
+  fputs (str, fp);
+  r = 0;
+  errno = 0;
+  if (fflush (fp) != EOF)
+    {
+      printf ("FAIL: fflush did not return EOF\n");
+      fclose (fp);
+      return 1;
+    }
+  if (errno != ENOSPC)
+    {
+      printf ("FAIL: errno is %i (expected ENOSPC)\n", errno);
+      fclose (fp);
+      return 1;
+    }
+
+  fclose (fp);
+
+  if (strcmp (buf, BUFCONTENTS) != 0)
+    {
+      printf ("FAIL: strcmp (%s, %s) failed\n", buf, BUFCONTENTS);
+      return 1;
+    }
+
+  /* Different than 'w' mode, 'w+' truncates the buffer.  */
+  fp = fmemopen (buf, nbuf, "w+");
+  if (fp == NULL)
+    {
+      printf ("FAIL: third fmemopen failed (%s)\n", __FUNCTION__);
+      return 1;
+    }
+
+  fclose (fp);
+
+  if (strcmp (buf, "") != 0)
+    {
+      printf ("FAIL: strcmp (%s, \"\") failed\n", buf);
+      return 1;
+    }
+
+  return result;
+}
+
+static int
+do_test (void)
+{
+  int ret = 0;
+
+  ret += do_test_with_buffer ();
+  ret += do_test_without_buffer ();
+  ret += do_test_length_zero ();
+
+  return ret;
+}
+
 #define TEST_FUNCTION do_test ()
 #include "../test-skeleton.c"