malloc: Add realloc test.

The current tests don't test the functionality of realloc in detail.
Add a new test for realloc that exercises some of the corner cases
that are not otherwise tested.

ChangeLog:

2013-09-09  Will Newton  <will.newton@linaro.org>

	* malloc/Makefile: Add tst-realloc to tests.
	* malloc/tst-realloc.c: New file.

2 files changed, 148 insertions, 1 deletions

diff --git a/malloc/Makefile b/malloc/Makefile
index 0fe31a4..b16dac8 100644
--- a/malloc/Makefile
+++ b/malloc/Makefile
@@ -25,7 +25,8 @@ all:
 dist-headers := malloc.h
 headers := $(dist-headers) obstack.h mcheck.h
 tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \
-	 tst-mallocstate tst-mcheck tst-mallocfork tst-trim1 tst-malloc-usable
+	 tst-mallocstate tst-mcheck tst-mallocfork tst-trim1 \
+	 tst-malloc-usable tst-realloc
 test-srcs = tst-mtrace
 
 routines = malloc morecore mcheck mtrace obstack
diff --git a/malloc/tst-realloc.c b/malloc/tst-realloc.c
new file mode 100644
index 0000000..9d290d2
--- /dev/null
+++ b/malloc/tst-realloc.c
@@ -0,0 +1,146 @@
+/* Copyright (C) 2013 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 <errno.h>
+#include <malloc.h>
+#include <stdio.h>
+#include <string.h>
+
+static int errors = 0;
+
+static void
+merror (const char *msg)
+{
+  ++errors;
+  printf ("Error: %s\n", msg);
+}
+
+static int
+do_test (void)
+{
+  void *p;
+  unsigned char *c;
+  int save, i, ok;
+
+  errno = 0;
+
+  /* realloc (NULL, ...) behaves similarly to malloc (C89).  */
+  p = realloc (NULL, -1);
+  save = errno;
+
+  if (p != NULL)
+    merror ("realloc (NULL, -1) succeeded.");
+
+  /* errno should be set to ENOMEM on failure (POSIX).  */
+  if (p == NULL && save != ENOMEM)
+    merror ("errno is not set correctly");
+
+  errno = 0;
+
+  /* realloc (NULL, ...) behaves similarly to malloc (C89).  */
+  p = realloc (NULL, 10);
+  save = errno;
+
+  if (p == NULL)
+    merror ("realloc (NULL, 10) failed.");
+
+  /* errno should be clear on success (POSIX).  */
+  if (p != NULL && save != 0)
+    merror ("errno is set but should not be");
+
+  free (p);
+
+  p = calloc (20, 1);
+  if (p == NULL)
+    merror ("calloc (20, 1) failed.");
+
+  /* Check increasing size preserves contents (C89).  */
+  p = realloc (p, 200);
+  if (p == NULL)
+    merror ("realloc (p, 200) failed.");
+
+  c = p;
+  ok = 1;
+
+  for (i = 0; i < 20; i++)
+    {
+      if (c[i] != 0)
+	ok = 0;
+    }
+
+  if (ok == 0)
+	merror ("first 20 bytes were not cleared");
+
+  free (p);
+
+  p = realloc (NULL, 100);
+  if (p == NULL)
+    merror ("realloc (NULL, 100) failed.");
+
+  memset (p, 0xff, 100);
+
+  /* Check decreasing size preserves contents (C89).  */
+  p = realloc (p, 16);
+  if (p == NULL)
+    merror ("realloc (p, 16) failed.");
+
+  c = p;
+  ok = 1;
+
+  for (i = 0; i < 16; i++)
+    {
+      if (c[i] != 0xff)
+	ok = 0;
+    }
+
+  if (ok == 0)
+	merror ("first 16 bytes were not correct");
+
+  /* Check failed realloc leaves original untouched (C89).  */
+  c = realloc (p, -1);
+  if (c != NULL)
+    merror ("realloc (p, -1) succeeded.");
+
+  c = p;
+  ok = 1;
+
+  for (i = 0; i < 16; i++)
+    {
+      if (c[i] != 0xff)
+	ok = 0;
+    }
+
+  if (ok == 0)
+	merror ("first 16 bytes were not correct after failed realloc");
+
+  /* realloc (p, 0) frees p (C89) and returns NULL (glibc).  */
+  p = realloc (p, 0);
+  if (p != NULL)
+    merror ("realloc (p, 0) returned non-NULL.");
+
+  /* realloc (NULL, 0) acts like malloc (0) (glibc).  */
+  p = realloc (NULL, 0);
+  if (p == NULL)
+    merror ("realloc (NULL, 0) returned NULL.");
+
+  free (p);
+
+  return errors != 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"