core: New function gpgrt_reallocarray.

* src/init.c (_gpgrt_reallocarray): New.
* src/visibility.c (gpgrt_reallocarray): New.
* src/gpg-error.vers, src/gpg-error.def.in: Add new function.
* src/gpg-error.h.in: Add new interface.
* tests/t-malloc.c: New.
* tests/Makefile.am (TESTS): Add new test.
--

Note that this function is different from the glibc function because
it has an extra parameter which allows to clear the new elements.  A
realloc after a calloc with forgotten memset after it is a common
source of error, thus we introduce this slightly different function.

Signed-off-by: Werner Koch <wk@gnupg.org>

2 files changed, 142 insertions, 1 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 2d199da..be04df3 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -30,7 +30,7 @@ EXTRA_DIST = t-argparse.conf etc/t-argparse.conf
 gpg_error_lib = ../src/libgpg-error.la
 
 TESTS = t-version t-strerror t-syserror t-lock t-printf t-poll t-b64 \
-	t-argparse t-logging t-stringutils
+	t-argparse t-logging t-stringutils t-malloc
 
 AM_CPPFLAGS = -I$(top_builddir)/src $(extra_includes)
 
diff --git a/tests/t-malloc.c b/tests/t-malloc.c
new file mode 100644
index 0000000..be2ec81
--- /dev/null
+++ b/tests/t-malloc.c
@@ -0,0 +1,141 @@
+/* t-malloc.c - Check some malloc functions
+ * Copyright (C) 2020 g10 Code GmbH
+ *
+ * This file is part of Libgpg-error.
+ *
+ * Libgpg-error 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.
+ *
+ * Libgpg-error 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 this program; if not, see <https://www.gnu.org/licenses/>.
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <unistd.h>
+#include <errno.h>
+
+#define PGM "t-malloc"
+#include "t-common.h"
+
+
+static const char *
+my_strusage (int level)
+{
+  const char *p;
+
+  switch (level)
+    {
+    case 9: p = "LGPL-2.1-or-later"; break;
+    case 11: p = PGM; break;
+    default: p = NULL;
+    }
+  return p;
+}
+
+
+static void
+check_reallocarray (void)
+{
+  struct foo_s { const char *a; int b; } *array;
+  size_t n;
+
+  array = gpgrt_calloc (10, sizeof *array);
+  if (!array)
+    die ("%s: malloc failed\n", __func__);
+
+  for (n=0; n < 10; n++)
+    if (array[n].a || array[n].b)
+      fail ("%s: array not cleared at index %zu\n", __func__, n);
+
+  for (n=0; n < 10; n++)
+    {
+      array[n].a = "dummy string";
+      array[n].b = 100+n;
+    }
+
+  array = gpgrt_reallocarray (array, 10, 20, sizeof *array);
+  if (!array)
+    die ("%s: realloc failed\n", __func__);
+
+  for (n=0; n < 10; n++)
+    {
+      if (!array[n].a || strcmp (array[n].a, "dummy string"))
+        fail ("%s: string in realloced array changed at index %zu\n",
+              __func__, n);
+
+      if (array[n].b != 100 + n)
+        fail ("%s: number in realloced array changed at index %zu\n",
+              __func__, n);
+    }
+  for (n=10; n < 20; n++)
+    if (array[n].a || array[n].b)
+      fail ("%s: realloced array not cleared at index %zu\n", __func__, n);
+
+  /* We can't easily check whether the reallocated array does not
+   * iniitialze in the case OLDN is equal or larger to N, so we skip
+   * this.  Let's do a simple shrink test instead.  */
+
+  array = gpgrt_reallocarray (array, 20, 7, sizeof *array);
+  if (!array)
+    die ("%s: realloc (shrinking) failed\n", __func__);
+
+  for (n=0; n < 7; n++)
+    {
+      if (!array[n].a || strcmp (array[n].a, "dummy string"))
+        fail ("%s: string in shrunk array changed at index %zu\n",
+              __func__, n);
+
+      if (array[n].b != 100 + n)
+        fail ("%s: number in shrunk array changed at index %zu\n",
+              __func__, n);
+    }
+
+  xfree (array);
+}
+
+
+int
+main (int argc, char **argv)
+{
+  gpgrt_opt_t opts[] = {
+    ARGPARSE_x  ('v', "verbose", NONE, 0, "Print more diagnostics"),
+    ARGPARSE_s_n('d', "debug", "Flyswatter"),
+    ARGPARSE_end()
+  };
+  gpgrt_argparse_t pargs = { &argc, &argv, 0 };
+
+  gpgrt_set_strusage (my_strusage);
+  gpgrt_log_set_prefix (gpgrt_strusage (11), GPGRT_LOG_WITH_PREFIX);
+
+  while (gpgrt_argparse  (NULL, &pargs, opts))
+    {
+      switch (pargs.r_opt)
+        {
+        case 'v': verbose++; break;
+        case 'd': debug++; break;
+        default : pargs.err = ARGPARSE_PRINT_ERROR; break;
+	}
+    }
+  gpgrt_argparse (NULL, &pargs, NULL);
+
+  show ("testing malloc functions\n");
+
+  check_reallocarray ();
+
+  return !!errorcount;
+}