support: Add TEST_COMPARE_BLOB, support_quote_blob

The declaration of support_test_compare_blob uses unsigned long int,
to avoid including <stddef.h>.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 76 insertions, 0 deletions

diff --git a/support/support_test_compare_blob.c b/support/support_test_compare_blob.c
new file mode 100644
index 0000000000..c5e63d1b93
--- /dev/null
+++ b/support/support_test_compare_blob.c
@@ -0,0 +1,76 @@
+/* Check two binary blobs for equality.
+   Copyright (C) 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 <support/check.h>
+#include <support/support.h>
+#include <support/xmemstream.h>
+
+static void
+report_length (const char *what, unsigned long int length, const char *expr)
+{
+  printf ("  %s %lu bytes (from %s)\n", what, length, expr);
+}
+
+static void
+report_blob (const char *what, const unsigned char *blob,
+             unsigned long int length, const char *expr)
+{
+  if (length > 0)
+    {
+      printf ("  %s (evaluated from %s):\n", what, expr);
+      char *quoted = support_quote_blob (blob, length);
+      printf ("      \"%s\"\n", quoted);
+      free (quoted);
+
+      fputs ("     ", stdout);
+      for (unsigned long i = 0; i < length; ++i)
+        printf (" %02X", blob[i]);
+      putc ('\n', stdout);
+    }
+}
+
+void
+support_test_compare_blob (const void *left, unsigned long int left_length,
+                           const void *right, unsigned long int right_length,
+                           const char *file, int line,
+                           const char *left_expr, const char *left_len_expr,
+                           const char *right_expr, const char *right_len_expr)
+{
+  /* No differences are possible if both lengths are null.  */
+  if (left_length == 0 && right_length == 0)
+    return;
+
+  if (left_length != right_length || left == NULL || right == NULL
+      || memcmp (left, right, left_length) != 0)
+    {
+      support_record_failure ();
+      printf ("%s:%d: error: blob comparison failed\n", file, line);
+      if (left_length == right_length)
+        printf ("  blob length: %lu bytes\n", left_length);
+      else
+        {
+          report_length ("left length: ", left_length, left_len_expr);
+          report_length ("right length:", right_length, right_len_expr);
+        }
+      report_blob ("left", left, left_length, left_expr);
+      report_blob ("right", right, right_length, right_expr);
+    }
+}