Optimize and test memrchr.

[gnulib.git] / tests / test-memrchr.c

diff --git a/tests/test-memrchr.c b/tests/test-memrchr.c
new file mode 100644 (file)
index 0000000..84f6c5b
--- /dev/null
+++ b/tests/test-memrchr.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2008 Free Software Foundation
+ * Written by Eric Blake and Bruno Haible
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+#include <string.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#define ASSERT(expr) \
+  do                                                                        \
+    {                                                                       \
+      if (!(expr))                                                          \
+       {                                                                    \
+         fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
+         fflush (stderr);                                                   \
+         abort ();                                                          \
+       }                                                                    \
+    }                                                                       \
+  while (0)
+
+/* Calculating void * + int is not portable, so this wrapper converts
+   to char * to make the tests easier to write.  */
+#define MEMRCHR (char *) memrchr
+
+int
+main ()
+{
+  size_t n = 0x100000;
+  char *input = malloc (n);
+  ASSERT (input);
+
+  input[n - 1] = 'a';
+  input[n - 2] = 'b';
+  memset (input + n - 1026, 'c', 1024);
+  memset (input + 2, 'd', n - 1028);
+  input[1] = 'e';
+  input[0] = 'a';
+
+  /* Basic behavior tests.  */
+  ASSERT (MEMRCHR (input, 'a', n) == input + n - 1);
+
+  ASSERT (MEMRCHR (input, 'a', 0) == NULL);
+  ASSERT (MEMRCHR (NULL, 'a', 0) == NULL);
+
+  ASSERT (MEMRCHR (input, 'b', n) == input + n - 2);
+  ASSERT (MEMRCHR (input, 'c', n) == input + n - 3);
+  ASSERT (MEMRCHR (input, 'd', n) == input + n - 1027);
+
+  ASSERT (MEMRCHR (input, 'a', n - 1) == input);
+  ASSERT (MEMRCHR (input, 'e', n - 1) == input + 1);
+
+  ASSERT (MEMRCHR (input, 'f', n) == NULL);
+  ASSERT (MEMRCHR (input, '\0', n) == NULL);
+
+  /* Check that a very long haystack is handled quickly if the byte is
+     found near the end.  */
+  {
+    size_t repeat = 10000;
+    for (; repeat > 0; repeat--)
+      {
+       ASSERT (MEMRCHR (input, 'c', n) == input + n - 3);
+      }
+  }
+
+  /* Alignment tests.  */
+  {
+    int i, j;
+    for (i = 0; i < 32; i++)
+      {
+       for (j = 0; j < 256; j++)
+         input[i + j] = j;
+       for (j = 0; j < 256; j++)
+         {
+           ASSERT (MEMRCHR (input + i, j, 256) == input + i + j);
+         }
+      }
+  }
+
+  free (input);
+
+  return 0;
+}