Initial commit: libft Part 1 with tests and documentation

Reimplements 24 libc functions with Doxygen-documented header
and test suite comparing against libc.

1 files changed, 279 insertions, 0 deletions

diff --git a/tests/test_cmp.c b/tests/test_cmp.c
new file mode 100644
index 0000000..eea0aea
--- /dev/null
+++ b/tests/test_cmp.c
@@ -0,0 +1,279 @@
+#include "../libft.h"
+#include "test_utils.h"
+
+static void
+_s_ft_memchr_null (void)
+{
+  _s_sink = (size_t)ft_memchr (NULL, 'a', 10);
+}
+static void
+_s_libc_memchr_null (void)
+{
+  _s_sink = (size_t)memchr (NULL, 'a', 10);
+}
+static void
+_s_ft_memcmp_null_s1 (void)
+{
+  _s_sink_i = ft_memcmp (NULL, "abc", 3);
+}
+static void
+_s_libc_memcmp_null_s1 (void)
+{
+  _s_sink_i = memcmp (NULL, "abc", 3);
+}
+static void
+_s_ft_memcmp_null_s2 (void)
+{
+  _s_sink_i = ft_memcmp ("abc", NULL, 3);
+}
+static void
+_s_libc_memcmp_null_s2 (void)
+{
+  _s_sink_i = memcmp ("abc", NULL, 3);
+}
+static void
+_s_ft_strncmp_null_s1 (void)
+{
+  _s_sink_i = ft_strncmp (NULL, "abc", 3);
+}
+static void
+_s_libc_strncmp_null_s1 (void)
+{
+  _s_sink_i = strncmp (NULL, "abc", 3);
+}
+static void
+_s_ft_strncmp_null_s2 (void)
+{
+  _s_sink_i = ft_strncmp ("abc", NULL, 3);
+}
+static void
+_s_libc_strncmp_null_s2 (void)
+{
+  _s_sink_i = strncmp ("abc", NULL, 3);
+}
+
+/* ======================================
+ *  memchr
+ * ====================================== */
+
+static void
+_s_test_memchr (void)
+{
+  char buf[] = "Hello, World!";
+  char all[256];
+  int i;
+  char label[64];
+
+  printf ("-- memchr --\n");
+
+  /* NULL */
+  _s_check_both_crash ("memchr NULL", _s_ft_memchr_null, _s_libc_memchr_null);
+
+  /* find existing char */
+  _s_check ("find 'W'", ft_memchr (buf, 'W', 13) == memchr (buf, 'W', 13));
+
+  /* find first byte */
+  _s_check ("find 'H'", ft_memchr (buf, 'H', 13) == memchr (buf, 'H', 13));
+
+  /* find last byte */
+  _s_check ("find '!'", ft_memchr (buf, '!', 13) == memchr (buf, '!', 13));
+
+  /* not found */
+  _s_check ("not found 'z'",
+            ft_memchr (buf, 'z', 13) == memchr (buf, 'z', 13));
+
+  /* n=0 */
+  _s_check ("n=0", ft_memchr (buf, 'H', 0) == NULL);
+
+  /* char beyond n */
+  _s_check ("beyond n", ft_memchr (buf, '!', 5) == memchr (buf, '!', 5));
+
+  /* search for null byte */
+  _s_check ("find '\\0'", ft_memchr (buf, '\0', 14) == memchr (buf, '\0', 14));
+
+  /* int truncation to unsigned char */
+  _s_check ("int truncation",
+            ft_memchr (buf, 'H' + 256, 13) == memchr (buf, 'H' + 256, 13));
+
+  /* all byte values */
+  for (i = 0; i < 256; i++)
+    all[i] = i;
+  for (i = 0; i < 256; i++)
+    {
+      snprintf (label, sizeof (label), "byte %d", i);
+      _s_check (label, ft_memchr (all, i, 256) == memchr (all, i, 256));
+    }
+
+  /* randomized */
+  srand (time (NULL));
+  for (i = 0; i < 50; i++)
+    {
+      unsigned char rnd[256];
+      int len = rand () % 256 + 1;
+      int c = rand () % 256;
+      int j;
+      for (j = 0; j < len; j++)
+        rnd[j] = rand () % 256;
+      snprintf (label, sizeof (label), "random len=%d c=%d", len, c);
+      _s_check (label, ft_memchr (rnd, c, len) == memchr (rnd, c, len));
+    }
+}
+
+/* ======================================
+ *  memcmp
+ * ====================================== */
+
+static void
+_s_test_memcmp (void)
+{
+  int i;
+  unsigned char a[256];
+  unsigned char b[256];
+  size_t len;
+  int pos;
+  char label[64];
+
+  printf ("-- memcmp --\n");
+
+  /* NULL */
+  _s_check_both_crash ("memcmp NULL s1", _s_ft_memcmp_null_s1,
+                       _s_libc_memcmp_null_s1);
+  _s_check_both_crash ("memcmp NULL s2", _s_ft_memcmp_null_s2,
+                       _s_libc_memcmp_null_s2);
+
+  /* equal */
+  _s_check ("equal", _s_sign (ft_memcmp ("abc", "abc", 3))
+                         == _s_sign (memcmp ("abc", "abc", 3)));
+
+  /* first less */
+  _s_check ("less", _s_sign (ft_memcmp ("abc", "abd", 3))
+                        == _s_sign (memcmp ("abc", "abd", 3)));
+
+  /* first greater */
+  _s_check ("greater", _s_sign (ft_memcmp ("abd", "abc", 3))
+                           == _s_sign (memcmp ("abd", "abc", 3)));
+
+  /* n=0 */
+  _s_check ("n=0", _s_sign (ft_memcmp ("abc", "xyz", 0))
+                       == _s_sign (memcmp ("abc", "xyz", 0)));
+
+  /* difference at last byte */
+  _s_check ("diff at end", _s_sign (ft_memcmp ("abcd", "abce", 4))
+                               == _s_sign (memcmp ("abcd", "abce", 4)));
+
+  /* unsigned comparison: 0 vs 200 */
+  {
+    unsigned char x[] = { 0 };
+    unsigned char y[] = { 200 };
+    _s_check ("unsigned 0 vs 200",
+              _s_sign (ft_memcmp (x, y, 1)) == _s_sign (memcmp (x, y, 1)));
+  }
+
+  /* randomized */
+  srand (time (NULL));
+  for (i = 0; i < 50; i++)
+    {
+      len = rand () % 255 + 1;
+      for (pos = 0; pos < (int)len; pos++)
+        a[pos] = b[pos] = rand () % 256;
+      /* introduce a random difference sometimes */
+      if (i % 2 == 0)
+        {
+          pos = rand () % len;
+          b[pos] = (a[pos] + 1 + rand () % 255) % 256;
+        }
+      snprintf (label, sizeof (label), "random len=%zu", len);
+      _s_check (label, _s_sign (ft_memcmp (a, b, len))
+                           == _s_sign (memcmp (a, b, len)));
+    }
+}
+
+/* ======================================
+ *  strncmp
+ * ====================================== */
+
+static void
+_s_test_strncmp (void)
+{
+  int i;
+  char a[128];
+  char b[128];
+  int len;
+  char label[64];
+
+  printf ("-- strncmp --\n");
+
+  /* NULL */
+  _s_check_both_crash ("strncmp NULL s1", _s_ft_strncmp_null_s1,
+                       _s_libc_strncmp_null_s1);
+  _s_check_both_crash ("strncmp NULL s2", _s_ft_strncmp_null_s2,
+                       _s_libc_strncmp_null_s2);
+
+  /* equal strings */
+  _s_check ("equal", _s_sign (ft_strncmp ("abc", "abc", 3))
+                         == _s_sign (strncmp ("abc", "abc", 3)));
+
+  /* less */
+  _s_check ("less", _s_sign (ft_strncmp ("abc", "abd", 3))
+                        == _s_sign (strncmp ("abc", "abd", 3)));
+
+  /* greater */
+  _s_check ("greater", _s_sign (ft_strncmp ("abd", "abc", 3))
+                           == _s_sign (strncmp ("abd", "abc", 3)));
+
+  /* n=0 */
+  _s_check ("n=0", _s_sign (ft_strncmp ("abc", "xyz", 0))
+                       == _s_sign (strncmp ("abc", "xyz", 0)));
+
+  /* n larger than strings */
+  _s_check ("n > len", _s_sign (ft_strncmp ("abc", "abc", 100))
+                           == _s_sign (strncmp ("abc", "abc", 100)));
+
+  /* difference beyond n */
+  _s_check ("diff beyond n", _s_sign (ft_strncmp ("abcX", "abcY", 3))
+                                 == _s_sign (strncmp ("abcX", "abcY", 3)));
+
+  /* empty strings */
+  _s_check ("both empty",
+            _s_sign (ft_strncmp ("", "", 5)) == _s_sign (strncmp ("", "", 5)));
+
+  /* one empty */
+  _s_check ("s1 empty", _s_sign (ft_strncmp ("", "a", 5))
+                            == _s_sign (strncmp ("", "a", 5)));
+  _s_check ("s2 empty", _s_sign (ft_strncmp ("a", "", 5))
+                            == _s_sign (strncmp ("a", "", 5)));
+
+  /* different lengths, equal prefix */
+  _s_check ("shorter s1", _s_sign (ft_strncmp ("ab", "abc", 5))
+                              == _s_sign (strncmp ("ab", "abc", 5)));
+
+  /* unsigned comparison */
+  _s_check ("unsigned", _s_sign (ft_strncmp ("\xff", "\x01", 1))
+                            == _s_sign (strncmp ("\xff", "\x01", 1)));
+
+  /* randomized */
+  for (i = 0; i < 50; i++)
+    {
+      len = rand () % 64 + 1;
+      for (int j = 0; j < len; j++)
+        a[j] = b[j] = 'A' + rand () % 26;
+      a[len] = '\0';
+      b[len] = '\0';
+      if (i % 2 == 0)
+        b[rand () % len] = 'A' + rand () % 26;
+      snprintf (label, sizeof (label), "random n=%d", len);
+      _s_check (label, _s_sign (ft_strncmp (a, b, len))
+                           == _s_sign (strncmp (a, b, len)));
+    }
+}
+
+int
+main (void)
+{
+  printf ("=== comparison functions ===\n");
+  _s_test_memchr ();
+  _s_test_memcmp ();
+  _s_test_strncmp ();
+  _s_print_results ();
+  return (_s_fail != 0);
+}