1 files changed, 132 insertions, 0 deletions
diff --git a/gnulib-tests/test-memchr.c b/gnulib-tests/test-memchr.c
new file mode 100644
index 0000000..ab8d2c0
--- /dev/null
+++ b/gnulib-tests/test-memchr.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2008-2020 Free Software Foundation, Inc.
+ * 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 <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+#include <string.h>
+
+#include "signature.h"
+SIGNATURE_CHECK (memchr, void *, (void const *, int, size_t));
+
+#include <stdlib.h>
+
+#include "zerosize-ptr.h"
+#include "macros.h"
+
+/* Calculating void * + int is not portable, so this wrapper converts
+   to char * to make the tests easier to write.  */
+#define MEMCHR (char *) memchr
+
+int
+main (void)
+{
+  size_t n = 0x100000;
+  char *input = malloc (n);
+  ASSERT (input);
+
+  input[0] = 'a';
+  input[1] = 'b';
+  memset (input + 2, 'c', 1024);
+  memset (input + 1026, 'd', n - 1028);
+  input[n - 2] = 'e';
+  input[n - 1] = 'a';
+
+  /* Basic behavior tests.  */
+  ASSERT (MEMCHR (input, 'a', n) == input);
+
+  ASSERT (MEMCHR (input, 'a', 0) == NULL);
+  ASSERT (MEMCHR (zerosize_ptr (), 'a', 0) == NULL);
+
+  ASSERT (MEMCHR (input, 'b', n) == input + 1);
+  ASSERT (MEMCHR (input, 'c', n) == input + 2);
+  ASSERT (MEMCHR (input, 'd', n) == input + 1026);
+
+  ASSERT (MEMCHR (input + 1, 'a', n - 1) == input + n - 1);
+  ASSERT (MEMCHR (input + 1, 'e', n - 1) == input + n - 2);
+  ASSERT (MEMCHR (input + 1, 0x789abc00 | 'e', n - 1) == input + n - 2);
+
+  ASSERT (MEMCHR (input, 'f', n) == NULL);
+  ASSERT (MEMCHR (input, '\0', n) == NULL);
+
+  /* Check that a very long haystack is handled quickly if the byte is
+     found near the beginning.  */
+  {
+    size_t repeat = 10000;
+    for (; repeat > 0; repeat--)
+      {
+        ASSERT (MEMCHR (input, 'c', n) == input + 2);
+      }
+  }
+
+  /* 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 (MEMCHR (input + i, j, 256) == input + i + j);
+          }
+      }
+  }
+
+  /* Check that memchr() does not read past the first occurrence of the
+     byte being searched.  See the Austin Group's clarification
+     <https://www.opengroup.org/austin/docs/austin_454.txt>.
+     Test both '\0' and something else, since some implementations
+     special-case searching for NUL.
+  */
+  {
+    char *page_boundary = (char *) zerosize_ptr ();
+    /* Too small, and we miss cache line boundary tests; too large,
+       and the test takes cubically longer to complete.  */
+    int limit = 257;
+
+    if (page_boundary != NULL)
+      {
+        for (n = 1; n <= limit; n++)
+          {
+            char *mem = page_boundary - n;
+            memset (mem, 'X', n);
+            ASSERT (MEMCHR (mem, 'U', n) == NULL);
+            ASSERT (MEMCHR (mem, 0, n) == NULL);
+
+            {
+              size_t i;
+              size_t k;
+
+              for (i = 0; i < n; i++)
+                {
+                  mem[i] = 'U';
+                  for (k = i + 1; k < n + limit; k++)
+                    ASSERT (MEMCHR (mem, 'U', k) == mem + i);
+                  mem[i] = 0;
+                  for (k = i + 1; k < n + limit; k++)
+                    ASSERT (MEMCHR (mem, 0, k) == mem + i);
+                  mem[i] = 'X';
+                }
+            }
+          }
+      }
+  }
+
+  free (input);
+
+  return 0;
+}