Re: [PATCH 2/7] stdlib: Simplify getenv

[Wilco Dijkstra <Wilco.Dijkstra@arm.com>]

Hi Adhemerval,

+  size_t len = __strchrnul (name, '=') - name;

This is a change in behaviour, ignoring anything behind a '=' in name. What is
wrong with strlen?

+  for (char **ep = __environ; *ep != NULL; ++ep)
     {
-      size_t len = strlen (name);
-#if _STRING_ARCH_unaligned
-      name_start = *(const uint16_t *) name;
-#else
-      name_start = (((const unsigned char *) name)[0]
-                   | (((const unsigned char *) name)[1] << 8));
-#endif
-      len -= 2;
-      name += 2;
-
-      for (ep = __environ; *ep != NULL; ++ep)
-       {
-#if _STRING_ARCH_unaligned
-         uint16_t ep_start = *(uint16_t *) *ep;
-#else
-         uint16_t ep_start = (((unsigned char *) *ep)[0]
-                              | (((unsigned char *) *ep)[1] << 8));
-#endif
-
-         if (name_start == ep_start && !strncmp (*ep + 2, name, len)
-             && (*ep)[len + 2] == '=')
-           return &(*ep)[len + 3];
-       }
+      if (strncmp (name, *ep, len) == 0 && (*ep)[len] == '=')
+       return *ep + len + 1;

It's still useful to keep a check for the first character, eg. name[0] == (*ep)[0] as this
is about twice as fast as always calling strncmp.

Cheers,
Wilco