Avoid use of "register" as optimization hint.

[thirdparty/glibc.git] / stdlib / setenv.c

diff --git a/stdlib/setenv.c b/stdlib/setenv.c
index 48aaecffe06fbb092f3d86241958140ebfa5b46a..fdcd8e1d080fc7d72adc5460c94b99917719cffd 100644 (file)
--- a/stdlib/setenv.c
+++ b/stdlib/setenv.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1992,1995-2001,2004 Free Software Foundation, Inc.
+/* Copyright (C) 1992-2013 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
@@ -12,9 +12,8 @@
    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, write to the Free
-   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-   02111-1307 USA.  */
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
 
 #if HAVE_CONFIG_H
 # include <config.h>
@@ -113,8 +112,8 @@ __add_to_environ (name, value, combined, replace)
      const char *combined;
      int replace;
 {
-  register char **ep;
-  register size_t size;
+  char **ep;
+  size_t size;
   const size_t namelen = strlen (name);
   const size_t vallen = value != NULL ? strlen (value) + 1 : 0;
 
@@ -136,6 +135,7 @@ __add_to_environ (name, value, combined, replace)
 
   if (ep == NULL || __builtin_expect (*ep == NULL, 1))
     {
+      const size_t varlen = namelen + 1 + vallen;
       char **new_environ;
 
       /* We allocated this space; we can extend it.  */
@@ -156,11 +156,21 @@ __add_to_environ (name, value, combined, replace)
        {
          /* See whether the value is already known.  */
 #ifdef USE_TSEARCH
-# ifdef __GNUC__
-         char new_value[namelen + 1 + vallen];
-# else
-         char *new_value = (char *) alloca (namelen + 1 + vallen);
-# endif
+         char *new_value;
+         int use_alloca = __libc_use_alloca (varlen);
+         if (__builtin_expect (use_alloca, 1))
+           new_value = (char *) alloca (varlen);
+         else
+           {
+             new_value = malloc (varlen);
+             if (new_value == NULL)
+               {
+                 UNLOCK;
+                 if (last_environ == NULL)
+                   free (new_environ);
+                 return -1;
+               }
+           }
 # ifdef _LIBC
          __mempcpy (__mempcpy (__mempcpy (new_value, name, namelen), "=", 1),
                     value, vallen);
@@ -174,21 +184,28 @@ __add_to_environ (name, value, combined, replace)
          if (__builtin_expect (new_environ[size] == NULL, 1))
 #endif
            {
-             new_environ[size] = (char *) malloc (namelen + 1 + vallen);
-             if (__builtin_expect (new_environ[size] == NULL, 0))
+#ifdef USE_TSEARCH
+             if (__builtin_expect (! use_alloca, 0))
+               new_environ[size] = new_value;
+             else
+#endif
                {
-                 __set_errno (ENOMEM);
-                 UNLOCK;
-                 return -1;
-               }
+                 new_environ[size] = (char *) malloc (varlen);
+                 if (__builtin_expect (new_environ[size] == NULL, 0))
+                   {
+                     UNLOCK;
+                     return -1;
+                   }
 
 #ifdef USE_TSEARCH
-             memcpy (new_environ[size], new_value, namelen + 1 + vallen);
+                 memcpy (new_environ[size], new_value, varlen);
 #else
-             memcpy (new_environ[size], name, namelen);
-             new_environ[size][namelen] = '=';
-             memcpy (&new_environ[size][namelen + 1], value, vallen);
+                 memcpy (new_environ[size], name, namelen);
+                 new_environ[size][namelen] = '=';
+                 memcpy (&new_environ[size][namelen + 1], value, vallen);
 #endif
+               }
+
              /* And save the value now.  We cannot do this when we remove
                 the string since then we cannot decide whether it is a
                 user string or not.  */
@@ -213,12 +230,21 @@ __add_to_environ (name, value, combined, replace)
        np = (char *) combined;
       else
        {
+         const size_t varlen = namelen + 1 + vallen;
 #ifdef USE_TSEARCH
-# ifdef __GNUC__
-         char new_value[namelen + 1 + vallen];
-# else
-         char *new_value = (char *) alloca (namelen + 1 + vallen);
-# endif
+         char *new_value;
+         int use_alloca = __libc_use_alloca (varlen);
+         if (__builtin_expect (use_alloca, 1))
+           new_value = (char *) alloca (varlen);
+         else
+           {
+             new_value = malloc (varlen);
+             if (new_value == NULL)
+               {
+                 UNLOCK;
+                 return -1;
+               }
+           }
 # ifdef _LIBC
          __mempcpy (__mempcpy (__mempcpy (new_value, name, namelen), "=", 1),
                     value, vallen);
@@ -232,20 +258,27 @@ __add_to_environ (name, value, combined, replace)
          if (__builtin_expect (np == NULL, 1))
 #endif
            {
-             np = malloc (namelen + 1 + vallen);
-             if (__builtin_expect (np == NULL, 0))
+#ifdef USE_TSEARCH
+             if (__builtin_expect (! use_alloca, 0))
+               np = new_value;
+             else
+#endif
                {
-                 UNLOCK;
-                 return -1;
-               }
+                 np = malloc (varlen);
+                 if (__builtin_expect (np == NULL, 0))
+                   {
+                     UNLOCK;
+                     return -1;
+                   }
 
 #ifdef USE_TSEARCH
-             memcpy (np, new_value, namelen + 1 + vallen);
+                 memcpy (np, new_value, varlen);
 #else
-             memcpy (np, name, namelen);
-             np[namelen] = '=';
-             memcpy (&np[namelen + 1], value, vallen);
+                 memcpy (np, name, namelen);
+                 np[namelen] = '=';
+                 memcpy (&np[namelen + 1], value, vallen);
 #endif
+               }
              /* And remember the value.  */
              STORE_VALUE (np);
            }
@@ -292,19 +325,20 @@ unsetenv (name)
   LOCK;
 
   ep = __environ;
-  while (*ep != NULL)
-    if (!strncmp (*ep, name, len) && (*ep)[len] == '=')
-      {
-       /* Found it.  Remove this pointer by moving later ones back.  */
-       char **dp = ep;
-
-       do
-         dp[0] = dp[1];
-       while (*dp++);
-       /* Continue the loop in case NAME appears again.  */
-      }
-    else
-      ++ep;
+  if (ep != NULL)
+    while (*ep != NULL)
+      if (!strncmp (*ep, name, len) && (*ep)[len] == '=')
+       {
+         /* Found it.  Remove this pointer by moving later ones back.  */
+         char **dp = ep;
+
+         do
+           dp[0] = dp[1];
+         while (*dp++);
+         /* Continue the loop in case NAME appears again.  */
+       }
+      else
+       ++ep;
 
   UNLOCK;