From 7fffbdfff7d39cec0783e5b9381fa4093484c235 Mon Sep 17 00:00:00 2001 From: 2012-12-27 Bruno Haible Date: Thu, 27 Dec 2012 22:37:39 +0100 Subject: BZ#14317: Optimze __xpg_strerror_r [BZ #14317] * string/xpg-strerror.c (__xpg_strerror_r): Optimize, call strlen only if needed. --- string/xpg-strerror.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) (limited to 'string') diff --git a/string/xpg-strerror.c b/string/xpg-strerror.c index 7e46b33183..73600fb6a2 100644 --- a/string/xpg-strerror.c +++ b/string/xpg-strerror.c @@ -1,5 +1,4 @@ -/* Copyright (C) 1991, 1993, 1995-1998, 2000, 2002, 2004, 2010, 2011 - Free Software Foundation, Inc. +/* Copyright (C) 1991-2012 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 @@ -28,20 +27,27 @@ int __xpg_strerror_r (int errnum, char *buf, size_t buflen) { const char *estr = __strerror_r (errnum, buf, buflen); - size_t estrlen = strlen (estr); + /* We know that __strerror_r returns buf (with a dynamically computed + string) if errnum is invalid, otherwise it returns a string whose + storage has indefinite extent. */ if (estr == buf) { assert (errnum < 0 || errnum >= _sys_nerr_internal || _sys_errlist_internal[errnum] == NULL); return EINVAL; } - assert (errnum >= 0 && errnum < _sys_nerr_internal - && _sys_errlist_internal[errnum] != NULL); + else + { + assert (errnum >= 0 && errnum < _sys_nerr_internal + && _sys_errlist_internal[errnum] != NULL); + + size_t estrlen = strlen (estr); - /* Terminate the string in any case. */ - if (buflen > 0) - *((char *) __mempcpy (buf, estr, MIN (buflen - 1, estrlen))) = '\0'; + /* Terminate the string in any case. */ + if (buflen > 0) + *((char *) __mempcpy (buf, estr, MIN (buflen - 1, estrlen))) = '\0'; - return buflen <= estrlen ? ERANGE : 0; + return buflen <= estrlen ? ERANGE : 0; + } } -- cgit 1.4.1