[google] Handle NULL return values in setlocale calls (issue4444046)

Jing Yu jingyu@google.com
Sun Apr 17 01:18:00 GMT 2011


Thanks Diego for committing this patch.

Yes, I would like to submit the patch to trunk. The reason is for this
patch is that setlocale() in bionicC always returns NULL (bionicC does
not support setlocale()), however libstdc++ does not handle the NULL
return value of setlocale(xxx,NULL) and thus causes segmentation
fault.

Thanks,
Jing

On Sat, Apr 16, 2011 at 1:20 PM, Diego Novillo <dnovillo@google.com> wrote:
> I'm committing this patch for Jing Yu on google/main.
>
> The patch handles NULL values returned from setlocale.  Jing, could
> you please describe why this was needed?  Is this a patch that you
> will want to submit for trunk?
>
> Tested on x86_64.  Committed to google/main.
>
>
> Diego.
>
> 2011-04-15  Jing Yu  <jingyu@google.com>
>
>        Google ref 46499.
>
>        * config/locale/generic/c_locale.cc (__convert_to_v): Handle
>        NULL return value from setlocale.
>        * config/locale/generic/c_locale.h (__convert_from_v): Likewise.
>        * config/locale/generic/time_members.cc (_M_put): Likewise.
>
> diff --git a/libstdc++-v3/config/locale/generic/c_locale.cc b/libstdc++-v3/config/locale/generic/c_locale.cc
> index fb9b425..7e34fcf 100644
> --- a/libstdc++-v3/config/locale/generic/c_locale.cc
> +++ b/libstdc++-v3/config/locale/generic/c_locale.cc
> @@ -52,10 +52,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>     {
>       // Assumes __s formatted for "C" locale.
>       char* __old = setlocale(LC_ALL, 0);
> -      const size_t __len = strlen(__old) + 1;
> -      char* __sav = new char[__len];
> -      memcpy(__sav, __old, __len);
> -      setlocale(LC_ALL, "C");
> +      char* __sav = NULL;
> +      if (__old != NULL)
> +        {
> +          const size_t __len = strlen(__old) + 1;
> +          __sav = new char[__len];
> +          memcpy(__sav, __old, __len);
> +          setlocale(LC_ALL, "C");
> +        }
>       char* __sanity;
>       bool __overflow = false;
>
> @@ -117,10 +121,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>     {
>       // Assumes __s formatted for "C" locale.
>       char* __old = setlocale(LC_ALL, 0);
> -      const size_t __len = strlen(__old) + 1;
> -      char* __sav = new char[__len];
> -      memcpy(__sav, __old, __len);
> -      setlocale(LC_ALL, "C");
> +      char* __sav = NULL;
> +      if (__old != NULL)
> +        {
> +          const size_t __len = strlen(__old) + 1;
> +          __sav = new char[__len];
> +          memcpy(__sav, __old, __len);
> +          setlocale(LC_ALL, "C");
> +        }
>       char* __sanity;
>
>  #if !__DBL_HAS_INFINITY__
> @@ -162,10 +170,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>     {
>       // Assumes __s formatted for "C" locale.
>       char* __old = setlocale(LC_ALL, 0);
> -      const size_t __len = strlen(__old) + 1;
> -      char* __sav = new char[__len];
> -      memcpy(__sav, __old, __len);
> -      setlocale(LC_ALL, "C");
> +      char* __sav = NULL;
> +      if (__old != NULL)
> +        {
> +          const size_t __len = strlen(__old) + 1;
> +          __sav = new char[__len];
> +          memcpy(__sav, __old, __len);
> +          setlocale(LC_ALL, "C");
> +        }
>
>  #if !__LDBL_HAS_INFINITY__
>       errno = 0;
> diff --git a/libstdc++-v3/config/locale/generic/c_locale.h b/libstdc++-v3/config/locale/generic/c_locale.h
> index 2c76000..6e6f673 100644
> --- a/libstdc++-v3/config/locale/generic/c_locale.h
> +++ b/libstdc++-v3/config/locale/generic/c_locale.h
> @@ -60,7 +60,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>   {
>     char* __old = std::setlocale(LC_NUMERIC, 0);
>     char* __sav = 0;
> -    if (__builtin_strcmp(__old, "C"))
> +    if (__old != NULL && __builtin_strcmp(__old, "C"))
>       {
>        const size_t __len = __builtin_strlen(__old) + 1;
>        __sav = new char[__len];
> diff --git a/libstdc++-v3/config/locale/generic/time_members.cc b/libstdc++-v3/config/locale/generic/time_members.cc
> index 3031075..fb9eb6e 100644
> --- a/libstdc++-v3/config/locale/generic/time_members.cc
> +++ b/libstdc++-v3/config/locale/generic/time_members.cc
> @@ -45,10 +45,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>           const tm* __tm) const throw()
>     {
>       char* __old = setlocale(LC_ALL, 0);
> -      const size_t __llen = strlen(__old) + 1;
> -      char* __sav = new char[__llen];
> -      memcpy(__sav, __old, __llen);
> -      setlocale(LC_ALL, _M_name_timepunct);
> +      char* __sav = NULL;
> +      if (__old != NULL)
> +        {
> +          const size_t __llen = strlen(__old) + 1;
> +          __sav = new char[__llen];
> +          memcpy(__sav, __old, __llen);
> +          setlocale(LC_ALL, _M_name_timepunct);
> +        }
>       const size_t __len = strftime(__s, __maxlen, __format, __tm);
>       setlocale(LC_ALL, __sav);
>       delete [] __sav;
> @@ -130,10 +134,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>           const tm* __tm) const throw()
>     {
>       char* __old = setlocale(LC_ALL, 0);
> -      const size_t __llen = strlen(__old) + 1;
> -      char* __sav = new char[__llen];
> -      memcpy(__sav, __old, __llen);
> -      setlocale(LC_ALL, _M_name_timepunct);
> +      char* __sav = NULL;
> +      if (__old != NULL)
> +        {
> +          const size_t __llen = strlen(__old) + 1;
> +          __sav = new char[__llen];
> +          memcpy(__sav, __old, __llen);
> +          setlocale(LC_ALL, _M_name_timepunct);
> +        }
>       const size_t __len = wcsftime(__s, __maxlen, __format, __tm);
>       setlocale(LC_ALL, __sav);
>       delete [] __sav;
>
>
> --
> This patch is available for review at http://codereview.appspot.com/4444046
>



More information about the Libstdc++ mailing list