This is the mail archive of the mailing list for the glibc project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: New Tot Build problem with Tot GCC (strncpy warnings)

On Tue, 12 Dec 2017, Steve Ellcey wrote:

> I am not sure if this is due to a GCC change or a glibc change but I am
> still unable to build the ToT glibc with the ToT GCC.  The
> nextafter/nexttoward problem has been fixed, the current errors I get
> are due to strncpy warnings.  I thought we had fixed these but either
> GCC changed or glibc changed and we have some new ones:
> Building glibc on aarch64:
> In file included from nss_files/files-init.c:22:
> nss_files/files-init.c: In function ‘_nss_files_init’:
> ../nscd/nscd.h:111:8: error: ‘strncpy’ output truncated copying 4 bytes
> from a string of length 11 [-Werror=stringop-truncation]
>         strncpy (file->dname, file->fname, len);
>         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

These look like they should be memcpy.  The truncation is intended (it's 
copying a directory name without the trailing '/' and filename in the 
source string), but since the exact amount to copy is known at that point, 
memcpy suffices to express the intent and should avoid the warning.

Joseph S. Myers

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]