On 03/05/2018 01:54 PM, Martin Sebor wrote: > Attribute nonstring is currently only allowed on arrays and > pointers to plain char, but -Wstringop-truncation triggers > even for strncpy calls whose arguments are arrays of signed > or unsigned char (with or without a cast to char*). > > To help deal with -Wstringop-truncation in the Linux kernel > it was suggested to me that it would be useful to be able > to make use of the attribute on all three narrow char types. > Apparently, there are enough calls to strncpy in the Linux > kernel with arguments of the other char types that trigger > the new warning, and the warning is considered sufficiently > useful that making use of the attribute to suppress > the warning rather than changing it ignore the other > two char types is preferable. > > The attached patch relaxes the restriction and lets GCC > accept attribute nonstring on all three narrow character > types as well as their qualified forms. > > Tested on x86_64-linux. > > Martin > > gcc-84725.diff > > > PR tree-optimization/84725 - enable attribute nonstring for all narrow > character types > > gcc/c-family/ChangeLog: > > PR tree-optimization/84725 > * c-attribs.c (handle_nonstring_attribute): Allow attribute nonstring > with all three narrow character types, including their qualified forms. > > gcc/testsuite/ChangeLog: > > PR tree-optimization/84725 > * c-c++-common/Wstringop-truncation-4.c: New test. > * c-c++-common/attr-nonstring-5.c: New test. While it's not a regression, I think getting this warning to a point where it's usable by the linux kernel is a notable win. So I'm going to ACK it as an exception to the regression bugfixes only policy.
jeff
