On 05/29/2018 01:21 PM, Martin Sebor wrote: > To make review and testing easier (thank you, Franz), attached > is an updated patch rebased on top of today's trunk. > > (Note that the patch intentionally doesn't suppress the warning > for the submitted test case without adding the nonstring attribute.) > > On 05/25/2018 02:59 PM, Martin Sebor wrote: >> Ping: >> https://gcc.gnu.org/ml/gcc-patches/2018-05/msg00869.html >> >> On 05/17/2018 08:01 PM, Martin Sebor wrote: >>> The -Wstringop-truncation and -Wsizeof-pointer-memaccess warnings >>> I added and enhanced, respectively, in GCC 8 are arguably overly >>> strict for source arguments declared with the nonstring attribute. >>> >>> For example, -Wsizeof-pointer-memaccess triggers for the strncat >>> call below: >>> >>> __attribute__ ((nonstring)) char nonstr[8]; >>> extern char *d; >>> strncat (d, nonstr, sizeof nonstr); >>> >>> even though it's still a fairly common (if unsafe) idiom from >>> the early UNIX days (V7 from 1979 to be exact) where strncat >>> was introduced. (This use case, modulo the attribute, was >>> reduced from coreutils.) >>> >>> Simialrly, -Wstringop-truncation warns for some strcat calls that >>> are actually safe, such as in: >>> >>> strcpy (nonstr, "123"); >>> strncat (d, nonstr, 32); >>> >>> To help with the adoption of the warnings and the attribute and >>> avoid unnecessary churn the attached patch relaxes both warnings >>> to accept code like this without diagnostics. >>> >>> The patch doesn't add any new warnings so I'd like it considered >>> for GCC 8 in addition to trunk. >>> >>> Thanks >>> Martin >> > > > gcc-85602.diff > > > PR middle-end/85602 - -Wsizeof-pointer-memaccess for strncat with size of > source > > gcc/c-family/ChangeLog: > > PR middle-end/85602 > * c-warn.c (sizeof_pointer_memaccess_warning): Check for attribute > nonstring. > > gcc/ChangeLog: > > PR middle-end/85602 > * calls.c (maybe_warn_nonstring_arg): Handle strncat. > * tree-ssa-strlen.c (is_strlen_related_p): Make extern. > Handle integer subtraction. > (maybe_diag_stxncpy_trunc): Handle nonstring source arguments. > * tree-ssa-strlen.h (is_strlen_related_p): Declare. > > gcc/testsuite/ChangeLog: > > PR middle-end/85602 > * c-c++-common/attr-nonstring-8.c: New test. I wonder if get_attr_nonstring_decl belongs somewhere other than calls.[ch]. It's really got nothing to do with calls. That might be a followup cleanup.
I suspect some of the hunks need updating now that MPX is gone. In particular you no longer need to worry about _BND calls which should simplify things somewhat. OK for the trunk after updating for MPX removal and re-bootstrapping & testing. jeff
