https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86345

            Bug ID: 86345
           Summary: Likely false warning with -Wstringop-overflow and
                    memset
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sirl at gcc dot gnu.org
  Target Milestone: ---

Created attachment 44335
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44335&action=edit
testcase

The attached testcase warns like this with trunk@262215:

gcc-trunk -c -O2 -Wstringop-overflow test-stringop-overflow.c
test-stringop-overflow.c: In function 'func2':
test-stringop-overflow.c:56:3: warning: 'memset' specified size between
18446744071562067968 and 18446744073709551615 exceeds maximum object size
9223372036854775807 [-Wstringop-overflow=]
   memset ((buf), 0, (len));
   ^~~~~~~~~~~~~~~~~~~~~~~~

This is a relatively new regression on trunk (gcc-8-branch is fine). The code
is quite sensitive to changes, so I didn't reduce it further.

Reply via email to