On 09/09/2015 03:44 PM, Mark Wielaard wrote:
The following found 14 bugs in my code base. I think it is useful to
warn about such usage since they are bugsr. If the argument is marked
as nonnull then passing in a NULL argument will produce bad results
even if the code checks against NULL.
GCC might optimize such checks away so warn the user when the function
contains such comparisions.
nn.c: In function ‘foo’:
nn.c:6:27: warning: nonnull argument ‘bar’ compared to NULL [-Wnonnull]
void foo(void *bar) { if (!bar) abort(); }
^
gcc/c/ChangeLog
* c-typeck.c (build_binary_op): Check and warn when nonnull arg
parm against NULL.
gcc/cp/ChangeLog
* typeck.c (cp_build_binary_op): Check and warn when nonnull arg
parm against NULL.
gcc/testsuite/ChangeLog
* gcc.dg/nonnull-4.c: New test.
* g++.dg/warn/nonnull3.C: Likewise.
Can you also upate the -Wnonnull documentation in invoke.texi to
indicate it also will warn if it discovers a non-null argument that is
compared against null?
With the doc fix and a bootstrap/regression test, this patch ought to be
fine.
jeff
