On Tue, Jun 08, 2021 at 09:42:55AM -0700, Paul Eggert wrote: > For what it's worth I'm more with Bruno on this. For the tests, the cost > of these warnings outweighs the benefit. > > It'd be OK with me to disable the troublesome warnings globally for the > tests subdirectory, using -Wno-missing-prototypes or whatever. > > For the -Wnull-dereference issue it may be worthwhile to use a > circumlocution that fools GCC into not issuing the warning. After all, a > compiler smart enough to warn about '*(volatile int *) 0 = 42' might > also be smart enough to see that it's undefined behavior and therefore > omit the assignment's effect entirely. Perhaps something like the > attached (untested) patch?
> diff --git a/tests/test-sigsegv-catch-stackoverflow2.c > b/tests/test-sigsegv-catch-stackoverflow2.c > index b94d1310b..bfd4617a3 100644 > --- a/tests/test-sigsegv-catch-stackoverflow2.c > +++ b/tests/test-sigsegv-catch-stackoverflow2.c > @@ -50,6 +50,7 @@ sigset_t mainsigset; > > volatile int pass = 0; > uintptr_t page; > +int volatile *null_pointer_to_volatile; > > static void > stackoverflow_handler_continuation (void *arg1, void *arg2, void *arg3) > @@ -183,7 +184,7 @@ main () > *(volatile int *) (page + 0x678) = 42; > break; > case 3: > - *(volatile int *) 0 = 42; > + *null_pointer_to_volatile = 42; > break; > case 4: > break; Thanks, this patch works, I'd definitely prefer applying it rather than disabling -Wnull-dereference. -- ldv
