Alfie Richards <alfie.richa...@arm.com> writes: > Hi, > > Small fix to resolve an UBSAN diagnostic. > > Reg tested for Aarch64 >
To be sure: checked with bootstrap-ubsan too? (though note that it doesn't error out by default, so you'd need to grep the logs or set UBSAN_OPTIONS to make it error out) > Thanks, > Alfie > > -- >8 -- > > This adds a nullptr check to fix a regression where it is possible to call > `memcmp (NULL, NULL, 0)` which is UB. > > This should fix the bootstrap-ubsan build. I can't approve but LGTM. > > gcc/ChangeLog: > PR middle-end/121261 > * vec.h: Add null ptr check. > --- > gcc/vec.h | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/gcc/vec.h b/gcc/vec.h > index 9604edb1c3c..1277a881f1c 100644 > --- a/gcc/vec.h > +++ b/gcc/vec.h > @@ -2514,6 +2514,10 @@ public: > return false; > if (lhs.size () != rhs.size ()) > return false; > + /* Case where either is a NULL pointer and therefore, as both are valid, > + both are empty slices with length 0. */ > + if (lhs.begin () == NULL || rhs.begin () == NULL) > + return true; > return memcmp (lhs.begin (), rhs.begin (), lhs.size ()) == 0; > }
