new ubsan handler

[Martin Uecker]

Am Montag, dem 19.12.2022 um 15:22 +0100 schrieb Martin Liška:
> On 12/19/22 10:25, Martin Uecker wrote:
> > Am Montag, dem 19.12.2022 um 09:44 +0100 schrieb Martin Liška:
> > > On 12/17/22 20:35, Martin Uecker wrote:
> > > > 
> > > > 
> > > > Hi all,
> > > > 
> > > > what is the process for adding a new UBsan handler?
> > > 
> > > Hello.
> > > 
> > > Yes, we sync the run-time library from LLVM project. So a new
> > > sanitizer
> > > should go there first.
> > > 
> > > > 
> > > > We have the source in the GCC tree, but I guess this
> > > > should go via LLVM?
> > > 
> > > And the compiler support (instrumentation) is independent.
> > 
> > Thanks Martin!
> > 
> > Does it make sense to send the full patch (with changes
> > to the compiler and library) to gcc-patches first for
> > review?
> 
> Yep, please CC me.
> 
> > 
> > I am working on a patch that calls a handler when bounds
> > for VM-types do not match on assignment.
> 
> Nice. So basically something like -fsanitize=bounds/bounds-
> strict/object-size ?

Yes, it would diagnose the following mismatch
and other similar cases:

int a[10];
int n = 5;
char (*p)[n] = &a;


Martin