Re: [PATCH] docs: Suggest options to improve ASAN stack traces

[Marek Polacek <polacek@redhat.com>]

On Thu, Dec 08, 2022 at 08:25:26AM +0100, Florian Weimer wrote:
> * Marek Polacek via Gcc-patches:
> 
> > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> > index 726392409b6..2de14466dd3 100644
> > --- a/gcc/doc/invoke.texi
> > +++ b/gcc/doc/invoke.texi
> > @@ -16510,6 +16510,14 @@ The option cannot be combined with @option{-fsanitize=thread} or
> >  @option{-fsanitize=hwaddress}.  Note that the only target
> >  @option{-fsanitize=hwaddress} is currently supported on is AArch64.
> >  
> > +To get more accurate stack traces, it is possible to use options such as
> > +@option{-O} (which, for instance, prevents most function inlining),
> > +@option{-fno-optimize-sibling-calls} (which prevents optimizing sibling
> > +and tail recursive calls), or @option{-fno-ipa-icf} (which disables Identical
> > +Code Folding for functions and read-only variables).  Since multiple runs
> > +of the program may yield backtraces with different addresses due to ASLR,
> > +it may be desirable to turn off ASLR: @samp{setarch `uname -m` -R ./prog}.
> 
> What about -fasynchronous-unwind-tables?  It should help if ASAN ever
> reports stray segmentation faults.  Whether it also helps in general
> depends on whether ASAN maintains ABI around its instrumentation.

I'm not sure.  Someone else will have to decide if we want to mention
that option as well.

Marek