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

[Florian Weimer <fweimer@redhat.com>]

* 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.

Thanks,
Florian