On Thu, Dec 08, 2022 at 05:56:41PM -0500, Marek Polacek wrote:
> Can't hurt. Here's an updated patch.
>
> -- >8 --
> I got a complaint that while Clang docs suggest options that improve
> the quality of the backtraces ASAN prints (cf.
> <https://clang.llvm.org/docs/AddressSanitizer.html#usage>), our docs
> don't say anything to that effect. This patch amends that with a new
> paragraph. (It deliberately doesn't mention -fno-omit-frame-pointer.)
>
> gcc/ChangeLog:
>
> * doc/invoke.texi (-fsanitize=address): Suggest options to improve
> stack traces.
Ok, thanks.
> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> index 726392409b6..3f2512ce16a 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -16510,6 +16510,16 @@ 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{-O0}, @option{-O1}, or @option{-Og} (which, for instance, prevent
> +most function inlining), @option{-fno-optimize-sibling-calls} (which prevents
> +optimizing sibling and tail recursive calls; this option is implicit for
> +@option{-O0}, @option{-O1}, or @option{-Og}), or @option{-fno-ipa-icf} (which
> +disables Identical Code Folding for functions). Since multiple runs of the
> +program may yield backtraces with different addresses due to ASLR (Address
> +Space Layout Randomization), it may be desirable to turn ASLR off. On Linux,
> +this can be achieved with @samp{setarch `uname -m` -R ./prog}.
> +
> @item -fsanitize=kernel-address
> @opindex fsanitize=kernel-address
> Enable AddressSanitizer for Linux kernel.
Jakub
