[Bug target/94891] aarch64: there is no way to strip PAC from a return address in c code

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891

--- Comment #17 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-8 branch has been updated by Szabolcs Nagy <nsz@gcc.gnu.org>:

https://gcc.gnu.org/g:74bffa9a325f7360dc9d105c2fc5719fe45164d3

commit r8-10644-g74bffa9a325f7360dc9d105c2fc5719fe45164d3
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Thu May 28 10:28:30 2020 +0100

    doc: Clarify __builtin_return_address [PR94891]

    The expected semantics and valid usage of __builtin_return_address is
    not clear since it exposes implementation internals that are normally
    not meaningful to portable c code.

    This documentation change tries to clarify the semantics in case the
    return address is stored in a mangled form. This affects AArch64 when
    pointer authentication is used for the return address signing (i.e.
    -mbranch-protection=pac-ret).

    2020-07-13  Szabolcs Nagy  <szabolcs.nagy@arm.com>

    gcc/ChangeLog:

            PR target/94891
            * doc/extend.texi: Update the text for  __builtin_return_address.

    (cherry picked from commit 6a391e06f953c3390b14020d8cacb6d55f81b2b9)