[Bug sanitizer/80168] [5/6/7 Regression] ICE in make_decl_rtl, at varasm.c:1311 w/ VLA and -fsanitize=address

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80168

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 41047
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41047&action=edit
gcc7-pr80168.patch

Untested fix.  Various comments e.g. in get_bit_range assert that
DECL_BIT_FIELD_REPRESENTATIVE in a VLA structure is guaranteed by construction
to have the same DECL_FIELD_OFFSET, so even when during low gimple they are not
the same, we should be able to use the 3rd COMPONENT_REF arguments from the
original field and the DECL_FIELD_BIT_OFFSET difference should give the actual
start differences between the field and its representative.