[Bug middle-end/94303] [8/9 Regression] Program result error When using global object array (partially initialized with a special constructor, and the rest with the default constructor)

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94303

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:56407bab53a514ffcd6ac011965cebdc5eb3ef54

commit r9-8471-g56407bab53a514ffcd6ac011965cebdc5eb3ef54
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue Apr 7 20:59:37 2020 +0200

    varasm: Fix output_constructor where a RANGE_EXPR index needs to skip some
elts [PR94303]

    The following testcase is miscompiled, because output_constructor doesn't
    output the initializer correctly.  The FE creates {[1...2] = 9} in this
    case, and we emit .long 9; long 9; .zero 8 instead of the expected
    .zero 8; .long 9; .long 9.  If the CONSTRUCTOR is {[1] = 9, [2] = 9},
    output_constructor_regular_field has code to notice that the current
    location (local->total_bytes) is smaller than the location we want to write
    to (1*sizeof(elt)) and will call assemble_zeros to skip those.  But
    RANGE_EXPRs are handled by a different function which didn't do this,
    so for RANGE_EXPRs we emitted them properly only if local->total_bytes
    was always equal to the location where the RANGE_EXPR needs to start.

    2020-03-25  Jakub Jelinek  <jakub@redhat.com>

            PR middle-end/94303
            * varasm.c (output_constructor_array_range): If local->index
            RANGE_EXPR doesn't start at the current location in the
constructor,
            skip needed number of bytes using assemble_zeros or assert we don't
            go backwards.

            PR middle-end/94303
            * g++.dg/torture/pr94303.C: New test.