[Bug c/94172] [arm-none-eabi] ICE in expand_debug_locations, at cfgexpand.c:5403

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94172

--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-8 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:cac1949a51e25360a7fd7dc8f473997b7ca048a9

commit r8-10470-gcac1949a51e25360a7fd7dc8f473997b7ca048a9
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue Mar 17 22:32:34 2020 +0100

    c: Handle C_TYPE_INCOMPLETE_VARS even for ENUMERAL_TYPEs [PR94172]

    The following testcases ICE, because they contain extern variable
    declarations with incomplete enum types that is later completed and after
    that those variables are accessed.  The ICEs are because the vars then may
have
    incorrect DECL_MODE etc., e.g. in the first case the var has SImode
    DECL_MODE (the guessed mode for the enum), but the enum then actually has
    DImode because its enumerators don't fit into unsigned int.

    The following patch fixes it by using C_TYPE_INCOMPLETE_VARS not just on
    incomplete struct/union types, but also incomplete enum types.
    TYPE_VFIELD can't be used as it is TYPE_MIN_VALUE on ENUMERAL_TYPE,
    thankfully TYPE_LANG_SLOT_1 has been used in the C FE only on
    FUNCTION_TYPEs.

    2020-03-17  Jakub Jelinek  <jakub@redhat.com>

            PR c/94172
            * c-tree.h (C_TYPE_INCOMPLETE_VARS): Define to TYPE_LANG_SLOT_1
            instead of TYPE_VFIELD, and support it on
{RECORD,UNION,ENUMERAL}_TYPE.
            (TYPE_ACTUAL_ARG_TYPES): Check that it is only used on
FUNCTION_TYPEs.
            * c-decl.c (pushdecl): Push C_TYPE_INCOMPLETE_VARS also to
            ENUMERAL_TYPEs.
            (finish_incomplete_vars): New function, moved from finish_struct. 
Use
            relayout_decl instead of layout_decl.
            (finish_struct): Remove obsolete comment about
C_TYPE_INCOMPLETE_VARS
            being TYPE_VFIELD.  Use finish_incomplete_vars.
            (finish_enum): Clear C_TYPE_INCOMPLETE_VARS.  Call
            finish_incomplete_vars.
            * c-typeck.c (c_build_qualified_type): Clear C_TYPE_INCOMPLETE_VARS
            also on ENUMERAL_TYPEs.

            * gcc.dg/pr94172-1.c: New test.
            * gcc.dg/pr94172-2.c: New test.

    (cherry picked from commit 87ce34fa00cd6b87452d747235da40dfe5b6e00f)