[Bug libstdc++/92906] [10 regression] FAIL: libstdc++-abi/abi_check

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92906

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:994e0ad41529f5518fd013474a657968807d9ca5

commit r10-6630-g994e0ad41529f5518fd013474a657968807d9ca5
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Fri Feb 14 00:11:24 2020 +0100

    c++: Emit DFP typeinfos even when DFP is disabled [PR92906]

    Before Joseph's changes when compiling
    libstdc++-v3/libsupc++/fundamental_type_info.cc
    we were emitting
    _ZTIPDd, _ZTIPDe, _ZTIPDf, _ZTIPKDd, _ZTIPKDe, _ZTIPKDf, _ZTIDd, _ZTIDe,
_ZTIDf
    symbols even when DFP wasn't usable, but now we don't and thus those 9
    symbols @@CXXABI_1.3.4 are gone from libstdc++.  While nothing could
    probably use it (except perhaps dlsym etc.), various tools don't really
like
    symbols disappearing from symbol versioned shared libraries with stable
ABI.
    Adding those in assembly would be possible, but would be a portability
    nightmare (the PR has something Red Hat uses in libstdc++_nonshared.a, but
that
    can handle only a handful of linux ELF targets we care about).
    So, instead this patch hacks up the FE, so that it emits those, but in a
way
    that won't make the DFP types available again on targets that don't support
    them.

    2020-02-14  Jakub Jelinek  <jakub@redhat.com>

        PR libstdc++/92906
        * cp-tree.h (enum cp_tree_index): Add CPTI_FALLBACK_DFLOAT32_TYPE,
        CPTI_FALLBACK_DFLOAT64_TYPE and CPTI_FALLBACK_DFLOAT128_TYPE.
        (fallback_dfloat32_type, fallback_dfloat64_type,
        fallback_dfloat128_type): Define.
        * mangle.c (write_builtin_type): Handle fallback_dfloat*_type like
        dfloat*_type_node.
        * rtti.c (emit_support_tinfos): Emit DFP typeinfos even when dfp
        is disabled for compatibility.