Re: [PATCH] [PR77760] [libstdc++] encode __time_get_state in tm

[Alexandre Oliva <oliva@adacore.com>]

On Feb 22, 2023, Alexandre Oliva <oliva@adacore.com> wrote:

>> Just curious, why doesn't the pmf hack work on arm-vxworks7?

> At first, I thought we were running into this just because we have to
> define __clang__ because of some vxworks system headers aimed at clang.
> But even as I tried to drop the #ifndef, the test still failed; I
> suspected it had to do with ARM's encoding of ptrmemfunc_vbit_in_delta,
> but I did not confirm that this was the case.

It was much simpler than that: patching locale_facets_nonio.tcc did not
affect the code generated for the tests, even though the modified
definition was present in the preprocessed version, and the patch didn't
cause locale-inst.o to be rebuilt.


With a build from scratch, the following patchlet is enough for time_get
tests to pass for us, and I assume we'll have to keep on carrying such
local changes, but I wonder if it would make sense to submit a patch to
adjust all preprocessor tests for __clang__ in libstdc++ to also test
for __clang_major__.

--- a/libstdc++-v3/include/bits/locale_facets_nonio.tcc
+++ b/libstdc++-v3/include/bits/locale_facets_nonio.tcc
@@ -1465,7 +1465,7 @@ _GLIBCXX_END_NAMESPACE_LDBL_OR_CXX11
       ctype<_CharT> const& __ctype = use_facet<ctype<_CharT> >(__loc);
       __err = ios_base::goodbit;
       bool __use_state = false;
-#if __GNUC__ >= 5 && !defined(__clang__)
+#if __GNUC__ >= 5 && !(defined(__clang__) && defined(__clang_major__))
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wpmf-conversions"
       // Nasty hack.  The C++ standard mandates that get invokes the do_get


-- 
Alexandre Oliva, happy hacker                https://FSFLA.org/blogs/lxo/
   Free Software Activist                       GNU Toolchain Engineer
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