[PATCH] sso-string@gnu-versioned-namespace [PR83077]

Iain Sandoe idsandoe@googlemail.com
Mon Oct 9 14:42:37 GMT 2023


Hi François,

> On 7 Oct 2023, at 20:32, François Dumont <frs.dumont@gmail.com> wrote:
> 
> I've been told that previous patch generated with 'git diff -b' was not applying properly so here is the same patch again with a simple 'git diff'.

Thanks, that did fix it - There are some training whitespaces in the config files, but I suspect that they need to be there since those have values appended during the configuration.

Anyway, with this + the coroutines and contract v2 (weak def) fix, plus a local patch to enable versioned namespace on Darwin, I get results comparable with the non-versioned case - but one more patchlet is needed on  yours (to allow for targets using emultated TLS):

diff --git a/libstdc++-v3/config/abi/pre/gnu-versioned-namespace.ver b/libstdc++-v3/config/abi/pre/gnu-versioned-namespace.ver
index 9fab8bead15..b7167fc0c2f 100644
--- a/libstdc++-v3/config/abi/pre/gnu-versioned-namespace.ver
+++ b/libstdc++-v3/config/abi/pre/gnu-versioned-namespace.ver
@@ -78,6 +78,7 @@ GLIBCXX_8.0 {
 
     # thread/mutex/condition_variable/future
     __once_proxy;
+    __emutls_v._ZNSt3__81?__once_call*;
 
     # std::__convert_to_v
     _ZNSt3__814__convert_to_v*;


thanks
Iain

> 
> 
> On 07/10/2023 14:25, François Dumont wrote:
>> Hi
>> 
>> Here is a rebased version of this patch.
>> 
>> There are few test failures when running 'make check-c++' but nothing new.
>> 
>> Still, there are 2 patches awaiting validation to fix some of them, PR c++/111524 to fix another bunch and I fear that we will have to live with the others.
>> 
>>     libstdc++: [_GLIBCXX_INLINE_VERSION] Use cxx11 abi [PR83077]
>> 
>>     Use cxx11 abi when activating versioned namespace mode. To do support
>>     a new configuration mode where !_GLIBCXX_USE_DUAL_ABI and _GLIBCXX_USE_CXX11_ABI.
>> 
>>     The main change is that std::__cow_string is now defined whenever _GLIBCXX_USE_DUAL_ABI
>>     or _GLIBCXX_USE_CXX11_ABI is true. Implementation is using available std::string in
>>     case of dual abi and a subset of it when it's not.
>> 
>>     On the other side std::__sso_string is defined only when _GLIBCXX_USE_DUAL_ABI is true
>>     and _GLIBCXX_USE_CXX11_ABI is false. Meaning that std::__sso_string is a typedef for the
>>     cow std::string implementation when dual abi is disabled and cow string is being used.
>> 
>>     libstdcxx-v3/ChangeLog:
>> 
>>             PR libstdc++/83077
>>             * acinclude.m4 [GLIBCXX_ENABLE_LIBSTDCXX_DUAL_ABI]: Default to "new" libstdcxx abi
>>             when enable_symvers is gnu-versioned-namespace.
>>             * config/locale/dragonfly/monetary_members.cc [!_GLIBCXX_USE_DUAL_ABI]: Define money_base
>>             members.
>>             * config/locale/generic/monetary_members.cc [!_GLIBCXX_USE_DUAL_ABI]: Likewise.
>>             * config/locale/gnu/monetary_members.cc [!_GLIBCXX_USE_DUAL_ABI]: Likewise.
>>             * config/locale/gnu/numeric_members.cc
>>             [!_GLIBCXX_USE_DUAL_ABI](__narrow_multibyte_chars): Define.
>>             * configure: Regenerate.
>>             * include/bits/c++config
>>             [_GLIBCXX_INLINE_VERSION](_GLIBCXX_NAMESPACE_CXX11, _GLIBCXX_BEGIN_NAMESPACE_CXX11):
>>             Define empty.
>> [_GLIBCXX_INLINE_VERSION](_GLIBCXX_END_NAMESPACE_CXX11, _GLIBCXX_DEFAULT_ABI_TAG):
>>             Likewise.
>>             * include/bits/cow_string.h [!_GLIBCXX_USE_CXX11_ABI]: Define a light version of COW
>>             basic_string as __std_cow_string for use in stdexcept.
>>             * include/std/stdexcept [_GLIBCXX_USE_CXX11_ABI]: Define __cow_string.
>>             (__cow_string(const char*)): New.
>>             (__cow_string::c_str()): New.
>>             * python/libstdcxx/v6/printers.py (StdStringPrinter::__init__): Set self.new_string to True
>>             when std::__8::basic_string type is found.
>>             * src/Makefile.am [ENABLE_SYMVERS_GNU_NAMESPACE](ldbl_alt128_compat_sources): Define empty.
>>             * src/Makefile.in: Regenerate.
>>             * src/c++11/Makefile.am (cxx11_abi_sources): Rename into...
>>             (dual_abi_sources): ...this. Also move cow-local_init.cc, cxx11-hash_tr1.cc,
>>             cxx11-ios_failure.cc entries to...
>>             (sources): ...this.
>>             (extra_string_inst_sources): Move cow-fstream-inst.cc, cow-sstream-inst.cc, cow-string-inst.cc,
>>             cow-string-io-inst.cc, cow-wtring-inst.cc, cow-wstring-io-inst.cc, cxx11-locale-inst.cc,
>>             cxx11-wlocale-inst.cc entries to...
>>             (inst_sources): ...this.
>>             * src/c++11/Makefile.in: Regenerate.
>>             * src/c++11/cow-fstream-inst.cc [_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++11/cow-locale_init.cc [_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++11/cow-sstream-inst.cc [_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++11/cow-stdexcept.cc [_GLIBCXX_USE_CXX11_ABI]: Include <bits/cow_string.h>.
>>             [_GLIBCXX_USE_DUAL_ABI || _GLIBCXX_USE_CXX11_ABI](__cow_string): Redefine before
>>             including <stdexcept>. Define _GLIBCXX_DEFINE_STDEXCEPT_INSTANTIATIONS so that
>>             __cow_string definition in <stdexcept> is skipped.
>>             [_GLIBCXX_USE_CXX11_ABI]: Skip Transaction Memory TS definitions.
>>             * src/c++11/string-inst.cc: Add sizeof/alignof static_assert on stdexcept
>>             __cow_string definition.
>>             (_GLIBCXX_DEFINING_CXX11_ABI_INSTANTIATIONS): Define following _GLIBCXX_USE_CXX11_ABI
>>             value.
>>             [_GLIBCXX_USE_CXX11_ABI && !_GLIBCXX_DEFINING_CXX11_ABI_INSTANTIATIONS]:
>>             Define _GLIBCXX_DEFINING_COW_STRING_INSTANTIATIONS. Include <bits/cow_string.h>.
>>             Define basic_string as __std_cow_string for the current translation unit.
>>             * src/c++11/cow-string-inst.cc [_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++11/cow-string-io-inst.cc [_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++11/cow-wstring-inst.cc [_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++11/cow-wstring-io-inst.cc [_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++11/cxx11-hash_tr1.cc [!_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++11/cxx11-ios_failure.cc [!_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             [!_GLIBCXX_USE_DUAL_ABI] (__ios_failure): Remove.
>>             * src/c++11/cxx11-locale-inst.cc: Cleanup, just include locale-inst.cc.
>>             * src/c++11/cxx11-stdexcept.cc [!_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++11/cxx11-wlocale-inst.cc [!_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++11/locale-inst-numeric.h
>> [!_GLIBCXX_USE_DUAL_ABI](std::use_facet<num_get<>>, std::use_facet<num_put<>>): Instantiate.
>> [!_GLIBCXX_USE_DUAL_ABI](std::has_facet<num_get<>>, std::has_facet<num_put<>>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](std::num_get<C, istreambuf_iterator<C>>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](std::num_put<C, ostreambuf_iterator<C>>): Instantiate.
>>             * src/c++11/locale-inst.cc [!_GLIBCXX_USE_DUAL_ABI]: Build only when configured
>>             _GLIBCXX_USE_CXX11_ABI is equal to currently built abi.
>>             [!_GLIBCXX_USE_DUAL_ABI](__moneypunct_cache<C, false>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](__moneypunct_cache<C, true>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](__numpunct_cache<C>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](__timepunct<C>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](__timepunct_cache<C>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](time_put<C, ostreambuf_iterator<C>>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](time_put_byname<C, ostreambuf_iterator<C>>): Instantiate.
>> [!_GLIBCXX_USE_DUAL_ABI](__ctype_abstract_base<C>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](ctype_byname<C>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](__codecvt_abstract_base<C, char, mbstate_t>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](codecvt_byname<C, char, mbstate_t>): Instantiate.
>> [!_GLIBCXX_USE_DUAL_ABI](use_facet<ctype<C>>(const locale&)): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](use_facet<codecvt<C, char, mbstate_t>>(const locale&)): Instantiate.
>> [!_GLIBCXX_USE_DUAL_ABI](use_facet<__timepunct<C>>(const locale&)): Instantiate.
>> [!_GLIBCXX_USE_DUAL_ABI](use_facet<time_put<C>>(const locale&)): Instantiate.
>> [!_GLIBCXX_USE_DUAL_ABI](has_facet<ctype<C>>(const locale&)): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](has_facet<codecvt<C, char, mbstate_t>>(const locale&)): Instantiate.
>> [!_GLIBCXX_USE_DUAL_ABI](has_facet<__timepunct<C>>(const locale&)): Instantiate.
>> [!_GLIBCXX_USE_DUAL_ABI](has_facet<time_put<C>>(const locale&)): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](__add_grouping<C>): Define.
>>             [!_GLIBCXX_USE_DUAL_ABI](__pad<C, char_traits<C>>): Instantiate.
>>             [!_GLIBCXX_USE_DUAL_ABI](__int_to_char(C*, unsigned long, const C*,
>>             ios_base::fmtflags, bool)): Define.
>>             [!_GLIBCXX_USE_DUAL_ABI](__int_to_char(C*, unsigned long long, const C*,
>>             ios_base::fmtflags, bool)): Define.
>>             * src/c++11/wlocale-inst.cc [!_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++98/Makefile.am (cxx11_abi_sources): Remove, unique cow-istream-string.cc entry
>>             move to...
>>             (inst_sources): ...this.
>>             * src/c++98/Makefile.in: Regenerate.
>>             * src/c++98/cow-istream-string.cc: Include <bits/c++config.h>.
>>             [_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++98/hash_tr1.cc [_GLIBCXX_USE_CXX11_ABI]: Skip definitions.
>>             * src/c++98/ios_failure.cc [_GLIBCXX_USE_CXX11_ABI][_GLIBCXX_USE_DUAL_ABI]: Skip definitions.
>>             * src/c++98/istream-string.cc [!_GLIBCXX_USE_DUAL_ABI]: Build only when configured
>>             _GLIBCXX_USE_CXX11_ABI is equal to currently built abi.
>>             * src/c++98/locale_facets.cc [_GLIBCXX_USE_CXX11_ABI](__verify_grouping): Remove.
>>             * src/c++98/stdexcept.cc
>>             [_GLIBCXX_USE_CXX11_ABI](logic_error(const string&): Remove.
>>             [_GLIBCXX_USE_CXX11_ABI](domain_error(const string&): Remove.
>>             [_GLIBCXX_USE_CXX11_ABI](invalid_argument(const string&): Remove.
>>             [_GLIBCXX_USE_CXX11_ABI](length_error(const string&): Remove.
>>             [_GLIBCXX_USE_CXX11_ABI](out_of_range(const string&): Remove.
>>             [_GLIBCXX_USE_CXX11_ABI](runtime_error(const string&): Remove.
>>             [_GLIBCXX_USE_CXX11_ABI](range_error(const string&): Remove.
>>             [_GLIBCXX_USE_CXX11_ABI](overflow_error(const string&): Remove.
>>             [_GLIBCXX_USE_CXX11_ABI](underflow_error(const string&): Remove.
>>             * src/c++98/compatibility.cc [_GLIBCXX_USE_CXX11_ABI]: Skip all definitions appart from
>>             istream::ignore(streamsize).
>> 
>> Tested under Linux x64_86, ok to commit ?
>> 
>> François
>> 
>> 
>> On 17/08/2023 19:22, Jonathan Wakely wrote:
>>> On Sun, 13 Aug 2023 at 14:27, François Dumont via Libstdc++
>>> <libstdc++@gcc.gnu.org> wrote:
>>>> Here is the fixed patch tested in all 3 modes:
>>>> 
>>>> - _GLIBCXX_USE_DUAL_ABI
>>>> 
>>>> - !_GLIBCXX_USE_DUAL_ABI && !_GLIBCXX_USE_CXX11_ABI
>>>> 
>>>> - !_GLIBCXX_USE_DUAL_ABI && _GLIBCXX_USE_CXX11_ABI
>>>> 
>>>> I don't know what you have in mind for the change below but I wanted to
>>>> let you know that I tried to put COW std::basic_string into a nested
>>>> __cow namespace when _GLIBCXX_USE_CXX11_ABI. But it had more impact on
>>>> string-inst.cc so I preferred the macro substitution approach.
>>> I was thinking of implementing the necessary special members functions
>>> of __cow_string directly, so they are ABI compatible with the COW
>>> std::basic_string but don't actually reuse the code. That would mean
>>> we don't need to compile and instantiate the whole COW string just to
>>> use a few members from it. But that can be done later, the macro
>>> approach seems OK for now.
>>> 
>>>> There are some test failing when !_GLIBCXX_USE_CXX11_ABI that are
>>>> unrelated with my changes. I'll propose fixes in coming days.
>>> Which tests? I run the entire testsuite with
>>> -D_GLIBCXX_USE_CXX11_ABI=0 several times per day and I'm not seeing
>>> failures.
>>> 
>>> I'll review the patch ASAP, thanks for working on it.
> <cxx11_gnu-versioned-ns.patch>



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