From: Jonathan Wakely Date: Mon, 14 Feb 2022 16:46:55 +0000 (+0000) Subject: libstdc++: Fix stream extraction of IEEE128 long double [PR100912] X-Git-Tag: upstream/12.2.0~1466 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3d50dede07de0923f0f320d385162e546445e640;p=platform%2Fupstream%2Fgcc.git libstdc++: Fix stream extraction of IEEE128 long double [PR100912] The std::__convert_from_v helper that formats double and long double values into a char buffer was not being duplicated for the two long double ABIs. This resulted in an ODR violation inside the library, where some callers needed it to use snprintf to format __ibm128 values and other callers needed it to use __snprintfieee128 to format __ieee128 values. The linker discarded one of the definitions, leaving one set of callers using the wrong code. This puts __convert_from_v in the __gnu_cxx_ieee128 inline namespace when long double is __ieee128, so that there are two different definitions of the function. The std::money_put::__do_put overload for __ibm128 values needs a different fix, because that is defined when long double is __ieee128 and so would call the one in the inline namespace. That can be fixed by just inlining the code directly into the function and using an asm alias to call the right version of snprintf for the __ibm128 format. The code to do that can be simpler than __convert_from_v because if we're defining the ALT128_COMPAT symbols we know that we have a recent glibc and so we can assume that uselocale and snprintf are supported. libstdc++-v3/ChangeLog: PR libstdc++/100912 * config/locale/gnu/c_locale.h (__convert_from_v): Use inline namespace for IEEE128 long double mode. * config/os/gnu-linux/ldbl-ieee128-extra.ver: Add new symbol version and export __gnu_cxx_ieee128::__convert_from_v. * include/bits/locale_facets_nonio.tcc (money_put::__do_put): Make __ibm128 overload use snprintf directly * testsuite/util/testsuite_abi.cc: Add new symbol version. Remove stable IEEE128/LDBL versions. --- diff --git a/libstdc++-v3/config/locale/gnu/c_locale.h b/libstdc++-v3/config/locale/gnu/c_locale.h index 176e022..526b622 100644 --- a/libstdc++-v3/config/locale/gnu/c_locale.h +++ b/libstdc++-v3/config/locale/gnu/c_locale.h @@ -61,6 +61,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION typedef __locale_t __c_locale; +#if defined _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT \ + && defined __LONG_DOUBLE_IEEE128__ +namespace __gnu_cxx_ieee128 { +#endif + // Convert numeric value of type double and long double to string and // return length of string. If vsnprintf is available use it, otherwise // fall back to the unsafe vsprintf which, in general, can be dangerous @@ -108,6 +113,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION return __ret; } +#if defined _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT \ + && defined __LONG_DOUBLE_IEEE128__ +} // namespace __gnu_cxx_ieee128 +#endif + _GLIBCXX_END_NAMESPACE_VERSION } // namespace diff --git a/libstdc++-v3/config/os/gnu-linux/ldbl-ieee128-extra.ver b/libstdc++-v3/config/os/gnu-linux/ldbl-ieee128-extra.ver index 9b421b6..830cb8c 100644 --- a/libstdc++-v3/config/os/gnu-linux/ldbl-ieee128-extra.ver +++ b/libstdc++-v3/config/os/gnu-linux/ldbl-ieee128-extra.ver @@ -2,7 +2,8 @@ GLIBCXX_IEEE128_3.4.29 { - *__gnu_cxx_ieee128*; + _Z*St17__gnu_cxx_ieee1287num_get*; + _Z*St17__gnu_cxx_ieee1287num_put*; _ZNSt14numeric_limitsIu9__ieee128E*; _ZNSirsERu9__ieee128; @@ -45,6 +46,10 @@ GLIBCXX_IEEE128_3.4.29 { } GLIBCXX_3.4.29; +GLIBCXX_IEEE128_3.4.30 { + _ZNSt17__gnu_cxx_ieee12816__convert_from_vERKP15__locale_structPciPKcz; +} GLIBCXX_3.4.30; + CXXABI_IEEE128_1.3.13 { _ZT[IS]u9__ieee128; diff --git a/libstdc++-v3/include/bits/locale_facets_nonio.tcc b/libstdc++-v3/include/bits/locale_facets_nonio.tcc index 6473782..9844241 100644 --- a/libstdc++-v3/include/bits/locale_facets_nonio.tcc +++ b/libstdc++-v3/include/bits/locale_facets_nonio.tcc @@ -635,6 +635,9 @@ _GLIBCXX_BEGIN_NAMESPACE_LDBL_OR_CXX11 #if defined _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT \ && defined __LONG_DOUBLE_IEEE128__ +extern "C" +__typeof__(__builtin_snprintf) __glibcxx_snprintfibm128 __asm__("snprintf"); + template _OutIter money_put<_CharT, _OutIter>:: @@ -643,30 +646,24 @@ _GLIBCXX_BEGIN_NAMESPACE_LDBL_OR_CXX11 { const locale __loc = __io.getloc(); const ctype<_CharT>& __ctype = use_facet >(__loc); -#if _GLIBCXX_USE_C99_STDIO // First try a buffer perhaps big enough. int __cs_size = 64; char* __cs = static_cast(__builtin_alloca(__cs_size)); + const __c_locale __old = __gnu_cxx::__uselocale(_S_get_c_locale()); + // _GLIBCXX_RESOLVE_LIB_DEFECTS // 328. Bad sprintf format modifier in money_put<>::do_put() - int __len = std::__convert_from_v(_S_get_c_locale(), __cs, __cs_size, - "%.*Lf", 0, __units); + int __len = __glibcxx_snprintfibm128(__cs, __cs_size, "%.*Lf", 0, + __units); // If the buffer was not large enough, try again with the correct size. if (__len >= __cs_size) { __cs_size = __len + 1; __cs = static_cast(__builtin_alloca(__cs_size)); - __len = std::__convert_from_v(_S_get_c_locale(), __cs, __cs_size, - "%.*Lf", 0, __units); + __len = __glibcxx_snprintfibm128(__cs, __cs_size, "%.*Lf", 0, + __units); } -#else - // max_exponent10 + 1 for the integer part, + 2 for sign and '\0'. - const int __cs_size = - __gnu_cxx::__numeric_traits::__max_exponent10 + 3; - char* __cs = static_cast(__builtin_alloca(__cs_size)); - int __len = std::__convert_from_v(_S_get_c_locale(), __cs, 0, "%.*Lf", - 0, __units); -#endif + __gnu_cxx::__uselocale(__old); string_type __digits(__len, char_type()); __ctype.widen(__cs, __cs + __len, &__digits[0]); return __intl ? _M_insert(__s, __io, __fill, __digits) diff --git a/libstdc++-v3/testsuite/util/testsuite_abi.cc b/libstdc++-v3/testsuite/util/testsuite_abi.cc index 0ac0ea3..3dee737 100644 --- a/libstdc++-v3/testsuite/util/testsuite_abi.cc +++ b/libstdc++-v3/testsuite/util/testsuite_abi.cc @@ -213,6 +213,7 @@ check_version(symbol& test, bool added) known_versions.push_back("GLIBCXX_3.4.30"); known_versions.push_back("GLIBCXX_LDBL_3.4.29"); known_versions.push_back("GLIBCXX_IEEE128_3.4.29"); + known_versions.push_back("GLIBCXX_IEEE128_3.4.30"); known_versions.push_back("CXXABI_1.3"); known_versions.push_back("CXXABI_LDBL_1.3"); known_versions.push_back("CXXABI_1.3.1"); @@ -247,11 +248,8 @@ check_version(symbol& test, bool added) // Check that added symbols are added in the latest pre-release version. bool latestp = (test.version_name == "GLIBCXX_3.4.30" - // XXX remove next 3 lines when baselines have been regenerated - // to include {IEEE128,LDBL} symbols: - || test.version_name == "GLIBCXX_LDBL_3.4.29" - || test.version_name == "GLIBCXX_IEEE128_3.4.29" - || test.version_name == "CXXABI_IEEE128_1.3.13" + // XXX remove next line when baselines have been regenerated. + || test.version_name == "GLIBCXX_IEEE128_3.4.30" || test.version_name == "CXXABI_1.3.13" || test.version_name == "CXXABI_FLOAT128" || test.version_name == "CXXABI_TM_1");