libstdc++: Fix up abi.exp FAILs on powerpc64le-linux

This is an ABI problem on powerpc64le-linux, introduced in 13.1.
When libstdc++ is configured against old glibc, the
_ZSt10from_charsPKcS0_RDF128_St12chars_format@@GLIBCXX_3.4.31
_ZSt8to_charsPcS_DF128_@@GLIBCXX_3.4.31
_ZSt8to_charsPcS_DF128_St12chars_format@@GLIBCXX_3.4.31
_ZSt8to_charsPcS_DF128_St12chars_formati@@GLIBCXX_3.4.31
symbols are exported from the library, while when it is configured against
new enough glibc, those symbols aren't exported and we export instead
_ZSt10from_charsPKcS0_Ru9__ieee128St12chars_format@@GLIBCXX_IEEE128_3.4.29
_ZSt8to_charsPcS_u9__ieee128@@GLIBCXX_IEEE128_3.4.29
_ZSt8to_charsPcS_u9__ieee128St12chars_format@@GLIBCXX_IEEE128_3.4.29
_ZSt8to_charsPcS_u9__ieee128St12chars_formati@@GLIBCXX_IEEE128_3.4.29
together with various other @@GLIBCXX_IEEE128_3.4.{29,30,31} and
@@CXXABI_IEEE128_1.3.13 symbols.  The idea was that those *IEEE128* symbol
versions (similarly to *LDBL* symbol versions) are optional (but if it
appears, all symbols from it up to the version of the library appears),
but the base appears always.
My _Float128 from_chars/to_chars changes unfortunately broke this.
I believe nothing really uses those symbols if libstdc++ has been
configured against old glibc, so if 13.1 wasn't already released, it might
be best to make sure they aren't exported on powerpc64le-linux.
But as they were exported, I think the best resolution for this ABI
difference is to add those 4 symbols as aliases to the
GLIBCXX_IEEE128_3.4.29 *u9__ieee128* symbols, which the following patch
does.

2023-05-03  Jakub Jelinek  <jakub@redhat.com>

	* src/c++17/floating_from_chars.cc
	(_ZSt10from_charsPKcS0_RDF128_St12chars_format): New alias to
	_ZSt10from_charsPKcS0_Ru9__ieee128St12chars_format.
	* src/c++17/floating_to_chars.cc (_ZSt8to_charsPcS_DF128_): New alias to
	_ZSt8to_charsPcS_u9__ieee128.
	(_ZSt8to_charsPcS_DF128_St12chars_format): New alias to
	_ZSt8to_charsPcS_u9__ieee128St12chars_format.
	(_ZSt8to_charsPcS_DF128_St12chars_formati): New alias to
	_ZSt8to_charsPcS_u9__ieee128St12chars_formati.
	* config/abi/post/powerpc64le-linux-gnu/baseline_symbols.txt: Updated.

diff --git a/libstdc++-v3/config/abi/post/powerpc64le-linux-gnu/baseline_symbols.txt b/libstdc++-v3/config/abi/post/powerpc64le-linux-gnu/baseline_symbols.txt
index 050375923814ccd29824151e6da619fc54c4894b..5250925ce4e195148f1a725e3b253ebedde08f35 100644 (file)
--- a/libstdc++-v3/config/abi/post/powerpc64le-linux-gnu/baseline_symbols.txt
+++ b/libstdc++-v3/config/abi/post/powerpc64le-linux-gnu/baseline_symbols.txt
@@ -4491,6 +4491,7 @@ FUNC:_ZNSt9type_infoD1Ev@@GLIBCXX_3.4
 FUNC:_ZNSt9type_infoD2Ev@@GLIBCXX_3.4
 FUNC:_ZNVSt9__atomic011atomic_flag12test_and_setESt12memory_order@@GLIBCXX_3.4.11
 FUNC:_ZNVSt9__atomic011atomic_flag5clearESt12memory_order@@GLIBCXX_3.4.11
+FUNC:_ZSt10from_charsPKcS0_RDF128_St12chars_format@@GLIBCXX_3.4.31
 FUNC:_ZSt10from_charsPKcS0_RdSt12chars_format@@GLIBCXX_3.4.29
 FUNC:_ZSt10from_charsPKcS0_ReSt12chars_format@@GLIBCXX_3.4.29
 FUNC:_ZSt10from_charsPKcS0_RfSt12chars_format@@GLIBCXX_3.4.29
@@ -4641,6 +4642,9 @@ FUNC:_ZSt7getlineIwSt11char_traitsIwESaIwEERSt13basic_istreamIT_T0_ES7_RNSt7__cx
 FUNC:_ZSt7getlineIwSt11char_traitsIwESaIwEERSt13basic_istreamIT_T0_ES7_RNSt7__cxx1112basic_stringIS4_S5_T1_EES4_@@GLIBCXX_3.4.21
 FUNC:_ZSt7getlineIwSt11char_traitsIwESaIwEERSt13basic_istreamIT_T0_ES7_RSbIS4_S5_T1_E@@GLIBCXX_3.4
 FUNC:_ZSt7getlineIwSt11char_traitsIwESaIwEERSt13basic_istreamIT_T0_ES7_RSbIS4_S5_T1_ES4_@@GLIBCXX_3.4
+FUNC:_ZSt8to_charsPcS_DF128_@@GLIBCXX_3.4.31
+FUNC:_ZSt8to_charsPcS_DF128_St12chars_format@@GLIBCXX_3.4.31
+FUNC:_ZSt8to_charsPcS_DF128_St12chars_formati@@GLIBCXX_3.4.31
 FUNC:_ZSt8to_charsPcS_d@@GLIBCXX_3.4.29
 FUNC:_ZSt8to_charsPcS_dSt12chars_format@@GLIBCXX_3.4.29
 FUNC:_ZSt8to_charsPcS_dSt12chars_formati@@GLIBCXX_3.4.29

diff --git a/libstdc++-v3/src/c++17/floating_from_chars.cc b/libstdc++-v3/src/c++17/floating_from_chars.cc
index 3a411cf546a2f496c2675c05f9eb701378cf9e5c..78b9d92cdc0fab26946a29ed47b920e39076ae68 100644 (file)
--- a/libstdc++-v3/src/c++17/floating_from_chars.cc
+++ b/libstdc++-v3/src/c++17/floating_from_chars.cc
@@ -1272,6 +1272,13 @@ from_chars(const char* first, const char* last, __ieee128& value,
   // fast_float doesn't support IEEE binary128 format, but we can use strtold.
   return from_chars_strtod(first, last, value, fmt);
 }
+
+extern "C" from_chars_result
+_ZSt10from_charsPKcS0_RDF128_St12chars_format(const char* first,
+                                             const char* last,
+                                             __ieee128& value,
+                                             chars_format fmt) noexcept
+__attribute__((alias ("_ZSt10from_charsPKcS0_Ru9__ieee128St12chars_format")));
 #elif defined(USE_STRTOF128_FOR_FROM_CHARS)
 from_chars_result
 from_chars(const char* first, const char* last, _Float128& value,

diff --git a/libstdc++-v3/src/c++17/floating_to_chars.cc b/libstdc++-v3/src/c++17/floating_to_chars.cc
index 06ba4dd0cd6d012183ca4a0877002be72af51a81..f0115c5cf5ce990d47171121f58951aed8f0eef6 100644 (file)
--- a/libstdc++-v3/src/c++17/floating_to_chars.cc
+++ b/libstdc++-v3/src/c++17/floating_to_chars.cc
@@ -1851,6 +1851,23 @@ to_chars(char* first, char* last, __float128 value, chars_format fmt,
 {
   return __floating_to_chars_precision(first, last, value, fmt, precision);
 }
+
+extern "C" to_chars_result
+_ZSt8to_charsPcS_DF128_(char* first, char* last, __float128 value) noexcept
+  __attribute__((alias ("_ZSt8to_charsPcS_u9__ieee128")));
+
+extern "C" to_chars_result
+_ZSt8to_charsPcS_DF128_St12chars_format(char* first, char* last,
+                                       __float128 value,
+                                       chars_format fmt) noexcept
+  __attribute__((alias ("_ZSt8to_charsPcS_u9__ieee128St12chars_format")));
+
+extern "C" to_chars_result
+_ZSt8to_charsPcS_DF128_St12chars_formati(char* first, char* last,
+                                        __float128 value,
+                                        chars_format fmt,
+                                        int precision) noexcept
+  __attribute__((alias ("_ZSt8to_charsPcS_u9__ieee128St12chars_formati")));
 #else
 to_chars_result
 to_chars(char* first, char* last, _Float128 value) noexcept