On 12 September 2014 06:40, Jan Hubicka wrote:
> Hi,
> I went through excercise of running LTO bootstrap with ODR verification on.
> There are some typename clashes
> I guess we want to fix. I wonder what approach is preferred, do we want to
> introduce anonymous
> namespaces for those?
> /usr/bin/ld.gold.real: warning: using 'GLIBCXX_3.4' as version for
> '_ZNKSt15basic_stringbufIwSt11char_traitsIwESaIwEE3strEv' which is also named
> in version 'GLIBCXX_3.4.6' in script
> /usr/bin/ld.gold.real: warning: using 'GLIBCXX_3.4' as version for
> '_ZNKSs11_M_disjunctEPKc' which is also named in version 'GLIBCXX_3.4.5' in
> script
> /usr/bin/ld.gold.real: warning: using 'GLIBCXX_3.4' as version for
> '_ZNKSbIwSt11char_traitsIwESaIwEE11_M_disjunctEPKw' which is also named in
> version 'GLIBCXX_3.4.5' in script
I think these are caused by two bugs in the libstdc++ linker script.
It looks like the duplicates should have been guarded by #ifndef
HAVE_SYMVER_SYMBOL_RENAMING_RUNTIME_SUPPORT (as per the attached
patch), but it's too late now and we export the symbols at GLIBCXX_3.4
unconditionally. Applying the patch now would alter the symbol version
for the wstringbuf::str() symbol.
Maybe we should just remove the duplicates in the later symbol version
sections, but I'm not confident enough to do it!
commit bd23198d87a6c04ea55410221f85ed79786b6478
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Fri Sep 12 11:27:32 2014 +0100
* config/abi/pre/gnu.ver: Prevent symbols appearing in two versions,
to fix warning from gold linker.
diff --git a/libstdc++-v3/config/abi/pre/gnu.ver
b/libstdc++-v3/config/abi/pre/gnu.ver
index 58c90d6..5f96a09 100644
--- a/libstdc++-v3/config/abi/pre/gnu.ver
+++ b/libstdc++-v3/config/abi/pre/gnu.ver
@@ -317,7 +317,10 @@ GLIBCXX_3.4 {
_ZNSt15basic_stringbufI[cw]St11char_traitsI[cw]ESaI[cw]EE[0-9]seek*;
_ZNSt15basic_stringbufI[cw]St11char_traitsI[cw]ESaI[cw]EE[0-9]set*;
_ZNKSt15basic_stringbufIcSt11char_traitsIcESaIcEE3strEv;
+
+#ifndef HAVE_SYMVER_SYMBOL_RENAMING_RUNTIME_SUPPORT
_ZNKSt15basic_stringbufIwSt11char_traitsIwESaIwEE3strEv;
+#endif
_ZNSt15basic_stringbufIcSt11char_traitsIcESaIcEE3strERKSs;
_ZNSt15basic_stringbufIwSt11char_traitsIwESaIwEE3strERKSbIwS1_S2_E;
_ZNSt15basic_stringbufI[cw]St11char_traitsI[cw]ESaI[cw]EE[0-9][t-z]*;
@@ -864,6 +867,7 @@ GLIBCXX_3.4.4 {
GLIBCXX_3.4.5 {
+#ifndef HAVE_SYMVER_SYMBOL_RENAMING_RUNTIME_SUPPORT
# std::string
_ZNKSs11_M_disjunctEPKc;
_ZNKSs15_M_check_lengthE[jmy][jmy]PKc;
@@ -888,6 +892,7 @@ GLIBCXX_3.4.5 {
_ZNSt13basic_istreamIwSt11char_traitsIwEE6ignoreE[ilvx];
_ZNSt11char_traitsI[cw]E2eqERK[cw]S2_;
+#endif
# Those template instantiations weren't exported on Solaris in GCC 4.6
# and aren't necessary for correct operation, so don't emit them now
