On Tue, Jan 26, 2016 at 8:38 AM, Khem Raj <[email protected]> wrote: > >> On Jan 26, 2016, at 12:10 AM, Andre McCurdy <[email protected]> wrote: >> >> Experimental hack, not expected to be merged. >> >> Without this, the http://www.cplusplus.com/reference/string/string/append/ >> example fails to build with -std=c++11 and it's not clear why (it's as if we >> build a version of libstdc++ which supports only the old ABI but with headers >> which try to use the new ABI when compiled with -std=c++11 ?). As a >> workaround, >> force libstdc++ to provide, and default to using, the old ABI in all cases. >> >> See also: >> >> https://gcc.gnu.org/onlinedocs/libstdc++/manual/configure.html >> https://mail.gnome.org/archives/gtkmm-list/2015-June/msg00026.html >> https://wiki.debian.org/GCC5 >> >> Signed-off-by: Andre McCurdy <[email protected]> >> --- >> meta/recipes-devtools/gcc/gcc-runtime.inc | 13 +++++++++++++ >> 1 file changed, 13 insertions(+) >> >> diff --git a/meta/recipes-devtools/gcc/gcc-runtime.inc >> b/meta/recipes-devtools/gcc/gcc-runtime.inc >> index f20d298..3a476cd 100644 >> --- a/meta/recipes-devtools/gcc/gcc-runtime.inc >> +++ b/meta/recipes-devtools/gcc/gcc-runtime.inc >> @@ -10,6 +10,19 @@ EXTRA_OECONF_PATHS = "\ >> >> EXTRA_OECONF_append_linuxstdbase = " --enable-clocale=gnu" >> >> +# gcc-runtime.inc: force libstdc++ to always use gcc4 compatible ABI >> +# Experimental hack. Without this, the >> http://www.cplusplus.com/reference/string/string/append/ >> +# example fails to build with -std=c++11 and it's not clear why (it's as if >> we >> +# build a version of libstdc++ which supports only the old ABI but with >> headers >> +# which try to use the new ABI when compiled with -std=c++11 ?). As a >> workaround, >> +# force libstdc++ to provide, and default to using, the old ABI in all >> cases. >> +# See also: >> +# https://gcc.gnu.org/onlinedocs/libstdc++/manual/configure.html >> +# https://mail.gnome.org/archives/gtkmm-list/2015-June/msg00026.html >> +# https://wiki.debian.org/GCC5 >> +# >> +EXTRA_OECONF_append = " --disable-libstdcxx-dual-abi >> --with-default-libstdcxx-abi=gcc4-compatible” > > This change while makes it work compatible to older libstdc++ ABI, we should > make the defaults to be > forward looking.
Yes, I agree. The problem is that currently our libstdc++ doesn't seem to support the new ABI. > I would rather keep --with-default-libstdcxx-abi=c++11 since gcc6 will switch > to newer > c++ std as default. If we revert like you suggest, we will be up for more > work in gcc6 time. > > please define _GLIBCXX_USE_CXX11_ABI=0 for your app, where you see the > problem. My test case is the example app from: http://www.cplusplus.com/reference/string/string/append/ It fails when I try to compile to use the new ABI (ie by using -stdc++11 or _GLIBCXX_USE_CXX11_ABI=1). There is no legacy code involved. > >> RUNTIMETARGET = "libssp libstdc++-v3 libgomp libatomic \ >> ${@bb.utils.contains_any('FORTRAN', [',fortran',',f77'], 'libquadmath', >> '', d)} \ >> " >> -- >> 1.9.1 >> >> -- >> _______________________________________________ >> Openembedded-core mailing list >> [email protected] >> http://lists.openembedded.org/mailman/listinfo/openembedded-core > -- _______________________________________________ Openembedded-core mailing list [email protected] http://lists.openembedded.org/mailman/listinfo/openembedded-core
