Old GCC can not automatically find the new version libstdc++? - c++

Question

I'm trying to use the 3rd-party lib, called DocToText, with gcc 4.4.7.
I compiled the program with:
g++ -I./doctotext/ -L./doctotext/ -Wl,-rpath=./doctotext -ldoctotext -o example test_doctotext.cpp
In the beginning, it returned libstdc++.so.6: version GLIBCXX_3.4.15 not found
I manually downloaded the newer version, and re-linked, here is the result
[root#mail]~xian# find / -name "libstdc++.so.6"
/lib64/libstdc++.so.6
/usr/lib64/libstdc++.so.6
[root#mail]~xian# strings /lib64/libstdc++.so.6 | grep GLIBCXX_3.4.15
GLIBCXX_3.4.15
[root#mail]~xian# strings /usr/lib64/libstdc++.so.6 | grep GLIBCXX_3.4.15
GLIBCXX_3.4.15
But when I compiled again, it returned:
[root#mail]~xian# g++ -I./doctotext/ -L./doctotext/ -Wl,-rpath=./doctotext -ldoctotext -o example test_doctotext.cpp
./doctotext//libdoctotext.so: undefined reference to `std::__detail::_List_node_base::swap(std::__detail::_List_node_base&, std::__detail::_List_node_base&)#GLIBCXX_3.4.15'
./doctotext//libdoctotext.so: undefined reference to `std::__detail::_List_node_base::_M_transfer(std::__detail::_List_node_base*, std::__detail::_List_node_base*)#GLIBCXX_3.4.15'
./doctotext//libdoctotext.so: undefined reference to `std::__detail::_List_node_base::_M_unhook()#GLIBCXX_3.4.15'
./doctotext//libdoctotext.so: undefined reference to `std::__detail::_List_node_base::_M_hook(std::__detail::_List_node_base*)#GLIBCXX_3.4.15'
collect2: ld returned 1 exit status
I also tried
g++ -I./doctotext/ -L./doctotext/ -L/lib64/ -Wl,-rpath=./doctotext,-rpath=/lib64 -ldoctotext -lstdc++ -o example test_doctotext.cpp
, and I got the same errors (undefined reference).
libdoctotext.so indeed link to /lib64/libstdc++.so.6
[root#mail]~xian# ldd doctotext/libdoctotext.so | grep libstdc++.so.6
libstdc++.so.6 => /lib64/libstdc++.so.6 (0x00007f96c7ab4000)
Fortunately, I found two method to solve this problem:
use newer gcc:
I used gcc 9.1.1 (with scl), then g++ -I./doctotext/ -L./doctotext/ -Wl,-rpath=./doctotext -ldoctotext -o example test_doctotext.cpp directly works.
specify the path to libstdc++.so.6 with gcc 4.4.7:
g++ -I./doctotext/ -L./doctotext/ -Wl,-rpath=./doctotext -ldoctotext /lib64/libstdc++.so.6 -o example test_doctotext.cpp
But I'm really curious about why my gcc 4.4.7 can not link to that libstdc++ under the system default path?
Is the version of libstdc++ be tightly coupled to the version of gcc in someway?
===============================================================================
Eventually, I found gcc would use
[root#mail]/usr/lib64# find / -name "libstdc++.so"
/opt/rh/devtoolset-9/root/usr/lib/gcc/x86_64-redhat-linux/9/32/libstdc++.so
/opt/rh/devtoolset-9/root/usr/lib/gcc/x86_64-redhat-linux/9/libstdc++.so
/usr/lib/gcc/x86_64-redhat-linux/4.4.4/32/libstdc++.so
/usr/lib/gcc/x86_64-redhat-linux/4.4.4/libstdc++.so
[root#mail]/usr/lib64# ll /usr/lib/gcc/x86_64-redhat-linux/4.4.4/libstdc++.so
lrwxrwxrwx. 1 root root 37 Aug 21 15:22 /usr/lib/gcc/x86_64-redhat-linux/4.4.4/libstdc++.so -> ../../../../lib64/libstdc++.so.6.0.13
6.0.13 doesn't have GLIBCXX_3.4.15
I re-link this to libstdc++.so.6.0.17, problem solved

Answer 1

Every GCC release is accompanied by its very own libstdc++ release.
The C++ standard library (and support libraries like libsupc++) often rely on specific implementation details in the compiler, including bugs, and specific changes in behaviour due to defect reports etc.
Sometimes even a new GCC release also needs a matching binutils (linker) release, as the way the code is generated changed to use a specific feature only available in the newer linker.
You can explicitly link it to the system libstdc++ by passing that path to the compiler/linker, but I don't recommend it, as the ABI may have changed in an incompatible way.