GDB Compilation Issue - gcc

Question

I have run in an issue with compiling gdb from source. I am downloading version 8.2.1 but when I try to compile it, I get the following error:
configure: error: *** A compiler with support for C++11 language features is required.
make[1]: *** [configure-gdb] Error 1
My operating system is Red Hat 7.6 (Maipo) but i have a compiled from source gcc(that i set as the default one with an alias in bashrc)
gcc --version
gcc (GCC) 8.2.0
Copyright (C) 2018 Free Software Foundation, Inc.
which gcc
alias gcc='/usr/local/gcc8.2/bin/gcc'
/usr/local/gcc8.2/bin/gcc
which g++
alias g++='/usr/local/gcc8.2/bin/g++'
/usr/local/gcc8.2/bin/g++
What i have tried/read so far
Read the gdb manual regarding the configure and instalation part, also various stackoverflow links but nobody seems to have this problem
Read the README file in the gdb folder/subfolders
Tried setting the following env options CXX_FOR_TARGET=/usr/local/gcc8.2/bin/g++ GCC_FOR_TARGET=/usr/local/gcc8.2/bin/gcc (not sure if i should replace target with my actual target architecture)
Looked in the gdb-8.2.1 folder at the file config.log and found these: ac_cv_env_GCC_FOR_TARGET_value=/usr/local/gcc8.2/bin/gcc
ac_cv_prog_CXX_FOR_TARGET=/usr/local/gcc8.2/bin/g++
ac_cv_prog_GCC_FOR_TARGET=/usr/local/gcc8.2/bin/gcc
However in the C compiler section of the same config log I have found the following:
configure:4284: checking for C compiler version
configure:4293: gcc --version >&5
gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36)
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
I am not sure ifi can use the devtoolset-8 gdb from RedHat because i have compiled gcc with GLIBCXX_USE_CXX11_ABI=1 and on RedHat due to a bug this is disabled by default and i am not sure if gdb will be able to manage the different binary interface.
Short version: What am I doing wrong that is making the GDB configure script not find the correct compiler and how can i fix/workaround this?
Thank you very much for your help!

Answer 1

A C++11-capable compiler for Red Hat Enterprise Linux 7 is provided as part of Red Hat Developer Toolset. It happens to include not just GCC 8, but GDB 8.2 as well, so you may not even have to compile it yourself. The DTS C++ compiler has been built in a special way so that it interoperates with the system C++ runtime. Unless you have replicated those modifications in your GCC build, it will not be compatible with the rest of the system (and you will have to replace the system libstdc++ library).
The system compiler in Red Hat Enterprise Linux 7 is based on GCC 4.8. In that version, C++11 support was still experimental and not enabled by default. You can try to configure GDB with
./configure CXX="g++ -std=gnu+11"
but this is not recommended (only the C++98 mode is supported).
The configure script does not use shell aliases because those are not inherited by shell scripts invoked from a shell. You will have to specify the full path to the C++ compiler explicitly (in the CXX= argument to configure), or adjust the PATH environment variable manually, or use scl enable to do so in a more polished fashion (for software collections such as Developer Toolset).