Fedora23 install Cpp older version compiler

edit

Hi, I made a gcc4.9 for these purposes in COPR...

How to install?

1) su

2) dnf -y copr enable davidva/gcc49

3) dnf install gcc49

Good luck. :)

I would like to suggest you consider cross-compilation approach. But for your purpose it will be not a real cross-compilation between different architectures, but just using standalone compiler with correct path to compiler's own libraries and headers. For example if you have a look into yocto, it could prepare for you any toolchain you want let's say for x86_64 architecture (or any other). After this you just need to use prepared shell script (just typing something like 'source x86_gcc_4.9.sh') it will switch all needed environment variables like CC, CXX, LD, SYSROOT, CPP, AR, etc... to the newly prepared compiler version.

So, the full instructions would be following:

1) Download poky toolchain:

git clone https://git.yoctoproject.org/poky

2) Prepare a project files:

source poky/oe-init-build-env new_project_dir  
cd new_project_dir

3) Build only compiler

MACHINE=x86_64 bitbake core-image-minimal -c populate_sdk

4) Install just built compiler
Run just prepared shell script

tmp/deploy/sdk/poky-glibc-x86_64-core-image-minimal-i586-toolchain-1.8.sh

(your script name could differ because it depends on target architecture and poky version)

That will generate the "switching" script to use newly prepared toolchain with needed version of compiler,linker and etc. seamlessly like it is a system default compiler set. It would not touch your system files, so you can be pretty sure that this is safe operation.

Details you can find here: http://www.yoctoproject.org/docs/1.8/... ( 3.4 Optionally Building a Toolchain Installer)
and good example here http://www.yoctoproject.org/docs/1.8/... ( 5.1.1 Creating and Running a Project Based on GNU Autotools)