CODEWITHSUNDEEP
c++linuxcross-compilingtoolchain
Sergey Kolesnik
Sergey Kolesnik

Reputation: 3630

How to set up a C++ toolchain for cross-compilation?

I have a target system Astra Linux Smolensk, which has access to very outdated packages with GCC 6 among them. It does not support C++17, which is required for some very useful 3rd party libraries and language features. At some point I am considering a possibility of using concepts from 20 standard. But there is no easy way to achieve that.
Basically, I see 2 ways:

  1. Compile needed version of GCC by myself and have a custom version of Astra Linux for building with additional packages (which is not a good option since we have restrictions for system modification). I am about to try out this option, but it is not the subject of this question.
  2. Cross-compile with latest GCC on Ubuntu using a toolchain.

So, what do I need in order to create a toolchain for a custom version of Linux? The only thing I am sure of is the Linux Core version. Can I use an existing Linux toolchain or do I have to export system libraries and create a custom toolchain?

Here I found out some tools that seem to be helpful. For instance:

Buildroot
Buildroot is a complete build system based on the Linux kernel configuration system and supports a wide range of target architectures. It generates root file system images ready to be written to flash. In addition to having a huge number of packages which can be compiled into the image, it also generates a cross toolchain to build those packages from source. Even if you don't want to use buildroot for your root filesystem, it is a useful tool for generating a toolchain. Buildroot supports uClibc-ng, glibc and musl.

I wonder if it does what I need and can I use a latest GCC compiler with those generated toolchains.

I found similar questions:
How to build C++17 application in old linux distro with old stdlib and libc?
https://askubuntu.com/questions/162465/are-gcc-versions-tied-to-kernel-versions
How can I link to a specific glibc version?

Some clarification is needed: The project relies heavily on a lot of 3rd party dependencies from the target linux's package repository. Moreover, I use dynamic .so modules that may be loaded both implicitly and explicitly.

Upvotes: 2

Views: 1526

Answers (1)

prehistoricpenguin
prehistoricpenguin

Reputation: 6326

Today with docker and modern CI/CD pipelines based on container, we don't rely on process compile very often as old days.

With the help of musl, we can even create universal Linux binaries with static linkage: We use all static libraries rather than dynamic libraries. Then we ship one executable file.

According to musl's doc, it needs

Linux kernel >=2.6.39

This is a very old version released around 2011, so even old Linux distro's can run our binaries.

Musl is widely used in many projects, especially in Rust projects, we provide Musl builds for users as conveniences.

Note that we may need to fix our codebase when using Musl, there are very slight differences with GNU libc, which we should be aware.

Upvotes: 1

Related Questions