How to change the build toolset?

[DoaJC_Blogger]

I'd like to build Chromium with an older Visual C++ runtime or one of the toolsets like v141_xp. I'm in a group that is backporting Chromium for Windows XP and we replaced almost all the missing functions a while ago.

The problem is that our current builds show errors for functions that aren't in the code. This wasn't a problem when our project started in April 2019. It started happening when I synced the code in either late 2019 or early 2020. I remember using VS 2015 at the beginning, but I just checked the Wayback Machine and it required VS 2017 at that time, so I think the toolset was changed somewhere in the Chromium code in 2019. I used the code search and searched for commits around that time that are related to the build tools but I couldn't find anything.

We would appreciate any advice you can think of. Thanks in advance.

[Bruce Dawson]

Changes to the prepackaged toolchain used to build Chromium are done by modifying the hash in this file:

https://source.chromium.org/chromium/chromium/src/+/main:build/vs_toolchain.py;l=2?q=vs_toolchain.py

The change from VS 2015 to VS 2017 would be reflected in a commit to this file - specifically crrev.com/c/678859. Changes to the SDK or other parts of the toolchain are also reflected in changes to the hash in this file. After the switch to make VS 2017 the default there were some changes to update the SDK versions, but then we  switched to compiling with clang-cl. Updates to the version of clang-cl that we use are done elsewhere, and the toolchain package is used for things like header files, libraries, and a few tools. Chromium doesn't build with VC++, and hasn't for quite a few years.

Good luck, I guess.

[DoaJC_Blogger]

Thank you. I'll see if this helps.