[Scons-users] Fwd: Dependency tree for test framework

[Mats Wichmann]

On 3/28/25 23:30, Oliver Koch via Scons-users wrote:
> Dear Scons developers and users,
> 
> I would like to set up a rather complex test framework to compare the
> changes between different versions (old vs. new) of an executable.
> The workflow also includes different steps (tools) to process resp.
> compare the output files.
> 
> See the attached HTML file (resp. the according Markdown file).
> Any green box should be regarded as an independent component the can be
> changed by me. Any white box is a dependent file that is generated from
> the independents.
> 
> The task is to create a dependency tree in SCons that re-generates the
> (necessary) final output files (b.out.diff resp.b.log.diff), if any of
> the dependent green boxes have been changed.
> 
> I am struggeling with your documentation to conclude, how a SCons script
> should look like for the above purpose, since I am not using any
> classical compiler or linker in this workflow.
> Could you indicate me, how the shown dependency tree must be implemented
> with a SCons script?
> (And maybe explain a little bit why?)
The way you declare a dependency with an associated action is to call a 
"builder": B depends on A, and if A is computed to be out of date, apply 
Action to create/recreate B.

SCons has a bunch of pre-made builders to anticipate things people are 
likely to do, but in your case, none are going to apply, so you'll need 
to write you own builders, or use the builder-like Command function if 
you can.

Command is much simpler because it works as a one-shot, while true 
builders require quite a bit more plumbing setup. Rather than go on 
about that, there are two chapters in the User Guide you can scan, then 
come back with more questions:

Writing Your Own Builders:
https://scons.org/doc/production/HTML/scons-user.html#chap-builders-writing

Not Writing Builders:
https://scons.org/doc/production/HTML/scons-user.html#chap-builders-commands