Proposal to improve platformio.ini

[softwaregravy]

• Feature Request.

Background

As my current project ramps up from tiny to small, I am looking for a more power config system. I see others with similar concerns. #3788 #4462 #3952 #4451

As I see it, the current model is override (or replace). Simply put, if a duplicate key is found the last one loaded wins and replaces all the options. The other issues and feature requests are looking for a merge option which combines other entries found.

To illustrate, consider the case of our code running in 2 modes: staging and production, and on 2 boards: esp32_s2 and esp32_s3. These two each have configs. And these configs makes sense across all combinations.

Current

[staging]
build_flags = -DStaging
[production]
build_flags = -DProduction
[esp32_s2]
build_flags = -DS2
[esp32_s3]
build_flags = -DS3

Currently extending directly via extends or indirectly via [env: prefix overrides values. So we have to currently include all previous flags by referencing them on a per-key basis

[s2_staging]
build_flags = ${staging.build_flags} ${esp32_s2.build_flags}
[s2_production]
build_flags = ${production.build_flags} ${esp32_s2.build_flags}
[s3_staging]
build_flags = ${staging.build_flags} ${esp32_s3.build_flags}
[s3_production]
build_flags = ${production.build_flags} ${esp32_s3.build_flags}

Hopefully my contrived example accurately illustrates the current status quo.

Proposal

I propose adding a an option that operates like extends, but it merges instead of overrides. For now, lets call this extend_merge (but we can call it whatever). In this case, we'd still have the first part.

[staging]
build_flags = -DStaging
[production]
build_flags = -DProduction
[esp32_s2]
build_flags = -DS2
[esp32_s3]
build_flags = -DS3

But then the 2nd part would reference this directly without knowing the keys:

[s2_staging]
extend_merge = staging, esp32_s2
[s2_production]
extend_merge = production, esp32_s2
[s3_staging]
extend_merge = staging, esp32_s3
[s3_production]
extend_merge = production, esp32_s3

In my little contrived case, the lines of code saved are minimal. But it is easy to imagine a case where the number of keys set in staging is 6-10, and then we'd save all those other lines.

[Jason2866]

What should happen if there are duplicate but different entrys defined?

[softwaregravy]

I don't follow what you mean by "duplicate but different"

[ivankravets]

Duplicates of #3788

I'll provide more details in #3788