813259 - GRE prefs files should be defined closer to their point of origin

Status: NEW

(Firefox Build System :: General, defect)

Description

[Gregory Szorc [:gps]]

Problem statement: I want to concatenate prefs .js files into greprefs.js because I want my prefs to be defined closer to the component they are related to. i.e. I don't want to define prefs inside modules/libpref/src/init/all.js because this breaks loose coupling and lessens "ownership" of those prefs.

In our current build system, there's no way to do this without violating loose coupling. In order to concatenate a file into greprefs.js, one needs to append to GREPREF_FILES in modules/libpref/src/Makefile.in. So, even though the prefs file itself lives outside /modules (good), a Makefile.in in /modules still needs to reference where that is (bad).

As we move things to mozbuild files, we should probably invent a better, loosely coupled way of handling this.

As a straw man, I propose a per mozbuild file variable GRE_PREF_FILES. The build system collects all seen values and concatenates them together when it creates the final greprefs.js file. As always, I'm open to other suggestions.

I'm filing this bug now so I have a bug I can reference when I edit the Makefile.in where all this is defined.