925536 - Bug 922461's changes (to ipc/ipdl/ipdl/lower.py) didn't fully take effect until after a clobber

Status: NEW

(Firefox Build System :: General, defect)

Description

[Daniel Holbert [:dholbert]]

STEPS TO REPRODUCE:
 1. Do a targeted build from before bug 922461's fix[1] landed (e.g. use the parent cset), with clang or GCC.

Notice that you get some "unused variable" build warnings for CloneManagees() functions.

 2. Now, apply bug 922461's fix[1] and run ./mach build.
(optional: apply bug 925243's fix[2] as well, to make the warning's fatal)


EXPECTED RESULTS: No more build warnings for unused variables in CloneManagees()

ACTUAL RESULTS: Build warnings are still there! (But they go away if you clobber)

This is a case where a code-change isn't taking effect until you clobber, so ehsan and Ms2ger both asked me to file a build config bug.

I hit this locally on Linux (with GCC 4.8), and we hit it on TBPL on Mac. (on whatever clang version we use there).  (I don't think we got these build warnings on Windows, so you can't really test this on Windows.)

[1] bug 922461's fix: https://hg.mozilla.org/integration/mozilla-inbound/rev/14fd6fa23a16
[2] bug 925243's fix: https://hg.mozilla.org/integration/mozilla-inbound/rev/6df392bd1087

Comment 1

[Daniel Holbert [:dholbert]]

(In reply to Daniel Holbert [:dholbert] from comment #0)
> (optional: apply bug 925243's fix[2] as well, to make the warning's fatal)

Yikes! s/warning's/warnings/.

/me embarrass'ed

Comment 2

[Gregory Szorc [:gps]]

Thank you for filing the bug. It's likely the imported python module isn't getting added to dependencies. We now have code in python/mozbuild/mozbuild/{pythonutil.py,makeutil.py} that can be combined to produce make dependency files that properly record all Python dependencies. We should hook that up to whatever deps files the ipdl codegen emits.