1586357 - Only force re-linking on 1-tier PGO builds

Status: RESOLVED FIXED

(Firefox Build System :: General, defect)

Description

[Michael Shal [:mshal]]

Local PGO builds (MOZ_PGO=1 ./mach build) still use 1-tier machinery until bug 1563403 is fixed. However, that doesn't stop someone from doing a 3-tier PGO build by fiddling with --enable-profile-generate/use flags and running the profile server. If they do, MOZ_AUTOMATION isn't set, which means buildsymbols recurses through the tree:

https://searchfox.org/mozilla-central/rev/2f29d53865cb895bf16c91336cc575aecd996a17/Makefile.in#242

Unfortunately 1-tier PGO uses a FORCE rule to force re-linking libraries & binaries in the profile-use stage, defined here:

https://searchfox.org/mozilla-central/rev/2f29d53865cb895bf16c91336cc575aecd996a17/config/rules.mk#478

So a subsequent buildsymbols will recurse through the tree, then forcefully re-link everything, which can add quite a bit of time to the build. Until bug 1563403 removes the rest of the 1-tier PGO stuff, we can hide the FORCE rule behind the MOZ_1TIER_PGO flag so it doesn't impact a local 3-tier PGO build.

Comment 1

[Michael Shal [:mshal]]

Attachment: Bug 1586357 - Only force re-linking on 1-tier PGO builds; r?#firefox-build-system-reviewers

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/70367c5e41fc
Only force re-linking on 1-tier PGO builds; r=firefox-build-system-reviewers,chmanchester

Comment 3

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/70367c5e41fc