664362 - Host objects are not rebuilt when a header changes

Status: RESOLVED FIXED

(Firefox Build System :: General, defect)

Description

[Mike Hommey [:glandium]]

The build system doesn't keep track of dependencies for host objects, and if a changeset modifies a header file that some source file built as host_*.o uses, nothing is rebuilt, which can lead to some interesting problems.

Comment 1

[Mike Hommey [:glandium]]

The more I'm thinking about it, the more it's an impossible mess, considering the spread of platform specific hacks all over the place, and considering cross-compilation complicates things. I'll just go the easy way and fix my problem locally, while leaving this bug open because it still exists.

Comment 2

[Mike Hommey [:glandium]]

Attachment: Generate depfiles for host objects/programs/libraries

This is kind of ugly, because it assumes the host and target toolchains use the same flags, but in practice, that works because we don't support things like (host=msvc, target=gcc). The most disparate mix we support is (host=clang, target=gcc), and in that case the flags *are* the same. Note that _DEPEND_CFLAGS is actually empty for msvc, so this doesn't change much for compilation on windows, but cl.py was already outputing the depfiles anyways for object files.

https://tbpl.mozilla.org/?tree=Try&rev=9cd92f4c1f17

I'd say it's about time to have proper dependencies for host object/programs/libraries.

Comment 3

[Gregory Szorc [:gps]]

Comment on attachment 818909 [details] [diff] [review]
Generate depfiles for host objects/programs/libraries

Review of attachment 818909 [details] [diff] [review]:
-----------------------------------------------------------------

::: other-licenses/bsdiff/Makefile.in
@@ -39,5 @@
>  LOCAL_INCLUDES += -I$(topsrcdir)/toolkit/mozapps/update/updater
>  
>  include $(topsrcdir)/config/rules.mk
>  
> -HOST_CXXFLAGS += $(MOZ_BZ2_CFLAGS)</textarea>

wat

Comment 4

[Mike Hommey [:glandium]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/79d67674300e

Comment 5

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/79d67674300e