GNOME Bugzilla – Bug 720063
Makefile.introspection ignores CFLAGS and LDFLAGS when scanning
Last modified: 2015-02-07 17:00:38 UTC
I'm trying to get jhbuild working on FreeBSD. I have the following CFLAGS and LDFLAGS: CFLAGS=-isystem /usr/local/include LDFLAGS=-Wl,-Y/usr/local/lib This is basically the same as -I and -L except that it adds /usr/local/lib in such a way that it is searched last, after all other -I and -L options. This is important to make sure builds pick up the things in the jhbuild prefix before the things in /usr/local. FreeBSD installs its packages and ports to /usr/local but the compiler search path does not include it by default for some reason. Easy enough to fix with the above in my jhbuild environment, though. Makefile.introspection, when calling the scanner, does this: ... $($(_gir_name)_SCANNERFLAGS) \ --cflags-begin \ $($(_gir_name)_CFLAGS) \ --cflags-end \ $($(_gir_name)_LDFLAGS) \ $$^ \ ... which doesn't use the user's $(CFLAGS) and $(LDFLAGS) at all I can modify this to also include $(CFLAGS) and that works nicely (due to the nice --cflags-begin --cflags-end stuff) but if I include my $(LDFLAGS) here as well then I have trouble, since the scanner doesn't recognise -Wl,... options, complaining "g-ir-scanner: error: no such option: -W". Two possible fixes there: - pass -Wl, options through unharmed, just as we do for -I and -L - add --ldflags-start and --ldflags-end and use them from the Makefile ...plus adding $(CFLAGS) and $(LDFLAGS) to the Makefile
How does the FreeBSD port system make this work? Or do they have a g-i build? (In reply to comment #0) > FreeBSD installs its packages and ports to /usr/local but the compiler search > path does not include it by default for some reason. Easy enough to fix with > the above in my jhbuild environment, though. But how does gtk+ find glib with the ports? I'm not opposed to adding CFLAGS/LDFLAGS, but a *lot* of components and apps use g-i, and it seems likely to provoke build breakage of some form. (Although I can't think offhand what that might be)
The reason that this works in ports builds on FreeBSD is pretty accidental. They use system pcre, which has an include dir of /usr/local/include. This gets returned by the pkg-config --cflags for glib-2.0, and thus ends up in the per-target CFLAGS and passed through accordingly. ie: <libintl.h> is only found because pcre happens to be in the same place. Gtk+ is able to find GLib because GLib's include path is -I/usr/local/include/glib-2.0 and that also comes from pkg-config. That's the usual behaviour. After doing a bit more checking, the dumper is fine because it does this: cflags = os.environ.get('CFLAGS', '') for cflag in cflags.split(): args.append(cflag) ldflags = os.environ.get('LDFLAGS', '') for ldflag in ldflags.split(): args.append(ldflag) The scanner doesn't do that, though. Adding CFLAGS there is probably the easiest way to solve this.
It could be argued that it is the fault of GLib for installing a .pc file that doesn't give the full arguments needed for building it correctly (since it is its headers that make use of libintl.h) but it's hard to argue that it should be aware of the user's choice of CFLAGS and attempt to interpret them, particular when they contain exotic things like "-isystem ...". I think the best expectation here is that if the user consistently uses the same set of CFLAGS/LDFLAGS then they should expect the whole stack to work... and that would be the case here, except that the scanner is running without those CFLAGS. I think that's why, above anything else, this change is justified.
Created attachment 263746 [details] [review] scanner: make sure we pass CFLAGS to cpp When doing the source scanning in giscanner, make sure we pass the user's CFLAGS environment variable to the compiler, as we do for the dumper.
Review of attachment 263746 [details] [review]: The main case I can think of where things might start failing is if builders have e.g. CFLAGS='-Werror=foo' where foo is some warning in the code generated by the scanner. But, I haven't see any warnings out of the scanner lately, so hopefully this'll be fine.
Strictly speaking, we should also add in CPPFLAGS since it was possible that CPPFLAGS was given when building GLib... In fact, now that I'm on to gdk-pixbuf I notice that some ./configure checks depend on my -isystem being in CPPFLAGS. CPPFLAGS would be slightly riskier because we don't have them in the dumper already, so we don't know if it could break stuff. Your call. Meanwhile, I've set both CFLAGS and CPPFLAGS.
Comment on attachment 263746 [details] [review] scanner: make sure we pass CFLAGS to cpp Attachment 263746 [details] pushed as cbafcdb - scanner: make sure we pass CFLAGS to cpp
(In reply to comment #6) > Strictly speaking, we should also add in CPPFLAGS since it was possible that > CPPFLAGS was given when building GLib... In fact, now that I'm on to gdk-pixbuf > I notice that some ./configure checks depend on my -isystem being in CPPFLAGS. > > CPPFLAGS would be slightly riskier because we don't have them in the dumper > already, so we don't know if it could break stuff. I'm ok with adding CPPFLAGS too.
Created attachment 264746 [details] [review] Honour CPPFLAGS as we do CFLAGS In all of the places that we pass through the CFLAGS, we should be doing the same with the CPPFLAGS.
Review of attachment 264746 [details] [review]: Looks reasonable to me.
Attachment 264746 [details] pushed as ce190a6 - Honour CPPFLAGS as we do CFLAGS
(In reply to comment #1) > I'm not opposed to adding CFLAGS/LDFLAGS, but a *lot* of components and apps > use g-i, and it seems likely to provoke build breakage of some form. (Although > I can't think offhand what that might be) This is causing Bug #726008#c10
Ryan, are you OK with reverting this change, since it caused bug #726008 and we don't know how to fix it? I'm getting quite tired of leaving my CFLAGS empty....
No -- I don't think reverting this is correct. Bug 726008 is really a bug in the gobject-introspection lexer/parser and ought to be fixed there.
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