Re: master fails to build/check

[Gary E. Miller]

Yo Ladislav!

On Fri, 31 Jan 2020 12:16:25 +0100
Ladislav Michl <address@hidden> wrote:

> > Yeah, I remember those.  Those were alst cycle, I'm talking about
> > this cycle.  
> 
> Sure, there's no way to fix things in the past, but those questions
> are still valid.

Or not.

> > The sysroot patch makes no sense.  As used by scons, sysroot is a
> > on the command line, yet you pull it from a non standard environment
> > variable.  Can't do both.  Does not compute.  
> 
> I'm pulling it the same way as other options from the very same group
> of options are pulled. See bellow.

Uh, no.  Looks similar, but different orderring.

> > If you want, let's discuss what the confusion is for the sysroot
> > variable first.  My quick take is you just did not notice it
> > belongs on the command line as an option.  
> 
> Fair enough. sysroot is listed in nonboolopts together with
> gpsd_group, gpsd_user, max_clients, max_devices, (those seems not to
> be used anywhere, btw)

Can you dispense with the digressions?  If you find unused variables
please file issues on them, individually.

> and others like prefix, python_coverage,
> target_python, etc. Values of these variables are read as
> env['python_coverage']

A vast over simplification, nut useful to start.

> and my build script just does:

Oh, my.  What a mess...  But that is yet another discussion...

> sysroot=/home/ladis/src/C-ITS.Devices.O2.Firmware/platform-imx6/sysroot-target

Looks good.  Except for the email mangled it, and more, badly.

> as you can see, sysroot is
> listed on the command line the same way as other options [*].

Yes.

> So now
> that sysroot value is used like this (SConstruct line 642):

Or rather 646 in git head.  If you are going to use line numbers, please
refer to git head.


> # while
> this makes perfect sense if env['target']: for (name, toolname) in
> devenv: env[name] = env['target'] + '-' + toolname # why this?

Uh, lost me.

> if env['sysroot']:
>     env.MergeFlags({"CFLAGS": ["--sysroot=%s" % env['sysroot']]})
>     env.MergeFlags({"LINKFLAGS": ["--sysroot=%s" % env['sysroot']]})

Looks correct.  sysroot just passed on the the C compiler and linker.

> Every single cross-compiler I've worked with so far is aware of it's
> own headers and passing --sysroot= here makes it blind.

So don't use sysroot.  Other people need it.  Your choice.

> - if SConstruct uses sysroot as a toolchain sysroot it is the only
>   tool doing so this way and question is why it is doing so.

Because some users insisted.  Find a cross-compile user to ask, or
look in the git log and email archive for why.

>   However it will work if:
>   - all libraries gpsd depends on are installed into toolchains
> sysroot. This pollutes toolchain installation.

And yet, quite common.  If they are NOT installed there, then how
is gpsd supposed to find them?  They are certainly NOT the ones
the host OS is using.

>   - toolchain sysroot is installed into staging area and then all
>     libraries are installed here. Unusual.

gpsd does not use any staging area.

> - if SConstruct is using sysroot as all other packages, passing
> --sysroot to toolchain is just wrong.

Hmm, so you are saying sysroot is not sysroot?  That makes no sense.
It is a gcc and ld option that you may use, or not.  If you don't want
it passed to gcc and ld, then don't call it sysroot.

> I would deeply appreciate if someone could explain me how is this
> SConstruct thing supposed to work.

Just like make and autoconfuse it takes a whole lot of work to understand.

Maybe better to just ask for what you need, and let those that understand
how gpsd builds come up with some solutions.

So, what do you need?

> [*] See here:
> https://git.pengutronix.de/cgit/ptxdist/tree/rules/gpsd.make#n55 and
> as PTXdist developers are trying to minimize out of tree patches and
> upstream them, I hope we can find solution.

That is a makefile. gpsd does not use makefiles.  And an ugly one at
that.  A perfect example of why gpsd is (slowly) getting rid of compile
time options.  I'll leave that mess to you.

OTOH, if you have suggestions for more/better/different scons options
then please ask.  One at a time.

After you explain what yuo think you need that is like sysroot but is
not sysroot.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

            Veritas liberabit vos. -- Quid est veritas?
    "If you can't measure it, you can't improve it." - Lord Kelvin

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