Re: Stop reading Makefile command?

[Cristian Morales Vega]

I ended up just calling only N-1 submakes, and making the main make
take care of one of the DEVICES. Breaks a bit the parallel jobs, but I
can live with that.

On 17 December 2015 at 21:35, Cristian Morales Vega
<address@hidden> wrote:
> On 17 December 2015 at 17:45, Paul Smith <address@hidden> wrote:
>> On Thu, 2015-12-17 at 12:41 -0500, Paul Smith wrote:
>>> On Thu, 2015-12-17 at 15:34 +0000, Cristian Morales Vega wrote:
>>> > There is any way to say: "stop reading here, suppose this Makefile
>>> > has no more contents, end the read-in phase and start the target
>>> > -update phase"?
>>>
>>> No, that's not possible.
>>
>> Well, besides the obvious of putting the entire rest of the makefile in
>> a conditional:
>>
>>   STOP = false
>>     ...
>>   STOP = true
>>
>>   # Don't read any of the rest of the makefile if STOP is true
>>   ifeq ($(STOP),true)
>>    ...
>>   endif
>>   <EOF>
>
> I was trying to avoid that.
>
> My usercase is this: I have a few programs that I want to build for
> multiple devices. Developers of each program create a Makefile
> defining some common variables and one include, e.g.
>
> -----------
> include $(BASE_MAKEFILE)
>
> BINARIES := myprogram
> myprogram_CFLAGS := $(shell pkg-config --cflags mydependency)
> -----------
>
> Then they can run make DEVICES="<device1> <device2>" and the program
> is built for both devices.
>
> Here "pkg-config", and other things in the real system, is a script
> which depends on some variables. These variables are different for
> each <deviceX>.
>
> What I am doing is checking DEVICES in BASE_MAKEFILE. If it contains
> more than one, I call the same Makefile again N times, each time with
> a single, different, <deviceX>. At this point the original make
> invocation just needs to take care of calling the sub-makes.
>
> The problem is that *once* the myprogram_CFLAGS definition is executed
> with DEVICES set with *all* the devices. And in this case pkg-config
> fails.
>
> This can be fixed changing the Makefile to either
>
> -----------
> include $(BASE_MAKEFILE)
>
> BINARIES := myprogram
> myprogram_CFLAGS = $(shell pkg-config --cflags mydependency)
> -----------
>
> or
>
> -----------
> include $(BASE_MAKEFILE)
> ifeq ($(STOP),true)
>
> BINARIES := myprogram
> myprogram_CFLAGS := $(shell pkg-config --cflags mydependency)
>
> endif
> -----------
>
> But I was trying to let developers use ":=", and avoid asking them to
> add two more lines. For that, and avoid an error output from the
> pkg-config call, I would need to to stop the read-in phase inside
> BASE_MAKEFILE.



-- 
Cristian Morales Vega

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