[omake] Is there a way to 'export' variable value from sub-OMakefile to parent?

[Nozomi Shibano]

Hi Gerd,

Thank you for your kind answer.

I have done some test with your idea and it works. Here is short
summary of test:

'export' in sub-OMakefile => doesn't work
'export' in included sub-OMakefile => works
.SUBDIR with 'export region'  => works

Test files are uploaded here:
https://github.com/nshibano/omake-export-from-sub-omakefile-sample/blob/master/OMakefile

Regards,
Nozomi Shibano

2016-02-21 20:24 GMT+09:00 Gerd Stolpmann <info at gerd-stolpmann.de>:
> Am Mittwoch, den 17.02.2016, 18:21 +0900 schrieb Nozomi Shibano:
>> Hi,
>>
>> I had a general question. Please help if someone had answer. (Also
>> advise if I should ask this question in other place.)
>>
>> Is there any way to 'export' variable value from sub-OMakefile to
>> parent? Sometimes I want to declare 'accumulator' variable in root
>> OMakefile and append to it in sub-OMakefiles using += operator, and
>> then do some task with accumulated values in root OMakefile. For
>> example, accumulate paths of all .o files in sub-directories and link
>> them into single .exe file in the root directory.
>>
>> It seems to me that, it is not possible.
>
> Right, normal .SUBDIRS (w/o section) always starts a new environment,
> and there is no way to export updated variables.
>
>>  (Exceptionally, when
>> sub-OMakefile is written as .SUBDIRS section in root OMakefile,
>> 'export' command works for this purpose.)
>
> Based on this observation, here is an idea: maybe the combo .SUBDIRS
> section with "include" works:
>
> .SUBDIRS: dir
>     include OMakefile
>     export variable
>
> This is not tested, though.
>
> Note that a simple "include dir/OMakefile" would not work because the
> rules in OMakefile wouldn't then be applied to the subdirectory.
>
> Gerd
>
>> Passing information from
>> sub-OMakefile to parent is only possible via target file in sub
>> directory and dependency to it from root OMakefile. For above example
>> case, I have to link .o files into .a file in sub-OMakefile and
>> declare dependency from .exe to that .a file in root OMakefile. Is
>> this correct understanding?
>>
>> Regards,
>> Nozomi Shibano
>> _______________________________________________
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>> Omake at lists.ocaml.org
>> http://lists.ocaml.org/listinfo/omake
>
> --
> ------------------------------------------------------------
> Gerd Stolpmann, Darmstadt, Germany    gerd at gerd-stolpmann.de
> My OCaml site:          http://www.camlcity.org
> Contact details:        http://www.camlcity.org/contact.html
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