[CMake] control dependencies in cmake stage

[Mark Abraham]

Hi,

In that case, you could have the generator generate a master source file
with a known name that #includes the real generated files. This means that
the generation can have clean dependencies, but does lose any benefits from
parallel make. It also keeps the intrinsic complexity of the generation
close to itself, rather than unduly complicating the build system. Up to
you.

Mark
On 11/03/2015 6:40 pm, "Tomasz Majchrowski" <contact at majchrowski.de> wrote:

> Thank you Mark for information. The input for the generator is in-house
> developed language. The decision what kind of files will be generated is
> made based on the grammar of this language.
>
> In the current implementation of the generator the extraction of the file
> list will take more or less the same time as execution of the generation
> phase itself. Otherwise we will definitely use make phase.
>
> Best regards, Tomasz.
>
> 2015-03-11 0:15 GMT+01:00 Mark Abraham <mark.j.abraham at gmail.com>:
>
>> Hi,
>>
>> Sure, this is straightforward to do all at make time, if you're prepared
>> to find out what the names of the generated files are. They must follow
>> some pattern ;-). Solutions with make-time globbing are surely impossible,
>> and Petr's IF idea seems brittle to me.
>>
>> See (for example)
>> https://github.com/gromacs/gromacs/blob/master/src/gromacs/CMakeLists.txt#L154.
>> The idea is that you have some target that does the generation, and you
>> make the eventual library/executable depend on its output files. The target
>> that contains the generation command has its own dependencies, so you don't
>> have to re-generate if those don't go out of date. In that example,
>> gmx_configure_version_file just wraps configure_file(), which sets up that
>> dependency chain. You'd need an add_custom_command(), it seems, whose
>> OUTPUT had the list of generated files. There's no problem to use
>> add_library() with a file generated in the build tree - just mention it in
>> an output.
>>
>> There are several much more complicated examples at
>> https://github.com/gromacs/gromacs/blob/master/docs/CMakeLists.txt. For
>> example, we build a gmx binary that writes the same text we display with
>> "gmx topic -h" instead as topic.rst restructedText, which is then parsed
>> with Sphinx to produce manpages that go in the tarball via CPack, or to
>> produce HTML to go on our webpage. Helper scripts mostly live in
>> https://github.com/gromacs/gromacs/tree/master/cmake
>>
>> Cheers,
>>
>> Mark
>>
>>
>> On Tue, Mar 10, 2015 at 6:06 PM, Tomasz Majchrowski <
>> usenet at majchrowski.de> wrote:
>>
>>> (sorry if you received this message twice)
>>>
>>> Hi Mark
>>>
>>> This is the  set of C++ source code files. This set will be compiled
>>> during the make stage. Ideally will be to move generation to make stage.
>>> Unfortunately I don't  know the name of the files that will be generated
>>> before generation phase occurs.
>>>
>>> Therefore I can't use set_source_files_properties( foo.cxx PROPERTIES
>>> GENERATED true) in cmake stage. Please drop a line if you know how to
>>> bypass this limitation.
>>>
>>> Thanks, Tomasz.
>>>
>>> 2015-03-10 7:05 GMT+01:00 Mark Abraham <mark.j.abraham at gmail.com>:
>>>
>>>> Hi,
>>>>
>>>> What are you generating that must be done at cmake time?
>>>>
>>>> Mark
>>>> On 09/03/2015 5:36 pm, "Tomasz Majchrowski" <usenet at majchrowski.de>
>>>> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> I'm wondering if there is an easy way to control the dependencies in
>>>>> the cmake stage. Basically I would like skip execution of some script run
>>>>> over execute_process in case some input files didn't change.
>>>>>
>>>>> The regular way will be to use add_custom_command & add_custom_target
>>>>> however those required targets, so the make stage.
>>>>>
>>>>> Please advice how to proceed in case there is need to control this
>>>>> already in cmake stage?
>>>>>
>>>>> Thanks, Tomasz.
>>>>>
>>>>>
>>>>> --
>>>>> Pozdrawiam/Best regards/Mit freundlichen Grüßen, Tomasz Majchrowski,
>>>>> Information Technology and Services Consultant and Contractor
>>>>>
>>>>> --
>>>>>
>>>>> Powered by www.kitware.com
>>>>>
>>>>> Please keep messages on-topic and check the CMake FAQ at:
>>>>> http://www.cmake.org/Wiki/CMake_FAQ
>>>>>
>>>>> Kitware offers various services to support the CMake community. For
>>>>> more information on each offering, please visit:
>>>>>
>>>>> CMake Support: http://cmake.org/cmake/help/support.html
>>>>> CMake Consulting: http://cmake.org/cmake/help/consulting.html
>>>>> CMake Training Courses: http://cmake.org/cmake/help/training.html
>>>>>
>>>>> Visit other Kitware open-source projects at
>>>>> http://www.kitware.com/opensource/opensource.html
>>>>>
>>>>> Follow this link to subscribe/unsubscribe:
>>>>> http://public.kitware.com/mailman/listinfo/cmake
>>>>>
>>>>> --
>>>>> Pozdrawiam/Best regards/Mit freundlichen Grüßen, Tomasz Majchrowski,
>>>>> Information Technology and Services Consultant and Contractor
>>>>>  <http://public.kitware.com/mailman/listinfo/cmake>
>>>>
>>>>
>>
>
>
> --
> Pozdrawiam/Best regards/Mit freundlichen Grüßen, Tomasz Majchrowski,
> Information Technology and Services Consultant and Contractor
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/cmake/attachments/20150312/6b932e19/attachment.html>