[CMake] [CMake 0012322]: Ability to add source files to target created with ExternalProject

[David Cole]

You can re-open the issue if you would like to have more discussion there.

The build step does not always re-run. If you have an "update" step
before the build step, then the update step always re-runs, and the
build step after it, but many external projects do not have an update
step, or anything else that "always" forces a build when there's a
"Build Solution" executed on the containing project. (If it does, then
that's a bug, because it's only supposed to re-execute steps that
*need* to be re-executed.)


Thanks,
David


On Fri, Aug 12, 2011 at 10:46 AM, Yuri Timenkov <yuri at timenkov.ru> wrote:
> Hello David,
> It seems that I can't add notes to closed bug, so I ask you directly.
> I don't quite understand what kind of automatic dependencies you're talking
> about.
> If I change file in this way and do "build solution" cmake will
> automatically launch build for external project. IIRC it always executes
> build when I build solution.
> As I said, for my local purposes I can use modified ExternalProject.cmake
> file, but I thought such feature might be useful for others.
>
> On Fri, Aug 12, 2011 at 5:24 PM, Mantis Bug Tracker
> <mantis at public.kitware.com> wrote:
>>
>> A NOTE has been added to this issue.
>> ======================================================================
>> http://public.kitware.com/Bug/view.php?id=12322
>> ======================================================================
>> Reported By:                Yuri
>> Assigned To:                David Cole
>> ======================================================================
>> Project:                    CMake
>> Issue ID:                   12322
>> Category:                   CMake
>> Reproducibility:            always
>> Severity:                   tweak
>> Priority:                   normal
>> Status:                     resolved
>> Resolution:                 won't fix
>> Fixed in Version:           CMake 2.8.6
>> ======================================================================
>> Date Submitted:             2011-07-08 05:27 EDT
>> Last Modified:              2011-08-12 09:24 EDT
>> ======================================================================
>> Summary:                    Ability to add source files to target created
>> with
>> ExternalProject
>> Description:
>> In my scenario I have part of project which should be built with different
>> toolset (Main project is built with VC2010, and some legacy libraries with
>> VC6
>> and VS2005).
>> Basically nested project contains
>> set(Proj_SRCS src1.cpp src2.cpp...)
>> add_library(Proj MODULE ${Proj_SRCS})
>>
>> So set() command may be moved into separate file which in turn could be
>> included
>> into main project. So I want to see them there to edit in IDE, but not
>> compile.
>>
>> The only possibility to add files to custom target - is specify SOURCES in
>> add_custom_target command (It's impossible to call cmTarget::AddSources
>> from
>> outside). However, ExternalProject_Add macro doesn't add any sources.
>>
>> Moreover, there is a kind of chicken-and-egg problem: all arguments are
>> parsed
>> and set as property on target. But you can't set property while there is
>> no
>> target.
>>
>> So as quick work-around I made private copy of ExternalProject.cmake and
>> pass
>> sources as directory property.
>>
>> So I'm asking for ideas how to properly implement this feature: modify
>> somehow
>> parameters parsing in ExternalProject, or may be introduce command which
>> allows
>> adding new sources to existing targets (I'm not sure if this will work,
>> but for
>> me it sounds like target_link_libraries command).
>> ======================================================================
>>
>> ----------------------------------------------------------------------
>>  (0027196) David Cole (manager) - 2011-08-12 09:23
>>  http://public.kitware.com/Bug/view.php?id=12322#c27196
>> ----------------------------------------------------------------------
>> I don't think we should do this.
>>
>> If we allow source files from external projects to be added directly to
>> the IDE
>> representations of the external projects in the containing project, then
>> people
>> will expect the dependencies to work correctly automatically...
>>
>> The dependencies will not work automatically. You will have to forcefully
>> trigger an incremental rebuild of the external project on *any* build of
>> the
>> containing project, and then hope that its build system appropriately
>> picks up
>> only the incremental build changes necessary.
>>
>> I view this as fragile, and would not like to see it go in CMake unless it
>> can
>> be made robust, and shown to work automatically and as developers would
>> expect
>> in the vast majority of use cases.
>>
>> ----------------------------------------------------------------------
>>  (0027197) David Cole (manager) - 2011-08-12 09:24
>>  http://public.kitware.com/Bug/view.php?id=12322#c27197
>> ----------------------------------------------------------------------
>> If you need more help on this issue/topic, please send email to the CMake
>> users
>> list asking for advice there. There's a much wider readership of the
>> mailing
>> list than there is of the bug database.
>>
>> Issue History
>> Date Modified    Username       Field                    Change
>> ======================================================================
>> 2011-07-08 05:27 Yuri           New Issue
>> 2011-08-12 09:19 David Cole     Assigned To               => David Cole
>> 2011-08-12 09:19 David Cole     Status                   new => assigned
>> 2011-08-12 09:23 David Cole     Note Added: 0027196
>> 2011-08-12 09:23 David Cole     Status                   assigned =>
>> resolved
>> 2011-08-12 09:23 David Cole     Fixed in Version          => CMake 2.8.6
>> 2011-08-12 09:23 David Cole     Resolution               open => won't fix
>> 2011-08-12 09:24 David Cole     Note Added: 0027197
>> ======================================================================
>>
>
>