[cmake-developers] [CMake 0015679]: ExternalProject with Ninja generator should import sub-project's build.ninja into the parent project

[Mantis Bug Tracker]

The following issue has been SUBMITTED. 
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http://public.kitware.com/Bug/view.php?id=15679 
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Reported By:                Chris
Assigned To:                
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Project:                    CMake
Issue ID:                   15679
Category:                   CMake
Reproducibility:            N/A
Severity:                   feature
Priority:                   normal
Status:                     new
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Date Submitted:             2015-08-04 12:45 EDT
Last Modified:              2015-08-04 12:45 EDT
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Summary:                    ExternalProject with Ninja generator should import
sub-project's build.ninja into the parent project
Description: 
Ninja's scheduling works best if it has a full picture of what you're building.
Doing that in projects that extensively use ExternalProject can be tricky. To
make this work I believe CMake needs to do 3 things that it doesn't do today.

(1) ExternalProject needs to prefix all the rules and targets in the ninja file
it generates so that they don't conflict with the parent project's rules or
targets
(2) ExternalProject calls to CMake need to be marked as Generator rules in Ninja
so that Ninja will re-exec itself after running CMake
(3) ExternalProject needs to generate Ninja includes in the parent project.

Additional Information: 
This request is coming out of the LLVM developer community. As we're moving more
actively to CMake we are leveraging ExternalProject more and more for generating
cross-compiled targets, bootstrapping the compiler and generating test targets.
We believe these improvements to ExternalProject will make for a better
developer experience on our end.

Thanks,
-Chris
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Issue History 
Date Modified    Username       Field                    Change               
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2015-08-04 12:45 Chris          New Issue                                    
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