[gdal-dev] Removal of Python SWIG python generated files from git

[Even Rouault]

Hi,

take this email as a mini-RFC regarding the changes in 
https://github.com/OSGeo/gdal/pull/7390 which remove the SWIG python 
generated files from git master, and thus make the SWIG binary a 
requirement to build the Python bindings.

Below, the text of the PR:

This removes a long-time oddity where the SWIG generated .py and .cpp 
files were stored in git, which was inconvenient for contributors, 
requiring them to have a precise SWIG version and enabling a specific 
CMake variable to resync the generated files to the source files, and 
causing confusion to occasional contributors who sometimes accidentally 
submitted changes to generated files instead of their source files. This 
was also different from the Java and CSharp bindings, which didn't have 
the generated files in git and required SWIG to be available to generate 
them.

Bonus of this move: in the process, due to some of our most up to date 
CI targets using SWIG 4.1, it enabled to fix 2 errors in SWIG syntax 
that were rejected by SWIG 4.1 (and hidden up to now due to using 4.0.2 
as our baseline)

This change shouldn't be a major hurdle for distributors, as most known 
binary distributions did regenerate the files anyway.

Note to people updating an existing git checkout: now the 
BUILD_JAVA/CSHARP/PYTHON_BINDINGS CMake variables are strictly honored. 
They are now initialized to ON only if all build requirements are 
available (SWIG and Python for the python bindings), and if set to ON 
but a requirement is missing, CMake fails. This might cause issues for 
people for example not having the requirements for the Java or CSharp 
bindings, but with an existing CMakeCache.txt with them set. Fix: run 
"cmake -UBUILD_JAVA_BINDINGS -UBUILD_CHSARP_BINDINGS 
-UBUILD_PYTHON_BINDINGS"

Even

-- 
http://www.spatialys.com
My software is free, but my time generally not.