Replace CMake generated version files with checked-in versions

[darbyjohnston]

In PR #1907 we added version headers so applications could identify which OpenTimelineIO they were using. However this also introduced a dependency on CMake to generate the headers, which can cause issues for other projects that use OTIO without CMake (for example the OTIO Swift bindings).

This PR replaces the CMake file generation with checked-in files, and instead has CMake parse the version from the checked-in header files. This is similar to what OpenEXR does for their version handling.

[meshula]

looking good, minor request

[meshula]

Here's a variant that leaves no room for human forgetfulness

#define OPENTIME_VERSION_MAJOR 0
#define OPENTIME_VERSION_MINOR 19
#define OPENTIME_VERSION_PATCH 0
#define OPENTIME_VERSION
v##OPENTIME_VERSION_MAJOR####OPENTIME_VERSION_MINOR####OPENTIME_VERSION_PATCH
#define OPENTIME_VERSION_NS
v##OPENTIME_VERSION_MAJOR##_##OPENTIME_VERSION_MINOR

[darbyjohnston]

Maybe I'm missing something, but that doesn't seem to be working for me using VS2022. I get: vOPENTIME_VERSION_MAJOR_OPENTIME_VERSION_MINOR_OPENTIME_VERSION_PATCH.

[jminor]

That looks like too many ## in a row, or missing some _ between?. Here's how that's supposed to work:
https://gcc.gnu.org/onlinedocs/cpp/Concatenation.html

[darbyjohnston]

Right, but I don't think the macros are expanding like expected. Running this simple example through cpp on Linux:

#define VERSION_MAJOR 1
#define VERSION_MINOR 2
#define VERSION_NS v##VERSION_MAJOR##_##VERSION_MINOR

namespace VERSION_NS {}

Results in this output:

namespace vVERSION_MAJOR_VERSION_MINOR {}

I can get it to work by using macro arguments, but I don't think the added complexity is worth it:

#define VERSION_MAJOR 1
#define VERSION_MINOR 2
#define VERSION_NS v##VERSION_MAJOR##_##VERSION_MINOR
#define VERSION_NS2(MAJOR, MINOR) v##MAJOR##_##MINOR
#define VERSION_NS3(MAJOR, MINOR) VERSION_NS2(MAJOR, MINOR)

namespace VERSION_NS {}
namespace VERSION_NS2(VERSION_MAJOR, VERSION_MINOR) {}
namespace VERSION_NS3(VERSION_MAJOR, VERSION_MINOR) {}

Results in this output:

namespace vVERSION_MAJOR_VERSION_MINOR {}
namespace vVERSION_MAJOR_VERSION_MINOR {}
namespace v1_2 {}

[meshula]

same DRY note as above

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.15%. Comparing base (f3cb304) to head (d3d5713).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1993   +/-   ##
=======================================
  Coverage   85.15%   85.15%           
=======================================
  Files         181      181           
  Lines       12783    12783           
  Branches     1206     1206           
=======================================
  Hits        10885    10885           
  Misses       1715     1715           
  Partials      183      183           

Flag	Coverage Δ
py-unittests	85.15% <ø> (ø)

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[meshula]

Sorry, I don't know how I typed 4 #'s in a row. I'm still in favor of concatenation even with a helpy macro!

[darbyjohnston]

Sorry, I don't know how I typed 4 #'s in a row. I'm still in favor of concatenation even with a helpy macro!

That requires updating every source file with the new macro. That seems like a lot of work to not duplicate a number, plus it also adds complexity which I think undermines the benefits of DRY.