This moves the generated files out of the source tree and into
the build directory. They are now regenerated each time they are
needed, based on the timestamp of the generated file compared to
the timestamp of the lemon file.
To do this, we also bundle lemon into the thirdparty directory
and build it for ourselves since it is a very tiny program and
not all platforms seem to distribute it in a consistent manner.
Fixes https://gitlab.com/kicad/code/kicad/issues/5013
This changes make_lexer() so that it no longer generates a custom target
but instead attaches the generated files to an existing one (so the first
argument now is the name of an existing library or executable, and it needs
to come after the add_library/add_executable call).
The generated source is no longer listed in the project sources, as it is
added by the function. The files are generated in the build tree rather
than the source tree, and the directory is added to the include path for
the respective project as well as exported to projects linking against it.
Generated files in subdirectories are somewhat supported, but need to be
referenced with the same name as they were generated (i.e. including the
subdirectory name).
Fixes: lp:1831643
* https://bugs.launchpad.net/kicad/+bug/1831643
Fixes: lp:1832357
* https://bugs.launchpad.net/kicad/+bug/1832357
Fixes: lp:1833851
* https://bugs.launchpad.net/kicad/+bug/1833851
eeschema cpp files consume generated header files that have targets in
the common directory, so no dependencies get created from eeschema. We
add the dependencies in common to force the setting through libraries.
Fixes: lp:1831643
* https://bugs.launchpad.net/kicad/+bug/1831643
Building custom targets that depend on custom commands such as our
keyword lexer requires two layers of indirection to pick up changes
properly and not overwrite the same file in parallel builds.
Fixes: lp:1831643
* https://bugs.launchpad.net/kicad/+bug/1831643