This avoids printing several 'Found:' messages during configure, and
also avoids doing several searches for the same binary. This is already
done by the interpreter for `find_program` calls from build files.
Also move it to the module-wide __init__.py file so it can be used by
other modules as-needed.
Also use it for g-ir-scanner where it was missed in one place, also fix
exception name in the same place.
Instead of adding it everywhere manually, create a wrapper called
mesonlib.Popen_safe and use that everywhere that we call an executable
and extract its output.
This will also allow us to tweak it to do more/different things if
needed for some locales and/or systems.
Closes#1079
Instead of blindly searching in PATH, use
Qt5Dependency.compilers_detect() (same for qt4) to get moc/uic/rcc.
This is much more robust, and it improves the chances that the correct
ones will be found. We still manually verify for now because the
fallback in dependencies.py for searching is stll to look in PATH for
backwards-compat, and because people probably have setups like that.
Also sync the qt4 module with the qt5 module w.r.t. resource compilation
and make the compiled qrc.cpp file unique in terms of the framework
version used (4 vs 5). This is needed for the test to work properly,
which now covers both Qt4 and 5.
Without this a strange exception is spewed that no one would be able to
understand. Finding each of those compilers isn't a problem unless
sources are specified that require those compilers, so only error out in
those cases.
Closes#758