Otherwise they are built regardless of whether they are actually used by
anything else. Only build them if they're going to be installed or
always-built.
Ideally, we should also do this with all BuildTargets, and provide
a mechanism for people to specify which targets they want built with
'all', and a way for people to add them to custom targets.. Without
this, things like tests and examples are *always* built with no way to
turn that off.
For now, we just do this because it also with tests that check for
dependency issues. Including all CustomTargets in `all` results in
dangling targets to also be built, which hides the problem and makes it
racy.
self.dep_rules is not set anywhere by anything, so this code always
results in a no-op. If it didn't result in a no-op, it would need to be
seriously rewritten because it has bitrotten and makes no sense anymore.
When installing Meson distutils may choose to put shim scripts in the
PATH that only set up the egg requirements before launching the real
`meson.py` contained in the egg.
This means that __file__ points to the real `meson.py` file, but
launching it directly is doomed to fail as it's missing the metadata
contained in the shim to set up the path egg, resulting in errors when
trying to import the `mesonbuild` module.
A similar issue affects Meson when installed as a zipapp, with the
current code going great lengths to figure out how to relaunch itself.
Using argv[0] avoids these issues as it gives us the way the current
executable has been launched, so we are pretty much guaranteed that
using it will create another instance of the same executable.
This is definitely more correct since it takes into account the
cross-compilation status. We also now do the Java and CSharp sanity
checks on the BuildTarget level instead of in the Ninja backend.
When the BuildTarget (executable, shared-library, static-library, etc)
is created, process the source list and assign compilers to this target.
This allows us to do compiler-specific file-naming without resorting to
ugly hacks.
This is one step towards consolidating all the 'what language does this
target use' checks and the 'this target should only have $lang files as
sources' checks we have all over the codebase. All those checks should
be done only when the target is created.
Fixes https://github.com/mesonbuild/meson/issues/526
Also removes useless and incorrect mesonlib.is_32bit() function. We
cannot trust that the architecture that Python is built for is the same
as the one we're targetting.
Nirbheek Chauhan
Elliott Sales de Andrade
Jussi Pakkanen
Patrick Griffis
Sam Thursfield
Emanuele Aina
Franz Zapata
Thibault Saunier