This further simplifies behavior to match the "build vs host" decision
we did with `c_args` vs `build_c_args`. The rules are now simply:
- `native: true` affects `native: true` targets
- `native: false` affects `native: false` targets
- No native flag is the same as `native: false`
I like this because you don't even have to know what "build" and "host"
mean to understand how it works, and it doesn't depend on whether the
overall build is cross or not.
Fixes#4933
In most cases instead pass `for_machine`, the name of the relevant
machines (what compilers target, what targets run on, etc). This allows
us to use the cross code path in the native case, deduplicating the
code.
As one can see, environment got bigger as more information is kept
structured there, while ninjabackend got a smaller. Overall a few amount
of lines were added, but the hope is what's added is a lot simpler than
what's removed.
It doesn't make much sense to have this and not also have
cross-compilers (so any use of this is already pretty suspect as
probably wrong when cross-compiling).
This information is accessible anyhow via environment.coredata.
Meson itself *almost* only cares about the build and host platforms. The
exception is it takes a `target_machine` in the cross file and exposes
it to the user; but it doesn't do anything else with it. It's therefore
overkill to put target in `PerMachine` and `MachineChoice`. Instead, we
make a `PerThreeMachine` only for the machine infos.
Additionally fix a few other things that were bugging me in the process:
- Get rid of `MachineInfos` class. Since `envconfig.py` was created, it
has no methods that couldn't just got on `PerMachine`
- Make `default_missing` and `miss_defaulting` work functionally. That
means we can just locally bind rather than bind as class vars the
"unfrozen" configuration. This helps prevent bugs where one forgets
to freeze a configuration.
This avoids the duplication where the option is stored in a dict at its
name, and also contains its own name. In general, the maxim in
programming is things shouldn't know their own name, so removed the name
field just leaving the option's position in the dictionary as its name.
This function is currently setup with keyword arguments defaulting to
None. However, it is never called without passing all of it's arguments
explicitly, and only one of it's arguments would actually be valid as
None. So just drop that, and make them all positional. And annotate
them.
This isn't safe given the way python implements default arguments.
Basically python store a reference to the instance it was passed, and
then if that argument is not provided it uses the default. That means
that two calls to the same function get the same instance, if one of
them mutates that instance every subsequent call that gets the default
will receive the mutated instance. The idiom to this in python is to use
None and replace the None,
def in(value: str, container: Optional[List[str]]) -> boolean:
return src in (container or [])
if there is no chance of mutation it's less code to use or and take
advantage of None being falsy. If you may want to mutate the value
passed in you need a ternary (this example is stupid):
def add(value: str, container: Optional[List[str]]) -> None:
container = container if container is not None else []
container.append(value)
I've used or everywhere I'm sure that the value will not be mutated by
the function and erred toward caution by using ternaries for the rest.
Warn when someone tries to use append() or prepend() on an env var
which already has an operation set on it. People seem to think that
multiple append/prepend operations stack, but they don't.
Closes https://github.com/mesonbuild/meson/issues/5087
we can avoid writing code like:
a = c[0]
b = c[1]
by using:
a, b = c
or
a = c[0]
b = c[1:]
by using:
a, *b = c
This saves just a bit of code and is a teeny bit faster. But mostly
for less code
Currently this is implemented as range(min(len(a), len(b)), an then
indexing into a and b to get what we actually want. Fortunately python
provides a function called zip that just does this.
Jussi Pakkanen
Dylan Baker
Xavier Claessens
Daniel Mensinger
John Ericson
Michael Hirsch, Ph.D
John Ericson
Mathieu Duponchelle
Jon Turney
Daniel Eklöf
Nirbheek Chauhan