declare_dependencies
This allows dependencies declared in subprojects to set variables, and
for those variables to be accessed via the get_variable method, just
like those from pkg-config and cmake. This makes it easier to use
projects from subprojects in a polymorphic manner, lowering the
distinction between a subproject and an external dependency every
further.
There are three problems:
1) Dunders like `__lt__` and `__gt__` don't return bool, they return
either a bool or the NotImplemented singleton to signal that they don't
know how to be compared.
2) The don't take type object, the take `typing.Any`
3) They need to return NotImplemented if the comparison is not
implemented, this allows python to try the inverse dunder from the
other object. If that object returns NotImplemented as well a
TypeError is raised.
t.pic won't be defined. We can only hope it has been built with -fPIC.
Linker will complain otherwise any way.
t.extract_all_objects_recurse() won't be defined. We could support this
case by extracting the archive somewhere and pick object files.
Some things, like `method[...](...)` or `x: ... = ...` python 3.5
doesn't support, so I made a comment instead with the intention that it
can someday be made into a real annotation.
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.
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.
Some things, like `method[...](...)` or `x: ... = ...` python 3.5
doesn't support, so I made a comment instead with the intention that it
can someday be made into a real annotation.
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.
If find_program() returns a file from the source directory, anything
that uses it should add the file to the dependencies, so that they are
rebuilt whenever the script changes. Generator is not doing that.
While at it, I am doing two related fixes:
- Generator is not checking whther the generator actually was found,
resulting in a Python error involving NoneType if it isn't. To minimize
backwards compatibility issues, I am only raising the error when
g.process() is acutally called.
- the error message for custom_target with a nonexisting program
erroneously mention a not-found external program "nonexistingprogram".
The new error is similar to the one I am adding for generators.
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
I'll be using this later, but it seems useful to allow dependencies to
that have special handlers to declare that they depend on other
dependencies. This should allow us to stop treating threads special
internally and just make it a normal dependency.
Nirbheek Chauhan
Dylan Baker
Daniel Mensinger
taz-007
Xavier Claessens
Jussi Pakkanen
Jakub Adam
Aleksey Gurtovoy
Rachel Mant
Marc-André Lureau
Cody Schafer
Roman Shpuntov
John Ericson
John Ericson
Jon Turney
Michael Hirsch, Ph.D
TheQwertiest
Paolo Bonzini