Commit 325a231a added stricter keyword argument checking, but didn't enable
keyword arguments for add_projects_link_arguments() and
add_global_link_arguments(). This makes them fail with this error:
Meson encountered an error in file meson.build, line 19, column 0:
Function does not take keyword arguments.
However, the language argument is required. Removing it produces this error
instead:
Meson encountered an error in file meson.build, line 19, column 0:
Missing language definition in add_project_link_arguments
Fix this by adding 'language' as a required keyword argument. Also add calls to
these in the "146 C and CPP link" test case.
This class now consolidates a lot of the logic that each external
dependency was duplicating in its class definition.
All external dependencies now set:
* self.version
* self.compile_args and self.link_args
* self.is_found (if found)
* self.sources
* etc
And the abstract ExternalDependency class defines the methods that
will fetch those properties. Some classes still override that for
various reasons, but those should also be migrated to properties as
far as possible.
Next step is to consolidate and standardize the way in which we call
'configuration binaries' such as sdl2-config, llvm-config, pkg-config,
etc. Currently each class has to duplicate code involved with that
even though the format is very similar.
Currently only pkg-config supports multiple version requirements, and
some classes don't even properly check the version requirement. That
will also become easier now.
This simplifies everything since it means we will always search for the
dependency again on the system if it wasn't found. This is particularly
important when running `ninja reconfigure` with an edited
PKG_CONFIG_PATH to point to a path that contains more pkg-config files.
The old caching was a mess of spaghetti code layered over pasta code.
The new code is well-commented, is clear about what it's trying to do,
and uses a blacklist of keyword arguments instead of a whitelist while
generating identifiers for dep caching which makes it much more robust
for future changes.
The only side-effect of forgetting about a new keyword argument would
be that the dependency would not be cached unless the values of that
keyword arguments were the same in the cached and new dependency.
There are also more tests which identify scenarios that were broken
earlier.
All our cached_dep magic was totally useless since we ended up using
the same identifier for native and cross deps. Just nuke all this
cached_dep code since it is very error-prone and improve the
identifier generation instead.
For instance, this is broken *right now* with the `type_name` kwarg.
Add a bunch of tests to ensure that all this actually works...
Closes https://github.com/mesonbuild/meson/issues/1736
Refactor to use ExternalProgram for the command instead of duplicating
that code (badly). Also improve messages to say "or not executable"
when a script/command is not found.
Also allow ExternalPrograms to be passed as arguments to
run_command(). The only thing we're doing by preventing that is
forcing people to use prog.path()
The file will always exist by the time run_command() is invoked, so
there is no reason why we should forbid it. Also allow using File
objects as the command to run since strings are also allowed.
Provide a proper error message, rather than the current
"Command cannot have '@INPUT0@', since no input files were specified"
which doesn't actually tell us where things are going wrong.
Meson has a common pattern of using 'if len(foo) == 0:' or
'if len(foo) != 0:', however, this is a common anti-pattern in python.
Instead tests for emptiness/non-emptiness should be done with a simple
'if foo:' or 'if not foo:'
Consider the following:
>>> import timeit
>>> timeit.timeit('if len([]) == 0: pass')
0.10730923599840025
>>> timeit.timeit('if not []: pass')
0.030033907998586074
>>> timeit.timeit('if len(['a', 'b', 'c', 'd']) == 0: pass')
0.1154778649979562
>>> timeit.timeit("if not ['a', 'b', 'c', 'd']: pass")
0.08259823200205574
>>> timeit.timeit('if len("") == 0: pass')
0.089759664999292
>>> timeit.timeit('if not "": pass')
0.02340641999762738
>>> timeit.timeit('if len("foo") == 0: pass')
0.08848102600313723
>>> timeit.timeit('if not "foo": pass')
0.04032287199879647
And for the one additional case of 'if len(foo.strip()) == 0', which can
be replaced with 'if not foo.isspace()'
>>> timeit.timeit('if len(" ".strip()) == 0: pass')
0.15294511600222904
>>> timeit.timeit('if " ".isspace(): pass')
0.09413968399894657
>>> timeit.timeit('if len(" abc".strip()) == 0: pass')
0.2023209120015963
>>> timeit.timeit('if " abc".isspace(): pass')
0.09571301700270851
In other words, it's always a win to not use len(), when you don't
actually want to check the length.
Ideally, all dependency objects should support this, but it's a lot of
work and isn't supported by all dependency types (like frameworks and
pkg-config), so for now just enable it for external libraries.
Jussi Pakkanen