We never use preprocessed output anywhere except compiler checks,
so we don't care about the debugging information that it adds.
Just always disable it.
Closes https://github.com/mesonbuild/meson/issues/1726
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.
This adds a depdendncy wrapper for llvm-config based on the wxwidgets
dependency. IT handles libs, version, include dir, and the llvm unique
concept of components. These components are individual pieces of the
LLVM library that may or may not be available depending on the platform.
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.
Elliott Sales de Andrade
Jussi Pakkanen
Mathieu Duponchelle
Sven Steinbauer
Patrick Griffis
Nirbheek Chauhan
Peter Hutterer
Chiu Yue Chun
Dylan Baker
Guillaume Poirier-Morency