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.
Use a titlecase for arbitrary language, this was we don't have 'C' in
lowercase.
Rename 'Static linking library $out' for 'Linking static target $out.'.
Add missing punctuation.
We receive these options from the 'argparse' module in a random
order. To ensure the build.ninja file doesn't include random variations
we should sort them before writing them back out.
We were more hesitant to do this earlier because it might have messed
up custom_target command lines, but since we always use a wrapper for
that now, it should be ok to do this.
Add a test in the form of a funky generator script.
Cygwin executables are still loaded by the Windows PE loader, so PATH needs
to include any extra directories where required DLLs can be found.
Cygwin uses a unix style ':'-separated PATH. os.pathsep is used correctly
on extra_paths in meson_exe.py, but not in mesontest.py
When install_dir was set for a shared_library, the import library
would not be installed at all, which is unintended.
Instead, install it into the custom directory if it is set, otherwise
install it in the default import library installation directory.
Includes a test for this.
You can now pass a list of strings to the install_dir: kwarg to
build_target and custom_target.
Custom Targets:
===============
Allows you to specify the installation directory for each
corresponding output. For example:
custom_target('different-install-dirs',
output : ['first.file', 'second.file'],
...
install : true,
install_dir : ['somedir', 'otherdir])
This would install first.file to somedir and second.file to otherdir.
If only one install_dir is provided, all outputs are installed there
(same behaviour as before).
To only install some outputs, pass `false` for the outputs that you
don't want installed. For example:
custom_target('only-install-second',
output : ['first.file', 'second.file'],
...
install : true,
install_dir : [false, 'otherdir])
This would install second.file to otherdir and not install first.file.
Build Targets:
==============
With build_target() (which includes executable(), library(), etc),
usually there is only one primary output. However some types of
targets have multiple outputs.
For example, while generating Vala libraries, valac also generates
a header and a .vapi file both of which often need to be installed.
This allows you to specify installation directories for those too.
# This will only install the library (same as before)
shared_library('somevalalib', 'somesource.vala',
...
install : true)
# This will install the library, the header, and the vapi into the
# respective directories
shared_library('somevalalib', 'somesource.vala',
...
install : true,
install_dir : ['libdir', 'incdir', 'vapidir'])
# This will install the library into the default libdir and
# everything else into the specified directories
shared_library('somevalalib', 'somesource.vala',
...
install : true,
install_dir : [true, 'incdir', 'vapidir'])
# This will NOT install the library, and will install everything
# else into the specified directories
shared_library('somevalalib', 'somesource.vala',
...
install : true,
install_dir : [false, 'incdir', 'vapidir'])
true/false can also be used for secondary outputs in the same way.
Valac can also generate a GIR file for libraries when the `vala_gir:`
keyword argument is passed to library(). In that case, `install_dir:`
must be given a list with four elements, one for each output.
Includes tests for all these.
Closes https://github.com/mesonbuild/meson/issues/705
Closes https://github.com/mesonbuild/meson/issues/891
Closes https://github.com/mesonbuild/meson/issues/892
Closes https://github.com/mesonbuild/meson/issues/1178
Closes https://github.com/mesonbuild/meson/issues/1193
Previously, two functionally identical builds could produce different
build.ninja files. The ordering of the rules themselves doesn't affect
behaviour, but unnecessary changes in commandline arguments can cause
spurious rebuilds and if the ordering of the overall file is stable
than it's easy to use `diff` to compare different build.ninja files
and spot the differences in ordering that are triggering the unnecessary
rebuilds.
The actual fix is quite involved (#1526), so just disable this for now
since it's much worse to not be able to generate static libraries at
all vs a minor bug in static libraries getting stale objects (#1356)
Closes https://github.com/mesonbuild/meson/issues/1517
Points to the `mesonintrospect.py` script corresponding to the
currently-running version of Meson.
Includes a test for all three methods of running scripts/commands.
Closes https://github.com/mesonbuild/meson/issues/1385
The paths are already relative to the target dir.
Includes a test for this which generates and builds in subdirs. If all
the generation and usage is done in the build root, this bug will
obviously not be triggered.
Besides fixing output capture, it also fixes a strange bug in MSBuild
where if the command list is too long, it will remove random
characters from the command list before passing it to the command.
Closes https://github.com/mesonbuild/meson/issues/1417
For newer VS versions, we can simply rely on 'VisualStudioVersion' being
set in the environment.
For VS2010, we fall back to check 'VSINSTALLDIR' for the version string.
If the backend can not be auto detected, we raise an exception to make the
user choose an explicit backend.
We also print the detected backend to the meson log.
We were adding them to the CompilerArgs instance in the order in which
they are specified, which is wrong because later dependencies would
override previous ones. Add them in the reverse order instead.
Closes https://github.com/mesonbuild/meson/issues/1495
Patrick Griffis
Peter Hutterer
Jussi Pakkanen
Elliott Sales de Andrade
Guillaume Poirier-Morency
Dylan Baker
Paolo Borelli
Nirbheek Chauhan
Matthias Klumpp
Sam Thursfield
Jon Turney
melak47
Nicolas Schneider