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.
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
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.
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
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
We check for the existence of PDB files in the install script, so we
don't need to do all this mucking about here. That's more robust too
because we don't need to parse build arguments in buildtype=plain
and decide if the PDB file would be generated.
Factor it out into a function in mesonlib.py. This will allow us to
reuse it for generators and for configure_file(). The latter doesn't
implement this at all right now.
Also includes unit tests.
And actually test that prog.path() works. The earlier test was just
running the command without checking if it succeeded.
Also make everything use prog.get_command() or get_path() instead of
accessing the internal member prog.fullpath directly.
Also, now the linker options are added from various sources in the same
order as compiler arguments for compile commands. As a result, all
libraries and library paths from external and internal sources are added
after all the linker options have been added.
As a result option_link_args() are added when libraries are added to the
list since currently the only thing they add are the libraries specific
in cpp_winlibs/c_winlibs. This fixes an issue where compilation with the
MinGW toolchain (which uses static libraries for winlibs) would result
in undefined symbol errors because the static libraries would be added
in the very beginning and hence would not be scanned for symbols.
Detailed comments have been added that explain where each option is
coming from and why it's been added at that specific point.
More improvements are necessary here because we currently still
unnecessarily repeat libraries from dependencies over and over, which
is a major problem in gst-build because inter-subproject dependencies
cause linker command-lines to almost exceed the argument list length
limit imposed by the kernel. It is also causing us to unnecessarily
add static libraries which have already been linked into a shared
library. See: self.build_target_link_arguments()
At the same time, also fix the order in which compile arguments are
added. Detailed comments have been added concerning the priority and
order of the arguments.
Also adds a unit test and an integration test for the same.
Always generate the vcxproj file, but only add it to the build
configuration if it's either supposed to be built by default, or is
a dependency of another target that is built by default.
The purpose of this class is to make it possible to sanely generate
compiler command-lines by ensuring that new arguments appended or added
to a list of arguments properly override previous arguments.
For instance:
>>> a = CompilerArgs(['-Lfoo', '-DBAR'])
>>> a += ['-Lgah', '-DTAZ']
>>> print(a)
['-Lgah', '-Lfoo', '-DBAR', '-DTAZ']
Arguments will be de-duped if it is safe to do so. Currently, this is
only done for -I and -L arguments (previous occurances are removed when
a new one is added) and arguments that once added cannot be overriden
such as -pipe are removed completely.
With the 'install_mode' kwarg, you can now specify the file and
directory permissions and the owner and the group to be used while
installing. You can pass either:
* A single string specifying just the permissions
* A list of strings with:
- The first argument a string of permissions
- The second argument a string specifying the owner or
an int specifying the uid
- The third argument a string specifying the group or
an int specifying the gid
Specifying `false` as any of the arguments skips setting that one.
The format of the permissions kwarg is the same as the symbolic
notation used by ls -l with the first character that specifies 'd',
'-', 'c', etc for the file type omitted since that is always obvious
from the context.
Includes unit tests for the same. Sadly these only run on Linux right
now, but we want them to run on all platforms. We do set the mode in the
integration tests for all platforms but we don't check if they were
actually set correctly.
Cache the absolute dir that the script is searched in and the name of
the script. These are the only two things that change.
Update the test to test for both #1235 and the case when a script of the
same name is in a different directory (which also covers the subproject
case).
Closes#1235
./mesonbuild/scripts/regen_checker.py:35:5: F841 local variable 'scriptdir' is assigned to but never used
scriptdir = os.path.split(__file__)[0]
^
./mesonbuild/scripts/yelphelper.py:84:13: F841 local variable 'symfile' is assigned to but never used
symfile = os.path.join(install_dir, m)
^
./mesonbuild/backend/backends.py:164:13: F841 local variable 'lang' is assigned to but never used
lang = comp.get_language()
^
./mesonbuild/backend/ninjabackend.py:1286:9: F841 local variable 'scriptdir' is assigned to but never used
scriptdir = self.environment.get_script_dir()
^
./mesonbuild/backend/vs2010backend.py:736:9: F841 local variable 'additional_options_set' is assigned to but never used
additional_options_set = True
^
Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
The script will manually delete all custom_target outputs that are
directories instead of files. This is needed because on platforms other
than Windows, Ninja only deletes directories while cleaning if they are
empty.
Closes#1220
Without this, the user has to both compile the resource with
gnome.compile_resources, pass that to the target sources, and also
pass --gresources=/path/to/gres.xml to vala_args in the target.
With this, we will do that automatically.
This greatly improves the logic for determining the linker. Previously,
we would completely break if a target contained only extracted objects
and we were using more than one compiler in our project.
This also fixes determination of the linker if our target only contains
generated objc++ sources, and other funky combinations.
This avoids us having no compilers at all for targets that are composed
entirely of objects with no sources.
Now we will always have a compiler for a target even if it is composed
entirely of objects generated with custom targets unless it has
completely unknown sources.
Instead of using a whitelist, use a blacklist. Also print a more useful
error if the regex fails to match.
Use an underscore in the gir test to trigger this.
Fixes#436
Make so both executable() targets that are marked as native and
external programs (which are usually build tools compiled for the
host machine) are not supposed to be run with the exe wrapper.
Not only does extract_all_objects() now work properly again,
extract_objects() also works if you specify a subset of sources all of
which have been compiled into a single unified object.
So, for instance, this allows you to extract all the objects
corresponding to the C sources compiled into a target consisting of
C and C++ sources.
Pre-calculate the output directory for GeneratedList and CustomTarget so
we can directly use the same code for both while compiling C/C++ files
and headers.
There is no reason to have separate branches for GeneratedList and
CustomTarget since both can be used in almost exactly the same way for
generating sources.
This is going to used next for adding generated sources support to Vala.
get_filename() made no sense for CustomTarget since it can have multiple
outputs. Also use get_outputs() for GeneratedList since it has the same
meaning and remove unused set_generated().
As a side-effect, we now install all the outputs of a CustomTarget.
This is done by adding a new compiler method called 'no_warn_args' which
returns the argument(s) required for the compiler to emit no warnings
for that compilation.
This take care of not disabling warnings for C code compiled into the
BuildTarget. Also includes tests for ensuring all this.
https://github.com/mesonbuild/meson/issues/864
With C/C++, on Windows you don't need to pass any arguments for a static
library to be PIC. On UNIX platforms you need to pass -fPIC.
Other languages such as D have compiler-specific PIC arguments required
for PIC support in static libraries on UNIX platforms.
This kwarg allows people to specify which static libraries should be
built with PIC support. This is usually used for static libraries that
will be linked into shared libraries.
self.dep_rules is not set anywhere by anything, so this code always
results in a no-op. If it didn't result in a no-op, it would need to be
seriously rewritten because it has bitrotten and makes no sense anymore.
This is definitely more correct since it takes into account the
cross-compilation status. We also now do the Java and CSharp sanity
checks on the BuildTarget level instead of in the Ninja backend.
For commands that always output to stdout and don't have a "-o" or
"--output" or some other similar option, this 'capture' setting allows
the build to capture the result and place it in the output file.
This allows us to output either the relative or absolute path as
requested. Fixes usage of configure_file inside CustomTarget commands
with the VS backends.
This commit contains several changes to the naming and versioning of
shared and static libraries. The details are documented at:
https://github.com/mesonbuild/meson/pull/417
Here's a brief summary:
* The results of binary and compiler detection via environment functions
are now cached so that they can be called repeatedly without
performance penalty. This is necessary because every
build.SharedLibrary object has to know whether the compiler is MSVC or
not (output filenames depend on that), and so the compiler detection
has to be called for each object instantiation.
* Linux shared libraries don't always have a library version. Sometimes
only soversions are specified (and vice-versa), so support both.
* Don't use versioned filenames when generating DLLs, DLLs are never
versioned using the suffix in the way that .so libraries are. Hence,
they don't use "aliases". Only Linux shared libraries use those.
* OS X dylibs do not use filename aliases at all. They only use the
soversion in the dylib name (libfoo.X.dylib), and that's it. If
there's no soversion specified, the dylib is called libfoo.dylib.
Further versioning in dylibs is supposed to be done with the
-current_version argument to clang, but this is TBD.
https://developer.apple.com/library/mac/documentation/DeveloperTools/Conceptual/DynamicLibraries/100-Articles/DynamicLibraryDesignGuidelines.html#//apple_ref/doc/uid/TP40002013-SW23
* Install DLLs into bindir and import libraries into libdir
* Static libraries are now always called libfoo.a, even with MSVC
* .lib import libraries are always generated when building with MSVC
* .dll.a import libraries are always generated when building with
MinGW/GCC or MinGW/clang
* TODO: Use dlltool if available to generate .dll.a when .lib is
generated and vice-versa.
* Library and executable suffix/prefixes are now always correctly
overriden by the values of the 'name_prefix' and 'name_suffix' keyword
arguments.
Instead, return the values of the test and benchmark setup data files so
that the ninja/osx/vs backends can use those filenames instead of
hard-coding them.
When a CustomTarget is run with a command that is an executable built
by the project which also has a DLL built in the same project as a
dependency, the EXE can't run on Windows because the DLL can't be found.
On UNIX-like systems, we set the RPATH using the linker so these
dependencies can be found, but on Windows the only way is to set the
PATH environment variable.
The same problem exists for tests, so we reuse that infrastructure by
creating a new meson_exe.py script that can be used as a wrapper to run
CustomTarget commands on Windows. This can later also be extended to add
support for setting an environment while calling the command needed to
generate a CustomTarget: https://github.com/mesonbuild/meson/issues/266
1. Dependencies must be set up with the target's id instead of its
basename.
2. Extracted object output file names must not include the directory
prefix, because MSBuild puts all object files into the same directory
and names them srcfilename.obj instead of dir/filename.obj or
dir_filename.obj.
Noticed when trying to pass custom optimization flags, and hence setting
buildtype to plain, that warnings for different levels were not passed to
compiler.
This was a bit confusing since mesonconf still displayed "warning_level=3"
and -Werror was passed correctly due to "werror=true". So this change
aligns warning_level behavior with werror. That is, heed what is in
project() in meson.build but user can still override if necessary.
This is very useful to prevent compiler noise about invalid cflags; particularly
for the -mms-bitfields cflag which most libraries send to the mingw-gcc
compiler. More can be added later.
Peter Hutterer