We have two concepts: a list of files that should be extracted from an
intermediate build artifact to be used in a later build artifact, and for a
given artifact, a list "donors". The first list was called "extract", because
it is passed to the .extract_objects() meson function, and the second was
called "objects", because that is the meson parameter to specify pre-built
objects files (6350d2dbd9). But this naming is
confusing: we don't care about the 'extract' step, this is something internal
to the build machinery. And 'objects' is a very generic term.
Let's use 'export' for the stuff that is "exported" for other binaries to use,
and 'import' to say where to import from. Those terms are symmetrical and the
association between them should be intuitive. (If you think the terms are
actually assymetrical, there are precedents for confusing the import with the
import sources. E.g. in modern English, turkeys are called so because they were
imported from the Americas and guineafowls were imported from Africa via
Türkiye and all that foreign stuff is alike.)
In all cases, everything that we list in 'extract', we also list in
'sources'. We can simplify things by automatically appending the first
list to the second.
In the listings, move 'extract' key right below 'sources', since now
they are both "sources", just with slightly different meanings.
Also, let's deflatten the lists of sources in preparation for the
next commit at the same time.
In systemctl, we split out systemctl-main.c to make sure the definition
of main() is in a separate object which allows us to extract the systemctl.c
object and link it in the fuzzer target without getting a multiple definition
error when linking.
Currently, when we want to add unit tests for code that is compiled into
an executable, we either compile the code at least twice (once for the
executable, and once for each test that uses it) or we create a static
library which is then used by both the executable and all the tests.
Both of these options are not ideal, compiling source files more than
once slows down the build for no reason and creating the intermediate
static libraries takes a lot of boilerplate.
Instead, let's use the extract_objects() method that meson exposes on
build targets. This allows us to extract the objects corresponding to
specific source files and use them in other executables. Because we
define all executables upfront into a dictionary, we integrate this into
the dictionary approach by adding two new fields:
- 'extract' takes a list of files for which objects should be extracted.
The extracted objects are stored in a dict keyed by the executable name
from which they were extracted.
- 'objects' takes the name of an executable from which the extracted
objects should be added to the current executable.
One side effect of this approach is that we can't build test executables
anymore without building the main executable, so we stop building test
executables unless we're also building the main executable. This allows
us to switch to using subdir_done() in all of these subdirectories to skip
parsing them if the corresponding component is disabled.
These changes get me down from 2439 => 2403 ninja targets on a full rebuild
from scratch.
Although this slightly more verbose it makes it much easier to reason
about. The code that produces the tests heavily benefits from this.
Test lists are also now sorted by test name.
Zbigniew Jędrzejewski-Szmek
Zbigniew Jędrzejewski-Szmek
Daan De Meyer
Yu Watanabe
Jan Janssen