GCC does not print a warning or error for unknown options if the options
are to disable warnings. Therefore, when checking for options starting
'-Wno-', also check the opposite enabling option. This fixes the case
where e.g. -Wno-implicit-fallthrough is incorrectly reported as supported
by gcc 5.4. To avoid missed warnings when using combinations of flags, such
as in test case "112 has arg", we limit the checking of for the positive
option to where the negative option is checked alone.
This patch exploits the information residing in ltversion to set the
-compatibility_version and -current_version flags that are passed to the
linker on macOS.
GNU LD does not use soname when linking a PE/COFF binary, so it makes no
difference, but it breaks when using the llvm linker (lld), which does
not support the soname flag when building PE/COFF binaries for Windows.
Fix#3179
This way they override all other arguments. This matches the order of
link arguments too.
Note that this means -I flags will come in afterwards and not override
anything else, but this is correct since that's how toolchain paths
work normally too -- they are searched last.
Closes https://github.com/mesonbuild/meson/issues/3089
Otherwise we can't do the following workflow:
if not find_program('foo', required : false).found()
subproject('provides-foo')
endif
Where 'provides-foo' has a meson.override_find_program() on
a configure_file() or similar.
The linkers currently do not support ninja compatible output of
dependencies used while linking. Try to guess which files will be used
while linking in python code and generate conservative dependencies to
ensure changes in linked libraries are detected.
This generates dependencies on the best match for static and shared
linking, but this should not be a problem, except for spurious
rebuilding when only one of them changes, which should not be a problem.
Also makes sure to ignore any libraries generated inside the build, to
keep the optimisation working where changes in a shared library only
cause relink if the symbols have changed as well.
Previously pkg-config files generated by the pkgconfig modules for static libraries
with dependencies could only be used in a dependencies with `static: true`.
This was caused by the dependencies only appearing in Libs.private even
if they are needed in the default linking mode. But a user of a
dependency should not have to know if the default linking mode is static
or dynamic; A dependency('somelib') call should always pull in all
needed pieces into the build.
Now for meson build static libraries passed via `libraries` to the generate
method automatically promote dependencies to public.
This caching is only for a single run, so it doesn't help reconfigure.
However, it is useful for subproject setups where different subprojects
will run the same compiler checks.
The cache is also per compiler instance and is not used for functions
that want to read or run the outputted object file or binary.
For gst-build, this halves the number of compiler checks that are run
and reduces configuration time by 20%.
when flattening the chained dependencies of an object, we don't need to
create any new internal dependencies if all the fields to be added to it
are empty.
For projects with a lot of libraries and dependency objects this can lead
to noticeable performance improvements.
fixup
When getting dependencies, we don't need to get the same dependencies and
dependency chains multiple times. If library a depends on x, y and z, and
library b depends on a, then we should not have to iterate through x, y and
z multiple times. Pruning at the stage of scanning the dependencies leads
to significant time savings when running meson
This halves the configure time in gst-build, the aggregate of all
GStreamer repositories.
We can't do this to Popen_safe because we can't be sure that other
programs have no side-effects and will always return the same output
for the same arguments and environment.
Goncalo Carvalho