* unittests: fix finding python2 if the binary is named python2
Because of the way the python module works the simplicity of the test
function is no longer valid, we need to have and additional name
parameter to make the python module work, as it doesn't look for an
entry called "python2" or "python3", only "python"
* unittests: Don't make our python 2.x check debian specific
* unittests: On macOS the python2 binary is still called python
When a source file for a library is changed without adding new extern
symbols, only that library should be rebuilt. Nothing that uses it
should be relinked.
Along the way, also remove trailing `.` in all Ninja rule
descriptions. It's very confusing to see messages like:
```
Linking target mylib.dll.
```
It's confusing that the period at the end of that is not part of the
filename. Instead of removing that period manually in the tests (which
feels wrong!) just don't print it at all.
This makes two basic changes, 1 it moves the name of the linker into the
linker class, this should reduce the number of errors and typos, and
ensure that a linker always has one name. This then renames the linkers
to have more consistent names.
Posix/gnu linkers are called ld.<name>: ld.gold, ld.lld, ld.solaris.
Apple linkers are renamed ld64.
This allows users to disable writing out the inbuilt variables to
the pkg-config file as they might actualy not be required.
One reason to have this is for architecture-independent pkg-config
files in projects which also have architecture-dependent outputs.
For example : https://gitlab.freedesktop.org/wayland/weston/issues/269Fixes#4011
* Extend test_prefix_dependent_defaults unit test to cover default case
Extend test_prefix_dependent_defaults unit test to cover the default
case, when the default prefix is '/usr/local'. (On Windows, the default
prefix is 'c:/')
* Restore adjusting option defaults depending on the default prefix
Restore adjusting option defaults, depending on the default prefix.
Droppped in d778a371
Error is raised due to Elbrus Fortran compiler can't
generate debug information for now, because it's a 2-step
compiler where 1st step is code conversion from Fortran to C,
so debug information which C compiler would produce, is useless.
When a dependency is required, not found on the system, and its fallback
is disabled with --wrap-mode=nofallback, meson should abort instead of
returning not-found.
pkgconf automatically prunes "system library paths" from its output. The
system library paths depend on the system toolchain. A common value on a
64-bit system is as follows:
/lib64:/usr/lib64:/usr/local/lib64
So, if -L/usr/lib64 appears in the Libs section, it will be pruned from
the output of pkg-config --libs.
The pc files generated for this test contain something like this:
libdir=/usr/lib
Libs: -L${libdir} ...
pkgconf may not consider /usr/lib to be a system library path, so it is
not pruned as the test expects. To work around this, override the
compiled-in list of paths via the PKG_CONFIG_SYSTEM_LIBRARY_PATH
environment variable.
Fixes: https://github.com/mesonbuild/meson/issues/6004
The rust code is ugly, because rust is annoying. It doesn't invoke a
linker directly (unless that linker is link.exe or lld-link.exe),
instead it invokes the C compiler (gcc or clang usually) to do it's
linking. Meson doesn't have good abstractions for this, though we
probably should because some of the D compilers do the same thing.
Either that or we should just call the c compiler directly, like vala
does.
This changes the public interface for meson, which we don't do unless we
absolutely have to. In this case I think we need to do it. A fair number
of projects have already been using 'ld' in their cross/native files to
get the ld binary and call it directly in custom_targets or generators,
and we broke that. While we could hit this problem again names like
`c_ld` and `cpp_ld` are far less likely to cause collisions than `ld`.
Additionally this gives a way to set the linker on a per-compiler basis,
which is probably in itself very useful.
Fixes#6442
When there is more than one path in PKG_CONFIG_PATH. It is almost always
preferred to find things in the order specified by PKG_CONFIG_PATH
instead of assuming pkg-config returns flags in a meaningful order.
For example:
/usr/local/lib/libgtk-3.so.0
/usr/local/lib/pkgconfig/gtk+-3.0.pc
/usr/local/lib/libcanberra-gtk3.so
/usr/local/lib/pkgconfig/libcanberra-gtk3.pc
/home/mesonuser/.local/lib/libgtk-3.so.0
/home/mesonuser/.local/lib/pkgconfig/gtk+-3.0.pc
PKG_CONFIG_PATH="/home/mesonuser/.local/lib/pkgconfig:/usr/local/lib/pkgconfig"
libcanberra-gtk3 is a library which depends on gtk+-3.0. The dependency
is mentioned in the .pc file with 'Requires', so flags from gtk+-3.0 are
used in both dynamic and static linking.
Assume the user wants to compile an application which needs both
libcanberra-gtk3 and gtk+-3.0. The application depends on features added
in the latest version of gtk+-3.0, which can be found in the home
directory of the user but not in /usr/local. When meson asks pkg-config
for linker flags of libcanberra-gtk3, pkg-config picks
/usr/local/lib/pkgconfig/libcanberra-gtk3.pc and
/home/mesonuser/.local/lib/pkgconfig/gtk+-3.0.pc. Since these two
libraries come from different prefixes, there will be two -L arguments
in the output of pkg-config. If -L/usr/local/lib is put before
-L/home/mesonuser/.local/lib, meson will find both libraries in
/usr/local/lib instead of picking libgtk-3.so.0 from the home directory.
This can result in linking failure such as undefined references error
when meson decides to put linker arguments of libcanberra-gtk3 before
linker arguments of gtk+-3.0. When both /usr/local/lib/libgtk-3.so.0 and
/home/mesonuser/.local/lib/libgtk-3.so.0 are present on the command
line, the linker chooses the first one and ignores the second one. If
the application needs new symbols that are only available in the second
one, the linker will throw an error because of missing symbols.
To resolve the issue, we should reorder -L flags according to
PKG_CONFIG_PATH ourselves before using it to find the full path of
library files. This makes sure that we always follow the preferences of
users, without depending on the unreliable part of pkg-config output.
Fixes https://github.com/mesonbuild/meson/issues/4271.
There are two awful things about CompilerArgs, one is that it directly
inherits from list, and there are a lot of subtle gotcahs with
inheriting from builtin types. The second is that the class allows
arguments to be passed in whatever order. That's bad. This also fully
annotates the CompilerArgs class, so mypy can type check it for us.