This is a side effect of requiring Python >= 3.7 which itself guarantees
dictionary order. This is now a Meson language guarantee as well which
is required for passing default_options as dict and is generally
expected by users.
The new splitlines method on str is intended to replace usage of
fs.read('whatever').strip().split('\n').
The problem with the .strip().split() approach is that it doesn't have a
way to represent empty lists (an empty string becomes a list with one
empty string, not an empty list), and it doesn't handle Windows-style
line endings.
We silently dropped all integer values to install_mode since the
original implementation of doing this in KwargInfo, in commit
596c8d4af5.
This happened because install_mode is supposed to convert False
(exactly) to None, and otherwise pass all arguments in place. But a
generator is homogeneous and attempting to do this correctly produced a
mypy error that FileMode arguments were allowed to be ints -- well of
course they are -- so that resulted in the convertor... treating ints
like False instead, to make mypy happy.
Fixes#11538
This allows changing the crate name with which a library ends up being
available inside the Rust code, similar to cargo's dependency renaming
feature or `extern crate foo as bar` inside Rust code.
We will still try to load `meson_options.txt` if `meson.options` doesn't
exist. Because there are some advantages to using `meson.options` even
with older versions of meson (such as better text editor handling)
we will not warn about the existence of a `meson.options` file if a
`meson_options.txt` file or symlink also exists.
The name `meson.options` was picked instead of alternative proposals,
such as `meson_options.build` for a couple of reasons:
1. meson.options is shorter
2. While the syntax is the same, only the `option()` function may be
called in meson.options, while, it may not be called in meson.build
3. While the two files share a syntax and elementary types (strings,
arrays, etc), they have different purposes: `meson.build` declares
build targets, `meson.options` declares options. This is similar to
the difference between C's `.c` and `.h` extensions.
As an implementation detail `Interpreter.option_file` has been removed,
as it is used exactly once, in the `project()` call to read the options,
and we can just calculate it there and not store it.
Fixes: #11176
As discussed in issue #8037, using `c_args` in `project()` leads to
`CFLAGS` not being respected, which is a common mistake. Document this
and suggest using `add_project_arguments()` instead.
Signed-off-by: John Levon <levon@movementarian.org>
This method allows meson.build to introspect on the changed options.
It works by merely exposing the same set of data that is logged by
MesonApp._generate.
Fixes#10898
This adds two new methods, that are conceptually related in the same way
that `enable_auto_if` and `disable_auto_if` are. They are different
however, in that they will always replace an `auto` value with an
`enabled` or `disabled` value, or error if the feature is in the
opposite state (calling `feature(disabled).enable_if(true)`, for
example). This matters when the feature will be passed to
dependency(required : …)`, which has different behavior when passed an
enabled feature than an auto one.
The `disable_if` method will be controversial, I'm sure, since it
can be expressed via `feature.require()` (`feature.require(not
condition) == feature.disable_if(condition)`). I have two defences of
this:
1) `feature.require` is difficult to reason about, I would expect
require to be equivalent to `feature.enable_if(condition)`, not to
`feature.disable_if(not condition)`.
2) mixing `enable_if` and `disable_if` in the same call chain is much
clearer than mixing `require` and `enable_if`:
```meson
get_option('feat') \
.enable_if(foo) \
.disable_if(bar) \
.enable_if(opt)
```
vs
```meson
get_option('feat') \
.enable_if(foo) \
.require(not bar) \
.enable_if(opt)
```
In the first chain it's immediately obvious what is happening, in the
second, not so much, especially if you're not familiar with what
`require` means.
It's always been strange to me we don't have an opposite method of the
`disable_auto_if` method, but I've been pressed to find a case where we
_need_ one, because `disable_auto_if` can't be logically contorted to
work. I finally found the case where they're not equivalent: when you
don't want to convert to a boolean:
```meson
f = get_option('feat').disable_auto_if(not foo)
g = get_option('feat').enable_auto_if(foo)
dep1 = dependency('foo', required : f)
dep2 = dependency('foo', required : g)
```
Generated objects can already be passed in the "objects" keyword argument
as long as you go through an extract_objects() indirection. Allow the
same even directly, since that is more intuitive than having to add them
to "sources".
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Hook this up to installed dependency manifests. This is often needed
above and beyond just an SPDX string -- e.g. many licenses have custom
copyright lines.
The documentation for build_target(...) does not list file or str as
the possible types for the "objects" keyword argument, even though in
theory the argument is meant for prebuild object files that are part
of the sources.
Of course that is only the theory, because an ExtractedObjects object
is probably used a lot more than a file in the source tree. But
at least make the reference manual's typing information accurate.
Link to feature options consistently, and point out that it controls
"whether" the function finds what it's trying to find. This clues people
in to the fact that disabled features exist.
Claiming that "it should literally never be used ever no matter what" is
confusing and wrong -- it's definitely useful sometimes, but does result
in downsides, like not tracking inter-target dependencies correctly.
Ref: #10901
This is based on searching for `@FeatureNew*` decorators.
There is also one correction to a version in a decorators;
`build_by_default` was added in #1303, which is 0.38.0, not 0.40.0.
custom_target allows selective installation if it outputs more than one
file. Mention this explicitly in install.
Additionally, fix the types for install_dir.
see: https://github.com/mesonbuild/meson/issues/505
Dlang uses both integer version "levels" and arbitrary string
identifiers, and we support both, but don't mention it in the docs.
Also update a test case to pass one via declare_dependency. We already
test this kwarg for build_target.
The type information is clearly wrong as it disagrees with the
description w.r.t. generated headers.
We also rely on it accepting custom targets for the obvious reason that
we accept it in a build target too! In fact, we rely on this in the
testsuite too.
The `install_headers` function now has an optional argument
`preserve_path` that allows installing multi-directory
headerfile structures that live alongside sourcecode with a
single command.
For example, the headerfile structure
headers = [
'one.h',
'two.h',
'alpha/one.h',
'alpha/two.h',
'alpha/three.h'
'beta/one.h'
]
can now be passed to `install_headers(headers, subdir: 'mylib', preserve_path: true)`
and the resulting directory tree will look like
{prefix}
└── include
└── mylib
├── alpha
│ ├── one.h
│ ├── two.h
│ └── three.h
├── beta
│ └── one.h
├── one.h
└── two.h
Fixes#3371
This function can be used to add fundamental dependencies such as glib
to all build products in one fell swoop. This can be useful whenever,
due to a project's coding conventions, it is not really possible to
compile any source file without including the dependency.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>