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)
```
Currently Meson allow the following (Muon does not):
```meson
option('foo', type : 'boolean', value : 'true')
option('bar', type : 'integer', value : '42')
```
This is possibly a holdover from very old code, but it's a bad idea and
we should stop doing it. This deprecation is the first stop on that
journey.
It is often more useful to generate shell script than dumping to stdout.
It is also important to be able to select the shell format.
Formats currently implemented:
- sh: Basic VAR=prepend_value:$VAR
- export: Same as 'sh', but also export VAR
- vscode: Same as 'sh', but without substitutions because they don't
seems to work. To be used in launch.json's envFile.
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.
I accidentally followed a very old link and was briefly discombobulated.
To save other people from this mistake, use the current location
of the Meson repository, and tweak the surrounding text so it is
more clear that it was written nearly 10 years ago.
Signed-off-by: Tony Finch <dot@dotat.at>
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
Adds a new maximum warning level that is roughly equivalent to "all warnings".
This adds a way to use `/Wall` with MSVC (without the previous broken warning),
`-Weverything` with clang, and almost all general warnings in GCC with
strictness roughly equivalent to clang's `-Weverything`.
The GCC case must be implemented by meson since GCC doesn't provide a similar
option. To avoid maintenance headaches for meson, this warning level is
defined objectively: all warnings are included except those that require
specific values or are specific to particular language revisions. This warning
level is mainly intended for new code, and it is expected (nearly guaranteed)
that projects will need to add some suppressions to build cleanly with it.
More commonly, it's just a handy way to occasionally take a look at what
warnings are present with some compiler, in case anything interesting shows up
you might want to enable in general.
Since the warnings enabled at this level are inherently unstable with respect
to compiler versions, it is intended for use by developers and not to be set as
the default.
Dylan Baker
Eli Schwartz
Xavier Claessens
Charles Brunet
Daniele Nicolodi
Dudemanguy
andy5995
groveer
Yue Yang
Luke Elliott
Paolo Bonzini
Stephan Lachnit
Jussi Pakkanen
Oliver Kraitschy
Amit D
Andreas Deininger
Ewout ter Hoeven
Tristan Partin
Marvin Scholz
Angelo Haller
Tony Finch
David Robillard