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
The code below this already handles being passed an Executable or
ExternalProgram, and it does it correctly, since it handles host
binaries that need an exe_wrapper correctly, while the code in the
generator paths doesn't.
The xcode backend is, like always, problematic, it doesn't handle things
the same way as the ninja and vscode backends, and generates a shell
script instead of using meson as a wrapper when needed (it seems likely
that just forcing the meson path for xcode would be better). I don't
have a working mac to develop a fix for, so I've left a todo comment
there.
Fixes: #11264
This finds uses of deny-listed functions, which defaults to map and
filter. These functions should be replaced by comprehensions in
idiomatic python because:
1. comprehensions are more heavily optimized and are often faster
2. They avoid the need for lambdas in some cases, which make them
faster
3. you can do the equivalent in one statement rather than two, which
is faster
4. They're easier to read
5. if you need a concrete instance (ie, a list) then you don't have
to convert the iterator to a list afterwards
https://github.com/mesonbuild/meson/pull/9287 changed the `optimization=0`
to pass `-O0` to the compiler. This change is reasonable by itself
but unfortunately, it breaks `buildtype=plain`, which promises
that “no extra build flags are used”.
`buildtype=plain` is important for distros like NixOS,
which manage compiler flags for optimization and hardening
themselves.
Let’s introduce a new optimization level that does nothing
and set it as the default for `buildtype=plain`.
Instead of asking the ExtractedObjects, but with a hook back into the backend,
use the existing function in the backend itself. This fixes using the
extract_objects(...) of a generated source file in a custom_target.
It should also fix recursive extract_all_objects with the Xcode backend.
Fixes: #10394
That method had nothing specific to the backend, it's purely a Target
method. This allows to cache the OptionOverrideProxy object on the
Target instance instead of creating a new one for each option lookup.
This caught a couple of cases of us doing:
```python
for i in range(len(x)):
v = x[i]
```
which are places to use enumerate instead.
It also caught a couple of cases of:
```python
assert len(x) == len(y)
for i in range(len(x)):
xv = x[i]
yv = y[i]
```
Which should instead be using zip()
```python
for xv, yv in zip(x, y):
...
```
We have a lot of these. Some of them are harmless, if unidiomatic, such
as `if (condition)`, others are potentially dangerous `assert(...)`, as
`assert(condtion)` works as expected, but `assert(condition, message)`
will result in an assertion that never triggers, as what you're actually
asserting is `bool(tuple[2])`, which will always be true.
This didn't actually catch what it's supposed to, which is cases of:
```python
for x in dict.keys():
y = dict[x]
```
But it did catch one unnecessary use of keys(), and one case where we
were doing something in an inefficient way. I've rewritten:
```python
if name.value in [x.value for x in self.kwargs.keys() if isinstance(x, IdNode)]:
```
as
``python
if any((isinstance(x, IdNode) and name.value == x.value) for x in self.kwargs):
```
Which avoids doing two iterations, one to build the list, and a
second to do a search for name.value in said list, which does a single
short circuiting walk, as any returns as soon as one check returns True.
Eli Schwartz