objc2 0.6.4

Objective-C interface and runtime bindings
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95

use core::fmt;
use core::panic::{RefUnwindSafe, UnwindSafe};

#[cfg(feature = "gnustep-1-7")]
use crate::encode::Encode;
use crate::encode::{Encoding, RefEncode};
use crate::ffi;

/// A type used to identify and manage memory zones.
///
/// Zones are ignored on all newer platforms, you should very rarely need to
/// use this, but may be useful if you need to implement `copyWithZone:` or
/// `allocWithZone:`.
///
/// See [Apple's documentation](https://developer.apple.com/documentation/foundation/nszone?language=objc).
#[repr(C)]
pub struct NSZone {
    _priv: [u8; 0],
    // Use `OpaqueData` to mark the types as !Send, !Sync and UnsafeCell.
    _inner: ffi::OpaqueData,
}

impl fmt::Debug for NSZone {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "<NSZone {self:p}>")
    }
}

// Note: We don't know anything about the internals of `NSZone`, so best not
// to make it `Send` and `Sync` for now.

impl UnwindSafe for NSZone {}
impl RefUnwindSafe for NSZone {}

unsafe impl RefEncode for NSZone {
    #[cfg(not(feature = "gnustep-1-7"))]
    const ENCODING_REF: Encoding = Encoding::Pointer(&Encoding::Struct("_NSZone", &[]));
    #[cfg(feature = "gnustep-1-7")]
    const ENCODING_REF: Encoding = Encoding::Pointer(&Encoding::Struct(
        "_NSZone",
        &[
            // Functions
            Encoding::Pointer(&Encoding::Unknown),
            Encoding::Pointer(&Encoding::Unknown),
            Encoding::Pointer(&Encoding::Unknown),
            Encoding::Pointer(&Encoding::Unknown),
            Encoding::Pointer(&Encoding::Unknown),
            Encoding::Pointer(&Encoding::Unknown),
            // Stats
            Encoding::Pointer(&Encoding::Unknown),
            // Zone granularity
            usize::ENCODING,
            // Name of zone
            Encoding::Object,
            // Next zone - note that the contents of this doesn't matter,
            // since this is nested far enough that the encoding string ends
            // up ignoring it.
            Encoding::Pointer(&Encoding::Struct("_NSZone", &[])),
        ],
    ));
}

#[cfg(test)]
mod tests {
    use alloc::string::ToString;
    use core::ptr;

    use super::*;
    use crate::msg_send;
    use crate::rc::Allocated;
    use crate::runtime::NSObject;
    use crate::ClassType;

    #[test]
    fn alloc_with_zone() {
        let zone: *const NSZone = ptr::null();
        let _obj: Allocated<NSObject> =
            unsafe { msg_send![NSObject::class(), allocWithZone: zone] };
    }

    #[test]
    fn verify_encoding() {
        let expected = if cfg!(all(feature = "gnustep-1-7", target_pointer_width = "64")) {
            "^{_NSZone=^?^?^?^?^?^?^?Q@^{_NSZone}}"
        } else if cfg!(all(
            feature = "gnustep-1-7",
            not(target_pointer_width = "64")
        )) {
            "^{_NSZone=^?^?^?^?^?^?^?I@^{_NSZone}}"
        } else {
            "^{_NSZone=}"
        };
        assert_eq!(NSZone::ENCODING_REF.to_string(), expected);
    }
}