ladybug 0.1.6

A small library for triggering a logic analyzer from program events
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

#![allow(dead_code, unused_imports, unused_mut, unused_variables)]
#![cfg_attr(feature = "nightly", feature(error_in_core))]
#![cfg_attr(feature = "nightly", feature(panic_info_message))]
#![cfg_attr(not(test), no_std)]

use core::cell::RefCell;
use core::marker::PhantomData;

// - public types -------------------------------------------------------------

#[derive(Clone, Copy)]
pub enum Channel {
    A,
    B,
    C,
    D,
    E,
    F,
    G,
    H,
}

pub trait LogicAnalyzer {
    fn high(&self, channel: Channel, bit_number: u8);
    fn low(&self, channel: Channel, bit_number: u8);
}

// - public methods -----------------------------------------------------------

/// Sets the [`LogicAnalyzer`] used by ladybug.
pub fn set_analyzer(analyzer: &'static dyn LogicAnalyzer) {
    unsafe {
        LADYBUG = analyzer;
    }
}

/// Returns a reference to the logic analyzer.
#[must_use]
pub fn ladybug() -> &'static dyn LogicAnalyzer {
    unsafe { LADYBUG }
}

/// Issues a pulse on the given GPIO channel and bit number.
///
/// # Safety
///
/// This is not interrupt safe so you'll want to make sure you use
/// separate channels for tracing in your main program loop vs
/// interrupt handlers.
#[allow(clippy::inline_always)]
#[inline(always)]
pub fn trace<R>(channel: Channel, bit_number: u8, f: impl FnOnce() -> R) -> R {
    #[cfg(not(feature = "enable"))]
    {
        f()
    }
    #[cfg(feature = "enable")]
    {
        ladybug().high(channel, bit_number);
        let result = f();
        ladybug().low(channel, bit_number);
        result
    }
}

// - No-op LogicAnalyzer ------------------------------------------------------

struct LadybugDummy;
impl LogicAnalyzer for LadybugDummy {
    fn high(&self, channel: Channel, bit_number: u8) {}
    fn low(&self, channel: Channel, bit_number: u8) {}
}

// - global singleton ---------------------------------------------------------

static mut LADYBUG: &dyn LogicAnalyzer = &LadybugDummy;