yash_env/trap/
cond.rs

1// This file is part of yash, an extended POSIX shell.
2// Copyright (C) 2023 WATANABE Yuki
3//
4// This program is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8//
9// This program is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12// GNU General Public License for more details.
13//
14// You should have received a copy of the GNU General Public License
15// along with this program.  If not, see <https://www.gnu.org/licenses/>.
16
17//! Items that define trap conditions
18
19#[cfg(doc)]
20use super::state::Action;
21use crate::signal;
22use crate::system::Signals;
23use itertools::Itertools as _;
24use std::borrow::Cow;
25
26/// Condition under which an [`Action`] is executed
27#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
28#[non_exhaustive]
29pub enum Condition {
30    /// When the shell exits
31    Exit,
32    /// When the specified signal is delivered to the shell process
33    Signal(signal::Number),
34}
35
36impl From<signal::Number> for Condition {
37    fn from(number: signal::Number) -> Self {
38        Self::Signal(number)
39    }
40}
41
42/// Conversion from raw signal number to `Condition`
43///
44/// If the number is zero, the result is [`Condition::Exit`]. Otherwise, the
45/// result is [`Condition::Signal`] with the signal number.
46impl From<signal::RawNumber> for Condition {
47    fn from(number: signal::RawNumber) -> Self {
48        if let Ok(non_zero) = number.try_into() {
49            Self::Signal(signal::Number::from_raw_unchecked(non_zero))
50        } else {
51            Self::Exit
52        }
53    }
54}
55
56impl From<Condition> for signal::RawNumber {
57    fn from(cond: Condition) -> Self {
58        match cond {
59            Condition::Exit => 0,
60            Condition::Signal(number) => number.as_raw(),
61        }
62    }
63}
64
65impl Condition {
66    /// Converts this `Condition` to a `String`.
67    ///
68    /// The result is an uppercase string representing the condition such as
69    /// `"EXIT"` and `"TERM"`. Signal names are obtained from
70    /// [`Signals::sig2str`].
71    #[must_use]
72    pub fn to_string<S: Signals>(&self, system: &S) -> Cow<'static, str> {
73        match self {
74            Self::Exit => Cow::Borrowed("EXIT"),
75            Self::Signal(number) => system.sig2str(*number).unwrap_or(Cow::Borrowed("?")),
76        }
77    }
78
79    /// Returns an iterator over all possible conditions.
80    ///
81    /// The iterator yields all the conditions supported by the given `Signals`
82    /// implementation.
83    /// The iteration starts with [`Condition::Exit`], followed by all the
84    /// signals in the ascending order of their signal numbers.
85    // TODO Most part of this function is duplicated from yash_builtin::kill::print::all_signals.
86    // Consider refactoring to share the code. Note that all_signals does not
87    // deduplicate the signals.
88    pub fn iter<S: Signals>(system: &S) -> impl Iterator<Item = Condition> + '_ {
89        let non_real_time = S::NAMED_SIGNALS
90            .iter()
91            .filter_map(|&(_, number)| Some(Condition::Signal(number?)));
92        let non_real_time_count = S::NAMED_SIGNALS.len();
93
94        let real_time = system.iter_sigrt().map(Condition::Signal);
95        let real_time_count = real_time.size_hint().1.unwrap_or_default();
96
97        let mut conditions = Vec::with_capacity(1 + non_real_time_count + real_time_count);
98        conditions.push(Condition::Exit);
99        conditions.extend(non_real_time);
100        conditions.extend(real_time);
101        conditions.sort();
102        // Some names may share the same number, so deduplicate.
103        conditions.into_iter().dedup()
104    }
105}
106
107#[cfg(test)]
108mod tests {
109    use super::*;
110    use crate::system::r#virtual::VirtualSystem;
111
112    #[test]
113    fn condition_iter_is_sorted() {
114        let system = VirtualSystem::new();
115        let iter = Condition::iter(&system);
116        assert!(iter.is_sorted());
117    }
118
119    #[test]
120    fn condition_iter_is_unique() {
121        let system = VirtualSystem::new();
122        let iter = Condition::iter(&system);
123        let iter_dedup = Condition::iter(&system).dedup();
124        assert!(iter.eq(iter_dedup));
125    }
126}
yash_env/trap/cond.rs

yash_env/trap/
cond.rs
