starnix_features/
lib.rs

1// Copyright 2025 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use strum_macros::EnumString;
6use thiserror::Error;
7
8use std::fmt::Display;
9use std::str::FromStr;
10
11/// A feature that can be specified in a starnix kernel or container's configuration.
12#[derive(Debug, Clone, Copy, PartialEq, EnumString, strum_macros::Display)]
13#[strum(serialize_all = "snake_case")]
14pub enum Feature {
15    AndroidFdr,
16    AndroidSerialno,
17    AndroidBootreason,
18    AspectRatio,
19    Container,
20    CustomArtifacts,
21    Ashmem,
22    Framebuffer,
23    Gralloc,
24    Kgsl,
25    Magma,
26    MagmaSupportedVendors,
27    Nanohub,
28    NetstackMark,
29    NetworkManager,
30    Gfxstream,
31    Bpf,
32    EnableSuid,
33    IoUring,
34    ErrorOnFailedReboot,
35    Perfetto,
36    PerfettoProducer,
37    RootfsRw,
38    RtnetlinkAssumeIfb0Existence,
39    SelfProfile,
40    Selinux,
41    SelinuxTestSuite,
42    TestData,
43    Thermal,
44    HvdcpOpti,
45}
46
47/// Error returned when a feature is not recognized.
48#[derive(Debug, Error)]
49#[error("unsupported feature: {0}")]
50pub struct UnsupportedFeatureError(String);
51
52impl Feature {
53    /// Parses the name of a feature from a string.
54    pub fn try_parse(s: &str) -> Result<Feature, UnsupportedFeatureError> {
55        Feature::from_str(s).map_err(|_| UnsupportedFeatureError(s.to_string()))
56    }
57
58    /// Parses a feature and args from a string.
59    pub fn try_parse_feature_and_args(
60        s: &str,
61    ) -> Result<(Feature, Option<String>), UnsupportedFeatureError> {
62        let (raw_flag, raw_args) =
63            s.split_once(':').map(|(f, a)| (f, Some(a.to_string()))).unwrap_or((s, None));
64        Self::try_parse(raw_flag).map(|feature| (feature, raw_args))
65    }
66}
67
68/// A feature together with any arguments that go along with it, if specified.
69#[derive(Debug, Clone, PartialEq)]
70pub struct FeatureAndArgs {
71    /// The feature.
72    pub feature: Feature,
73    /// If specified, the (unparsed) arguments for the feature.
74    pub raw_args: Option<String>,
75}
76
77impl FeatureAndArgs {
78    /// Parses a feature and args from a string that separates them with `:`, e.g. "bpf:v2".
79    ///
80    /// If there is no `:` then the whole string is interpreted as the feature name.
81    pub fn try_parse(s: &str) -> Result<FeatureAndArgs, UnsupportedFeatureError> {
82        let (raw_flag, raw_args) =
83            s.split_once(':').map(|(f, a)| (f, Some(a.to_string()))).unwrap_or((s, None));
84        let feature = Feature::try_parse(raw_flag)?;
85        Ok(FeatureAndArgs { feature, raw_args })
86    }
87}
88
89impl Display for FeatureAndArgs {
90    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
91        let FeatureAndArgs { feature, raw_args } = self;
92        match raw_args {
93            None => feature.fmt(f),
94            Some(raw_args) => format_args!("{feature}:{raw_args}").fmt(f),
95        }
96    }
97}
98
99#[cfg(test)]
100mod test {
101    use super::*;
102
103    #[test]
104    fn feature_serde() {
105        for (feature, expected_str) in [
106            (Feature::AndroidFdr, "android_fdr"),
107            (Feature::AndroidSerialno, "android_serialno"),
108            (Feature::AndroidBootreason, "android_bootreason"),
109            (Feature::AspectRatio, "aspect_ratio"),
110            (Feature::Container, "container"),
111            (Feature::CustomArtifacts, "custom_artifacts"),
112            (Feature::Ashmem, "ashmem"),
113            (Feature::Framebuffer, "framebuffer"),
114            (Feature::Gralloc, "gralloc"),
115            (Feature::Kgsl, "kgsl"),
116            (Feature::Magma, "magma"),
117            (Feature::MagmaSupportedVendors, "magma_supported_vendors"),
118            (Feature::Nanohub, "nanohub"),
119            (Feature::NetstackMark, "netstack_mark"),
120            (Feature::NetworkManager, "network_manager"),
121            (Feature::Gfxstream, "gfxstream"),
122            (Feature::Bpf, "bpf"),
123            (Feature::EnableSuid, "enable_suid"),
124            (Feature::IoUring, "io_uring"),
125            (Feature::ErrorOnFailedReboot, "error_on_failed_reboot"),
126            (Feature::Perfetto, "perfetto"),
127            (Feature::PerfettoProducer, "perfetto_producer"),
128            (Feature::RootfsRw, "rootfs_rw"),
129            (Feature::RtnetlinkAssumeIfb0Existence, "rtnetlink_assume_ifb0_existence"),
130            (Feature::SelfProfile, "self_profile"),
131            (Feature::Selinux, "selinux"),
132            (Feature::SelinuxTestSuite, "selinux_test_suite"),
133            (Feature::TestData, "test_data"),
134            (Feature::Thermal, "thermal"),
135            (Feature::HvdcpOpti, "hvdcp_opti"),
136        ] {
137            let string = feature.to_string();
138            assert_eq!(string.as_str(), expected_str);
139            assert_eq!(Feature::try_parse(&string).expect("should parse"), feature);
140        }
141    }
142
143    #[test]
144    fn deserialize_feature_and_args() {
145        let FeatureAndArgs { feature, raw_args } =
146            FeatureAndArgs::try_parse("bpf:v2").expect("should parse successfully");
147        assert_eq!(feature, Feature::Bpf);
148        assert_eq!(raw_args.as_ref().expect("should be populated"), "v2");
149    }
150}
starnix_features/lib.rs

starnix_features/
lib.rs
