proc_macro/
diagnostic.rs

1use crate::Span;
2
3/// An enum representing a diagnostic level.
4#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
5#[derive(Copy, Clone, Debug)]
6#[non_exhaustive]
7pub enum Level {
8    /// An error.
9    Error,
10    /// A warning.
11    Warning,
12    /// A note.
13    Note,
14    /// A help message.
15    Help,
16}
17
18/// Trait implemented by types that can be converted into a set of `Span`s.
19#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
20pub trait MultiSpan {
21    /// Converts `self` into a `Vec<Span>`.
22    fn into_spans(self) -> Vec<Span>;
23}
24
25#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
26impl MultiSpan for Span {
27    fn into_spans(self) -> Vec<Span> {
28        vec![self]
29    }
30}
31
32#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
33impl MultiSpan for Vec<Span> {
34    fn into_spans(self) -> Vec<Span> {
35        self
36    }
37}
38
39#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
40impl<'a> MultiSpan for &'a [Span] {
41    fn into_spans(self) -> Vec<Span> {
42        self.to_vec()
43    }
44}
45
46/// A structure representing a diagnostic message and associated children
47/// messages.
48#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
49#[derive(Clone, Debug)]
50pub struct Diagnostic {
51    level: Level,
52    message: String,
53    spans: Vec<Span>,
54    children: Vec<Diagnostic>,
55}
56
57macro_rules! diagnostic_child_methods {
58    ($spanned:ident, $regular:ident, $level:expr) => {
59        #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
60        #[doc = concat!("Adds a new child diagnostics message to `self` with the [`",
61                        stringify!($level), "`] level, and the given `spans` and `message`.")]
62        pub fn $spanned<S, T>(mut self, spans: S, message: T) -> Diagnostic
63        where
64            S: MultiSpan,
65            T: Into<String>,
66        {
67            self.children.push(Diagnostic::spanned(spans, $level, message));
68            self
69        }
70
71        #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
72        #[doc = concat!("Adds a new child diagnostic message to `self` with the [`",
73                        stringify!($level), "`] level, and the given `message`.")]
74        pub fn $regular<T: Into<String>>(mut self, message: T) -> Diagnostic {
75            self.children.push(Diagnostic::new($level, message));
76            self
77        }
78    };
79}
80
81/// Iterator over the children diagnostics of a `Diagnostic`.
82#[derive(Debug, Clone)]
83#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
84pub struct Children<'a>(std::slice::Iter<'a, Diagnostic>);
85
86#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
87impl<'a> Iterator for Children<'a> {
88    type Item = &'a Diagnostic;
89
90    fn next(&mut self) -> Option<Self::Item> {
91        self.0.next()
92    }
93}
94
95#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
96impl Diagnostic {
97    /// Creates a new diagnostic with the given `level` and `message`.
98    #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
99    pub fn new<T: Into<String>>(level: Level, message: T) -> Diagnostic {
100        Diagnostic { level, message: message.into(), spans: vec![], children: vec![] }
101    }
102
103    /// Creates a new diagnostic with the given `level` and `message` pointing to
104    /// the given set of `spans`.
105    #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
106    pub fn spanned<S, T>(spans: S, level: Level, message: T) -> Diagnostic
107    where
108        S: MultiSpan,
109        T: Into<String>,
110    {
111        Diagnostic { level, message: message.into(), spans: spans.into_spans(), children: vec![] }
112    }
113
114    diagnostic_child_methods!(span_error, error, Level::Error);
115    diagnostic_child_methods!(span_warning, warning, Level::Warning);
116    diagnostic_child_methods!(span_note, note, Level::Note);
117    diagnostic_child_methods!(span_help, help, Level::Help);
118
119    /// Returns the diagnostic `level` for `self`.
120    #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
121    pub fn level(&self) -> Level {
122        self.level
123    }
124
125    /// Sets the level in `self` to `level`.
126    #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
127    pub fn set_level(&mut self, level: Level) {
128        self.level = level;
129    }
130
131    /// Returns the message in `self`.
132    #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
133    pub fn message(&self) -> &str {
134        &self.message
135    }
136
137    /// Sets the message in `self` to `message`.
138    #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
139    pub fn set_message<T: Into<String>>(&mut self, message: T) {
140        self.message = message.into();
141    }
142
143    /// Returns the `Span`s in `self`.
144    #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
145    pub fn spans(&self) -> &[Span] {
146        &self.spans
147    }
148
149    /// Sets the `Span`s in `self` to `spans`.
150    #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
151    pub fn set_spans<S: MultiSpan>(&mut self, spans: S) {
152        self.spans = spans.into_spans();
153    }
154
155    /// Returns an iterator over the children diagnostics of `self`.
156    #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
157    pub fn children(&self) -> Children<'_> {
158        Children(self.children.iter())
159    }
160
161    /// Emit the diagnostic.
162    #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
163    pub fn emit(self) {
164        fn to_internal(diag: Diagnostic) -> crate::bridge::Diagnostic<crate::bridge::client::Span> {
165            crate::bridge::Diagnostic {
166                level: diag.level,
167                message: diag.message,
168                spans: diag.spans.into_iter().map(|s| s.0).collect(),
169                children: diag.children.into_iter().map(to_internal).collect(),
170            }
171        }
172
173        crate::bridge::client::FreeFunctions::emit_diagnostic(to_internal(self));
174    }
175}