summaryrefslogtreecommitdiffstats
path: root/third_party/rust/bindgen/diagnostics.rs
blob: f765afe97097f90be71dbac15e4b98ca689b6fe1 (plain)
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
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
//! Types and function used to emit pretty diagnostics for `bindgen`.
//!
//! The entry point of this module is the [`Diagnostic`] type.

use std::fmt::Write;
use std::io::{self, BufRead, BufReader};
use std::{borrow::Cow, fs::File};

use annotate_snippets::{
    display_list::{DisplayList, FormatOptions},
    snippet::{Annotation, Slice as ExtSlice, Snippet},
};

use annotate_snippets::snippet::AnnotationType;

#[derive(Clone, Copy, Debug)]
pub(crate) enum Level {
    Error,
    Warn,
    Info,
    Note,
    Help,
}

impl From<Level> for AnnotationType {
    fn from(level: Level) -> Self {
        match level {
            Level::Error => Self::Error,
            Level::Warn => Self::Warning,
            Level::Info => Self::Info,
            Level::Note => Self::Note,
            Level::Help => Self::Help,
        }
    }
}

/// A `bindgen` diagnostic.
#[derive(Default)]
pub(crate) struct Diagnostic<'a> {
    title: Option<(Cow<'a, str>, Level)>,
    slices: Vec<Slice<'a>>,
    footer: Vec<(Cow<'a, str>, Level)>,
}

impl<'a> Diagnostic<'a> {
    /// Add a title to the diagnostic and set its type.
    pub(crate) fn with_title(
        &mut self,
        title: impl Into<Cow<'a, str>>,
        level: Level,
    ) -> &mut Self {
        self.title = Some((title.into(), level));
        self
    }

    /// Add a slice of source code to the diagnostic.
    pub(crate) fn add_slice(&mut self, slice: Slice<'a>) -> &mut Self {
        self.slices.push(slice);
        self
    }

    /// Add a footer annotation to the diagnostic. This annotation will have its own type.
    pub(crate) fn add_annotation(
        &mut self,
        msg: impl Into<Cow<'a, str>>,
        level: Level,
    ) -> &mut Self {
        self.footer.push((msg.into(), level));
        self
    }

    /// Print this diagnostic.
    ///
    /// The diagnostic is printed using `cargo:warning` if `bindgen` is being invoked by a build
    /// script or using `eprintln` otherwise.
    pub(crate) fn display(&self) {
        std::thread_local! {
            static INVOKED_BY_BUILD_SCRIPT: bool =  std::env::var_os("CARGO_CFG_TARGET_ARCH").is_some();
        }

        let mut title = None;
        let mut footer = vec![];
        let mut slices = vec![];
        if let Some((msg, level)) = &self.title {
            title = Some(Annotation {
                id: Some("bindgen"),
                label: Some(msg.as_ref()),
                annotation_type: (*level).into(),
            })
        }

        for (msg, level) in &self.footer {
            footer.push(Annotation {
                id: None,
                label: Some(msg.as_ref()),
                annotation_type: (*level).into(),
            });
        }

        // add additional info that this is generated by bindgen
        // so as to not confuse with rustc warnings
        footer.push(Annotation {
            id: None,
            label: Some("This diagnostic was generated by bindgen."),
            annotation_type: AnnotationType::Info,
        });

        for slice in &self.slices {
            if let Some(source) = &slice.source {
                slices.push(ExtSlice {
                    source: source.as_ref(),
                    line_start: slice.line.unwrap_or_default(),
                    origin: slice.filename.as_deref(),
                    annotations: vec![],
                    fold: false,
                })
            }
        }

        let snippet = Snippet {
            title,
            footer,
            slices,
            opt: FormatOptions {
                color: true,
                ..Default::default()
            },
        };
        let dl = DisplayList::from(snippet);

        if INVOKED_BY_BUILD_SCRIPT.with(Clone::clone) {
            // This is just a hack which hides the `warning:` added by cargo at the beginning of
            // every line. This should be fine as our diagnostics already have a colorful title.
            // FIXME (pvdrz): Could it be that this doesn't work in other languages?
            let hide_warning = "\r        \r";
            let string = dl.to_string();
            for line in string.lines() {
                println!("cargo:warning={}{}", hide_warning, line);
            }
        } else {
            eprintln!("{}\n", dl);
        }
    }
}

/// A slice of source code.
#[derive(Default)]
pub(crate) struct Slice<'a> {
    source: Option<Cow<'a, str>>,
    filename: Option<String>,
    line: Option<usize>,
}

impl<'a> Slice<'a> {
    /// Set the source code.
    pub(crate) fn with_source(
        &mut self,
        source: impl Into<Cow<'a, str>>,
    ) -> &mut Self {
        self.source = Some(source.into());
        self
    }

    /// Set the file, line and column.
    pub(crate) fn with_location(
        &mut self,
        mut name: String,
        line: usize,
        col: usize,
    ) -> &mut Self {
        write!(name, ":{}:{}", line, col)
            .expect("Writing to a string cannot fail");
        self.filename = Some(name);
        self.line = Some(line);
        self
    }
}

pub(crate) fn get_line(
    filename: &str,
    line: usize,
) -> io::Result<Option<String>> {
    let file = BufReader::new(File::open(filename)?);
    if let Some(line) = file.lines().nth(line.wrapping_sub(1)) {
        return line.map(Some);
    }

    Ok(None)
}