compiletest/directives/
line.rs

1use std::fmt;
2
3use camino::Utf8Path;
4
5use crate::directives::LineNumber;
6
7const COMPILETEST_DIRECTIVE_PREFIX: &str = "//@";
8
9/// If the given line begins with the appropriate comment prefix for a directive,
10/// returns a struct containing various parts of the directive.
11pub(crate) fn line_directive<'a>(
12    file_path: &'a Utf8Path,
13    line_number: LineNumber,
14    original_line: &'a str,
15) -> Option<DirectiveLine<'a>> {
16    // Ignore lines that don't start with the comment prefix.
17    let after_comment =
18        original_line.trim_start().strip_prefix(COMPILETEST_DIRECTIVE_PREFIX)?.trim_start();
19
20    let revision;
21    let raw_directive;
22
23    if let Some(after_open_bracket) = after_comment.strip_prefix('[') {
24        // A comment like `//@[foo]` only applies to revision `foo`.
25        let Some((line_revision, after_close_bracket)) = after_open_bracket.split_once(']') else {
26            panic!(
27                "malformed condition directive: expected `{COMPILETEST_DIRECTIVE_PREFIX}[foo]`, found `{original_line}`"
28            )
29        };
30
31        revision = Some(line_revision);
32        raw_directive = after_close_bracket.trim_start();
33    } else {
34        revision = None;
35        raw_directive = after_comment;
36    };
37
38    // The directive name ends at the first occurrence of colon, space, or end-of-string.
39    let name = raw_directive.split([':', ' ']).next().expect("split is never empty");
40
41    Some(DirectiveLine { file_path, line_number, revision, raw_directive, name })
42}
43
44/// The (partly) broken-down contents of a line containing a test directive,
45/// which `iter_directives` passes to its callback function.
46///
47/// For example:
48///
49/// ```text
50/// //@ compile-flags: -O
51///     ^^^^^^^^^^^^^^^^^ raw_directive
52///     ^^^^^^^^^^^^^     name
53///
54/// //@ [foo] compile-flags: -O
55///      ^^^                    revision
56///           ^^^^^^^^^^^^^^^^^ raw_directive
57///           ^^^^^^^^^^^^^     name
58/// ```
59pub(crate) struct DirectiveLine<'a> {
60    /// Path of the file containing this line.
61    ///
62    /// Mostly used for diagnostics, but some directives (e.g. `//@ pp-exact`)
63    /// also use it to compute a value based on the filename.
64    pub(crate) file_path: &'a Utf8Path,
65    pub(crate) line_number: LineNumber,
66
67    /// Some test directives start with a revision name in square brackets
68    /// (e.g. `[foo]`), and only apply to that revision of the test.
69    /// If present, this field contains the revision name (e.g. `foo`).
70    pub(crate) revision: Option<&'a str>,
71
72    /// The main part of the directive, after removing the comment prefix
73    /// and the optional revision specifier.
74    ///
75    /// This is "raw" because the directive's name and colon-separated value
76    /// (if present) have not yet been extracted or checked.
77    raw_directive: &'a str,
78
79    /// Name of the directive.
80    ///
81    /// Invariant: `self.raw_directive.starts_with(self.name)`
82    pub(crate) name: &'a str,
83}
84
85impl<'ln> DirectiveLine<'ln> {
86    pub(crate) fn applies_to_test_revision(&self, test_revision: Option<&str>) -> bool {
87        self.revision.is_none() || self.revision == test_revision
88    }
89
90    /// Helper method used by `value_after_colon` and `remark_after_space`.
91    /// Don't call this directly.
92    fn rest_after_separator(&self, separator: u8) -> Option<&'ln str> {
93        let n = self.name.len();
94        if self.raw_directive.as_bytes().get(n) != Some(&separator) {
95            return None;
96        }
97
98        Some(&self.raw_directive[n + 1..])
99    }
100
101    /// If this directive uses `name: value` syntax, returns the part after
102    /// the colon character.
103    pub(crate) fn value_after_colon(&self) -> Option<&'ln str> {
104        self.rest_after_separator(b':')
105    }
106
107    /// If this directive uses `name remark` syntax, returns the part after
108    /// the separating space.
109    pub(crate) fn remark_after_space(&self) -> Option<&'ln str> {
110        self.rest_after_separator(b' ')
111    }
112
113    /// Allows callers to print `raw_directive` if necessary,
114    /// without accessing the field directly.
115    pub(crate) fn display(&self) -> impl fmt::Display {
116        self.raw_directive
117    }
118}
compiletest/directives/line.rs

compiletest/directives/
line.rs
