rustc_session/
search_paths.rs

1use std::path::{Path, PathBuf};
2use std::sync::Arc;
3
4use rustc_macros::{Decodable, Encodable, HashStable_Generic};
5use rustc_target::spec::TargetTuple;
6
7use crate::EarlyDiagCtxt;
8use crate::filesearch::make_target_lib_path;
9
10#[derive(Clone, Debug)]
11pub struct SearchPath {
12    pub kind: PathKind,
13    pub dir: PathBuf,
14    pub files: FilesIndex,
15}
16
17/// [FilesIndex] contains paths that can be efficiently looked up with (prefix, suffix) pairs.
18#[derive(Clone, Debug)]
19pub struct FilesIndex(Vec<(Arc<str>, SearchPathFile)>);
20
21impl FilesIndex {
22    /// Look up [SearchPathFile] by (prefix, suffix) pair.
23    pub fn query<'s>(
24        &'s self,
25        prefix: &str,
26        suffix: &str,
27    ) -> Option<impl Iterator<Item = (String, &'s SearchPathFile)>> {
28        let start = self.0.partition_point(|(k, _)| **k < *prefix);
29        if start == self.0.len() {
30            return None;
31        }
32        let end = self.0[start..].partition_point(|(k, _)| k.starts_with(prefix));
33        let prefixed_items = &self.0[start..][..end];
34
35        let ret = prefixed_items.into_iter().filter_map(move |(k, v)| {
36            k.ends_with(suffix).then(|| {
37                (
38                    String::from(
39                        &v.file_name_str[prefix.len()..v.file_name_str.len() - suffix.len()],
40                    ),
41                    v,
42                )
43            })
44        });
45        Some(ret)
46    }
47    pub fn retain(&mut self, prefixes: &[&str]) {
48        self.0.retain(|(k, _)| prefixes.iter().any(|prefix| k.starts_with(prefix)));
49    }
50}
51/// The obvious implementation of `SearchPath::files` is a `Vec<PathBuf>`. But
52/// it is searched repeatedly by `find_library_crate`, and the searches involve
53/// checking the prefix and suffix of the filename of each `PathBuf`. This is
54/// doable, but very slow, because it involves calls to `file_name` and
55/// `extension` that are themselves slow.
56///
57/// This type augments the `PathBuf` with an `String` containing the
58/// `PathBuf`'s filename. The prefix and suffix checking is much faster on the
59/// `String` than the `PathBuf`. (The filename must be valid UTF-8. If it's
60/// not, the entry should be skipped, because all Rust output files are valid
61/// UTF-8, and so a non-UTF-8 filename couldn't be one we're looking for.)
62#[derive(Clone, Debug)]
63pub struct SearchPathFile {
64    pub path: Arc<Path>,
65    pub file_name_str: Arc<str>,
66}
67
68#[derive(PartialEq, Clone, Copy, Debug, Hash, Eq, Encodable, Decodable, HashStable_Generic)]
69pub enum PathKind {
70    Native,
71    Crate,
72    Dependency,
73    Framework,
74    All,
75}
76
77impl PathKind {
78    pub fn matches(&self, kind: PathKind) -> bool {
79        match (self, kind) {
80            (PathKind::All, _) | (_, PathKind::All) => true,
81            _ => *self == kind,
82        }
83    }
84}
85
86impl SearchPath {
87    pub fn from_cli_opt(
88        sysroot: &Path,
89        triple: &TargetTuple,
90        early_dcx: &EarlyDiagCtxt,
91        path: &str,
92        is_unstable_enabled: bool,
93    ) -> Self {
94        let (kind, path) = if let Some(stripped) = path.strip_prefix("native=") {
95            (PathKind::Native, stripped)
96        } else if let Some(stripped) = path.strip_prefix("crate=") {
97            (PathKind::Crate, stripped)
98        } else if let Some(stripped) = path.strip_prefix("dependency=") {
99            (PathKind::Dependency, stripped)
100        } else if let Some(stripped) = path.strip_prefix("framework=") {
101            (PathKind::Framework, stripped)
102        } else if let Some(stripped) = path.strip_prefix("all=") {
103            (PathKind::All, stripped)
104        } else {
105            (PathKind::All, path)
106        };
107        let dir = match path.strip_prefix("@RUSTC_BUILTIN") {
108            Some(stripped) => {
109                if !is_unstable_enabled {
110                    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
111                    early_dcx.early_fatal(
112                        "the `-Z unstable-options` flag must also be passed to \
113                         enable the use of `@RUSTC_BUILTIN`",
114                    );
115                }
116
117                make_target_lib_path(sysroot, triple.tuple()).join("builtin").join(stripped)
118            }
119            None => PathBuf::from(path),
120        };
121        if dir.as_os_str().is_empty() {
122            #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
123            early_dcx.early_fatal("empty search path given via `-L`");
124        }
125
126        Self::new(kind, dir)
127    }
128
129    pub fn from_sysroot_and_triple(sysroot: &Path, triple: &str) -> Self {
130        Self::new(PathKind::All, make_target_lib_path(sysroot, triple))
131    }
132
133    pub fn new(kind: PathKind, dir: PathBuf) -> Self {
134        // Get the files within the directory.
135        let mut files = match std::fs::read_dir(&dir) {
136            Ok(files) => files
137                .filter_map(|e| {
138                    e.ok().and_then(|e| {
139                        e.file_name().to_str().map(|s| {
140                            let file_name_str: Arc<str> = s.into();
141                            (
142                                Arc::clone(&file_name_str),
143                                SearchPathFile { path: e.path().into(), file_name_str },
144                            )
145                        })
146                    })
147                })
148                .collect::<Vec<_>>(),
149
150            Err(..) => Default::default(),
151        };
152        files.sort_by(|(lhs, _), (rhs, _)| lhs.cmp(rhs));
153        let files = FilesIndex(files);
154        SearchPath { kind, dir, files }
155    }
156}
rustc_session/search_paths.rs

rustc_session/
search_paths.rs
