moire_web/util/
source_path.rs

1static SYSROOT_BY_HASH: std::sync::OnceLock<std::collections::HashMap<String, String>> =
2    std::sync::OnceLock::new();
3
4fn sysroot_by_commit_hash() -> &'static std::collections::HashMap<String, String> {
5    SYSROOT_BY_HASH.get_or_init(|| {
6        let mut map = std::collections::HashMap::new();
7        let home = match std::env::var("RUSTUP_HOME")
8            .ok()
9            .or_else(|| std::env::var("HOME").ok().map(|h| format!("{h}/.rustup")))
10        {
11            Some(h) => h,
12            None => return map,
13        };
14        let toolchains_dir = format!("{home}/toolchains");
15        let entries = match std::fs::read_dir(&toolchains_dir) {
16            Ok(e) => e,
17            Err(_) => return map,
18        };
19        for entry in entries.flatten() {
20            let intro = entry.path().join("share/doc/rust/html/intro.html");
21            let html = match std::fs::read_to_string(&intro) {
22                Ok(s) => s,
23                Err(_) => continue,
24            };
25            let needle = "/rust-lang/rust/commit/";
26            let commit_hash = html.find(needle).and_then(|pos| {
27                let after = &html[pos + needle.len()..];
28                let end = after
29                    .find(|c: char| !c.is_ascii_hexdigit())
30                    .unwrap_or(after.len());
31                let hash = &after[..end];
32                if hash.len() == 40 {
33                    Some(hash.to_owned())
34                } else {
35                    None
36                }
37            });
38            if let Some(hash) = commit_hash {
39                let sysroot = entry.path().to_string_lossy().into_owned();
40                map.insert(hash, sysroot);
41            }
42        }
43        map
44    })
45}
46
47/// Remaps `/rustc/{hash}/...` to the matching rustup toolchain's rust-src component.
48pub fn resolve_source_path(path: &str) -> std::borrow::Cow<'_, str> {
49    if let Some(after_rustc) = path.strip_prefix("/rustc/")
50        && let Some(slash) = after_rustc.find('/')
51    {
52        let hash = &after_rustc[..slash];
53        if hash.len() == 40 && hash.chars().all(|c| c.is_ascii_hexdigit()) {
54            let rest = &after_rustc[slash + 1..];
55            if let Some(sysroot) = sysroot_by_commit_hash().get(hash) {
56                let remapped = format!("{sysroot}/lib/rustlib/src/rust/{rest}");
57                return std::borrow::Cow::Owned(remapped);
58            }
59        }
60    }
61    std::borrow::Cow::Borrowed(path)
62}
moire_web/util/source_path.rs

moire_web/util/
source_path.rs
