cargo/core/compiler/
links.rs

1use super::unit_graph::UnitGraph;
2use crate::core::resolver::errors::describe_path;
3use crate::core::{PackageId, Resolve};
4use crate::util::errors::CargoResult;
5use std::collections::{HashMap, HashSet};
6
7/// Validates [`package.links`] field in the manifest file does not conflict
8/// between packages.
9///
10/// NOTE: This is the *old* links validator. Links are usually validated in the
11/// resolver. However, the `links` field was added to the index in early 2018
12/// (see [rust-lang/cargo#4978]). However, `links` has been around since 2014,
13/// so there are still many crates in the index that don't have `links`
14/// properly set in the index (over 600 at the time of this writing in 2019).
15/// This can probably be removed at some point in the future, though it might
16/// be worth considering fixing the index.
17///
18/// [rust-lang/cargo#4978]: https://github.com/rust-lang/cargo/pull/4978
19/// [`package.links`]: https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#the-links-manifest-key
20pub fn validate_links(resolve: &Resolve, unit_graph: &UnitGraph) -> CargoResult<()> {
21    let mut validated: HashSet<PackageId> = HashSet::new();
22    let mut links: HashMap<String, PackageId> = HashMap::new();
23    let mut units: Vec<_> = unit_graph.keys().collect();
24    // Sort primarily to make testing easier.
25    units.sort_unstable();
26    for unit in units {
27        if !validated.insert(unit.pkg.package_id()) {
28            continue;
29        }
30        let Some(lib) = unit.pkg.manifest().links() else {
31            continue;
32        };
33        if let Some(&prev) = links.get(lib) {
34            let prev_path = resolve
35                .path_to_top(&prev)
36                .into_iter()
37                .map(|(p, d)| (p, d.and_then(|d| d.iter().next())));
38            let pkg = unit.pkg.package_id();
39            let path = resolve
40                .path_to_top(&pkg)
41                .into_iter()
42                .map(|(p, d)| (p, d.and_then(|d| d.iter().next())));
43            anyhow::bail!(
44                "multiple packages link to native library `{}`, \
45                 but a native library can be linked only once\n\
46                 \n\
47                 {}\nlinks to native library `{}`\n\
48                 \n\
49                 {}\nalso links to native library `{}`",
50                lib,
51                describe_path(prev_path),
52                lib,
53                describe_path(path),
54                lib
55            )
56        }
57        links.insert(lib.to_string(), unit.pkg.package_id());
58    }
59    Ok(())
60}
cargo/core/compiler/links.rs

cargo/core/compiler/
links.rs
