rust/clippy_lints/src/multiple_crate_versions.rs
2020-07-03 00:04:48 +03:00

97 lines
3.4 KiB
Rust

//! lint on multiple versions of a crate being used
use crate::utils::{run_lints, span_lint};
use rustc_hir::def_id::LOCAL_CRATE;
use rustc_hir::{Crate, CRATE_HIR_ID};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::source_map::DUMMY_SP;
use cargo_metadata::{DependencyKind, Node, Package, PackageId};
use if_chain::if_chain;
use itertools::Itertools;
declare_clippy_lint! {
/// **What it does:** Checks to see if multiple versions of a crate are being
/// used.
///
/// **Why is this bad?** This bloats the size of targets, and can lead to
/// confusing error messages when structs or traits are used interchangeably
/// between different versions of a crate.
///
/// **Known problems:** Because this can be caused purely by the dependencies
/// themselves, it's not always possible to fix this issue.
///
/// **Example:**
/// ```toml
/// # This will pull in both winapi v0.3.x and v0.2.x, triggering a warning.
/// [dependencies]
/// ctrlc = "=3.1.0"
/// ansi_term = "=0.11.0"
/// ```
pub MULTIPLE_CRATE_VERSIONS,
cargo,
"multiple versions of the same crate being used"
}
declare_lint_pass!(MultipleCrateVersions => [MULTIPLE_CRATE_VERSIONS]);
impl LateLintPass<'_> for MultipleCrateVersions {
fn check_crate(&mut self, cx: &LateContext<'_>, _: &Crate<'_>) {
if !run_lints(cx, &[MULTIPLE_CRATE_VERSIONS], CRATE_HIR_ID) {
return;
}
let metadata = unwrap_cargo_metadata!(cx, MULTIPLE_CRATE_VERSIONS, true);
let local_name = cx.tcx.crate_name(LOCAL_CRATE).as_str();
let mut packages = metadata.packages;
packages.sort_by(|a, b| a.name.cmp(&b.name));
if_chain! {
if let Some(resolve) = &metadata.resolve;
if let Some(local_id) = packages
.iter()
.find_map(|p| if p.name == *local_name { Some(&p.id) } else { None });
then {
for (name, group) in &packages.iter().group_by(|p| p.name.clone()) {
let group: Vec<&Package> = group.collect();
if group.len() <= 1 {
continue;
}
if group.iter().all(|p| is_normal_dep(&resolve.nodes, local_id, &p.id)) {
let mut versions: Vec<_> = group.into_iter().map(|p| &p.version).collect();
versions.sort();
let versions = versions.iter().join(", ");
span_lint(
cx,
MULTIPLE_CRATE_VERSIONS,
DUMMY_SP,
&format!("multiple versions for dependency `{}`: {}", name, versions),
);
}
}
}
}
}
}
fn is_normal_dep(nodes: &[Node], local_id: &PackageId, dep_id: &PackageId) -> bool {
fn depends_on(node: &Node, dep_id: &PackageId) -> bool {
node.deps.iter().any(|dep| {
dep.pkg == *dep_id
&& dep
.dep_kinds
.iter()
.any(|info| matches!(info.kind, DependencyKind::Normal))
})
}
nodes
.iter()
.filter(|node| depends_on(node, dep_id))
.any(|node| node.id == *local_id || is_normal_dep(nodes, local_id, &node.id))
}