feat(cargo-lints): Add a lint verification step

Author: Muscraft

src/cargo/core/features.rs

@@ -515,7 +515,7 @@ features! {
 #[derive(Debug)]
 pub struct Feature {
     /// Feature name. This is valid Rust identifer so no dash only underscore.
-    name: &'static str,
+    pub name: &'static str,
     stability: Status,
     /// Version that this feature was stabilized or removed.
     version: &'static str,

src/cargo/core/workspace.rs

@@ -24,7 +24,9 @@ use crate::sources::{PathSource, CRATES_IO_INDEX, CRATES_IO_REGISTRY};
 use crate::util::edit_distance;
 use crate::util::errors::{CargoResult, ManifestError};
 use crate::util::interning::InternedString;
-use crate::util::lints::{check_im_a_teapot, check_implicit_features, unused_dependencies};
+use crate::util::lints::{
+    check_im_a_teapot, check_implicit_features, unused_dependencies, verify_lints,
+};
 use crate::util::toml::{read_manifest, InheritableFields};
 use crate::util::{
     context::CargoResolverConfig, context::CargoResolverPrecedence, context::ConfigRelativePath,
@@ -1227,6 +1229,26 @@ impl<'gctx> Workspace<'gctx> {
             .is_some_and(|l| l.workspace)
             .then(|| ws_cargo_lints);
 
+        let ws_contents = match self.root_maybe() {
+            MaybePackage::Package(pkg) => pkg.manifest().contents(),
+            MaybePackage::Virtual(v) => v.contents(),
+        };
+
+        let ws_document = match self.root_maybe() {
+            MaybePackage::Package(pkg) => pkg.manifest().document(),
+            MaybePackage::Virtual(v) => v.document(),
+        };
+
+        verify_lints(
+            pkg,
+            &path,
+            &normalized_lints,
+            ws_cargo_lints,
+            ws_contents,
+            ws_document,
+            self.root_manifest(),
+            self.gctx,
+        )?;
         check_im_a_teapot(
             pkg,
             &path,

src/cargo/util/lints.rs

@@ -12,6 +12,160 @@ use std::ops::Range;
 use std::path::Path;
 use toml_edit::ImDocument;
 
+const LINTS: &[Lint] = &[IM_A_TEAPOT, IMPLICIT_FEATURES, UNUSED_OPTIONAL_DEPENDENCY];
+
+pub fn verify_lints(
+    pkg: &Package,
+    path: &Path,
+    pkg_lints: &TomlToolLints,
+    ws_lints: Option<&TomlToolLints>,
+    ws_contents: &str,
+    ws_document: &ImDocument<String>,
+    ws_path: &Path,
+    gctx: &GlobalContext,
+) -> CargoResult<()> {
+    let mut error_count = 0;
+    let manifest = pkg.manifest();
+    let manifest_path = rel_cwd_manifest_path(path, gctx);
+    let ws_path = rel_cwd_manifest_path(ws_path, gctx);
+
+    for lint_name in pkg_lints
+        .keys()
+        .chain(ws_lints.map(|l| l.keys()).unwrap_or_default())
+    {
+        if let Some(lint) = LINTS.iter().find(|l| l.name == lint_name) {
+            let (_, reason) = lint.level(pkg_lints, ws_lints, manifest.edition());
+            if let Some(feature_gate) = lint.feature_gate {
+                feature_gated_lint(
+                    lint.name,
+                    feature_gate,
+                    reason,
+                    manifest,
+                    &manifest_path,
+                    ws_contents,
+                    ws_document,
+                    &ws_path,
+                    &mut error_count,
+                    gctx,
+                )?;
+            }
+        }
+    }
+    if error_count > 0 {
+        Err(anyhow::anyhow!(
+            "encountered {error_count} errors(s) while verifying lints",
+        ))
+    } else {
+        Ok(())
+    }
+}
+
+fn feature_gated_lint(
+    lint_name: &str,
+    feature_gate: &Feature,
+    reason: LintLevelReason,
+    manifest: &Manifest,
+    manifest_path: &str,
+    ws_contents: &str,
+    ws_document: &ImDocument<String>,
+    ws_path: &str,
+    error_count: &mut usize,
+    gctx: &GlobalContext,
+) -> CargoResult<()> {
+    if !manifest.unstable_features().is_enabled(feature_gate) {
+        let dash_name = lint_name.replace("_", "-");
+        let dash_feature_name = feature_gate.name.replace("_", "-");
+        let title = format!("use of unstable lint `{}`", dash_name);
+        let label = format!(
+            "this is behind `{}`, which is not enabled",
+            dash_feature_name
+        );
+        let second_title = format!("`cargo::{}` was inherited", dash_name);
+        let help = format!(
+            "consider adding `cargo-features = [\"{}\"]` to the top of the manifest",
+            dash_feature_name
+        );
+        let message = match reason {
+            LintLevelReason::Package => {
+                let span = get_span(
+                    manifest.document(),
+                    &["lints", "cargo", dash_name.as_str()],
+                    false,
+                )
+                .or(get_span(
+                    manifest.document(),
+                    &["lints", "cargo", lint_name],
+                    false,
+                ))
+                .unwrap();
+                Some(
+                    Level::Error
+                        .title(&title)
+                        .snippet(
+                            Snippet::source(manifest.contents())
+                                .origin(&manifest_path)
+                                .annotation(Level::Error.span(span).label(&label))
+                                .fold(true),
+                        )
+                        .footer(Level::Help.title(&help)),
+                )
+            }
+            LintLevelReason::Workspace => {
+                let lint_span = get_span(
+                    ws_document,
+                    &["workspace", "lints", "cargo", dash_name.as_str()],
+                    false,
+                )
+                .or(get_span(
+                    ws_document,
+                    &["workspace", "lints", "cargo", lint_name],
+                    false,
+                ))
+                .unwrap();
+                let inherit_span_key =
+                    get_span(manifest.document(), &["lints", "workspace"], false).unwrap();
+                let inherit_span_value =
+                    get_span(manifest.document(), &["lints", "workspace"], true).unwrap();
+                Some(
+                    Level::Error
+                        .title(&title)
+                        .snippet(
+                            Snippet::source(ws_contents)
+                                .origin(&ws_path)
+                                .annotation(Level::Error.span(lint_span).label(&label))
+                                .fold(true),
+                        )
+                        .footer(
+                            Level::Note.title(&second_title).snippet(
+                                Snippet::source(manifest.contents())
+                                    .origin(&manifest_path)
+                                    .annotation(
+                                        Level::Note
+                                            .span(inherit_span_key.start..inherit_span_value.end),
+                                    )
+                                    .fold(true),
+                            ),
+                        )
+                        .footer(Level::Help.title(&help)),
+                )
+            }
+            _ => None,
+        };
+
+        if let Some(message) = message {
+            *error_count += 1;
+            let renderer = Renderer::styled().term_width(
+                gctx.shell()
+                    .err_width()
+                    .diagnostic_terminal_width()
+                    .unwrap_or(annotate_snippets::renderer::DEFAULT_TERM_WIDTH),
+            );
+            writeln!(gctx.shell().err(), "{}", renderer.render(message))?;
+        }
+    }
+    Ok(())
+}
+
 fn get_span(document: &ImDocument<String>, path: &[&str], get_value: bool) -> Option<Range<usize>> {
     let mut table = document.as_item().as_table_like()?;
     let mut iter = path.into_iter().peekable();
@@ -122,12 +276,6 @@ impl Lint {
             .map(|(_, (l, r, _))| (l, r))
             .unwrap()
     }
-
-    /// Returns true if the lint is feature gated and the feature is not enabled
-    fn is_feature_gated(&self, manifest: &Manifest) -> bool {
-        self.feature_gate
-            .map_or(false, |f| !manifest.unstable_features().is_enabled(f))
-    }
 }
 
 #[derive(Copy, Clone, Debug, PartialEq)]
@@ -250,39 +398,6 @@ pub fn check_im_a_teapot(
     let manifest_path = rel_cwd_manifest_path(path, gctx);
     let (lint_level, reason) = IM_A_TEAPOT.level(pkg_lints, ws_lints, manifest.edition());
 
-    if IM_A_TEAPOT.is_feature_gated(manifest) {
-        if reason == LintLevelReason::Package || reason == LintLevelReason::Workspace {
-            *error_count += 1;
-            let span = get_span(
-                manifest.document(),
-                &["lints", "cargo", "im-a-teapot"],
-                false,
-            )
-            .or(get_span(
-                manifest.document(),
-                &["lints", "cargo", "im_a_teapot"],
-                false,
-            ))
-            .unwrap();
-            let message = Level::Error
-                .title("use of unstable lint `im-a-teapot`")
-                .snippet(
-                    Snippet::source(manifest.contents())
-                        .origin(&manifest_path)
-                        .annotation(Level::Error.span(span))
-                        .fold(true),
-                );
-            let renderer = Renderer::styled().term_width(
-                gctx.shell()
-                    .err_width()
-                    .diagnostic_terminal_width()
-                    .unwrap_or(annotate_snippets::renderer::DEFAULT_TERM_WIDTH),
-            );
-            writeln!(gctx.shell().err(), "{}", renderer.render(message))?;
-        }
-        return Ok(());
-    }
-
     if lint_level == LintLevel::Allow {
         return Ok(());
     }

tests/testsuite/lints_table.rs

@@ -1107,8 +1107,64 @@ error: use of unstable lint `im-a-teapot`
  --> Cargo.toml:9:1
   |
 9 | im-a-teapot = \"warn\"
-  | ^^^^^^^^^^^
+  | ^^^^^^^^^^^ this is behind `test-dummy-unstable`, which is not enabled
   |
+  = help: consider adding `cargo-features = [\"test-dummy-unstable\"]` to the top of the manifest
+error: encountered 1 errors(s) while verifying lints
+",
+        )
+        .run();
+}
+
+#[cargo_test]
+fn check_feature_gated_workspace() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+[workspace]
+members = ["foo"]
+
+[workspace.lints.cargo]
+im-a-teapot = { level = "warn", priority = 10 }
+test-dummy-unstable = { level = "forbid", priority = -1 }
+            "#,
+        )
+        .file(
+            "foo/Cargo.toml",
+            r#"
+[package]
+name = "foo"
+version = "0.0.1"
+edition = "2015"
+authors = []
+
+[lints]
+workspace = true
+            "#,
+        )
+        .file("foo/src/lib.rs", "")
+        .build();
+
+    p.cargo("check -Zcargo-lints")
+        .masquerade_as_nightly_cargo(&["cargo-lints"])
+        .with_status(101)
+        .with_stderr(
+            "\
+error: use of unstable lint `im-a-teapot`
+ --> Cargo.toml:6:1
+  |
+6 | im-a-teapot = { level = \"warn\", priority = 10 }
+  | ^^^^^^^^^^^ this is behind `test-dummy-unstable`, which is not enabled
+  |
+note: `cargo::im-a-teapot` was inherited
+ --> foo/Cargo.toml:9:1
+  |
+9 | workspace = true
+  | ----------------
+  |
+  = help: consider adding `cargo-features = [\"test-dummy-unstable\"]` to the top of the manifest
+error: encountered 1 errors(s) while verifying lints
 ",
         )
         .run();