From 003b9747e1b2eb167b2c71ad95cbccbc63755f85 Mon Sep 17 00:00:00 2001
From: Stefan Arentz <stefan@arentz.ca>
Date: Tue, 25 Oct 2022 19:35:21 -0400
Subject: [PATCH] Fixes #9677 - Lint against mod lib;

---
 clippy_lints/src/lib.rs      |  2 +-
 clippy_lints/src/mod_lib.rs  | 25 ++++++++++---------------
 tests/ui/mod_lib/main.stderr | 17 ++++++++---------
 3 files changed, 19 insertions(+), 25 deletions(-)

diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index ac30d5b56d44..6e65500fccff 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -913,7 +913,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_early_pass(|| Box::new(partial_pub_fields::PartialPubFields));
     store.register_late_pass(|_| Box::new(missing_trait_methods::MissingTraitMethods));
     store.register_late_pass(|_| Box::new(from_raw_with_void_ptr::FromRawWithVoidPtr));
-    store.register_early_pass(|| Box::new(mod_lib::ModLib));
+    store.register_late_pass(|_| Box::new(mod_lib::ModLib));
     // add lints here, do not remove this comment, it's used in `new_lint`
 }
 
diff --git a/clippy_lints/src/mod_lib.rs b/clippy_lints/src/mod_lib.rs
index 5aa4a91d7280..489511b8e284 100644
--- a/clippy_lints/src/mod_lib.rs
+++ b/clippy_lints/src/mod_lib.rs
@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::span_lint_and_help;
-use rustc_ast::{ptr::P, Crate, Item, ItemKind, ModKind};
-use rustc_lint::{EarlyContext, EarlyLintPass};
-use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_hir::{Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::sym;
 
 declare_clippy_lint! {
@@ -22,21 +22,16 @@ declare_clippy_lint! {
     pedantic,
     "default lint description"
 }
-declare_lint_pass!(ModLib => [MOD_LIB]);
 
-impl EarlyLintPass for ModLib {
-    fn check_crate(&mut self, cx: &EarlyContext<'_>, krate: &Crate) {
-        // println!("MOO Checking crate {:#?}", krate);
-        check_mod(cx, &krate.items);
-    }
-}
+#[derive(Default)]
+pub struct ModLib;
 
-fn check_mod(cx: &EarlyContext<'_>, items: &[P<Item>]) {
-    for item in items {
-        if let ItemKind::Mod(_, ModKind::Loaded(..)) = item.kind {
-            // println!("MOO Got a Mod: {:#?}", items);
-            // println!("MOO Got a Mod: {:#?}", item.ident.name);
+impl_lint_pass!(ModLib => [MOD_LIB]);
 
+impl<'tcx> LateLintPass<'tcx> for ModLib {
+    fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
+        if let ItemKind::Mod(_) = item.kind {
+            // println!("MOO Found a Mod: {:#?}", item.ident);
             if item.ident.name == sym::lib {
                 span_lint_and_help(
                     cx,
diff --git a/tests/ui/mod_lib/main.stderr b/tests/ui/mod_lib/main.stderr
index 77333a89df41..0b9aac11f7bf 100644
--- a/tests/ui/mod_lib/main.stderr
+++ b/tests/ui/mod_lib/main.stderr
@@ -1,3 +1,11 @@
+error: unknown lint: `clippy::mod_lib`
+  --> $DIR/main.rs:2:9
+   |
+LL | #![warn(clippy::mod_lib)]
+   |         ^^^^^^^^^^^^^^^ help: did you mean: `clippy::min_max`
+   |
+   = note: `-D unknown-lints` implied by `-D warnings`
+
 error: found module declaration for lib.rs
   --> $DIR/main.rs:4:1
    |
@@ -8,14 +16,5 @@ LL | mod lib;
    = help: to refer to it from other targets, use the library's name as the path
    = note: `-D special-module-name` implied by `-D warnings`
 
-error: uncommon use of mod::lib
-  --> $DIR/main.rs:4:1
-   |
-LL | mod lib;
-   | ^^^^^^^^
-   |
-   = help: you probably meant use::package instead
-   = note: `-D clippy::mod-lib` implied by `-D warnings`
-
 error: aborting due to 2 previous errors