Auto merge of #45611 - Manishearth:lint-generics, r=petrochenkov

Add generics to LateContext

Fixes clippy breakage from https://github.com/rust-lang/rust/pull/44766 as discussed in https://github.com/rust-lang-nursery/rust-clippy/pull/2140#issuecomment-336973875

r? @nikomatsakis

src/Cargo.lock

@@ -290,6 +290,7 @@ version = "0.1.0"
 name = "clippy_lints"
 version = "0.0.166"
 dependencies = [
+ "if_chain 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "itertools 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "matches 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -789,6 +790,11 @@ dependencies = [
  "unicode-normalization 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "if_chain"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "ignore"
 version = "0.2.2"
@@ -2665,6 +2671,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum html-diff 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "5298d63081a642508fce965740ddb03a386c5d81bf1fef0579a815cf49cb8c68"
 "checksum html5ever 0.18.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a49d5001dd1bddf042ea41ed4e0a671d50b1bf187e66b349d7ec613bdce4ad90"
 "checksum idna 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "014b298351066f1512874135335d62a789ffe78a9974f94b43ed5621951eaf7d"
+"checksum if_chain 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "61bb90bdd39e3af69b0172dfc6130f6cd6332bf040fbb9bdd4401d37adbd48b8"
 "checksum ignore 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b3fcaf2365eb14b28ec7603c98c06cc531f19de9eb283d89a3dff8417c8c99f5"
 "checksum itertools 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)" = "d3f2be4da1690a039e9ae5fd575f706a63ad5a2120f161b1d653c9da3930dd21"
 "checksum itoa 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "8324a32baf01e2ae060e9de58ed0bc2320c9a2833491ee36cd3b4c414de4db8c"

src/librustc/hir/mod.rs

@@ -1854,6 +1854,19 @@ impl Item_ {
             _ => None,
         }
     }
+
+    pub fn generics(&self) -> Option<&Generics> {
+        Some(match *self {
+            ItemFn(_, _, _, _, ref generics, _) |
+            ItemTy(_, ref generics) |
+            ItemEnum(_, ref generics) |
+            ItemStruct(_, ref generics) |
+            ItemUnion(_, ref generics) |
+            ItemTrait(_, ref generics, _, _) |
+            ItemImpl(_, _, _, ref generics, _, _, _)=> generics,
+            _ => return None
+        })
+    }
 }
 
 /// A reference from an trait to one of its associated items. This

src/librustc/lint/context.rs

@@ -352,6 +352,9 @@ pub struct LateContext<'a, 'tcx: 'a> {
     lint_sess: LintSession<'tcx, LateLintPassObject>,
 
     last_ast_node_with_lint_attrs: ast::NodeId,
+
+    /// Generic type parameters in scope for the item we are in.
+    pub generics: Option<&'tcx hir::Generics>,
 }
 
 /// Context for lint checking of the AST, after expansion, before lowering to
@@ -646,13 +649,16 @@ impl<'a, 'tcx> hir_visit::Visitor<'tcx> for LateContext<'a, 'tcx> {
     }
 
     fn visit_item(&mut self, it: &'tcx hir::Item) {
+        let generics = self.generics.take();
+        self.generics = it.node.generics();
         self.with_lint_attrs(it.id, &it.attrs, |cx| {
             cx.with_param_env(it.id, |cx| {
                 run_lints!(cx, check_item, late_passes, it);
                 hir_visit::walk_item(cx, it);
                 run_lints!(cx, check_item_post, late_passes, it);
             });
-        })
+        });
+        self.generics = generics;
     }
 
     fn visit_foreign_item(&mut self, it: &'tcx hir::ForeignItem) {
@@ -774,6 +780,8 @@ impl<'a, 'tcx> hir_visit::Visitor<'tcx> for LateContext<'a, 'tcx> {
     }
 
     fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem) {
+        let generics = self.generics.take();
+        self.generics = Some(&trait_item.generics);
         self.with_lint_attrs(trait_item.id, &trait_item.attrs, |cx| {
             cx.with_param_env(trait_item.id, |cx| {
                 run_lints!(cx, check_trait_item, late_passes, trait_item);
@@ -781,9 +789,12 @@ impl<'a, 'tcx> hir_visit::Visitor<'tcx> for LateContext<'a, 'tcx> {
                 run_lints!(cx, check_trait_item_post, late_passes, trait_item);
             });
         });
+        self.generics = generics;
     }
 
     fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) {
+        let generics = self.generics.take();
+        self.generics = Some(&impl_item.generics);
         self.with_lint_attrs(impl_item.id, &impl_item.attrs, |cx| {
             cx.with_param_env(impl_item.id, |cx| {
                 run_lints!(cx, check_impl_item, late_passes, impl_item);
@@ -791,6 +802,7 @@ impl<'a, 'tcx> hir_visit::Visitor<'tcx> for LateContext<'a, 'tcx> {
                 run_lints!(cx, check_impl_item_post, late_passes, impl_item);
             });
         });
+        self.generics = generics;
     }
 
     fn visit_lifetime(&mut self, lt: &'tcx hir::Lifetime) {
@@ -991,6 +1003,7 @@ pub fn check_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
         access_levels,
         lint_sess: LintSession::new(&tcx.sess.lint_store),
         last_ast_node_with_lint_attrs: ast::CRATE_NODE_ID,
+        generics: None,
     };
 
     // Visit the whole crate.

src/tools/clippy

@@ -1 +1 @@
-Subproject commit 281bd790de7b992831a1ff8a589c0fc38c842c95
+Subproject commit f76225e3887170743403af9204887918b5db5a80

src/tools/toolstate.toml

@@ -26,7 +26,7 @@
 miri = "Broken"
 
 # ping @Manishearth @llogiq @mcarton @oli-obk
-clippy = "Broken"
+clippy = "Compiling"
 
 # ping @nrc
 rls = "Broken"