From 71450c7aadac3a94889744143127962c4e991f60 Mon Sep 17 00:00:00 2001
From: Mazdak Farrokhzad <twingoow@gmail.com>
Date: Mon, 20 Jan 2020 17:57:08 +0100
Subject: [PATCH] generalize bindings_with_variant_name lint

---
 .../hair/pattern/check_match.rs               | 19 +++-------
 src/test/ui/lint/lint-uppercase-variables.rs  | 10 +++++
 .../ui/lint/lint-uppercase-variables.stderr   | 38 ++++++++++++++++++-
 3 files changed, 53 insertions(+), 14 deletions(-)

diff --git a/src/librustc_mir_build/hair/pattern/check_match.rs b/src/librustc_mir_build/hair/pattern/check_match.rs
index eac52da7ba4..ced0d5ed935 100644
--- a/src/librustc_mir_build/hair/pattern/check_match.rs
+++ b/src/librustc_mir_build/hair/pattern/check_match.rs
@@ -67,18 +67,13 @@ impl<'tcx> Visitor<'tcx> for MatchVisitor<'_, 'tcx> {
             hir::LocalSource::AwaitDesugar => ("`await` future binding", None),
         };
         self.check_irrefutable(&loc.pat, msg, sp);
-
-        // Check legality of move bindings and `@` patterns.
         self.check_patterns(false, &loc.pat);
     }
 
-    fn visit_body(&mut self, body: &'tcx hir::Body<'tcx>) {
-        intravisit::walk_body(self, body);
-
-        for param in body.params {
-            self.check_irrefutable(&param.pat, "function argument", None);
-            self.check_patterns(false, &param.pat);
-        }
+    fn visit_param(&mut self, param: &'tcx hir::Param<'tcx>) {
+        intravisit::walk_param(self, param);
+        self.check_irrefutable(&param.pat, "function argument", None);
+        self.check_patterns(false, &param.pat);
     }
 }
 
@@ -123,6 +118,7 @@ impl<'tcx> MatchVisitor<'_, 'tcx> {
         if !self.tcx.features().bindings_after_at {
             check_legality_of_bindings_in_at_patterns(self, pat);
         }
+        check_for_bindings_named_same_as_variants(self, pat);
     }
 
     fn check_match(
@@ -132,11 +128,8 @@ impl<'tcx> MatchVisitor<'_, 'tcx> {
         source: hir::MatchSource,
     ) {
         for arm in arms {
-            // First, check legality of move bindings.
+            // Check the arm for some things unrelated to exhaustiveness.
             self.check_patterns(arm.guard.is_some(), &arm.pat);
-
-            // Second, perform some lints.
-            check_for_bindings_named_same_as_variants(self, &arm.pat);
         }
 
         let module = self.tcx.hir().get_module_parent(scrut.hir_id);
diff --git a/src/test/ui/lint/lint-uppercase-variables.rs b/src/test/ui/lint/lint-uppercase-variables.rs
index 86a39502a81..a98b4f2fd44 100644
--- a/src/test/ui/lint/lint-uppercase-variables.rs
+++ b/src/test/ui/lint/lint-uppercase-variables.rs
@@ -25,6 +25,16 @@ fn main() {
 //~^^^ WARN unused variable: `Foo`
     }
 
+    let Foo = foo::Foo::Foo;
+    //~^ ERROR variable `Foo` should have a snake case name
+    //~^^ WARN `Foo` is named the same as one of the variants of the type `foo::Foo`
+    //~^^^ WARN unused variable: `Foo`
+
+    fn in_param(Foo: foo::Foo) {}
+    //~^ ERROR variable `Foo` should have a snake case name
+    //~^^ WARN `Foo` is named the same as one of the variants of the type `foo::Foo`
+    //~^^^ WARN unused variable: `Foo`
+
     test(1);
 
     let _ = Something { X: 0 };
diff --git a/src/test/ui/lint/lint-uppercase-variables.stderr b/src/test/ui/lint/lint-uppercase-variables.stderr
index b937832ac62..a38f3e7626b 100644
--- a/src/test/ui/lint/lint-uppercase-variables.stderr
+++ b/src/test/ui/lint/lint-uppercase-variables.stderr
@@ -6,6 +6,18 @@ LL |         Foo => {}
    |
    = note: `#[warn(bindings_with_variant_name)]` on by default
 
+warning[E0170]: pattern binding `Foo` is named the same as one of the variants of the type `foo::Foo`
+  --> $DIR/lint-uppercase-variables.rs:28:9
+   |
+LL |     let Foo = foo::Foo::Foo;
+   |         ^^^ help: to match on the variant, qualify the path: `foo::Foo::Foo`
+
+warning[E0170]: pattern binding `Foo` is named the same as one of the variants of the type `foo::Foo`
+  --> $DIR/lint-uppercase-variables.rs:33:17
+   |
+LL |     fn in_param(Foo: foo::Foo) {}
+   |                 ^^^ help: to match on the variant, qualify the path: `foo::Foo::Foo`
+
 warning: unused variable: `Foo`
   --> $DIR/lint-uppercase-variables.rs:22:9
    |
@@ -19,6 +31,18 @@ LL | #![warn(unused)]
    |         ^^^^^^
    = note: `#[warn(unused_variables)]` implied by `#[warn(unused)]`
 
+warning: unused variable: `Foo`
+  --> $DIR/lint-uppercase-variables.rs:28:9
+   |
+LL |     let Foo = foo::Foo::Foo;
+   |         ^^^ help: consider prefixing with an underscore: `_Foo`
+
+warning: unused variable: `Foo`
+  --> $DIR/lint-uppercase-variables.rs:33:17
+   |
+LL |     fn in_param(Foo: foo::Foo) {}
+   |                 ^^^ help: consider prefixing with an underscore: `_Foo`
+
 error: structure field `X` should have a snake case name
   --> $DIR/lint-uppercase-variables.rs:10:5
    |
@@ -49,6 +73,18 @@ error: variable `Foo` should have a snake case name
 LL |         Foo => {}
    |         ^^^ help: convert the identifier to snake case (notice the capitalization): `foo`
 
-error: aborting due to 4 previous errors
+error: variable `Foo` should have a snake case name
+  --> $DIR/lint-uppercase-variables.rs:28:9
+   |
+LL |     let Foo = foo::Foo::Foo;
+   |         ^^^ help: convert the identifier to snake case (notice the capitalization): `foo`
+
+error: variable `Foo` should have a snake case name
+  --> $DIR/lint-uppercase-variables.rs:33:17
+   |
+LL |     fn in_param(Foo: foo::Foo) {}
+   |                 ^^^ help: convert the identifier to snake case (notice the capitalization): `foo`
+
+error: aborting due to 6 previous errors
 
 For more information about this error, try `rustc --explain E0170`.