From 51e9113c60ce0699c8d343102828f26928081dc3 Mon Sep 17 00:00:00 2001
From: dswij <dswijj@gmail.com>
Date: Mon, 1 Aug 2022 20:31:23 +0800
Subject: [PATCH 1/2] Add `span_contains_comments` util

---
 clippy_utils/src/lib.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs
index 9308f085214f..4c5adde61906 100644
--- a/clippy_utils/src/lib.rs
+++ b/clippy_utils/src/lib.rs
@@ -87,6 +87,7 @@ use rustc_hir::{
     Mutability, Node, Param, Pat, PatKind, Path, PathSegment, PrimTy, QPath, Stmt, StmtKind, TraitItem, TraitItemKind,
     TraitRef, TyKind, UnOp,
 };
+use rustc_lexer::{tokenize, TokenKind};
 use rustc_lint::{LateContext, Level, Lint, LintContext};
 use rustc_middle::hir::place::PlaceBase;
 use rustc_middle::ty as rustc_ty;
@@ -104,6 +105,7 @@ use rustc_semver::RustcVersion;
 use rustc_session::Session;
 use rustc_span::hygiene::{ExpnKind, MacroKind};
 use rustc_span::source_map::original_sp;
+use rustc_span::source_map::SourceMap;
 use rustc_span::sym;
 use rustc_span::symbol::{kw, Symbol};
 use rustc_span::{Span, DUMMY_SP};
@@ -2278,6 +2280,18 @@ pub fn walk_to_expr_usage<'tcx, T>(
     None
 }
 
+/// Checks whether a given span has any comment token
+/// This checks for all types of comment: line "//", block "/**", doc "///" "//!"
+pub fn span_contains_comment(sm: &SourceMap, span: Span) -> bool {
+    let Ok(snippet) = sm.span_to_snippet(span) else { return false };
+    return tokenize(&snippet).any(|token| {
+        matches!(
+            token.kind,
+            TokenKind::BlockComment { .. } | TokenKind::LineComment { .. }
+        )
+    });
+}
+
 macro_rules! op_utils {
     ($($name:ident $assign:ident)*) => {
         /// Binary operation traits like `LangItem::Add`

From b07d72b69eac4f37081316801fa2979d904bbe13 Mon Sep 17 00:00:00 2001
From: dswij <dswijj@gmail.com>
Date: Sun, 28 Aug 2022 00:06:30 +0800
Subject: [PATCH 2/2] Ignore  when there is comment

---
 .../src/matches/match_like_matches.rs         |  4 ++-
 tests/ui/match_expr_like_matches_macro.fixed  | 25 +++++++++++++++++++
 tests/ui/match_expr_like_matches_macro.rs     | 25 +++++++++++++++++++
 3 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/clippy_lints/src/matches/match_like_matches.rs b/clippy_lints/src/matches/match_like_matches.rs
index 0da4833f1dfe..34cc082687ec 100644
--- a/clippy_lints/src/matches/match_like_matches.rs
+++ b/clippy_lints/src/matches/match_like_matches.rs
@@ -1,10 +1,11 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::is_wild;
 use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::span_contains_comment;
 use rustc_ast::{Attribute, LitKind};
 use rustc_errors::Applicability;
 use rustc_hir::{Arm, BorrowKind, Expr, ExprKind, Guard, Pat};
-use rustc_lint::LateContext;
+use rustc_lint::{LateContext, LintContext};
 use rustc_middle::ty;
 use rustc_span::source_map::Spanned;
 
@@ -76,6 +77,7 @@ where
         >,
 {
     if_chain! {
+        if !span_contains_comment(cx.sess().source_map(), expr.span);
         if iter.len() >= 2;
         if cx.typeck_results().expr_ty(expr).is_bool();
         if let Some((_, last_pat_opt, last_expr, _)) = iter.next_back();
diff --git a/tests/ui/match_expr_like_matches_macro.fixed b/tests/ui/match_expr_like_matches_macro.fixed
index 1ccbfda64b73..95ca571d07bf 100644
--- a/tests/ui/match_expr_like_matches_macro.fixed
+++ b/tests/ui/match_expr_like_matches_macro.fixed
@@ -167,4 +167,29 @@ fn main() {
             _ => false,
         };
     }
+
+    let x = ' ';
+    // ignore if match block contains comment
+    let _line_comments = match x {
+        // numbers are bad!
+        '1' | '2' | '3' => true,
+        // spaces are very important to be true.
+        ' ' => true,
+        // as are dots
+        '.' => true,
+        _ => false,
+    };
+
+    let _block_comments = match x {
+        /* numbers are bad!
+         */
+        '1' | '2' | '3' => true,
+        /* spaces are very important to be true.
+         */
+        ' ' => true,
+        /* as are dots
+         */
+        '.' => true,
+        _ => false,
+    };
 }
diff --git a/tests/ui/match_expr_like_matches_macro.rs b/tests/ui/match_expr_like_matches_macro.rs
index a49991f59417..3b9c8cadadcc 100644
--- a/tests/ui/match_expr_like_matches_macro.rs
+++ b/tests/ui/match_expr_like_matches_macro.rs
@@ -208,4 +208,29 @@ fn main() {
             _ => false,
         };
     }
+
+    let x = ' ';
+    // ignore if match block contains comment
+    let _line_comments = match x {
+        // numbers are bad!
+        '1' | '2' | '3' => true,
+        // spaces are very important to be true.
+        ' ' => true,
+        // as are dots
+        '.' => true,
+        _ => false,
+    };
+
+    let _block_comments = match x {
+        /* numbers are bad!
+         */
+        '1' | '2' | '3' => true,
+        /* spaces are very important to be true.
+         */
+        ' ' => true,
+        /* as are dots
+         */
+        '.' => true,
+        _ => false,
+    };
 }