[clang-tools-extra] [clang-tidy] fix false positive of parentheses removal for overloaded operator (PR #192254)

[Gaurav Dhingra via cfe-commits]

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@@ -121,3 +121,36 @@ void memberExpr() {
    // CHECK-FIXES:    if (foo.fooBar().z) {
   }
 }
+
+enum class FoldLevel {
+  None = 0x0,
+  HeaderFlag = 0x2000,
+};
+
+constexpr FoldLevel operator&(FoldLevel lhs, FoldLevel rhs) {
+  return static_cast<FoldLevel>(static_cast<int>(lhs) & static_cast<int>(rhs));
+}
+
+constexpr bool UseOperatorAmpersand1(FoldLevel level) {
+  return (level & FoldLevel::HeaderFlag) != FoldLevel::None;
+}
+
+constexpr bool UseOperatorAmpersand2(FoldLevel level) {
+  const FoldLevel l = (level & FoldLevel::HeaderFlag);
+  // CHECK-MESSAGES: :[[@LINE-1]]:23: warning: redundant parentheses around expression [readability-redundant-parentheses]
+  // CHECK-FIXES:    const FoldLevel l = level & FoldLevel::HeaderFlag;
+  return l != FoldLevel::None;
+}
+
+constexpr bool UseOperatorAmpersand3(FoldLevel level) {
+  const FoldLevel l = level & FoldLevel::HeaderFlag;
+  return (l != FoldLevel::None);
+}
+
+constexpr bool UseOperatorAmpersand4(FoldLevel level) {
+  return ((level & FoldLevel::HeaderFlag) != FoldLevel::None);
+}
+
+const int bracket_int_plus_num = (4) + 5;
+// CHECK-MESSAGES: :[[@LINE-1]]:34: warning: redundant parentheses around expression [readability-redundant-parentheses]
+// CHECK-FIXES:    const int bracket_int_plus_num = 4 + 5;
----------------
gxyd wrote:

There is no existing test case in our test-suite which tests this.

When working on this PR, I was able to create a solution which fixes the MRE in linked issue and passed out existing test-suite as well, but it broke this test-case. Hence confirming the need for this particular case.

https://github.com/llvm/llvm-project/pull/192254