[clang-tools-extra] [clang-tidy] Exclude bitwise operators in bugprone-non-zero-enum-to-bool-conversion (PR #65498)

[Piotr Zegar via cfe-commits]

https://github.com/PiotrZSL updated https://github.com/llvm/llvm-project/pull/65498:

>From 79b61b63896a203793bdb0af62c8bee4f676a5c1 Mon Sep 17 00:00:00 2001
From: Piotr Zegar <me at piotrzegar.pl>
Date: Wed, 6 Sep 2023 16:41:22 +0000
Subject: [PATCH 1/2] [clang-tidy] Exclude bitwise operators in
 bugprone-non-zero-enum-to-bool-conversion

Improved bugprone-non-zero-enum-to-bool-conversion check by
eliminating false positives resulting from direct usage of
bitwise operators.
---
 .../NonZeroEnumToBoolConversionCheck.cpp      |  6 +++++-
 clang-tools-extra/docs/ReleaseNotes.rst       |  6 +++++-
 .../non-zero-enum-to-bool-conversion.cpp      | 20 +++++++++++++++++++
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/bugprone/NonZeroEnumToBoolConversionCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/NonZeroEnumToBoolConversionCheck.cpp
index a59c4fc47c0b4e9..8a945ac65cfc9b2 100644
--- a/clang-tools-extra/clang-tidy/bugprone/NonZeroEnumToBoolConversionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/NonZeroEnumToBoolConversionCheck.cpp
@@ -49,6 +49,9 @@ bool NonZeroEnumToBoolConversionCheck::isLanguageVersionSupported(
 }
 
 void NonZeroEnumToBoolConversionCheck::registerMatchers(MatchFinder *Finder) {
+  auto ExcludedOperators = binaryOperation(hasAnyOperatorName(
+      "|", "&", "^", "<<", ">>", "~", "|=", "&=", "^=", "<<=", ">>="));
+
   Finder->addMatcher(
       castExpr(hasCastKind(CK_IntegralToBoolean),
                unless(isExpansionInSystemHeader()), hasType(booleanType()),
@@ -58,7 +61,8 @@ void NonZeroEnumToBoolConversionCheck::registerMatchers(MatchFinder *Finder) {
                                      unless(matchers::matchesAnyListedName(
                                          EnumIgnoreList)))
                                 .bind("enum"))))),
-                        unless(declRefExpr(to(enumConstantDecl()))))),
+                        unless(declRefExpr(to(enumConstantDecl()))),
+                        unless(ignoringImplicit(ExcludedOperators)))),
                unless(hasAncestor(staticAssertDecl())))
           .bind("cast"),
       this);
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index a2cde526a8c04d9..0bccc0b4023eaa7 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -183,6 +183,10 @@ Changes in existing checks
   <clang-tidy/checks/bugprone/lambda-function-name>` check by adding option
   `IgnoreMacros` to ignore warnings in macros.
 
+- Improved :doc:`bugprone-non-zero-enum-to-bool-conversion
+  <clang-tidy/checks/bugprone/non-zero-enum-to-bool-conversion>` check by
+  eliminating false positives resulting from direct usage of bitwise operators.
+
 - Improved :doc:`bugprone-reserved-identifier
   <clang-tidy/checks/bugprone/reserved-identifier>` check, so that it does not
   warn on macros starting with underscore and lowercase letter.
@@ -227,7 +231,7 @@ Changes in existing checks
   `DeduplicateFindings` to output one finding per symbol occurrence.
 
 - Improved :doc:`misc-include-cleaner
-  <clang-tidy/checks/misc/include-cleaner>` check to avoid fixes insert 
+  <clang-tidy/checks/misc/include-cleaner>` check to avoid fixes insert
   same include header multiple times.
 
 - Improved :doc:`misc-redundant-expression
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/non-zero-enum-to-bool-conversion.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/non-zero-enum-to-bool-conversion.cpp
index e0728680d4c6ad1..794e7b20c8ca53c 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/non-zero-enum-to-bool-conversion.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/non-zero-enum-to-bool-conversion.cpp
@@ -82,6 +82,14 @@ bool explicitCompare(EStatus value) {
   return value == SUCCESS;
 }
 
+bool explicitBitUsage1(EStatus value) {
+  return (value & SUCCESS);
+}
+
+bool explicitBitUsage2(EStatus value) {
+  return (value | SUCCESS);
+}
+
 bool testEnumeratorCompare() {
   return SUCCESS;
 }
@@ -104,4 +112,16 @@ bool testIgnored(IgnoredSecondEnum value) {
   return value;
 }
 
+enum CustomOperatorEnum {
+    E0 = 0x1,
+    E1 = 0x2,
+    E2 = 0x4
+};
+
+CustomOperatorEnum operator&(CustomOperatorEnum a, CustomOperatorEnum b) { return static_cast<CustomOperatorEnum>(a & b); }
+
+void testCustomOperator(CustomOperatorEnum e) {
+    if (e & E1) {}
+}
+
 }

>From fa6fc6bd7bb168e8664b7c347973e03ef33c3ca8 Mon Sep 17 00:00:00 2001
From: Piotr Zegar <me at piotrzegar.pl>
Date: Thu, 7 Sep 2023 17:36:29 +0000
Subject: [PATCH 2/2] Add comment

---
 .../clang-tidy/bugprone/NonZeroEnumToBoolConversionCheck.cpp    | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/clang-tools-extra/clang-tidy/bugprone/NonZeroEnumToBoolConversionCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/NonZeroEnumToBoolConversionCheck.cpp
index 8a945ac65cfc9b2..918b6e3824f0b1b 100644
--- a/clang-tools-extra/clang-tidy/bugprone/NonZeroEnumToBoolConversionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/NonZeroEnumToBoolConversionCheck.cpp
@@ -49,6 +49,8 @@ bool NonZeroEnumToBoolConversionCheck::isLanguageVersionSupported(
 }
 
 void NonZeroEnumToBoolConversionCheck::registerMatchers(MatchFinder *Finder) {
+  // Excluding bitwise operators (binary and overload) to avoid false-positives
+  // in code like this 'if (e & SUCCESS) {'.
   auto ExcludedOperators = binaryOperation(hasAnyOperatorName(
       "|", "&", "^", "<<", ">>", "~", "|=", "&=", "^=", "<<=", ">>="));