[clang-tools-extra] [clang-tidy]fix readability-implicit-bool-conversion false-positives when comparison bool bitfield (PR #77878)

[Congcong Cai via cfe-commits]

https://github.com/HerrCai0907 created https://github.com/llvm/llvm-project/pull/77878

Fixes: #76817
For ignoring comparison and xor operator, it needs to use ImplicitCastFromBool without ignoring exception cases. This patch splits ignoring exception cases logic from ImplicitCastFromBool and only applies it when add matcher

>From 0424444c994785c06ed813fdf13c47c30e378c16 Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907 at 163.com>
Date: Fri, 12 Jan 2024 14:22:31 +0800
Subject: [PATCH] [clang-tidy]avoid readability-implicit-bool-conversion
 false-positives when comparison bool bitfield

Fixes: #76817
For ignoring comparison and xor operator, it needs to use ImplicitCastFromBool without ignoring exception cases.
This patch splits ignoring exception cases logic from ImplicitCastFromBool and only applies it when add matcher
---
 .../clang-tidy/readability/ImplicitBoolConversionCheck.cpp   | 5 ++---
 clang-tools-extra/docs/ReleaseNotes.rst                      | 3 ++-
 .../implicit-bool-conversion-allow-in-conditions.cpp         | 3 +++
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/readability/ImplicitBoolConversionCheck.cpp b/clang-tools-extra/clang-tidy/readability/ImplicitBoolConversionCheck.cpp
index f0fca30de3b3c4..672f28721114c9 100644
--- a/clang-tools-extra/clang-tidy/readability/ImplicitBoolConversionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ImplicitBoolConversionCheck.cpp
@@ -274,8 +274,7 @@ void ImplicitBoolConversionCheck::registerMatchers(MatchFinder *Finder) {
             allOf(anyOf(hasCastKind(CK_NullToPointer),
                         hasCastKind(CK_NullToMemberPointer)),
                   hasSourceExpression(cxxBoolLiteral()))),
-      hasSourceExpression(expr(hasType(booleanType()))),
-      unless(ExceptionCases));
+      hasSourceExpression(expr(hasType(booleanType()))));
   auto BoolXor =
       binaryOperator(hasOperatorName("^"), hasLHS(ImplicitCastFromBool),
                      hasRHS(ImplicitCastFromBool));
@@ -315,7 +314,7 @@ void ImplicitBoolConversionCheck::registerMatchers(MatchFinder *Finder) {
       traverse(
           TK_AsIs,
           implicitCastExpr(
-              ImplicitCastFromBool,
+              ImplicitCastFromBool, unless(ExceptionCases),
               // Exclude comparisons of bools, as they are always cast to
               // integers in such context:
               //   bool_expr_a == bool_expr_b
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index b4d87e0ed2a67a..f7274229bf52ce 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -478,7 +478,8 @@ Changes in existing checks
   <clang-tidy/checks/readability/implicit-bool-conversion>` check to take
   do-while loops into account for the `AllowIntegerConditions` and
   `AllowPointerConditions` options. It also now provides more consistent
-  suggestions when parentheses are added to the return value.
+  suggestions when parentheses are added to the return value. It also ignores
+  false-positives for comparison containing bool bitfield.
 
 - Improved :doc:`readability-misleading-indentation
   <clang-tidy/checks/readability/misleading-indentation>` check to ignore
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/implicit-bool-conversion-allow-in-conditions.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/implicit-bool-conversion-allow-in-conditions.cpp
index e393e297140cbd..48984d29322872 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/implicit-bool-conversion-allow-in-conditions.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/implicit-bool-conversion-allow-in-conditions.cpp
@@ -12,6 +12,7 @@ int* functionReturningPointer();
 struct Struct {
   int member;
   unsigned bitfield : 1;
+  bool boolfield : 1;
 };
 
 
@@ -28,6 +29,8 @@ void implicitConversionIntegerToBoolInConditionalsIsAllowed() {
   if (!s.member) {}
   if (s.bitfield) {}
   if (!s.bitfield) {}
+  if (s.boolfield == true) {}
+  if (s.boolfield != true) {}
   if (functionReturningInt()) {}
   if (!functionReturningInt()) {}
   if (functionReturningInt() && functionReturningPointer()) {}