[clang-tools-extra] [clang-tidy] Improved readability-bool-conversion to be more consistent when using parentheses (PR #72068)

[Félix-Antoine Constantin via cfe-commits]

https://github.com/felix642 created https://github.com/llvm/llvm-project/pull/72068

Fixes #71852

>From 54743ceec9845cdc450d5c163a293e73884a8df9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A9lix-Antoine=20Constantin?=
 <felix-antoine.constantin at polymtl.ca>
Date: Sun, 12 Nov 2023 16:07:13 -0500
Subject: [PATCH] [clang-tidy] Improved readability-bool-conversion to be more
 consistent when using parentheses

Fixes #71852
---
 .../ImplicitBoolConversionCheck.cpp           |  4 +--
 clang-tools-extra/docs/ReleaseNotes.rst       |  4 +++
 .../readability/implicit-bool-conversion.cpp  | 30 +++++++++++++++++++
 3 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/readability/ImplicitBoolConversionCheck.cpp b/clang-tools-extra/clang-tidy/readability/ImplicitBoolConversionCheck.cpp
index 69e6d73c4fcd7bb..9e627d281e4b0f9 100644
--- a/clang-tools-extra/clang-tidy/readability/ImplicitBoolConversionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ImplicitBoolConversionCheck.cpp
@@ -152,7 +152,7 @@ StringRef getEquivalentBoolLiteralForExpr(const Expr *Expression,
     return "false";
   }
 
-  if (const auto *IntLit = dyn_cast<IntegerLiteral>(Expression)) {
+  if (const auto *IntLit = dyn_cast<IntegerLiteral>(Expression->IgnoreParens())) {
     return (IntLit->getValue() == 0) ? "false" : "true";
   }
 
@@ -385,7 +385,7 @@ void ImplicitBoolConversionCheck::handleCastFromBool(
               << DestType;
 
   if (const auto *BoolLiteral =
-          dyn_cast<CXXBoolLiteralExpr>(Cast->getSubExpr())) {
+          dyn_cast<CXXBoolLiteralExpr>(Cast->getSubExpr()->IgnoreParens())) {
     Diag << tooling::fixit::createReplacement(
         *Cast, getEquivalentForBoolLiteral(BoolLiteral, DestType, Context));
   } else {
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index f49c412118e7d98..ab9ef8cdfb37a00 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -412,6 +412,10 @@ Changes in existing checks
   do-while loops into account for the `AllowIntegerConditions` and
   `AllowPointerConditions` options.
 
+- Improved :doc:`readability-implicit-bool-conversion
+  <clang-tidy/checks/readability/implicit-bool-conversion>` check to provide
+  consistent suggestions when parentheses are added to the return value. 
+
 - Improved :doc:`readability-non-const-parameter
   <clang-tidy/checks/readability/non-const-parameter>` check to ignore
   false-positives in initializer list of record.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/implicit-bool-conversion.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/implicit-bool-conversion.cpp
index 323cf813c047000..f7f5d506a9ce0e0 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/implicit-bool-conversion.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/implicit-bool-conversion.cpp
@@ -472,6 +472,36 @@ bool f(S& s) {
 
 } // namespace ignore_1bit_bitfields
 
+int implicitConversionReturnInt()
+{
+    return true;
+    // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: implicit conversion bool -> 'int'
+    // CHECK-FIXES: return 1
+}
+
+int implicitConversionReturnIntWithParens()
+{
+    return (true);
+    // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: implicit conversion bool -> 'int'
+    // CHECK-FIXES: return 1
+}
+
+
+bool implicitConversionReturnBool()
+{
+    return 1;
+    // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: implicit conversion 'int' -> bool
+    // CHECK-FIXES: return true
+}
+
+bool implicitConversionReturnBoolWithParens()
+{
+    return (1);
+    // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: implicit conversion 'int' -> bool
+    // CHECK-FIXES: return true
+}
+
+
 namespace PR47000 {
   int to_int(bool x) { return int{x}; }