[clang-tools-extra] dc2963c - [clang-tidy] exclude CXXParenListInitExpr from RedundantCastingCheck (#109741)

[via cfe-commits]

Author: Tommy Chen
Date: 2025-01-11T11:04:19+01:00
New Revision: dc2963c8d77229ca1b20663beddef2323cc69a88

URL: https://github.com/llvm/llvm-project/commit/dc2963c8d77229ca1b20663beddef2323cc69a88
DIFF: https://github.com/llvm/llvm-project/commit/dc2963c8d77229ca1b20663beddef2323cc69a88.diff

LOG: [clang-tidy] exclude CXXParenListInitExpr from RedundantCastingCheck (#109741)

Exclude CXXParenListInitExpr from RedundantCastingCheck because there
are false positive cases. Currently, we can't think of positive cases
for CXXParenListInitExpr. This can be improved by following the
initListExpr method if we can come up with some positive cases.

Fixes #108846

Added: 
    

Modified: 
    clang-tools-extra/clang-tidy/readability/RedundantCastingCheck.cpp
    clang-tools-extra/docs/ReleaseNotes.rst
    clang-tools-extra/test/clang-tidy/checkers/readability/redundant-casting.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clang-tidy/readability/RedundantCastingCheck.cpp b/clang-tools-extra/clang-tidy/readability/RedundantCastingCheck.cpp
index 4d5adbe02f5256..768540e05c7597 100644
--- a/clang-tools-extra/clang-tidy/readability/RedundantCastingCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/RedundantCastingCheck.cpp
@@ -108,6 +108,10 @@ void RedundantCastingCheck::registerMatchers(MatchFinder *Finder) {
 
   auto BitfieldMemberExpr = memberExpr(member(fieldDecl(isBitField())));
 
+  const ast_matchers::internal::VariadicDynCastAllOfMatcher<
+      Stmt, CXXParenListInitExpr>
+      cxxParenListInitExpr; // NOLINT(readability-identifier-naming)
+
   Finder->addMatcher(
       explicitCastExpr(
           unless(hasCastKind(CK_ConstructorConversion)),
@@ -117,6 +121,7 @@ void RedundantCastingCheck::registerMatchers(MatchFinder *Finder) {
           hasDestinationType(qualType().bind("dstType")),
           hasSourceExpression(anyOf(
               expr(unless(initListExpr()), unless(BitfieldMemberExpr),
+                   unless(cxxParenListInitExpr()),
                    hasType(qualType().bind("srcType")))
                   .bind("source"),
               initListExpr(unless(hasInit(1, expr())),

diff  --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 684ba77d8f0f53..9cdad8fb6b58f2 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -360,6 +360,11 @@ Changes in existing checks
   case of the literal suffix in fixes and fixing false positive for implicit
   conversion of comparison result in C23.
 
+- Improved :doc:`readability-redundant-casting
+  <clang-tidy/checks/readability/redundant-casting>` check
+  by addressing a false positive in aggregate initialization through
+  parenthesized list.
+
 - Improved :doc:`readability-redundant-smartptr-get
   <clang-tidy/checks/readability/redundant-smartptr-get>` check to
   remove `->`, when redundant `get()` is removed.

diff  --git a/clang-tools-extra/test/clang-tidy/checkers/readability/redundant-casting.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/redundant-casting.cpp
index 30cac6bd5cca06..9c3c90bfaf4595 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/redundant-casting.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/redundant-casting.cpp
@@ -1,10 +1,18 @@
-// RUN: %check_clang_tidy -std=c++11-or-later %s readability-redundant-casting %t -- -- -fno-delayed-template-parsing
-// RUN: %check_clang_tidy -std=c++11-or-later -check-suffix=,MACROS %s readability-redundant-casting %t -- \
+// RUN: %check_clang_tidy -std=c++11,c++14,c++17 %s readability-redundant-casting %t -- -- -fno-delayed-template-parsing
+// RUN: %check_clang_tidy -std=c++11,c++14,c++17 -check-suffix=,MACROS %s readability-redundant-casting %t -- \
 // RUN:   -config='{CheckOptions: { readability-redundant-casting.IgnoreMacros: false }}' \
 // RUN:   -- -fno-delayed-template-parsing
-// RUN: %check_clang_tidy -std=c++11-or-later -check-suffix=,ALIASES %s readability-redundant-casting %t -- \
+// RUN: %check_clang_tidy -std=c++11,c++14,c++17 -check-suffix=,ALIASES %s readability-redundant-casting %t -- \
 // RUN:   -config='{CheckOptions: { readability-redundant-casting.IgnoreTypeAliases: true }}' \
 // RUN:   -- -fno-delayed-template-parsing
+// RUN: %check_clang_tidy -std=c++20 %s readability-redundant-casting %t -- \
+// RUN:   -- -fno-delayed-template-parsing -D CXX_20=1
+// RUN: %check_clang_tidy -std=c++20 -check-suffix=,MACROS %s readability-redundant-casting %t -- \
+// RUN:   -config='{CheckOptions: { readability-redundant-casting.IgnoreMacros: false }}' \
+// RUN:   -- -fno-delayed-template-parsing -D CXX_20=1
+// RUN: %check_clang_tidy -std=c++20 -check-suffix=,ALIASES %s readability-redundant-casting %t -- \
+// RUN:   -config='{CheckOptions: { readability-redundant-casting.IgnoreTypeAliases: true }}' \
+// RUN:   -- -fno-delayed-template-parsing -D CXX_20=1
 
 struct A {};
 struct B : A {};
@@ -57,6 +65,12 @@ void testDiffrentTypesCast(B& value) {
   A& a7 = static_cast<A&>(value);
 }
 
+#ifdef CXX_20
+void testParenListInitExpr(A value) {
+  B b = static_cast<B>(value);
+}
+#endif
+
 void testCastingWithAuto() {
   auto a = getA();
   A& a8 = static_cast<A&>(a);