[clang-tools-extra] [clang-tidy] Fix identifier-naming style lookup in macro arguments (PR #206809)

[via cfe-commits]

https://github.com/savchart updated https://github.com/llvm/llvm-project/pull/206809

>From dd7869dd81dd10d6d0b6c6f93d4a43f1d6931371 Mon Sep 17 00:00:00 2001
From: savchart <metaartem at protonmail.com>
Date: Tue, 30 Jun 2026 20:48:18 +0200
Subject: [PATCH 1/2] [clang-tidy] Fix identifier-naming style lookup in macro
 arguments

---
 .../readability/IdentifierNamingCheck.cpp     |  3 ++-
 .../identifier-naming-macro-argument.cpp      | 23 +++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming-macro-argument.cpp

diff --git a/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp b/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp
index a356e1390b62d..2f66eb7248d1e 100644
--- a/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp
@@ -1395,7 +1395,8 @@ IdentifierNamingCheck::getDeclFailureInfo(const NamedDecl *Decl,
     return std::nullopt;
 
   const SourceLocation Loc = Decl->getLocation();
-  const FileStyle &FileStyle = getStyleForFile(SM.getFilename(Loc));
+  const SourceLocation StyleLoc = SM.getFileLoc(Loc);
+  const FileStyle &FileStyle = getStyleForFile(SM.getFilename(StyleLoc));
   if (!FileStyle.isActive())
     return std::nullopt;
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming-macro-argument.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming-macro-argument.cpp
new file mode 100644
index 0000000000000..9774da8c7b076
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming-macro-argument.cpp
@@ -0,0 +1,23 @@
+// RUN: %check_clang_tidy %s readability-identifier-naming %t -- \
+// RUN:   -config='{CheckOptions: { \
+// RUN:     readability-identifier-naming.FunctionCase: camelBack, \
+// RUN:     readability-identifier-naming.ParameterCase: camelBack, \
+// RUN:     readability-identifier-naming.VariableCase: camelBack \
+// RUN:   }}'
+
+#define WRAP(E) E
+
+WRAP(int foo(int v) { return v; })
+
+void testLambdaInMacroArgument() {
+  WRAP([](int var) {
+    return var;
+  }(1));
+}
+
+int badFunction(int BadParam) {
+  // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: invalid case style for parameter 'BadParam' [readability-identifier-naming]
+  // CHECK-FIXES: int badFunction(int badParam) {
+  return BadParam;
+  // CHECK-FIXES: return badParam;
+}
\ No newline at end of file

>From 8df16ae197e04779b44ae2812cae8c8b04948f79 Mon Sep 17 00:00:00 2001
From: savchart <metaartem at protonmail.com>
Date: Wed, 1 Jul 2026 10:41:10 +0200
Subject: [PATCH 2/2] [clang-tidy] Add release note for identifier-naming macro
 fix

---
 clang-tools-extra/docs/ReleaseNotes.rst                        | 3 +++
 .../checkers/readability/identifier-naming-macro-argument.cpp  | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index fca6c21f22768..a412de4ad319c 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -758,6 +758,9 @@ Changes in existing checks
   - Fixed a false positive where function templates could be diagnosed as generic
     identifiers when `DefaultCase` was enabled.
 
+  - Fixed a false positive from naming style lookup for declarations inside macro
+    arguments.
+
 - Improved :doc:`readability-implicit-bool-conversion
   <clang-tidy/checks/readability/implicit-bool-conversion>` check:
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming-macro-argument.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming-macro-argument.cpp
index 9774da8c7b076..ca34cf8edcbc8 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming-macro-argument.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming-macro-argument.cpp
@@ -20,4 +20,4 @@ int badFunction(int BadParam) {
   // CHECK-FIXES: int badFunction(int badParam) {
   return BadParam;
   // CHECK-FIXES: return badParam;
-}
\ No newline at end of file
+}