https://github.com/jjmarr-amd updated
https://github.com/llvm/llvm-project/pull/160150
>From 35df1c6ea3af8dbaea2d7049ae79b14ce39f0774 Mon Sep 17 00:00:00 2001
From: JJ Marr <jj.m...@amd.com>
Date: Fri, 11 Jul 2025 14:40:57 -0400
Subject: [PATCH 01/21] Bugprone-default-lambda-capture
on-behalf-of: @AMD <jj.m...@amd.com>
---
.../bugprone/BugproneTidyModule.cpp | 3 +
.../clang-tidy/bugprone/CMakeLists.txt | 1 +
.../bugprone/DefaultLambdaCaptureCheck.cpp | 35 +++++++
.../bugprone/DefaultLambdaCaptureCheck.h | 26 +++++
clang-tools-extra/docs/ReleaseNotes.rst | 9 ++
.../bugprone/default-lambda-capture.rst | 42 ++++++++
.../docs/clang-tidy/checks/list.rst | 1 +
.../bugprone/default-lambda-capture.cpp | 98 +++++++++++++++++++
8 files changed, 215 insertions(+)
create mode 100644
clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
create mode 100644
clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
create mode 100644
clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
create mode 100644
clang-tools-extra/test/clang-tidy/checkers/bugprone/default-lambda-capture.cpp
diff --git a/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
b/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
index 491de6acea2b7..db99d57c511b8 100644
--- a/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
@@ -23,6 +23,7 @@
#include "CopyConstructorInitCheck.h"
#include "CrtpConstructorAccessibilityCheck.h"
#include "DanglingHandleCheck.h"
+#include "DefaultLambdaCaptureCheck.h"
#include "DynamicStaticInitializersCheck.h"
#include "EasilySwappableParametersCheck.h"
#include "EmptyCatchCheck.h"
@@ -134,6 +135,8 @@ class BugproneModule : public ClangTidyModule {
"bugprone-copy-constructor-init");
CheckFactories.registerCheck<DanglingHandleCheck>(
"bugprone-dangling-handle");
+ CheckFactories.registerCheck<DefaultLambdaCaptureCheck>(
+ "bugprone-default-lambda-capture");
CheckFactories.registerCheck<DynamicStaticInitializersCheck>(
"bugprone-dynamic-static-initializers");
CheckFactories.registerCheck<EasilySwappableParametersCheck>(
diff --git a/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
b/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
index 46bc8efd44bc5..66125c9d22c1c 100644
--- a/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
@@ -19,6 +19,7 @@ add_clang_library(clangTidyBugproneModule STATIC
CopyConstructorInitCheck.cpp
CrtpConstructorAccessibilityCheck.cpp
DanglingHandleCheck.cpp
+ DefaultLambdaCaptureCheck.cpp
DynamicStaticInitializersCheck.cpp
EasilySwappableParametersCheck.cpp
EmptyCatchCheck.cpp
diff --git
a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
new file mode 100644
index 0000000000000..6c95fbc984c5a
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
@@ -0,0 +1,35 @@
+#include "DefaultLambdaCaptureCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::bugprone {
+
+void DefaultLambdaCaptureCheck::registerMatchers(MatchFinder *Finder) {
+ // Match any lambda expression
+ Finder->addMatcher(lambdaExpr().bind("lambda"), this);
+}
+
+void DefaultLambdaCaptureCheck::check(const MatchFinder::MatchResult &Result) {
+ const auto *Lambda = Result.Nodes.getNodeAs<LambdaExpr>("lambda");
+ if (!Lambda)
+ return;
+
+ // Check if lambda has a default capture
+ if (Lambda->getCaptureDefault() == LCD_None)
+ return;
+
+ SourceLocation DefaultCaptureLoc = Lambda->getCaptureDefaultLoc();
+ if (DefaultCaptureLoc.isInvalid())
+ return;
+
+ const char *CaptureKind =
+ (Lambda->getCaptureDefault() == LCD_ByCopy) ? "by-copy" : "by-reference";
+
+ diag(DefaultCaptureLoc, "lambda %0 default capture is discouraged; "
+ "prefer to capture specific variables explicitly")
+ << CaptureKind;
+}
+
+} // namespace clang::tidy::bugprone
diff --git a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
new file mode 100644
index 0000000000000..ac47c866cfccd
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
@@ -0,0 +1,26 @@
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULT_LAMBDA_CAPTURE_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULT_LAMBDA_CAPTURE_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::bugprone {
+
+/** Flags lambdas that use default capture modes
+ *
+ * For the user-facing documentation see:
+ *
http://clang.llvm.org/extra/clang-tidy/checks/bugprone/default-lambda-capture.html
+ */
+class DefaultLambdaCaptureCheck : public ClangTidyCheck {
+public:
+ DefaultLambdaCaptureCheck(StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context) {}
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+ std::optional<TraversalKind> getCheckTraversalKind() const override {
+ return TK_IgnoreUnlessSpelledInSource;
+ }
+};
+
+} // namespace clang::tidy::bugprone
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULT_LAMBDA_CAPTURE_H
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst
b/clang-tools-extra/docs/ReleaseNotes.rst
index 7cdff86beeec6..30d0bffb78f39 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -194,6 +194,15 @@ New checks
Finds virtual function overrides with different visibility than the function
in the base class.
+- New :doc:`bugprone-default-lambda-capture
+ <clang-tidy/checks/bugprone/default-lambda-capture>` check.
+
+ Finds lambda expressions that use default capture modes (``[=]`` or ``[&]``)
+ and suggests using explicit captures instead. Default captures can lead to
+ subtle bugs including dangling references with ``[&]``, unnecessary copies
+ with ``[=]``, and make code less maintainable by hiding which variables are
+ actually being captured.
+
New check aliases
^^^^^^^^^^^^^^^^^
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
new file mode 100644
index 0000000000000..026acf9f1894b
--- /dev/null
+++
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
@@ -0,0 +1,42 @@
+.. title:: clang-tidy - bugprone-default-lambda-capture
+
+bugprone-default-lambda-capture
+===============================
+
+Warns when lambda expressions use default capture modes (``[=]`` or ``[&]``)
+instead of explicitly capturing specific variables. Default captures can make
+code less readable and more error-prone by making it unclear which variables
+are being captured and how.
+
+Implements Item 31 of Effective Modern C++ by Scott Meyers.
+
+Example
+-------
+
+.. code-block:: c++
+
+ void example() {
+ int x = 1;
+ int y = 2;
+
+ // Bad - default capture by copy
+ auto lambda1 = [=]() { return x + y; };
+
+ // Bad - default capture by reference
+ auto lambda2 = [&]() { return x + y; };
+
+ // Good - explicit captures
+ auto lambda3 = [x, y]() { return x + y; };
+ auto lambda4 = [&x, &y]() { return x + y; };
+ }
+
+The check will warn on:
+
+- Default capture by copy: ``[=]``
+- Default capture by reference: ``[&]``
+- Mixed captures with defaults: ``[=, &x]`` or ``[&, x]``
+
+The check will not warn on:
+
+- Explicit captures: ``[x]``, ``[&x]``, ``[x, y]``, ``[this]``
+- Empty capture lists: ``[]``
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst
b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index c490d2ece2e0a..cb6254ee36f42 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -91,6 +91,7 @@ Clang-Tidy Checks
:doc:`bugprone-copy-constructor-init <bugprone/copy-constructor-init>`,
"Yes"
:doc:`bugprone-crtp-constructor-accessibility
<bugprone/crtp-constructor-accessibility>`, "Yes"
:doc:`bugprone-dangling-handle <bugprone/dangling-handle>`,
+ :doc:`bugprone-default-lambda-capture <bugprone/default-lambda-capture>`,
:doc:`bugprone-dynamic-static-initializers
<bugprone/dynamic-static-initializers>`,
:doc:`bugprone-easily-swappable-parameters
<bugprone/easily-swappable-parameters>`,
:doc:`bugprone-empty-catch <bugprone/empty-catch>`,
diff --git
a/clang-tools-extra/test/clang-tidy/checkers/bugprone/default-lambda-capture.cpp
b/clang-tools-extra/test/clang-tidy/checkers/bugprone/default-lambda-capture.cpp
new file mode 100644
index 0000000000000..f820b4c9b8a0e
--- /dev/null
+++
b/clang-tools-extra/test/clang-tidy/checkers/bugprone/default-lambda-capture.cpp
@@ -0,0 +1,98 @@
+// RUN: %check_clang_tidy %s bugprone-default-lambda-capture %t
+
+void test_default_captures() {
+ int value = 42;
+ int another = 10;
+
+ auto lambda1 = [=](int x) { return value + x; };
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda by-copy default capture
is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+
+ auto lambda2 = [&](int x) { return value + x; };
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda by-reference default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+
+ auto lambda3 = [=, &another](int x) { return value + another + x; };
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda by-copy default capture
is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+
+ auto lambda4 = [&, value](int x) { return value + another + x; };
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda by-reference default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+}
+
+void test_acceptable_captures() {
+ int value = 42;
+ int another = 10;
+
+ auto lambda1 = [value](int x) { return value + x; };
+ auto lambda2 = [&value](int x) { return value + x; };
+ auto lambda3 = [value, another](int x) { return value + another + x; };
+ auto lambda4 = [&value, &another](int x) { return value + another + x; };
+
+ auto lambda5 = [](int x, int y) { return x + y; };
+
+ struct S {
+ int member = 5;
+ void foo() {
+ auto lambda = [this]() { return member; };
+ }
+ };
+}
+
+void test_nested_lambdas() {
+ int outer_var = 1;
+ int middle_var = 2;
+ int inner_var = 3;
+
+ auto outer = [=]() {
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda by-copy default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+
+ auto inner = [&](int x) { return outer_var + middle_var + inner_var + x; };
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda by-reference default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+
+ return inner(10);
+ };
+}
+
+void test_lambda_returns() {
+ int a = 1, b = 2, c = 3;
+
+ auto create_adder = [=](int x) {
+ // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: lambda by-copy default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ return [x](int y) { return x + y; }; // Inner lambda is fine - explicit
capture
+ };
+
+ auto func1 = [&]() { return a; };
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda by-reference default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+
+ auto func2 = [=]() { return b; };
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda by-copy default capture
is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+}
+
+class TestClass {
+ int member = 42;
+
+public:
+ void test_member_function_lambdas() {
+ int local = 10;
+
+ auto lambda1 = [=]() { return member + local; };
+ // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda by-copy default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+
+ auto lambda2 = [&]() { return member + local; };
+ // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda by-reference default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+
+ auto lambda3 = [this, local]() { return member + local; };
+ auto lambda4 = [this, &local]() { return member + local; };
+ }
+};
+
+template<typename T>
+void test_template_lambdas() {
+ T value{};
+
+ auto lambda = [=](T x) { return value + x; };
+ // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: lambda by-copy default capture
is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+}
+
+void instantiate_templates() {
+ test_template_lambdas<int>();
+ test_template_lambdas<double>();
+}
>From 689f95b2ba46d6ca319e0735b5f5474bfc14f999 Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Mon, 22 Sep 2025 09:58:59 -0400
Subject: [PATCH 02/21] Fix headers
on-behalf-of: @amd <jj.m...@amd.com>
---
.../clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp | 8 ++++++++
.../clang-tidy/bugprone/DefaultLambdaCaptureCheck.h | 8 ++++++++
2 files changed, 16 insertions(+)
diff --git
a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
index 6c95fbc984c5a..0ee65df4b9860 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM
Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
#include "DefaultLambdaCaptureCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
diff --git a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
index ac47c866cfccd..9af861aaf2e93 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM
Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULT_LAMBDA_CAPTURE_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULT_LAMBDA_CAPTURE_H
>From 9991b9ceda13c036e78c0e95978fe16f0bde5959 Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Mon, 22 Sep 2025 10:21:44 -0400
Subject: [PATCH 03/21] remove superfluous comments.
on-behalf-of: @amd <jj.m...@amd.com>
---
.../clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp | 2 --
1 file changed, 2 deletions(-)
diff --git
a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
index 0ee65df4b9860..6db5cc8fc10bb 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
@@ -15,7 +15,6 @@ using namespace clang::ast_matchers;
namespace clang::tidy::bugprone {
void DefaultLambdaCaptureCheck::registerMatchers(MatchFinder *Finder) {
- // Match any lambda expression
Finder->addMatcher(lambdaExpr().bind("lambda"), this);
}
@@ -24,7 +23,6 @@ void DefaultLambdaCaptureCheck::check(const
MatchFinder::MatchResult &Result) {
if (!Lambda)
return;
- // Check if lambda has a default capture
if (Lambda->getCaptureDefault() == LCD_None)
return;
>From db17a4c5a29faa47c69ddb48edb2b0316287c5bc Mon Sep 17 00:00:00 2001
From: "Marr, J J" <jj.m...@amd.com>
Date: Mon, 22 Sep 2025 10:37:30 -0400
Subject: [PATCH 04/21] add new matcher
on-behalf-of: @AMD <jj.m...@amd.com>
---
.../bugprone/DefaultLambdaCaptureCheck.cpp | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git
a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
index 6db5cc8fc10bb..7fc3e571db220 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
@@ -14,8 +14,15 @@ using namespace clang::ast_matchers;
namespace clang::tidy::bugprone {
+namespace {
+AST_MATCHER(LambdaExpr, hasDefaultCapture) {
+ return Node.getCaptureDefault() != LCD_None;
+}
+
+} // namespace
+
void DefaultLambdaCaptureCheck::registerMatchers(MatchFinder *Finder) {
- Finder->addMatcher(lambdaExpr().bind("lambda"), this);
+ Finder->addMatcher(lambdaExpr(hasDefaultCapture()).bind("lambda"), this);
}
void DefaultLambdaCaptureCheck::check(const MatchFinder::MatchResult &Result) {
@@ -23,8 +30,8 @@ void DefaultLambdaCaptureCheck::check(const
MatchFinder::MatchResult &Result) {
if (!Lambda)
return;
- if (Lambda->getCaptureDefault() == LCD_None)
- return;
+ // No need to check getCaptureDefault() != LCD_None since our custom matcher
+ // hasDefaultCapture() already ensures this condition
SourceLocation DefaultCaptureLoc = Lambda->getCaptureDefaultLoc();
if (DefaultCaptureLoc.isInvalid())
>From 7dcf2162c2a6df4057585e2898bc8feb4536a67c Mon Sep 17 00:00:00 2001
From: "Marr, J J" <jj.m...@amd.com>
Date: Mon, 22 Sep 2025 11:51:27 -0400
Subject: [PATCH 05/21] Replace if with assert
on-behalf-of: @amd <jj.m...@amd.com>
---
.../clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git
a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
index 7fc3e571db220..4db95101025cc 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
@@ -27,11 +27,7 @@ void DefaultLambdaCaptureCheck::registerMatchers(MatchFinder
*Finder) {
void DefaultLambdaCaptureCheck::check(const MatchFinder::MatchResult &Result) {
const auto *Lambda = Result.Nodes.getNodeAs<LambdaExpr>("lambda");
- if (!Lambda)
- return;
-
- // No need to check getCaptureDefault() != LCD_None since our custom matcher
- // hasDefaultCapture() already ensures this condition
+ assert(Lambda);
SourceLocation DefaultCaptureLoc = Lambda->getCaptureDefaultLoc();
if (DefaultCaptureLoc.isInvalid())
>From 176d195cc753b3c95b9a82305e1fe1267e181cfa Mon Sep 17 00:00:00 2001
From: "Marr, J J" <jj.m...@amd.com>
Date: Mon, 22 Sep 2025 11:52:40 -0400
Subject: [PATCH 06/21] Remove specific warning type
on-behalf-of: @amd <jj.m...@amd.com>
---
.../bugprone/DefaultLambdaCaptureCheck.cpp | 8 ++-----
.../bugprone/default-lambda-capture.cpp | 24 +++++++++----------
2 files changed, 14 insertions(+), 18 deletions(-)
diff --git
a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
index 4db95101025cc..288feb7853e0b 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
@@ -33,12 +33,8 @@ void DefaultLambdaCaptureCheck::check(const
MatchFinder::MatchResult &Result) {
if (DefaultCaptureLoc.isInvalid())
return;
- const char *CaptureKind =
- (Lambda->getCaptureDefault() == LCD_ByCopy) ? "by-copy" : "by-reference";
-
- diag(DefaultCaptureLoc, "lambda %0 default capture is discouraged; "
- "prefer to capture specific variables explicitly")
- << CaptureKind;
+ diag(DefaultCaptureLoc, "lambda default captures are discouraged; "
+ "prefer to capture specific variables explicitly");
}
} // namespace clang::tidy::bugprone
diff --git
a/clang-tools-extra/test/clang-tidy/checkers/bugprone/default-lambda-capture.cpp
b/clang-tools-extra/test/clang-tidy/checkers/bugprone/default-lambda-capture.cpp
index f820b4c9b8a0e..010edf11f0a2b 100644
---
a/clang-tools-extra/test/clang-tidy/checkers/bugprone/default-lambda-capture.cpp
+++
b/clang-tools-extra/test/clang-tidy/checkers/bugprone/default-lambda-capture.cpp
@@ -5,16 +5,16 @@ void test_default_captures() {
int another = 10;
auto lambda1 = [=](int x) { return value + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda by-copy default capture
is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
auto lambda2 = [&](int x) { return value + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda by-reference default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
auto lambda3 = [=, &another](int x) { return value + another + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda by-copy default capture
is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
auto lambda4 = [&, value](int x) { return value + another + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda by-reference default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
}
void test_acceptable_captures() {
@@ -42,10 +42,10 @@ void test_nested_lambdas() {
int inner_var = 3;
auto outer = [=]() {
- // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda by-copy default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
auto inner = [&](int x) { return outer_var + middle_var + inner_var + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda by-reference default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
return inner(10);
};
@@ -55,15 +55,15 @@ void test_lambda_returns() {
int a = 1, b = 2, c = 3;
auto create_adder = [=](int x) {
- // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: lambda by-copy default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
return [x](int y) { return x + y; }; // Inner lambda is fine - explicit
capture
};
auto func1 = [&]() { return a; };
- // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda by-reference default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
auto func2 = [=]() { return b; };
- // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda by-copy default capture
is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
}
class TestClass {
@@ -74,10 +74,10 @@ class TestClass {
int local = 10;
auto lambda1 = [=]() { return member + local; };
- // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda by-copy default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
auto lambda2 = [&]() { return member + local; };
- // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda by-reference default
capture is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
auto lambda3 = [this, local]() { return member + local; };
auto lambda4 = [this, &local]() { return member + local; };
@@ -89,7 +89,7 @@ void test_template_lambdas() {
T value{};
auto lambda = [=](T x) { return value + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: lambda by-copy default capture
is discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
}
void instantiate_templates() {
>From 5f23dfff1a8368ebca7c2da691201ea1277ad128 Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Mon, 22 Sep 2025 12:25:50 -0400
Subject: [PATCH 07/21] Sync documentation to release notes
on-behalf-of: @amd <jj.m...@amd.com>
---
.../checks/bugprone/default-lambda-capture.rst | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
index 026acf9f1894b..f1fcf3ec52948 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
@@ -3,10 +3,11 @@
bugprone-default-lambda-capture
===============================
-Warns when lambda expressions use default capture modes (``[=]`` or ``[&]``)
-instead of explicitly capturing specific variables. Default captures can make
-code less readable and more error-prone by making it unclear which variables
-are being captured and how.
+ Finds lambda expressions that use default capture modes (``[=]`` or ``[&]``)
+ and suggests using explicit captures instead. Default captures can lead to
+ subtle bugs including dangling references with ``[&]``, unnecessary copies
+ with ``[=]``, and make code less maintainable by hiding which variables are
+ actually being captured.
Implements Item 31 of Effective Modern C++ by Scott Meyers.
>From 4c413327a64669d5254f0d6e343ca5c394701611 Mon Sep 17 00:00:00 2001
From: JJ Marr <jjmar...@amd.com>
Date: Mon, 22 Sep 2025 13:00:22 -0400
Subject: [PATCH 08/21] Update
clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
Co-authored-by: EugeneZelenko <eugene.zele...@gmail.com>
---
.../clang-tidy/bugprone/DefaultLambdaCaptureCheck.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
index 9af861aaf2e93..ad48316708b1b 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
@@ -16,7 +16,7 @@ namespace clang::tidy::bugprone {
/** Flags lambdas that use default capture modes
*
* For the user-facing documentation see:
- *
http://clang.llvm.org/extra/clang-tidy/checks/bugprone/default-lambda-capture.html
+ *
https://clang.llvm.org/extra/clang-tidy/checks/bugprone/default-lambda-capture.html
*/
class DefaultLambdaCaptureCheck : public ClangTidyCheck {
public:
>From 330dbd8ca5eeed45d63d1a44c15eeb5357a8a4ef Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Mon, 22 Sep 2025 13:01:23 -0400
Subject: [PATCH 09/21] Remove superfluous include
on-behalf-of: @amd <jj.m...@amd.com>
---
.../clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp | 1 -
1 file changed, 1 deletion(-)
diff --git
a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
index 288feb7853e0b..8f52aeb59ead6 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
@@ -7,7 +7,6 @@
//===----------------------------------------------------------------------===//
#include "DefaultLambdaCaptureCheck.h"
-#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
using namespace clang::ast_matchers;
>From 31366e6b34dce3ab7e5f24d07f81ad10ecd9b875 Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Mon, 22 Sep 2025 13:09:55 -0400
Subject: [PATCH 10/21] Fix doc and release notes
on-behalf-of: @amd <jj.m...@amd.com>
---
clang-tools-extra/docs/ReleaseNotes.rst | 14 +++++---------
.../checks/bugprone/default-lambda-capture.rst | 10 +++++-----
2 files changed, 10 insertions(+), 14 deletions(-)
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst
b/clang-tools-extra/docs/ReleaseNotes.rst
index 780cf41373128..9d2e8dcad7045 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -167,6 +167,11 @@ New checks
Detects default initialization (to 0) of variables with ``enum`` type where
the enum has no enumerator with value of 0.
+- New :doc:`bugprone-default-lambda-capture
+ <clang-tidy/checks/bugprone/default-lambda-capture>` check.
+
+ Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
+
- New :doc:`bugprone-derived-method-shadowing-base-method
<clang-tidy/checks/bugprone/derived-method-shadowing-base-method>` check.
@@ -203,15 +208,6 @@ New checks
Finds virtual function overrides with different visibility than the function
in the base class.
-- New :doc:`bugprone-default-lambda-capture
- <clang-tidy/checks/bugprone/default-lambda-capture>` check.
-
- Finds lambda expressions that use default capture modes (``[=]`` or ``[&]``)
- and suggests using explicit captures instead. Default captures can lead to
- subtle bugs including dangling references with ``[&]``, unnecessary copies
- with ``[=]``, and make code less maintainable by hiding which variables are
- actually being captured.
-
New check aliases
^^^^^^^^^^^^^^^^^
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
index f1fcf3ec52948..9cedc6276e1b3 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
@@ -3,11 +3,11 @@
bugprone-default-lambda-capture
===============================
- Finds lambda expressions that use default capture modes (``[=]`` or ``[&]``)
- and suggests using explicit captures instead. Default captures can lead to
- subtle bugs including dangling references with ``[&]``, unnecessary copies
- with ``[=]``, and make code less maintainable by hiding which variables are
- actually being captured.
+Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
+
+Default captures can lead to subtle bugs including dangling references with
+``[&]``, unnecessary copies with ``[=]``, and make code less maintainable by
+hiding which variables are actually being captured.
Implements Item 31 of Effective Modern C++ by Scott Meyers.
>From 70df9dff73c3b3de4dcdfbed8b44186ff2000997 Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Mon, 22 Sep 2025 14:43:19 -0400
Subject: [PATCH 11/21] Fix const
on-behalf-of: @amd <jj.m...@amd.com>
---
.../clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git
a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
index 8f52aeb59ead6..a7a18ccb30864 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
@@ -28,7 +28,7 @@ void DefaultLambdaCaptureCheck::check(const
MatchFinder::MatchResult &Result) {
const auto *Lambda = Result.Nodes.getNodeAs<LambdaExpr>("lambda");
assert(Lambda);
- SourceLocation DefaultCaptureLoc = Lambda->getCaptureDefaultLoc();
+ const SourceLocation DefaultCaptureLoc = Lambda->getCaptureDefaultLoc();
if (DefaultCaptureLoc.isInvalid())
return;
>From 0bcdbc4373a6d320f49f30a64c647b1da3956756 Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Tue, 23 Sep 2025 13:15:11 -0400
Subject: [PATCH 12/21] Fix header guard
on-behalf-of: @amd <jj.m...@amd.com>
---
.../clang-tidy/bugprone/DefaultLambdaCaptureCheck.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
index ad48316708b1b..fa69245b91c94 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
@@ -6,8 +6,8 @@
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULT_LAMBDA_CAPTURE_H
-#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULT_LAMBDA_CAPTURE_H
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURE_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURE_H
#include "../ClangTidyCheck.h"
@@ -31,4 +31,4 @@ class DefaultLambdaCaptureCheck : public ClangTidyCheck {
} // namespace clang::tidy::bugprone
-#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULT_LAMBDA_CAPTURE_H
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURE_H
>From ac709f4fcf092da2b240b9e0a62d1f8c314fdebb Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Tue, 23 Sep 2025 16:07:45 -0400
Subject: [PATCH 13/21] Fix header spelling
on-behalf-of: @amd <jj.m...@amd.com>
---
.../clang-tidy/bugprone/DefaultLambdaCaptureCheck.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
index fa69245b91c94..c41d7257592d5 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
+++ b/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
@@ -6,8 +6,8 @@
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURE_H
-#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURE_H
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURECHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURECHECK_H
#include "../ClangTidyCheck.h"
@@ -31,4 +31,4 @@ class DefaultLambdaCaptureCheck : public ClangTidyCheck {
} // namespace clang::tidy::bugprone
-#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURE_H
+#endif //
LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURECHECK_H
>From 5d4c2ca704cce01a491ac38ecd25bf722b94ad78 Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Wed, 24 Sep 2025 13:24:17 -0400
Subject: [PATCH 14/21] Rename check to readability-default-lambda-capture
on-behalf-of: @amd <jj.m...@amd.com>
---
.../bugprone/BugproneTidyModule.cpp | 3 ---
.../clang-tidy/bugprone/CMakeLists.txt | 1 -
.../clang-tidy/readability/CMakeLists.txt | 1 +
.../DefaultLambdaCaptureCheck.cpp | 4 +--
.../DefaultLambdaCaptureCheck.h | 12 ++++-----
.../readability/ReadabilityTidyModule.cpp | 3 +++
clang-tools-extra/docs/ReleaseNotes.rst | 10 +++----
.../docs/clang-tidy/checks/list.rst | 2 +-
.../default-lambda-capture.rst | 4 +--
.../default-lambda-capture.cpp | 26 +++++++++----------
10 files changed, 33 insertions(+), 33 deletions(-)
rename clang-tools-extra/clang-tidy/{bugprone =>
readability}/DefaultLambdaCaptureCheck.cpp (94%)
rename clang-tools-extra/clang-tidy/{bugprone =>
readability}/DefaultLambdaCaptureCheck.h (69%)
rename clang-tools-extra/docs/clang-tidy/checks/{bugprone =>
readability}/default-lambda-capture.rst (91%)
rename clang-tools-extra/test/clang-tidy/checkers/{bugprone =>
readability}/default-lambda-capture.cpp (84%)
diff --git a/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
b/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
index 67222cbafb5f9..8baa8f6b35d4c 100644
--- a/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
@@ -23,7 +23,6 @@
#include "CopyConstructorInitCheck.h"
#include "CrtpConstructorAccessibilityCheck.h"
#include "DanglingHandleCheck.h"
-#include "DefaultLambdaCaptureCheck.h"
#include "DerivedMethodShadowingBaseMethodCheck.h"
#include "DynamicStaticInitializersCheck.h"
#include "EasilySwappableParametersCheck.h"
@@ -137,8 +136,6 @@ class BugproneModule : public ClangTidyModule {
"bugprone-copy-constructor-init");
CheckFactories.registerCheck<DanglingHandleCheck>(
"bugprone-dangling-handle");
- CheckFactories.registerCheck<DefaultLambdaCaptureCheck>(
- "bugprone-default-lambda-capture");
CheckFactories.registerCheck<DerivedMethodShadowingBaseMethodCheck>(
"bugprone-derived-method-shadowing-base-method");
CheckFactories.registerCheck<DynamicStaticInitializersCheck>(
diff --git a/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
b/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
index c8c31f9f96bb0..b0dbe84a16cd4 100644
--- a/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
@@ -19,7 +19,6 @@ add_clang_library(clangTidyBugproneModule STATIC
CopyConstructorInitCheck.cpp
CrtpConstructorAccessibilityCheck.cpp
DanglingHandleCheck.cpp
- DefaultLambdaCaptureCheck.cpp
DerivedMethodShadowingBaseMethodCheck.cpp
DynamicStaticInitializersCheck.cpp
EasilySwappableParametersCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
index 4b4c49d3b17d1..829caa15377e6 100644
--- a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
@@ -15,6 +15,7 @@ add_clang_library(clangTidyReadabilityModule STATIC
ContainerDataPointerCheck.cpp
ContainerSizeEmptyCheck.cpp
ConvertMemberFunctionsToStatic.cpp
+ DefaultLambdaCaptureCheck.cpp
DeleteNullPointerCheck.cpp
DuplicateIncludeCheck.cpp
ElseAfterReturnCheck.cpp
diff --git
a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
b/clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.cpp
similarity index 94%
rename from clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
rename to clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.cpp
index a7a18ccb30864..60914fc7e7069 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.cpp
@@ -11,7 +11,7 @@
using namespace clang::ast_matchers;
-namespace clang::tidy::bugprone {
+namespace clang::tidy::readability {
namespace {
AST_MATCHER(LambdaExpr, hasDefaultCapture) {
@@ -36,4 +36,4 @@ void DefaultLambdaCaptureCheck::check(const
MatchFinder::MatchResult &Result) {
"prefer to capture specific variables explicitly");
}
-} // namespace clang::tidy::bugprone
+} // namespace clang::tidy::readability
diff --git a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
b/clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.h
similarity index 69%
rename from clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
rename to clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.h
index c41d7257592d5..fd29d71b7c542 100644
--- a/clang-tools-extra/clang-tidy/bugprone/DefaultLambdaCaptureCheck.h
+++ b/clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.h
@@ -6,17 +6,17 @@
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURECHECK_H
-#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURECHECK_H
+#ifndef
LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_DEFAULTLAMBDACAPTURECHECK_H
+#define
LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_DEFAULTLAMBDACAPTURECHECK_H
#include "../ClangTidyCheck.h"
-namespace clang::tidy::bugprone {
+namespace clang::tidy::readability {
/** Flags lambdas that use default capture modes
*
* For the user-facing documentation see:
- *
https://clang.llvm.org/extra/clang-tidy/checks/bugprone/default-lambda-capture.html
+ *
https://clang.llvm.org/extra/clang-tidy/checks/readability/default-lambda-capture.html
*/
class DefaultLambdaCaptureCheck : public ClangTidyCheck {
public:
@@ -29,6 +29,6 @@ class DefaultLambdaCaptureCheck : public ClangTidyCheck {
}
};
-} // namespace clang::tidy::bugprone
+} // namespace clang::tidy::readability
-#endif //
LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_DEFAULTLAMBDACAPTURECHECK_H
+#endif //
LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_DEFAULTLAMBDACAPTURECHECK_H
diff --git a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
index d01882dfc9daa..4b9bf3d417a7b 100644
--- a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
@@ -20,6 +20,7 @@
#include "ContainerDataPointerCheck.h"
#include "ContainerSizeEmptyCheck.h"
#include "ConvertMemberFunctionsToStatic.h"
+#include "DefaultLambdaCaptureCheck.h"
#include "DeleteNullPointerCheck.h"
#include "DuplicateIncludeCheck.h"
#include "ElseAfterReturnCheck.h"
@@ -92,6 +93,8 @@ class ReadabilityModule : public ClangTidyModule {
"readability-container-size-empty");
CheckFactories.registerCheck<ConvertMemberFunctionsToStatic>(
"readability-convert-member-functions-to-static");
+ CheckFactories.registerCheck<DefaultLambdaCaptureCheck>(
+ "readability-default-lambda-capture");
CheckFactories.registerCheck<DeleteNullPointerCheck>(
"readability-delete-null-pointer");
CheckFactories.registerCheck<DuplicateIncludeCheck>(
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst
b/clang-tools-extra/docs/ReleaseNotes.rst
index 9d2e8dcad7045..6f29f0e99d6f7 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -167,11 +167,6 @@ New checks
Detects default initialization (to 0) of variables with ``enum`` type where
the enum has no enumerator with value of 0.
-- New :doc:`bugprone-default-lambda-capture
- <clang-tidy/checks/bugprone/default-lambda-capture>` check.
-
- Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
-
- New :doc:`bugprone-derived-method-shadowing-base-method
<clang-tidy/checks/bugprone/derived-method-shadowing-base-method>` check.
@@ -356,6 +351,11 @@ Changes in existing checks
<clang-tidy/checks/readability/uppercase-literal-suffix>` check to recognize
literal suffixes added in C++23 and C23.
+- New :doc:`readability-default-lambda-capture
+ <clang-tidy/checks/readability/default-lambda-capture>` check.
+
+ Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
+
Removed checks
^^^^^^^^^^^^^^
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst
b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index 5232f650f6579..e72cbf75fa03f 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -91,7 +91,6 @@ Clang-Tidy Checks
:doc:`bugprone-copy-constructor-init <bugprone/copy-constructor-init>`,
"Yes"
:doc:`bugprone-crtp-constructor-accessibility
<bugprone/crtp-constructor-accessibility>`, "Yes"
:doc:`bugprone-dangling-handle <bugprone/dangling-handle>`,
- :doc:`bugprone-default-lambda-capture <bugprone/default-lambda-capture>`,
:doc:`bugprone-derived-method-shadowing-base-method
<bugprone/derived-method-shadowing-base-method>`,
:doc:`bugprone-dynamic-static-initializers
<bugprone/dynamic-static-initializers>`,
:doc:`bugprone-easily-swappable-parameters
<bugprone/easily-swappable-parameters>`,
@@ -378,6 +377,7 @@ Clang-Tidy Checks
:doc:`readability-container-data-pointer
<readability/container-data-pointer>`, "Yes"
:doc:`readability-container-size-empty <readability/container-size-empty>`,
"Yes"
:doc:`readability-convert-member-functions-to-static
<readability/convert-member-functions-to-static>`, "Yes"
+ :doc:`readability-default-lambda-capture
<readability/default-lambda-capture>`,
:doc:`readability-delete-null-pointer <readability/delete-null-pointer>`,
"Yes"
:doc:`readability-duplicate-include <readability/duplicate-include>`, "Yes"
:doc:`readability-else-after-return <readability/else-after-return>`, "Yes"
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
b/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
similarity index 91%
rename from
clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
rename to
clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
index 9cedc6276e1b3..00734b427d131 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/default-lambda-capture.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
@@ -1,6 +1,6 @@
-.. title:: clang-tidy - bugprone-default-lambda-capture
+.. title:: clang-tidy - readability-default-lambda-capture
-bugprone-default-lambda-capture
+readability-default-lambda-capture
===============================
Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
diff --git
a/clang-tools-extra/test/clang-tidy/checkers/bugprone/default-lambda-capture.cpp
b/clang-tools-extra/test/clang-tidy/checkers/readability/default-lambda-capture.cpp
similarity index 84%
rename from
clang-tools-extra/test/clang-tidy/checkers/bugprone/default-lambda-capture.cpp
rename to
clang-tools-extra/test/clang-tidy/checkers/readability/default-lambda-capture.cpp
index 010edf11f0a2b..ecc45130a6cdf 100644
---
a/clang-tools-extra/test/clang-tidy/checkers/bugprone/default-lambda-capture.cpp
+++
b/clang-tools-extra/test/clang-tidy/checkers/readability/default-lambda-capture.cpp
@@ -1,20 +1,20 @@
-// RUN: %check_clang_tidy %s bugprone-default-lambda-capture %t
+// RUN: %check_clang_tidy %s readability-default-lambda-capture %t
void test_default_captures() {
int value = 42;
int another = 10;
auto lambda1 = [=](int x) { return value + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
auto lambda2 = [&](int x) { return value + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
auto lambda3 = [=, &another](int x) { return value + another + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
auto lambda4 = [&, value](int x) { return value + another + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
}
void test_acceptable_captures() {
@@ -42,10 +42,10 @@ void test_nested_lambdas() {
int inner_var = 3;
auto outer = [=]() {
- // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
auto inner = [&](int x) { return outer_var + middle_var + inner_var + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
return inner(10);
};
@@ -55,15 +55,15 @@ void test_lambda_returns() {
int a = 1, b = 2, c = 3;
auto create_adder = [=](int x) {
- // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
return [x](int y) { return x + y; }; // Inner lambda is fine - explicit
capture
};
auto func1 = [&]() { return a; };
- // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
auto func2 = [=]() { return b; };
- // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
}
class TestClass {
@@ -74,10 +74,10 @@ class TestClass {
int local = 10;
auto lambda1 = [=]() { return member + local; };
- // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
auto lambda2 = [&]() { return member + local; };
- // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
auto lambda3 = [this, local]() { return member + local; };
auto lambda4 = [this, &local]() { return member + local; };
@@ -89,7 +89,7 @@ void test_template_lambdas() {
T value{};
auto lambda = [=](T x) { return value + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[bugprone-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
}
void instantiate_templates() {
>From c0b90d1d0a20ac71d4f6944e0818a1d56eba4acd Mon Sep 17 00:00:00 2001
From: JJ Marr <jjmar...@amd.com>
Date: Wed, 24 Sep 2025 13:32:04 -0400
Subject: [PATCH 15/21] Update
clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
Co-authored-by: EugeneZelenko <eugene.zele...@gmail.com>
---
.../clang-tidy/checks/readability/default-lambda-capture.rst | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
b/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
index 00734b427d131..785f112a70b11 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
@@ -1,7 +1,7 @@
.. title:: clang-tidy - readability-default-lambda-capture
readability-default-lambda-capture
-===============================
+==================================
Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
>From 1172f730ba67151e560dc4ec46a203a8bf83a52b Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Thu, 25 Sep 2025 10:29:37 -0400
Subject: [PATCH 16/21] update doc
on-behalf-of: @amd <jj.m...@amd.com>
---
.../readability/default-lambda-capture.rst | 62 +++++++++++--------
1 file changed, 37 insertions(+), 25 deletions(-)
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
b/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
index 785f112a70b11..daabdd1a92995 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
@@ -5,39 +5,51 @@ readability-default-lambda-capture
Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
-Default captures can lead to subtle bugs including dangling references with
-``[&]``, unnecessary copies with ``[=]``, and make code less maintainable by
-hiding which variables are actually being captured.
+Captures can lead to subtle bugs including dangling references and unnecessary
+copies. Writing out the name of the variables being captured reminds
programmers
+and reviewers to know what is being captured. And knowing is half the battle.
-Implements Item 31 of Effective Modern C++ by Scott Meyers.
+Coding guidelines that recommend against defaulted lambda captures include:
+
+* Item 31 of Effective Modern C++ by Scott Meyers
+* `AUTOSAR C++ Rule A5-1-2 <https://www.mathworks.com/help//releases/
+ R2021a/bugfinder/ref/autosarc14rulea512.html>`__
Example
-------
.. code-block:: c++
- void example() {
- int x = 1;
- int y = 2;
-
- // Bad - default capture by copy
- auto lambda1 = [=]() { return x + y; };
-
- // Bad - default capture by reference
- auto lambda2 = [&]() { return x + y; };
-
- // Good - explicit captures
- auto lambda3 = [x, y]() { return x + y; };
- auto lambda4 = [&x, &y]() { return x + y; };
+ #include <iostream>
+
+ class Widget {
+ std::vector<std::function<void(int)>> callbacks;
+ int widgetId;
+ void addCallback(int factoryId) {
+ callbacks.emplace_back(
+ [&](){
+ std::cout << "Widget " << widgetId << " made in factory " <<
factoryId;
+ }
+ );
+ }
}
-The check will warn on:
-
-- Default capture by copy: ``[=]``
-- Default capture by reference: ``[&]``
-- Mixed captures with defaults: ``[=, &x]`` or ``[&, x]``
+When ``callbacks`` is executed, ``factoryId`` will dangle. Writing the name of
+``factoryId`` in the capture list makes it easy to review the captures and
+detect obvious bugs.
-The check will not warn on:
+.. code-block:: c++
-- Explicit captures: ``[x]``, ``[&x]``, ``[x, y]``, ``[this]``
-- Empty capture lists: ``[]``
+ #include <iostream>
+
+ class Widget {
+ std::vector<std::function<void(int)>> callbacks;
+ int widgetId;
+ void addCallback(int factoryId) {
+ callbacks.emplace_back(
+ [&factoryId, &widgetId](){ // Why isn't factoryId captured by value??
+ std::cout << "Widget " << widgetId << " made in factory " <<
factoryId;
+ }
+ );
+ }
+ }
>From 66e6aaa168928f18e8a427b0cf4abe21fb52fb9b Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Thu, 25 Sep 2025 11:04:26 -0400
Subject: [PATCH 17/21] rename check to
readability-avoid-default-lambda-capture
on-behalf-of: @amd <jj.m...@amd.com>
---
...cpp => AvoidDefaultLambdaCaptureCheck.cpp} | 7 ++--
...eck.h => AvoidDefaultLambdaCaptureCheck.h} | 12 +++----
.../clang-tidy/readability/CMakeLists.txt | 2 +-
.../readability/ReadabilityTidyModule.cpp | 6 ++--
clang-tools-extra/docs/ReleaseNotes.rst | 4 +--
.../docs/clang-tidy/checks/list.rst | 2 +-
...e.rst => avoid-default-lambda-capture.rst} | 6 ++--
...e.cpp => avoid-default-lambda-capture.cpp} | 32 +++++++++----------
8 files changed, 36 insertions(+), 35 deletions(-)
rename clang-tools-extra/clang-tidy/readability/{DefaultLambdaCaptureCheck.cpp
=> AvoidDefaultLambdaCaptureCheck.cpp} (83%)
rename clang-tools-extra/clang-tidy/readability/{DefaultLambdaCaptureCheck.h
=> AvoidDefaultLambdaCaptureCheck.h} (64%)
rename
clang-tools-extra/docs/clang-tidy/checks/readability/{default-lambda-capture.rst
=> avoid-default-lambda-capture.rst} (91%)
rename
clang-tools-extra/test/clang-tidy/checkers/readability/{default-lambda-capture.cpp
=> avoid-default-lambda-capture.cpp} (83%)
diff --git
a/clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.cpp
b/clang-tools-extra/clang-tidy/readability/AvoidDefaultLambdaCaptureCheck.cpp
similarity index 83%
rename from
clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.cpp
rename to
clang-tools-extra/clang-tidy/readability/AvoidDefaultLambdaCaptureCheck.cpp
index 60914fc7e7069..1036d764497b4 100644
--- a/clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.cpp
+++
b/clang-tools-extra/clang-tidy/readability/AvoidDefaultLambdaCaptureCheck.cpp
@@ -6,7 +6,7 @@
//
//===----------------------------------------------------------------------===//
-#include "DefaultLambdaCaptureCheck.h"
+#include "AvoidDefaultLambdaCaptureCheck.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
using namespace clang::ast_matchers;
@@ -20,11 +20,12 @@ AST_MATCHER(LambdaExpr, hasDefaultCapture) {
} // namespace
-void DefaultLambdaCaptureCheck::registerMatchers(MatchFinder *Finder) {
+void AvoidDefaultLambdaCaptureCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(lambdaExpr(hasDefaultCapture()).bind("lambda"), this);
}
-void DefaultLambdaCaptureCheck::check(const MatchFinder::MatchResult &Result) {
+void AvoidDefaultLambdaCaptureCheck::check(
+ const MatchFinder::MatchResult &Result) {
const auto *Lambda = Result.Nodes.getNodeAs<LambdaExpr>("lambda");
assert(Lambda);
diff --git
a/clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.h
b/clang-tools-extra/clang-tidy/readability/AvoidDefaultLambdaCaptureCheck.h
similarity index 64%
rename from clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.h
rename to
clang-tools-extra/clang-tidy/readability/AvoidDefaultLambdaCaptureCheck.h
index fd29d71b7c542..604cf85b2a71f 100644
--- a/clang-tools-extra/clang-tidy/readability/DefaultLambdaCaptureCheck.h
+++ b/clang-tools-extra/clang-tidy/readability/AvoidDefaultLambdaCaptureCheck.h
@@ -6,8 +6,8 @@
//
//===----------------------------------------------------------------------===//
-#ifndef
LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_DEFAULTLAMBDACAPTURECHECK_H
-#define
LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_DEFAULTLAMBDACAPTURECHECK_H
+#ifndef
LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_AVOIDDEFAULTLAMBDACAPTURECHECK_H
+#define
LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_AVOIDDEFAULTLAMBDACAPTURECHECK_H
#include "../ClangTidyCheck.h"
@@ -16,11 +16,11 @@ namespace clang::tidy::readability {
/** Flags lambdas that use default capture modes
*
* For the user-facing documentation see:
- *
https://clang.llvm.org/extra/clang-tidy/checks/readability/default-lambda-capture.html
+ *
https://clang.llvm.org/extra/clang-tidy/checks/readability/avoid-default-lambda-capture.html
*/
-class DefaultLambdaCaptureCheck : public ClangTidyCheck {
+class AvoidDefaultLambdaCaptureCheck : public ClangTidyCheck {
public:
- DefaultLambdaCaptureCheck(StringRef Name, ClangTidyContext *Context)
+ AvoidDefaultLambdaCaptureCheck(StringRef Name, ClangTidyContext *Context)
: ClangTidyCheck(Name, Context) {}
void registerMatchers(ast_matchers::MatchFinder *Finder) override;
void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
@@ -31,4 +31,4 @@ class DefaultLambdaCaptureCheck : public ClangTidyCheck {
} // namespace clang::tidy::readability
-#endif //
LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_DEFAULTLAMBDACAPTURECHECK_H
+#endif //
LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_AVOIDDEFAULTLAMBDACAPTURECHECK_H
diff --git a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
index 829caa15377e6..b4e0c7b8a4a43 100644
--- a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
@@ -6,6 +6,7 @@ set(LLVM_LINK_COMPONENTS
add_clang_library(clangTidyReadabilityModule STATIC
AmbiguousSmartptrResetCallCheck.cpp
AvoidConstParamsInDecls.cpp
+ AvoidDefaultLambdaCaptureCheck.cpp
AvoidNestedConditionalOperatorCheck.cpp
AvoidReturnWithVoidValueCheck.cpp
AvoidUnconditionalPreprocessorIfCheck.cpp
@@ -15,7 +16,6 @@ add_clang_library(clangTidyReadabilityModule STATIC
ContainerDataPointerCheck.cpp
ContainerSizeEmptyCheck.cpp
ConvertMemberFunctionsToStatic.cpp
- DefaultLambdaCaptureCheck.cpp
DeleteNullPointerCheck.cpp
DuplicateIncludeCheck.cpp
ElseAfterReturnCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
index 4b9bf3d417a7b..34c9e71926d18 100644
--- a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
@@ -11,6 +11,7 @@
#include "../ClangTidyModuleRegistry.h"
#include "AmbiguousSmartptrResetCallCheck.h"
#include "AvoidConstParamsInDecls.h"
+#include "AvoidDefaultLambdaCaptureCheck.h"
#include "AvoidNestedConditionalOperatorCheck.h"
#include "AvoidReturnWithVoidValueCheck.h"
#include "AvoidUnconditionalPreprocessorIfCheck.h"
@@ -20,7 +21,6 @@
#include "ContainerDataPointerCheck.h"
#include "ContainerSizeEmptyCheck.h"
#include "ConvertMemberFunctionsToStatic.h"
-#include "DefaultLambdaCaptureCheck.h"
#include "DeleteNullPointerCheck.h"
#include "DuplicateIncludeCheck.h"
#include "ElseAfterReturnCheck.h"
@@ -93,8 +93,8 @@ class ReadabilityModule : public ClangTidyModule {
"readability-container-size-empty");
CheckFactories.registerCheck<ConvertMemberFunctionsToStatic>(
"readability-convert-member-functions-to-static");
- CheckFactories.registerCheck<DefaultLambdaCaptureCheck>(
- "readability-default-lambda-capture");
+ CheckFactories.registerCheck<AvoidDefaultLambdaCaptureCheck>(
+ "readability-avoid-default-lambda-capture");
CheckFactories.registerCheck<DeleteNullPointerCheck>(
"readability-delete-null-pointer");
CheckFactories.registerCheck<DuplicateIncludeCheck>(
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst
b/clang-tools-extra/docs/ReleaseNotes.rst
index 6f29f0e99d6f7..d3edc1a9865ab 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -351,8 +351,8 @@ Changes in existing checks
<clang-tidy/checks/readability/uppercase-literal-suffix>` check to recognize
literal suffixes added in C++23 and C23.
-- New :doc:`readability-default-lambda-capture
- <clang-tidy/checks/readability/default-lambda-capture>` check.
+- New :doc:`readability-avoid-default-lambda-capture
+ <clang-tidy/checks/readability/avoid-default-lambda-capture>` check.
Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst
b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index e72cbf75fa03f..0b8dcd440e1f6 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -377,7 +377,7 @@ Clang-Tidy Checks
:doc:`readability-container-data-pointer
<readability/container-data-pointer>`, "Yes"
:doc:`readability-container-size-empty <readability/container-size-empty>`,
"Yes"
:doc:`readability-convert-member-functions-to-static
<readability/convert-member-functions-to-static>`, "Yes"
- :doc:`readability-default-lambda-capture
<readability/default-lambda-capture>`,
+ :doc:`readability-avoid-default-lambda-capture
<readability/avoid-default-lambda-capture>`,
:doc:`readability-delete-null-pointer <readability/delete-null-pointer>`,
"Yes"
:doc:`readability-duplicate-include <readability/duplicate-include>`, "Yes"
:doc:`readability-else-after-return <readability/else-after-return>`, "Yes"
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
b/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
similarity index 91%
rename from
clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
rename to
clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
index daabdd1a92995..9851896026be5 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/readability/default-lambda-capture.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
@@ -1,7 +1,7 @@
-.. title:: clang-tidy - readability-default-lambda-capture
+.. title:: clang-tidy - readability-avoid-default-lambda-capture
-readability-default-lambda-capture
-==================================
+readability-avoid-default-lambda-capture
+=========================================
Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
diff --git
a/clang-tools-extra/test/clang-tidy/checkers/readability/default-lambda-capture.cpp
b/clang-tools-extra/test/clang-tidy/checkers/readability/avoid-default-lambda-capture.cpp
similarity index 83%
rename from
clang-tools-extra/test/clang-tidy/checkers/readability/default-lambda-capture.cpp
rename to
clang-tools-extra/test/clang-tidy/checkers/readability/avoid-default-lambda-capture.cpp
index ecc45130a6cdf..f452ea6f6ccb1 100644
---
a/clang-tools-extra/test/clang-tidy/checkers/readability/default-lambda-capture.cpp
+++
b/clang-tools-extra/test/clang-tidy/checkers/readability/avoid-default-lambda-capture.cpp
@@ -1,20 +1,20 @@
-// RUN: %check_clang_tidy %s readability-default-lambda-capture %t
+// RUN: %check_clang_tidy %s readability-avoid-default-lambda-capture %t
void test_default_captures() {
int value = 42;
int another = 10;
auto lambda1 = [=](int x) { return value + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
auto lambda2 = [&](int x) { return value + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
auto lambda3 = [=, &another](int x) { return value + another + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
auto lambda4 = [&, value](int x) { return value + another + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
}
void test_acceptable_captures() {
@@ -42,10 +42,10 @@ void test_nested_lambdas() {
int inner_var = 3;
auto outer = [=]() {
- // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
-
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
+
auto inner = [&](int x) { return outer_var + middle_var + inner_var + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
return inner(10);
};
@@ -55,15 +55,15 @@ void test_lambda_returns() {
int a = 1, b = 2, c = 3;
auto create_adder = [=](int x) {
- // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
return [x](int y) { return x + y; }; // Inner lambda is fine - explicit
capture
};
auto func1 = [&]() { return a; };
- // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
-
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
+
auto func2 = [=]() { return b; };
- // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
}
class TestClass {
@@ -74,10 +74,10 @@ class TestClass {
int local = 10;
auto lambda1 = [=]() { return member + local; };
- // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
-
+ // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
+
auto lambda2 = [&]() { return member + local; };
- // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
auto lambda3 = [this, local]() { return member + local; };
auto lambda4 = [this, &local]() { return member + local; };
@@ -89,7 +89,7 @@ void test_template_lambdas() {
T value{};
auto lambda = [=](T x) { return value + x; };
- // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-default-lambda-capture]
+ // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: lambda default captures are
discouraged; prefer to capture specific variables explicitly
[readability-avoid-default-lambda-capture]
}
void instantiate_templates() {
>From 4bf58b6eddee9b1027654653fa409d6bd668e79c Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Thu, 25 Sep 2025 11:05:23 -0400
Subject: [PATCH 18/21] use C++ style comments
on-behalf-of: @amd <jj.m...@amd.com>
---
.../readability/AvoidDefaultLambdaCaptureCheck.h | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git
a/clang-tools-extra/clang-tidy/readability/AvoidDefaultLambdaCaptureCheck.h
b/clang-tools-extra/clang-tidy/readability/AvoidDefaultLambdaCaptureCheck.h
index 604cf85b2a71f..82262a210e4c4 100644
--- a/clang-tools-extra/clang-tidy/readability/AvoidDefaultLambdaCaptureCheck.h
+++ b/clang-tools-extra/clang-tidy/readability/AvoidDefaultLambdaCaptureCheck.h
@@ -13,11 +13,10 @@
namespace clang::tidy::readability {
-/** Flags lambdas that use default capture modes
- *
- * For the user-facing documentation see:
- *
https://clang.llvm.org/extra/clang-tidy/checks/readability/avoid-default-lambda-capture.html
- */
+/// Flags lambdas that use default capture modes
+///
+/// For the user-facing documentation see:
+///
https://clang.llvm.org/extra/clang-tidy/checks/readability/avoid-default-lambda-capture.html
class AvoidDefaultLambdaCaptureCheck : public ClangTidyCheck {
public:
AvoidDefaultLambdaCaptureCheck(StringRef Name, ClangTidyContext *Context)
>From a807dd0e29f5af7af8cc6747082bac606b3ea2ec Mon Sep 17 00:00:00 2001
From: JJ Marr <jjmar...@amd.com>
Date: Thu, 25 Sep 2025 11:19:41 -0400
Subject: [PATCH 19/21] Update
clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
Co-authored-by: EugeneZelenko <eugene.zele...@gmail.com>
---
.../checks/readability/avoid-default-lambda-capture.rst | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
b/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
index 9851896026be5..4513e5d1ef305 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
@@ -1,7 +1,7 @@
.. title:: clang-tidy - readability-avoid-default-lambda-capture
readability-avoid-default-lambda-capture
-=========================================
+========================================
Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
>From 8fdc0974ed84e8177ab61c6dbeeccf6b43ed1593 Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Thu, 25 Sep 2025 11:20:22 -0400
Subject: [PATCH 20/21] fix doc again
on-behalf-of: @amd <jj.m...@amd.com>
---
clang-tools-extra/docs/ReleaseNotes.rst | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst
b/clang-tools-extra/docs/ReleaseNotes.rst
index d3edc1a9865ab..583d4de022218 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -203,6 +203,11 @@ New checks
Finds virtual function overrides with different visibility than the function
in the base class.
+- New :doc:`readability-avoid-default-lambda-capture
+ <clang-tidy/checks/readability/avoid-default-lambda-capture>` check.
+
+ Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
+
New check aliases
^^^^^^^^^^^^^^^^^
@@ -351,11 +356,6 @@ Changes in existing checks
<clang-tidy/checks/readability/uppercase-literal-suffix>` check to recognize
literal suffixes added in C++23 and C23.
-- New :doc:`readability-avoid-default-lambda-capture
- <clang-tidy/checks/readability/avoid-default-lambda-capture>` check.
-
- Warns on default lambda captures (e.g. ``[&](){ ... }``, ``[=](){ ... }``)
-
Removed checks
^^^^^^^^^^^^^^
>From ab8f4b9db4011587bc51407abf4f2a4ad9d7920c Mon Sep 17 00:00:00 2001
From: jjmarr-amd <jj.m...@amd.com>
Date: Thu, 25 Sep 2025 12:58:26 -0400
Subject: [PATCH 21/21] remove reference to coding guideline
on-behalf-of: @amd <jj.m...@amd.com>
---
.../checks/readability/avoid-default-lambda-capture.rst | 2 --
1 file changed, 2 deletions(-)
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
b/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
index 4513e5d1ef305..6b63e103e588e 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-default-lambda-capture.rst
@@ -12,8 +12,6 @@ and reviewers to know what is being captured. And knowing is
half the battle.
Coding guidelines that recommend against defaulted lambda captures include:
* Item 31 of Effective Modern C++ by Scott Meyers
-* `AUTOSAR C++ Rule A5-1-2 <https://www.mathworks.com/help//releases/
- R2021a/bugfinder/ref/autosarc14rulea512.html>`__
Example
-------
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