[clang-tools-extra] [clang-tidy] Add check readability-return-expression-in-void-function (PR #76249)
Danny Mösch via cfe-commits
cfe-commits at lists.llvm.org
Sat Dec 23 08:12:27 PST 2023
https://github.com/SimplyDanny updated https://github.com/llvm/llvm-project/pull/76249
>From 0daffd13160bc10e15e36327e596f8cabb96706e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Danny=20M=C3=B6sch?= <danny.moesch at icloud.com>
Date: Fri, 22 Dec 2023 17:09:59 +0100
Subject: [PATCH 1/9] [clang-tidy] Add check
readability-return-expression-in-void-function
---
.../clang-tidy/readability/CMakeLists.txt | 1 +
.../readability/ReadabilityTidyModule.cpp | 3 ++
.../ReturnExpressionInVoidFunctionCheck.cpp | 31 +++++++++++++++++++
.../ReturnExpressionInVoidFunctionCheck.h | 30 ++++++++++++++++++
clang-tools-extra/docs/ReleaseNotes.rst | 7 +++++
.../docs/clang-tidy/checks/list.rst | 1 +
.../return-expression-in-void-function.rst | 30 ++++++++++++++++++
.../return-expression-in-void-function.cpp | 23 ++++++++++++++
8 files changed, 126 insertions(+)
create mode 100644 clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.cpp
create mode 100644 clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.h
create mode 100644 clang-tools-extra/docs/clang-tidy/checks/readability/return-expression-in-void-function.rst
create mode 100644 clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp
diff --git a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
index 5452c2d48a4617..7d0399ed901267 100644
--- a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
@@ -42,6 +42,7 @@ add_clang_library(clangTidyReadabilityModule
RedundantStringCStrCheck.cpp
RedundantStringInitCheck.cpp
ReferenceToConstructedTemporaryCheck.cpp
+ ReturnExpressionInVoidFunctionCheck.cpp
SimplifyBooleanExprCheck.cpp
SimplifySubscriptExprCheck.cpp
StaticAccessedThroughInstanceCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
index b8e6e641432060..2a9134071b9a72 100644
--- a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
@@ -45,6 +45,7 @@
#include "RedundantStringCStrCheck.h"
#include "RedundantStringInitCheck.h"
#include "ReferenceToConstructedTemporaryCheck.h"
+#include "ReturnExpressionInVoidFunctionCheck.h"
#include "SimplifyBooleanExprCheck.h"
#include "SimplifySubscriptExprCheck.h"
#include "StaticAccessedThroughInstanceCheck.h"
@@ -119,6 +120,8 @@ class ReadabilityModule : public ClangTidyModule {
"readability-redundant-preprocessor");
CheckFactories.registerCheck<ReferenceToConstructedTemporaryCheck>(
"readability-reference-to-constructed-temporary");
+ CheckFactories.registerCheck<ReturnExpressionInVoidFunctionCheck>(
+ "readability-return-expression-in-void-function");
CheckFactories.registerCheck<SimplifySubscriptExprCheck>(
"readability-simplify-subscript-expr");
CheckFactories.registerCheck<StaticAccessedThroughInstanceCheck>(
diff --git a/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.cpp b/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.cpp
new file mode 100644
index 00000000000000..2308d0782ae1c3
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.cpp
@@ -0,0 +1,31 @@
+//===--- ReturnExpressionInVoidFunctionCheck.cpp - clang-tidy -------------===//
+//
+// 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 "ReturnExpressionInVoidFunctionCheck.h"
+#include "clang/AST/Stmt.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::readability {
+
+void ReturnExpressionInVoidFunctionCheck::registerMatchers(
+ MatchFinder *Finder) {
+ Finder->addMatcher(
+ returnStmt(hasReturnValue(hasType(voidType()))).bind("void_return"),
+ this);
+}
+
+void ReturnExpressionInVoidFunctionCheck::check(
+ const MatchFinder::MatchResult &Result) {
+ const auto *VoidReturn = Result.Nodes.getNodeAs<ReturnStmt>("void_return");
+ diag(VoidReturn->getBeginLoc(), "return statements should not return void");
+}
+
+} // namespace clang::tidy::readability
diff --git a/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.h b/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.h
new file mode 100644
index 00000000000000..e28f9cebd2620e
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.h
@@ -0,0 +1,30 @@
+//===--- ReturnExpressionInVoidFunctionCheck.h - clang-tidy -----*- C++ -*-===//
+//
+// 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_READABILITY_RETURNEXPRESSIONINVOIDFUNCTIONCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_RETURNEXPRESSIONINVOIDFUNCTIONCHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::readability {
+
+/// Looks for statements returning expressions of type `void`.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/readability/return-expression-in-void-function.html
+class ReturnExpressionInVoidFunctionCheck : public ClangTidyCheck {
+public:
+ ReturnExpressionInVoidFunctionCheck(StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context) {}
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace clang::tidy::readability
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_RETURNEXPRESSIONINVOIDFUNCTIONCHECK_H
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 6d91748e4cef18..20896df0d340aa 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -218,6 +218,13 @@ New checks
Detects C++ code where a reference variable is used to extend the lifetime
of a temporary object that has just been constructed.
+- New :doc:`readability-return-expression-in-void-function
+ <clang-tidy/checks/readability/return-expression-in-void-function>` check.
+
+ Complains about statements returning expressions of type ``void``. It can be
+ confusing if a function returns an expression even though its return type is
+ ``void``.
+
New check aliases
^^^^^^^^^^^^^^^^^
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index 31f0e090db1d7d..f1282b4a6b766e 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -371,6 +371,7 @@ Clang-Tidy Checks
:doc:`readability-redundant-string-cstr <readability/redundant-string-cstr>`, "Yes"
:doc:`readability-redundant-string-init <readability/redundant-string-init>`, "Yes"
:doc:`readability-reference-to-constructed-temporary <readability/reference-to-constructed-temporary>`,
+ :doc:`readability-return-expression-in-void-function <readability/return-expression-in-void-function>`, "Yes"
:doc:`readability-simplify-boolean-expr <readability/simplify-boolean-expr>`, "Yes"
:doc:`readability-simplify-subscript-expr <readability/simplify-subscript-expr>`, "Yes"
:doc:`readability-static-accessed-through-instance <readability/static-accessed-through-instance>`, "Yes"
diff --git a/clang-tools-extra/docs/clang-tidy/checks/readability/return-expression-in-void-function.rst b/clang-tools-extra/docs/clang-tidy/checks/readability/return-expression-in-void-function.rst
new file mode 100644
index 00000000000000..dd07b95550e6f8
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/readability/return-expression-in-void-function.rst
@@ -0,0 +1,30 @@
+.. title:: clang-tidy - readability-return-expression-in-void-function
+
+readability-return-expression-in-void-function
+==============================================
+
+Complains about statements returning expressions of type ``void``. It can be
+confusing if a function returns an expression even though its return type is
+``void``.
+
+Example:
+
+.. code-block::
+
+ void g();
+ void f() {
+ // ...
+ return g();
+ }
+
+In a long function body, the ``return`` statements suggests that the function
+returns a value. However, ``return g();`` is combination of two statements that
+should be written as
+
+.. code-block::
+
+ g();
+ return;
+
+to make clear that ``g()`` is called and immediately afterwards the function
+returns (nothing).
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp
new file mode 100644
index 00000000000000..05e2f454abcd35
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp
@@ -0,0 +1,23 @@
+// RUN: %check_clang_tidy %s readability-return-expression-in-void-function %t
+
+void f1();
+
+void f2() {
+ return f1();
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statements should not return void [readability-return-expression-in-void-function]
+}
+
+void f3(bool b) {
+ if (b) return f1();
+ // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: return statements should not return void [readability-return-expression-in-void-function]
+ return f2();
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statements should not return void [readability-return-expression-in-void-function]
+}
+
+template<class T>
+T f4() {}
+
+void f5() {
+ return f4<void>();
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statements should not return void [readability-return-expression-in-void-function]
+}
>From 6c23b9e929d406f79c1b2c1fee7ea2b282b544ec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Danny=20M=C3=B6sch?= <danny.moesch at icloud.com>
Date: Fri, 22 Dec 2023 18:14:07 +0100
Subject: [PATCH 2/9] Clarify check message
---
.../readability/ReturnExpressionInVoidFunctionCheck.cpp | 3 ++-
.../readability/return-expression-in-void-function.cpp | 8 ++++----
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.cpp b/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.cpp
index 2308d0782ae1c3..6517a4f8323c6b 100644
--- a/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.cpp
@@ -25,7 +25,8 @@ void ReturnExpressionInVoidFunctionCheck::registerMatchers(
void ReturnExpressionInVoidFunctionCheck::check(
const MatchFinder::MatchResult &Result) {
const auto *VoidReturn = Result.Nodes.getNodeAs<ReturnStmt>("void_return");
- diag(VoidReturn->getBeginLoc(), "return statements should not return void");
+ diag(VoidReturn->getBeginLoc(),
+ "return statement in void function should not return a value");
}
} // namespace clang::tidy::readability
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp
index 05e2f454abcd35..eda7bcd36c2ea5 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp
@@ -4,14 +4,14 @@ void f1();
void f2() {
return f1();
- // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statements should not return void [readability-return-expression-in-void-function]
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-return-expression-in-void-function]
}
void f3(bool b) {
if (b) return f1();
- // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: return statements should not return void [readability-return-expression-in-void-function]
+ // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: return statement in void function should not return a value [readability-return-expression-in-void-function]
return f2();
- // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statements should not return void [readability-return-expression-in-void-function]
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-return-expression-in-void-function]
}
template<class T>
@@ -19,5 +19,5 @@ T f4() {}
void f5() {
return f4<void>();
- // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statements should not return void [readability-return-expression-in-void-function]
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-return-expression-in-void-function]
}
>From f4f9378f2b09f8342236532f1bf1dd76bac009b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Danny=20M=C3=B6sch?= <danny.moesch at icloud.com>
Date: Fri, 22 Dec 2023 18:14:24 +0100
Subject: [PATCH 3/9] Specify traversal kind
---
.../readability/ReturnExpressionInVoidFunctionCheck.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.h b/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.h
index e28f9cebd2620e..39c9553d602728 100644
--- a/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.h
+++ b/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.h
@@ -23,6 +23,9 @@ class ReturnExpressionInVoidFunctionCheck : public ClangTidyCheck {
: 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::readability
>From 7217d5623c5cbf57fb8672056b8274ad7118c882 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Danny=20M=C3=B6sch?= <danny.moesch at icloud.com>
Date: Fri, 22 Dec 2023 18:15:41 +0100
Subject: [PATCH 4/9] Do not claim that check provides fixes
---
clang-tools-extra/docs/clang-tidy/checks/list.rst | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index f1282b4a6b766e..b32660aac7e6d0 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -371,7 +371,7 @@ Clang-Tidy Checks
:doc:`readability-redundant-string-cstr <readability/redundant-string-cstr>`, "Yes"
:doc:`readability-redundant-string-init <readability/redundant-string-init>`, "Yes"
:doc:`readability-reference-to-constructed-temporary <readability/reference-to-constructed-temporary>`,
- :doc:`readability-return-expression-in-void-function <readability/return-expression-in-void-function>`, "Yes"
+ :doc:`readability-return-expression-in-void-function <readability/return-expression-in-void-function>`,
:doc:`readability-simplify-boolean-expr <readability/simplify-boolean-expr>`, "Yes"
:doc:`readability-simplify-subscript-expr <readability/simplify-subscript-expr>`, "Yes"
:doc:`readability-static-accessed-through-instance <readability/static-accessed-through-instance>`, "Yes"
>From a4de6fd462af98e8286f38531aee20baae26b7eb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Danny=20M=C3=B6sch?= <danny.moesch at icloud.com>
Date: Fri, 22 Dec 2023 18:19:57 +0100
Subject: [PATCH 5/9] Add non-triggering test cases
---
.../return-expression-in-void-function.cpp | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp
index eda7bcd36c2ea5..7398e29c7fb3d5 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp
@@ -21,3 +21,14 @@ void f5() {
return f4<void>();
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-return-expression-in-void-function]
}
+
+void f6() { return; }
+
+int f7() { return 1; }
+
+int f8() { return f7(); }
+
+void f9() {
+ return (void)f7();
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-return-expression-in-void-function]
+}
\ No newline at end of file
>From 5826c06ccbd4b8f7b10b80784f194d01ebf4c16e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Danny=20M=C3=B6sch?= <danny.moesch at icloud.com>
Date: Fri, 22 Dec 2023 18:32:32 +0100
Subject: [PATCH 6/9] Rename check
---
...Check.cpp => AvoidReturnWithVoidValueCheck.cpp} | 9 ++++-----
...tionCheck.h => AvoidReturnWithVoidValueCheck.h} | 14 +++++++-------
.../clang-tidy/readability/CMakeLists.txt | 2 +-
.../readability/ReadabilityTidyModule.cpp | 6 +++---
clang-tools-extra/docs/ReleaseNotes.rst | 4 ++--
clang-tools-extra/docs/clang-tidy/checks/list.rst | 2 +-
...nction.rst => avoid-return-with-void-value.rst} | 6 +++---
...nction.cpp => avoid-return-with-void-value.cpp} | 12 ++++++------
8 files changed, 27 insertions(+), 28 deletions(-)
rename clang-tools-extra/clang-tidy/readability/{ReturnExpressionInVoidFunctionCheck.cpp => AvoidReturnWithVoidValueCheck.cpp} (76%)
rename clang-tools-extra/clang-tidy/readability/{ReturnExpressionInVoidFunctionCheck.h => AvoidReturnWithVoidValueCheck.h} (58%)
rename clang-tools-extra/docs/clang-tidy/checks/readability/{return-expression-in-void-function.rst => avoid-return-with-void-value.rst} (77%)
rename clang-tools-extra/test/clang-tidy/checkers/readability/{return-expression-in-void-function.cpp => avoid-return-with-void-value.cpp} (52%)
diff --git a/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.cpp b/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp
similarity index 76%
rename from clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.cpp
rename to clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp
index 6517a4f8323c6b..377ce02dc3edf2 100644
--- a/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp
@@ -1,4 +1,4 @@
-//===--- ReturnExpressionInVoidFunctionCheck.cpp - clang-tidy -------------===//
+//===--- AvoidReturnWithVoidValueCheck.cpp - clang-tidy -------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
@@ -6,7 +6,7 @@
//
//===----------------------------------------------------------------------===//
-#include "ReturnExpressionInVoidFunctionCheck.h"
+#include "AvoidReturnWithVoidValueCheck.h"
#include "clang/AST/Stmt.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/ASTMatchers/ASTMatchers.h"
@@ -15,14 +15,13 @@ using namespace clang::ast_matchers;
namespace clang::tidy::readability {
-void ReturnExpressionInVoidFunctionCheck::registerMatchers(
- MatchFinder *Finder) {
+void AvoidReturnWithVoidValueCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
returnStmt(hasReturnValue(hasType(voidType()))).bind("void_return"),
this);
}
-void ReturnExpressionInVoidFunctionCheck::check(
+void AvoidReturnWithVoidValueCheck::check(
const MatchFinder::MatchResult &Result) {
const auto *VoidReturn = Result.Nodes.getNodeAs<ReturnStmt>("void_return");
diag(VoidReturn->getBeginLoc(),
diff --git a/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.h b/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.h
similarity index 58%
rename from clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.h
rename to clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.h
index 39c9553d602728..209de70dfb06ff 100644
--- a/clang-tools-extra/clang-tidy/readability/ReturnExpressionInVoidFunctionCheck.h
+++ b/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.h
@@ -1,4 +1,4 @@
-//===--- ReturnExpressionInVoidFunctionCheck.h - clang-tidy -----*- C++ -*-===//
+//===--- AvoidReturnWithVoidValueCheck.h - clang-tidy -----------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
@@ -6,8 +6,8 @@
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_RETURNEXPRESSIONINVOIDFUNCTIONCHECK_H
-#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_RETURNEXPRESSIONINVOIDFUNCTIONCHECK_H
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_AVOIDRETURNWITHVOIDVALUECHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_AVOIDRETURNWITHVOIDVALUECHECK_H
#include "../ClangTidyCheck.h"
@@ -16,10 +16,10 @@ namespace clang::tidy::readability {
/// Looks for statements returning expressions of type `void`.
///
/// For the user-facing documentation see:
-/// http://clang.llvm.org/extra/clang-tidy/checks/readability/return-expression-in-void-function.html
-class ReturnExpressionInVoidFunctionCheck : public ClangTidyCheck {
+/// http://clang.llvm.org/extra/clang-tidy/checks/readability/avoid-return-with-void-value.html
+class AvoidReturnWithVoidValueCheck : public ClangTidyCheck {
public:
- ReturnExpressionInVoidFunctionCheck(StringRef Name, ClangTidyContext *Context)
+ AvoidReturnWithVoidValueCheck(StringRef Name, ClangTidyContext *Context)
: ClangTidyCheck(Name, Context) {}
void registerMatchers(ast_matchers::MatchFinder *Finder) override;
void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
@@ -30,4 +30,4 @@ class ReturnExpressionInVoidFunctionCheck : public ClangTidyCheck {
} // namespace clang::tidy::readability
-#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_RETURNEXPRESSIONINVOIDFUNCTIONCHECK_H
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_AVOIDRETURNWITHVOIDVALUECHECK_H
diff --git a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
index 7d0399ed901267..408c822b861c5f 100644
--- a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
@@ -5,6 +5,7 @@ set(LLVM_LINK_COMPONENTS
add_clang_library(clangTidyReadabilityModule
AvoidConstParamsInDecls.cpp
+ AvoidReturnWithVoidValueCheck.cpp
AvoidUnconditionalPreprocessorIfCheck.cpp
BracesAroundStatementsCheck.cpp
ConstReturnTypeCheck.cpp
@@ -42,7 +43,6 @@ add_clang_library(clangTidyReadabilityModule
RedundantStringCStrCheck.cpp
RedundantStringInitCheck.cpp
ReferenceToConstructedTemporaryCheck.cpp
- ReturnExpressionInVoidFunctionCheck.cpp
SimplifyBooleanExprCheck.cpp
SimplifySubscriptExprCheck.cpp
StaticAccessedThroughInstanceCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
index 2a9134071b9a72..0b0aad7c0dcb36 100644
--- a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
@@ -10,6 +10,7 @@
#include "../ClangTidyModule.h"
#include "../ClangTidyModuleRegistry.h"
#include "AvoidConstParamsInDecls.h"
+#include "AvoidReturnWithVoidValueCheck.h"
#include "AvoidUnconditionalPreprocessorIfCheck.h"
#include "BracesAroundStatementsCheck.h"
#include "ConstReturnTypeCheck.h"
@@ -45,7 +46,6 @@
#include "RedundantStringCStrCheck.h"
#include "RedundantStringInitCheck.h"
#include "ReferenceToConstructedTemporaryCheck.h"
-#include "ReturnExpressionInVoidFunctionCheck.h"
#include "SimplifyBooleanExprCheck.h"
#include "SimplifySubscriptExprCheck.h"
#include "StaticAccessedThroughInstanceCheck.h"
@@ -64,6 +64,8 @@ class ReadabilityModule : public ClangTidyModule {
void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
CheckFactories.registerCheck<AvoidConstParamsInDecls>(
"readability-avoid-const-params-in-decls");
+ CheckFactories.registerCheck<AvoidReturnWithVoidValueCheck>(
+ "readability-avoid-return-with-void-value");
CheckFactories.registerCheck<AvoidUnconditionalPreprocessorIfCheck>(
"readability-avoid-unconditional-preprocessor-if");
CheckFactories.registerCheck<BracesAroundStatementsCheck>(
@@ -120,8 +122,6 @@ class ReadabilityModule : public ClangTidyModule {
"readability-redundant-preprocessor");
CheckFactories.registerCheck<ReferenceToConstructedTemporaryCheck>(
"readability-reference-to-constructed-temporary");
- CheckFactories.registerCheck<ReturnExpressionInVoidFunctionCheck>(
- "readability-return-expression-in-void-function");
CheckFactories.registerCheck<SimplifySubscriptExprCheck>(
"readability-simplify-subscript-expr");
CheckFactories.registerCheck<StaticAccessedThroughInstanceCheck>(
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 20896df0d340aa..147d3cc8bf1d21 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -218,8 +218,8 @@ New checks
Detects C++ code where a reference variable is used to extend the lifetime
of a temporary object that has just been constructed.
-- New :doc:`readability-return-expression-in-void-function
- <clang-tidy/checks/readability/return-expression-in-void-function>` check.
+- New :doc:`readability-avoid-return-with-void-value
+ <clang-tidy/checks/readability/avoid-return-with-void-value>` check.
Complains about statements returning expressions of type ``void``. It can be
confusing if a function returns an expression even though its return type is
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index b32660aac7e6d0..06aa53a6e56cb5 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -336,6 +336,7 @@ Clang-Tidy Checks
:doc:`portability-simd-intrinsics <portability/simd-intrinsics>`,
:doc:`portability-std-allocator-const <portability/std-allocator-const>`,
:doc:`readability-avoid-const-params-in-decls <readability/avoid-const-params-in-decls>`, "Yes"
+ :doc:`readability-avoid-return-with-void-value <readability/avoid-return-with-void-value>`,
:doc:`readability-avoid-unconditional-preprocessor-if <readability/avoid-unconditional-preprocessor-if>`,
:doc:`readability-braces-around-statements <readability/braces-around-statements>`, "Yes"
:doc:`readability-const-return-type <readability/const-return-type>`, "Yes"
@@ -371,7 +372,6 @@ Clang-Tidy Checks
:doc:`readability-redundant-string-cstr <readability/redundant-string-cstr>`, "Yes"
:doc:`readability-redundant-string-init <readability/redundant-string-init>`, "Yes"
:doc:`readability-reference-to-constructed-temporary <readability/reference-to-constructed-temporary>`,
- :doc:`readability-return-expression-in-void-function <readability/return-expression-in-void-function>`,
:doc:`readability-simplify-boolean-expr <readability/simplify-boolean-expr>`, "Yes"
:doc:`readability-simplify-subscript-expr <readability/simplify-subscript-expr>`, "Yes"
:doc:`readability-static-accessed-through-instance <readability/static-accessed-through-instance>`, "Yes"
diff --git a/clang-tools-extra/docs/clang-tidy/checks/readability/return-expression-in-void-function.rst b/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-return-with-void-value.rst
similarity index 77%
rename from clang-tools-extra/docs/clang-tidy/checks/readability/return-expression-in-void-function.rst
rename to clang-tools-extra/docs/clang-tidy/checks/readability/avoid-return-with-void-value.rst
index dd07b95550e6f8..e8e759b316da6b 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/readability/return-expression-in-void-function.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-return-with-void-value.rst
@@ -1,7 +1,7 @@
-.. title:: clang-tidy - readability-return-expression-in-void-function
+.. title:: clang-tidy - readability-avoid-return-with-void-value
-readability-return-expression-in-void-function
-==============================================
+readability-avoid-return-with-void-value
+========================================
Complains about statements returning expressions of type ``void``. It can be
confusing if a function returns an expression even though its return type is
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/avoid-return-with-void-value.cpp
similarity index 52%
rename from clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp
rename to clang-tools-extra/test/clang-tidy/checkers/readability/avoid-return-with-void-value.cpp
index 7398e29c7fb3d5..e4ffa352b4ca7b 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/return-expression-in-void-function.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/avoid-return-with-void-value.cpp
@@ -1,17 +1,17 @@
-// RUN: %check_clang_tidy %s readability-return-expression-in-void-function %t
+// RUN: %check_clang_tidy %s readability-avoid-return-with-void-value %t
void f1();
void f2() {
return f1();
- // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-return-expression-in-void-function]
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-avoid-return-with-void-value]
}
void f3(bool b) {
if (b) return f1();
- // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: return statement in void function should not return a value [readability-return-expression-in-void-function]
+ // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: return statement in void function should not return a value [readability-avoid-return-with-void-value]
return f2();
- // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-return-expression-in-void-function]
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-avoid-return-with-void-value]
}
template<class T>
@@ -19,7 +19,7 @@ T f4() {}
void f5() {
return f4<void>();
- // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-return-expression-in-void-function]
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-avoid-return-with-void-value]
}
void f6() { return; }
@@ -30,5 +30,5 @@ int f8() { return f7(); }
void f9() {
return (void)f7();
- // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-return-expression-in-void-function]
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-avoid-return-with-void-value]
}
\ No newline at end of file
>From 3a87d499a39099f65778004fc74d41f461543a21 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Danny=20M=C3=B6sch?= <danny.moesch at icloud.com>
Date: Sat, 23 Dec 2023 17:08:38 +0100
Subject: [PATCH 7/9] Improve descriptions
---
clang-tools-extra/docs/ReleaseNotes.rst | 5 ++---
.../readability/avoid-return-with-void-value.rst | 15 +++++++++------
2 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 147d3cc8bf1d21..299a47c1d48e4b 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -221,9 +221,8 @@ New checks
- New :doc:`readability-avoid-return-with-void-value
<clang-tidy/checks/readability/avoid-return-with-void-value>` check.
- Complains about statements returning expressions of type ``void``. It can be
- confusing if a function returns an expression even though its return type is
- ``void``.
+ Finds return statements with ``void`` values used within functions with
+ ``void`` result types.
New check aliases
^^^^^^^^^^^^^^^^^
diff --git a/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-return-with-void-value.rst b/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-return-with-void-value.rst
index e8e759b316da6b..92c987034c01c7 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-return-with-void-value.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/readability/avoid-return-with-void-value.rst
@@ -3,9 +3,9 @@
readability-avoid-return-with-void-value
========================================
-Complains about statements returning expressions of type ``void``. It can be
-confusing if a function returns an expression even though its return type is
-``void``.
+A function with a ``void`` return type is intended to perform a task without
+producing a return value. Return statements with expressions could lead
+to confusion and may miscommunicate the function's intended behavior.
Example:
@@ -17,9 +17,9 @@ Example:
return g();
}
-In a long function body, the ``return`` statements suggests that the function
-returns a value. However, ``return g();`` is combination of two statements that
-should be written as
+In a long function body, the ``return`` statement suggests that the function
+returns a value. However, ``return g();`` is a combination of two statements
+that should be written as
.. code-block::
@@ -28,3 +28,6 @@ should be written as
to make clear that ``g()`` is called and immediately afterwards the function
returns (nothing).
+
+In C, the same issue is detected by the compiler if the ``-Wpedantic`` mode
+is enabled.
>From affa9d768fd6199b1bdc2fa669c1924f6d606cf0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Danny=20M=C3=B6sch?= <danny.moesch at icloud.com>
Date: Sat, 23 Dec 2023 17:08:58 +0100
Subject: [PATCH 8/9] Update message
---
.../readability/AvoidReturnWithVoidValueCheck.cpp | 6 +++---
.../readability/avoid-return-with-void-value.cpp | 10 +++++-----
2 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp b/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp
index 377ce02dc3edf2..5b90f7ab0a0625 100644
--- a/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp
@@ -1,4 +1,4 @@
-//===--- AvoidReturnWithVoidValueCheck.cpp - clang-tidy -------------===//
+//===--- AvoidReturnWithVoidValueCheck.cpp - clang-tidy -------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
@@ -24,8 +24,8 @@ void AvoidReturnWithVoidValueCheck::registerMatchers(MatchFinder *Finder) {
void AvoidReturnWithVoidValueCheck::check(
const MatchFinder::MatchResult &Result) {
const auto *VoidReturn = Result.Nodes.getNodeAs<ReturnStmt>("void_return");
- diag(VoidReturn->getBeginLoc(),
- "return statement in void function should not return a value");
+ diag(VoidReturn->getBeginLoc(), "return statement within a void function "
+ "should not have a specified return value");
}
} // namespace clang::tidy::readability
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/avoid-return-with-void-value.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/avoid-return-with-void-value.cpp
index e4ffa352b4ca7b..3988be1a4d9000 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/avoid-return-with-void-value.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/avoid-return-with-void-value.cpp
@@ -4,14 +4,14 @@ void f1();
void f2() {
return f1();
- // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-avoid-return-with-void-value]
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement within a void function should not have a specified return value [readability-avoid-return-with-void-value]
}
void f3(bool b) {
if (b) return f1();
- // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: return statement in void function should not return a value [readability-avoid-return-with-void-value]
+ // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: return statement within a void function should not have a specified return value [readability-avoid-return-with-void-value]
return f2();
- // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-avoid-return-with-void-value]
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement within a void function should not have a specified return value [readability-avoid-return-with-void-value]
}
template<class T>
@@ -19,7 +19,7 @@ T f4() {}
void f5() {
return f4<void>();
- // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-avoid-return-with-void-value]
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement within a void function should not have a specified return value [readability-avoid-return-with-void-value]
}
void f6() { return; }
@@ -30,5 +30,5 @@ int f8() { return f7(); }
void f9() {
return (void)f7();
- // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement in void function should not return a value [readability-avoid-return-with-void-value]
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: return statement within a void function should not have a specified return value [readability-avoid-return-with-void-value]
}
\ No newline at end of file
>From 3984ddbcd5ebc8ec33eadf941770275c00ad54e4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Danny=20M=C3=B6sch?= <danny.moesch at icloud.com>
Date: Sat, 23 Dec 2023 17:12:09 +0100
Subject: [PATCH 9/9] Restrict check to C++
---
.../clang-tidy/readability/AvoidReturnWithVoidValueCheck.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.h b/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.h
index 209de70dfb06ff..c9331fe38e8c90 100644
--- a/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.h
+++ b/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.h
@@ -21,11 +21,17 @@ class AvoidReturnWithVoidValueCheck : public ClangTidyCheck {
public:
AvoidReturnWithVoidValueCheck(StringRef Name, ClangTidyContext *Context)
: ClangTidyCheck(Name, Context) {}
+
void registerMatchers(ast_matchers::MatchFinder *Finder) override;
void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+
+private:
std::optional<TraversalKind> getCheckTraversalKind() const override {
return TK_IgnoreUnlessSpelledInSource;
}
+ bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
+ return LangOpts.CPlusPlus;
+ }
};
} // namespace clang::tidy::readability
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