[clang-tools-extra] [tidy] add new check bugprone-return-const-ref-from-parameter (PR #89497)
Congcong Cai via cfe-commits
cfe-commits at lists.llvm.org
Sun Apr 21 22:58:12 PDT 2024
https://github.com/HerrCai0907 updated https://github.com/llvm/llvm-project/pull/89497
>From 91915f68902ade86c0bf8eba643428017ae8bb3c Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907 at 163.com>
Date: Sat, 20 Apr 2024 17:58:19 +0800
Subject: [PATCH 1/4] [tidy] add new check
bugprone-return-const-ref-from-parameter
Detects the function which returns the const reference from parameter which
causes potential use after free if the caller uses xvalue as argument.
In c++, const reference parameter can accept xvalue which will be destructed
after the call. When the function returns this parameter also as const reference,
then the returned reference can be used after the object it refers to has been
destroyed.
Fixes: #85253
---
.../bugprone/BugproneTidyModule.cpp | 3 ++
.../clang-tidy/bugprone/CMakeLists.txt | 1 +
.../ReturnConstRefFromParameterCheck.cpp | 41 +++++++++++++++++++
.../ReturnConstRefFromParameterCheck.h | 35 ++++++++++++++++
clang-tools-extra/docs/ReleaseNotes.rst | 6 +++
.../return-const-ref-from-parameter.rst | 30 ++++++++++++++
.../docs/clang-tidy/checks/list.rst | 9 ++--
.../return-const-ref-from-parameter.cpp | 31 ++++++++++++++
8 files changed, 152 insertions(+), 4 deletions(-)
create mode 100644 clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp
create mode 100644 clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h
create mode 100644 clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst
create mode 100644 clang-tools-extra/test/clang-tidy/checkers/bugprone/return-const-ref-from-parameter.cpp
diff --git a/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp b/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
index 2931325d8b5798..1b92d2e60cc173 100644
--- a/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
@@ -54,6 +54,7 @@
#include "PosixReturnCheck.h"
#include "RedundantBranchConditionCheck.h"
#include "ReservedIdentifierCheck.h"
+#include "ReturnConstRefFromParameterCheck.h"
#include "SharedPtrArrayMismatchCheck.h"
#include "SignalHandlerCheck.h"
#include "SignedCharMisuseCheck.h"
@@ -137,6 +138,8 @@ class BugproneModule : public ClangTidyModule {
"bugprone-inaccurate-erase");
CheckFactories.registerCheck<IncorrectEnableIfCheck>(
"bugprone-incorrect-enable-if");
+ CheckFactories.registerCheck<ReturnConstRefFromParameterCheck>(
+ "bugprone-return-const-ref-from-parameter");
CheckFactories.registerCheck<SwitchMissingDefaultCaseCheck>(
"bugprone-switch-missing-default-case");
CheckFactories.registerCheck<IncDecInConditionsCheck>(
diff --git a/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt b/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
index 081ba67efe1538..2d303191f88650 100644
--- a/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
@@ -26,6 +26,7 @@ add_clang_library(clangTidyBugproneModule
ImplicitWideningOfMultiplicationResultCheck.cpp
InaccurateEraseCheck.cpp
IncorrectEnableIfCheck.cpp
+ ReturnConstRefFromParameterCheck.cpp
SuspiciousStringviewDataUsageCheck.cpp
SwitchMissingDefaultCaseCheck.cpp
IncDecInConditionsCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp
new file mode 100644
index 00000000000000..87fc663231496e
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp
@@ -0,0 +1,41 @@
+//===--- ReturnConstRefFromParameterCheck.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 "ReturnConstRefFromParameterCheck.h"
+#include "../utils/Matchers.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::bugprone {
+
+std::optional<TraversalKind>
+ReturnConstRefFromParameterCheck::getCheckTraversalKind() const {
+ // Use 'AsIs' to make sure the return type is exactly the same as the
+ // parameter type.
+ return TK_AsIs;
+}
+
+void ReturnConstRefFromParameterCheck::registerMatchers(MatchFinder *Finder) {
+ Finder->addMatcher(
+ returnStmt(hasReturnValue(declRefExpr(to(parmVarDecl(hasType(
+ hasCanonicalType(matchers::isReferenceToConst())))))))
+ .bind("ret"),
+ this);
+}
+
+void ReturnConstRefFromParameterCheck::check(
+ const MatchFinder::MatchResult &Result) {
+ const auto *R = Result.Nodes.getNodeAs<ReturnStmt>("ret");
+ diag(R->getRetValue()->getBeginLoc(),
+ "return const reference parameter cause potential use-after-free "
+ "when function accepts immediately constructed value.");
+}
+
+} // namespace clang::tidy::bugprone
diff --git a/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h
new file mode 100644
index 00000000000000..96d02aa2563edf
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h
@@ -0,0 +1,35 @@
+//===--- ReturnConstRefFromParameterCheck.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_BUGPRONE_RETURNCONSTREFFROMPARAMETERCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_RETURNCONSTREFFROMPARAMETERCHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::bugprone {
+
+/// Detects the function which returns the const reference from parameter which
+/// causes potential use after free if the caller uses xvalue as argument.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/bugprone/return-const-ref-from-parameter.html
+class ReturnConstRefFromParameterCheck : public ClangTidyCheck {
+public:
+ ReturnConstRefFromParameterCheck(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;
+ bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
+ return LangOpts.CPlusPlus;
+ }
+};
+
+} // namespace clang::tidy::bugprone
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_RETURNCONSTREFFROMPARAMETERCHECK_H
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index a457e6fcae9462..3e5ad76bde3243 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -112,6 +112,12 @@ New checks
Detects error-prone Curiously Recurring Template Pattern usage, when the CRTP
can be constructed outside itself and the derived class.
+- New :doc:`bugprone-return-const-ref-from-parameter
+ <clang-tidy/checks/bugprone/return-const-ref-from-parameter>` check.
+
+ Detects the function which returns the const reference from parameter which
+ causes potential use after free if the caller uses xvalue as argument.
+
- New :doc:`bugprone-suspicious-stringview-data-usage
<clang-tidy/checks/bugprone/suspicious-stringview-data-usage>` check.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst b/clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst
new file mode 100644
index 00000000000000..ec3fd439feb623
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst
@@ -0,0 +1,30 @@
+.. title:: clang-tidy - bugprone-return-const-ref-from-parameter
+
+bugprone-return-const-ref-from-parameter
+========================================
+
+Detects the function which returns the const reference from parameter which
+causes potential use after free if the caller uses xvalue as argument.
+
+In c++, const reference parameter can accept xvalue which will be destructed
+after the call. When the function returns this parameter also as const reference,
+then the returned reference can be used after the object it refers to has been
+destroyed.
+
+Example
+-------
+
+.. code-block:: c++
+
+ struct S {
+ int v;
+ S(int);
+ ~S();
+ };
+
+ const S &fn(const S &a) {
+ return a;
+ }
+
+ const S& s = fn(S{1});
+ s.v; // use after free
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index 8bc46acad56c84..5d9d487f75f9cb 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -120,6 +120,7 @@ Clang-Tidy Checks
:doc:`bugprone-posix-return <bugprone/posix-return>`, "Yes"
:doc:`bugprone-redundant-branch-condition <bugprone/redundant-branch-condition>`, "Yes"
:doc:`bugprone-reserved-identifier <bugprone/reserved-identifier>`, "Yes"
+ :doc:`bugprone-return-const-ref-from-parameter <bugprone/return-const-ref-from-parameter>`
:doc:`bugprone-shared-ptr-array-mismatch <bugprone/shared-ptr-array-mismatch>`, "Yes"
:doc:`bugprone-signal-handler <bugprone/signal-handler>`,
:doc:`bugprone-signed-char-misuse <bugprone/signed-char-misuse>`,
@@ -341,9 +342,9 @@ Clang-Tidy Checks
: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-nested-conditional-operator <readability/avoid-nested-conditional-operator>`,
- :doc:`readability-avoid-return-with-void-value <readability/avoid-return-with-void-value>`,
+ :doc:`readability-avoid-return-with-void-value <readability/avoid-return-with-void-value>`, "Yes"
:doc:`readability-avoid-unconditional-preprocessor-if <readability/avoid-unconditional-preprocessor-if>`,
- :doc:`readability-braces-around-statements <readability/braces-around-statements>`, "Yes"
+ :doc:`readability-braces-around-statements <readability/braces-around-statements>`,
:doc:`readability-const-return-type <readability/const-return-type>`, "Yes"
:doc:`readability-container-contains <readability/container-contains>`, "Yes"
:doc:`readability-container-data-pointer <readability/container-data-pointer>`, "Yes"
@@ -529,12 +530,12 @@ Clang-Tidy Checks
:doc:`cppcoreguidelines-non-private-member-variables-in-classes <cppcoreguidelines/non-private-member-variables-in-classes>`, :doc:`misc-non-private-member-variables-in-classes <misc/non-private-member-variables-in-classes>`,
:doc:`cppcoreguidelines-use-default-member-init <cppcoreguidelines/use-default-member-init>`, :doc:`modernize-use-default-member-init <modernize/use-default-member-init>`, "Yes"
:doc:`fuchsia-header-anon-namespaces <fuchsia/header-anon-namespaces>`, :doc:`google-build-namespaces <google/build-namespaces>`,
- :doc:`google-readability-braces-around-statements <google/readability-braces-around-statements>`, :doc:`readability-braces-around-statements <readability/braces-around-statements>`, "Yes"
+ :doc:`google-readability-braces-around-statements <google/readability-braces-around-statements>`, :doc:`readability-braces-around-statements <readability/braces-around-statements>`,
:doc:`google-readability-function-size <google/readability-function-size>`, :doc:`readability-function-size <readability/function-size>`,
:doc:`google-readability-namespace-comments <google/readability-namespace-comments>`, :doc:`llvm-namespace-comment <llvm/namespace-comment>`,
:doc:`hicpp-avoid-c-arrays <hicpp/avoid-c-arrays>`, :doc:`modernize-avoid-c-arrays <modernize/avoid-c-arrays>`,
:doc:`hicpp-avoid-goto <hicpp/avoid-goto>`, :doc:`cppcoreguidelines-avoid-goto <cppcoreguidelines/avoid-goto>`,
- :doc:`hicpp-braces-around-statements <hicpp/braces-around-statements>`, :doc:`readability-braces-around-statements <readability/braces-around-statements>`, "Yes"
+ :doc:`hicpp-braces-around-statements <hicpp/braces-around-statements>`, :doc:`readability-braces-around-statements <readability/braces-around-statements>`,
:doc:`hicpp-deprecated-headers <hicpp/deprecated-headers>`, :doc:`modernize-deprecated-headers <modernize/deprecated-headers>`, "Yes"
:doc:`hicpp-explicit-conversions <hicpp/explicit-conversions>`, :doc:`google-explicit-constructor <google/explicit-constructor>`, "Yes"
:doc:`hicpp-function-size <hicpp/function-size>`, :doc:`readability-function-size <readability/function-size>`,
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/return-const-ref-from-parameter.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/return-const-ref-from-parameter.cpp
new file mode 100644
index 00000000000000..35e4476298b55f
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/return-const-ref-from-parameter.cpp
@@ -0,0 +1,31 @@
+// RUN: %check_clang_tidy %s bugprone-return-const-ref-from-parameter %t
+
+using T = int;
+using TConst = int const;
+using TConstRef = int const&;
+
+namespace invalid {
+
+int const &f1(int const &a) { return a; }
+// CHECK-MESSAGES: :[[@LINE-1]]:38: warning: return const reference parameter
+
+int const &f2(T const &a) { return a; }
+// CHECK-MESSAGES: :[[@LINE-1]]:36: warning: return const reference parameter
+
+int const &f3(TConstRef a) { return a; }
+// CHECK-MESSAGES: :[[@LINE-1]]:37: warning: return const reference parameter
+
+int const &f4(TConst &a) { return a; }
+// CHECK-MESSAGES: :[[@LINE-1]]:35: warning: return const reference parameter
+
+} // namespace invalid
+
+namespace valid {
+
+int const &f1(int &a) { return a; }
+
+int const &f2(int &&a) { return a; }
+
+int f1(int const &a) { return a; }
+
+} // namespace valid
>From 401c775665159026a6b90158d21709948a1e7306 Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907 at 163.com>
Date: Sun, 21 Apr 2024 11:55:22 +0800
Subject: [PATCH 2/4] fix doc
---
.../bugprone/ReturnConstRefFromParameterCheck.cpp | 7 -------
.../bugprone/ReturnConstRefFromParameterCheck.h | 11 ++++++++---
.../bugprone/return-const-ref-from-parameter.rst | 9 +++++----
3 files changed, 13 insertions(+), 14 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp
index 87fc663231496e..7670bf05b91192 100644
--- a/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp
@@ -15,13 +15,6 @@ using namespace clang::ast_matchers;
namespace clang::tidy::bugprone {
-std::optional<TraversalKind>
-ReturnConstRefFromParameterCheck::getCheckTraversalKind() const {
- // Use 'AsIs' to make sure the return type is exactly the same as the
- // parameter type.
- return TK_AsIs;
-}
-
void ReturnConstRefFromParameterCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
returnStmt(hasReturnValue(declRefExpr(to(parmVarDecl(hasType(
diff --git a/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h
index 96d02aa2563edf..57e5732e8c0a98 100644
--- a/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h
+++ b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h
@@ -13,8 +13,9 @@
namespace clang::tidy::bugprone {
-/// Detects the function which returns the const reference from parameter which
-/// causes potential use after free if the caller uses xvalue as argument.
+/// Detects the function which returns the const reference parameter as const
+/// reference. This might causes potential use after free errors if the caller
+/// uses xvalue as arguments.
///
/// For the user-facing documentation see:
/// http://clang.llvm.org/extra/clang-tidy/checks/bugprone/return-const-ref-from-parameter.html
@@ -24,7 +25,11 @@ class ReturnConstRefFromParameterCheck : 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;
+ std::optional<TraversalKind> getCheckTraversalKind() const override {
+ // Use 'AsIs' to make sure the return type is exactly the same as the
+ // parameter type.
+ return TK_AsIs;
+ }
bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
return LangOpts.CPlusPlus;
}
diff --git a/clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst b/clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst
index ec3fd439feb623..f61f24ca1a263d 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst
@@ -3,11 +3,12 @@
bugprone-return-const-ref-from-parameter
========================================
-Detects the function which returns the const reference from parameter which
-causes potential use after free if the caller uses xvalue as argument.
+Detects the function which returns the const reference parameter as const
+reference. This might causes potential use after free errors if the caller
+uses xvalue as arguments.
-In c++, const reference parameter can accept xvalue which will be destructed
-after the call. When the function returns this parameter also as const reference,
+In C++, const reference parameters can accept xvalues which will be destructed
+after the call. When the function returns such a parameter also as const reference,
then the returned reference can be used after the object it refers to has been
destroyed.
>From 322a81986f3337b610bc2c806a0aef72013faa75 Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907 at 163.com>
Date: Sun, 21 Apr 2024 11:56:59 +0800
Subject: [PATCH 3/4] revert list
---
clang-tools-extra/docs/clang-tidy/checks/list.rst | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index 5d9d487f75f9cb..35633151b9f249 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -342,9 +342,9 @@ Clang-Tidy Checks
: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-nested-conditional-operator <readability/avoid-nested-conditional-operator>`,
- :doc:`readability-avoid-return-with-void-value <readability/avoid-return-with-void-value>`, "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>`,
+ :doc:`readability-braces-around-statements <readability/braces-around-statements>`, "Yes"
:doc:`readability-const-return-type <readability/const-return-type>`, "Yes"
:doc:`readability-container-contains <readability/container-contains>`, "Yes"
:doc:`readability-container-data-pointer <readability/container-data-pointer>`, "Yes"
@@ -530,12 +530,12 @@ Clang-Tidy Checks
:doc:`cppcoreguidelines-non-private-member-variables-in-classes <cppcoreguidelines/non-private-member-variables-in-classes>`, :doc:`misc-non-private-member-variables-in-classes <misc/non-private-member-variables-in-classes>`,
:doc:`cppcoreguidelines-use-default-member-init <cppcoreguidelines/use-default-member-init>`, :doc:`modernize-use-default-member-init <modernize/use-default-member-init>`, "Yes"
:doc:`fuchsia-header-anon-namespaces <fuchsia/header-anon-namespaces>`, :doc:`google-build-namespaces <google/build-namespaces>`,
- :doc:`google-readability-braces-around-statements <google/readability-braces-around-statements>`, :doc:`readability-braces-around-statements <readability/braces-around-statements>`,
+ :doc:`google-readability-braces-around-statements <google/readability-braces-around-statements>`, :doc:`readability-braces-around-statements <readability/braces-around-statements>`, "Yes"
:doc:`google-readability-function-size <google/readability-function-size>`, :doc:`readability-function-size <readability/function-size>`,
:doc:`google-readability-namespace-comments <google/readability-namespace-comments>`, :doc:`llvm-namespace-comment <llvm/namespace-comment>`,
:doc:`hicpp-avoid-c-arrays <hicpp/avoid-c-arrays>`, :doc:`modernize-avoid-c-arrays <modernize/avoid-c-arrays>`,
:doc:`hicpp-avoid-goto <hicpp/avoid-goto>`, :doc:`cppcoreguidelines-avoid-goto <cppcoreguidelines/avoid-goto>`,
- :doc:`hicpp-braces-around-statements <hicpp/braces-around-statements>`, :doc:`readability-braces-around-statements <readability/braces-around-statements>`,
+ :doc:`hicpp-braces-around-statements <hicpp/braces-around-statements>`, :doc:`readability-braces-around-statements <readability/braces-around-statements>`, "Yes"
:doc:`hicpp-deprecated-headers <hicpp/deprecated-headers>`, :doc:`modernize-deprecated-headers <modernize/deprecated-headers>`, "Yes"
:doc:`hicpp-explicit-conversions <hicpp/explicit-conversions>`, :doc:`google-explicit-constructor <google/explicit-constructor>`, "Yes"
:doc:`hicpp-function-size <hicpp/function-size>`, :doc:`readability-function-size <readability/function-size>`,
>From 2ce9fe7d11cd156cf49f84a858ff267c0c2168eb Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907 at 163.com>
Date: Mon, 22 Apr 2024 13:57:07 +0800
Subject: [PATCH 4/4] fix comment
---
.../bugprone/ReturnConstRefFromParameterCheck.cpp | 4 ++--
.../bugprone/ReturnConstRefFromParameterCheck.h | 6 +++---
clang-tools-extra/docs/ReleaseNotes.rst | 5 +++--
.../bugprone/return-const-ref-from-parameter.rst | 10 +++++-----
.../bugprone/return-const-ref-from-parameter.cpp | 8 ++++----
5 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp
index 7670bf05b91192..8ae37d4f774d23 100644
--- a/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.cpp
@@ -27,8 +27,8 @@ void ReturnConstRefFromParameterCheck::check(
const MatchFinder::MatchResult &Result) {
const auto *R = Result.Nodes.getNodeAs<ReturnStmt>("ret");
diag(R->getRetValue()->getBeginLoc(),
- "return const reference parameter cause potential use-after-free "
- "when function accepts immediately constructed value.");
+ "returning a constant reference parameter may cause a use-after-free "
+ "when the parameter is constructed from a temporary");
}
} // namespace clang::tidy::bugprone
diff --git a/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h
index 57e5732e8c0a98..1e87a72901eb8e 100644
--- a/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h
+++ b/clang-tools-extra/clang-tidy/bugprone/ReturnConstRefFromParameterCheck.h
@@ -13,9 +13,9 @@
namespace clang::tidy::bugprone {
-/// Detects the function which returns the const reference parameter as const
-/// reference. This might causes potential use after free errors if the caller
-/// uses xvalue as arguments.
+/// Detects return statements that return constant reference parameter as
+/// constant reference. This may cause use-after-free errors if the caller uses
+/// xvalue as arguments.
///
/// For the user-facing documentation see:
/// http://clang.llvm.org/extra/clang-tidy/checks/bugprone/return-const-ref-from-parameter.html
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 3e5ad76bde3243..e4057ec2fd8525 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -115,8 +115,9 @@ New checks
- New :doc:`bugprone-return-const-ref-from-parameter
<clang-tidy/checks/bugprone/return-const-ref-from-parameter>` check.
- Detects the function which returns the const reference from parameter which
- causes potential use after free if the caller uses xvalue as argument.
+ Detects return statements that return constant reference parameter as constant
+ reference. This may cause use-after-free errors if the caller uses xvalue as
+ arguments.
- New :doc:`bugprone-suspicious-stringview-data-usage
<clang-tidy/checks/bugprone/suspicious-stringview-data-usage>` check.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst b/clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst
index f61f24ca1a263d..52f76fde43c6b1 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/bugprone/return-const-ref-from-parameter.rst
@@ -3,12 +3,12 @@
bugprone-return-const-ref-from-parameter
========================================
-Detects the function which returns the const reference parameter as const
-reference. This might causes potential use after free errors if the caller
-uses xvalue as arguments.
+Detects return statements that return constant reference parameter as constant
+reference. This may cause use-after-free errors if the caller uses xvalue as
+arguments.
-In C++, const reference parameters can accept xvalues which will be destructed
-after the call. When the function returns such a parameter also as const reference,
+In C++, constant reference parameters can accept xvalues which will be destructed
+after the call. When the function returns such a parameter also as constant reference,
then the returned reference can be used after the object it refers to has been
destroyed.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/return-const-ref-from-parameter.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/return-const-ref-from-parameter.cpp
index 35e4476298b55f..a83a019ec7437d 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/return-const-ref-from-parameter.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/return-const-ref-from-parameter.cpp
@@ -7,16 +7,16 @@ using TConstRef = int const&;
namespace invalid {
int const &f1(int const &a) { return a; }
-// CHECK-MESSAGES: :[[@LINE-1]]:38: warning: return const reference parameter
+// CHECK-MESSAGES: :[[@LINE-1]]:38: warning: returning a constant reference parameter
int const &f2(T const &a) { return a; }
-// CHECK-MESSAGES: :[[@LINE-1]]:36: warning: return const reference parameter
+// CHECK-MESSAGES: :[[@LINE-1]]:36: warning: returning a constant reference parameter
int const &f3(TConstRef a) { return a; }
-// CHECK-MESSAGES: :[[@LINE-1]]:37: warning: return const reference parameter
+// CHECK-MESSAGES: :[[@LINE-1]]:37: warning: returning a constant reference parameter
int const &f4(TConst &a) { return a; }
-// CHECK-MESSAGES: :[[@LINE-1]]:35: warning: return const reference parameter
+// CHECK-MESSAGES: :[[@LINE-1]]:35: warning: returning a constant reference parameter
} // namespace invalid
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