[clang-tools-extra] [clang-tidy] add new check: modernize-use-scoped-lock (PR #126434)
Baranov Victor via cfe-commits
cfe-commits at lists.llvm.org
Tue Mar 11 04:18:36 PDT 2025
https://github.com/vbvictor updated https://github.com/llvm/llvm-project/pull/126434
>From bc1b4ada7615d407c2df009f414d62da3857ee86 Mon Sep 17 00:00:00 2001
From: Victor Baranov <bar.victor.2002 at gmail.com>
Date: Mon, 3 Mar 2025 09:25:03 +0300
Subject: [PATCH 1/4] [clang-tidy] add scoped-lock-check
---
.../clang-tidy/modernize/CMakeLists.txt | 1 +
.../modernize/ModernizeTidyModule.cpp | 3 +
.../modernize/UseScopedLockCheck.cpp | 319 +++++++++++++++
.../clang-tidy/modernize/UseScopedLockCheck.h | 54 +++
clang-tools-extra/docs/ReleaseNotes.rst | 6 +
.../docs/clang-tidy/checks/list.rst | 1 +
.../checks/modernize/use-scoped-lock.rst | 102 +++++
.../clang-tidy/checkers/Inputs/Headers/mutex | 33 ++
...e-lock-warn-on-using-and-typedef-false.cpp | 31 ++
...scoped-lock-warn-on-single-locks-false.cpp | 96 +++++
.../checkers/modernize/use-scoped-lock.cpp | 372 ++++++++++++++++++
11 files changed, 1018 insertions(+)
create mode 100644 clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp
create mode 100644 clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.h
create mode 100644 clang-tools-extra/docs/clang-tidy/checks/modernize/use-scoped-lock.rst
create mode 100644 clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/mutex
create mode 100644 clang-tools-extra/test/clang-tidy/checkers/modernize/use-scope-lock-warn-on-using-and-typedef-false.cpp
create mode 100644 clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock-warn-on-single-locks-false.cpp
create mode 100644 clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp
diff --git a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
index bab1167fb15ff..619a27b2f9bb6 100644
--- a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
@@ -42,6 +42,7 @@ add_clang_library(clangTidyModernizeModule STATIC
UseNullptrCheck.cpp
UseOverrideCheck.cpp
UseRangesCheck.cpp
+ UseScopedLockCheck.cpp
UseStartsEndsWithCheck.cpp
UseStdFormatCheck.cpp
UseStdNumbersCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
index fc46c72982fdc..b2d4ddd667502 100644
--- a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
@@ -43,6 +43,7 @@
#include "UseNullptrCheck.h"
#include "UseOverrideCheck.h"
#include "UseRangesCheck.h"
+#include "UseScopedLockCheck.h"
#include "UseStartsEndsWithCheck.h"
#include "UseStdFormatCheck.h"
#include "UseStdNumbersCheck.h"
@@ -80,6 +81,8 @@ class ModernizeModule : public ClangTidyModule {
CheckFactories.registerCheck<UseIntegerSignComparisonCheck>(
"modernize-use-integer-sign-comparison");
CheckFactories.registerCheck<UseRangesCheck>("modernize-use-ranges");
+ CheckFactories.registerCheck<UseScopedLockCheck>(
+ "modernize-use-scoped-lock");
CheckFactories.registerCheck<UseStartsEndsWithCheck>(
"modernize-use-starts-ends-with");
CheckFactories.registerCheck<UseStdFormatCheck>("modernize-use-std-format");
diff --git a/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp
new file mode 100644
index 0000000000000..5dbb3a2f671e6
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp
@@ -0,0 +1,319 @@
+//===--- UseScopedLockCheck.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 "UseScopedLockCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/Stmt.h"
+#include "clang/AST/Type.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Lex/Lexer.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Twine.h"
+#include <iterator>
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::modernize {
+
+namespace {
+
+bool isLockGuard(const QualType &Type) {
+ if (const auto *Record = Type->getAs<RecordType>()) {
+ if (const RecordDecl *Decl = Record->getDecl()) {
+ return Decl->getName() == "lock_guard" && Decl->isInStdNamespace();
+ }
+ }
+
+ if (const auto *TemplateSpecType =
+ Type->getAs<TemplateSpecializationType>()) {
+ if (const TemplateDecl *Decl =
+ TemplateSpecType->getTemplateName().getAsTemplateDecl()) {
+ return Decl->getName() == "lock_guard" && Decl->isInStdNamespace();
+ }
+ }
+
+ return false;
+}
+
+llvm::SmallVector<const VarDecl *> getLockGuardsFromDecl(const DeclStmt *DS) {
+ llvm::SmallVector<const VarDecl *> LockGuards;
+
+ for (const Decl *Decl : DS->decls()) {
+ if (const auto *VD = dyn_cast<VarDecl>(Decl)) {
+ const QualType Type = VD->getType().getCanonicalType();
+ if (isLockGuard(Type)) {
+ LockGuards.push_back(VD);
+ }
+ }
+ }
+
+ return LockGuards;
+}
+
+// Scans through the statements in a block and groups consecutive
+// 'std::lock_guard' variable declarations together.
+llvm::SmallVector<llvm::SmallVector<const VarDecl *>>
+findLocksInCompoundStmt(const CompoundStmt *Block,
+ const ast_matchers::MatchFinder::MatchResult &Result) {
+ // store groups of consecutive 'std::lock_guard' declarations
+ llvm::SmallVector<llvm::SmallVector<const VarDecl *>> LockGuardGroups;
+ llvm::SmallVector<const VarDecl *> CurrentLockGuardGroup;
+
+ auto AddAndClearCurrentGroup = [&]() {
+ if (!CurrentLockGuardGroup.empty()) {
+ LockGuardGroups.push_back(CurrentLockGuardGroup);
+ CurrentLockGuardGroup.clear();
+ }
+ };
+
+ for (const Stmt *Stmt : Block->body()) {
+ if (const auto *DS = dyn_cast<DeclStmt>(Stmt)) {
+ llvm::SmallVector<const VarDecl *> LockGuards = getLockGuardsFromDecl(DS);
+
+ if (!LockGuards.empty()) {
+ CurrentLockGuardGroup.insert(
+ CurrentLockGuardGroup.end(),
+ std::make_move_iterator(LockGuards.begin()),
+ std::make_move_iterator(LockGuards.end()));
+ continue;
+ }
+ }
+ AddAndClearCurrentGroup();
+ }
+
+ AddAndClearCurrentGroup();
+
+ return LockGuardGroups;
+}
+
+TemplateSpecializationTypeLoc
+getTemplateLockGuardTypeLoc(const TypeSourceInfo *SourceInfo) {
+ const TypeLoc Loc = SourceInfo->getTypeLoc();
+
+ const auto ElaboratedLoc = Loc.getAs<ElaboratedTypeLoc>();
+ if (!ElaboratedLoc)
+ return {};
+
+ return ElaboratedLoc.getNamedTypeLoc().getAs<TemplateSpecializationTypeLoc>();
+}
+
+// Find the exact source range of the 'lock_guard<...>' token
+SourceRange getLockGuardTemplateRange(const TypeSourceInfo *SourceInfo) {
+ const TemplateSpecializationTypeLoc TemplateLoc =
+ getTemplateLockGuardTypeLoc(SourceInfo);
+ if (!TemplateLoc)
+ return {};
+
+ return SourceRange(TemplateLoc.getTemplateNameLoc(),
+ TemplateLoc.getRAngleLoc());
+}
+
+// Find the exact source range of the 'lock_guard' token
+SourceRange getLockGuardRange(const TypeSourceInfo *SourceInfo) {
+ const TemplateSpecializationTypeLoc TemplateLoc =
+ getTemplateLockGuardTypeLoc(SourceInfo);
+ if (!TemplateLoc)
+ return {};
+
+ return SourceRange(TemplateLoc.getTemplateNameLoc(),
+ TemplateLoc.getLAngleLoc().getLocWithOffset(-1));
+}
+
+const StringRef UseScopedLockMessage =
+ "use 'std::scoped_lock' instead of 'std::lock_guard'";
+
+} // namespace
+
+UseScopedLockCheck::UseScopedLockCheck(StringRef Name,
+ ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context),
+ WarnOnSingleLocks(Options.get("WarnOnSingleLocks", true)),
+ WarnOnUsingAndTypedef(Options.get("WarnOnUsingAndTypedef", true)) {}
+
+void UseScopedLockCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+ Options.store(Opts, "WarnOnSingleLocks", WarnOnSingleLocks);
+ Options.store(Opts, "WarnOnUsingAndTypedef", WarnOnUsingAndTypedef);
+}
+
+void UseScopedLockCheck::registerMatchers(MatchFinder *Finder) {
+ auto LockGuardClassDecl =
+ namedDecl(anyOf(classTemplateDecl(), classTemplateSpecializationDecl()),
+ hasName("lock_guard"), isInStdNamespace());
+ auto LockGuardType = qualType(hasDeclaration(LockGuardClassDecl));
+ auto LockVarDecl = varDecl(hasType(LockGuardType));
+
+ if (WarnOnSingleLocks) {
+ // Match CompoundStmt with only one 'std::lock_guard'
+ Finder->addMatcher(
+ compoundStmt(unless(isExpansionInSystemHeader()),
+ has(declStmt(has(LockVarDecl.bind("lock-decl-single")))),
+ unless(hasDescendant(declStmt(has(varDecl(
+ hasType(LockGuardType),
+ unless(equalsBoundNode("lock-decl-single")))))))),
+ this);
+ }
+
+ // Match CompoundStmt with multiple 'std::lock_guard'
+ Finder->addMatcher(
+ compoundStmt(unless(isExpansionInSystemHeader()),
+ has(declStmt(has(LockVarDecl.bind("lock-decl-multiple")))),
+ hasDescendant(declStmt(has(varDecl(
+ hasType(LockGuardType),
+ unless(equalsBoundNode("lock-decl-multiple")))))))
+ .bind("block-multiple"),
+ this);
+
+ if (WarnOnUsingAndTypedef) {
+ // Match 'typedef std::lock_guard<std::mutex> Lock'
+ Finder->addMatcher(typedefDecl(unless(isExpansionInSystemHeader()),
+ hasUnderlyingType(LockGuardType))
+ .bind("lock-guard-typedef"),
+ this);
+
+ // Match 'using Lock = std::lock_guard<std::mutex>'
+ Finder->addMatcher(
+ typeAliasDecl(
+ unless(isExpansionInSystemHeader()),
+ hasType(elaboratedType(namesType(templateSpecializationType(
+ hasDeclaration(LockGuardClassDecl))))))
+ .bind("lock-guard-using-alias"),
+ this);
+
+ // Match 'using std::lock_guard'
+ Finder->addMatcher(
+ usingDecl(unless(isExpansionInSystemHeader()),
+ hasAnyUsingShadowDecl(hasTargetDecl(LockGuardClassDecl)))
+ .bind("lock-guard-using-decl"),
+ this);
+ }
+}
+
+void UseScopedLockCheck::check(const MatchFinder::MatchResult &Result) {
+ if (const auto *Decl = Result.Nodes.getNodeAs<VarDecl>("lock-decl-single")) {
+ emitDiag(Decl, Result);
+ return;
+ }
+
+ if (const auto *Compound =
+ Result.Nodes.getNodeAs<CompoundStmt>("block-multiple")) {
+ emitDiag(findLocksInCompoundStmt(Compound, Result), Result);
+ return;
+ }
+
+ if (const auto *Typedef =
+ Result.Nodes.getNodeAs<TypedefDecl>("lock-guard-typedef")) {
+ emitDiag(Typedef->getTypeSourceInfo(), Result);
+ return;
+ }
+
+ if (const auto *UsingAlias =
+ Result.Nodes.getNodeAs<TypeAliasDecl>("lock-guard-using-alias")) {
+ emitDiag(UsingAlias->getTypeSourceInfo(), Result);
+ return;
+ }
+
+ if (const auto *Using =
+ Result.Nodes.getNodeAs<UsingDecl>("lock-guard-using-decl")) {
+ emitDiag(Using, Result);
+ }
+}
+
+void UseScopedLockCheck::emitDiag(const VarDecl *LockGuard,
+ const MatchFinder::MatchResult &Result) {
+ auto Diag = diag(LockGuard->getBeginLoc(), UseScopedLockMessage);
+
+ const SourceRange LockGuardTypeRange =
+ getLockGuardTemplateRange(LockGuard->getTypeSourceInfo());
+
+ if (LockGuardTypeRange.isInvalid()) {
+ return;
+ }
+
+ // Create Fix-its only if we can find the constructor call to properly handle
+ // 'std::lock_guard l(m, std::adopt_lock)' case.
+ const auto *CtorCall = dyn_cast<CXXConstructExpr>(LockGuard->getInit());
+ if (!CtorCall) {
+ return;
+ }
+
+ if (CtorCall->getNumArgs() == 1) {
+ Diag << FixItHint::CreateReplacement(LockGuardTypeRange, "scoped_lock");
+ return;
+ }
+
+ if (CtorCall->getNumArgs() == 2) {
+ const Expr *const *CtorArgs = CtorCall->getArgs();
+
+ const Expr *MutexArg = CtorArgs[0];
+ const Expr *AdoptLockArg = CtorArgs[1];
+
+ const StringRef MutexSourceText = Lexer::getSourceText(
+ CharSourceRange::getTokenRange(MutexArg->getSourceRange()),
+ *Result.SourceManager, Result.Context->getLangOpts());
+ const StringRef AdoptLockSourceText = Lexer::getSourceText(
+ CharSourceRange::getTokenRange(AdoptLockArg->getSourceRange()),
+ *Result.SourceManager, Result.Context->getLangOpts());
+
+ Diag << FixItHint::CreateReplacement(LockGuardTypeRange, "scoped_lock")
+ << FixItHint::CreateReplacement(
+ SourceRange(MutexArg->getBeginLoc(), AdoptLockArg->getEndLoc()),
+ (llvm::Twine(AdoptLockSourceText) + ", " + MutexSourceText)
+ .str());
+ return;
+ }
+
+ llvm_unreachable("Invalid argument number of std::lock_guard constructor");
+}
+
+void UseScopedLockCheck::emitDiag(
+ const llvm::SmallVector<llvm::SmallVector<const VarDecl *>> &LockGroups,
+ const ast_matchers::MatchFinder::MatchResult &Result) {
+ for (const llvm::SmallVector<const VarDecl *> &Group : LockGroups) {
+ if (Group.size() == 1 && WarnOnSingleLocks) {
+ emitDiag(Group[0], Result);
+ } else {
+ diag(Group[0]->getBeginLoc(),
+ "use single 'std::scoped_lock' instead of multiple "
+ "'std::lock_guard'");
+
+ for (const VarDecl *Lock : llvm::drop_begin(Group)) {
+ diag(Lock->getLocation(), "additional 'std::lock_guard' declared here",
+ DiagnosticIDs::Note);
+ }
+ }
+ }
+}
+
+void UseScopedLockCheck::emitDiag(
+ const TypeSourceInfo *LockGuardSourceInfo,
+ const ast_matchers::MatchFinder::MatchResult &Result) {
+ const TypeLoc TL = LockGuardSourceInfo->getTypeLoc();
+
+ if (const auto ElaboratedTL = TL.getAs<ElaboratedTypeLoc>()) {
+ auto Diag = diag(ElaboratedTL.getBeginLoc(), UseScopedLockMessage);
+
+ const SourceRange LockGuardRange = getLockGuardRange(LockGuardSourceInfo);
+ if (LockGuardRange.isInvalid()) {
+ return;
+ }
+
+ Diag << FixItHint::CreateReplacement(LockGuardRange, "scoped_lock");
+ }
+}
+
+void UseScopedLockCheck::emitDiag(
+ const UsingDecl *UsingDecl,
+ const ast_matchers::MatchFinder::MatchResult &Result) {
+ diag(UsingDecl->getLocation(), UseScopedLockMessage)
+ << FixItHint::CreateReplacement(UsingDecl->getLocation(), "scoped_lock");
+}
+
+} // namespace clang::tidy::modernize
diff --git a/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.h b/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.h
new file mode 100644
index 0000000000000..790d9205c6121
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.h
@@ -0,0 +1,54 @@
+//===--- UseScopedLockCheck.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_MODERNIZE_USESCOPEDLOCKCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USESCOPEDLOCKCHECK_H
+
+#include "../ClangTidyCheck.h"
+#include "clang/AST/ASTTypeTraits.h"
+#include "clang/AST/Stmt.h"
+#include <optional>
+
+namespace clang::tidy::modernize {
+
+/// Finds uses of ``std::lock_guard`` and suggests replacing them with C++17's
+/// alternative ``std::scoped_lock``.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/modernize/use-scoped-lock.html
+class UseScopedLockCheck : public ClangTidyCheck {
+public:
+ UseScopedLockCheck(StringRef Name, ClangTidyContext *Context);
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+ bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
+ return LangOpts.CPlusPlus17;
+ }
+ std::optional<TraversalKind> getCheckTraversalKind() const override {
+ return TK_IgnoreUnlessSpelledInSource;
+ }
+
+private:
+ void emitDiag(const VarDecl *LockGuard,
+ const ast_matchers::MatchFinder::MatchResult &Result);
+ void emitDiag(
+ const llvm::SmallVector<llvm::SmallVector<const VarDecl *>> &LockGroups,
+ const ast_matchers::MatchFinder::MatchResult &Result);
+ void emitDiag(const TypeSourceInfo *LockGuardSourceInfo,
+ const ast_matchers::MatchFinder::MatchResult &Result);
+ void emitDiag(const UsingDecl *UsingDecl,
+ const ast_matchers::MatchFinder::MatchResult &Result);
+
+ const bool WarnOnSingleLocks;
+ const bool WarnOnUsingAndTypedef;
+};
+
+} // namespace clang::tidy::modernize
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USESCOPEDLOCKCHECK_H
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index fa68b6fabd549..ad0bc624a21a4 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -100,6 +100,12 @@ New checks
Finds unintended character output from ``unsigned char`` and ``signed char`` to an
``ostream``.
+- New :doc:`modernize-use-scoped-lock
+ <clang-tidy/checks/modernize/use-scoped-lock>` check.
+
+ Finds uses of ``std::lock_guard`` and suggests replacing them with C++17's
+ alternative ``std::scoped_lock``.
+
- New :doc:`readability-ambiguous-smartptr-reset-call
<clang-tidy/checks/readability/ambiguous-smartptr-reset-call>` check.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index c73bc8bff3539..d9515a1b4b4cd 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -309,6 +309,7 @@ Clang-Tidy Checks
:doc:`modernize-use-nullptr <modernize/use-nullptr>`, "Yes"
:doc:`modernize-use-override <modernize/use-override>`, "Yes"
:doc:`modernize-use-ranges <modernize/use-ranges>`, "Yes"
+ :doc:`modernize-use-scoped-lock <modernize/use-scoped-lock>`, "Yes"
:doc:`modernize-use-starts-ends-with <modernize/use-starts-ends-with>`, "Yes"
:doc:`modernize-use-std-format <modernize/use-std-format>`, "Yes"
:doc:`modernize-use-std-numbers <modernize/use-std-numbers>`, "Yes"
diff --git a/clang-tools-extra/docs/clang-tidy/checks/modernize/use-scoped-lock.rst b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-scoped-lock.rst
new file mode 100644
index 0000000000000..84c896efd6258
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-scoped-lock.rst
@@ -0,0 +1,102 @@
+.. title:: clang-tidy - modernize-use-scoped-lock
+
+modernize-use-scoped-lock
+=========================
+
+Finds uses of ``std::lock_guard`` and suggests replacing them with C++17's
+alternative ``std::scoped_lock``. The check will automatically transform only
+single declarations of ``std::lock_guard`` and emit warnings for multiple
+declarations of ``std::lock_guard`` that can be replaced with a single
+declaration of ``std::scoped_lock``.
+
+Examples
+--------
+
+Single ``std::lock_guard`` declaration:
+
+.. code-block:: c++
+
+ std::mutex M;
+ std::lock_guard<std::mutex> L(M);
+
+
+Transforms to:
+
+.. code-block:: c++
+
+ std::mutex M;
+ std::scoped_lock L(M);
+
+Single ``std::lock_guard`` declaration with ``std::adopt_lock``:
+
+.. code-block:: c++
+
+ std::mutex M;
+ std::lock(M);
+ std::lock_guard<std::mutex> L(M, std::adopt_lock);
+
+
+Transforms to:
+
+.. code-block:: c++
+
+ std::mutex M;
+ std::lock(M);
+ std::scoped_lock L(std::adopt_lock, M);
+
+Multiple ``std::lock_guard`` declarations only emit warnings:
+
+.. code-block:: c++
+
+ std::mutex M1, M2;
+ std::lock(M1, M2);
+ std::lock_guard Lock1(M, std::adopt_lock); // warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ std::lock_guard Lock2(M, std::adopt_lock); // note: additional 'std::lock_guard' declared here
+
+
+Limitations
+-----------
+
+The check will not emit warnings if ``std::lock_guard`` is used implicitly via
+``using``, ``typedef`` or as ``template`` parameter:
+
+.. code-block:: c++
+
+ template <template <typename> typename Lock>
+ void TemplatedLock() {
+ std::mutex M;
+ Lock<std::mutex> L(M); // no warning
+ }
+
+ void UsingLock() {
+ using Lock = std::lock_guard<std::mutex>;
+ std::mutex M;
+ Lock L(M); // no warning
+ }
+
+
+Options
+-------
+
+.. option:: WarnOnSingleLocks
+
+ When `true`, the check will warn on single ``std::lock_guard`` declarations.
+ Set this option to `false` if you want to get warnings only on multiple
+ ``std::lock_guard`` declarations that can be replaced with a single
+ ``std::scoped_lock``. Default is `true`.
+
+.. option:: WarnOnUsingAndTypedef
+
+ When `true`, the check will emit warnings if ``std::lock_guard`` is used
+ in ``using`` or ``typedef`` context. Default is `true`.
+
+ .. code-block:: c++
+
+ template <typename T>
+ using Lock = std::lock_guard<T>; // warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+
+ using LockMutex = std::lock_guard<std::mutex>; // warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+
+ typedef std::lock_guard<std::mutex> LockDef; // warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+
+ using std::lock_guard; // warning: use 'std::scoped_lock' instead of 'std::lock_guard'
\ No newline at end of file
diff --git a/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/mutex b/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/mutex
new file mode 100644
index 0000000000000..6045342b39d7a
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/mutex
@@ -0,0 +1,33 @@
+#ifndef _MUTEX_
+#define _MUTEX_
+
+namespace std {
+
+struct mutex {
+ void lock() {}
+ void unlock() {}
+};
+
+template<class Lockable1, class Lockable2, class... LockableN >
+void lock(Lockable1& lock1, Lockable2& lock2, LockableN&... lockn );
+
+struct adopt_lock_t { };
+std::adopt_lock_t adopt_lock {};
+
+template <typename Mutex>
+struct lock_guard {
+ lock_guard(Mutex &m) { }
+ lock_guard(Mutex &m, std::adopt_lock_t t) {}
+ lock_guard(const lock_guard&) = delete;
+};
+
+template <typename... MutexTypes>
+struct scoped_lock {
+ scoped_lock(MutexTypes&... m) {}
+ scoped_lock(std::adopt_lock_t t, MutexTypes&... m) {}
+ scoped_lock(const scoped_lock&) = delete;
+};
+
+} // namespace std
+
+#endif // _MUTEX_
\ No newline at end of file
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scope-lock-warn-on-using-and-typedef-false.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scope-lock-warn-on-using-and-typedef-false.cpp
new file mode 100644
index 0000000000000..a33758fa9c702
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scope-lock-warn-on-using-and-typedef-false.cpp
@@ -0,0 +1,31 @@
+// RUN: %check_clang_tidy -std=c++17-or-later %s modernize-use-scoped-lock %t -- \
+// RUN: -config="{CheckOptions: {modernize-use-scoped-lock.WarnOnUsingAndTypedef: false}}" \
+// RUN: -- -isystem %clang_tidy_headers -fno-delayed-template-parsing
+
+#include <mutex>
+
+template <typename T>
+using Lock = std::lock_guard<T>;
+
+using LockM = std::lock_guard<std::mutex>;
+
+typedef std::lock_guard<std::mutex> LockDef;
+
+void PositiveUsingDecl() {
+ using std::lock_guard;
+
+ using LockMFun = std::lock_guard<std::mutex>;
+
+ typedef std::lock_guard<std::mutex> LockDefFun;
+}
+
+template <typename T>
+void PositiveUsingDeclTemplate() {
+ using std::lock_guard;
+
+ using LockFunT = std::lock_guard<T>;
+
+ using LockMFunT = std::lock_guard<std::mutex>;
+
+ typedef std::lock_guard<std::mutex> LockDefFunT;
+}
\ No newline at end of file
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock-warn-on-single-locks-false.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock-warn-on-single-locks-false.cpp
new file mode 100644
index 0000000000000..7a59dda18f941
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock-warn-on-single-locks-false.cpp
@@ -0,0 +1,96 @@
+// RUN: %check_clang_tidy -std=c++17-or-later %s modernize-use-scoped-lock %t -- \
+// RUN: -config="{CheckOptions: {modernize-use-scoped-lock.WarnOnSingleLocks: false}}" \
+// RUN: -- -isystem %clang_tidy_headers -fno-delayed-template-parsing
+
+#include <mutex>
+
+void Positive() {
+ std::mutex m;
+
+ {
+ std::lock_guard<std::mutex> l1(m);
+ std::lock_guard<std::mutex> l2(m);
+ // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:33: note: additional 'std::lock_guard' declared here
+ }
+
+ {
+ std::lock_guard<std::mutex> l1(m), l2(m), l3(m);
+ std::lock_guard<std::mutex> l4(m);
+ // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-3]]:40: note: additional 'std::lock_guard' declared here
+ // CHECK-MESSAGES: :[[@LINE-4]]:47: note: additional 'std::lock_guard' declared here
+ // CHECK-MESSAGES: :[[@LINE-4]]:33: note: additional 'std::lock_guard' declared here
+ }
+
+ {
+ std::lock(m, m);
+ std::lock_guard<std::mutex> l1(m, std::adopt_lock);
+ std::lock_guard<std::mutex> l2(m, std::adopt_lock);
+ // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:33: note: additional 'std::lock_guard' declared here
+ }
+}
+
+void Negative() {
+ std::mutex m;
+ {
+ std::lock_guard<std::mutex> l(m);
+ }
+
+ {
+ std::lock_guard<std::mutex> l(m, std::adopt_lock);
+ }
+}
+
+void PositiveInsideArg(std::mutex &m1, std::mutex &m2, std::mutex &m3) {
+ std::lock_guard<std::mutex> l1(m1);
+ std::lock_guard<std::mutex> l2(m2);
+ // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:31: note: additional 'std::lock_guard' declared here
+}
+
+
+void NegativeInsideArg(std::mutex &m1, std::mutex &m2, std::mutex &m3) {
+ std::lock_guard<std::mutex> l3(m3);
+}
+
+template <typename T>
+void PositiveTemplated() {
+ std::mutex m1, m2;
+
+ std::lock_guard<std::mutex> l1(m1);
+ std::lock_guard<std::mutex> l2(m2);
+ // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:31: note: additional 'std::lock_guard' declared here
+}
+
+template <typename T>
+void NegativeTemplated() {
+ std::mutex m1, m2, m3;
+ std::lock_guard<std::mutex> l(m1);
+}
+
+template <typename Mutex>
+void PositiveTemplatedMutex() {
+ Mutex m1, m2;
+
+ std::lock_guard<Mutex> l1(m1);
+ std::lock_guard<Mutex> l2(m2);
+ // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:26: note: additional 'std::lock_guard' declared here
+}
+
+template <typename Mutex>
+void NegativeTemplatedMutex() {
+ Mutex m1;
+ std::lock_guard<Mutex> l(m1);
+}
+
+struct NegativeClass {
+ void Negative() {
+ std::lock_guard<std::mutex> l(m1);
+ }
+
+ std::mutex m1;
+};
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp
new file mode 100644
index 0000000000000..1957a4b7daa1f
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp
@@ -0,0 +1,372 @@
+// RUN: %check_clang_tidy -std=c++17-or-later %s modernize-use-scoped-lock %t -- -- -isystem %clang_tidy_headers -fno-delayed-template-parsing
+
+#include <mutex>
+
+void Positive() {
+ std::mutex m;
+ {
+ std::lock_guard<std::mutex> l(m);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(m);
+ }
+
+ {
+ std::lock_guard<std::mutex> l(m, std::adopt_lock);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(std::adopt_lock, m);
+ }
+
+ {
+ std::lock_guard<std::mutex> l1(m);
+ std::lock_guard<std::mutex> l2(m);
+ // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:33: note: additional 'std::lock_guard' declared here
+ }
+
+ {
+ std::lock_guard<std::mutex> l1(m), l2(m), l3(m);
+ std::lock_guard<std::mutex> l4(m);
+ // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-3]]:40: note: additional 'std::lock_guard' declared here
+ // CHECK-MESSAGES: :[[@LINE-4]]:47: note: additional 'std::lock_guard' declared here
+ // CHECK-MESSAGES: :[[@LINE-4]]:33: note: additional 'std::lock_guard' declared here
+ }
+
+ {
+ std::lock(m, m);
+ std::lock_guard<std::mutex> l1(m, std::adopt_lock);
+ std::lock_guard<std::mutex> l2(m, std::adopt_lock);
+ // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:33: note: additional 'std::lock_guard' declared here
+ int a = 0;
+ std::lock_guard<std::mutex> l3(m);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l3(m);
+ int b = 0;
+ std::lock_guard<std::mutex> l4(m, std::adopt_lock);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l4(std::adopt_lock, m);
+ }
+}
+
+
+std::mutex p_m1;
+void PositiveShortFunction() {
+ std::lock_guard<std::mutex> l(p_m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(p_m1);
+}
+
+
+void PositiveNested() {
+ std::mutex m1;
+ if (true) {
+ std::lock_guard<std::mutex> l(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(m1);
+ {
+ std::lock_guard<std::mutex> l2(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l2(m1);
+ {
+ std::lock_guard<std::mutex> l3(m1);
+ std::lock_guard<std::mutex> l4(m1);
+ // CHECK-MESSAGES: :[[@LINE-2]]:9: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:37: note: additional 'std::lock_guard' declared here
+ }
+ {
+ std::lock_guard<std::mutex> l2(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l2(m1);
+ }
+ }
+ }
+ std::lock_guard<std::mutex> l(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(m1);
+}
+
+
+void PositiveInsideArg(std::mutex &m1, std::mutex &m2, std::mutex &m3) {
+ std::lock_guard<std::mutex> l1(m1);
+ std::lock_guard<std::mutex> l2(m2);
+ // CHECK-MESSAGES: :[[@LINE-2]]:3: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:31: note: additional 'std::lock_guard' declared here
+ int a = 0;
+ std::lock_guard<std::mutex> l3(m3);
+ // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l3(m3);
+}
+
+
+void PositiveInsideConditional() {
+ std::mutex m1;
+ if (true) {
+ std::lock_guard<std::mutex> l1(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l1(m1);
+ } else {
+ std::lock_guard<std::mutex> l1(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l1(m1);
+ }
+
+ while (true) {
+ std::lock_guard<std::mutex> l1(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l1(m1);
+ }
+
+ for (int i = 0; i < 10; ++i) {
+ std::lock_guard<std::mutex> l1(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l1(m1);
+ }
+}
+
+
+template <typename T>
+void PositiveTemplated() {
+ std::mutex m1, m2, m3;
+ {
+ std::lock_guard<std::mutex> l(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(m1);
+ }
+
+ {
+ std::lock_guard<std::mutex> l1(m1);
+ std::lock_guard<std::mutex> l2(m2);
+ // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:33: note: additional 'std::lock_guard' declared here
+ }
+
+ {
+ std::lock(m1, m2);
+ std::lock_guard<std::mutex> l1(m1, std::adopt_lock);
+ std::lock_guard<std::mutex> l2(m2, std::adopt_lock);
+ // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:33: note: additional 'std::lock_guard' declared here
+ int a = 0;
+ std::lock_guard<std::mutex> l3(m3);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l3(m3);
+ }
+}
+
+
+template <typename Mutex>
+void PositiveTemplatedMutex() {
+ Mutex m1, m2, m3;
+ {
+ std::lock_guard<Mutex> l(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ }
+
+ {
+ std::lock_guard<Mutex> l1(m1);
+ std::lock_guard<Mutex> l2(m2);
+ // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:28: note: additional 'std::lock_guard' declared here
+ }
+
+ {
+ std::lock(m1, m2);
+ std::lock_guard<Mutex> l1(m1, std::adopt_lock);
+ std::lock_guard<Mutex> l2(m2, std::adopt_lock);
+ // CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:28: note: additional 'std::lock_guard' declared here
+ int a = 0;
+ std::lock_guard<Mutex> l3(m3);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ }
+}
+
+
+template <template <typename> typename Lock>
+void NegativeTemplate() {
+ std::mutex m1, m2;
+ {
+ Lock<std::mutex> l(m1);
+ }
+
+ {
+ Lock<std::mutex> l1(m1);
+ Lock<std::mutex> l2(m2);
+ }
+}
+
+void instantiate() {
+ NegativeTemplate<std::lock_guard>();
+}
+
+
+struct PositiveClass {
+ void Positive() {
+ {
+ std::lock_guard<std::mutex> l(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(m1);
+ }
+
+ {
+ std::lock_guard<std::mutex> l1(m1);
+ std::lock_guard<std::mutex> l2(m2);
+ // CHECK-MESSAGES: :[[@LINE-2]]:7: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:35: note: additional 'std::lock_guard' declared here
+ }
+
+ {
+ std::lock(m1, m2);
+ std::lock_guard<std::mutex> l1(m1, std::adopt_lock);
+ std::lock_guard<std::mutex> l2(m2, std::adopt_lock);
+ // CHECK-MESSAGES: :[[@LINE-2]]:7: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:35: note: additional 'std::lock_guard' declared here
+ int a = 0;
+ std::lock_guard<std::mutex> l3(m3);
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l3(m3);
+ }
+ }
+
+ std::mutex m1;
+ std::mutex m2;
+ std::mutex m3;
+};
+
+
+template <typename T>
+struct PositiveTemplatedClass {
+ void Positive() {
+ {
+ std::lock_guard<std::mutex> l(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(m1);
+ }
+
+ {
+ std::lock(m1, m2);
+ std::lock_guard<std::mutex> l1(m1, std::adopt_lock);
+ std::lock_guard<std::mutex> l2(m2, std::adopt_lock);
+ // CHECK-MESSAGES: :[[@LINE-2]]:7: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:35: note: additional 'std::lock_guard' declared here
+ int a = 0;
+ std::lock_guard<std::mutex> l3(m3);
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l3(m3);
+ }
+ }
+
+ template <typename... Ts>
+ void TemplatedPositive() {
+ {
+ std::lock_guard<std::mutex> l(m1);
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(m1);
+ }
+
+ {
+ std::lock(m1, m2);
+ std::lock_guard<std::mutex> l1(m1, std::adopt_lock);
+ std::lock_guard<std::mutex> l2(m2, std::adopt_lock);
+ // CHECK-MESSAGES: :[[@LINE-2]]:7: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-2]]:35: note: additional 'std::lock_guard' declared here
+ int a = 0;
+ std::lock_guard<std::mutex> l3(m3);
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l3(m3);
+ }
+ }
+
+ std::mutex m1;
+ std::mutex m2;
+ std::mutex m3;
+};
+
+
+template <typename T>
+using Lock = std::lock_guard<T>;
+// CHECK-MESSAGES: :[[@LINE-1]]:14: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+// CHECK-FIXES: using Lock = std::scoped_lock<T>;
+
+using LockM = std::lock_guard<std::mutex>;
+// CHECK-MESSAGES: :[[@LINE-1]]:15: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+// CHECK-FIXES: using LockM = std::scoped_lock<std::mutex>;
+
+typedef std::lock_guard<std::mutex> LockDef;
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+// CHECK-FIXES: typedef std::scoped_lock<std::mutex> LockDef;
+
+
+void PositiveUsingDecl() {
+ using std::lock_guard;
+ // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: using std::scoped_lock;
+
+ using LockMFun = std::lock_guard<std::mutex>;
+ // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: using LockMFun = std::scoped_lock<std::mutex>;
+
+ typedef std::lock_guard<std::mutex> LockDefFun;
+ // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: typedef std::scoped_lock<std::mutex> LockDefFun;
+}
+
+template <typename T>
+void PositiveUsingDeclTemplate() {
+ using std::lock_guard;
+ // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: using std::scoped_lock;
+
+ std::mutex m;
+ lock_guard<std::mutex> l(m);
+ // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: scoped_lock l(m);
+
+ using LockFunT = std::lock_guard<T>;
+ // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: using LockFunT = std::scoped_lock<T>;
+
+ using LockMFunT = std::lock_guard<std::mutex>;
+ // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: using LockMFunT = std::scoped_lock<std::mutex>;
+
+ typedef std::lock_guard<std::mutex> LockDefFunT;
+ // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: typedef std::scoped_lock<std::mutex> LockDefFunT;
+}
+
+void NegativeUsingTypedefs() {
+ std::mutex m;
+
+ {
+ Lock<std::mutex> l(m);
+ }
+
+ {
+ LockM l(m);
+ }
+
+ {
+ LockDef l(m);
+ }
+}
+
+// Non-STD lock_guard.
+template <typename Mutex>
+struct lock_guard {
+ lock_guard(Mutex &m) { }
+ lock_guard(const lock_guard& ) = delete;
+};
+
+void NegativeNonStdLockGuard() {
+ std::mutex m;
+ {
+ lock_guard<std::mutex> l(m);
+ }
+
+ {
+ lock_guard<std::mutex> l1(m);
+ lock_guard<std::mutex> l2(m);
+ }
+}
\ No newline at end of file
>From fc9c1b5498624eccb223196d4b2abf322ba384c9 Mon Sep 17 00:00:00 2001
From: Victor Baranov <bar.victor.2002 at gmail.com>
Date: Mon, 3 Mar 2025 09:28:38 +0300
Subject: [PATCH 2/4] add newlines to test files
---
clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/mutex | 2 +-
.../use-scope-lock-warn-on-using-and-typedef-false.cpp | 2 +-
.../test/clang-tidy/checkers/modernize/use-scoped-lock.cpp | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/mutex b/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/mutex
index 6045342b39d7a..a0030a2b9da0a 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/mutex
+++ b/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/mutex
@@ -30,4 +30,4 @@ struct scoped_lock {
} // namespace std
-#endif // _MUTEX_
\ No newline at end of file
+#endif // _MUTEX_
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scope-lock-warn-on-using-and-typedef-false.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scope-lock-warn-on-using-and-typedef-false.cpp
index a33758fa9c702..77df845756530 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scope-lock-warn-on-using-and-typedef-false.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scope-lock-warn-on-using-and-typedef-false.cpp
@@ -28,4 +28,4 @@ void PositiveUsingDeclTemplate() {
using LockMFunT = std::lock_guard<std::mutex>;
typedef std::lock_guard<std::mutex> LockDefFunT;
-}
\ No newline at end of file
+}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp
index 1957a4b7daa1f..68201612a973b 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp
@@ -369,4 +369,4 @@ void NegativeNonStdLockGuard() {
lock_guard<std::mutex> l1(m);
lock_guard<std::mutex> l2(m);
}
-}
\ No newline at end of file
+}
>From f34c9aef97f73f7309f3372956a01c921a50a366 Mon Sep 17 00:00:00 2001
From: Victor Baranov <bar.victor.2002 at gmail.com>
Date: Mon, 10 Mar 2025 00:12:09 +0300
Subject: [PATCH 3/4] Add UnqualifiedDesugaredType to match more cases
---
.../modernize/UseScopedLockCheck.cpp | 45 ++++++++++--------
.../checks/modernize/use-scoped-lock.rst | 8 ++--
.../checkers/modernize/use-scoped-lock.cpp | 47 ++++++++++++++++++-
3 files changed, 74 insertions(+), 26 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp
index 5dbb3a2f671e6..73c4cc4906fba 100644
--- a/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp
@@ -48,7 +48,8 @@ llvm::SmallVector<const VarDecl *> getLockGuardsFromDecl(const DeclStmt *DS) {
for (const Decl *Decl : DS->decls()) {
if (const auto *VD = dyn_cast<VarDecl>(Decl)) {
- const QualType Type = VD->getType().getCanonicalType();
+ const QualType Type =
+ VD->getType().getUnqualifiedType().getCanonicalType();
if (isLockGuard(Type)) {
LockGuards.push_back(VD);
}
@@ -105,19 +106,16 @@ getTemplateLockGuardTypeLoc(const TypeSourceInfo *SourceInfo) {
return ElaboratedLoc.getNamedTypeLoc().getAs<TemplateSpecializationTypeLoc>();
}
-// Find the exact source range of the 'lock_guard<...>' token
-SourceRange getLockGuardTemplateRange(const TypeSourceInfo *SourceInfo) {
- const TemplateSpecializationTypeLoc TemplateLoc =
- getTemplateLockGuardTypeLoc(SourceInfo);
- if (!TemplateLoc)
- return {};
+// Find the exact source range of the 'lock_guard' token
+SourceRange getLockGuardRange(const TypeSourceInfo *SourceInfo) {
+ const TypeLoc LockGuardTypeLoc = SourceInfo->getTypeLoc();
- return SourceRange(TemplateLoc.getTemplateNameLoc(),
- TemplateLoc.getRAngleLoc());
+ return SourceRange(LockGuardTypeLoc.getBeginLoc(),
+ LockGuardTypeLoc.getEndLoc());
}
-// Find the exact source range of the 'lock_guard' token
-SourceRange getLockGuardRange(const TypeSourceInfo *SourceInfo) {
+// Find the exact source range of the 'lock_guard' name token
+SourceRange getLockGuardNameRange(const TypeSourceInfo *SourceInfo) {
const TemplateSpecializationTypeLoc TemplateLoc =
getTemplateLockGuardTypeLoc(SourceInfo);
if (!TemplateLoc)
@@ -144,11 +142,16 @@ void UseScopedLockCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
}
void UseScopedLockCheck::registerMatchers(MatchFinder *Finder) {
- auto LockGuardClassDecl =
- namedDecl(anyOf(classTemplateDecl(), classTemplateSpecializationDecl()),
- hasName("lock_guard"), isInStdNamespace());
- auto LockGuardType = qualType(hasDeclaration(LockGuardClassDecl));
- auto LockVarDecl = varDecl(hasType(LockGuardType));
+ const auto LockGuardClassDecl =
+ namedDecl(hasName("lock_guard"), isInStdNamespace());
+
+ const auto LockGuardType = qualType(anyOf(
+ hasUnqualifiedDesugaredType(
+ recordType(hasDeclaration(LockGuardClassDecl))),
+ elaboratedType(namesType(hasUnqualifiedDesugaredType(
+ templateSpecializationType(hasDeclaration(LockGuardClassDecl)))))));
+
+ const auto LockVarDecl = varDecl(hasType(LockGuardType));
if (WarnOnSingleLocks) {
// Match CompoundStmt with only one 'std::lock_guard'
@@ -231,7 +234,7 @@ void UseScopedLockCheck::emitDiag(const VarDecl *LockGuard,
auto Diag = diag(LockGuard->getBeginLoc(), UseScopedLockMessage);
const SourceRange LockGuardTypeRange =
- getLockGuardTemplateRange(LockGuard->getTypeSourceInfo());
+ getLockGuardRange(LockGuard->getTypeSourceInfo());
if (LockGuardTypeRange.isInvalid()) {
return;
@@ -245,7 +248,8 @@ void UseScopedLockCheck::emitDiag(const VarDecl *LockGuard,
}
if (CtorCall->getNumArgs() == 1) {
- Diag << FixItHint::CreateReplacement(LockGuardTypeRange, "scoped_lock");
+ Diag << FixItHint::CreateReplacement(LockGuardTypeRange,
+ "std::scoped_lock");
return;
}
@@ -262,7 +266,7 @@ void UseScopedLockCheck::emitDiag(const VarDecl *LockGuard,
CharSourceRange::getTokenRange(AdoptLockArg->getSourceRange()),
*Result.SourceManager, Result.Context->getLangOpts());
- Diag << FixItHint::CreateReplacement(LockGuardTypeRange, "scoped_lock")
+ Diag << FixItHint::CreateReplacement(LockGuardTypeRange, "std::scoped_lock")
<< FixItHint::CreateReplacement(
SourceRange(MutexArg->getBeginLoc(), AdoptLockArg->getEndLoc()),
(llvm::Twine(AdoptLockSourceText) + ", " + MutexSourceText)
@@ -300,7 +304,8 @@ void UseScopedLockCheck::emitDiag(
if (const auto ElaboratedTL = TL.getAs<ElaboratedTypeLoc>()) {
auto Diag = diag(ElaboratedTL.getBeginLoc(), UseScopedLockMessage);
- const SourceRange LockGuardRange = getLockGuardRange(LockGuardSourceInfo);
+ const SourceRange LockGuardRange =
+ getLockGuardNameRange(LockGuardSourceInfo);
if (LockGuardRange.isInvalid()) {
return;
}
diff --git a/clang-tools-extra/docs/clang-tidy/checks/modernize/use-scoped-lock.rst b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-scoped-lock.rst
index 84c896efd6258..02af2481ef251 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/modernize/use-scoped-lock.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-scoped-lock.rst
@@ -58,7 +58,7 @@ Limitations
-----------
The check will not emit warnings if ``std::lock_guard`` is used implicitly via
-``using``, ``typedef`` or as ``template`` parameter:
+``template`` parameter:
.. code-block:: c++
@@ -68,10 +68,8 @@ The check will not emit warnings if ``std::lock_guard`` is used implicitly via
Lock<std::mutex> L(M); // no warning
}
- void UsingLock() {
- using Lock = std::lock_guard<std::mutex>;
- std::mutex M;
- Lock L(M); // no warning
+ void instantiate() {
+ TemplatedLock<std::lock_guard>();
}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp
index 68201612a973b..32b18b3ddcc7e 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock.cpp
@@ -336,19 +336,64 @@ void PositiveUsingDeclTemplate() {
// CHECK-FIXES: typedef std::scoped_lock<std::mutex> LockDefFunT;
}
-void NegativeUsingTypedefs() {
+void PositiveInUsingTypedefs() {
std::mutex m;
{
Lock<std::mutex> l(m);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(m);
}
{
LockM l(m);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(m);
}
{
LockDef l(m);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l(m);
+ }
+
+ {
+ std::lock(m, m);
+ Lock<std::mutex> l1(m, std::adopt_lock);
+ LockM l2(m, std::adopt_lock);
+ LockDef l3(m), l4(m);
+ // CHECK-MESSAGES: :[[@LINE-3]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-3]]:11: note: additional 'std::lock_guard' declared here
+ // CHECK-MESSAGES: :[[@LINE-3]]:13: note: additional 'std::lock_guard' declared here
+ // CHECK-MESSAGES: :[[@LINE-4]]:20: note: additional 'std::lock_guard' declared here
+ int a = 0;
+ LockDef l5(m);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ // CHECK-FIXES: std::scoped_lock l5(m);
+ }
+}
+
+template <typename Mutex>
+void PositiveInUsingTypedefsTemplated() {
+ Mutex m;
+
+ {
+ Lock<Mutex> l(m);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
+ }
+
+ {
+ std::lock(m, m);
+ Lock<Mutex> l1(m, std::adopt_lock);
+ LockM l2(m, std::adopt_lock);
+ LockDef l3(m), l4(m);
+ // CHECK-MESSAGES: :[[@LINE-3]]:5: warning: use single 'std::scoped_lock' instead of multiple 'std::lock_guard'
+ // CHECK-MESSAGES: :[[@LINE-3]]:11: note: additional 'std::lock_guard' declared here
+ // CHECK-MESSAGES: :[[@LINE-3]]:13: note: additional 'std::lock_guard' declared here
+ // CHECK-MESSAGES: :[[@LINE-4]]:20: note: additional 'std::lock_guard' declared here
+ int a = 0;
+ LockDef l5(m);
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use 'std::scoped_lock' instead of 'std::lock_guard'
}
}
>From be8cfb197295c81559bfd8e0dbace447e1f3678c Mon Sep 17 00:00:00 2001
From: Victor Baranov <bar.victor.2002 at gmail.com>
Date: Mon, 10 Mar 2025 00:33:33 +0300
Subject: [PATCH 4/4] add more tests to WarnOnSingleLock opt
---
.../clang-tidy/modernize/UseScopedLockCheck.cpp | 6 ++++--
.../use-scoped-lock-warn-on-single-locks-false.cpp | 6 ++++++
2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp
index 73c4cc4906fba..27ac70d10d074 100644
--- a/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseScopedLockCheck.cpp
@@ -281,8 +281,10 @@ void UseScopedLockCheck::emitDiag(
const llvm::SmallVector<llvm::SmallVector<const VarDecl *>> &LockGroups,
const ast_matchers::MatchFinder::MatchResult &Result) {
for (const llvm::SmallVector<const VarDecl *> &Group : LockGroups) {
- if (Group.size() == 1 && WarnOnSingleLocks) {
- emitDiag(Group[0], Result);
+ if (Group.size() == 1) {
+ if (WarnOnSingleLocks) {
+ emitDiag(Group[0], Result);
+ }
} else {
diag(Group[0]->getBeginLoc(),
"use single 'std::scoped_lock' instead of multiple "
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock-warn-on-single-locks-false.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock-warn-on-single-locks-false.cpp
index 7a59dda18f941..7b30cdd75c801 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock-warn-on-single-locks-false.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-scoped-lock-warn-on-single-locks-false.cpp
@@ -41,6 +41,12 @@ void Negative() {
{
std::lock_guard<std::mutex> l(m, std::adopt_lock);
}
+
+ {
+ std::lock_guard<std::mutex> l3(m);
+ int a = 0;
+ std::lock_guard<std::mutex> l4(m, std::adopt_lock);
+ }
}
void PositiveInsideArg(std::mutex &m1, std::mutex &m2, std::mutex &m3) {
More information about the cfe-commits
mailing list