a3a60e03e2
Add new clang-tidy check that finds uses of `std::lock_guard` and suggests
replacing them with C++17's more flexible and safer alternative
`std::scoped_lock`.
Here is a small description of how it works for better understanding of
the code:
Two separate AST matchers are registered:
- The first one matches declarations of `std::lock_guard` that are
single in their scope (only one `std::lock_guard` in `CompoundStmt`).
It's an easy case, we can emit warning right away.
- The second one matches `CompoundStmt`'s that have multiple
`std::lock_guard` declarations, which means that we may have consecutive
declarations of `std::lock_guard` that can be replaced by a single
`std::scoped_lock`. In order to ensure that declarations are
consecutive, we need to loop over `Stmt`'s in `CompoundStmt`. Here is a
small example:
```cpp
{
std::mutex m1, m2;
std::lock(m1, m2);
std::lock_guard<std::mutex> l1(m, std::adopt_lock); // first declaration of 'std::lock_guard'
std::lock_guard<std::mutex> l2(m, std::adopt_lock); // second declaration of 'std::lock_guard' that can be merged with first using 'scoped_lock'
}
```
This PR closes https://github.com/llvm/llvm-project/issues/107839.
55 lines
2.2 KiB
C++
55 lines
2.2 KiB
C++
//===--- UseScopedLockCheck.h - clang-tidy ----------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USESCOPEDLOCKCHECK_H
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#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USESCOPEDLOCKCHECK_H
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#include "../ClangTidyCheck.h"
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#include "clang/AST/ASTTypeTraits.h"
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#include "clang/AST/Stmt.h"
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#include <optional>
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namespace clang::tidy::modernize {
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/// Finds uses of ``std::lock_guard`` and suggests replacing them with C++17's
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/// alternative ``std::scoped_lock``.
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///
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/// For the user-facing documentation see:
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/// http://clang.llvm.org/extra/clang-tidy/checks/modernize/use-scoped-lock.html
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class UseScopedLockCheck : public ClangTidyCheck {
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public:
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UseScopedLockCheck(StringRef Name, ClangTidyContext *Context);
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void registerMatchers(ast_matchers::MatchFinder *Finder) override;
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void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
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void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
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bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
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return LangOpts.CPlusPlus17;
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}
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std::optional<TraversalKind> getCheckTraversalKind() const override {
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return TK_IgnoreUnlessSpelledInSource;
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}
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private:
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void diagOnSingleLock(const VarDecl *LockGuard,
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const ast_matchers::MatchFinder::MatchResult &Result);
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void diagOnMultipleLocks(
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const llvm::SmallVector<llvm::SmallVector<const VarDecl *>> &LockGroups,
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const ast_matchers::MatchFinder::MatchResult &Result);
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void diagOnSourceInfo(const TypeSourceInfo *LockGuardSourceInfo,
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const ast_matchers::MatchFinder::MatchResult &Result);
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void diagOnUsingDecl(const UsingDecl *UsingDecl,
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const ast_matchers::MatchFinder::MatchResult &Result);
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const bool WarnOnSingleLocks;
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const bool WarnOnUsingAndTypedef;
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};
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} // namespace clang::tidy::modernize
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#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_USESCOPEDLOCKCHECK_H
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