[clang-tools-extra] [llvm] [clang-tidy] Add bugprone-move-shared-pointer-contents check. (PR #67467)
Johannes Doerfert via cfe-commits
cfe-commits at lists.llvm.org
Fri Dec 1 14:59:43 PST 2023
https://github.com/jdoerfert updated https://github.com/llvm/llvm-project/pull/67467
>From 6d5d35e1273f595e8a0382053d5183cbce7a9d8a Mon Sep 17 00:00:00 2001
From: David Pizzuto <pizzud at google.com>
Date: Tue, 26 Sep 2023 10:45:42 -0700
Subject: [PATCH] [clang-tidy] Add bugprone-move-shared-pointer-contents check.
This check detects moves of the contents of a shared pointer rather than the
pointer itself. Other code with a reference to the shared pointer is probably
not expecting the move.
The set of shared pointer classes is configurable via options to allow individual
projects to cover additional types.
---
.../bugprone/BugproneTidyModule.cpp | 3 +
.../clang-tidy/bugprone/CMakeLists.txt | 2 +
.../MoveSharedPointerContentsCheck.cpp | 60 ++++++++++++++++
.../bugprone/MoveSharedPointerContentsCheck.h | 37 ++++++++++
clang-tools-extra/docs/ReleaseNotes.rst | 6 ++
.../bugprone/move-shared-pointer-contents.rst | 17 +++++
.../docs/clang-tidy/checks/list.rst | 2 +
.../bugprone/move-shared-pointer-contents.cpp | 68 +++++++++++++++++++
8 files changed, 195 insertions(+)
create mode 100644 clang-tools-extra/clang-tidy/bugprone/MoveSharedPointerContentsCheck.cpp
create mode 100644 clang-tools-extra/clang-tidy/bugprone/MoveSharedPointerContentsCheck.h
create mode 100644 clang-tools-extra/docs/clang-tidy/checks/bugprone/move-shared-pointer-contents.rst
create mode 100644 clang-tools-extra/test/clang-tidy/checkers/bugprone/move-shared-pointer-contents.cpp
diff --git a/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp b/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
index a67a91eedd10482..7f4a504f9930f17 100644
--- a/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/BugproneTidyModule.cpp
@@ -39,6 +39,7 @@
#include "MisplacedPointerArithmeticInAllocCheck.h"
#include "MisplacedWideningCastCheck.h"
#include "MoveForwardingReferenceCheck.h"
+#include "MoveSharedPointerContentsCheck.h"
#include "MultiLevelImplicitPointerConversionCheck.h"
#include "MultipleNewInOneExpressionCheck.h"
#include "MultipleStatementMacroCheck.h"
@@ -125,6 +126,8 @@ class BugproneModule : public ClangTidyModule {
"bugprone-inaccurate-erase");
CheckFactories.registerCheck<IncorrectEnableIfCheck>(
"bugprone-incorrect-enable-if");
+ CheckFactories.registerCheck<MoveSharedPointerContentsCheck>(
+ "bugprone-move-shared-pointer-contents");
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 3c768021feb1502..c017f0c0cc52021 100644
--- a/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt
@@ -23,6 +23,7 @@ add_clang_library(clangTidyBugproneModule
ImplicitWideningOfMultiplicationResultCheck.cpp
InaccurateEraseCheck.cpp
IncorrectEnableIfCheck.cpp
+ MoveSharedPointerContentsCheck.cpp
SwitchMissingDefaultCaseCheck.cpp
IncDecInConditionsCheck.cpp
IncorrectRoundingsCheck.cpp
@@ -35,6 +36,7 @@ add_clang_library(clangTidyBugproneModule
MisplacedPointerArithmeticInAllocCheck.cpp
MisplacedWideningCastCheck.cpp
MoveForwardingReferenceCheck.cpp
+ MoveSharedPointerContentsCheck.cpp
MultiLevelImplicitPointerConversionCheck.cpp
MultipleNewInOneExpressionCheck.cpp
MultipleStatementMacroCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/bugprone/MoveSharedPointerContentsCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/MoveSharedPointerContentsCheck.cpp
new file mode 100644
index 000000000000000..b4a393b7f2f2000
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/bugprone/MoveSharedPointerContentsCheck.cpp
@@ -0,0 +1,60 @@
+//===--- MoveSharedPointerContentsCheck.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 "MoveSharedPointerContentsCheck.h"
+#include "../ClangTidyCheck.h"
+#include "../utils/Matchers.h"
+#include "../utils/OptionsUtils.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::bugprone {
+
+MoveSharedPointerContentsCheck::MoveSharedPointerContentsCheck(
+ StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context),
+ SharedPointerClasses(utils::options::parseStringList(
+ Options.get("SharedPointerClasses", "std::shared_ptr"))) {}
+
+MoveSharedPointerContentsCheck::~MoveSharedPointerContentsCheck() = default;
+
+bool MoveSharedPointerContentsCheck::isLanguageVersionSupported(
+ const LangOptions &LangOptions) const {
+ return LangOptions.CPlusPlus11;
+}
+
+void MoveSharedPointerContentsCheck::registerMatchers(MatchFinder *Finder) {
+ Finder->addMatcher(
+ callExpr(
+ callee(functionDecl(hasName("std::move"))),
+ hasArgument(0, cxxOperatorCallExpr(hasOverloadedOperatorName("*"),
+ callee(cxxMethodDecl(ofClass(
+ matchers::matchesAnyListedName(
+ SharedPointerClasses)))))
+ .bind("op")))
+ .bind("call"),
+ this);
+}
+
+void MoveSharedPointerContentsCheck::check(
+ const MatchFinder::MatchResult &Result) {
+ const auto *Call = Result.Nodes.getNodeAs<CallExpr>("call");
+ const auto *Op = Result.Nodes.getNodeAs<Expr>("op");
+
+ if (Op) {
+ diag(Call->getBeginLoc(),
+ "don't move the contents out of a shared pointer, as other accessors "
+ "expect them to remain in a determinate state")
+ << FixItHint::CreateInsertion(Call->getBeginLoc(), "*")
+ << FixItHint::CreateRemoval(Op->getBeginLoc());
+ }
+}
+
+} // namespace clang::tidy::bugprone
diff --git a/clang-tools-extra/clang-tidy/bugprone/MoveSharedPointerContentsCheck.h b/clang-tools-extra/clang-tidy/bugprone/MoveSharedPointerContentsCheck.h
new file mode 100644
index 000000000000000..a9ae8d335941e8d
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/bugprone/MoveSharedPointerContentsCheck.h
@@ -0,0 +1,37 @@
+//===--- MoveSharedPointerContentsCheck.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_MOVESHAREDPOINTERCONTENTSCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_MOVESHAREDPOINTERCONTENTSCHECK_H
+
+#include <vector>
+
+#include "../ClangTidyCheck.h"
+
+namespace clang::tidy::bugprone {
+
+/// FIXME: Write a short description.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/bugprone/move-shared-pointer-contents.html
+class MoveSharedPointerContentsCheck : public ClangTidyCheck {
+public:
+ MoveSharedPointerContentsCheck(StringRef Name, ClangTidyContext *Context);
+ ~MoveSharedPointerContentsCheck() override;
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+ bool
+ isLanguageVersionSupported(const LangOptions &LangOptions) const override;
+
+private:
+ const std::vector<StringRef> SharedPointerClasses;
+};
+
+} // namespace clang::tidy::bugprone
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_MOVESHAREDPOINTERCONTENTSCHECK_H
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 19c977977f9044c..cbd472d86c42273 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -138,6 +138,12 @@ New checks
Detects incorrect usages of ``std::enable_if`` that don't name the nested
``type`` type.
+- New :doc:`bugprone-move-shared-pointer-contents
+ <clang-tidy/checks/bugprone/move-shared-pointer-contents>` check.
+
+ Detects calls to move the contents out of a ``std::shared_ptr`` rather than
+ moving the pointer itself.
+
- New :doc:`bugprone-multi-level-implicit-pointer-conversion
<clang-tidy/checks/bugprone/multi-level-implicit-pointer-conversion>` check.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/bugprone/move-shared-pointer-contents.rst b/clang-tools-extra/docs/clang-tidy/checks/bugprone/move-shared-pointer-contents.rst
new file mode 100644
index 000000000000000..4536663a1b74704
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/bugprone/move-shared-pointer-contents.rst
@@ -0,0 +1,17 @@
+.. title:: clang-tidy - bugprone-move-shared-pointer-contents
+
+bugprone-move-shared-pointer-contents
+=====================================
+
+Detects calls to move the contents out of a ``std::shared_ptr`` rather than
+moving the pointer itself. In other words, calling ``std::move(*p)``. Other
+reference holders may not be expecting the move and suddenly getting empty or
+otherwise indeterminate states can cause issues.
+
+Options
+-------
+
+.. option :: SharedPointerClasses
+
+ A semicolon-separated list of class names that should be treated as shared
+ pointers. By default only `std::shared_ptr` is included.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index 75a86431d264412..bfe8b15ccc7ea3a 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -105,6 +105,7 @@ Clang-Tidy Checks
:doc:`bugprone-misplaced-pointer-arithmetic-in-alloc <bugprone/misplaced-pointer-arithmetic-in-alloc>`, "Yes"
:doc:`bugprone-misplaced-widening-cast <bugprone/misplaced-widening-cast>`,
:doc:`bugprone-move-forwarding-reference <bugprone/move-forwarding-reference>`, "Yes"
+ :doc:`bugprone-move-shared-pointer-contents <bugprone/move-shared-pointer-contents>`, "Yes"
:doc:`bugprone-multi-level-implicit-pointer-conversion <bugprone/multi-level-implicit-pointer-conversion>`,
:doc:`bugprone-multiple-new-in-one-expression <bugprone/multiple-new-in-one-expression>`,
:doc:`bugprone-multiple-statement-macro <bugprone/multiple-statement-macro>`,
@@ -116,6 +117,7 @@ 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-shared-pointer-contents-move <bugprone/shared-pointer-contents-move>`, "Yes"
: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>`,
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/move-shared-pointer-contents.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/move-shared-pointer-contents.cpp
new file mode 100644
index 000000000000000..0837708a7171c5b
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/move-shared-pointer-contents.cpp
@@ -0,0 +1,68 @@
+// RUN: %check_clang_tidy %s bugprone-move-shared-pointer-contents %t -- -config="{CheckOptions: {bugprone-move-shared-pointer-contents.SharedPointerClasses: 'std::shared_ptr;my::OtherSharedPtr;'}}"
+
+// Some dummy definitions we'll need.
+
+namespace std {
+
+using size_t = int;
+
+template <typename> struct remove_reference;
+template <typename _Tp> struct remove_reference { typedef _Tp type; };
+template <typename _Tp> struct remove_reference<_Tp &> { typedef _Tp type; };
+template <typename _Tp> struct remove_reference<_Tp &&> { typedef _Tp type; };
+
+template <typename _Tp>
+constexpr typename std::remove_reference<_Tp>::type &&move(_Tp &&__t) {
+ return static_cast<typename std::remove_reference<_Tp>::type &&>(__t);
+}
+
+template <typename T>
+struct shared_ptr {
+ shared_ptr();
+ T *get() const;
+ explicit operator bool() const;
+ void reset(T *ptr);
+ T &operator*() const;
+ T *operator->() const;
+};
+
+} // namespace std
+
+namespace my {
+template <typename T>
+using OtherSharedPtr = std::shared_ptr<T>;
+} // namespace my
+
+void correct() {
+ std::shared_ptr<int> p;
+ int x = *std::move(p);
+}
+
+void simpleFinding() {
+ std::shared_ptr<int> p;
+ int y = std::move(*p);
+ // CHECK-FIXES: *std::move(p)
+}
+// CHECK-MESSAGES: :[[@LINE-3]]:11: warning: don't move the contents out of a shared pointer, as other accessors expect them to remain in a determinate state [bugprone-move-shared-pointer-contents]
+
+void aliasedType() {
+ using int_ptr = std::shared_ptr<int>;
+ int_ptr p;
+ int x = std::move(*p);
+ // CHECK-FIXES: *std::move(p)
+}
+// CHECK-MESSAGES: :[[@LINE-3]]:11: warning: don't move the contents out of a shared pointer, as other accessors expect them to remain in a determinate state [bugprone-move-shared-pointer-contents]
+
+void configWorks() {
+ my::OtherSharedPtr<int> p;
+ int x = std::move(*p);
+ // CHECK-FIXES: *std::move(p)
+}
+// CHECK-MESSAGES: :[[@LINE-3]]:11: warning: don't move the contents out of a shared pointer, as other accessors expect them to remain in a determinate state [bugprone-move-shared-pointer-contents]
+
+void multiStars() {
+ std::shared_ptr<int> p;
+ int x = 2 * std::move(*p) * 3;
+ // CHECK-FIXES: *std::move(p)
+}
+// CHECK-MESSAGES: :[[@LINE-3]]:15: warning: don't move the contents out of a shared pointer, as other accessors expect them to remain in a determinate state [bugprone-move-shared-pointer-contents]
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