Extend bugprone-use-after-move check to allow custom invalidation functions

Author: higher-performance

clang-tools-extra/clang-tidy/bugprone/UseAfterMoveCheck.cpp

@@ -19,6 +19,7 @@
 
 #include "../utils/ExprSequence.h"
 #include "../utils/Matchers.h"
+#include "../utils/OptionsUtils.h"
 #include <optional>
 
 using namespace clang::ast_matchers;
@@ -48,7 +49,8 @@ struct UseAfterMove {
 /// various internal helper functions).
 class UseAfterMoveFinder {
 public:
-  UseAfterMoveFinder(ASTContext *TheContext);
+  UseAfterMoveFinder(ASTContext *TheContext,
+                     llvm::ArrayRef<StringRef> InvalidationFunctions);
 
   // Within the given code block, finds the first use of 'MovedVariable' that
   // occurs after 'MovingCall' (the expression that performs the move). If a
@@ -71,13 +73,19 @@ class UseAfterMoveFinder {
                   llvm::SmallPtrSetImpl<const DeclRefExpr *> *DeclRefs);
 
   ASTContext *Context;
+  llvm::ArrayRef<StringRef> InvalidationFunctions;
   std::unique_ptr<ExprSequence> Sequence;
   std::unique_ptr<StmtToBlockMap> BlockMap;
   llvm::SmallPtrSet<const CFGBlock *, 8> Visited;
 };
 
 } // namespace
 
+static auto getNameMatcher(llvm::ArrayRef<StringRef> InvalidationFunctions) {
+  return anyOf(hasAnyName("::std::move", "::std::forward"),
+               matchers::matchesAnyListedName(InvalidationFunctions));
+}
+
 // Matches nodes that are
 // - Part of a decltype argument or class template argument (we check this by
 //   seeing if they are children of a TypeLoc), or
@@ -92,8 +100,9 @@ static StatementMatcher inDecltypeOrTemplateArg() {
                hasAncestor(expr(hasUnevaluatedContext())));
 }
 
-UseAfterMoveFinder::UseAfterMoveFinder(ASTContext *TheContext)
-    : Context(TheContext) {}
+UseAfterMoveFinder::UseAfterMoveFinder(
+    ASTContext *TheContext, llvm::ArrayRef<StringRef> InvalidationFunctions)
+    : Context(TheContext), InvalidationFunctions(InvalidationFunctions) {}
 
 std::optional<UseAfterMove>
 UseAfterMoveFinder::find(Stmt *CodeBlock, const Expr *MovingCall,
@@ -359,7 +368,7 @@ void UseAfterMoveFinder::getReinits(
                             unless(parmVarDecl(hasType(
                                 references(qualType(isConstQualified())))))),
                         unless(callee(functionDecl(
-                            hasAnyName("::std::move", "::std::forward")))))))
+                            getNameMatcher(InvalidationFunctions)))))))
           .bind("reinit");
 
   Stmts->clear();
@@ -388,9 +397,10 @@ void UseAfterMoveFinder::getReinits(
   }
 }
 
-enum class MoveType {
-  Move,    // std::move
-  Forward, // std::forward
+enum MoveType {
+  Forward,      // std::forward
+  Move,         // std::move
+  Invalidation, // other
 };
 
 static MoveType determineMoveType(const FunctionDecl *FuncDecl) {
@@ -399,7 +409,7 @@ static MoveType determineMoveType(const FunctionDecl *FuncDecl) {
   if (FuncDecl->getName() == "forward")
     return MoveType::Forward;
 
-  llvm_unreachable("Invalid move type");
+  return MoveType::Invalidation;
 }
 
 static void emitDiagnostic(const Expr *MovingCall, const DeclRefExpr *MoveArg,
@@ -408,41 +418,53 @@ static void emitDiagnostic(const Expr *MovingCall, const DeclRefExpr *MoveArg,
   const SourceLocation UseLoc = Use.DeclRef->getExprLoc();
   const SourceLocation MoveLoc = MovingCall->getExprLoc();
 
-  const bool IsMove = (Type == MoveType::Move);
-
-  Check->diag(UseLoc, "'%0' used after it was %select{forwarded|moved}1")
-      << MoveArg->getDecl()->getName() << IsMove;
-  Check->diag(MoveLoc, "%select{forward|move}0 occurred here",
+  Check->diag(UseLoc,
+              "'%0' used after it was %select{forwarded|moved|invalidated}1")
+      << MoveArg->getDecl()->getName() << Type;
+  Check->diag(MoveLoc, "%select{forward|move|invalidation}0 occurred here",
               DiagnosticIDs::Note)
-      << IsMove;
+      << Type;
   if (Use.EvaluationOrderUndefined) {
     Check->diag(
         UseLoc,
-        "the use and %select{forward|move}0 are unsequenced, i.e. "
+        "the use and %select{forward|move|invalidation}0 are unsequenced, i.e. "
         "there is no guarantee about the order in which they are evaluated",
         DiagnosticIDs::Note)
-        << IsMove;
+        << Type;
   } else if (Use.UseHappensInLaterLoopIteration) {
     Check->diag(UseLoc,
                 "the use happens in a later loop iteration than the "
-                "%select{forward|move}0",
+                "%select{forward|move|invalidation}0",
                 DiagnosticIDs::Note)
-        << IsMove;
+        << Type;
   }
 }
 
+UseAfterMoveCheck::UseAfterMoveCheck(StringRef Name, ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      InvalidationFunctions(utils::options::parseStringList(
+          Options.get("InvalidationFunctions", ""))) {}
+
+void UseAfterMoveCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "InvalidationFunctions",
+                utils::options::serializeStringList(InvalidationFunctions));
+}
+
 void UseAfterMoveCheck::registerMatchers(MatchFinder *Finder) {
   // try_emplace is a common maybe-moving function that returns a
   // bool to tell callers whether it moved. Ignore std::move inside
   // try_emplace to avoid false positives as we don't track uses of
   // the bool.
   auto TryEmplaceMatcher =
       cxxMemberCallExpr(callee(cxxMethodDecl(hasName("try_emplace"))));
+  auto Arg = declRefExpr().bind("arg");
+  auto IsMemberCallee = callee(functionDecl(unless(isStaticStorageClass())));
   auto CallMoveMatcher =
-      callExpr(argumentCountIs(1),
-               callee(functionDecl(hasAnyName("::std::move", "::std::forward"))
+      callExpr(callee(functionDecl(getNameMatcher(InvalidationFunctions))
                           .bind("move-decl")),
-               hasArgument(0, declRefExpr().bind("arg")),
+               anyOf(cxxMemberCallExpr(IsMemberCallee, on(Arg)),
+                     callExpr(unless(cxxMemberCallExpr(IsMemberCallee)),
+                              hasArgument(0, Arg))),
                unless(inDecltypeOrTemplateArg()),
                unless(hasParent(TryEmplaceMatcher)), expr().bind("call-move"),
                anyOf(hasAncestor(compoundStmt(
@@ -521,7 +543,7 @@ void UseAfterMoveCheck::check(const MatchFinder::MatchResult &Result) {
   }
 
   for (Stmt *CodeBlock : CodeBlocks) {
-    UseAfterMoveFinder Finder(Result.Context);
+    UseAfterMoveFinder Finder(Result.Context, InvalidationFunctions);
     if (auto Use = Finder.find(CodeBlock, MovingCall, Arg))
       emitDiagnostic(MovingCall, Arg, *Use, this, Result.Context,
                      determineMoveType(MoveDecl));

clang-tools-extra/clang-tidy/bugprone/UseAfterMoveCheck.h

@@ -20,13 +20,16 @@ namespace clang::tidy::bugprone {
 /// https://clang.llvm.org/extra/clang-tidy/checks/bugprone/use-after-move.html
 class UseAfterMoveCheck : public ClangTidyCheck {
 public:
-  UseAfterMoveCheck(StringRef Name, ClangTidyContext *Context)
-      : ClangTidyCheck(Name, Context) {}
+  UseAfterMoveCheck(StringRef Name, ClangTidyContext *Context);
+  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
     return LangOpts.CPlusPlus11;
   }
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+
+private:
+  std::vector<StringRef> InvalidationFunctions;
 };
 
 } // namespace clang::tidy::bugprone

clang-tools-extra/docs/ReleaseNotes.rst

@@ -400,6 +400,10 @@ Changes in existing checks
   suffix when the reason starts with the character `>` in the `CustomFunctions`
   option.
 
+- Improved :doc:`bugprone-use-after-move
+  <clang-tidy/checks/bugprone/use-after-move>` check by adding
+  `InvalidationFunctions` option to support custom invalidation functions.
+
 - Improved :doc:`cppcoreguidelines-avoid-non-const-global-variables
   <clang-tidy/checks/cppcoreguidelines/avoid-non-const-global-variables>` check
   by adding a new option `AllowThreadLocal` that suppresses warnings on

clang-tools-extra/docs/clang-tidy/checks/bugprone/use-after-move.rst

@@ -253,3 +253,13 @@ For example, if an additional member variable is added to ``S``, it is easy to
 forget to add the reinitialization for this additional member. Instead, it is
 safer to assign to the entire struct in one go, and this will also avoid the
 use-after-move warning.
+
+Options
+-------
+
+.. option:: InvalidationFunctions
+
+  A semicolon-separated list of names of functions that cause their initial
+  arguments to be invalidated (e.g., closing a handle).
+  For member functions, the initial argument is considered to be the implicit
+  object argument (`this`). Default value is an empty string.

clang-tools-extra/test/clang-tidy/checkers/bugprone/use-after-move.cpp

@@ -1,5 +1,13 @@
-// RUN: %check_clang_tidy -std=c++11 -check-suffixes=,CXX11 %s bugprone-use-after-move %t -- -- -fno-delayed-template-parsing
-// RUN: %check_clang_tidy -std=c++17-or-later %s bugprone-use-after-move %t -- -- -fno-delayed-template-parsing
+// RUN: %check_clang_tidy -std=c++11 -check-suffixes=,CXX11 %s bugprone-use-after-move %t -- \
+// RUN:   -config='{CheckOptions: { \
+// RUN:     bugprone-use-after-move.InvalidationFunctions: "::Database<>::StaticCloseConnection;Database<>::CloseConnection;FriendCloseConnection" \
+// RUN:   }}' -- \
+// RUN:   -fno-delayed-template-parsing
+// RUN: %check_clang_tidy -std=c++17-or-later %s bugprone-use-after-move %t -- \
+// RUN:   -config='{CheckOptions: { \
+// RUN:     bugprone-use-after-move.InvalidationFunctions: "::Database<>::StaticCloseConnection;Database<>::CloseConnection;FriendCloseConnection" \
+// RUN:   }}' -- \
+// RUN:   -fno-delayed-template-parsing
 
 typedef decltype(nullptr) nullptr_t;
 
@@ -1645,3 +1653,47 @@ void create() {
 }
 
 } // namespace issue82023
+
+namespace custom_invalidation
+{
+
+template<class T = int>
+struct Database {
+  template<class...>
+  void CloseConnection(T = T()) {}
+  template<class...>
+  static void StaticCloseConnection(Database&, T = T()) {}
+  template<class...>
+  friend void FriendCloseConnection(Database&, T = T()) {}
+  void Query();
+};
+
+void Run() {
+  using DB = Database<>;
+
+  DB db1;
+  db1.CloseConnection();
+  db1.Query();
+  // CHECK-NOTES: [[@LINE-1]]:3: warning: 'db1' used after it was invalidated
+  // CHECK-NOTES: [[@LINE-3]]:7: note: invalidation occurred here
+
+  DB db2;
+  DB::StaticCloseConnection(db2);
+  db2.Query();
+  // CHECK-NOTES: [[@LINE-1]]:3: warning: 'db2' used after it was invalidated
+  // CHECK-NOTES: [[@LINE-3]]:3: note: invalidation occurred here
+
+  DB db3;
+  DB().StaticCloseConnection(db3);
+  db3.Query();
+  // CHECK-NOTES: [[@LINE-1]]:3: warning: 'db3' used after it was invalidated
+  // CHECK-NOTES: [[@LINE-3]]:3: note: invalidation occurred here
+
+  DB db4;
+  FriendCloseConnection(db4);
+  db4.Query();
+  // CHECK-NOTES: [[@LINE-1]]:3: warning: 'db4' used after it was invalidated
+  // CHECK-NOTES: [[@LINE-3]]:3: note: invalidation occurred here
+}
+
+} // namespace custom_invalidation