[clang-tidy] Add new check 'shared-ptr-array-mismatch'.

Reviewed By: LegalizeAdulthood

Differential Revision: https://reviews.llvm.org/D117306

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

@@ -42,6 +42,7 @@
 #include "PosixReturnCheck.h"
 #include "RedundantBranchConditionCheck.h"
 #include "ReservedIdentifierCheck.h"
+#include "SharedPtrArrayMismatchCheck.h"
 #include "SignalHandlerCheck.h"
 #include "SignedCharMisuseCheck.h"
 #include "SizeofContainerCheck.h"
@@ -143,6 +144,8 @@ class BugproneModule : public ClangTidyModule {
         "bugprone-posix-return");
     CheckFactories.registerCheck<ReservedIdentifierCheck>(
         "bugprone-reserved-identifier");
+    CheckFactories.registerCheck<SharedPtrArrayMismatchCheck>(
+        "bugprone-shared-ptr-array-mismatch");
     CheckFactories.registerCheck<SignalHandlerCheck>("bugprone-signal-handler");
     CheckFactories.registerCheck<SignedCharMisuseCheck>(
         "bugprone-signed-char-misuse");

clang-tools-extra/clang-tidy/bugprone/CMakeLists.txt

@@ -37,6 +37,8 @@ add_clang_library(clangTidyBugproneModule
   PosixReturnCheck.cpp
   RedundantBranchConditionCheck.cpp
   ReservedIdentifierCheck.cpp
+  SharedPtrArrayMismatchCheck.cpp
+  SmartPtrArrayMismatchCheck.cpp
   SignalHandlerCheck.cpp
   SignedCharMisuseCheck.cpp
   SizeofContainerCheck.cpp

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

@@ -0,0 +1,31 @@
+//===--- SharedPtrArrayMismatchCheck.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 "SharedPtrArrayMismatchCheck.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace bugprone {
+
+SharedPtrArrayMismatchCheck::SharedPtrArrayMismatchCheck(
+    StringRef Name, ClangTidyContext *Context)
+    : SmartPtrArrayMismatchCheck(Name, Context, "shared") {}
+
+SharedPtrArrayMismatchCheck::SmartPtrClassMatcher
+SharedPtrArrayMismatchCheck::getSmartPointerClassMatcher() const {
+  return classTemplateSpecializationDecl(
+      hasName("::std::shared_ptr"), templateArgumentCountIs(1),
+      hasTemplateArgument(
+          0, templateArgument(refersToType(qualType().bind(PointerTypeN)))));
+}
+
+} // namespace bugprone
+} // namespace tidy
+} // namespace clang

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

@@ -0,0 +1,38 @@
+//===--- SharedPtrArrayMismatchCheck.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_SHAREDPTRARRAYMISMATCHCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SHAREDPTRARRAYMISMATCHCHECK_H
+
+#include "SmartPtrArrayMismatchCheck.h"
+
+namespace clang {
+namespace tidy {
+namespace bugprone {
+
+/// Find `std::shared_ptr<T>(new T[...])`, replace it (if applicable) with
+/// `std::shared_ptr<T[]>(new T[...])`.
+///
+/// Example:
+///
+/// \code
+///   std::shared_ptr<int> PtrArr{new int[10]};
+/// \endcode
+class SharedPtrArrayMismatchCheck : public SmartPtrArrayMismatchCheck {
+public:
+  SharedPtrArrayMismatchCheck(StringRef Name, ClangTidyContext *Context);
+
+protected:
+  virtual SmartPtrClassMatcher getSmartPointerClassMatcher() const;
+};
+
+} // namespace bugprone
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SHAREDPTRARRAYMISMATCHCHECK_H

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

@@ -0,0 +1,121 @@
+//===--- SmartPtrArrayMismatchCheck.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 "SmartPtrArrayMismatchCheck.h"
+#include "../utils/ASTUtils.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace bugprone {
+
+namespace {
+
+constexpr char ConstructExprN[] = "found_construct_expr";
+constexpr char NewExprN[] = "found_new_expr";
+constexpr char ConstructorN[] = "found_constructor";
+
+bool isInSingleDeclStmt(const DeclaratorDecl *D) {
+  const DynTypedNodeList Parents =
+      D->getASTContext().getParentMapContext().getParents(*D);
+  for (const DynTypedNode &PNode : Parents)
+    if (const auto *PDecl = PNode.get<DeclStmt>())
+      return PDecl->isSingleDecl();
+  return false;
+}
+
+const DeclaratorDecl *getConstructedVarOrField(const Expr *FoundConstructExpr,
+                                               ASTContext &Ctx) {
+  const DynTypedNodeList ConstructParents =
+      Ctx.getParentMapContext().getParents(*FoundConstructExpr);
+  if (ConstructParents.size() != 1)
+    return nullptr;
+  const auto *ParentDecl = ConstructParents.begin()->get<DeclaratorDecl>();
+  if (isa_and_nonnull<VarDecl, FieldDecl>(ParentDecl))
+    return ParentDecl;
+
+  return nullptr;
+}
+
+} // namespace
+
+const char SmartPtrArrayMismatchCheck::PointerTypeN[] = "pointer_type";
+
+SmartPtrArrayMismatchCheck::SmartPtrArrayMismatchCheck(
+    StringRef Name, ClangTidyContext *Context, StringRef SmartPointerName)
+    : ClangTidyCheck(Name, Context), SmartPointerName(SmartPointerName) {}
+
+void SmartPtrArrayMismatchCheck::storeOptions(
+    ClangTidyOptions::OptionMap &Opts) {}
+
+void SmartPtrArrayMismatchCheck::registerMatchers(MatchFinder *Finder) {
+  // For both shared and unique pointers, we need to find constructor with
+  // exactly one parameter that has the pointer type. Other constructors are
+  // not applicable for this check.
+  auto FindConstructor =
+      cxxConstructorDecl(ofClass(getSmartPointerClassMatcher()),
+                         parameterCountIs(1), isExplicit())
+          .bind(ConstructorN);
+  auto FindConstructExpr =
+      cxxConstructExpr(
+          hasDeclaration(FindConstructor), argumentCountIs(1),
+          hasArgument(
+              0, cxxNewExpr(isArray(), hasType(pointerType(pointee(
+                                           equalsBoundNode(PointerTypeN)))))
+                     .bind(NewExprN)))
+          .bind(ConstructExprN);
+  Finder->addMatcher(FindConstructExpr, this);
+}
+
+void SmartPtrArrayMismatchCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *FoundNewExpr = Result.Nodes.getNodeAs<CXXNewExpr>(NewExprN);
+  const auto *FoundConstructExpr =
+      Result.Nodes.getNodeAs<CXXConstructExpr>(ConstructExprN);
+  const auto *FoundConstructorDecl =
+      Result.Nodes.getNodeAs<CXXConstructorDecl>(ConstructorN);
+
+  ASTContext &Ctx = FoundConstructorDecl->getASTContext();
+  const DeclaratorDecl *VarOrField =
+      getConstructedVarOrField(FoundConstructExpr, Ctx);
+
+  auto D = diag(FoundNewExpr->getBeginLoc(),
+                "%0 pointer to non-array is initialized with array")
+           << SmartPointerName;
+  D << FoundNewExpr->getSourceRange();
+
+  if (VarOrField) {
+    auto TSTypeLoc = VarOrField->getTypeSourceInfo()
+                         ->getTypeLoc()
+                         .getAsAdjusted<clang::TemplateSpecializationTypeLoc>();
+    assert(TSTypeLoc.getNumArgs() >= 1 &&
+           "Matched type should have at least 1 template argument.");
+
+    SourceRange TemplateArgumentRange = TSTypeLoc.getArgLoc(0)
+                                            .getTypeSourceInfo()
+                                            ->getTypeLoc()
+                                            .getLocalSourceRange();
+    D << TemplateArgumentRange;
+
+    if (isInSingleDeclStmt(VarOrField)) {
+      const SourceManager &SM = Ctx.getSourceManager();
+      if (!utils::rangeCanBeFixed(TemplateArgumentRange, &SM))
+        return;
+
+      SourceLocation InsertLoc = Lexer::getLocForEndOfToken(
+          TemplateArgumentRange.getEnd(), 0, SM, Ctx.getLangOpts());
+      D << FixItHint::CreateInsertion(InsertLoc, "[]");
+    }
+  }
+}
+
+} // namespace bugprone
+} // namespace tidy
+} // namespace clang

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

@@ -0,0 +1,52 @@
+//===--- SharedPtrArrayMismatchCheck.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_SMARTPTRARRAYMISMATCHCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SMARTPTRARRAYMISMATCHCHECK_H
+
+#include "../ClangTidyCheck.h"
+
+namespace clang {
+namespace tidy {
+namespace bugprone {
+
+/// Find constructions of smart (unique or shared) pointers where the pointer
+/// is declared with non-array target type and an array (created with a
+/// new-expression) is passed to it.
+class SmartPtrArrayMismatchCheck : public ClangTidyCheck {
+public:
+  SmartPtrArrayMismatchCheck(StringRef Name, ClangTidyContext *Context,
+                             StringRef SmartPointerName);
+
+  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;
+  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
+
+protected:
+  using SmartPtrClassMatcher = ast_matchers::internal::BindableMatcher<Decl>;
+
+  /// Returns matcher that match with different smart pointer classes.
+  ///
+  /// Requires to bind pointer type (qualType) with PointerTypeN string declared
+  /// in this class.
+  virtual SmartPtrClassMatcher getSmartPointerClassMatcher() const = 0;
+
+  static const char PointerTypeN[];
+
+private:
+  StringRef const SmartPointerName;
+};
+
+} // namespace bugprone
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SMARTPTRARRAYMISMATCHCHECK_H

clang-tools-extra/docs/ReleaseNotes.rst

@@ -99,6 +99,10 @@ Improvements to clang-tidy
 New checks
 ^^^^^^^^^^
 
+- New :doc:`bugprone-shared-ptr-array-mismatch <clang-tidy/checks/bugprone-shared-ptr-array-mismatch>` check.
+
+  Finds initializations of C++ shared pointers to non-array type that are initialized with an array.
+
 New check aliases
 ^^^^^^^^^^^^^^^^^
 

clang-tools-extra/docs/clang-tidy/checks/bugprone-shared-ptr-array-mismatch.rst

@@ -0,0 +1,31 @@
+.. title:: clang-tidy - bugprone-shared-ptr-array-mismatch
+
+bugprone-shared-ptr-array-mismatch
+==================================
+
+Finds initializations of C++ shared pointers to non-array type that are
+initialized with an array.
+
+If a shared pointer ``std::shared_ptr<T>`` is initialized with a new-expression
+``new T[]`` the memory is not deallocated correctly. The pointer uses plain
+``delete`` in this case to deallocate the target memory. Instead a ``delete[]``
+call is needed. A ``std::shared_ptr<T[]>`` calls the correct delete operator.
+
+The check offers replacement of ``shared_ptr<T>`` to ``shared_ptr<T[]>`` if it
+is used at a single variable declaration (one variable in one statement).
+
+Example:
+
+.. code-block:: c++
+
+  std::shared_ptr<Foo> x(new Foo[10]); // -> std::shared_ptr<Foo[]> x(new Foo[10]);
+  //                     ^ warning: shared pointer to non-array is initialized with array [bugprone-shared-ptr-array-mismatch]
+  std::shared_ptr<Foo> x1(new Foo), x2(new Foo[10]); // no replacement
+  //                                   ^ warning: shared pointer to non-array is initialized with array [bugprone-shared-ptr-array-mismatch]
+
+  std::shared_ptr<Foo> x3(new Foo[10], [](const Foo *ptr) { delete[] ptr; }); // no warning
+
+  struct S {
+    std::shared_ptr<Foo> x(new Foo[10]); // no replacement in this case
+    //                     ^ warning: shared pointer to non-array is initialized with array [bugprone-shared-ptr-array-mismatch]
+  };

clang-tools-extra/docs/clang-tidy/checks/list.rst

@@ -84,6 +84,7 @@ Clang-Tidy Checks
    `bugprone-posix-return <bugprone-posix-return.html>`_, "Yes"
    `bugprone-redundant-branch-condition <bugprone-redundant-branch-condition.html>`_, "Yes"
    `bugprone-reserved-identifier <bugprone-reserved-identifier.html>`_, "Yes"
+   `bugprone-shared-ptr-array-mismatch <bugprone-shared-ptr-array-mismatch.html>`_, "Yes"
    `bugprone-signal-handler <bugprone-signal-handler.html>`_,
    `bugprone-signed-char-misuse <bugprone-signed-char-misuse.html>`_,
    `bugprone-sizeof-container <bugprone-sizeof-container.html>`_,