[clang-tidy] Ignore implcit casts in cppcoreguidelines-owning-memory

[PiotrZSL]

Summary

Add getCheckTraversalKind to the check in order
to ignore some implicit casts when matching
expresions.

Fixes: #63994

[carlosgalvezp]

LGTM!

clang-tools-extra/clang-tidy/cppcoreguidelines/OwningMemoryCheck.h

bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
     return LangOpts.CPlusPlus11;
   }
 
   /// Make configuration of checker discoverable.
   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
 
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  std::optional<TraversalKind> getCheckTraversalKind() const override {
+    return TK_IgnoreUnlessSpelledInSource;
+  }
 
 private:
   bool handleDeletion(const ast_matchers::BoundNodes &Nodes);
   bool handleLegacyConsumers(const ast_matchers::BoundNodes &Nodes);
   bool handleExpectedOwner(const ast_matchers::BoundNodes &Nodes);
   bool handleAssignmentAndInit(const ast_matchers::BoundNodes &Nodes);
   bool handleAssignmentFromNewOwner(const ast_matchers::BoundNodes &Nodes);
   bool handleReturnValues(const ast_matchers::BoundNodes &Nodes);

clang-tools-extra/docs/ReleaseNotes.rst

 - Deprecated :doc:`cert-dcl21-cpp
   <clang-tidy/checks/cert/dcl21-cpp>` check.
 
 - Fixed :doc:`cppcoreguidelines-avoid-const-or-ref-data-members
   <clang-tidy/checks/cppcoreguidelines/avoid-const-or-ref-data-members>` check
   to emit warnings only on classes that are copyable/movable, as required by the
   corresponding rule.
 
+- Improved :doc:`cppcoreguidelines-owning-memory
+  <clang-tidy/checks/cppcoreguidelines/owning-memory>` check now finds more
+  issues, especially those related to implicit casts.
+
 - Deprecated C.48 enforcement from :doc:`cppcoreguidelines-prefer-member-initializer
   <clang-tidy/checks/cppcoreguidelines/prefer-member-initializer>`. Please use
   :doc:`cppcoreguidelines-use-default-member-init
   <clang-tidy/checks/cppcoreguidelines/use-default-member-init>` instead.
 
 - Improved :doc:`cppcoreguidelines-pro-bounds-constant-array-index
   <clang-tidy/checks/cppcoreguidelines/pro-bounds-constant-array-index>` check
   to cover type aliases of ``std::array``.

clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/owning-memory.cpp

void test_templates() {
 
   TemplateValue<int *> NonOwner1(new int(42));      // Bad, T is int *, hence dynamic memory to non-owner
   gsl::owner<int *> IntOwner1 = NonOwner1.getVal(); // Bad, since owner initialized with non-owner
   // CHECK-NOTES: [[@LINE-1]]:3: warning: expected initialization with value of type 'gsl::owner<>'; got 'int *'
 
   template_function(IntOwner1);  // Ok, but not actually ok, since type deduction removes owner
   template_function(stack_ptr1); // Bad, but type deduction gets it wrong
 }
+
+namespace PR63994 {
+  struct A {
+    virtual ~A() {}
+  };
+
+  struct B : public A {};
+
+  A* foo(int x) {
+    return new B;
+    // CHECK-NOTES: [[@LINE-1]]:5: warning: returning a newly created resource of type 'A *' or 'gsl::owner<>' from a function whose return type is not 'gsl::owner<>'
+  }
+}