[clang-tools-extra] [clang-tidy] Add bugprone-smartptr-reset-ambiguous-call check (PR #121291)

[via cfe-commits]

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+.. title:: clang-tidy - bugprone-smartptr-reset-ambiguous-call
+
+bugprone-smartptr-reset-ambiguous-call
+======================================
+
+Finds potentially erroneous calls to ``reset`` method on
+smart pointers when the pointee type also has a ``reset`` method.
+Having a ``reset`` method in both classes makes it easy to accidentally
+make the pointer null when intending to reset the underlying object.
+
+.. code-block:: c++
+
+  struct Resettable {
+    void reset() { /* Own reset logic */ }
+  };
+
+  auto ptr = std::make_unique<Resettable>();
+
+  ptr->reset();  // Calls underlying reset method
+  ptr.reset();   // Makes the pointer null
+
+Both calls are valid C++ code, but the second one might not be
+what the developer intended, as it destroys the pointed-to object
+rather than resetting its state.
+It's easy to make such a typo because the difference
+between ``.`` and ``->`` is really small.
+
+The recommended approach is to make the intent explicit by
+using either member access or direct assignment:
+
+.. code-block:: c++
+
+  std::unique_ptr<Resettable> ptr = std::make_unique<Resettable>();
+
+  (*ptr).reset();  // Clearly calls underlying reset method
+  ptr = nullptr;   // Clearly makes the pointer null
+
+The default smart pointers that are considered are ``std::unique_ptr``,
+``std::shared_ptr``. To specify other smart pointers or
+other classes use the :option:`SmartPointers` option.
+
+Options
+-------
+
+.. option:: SmartPointers
+
+    Semicolon-separated list of class names of custom smart pointers.
----------------
EugeneZelenko wrote:

Please add default value.

https://github.com/llvm/llvm-project/pull/121291