diff --git a/clang-tools-extra/docs/clang-tidy/checks/bugprone-unhandled-exception-at-new.rst b/clang-tools-extra/docs/clang-tidy/checks/bugprone-unhandled-exception-at-new.rst --- a/clang-tools-extra/docs/clang-tidy/checks/bugprone-unhandled-exception-at-new.rst +++ b/clang-tools-extra/docs/clang-tidy/checks/bugprone-unhandled-exception-at-new.rst @@ -5,21 +5,51 @@ Finds calls to ``new`` with missing exception handler for ``std::bad_alloc``. +Calls to ``new`` may throw exceptions of type ``std::bad_alloc`` that should +be handled. Alternatively, the nonthrowing form of ``new`` can be +used. The check verifies that the exception is handled in the function +that calls ``new``. + +If a nonthrowing version is used or the exception is allowed to propagate out +of the function no warning is generated. + +The exception handler is checked if it catches a ``std::bad_alloc`` or +``std::exception`` exception type, or all exceptions (catch-all). +The check assumes that any user-defined ``operator new`` is either +``noexcept`` or may throw an exception of type ``std::bad_alloc`` (or one +derived from it). Other exception class types are not taken into account. + .. code-block:: c++ int *f() noexcept { - int *p = new int[1000]; + int *p = new int[1000]; // warning: missing exception handler for allocation failure at 'new' + // ... + return p; + } + +.. code-block:: c++ + + int *f1() { // not 'noexcept' + int *p = new int[1000]; // no warning: exception can be handled outside + // of this function + // ... + return p; + } + + int *f2() noexcept { + try { + int *p = new int[1000]; // no warning: exception is handled + // ... + return p; + } catch (std::bad_alloc &) { + // ... + } + // ... + } + + int *f3() noexcept { + int *p = new (std::nothrow) int[1000]; // no warning: "nothrow" is used // ... return p; } -Calls to ``new`` can throw exceptions of type ``std::bad_alloc`` that should -be handled by the code. Alternatively, the nonthrowing form of ``new`` can be -used. The check verifies that the exception is handled in the function -that calls ``new``, unless a nonthrowing version is used or the exception -is allowed to propagate out of the function (exception handler is checked for -types ``std::bad_alloc``, ``std::exception``, and catch-all handler). -The check assumes that any user-defined ``operator new`` is either -``noexcept`` or may throw an exception of type ``std::bad_alloc`` (or derived -from it). Other exception types or exceptions occurring in the object's -constructor are not taken into account.