| .. title:: clang-tidy - readability-else-after-return |
| |
| readability-else-after-return |
| ============================= |
| |
| `LLVM Coding Standards <https://llvm.org/docs/CodingStandards.html>`_ advises to |
| reduce indentation where possible and where it makes understanding code easier. |
| Early exit is one of the suggested enforcements of that. Please do not use |
| ``else`` or ``else if`` after something that interrupts control flow - like |
| ``return``, ``break``, ``continue``, ``throw``. |
| |
| The following piece of code illustrates how the check works. This piece of code: |
| |
| .. code-block:: c++ |
| |
| void foo(int Value) { |
| int Local = 0; |
| for (int i = 0; i < 42; i++) { |
| if (Value == 1) { |
| return; |
| } else { |
| Local++; |
| } |
| |
| if (Value == 2) |
| continue; |
| else |
| Local++; |
| |
| if (Value == 3) { |
| throw 42; |
| } else { |
| Local++; |
| } |
| } |
| } |
| |
| |
| Would be transformed into: |
| |
| .. code-block:: c++ |
| |
| void foo(int Value) { |
| int Local = 0; |
| for (int i = 0; i < 42; i++) { |
| if (Value == 1) { |
| return; |
| } |
| Local++; |
| |
| if (Value == 2) |
| continue; |
| Local++; |
| |
| if (Value == 3) { |
| throw 42; |
| } |
| Local++; |
| } |
| } |
| |
| Options |
| ------- |
| |
| .. option:: WarnOnUnfixable |
| |
| When `true`, emit a warning for cases where the check can't output a |
| Fix-It. These can occur with declarations inside the ``else`` branch that |
| would have an extended lifetime if the ``else`` branch was removed. |
| Default value is `true`. |
| |
| .. option:: WarnOnConditionVariables |
| |
| When `true`, the check will attempt to refactor a variable defined inside |
| the condition of the ``if`` statement that is used in the ``else`` branch |
| defining them just before the ``if`` statement. This can only be done if |
| the ``if`` statement is the last statement in its parent's scope. |
| Default value is `true`. |
| |
| |
| LLVM alias |
| ---------- |
| |
| There is an alias of this check called llvm-else-after-return. |
| In that version the options :option:`WarnOnUnfixable` and |
| :option:`WarnOnConditionVariables` are both set to `false` by default. |
| |
| This check helps to enforce this `LLVM Coding Standards recommendation |
| <https://llvm.org/docs/CodingStandards.html#don-t-use-else-after-a-return>`_. |