xref: /llvm-project/clang-tools-extra/docs/clang-tidy/checks/modernize/use-override.rst (revision 00e80fbfb9151a68e7383dcec7da69c867225e54)
1.. title:: clang-tidy - modernize-use-override
2
3modernize-use-override
4======================
5
6Adds ``override`` (introduced in C++11) to overridden virtual functions and
7removes ``virtual`` from those functions as it is not required.
8
9``virtual`` on non base class implementations was used to help indicate to the
10user that a function was virtual. C++ compilers did not use the presence of
11this to signify an overridden function.
12
13In C++11 ``override`` and ``final`` keywords were introduced to allow
14overridden functions to be marked appropriately. Their presence allows
15compilers to verify that an overridden function correctly overrides a base
16class implementation.
17
18This can be useful as compilers can generate a compile time error when:
19
20 - The base class implementation function signature changes.
21 - The user has not created the override with the correct signature.
22
23Options
24-------
25
26.. option:: IgnoreDestructors
27
28   If set to `true`, this check will not diagnose destructors. Default is `false`.
29
30.. option:: IgnoreTemplateInstantiations
31
32   If set to `true`, instructs this check to ignore virtual function overrides
33   that are part of template instantiations. Default is `false`.
34
35.. option:: AllowOverrideAndFinal
36
37   If set to `true`, this check will not diagnose ``override`` as redundant
38   with ``final``. This is useful when code will be compiled by a compiler with
39   warning/error checking flags requiring ``override`` explicitly on overridden
40   members, such as ``gcc -Wsuggest-override``/``gcc -Werror=suggest-override``.
41   Default is `false`.
42
43.. option:: OverrideSpelling
44
45   Specifies a macro to use instead of ``override``. This is useful when
46   maintaining source code that also needs to compile with a pre-C++11
47   compiler.
48
49.. option:: FinalSpelling
50
51   Specifies a macro to use instead of ``final``. This is useful when
52   maintaining source code that also needs to compile with a pre-C++11
53   compiler.
54
55.. note::
56
57   For more information on the use of ``override`` see https://en.cppreference.com/w/cpp/language/override
58