clang-tidy readability-identifier-naming for Google's naming convention

clang-tidy-readability-identifier-naming-google.yml

CheckOptions:
  - key:             readability-identifier-naming.ClassCase
    value:           CamelCase
  - key:             readability-identifier-naming.ClassMemberCase
    value:           lower_case
  - key:             readability-identifier-naming.ConstexprVariableCase
    value:           CamelCase
  - key:             readability-identifier-naming.ConstexprVariablePrefix
    value:           k
  - key:             readability-identifier-naming.EnumCase
    value:           CamelCase
  - key:             readability-identifier-naming.EnumConstantCase
    value:           CamelCase
  - key:             readability-identifier-naming.EnumConstantPrefix
    value:           k
  - key:             readability-identifier-naming.FunctionCase
    value:           CamelCase
  - key:             readability-identifier-naming.GlobalConstantCase
    value:           CamelCase
  - key:             readability-identifier-naming.GlobalConstantPrefix
    value:           k
  - key:             readability-identifier-naming.StaticConstantCase
    value:           CamelCase
  - key:             readability-identifier-naming.StaticConstantPrefix
    value:           k
  - key:             readability-identifier-naming.StaticVariableCase
    value:           lower_case
  - key:             readability-identifier-naming.MacroDefinitionCase
    value:           UPPER_CASE
  - key:             readability-identifier-naming.MacroDefinitionIgnoredRegexp
    value:           '^[A-Z]+(_[A-Z]+)*_$'
  - key:             readability-identifier-naming.MemberCase
    value:           lower_case
  - key:             readability-identifier-naming.PrivateMemberSuffix
    value:           _
  - key:             readability-identifier-naming.PublicMemberSuffix
    value:           ''
  - key:             readability-identifier-naming.NamespaceCase
    value:           lower_case
  - key:             readability-identifier-naming.ParameterCase
    value:           lower_case
  - key:             readability-identifier-naming.TypeAliasCase
    value:           CamelCase
  - key:             readability-identifier-naming.TypedefCase
    value:           CamelCase
  - key:             readability-identifier-naming.VariableCase
    value:           lower_case
  - key:             readability-identifier-naming.IgnoreMainLikeFunctions
    value:           1

Hi, thank you for sharing this.

Are you sure static should have kCamelCase instead of lower_case?

  - key:             readability-identifier-naming.StaticVariableCase
    value:           CamelCase
  - key:             readability-identifier-naming.StaticVariablePrefix
    value:           k

@rsglobal As per Google C++ Style Guide,

All such variables with static storage duration (i.e., statics and globals, see Storage Duration for details) should be named this way. This convention is optional for variables of other storage classes, e.g., automatic variables, otherwise the usual variable naming rules apply.

this way refers to the naming convention of constant names.

@airglow923,

But it looks like .StaticVariableCase is designed not for consts:
With this rule I have the following failure:

error: invalid case style for static variable 'backend_manager' [readability-identifier-naming,-warnings-as-errors]

BackendManager &BackendManager::GetInstance() {
  static BackendManager backend_manager;                                                                    
                        ^~~~~~~~~~~~~~~ 
                        kBackendManager                     

@rsglobal I think you're right. I thought all such variables mean variables regardless of their constness. However, after going through Google's source code, I could see non-const static variables are written with snake case:

1. protobuf/stubs/common.cc
2. protobuf/io/coded_stream_unittest.cc
3. protobuf/testing/googletest.cc
4. protobuf/extension_set.cc
5. googletest/include/gtest/internal/gtest-port.h
6. googletest/test/gtest_pred_impl_unittest.cc

I'm going to fix the error Thanks for letting me know.

@airglow23,

Thank you.

Could you also add this lines?:

  - key:             readability-identifier-naming.ConstexprVariableCase                                               
    value:           CamelCase                                                                                         
  - key:             readability-identifier-naming.ConstexprVariablePrefix                                             
    value:           k                                                                                                  

Currently constexpr variables are lower_case for some reason on tidy-11.

And also there is one more false positive in macros:

error: invalid case style for macro definition 'DRM_DRMFBIMPORTER_H_' [readability-identifier-naming,-warnings-as-errors]   
#define DRM_DRMFBIMPORTER_H_
        ^~~~~~~~~~~~~~~~~~~~
        DRM_DRMFBIMPORTER_H 

Do you have any ideas how to fix it?

@rsglobal

UPDATE

I forgot to mention that IgnoredRegexp is only supported in clang-tidy 12 onwards.

---

Thanks. I included ConstexprVariableCase and Prefix as well to the file.

I think the error is due to the trailing underline. You can make use of MacroDefinitionIgnoredRegexp to allow trailing underline.

For example,

- key: readability-identifier-naming.MacroDefinitionIgnoredRegexp
  value: '^[A-Z]+(_[A-Z]+)*_$'

Note that IgnoredRegexp uses POSIX Extended Regular Expressions (POSIX ERE) for its regex engine.

@airglow923,

Thank you, it worked for me out-of-the-box after upgrading to v12.
I think it worth adding into your CheckOptions list

@rsglobal Updated. Thanks

Hello,

To fix this:

Data members of structs, both static and non-static, are named like ordinary nonmember variables. They do not have the trailing underscores that data members in classes have.

the following diff has to be applied:

-  - key:             readability-identifier-naming.MemberSuffix
+  - key:             readability-identifier-naming.PrivateMemberSuffix
     value:           _
+  - key:             readability-identifier-naming.PublicMemberSuffix
+    value:           ''

@rsglobal Thank you for pointing that out

How to use it in CMake Project.

@ehds I made a tutorial: https://itnext.io/save-your-sanity-and-time-beyond-clang-format-2b929b9120b8

@ehds I made a tutorial: https://itnext.io/save-your-sanity-and-time-beyond-clang-format-2b929b9120b8

Thanks, it's work for me.