llvm-project/clang-tools-extra
Yan Zhang 2d83647007 [clang-tidy/google] Improve the Objective-C global variable declaration check 🔧
Summary:
The current Objective-C global variable declaration check restricts naming that is permitted by the Google Objective-C style guide.

The Objective-C style guide states the following:
"Global and file scope constants should have an appropriate prefix. [...] Constants may use a lowercase k prefix when appropriate"
http://google.github.io/styleguide/objcguide#constants

This change fixes the check to allow two or more capital letters as an appropriate prefix. This change intentionally avoids making a decision regarding whether to flag constants that use a two letter prefix (two letter prefixes are reserved by Apple¹ but many projects seem to violate this guideline).

This change eliminates an important category of false positives (constants prefixed with '[A-Z]{2,}') at the cost of introducing a less important category of false negatives (constants prefixed with only '[A-Z]'). The false positives are observed in standard recommended code while the false negatives occur in non-standard unrecommended code. The number of eliminated false positives is expected to be significantly larger than the number of exposed false negatives.

❧

(1)
"Two-letter prefixes like these are reserved by Apple for use in framework classes."
https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/Conventions/Conventions.html

Reviewers: aaron.ballman, Wizard, hokein, benhamilton

Reviewed By: aaron.ballman, Wizard

Subscribers: aaron.ballman, cfe-commits

Differential Revision: https://reviews.llvm.org/D43581

llvm-svn: 326046
2018-02-25 04:11:26 +00:00
..
change-namespace [change-namespace] Fix crash when injected base-class name is used in friend declarations. 2017-12-08 10:06:16 +00:00
clang-apply-replacements [CMake] Use PRIVATE in target_link_libraries for executables 2017-12-05 21:49:56 +00:00
clang-move [clang-move] Fix the incorrect expansion end location. 2018-02-12 12:26:12 +00:00
clang-query [CMake] Use PRIVATE in target_link_libraries for executables 2017-12-05 21:49:56 +00:00
clang-reorder-fields [CMake] Use PRIVATE in target_link_libraries for executables 2017-12-05 21:49:56 +00:00
clang-tidy [clang-tidy/google] Improve the Objective-C global variable declaration check 🔧 2018-02-25 04:11:26 +00:00
clang-tidy-vs Remove 'misc-pointer-and-integral-operation' clang-tidy check. The only cases 2016-10-21 21:50:28 +00:00
clangd [clangd] BindWithForward -> Bind. NFC 2018-02-23 07:54:17 +00:00
docs [clang-tidy] Replace the usage of std::uncaught_exception with std::uncaught_exceptions 2018-02-20 10:48:38 +00:00
include-fixer [clang-include-fixer] Use add_clang_tool instead add_clang_executable 2018-02-16 20:25:45 +00:00
modularize [CMake] Use PRIVATE in target_link_libraries for executables 2017-12-05 21:49:56 +00:00
pp-trace [CMake] Use PRIVATE in target_link_libraries for executables 2017-12-05 21:49:56 +00:00
test [clang-tidy/google] Improve the Objective-C global variable declaration check 🔧 2018-02-25 04:11:26 +00:00
tool-template [CMake] Use PRIVATE in target_link_libraries for executables 2017-12-05 21:49:56 +00:00
unittests [clangd] BindWithForward -> Bind. NFC 2018-02-23 07:54:17 +00:00
.arcconfig [clang-tools-extra] Set up .arcconfig to point to new Diffusion CTE repository 2017-11-27 15:58:25 +00:00
.gitignore
CMakeLists.txt [cmake] Support running extra clang tool tests without static analyzer 2017-08-29 05:58:08 +00:00
CODE_OWNERS.TXT Updating the code owners list. 2015-09-02 20:00:41 +00:00
LICENSE.TXT Rename the clang-tidy safety module to be hicpp, for the High-Integrity C++ coding standard from PRQA. 2017-03-19 17:23:23 +00:00
README.txt Update references to new lists.llvm.org mailing lists. 2015-08-05 03:56:44 +00:00

README.txt

//===----------------------------------------------------------------------===//
// Clang Tools repository
//===----------------------------------------------------------------------===//

Welcome to the repository of extra Clang Tools.  This repository holds tools
that are developed as part of the LLVM compiler infrastructure project and the
Clang frontend.  These tools are kept in a separate "extra" repository to
allow lighter weight checkouts of the core Clang codebase.

This repository is only intended to be checked out inside of a full LLVM+Clang
tree, and in the 'tools/extra' subdirectory of the Clang checkout.

All discussion regarding Clang, Clang-based tools, and code in this repository
should be held using the standard Clang mailing lists:
  http://lists.llvm.org/mailman/listinfo/cfe-dev

Code review for this tree should take place on the standard Clang patch and
commit lists:
  http://lists.llvm.org/mailman/listinfo/cfe-commits

If you find a bug in these tools, please file it in the LLVM bug tracker:
  http://llvm.org/bugs/