forked from OSchip/llvm-project
ace644030e
Currently, there is basically just one clang-tidy check to impose some sanity limits on functions - `clang-tidy-readability-function-size`. It is nice, allows to limit line count, total number of statements, number of branches, number of function parameters (not counting implicit `this`), nesting level. However, those are simple generic metrics. It is still trivially possible to write a function, which does not violate any of these metrics, yet is still rather unreadable. Thus, some additional, slightly more complicated metric is needed. There is a well-known [[ https://en.wikipedia.org/wiki/Cyclomatic_complexity | Cyclomatic complexity]], but certainly has its downsides. And there is a [[ https://www.sonarsource.com/docs/CognitiveComplexity.pdf | COGNITIVE COMPLEXITY by SonarSource ]], which is available for opensource on https://sonarcloud.io/. This check checks function Cognitive Complexity metric, and flags the functions with Cognitive Complexity exceeding the configured limit. The default limit is `25`, same as in 'upstream'. The metric is implemented as per [[ https://www.sonarsource.com/docs/CognitiveComplexity.pdf | COGNITIVE COMPLEXITY by SonarSource ]] specification version 1.2 (19 April 2017), with two notable exceptions: * `preprocessor conditionals` (`#ifdef`, `#if`, `#elif`, `#else`, `#endif`) are not accounted for. Could be done. Currently, upstream does not account for them either. * `each method in a recursion cycle` is not accounted for. It can't be fully implemented, because cross-translational-unit analysis would be needed, which is not possible in clang-tidy. Thus, at least right now, i completely avoided implementing it. There are some further possible improvements: * Are GNU statement expressions (`BinaryConditionalOperator`) really free? They should probably cause nesting level increase, and complexity level increase when they are nested within eachother. * Microsoft SEH support * ??? Reviewed By: aaron.ballman, JonasToth, lattner Differential Revision: https://reviews.llvm.org/D36836 |
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| .. | ||
| _static | ||
| _templates | ||
| clang-tidy | ||
| clangd | ||
| CMakeLists.txt | ||
| ModularizeUsage.rst | ||
| README.txt | ||
| ReleaseNotes.rst | ||
| clang-doc.rst | ||
| clang-include-fixer.rst | ||
| clang-modernize.rst | ||
| clang-rename.rst | ||
| clang-tidy.rst | ||
| clangd.rst | ||
| conf.py | ||
| cpp11-migrate.rst | ||
| doxygen-mainpage.dox | ||
| doxygen.cfg.in | ||
| index.rst | ||
| make.bat | ||
| modularize.rst | ||
| pp-trace.rst | ||
README.txt
---------------------------------- Documentation in clang-tools-extra ---------------------------------- To generate documentation in HTML format from files in clang-tools-extra/docs, build the docs-clang-tools-html target. To generate documentation from the source code using Doxygen, build the doxygen-clang-tools target.