fixed #14261 - Regex: added `std::regex` implementation / added `engine` to rule XML to specify regex engine

[firewave]

[firewave]

Might make sense to be able to specify the type via a rule file as well. That would also allow to mix and match the engines depending on required performance/features. Or maybe even only allow it via a file so to not add another CLI option and not having to deal with the left-to-right issues.

[firewave]

This will only add the additional engine. I will also do some performance tests.

The follow-up steps are:

• implement PCRE2 as an additional engine and make it optional via a new build flag
• make std::regex the default and deprecate HAVE_RULES and PCRE1 so the feature works without any build dependencies
• remove HAVE_RULES and PCRE1 shortly after (most distros have already dropped the dependency since the library has long been EOL)

[danmar]

thanks for working on this. :+1:

[firewave]

Might make sense to be able to specify the type via a rule file as well. That would also allow to mix and match the engines depending on required performance/features. Or maybe even only allow it via a file so to not add another CLI option and not having to deal with the left-to-right issues.

@danmar any comment on this?

[firewave]

No comment so I will go with the way to specify the engine via XML only and not providing a CLI option for it.

[firewave]

The follow-up steps are:

I filed some tickets for those: https://trac.cppcheck.net/ticket/14262 https://trac.cppcheck.net/ticket/14263

[firewave]

The documentation on how to use rules is unfortunately some PDFs hosted at Sourceforge so there is nowhere to add the new field. I filed https://trac.cppcheck.net/ticket/14264 about migrating the documentation.

[firewave]

Great - std::regex appears to behave differently in Visual Studio:

D:\a\cppcheck\cppcheck\test\testregex.cpp:181(TestRegExStd::exactmatch): Assertion failed. 
Expected: 
0

Actual: 
2

Why am I not surprised?!

And on macos testrunner is not showing the failed test:

TestVarID::structuredBindings


Testing Complete
Number of tests: 5164
Number of todos: 371
make: *** [test] Error 1
Error: Process completed with exit code 2.

[firewave]

Great - std::regex appears to behave differently in Visual Studio:

Apparently std::regex is partially broken in the current Visual Studio version (not sure if it is what affects the test): https://developercommunity.visualstudio.com/t/std::regex-gives-a-different-result-in-m/10417784

So that partially derails the plan going forward and makes things more awkward. And I have not even profiled it yet...

[sonarqubecloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[firewave]

Coincidentally Visual Studio 2026 was released just a few hours ago and I can confirm that the test passes in it.