Cppcheck should only be invoked with a single configuration

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Environment

• Operating System (e.g. Ubuntu 16.04 x64): Windows 10
• IDE Version (e.g. CLion 2016.3.2): Clion 2020.1 (201.6668.86)
• Cppcheck executable version (cppcheck --version): 1.90
• Cppcheck plugin version: 1.4.2

Expected behaviour

The inspections show issues in active code only.

Actual behaviour

The inspection may should code in non-active (i.e. _MSC_VER although GCC is being used) blocks.

If Cppcheck is invoked with just a source file it tries to detect and process all configuration (i.e. defines) in the source. In case of the IDE it should only do a scan for that current configuration. This requires the plugin to get this from the IDE (if possible) and provide it to the call.

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A workaround is using --max-configs=1 in the command-line parameters. This will greatly improve the scan times for files with a lot of detected configuration.

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If there's too many configuration Cppcheck will bail out and only check at most what is configured via --max-configs (default is 12) anyways:

Too many #ifdef configurations - cppcheck only checks 12 of 17 configurations. Use --force to check all configurations.

The checking of the file will be interrupted because there are too many #ifdef configurations. Checking of all #ifdef configurations can be forced by --force command line option or from GUI preferences. However that may increase the checking time.

So I think for the time being we should always invoke it with either --max-configs=1 or --force for consistency.

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I contacted JetBrains about this and got a contact regarding CLion plugin development. Hopefully I will get some input on this soon.

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To get the project configurations it is necessary to use CLion-specific functionality. I haven't figured out yet how to develop with them. There also were some recent changes outlined in https://blog.jetbrains.com/clion/2020/12/migration-guide-for-plugins-2020-3/

This probably makes the plugin CLion/AppCode-only but to be honest without the proper data for the file Cppcheck will never give you all the actual results.

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If we have access to the build path (I know we can access the workspace path) we could leverage a potentially existing compile_commands.json to get the configuration. Maybe this could be done by leveraging the internal macros mentioned in #40.