Inactive code regions with #include fail

[xamix]

Environment

• OS and Version: W10
• VS Code Version: 1.95.3
• C/C++ Extension Version: 1.22.11 and also 1.23.2 (pre release)
• CMake Tools extension v1.19.52

Bug Summary and Steps to Reproduce

Bug Summary:

The disabled code region fail on simple case.
I'm using CMake and the MSVC 2022 C compiler, with the following simple code

#define USE_FIRST
#define USE_ANTYHING

#if defined(USE_FIRST)
    #include <stdio.h>
#elif defined(USE_SECOND)
    #include <stdio.h>
#else
    #error Either USE_FIRST or USE_SECOND must be defined
#endif

int main(int argc, char *argv[]) {
    printf("Main executed\r\n");
    return 0;
}

The normal output is the following:

However sometimes it's failing
For example when you press one or two times the Ctrl+S (save file) then the disabled dimed area fail:

Steps to reproduce:

You can check the simple code here to reproduce, it use CMake:
Bug.zip

Configuration and Logs

Here is the generated `c_cpp_properties.json`


{
    "configurations": [
        {
            "name": "Win32",
            "includePath": [
                "${workspaceFolder}/**"
            ],
            "defines": [
                "_DEBUG",
                "UNICODE",
                "_UNICODE"
            ],
            "windowsSdkVersion": "10.0.22000.0",
            "compilerPath": "cl.exe",
            "cStandard": "c17",
            "cppStandard": "c++17",
            "intelliSenseMode": "windows-msvc-x64",
            "configurationProvider": "ms-vscode.cmake-tools"
        }
    ],
    "version": 4
}

Other Extensions

No response

Additional context

No response

[sean-mcmanus]

@xamix Thanks for reporting this. I've filed bug https://developercommunity.visualstudio.com/t/C-IntelliSense-inactive-regions-are-in/10808031 against our shared IntelliSense parser.