Language Server crashes when CTRE is in view

[nixxquality]

Environment

• OS and Version: Windows 10
• VS Code Version: 1.87.0
• C/C++ Extension Version: v1.19.5

Bug Summary and Steps to Reproduce

Bug Summary:
I wanted to try the interesting looking https://github.com/hanickadot/compile-time-regular-expressions project, so I downloaded the single header version and put it in my workspace. The C++ language server immediately crashes and refuses to work as long as the header is in view.

Steps to reproduce:

1. Open a new, empty folder in VS Code.
2. Create a new main.cpp file and enter your favorite Hello world

#include <iostream>

using namespace std;

int main()
{
    cout << "Hello world" << endl;
}

3. Download the single header version of CTRE: https://raw.githubusercontent.com/hanickadot/compile-time-regular-expressions/main/single-header/ctre.hpp
4. Put ctre.hpp in the folder
5. The language server will immediately crash and fail to recover as long as ctre.hpp is in the folder

Configuration and Logs

c_cpp_properties.json is default, because it happens in a new folder as well.

-------- Diagnostics - 3/5/2024, 11:25:44 AM
Version: 1.19.5
Current Configuration:
{
    "name": "Win32",
    "includePath": [
        "c:/Users/Linus/Code/basic test/**",
        "C:/Users/Linus/Code/vcpkg/installed/x64-windows/include",
        "C:/Users/Linus/Code/vcpkg/installed/x86-windows/include"
    ],
    "defines": [
        "_DEBUG",
        "UNICODE",
        "_UNICODE"
    ],
    "windowsSdkVersion": "10.0.22000.0",
    "compilerPath": "cl.exe",
    "cStandard": "c17",
    "cppStandard": "c++17",
    "intelliSenseMode": "windows-msvc-x64",
    "compilerPathInCppPropertiesJson": "cl.exe",
    "intelliSenseModeIsExplicit": false,
    "cStandardIsExplicit": false,
    "cppStandardIsExplicit": false,
    "mergeConfigurations": false,
    "compilerPathIsExplicit": false,
    "browse": {
        "path": [
            "c:/Users/Linus/Code/basic test/**",
            "C:/Users/Linus/Code/vcpkg/installed/x64-windows/include",
            "C:/Users/Linus/Code/vcpkg/installed/x86-windows/include",
            "${workspaceFolder}"
        ],
        "limitSymbolsToIncludedHeaders": true
    }
}
cpptools version (native): 1.19.5.0
No active translation units.

------- Workspace parsing diagnostics -------
Number of files discovered (not excluded): 5356

There's nothing of interest even with debug logging, it's just a bunch of junk and then it ends and restarts after printing

  tag parsing file: C:\Users\Linus\Code\basic test\ctre.hpp

### Other Extensions

_No response_

### Additional context

_No response_

[bobbrow]

Thank you for the easy repro steps. I took a quick look at it this morning. This code suffers from an issue caused by how our indexer works. To work around the crash until we can come up with a patch for this, you can replace the closing curly brace on line 3561 of ctre.hpp with the following:

#if CTRE_CNTTP_COMPILER_CHECK
	}
#else
	}
#endif

[nixxquality]

Thank you for the workaround. That will do for now :)