Intellisense doesn't parse system includes correctly

[nolankramer]

Type: Bug

System includes are completely broken with clang and libstdc++. Intellisense claims std::filesystem::path is not a type, among other things.

This obviously causes a massive amount of "errors" to show up in the editor.

Here's my clang -v:

Ubuntu clang version 18.1.3 (1ubuntu1)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/13
Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/13
Candidate multilib: .;@m64
Selected multilib: .;@m64

And my Linux configuration in c_cpp_properties.json:

{
            "name": "Linux",
            "includePath": [
                "${workspaceFolder}/**"
            ],
            "defines": [],
            "compilerPath": "/usr/bin/clang++",
            "cStandard": "c17",
            "cppStandard": "c++17",
            "intelliSenseMode": "linux-clang-x64",
            "configurationProvider": "ms-vscode.cmake-tools"
        }

The std version being passed into the compile commands is: -std=gnu++17

Extension version: 1.21.6
VS Code version: Code 1.93.1 (38c31bc77e0dd6ae88a4e9cc93428cc27a56ba40, 2024-09-11T17:20:05.685Z)
OS version: Linux x64 6.8.0-45-generic snap
Modes:

System Info

Item	Value
CPUs	AMD Ryzen 7 PRO 6850H with Radeon Graphics (16 x 2393)
GPU Status	2d_canvas: unavailable_software canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: disabled_software multiple_raster_threads: enabled_on opengl: disabled_off rasterization: disabled_software raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: disabled_software video_encode: disabled_software vulkan: disabled_off webgl: unavailable_software webgl2: unavailable_software webgpu: disabled_off webnn: disabled_off
Load (avg)	2, 1, 2
Memory (System)	14.89GB (7.96GB free)
Process Argv	--no-sandbox --force-user-env --crash-reporter-id 0075ae52-00ae-4c27-9257-6ea0067d3b86
Screen Reader	no
VM	0%
DESKTOP_SESSION	plasma
XDG_CURRENT_DESKTOP	KDE
XDG_SESSION_DESKTOP	KDE
XDG_SESSION_TYPE	x11

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[Colengms]

Hi @nolankramer . I'm not easily able to repro an issue with the configuration you provided (without the custom configuration provider specified), clang 18.1.3, and the following code:

#include <filesystem>

void foo()
{
    std::filesystem::path a;
}

However, your configuration does include:

"configurationProvider": "ms-vscode.cmake-tools"

So your IntelliSense configuration may be based on whatever CMake Tools has provided (which would require a CMakeLists.txt and have specified the source file there).

We are aware of the following issue with clang 18. You might try the work around here: #12618