Use a glob pattern to add all files under system include paths to files.associations with a single entry

[gatopeich]

Issue Type: LanguageService

C/C++: Auto Add File Associations setting has a side effect of changing workspace settings whenever user navigates to the C++ standard library headers.
e.g.:
"array": "cpp",
"istream": "cpp",
"tuple": "cpp",
"utility": "cpp",
"variant": "cpp"

This is a problem when the workspace settings are under version control.

A simple improvement would be to add the C++ standard library path to the associations. E.g.:

  "files.associations": {
        "**/include/c++/**": "cpp"
    }

Or the path to the given header, rather than every individual file name.

Extension version: 0.28.0
VS Code version: Code 1.45.1 (5763d909d5f12fe19f215cbfdd29a91c0fa9208a, 2020-05-14T08:27:22.494Z)
OS version: Linux x64 4.15.0-101-generic
Remote OS version: Linux x64 4.15.0-88-generic

System Info

Item	Value
CPUs	AMD A8-4500M APU with Radeon(tm) HD Graphics (4 x 1644)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on oop_rasterization: disabled_off protected_video_decode: unavailable_off rasterization: disabled_software skia_renderer: disabled_off_ok video_decode: unavailable_off viz_display_compositor: enabled_on viz_hit_test_surface_layer: disabled_off_ok webgl: enabled webgl2: enabled
Load (avg)	1, 1, 1
Memory (System)	7.00GB (2.73GB free)
Process Argv	--no-sandbox --unity-launch
Screen Reader	no
VM	0%
DESKTOP_SESSION	xfce
XDG_CURRENT_DESKTOP	XFCE
XDG_SESSION_DESKTOP	xfce
XDG_SESSION_TYPE	x11

Item	Value
Remote	SSH: viavi-reverse-ssh
OS	Linux x64 4.15.0-88-generic
CPUs	Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz (8 x 1697)
Memory (System)	31.31GB (7.96GB free)
VM	0%

[gatopeich]

It seems to be an intended effect of this setting, enabled by default:

C_Cpp: Auto Add File Associations

[gatopeich]

Workaround

Can be avoided by adding a file association that captures C++ standard library headers like this:

    "files.associations": {
        "**/include/c++/**": "cpp"
    }

[sean-mcmanus]

Adding that particular system path would only work on certain Linux OS's, but adding a glob pattern using the 2 parent folders might work. Might be fixable via changes to addFileAssociations at https://github.com/microsoft/vscode-cpptools/blob/master/Extension/src/LanguageServer/client.ts#L2008 .