C/C++ cannot mark the wrong declaration order

[mxdh]

Issue Type: Bug

int GetFa(int k) { return k == fa[k] ? k : fa[k] = GetFa(fa[k]); }
int fa[10000];

C/C++ should report an error because fa is not declared

Extension version: 0.23.1
VS Code version: Code 1.35.0 (553cfb2c2205db5f15f3ee8395bbd5cf066d357d, 2019-06-04T01:17:12.481Z)
OS version: Windows_NT x64 10.0.18362

System Info

Item	Value
CPUs	Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz (4 x 3192)
GPU Status	2d_canvas: enabled checker_imaging: disabled_off flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on native_gpu_memory_buffers: disabled_software rasterization: enabled surface_synchronization: enabled_on video_decode: enabled webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	7.88GB (2.75GB free)
Process Argv
Screen Reader	no
VM	0%

[sean-mcmanus]

I've filed VS bug https://developercommunity.visualstudio.com/content/problem/605076/cc-cannot-mark-the-wrong-declaration-order.html . However, from what I understand it may be a "by design" limitation of the implementation, so I do not expect it to get fixed.

[sean-mcmanus]

Also being tracked by https://developercommunity.visualstudio.com/t/C-IntelliSense-does-not-detect-issue-w/910053