Report an error when formatting fails instead of failing silently

[OlafvdSpek]

Issue Type: Bug

After generating a .clang-format file with clang-format -style=llvm -dump-config > .clang-format, Format Document stopped working, without reporting any errors.
I assume there was some issue with the format file, but without any info it's hard to tell. Could Format Document report errors?

VS Code version: Code 1.64.2 (f80445acd5a3dadef24aa209168452a3d97cc326, 2022-02-09T22:02:28.252Z)
OS version: Windows_NT x64 10.0.19044
Restricted Mode: No
Remote OS version: Linux x64 5.16.0-1-amd64

System Info

Item	Value
CPUs	Intel(R) Core(TM) i3 CPU 530 @ 2.93GHz (4 x 2946)
GPU Status	2d_canvas: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on rasterization: enabled skia_renderer: enabled_on video_decode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	7.99GB (1.50GB free)
Process Argv	--crash-reporter-id 4bd850b3-a2f9-42c9-8c89-3a102309506b
Screen Reader	no
VM	0%

Item	Value
Remote	SSH: debian
OS	Linux x64 5.16.0-1-amd64
CPUs	Intel(R) Core(TM) i3 CPU 530 @ 2.93GHz (2 x 2945)
Memory (System)	1.89GB (0.11GB free)
VM	100%

Extensions (16)

Extension	Author (truncated)	Version
better-cpp-syntax	jef	1.15.13
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remote-containers	ms-	0.217.4
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remote-ssh-edit	ms-	0.70.0
remote-wsl	ms-	0.64.2
doxdocgen	csc	1.3.2
EditorConfig	Edi	0.16.4
better-cpp-syntax	jef	1.15.13
python	ms-	2022.0.1814523869
vscode-pylance	ms-	2022.2.1
jupyter	ms-	2022.1.1201831736
cmake-tools	ms-	1.9.2
cpptools	ms-	1.8.4
cpptools-extension-pack	ms-	1.1.0
cmake	twx	0.0.17

(2 theme extensions excluded)

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microsoft/vscode#142964

[OlafvdSpek]

The first time I try to format, it says: "Formatting failed. See the output window for details." The error is easy to miss.
If I try to format again, it doesn't say anything.. why not?

The output window is empty, until you select "C/C++" in the dropdown. Then it says:

Formatting failed:
/home/olaf/.vscode-server/extensions/ms-vscode.cpptools-1.8.4/bin/../LLVM/bin/clang-format -style=file -fallback-style= -assume-filename=/home/olaf/cpp/packed.cpp
Invalid fallback style "

Apparently I cleared the fallback style in settings, but this doesn't work and it's not using the default.

Maybe Clang_format_fallback Style should be a dropdown?

[Colengms]

Hi @OlafvdSpek . C_Cpp.clang_format_fallbackStyle is a free form field, as it supports defining a style inline. I assume your reference to a dropdown would be referring to VS Code's settings UI? Unfortunately, extensions have relatively little control over how VS Code represents settings in that UI.

Would you like us to use this issue to track adding a more clear error message when formatting fails?

[OlafvdSpek]

Would you like us to use this issue to track adding a more clear error message when formatting fails?

Yes please.
And perhaps an empty C_Cpp.clang_format_fallbackStyle should be equivalent to an unset / default field.

[sean-mcmanus]

Fixed with https://github.com/microsoft/vscode-cpptools/releases/tag/v1.19.0 (pre-release)