The argument --fallback-style={...} for clangd is not working with coc-clangd

[matevskial]

Problem

I want to set up a fallback formatter for clangd with the concrete argument --fallback-style={--fallback-style="{BasedOnStyle: LLVM, IndentWidth: 4}"} in file coc-settings.json so the formatted code has indentation width of 4, but then the coc command in nvim :Format still indents the code with indetntation width of 2.

This is the coc-settings.json config file:

{
  "clangd.path":"clangd-9",
  "clangd.arguments":["--fallback-style=\"{BasedOnStyle: LLVM, IndentWidth: 4}\""]
}

Expected behaviour

The coc command in nvim :Format should format the code with indent width 4

Current behaviour

The formatted code is with indent width 2

[sam-mccall]

Huh, I was certain that clang-format's --fallback-style was parsed the same way as --style, but it seems --fallback-style must be a predefined style (and clangd follows clang-format here).

We could diverge from clang-format, or change clang-format to allow this too.

[sam-mccall]

(This is a clangd bug/feature)

[sam-mccall]

We'll almost certainly address this when we add config files, allowing something like:

Format:
  FallbackStyle:
    BasedOnStyle: LLVM
    IndentWidth: 4

to be placed in a dotfile. It's unlikely we'll fix this in the command-line flag, as we'll likely deprecate that in favor of user config files.

[1m188]

when write some personal small files like algorithm practice and so on, it is cumbersome to configure .clang-format every time, may be it's greater to support both config file and command-line flag?

[thebeastxdxd]

i agree i think you should still support the command line flags, config files (with 1 line) in every project is very cumbersome.

[arminveres]

Did something change here or is there a solution to this? I'm using native lsp of nvim and the issue seemingly still persists.

[chrinkis]

At the moment, is there any way to change the (default) format settings, in order to be applied when the .clang-format file is missing?

[GZGavinZhao]

My current solution is to add a file at $HOME/.clang-format. clangd/clang-format will traverse upwards the filesystem to find the closest .clang-format file, so if you don't have a .clang-format file all the way from your current directory to your $HOME directory, the $HOME/.clang-format file will be picked up and used by clangd/clang-format.

For example:

# ~/.clang-format
---
BasedOnStyle: Microsoft
IndentWidth: 4
---
Language: Cpp
# Force pointers to the type for C++.
DerivePointerAlignment: false
PointerAlignment: Left

And my file at ~/CS/Practice/main.cpp becomes:

#include <iostream>

using namespace std;

int N, D;

int main()
{
    int* a;
    cin >> N >> D;
}

For Linux/Windows users, you can put the file at /.clang-format or C:\.clang-format (with sudo). I'm on Mac and it has this whatever system integrity thing that I don't want to break, so I just put it at my home directory.

[tae-soo-kim]

Why not add the --style option in clang-format to clangd?

[FalcoGer]

It would be nice if there could be a command line flag for clangd to load the format configuration file from a specified path instead of putting in a string in the command line. All my projects have the same format, and putting a format file into every one, even little test projects that live for less than a day is cumbersome. I would much rather like a fall back format file, such as the $HOME/.config/clangd/config.yaml file, define where the fallback format file lives in that config file, or provide a command line argument on where that file lives.
Having yet another dotfile in my overbloated home directory that consists of 95% dotfiles is not desirable.

[HighCommander4]

It would be nice if there could be a command line flag for clangd to load the format configuration file from a specified path instead of putting in a string in the command line.

We have #805 open for this.