Parameter hints for call to overloaded function

[HighCommander4]

In the following code:

void foo(int);
void foo(std::string);

void bar() {
   foo/*cursor*/
}

If I invoke completion with the cursor at the indicated location, I get a single entry that says

foo(...)    [2 overloads]

It would be nicer to show the two overloads as separate entries, so I can see the signature for each, pick the one I want to call, and then get parameter hints for the selected function's parameters.

[kadircet]

Once you put parentheses, you should get a signature help showing both.

Also you can change the behaviour by passing --completion-style=detailed into clangd. But IIRC, we are only turning this to bundled in the presence of signature help functionality.

[HighCommander4]

Once you put parentheses, you should get a signature help showing both.

I tried this, but I get the same result ([2 overloads]) with or without parentheses.

[HighCommander4]

I can confirm that using --completion-style=detailed gives the desired behaviour.

[HighCommander4]

I am using VSCode as a client. Does this suggest that clangd is expecting VSCode to do something more helpful, that it's not doing?

[HighCommander4]

Ok, I see: VSCode has a separate command ("Trigger Parameter Hints", shortcut Ctrl+Shift+Space) which shows the individual signatures when activated. I was expecting that to activate automatically when the completion entry is selected, but it looks like it doesn't.

I think this is just a case of sub-optimal usability on the client side then. I still prefer the --completion-styled=detailed behaviour, because you might as well see all the signatures up-front, but I guess that's what the flag is for.

[LeeProkhor]

How can I set --completion-style=detailed on Ubuntu? Where is conf file?

[HighCommander4]

How can I set --completion-style=detailed on Ubuntu? Where is conf file?

It's a command-line argument to clangd. The method of setting it depends on the client. For vscode, it can be added to "clangd.arguments" in the vscode user or workspace settings.

[LeeProkhor]

Thanks, I use neovim and installed clangd using by kabouzeid/nvim-lspinstall plugin.
In my .config/nvim/init.lua file I added nvim-lspconfig and nvim-compe plugins for C++ coding, they work OK,
but if method has several overloads (say 3 overloads as on picture below) I can't expand them.
If I understood right, I should set --completion-style=detailed [ (https://github.com//issues/172) ]
but I can't figure out where is clangd config-file, where I have to add --completion-style=detailed ("clangd.arguments")

[HighCommander4]

It's not going to be a clangd config file, it's going to be a neovim-related config file.

I'm not really familiar with neovim, but a quick read of the nvim-lspconfig readme suggests the file to specify the language server setup is "init.vim".

[HighCommander4]

Looking at example config snippets in e.g. this issue, it looks like the snippet you'll want is something like:

require'lspconfig'.clangd.setup {
  cmd = { "clangd", "--completion-style=detailed" }
}

[LeeProkhor]

Thanks, tried it. Don't have any errors, but still not expand overloaded methods.

[HighCommander4]

Can you share clangd logs? That should at least allow us to confirm that clangd is seeing the command-line parameter.

[LeeProkhor]

I am afraid my system doesn't have clangd logs, cause I installed clangd not from repos, but via kabouzeid/nvim-lspinstall plugin.
So I can't find where is clangd logs placed even.

[LeeProkhor]

I found where is clangd log on my machine. It was in ~/.cache/nvim/lsp.log
Here is my log

lsp.log

[HighCommander4]

Ok, so the important line is this one near the top:

[ ERROR ] 2021-07-09T15:14:23+0300 ] /usr/local/share/nvim/runtime/lua/vim/lsp/rpc.lua:462 ] "rpc" "/home/rock/.local/share/nvim/lspinstall/cpp/./clangd/bin/clangd" "stderr" "I[15:14:23.122] Working directory: /home/rock/.local/share/nvim/lspinstall/cpp\nI[15:14:23.122] argv[0]: /home/rock/.local/share/nvim/lspinstall/cpp/./clangd/bin/clangd\nI[15:14:23.122] argv[1]: --background-index\nI[15:14:23.154] Starting LSP over stdin/stdout\n"

Clangd is being started with the --background-index command-line argument, but not --completion-style=detailed.

So, whatever you did to configure --completion-style=detailed didn't take effect.

[LeeProkhor]

Thanks HighCommander4.
I added this code:

require'lspconfig'.clangd.setup {
  cmd = { "clangd", "--completion-style=detailed" } 
}

to my ~/.config/nvim/init.lua file, but it looks like there isn't any effect.

[HighCommander4]

Yup, I understand. I tried to figure out how to configure neovim to provide a command-line argument to clangd based on their documentation, and that's what I came up with, but clearly I'm missing something.

I suggest you ask for further help from people who are actually familar with neovim, such as in the https://github.com/neovim/nvim-lspconfig issue tracker.