vim.lsp.buf.hover don't have any syntax highlight in C file

[HalmondD]

Problem

The vim.lsp.buf.hover work nicely with Lua language.

However, when using it with C file, the feature doesn't have any syntax coloring and look bad.

I try using lspsaga plugin and use the command :Lspsaga hover_doc, also doesn't work. Of course I also download markdown, markdown_inline on treesitter, but still nothing change.

Steps to reproduce using "nvim -u minimal_init.lua"

I don't really know how to do this step, there seem don't have any guide for me to follow since I am not really good with Lua.

Expected behavior

It should have the syntax highlight and format like the one in Lua file but for C file.

Neovim version (nvim -v)

NVIM v0.8.3 installed via appimage since Unbuntu apt don't have the latest version.

Language server name/version

clangd version 17.0.3 install via zip file since Ubuntu apt don't have the latest version.

Operating system/version

Ubuntu 22.04.4 LTS.

Log file

no log.

[clason]

Your Neovim version is much too old. Please test the latest nightly.

[zeertzjq]

Not an Nvim issue. The hover content comes from the language server and the highlights are provided by your colorscheme.

[HalmondD]

No it seem that the colorscheme is not the issue here, I change it from dracula to catppuccin - which a very popular colorscheme and you tell me that it does not have the syntax highlight for vim.lsp.buf.hover?

[clason]

Who knows; we don't maintain these. (There's a reason the issue template requests reproduction steps with nvim --clean.)

[HalmondD]

And how I can I do that step, can you guide me please?

[clason]

https://github.com/neovim/neovim/blob/master/CONTRIBUTING.md#reporting-problems

[HalmondD]

Continue this thread, I have gone to the clangd issue and have some progress:
After reading the lsp.log, they find out that:

• clangd is indeed sending plain-text hover information instead of markdown
• the reason for this in turn is that the client does not indicate support for markdown in its client capabilities

So the first conclusion is that this is the client issue.

and after extracting the lsp.log, they say this.

Here is my lsp capabilities and attatch:

local lsp_servers = {
  'clangd',
  'lua_ls',
}


local lspconfig_status_ok, lspconfig = pcall(require, "lspconfig")
if not lspconfig_status_ok then
	return
end

local my_on_attatch = function(client)
  -- function lsp_highlight_document
  if client.server_capabilities.documentHighlight then
    vim.api.nvim_exec(
      [[
      augroup lsp_document_highlight
        autocmd! * <buffer>
        autocmd CursorHold <buffer> lua vim.lsp.buf.document_highlight()
        autocmd CursorMoved <buffer> lua vim.lsp.buf.clear_references()
      augroup END
    ]],
      false
    )
  end

  client.server_capabilities.documentFormattingProvider = true

  -- import lsp_keymaps function
  require('user.configs.nvim_keymap').lsp_keymaps()
end

local my_capabilities = {
  require('cmp_nvim_lsp').default_capabilities(),
}

for _, lsp_server in pairs(lsp_servers) do
	local opts = {
		on_attach = my_on_attatch,
    capabilities = my_capabilities,
	}

	lsp_server = vim.split(lsp_server, "@")[1]

	local require_ok, conf_opts = pcall(require, "user.configs.plugin_lsp.settings." .. lsp_server)
	if require_ok then
		opts = vim.tbl_deep_extend("force", conf_opts, opts)
	end

	lspconfig[lsp_server].setup(opts)
end

vim.lsp.set_log_level("DEBUG")

My apologize, gently ping @clason.

[clason]

Please try the latest development version; the hover support has been extensively rewritten.

[HalmondD]

Ok I change my nvim to 0.9.5, if this is not the version you want me to change to please tell me, here is the lsp.log.

[clason]

I meant the latest nightly (which you can download as an appimage from our releases page).

[HalmondD]

NVIM v0.10.0-dev-2427+geb4783fb6
Build type: RelWithDebInfo
LuaJIT 2.1.1707061634

this one?

[clason]

Yes.

[HalmondD]

Here is the lsp.log for nvim 0.10.0 nightly. The hover still don't work on this version.

[clason]

Works for me. So please create a minimal reproducible example (without plugins) I can test with nvim --clean -u test.lua together with a C file.

[clason]

And your log is full of ERRORs; I'd recommend looking at and fixing those first.

[HighCommander4]

Here is the lsp.log for nvim 0.10.0 nightly. The hover still don't work on this version.

The log still shows the client sending broken client capabilities.

I'm pretty sure the issue is related to the lines mentioning capabilities in your config.

[HalmondD]

Ok the issue fix somewhat thanks to @HighCommander4, I change:

local my_capabilities = {
  require('cmp_nvim_lsp').default_capabilities(),
}

to:

local my_capabilities = require('cmp_nvim_lsp').default_capabilities()

but the format not the syntax color still don't work like I want:
The hover still don't show any comment of the function, it did have syntax highlight but it should have more information like the next image. This only happen when I'm in main.c.

Like this, this is when I'm in the file the function is define:

However it should separate the @param and the brief comment of the function. Something like how the vscode is showing:

The function it self:

/*
 * The function creates a GPIO driver object and initializes it with the specified device driver.
 *
 * @param dev_driver The dev_driver parameter is a pointer to a structure of type gpio_dt_spec. This
 * structure contains the necessary information for initializing the GPIO driver, such as pin
 * configurations and other settings.
 *  
 * @return a pointer to a gpio_driver_t structure.
 */
gpio_driver_t *GPIO_DRIVER_Create(const struct gpio_dt_spec *dev_driver){
    gpio_driver_t *dev = malloc(sizeof(gpio_driver_t));
    dev->driver = dev_driver;
    if (dev != NULL)
    {
        GPIO_DRIVER_Init(dev, GPIO_CONFIG_Input, GPIO_CONFIG_Output,
                    GPIO_SET, GPIO_RESET);
    }
    return dev;
}

Here is the lsp.log.

[clason]

Works for me:

Again, your setup is broken, as your log clearly shows. Clangd needs a project database to get cross-file information.

And we don't care what VS Code does; we implement the LSP specification, and nothing else.

[HalmondD]

Thanks clason for your help.

[HighCommander4]

However it should separate the @param and the brief comment of the function. Something like how the vscode is showing:

This part is a missing feature in clangd (parsing doxygen the way vscode's default c++ language server does it). We have clangd/clangd#529 on file about it.