update

nvim/lua/configs/lspconfig.lua

@@ -47,13 +47,7 @@ lspconfig.gopls.setup({
   },
 })
 
-lspconfig.clangd.setup{
+lspconfig.clangd.setup{}
-  on_attach = function (client, bufnr)
-    client.server_capabilities.signatureHelpProvider = false
-    on_attach(client, bufnr)
-  end,
-  capabilities = capabilities
-}
 
 -- typescript
 -- lspconfig.tsserver.setup {

nvim/lua/configs/null-ls.lua

@@ -0,0 +1,25 @@
+local augroup = vim.api.nvim_create_augroup("LspFormatting", {})
+local null_ls = require("null-ls")
+
+local opts = {
+  sources = {
+    null_ls.builtins.formatting.clang_format,
+  },
+  on_attach = function (client, bufnr)
+    if client.supports_method("textDocument/formatting") then
+      vim.api.nvim_clear_autocmds({
+        group = augroup,
+        buffer = bufnr,
+      })
+      vim.api.nvim_create_autocmd("BufWritePre", {
+        group = augroup,
+        buffer = bufnr,
+        callback = function ()
+          vim.lsp.buf.format({ bufnr = bufnr })
+        end
+      })
+    end
+  end
+}
+
+return opts