my_nvim_config/after/plugin/lsp.lua

vim.api.nvim_create_autocmd('LspAttach', {
  desc = 'LSP actions',
  callback = function(event)
    local bufmap = function(mode, lhs, rhs)
      local opts = {buffer = event.buf}
      vim.keymap.set(mode, lhs, rhs, opts)
    end

    -- Trigger code completion
    bufmap('i', '<C-Space>', '<C-x><C-o>')
    -- Display documentation of the symbol under the cursor
    bufmap('n', 'K', '<cmd>lua vim.lsp.buf.hover()<cr>')
    -- Jump to the definition
    bufmap('n', 'gd', '<cmd>lua vim.lsp.buf.definition()<cr>')
    -- Jump to declaration
    bufmap('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<cr>')
    -- Lists all the implementations for the symbol under the cursor
    bufmap('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<cr>')
    -- Jumps to the definition of the type symbol
    bufmap('n', 'go', '<cmd>lua vim.lsp.buf.type_definition()<cr>')
    -- Lists all the references 
    bufmap('n', 'gr', '<cmd>lua vim.lsp.buf.references()<cr>')
    -- Displays a function's signature information
    bufmap('n', '<C-k>', '<cmd>lua vim.lsp.buf.signature_help()<cr>')
    -- Renames all references to the symbol under the cursor
    bufmap('n', '<F2>', '<cmd>lua vim.lsp.buf.rename()<cr>')
    -- Format current file
    bufmap('n', '<F3>', '<cmd>lua vim.lsp.buf.format()<cr>')
    -- Selects a code action available at the current cursor position
    bufmap('n', '<F4>', '<cmd>lua vim.lsp.buf.code_action()<cr>')
  end
})

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

require('mason').setup({})
require('mason-lspconfig').setup({
    ensure_installed = {'lua_ls', 'jedi_language_server', 'rust_analyzer', 'clangd' },
    handlers = {
        require('lspconfig').clangd.setup({
            filetypes = { "c", "cpp", "objc", "objcpp", "cuda", "proto","hpp"},
            capabilities = capabilities,
        }),
        require('lspconfig').rust_analyzer.setup({
            capabilities = capabilities,
            cmd = {
                "rustup", "run", "stable", "rust-analyzer",
            }

        }),
        require('lspconfig').jedi_language_server.setup{
            capabilities = capabilities,
        },
        require('lspconfig').lua_ls.setup{
            capabilities = capabilities,
            -- settings = {
            --     workspace = {
            --         environmentPath = "./venv/bin/python",
            --     }
            -- }
        },
    },
})

local cmp = require('cmp')
local cmp_select = {behavior = cmp.SelectBehavior.Select}

cmp.setup({
    sources = {
        {name = 'path'},
        {name = 'nvim_lsp'},
        {name = 'nvim_lua'},
    },
    mapping = cmp.mapping.preset.insert({
        ['<C-p>'] = cmp.mapping.select_prev_item(cmp_select),
        ['<C-n>'] = cmp.mapping.select_next_item(cmp_select),
        ['<Tab>'] = cmp.mapping.confirm({ select = true }),
        ['<C-Space>'] = cmp.mapping.complete(),
    }),
})